SWODY1
SPC AC 072000
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0300 PM CDT TUE JUN 07 2011
VALID 072000Z - 081200Z
...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE NRN PLAINS AND INTO
THE UPPER MS VALLEY/UPPER GREAT LAKES REGION...
...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF CENTRAL AND SRN
MS AND ADJACENT LA...
...NRN PLAINS/UPPER MS VALLEY REGION...
THE FORECAST REMAINS ON TRACK ACROSS THE NRN PLAINS...AS THE UPPER
LOW SHIFTS OUT OF ERN MT AND INTO THE WRN DAKOTAS ATTM. WHILE
STORMS -- AND LIMITED SEVERE THREAT -- WILL CONTINUE TO EVOLVE
ACROSS WRN ND...MORE SUBSTANTIAL SEVERE POTENTIAL STILL APPEARS TO
BE A FEW HOURS OFF -- FARTHER E INTO ERN ND AND INTO MN. STORMS MAY
ALSO DEVELOP FARTHER SE INTO WI/SRN MN/NRN IA...AS LOW-LEVEL JET AND
ASSOCIATED WARM ADVECTION-INDUCED ASCENT INCREASE TONIGHT. ALONG
WITH A THREAT FOR HAIL AND LOCALLY-DAMAGING WINDS...A COUPLE OF
ISOLATED TORNADOES WILL ALSO BE POSSIBLE NEAR AND AHEAD OF THE
SURFACE LOW -- PROGGED TO CROSS NRN MN THROUGH THE EVENING.
...GULF COAST REGION FOCUSED ON MS...
STORMS ARE ONGOING ATTM FROM NRN FL WWD TO E TX...WITH MORE
WIDESPREAD/STRONGER CELLS FROM THE FL PANHANDLE WNWWD INTO SRN MS.
WHILE THIS REGION REMAINS IN A ZONE OF FAIRLY WEAK FLOW...A SUBTLE
CIRCULATION ALOFT EVIDENT IN WV IMAGERY MOVING INTO SRN MS/ERN LA
SHOULD SUPPORT A MORE CONCENTRATED CLUSTER OF STORMS INTO THIS
EVENING. IF ENOUGH STORMS CAN EVOLVE AND CONGEAL -- RESULTING IN
PROPAGATION ALONG AN ORGANIZED COLD POOL/OUTFLOW...RELATIVELY HIGHER
AREA OF DAMAGING WIND POTENTIAL COULD EVOLVE -- WHICH APPEARS TO
WARRANT UPGRADE TO SLIGHT RISK THIS FORECAST.
...OH/WV/KY AND THE CENTRAL/SRN APPALACHIANS...
STORMS CONTINUE TO BECOME MORE DISORGANIZED IN GENERAL ACROSS THE
OH/WV AREA...WITH MOST CONVECTION MORE CELLULAR AND TO THE COOL SIDE
OF THE COMPOSITE OUTFLOW BOUNDARY. GIVEN THIS -- WHICH SUGGESTS
LESSENING POTENTIAL FOR LOCALLY DAMAGING WINDS...WILL REMOVE SLIGHT
RISK FROM THE FORECAST AND MAINTAIN ONLY LOW PROBABILITIES FOR
HAIL/WIND.
..GOSS.. 06/07/2011
.PREV DISCUSSION... /ISSUED 1115 AM CDT TUE JUN 07 2011/
...NORTHERN PLAINS...
A STRONG SHORTWAVE TROUGH CURRENTLY OVER EASTERN MT WILL TRACK
NORTHEASTWARD TODAY ACROSS THE NORTHERN PLAINS AND INTO SOUTHERN
CANADA. AS THIS OCCURS...A DEEP SURFACE LOW WILL MOVE FROM ND INTO
NORTHWEST MN. BACKED LOW LEVEL WINDS NEAR AND TO THE NORTH OF THE
SURFACE LOW WILL PROVIDE LOW LEVEL WARM ADVECTION AND LIFT...HELPING
TO INITIATE SCATTERED AFTERNOON AND EVENING THUNDERSTORMS OVER
ND/MN. INITIAL CONVECTION WILL LIKELY BE OVER CENTRAL ND ALONG
WESTERN EDGE OF DEEPER LOW LEVEL MOISTURE AND WHERE SUBSTANTIAL
DAYTIME HEATING IS OCCURRING. VERTICAL SHEAR PROFILES IN THIS
REGION WILL FAVOR SUPERCELL STRUCTURES CAPABLE OF VERY LARGE
HAIL...DAMAGING WINDS...AND PERHAPS A TORNADO. STORMS SHOULD MOVE
QUICKLY NORTHEASTWARD THIS EVENING INTO NORTHERN MN WITH A CONTINUED
SEVERE RISK.
...GREAT LAKES REGION...
OTHER STORMS ARE POSSIBLE THIS AFTERNOON AND EVENING ATOP THE UPPER
RIDGE OVER THE MS/OH VALLEYS FROM WI/UPPER MI INTO LOWER MI.
INITIATION WILL BE UNCERTAIN DUE TO RELATIVELY WEAK FORCING.
HOWEVER...STRONG INSTABILITY AND FAVORABLE VERTICAL SHEAR INDICATE A
RISK OF SEVERE WEATHER IN ANY STORMS THAT CAN FORM IN THIS REGION.
THE HIGHEST POTENTIAL FOR INITIATION WILL BE OVER NORTHERN WI AND
WESTERN UPPER MI LATER THIS AFTERNOON ALONG THE SURFACE WARM FRONT.
...MN/IA...
12Z MODEL SOLUTIONS ARE SUGGESTING A GREATER POTENTIAL FOR ISOLATED
THUNDERSTORM DEVELOPMENT SOUTHWARD ALONG THE COLD FRONT OVER
SOUTHERN MN/NORTHERN IA. STRONG INSTABILITY WILL BE PRESENT ALONG
THE FRONT...AS WELL AS AN INCREASING LOW LEVEL JET AND SUFFICIENT
MID LEVEL FLOW FOR ORGANIZED/SEVERE STORMS.
...OH/WV...
A LINEAR MCS OVER EASTERN OH CONTINUES TO MOVE SOUTHWARD TOWARD THE
OH RIVER. OVERALL CONDITIONS FOR SEVERE STORMS ARE EXPECTED TO
SLOWLY WEAKEN THROUGH THE DAY AS THE UPPER RIDGE BUILDS AND MID
LEVEL WINDS WEAKEN. HOWEVER...MESOSCALE ORGANIZATION OF MCS MAY BE
SUFFICIENT TO MAINTAIN SOME RISK OF GUSTY WINDS AND HAIL THROUGH THE
AFTERNOON INTO WESTERN WV AND SOUTHERN OH.
...GULF COAST REGION...
A BROAD AREA OF MOIST AND MODERATELY UNSTABLE CONDITIONS ARE IN
PLACE TODAY FROM SOUTHEAST TX INTO FL. VISIBLE SATELLITE IMAGERY
SHOWS A COUPLE OF WEAK REMNANT MCVS IN THIS AREA WHICH MAY HELP TO
FOCUS CONVECTIVE DEVELOPMENT LATER TODAY. A COMBINATION OF STEEP
LOW LEVEL LAPSE RATES...DRY AIR ALOFT...AND AMPLE INSTABILITY...WILL
POSE A RISK OF GUSTY DOWNBURST WINDS AND/OR HAIL IN THE STRONGEST
CORES THROUGHOUT THIS REGION.
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