Tuesday, September 4, 2007

DAY3SVR: Nws Storm Prediction Center Norman Ok

ACUS03 KWNS 040730
SWODY3
SPC AC 040729

DAY 3 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0229 AM CDT TUE SEP 04 2007

VALID 061200Z - 071200Z

..THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF THE
CNTRL/NRN PLAINS...

..CNTRL/NRN PLAINS...
00Z ECMWF/NAM/GFS SUGGEST THAT MID-LEVEL WAVE MOVING INTO THE CNTRL
ROCKIES LATE ON WEDNESDAY WILL EJECT ENEWD AS A STRONGER ENTITY
TOWARD THE CNTRL/NRN PLAINS ON THURSDAY THAN PREVIOUSLY THOUGHT.
BASED ON CURRENT WATER VAPOR IMAGERY...THE STRONGER SOLUTIONS MAY
INDEED BE JUSTIFIED. SFC CYCLONE WILL LIKELY FORM AT THE
INTERSECTION OF A LEE-TROUGH AND W-E ORIENTED FRONT ACROSS CNTRL SD
EARLY THURSDAY...THEN DEVELOP NEWD ALONG THE FRONT DURING THE AFTN.


A NARROW PLUME OF RESIDUAL STEEP LAPSE RATES ALOFT WILL EXIST
IMMEDIATELY DOWNSTREAM FROM THE COLD FRONT/LEE TROUGH FROM CNTRL NEB
NEWD INTO NRN MN DURING THE AFTN...CONTRIBUTING TO MODEST
INSTABILITY. AS THE LARGER SCALE HEIGHT FALLS SPREAD EWD INTO THE
PLAINS...TSTMS WILL LIKELY FORM ALONG THE LEE TROUGH AND NEWD
ALONG/N OF THE FRONT THROUGH THURSDAY NIGHT. STRONGEST VERTICAL
SHEAR WILL EXIST IN THE COLDER AIR INITIALLY...BUT WILL IMPROVE WITH
TIME AS A 40-50 KT JET MAX ROUNDS THE BASE OF THE TROUGH TOWARD THE
WARM SECTOR THU NIGHT.

GIVEN THE STEEP LAPSE RATES...RATHER STRONG IMPULSE AND MODEST
INSTABILITY...THREAT FOR A FEW ORGANIZED SVR STORMS SEEMS PROBABLE.
ACTIVITY MAY EVOLVE INTO LINE SEGMENTS AND MOVE ENEWD FROM NEB AND
SD INTO PARTS OF WRN/NRN MN DURING THE EVENING. SRN EDGE OF THE
ACTIVITY MAY LINGER/DEVELOP EWD TOWARD THE MO RVR/ERN NEB OVERNIGHT
AS THE LOW-LEVEL FLOW RESPONDS TO THE MID-LEVEL JET MAX.

.RACY.. 09/04/2007

+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
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 chris@lib.siu.edu.

No comments: