SPC MD 1568

MD 1568 CONCERNING SEVERE POTENTIAL…WATCH UNLIKELY FOR PORTIONS OF SWRN NEB…WRN KS…ERN CO…A SMALL PART OF THE OK PANHANDLE


MESOSCALE DISCUSSION 1568
NWS STORM PREDICTION CENTER NORMAN OK
0534 PM CDT TUE JUL 30 2013

AREAS AFFECTED...PORTIONS OF SWRN NEB...WRN KS...ERN CO...A SMALL
PART OF THE OK PANHANDLE

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY

VALID 302234Z - 310100Z

PROBABILITY OF WATCH ISSUANCE...5 PERCENT

SUMMARY...A VERY ISOLATED SVR POTENTIAL MAY EXIST INTO THE
EVENING...THOUGH A WW IS NOT NEEDED.

DISCUSSION...LOW-LEVEL ASCENT INVOF A LEE TROUGH THAT EXTENDS
APPROXIMATELY ALONG THE ERN CO BORDER AND INTO THE CNTRL OK
PANHANDLE HAS BEEN SUFFICIENT TO SUPPORT AN AGITATED CUMULUS FIELD
AND VERY ISOLATED DEEP CONVECTION. WATER VAPOR IMAGERY DEPICTS A
WELL-DEFINED MID-LEVEL DRY SLOT OVERLYING MUCH OF THE
REGION...ESPECIALLY ACROSS SRN PARTS OF THE MCD AREA. THE ABUNDANCE
OF DRY AIR MAY PROVE TO BE DELETERIOUS FOR THE MAINTENANCE OF
SUSTAINED UPDRAFTS. THIS IS THE CASE GIVEN THE PRESENCE OF ONLY
MARGINAL TO LOCALLY MODERATE INSTABILITY...OWING TO LIMITED
BOUNDARY-LAYER THETA-E DERIVED FROM SFC TEMPERATURES ONLY IN THE
LOWER/MIDDLE 80S AMID DEWPOINTS IN THE MIDDLE 50S TO THE LOWER 60S.
HOWEVER...PLATTEVILLE PROFILER DATA AND GOODLAND VWP DATA INDICATE
AROUND 20-30 KT OF FLOW IN THE 4-6-KM LAYER SUPPORTING SUFFICIENT
DEEP SHEAR FOR MARGINAL SUPERCELL STRUCTURES. A CONDITIONAL
POTENTIAL FOR LARGE HAIL AND DMGG WIND GUSTS CANNOT BE RULED OUT
WITH ANY SUSTAINED CONVECTIVE CORES. THE ERN EXTENT OF SUCH
POTENTIAL WILL BE CURTAILED BY MORE STATICALLY STABLE AIR E OF A
DIFFERENTIAL HEATING ZONE THAT ARCS FROM S-CNTRL NEB INTO NWRN OK. E
OF THIS ZONE...DIURNAL DIABATIC HEATING HAS BEEN LIMITED BY A
WIDESPREAD CLOUD CANOPY. REGARDLESS...ANY SUCH POTENTIAL SHOULD BE
VERY ISOLATED AND CONDITIONAL...AND IT IS ENTIRELY POSSIBLE THAT THE
AREA WILL BE VOID OF SEVERE CONVECTION.

..COHEN/EDWARDS.. 07/30/2013

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

ATTN...WFO...GID...LBF...DDC...GLD...AMA...PUB...BOU...

LAT...LON   40930209 41120116 40840001 39610000 38330088 37480138
            36900193 36820219 37000234 37470249 39240276 40930209

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