Friday, January 29, 2010

Southern Snowstorm Threatens Few Records: Historical Perspective

Jan. 31 Update: Storm snow totals reported by the National Weather Service:
Greensboro NC     6.4"
Charlotte NC 2.7"
Raleigh NC 5.0"
Lynchburg VA 7.1"
Roanoke VA 9.9"
Blacksburg VA 11.3"
Richmond VA 8.0"
Norfolk VA 6.1"
Wallops Island VA 10.0"
Washington Nat'l 6.4"
Washington Dulles 4.5"
Baltimore BWI 5.5"
Atlantic City NJ 7.6"
Wilmington DE 4.3"
Philadelphia PA 2.1"
The amounts for Norfolk and Wallops Island were daily records for January 30.

In the immediate Washington DC area, reports ranged mainly from 4 to 6 inches, with much higher amounts in southern Maryland:
********************STORM TOTAL SNOWFALL********************  

LOCATION STORM TOTAL TIME/DATE COMMENTS
SNOWFALL OF
/INCHES/ MEASUREMENT

DISTRICT OF COLUMBIA

..DISTRICT OF COLUMBIA

1 SW AMERICAN UNIVER 5.5 730 PM 1/30
NATIONAL ARBORETUM 5.0 905 AM 1/31
WASHINGTON 4.0 400 PM 1/30 LOGAN CIRCLE

MARYLAND

..HOWARD COUNTY

1 SSE SIMPSONVILLE 6.7 900 PM 1/30
2 N COLUMBIA 6.0 800 PM 1/30
2 W ELKRIDGE 5.8 530 PM 1/30
1 WSW SAVAGE 5.7 1135 PM 1/30
1 WNW JESSUP 5.5 1000 PM 1/30
1 N SAVAGE 5.5 900 PM 1/30
1 SE CLARKSVILLE 5.5 730 PM 1/30
ELLICOTT CITY 4.0 400 PM 1/30

..MONTGOMERY COUNTY

2 WSW DAMASCUS 7.2 907 PM 1/30
GLENMONT 7.0 945 PM 1/30 NCEP EMPLOYEE
CLARKSBURG 7.0 600 PM 1/30
1 SE GLEN ECHO 7.0 1025 PM 1/30
1 SE NORBECK 6.6 657 AM 1/31
1 SSW MONTGOMERY VIL 6.0 1225 AM 1/31
1 WSW DARNESTOWN 6.0 1015 PM 1/30
1 E CLOVERLY 6.0 536 PM 1/30
1 S OLNEY 6.0 1000 PM 1/30
MONTGOMERY VILLAGE 6.0 1244 AM 1/31
5 N LAYTONSVILLE 5.8 530 PM 1/30
1 NE ASPEN HILL 5.7 445 PM 1/30
POOLESVILLE 5.5 1255 AM 1/31
GERMANTOWN 5.5 545 PM 1/30
GAITHERSBURG 5.2 515 PM 1/30
2 WNW GAITHERSBURG 5.2 500 PM 1/30
COLESVILLE 5.0 400 PM 1/30
2 N BETHESDA 5.0 410 PM 1/30
2 SSW ROCKVILLE 5.0 500 PM 1/30
BETHESDA 5.0 400 PM 1/30
DAMASCUS 5.0 203 PM 1/30
1 NE MONTGOMERY VILL 4.5 300 PM 1/30
2 WNW OLNEY 4.5 400 PM 1/30
1 NE DERWOOD 3.5 300 PM 1/30
1 SE OLNEY 1.0 1204 PM 1/30

..PRINCE GEORGES COUNTY

N FRIENDLY 7.6 1015 PM 1/30
1 N FRIENDLY 7.2 736 PM 1/30
1 SSE FOREST HEIGHTS 6.8 905 AM 1/31
LAUREL 6.4 1200 AM 1/31
1 E BOWIE 6.4 530 PM 1/30
CAMP SPRINGS 6.0 455 PM 1/30
1 NE COLLEGE PARK 6.0 540 PM 1/30
1 WNW BELTSVILLE 5.5 630 PM 1/30
OXON HILL 5.1 400 PM 1/30
GREENBELT 5.0 645 PM 1/30
1 SSW BELTSVILLE 4.3 515 PM 1/30
1 ENE ADELPHI 3.5 900 PM 1/30
2 NNW BOWIE 3.0 215 PM 1/30
1 SW OXON HILL 1.6 1130 AM 1/30

..ST. MARYS COUNTY

RIDGE 15.2 712 AM 1/31
1 NNE HOLLYWOOD 12.3 656 AM 1/31
1 ESE HILLVILLE 11.8 130 AM 1/31
HOLLYWOOD 10.5 500 PM 1/30
2 SE SOTTERLEY 10.0 500 PM 1/30
2 NNW DAMERON 8.0 321 PM 1/30
GREAT MILLS 8.0 345 PM 1/30
2 N GREAT MILLS 6.8 330 PM 1/30
LEONARDTOWN 4.5 1200 PM 1/30

VIRGINIA

..ARLINGTON COUNTY

REAGAN NATIONAL AIRP 6.4 1200 AM 1/31
1 NNE BAILEYS CROSSR 6.4 1155 PM 1/30
1 SW BALLSTON 6.0 630 PM 1/30
2 ESE BARCROFT 5.7 1000 PM 1/30 NCEP METEOROLOGIST
BALLSTON 4.3 405 PM 1/30
ARLINGTON 4.0 330 PM 1/30 NCEP MET

..CITY OF ALEXANDRIA

1 SSW ALEXANDRIA 5.8 700 AM 1/31

..FAIRFAX COUNTY

1 SE CENTREVILLE 7.0 1115 PM 1/30
1 NNE FAIRFAX STATIO 6.5 1150 PM 1/30
VIENNA 6.0 530 PM 1/30
1 W CENTREVILLE 6.0 1200 AM 1/31
1 N FRANCONIA 6.0 1246 AM 1/31
RAVENSWORTH 6.0 800 PM 1/30
1 NW MERRIFIELD 6.0 1210 AM 1/31
BURKE 6.0 1230 AM 1/31
HYBLA VALLEY 6.0 900 PM 1/30
MERRIFIELD 5.7 730 PM 1/30
LORTON 5.6 900 AM 1/31
1 ENE CENTREVILLE 5.3 1159 PM 1/30
1 NNE HERNDON 5.2 900 PM 1/30 NWS EMPLOYEE
2 N RESTON 5.2 800 PM 1/30
MCLEAN 2.0 1150 AM 1/30

..LOUDOUN COUNTY

COUNTRYSIDE 5.8 108 AM 1/31
BLUEMONT 5.8 456 PM 1/30
LOVETTSVILLE 5.5 422 PM 1/30
1 SSW ARCOLA 5.5 1045 PM 1/30
ASHBURN 5.4 945 PM 1/30
3 WSW ASHBURN 5.0 445 PM 1/30
2 WNW PURCELLVILLE 5.0 400 PM 1/30
1 NNE DULLES INTERNA 4.5 1200 AM 1/31
1 NE ASHBURN 4.5 1030 PM 1/30
3 NW DULLES INTERNAT 4.0 640 PM 1/30 LWX OFFICE
LEESBURG 2.8 233 PM 1/30
Original post:
The storm now spreading wintry precipitation from Oklahoma through the Tennessee Valley toward North Carolina and southern Virginia is likely to set few records inland, but some records may be threatened near the coast, particularly Tidewater Virginia. Here are forecast amounts and January daily records for some representative stations along the storm's path, compiled form National Weather Service reports; also shown are the January month-to-date temperature departures from average:
Location      Forecast  Record        Date      Jan. Temp.
Tulsa OK 5-6" 8.6" Jan. 6, 1988 -1.6°F
Nashville TN 1-4" 8.5" Jan. 29, 1905 -2.8°F
Greensboro NC 8-12" 10.2" Jan. 22, 1987
Roanoke VA 7-11" 20.0" Jan. 10, 1921 -1.4°F
Richmond VA 6-10" 9.9" Jan. 24, 1940 +0.9°F
Norfolk VA 12-16" 9.8" Jan. 19, 1893 -1.2°F
Note: Norfolk's top 10 snowfalls have all been in December, February, and March; the record is 18.6" on Dec. 27-28, 1892.

Images (click to enlarge): Surface weather map near 6 pm EST, Jan. 29, 2010 from The Weather Channel; Total snowfall forecasts for southern Virginia and northern North Carolina from National Weather Service

Wednesday, January 27, 2010

2010 Hurricane Season Forecast: More Active

The WaPo's wishcasting Washington weather weenies are still generating a hype-o-cane of hyperventilation over the minimal possibility of some of the weather s-word on Saturday, but Bloomberg's Business Week reports that WSI Corp. has issued their early outlook for the 2010 hurricane season. They are predicting an above-average number of named storms, making this year much more active than 2009:
         Total storms Hurricanes Major
2010 13 7 3
2009 9 3 2
Average 11 6 2
WSI's statistical landfall model suggests that Georgia and the Carolinas are the most likely areas to see a hurricane landfall in 2010.

WSI will issue a hurricane season update on April 12; the National Weather Service's Climate Prediction Center will issue its outlook in May.

Monday, January 25, 2010

Washington DC Precipitation Update

See here for more Washington, DC weather records.

Despite some hyperventilation in the media about potential 1"/hour precipitation rates, the official Washington, DC storm total overnight and Monday morning was (much) less than 1"/day. Today's 0.29", added to the 0.10" which fell before midnight, brings the January 2010 total to only 1.24", less than 50% of the normal month-to-date amount.

Thanks to the very wet December, winter is still well above average just past the halfway point. With another chance for precipitation near the end of the week, there is still a possibility for the month to avoid being the third in the last 12 to be less than 50% of average. Here are the daily, monthly, and seasonal (since Dec. 1) totals around the region:
National        0.29"/1.24"/8.03"
Dulles 0.40"/1.70"/7.68"
Baltimore (BWI) 0.47"/1.94"/10.00"
Further to the west, Bluefield West Virginia set a daily rainfall record (in a relatively short station history) of 0.87" yesterday (January 24). Roanoke also set a daily record of 1.34". The 1.59" at Martinsburg WV was a record for today.

Images (click to enlarge):
Washington DC 2009-10 monthly precipitation amounts and percentages above or below average, CapitalClimate charts from NWS data

Seasonal Outlook

Latest seasonal forecast: Click here.


Latest 3-month temperature outlook from Climate Prediction Center/NWS/NOAA.