1. Forecast Verification time!
2 pm – 7:40 pm
Wednesday 77
0.07”
Mr. Perfect Forecast 77
YES
0.07” 10

3. What is CLIMATE ?? (vs. weather)
CLIMATOLOGY
TEMPS
Average: 79
(72/71/77/77/?)
Median
Range 81
Standard Dev. +/- 8
RAIN
Average:
Range:
% time:
0.16”
0-1.13”
53%
(0.64”/0.67”/0.04”/0.28”/?)
What is CLIMATE ?? (vs. weather)

4. De donde son ustedes?
(Where are you from)
Most interesting weather
at your hometown?

5. SURFACE PRESSURE
… corrected to sea level
Wind flow crosses isobars at the ground due to friction force

6. Flow at 500mb (upper levels of troposphere ~ 5,500m, or 18,000 ft.)
Flow at 500mb (upper levels of atm. ~ 5,500m, or 18,000 ft.)
Wind flow nearly parallel to isobars in upper levels = minimal friction

7. Surface Weather Map (radar overlay)

8. Today at 11z (7 am)
SL Pressure
Winds H L

9. Today at 11z (7 am)
Temps
Dew Points

10. Penn State Weather Camps
Basic Weather Forecasting Guidelines
Sat I – Sat II – Sat III - NWS - NHC – Radar - Radar - Radar
sfc. map 1 - sfc. map 2 - EWALL

11. NAM Forecast – Surface Pressure
New Model Run
NAM Forecast – Surface Pressure
This evening L

12. NAM MODEL - THIS EVENING – Jet Stream (500mb)X

13. Yesterday’s Model Run
NAM MODEL
GFS MODEL LI
LIFTED INDEX
THURS EVE

14. New Model Run
NAM MODEL
GFS MODEL LI
THURS PM
LIFTED INDEX

15. NAM MODEL
GFS MODEL
THIS EVE
Precipitable Water = If we “wrung” out all the moisture
in the atmosphere, how much precipitation would we get?

16. SPC Forecast – Tomorrow (Thursday)

18. ...Eastern States...
An upper-level trough will move eastward from the Ohio and
Tennessee Valleys across the Southern and Central Appalachians into
the Carolinas today.
Ahead of the trough, a moist air mass will be in
place with surface dew points in the upper 60s and lower 70s creating
a large corridor of moderate from the southern Appalachian foothills to
the Atlantic coast.
Thunderstorms should initiate just ahead of the shortwave trough in
the southern Appalachians at midday with storms moving east to the
foothills in the afternoon.
Forecast soundings in northwest South Carolina and west-central
North Carolina at 21Z show MLCAPE values reaching 2,000 J/kg with
0-6 km shear of kt. This combined with veered southwesterly
winds at the surface and westerly flow in the low to mid-levels will be
favorable for quasi-linear development.

19. ...Eastern States...
As low-level lapse rates become steep in the afternoon, conditions will
become favorable for wind damage along the leading edge of an MCS
moving east from the southern Appalachians. For this reason, will
upgrade to Enhanced risk for wind damage across parts of northern
South Carolina, North Carolina and southern Virginia. Isolated large
hail will also be possible with the stronger parts of the linear MCS.
Further north into the Mid-Atlantic, instability is not forecast
to be quite as strong as across the Carolinas. For that reason,
the wind damage threat is expected to remain more isolated
and will depend upon which areas destabilize the most. Wind
damage would be the primary threat across the Mid-Atlantic
this afternoon.
Model cloud product

20. Upper-level trough lingers …. Cool air aloft = Cu cloud maker
NAM MODEL - FRI EVENING – Jet Stream (500mb) L X
Upper-level trough lingers ….
Cool air aloft = Cu cloud maker
Model cloud product

21. Upper-level trough departs ….
NAM MODEL - SAT EVENING – Jet Stream (500mb)
Upper-level trough departs ….
Let the return!
Model cloud product

22. Today’s Forecast ?

23. Penn State Weather Camps
Basic Weather Forecasting Guidelines
Sat I – Sat II – Sat III - NWS - NHC – Radar - Radar - Radar
sfc. map 1 - sfc. map 2 - EWALL

26. Surface Observations YYZ = Station 57 = 50 = 155 = Temp Dewpoint
SL Pressure =
Sky cover
Station =
Temp =
Dewpoint =
Pressure =
PIT 66 65
1013.8mb =
SSW 5 kts
=Lt. Rain