[SWODY1] SWODY1

[SWODY1 at goshenarc.org]

ACUS01 KWNS 251227
SWODY1
SPC AC 251225

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0725 AM CDT WED AUG 25 2004

VALID 251300Z - 261200Z

THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 70 W
RRT 45 NE FAR AXN FRM ALO RFD MKE GRR 10 NNW FWA BMG POF HRO PRX 35
NNE MWL FSI PNC 30 WSW EMP 15 NNW SLN 40 S EAR BBW 9V9 50 WSW JMS 60
NNE MOT.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 35 WSW ART AOO 25 SE
TRI 35 NNE ABY 30 ENE MGR 35 WSW SAV 20 WSW FLO 25 SW ILM.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 15 SE PSX 25 E SAT 15
SE DRT.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 70 SSW GDP MAF 55 E
LBB 30 E CSM 15 NE P28 40 NNE DDC 20 NNW LAA 15 E DEN 45 N GJT 35
WSW MLD 20 SW SUN 50 W BOI 65 SW PDT 30 S AST.

...THERE IS A SLGT RISK OF SVR TSTMS TODAY ACROSS EASTERN PORTIONS
OF THE NRN/CNTRL PLAINS AND THE MIDDLE MISSISSIPPI VALLEY....

BROAD CYCLONIC UPPER FLOW REGIME PERSISTS ACROSS THE WESTERN/CENTRAL
STATES.  A PAIR OF VIGOROUS JET STREAKS ARE EMBEDDED WITHIN THIS
REGIME...AND WILL PLAY A PROMINENT ROLE IN SUPPORTING INTENSE
CONVECTIVE DEVELOPMENT ACROSS THE CENTRAL STATES TODAY INTO TONIGHT.
 IN THE SUBTROPICAL WESTERLIES...LEAD JET STREAK AND ASSOCIATED
SHORT WAVE TROUGH ARE ALREADY ACCELERATING THROUGH THE CENTRAL
PLAINS.  THIS SYSTEM IS PROGGED TO CONTINUE RAPIDLY NORTHEASTWARD
INTO THE UPPER GREAT LAKES REGION BY LATE TONIGHT.  THIS WILL OCCUR
AS INTENSE CYCLONIC POLAR JET STREAK NOSES FROM THE PACIFIC
NORTHWEST COAST STATES THROUGH THE NORTH CENTRAL ROCKIES/PLAINS.

BOTH FEATURES ARE ALREADY CONTRIBUTING TO FORCING FOR ONGOING...
INCREASINGLY WIDESPREAD CONVECTIVE DEVELOPMENT NEAR/JUST NORTH OF
THE KANSAS/NEBRASKA BORDER INTO THE VICINITY OF THE MISSOURI/IOWA
BORDER AND WEST CENTRAL ILLINOIS.  THIS ACTIVITY IS BEING SUPPORTED
BY ENHANCED ISENTROPIC ASCENT ON LEADING EDGE OF MOIST BOUNDARY
LAYER WITH LOWER/MID 70S DEW POINTS...WHICH HAS RETURNED NORTHWARD
THROUGH THE SOUTHERN/CENTRAL PLAINS.

CONTINUED NORTHWARD ADVECTION OF MOISTURE LIKELY WILL BE SLOWED BY
EXPANDING CLUSTER /OR CLUSTERS/ OF STORMS...UNTIL EXIT REGION OF
POLAR JET OVERSPREADS THE MID MISSOURI VALLEY LATE THIS EVENING/
OVERNIGHT.  THIS MAY TEND TO MITIGATE SEVERE THREAT ACROSS A
CONSIDERABLE PORTION OF THE MID MISSOURI/MID AND UPPER MISSISSIPPI
VALLEY REGION. HOWEVER...GRADUAL INCREASE IN SEVERE STORM ACTIVITY
OVER THE PAST SEVERAL DAYS APPEARS LIKELY TO CONTINUE TODAY...WITH
RISK PERHAPS BECOMING CONCENTRATED IN SEVERAL AREAS.

...EAST CENTRAL PLAINS INTO OZARKS...
POTENTIAL FOR MOST INTENSE STORMS TODAY APPEARS LIKELY TO DEVELOP
ACROSS PARTS OF EASTERN KANSAS AND OKLAHOMA.  GENERALLY IN WAKE OF
SUBTROPICAL SHORT WAVE TROUGH AXIS BY MID AFTERNOON...LOW/ MID-LEVEL
FLOW REGIME IS PROGGED TO REMAIN CYCLONIC AS FAR SOUTH AS THE RED
RIVER VALLEY.  MID-LEVEL INHIBITION IS EXPECTED TO REMAIN IN
WEAKENED STATE UNTIL SHORT WAVE RIDGE BUILDS INTO REGION LATE THIS
EVENING/OVERNIGHT.  THUS...COMBINATION OF LOW-LEVEL WARM ADVECTION
AND  STRONG HEATING TOWARD CONVECTIVE TEMPERATURES IS EXPECTED TO BE
SUFFICIENT TO INITIATE SCATTERED CONVECTIVE DEVELOPMENT BY LATE
AFTERNOON...ON WESTERN EDGE OF LOW-LEVEL MOIST TONGUE.

THIS APPEARS MOST LIKELY ALONG/EAST OF INTERSTATE 35... WHERE
THERMODYNAMIC ENVIRONMENT...WITH STEEP LAPSE RATES/DRY MID-LEVELS
AND WARM/MOIST BOUNDARY LAYER WITH CAPE IN EXCESS OF 3000 J/KG...
WILL BE FAVORABLE FOR SEVERE STORMS.  VEERING PROFILES WITH HEIGHT
ALONG 30 KT SOUTHWESTERLY LOW-LEVEL JET AXIS WILL PROVIDE SUFFICIENT
SHEAR FOR SUPERCELLS BENEATH MODERATE WESTERLY MID/UPPER FLOW. 
STRONGEST CELLS WILL BE CAPABLE OF PRODUCING VERY LARGE
HAIL/DAMAGING WIND GUSTS AND ISOLATED TORNADOES...BEFORE ACTIVITY
WEAKENS AFTER NIGHTFALL.

...MID MISSOURI VALLEY INTO NORTHERN PLAINS...
NORTH OF CONVECTIVELY GENERATED/ENHANCED BOUNDARY...LOW-LEVEL
MOISTURE RETURN AHEAD OF PLAINS SURFACE TROUGH WILL BE MORE LIMITED
FROM NORTHEAST NEBRASKA INTO THE CENTRAL/EASTERN DAKOTAS. 
HOWEVER...MOISTURE CURRENTLY IN PLACE...IN CONJUNCTION WITH STRONG
HEATING/STEEP MID-LEVEL LAPSE RATES SHOULD CREATE FAVORABLE
ENVIRONMENT FOR SEVERE STORMS.

MODELS SUGGEST UPPER TROUGH/SHEAR AXIS...CURRENTLY EVIDENT IN
SATELLITE IMAGERY IN THE LEE OF THE NORTH CENTRAL ROCKIES /WELL IN
ADVANCE OF STRONGER POLAR JET CORE/...WILL LIFT ACROSS THE NORTHERN
PLAINS BY PEAK AFTERNOON HEATING.  THIS SHOULD AID CONVECTIVE
INITIATION...WITH ACTIVITY BECOMING MOST CONCENTRATED SOUTH/EAST OF
DEEPENING SURFACE LOW ACROSS THE CENTRAL DAKOTAS.  THOUGH FLOW
FIELDS ARE PROGGED TO BE RELATIVELY MARGINAL ACROSS THIS
REGION...VEERING WITH HEIGHT MAY CREATE SUFFICIENT SHEAR FOR A FEW
SUPERCELLS...ENHANCING SEVERE POTENTIAL.  PRIMARY THREATS APPEAR TO
BE VERY LARGE HAIL/DAMAGING WINDS GUSTS...BUT ISOLATED TORNADOES ARE
POSSIBLE...UNTIL BOUNDARY LAYER BEGINS TO COOL/STABILIZE THIS
EVENING.

...SOUTHERN/EASTERN MISSOURI INTO ILLINOIS/INDIANA...
SEVERE THREAT IS MORE UNCERTAIN ACROSS THIS AREA DUE TO CONCERNS
ABOUT CLOUD COVER/CONVECTIVE ACTIVITY DEVELOPING AHEAD OF
SUBTROPICAL SHORT WAVE TROUGH...BEFORE BOUNDARY LAYER HAS A CHANCE
TO HEAT/DESTABILIZE SIGNIFICANTLY.  HOWEVER...WITH BOUNDARY LAYER
DEW POINTS AT OR INCREASING TO AROUND 70F...MODERATE SHEAR
ASSOCIATED WITH MID/UPPER JET STREAK ON SOUTHEASTERN PERIPHERY OF
NEGATIVELY TILTED TROUGH AXIS WILL PROVIDE POTENTIAL FOR AT LEAST
ISOLATED SEVERE STORMS.

...NORTHERN INTERMOUNTAIN REGION...
STRONG MID-LEVEL COOLING /500 MB TEMPS AS LOW AS -18C/ IS PROGGED
ALONG/NORTH OF POLAR JET AXIS ACROSS THE NORTHERN INTERMOUNTAIN
REGION TODAY.  THIS SHOULD ENHANCE CONVECTIVE POTENTIAL ACROSS PARTS
OF EASTERN IDAHO/SOUTHWEST MONTANA/NORTHEAST WYOMING DURING THE PEAK
HEATING HOURS. MODEL FORECAST SOUNDINGS SUGGEST LIMITED CAPE...BUT
INSTABILITY...SHEAR AND FORCING ACROSS THE HIGHER TERRAIN COULD
STILL BE SUFFICIENT FOR A COUPLE OF STRONG CELLS WITH SOME SMALL TO
MARGINALLY SEVERE HAIL.

...FLORIDA PENINSULA...
MOIST BOUNDARY LAYER WITH LOWER/MID 70S F DEW POINTS SHOULD
DESTABILIZE FAIRLY QUICKLY THIS MORNING WITH SURFACE HEATING.  AIDED
BY CONTINUING PRESENCE OF CYCLONIC MID-LEVEL SHEAR AXIS...FROM JUST
OFF THE SOUTH ATLANTIC COAST INTO THE FLORIDA PENINSULA...SEA
BREEZES ARE EXPECTED TO SUPPORT INITIATION OF FAIRLY WIDESPREAD
CONVECTION AGAIN BY EARLY AFTERNOON.

..KERR/TAYLOR.. 08/25/2004

...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.