SPC AC 112000
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0300 PM CDT FRI JUN 11 2010
VALID 112000Z - 121200Z
...THERE IS A SLGT RISK OF SVR TSTMS FROM THE CENTRAL HIGH PLAINS TO
THE UPPER MS VALLEY/LAKE MI VICINITY...
...EASTERN CO TO NEB/KS...
FEW CHANGES TO EXISTING CONVECTIVE OUTLOOK. REFERENCE MESOSCALE
DISCUSSION 895 AND ANY SUBSEQUENT WATCH/ES FOR THE LATEST DETAILS.
...UPPER MS RIVER VALLEY/LAKE MI VICINITY...
REMNANTS OF MCS/LINGERING MCV CONTINUES TO QUICKLY ADVANCE
EAST-NORTHEASTWARD ACROSS UPPER MI AT MID AFTERNOON. SOME
STRONG/SEVERE TSTMS MAY YET DEVELOP ON THE SOUTHERN PERIPHERY OF THE
PASSING MCV IN VICINITY OF THE LOWER MI WARM FRONT.
ADDITIONALLY...AT LEAST CONDITIONAL-TYPE SEVERE PROSPECTS WILL EXIST
ACROSS PORTIONS OF SOUTHERN WI/IA LATE THIS AFTERNOON/EARLY EVENING
NEAR THE SOUTHERN WI SURFACE LOW AND ALONG THE EFFECTIVE SURFACE
FRONT. HOWEVER...A BOUT OF POST-MCS RISING HEIGHTS ALOFT LIMITS
CONFIDENCE IN THE LIKELIHOOD/EXTENT OF VIGOROUS STORM DEVELOPMENT IN
AN OTHERWISE POTENTIALLY UNSTABLE AIRMASS.
...SOUTH FL...
REFERENCE MESOSCALE DISCUSSION 894.
..GUYER.. 06/11/2010
.PREV DISCUSSION... /ISSUED 1130 AM CDT FRI JUN 11 2010/
...ERN CO TO ADJACENT AREAS OF NEB/KS...
OVERNIGHT MCS AND ASSOCIATED SHORT WAVE TROUGH HAVE CONTRIBUTED TO A
SWD SURGE OF EFFECTIVE SYNOPTIC FRONTAL BOUNDARY ACROSS THE PLAINS
AND ERN CO NOT UNLIKE YESTERDAY. AIRMASS RECOVERY ALONG AND NORTH OF
THE WEAK FRONT WAS ALREADY WELL UNDERWAY AS SELY LOW LEVEL FLOW HAS
RETURNED TO MUCH OF NRN KS...AND UPSLOPE FLOW HAS BECOME WELL
ESTABLISHED ALONG THE FRONT RANGE.
STRONG HEATING OF VERY MOIST AIRMASS WILL AGAIN CONTRIBUTE TO THE
DEVELOPMENT OF STRONG TO LOCALLY EXTREME INSTABILITY WITH 2000-2500
J/KG MLCAPE LIKELY FROM SERN CO ENEWD ACROSS KS. THIS
DESTABILIZATION WILL AGAIN OCCUR AMIDST A STOUT CAPPING INVERSION
WITH 700MB TEMPS OF 12-16C LIKELY LIMITING CONVECTIVE INITIATION
POTENTIAL TO THE EAST AND SOUTH OF THE HIGHER ELEVATIONS OF THE HIGH
PLAINS...AT LEAST THROUGH LATE AFTERNOON.
DESPITE WEAK HEIGHT FALLS...ERN CO AND ADJACENT AREAS OF WRN NEB AND
KS WILL LIE BENEATH MODEST DIFLUENT MID LEVEL FLOW ON THE ERN FLANK
OF AMPLIFYING LARGE SCALE TROUGH OVER THE SOUTHWEST. EXPECT NEUTRAL
TO MARGINALLY SUPPORTIVE LARGE SCALE ASCENT AND SWLY FLOW ALOFT TO
MAINTAIN QUASI-STATIONARY LEE-SIDE CYCLONE OVER SERN CO AND WRN KS
THROUGH THE PERIOD.
MOIST UPSLOPE FLOW NORTH OF THE LEE CYCLONE...COUPLED WITH DIURNAL
HEATING...WILL CONTRIBUTE TO THE DEVELOPMENT OF TSTMS ACROSS THE
FRONT RANGE. ADDITIONAL NUMEROUS STORMS IN WEAKER INSTABILITY ARE
LIKELY ACROSS THE MOUNTAINS AND SHOULD POSE SOME THREAT FOR
MARGINALLY SEVERE HAIL/WIND.
GREATEST SEVERE WEATHER POTENTIAL SHOULD EVOLVE WITH STORMS
INITIATING ALONG THE FRONT RANGE WHERE LOW LEVEL ELY FLOW WILL BE
TOPPED BY 40KT SWLY FLOW ALOFT. SHEAR PROFILES STRONGLY SUPPORT
ROTATING UPDRAFTS AND MAGNITUDE OF CAPE AVAILABLE TO THIS DEVELOPING
CONVECTION WILL BE ADEQUATE FOR LARGE HAIL PRODUCTION. EXPECT STORMS
TO MOVE OFF THE HIGHER TERRAIN INTO THE EVENING. ADDITIONAL
DEVELOPMENT IS EXPECTED TO INITIATE AND BECOME BETTER FOCUSED ALONG
AND NORTH OF RETREATING WEST-EAST BOUNDARY...NEAR THE KS/NEB
BORDER....AS INHIBITION IS GRADUALLY OVERCOME BY COMBINATION OF
HEATING AND PERSISTENT CONVERGENCE ALONG THIS RESIDUAL FRONTAL ZONE.
A FEW TO SEVERAL LONGER-LIVED SUPERCELLS APPEAR POSSIBLE IN THIS
REGIME WITH DAMAGING WINDS AND A COUPLE OF TORNADOES
POSSIBLE...ESPECIALLY FROM ERN CO TO WRN NEB/KS DURING THE EVENING.
THIS ACTIVITY MAY PERSIST INTO THE NIGHT...POSSIBLY IN THE FORM OF
AN MCS OR TWO. DAMAGING WIND...HAIL...AND PERHAPS A TORNADO EVENT
ALL APPEAR POSSIBLE EWD ACROSS NEB...AND PERHAPS AS FAR EAST AS
IA...THROUGH EARLY SATURDAY.
...WI/MI SWWD ACROSS IA/IL...
A NON-SEVERE MCS WAS LIFTING NEWD TO U.P. OF MI WITH WAKE LOW
EVIDENT ACROSS WRN WI ATTM. SOME UNCERTAINTY EXISTS WITH REGARD TO
AIRMASS RECOVERY IN THE WAKE OF THIS SYSTEM BUT IT APPEARS THAT
CHANCES FOR SURFACE-BASED STORM DEVELOPMENT MAY BECOME BETTER AHEAD
OF CONVECTIVE OUTFLOW AND WAKE LOW IN WI THIS AFTERNOON. FORECAST
SHEAR AOB 30KT SUGGESTS LIMITED ORGANIZATION TO STORMS DEVELOPING IN
REGION WITH POTENTIALLY STRONGEST INSTABILITY BUT DEGREE OF
DESTABILIZATION ON THE EDGE OF THE CAP SHOULD SUPPORT SOME SEVERE
HAIL/WIND. A BRIEF TORNADO COULD OCCUR NEAR WAKE LOW/OUTFLOW WHERE
SHEAR WILL BE LOCALLY STRONGER.
...TX/OK DRYLINE...
ISOLATED DEVELOPMENT AGAIN LIKELY AS CAP IS BREACHED AHEAD OF THE
DRYLINE. A FEW HAIL/WIND EVENTS APPEAR POSSIBLE.
...LOWER OH VALLEY TO SOUTHEAST AND SOUTH FL...
SCATTERED STRONG DIURNAL PULSE STORMS IN MOIST AIRMASS WILL POSE
SOME THREAT OF SEVERE HAIL AND MICROBURST WINDS.
...AREA 1...
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