Results from Winter Storm Reconnaissance (WSR) 2005

programs

Yucheng Song IMSG at EMC/NCEPZoltan Toth EMC/NCEP/NWS Sharan Majumdar Univ. of MiamiCraig H. Bishop NRLRoy Smith NCO/NCEP/NWS

Acknowledgments• NWS field offices, HPC/NCEP and SDMs• NOAA G-IV and the USAFR C-130 flight

crews• CARCAH (John Pavone)• Jack Woollen - EMC• Russ Treadon - EMC• Mark Iredell - EMC• Istvan Szunyogh – Univ. of Maryland• + others who have contributed!

About the Winter Storm Reconnaissance (WSR) Program

• Took place 20 Jan – 17 March 2005• Dropwinsonde observations taken over the

NE Pacific by aircraft operated by NOAA’s Aircraft Operations Center (G-IV) and the US Air Force Reserve (C-130s).

• Observations are adaptive – – collected only prior to significant winter weather

events of interest – in areas that might influence forecast the most.

• Operational since January 2001• 31 flights, around 500 dropsondes this winter

which is reduced from 720 drops last year

ETKF-based targeting strategy

A Typical Winter Storm

NOAA G-IV and US Air Force Reserve (C-130s)

G-IV

C-130

Evaluation methodology• Compare two parallel runs from NCEP GFS

analysis and forecast cycles (T126L28 resolution)– Operational: including all operationally available data

(includes dropsondes)– Control: excluding only dropsonde data in the targeted

area

• Verify against observations over the pre-selected area of interest (verification region)– Rawinsonde observations for surface pressure, 1000-

250mb temperature, wind speed and moisture– Rain gauge data for precipitation

Blizzard of 2005(Jan 22-23,2005)

Blizzard of 2005(Jan 22-23,2005)

The ETKF spotted the target area

Forecast verification(Jan 22-23,2005)

250mb Height SLP

Forecast Impact(Jan 22-23,2005)

Results for Surface Pressure

Of the cases:20 improved 1 neutral 9 degraded

Results for TemperatureOf the cases:22 improved 1 neutral 7 degraded

Results for Vector Wind

Of all cases:19 improved 0 neutral11 degraded

Results for Specific humidity

Of all cases:19 improved 0 neutral11 degraded

Breakdown for casesVariable # cases

improved# cases neutral

#cases degraded

Surface pressure 20 1 9

Temperature 22 1 7

Vector Wind 19 0 11

Humidity 19 0 11

Individual Case Comparison 1 denotes positive effect

0 denotes neutral effect

-1 denotes negative effect

22 OVERALL POSITIVE

1 OVERALL NEUTRAL

7 OVERALL NEGATIVE

73% improved 23 % degraded

VR OBSDATE P T V OVERALL REGION FHOUR E 20050120 1 1 1 1 82W ,37N 72 W 20050128 1 1 1 1 123W ,40N 24 C 20050205 1 1 1 1 97W ,31N 36 H 20050206 1 1 1 1 155W ,19.5N 24 C 20050206 1 1 1 1 90W ,43N 72 C 20050207 1 1 1 1 90W ,42N 60 C 20050208 1 -1 1 1 90W ,42N 36 AK 20050208 -1 -1 -1 -1 150W ,61N 48 E 20050208 1 0 -1 0 74W ,43N 48 C 20050209 -1 1 1 1 93W ,35N 96 AK 20050210 -1 -1 1 -1 135W ,55N 24 E 20050212 1 1 1 1 88W ,46N 48 W 20050213 1 1 1 1 123W ,38N 48 W 20050213 1 1 -1 1 123W ,38N 60 W 20050213 1 1 -1 1 123W ,38N 72 AK 20050219 1 1 1 1 150W ,61N 48 W 20050220 -1 1 1 1 118W ,34N 48 W 20050221 1 1 1 1 118W ,34N 24 AK 20050222 -1 -1 -1 -1 138W ,58N 24 AK 20050223 -1 1 1 1 140W ,60N 24 AK 20050225 1 1 1 1 140W ,60N 48 W 20050225 1 1 -1 1 123W ,40N 72 E 20050225 1 1 -1 1 75W ,40N 96 E 20050303 -1 1 1 1 86W ,41N 48 AK 20050309 -1 1 -1 -1 130W ,57N 36 H 20050312 1 -1 -1 -1 157W ,21N 24 E 20050313 0 1 1 1 81W ,32N 96 E 20050314 1 -1 -1 -1 79W ,32N 72 E 20050316 -1 -1 -1 -1 78W ,37N 48 W 20050317 1 1 1 1 122W ,38N 48

Negative Cases Breakdown 1 denotes positive effect

0 denotes neutral effect

-1 denotes negative effect

•Of all the negative cases – four are for Alaska

•One for Hawaii (as this is only experimental stage)

•Two cases for East Coast

•It seems that if the signal affecting the verification region is coming from Arctic, forecasts are hard to improve

VR OBSDATE P T V OVERALL REGION FHOURAK 20050208 -1 -1 -1 -1 150W ,61N 48AK 20050210 -1 -1 1 -1 135W ,55N 24AK 20050222 -1 -1 -1 -1 138W ,58N 24AK 20050309 -1 1 -1 -1 130W ,57N 36 H 20050312 1 -1 -1 -1 157W ,21N 24 E 20050314 1 -1 -1 -1 79W ,32N 72 E 20050316 -1 -1 -1 -1 78W ,37N 48

March 14, 2004 flight P34 – 72 hour verification

March 16, 2004 flight P43 – 48 hour verification

March 12, 2004 flight P38 – 24 hour verification

Hawaii case

Future Work• Examine the effect of dropsondes on

precipitation• Improve targeting method based on ETKF

method with increasing resolution and ensemble membership

• Examine general target areas based on classified verification regions

• Improve verification techniques• Increased duration of program for WSR06-07?• Expand program to cover adaptive observation

over Gulf of Mexico/Western Atlantic for 12-24 hr Eastern short storm forecast

Background

• Preliminary Precipitation verification results

• Composite summary maps• ETKF predicted signal propagation

Precipitation verification

• Precipitation verification is still in a testing stage due to the lack of station observation data in some regions.

20.4416.50OPR

18.5616.35CTL

3:14:1Positive vs. negative cases

10mm 5mm ETS

Composite summary maps

139.6W 59.8N 36hrs (7 cases) - 1422km 92W 38.6N 60hrs (5 cases)- 4064km

122W 37.5N 49.5hrs (8 cases) - 2034km 80W 38.6N 63.5hrs (8 cases) - 5143km

Verification Region

Verification Region

3649.5

60

63.5

0

1000

2000

3000

4000

5000

6000

0 20 40 60 80

Forecast Hours

Dis

tanc

e (k

m)

ETKF predicted signal propagation

5143km63.5hrs (East Coast)4064km60hrs (Central U.S)2034km49.5hrs (West Coast)1422km36 hrs (Alaska)

Forecast hours vs. Distance

The above table listed forecast hours and the distance between the centers of sensitivity and verification regions