[SWODY1] SWODY1

[SWODY1 at goshenarc.org]

ACUS01 KWNS 230606
SWODY1
SPC AC 230603

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0103 AM CDT MON AUG 23 2004

VALID 231200Z - 241200Z

THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 10 WNW
RRT 40 NE RWF 15 NW FOD 15 NNW OMA 10 ESE GRI 45 S EAR 35 W P28 40 E
LBL 45 SSW MHN 25 NNW PHP 20 WNW DIK 55 NNE MOT.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM ISP 15 W TOL 30 NNW
DAY 20 N HTS 10 NNE GSO 15 ESE ILM.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 15 SE YUM 45 NE IGM
15 NNW GCN 80 NW GUP 55 NNE SOW 10 WSW FHU.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 45 NE ELO 50 ENE GRB
50 SE OSC.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 75 SSE MRF 25 SW EHA
15 SSE AKO FCL 35 SSW ELY 10 SE RNO 4BK.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 35 NW BML 15 SSW BHB.

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE DAKOTAS AND NEB SWD
INTO THE SRN HIGH PLAINS...

...SYNOPSIS...
WEAK MID-LEVEL TROUGH IS FORECAST TO SHIFT EWD ACROSS THE PLAINS
DURING THE DAY AHEAD OF MAIN UPPER TROUGH MOVING NEWD ACROSS THE
CENTRAL AND NRN ROCKIES.  ALTHOUGH STORMS AND ASSOCIATED / ISOLATED
SEVERE THREAT IS ANTICIPATED WITH LEAD SHORT-WAVE...MOST SIGNIFICANT
THREAT FOR SEVERE WEATHER IS EXPECTED ACROSS THE NRN PLAINS AS JET
STREAK ASSOCIATED WITH MAIN TROUGH SHIFTS INTO THIS REGION DURING
THE AFTERNOON / EVENING.

AT THE SURFACE...BAROCLINIC ZONE INITIALLY EXTENDING FROM A LOW OVER
ERN MT ESEWD ACROSS SD INTO IA / NRN IL SHOULD RETREAT NEWD THROUGH
THE PERIOD...WITH LOW REACHING SERN SASKATCHEWAN / SWRN MANITOBA BY
THE END OF THE PERIOD. MEANWHILE...LEE TROUGH EXTENDING SWD ACROSS
THE HIGH PLAINS WILL ALSO MOVE EWD THROUGH THE PERIOD.

...NRN PLAINS...
SUBSIDENCE IS FORECAST ACROSS THE DAKOTAS AND INTO NEB BEHIND
INITIAL SHORT-WAVE TROUGH...LIKELY RESULTING IN A CAPPED LOW-LEVEL
AIRMASS AHEAD OF MAIN UPPER TROUGH.  DAYTIME HEATING COMBINED WITH
STEEP LAPSE RATES ABOVE CAP WILL ALLOW AIRMASS TO DESTABILIZE...AND
APPROACH OF UPPER TROUGH SHOULD ALLOW CAP TO WEAKEN -- PARTICULARLY
ALONG WARM FRONT EXTENDING FROM NW-SE ACROSS THE DAKOTAS AS WELL AS
INVOF LEE TROUGH FORECAST ACROSS WRN SD / WRN NEB.  STORMS ARE
FORECAST TO DEVELOP BY MID AFTERNOON -- PARTICULARLY INVOF SURFACE
LOW NEAR LEE TROUGH / WARM FRONT INTERSECTION EXPECTED ACROSS WRN
SD.  CONVECTION SHOULD THEN INCREASE / SPREAD NEWD WITH TIME ACROSS
THE DAKOTAS / NEB.

WITH 40 TO 50 KT SWLY MID-LEVEL FLOW SHIFTING NEWD OUT OF WY ACROSS
THE WRN DAKOTAS DURING THE AFTERNOON...DEVELOPING STORMS SHOULD
BECOME SUPERCELLULAR.  EXPECT MAIN SEVERE THREAT TO BE
HAIL...ALTHOUGH LOCALLY DAMAGING WINDS ARE ALSO ANTICIPATED.  THREAT
SHOULD CONTINUE THROUGH THE EVENING AS LOW-LEVEL JET
INCREASES...WITH STORMS LIKELY SPREADING INTO WRN MN / WRN IA LATE
IN THE PERIOD. 

...CENTRAL AND SRN HIGH PLAINS...
ISOLATED STORMS ARE FORECAST TO DEVELOP WITHIN ZONE OF WEAK
LOW-LEVEL CONVERGENCE ALONG LEE TROUGH BY LATE AFTERNOON...ON WRN
FRINGE OF MODERATELY-UNSTABLE AIRMASS ANTICIPATED ACROSS THE PLAINS.
 WITH 20 TO 30 KT MID-LEVEL WLYS SPREADING EWD ABOVE SLY LOW-LEVEL
WIND FIELD...SUFFICIENT SHEAR WILL EXIST FOR MULTICELLS AND A FEW
ROTATING STORMS.  HAIL AND LOCALLY DAMAGING WINDS CAN BE EXPECTED
WITH A FEW OF THE STRONGER STORMS THROUGH THE EVENING.

...MO / IA...
WEAK SHORT-WAVE TROUGH MOVING EWD ACROSS THE MO VALLEY REGION DURING
THE DAY MAY SUPPORT ISOLATED STORM DEVELOPMENT -- PARTICULARLY NEAR
SURFACE BOUNDARY LYING ACROSS IA / NRN IL.  WEAK LAPSE RATES SHOULD
LIMIT DEGREE OF INSTABILITY DESPITE MOIST LOW-LEVEL AIRMASS...BUT
EXPECT AROUND 1000 J/KG MEAN-LAYER CAPE BY AFTERNOON ACROSS MUCH OF
THIS REGION.

FAIRLY WEAK /15 TO 25 KT/ MID-LEVEL FLOW IS FORECAST...BUT LOW-LEVEL
SLY FLOW WILL RESULT IN SUFFICIENT VEERING / SHEAR TO SUPPORT SOME
UPDRAFT ORGANIZATION.  THEREFORE...EXPECT LOCALLY GUSTY WINDS / HAIL
WITH A FEW OF THE STRONGER STORMS OVER THIS REGION.

..GOSS.. 08/23/2004

...NOTICE...
FOR USERS DECODING THE POINTS PARAGRAPH HEREIN...LATITUDE AND
LONGITUDE POINTS FOR THE CATEGORICAL AND PROBABILISTIC OUTLOOK
GRAPHICS ALSO ARE LOCATED IN A SEPARATE PRODUCT UNDER THE WMO
HEADINGS WUUS01 PTSDY1...WUUS02 PTSDY2...AND WUUS03 PTSDY3.  THE
INCLUSION OF POINTS IN THIS PRODUCT WILL EVENTUALLY BE DISCONTINUED.