[SWODY1] SWODY1

[SWODY1 at goshenarc.org]

ACUS01 KWNS 120601
SWODY1
SPC AC 120559

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1259 AM CDT FRI AUG 12 2005

VALID 121200Z - 131200Z

THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM GCC
RAP PIR 10 SE 9V9 45 ENE BUB LBF SNY DGW GCC.

THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 25 N
PBG RUT MSV 10 SSE IPT PIT IND DEC CGX MBS 50 ESE OSC.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 30 SW 7R4 MLU GGG AUS
50 SSE DRT ...CONT... 10 S CZZ DRA 45 N P38 U24 U28 40 NNE 4BL MTJ
EGE CAG 10 ENE RKS EVW 30 NNE BKE 60 NW 4OM ...CONT... 30 NNW CTB
GTF MLS DIK FAR AXN MKT DBQ HTL 35 E OSC.

...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTN/EVE ACROSS PARTS OF
THE LWR OH VLY/GREAT LAKES REGION....

...THERE IS A SLGT RISK OF SVR TSTMS LATE THIS AFTN/EVE ACROSS PARTS
OF THE N CNTRL HIGH PLAINS....

BLOCK PERSISTS IN UPPER FLOW REGIME ACROSS THE NORTHEAST PACIFIC/
ALASKA/WESTERN CANADA...AND CHANGES TO PATTERN THROUGH THIS FORECAST
PERIOD WILL BE SLOW/MOSTLY MINOR.  WESTERN EXTENSION OF ATLANTIC
SUBTROPICAL RIDGE WILL REMAIN OVER MUCH OF THE GULF/ ATLANTIC COAST
STATES AND GULF OF MEXICO.  PLUME OF MID/HIGH-LEVEL MOISTURE WILL
CONTINUE TO ADVECT FROM ITS WESTERN PERIPHERY... ACROSS THE
SOUTHWESTERN STATES...INTO SOUTHERN FRINGE OF STRONGER HIGH-LEVEL
WESTERLIES...WHICH EXTEND FROM THE NORTH CENTRAL PLAINS THROUGH THE
ST. LAWRENCE VALLEY.

SERIES OF IMPULSES ROTATING THROUGH BROAD CENTRAL/EASTERN CANADIAN
TROUGH HAVE CONTRIBUTED TO SEVERAL FRONTAL SURGES INTO THE NORTHERN
TIER STATES.  LEADING FRONTAL SURGE WILL BEGIN TO ADVANCE SOUTH OF
MAIN BELT OF WESTERLIES...THROUGH THE MIDDLE MISSISSIPPI VALLEY AND
CENTRAL PLAINS...AS A SIGNIFICANT SHORT WAVE TROUGH ACCELERATES
EASTWARD FROM THE CENTRAL CANADIAN/U.S. BORDER THROUGH ONTARIO BY
EARLY SATURDAY MORNING.

UPSTREAM...ANOTHER SHORT WAVE/JET STREAK DIGGING SOUTHWARD TO THE
LEE OF BLOCKING RIDGE IS PROGGED TO GRADUALLY MERGE WITH SOUTHERN
STREAM TROUGH SHIFTING EAST OF THE PACIFIC COAST STATES...SOMEWHERE 
ACROSS THE NORTHERN ROCKIES LATE TODAY INTO TONIGHT.

...NORTHEAST STATES INTO THE CENTRAL PLAINS...
WAVE DEVELOPING ALONG SURFACE FRONT ACROSS THE UPPER MISSISSIPPI
VALLEY/GREAT LAKES IS FORECAST TO CONTINUE EAST NORTHEASTWARD
THROUGH THE LOWER LAKES/SOUTHERN ONTARIO TODAY...INTO THE ST.
LAWRENCE VALLEY TONIGHT.  BELT OF STRONGER FLOW WITH THIS FEATURE
SEEMS LIKELY TO CONTRIBUTE TO THE BEST POTENTIAL FOR SEVERE
CONVECTION ALONG FRONT...WHICH BY PEAK HEATING IS EXPECTED TO EXTEND
WESTWARD THROUGH THE LOWER OHIO AND OZARKS INTO THE VICINITY OF THE
KANSAS/OKLAHOMA BORDER.

30+ KT MEAN FLOW COULD ENHANCE POTENTIAL FOR DAMAGING WINDS WITH 
ORGANIZED CLUSTER OR CLUSTERS OF STORMS FROM SOUTHERN LOWER
MICHIGAN/NORTHERN INDIANA INTO OHIO BY EARLY AFTERNOON.  THIS
ACTIVITY MAY CONTINUE INTO THE LEE OF THE LOWER LAKES...ACROSS PARTS
OF PENNSYLVANIA AND NEW YORK STATE...BEFORE DIMINISHING THIS
EVENING.

FROM SOUTHERN ILLINOIS AND MISSOURI WESTWARD INTO THE CENTRAL
PLAINS...WARM MID-LEVEL ENVIRONMENT AND WEAK FLOW/SHEAR IS EXPECTED
TO MINIMIZE SEVERE THREAT.  MUCH OF THE EXPECTED CONVECTIVE
DEVELOPMENT IS EXPECTED TO REMAIN CONFINED TO SUBTROPICAL MOIST
PLUME...ON COOL SIDE OF SURFACE BOUNDARY.

...NORTH CENTRAL HIGH PLAINS...
STRONG HEATING IN THE LEE OF THE NORTH CENTRAL ROCKIES IS EXPECTED
TO CONTRIBUTE TO STEEP LAPSE RATES AND WEAK TO MODERATE INSTABILITY
BY THIS AFTERNOON...FROM EASTERN WYOMING INTO SOUTHWESTERN SOUTH
DAKOTA AND WESTERN NEBRASKA.  THIS WILL OCCUR AHEAD OF NEXT FRONTAL
SURGE THROUGH THE NORTHERN PLAINS.  IN ASSOCIATION WITH EVOLVING
UPSTREAM UPPER PATTERN...WEAK SURFACE LOW IS PROGGED TO DEVELOP
ACROSS THIS REGION...AND SHOULD PROVIDE FOCUS FOR CONVECTIVE
DEVELOPMENT NEAR/SHORTLY AFTER PEAK HEATING.

SOUTHEASTERLY UPSLOPE FLOW COMPONENT EAST OF LOW...BENEATH 30 TO 50
KT WESTERLY MID-LEVEL FLOW...WILL CONTRIBUTE TO FAVORABLE SHEAR
PROFILES FOR A COUPLE OF SUPERCELLS IN ENVIRONMENT WITH CAPE OF 1000
TO 2000 J/KG.  MODELS SUGGEST LARGE-SCALE FORCING COULD EVENTUALLY
BECOME SUPPORTIVE OF A LARGER CLUSTER OF STORMS ACROSS SOUTH
DAKOTA/NEBRASKA TONIGHT...BUT STABILIZATION OF BOUNDARY LAYER DUE TO
SURFACE COOLING/FRONTAL PASSAGE SHOULD LIMIT SEVERE THREAT BEYOND
THE EARLY EVENING HOURS.

...SOUTHWEST STATES...
MID-LEVEL SHEAR AXIS WILL PROVIDE A FOCUS FOR CONVECTIVE DEVELOPMENT
ACROSS THE FOUR CORNERS STATES.  BEST CHANCE FOR LOCALIZED
DOWNBURSTS SEEMS TO EXIST ACROSS CENTRAL/SOUTHERN ARIZONA...BUT
THREAT COULD BE MITIGATED BY CLOUD COVER...WHICH MAY LIMIT SURFACE
HEATING.

..KERR.. 08/12/2005

...NOTICE...
THE STATION RELATIVE POINTS IN THIS PRODUCT ARE NOW AVAILABLE
SEPARATELY UNDER THE WMO HEADINGS WUUS01 PTSDY1...
WUUS02 PTSDY2...WUUS03 PTSDY3.  THE INCLUSION OF POINTS
IN THIS DISCUSSION WILL BE DISCONTINUED AFTER THE 2005
CONVECTIVE SEASON.  A PUBLIC NOTIFICATION STATEMENT (PNS)
WILL PROVIDE DETAILS ON THE TRANSITION.