[SWODY1] SWODY1

[SWODY1 at goshenarc.org]

ACUS01 KWNS 111244
SWODY1
SPC AC 111242

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0742 AM CDT FRI JUN 11 2004

VALID 111300Z - 121200Z

THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 30 SE
EWN 50 N RWI PSK 15 WSW HTS 35 NNW SDF MDH 10 SW CGI SGF 20 NW MKO
ABI BGS 35 ESE PVW P28 15 NW MHK SUX 40 WSW FAR TVF HIB CWA 10 ESE
MKE 10 SSE CGX LAF MIE MFD PIT MRB DCA 15 NE WAL.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 75 S MRF 35 SSW MAF
30 E PVW 15 WSW SLN 10 N CNK 45 N GRI 10 WSW 9V9 20 NE RAP 55 SSW
GCC 55 NW CAG 55 NNE U28 25 E U24 55 S ENV 10 W BOI 25 SE LWS 35 NNW
4OM ...CONT... 70 NNW CMX 50 ESE ESC 15 ESE FNT 15 NNW CLE 20 ENE
HGR 20 E DOV.

...THERE IS A SLGT RISK OF SVR TSTMS TODAY/TONIGHT ACROSS  MUCH OF
THE UPPER MISSISSIPPI VALLEY...PARTS OF THE CENTRAL/SOUTHERN
PLAINS...AND PORTIONS OF THE LOWER OHIO VALLEY INTO THE MID ATLANTIC
COAST STATES....

SEVERAL LARGE UPPER TROUGHS ARE STILL PROMINENT IN THE UPPER FLOW 
PATTERN FROM THE EASTERN PACIFIC INTO THE ATLANTIC COAST STATES. 
THIS INCLUDES LEAD SYSTEM OVER THE CANADIAN MARITIME/NEW
ENGLAND...WHICH MODELS INDICATE WILL SLOWLY SHIFT OFF THE NORTH
ATLANTIC COAST DURING THIS FORECAST PERIOD.  AS THIS OCCURS...BROAD
TROUGH WILL CONTINUE TO GRADUALLY LIFT OUT OF THE WESTERN/CENTRAL
STATES...AS STRONG UPSTREAM JET STREAK...ASSOCIATED WITH GULF OF
ALASKA CLOSED LOW...NOSES TOWARD THE PACIFIC NORTHWEST COAST.

...PLAINS INTO MISSISSIPPI VALLEY...
MOST SIGNIFICANT SHORT WAVE TROUGH EMBEDDED WITH BROADER SCALE
WESTERN/CENTRAL U.S. TROUGH IS ALREADY LIFTING OUT OF THE ROCKIES
INTO THE NORTHERN/CENTRAL PLAINS.  NORTHEAST PROGRESSION INTO
MANITOBA AND THE UPPER MISSISSIPPI VALLEY WILL CONTINUE THROUGH THE
REMAINDER OF THE FORECAST PERIOD...WHILE ANOTHER SHORT WAVE TROUGH
AMPLIFIES AND SHIFTS EASTWARD ACROSS THE INTERMOUNTAIN WEST.

WITH LOW-LEVEL RIDGE REMAINING STRONG ACROSS THE LOWER GREAT LAKES
REGION THROUGH THIS PERIOD...RATHER SHARP BAROCLINIC ZONE IS
EXPECTED TO PERSIST ACROSS AREAS NEAR/WEST OF THE UPPER GREAT LAKES.
 THIS WILL PROVIDE EASTERN LIMIT TO SIGNIFICANT CONVECTIVE THREAT...
BUT SLOW SHIFT TO THE EAST OF THE UPPER MISSISSIPPI VALLEY IS
PROGGED LATER THIS EVENING/OVERNIGHT.

AS WEAK COLD FRONT ASSOCIATED WITH NORTHERN PLAINS SHORT WAVE
ADVANCES EASTWARD TOWARD THE UPPER MISSISSIPPI VALLEY DURING THE
DAY...BOUNDARY INTERSECTION OVER IOWA BY THE PEAK HEATING HOURS IS
EXPECTED TO PROVIDE FOCUS FOR PRIMARY CONVECTIVE DEVELOPMENT.  LIFT
ACROSS THIS REGION WILL BE ENHANCED BY SHARP CYCLONIC MID-LEVEL FLOW
IN BASE OF SHORT WAVE TROUGH...FORCING MOIST/MODERATE TO STRONGLY
UNSTABLE BOUNDARY LAYER PARCELS TO LEVEL OF FREE CONVECTION.

SURFACE DEW POINTS ACROSS MUCH OF SOUTHERN/EASTERN IOWA WILL REMAIN
AROUND 70F...AND MODEL FORECAST SOUNDINGS SUGGEST STRONG CONVECTIVE
INSTABILITY ON NOSE OF MID-LEVEL SUBSIDENCE/DRYING BY LATE AFTERNOON
...WITH 100 MB MEAN MIXED LAYER CAPE RANGE FROM 2000 TO 4000 J/KG. 
THIS WILL BE SUPPORTIVE OF A FEW INTENSE UPDRAFTS CAPABLE OF
PRODUCING VERY LARGE HAIL.  SHEAR PROFILES WILL BE SUPPORTIVE OF
SUPERCELLS...WITH HODOGRAPHS EXPECTED TO BECOME MORE FAVORABLE FOR
TORNADOES AFTER 12/00Z... AS LOWER/MID TROPOSPHERIC FLOW STRENGTHENS
AND VEERS FROM A MORE SOUTHERLY TO WESTERLY COMPONENT. GREATEST
POTENTIAL APPEARS TO LIE ALONG/ NORTH OF DEVELOPING WARM FRONTAL
ZONE EAST OF FORT DODGE IA INTO THE WATERLOO AREA.

OTHER SCATTERED STRONG/SEVERE STORMS...INCLUDING ISOLATED
SUPERCELLS...ARE POSSIBLE NORTHWARD AHEAD OF WEAK COLD FRONT INTO
PARTS OF THE EASTERN DAKOTAS AND NORTHWEST MINNESOTA DURING THE LATE
AFTERNOON HOURS.  HOWEVER...MUCH COOLER LOWER-LEVELS WILL LIMIT CAPE
AND OVERALL MAGNITUDE OF SEVERE THREAT.

ALONG DRY LINE TRAILING ACROSS SOUTHEAST NEBRASKA INTO NORTHWEST
TEXAS...MID-LEVEL SUBSIDENCE SHOULD PROVE INHIBITIVE TO CONVECTIVE
DEVELOPMENT THROUGH MUCH OF THE DAY.  HOWEVER...IN WAKE OF UPPER
TROUGH LIFTING INTO THE UPPER MISSISSIPPI VALLEY...MID-LEVEL COOLING
MAY WEAKEN INHIBITION SUFFICIENTLY FOR AT LEAST WIDELY SCATTERED
THUNDERSTORMS. SHEAR/INSTABILITY SHOULD BE SUPPORTIVE OF SUPERCELLS
WITH LARGE HAIL/ISOLATED WIND GUSTS PRIMARY THREAT.  ACTIVITY IS
EXPECTED TO WEAKEN THIS EVENING WITH LOSS OF DAYTIME HEATING...AND
AS DRY LINE BEGINS TO RETREAT IN RESPONSE TO UPSTREAM SHORT WAVE
TROUGH.

...OHIO VALLEY INTO THE MID ATLANTIC COAST AND NORTHEAST...
DEFORMATION ZONE BETWEEN TROUGH SHIFTING OFF THE ATLANTIC COAST AND
SHORT WAVE LIFTING INTO THE UPPER MISSISSIPPI VALLEY WILL PROVIDE
NORTHERN LIMIT TO CONVECTIVE THREAT THROUGH THIS FORECAST PERIOD. 
THIS WILL EXTEND FROM THE LEE OF THE LOWER LAKES INTO THE NORTHERN
MID ATLANTIC COAST.  ALONG AND TO THE SOUTH OF THIS ZONE...BOUNDARY
LAYER IS MOIST AND WILL BECOME POTENTIALLY UNSTABLE WITH DAYTIME
HEATING.

PRIMARY CONVECTIVE ACTIVITY IS EXPECTED IN ASSOCIATION WITH SHORT
WAVE EMBEDDED WITHIN WEAK SUBTROPICAL BRANCH OF WESTERLIES ACROSS
THE OHIO VALLEY.  FORCING ASSOCIATED WITH THIS FEATURE MAY SUPPORT
ORGANIZING MESOSCALE CONVECTIVE SYSTEM OUT OF ONGOING STORMS OVER
CENTRAL OHIO...WHICH SHOULD GRADUALLY PROGRESS ACROSS THE CENTRAL
APPALACHIANS DURING THE DAYTIME HOURS. BOUNDARY LAYER SHOULD HEAT
UP QUICKLY THROUGH MID DAY AHEAD OF CONVECTION ACROSS THIS
REGION...CONTRIBUTING TO POTENTIAL FOR DAMAGING WIND GUSTS IN 30-35
KT MEAN FLOW REGIME.

MID-LEVEL/UPPER SHORT WAVE AND ASSOCIATED CONVECTIVE CLUSTER WILL
PROGRESS EAST OF THE MOUNTAINS BY LATE AFTERNOON.  RISK FOR DAMAGING
WIND GUSTS MAY PERSIST WITH CLUSTER ALL THE WAY THROUGH SOUTHEAST
VIRGINIA/PARTS OF NORTHEAST NORTH CAROLINA TONIGHT...AS MOIST
BOUNDARY LAYER WILL BE SLOW TO COOL/STABILIZE.

..KERR/GUYER.. 06/11/2004

...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.