SWODY1
SPC AC 120600
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0100 AM CDT WED MAY 12 2010
VALID 121200Z - 131200Z
...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE SRN AND
CNTRL PLAINS...MID-MS VALLEY AND OH VALLEY...
...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE
MID-ATLANTIC...
...SRN AND CNTRL PLAINS/MID-MO VALLEY
AN UPPER-LEVEL LOW IN THE CNTRL ROCKIES TODAY WILL ACCELERATE NEWD
AS A MID-LEVEL JET EJECTS NEWD ACROSS THE CNTRL AND SRN PLAINS. AT
THE SFC...A COLD FRONT WILL MOVE SSEWD ACROSS THE CNTRL PLAINS WITH
A MOIST AND VERY UNSTABLE AIRMASS IN PLACE ACROSS THE SLIGHT RISK
AREA. FORECAST SOUNDINGS JUST AHEAD OF THE FRONT AT 21Z FROM THE
MID-MO VALLEY TO THE SRN PLAINS SHOW MLCAPE VALUES IN THE 3000 TO
4000 J/KG RANGE. FORECAST SOUNDINGS DURING THE DAY SUGGEST THE WARM
SECTOR WILL REMAIN CAPPED UNTIL LATE AFTERNOON WHEN THE MODELS
INTIATE NUMEROUS THUNDERSTORMS FROM NRN MO SSWWD ACROSS ERN KS INTO
NRN OK. THIS ACTIVITY WILL BE LOCATED ON THE ERN EDGE OF A 60 TO 80
KT MID-LEVEL JET CREATING STRONG VERTICAL SHEAR PROFILES FAVORABLE
FOR SUPERCELLS. SUPERCELL DEVELOPMENT SHOULD BE RATHER QUICK DUE TO
THE STRONG INSTABILITY IN PLACE WITH VERY LARGE HAIL POSSIBLE WITH
THE MORE DOMINANT CELLS.
THE CURRENT THINKING IS THAT A BROKEN LINE OF INTENSE STORMS WILL
DEVELOP IN THE LATE AFTERNOON FROM NRN MO SSWWD ACROSS ERN KS INTO
NRN OK ON THE WRN EDGE OF THE LOW-LEVEL JET. THE JET SHOULD CREATE
STRONG LOW-LEVEL SHEAR PROFILES FAVORABLE FOR TORNADOES WITH THE
MORE DOMINANT SUPERCELLS. MODEL FORECASTS ALSO SUGGEST STORM MODE
MAY GRADUALLY TRANSITION TO A LINEAR STRUCTURE DURING THE EVENING AS
A LARGE MCS ORGANIZES FROM THE OZARKS SWWD TO THE LOW-ROLLING PLAINS
OF WEST TX. LARGE HAIL AND WIND DAMAGE WILL BE LIKELY WITH THE
STRONGER CELLS ELEMENTS IN THE MCS.
...MID-MS AND OH VALLEYS...
AN UPPER-LEVEL RIDGE IS FORECAST TO MOVE NEWD FROM THE MID-MS VALLEY
INTO THE OH VALLEY TODAY. A LARGE WARM SECTOR SHOULD BE IN PLACE
THIS AFTERNOON FROM MO EWD ACROSS MUCH OF SRN IL...SRN IND AND KY
WHERE FORECAST SOUNDINGS SHOW MODERATE TO STRONG INSTABILITY.
ALTHOUGH LARGE-SCALE ASCENT SHOULD REMAIN QUITE WEAK ACROSS THE
REGION...THE NAM AND GFS SOLUTIONS DO INITIATE A CLUSTER OF
THUNDERSTORMS FROM NEAR ST LOUIS ENEWD TO AROUND INDIANAPOLIS TODAY
BUT DIFFER ON THE TIMING. THE CURRENT THINKING IS THAT ELEVATED
THUNDERSTORMS WILL MOVE ACROSS THE REGION THIS MORNING WITH
SFC-BASED STORM DEVELOPMENT HOLDING OFF UNTIL EARLY THIS AFTERNOON
IN NRN MO MOVING EWD ACROSS THE OH VALLEY DURING THE LATE AFTERNOON.
FORECAST SOUNDINGS ACROSS THE OH VALLEY AT 21Z SHOW 40 TO 50 KT OF
0-6KM SHEAR SUGGESTING VERTICAL SHEAR WILL BE SUFFICIENT FOR
ROTATING STORMS BUT SOME MULTICELL LINE-SEGMENTS MAY ALSO DEVELOP.
STEEP LOW-LEVEL LAPSE RATES...UNIDIRECTIONAL WINDS AND INCREASING
LOW-LEVEL FLOW MAY BE FAVORABLE FOR A WIND DAMAGE THREAT. HAIL WILL
ALSO BE POSSIBLE WITH THE STRONGER UPDRAFTS.
...MID-ATLANTIC...
NORTHWEST FLOW WILL BE IN PLACE ACROSS THE MID-ATLANTIC TODAY AS A
COLD FRONT MOVES SLOWLY SWD ACROSS THE REGION. WARMING SFC TEMPS AND
MODERATE DESTABILIZATION SHOULD RESULT IN SCATTERED THUNDERSTORM
DEVELOPMENT AROUND MIDDAY ACROSS VA AND SRN MD. FORECAST SOUNDINGS
IN NRN VA SHOW MODERATE DEEP LAYER SHEAR WITH UNIDIRECTIONAL WIND
PROFILES SUGGESTING SEVERAL LINE-SEGMENTS WITH WIND DAMAGE POTENTIAL
MAY DEVELOP AND MOVE EWD INTO THE IMMEDIATE COASTAL AREAS BY EARLY
EVENING. HAIL WILL ALSO BE POSSIBLE WITH COVERAGE DEPENDENT UPON THE
AMOUNT OF DESTABILIZATION.
..BROYLES/STOPPKOTTE.. 05/12/2010
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
To unsubscribe from WX-STORM send e-mail to LISTSERV@LISTSERV.ILLINOIS.EDU with
"unsub wx-storm" in the body of your message. For more information write cnovy@cox.net.
No comments:
Post a Comment