[MCD] SWOMCD

[MCD at goshenarc.org]

ACUS11 KWNS 210846
SWOMCD
SPC MCD 210845 
PAZ000-WVZ000-OHZ000-210945-

MESOSCALE DISCUSSION 0790
NWS STORM PREDICTION CENTER NORMAN OK
0345 AM CDT FRI MAY 21 2004

AREAS AFFECTED...SRN-SERN OH/WRN PA/NRN WV

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 210845Z - 210945Z

LINE OF THUNDERSTORMS MOVING SEWD ACROSS CENTRAL-ERN OH AND WRN PA
ARE EXPECTED TO PRODUCE WIND GUSTS FROM 30-40 KT...WITH A FEW GUSTS
TO AOA SEVERE LEVELS THROUGH 11-12Z AS ACTIVITY MOVES ACROSS SERN
OH/SWRN PA/NRN WV.

REGIONAL RADARS SHOW A LINE OF THUNDERSTORMS EXTENDING FROM VENANGO
COUNTY PA SWWD TO FRANKLIN COUNTY OH WITH A SEWD MOVEMENT AT 25-30
KT.  OBJECTIVE ANALYSIS OF COLD POOL STRUCTURE WITH THIS ACTIVITY
SHOWS A WEAK SURFACE TEMPERATURE GRADIENT WITH VALUES IN THE COOL
AIR IN THE WAKE OF THE THUNDERSTORMS 5-8 DEGREES COOLER THAN IN
ADVANCE OF THIS ACTIVITY.  ALTHOUGH 40 KT OF WLY FLOW IS LOCATED
0.5-1 KM AGL...THIS WLY ORIENTATION TO A SEWD MOVING LINE OF
THUNDERSTORMS SHOULD LIMIT THE WIND SPEED THAT IS ABLE TO TRANSLATE
TO THE SURFACE.  THIS APPEARS TO BE A REASONABLE SCENARIO GIVEN THAT
AS THIS LINE OF STORMS MOVED ACROSS SEVERAL SURFACE OBSERVATION
POINTS...MEASURED GUSTS RANGED FROM 25-30 KT.

THE ESTABLISHED COLD POOL WILL CONTINUE TO ENHANCE THE SEWD MOVEMENT
OF THESE STORMS ACROSS SERN OH/SWRN PA AND NRN WV DURING THE NEXT
2-3 HOURS...WITH MOST WIND GUSTS EXPECTED TO REMAIN BELOW SEVERE
LEVELS.

..PETERS.. 05/21/2004

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...CTP...PBZ...RLX...CLE...ILN...

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