Tuesday, February 10, 2009

DAY1SVR: Day 1 Convective Outlook

ACUS01 KWNS 101952
SWODY1
SPC AC 101949

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0149 PM CST TUE FEB 10 2009

VALID 102000Z - 111200Z

...THERE IS A MDT RISK OF SVR TSTMS ACROSS MUCH OF OK/NCNTRL TX
AR/NWRN LA...

...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MDT RISK FROM
SERN TX INTO KS/MO/SRN IL...

...SRN/CNTRL PLAINS...MS VALLEY...

STRONG BOUNDARY LAYER HEATING CONTINUES ALONG WRN FRINGE OF RAPIDLY
MOISTENING WARM SECTOR FROM NWRN TX...NNEWD INTO NCNTRL OK. LATEST
DIAGNOSTIC DATA INDICATES MINIMAL INHIBITION EXISTS ALONG AN AXIS
FROM NEAR ABI TO FSI WHERE SFC-3KM LAPSE RATES ARE NOW ROUGHLY
9C/KM. CU FIELD IS EXPANDING/DEEPENING RAPIDLY ALONG THIS
DESTABILIZING AXIS AND SUPERCELLS ARE DEVELOPING NE OF FSI TO WEST
OF PNC. 18Z SOUNDINGS FROM OKC AND FTW STRONGLY SUPPORT RAPID
DEVELOPMENT OVER THE NEXT FEW HOURS WITH STEEP MID LEVEL LAPSE RATES
AND MUCAPE ON THE ORDER OF 2000 J/KG...ABOUT 1000 J/KG HIGHER WITHIN
WARMER ENVIRONMENT JUST WEST OF I-35. INITIAL STORM MODE WILL BE
SUPERCELLULAR IN NATURE AND VERY LARGE HAIL IS CERTAINLY POSSIBLE
GIVEN THE VERY UNSTABLE COLD PROFILES OBSERVED...ROUGHLY -20 AT
500MB. TORNADOES ARE ALSO POSSIBLE AS NEAR 60F DEW POINTS ARE
INGESTED INTO THESE UPDRAFTS.

JUST DOWNSTREAM FROM NERN TX INTO CNTRL AR...WARM ADVECTION IS
GRADUALLY INCREASING AND LARGE SCALE ASCENT APPEARS TO BE PRIMARILY
RESPONSIBLE FOR EXPANDING SHOWERS/THUNDERSTORMS. 18Z SOUNDING FROM
SHV DEPICTS STRONG SHEAR THROUGH MID LEVELS AND MORE THAN SUFFICIENT
INSTABILITY FOR SUPERCELL STRUCTURES.

LATEST THINKING IS LLJ WILL BEGIN TO INCREASE BY LATE AFTERNOON IN
RESPONSE TO APPROACHING UPPER TROUGH...LIKELY IN EXCESS OF 70KT
ACROSS THE ARKLATEX. THIS WILL UNDOUBTEDLY ENHANCE LOW LEVEL
SHEAR/HELICITY ACROSS A GOOD PORTION OF THE WARM SECTOR WHERE
SUPERCELLS WILL LIKELY BE ONGOING. AS DEW POINTS RISE INTO THE
LOWER 60S THE TORNADO THREAT WILL LIKELY INCREASE...ESPECIALLY
DURING THE EVENING HOURS. A FEW STRONG TORNADOES ARE POSSIBLE WITH
ANY DISCRETE SUPERCELLS...ESPECIALLY IN THE MDT RISK REGION. LATE
TONIGHT STRONG FORCING WILL ENHANCE STORM MERGERS AND PERHAPS ASSIST
IN THE DEVELOPMENT OF A LINEAR MCS OVER THE MS VALLEY. IF THIS
OCCURS THEN DAMAGING WINDS WILL BECOME LIKELY ACROSS PORTIONS OF SRN
MO/AR INTO NRN LA.

..DARROW.. 02/10/2009

+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
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: