1. Turbulence Diagnoses and Forecasts
Bob Sharman
NCAR/RAL
Weather in the Cockpit Workshop
8 August 2006

2. FAA AWRP Turbulence PDT work areas
Develop/implement in situ turbulence observations
UAL, SWA, Delta
Develop/implement remotely sensed turbulence observations
NEXRAD Turbulence Detection Algorithm (NTDA)
Develop turbulence nowcasting and forecasting systems
Graphical Turbulence Guidance (GTG)
GTGN
All products can be uplinked to the cockpit

3. In situ turbulence measurement and reporting program
Goal: To augment/replace subjective PIREPs with objective and precise turbulence measurements
Features:
Automatically computes
atmospheric turbulence intensities
Aircraft independent (eddy dissipation rate, EDR)
Automatically downloads data periodically during flight using ACARS network
Can convert EDR to aircraft loads and vice versa given information about aircraft
Adopted as ICAO Standard

4. UAL in-situ compared to pireps

5. NEXRAD in-cloud turbulence detection algorithm (NTDA)
Graphic courtesy of virtualskies.arc.nasa.gov
Cockpit display or radioed alert
Dispatch, ATC, etc.
TPAWS
EDR
In-cloud edr display
NEXRAD or TDWR

6. NTDA status Ongoing verification against in situ data
EXP TURB FI UAL███████████
-- 20 Oct :08:57Z
FL 360 orient. 95 deg
'X'=aircraft, '+'=waypoint, '*'=route
' '=no_data, 'o'=smooth, 'l'=light
'M'=mod, 'S'=severe
(36nm to COWES)
llll l*MMMMMMll
112nm lll ll*llMMMMlll
llM*MMMMMMMl
108nm llM*MMlMMMMM
llM*MMlllMM
104nm lMM*llll
Ml*l
100nm l**l
ll ol l*ll
096nm llllllllll*lll
llllllllllll*ll
092nm llllllllllll*ll l
llllllllll l*ll llllllll
088nm lllllMllMMlll*l lllllllll
lllMMMMMMll * lllllllllll
084nm llllMMMMMMM ** llllllllllllll
lllllMMMMMMl *llllllllllllllll
080nm llllllMMMMM *llllllllllllllll
llllMMlMMM l*lllllllllllllll
076nm ollMMMlll l l*lllllllllllllll
ollMMMllllllM*llll lllllll
+STL llllllllllMMl+lll lllllll
ll lll Mll*lll llllll
068nm ll llllllMMll*lllM llllll
lll lllllllll*llMM llllll
064nm lll llllllll*llMM llllll
l ll llllllll*lMMM lllMll
060nm lll llllllllllM*MMM lllMMMl
ll lllllllMMlM*M MMllMMMM
056nm Ml llllllMMlM*M MlMMMMMM
M l llllllMMlM*Ml MMMMMMMMM
052nm l lllllllllllM*MlllMMMMMMMMMMM
lll lllllllllllMM*MllMMMMMMMMMMMM
048nm lll lll ollllllMM*MllMMMSSMMMMMMM
llM llloollllllll*llllMMSSMMMMMMM
044nm llMMMlllollllllll*llllMMMSSMMMMMM
llMMM llll lllll*llllMMMMMMMlMMM
040nm M lllllllllll*lllllMMMMMllMMM
lllMMlllllll*llllllMMMlllllM
036nm MMllMMll ll*llllllllllllllM
MMMlMMll lll*lllllllllll
032nm MMMllllll ool*l lll llll
MMMlllllllol*l l
028nm MMMllllllMMl*
lMMlll MMl*
024nm M M *
M *
020nm MMll *
Mlllll ** MMM
+WELTS llll llMMM
lll * llMMM
012nm ll * llMM *
008nm *
004nm *
valid X
2205Z -40nm (39.0N, 92.1W) nm
Ongoing verification against in situ data
Web-based display of NTDA product
Successful demonstration last summer of NTDA text graphic uplink to selected UAL aircraft with character printer
severe
In situ edr tracks
NTDA
edr
contours
SFO-BWI 20 Oct 05

7. NTDA turbulence display
/EXPERIMENTAL TURBULENCE FI UAL███/AN N███UA UPLINK
-- 01 Jul :08:10Z FL 360 orient. 88 deg
'+'=waypoint, '*'=route, 'X'=aircraft at 43.2N, 86.3W
' '=no_data, 'o'=smooth, 'l'=light, 'M'=mod, 'S'=severe
(25 to EJOYS)
ll | *
lll | *
lll | lllll*
lll l | ollll*
lll M | oolll*l
lll | llll *
lll +MONEE llllllll +
lll l | ll llllll *
lll l | llll lllllll*ll
lll l | oll lllllllll*ll
lll l | ool lllllllll *
lll | lllllll *
lll | llllll *
lll l | llllllll *
lll l | olllllllll *
lll l | ooo lllllll *
Mll | o lllllll *
lll | lllll *
lll | lloo *
lol | *
llo | *
lll | *
lll l | ll *
lll l | lll *
lll l +GRUBB lll +
lll | ll *
ll | *
| *
| valid X
|Left Z (86 from BAE) Right 40
NTDA turbulence display
at 2210 UTC
Radar at ~2215 UTC
(deviation began at 2213)
NTDA uplink message at 2208 UTC
View toward left at about 2215 UTC

8. TPDT forecasting Graphical Turbulence Guidance (GTG) forecast product
Combines many turbulence indicators + observations
Rapid updates
4D gridded output
ADDS displays
GTG2 early 2007
GTG3 early 2010
GTG1
GTG2
GTG4
GTG3
GTG5

9. Turbulence nowcasting - GTGN
0-1 hr forecast
Real-time pireps
Lightning
Real-time in situ
data
NTDA
Real-time
ACARS
winds/temp
Wind profilers
3D data cube of
observed/inferred
turbulence updated
every few minutes
Satellite features
Metars

10. Global GTG (TFO) Uses NOAA’s GFS model
Diagnoses and forecasts of CAT > FL200
Experimental product should be available by early 2008
Example:
Upper: RUC20
Lower: GFS

11. 07/06/2005 CIT (>FL200 in situ)

12. Summary
Enhanced situational awareness for tactical decisions about turbulence avoidance can be provided through uplinks to the cockpit
In situ + pireps
NTDA AVAILABLE NOW!
GTG
GTGN (~ 5-10 min update)
In-flight strategic planning can use GTG or TFO
Updated consistent with WRF, GFS forecast cycles
Probabilistic forecasts

13. Demos…