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| May 25, 2006 1300 UTC Day 1 Convective Outlook |
| Updated: Thu May 25 16:36:18 UTC 2006 |
| Probabilistic to Categorical Outlook Conversion Table (Effective Feb 14, 2006). |
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Public Severe Weather Outlook |
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The SPC is forecasting an outbreak of severe thunderstorms today and tonight
across portions of the United States.
This is an extremely dangerous situation.
Please read the latest public
statement about this event.
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| Categorical Graphic |
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| Probabilistic Tornado Graphic |
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| Probabilistic Damaging Wind Graphic |
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| Probabilistic Large Hail Graphic |
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SPC AC 251250
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0750 AM CDT THU MAY 25 2006
VALID 251300Z - 261200Z
...THERE IS A MDT RISK OF SVR TSTMS OVER PARTS OF
IND...OH...IL...AND KY...
...THERE IS A SLGT RISK OF SVR TSTMS FROM THE MID ATL CST THROUGH
THE TN VLY TO OZARKS/SRN PLNS...
...SYNOPSIS...
WI UPR LOW SHOULD CONTINUE ESE THROUGH EARLY FRIDAY AS 60+ KT MID
LEVEL JET STREAK AND ASSOCIATED MID LEVEL DRY PUNCH NOW OVER SRN
IA/WRN IL...PER WV AND VWP DATA...SWEEP E/SE INTO SRN IND/NRN KY BY
THIS EVENING. COUPLED WITH PERSISTENT INFLUX OF INCREASINGLY MOIST
BOUNDARY LAYER FLOW FROM MO/AR AND THE LWR TN VLY...STAGE APPEARS
SET FOR A SIGNIFICANT SEVERE WEATHER EPISODE THIS AFTERNOON INTO
TONIGHT OVER PARTS OF THE OH VLY. A MORE LIMITED SEVERE THREAT MAY
EXTEND E ACROSS THE CNTRL/SRN APLCNS TO THE VA CST. LATER IN THE
PERIOD...STRONG TO SEVERE STORMS MAY DEVELOP W INTO THE OZARKS AND
KANSAS.
COLD FRONT NOW EXTENDING FROM CNTRL WI SWD INTO NRN IL AND THEN SW
INTO CNTRL KS SHOULD ACCELERATE SE TODAY AS MID/UPR LEVEL JET STREAK
REDEVELOPS ESEWD. BY EARLY AFTERNOON...FRONT SHOULD EXTEND FROM WRN
LOWER MI AND INTO SW MO. THE TRAILING WRN PART OF THE BOUNDARY
SHOULD BECOME STATIONARY OVER SRN KS. FARTHER E...MODERATE/DEEP WLY
FLOW AND SURFACE HEATING SHOULD PROMOTE N/EWD REDEVELOPMENT OF
DIFFUSE WARM FRONT INTO ERN OH/NRN WV AND ERN VA/SRN MD BY LATE IN
THE DAY.
...OH VLY...
SEVERAL BANDS OF TSTMS EXPECTED TO DEVELOP IN BROAD ZONE OF
CONFLUENT/MOIST WSWLY LOWER TROPOSPHERIC FLOW ALONG AND AHEAD OF
MI/IL COLD FRONT THIS AFTERNOON INTO TONIGHT AS SURFACE HEATING AND
LARGE SCALE ASCENT IN EXIT REGION OF APPROACHING JET STREAK FURTHER
DESTABILIZE REGION. WITH MLCAPE LIKELY TO RANGE FROM 1500 TO 3000
J/KG AND 50 KT WSWLY 700 MB FLOW PRESENT TO ENHANCE TROPOSPHERIC
SHEAR...SUSTAINED SUPERCELLS APPEAR LIKELY OVER IND/WRN OH/SRN
MI...AND PERHAPS SE IL/WRN KY. MEAN LOW LEVEL WSWLY FLOW SUGGESTS
THAT CONVERGENCE WILL NOT BE PARTICULARLY STRONG ALONG FRONT.
COUPLED WITH EXISTING W/E BREADTH OF WARM SECTOR...POTENTIAL WILL
THEREFORE EXIST FOR A FEW LONG-LIVED DISCRETE STORMS AND STRONG
TORNADOES...ESPECIALLY IN IND/WRN OH.
PERSISTENCE/DEGREE OF FORCING FOR ASCENT...AND WIDESPREAD NATURE OF
INSTABILITY FIELD...SUGGEST THAT STORMS WILL MERGE INTO MORE OR LESS
SOLID LINES BY THIS EVENING. THE MAIN SEVERE THREATS SHOULD
TRANSITION TO WIND/HAIL AS THE MCSS CONTINUE E/SE INTO PA/WV CNTRL
KY BY MID TO LATE EVENING.
...TN VLY...
TWO AREAS OF TSTMS LEFTOVER FROM YESTERDAY'S ACTIVITY CONTINUE ATTM
OVER SRN KY/NRN TN. THIS ACTIVITY IS BEING FED BY A WEAKER BRANCH
OF THE SAME WSWLY LLJ EXPECTED TO CONTRIBUTE TO THE OH VLY STORMS.
GIVEN CLEAR SKIES S OF THE STORMS...EXPECTED PERSISTENCE OF WLY LOW
LEVEL/UPSLOPE FLOW...POTENTIAL WILL EXIST FOR DIURNAL
REINTENSIFICATION OF THESE STORMS ACROSS THE TN VLY/SRN APLCNS
LATER TODAY. THE MAIN THREATS SHOULD BE DAMAGING WIND/HAIL FROM
FORWARD-PROPAGATING/BOWING LINE SEGMENTS.
...VA/NRN NC...
LOW LEVEL MOISTURE WILL CONTINUE TO SPREAD NWD OVER THE NC/VA
PIEDMONT AND CSTL PLN TODAY AS LEE TROUGH SETS UP E OF THE SRN/CNTRL
APLCNS. AT THE SAME TIME...SURFACE HEATING AND WLY FLOW ALOFT
SHOULD ALLOW A SEGMENT OF SYNOPTIC SCALE WARM FRONT NOW IN THE OH
VLY REFORM N INTO CNTRL/ERN VA. SURFACE HEATING ALONG THIS
FEATURE...ALONG WITH ARRIVAL OF ENHANCED LOW LEVEL MOISTURE...MAY
SUPPORT STORM DEVELOPMENT OVER PARTS OF NC/VA LATER TODAY. STORMS
MAY ALSO REDEVELOP E ACROSS THE MTNS FROM ACTIVITY NOW IN ERN KY.
SUFFICIENT DEEP SWLY SHEAR AWAY FROM BOUNDARY WILL BE PRESENT TO
SUPPORT ORGANIZED STORMS WITH STRONG WINDS/POSSIBLE HAIL. IN
ADDITION...A CONDITIONAL THREAT MAY SLOW DEVELOP FOR A TORNADO OR
TWO LATE IN THE DAY IN ZONE OF ENHANCED LOW LEVEL SHEAR IN SE VA.
...SRN HI PLNS...
TERRAIN-DRIVEN UPSLOPE CIRCULATIONS AND SUBTLE IMPULSES ALOFT
EXPECTED TO SUPPORT WIDELY SCATTERED LATE AFTERNOON/EVENING STORMS
IN STRONGLY HEATED/WEAKLY SHEARED ENVIRONMENT OVER THE SRN HI PLNS.
LARGE T/TD SPREADS OF 30-35 DEGREES F WILL FOSTER MICROBURSTS...BUT
SUFFICIENT MOISTURE MAY ALSO BECOME INVOLVED IN STORM UPDRAFTS TO
YIELD LARGE HAIL.
...KS/OZARKS TONIGHT/EARLY FRIDAY...
ELEVATED STORMS WITH LARGE HAIL MAY DEVELOP LATE TONIGHT/EARLY
FRIDAY ACROSS PARTS OF KS/MO AND NRN AR...IN ZONE OF INCREASING WAA
ASSOCIATED WITH NOCTURNALLY-STRENGTHENED MOIST LLJ.
..CORFIDI/MEAD/JEWELL.. 05/25/2006
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NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1630Z
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