SPC MD 579

MD 0579 CONCERNING SEVERE POTENTIAL…WATCH UNLIKELY FOR PORTIONS CENTRAL/N-CENTRAL KS.


MESOSCALE DISCUSSION 0579
NWS STORM PREDICTION CENTER NORMAN OK
0605 PM CDT MON APR 29 2013

AREAS AFFECTED...PORTIONS CENTRAL/N-CENTRAL KS.

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY

VALID 292305Z - 300100Z

PROBABILITY OF WATCH ISSUANCE...5 PERCENT

SUMMARY...CONDITIONAL RISK FOR DAMAGING GUST EXISTS WITH ANY
CONVECTION THAT CAN DEVELOP OVER DISCUSSION AREA NEXT 2-3
HOURS...BEFORE LOSS OF INSOLATION STABILIZES BOUNDARY-LAYER AIR
MASS.  POTENTIAL APPEARS TOO ISOLATED/DISORGANIZED AND CONDITIONAL
FOR WW.

DISCUSSION...SFC MESOANALYSIS SHOWS LOW NW DDC...SUPPORTED BY SMALL
CYCLONIC GYRE EVIDENT IN ANIMATED RADAR REFLECTIVITIES.  THIS LOW
MAY CONTINUE TO DRIFT ENEWD-NEWD ALONG DISSIPATING WARM FRONT THAT
EXTENDS NEWD ACROSS SERN NEB INTO CENTRAL IA.  E OF LOW...PRONOUNCED
CONFLUENCE LINE WAS DRAWN FROM BARTON COUNTY KS SWWD ACROSS AMA
AREA.  THIS BOUNDARY CORRESPONDS TO CORRIDOR OF CONVERGENCE
INDICATED BY AUTOMATED MESOANALYSES.  VIS IMAGERY INDICATES
COLLOCATED/BKN LINE OF TCU...HIGH-BASED ATTM GIVEN DISTANCE FROM
CLOUDS TO SHADOWS.  PERSISTENT/THICKENING AREA OF CONVECTION WAS
LOCATED NEAR DRYLINE/CONFLUENCE LINE INTERSECTION OVER BARTON COUNTY
AS OF 2245Z.

MAIN CONCERN FOR AT LEAST MRGL/CONDITIONAL NEAR-TERM SVR POTENTIAL
IS WITH TOWERS OVER CENTRAL KS...WHICH HAVE GREATEST ACCESS TO BOTH
INTENSE DIABATIC HEATING/MIXING OF BOUNDARY LAYER AND INCREASING
MOISTURE TO THEIR E OVER ERN KS.  ALTHOUGH 12Z CONVENTIONAL NETWORK
RAOBS REVEALED STG EML-RELATED CAPPING OVER THIS
REGION...MODIFICATION TO 17Z SPECIAL LMN RAOB SUGGEST POTENTIAL FOR
AT LEAST BRIEF TSTMS WITH ESSENTIALLY UNCAPPED MLCAPE 700-800 J/KG
AND DEEP/WELL-MIXED SUBCLOUD LAYER WITH NEARLY 1500 J/KG DCAPE.
CINH STRENGTHENS FARTHER NE ALONG FRONTOLYTIC ZONE WHERE HEATING IS
WEAKER AND SFC CONVERGENCE IS MINIMAL AT BEST.  LOW-LEVEL
HODOGRAPHS...WHILE NOT LARGE FROM 0-1 KM...HAVE GROWN OVER THIS
REGION BASED ON VWP/PROFILER TRENDS...AND MAY CONTINUE TO DO SO AS
LLJ INTENSIFIES THIS EVENING.  35-45 KT EFFECTIVE SHEAR MAGNITUDE
ALSO POINTS TO SOME POTENTIAL FOR ORGANIZATION OF ANY TSTMS...BUT
POTENTIAL LONGEVITY OF ANY CONVECTION IS IN QUESTION GIVEN EXPECTED
INCREASE IN MLCINH WITH TIME.

..EDWARDS/KERR.. 04/29/2013

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

ATTN...WFO...TOP...ICT...GID...DDC...

LAT...LON   38029894 38639899 39089888 39429866 39679761 39319715
            38449743 38069785 38029894

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