Probability of damaging thunderstorm winds or wind gusts of 50 knots or higher within 25 miles of a point. Hatched Area: 10% of greater probability of wind gusts 65 knots or greater within 25 miles of a point.
Jacksonville, FL...Memphis, TN...Denver, CO...New Orleans, LA...Colorado Springs, CO...
SPC AC 122000
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0300 PM CDT THU JUN 12 2014
VALID 122000Z - 131200Z
...THERE IS A SLGT RISK OF SVR TSTMS FROM CNTRL AND ERN TX INTO THE
LOWER MS VALLEY...
...SUMMARY...
SEVERE THUNDERSTORMS ARE EXPECTED ACROSS PORTIONS OF TEXAS EASTWARD
INTO THE LOWER MISSISSIPPI VALLEY. VERY LARGE HAIL AND DAMAGING
WINDS WILL BE THE MAIN THREATS...BUT A FEW TORNADOES ARE POSSIBLE.
ADDITIONAL...BUT MORE ISOLATED...STRONG TO SEVERE STORMS WILL BE
POSSIBLE IN THE NORTHERN AND CENTRAL ROCKIES...THE HIGH PLAINS...AND
ACROSS PARTS OF MID-ATLANTIC STATES TO LOWER GREAT LAKES REGION.
...TX THROUGH LOWER MS VALLEY AREA...
HAVE ADJUSTED PROBABILITY AND CATEGORICAL GRAPHICS TO ACCOUNT FOR
EFFECTS OF AN EXPANSIVE OUTFLOW BOUNDARY THAT CURRENTLY EXTENDS FROM
CNTRL ARKANSAS SWWD THROUGH NWRN LA THEN WWD THROUGH CNTRL TX TO A
THERMAL LOW NEAR JUNCTION. MEANWHILE A COLD FRONT EXTENDING FROM
SWRN MO THROUGH SRN OK INTO SWRN TX IS ADVANCING SWD. DRYLINE
EXTENDS FROM EAST OF SANDERSON NEWD TO THE THERMAL LOW JUST WEST OF
JUNCTION. THE ATMOSPHERE IN VCNTY OF AND JUST SOUTH OF THE OUTFLOW
BOUNDARY ACROSS MUCH OF CNTRL AND SCNTRL TX HAS BECOME VERY UNSTABLE
WITH 3000-4000 J/KG MLCAPE AND VERY STEEP LAPSE RATES.
MEANWHILE...NEAR SFC WINDS REMAIN ELY JUST NORTH OF THE OUTFLOW
BOUNDARY AND SELY IN WARM SECTOR BENEATH MODEST /30-35 KT/ MID LEVEL
FLOW RESULTING IN VEERING LOW WIND PROFILES AND 30-35 KT EFFECTIVE
BULK SHEAR. THE MOST LIKELY AREA FOR INITIAL ROBUST THUNDERSTORM
INITIATION APPEARS TO BE NEAR JUNCTION WHERE CUMULUS IS INCREASING
IN VICINITY OF THE DRYLINE-OUTFLOW BOUNDARY INTERSECTION. ONCE
STORMS INITIATE...THEY WILL LIKELY TAKE ON SUPERCELL STRUCTURES WITH
A THREAT FOR VERY LARGE HAIL AND POSSIBLY A FEW TORNADOES AS THE
STORMS MOVE EAST AND INTERACT WITH THE MODIFYING OUTFLOW BOUNDARY.
EVENTUALLY STORMS MAY CONGEAL INTO AN MCS WITH AN INCREASING THREAT
FOR DAMAGING WIND.
ADDITIONAL STRONG TO SEVERE STORMS MAY DEVELOP ALONG SWD ADVANCING
FRONT OVER NRN AND NERN TX INTO EARLY EVENING...BUT THE ATMOSPHERE
HAS BEEN OVERTURNED BY PREVIOUS CONVECTION IN THIS REGION WITH
LIMITED REMAINING RECOVERY TIME.
..DIAL.. 06/12/2014
.PREV DISCUSSION... /ISSUED 1132 AM CDT THU JUN 12 2014/
...SOUTHERN PLAINS TO LOWER MS RIVER VALLEY...
THE DECAYING REMNANTS OF AN MCS/TRAILING COLD POOL CONTINUE TO
SPREAD SOUTHEASTWARD ACROSS PARTS OF NORTH TX/FAR SOUTHERN OK LATE
THIS MORNING. INITIAL SEVERE THREAT THIS AFTERNOON WILL BE IN
ASSOCIATION WITH WHAT MAY BE AN UPSCALE DEVELOPING QUASI-LINEAR
COMPLEX AND/OR AN MCV ACROSS PARTS OF EAST TX INTO LA AND PERHAPS
OTHER PARTS OF THE MID-SOUTH/LOWER MS RIVER VALLEY. THE PRECEDING
AIR MASS ACROSS THE CORRIDOR WILL CONTINUE TO STEADILY
WARM/DESTABILIZE COINCIDENT WITH AMPLE HEATING AND LOWER TO MIDDLE
70S F SURFACE DEWPOINTS. DAMAGING WINDS/BOUTS OF SEVERE HAIL WILL BE
POSSIBLE.
FARTHER WEST...ADDITIONAL INTENSE STORM DEVELOPMENT IS ANTICIPATED
ESPECIALLY ACROSS PARTS OF CENTRAL/WEST-CENTRAL TX INTO LATE
AFTERNOON/EARLY EVENING. THIS WILL BE VICINITY OF THE SYNOPTIC FRONT
IN CONJUNCTION WITH RESIDUAL INFLUENCES OF EARLY DAY
OUTFLOW/DIFFERENTIAL HEATING. THIS SCENARIO WILL LIKELY BE AIDED BY
THE APPROACH OF A SHORTWAVE TROUGH/SPEED MAX...WITH ATTENDANT
STRONGER MID/HIGH-LEVEL WESTERLIES...NOTED TO BE MOVING EASTWARD
OVER NM AT MID-MORNING. SUPERCELLS CAPABLE OF LARGE HAIL AND
POSSIBLY A COUPLE OF TORNADOES WILL INITIALLY BE POSSIBLE...WITH
STORMS LIKELY GROWING UPSCALE AND ADDITIONALLY POSING A DAMAGING
WIND RISK AS THEY SPREAD GENERALLY SOUTHEASTWARD TONIGHT. PENDING
EARLY AFTERNOON TRENDS AND GREATER CONFIDENCE IN A PEAK RISK
CORRIDOR...AREAS SUCH AS WEST-CENTRAL/CENTRAL TX COULD WARRANT AN
UPGRADE TO MODERATE RISK /MAINLY FOR VERY LARGE HAIL/ WITH THE 20Z
DAY 1 UPDATE.
...CO/NM...
STORMS ARE EXPECTED TO DEVELOP/INCREASE THIS AFTERNOON ACROSS THE
FRONT RANGE/ADJACENT HIGH PLAINS IN ASSOCIATION WITH A LOW-LEVEL
UPSLOPE REGIME. WEAK DESTABILIZATION IN CONJUNCTION WITH VEERING
WIND PROFILES AND 40+ KT OF EFFECTIVE SHEAR MAY ALLOW FOR SOME
SUPERCELLS CAPABLE OF SEVERE HAIL.
...PORTIONS OF THE MID-ATLANTIC/NORTHEAST STATES...
ESPECIALLY GIVEN RELATIVELY PREVALENT EARLY DAY CLOUD
COVER...RELATIVELY WEAK MID-LAPSE RATES/MODEST VERTICAL SHEAR SHOULD
LIMIT THE OVERALL MAGNITUDE/EXTENT OF THE SEVERE RISK IN MOST AREAS
TODAY. NONETHELESS...AS THE BOUNDARY LAYER GRADUALLY WARMS...LOCALLY
DAMAGING WINDS AND POTENTIALLY SOME HAIL WILL BE POSSIBLE THIS
AFTERNOON/EARLY EVENING.
...FL PENINSULA...
IN THE PRESENCE OF RELATIVELY COOL MID-LEVEL TEMPERATURES...THE
BOUNDARY LAYER WILL CONTINUE TO WARM/DESTABILIZE PARTICULARLY ACROSS
THE CENTRAL FL TO THE SOUTH OF STORMS ONGOING THIS MORNING ACROSS
THE NORTHERN PENINSULA. ISOLATED BOUTS OF LOCALLY DAMAGING WINDS AND
MARGINALLY SEVERE HAIL WILL BE POSSIBLE THROUGH THE AFTERNOON.
...NORTHERN INTERMOUNTAIN REGION/EASTERN GREAT BASIN...
AN UPPER TROUGH WILL CONTINUE TO MOVE INLAND/EASTWARD OVER THE
PACIFIC NORTHWEST AND NORTHERN INTERMOUNTAIN WEST THROUGH TONIGHT.
AHEAD OF IT...STRENGTHENING CYCLONIC WESTERLIES WILL OVERSPREAD
AREAS AS FAR SOUTH AS THE GREAT BASIN/UT VICINITY. ISOLATED
STRONG/SEVERE THUNDERSTORMS WILL BE POSSIBLE BY LATE AFTERNOON/EARLY
EVENING ACROSS THE NORTHERN INTERMOUNTAIN REGION INCLUDING PARTS OF
EASTERN ORE/WA AND ID/WESTERN MT. FARTHER SOUTH...OTHER HIGH-BASED
THUNDERSTORMS CAPABLE OF DOWNBURSTS WILL BE POSSIBLE ACROSS PORTIONS
OF UT.
...SOUTHEAST MO TO SOUTHERN IL...
MARGINAL SEVERE WIND/HAIL MAY BE POSSIBLE ACROSS THE REGION.
REFERENCE MESOSCALE DISCUSSION 971 FOR MORE SHORT-TERM DETAILS.
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