SPC MD 838

MD 0838 CONCERNING SEVERE POTENTIAL…WATCH POSSIBLE FOR TX PANHANDLE…ERN OK PANHANDLE…NW OK…S-CNTRL KS


MESOSCALE DISCUSSION 0838
NWS STORM PREDICTION CENTER NORMAN OK
0228 PM CDT TUE MAY 28 2013

AREAS AFFECTED...TX PANHANDLE...ERN OK PANHANDLE...NW OK...S-CNTRL
KS

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 281928Z - 282030Z

PROBABILITY OF WATCH ISSUANCE...60 PERCENT

SUMMARY...INCREASING TSTM COVERAGE IS EXPECTED ALONG A RETREATING
DRYLINE THIS AFTERNOON. SVR STORMS ARE EXPECTED. SOME SIGNIFICANT
HAIL AND WINDS ARE POSSIBLE. RADAR AND SATELLITE TRENDS WILL BE
MONITORED FOR POSSIBLE WW.

DISCUSSION...SURFACE ANALYSIS AND VISIBLE SATELLITE IMAGERY REVEAL A
DRYLINE EXTENDING SWWD FROM A WEAKENING LEE LOW ACROSS S-CNTRL.
HEIGHT FALLS ASSOCIATED WITH THE DEEPENING UPPER TROUGH OVER THE WRN
CONUS WILL CONTINUE TO WEAKEN THIS LEE LOW AND PULL THE DRYLINE
NWWD. AS THIS OCCURS...LOW-LEVEL MOISTURE WILL ADVECT INTO THE
REGION. AMA SURFACE OBSERVATION SHOWED A CHANGE FROM 91/34 AT 17Z TO
90/57 AT 18Z AFTER THE DRYLINE RETREATED THROUGH THE REGION. 18Z AMA
SOUNDING SAMPLED THIS MORE MOIST ENVIRONMENT AND REVEALS LITTLE TO
NO CINH REMAINING AS WELL AS STRONG INSTABILITY WITH A MID-LEVEL
LAPSE RATE OF 8.7 DEG C/KM AND SBCAPE GREATER THAN 3000 J/KG.

VISIBLE SATELLITE SHOWS NUMEROUS CU AND A FEW CB ALONG THE
RETREATING DRYLINE...INDICATING CONVECTION INITIATION IS LIKELY
SOON. SHEAR PROFILES ARE SUFFICIENT FOR STORM ORGANIZATION AND SVR
STORMS ARE EXPECTED. PRIMARY THREAT IS SVR HAIL/WINDS. SOME HAIL MAY
BE SIGNIFICANT...EXCEEDING 2 INCHES IN DIAMETER. ADDITIONALLY...
GIVEN THE STEEP LOW-LEVEL LAPSE RATES AND TEMPERATURE/DEWPOINT
SPREADS AROUND 30 DEG F...SOME LOCALLY SIGNIFICANT WINDS -- I.E. IN
EXCESS OF 65 KT -- APPEAR POSSIBLE. TSTMS ARE EXPECTED TO INITIATE
ACROSS THE TX AND OK PANHANDLES WITH EWD STORM MOTION BRINGING THEM
INTO WRN OK AND POSSIBLY S-CNTRL KS LATE THIS AFTERNOON.

..MOSIER/MEAD.. 05/28/2013

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...ICT...OUN...DDC...LUB...AMA...MAF...ABQ...

LAT...LON   34860320 35790247 37090043 37819930 37899879 37359837
            37059846 36639872 34939985 33900067 33200181 32840334
            34860320

via SPC Forecast Products http://www.spc.noaa.gov/products/md/md0838.html