000
ACUS11 KWNS 260243
SWOMCD
SPC MCD 260243
NEZ000-KSZ000-260415-

MESOSCALE DISCUSSION 0801
NWS STORM PREDICTION CENTER NORMAN OK
0943 PM CDT SAT MAY 25 2013

AREAS AFFECTED...NWRN KS...SWRN/S-CNTRL NEB

CONCERNING...SEVERE THUNDERSTORM WATCH 218...220...

VALID 260243Z - 260415Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH
218...220...CONTINUES.

SUMMARY...THE SEVERE THREAT CONTINUES ACROSS NWRN KS INTO CNTRL
NEB...BUT A DOWNWARD TREND IN COVERAGE/INTENSITY HAS RECENTLY BEEN
NOTED. WHILE SOME REDEVELOPMENT OF ELEVATED CONVECTION IS POSSIBLE
LATER THIS EVENING...MAINLY IN AND NORTHEAST OF WW 220 IN CNTRL
NEB...SEVERE THREAT MAY CONTINUE TO WANE ACROSS WW 218 UNTIL
SCHEDULED 0400Z EXPIRATION.

DISCUSSION...A GENERAL DOWNWARD TREND IN COVERAGE OF STORMS ACROSS
NWRN KS IN WW 218 HAS BEEN NOTED IN THE LAST HOUR...THOUGH AN
INTENSE STORM REMAINS ACROSS SHERIDAN COUNTY. DIURNAL COOLING AND
INCREASINGLY MARGINAL EFFECTIVE SHEAR TO THE EAST OF THE NWRN KS
ACTIVITY SHOULD RESULT IN A CONTINUED SLOW DECREASE IN THE SEVERE
THREAT. DOWNSTREAM WW ISSUANCE NOT CURRENTLY ANTICIPATED ACROSS
N-CNTRL KS...THOUGH A LOCAL EXTENSION MAY BE REQUIRED IF CURRENT
ACTIVITY SUSTAINS ITSELF PAST THE EXPIRATION TIME.

FURTHER NORTH ACROSS SWRN/S-CNTRL NEB IN WW 220...STORMS THAT
DEVELOPED ALONG THE STATIONARY FRONT QUICKLY INTENSIFIED AND
PRODUCED LARGE HAIL...BUT MOST OF THIS ACTIVITY HAS SINCE WEAKENED.
WHILE THE WINDOW OF OPPORTUNITY FOR SURFACE-BASED STORMS IS
WANING...ANY SUCH ACTIVITY WILL BE POTENTIALLY SUPERCELLULAR WITH
VERY LARGE HAIL GIVEN MLCAPE VALUES AOA 2000 J/KG AND EFFECTIVE
SHEAR OF 30-40 KTS PER RECENT MESOANALYSIS. AS THE LOW-LEVEL JET
INCREASES THROUGH THE EVENING...ELEVATED CONVECTION MAY INCREASE
NORTH OF THE BOUNDARY...WITH A CONTINUED THREAT FOR LARGE HAIL GIVEN
MODERATE CAPE/SHEAR FOR PARCELS ROOTED AROUND 850-900 MB. THIS
THREAT WILL EXTEND NORTHEAST OF THE WW220 AND AREAS INTO NERN NEB
WILL BE MONITORED FOR POTENTIAL WW ISSUANCE LATER TONIGHT.

..DEAN.. 05/26/2013

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

ATTN...WFO...OAX...ICT...GID...LBF...DDC...GLD...

LAT...LON   39040134 39420137 40160129 40810114 41390091 42000030
            42229933 42199789 42029722 41809662 40549744 40209784
            39729830 39229878 38939926 38779984 38860092 38920108
            39040134