1. Lack of precipitation in this area may limit Doppler interpretation
Ahead of WCB
Classic area for virga
Probability of virga increases with strength and dryness of the CCB and the strength and moisture of leading branch of the WCB
Katabatic portion of warm front – winds veer above the warm frontal mixing zone
Lack of precipitation in this area may limit Doppler interpretation
There are 10 slides (1 through 10 inclusive) to be used for each of the conceptual models for each of the locations and for each of the radar data types.
Click for the Conceptual Model and Explanation

2. Common location for virga AB
Warm Frontal Cross-section along Leading Branch of the Warm Conveyor Belt (WCB)
Common location for virga A
WCB
WCB oriented for
maximum frontal lift
Virga Precipitation
Increasing CCB
Moistening
WCB oriented for
less frontal lift
Lower
Hydrometeor
Density
Mixing Zone
Surface
Warm Front
CCB
Link to Classic
Example A B
Cold air in Cold Conveyor Belt (CCB) deep and dry
Notes:
All descriptive terms are intended to be comparative between the various conveyor belts in the Conveyor Belt Conceptual Model.
All quantities are intended to be the average or typical values
Virga may be the result of melting snow or evapourating rain to cause the reduced hydrometeor density and thus increased visibility or reduced obstruction to visibility
These comments will need validation – many are just my simple operational observations
The slope of the warm front should be more shallow because this portion of the WCB is not as strong suggesting that the isentropic lift is more gentle and more spread out over a broader distance. This is also consistent with the observed cloud types of cirrostratus.
This portion of the cold front should be colder and drier as it is fresh out of the preceding ridge of high pressure. This helps evapouration of the precipitation.
Only the highest portions of the WCB are likely to experience frontal lift and thus possible produce hydrometeors.
This portion of the warm front is most likely to be inactive or katabaic so that precipitation processes are less likely and if they do occur, they are less likely to be intense enough to produce precipitation to the ground.
Just poleward of the warm front, the cloud type is likely to be altostratus or cirrostratus.
Moist portion of Warm Conveyor Belt (WCB) is high and veered from frontal perpendicular – katabatic tendency
Dry lower levels of WCB originate from ahead of the system and backed from frontal perpendicular
WCB typically veers with height (it is after all, a warm front)
Frontal slope is more shallow than the typical 1:200
Precipitation extends equidistant into the unmodified CCB
Precipitation extends further into the moistened, modified CCB

3. Vertical Deformation Zone Distribution and the CBM Simplified Summary
The WCB overrides the warm front
CCB
The CCB undercuts the warm front C
The frontal surface overlies the mixing layer
Wind shear in the CCB is variable
Looking along the flow:
In WCB to the right of the Col expect veering winds with height – Katabatic warm front
In WCB approach to the Col expect maximum divergence – the eagle pattern with ascent and increasing pcpn
In WCB to the left of the Col expect backing winds with height – Anabatic warm front
WCB
DCB C C
DCB
Typical distributions of the conveyor belts and the associated deformation zones. Recall from the satellite palette that the deformation zone is actually a cross-section of the deformation sheath that encases an isentropic flow. Similarly, the vorticity centres depicted in the deformation zone conceptual model are actually vortex tubes that also slope in the vertical along with the deformation sheath.
The Warm Conveyor Belt (WCB) typically rises isentropically with poleward (both northeasterly and northwesterly) motion and time. The WCB is shown with no vertical wind shift but typically it veers with height which is consistent with warm air advection.
The Cold Conveyor Belt (CCB) typically sinks isentropically with equatorward (southwesterly) motion and time. The CCB typically backs with height which is consistent with cold air advection.
The Dry Conveyor Belt (DCB) typically sinks isentropically with equatorward (southeasterly) motion and time. In the “dry slot” of the comma pattern, the DCB is typically rising isentropically with poleward (northeasterly) motion and time. The DCB typically veers with height with the approaching upper ridge.
The flow ahead of the conveyor belt system has not been typically described but is the remains of the dry conveyor belt caught up in the upper ridge circulation. (Chadwick has described it in unpublished work.) This circulation is dry and subsiding with poleward (northwesterly) motion and time. The portion of the flow that turns southwesterly dry rises with equatorward (southwesterly) motion and time. This portion of the CCB typically veers with height which is consistent with warm air advection west of the upper ridge.
The slope of the isentropic surfaces can be inferred from the overlap of the deformation zones. The slope of the isentropic surfaces can also be used to analyze instability. Isentropically speaking, sinking cold air and rising warm air converts thermal energy into kinetic energy. The vertical motions of dry air is not so simple isentropically speaking – have to ponder this!
The introduction of isentropic thinking to NinJo will make the investigation of these concepts much easier.

4. Vertical Deformation Zone Distribution and the CBM Simplified Flows in the Vertical
CCB
Above frontal surface: Winds back with
Height and distance from Xl
Above frontal surface: Winds veer with
Height and distance from Xr
Below frontal surface: Winds could veer or back but likely veer C Xc Xr
Below frontal surface: Winds could veer or back Xl
Warm Sector: Winds back with
Height and distance from Xl
Warm Sector: Winds veer with
Height and distance from Xr
No VWS
DCB
WCB C C
DCB
Typical distributions of the conveyor belts and the associated deformation zones. Recall from the satellite palette that the deformation zone is actually a cross-section of the deformation sheath that encases an isentropic flow. Similarly, the vorticity centres depicted in the deformation zone conceptual model are actually vortex tubes that also slope in the vertical along with the deformation sheath.
The Warm Conveyor Belt (WCB) typically rises isentropically with poleward (both northeasterly and northwesterly) motion and time. The WCB is shown with no vertical wind shift but typically it veers with height which is consistent with warm air advection.
The Cold Conveyor Belt (CCB) typically sinks isentropically with equatorward (southwesterly) motion and time. The CCB typically backs with height which is consistent with cold air advection.
The Dry Conveyor Belt (DCB) typically sinks isentropically with equatorward (southeasterly) motion and time. In the “dry slot” of the comma pattern, the DCB is typically rising isentropically with poleward (northeasterly) motion and time. The DCB typically veers with height with the approaching upper ridge.
The flow ahead of the conveyor belt system has not been typically described but is the remains of the dry conveyor belt caught up in the upper ridge circulation. (Chadwick has described it in unpublished work.) This circulation is dry and subsiding with poleward (northwesterly) motion and time. The portion of the flow that turns southwesterly dry rises with equatorward (southwesterly) motion and time. This portion of the CCB typically veers with height which is consistent with warm air advection west of the upper ridge.
The slope of the isentropic surfaces can be inferred from the overlap of the deformation zones. The slope of the isentropic surfaces can also be used to analyze instability. Isentropically speaking, sinking cold air and rising warm air converts thermal energy into kinetic energy. The vertical motions of dry air is not so simple isentropically speaking – have to ponder this!
The introduction of isentropic thinking to NinJo will make the investigation of these concepts much easier.

5. WCB to the Right of the Col
The Warm Right Wing Stoop CM
The eagles right wing is folded in as if it is about to swoop down.
The left wing is still fully extended to catch the lift of the WCB. C o
Signature of
Warm Frontal surface
Warm advection
Within the CCB:
Probable Ekman spiral nearest surface
Probable cold advection above Ekman spiral
Cold CB
Stoop
To bend or sag downward.
To lower or debase oneself.
To descend from a superior position; condescend.
To yield; submit.
To swoop down, as a bird in pursuing its prey.
Mixing layer
Warm frontal surface
Left Wing
Right Wing
Warm CB
Within the WCB:
East of radar veering, warm advection
West of radar nil VWS

6. Inactive or Katabatic Warm Front
One only needs to apply the equation of continuity to explain the impact of a veering wind in the warm air above the warm frontal surface.
If the wind veers above the frontal surface, then that wind is less than the forward speed of the warm front. The air is divergent at this height and air must be descending to fill the void through continuity. Such a warm front with veering winds above the frontal surface must be katabatic.

7. WCB Approaching the Col
The Warm Screaming Eagle CM
Both wings are fully extended to catch the lift of the WCB.
This is a divergent signature. C
Warm CB
Warm frontal surface o
Mixing layer
Signature of
Warm Frontal surface
discontinuity
Within the CCB:
Probable Ekman spiral nearest surface
Probable cold advection above Ekman spiral
Cold CB
Stoop
To bend or sag downward.
To lower or debase oneself.
To descend from a superior position; condescend.
To yield; submit.
To swoop down, as a bird in pursuing its prey.
Left Wing
Right Wing
Within the WCB:
East of radar veering, warm advection – katabatic warm front.
West of radar backing, cold advection – anabatic warm front.

8. The Warm Screaming Eagle Conceptual Model
Need to emphasize
The PPI nature of the
Doppler scan
- The cone D A G C B E F
This is the idea. I am contemplating:
Leaving this material as is and letting COMET build it in Flash from the letters and the descriptive text
Building this in HTML as the roll-overs area easier in HTML Note that this may also be done using links to text files. I will format the text box to be as small as possible and located where it does not obscure the image. This apporach works fairly well.
Note that the animations in PPT obscure the lettering unless the presentation is in “play” mode. It makes it more difficult to work on.
The animations highlight the best way to deduce winds vectors from the Doppler signal. The work below should highlight how the winds in the CCB are diagnosed separately from the winds in the WCB. The resultant diagnoses are then added together to create the mythical creature desired.
A is at the radar site.
The arc A to B represents the veering wind associated with the warm front as seen to the east of the radar. Is this the mixing zone or the warm air advection in the CCB? The warm frontal surface must be at the top of the mixing zone.
The arc A to C is the same representation to the west.
The difference in the height of B and C represents the slope of the warm front.
The shape of the outbound reds in the arc A to B defines the eagles head.
The stronger the low level CCB the “brighter” will be the “beak”.
The more curved the A to B veering wind is the more prominent will be the beak.
The best “beak” will be displayed by a backing wind in the lower part of the A to B layer. This backing wind is indicative of cold air advection within the CCB. This is suggestive that the cold layer underneath the warm frontal surface coninutes to cool with fresh reinforcements. The cold air is likely to become deeper and more entrenched thus preventing the northward progression of the warm front which is really the southward advance of the cold air.
The smallest “beak” will be displayed by a veering wind in the lower part of the A to B layer. This veering wind is indicative of warm air advection within the CCB. This is suggestive that the cold layer underneath the warm frontal surface is warming and is likely to dissipate allowing the northward progression of the warm front which is really the northward retreat of the cold air.
B and E are very close to being on the same radial which means that there is no change in wind direction and no thermal advection.
From C to D there is a slight backing of the wind which becomes more pronounced at point F. This backing of the winds increases the height of the right wing.
If we look at the radial from A to F and the winds are at right angles, then at point F our winds are from 160 degrees. Contrast this with what happens west of the radar.
Between points E and G the winds back slightly and are about 180 degrees at point G. This backing of the winds increases the height of the right wing.
Between points G and H the winds veer. At point H if we look at the A to H radial and go 90 degrees we define a wind direction of about 215 degrees. The 20 to 40 degree wind direction difference between D to F and G to H is what gives our eagle it’s wing shape. The 215 winds to the east of the radar and the 160 winds to the west indicate we are close to the col of the conveyor belt.
As we move further west or as the warm conveyor belt moves over this radar the left wing of the eagle should maintain itself or become more curved and the right wing should straighten out. I think a simple streamline example will illustrate this. H
The Warm Screaming Eagle Conceptual Model

9. Inactive or Katabatic Warm Front
Active or Anabatic Warm Front
Approaching the Col the Warm Front should have characteristics intermediate between the Anabatic Warm Front to the Left of the Col and the Katabatic Warm Front to the Right of the Col
Inactive or Katabatic Warm Front
One only needs to apply the equation of continuity to explain the impact of a veering wind in the warm air above the warm frontal surface.
If the wind veers above the frontal surface, then that wind is less than the forward speed of the warm front. The air is divergent at this height and air must be descending to fill the void through continuity. Such a warm front with veering winds above the frontal surface must be katabatic.

10. The PPI Virga Hole Signature – Typical in this Region of the CBCM
The difference between PPI and CAPPI displays can be used to advantage. Each display must be consulted in an analysis of the atmosphere. This is most often seen in Doppler Radar which is typically a PPI display. A B
Cross-section from
A (left) to B (right)
1.5km CAPPI
3.5 PPI
Virga Hole
The Virga Hole signature is only revealed in the PPI radar display. The CAPPI cannot reveal the true extent of the precipitation if the precipitation lies above the CAPPI level. A cross-section can reveal the vertical distribution of the precipitation.
The lowest level CAPPI display can be misleading as at longer ranges, the true level of the radar rises to follow the lowest PPI scan of the radar. This is depicted in this 1.5km CAPPI example. Click.

11. Virga only likely on the leading edge of the WCB
Under WCB
Virga only likely on the leading edge of the WCB
The CCB is becoming increasingly moist
Frontal overrunning and isentropic lift is increasing thus increasing the intensity of the precipitation process.
Warm front becoming more likely Anabatic
This must be slide 11 for the links form the Radar Conveyor Belt Conceptual Model PowerPoint to work.
Click for the Conceptual Model and Explanation

12. Common location for virgaB
Warm Frontal Cross-section along Central Branch of the Warm Conveyor Belt (WCB) A
Common location for virga
WCB
WCB oriented for
maximum frontal lift
Virga Precipitation
Increasing CCB
Moistening
Lower
Hydrometeor
Density
Mixing Zone
Surface
Warm Front
Precipitation
At Surface
CCB A B
Cold air in Cold Conveyor Belt (CCB) more shallow and moist
Notes:
All descriptive terms are intended to be comparative between the various conveyor belts in the Conveyor Belt Conceptual Model.
All quantities are intended to be the average or typical values
Virga may be the result of melting snow or evapourating rain to cause the reduced hydrometeor density and thus increased visibility or reduced obstruction to visibility
These comments will need validation – many are just my simple operational observations. This will be made easier with isentropic thinking and NinJo.
Compared to the previous slide and the leading branch of the WCB cross-section:
The depth of the WCB with a component of flow normal to the warm front is deeper.
The cold air mass is increasing moist from the precipitation.
The area of precipitation at the ground will show rapid increase as a result of the precipitation extending further downward into the moistened, modified CCB. The expansion of the precipitation area is a result of the moistened CCB and not any increases in the precipitation processes.
The warm front has equal probability of being anabatic or katabatic.
Just poleward of the warm front, the cloud type is likely to be altostratus
Moist portion of Warm Conveyor Belt (WCB) is thicker, higher and perpendicular to front
Lower levels of WCB have the same origin as the upper level of the WCB - frontal perpendicular
WCB shows little directional shift with height. A greater WCB depth is frontal perpendicular
Frontal slope is near the typical 1:200
Precipitation extends further into the moistened, modified CCB.
Horizontal rain area begins to expand as CCB moistens.

13. Vertical Deformation Zone Distribution and the CBM Simplified Summary
The WCB overrides the warm front
CCB
The CCB undercuts the warm front C
The frontal surface overlies the mixing layer
Wind shear in the CCB is variable
Looking along the flow:
In WCB to the right of the Col expect veering winds with height – Katabatic warm front
In WCB approach to the right of the Col expect maximum divergence – the eagle pattern with ascent and increasing pcpn
In WCB to the left of the Col expect backing winds with height – Anabatic warm front
WCB
DCB C C
DCB
Typical distributions of the conveyor belts and the associated deformation zones. Recall from the satellite palette that the deformation zone is actually a cross-section of the deformation sheath that encases an isentropic flow. Similarly, the vorticity centres depicted in the deformation zone conceptual model are actually vortex tubes that also slope in the vertical along with the deformation sheath.
The Warm Conveyor Belt (WCB) typically rises isentropically with poleward (both northeasterly and northwesterly) motion and time. The WCB is shown with no vertical wind shift but typically it veers with height which is consistent with warm air advection.
The Cold Conveyor Belt (CCB) typically sinks isentropically with equatorward (southwesterly) motion and time. The CCB typically backs with height which is consistent with cold air advection.
The Dry Conveyor Belt (DCB) typically sinks isentropically with equatorward (southeasterly) motion and time. In the “dry slot” of the comma pattern, the DCB is typically rising isentropically with poleward (northeasterly) motion and time. The DCB typically veers with height with the approaching upper ridge.
The flow ahead of the conveyor belt system has not been typically described but is the remains of the dry conveyor belt caught up in the upper ridge circulation. (Chadwick has described it in unpublished work.) This circulation is dry and subsiding with poleward (northwesterly) motion and time. The portion of the flow that turns southwesterly dry rises with equatorward (southwesterly) motion and time. This portion of the CCB typically veers with height which is consistent with warm air advection west of the upper ridge.
The slope of the isentropic surfaces can be inferred from the overlap of the deformation zones. The slope of the isentropic surfaces can also be used to analyze instability. Isentropically speaking, sinking cold air and rising warm air converts thermal energy into kinetic energy. The vertical motions of dry air is not so simple isentropically speaking – have to ponder this!
The introduction of isentropic thinking to NinJo will make the investigation of these concepts much easier.

14. WCB Approaching the Col
The Warm Screaming Eagle CM
Both wings are fully extended to catch the lift of the WCB.
This is a divergent signature. C
Warm CB
Warm frontal surface o
Mixing layer
Signature of
Warm Frontal surface
discontinuity
Within the CCB:
Probable Ekman spiral nearest surface
Probable cold advection above Ekman spiral
Cold CB
Stoop
To bend or sag downward.
To lower or debase oneself.
To descend from a superior position; condescend.
To yield; submit.
To swoop down, as a bird in pursuing its prey.
Left Wing
Right Wing
Within the WCB:
East of radar veering, warm advection – katabatic warm front.
West of radar backing, cold advection – anabatic warm front.

15. The Warm Screaming Eagle Conceptual Model
Need to emphasize
The PPI nature of the
Doppler scan
- The cone D A G C B E F
This is the idea. I am contemplating:
Leaving this material as is and letting COMET build it in Flash from the letters and the descriptive text
Building this in HTML as the roll-overs area easier in HTML Note that this may also be done using links to text files. I will format the text box to be as small as possible and located where it does not obscure the image. This apporach works fairly well.
Note that the animations in PPT obscure the lettering unless the presentation is in “play” mode. It makes it more difficult to work on.
The animations highlight the best way to deduce winds vectors from the Doppler signal. The work below should highlight how the winds in the CCB are diagnosed separately from the winds in the WCB. The resultant diagnoses are then added together to create the mythical creature desired.
A is at the radar site.
The arc A to B represents the veering wind associated with the warm front as seen to the east of the radar. Is this the mixing zone or the warm air advection in the CCB? The warm frontal surface must be at the top of the mixing zone.
The arc A to C is the same representation to the west.
The difference in the height of B and C represents the slope of the warm front.
The shape of the outbound reds in the arc A to B defines the eagles head.
The stronger the low level CCB the “brighter” will be the “beak”.
The more curved the A to B veering wind is the more prominent will be the beak.
The best “beak” will be displayed by a backing wind in the lower part of the A to B layer. This backing wind is indicative of cold air advection within the CCB. This is suggestive that the cold layer underneath the warm frontal surface coninutes to cool with fresh reinforcements. The cold air is likely to become deeper and more entrenched thus preventing the northward progression of the warm front which is really the southward advance of the cold air.
The smallest “beak” will be displayed by a veering wind in the lower part of the A to B layer. This veering wind is indicative of warm air advection within the CCB. This is suggestive that the cold layer underneath the warm frontal surface is warming and is likely to dissipate allowing the northward progression of the warm front which is really the northward retreat of the cold air.
B and E are very close to being on the same radial which means that there is no change in wind direction and no thermal advection.
From C to D there is a slight backing of the wind which becomes more pronounced at point F. This backing of the winds increases the height of the right wing.
If we look at the radial from A to F and the winds are at right angles, then at point F our winds are from 160 degrees. Contrast this with what happens west of the radar.
Between points E and G the winds back slightly and are about 180 degrees at point G. This backing of the winds increases the height of the right wing.
Between points G and H the winds veer. At point H if we look at the A to H radial and go 90 degrees we define a wind direction of about 215 degrees. The 20 to 40 degree wind direction difference between D to F and G to H is what gives our eagle it’s wing shape. The 215 winds to the east of the radar and the 160 winds to the west indicate we are close to the col of the conveyor belt.
As we move further west or as the warm conveyor belt moves over this radar the left wing of the eagle should maintain itself or become more curved and the right wing should straighten out. I think a simple streamline example will illustrate this. H
The Warm Screaming Eagle Conceptual Model

16. Inactive or Katabatic Warm Front
Active or Anabatic Warm Front
Approaching the Col the Warm Front should have characteristics intermediate between the Anabatic Warm Front to the Left of the Col and the Katabatic Warm Front to the Right of the Col
Inactive or Katabatic Warm Front
One only needs to apply the equation of continuity to explain the impact of a veering wind in the warm air above the warm frontal surface.
If the wind veers above the frontal surface, then that wind is less than the forward speed of the warm front. The air is divergent at this height and air must be descending to fill the void through continuity. Such a warm front with veering winds above the frontal surface must be katabatic.

17. CCB Doppler Diagnosis B B C C A A The Beaked Eagle The Headless Eagle
A is the radar site
AB is backing with height indicative of cold advection where really there should be veering with the Ekman Spiral
BC is veering with height indicative of warm advection
B is the front with the mixing layer hidden in the cold advection
This is a strong cold advection
The warm front will be slow moving or stationary
A is the radar site
ABC is all veering with height indicative of warm advection. Layer AB is apt to be partially the result of the Ekman Spiral
BC is veering with height indicative of warm advection
Where is the front and the mixing layer?
The cold advection is not apparent and the warm front will advance
One must always attempt to identify the location of the boundaries between the conveyor belts. The methods to do this are:
Consider the ever present Ekman Spiral which should cause veering with height. There will be an abrupt change in the wind direction and speed (gradient wind) at the top of the PBL and the Ekman Spiral.
Know the expected characteristics of the conveyor belt one is diagnosing by placing the Doppler data into the conveyor belt pattern and employing situational awareness.
Keep the mixing layer of any front within the cold air mass. The frontal surface is always higher than this mixing layer.

18. WCB Doppler Diagnosis D A G C B E F H WCB Doppler Diagnosis.
Almost by definition, the lowest level of the WCB is also the frontal surface. The baroclinic frontal mixing zone is always within the cold air and thus must be predominantly within the CCB.
E (I believe) is the warm front at the top of the mixing zone. The veering in the layer AE is explainable by both the Ekman Spiral and the warm air advection in the warm frontal mixing zone. EG backs slightly and is a marked difference from AE.
C is the western counterpart to E but its placement is uncertain and it should be at roughly the same height as E.
D and G identify the maximum penetration of the “toward” component into the “away” component. Any further displacement than these points and everything is “away” with respect to the radar origin.
These points are far apart and opposite each other across the origin in a divergent flow. The winds of the eagle are fully extended.
These points are closer together and opposite each other across the origin in a convergent flow. The winds of the eagle are folded inward.
Can these toward (or away extremes) ever be more than directly across the origin (radar site) from each other? I think not.
These primary points (after the bird’s primary feathers) occur at the crest of the wind and separate backing from veering winds.
The magnitude difference between the backing and veering determines the size of the wing. More backing separating more veering is associated with more significant thermal advections and a broader wing like that of an eagle.
Less backing separating less veering is associated with less significcant thermal advections and a shallow wing like that of a gull. H

21. The CCB has become moist
Behind WCB
Virga much less likely
The CCB has become moist
Frontal overrunning and isentropic lift is maximized thus maximizing the intensity of the precipitation process.
Warm front is likely Anabatic
This must be slide 21 for the links form the Radar Conveyor Belt Conceptual Model PowerPoint to work.
Click for the Conceptual Model and Explanation

22. Common location for virgaB
Warm Frontal Cross-section along Trailing Branch of the Warm Conveyor Belt (WCB) A
Common location for virga
WCB
WCB oriented for
maximum frontal lift
Virga Precipitation
Increasing CCB
Moistening
Lower
Hydrometeor
Density
Mixing Zone
Surface
Warm Front
Precipitation
At Surface
CCB A B
Cold air in Cold Conveyor Belt (CCB) even more shallow and more moist
Notes:
All descriptive terms are intended to be comparative between the various conveyor belts in the Conveyor Belt Conceptual Model.
All quantities are intended to be the average or typical values
Virga may be the result of melting snow or evapourating rain to cause the reduced hydrometeor density and thus increased visibility or reduced obstruction to visibility
These comments will need validation – many are just my simple operational observations
Compared to the previous slide and the central branch of the WCB cross-section:
The depth of the WCB with a component of flow normal to the warm front is even deeper.
The cold air mass is increasing moist from the precipitation.
The area of precipitation at the ground will continue to show rapid increase as a result of the precipitation extending further downward into the moistened, modified CCB. The expansion of the precipitation area is a result of the moistened CCB and not any increases in the precipitation processes.
The warm front is more likely to be anabatic or active.
Just poleward of the warm front, the cloud type will certainly be nimbostratus
Moist portion of Warm Conveyor Belt (WCB) is thicker, higher and backed from frontal perpendicular – anabatic tendency
Lower levels of WCB have the same origin as the upper level of the WCB
WCB probably backs slightly with height in spite of the warm air advection. A greater WCB depth is frontal perpendicular
Frontal slope likely steeper than the typical 1:200
Precipitation extends further into the moistened, modified CCB.
Horizontal rain area expands rapidly as CCB moistened.

23. Vertical Deformation Zone Distribution and the CBM Summary
CCB C
WCB
DCB C C C C
DCB
Typical distributions of the conveyor belts and the associated deformation zones. Recall from the satellite palette that the deformation zone is actually a cross-section of the deformation sheath that encases an isentropic flow. Similarly, the vorticity centres depicted in the deformation zone conceptual model are actually vortex tubes that also slope in the vertical along with the deformation sheath.
The Warm Conveyor Belt (WCB) typically rises isentropically with poleward (both northeasterly and northwesterly) motion and time. The WCB is shown with no vertical wind shift but typically it veers with height which is consistent with warm air advection.
The Cold Conveyor Belt (CCB) typically sinks isentropically with equatorward (southwesterly) motion and time. The CCB typically backs with height which is consistent with cold air advection.
The Dry Conveyor Belt (DCB) typically sinks isentropically with equatorward (southeasterly) motion and time. In the “dry slot” of the comma pattern, the DCB is typically rising isentropically with poleward (northeasterly) motion and time. The DCB typically veers with height with the approaching upper ridge.
The flow ahead of the conveyor belt system has not been typically described but is the remains of the dry conveyor belt caught up in the upper ridge circulation. (Chadwick has described it in unpublished work.) This circulation is dry and subsiding with poleward (northwesterly) motion and time. The portion of the flow that turns southwesterly dry rises with equatorward (southwesterly) motion and time. This portion of the CCB typically veers with height which is consistent with warm air advection west of the upper ridge.
The slope of the isentropic surfaces can be inferred from the overlap of the deformation zones. The slope of the isentropic surfaces can also be used to analyze instability. Isentropically speaking, sinking cold air and rising warm air converts thermal energy into kinetic energy. The vertical motions of dry air is not so simple isentropically speaking – have to ponder this!
The introduction of isentropic thinking to NinJo will make the investigation of these concepts much easier.

24. WCB to the Left of the Col
The Warm Left Wing Stoop CM
The eagles left wing is folded in as if it is about to swoop down.
The right wing is still fully extended to catch the lift of the WCB. C o
Signature of
Warm Frontal surface
… odd?
Signature of
Warm Frontal surface
Warm advection
Within the CCB:
Probable Ekman spiral nearest surface
Probable cold advection above Ekman spiral
Cold CB
Stoop
To bend or sag downward.
To lower or debase oneself.
To descend from a superior position; condescend.
To yield; submit.
To swoop down, as a bird in pursuing its prey.
Mixing layer
Right Wing
Warm frontal surface
Left Wing
Warm CB
Within the WCB:
West of radar backing, cold advection
East of radar nil VWS

25. G D A C B F The Left Wing Stoop CM
On the west side of the warm conveyor belt the eagle has indeed lost it’s right wing. The left wing continues to show the 40 degrees of backing of the winds into the southeast. But now the right wing is also backing but by only about 10 or 15 degrees. The flow is still diffluent but not as much as in the middle of the arm conveyor belt.

26. Active or Anabatic Warm Front

27. WCB Doppler Diagnosis – Diagnosis of the Eagle Wing
The Left Eagle Wing
The Right Eagle Wing
A is the radar site
BC is veering with height indicative of warm advection.
CD is backing with height indicative of cold advection
Larger angles subtended by the arcs BC and CD by the radar site A, are associated with strong thermal advections
A broad wing in the eagle is associated with strong advections
A is the radar site
BC is backing with height indicative of cold advection.
CD is veering with height indicative of warm advection
Larger angles subtended by the arcs BC and CD by the radar site A, are associated with strong thermal advections
A broad wing in the eagle is associated with strong advections
The eagle wing analogy works – I am certain there are many more analogies that could be employed.
Notice that the type and intensity of the thermal advections can be determined by the size of the angle that the arc subtends and the direction of the arc.
Thermal Advection Intensity
The larger the angle subtended by the arc, the stronger the advections.
The smaller the angle subtended by the arc, the weaker the advections.
Thermal Advection Type
If the arc rotates cyclonically or clockwise with height, the arc is associated with warm thermal advection.
If the arc rotates anticyclonically or counterclockwise with height, the arc is associated with cold thermal advection.

28. WCB Doppler Diagnosis – Diagnosis on the Gull Wing
The Gull Conceptual Model - weaker thermal advections C C A A D D B B
The Left Eagle Wing
The Right Eagle Wing
A is the radar site
BC is veering with height indicative of warm advection.
CD is backing with height indicative of cold advection
Larger angles subtended by the arcs BC and CD by the radar site A, are associated with strong thermal advections
A narrow wing in the gull is associated with weak advections
A is the radar site
BC is backing with height indicative of cold advection.
CD is veering with height indicative of warm advection
Larger angles subtended by the arcs BC and CD by the radar site A, are associated with strong thermal advections
A narrow wing in the gull is associated with weak advections
The important concept is to realize that in Doppler radar data, the size of the backing or veering arc is directly related to the intensity of the thermal advections.

31. Doppler Oriented Reference Conceptual Models

32. Doppler Analysis and Diagnosis Strategies
An operational guide to getting the most information from Doppler radar:
Determining the actual wind direction
Determining wind backing and veering
Diagnosing spatial versus vertical wind variations
The Screaming Eagle and Gull Patterns

33. Diagnosis of the Conveyor Belts
Wind direction and speed diagnosis should be completed independently in each conveyor belt
Given the nature of isentropic flow, this is a prudent mode of diagnosis. Isentropic flows stay relatively separate and maintain their distinctive properties.
The Doppler characteristics depicted in the CCB are separate from those in the WCB. When added, instructive patterns are revealed.

34. Range Ring versus Radial Zero Velocity Doppler LinesB A B C A C
Radial Zero Lines
Range Ring Zero Lines
A is the radar site
Zero Doppler Velocity line that follows a radial from the radar like BC depicts velocity vectors that are:
At ever increasing heights
Depictions of vertical speed shear wind differences (no directional shear)
Radial Zero Lines thus depict vertical wind difference/shear
A is the radar site
Zero Doppler Velocity line that follows a range ring like BC depicts velocity vectors that are:
All at the same elevation
Depictions of horizontal wind differences – primarily directional wind shear
Range Ring Zero Lines thus depict spatial wind difference (primarily directional shear)
These are important conceptual models in order to make the use of Doppler information. The characterisitcs of the Doppler Zero line reveals must about the wind shear. There are even many more signatures that reveal characteristics of the relative wind magnitude.
The real Doppler data is a combination of these two patterns

35. Diagnosis of Wind Direction – Using the Zero Line
Draw a radial line from the radar site to the zero line
The wind must be either zero or the wind direction must be exactly perpendicular to the radial line
The wind direction can be determined as blowing from the toward colours (blue) to the away colours (red) perpendicular to the radial
Click now
Zero Line A B
A is the radar site
BC the zero line
Everywhere along the zero line the radial component of the real wind detected by Doppler must be zero – meaning the total wind must be perpendicular to the radar radial – or actually zero which is unlikely.
Thermal Advection Intensity
The larger the angle subtended by the arc, the stronger the advections.
The smaller the angle subtended by the arc, the weaker the advections.
Thermal Advection Type
If the arc rotates cyclonically or clockwise with height, the arc is associated with warm thermal advection.
If the arc rotates anticyclonically or counterclockwise with height, the arc is associated with cold thermal advection.
In Doppler wind analysis always establish the layers where the zero line veers (turns clockwise with range/height) and layers where the zero line backs (turns counterclockwise with range/height. These are the thermal advection layers. The point of inflection between backing and veering separates these important analytical layers.

36. Diagnosis of Vertical Windshear – Using the Zero line
Determine the wind at B. Draw a radial line from the radar site to the zero line at B. Click
Determine the wind at C. Click
The wind backs from B to C
Determine the wind at D. Click
The wind veers from C to D B C D A
Summary - Generalizations
Thermal Advection Intensity
The larger the angle subtended by the arc, the stronger the thermal advections.
The smaller the angle subtended by the arc, the weaker the advections.
This angle is independent of range from the radar
Thermal Advection Type
If the arc rotates cyclonically with height (increasing range) the arc is associated with warm advection.
If the arc rotates anticyclonically with height, the arc is associated with cold advection.
Note that the directional wind shear increases with the angle subtended by the arc – This angle does not change with range from the radar (directional shear).
The angle subtended by the zero line arc is the directional wind shear component of the velocity vector shear.
Thermal Advection Intensity
The larger the angle subtended by the arc, the stronger the advections.
The smaller the angle subtended by the arc, the weaker the advections.
Thermal Advection Type
If the arc rotates cyclonically or clockwise with height, the arc is associated with warm thermal advection.
If the arc rotates anticyclonically or counterclockwise with height, the arc is associated with cold thermal advection.
… and yes, I made this up – maybe even invented it for the first time. Who knows?
Phil

37. Diagnosis of Vertical Windshear – Using the Zero lineB C D A B C D A
The angle subtended by the counter-clockwise arc BC would be the same regardless of the exact location of C anywhere along the radial AC from the Doppler radar. The amount of backing with height is also independent of the location of C along the radial AC. The amount of wind shear (cold advection) is dependent only on the subtended angle and not the orientation of the arc.
The angle subtended by the clockwise arc CD would be the same regardless of the exact location of D anywhere along the radial AD from the Doppler radar. The amount of veering with height is also independent of the location of D along the radial AD. The amount of wind shear (warm advection) is dependent only on the subtended angle and not the orientation of the arc.
Thermal Advection Intensity
The larger the angle subtended by the arc, the stronger the advections.
The smaller the angle subtended by the arc, the weaker the advections.
Thermal Advection Type
If the arc rotates cyclonically or clockwise with height, the arc is associated with warm thermal advection.
If the arc rotates anticyclonically or counterclockwise with height, the arc is associated with cold thermal advection.
… and yes, I made this up – maybe even invented it for the first time. Who knows?
Phil
The thermal VWS is thus the angle subtended by the arc divided by the elevation change that this thermal advection occurred over. The following slide illustrates these concepts.

38. Thermal Advections and Vertical Wind Shear
The angle subtended by the counter-clockwise arc BC is identical in 1, 2 and 3.
In 1, the backing winds occur over a short radial range and thus a short height interval.
The radial range difference increases for case 2 and is even more for case 3. The height interval for the Thermal VWS increases with the length of the radial AC from case 1 to case 3.
The Thermal VWS determined by dividing the direction shear (subtended angle dependent) by the height interval (difference between AC and AB=AD) that it occurs over, is strongest for 1 and weakest for 3.
As detailed, Thermal VWS is a combination of the size of the subtended angle and the radial range (AC-AB=AD) which when combined, is inversely proportional to the area CBD.
This could feasibly be automatically calculated in URP. I sincerely doubt if it is. D C 1. A B A B C D 2. A B C D 3.

39. Thermal Advections and Vertical Wind Shear
Which has the strongest Thermal VWS?
The smaller the area CBD, the more intense the Thermal VWS and thus the more intense the thermal advections. D C 1. A B
For a given subtended angle:
the strongest Thermal VWS occurs with a Doppler Zero Line closely following the range rings
the weakest Thermal VWS occurs with a Doppler Zero Line closely following the radar radial lines C D 2. A B C
Similarly for a given height interval CD radial:
the strongest Thermal VWS occurs with the largest subtended angle
the weakest Thermal VWS occurs with the smallest subtended angle D 3. A B

40. Diagnosis of Stability Trends
Stability increases with:
Cold advection decreasing with height:
Angle of Doppler arc backing counterclockwise decreasing (rate of cooling decreases) with height (range) increasing (Area CBD increasing),
Warm advection increasing with height:
Angle of Doppler arc veering clockwise increasing (rate of warming increases) with height (range) decreasing (Area CBD decreasing),
Warm advection over cold advection:
Doppler arc veering clockwise with height (range) over Doppler arc backing counterclockwise with height (range).
Using the zero line to establish wind shear:
For a fixed length of arc, if the wind shear is aligned along a range ring (spatial distribution of wind shear), then it is likely that the same wind shear is also experienced in the short vertical distance. Strong wind shear over a short vertical distance is associated with strong thermal advections.
For a fixed length of arc, if the wind shear is aligned along a radar radial (vertical distribution of wind shear), then it is certain that the wind shear is also experienced in the larger vertical distance. Strong wind shear spread over a larger vertical distance is associated with weaker thermal advections.
The conceptual model summary for this is that thermal advections should generally decrease as the angle between the range ring and the arc (zero line) increases. Of course, the exact about of wind shear can probably be determined by making the best estimate of the actual winds and wind shear from the colour display. This approach would take longer and not be used operationally.

41. Doppler Examples for Increasing Stability
Level D
Weaker cold advection CD
Level C
Stabilization
Stronger cold advection BC C
Level B 1. A B
Level D
Stronger warm advection CD C
Level C
Stabilization B
Weaker warm advection BC
Level B 2. A D
Level D
(Strong) Warm advection CD C
Level C
Stabilization
(Weak) Cold advection BC
Level B 3. A D B
Note: Angles kept constant.
Changing the Thermal Advection Intensity by changing the depth of the directional wind shear.

42. Diagnosis of Stability Trends
Stability decreases (Destabilization) with:
Cold advection increasing with height:
Angle of Doppler arc backing counterclockwise decreasing (rate of cooling increases) with height (range)
Warm advection decreasing with height:
Doppler arc veering clockwise with height (range) under Doppler arc backing counterclockwise with height (range).
Angle of of Doppler zero arc veering clockwise increasing (rate of warming decreases) with height (range),
Warm advection under cold advection:
This needs to be checked more thoroughly… it might be a good idea but will take some study to be certain.

43. Doppler Examples for Increasing Instability
Level D
Stronger cold advection CD
Level C
Destabilization C
Weaker cold advection BC
Level B 1. A B D
Level D
Weaker warm advection BC
Level C
Destabilization C
Stronger warm advection BC
Level B 2. A B D
Level D
(Weak) Cold advection CD B
Level C
Destabilization C
(Strong) Warm advection BC
Level B 3. A
Note: Angles kept constant.
Changing the Thermal Advection Intensity by changing the depth of the directional wind shear.

44. Changing Stability by Changing the Angle of the Vertical Wind Shear
As the angle subtended by the zero line increases, the amount of directional wind shear also increases.
The directional wind shear must be divided by the height over which this shear occurs in able to determine the magnitude of the thermal advections.
Generally, as the angle increases, so does the thermal advections. The angle of the zero line relative to the range rings is essential to use this technique in an operational setting.

45. Doppler Examples for Increasing Stability
Level D
Weaker cold advection CD C
Level C
Stabilization
Stronger cold advection BC
Level B 1. A B
Level D
Stronger warm advection CD C
Stabilization B
Level C
Weaker warm advection BC
Level B 2. A D
Cold Advection
Decreasing with Height
Stabilization
Warm Advection
Increasing with Height
Stabilization
The angles that the zero line makes with the range rings is the operational approach to employ. o o
CAA angle increasing with range/height.
WAA angle decreasing with range/height.
Note: VWS Depth kept constant. Changing the Thermal Advection Intensity by changing the subtended angle (amount) of the directional wind shear. Increasing the angle, decreases the enclosed area.

46. Doppler Examples for Increasing Instability
Level D
Stronger cold advection CD
Level C
Destabilization
Weaker cold advection BC C
Level B 1. A B
Level D
Weaker warm advection CD
Destabilization B
Level C
Stronger warm advection BC
Level B 2. A C D
Cold Advection
Increasing with Height
Destabilization
Warm Advection
Decreasing with Height
Destabilization
The angles that the zero line makes with the range rings is the operational approach to employ. o o
CAA angle decreasing with range/height.
WAA angle increasing with range/height.
Note: VWS Depth kept constant. Changing the Thermal Advection Intensity by changing the subtended angle (amount) of the directional wind shear. Increasing the angle, decreases the enclosed area.

47. Doppler Rate of Thermal Advections with Height
Consider the angle between the veering or backing arc and the radar range ring.
If this angle increases (in time) from previous values then the rate of wind shear with height is decreasing, since height is a function of radial range. This must imply that for a given arc, the thermal advections have decreased.
If this angle decreases (in space) along the arc then the rate of wind shear with height is increasing, since height is a function of radial range. This must imply that for a given arc, the thermal advections have increased.
Track the angle the arc makes with the radar rings with both time (between scans) and in space along the trace of the arc… if the angle increases, then the associated thermal advections are decreasing. o

48. Doppler Rate of Thermal Advections with Height
For example:
A clockwise, veering arc associated with warm advection vertical wind shear:
Indicates that the layer is becoming more stable if the angle with the range rings decreases with range. (warm advection increasing with height)
Indicates that the layer is becoming more unstable if the angle with the range rings increases with range. (warm advection decreasing with height)
To my knowledge, I invented this. I haven’t seen anyone else present this material.

49. Doppler Rate of Thermal Advections with Height
For example:
A counterclockwise, backing arc associated with cold advection vertical wind shear:
Indicates that the layer is becoming more stable if the angle with the range rings increases with range. (cold advection decreasing with height)
Indicates that the layer is becoming more unstable if the angle with the range rings decreases with range. (cold advection increasing with height)
To my knowledge, I invented this. I haven’t seen anyone else present this material. This can get complicated.

50. WCB Doppler Diagnosis – Diagnosis of the Eagle Wing
The Left Eagle Wing
The Right Eagle Wing
A is the radar site
BC is veering with height indicative of warm advection.
CD is backing with height indicative of cold advection
Larger angles subtended by the arcs BC and CD by the radar site A, are associated with strong thermal advections
A broad wing in the eagle is associated with strong advections
A is the radar site
BC is backing with height indicative of cold advection.
CD is veering with height indicative of warm advection
Larger angles subtended by the arcs BC and CD by the radar site A, are associated with strong thermal advections
A broad wing in the eagle is associated with strong advections
The eagle wing analogy works – I am certain there are many more analogies that could be employed.
Notice that the type and intensity of the thermal advections can be determined by the size of the angle that the arc subtends and the direction of the arc.
Thermal Advection Intensity
The larger the angle subtended by the arc, the stronger the advections.
The smaller the angle subtended by the arc, the weaker the advections.
Thermal Advection Type
If the arc rotates cyclonically or clockwise with height, the arc is associated with warm thermal advection.
If the arc rotates anticyclonically or counterclockwise with height, the arc is associated with cold thermal advection.

51. WCB Doppler Diagnosis – Diagnosis on the Gull Wing
The Gull Conceptual Model - weaker thermal advections C C A A D D B B
The Left Eagle Wing
The Right Eagle Wing
A is the radar site
BC is veering with height indicative of warm advection.
CD is backing with height indicative of cold advection
Larger angles subtended by the arcs BC and CD by the radar site A, are associated with strong thermal advections
A narrow wing in the gull is associated with weak advections
A is the radar site
BC is backing with height indicative of cold advection.
CD is veering with height indicative of warm advection
Larger angles subtended by the arcs BC and CD by the radar site A, are associated with strong thermal advections
A narrow wing in the gull is associated with weak advections
The important concept is to realize that in Doppler radar data, the size of the backing or veering arc is directly related to the intensity of the thermal advections.