SWODY1
SPC AC 080538
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1238 AM CDT FRI OCT 08 2010
VALID 081200Z - 091200Z
...NO SVR TSTM AREAS FORECAST...
...SYNOPSIS...
PRIMARY UPPER AIR FEATURE FOR THIS PERIOD WILL REMAIN STG SHORTWAVE
TROUGH -- PRESENTLY LOSING CLOSED-LOW CHARACTERISTICS AS IT EJECTS
ENEWD ACROSS NRN ROCKIES AND ERN GREAT BASIN/INTERMOUNTAIN REGION.
THIS PERTURBATION IS FCST TO MOVE THROUGH ROCKIES/HIGH-PLAINS MEAN
RIDGE POSITION DURING PERIOD. EMBEDDED VORTICITY MAX SHOULD REACH
CENTRAL HIGH PLAINS BY 9/12Z...PROBABLY REDEVELOPING CLOSED 500 MB
LOW AGAIN PER MAJORITY/CONSENSUS OF SREF MEMBERS.
AT SFC...LEE TROUGHING NOW EVIDENT OVER HIGH PLAINS IS EXPECTED TO
BE OVERTAKEN BY COLD FRONT NOW MOVING ACROSS ERN INTERMOUNTAIN
REGION AND CENTRAL ROCKIES. MEANWHILE SFC LOW SHOULD DEVELOP OVER
NRN HIGH PLAINS AND MOVE EWD ACROSS SD. BY 9/00Z...SFC LOW SHOULD
BE LOCATED OVER CENTRAL/W-CENTRAL SD...COLD FRONT SWD OVER NEB
SANDHILLS THEN SWWD ACROSS ERN CO...WEAK WARM FRONT EWD ACROSS ERN
SD AND SRN MN...AND TROUGH FROM SWRN NEB SSWWD OVER NERN NM.
...CENTRAL-NRN PLAINS...
SVR POTENTIAL THIS PERIOD APPEARS MRGL AND WILL BE ASSOCIATED WITH
TWO TEMPORAL AND SPATIAL REGIMES THAT MAY OVERLAP SOMEWHAT...
1. WIDELY SCATTERED TSTMS MAY DEVELOP THIS AFTERNOON FROM
CENTRAL/SWRN SD SWD ACROSS WRN NEB...PERHAPS OVER PORTIONS ERN CO
AND WRN KS AS WELL. ALTHOUGH MLCINH IS FCST TO BECOME QUITE STG
BENEATH ELEVATED MIXED-LAYER AIR FARTHER E...DIABATIC HEATING OF
HIGH PLAINS SFC...COMBINED WITH FRONTAL/TROUGH CONVERGENCE...MAY
OVERCOME CAPPING AND RESULT IN HIGH-BASED CONVECTION FOR A FEW HOURS
LATE AFTERNOON INTO EARLY EVENING. MRGL MOISTURE -- I.E. SFC DEW
POINTS MAINLY 40S F DURING PEAK OF VERTICAL MIXING -- WILL LIMIT
MLCAPE GENERALLY TO BELOW 500 J/KG MOST AREAS...AND WILL RESTRICT
OVERALL SVR THREAT. SO WILL LACK OF MORE ROBUST VERTICAL SHEAR IN
WARM SECTOR. HOWEVER...WELL-MIXED SUBCLOUD LAYERS WILL SUPPORT
POTENTIAL FOR ISOLATED STG/DAMAGING GUSTS.
2. FROM NWRN NEB NWD OVER WRN DAKOTAS...AT LEAST MRGL HAIL WILL
BECOME MORE PROBABLE NEAR AND EVEN BEHIND FRONT. WIDELY SCATTERED
TO SCATTERED TSTMS IN CLUSTERS AND DISCRETE CELLS ARE EXPECTED TO
DEVELOP IN REGIME OF STRENGTHENING LARGE-SCALE ASCENT AND WEAK
POSTFRONTAL MUCINH...FROM LATE AFTERNOON THROUGH AT LEAST 06Z.
ELEVATED WAA CONVEYOR ATOP NRN SEMICIRCLE OF SFC CYCLONE WILL
SUSTAIN SOME TSTMS OVERNIGHT ACROSS PORTIONS WRN DAKOTAS. WITH
30-40 KT EFFECTIVE SHEAR MAGNITUDE CONTRIBUTING TO CONVECTIVE
ORGANIZATION.
..EDWARDS/ROGERS.. 10/08/2010
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