Wednesday, May 7, 2008

DAY1SVR: Day 1 Convective Outlook

ACUS01 KWNS 080103
SWODY1
SPC AC 080100

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0800 PM CDT WED MAY 07 2008

VALID 080100Z - 081200Z

...THERE IS A SLGT RISK OF SVR TSTMS PORTIONS ERN TX/ERN OK TO LOWER
MS VALLEY...

...SYNOPSIS...
PROGRESSIVE MID/UPPER LEVEL PATTERN FEATURES PRONOUNCED LOW OVER
CENTRAL OK...AND SHORTWAVE TROUGH FROM NRN ROCKIES SSWWD ACROSS
SIERRA NV RANGE AND COASTAL SRN CA. SRN PLAINS CYCLONE ALOFT IS
FCST TO CONTINUE EJECTING ENEWD ACROSS MUCH OF OZARKS REGION
OVERNIGHT...ITS CENTER ALMOST VERTICALLY COLOCATED WITH SFC CYCLONE.
SFC COLD FRONT -- INITIALLY ANALYZED FROM NERN OK LOW SWWD ACROSS
W-CENTRAL TX...IS FCST TO OVERTAKE DRYLINE FROM N-S AND MOVE SEWD
OVER MUCH OF TX..ERN OK AND WRN AR.

MEANWHILE...POSITIVELY TILTED MIDLEVEL WAVE OVER INTERMOUNTAIN W
WILL MOVE GENERALLY ESEWD AS UPPER LOW DIGS SSEWD ACROSS BC.
FOREGOING LARGE SCALE ASCENT AND RELATED DESTABILIZATION WILL
OVERSPREAD AT LEAST MRGL LOW LEVEL THETAE TO CONTRIBUTE TO GEN
THUNDER POTENTIAL OVER BROAD AREA...CONVECTION BECOMING MORE
SPORADIC WITH TIME. ALTHOUGH A FEW TSTMS MAY PRODUCE HAIL/GUSTS
APCHG SVR LEVELS...PRIND SVR POTENTIAL HAS BECOME TOO LOW FOR
REMAINDER PERIOD TO INTRODUCE PROBABILITIES ATTM.

...ERN PORTIONS TX/OK TO LOWER/MID MS VALLEY...
SEVERAL LINES AND CLUSTERS OF TSTMS WILL CONTINUE TO MOVE EWD TO
NEWD ACROSS THIS REGION THROUGH REMAINDER EVENING...WITH DAMAGING
WIND AND OCCASIONAL LARGE HAIL POSSIBLE. A FEW SHORT-LIVED
TORNADOES ARE POSSIBLE WITH BOW/LEWP CIRCULATIONS AS WELL. HAIL
SIZES AND TORNADO POTENTIAL EACH SHOULD BE LARGEST IN ASSOCIATED
WITH SUPERCELLS...ESPECIALLY ANY RELATIVELY DISCRETE/SUSTAINED
STORMS. REF WWS 274-275 AND RELATED MESOSCALE DISCUSSIONS FOR INFO
ON NEAR-TERM SVR THREATS.

POTENTIAL FOR SUPERCELLS OVERNIGHT WILL BE GREATER WITH SWD EXTENT
FROM OZARKS INTO ARKLATEX REGION...HENCE RELATIVELY MAXIMIZED
TORNADO PROBABILITIES FROM SE OK ACROSS SRN AR...EXTREME NE TX AND
NRN LA. ALTHOUGH UNMODIFIED LZK/SHV RAOBS SUGGEST RELATIVELY WEAK
LAPSE RATES ALOFT AND MODEST CAPE...VERY STG LOW LEVEL SHEAR AND
SFC-BASED EFFECTIVE INFLOW PARCELS SHOULD BE MAINTAINED BENEATH
50-60 KT LLJ. COLDER MIDLEVEL AIR MASS ALSO WILL OVERSPREAD WRN
PORTION OF MOIST SECTOR...COMBINING WITH RELATIVELY RICH SFC THETAE
TO MAINTAIN BUOYANCY AOA THAT SAMPLED BY THOSE RAOBS.

FARTHER SW...A FEW TORNADOES ARE STILL POSSIBLE FROM TSTMS WITHIN
THAT PORTION OF PREVIOUS MDT RISK AREA STILL AHEAD OF DRYLINE.
HOWEVER...TRENDS IN CONVECTIVE MODES/COVERAGE...AND LOSS OF GREATEST
SFC HEATING/BUOYANCY SUGGESTS POTENTIAL WILL SHIFT E OF THAT AREA
INTO SOMEWHAT LESS UNSTABLE AIR MASS WITHIN NEXT 1-2 HOURS.

..EDWARDS.. 05/08/2008

+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
To unsubscribe from WX-STORM send e-mail to LISTSERV@PO.UIUC.EDU with
"unsub wx-storm" in the body of your message. For more information write cnovy@cox.net.

No comments: