SPC MD 1265

MD 1265 CONCERNING SEVERE THUNDERSTORM WATCH 376… FOR PORTIONS CENTRAL/ERN KS…SERN NEB…EXTREME SWRN IA…WRN/SRN MO.


MESOSCALE DISCUSSION 1265
NWS STORM PREDICTION CENTER NORMAN OK
1135 AM CDT THU JUN 27 2013

AREAS AFFECTED...PORTIONS CENTRAL/ERN KS...SERN NEB...EXTREME SWRN
IA...WRN/SRN MO.

CONCERNING...SEVERE THUNDERSTORM WATCH 376...

VALID 271635Z - 271830Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 376
CONTINUES.

SUMMARY...CONTINUE WW. THOUGH PRIMARY SVR THREAT SHOULD REMAIN IN WW
FOR ANOTHER 2-3 HOURS...ISOLATED LARGE HAIL AND DAMAGING GUSTS MAY
OCCUR WITH TRAILING TSTMS INITIALLY OVER E-CENTRAL NEB...AND MOVING
SEWD TOWARD SERN NEB/SWRN IA/NWRN MO AREA.  LEADING
CONVECTION...WHICH ALREADY HAS PRODUCED REPORTS OF 4.25 INCH HAIL
AND GUSTS NEAR 65 KT OVER SERN NEB AND NERN KS RESPECTIVELY...MAY
REMAIN SVR AS IT MOVES ALONG NERN MARGINS OF MOST UNSTABLE AIR MASS
AND EXITS WW OVER WRN/CENTRAL MO EARLY THIS AFTN.  AS
SUCH...ADDITIONAL WW MAY BE REQUIRED FARTHER SE.  ALSO...AREAS W OF
WW OVER KS WILL BE MONITORED FOR INCREASING SVR THREAT ALONG AND W
OF RESULTING OUTFLOW BOUNDARY AND SE OF COLD FRONT DESCRIBED BELOW.

DISCUSSION...SFC MESOANALYSIS SHOWS WEAK LOW OVER MKC AREA...NEAR
LEADING EDGE OF SVR TSTM CLUSTER MOVING SEWD.  WEAK/QUASISTATIONARY
BAROCLINIC ZONE AND ACCOMPANYING/BETTER-DEFINED THETAE BOUNDARY
EXTEND SEWD FROM THAT LOW ACROSS S-CENTRAL MO.  OUTFLOW/DIFFERENTIAL
HEATING BOUNDARY ARCS FROM NWRN MO/NERN KS CONVECTION ACROSS MHK/CNK
AREAS THEN INTO S-CENTRAL NEB...AND SHOULD DECELERATE SOONER WITH
WWD EXTENT.  SFC LOW WAS ANALYZED BETWEEN MCK-LBF WITH COLD FRONT
SWWD ACROSS NWRN KS.  FRONT EXTENDS GENERALLY EWD TO INTERSECT
OUTFLOW BOUNDARY OVER S-CENTRAL NEB.

OUTFLOW BOUNDARY SHOULD ALIGN ITSELF NW-SE ACROSS NRN/ERN KS WITH
TIME...PARALLEL TO THETAE GRADIENT INITIALLY TO ITS E...AS
ADDITIONAL FOCUS FOR LATER CONVECTION.  THOUGH LOW-LEVEL FLOW IS
WEAK...VWP AND FCST SOUNDINGS SUGGEST STG VEERING WITH HEIGHT INVOF
THAT BOUNDARY...AMIDST LOW-LEVEL WAA PROFILE.  POCKETS OF 30-40 KT
EFFECTIVE SHEAR MAGNITUDE ARE EVIDENT ALONG AND W OF
BOUNDARIES...WHERE SFC DEW POINTS MID-70S F AND TEMPS RISING INTO
90S WILL BUILD STG-EXTREME INSTABILITY WITH MLCAPE VALUES EXCEEDING
4000 J/KG BY EARLY AFTN.  VIS IMAGERY ALSO INDICATES INITIALLY
ELEVATED CONVECTION OVER CENTRAL KS THAT MAY BECOME SFC-BASED W OF
OUTFLOW.

..EDWARDS.. 06/27/2013

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

ATTN...WFO...LSX...SGF...DMX...EAX...OAX...TOP...ICT...GID...
DDC...

LAT...LON   41089741 41579648 40919534 39889380 38449227 37119172
            37259490 37549813 38859921 41089741

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