SWODY1
SPC AC 141959
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0259 PM CDT THU JUN 14 2007
VALID 142000Z - 151200Z
..THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON AND EVENING FROM
PARTS OF THE CNTRL AND SRN APPALACHIANS TO THE CNTRL GULF COAST...
..THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON INTO TONIGHT
OVER PARTS OF THE SRN PLAINS...
..THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON AND TONIGHT OVER
ND INTO NWRN MN...
..CNTRL/SRN APPALACHIANS TO CNTRL GULF COAST...
AFTERNOON WATER VAPOR IMAGERY INDICATES WELL-DEFINED VORTICITY
MAXIMUM OVER THE UPPER OH VALLEY TRANSLATING SSWWD...WITH A
SECONDARY...WEAKER IMPULSE NOTED OVER NRN AL. IN THE
LOW-LEVELS...RECENT MESOANALYSIS SHOWS THAT WARMEST AND POTENTIALLY
MOST UNSTABLE AIR MASS /MLCAPES OF 1000-1500 J PER KG/ RESIDES ALONG
AND JUST W OF THE HIGHER TERRAIN FROM ERN KY/WRN WV SWWD INTO NRN
AL.
THROUGH THE REMAINDER OF THE AFTERNOON...EXPECT THE GREATEST SEVERE
THREAT /IN THE FORM OF LOCALLY DAMAGING WINDS AND SOME HAIL/ TO
PERSIST AHEAD OF PRIMARY VORTICITY MAXIMUM SWD THROUGH INSTABILITY
AXIS...OR GENERALLY FROM WV/ERN KY SWD THROUGH ERN TN...WRN NC INTO
NRN GA AND AL. SEVERE THREAT SHOULD DIMINISH BY MID TO LATE EVENING
AS BOUNDARY LAYER COOLS AND SLOWLY STABILIZES.
..SRN/CNTRL PLAINS...
TSTMS ARE SLOWLY INCREASING IN COVERAGE AND INTENSITY THIS AFTERNOON
IN WAKE OF NOCTURNAL CONVECTIVE DEBRIS FROM PORTIONS OF SRN OK SWD
INTO NRN AND CNTRL TX WHERE RICH BOUNDARY LAYER MOISTURE /I.E.
DEWPOINTS IN THE UPPER 60S TO LOWER 70S/ IS CONTRIBUTING TO MLCAPES
OF 1500-3000 J/KG. RESIDUAL OUTFLOW BOUNDARIES COUPLED WITH
LARGER-SCALE FORCING FOR ASCENT ATTENDANT TO MCV OVER N-CNTRL TX
APPEAR TO BE SUPPORTING ONGOING STORMS ACROSS REGION.
FURTHER HEATING/DESTABILIZATION WILL LIKELY CONTRIBUTE TO ADDITIONAL
STORM DEVELOPMENT THIS AFTERNOON INTO TONIGHT FROM VICINITY OF WEAK
SURFACE LOW AND INVERTED TROUGH OVER WRN OK AND NWRN TX EWD THROUGH
PORTIONS OF CNTRL OK...AND SWWD INTO THE EDWARDS PLATEAU REGION OF
TX. REGIONAL PROFILERS/VWPS INDICATE THAT VERTICAL SHEAR REMAINS
RELATIVELY WEAK WITH GENERALLY 25 KTS OR LESS OBSERVED THROUGH THE
LOWEST 6 KM AGL. STILL...THE DEGREE OF INSTABILITY SUGGESTS THE
POTENTIAL FOR ORGANIZED...SEVERE STORMS CAPABLE OF LARGE HAIL AND
LOCALLY DAMAGING WINDS.
SOME THREAT OF A FEW BRIEF TORNADOES WILL EXIST FROM VICINITY OF
SURFACE LOW OVER NWRN TX NNWWD ALONG INVERTED TROUGH INTO WRN KS
WHERE STRONGER LOW-LEVEL CAPE AND VORTICITY COINCIDE. FOR
ADDITIONAL SHORT TERM GUIDANCE ON THIS AREA...PLEASE SEE MCD 1151.
..ND INTO NWRN MN...
AFTERNOON VISIBLE SATELLITE SHOWS MCV OVER N-CNTRL SD SLOWLY LIFTING
NEWD. AT THE SURFACE...AN AXIS OF HIGHER DEWPOINTS /MID TO UPPER
60S/ RESIDED FROM THE RED RIVER VALLEY SWD INTO ERN SD WHERE AIR
MASS HAS BECOME MARGINALLY UNSTABLE WITH MLCAPES OF AROUND 500 J/KG.
ISOLATED/SCATTERED TSTMS HAVE DEVELOPED SO FAR TODAY FROM PORTIONS
OF ERN ND AND WRN SD INTO ERN SD...DRIVEN BY WEAK LOW-LEVEL WAA AND
DEEPER LAYER FORCING FOR ASCENT ASSOCIATED WITH MCV.
EXPECT TSTMS TO CONTINUE THIS AFTERNOON AND TONIGHT ACROSS SAME
GENERAL AREA /I.E. ERN ND INTO NWRN MN/ AS LLJ AND ASSOCIATED WAA
REGIME STRENGTHEN IN RESPONSE TO APPROACH OF SHORT WAVE TROUGH
MOVING THROUGH THE NRN HIGH PLAINS. A FEW OF THE MORE INTENSE
STORMS WILL BE CAPABLE OF LOCALLY DAMAGING WINDS...SOME SEVERE HAIL
AND PERHAPS A BRIEF TORNADO.
OTHER STORMS ARE EXPECTED TO DEVELOP LATER THIS AFTERNOON INTO
TONIGHT ALONG PRIMARY SURFACE BOUNDARY NOW MOVING INTO THE WRN
DAKOTAS AS LARGE-SCALE FORCING ASSOCIATED WITH UPSTREAM SHORT WAVE
TROUGH OVERSPREADS FRONTAL ZONE. CONSIDERABLE MID AND HIGH CLOUDS
COUPLED WITH MARGINAL BOUNDARY LAYER MOISTURE HAVE LIMITED AIR MASS
DESTABILIZATION SO FAR TODAY AHEAD OF FRONT. HOWEVER...FURTHER
LOW-LEVEL MOISTENING IS ANTICIPATED WITH MLCAPES GRADUALLY
INCREASING TO AROUND 1000 J/KG. DEEP LAYER VERTICAL SHEAR WILL
CONCURRENTLY INCREASE...BECOMING SUPPORTIVE OF ORGANIZED...ROTATING
UPDRAFTS CAPABLE OF LARGE HAIL AND STRONG WIND GUSTS. SEVERE THREAT
SHOULD SPREAD EWD THROUGH CNTRL ND OVERNIGHT.
.MEAD.. 06/14/2007
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