[FARC] THE NWS STORM PREDICTION CENTER

[Howard W3CQH]

THE NWS STORM PREDICTION CENTER HAS ISSUED A SEVERE THUNDERSTORM WATCH UNTIL 
4:00PM EDT

Event Start: 9:50AM EDT, Thursday Aug 9, 2007
Event End: 4:00PM EDT, Thursday Aug 9, 2007

THE NWS STORM PREDICTION CENTER HAS ISSUED A SEVERE THUNDERSTORM WATCH UNTIL 
4:00PM EDT
Sel3 Spc Ww 091351

Urgent - Immediate Broadcast Requested Severe Thunderstorm Watch Number 573 
Nws Storm Prediction Center Norman Ok 950 AM EDT Thu Aug 9 2007

The Nws Storm Prediction Center Has Issued A Severe Thunderstorm Watch For 
Portions Of District Of Columbia Maryland Central And Southeast Pennsylvania 
Northern Virginia Eastern West Virginia Panhandle Coastal Waters

Effective This Thursday Morning And Afternoon From 950 AM Until 400 PM EDT.

Hail To 2 Inches In Diameter... Thunderstorm Wind Gusts To 70 Mph... And 
Dangerous Lightning Are Possible In These Areas.

The Severe Thunderstorm Watch Area Is Approximately Along And 60 Statute 
Miles Either Side Of A Line From 30 Miles West Of Altoona Pennsylvania To 40 
Miles Northeast Of Baltimore Maryland. For A Complete Depiction Of The Watch 
See The Associated Watch Outline Update (wous64 Kwns Wou3).

Remember... A Severe Thunderstorm Watch Means Conditions Are Favorable For 
Severe Thunderstorms In And Close To The Watch Area. Persons In These Areas 
Should Be On The Lookout For Threatening Weather Conditions And Listen For 
Later Statements And Possible Warnings. Severe Thunderstorms Can And 
Occasionally Do Produce Tornadoes.

Discussion... Line Of Strong/Severe Thunderstorms Has Developed Over Swrn 
PA. This Is Expected To Move Ewd/Esewd As New Development Occurs On The Srn 
End Of The Line. 12z Soundings At Iad And Wal Indicate Little Remaining Cap 
As Low Level Air Mass Rapidly Warms With Surface Temperatures Already Around 
90f. Mid Level Flow Of 30-40 Kt Indicated On Pbz Vad Profile Should Maintain 
Forward Propagation Of Convective System As It Moves Into Very Moist And 
Moderately Unstable Environment.

Aviation... A Few Severe Thunderstorms With Hail Surface And Aloft To 2 
Inches. Extreme Turbulence And Surface Wind Gusts To 60 Knots. A Few 
Cumulonimbi With Maximum Tops To 550. Mean Storm Motion Vector 27020.

... Weiss

Bulletin Issued: 9:45AM EDT, Thursday Aug 9, 2007
Bulletin Expired: 4:00PM EDT, Thursday Aug 9, 2007