[SWODY1] SWODY1

[SWODY1 at goshenarc.org]

ACUS01 KWNS 290605
SWODY1
SPC AC 290603

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0103 AM CDT FRI OCT 29 2004

VALID 291200Z - 301200Z

THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 30 NE
MTC MBS 45 NNE GRR MKG CGX 45 WSW ARG 45 NNE HOT 40 ENE PGO MLC OKC
FLV DSM FOD SPW FSD MHE HON ABR HIB 40 NNE CMX.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 20 SE JAX 20 W CTY
...CONT... PFN 0A8 HOP 35 SSW PAH 35 SSE SHV AUS 40 SSE DRT
...CONT... 75 SSW P07 FST 65 WSW SPS MHK 40 SE OMA 50 ESE SUX 25 ESE
YKN 30 NNW BUB MHN DGW 30 SE SHR 40 NNE 4BQ BIS 15 WNW INL
...CONT... 25 N ART ABE DCA CLT 40 SW CHS.

...THERE IS A SLGT RISK OF SVR TSTMS UPPER MS VALLEY TO ERN OK...

...SYNOPSIS...
STRONG MID/UPPER LEVEL TROUGH -- NOW EVIDENT IN MOISTURE CHANNEL
IMAGERY OVER GREAT BASIN -- WILL MOVE ENEWD ACROSS CENTRAL/NRN
PLAINS THROUGH THIS PERIOD...WITH EMBEDDED CYCLONE TRACKING TOWARD
SRN MN.  ASSOCIATED SFC LOW -- NOW CONSOLIDATING OVER CENTRAL/WRN
NEB -- WILL DEEPEN THROUGH MOST OF DAY AS IT CROSSES SERN SD AND SRN
MN.  THIS CYCLONE MAY OCCLUDE BEFORE END OF PERIOD ACROSS ERN
MN/NWRN WI AS ASSOCIATED SFC COLD FRONT SURGES EWD OVER NRN MS
VALLEY.  COLD FRONT ALSO WILL MOVE SEWD THROUGH CENTRAL PLAINS...AND
MERGE IN NNE-SSW ALIGNED ZIPPER PROCESS WITH WEAKER COMBINED PACIFIC
FRONT AND DRYLINE OVER ERN KS AND OK.

DRYLINE/FRONT SHOULD MOVE SLOWLY SEWD ACROSS WRN AND NRN TX. 
RESULTANT INSTABILITY GRADIENT -- SIGNIFYING WRN EDGE OF MOIST
SECTOR -- SHOULD EXTEND FROM CENTRAL IA SWWD INVOF MKC-OKC-ABI LINE
DURING 29/23Z-30/00Z TIME FRAME...BASED ON STRONG AGREEMENT AMONG
GUIDANCE FROM LATEST SREF MEMBERS AND 00Z OPERATIONAL MODELS.  WARM
FRONT -- NOW ANALYZED FROM NWRN IA SEWD ACROSS NERN MO AND SRN IL --
WILL LIFT NWD THROUGH WRN GREAT LAKES STATES AND MI THROUGHOUT
PERIOD...REACHING SRN AND CENTRAL ONT BY 30/12Z.

...UPPER MS VALLEY TO ERN OK...
ARC OF SEVERE TSTMS -- CONSISTING OF SUPERCELLS AND/OR SMALL BOWS --
IS POSSIBLE DURING AFTERNOON AND EARLY EVENING INVOF SFC COLD
FRONT...AND BENEATH AND N OF NOSE OF MIDLEVEL DRY SURGE.  A FEW
SUPERCELLS ALSO MAY FORM IN WARM SECTOR OR ALONG WARM FRONT WHERE
DIURNAL HEATING AND GRADUAL INCREASE IN CONVERGENCE SHOULD WEAKEN
CINH.  STORMS MOVING N OF WARM FRONT SHOULD BE LIMITED TO HAIL
THREAT...BUT DAMAGING WIND AND TORNADOES ALSO ARE POSSIBLE IN STORMS
HAVING SFC-BASED INFLOW IN WARM SECTOR.  STRONGEST ISALLOBARIC
RESPONSE WILL OCCUR OVER THIS REGION...RESULTING IN MAXIMIZED LOW
LEVEL SHEAR...AHEAD OF DEEPENING CYCLONE.  MODIFIED MODEL SOUNDINGS
SUGGEST LARGE BOUNDARY LAYER HODOGRAPHS BETWEEN COLD AND WARM FRONTS
-- WITH 0-1 KM SRH 150-250 J/KG.  CORRIDOR OF MOST FAVORABLE SFC
BASED INSTABILITY WILL BE RELATIVELY NARROW BUT MLCAPES UP TO NEAR
1500 J/KG ARE POSSIBLE IN RELATIVELY CLOUD FREE AREAS ALLOWING
SEVERAL HOURS OF PEAK AFTERNOON HEATING.

FARTHER S...PROBABLE COLD FRONTAL ALIGNMENT ACROSS SRN IA AND MO IS
MORE PARALLEL TO MEAN WIND AND PROJECTED STORM MOTION VECTORS THAN
FARTHER N.  THIS...COMBINED WITH STEEPNESS OF FRONT BASED ON PROGGED
LOW LEVEL CROSS SECTIONS...SUGGEST QUICK DEVELOPMENT OF LINEAR
CONVECTIVE MODE AND PRIMARY DAMAGING WIND THREAT...THOUGH EMBEDDED
OR EARLY STAGE SUPERCELLS ARE POSSIBLE GIVEN AT LEAST MARGINAL LOW
LEVEL SRH AND 40-50 KT 0-6 KM SHEAR.

VERTICAL SHEAR AND DISCRETE SUPERCELL PROBABILITIES SHOULD INCREASE
AGAIN FARTHER SWD INTO WRN MO...ERN KS AND NERN OK...WHERE
1. MEAN FLOW VECTORS ARE SOMEWHAT MORE WLY AND ACROSS FORCING
BOUNDARY AND
2. CAPPING WILL BE STRONGER THROUGH MOST OF AFTERNOON...AND
3. BUOYANCY WILL BE RELATIVELY LARGE WITH UPPER 60S/70S F SFC DEW
POINTS SUPPORTING 2000-3000 J/KG MLCAPE.

CAPPING...HOWEVER...MAY ALSO SUPPRESS DEVELOPMENT ENOUGH TO LIMIT
COVERAGE AND THEREFORE OVERALL SEVERE PROBABILITIES.  STILL...ANY
SUSTAINED STORMS WHICH FORM MAY PRODUCE FULL SPECTRUM OF SEVERE.

LINEAR FORCING SHOULD DOMINATE CONVECTIVE MODE AFTER DARK INVOF
FRONT...RESULTING IN THREAT BECOMING PRIMARILY DAMAGING GUSTS. 
CONVECTIVE AND SEVERE PROBABILITIES DECREASE WITH SWWD EXTENT
THROUGH CENTRAL/SERN OK AND WRN/CENTRAL TX WITH WEAKENING OF BOTH
CONVERGENCE AND LAPSE RATES ALOFT.

...NERN WI...UPPER MI...NRN LOWER MI...LS AND NRN LM...
ELEVATED CONVECTION IS EXPECTED TO BE ONGOING AT BEGINNING OF PERIOD
ACROSS PORTIONS OF THIS REGION INVOF NOSE OF 35-45 KT LLJ.  EXPECT
LOW LEVEL WAA AND INCREASING THETAE ABOVE RELATIVELY COOL...PRE
WARM-FRONTAL BOUNDARY LAYER THROUGHOUT THE DAY AS WELL.  BY LATE
AFTERNOON/EVENING EXPECT MUCAPES TO BETWEEN 500-1500 J/KG AWAY FROM
EXISTING CONVECTIVE CLUSTERS...INCREASING WITH PROXIMITY TO SFC WARM
FRONT. SUCH DESTABILIZATION WILL SUPPORT EPISODES OF TSTMS WITH
HAIL BEING MAIN CONCERN.  AFTER DARK ADDITIONAL CONVECTION
ASSOCIATED MODE CLOSELY WITH SFC COLD FRONT AND UPPER LOW WILL MOVE
ACROSS PORTIONS OF THIS REGION AS DESCRIBED ABOVE.

..EDWARDS/CROSBIE.. 10/29/2004

...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.