SWODY1
SPC AC 110558
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1158 PM CST SUN FEB 10 2008
VALID 111200Z - 121200Z
..THERE IS A SLGT RISK OF SVR TSTMS FROM PARTS OF NRN TX/SRN OK TO
THE ARKLATEX REGION...
..SYNOPSIS...
SHORT WAVE TROUGH LOCATED OVER BC/NRN ROCKIES PER WATER VAPOR
IMAGERY WILL AMPLIFY SEWD ACROSS THE PLAINS STATES TODAY AND SHOULD
BE POSITIVELY-TILTED FROM SRN PLAINS TO UPPER MS VALLEY/WRN GREAT
LAKES BY 12Z TUESDAY. MEANWHILE...A LARGE UPPER TROUGH...CURRENTLY
LOCATED OVER NRN MEXICO...SHOULD DE-AMPLIFY SOME AS IT TRANSLATES
ENEWD THROUGH THE SRN TX/NWRN GULF COAST REGION INTO THE NRN GULF/
CENTRAL GULF COAST STATES.
IN THE LOW LEVELS...LEE SURFACE LOW AND TRAILING COLD FRONT
ATTENDANT TO NRN ROCKIES TROUGH ARE EXPECTED TO SPREAD SEWD ACROSS
THE CENTRAL PLAINS THIS AFTERNOON WITH THE LOW REACHING SERN KS/NERN
OK AREA BY 12/00Z. THIS LOW WILL THEN TRACK NEWD INTO THE LOWER OH
VALLEY WITH THE COLD FRONT SURGING SEWD ACROSS THE SRN PLAINS AND
OZARKS OVERTAKING AN INVERTED TROUGH EXTENDING FROM N CENTRAL TX TO
SWRN/SRN MO. THE COLD FRONT SHOULD EXTEND FROM THE LOWER OH/TN
VALLEYS TO CENTRAL TX BY 12Z TUESDAY.
..SOUTH CENTRAL STATES...
ELEVATED TSTMS SHOULD BE ONGOING AT 12Z TODAY ACROSS PARTS OF
CENTRAL OK INTO SERN KS AND POSSIBLY FAR SWRN MO...WITH MUCH OF THIS
ACTIVITY RESULTING IN THUNDER SLEET AND FREEZING RAIN DUE TO
SUB-FREEZING SURFACE TEMPERATURES. THIS ACTIVITY IS EXPECTED TO
SPREAD ENEWD ACROSS ERN OK INTO THE OZARKS THIS MORNING AND
AFTERNOON AS NOSE OF LLJ TRANSLATES NEWD INTO THIS REGION. THUS...
STRONGEST LOW LEVEL MOISTURE/WAA BENEATH LEADING EXTENT OF ELEVATED
MIXED LAYER WILL SUPPORT MUCAPE VALUES OF 250-500 J/KG FROM ERN OK
INTO THE OZARKS FOR AN INCREASING HAIL POTENTIAL WITH THESE ELEVATED
TSTMS. FARTHER N INTO SRN MO TO LOWER OH RIVER VALLEY...STRONG UVVS
WILL SUPPORT A CONVECTIVE THREAT...BUT SUB-FREEZING SURFACE
TEMPERATURES SUGGEST THUNDER WITH MIXED WINTER-TYPE PRECIPITATION.
ALTHOUGH LLJ IS EXPECTED TO TRANSLATE NEWD AWAY FROM OK/N TX
TODAY...HEIGHT FALLS ACROSS THE SOUTH CENTRAL STATES WILL MAINTAIN
MOISTURE RETURN WITHIN MODEST SSWLY LOW LEVEL FLOW EXTENDING FROM
SRN TX TO SERN OK/ARKLATEX REGION. THIS COMBINED WITH STEEP MID
LEVEL LAPSE RATES AND SOME SURFACE INSOLATION IS EXPECTED TO ALLOW
FOR MUCAPE VALUES OF 500-1000 J/KG EXTENDING SWWD FROM SERN OK TO
CENTRAL/SRN TX WITH HIGHER VALUES IN TX. FORECAST SOUNDINGS SUGGEST
WARM AIR ADVECTION AROUND 700 MB IN WAKE OF NRN MEXICO TROUGH AND
AHEAD OF AMPLIFYING PLAINS SYSTEM MAY MAINTAIN STRONGER CAP ACROSS
SOUTH CENTRAL OK/NRN CENTRAL TX THIS AFTERNOON. THIS WOULD INHIBIT
SURFACE BASED TSTM DEVELOPMENT NEAR INFLECTION POINT/SRN EXTENT OF
INVERTED TROUGH IN NRN TX AND NEWD INTO SRN OK. IF SURFACE BASED
TSTMS CAN DEVELOP...THERE WOULD BE A NONZERO THREAT FOR TORNADOES
FOR A FEW HOURS EITHER SIDE OF 00Z.
OTHERWISE...MODELS ALL TEND TO AGREE THAT TSTMS ARE EXPECTED TO
INCREASE IN COVERAGE AS COLD FRONT SURGES SSEWD ACROSS SRN PLAINS
AND OZARKS INTO LOWER TN/MS VALLEYS. STRONG MODEL SIGNAL OF UVVS
REMAINING IN THE POST-FRONTAL AIR MASS SUGGESTS ACTIVITY WILL BE
QUICKLY UNDERCUT BY COLD FRONT. THIS SHOULD RESULT IN HAIL BEING
THE PRIMARY THREAT WITH ELEVATED ACTIVITY AS STRENGTHENING DEEP
LAYER SHEAR SUPPORTS ROTATING UPDRAFTS.
.PETERS.. 02/11/2008
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
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:
Post a Comment