[SWODY1] SWODY1

[SWODY1 at goshenarc.org]

ACUS01 KWNS 171239
SWODY1
SPC AC 171237

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0737 AM CDT SAT JUL 17 2004

VALID 171300Z - 181200Z

THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM SEM 45
ENE MEI 40 SW CBM 30 SSW UOX 35 S MKL 45 N MSL 35 SSE BNA 10 SW CSV
10 WNW AVL 45 NNW FLO 30 W CRE 15 NW SAV 35 ENE CSG SEM.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 35 N CTB 10 ESE LVM
50 SSW COD 45 N CPR 30 SSE 4BQ 15 N Y22 65 NNE BUB 30 WNW SLN 15 S
P28 25 ENE FSI 50 NW TXK 45 ENE PBF 25 S DNV 50 WNW MKG 40 W ANJ
...CONT... 35 NE CRP 55 WSW HDO 10 SSE FST 10 W ALM SVC 45 E DUG
...CONT... 15 W YUM 40 SW EED 55 SW LAS 60 NW NID 65 SE RBL 35 SW
MFR 25 ENE UIL.

...THERE IS A SLGT RISK OF SVR TSTMS TODAY AND TONIGHT FROM PARTS OF
THE NORTHERN GULF STATES INTO PARTS OF THE SOUTHERN ATLANTIC COAST
STATES....

UPPER RIDGE HAS SHARPENED DURING THE PAST 24 HOURS...ALONG AN AXIS
EXTENDING FROM A CENTER OF HIGHER HEIGHTS NEAR THE FOUR CORNERS
REGION NORTHWARD INTO THE CANADIAN ROCKIES.  MODELS SUGGEST THIS
RIDGE WILL GENERALLY REMAIN STRONG THROUGH THIS FORECAST
PERIOD...AND LITTLE EASTWARD PROGRESSION OF UPPER TROUGH OFF THE
PACIFIC NORTHWEST COAST IS PROGGED TO OCCUR.  DOWNSTREAM OF
RIDGE...SHORT WAVE TROUGH IS NOW DIGGING INTO THE LOWER OHIO/MIDDLE
MISSISSIPPI VALLEY REGION...AND PROGGED TO CONTINUE SOUTHEASTWARD
INTO BASE OF LARGER SCALE TROUGH OVER THE GULF COAST STATES BY LATE
TONIGHT.

...GULF COAST STATES INTO SOUTHERN ATLANTIC COAST STATES..
COMPOSITE OUTFLOW BOUNDARY HAS ADVANCED INTO CENTRAL GULF COASTAL
AREAS AND THE NORTHEASTERN GULF OF MEXICO.  TROPICAL BOUNDARY LAYER
AIR MASS WITH MID 70S DEW POINTS HAS BEEN SUPPRESSED SOUTHWARD AHEAD
OF THIS BOUNDARY...AND MID-LEVEL LAPSE RATES HAVE WEAKENED DUE TO 
EXTENSIVE PRIOR CONVECTION AND PERSISTENT NORTHWESTERLY FLOW. 
CONSIDERABLE CLOUD COVER WILL FURTHER COMPLICATE POTENTIAL FOR
DESTABILIZATION TODAY...AND UNCERTAINTY EXISTS WITH REGARD TO SEVERE
THREAT.

HOWEVER...SURFACE DEW POINTS REMAIN AT LEAST NEAR 70F ALONG PRIMARY
BAROCLINIC ZONE ASSOCIATED WITH LARGE-SCALE EASTERN U.S. TROUGH...
WHICH EXTENDS ACROSS THE NORTHERN GULF STATES. ALTHOUGH DIFFERENCES
EXIST...MODELS SUGGEST AMPLIFICATION OF WAVE ALONG THIS FRONTAL ZONE
TODAY IN RESPONSE TO APPROACHING SHORT WAVE TROUGH.  THIS MAY OCCUR
AS EARLY AS MIDDAY FROM PARTS OF NORTHEAST MISSISSIPPI INTO NORTHERN
ALABAMA...BEFORE WAVE CONTINUES SLOWLY EASTWARD ACROSS NORTHERN
GEORGIA BY EARLY THIS EVENING...INTO THE CAROLINAS OVERNIGHT.

WHILE MAGNITUDE OF THIS DEVELOPMENT IS STILL UNCERTAIN...SHEAR
PROFILES WILL STRENGTHEN BENEATH MODERATELY STRONG CYCLONIC MID/HIGH
LEVEL JET NOSING INTO THE NORTHERN GULF STATES.  GIVEN AT LEAST WEAK
CONDITIONAL INSTABILITY...LARGE-SCALE FORCING FOR UPWARD VERTICAL
MOTION AND INCREASINGLY FAVORABLE SHEAR PROFILES WILL CONTRIBUTE TO
POTENTIAL FOR ORGANIZED CONVECTIVE DEVELOPMENT WITH RISK OF DAMAGING
WIND GUSTS...PERHAPS ISOLATED TORNADOES.

CONFIDENCE IS LOW...BUT IF SURFACE CYCLONE DEEPENS AS SIGNIFICANTLY
AS SUGGESTED BY GFS...SEVERE THREAT COULD PERSIST/INCREASE OVERNIGHT
EASTWARD INTO THE CAROLINAS.

...INTERMOUNTAIN WEST/ROCKIES...
PLUME OF MID/HIGH-LEVEL MOISTURE ADVECTING NORTHWARD OFF THE LOWER
LATITUDE PACIFIC WILL CONTRIBUTE TO FAVORABLE ENVIRONMENT FOR
CONVECTIVE DEVELOPMENT.  DEEPLY MIXED BOUNDARY LAYER WILL DEVELOP
WITH STRONG HEATING...AND WILL PROVE FAVORABLE FOR ISOLATED
MICROBURSTS...IN ADDITION TO A FEW STORMS WITH HAIL.  PERTURBATIONS
MIGRATING AROUND WESTERN PERIPHERY OF UPPER RIDGE AXIS...ONE NOW
NEAR THE CENTRAL PACIFIC COAST...ANOTHER LIFTING INTO THE LOWER
COLORADO VALLEY...WILL AID CONVECTIVE DEVELOPMENT AS THEY PROGRESS
NORTHWARD INTO THE NORTHERN INTERMOUNTAIN REGION AND GREAT BASIN
LATER TODAY.

...NORTH CENTRAL PLAINS...
SHORT WAVE TROUGH TOPPING RIDGE HAS CONTRIBUTED TO FORCING FOR
ONGOING CONVECTIVE DEVELOPMENT ACROSS THE WESTERN DAKOTAS.  A
GRADUAL SOUTHWARD SHIFT OF STRONGER FORCING WILL CONTINUE WITH UPPER
SYSTEM THROUGH THE DAY...AND THIS APPEARS LIKELY TO SUPPORT
CONVECTIVE DEVELOPMENT ACROSS PARTS OF WESTERN/CENTRAL NEBRASKA
...PERHAPS INTO NORTHWEST KANSAS...DURING THE PEAK HEATING HOURS.

THIS WILL OCCUR ON EASTERN PERIPHERY OF PLATEAU/ROCKIES THERMAL
RIDGE...WHERE STEEP MID-LEVEL LAPSE RATES AND DEEPLY MIXED BOUNDARY
LAYER WILL PROVIDE FAVORABLE ENVIRONMENT FOR MICROBURSTS AND SOME
HAIL.  WEAK BUT VEERING WINDS WITH HEIGHT BENEATH MODERATELY STRONG
NORTHERLY MID/UPPER FLOW MAY SUPPORT AN ISOLATED/BRIEF HIGH-BASED
SUPERCELL OR TWO.  THREAT SHOULD DIMINISH LATE THIS
AFTERNOON/EVENING AS UPPER SYSTEM PROGRESSES FURTHER
SOUTHEASTWARD...AND BOUNDARY LAYER BEGINS TO STABILIZE WITH LOSS OF
HEATING.

..KERR/CROSBIE.. 07/17/2004

...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.