Thursday, October 8, 2009

DAY1SVR: Day 1 Convective Outlook

ACUS01 KWNS 080554
SWODY1
SPC AC 080551

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1251 AM CDT THU OCT 08 2009

VALID 081200Z - 091200Z

...THERE IS A SLGT RISK OF SVR TSTMS FROM THE LWR OH VLY TO
CNTRL/SWRN TX...

...SYNOPSIS...
UPR LOW OVER THE DESERT SW IS EXPECTED TO OPEN INTO A WAVE THEN
MERGE WITH THE NRN BRANCH OF THE POLAR WLYS BEFORE EJECTING ENE
ACROSS THE CNTRL/SRN PLNS THURSDAY NIGHT. A MUCH WEAKER LEAD
IMPULSE IS EXPECTED TO TRAVEL FROM THE SRN HIGH PLNS TO THE LWR OH
VLY BY THURSDAY EVENING.

AT THE SFC...A WRMFNT SITUATED FROM CNTRL TX TO THE CNTRL GULF CST
WILL REDEVELOP NWD INTO PARTS OF OK...THE OZARK PLATEAU AND THE LWR
OH VLY THURSDAY AFTN. A WEAK LOW...TIED TO THE AFOREMENTIONED LEAD
WAVE...WILL TRAVEL ALONG THE FRONT FROM SRN MO INTO THE LWR OH VLY
THURSDAY AFTN/EVE. BEHIND THIS WAVE...A CDFNT ASSOCD WITH THE NRN
STREAM WAVE WILL SETTLE SEWD...REACHING THE OH VLY SWWD INTO CNTRL
TX BY 12Z FRIDAY.

...LWR OH VLY TO SWRN TX...
ELEVATED TSTM CLUSTERS...POSSIBLY PRODUCING MARGINALLY SVR
HAIL...WILL BE ONGOING THURSDAY MORNING FROM CNTRL MO SWWD INTO NWRN
OK AND THE TX PNHDL. ACTIVITY WILL BE ENHANCED BY A 50-55 KT SSWLY
LLJ...AUGMENTED BY A WEAK MID-LVL WAVE AND ENTRANCE REGION OF A 160
KT H25 JET. THIS ACTIVITY WILL DEVELOP DOWNSTREAM INTO THE MIDWEST
DURING THE DAY. RAPID RECOVERY OF LLVL MOISTURE ALONG/S OF THE
BANDED CONVECTION WILL PROBABLY RESULT IN MODEST DESTABILIZATION AND
STRONG/SVR STORMS SHOULD DEVELOP ALONG SRN FRINGES OF THIS ACTIVITY.
FCST HODOGRAPHS EXHIBIT SUBSTANTIAL LLVL SHEAR INVOF THE TRACK OF
THE SFC LOW FROM PARTS OF SRN MO ENE INTO SRN IND LATE THURSDAY
AFTN/EVE. HERE...ISOLD TORNADOES AND/OR DMGG WIND GUSTS CANNOT BE
RULED OUT WITH EMBEDDED ROTATING CELLS.

FARTHER SW...THERMODYNAMIC/KINEMATIC SET-UPS CONSISTING OF VERY HIGH
PWATS...NEARLY PARALLEL MEAN 0-6KM SHEAR WITH RESPECT TO SW-NE
ORIENTED CONVERGENCE ZONES...AND APCH OF THE POSITIVE-TILTED SWRN
UPR WAVE SUGGEST A FAIRLY PROLONGED AND WIDESPREAD ZONE OF TSTMS
FROM NWRN AR SWWD INTO SWRN TX. RATHER SHORT WAVELENGTH BETWEEN THE
MORNING WAVE AND APCH OF THE PARENT UPR WAVE AND ASSOCD JETLETS WILL
PROBABLY RESULT IN ONLY A BRIEF BREAK IN MORNING CONVECTION. THIS
WILL ALLOW THE WARM SECTOR TO EXPAND N AND NW THROUGH THE AFTN.

OVERALL WEAK CINH EXPECTED WILL LEAD TO A GRADUAL INCREASE IN TSTMS
FROM NCNTRL/CNTRL OK SWWD INTO THE EDWARDS PLATEAU REGION AS EARLY
AS LATE MORNING WITH SUBSEQUENT WAVES OF STORMS DEVELOPING WELL INTO
THE EVENING HOURS...ESPECIALLY FROM ERN OK INTO CNTRL TX. SWLY DEEP
LAYER SHEAR WILL INCREASE THROUGH THE EVENING WITH AN EXTENSIVE BAND
OF TSTMS. EMBEDDED BRIEF SUPERCELLS CAN BE EXPECTED...WITH
TRANSITIONS INTO SMALL-SCALE LEWPS AND BOWS AS THE CELLS TRANSLATE
ENE. WHILE A BRIEF TORNADO CANNOT BE RULED OUT...THE PRIMARY SVR
THREAT WILL BE DMGG WINDS.

..RACY/JEWELL.. 10/08/2009

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