[SWODY1] SWODY1

[SWODY1 at goshenarc.org]

ACUS01 KWNS 070550
SWODY1
SPC AC 070547

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1247 AM CDT FRI MAY 07 2004

VALID 071200Z - 081200Z

THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM HSE
GSB GSO BLF HTS LUK IND DNV 30 NE PIA BRL LWD FNB CNK EAR BBW ANW
9V9 ATY STC 45 NNE EAU MTW GRR TOL CAK ABE 20 E NEL.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 60 SSW MRF GDP 4CR
LHX BFF SHR 25 NE COD 10 SE JAC 25 WNW SLC ELY TPH TVL RBL DLS 30 N
63S ...CONT... 55 NNE MOT 25 NNE GFK BJI HIB IMT 40 NNE MTC
...CONT... 20 WSW ERI BFD BAF 10 E BOS ...CONT... ILM 45 S CLT AVL
5I3 BMG BMI P35 MHK P28 LTS ABI 10 WNW DRT.

...THERE IS A SLGT RISK OF SVR TSTMS FROM THE MID ATLANTIC STATES
INTO THE UPPER MISSISSIPPI AND MID MO VALLEY....

...OHIO VALLEY INTO THE MID ATLANTIC COAST STATES...
DOWNSTREAM OF NORTHEAST PACIFIC BLOCK...WHICH MODELS SUGGEST WILL
PERSIST THROUGH AT LEAST THIS FORECAST PERIOD...MERGING BRANCHES OF
STRONGER FLOW WILL EXTEND IN MORE OR LESS ZONAL FASHION ALONG THE
CANADIAN/U.S. BORDER.  NORTHERN BRANCH WILL REMAIN MOST PROMINENT...
WITH AN INTENSE JET STREAK NOSING ACROSS THE ST. LAWRENCE VALLEY/
NORTHERN NEW ENGLAND...SUPPORTING A DEEPENING LOW/MID-LEVEL CYCLONE
OVER THE CANADIAN MARITIMES.  IN ASSOCIATION WITH THIS FEATURE...A
COLD FRONT...ALREADY PROGRESSING INTO THE NORTHEAST STATES...WILL
CONTINUE TO ADVANCE SOUTHWARD THROUGH THE OHIO VALLEY AND MID
ATLANTIC COAST STATES TODAY.

FRONTAL ZONE HAS ALREADY BECOME FOCUS FOR INCREASING CONVECTIVE
DEVELOPMENT...WHICH WILL LIKELY BE ONGOING FROM PARTS OF NORTHERN
OHIO INTO NEW JERSEY AT 07/12Z.  AS SHORT WAVE EMBEDDED WITHIN
WEAKER SOUTHERN BRANCH SHIFTS EAST OF THE UPPER OHIO VALLEY INTO THE
NORTHERN MID ATLANTIC COAST STATES BY MIDDAY...THUNDERSTORM ACTIVITY
WILL SPREAD SOUTHWARD ACROSS WEST VIRGINIA/VIRGINIA.

DAYTIME HEATING AND INCREASING LOW/MID-LEVEL MOISTURE ON
WEST/NORTHWEST FLOW ARE EXPECTED TO CONTRIBUTE TO DESTABILIZATION
AHEAD OF FRONT/THUNDERSTORM ACTIVITY...AND INTENSIFICATION OF STORMS
APPEARS LIKELY.  THOUGH FLOW/SHEAR PROFILES LIKELY WILL BE ONLY
MODERATE IN STRENGTH...THERMODYNAMIC ENVIRONMENT WITH SUFFICIENTLY
STEEP LAPSE RATES FOR MEAN MIXED LAYER CAPE OF 1000 TO 2000 J/KG
WILL BE FAVORABLE FOR A FEW SEVERE STORMS.  LARGE HAIL IS EXPECTED
TO BE PRIMARY THREAT...BUT GUSTY WINDS ARE POSSIBLE NEAR MORE
ORGANIZED CLUSTERS.

OTHER SMALL CLUSTERS OF STORMS LIKELY WILL DEVELOP IN CONFLUENT
LOW-LEVEL FLOW NEAR FRONT UPSTREAM INTO THE LOWER OHIO VALLEY...
WHICH MAY TRACK BACK ACROSS THE CENTRAL APPALACHIANS/MID ATLANTIC
COAST STATES ON WEST NORTHWEST FLOW.

...MID MO VALLEY INTO UPPER MISSISSIPPI VALLEY...
IN WAKE OF EASTERN CANADIAN LOW/TROUGH...MID-LEVEL HEIGHT RISES ARE
PROGGED ACROSS THE CENTRAL CANADIAN PROVINCES/PARTS OF THE UPPER
MISSISSIPPI VALLEY AND UPPER GREAT LAKES.  AS THIS OCCURS...FRONTAL
ZONE...WHICH HAS SURGED INTO THE MIDDLE MISSISSIPPI VALLEY AND NORTH
CENTRAL PLAINS...WILL BEGIN RETREATING NORTHWARD.  MODELS SUGGEST
THIS MAY NOT OCCUR UNTIL LATE THIS EVENING/OVERNIGHT. 
HOWEVER...NORTHWARD ADVECTION OF MOIST/ POTENTIALLY UNSTABLE AIR ON
30-40 KT LOW-LEVEL JET AND AGEOSTROPHIC FORCING IN RIGHT ENTRANCE
REGION OF UPPER JET LIKELY WILL SUPPORT INCREASING CONVECTION OVER
BROAD AREA OF THE UPPER MIDWEST.

TIMING OF INITIAL CONVECTIVE DEVELOPMENT IS UNCERTAIN DUE TO STRONG
CAPPING LIKELY TO STILL BE IN PLACE NEAR WARM FRONT ACROSS THE MID
MISSOURI VALLEY THIS AFTERNOON.  MODELS DO SUGGEST A MID-LEVEL SHORT
WAVE TROUGH WILL PROGRESS OUT OF THE GREAT BASIN INTO THE NORTH
CENTRAL PLAINS BY THE PEAK AFTERNOON HEATING HOURS.  THIS IS
SUPPORTED BY LATEST WATER VAPOR IMAGERY.

AS CONVECTIVE TEMPERATURES ARE APPROACHED...FORCING MAY BECOME
SUFFICIENT FOR AT LEAST ISOLATED CONVECTIVE DEVELOPMENT IN
ENVIRONMENT WITH VERY STEEP LAPSE RATES AND MEAN MIXED LAYER CAPE IN
EXCESS OF 2000 J/KG.  SHEAR PROFILES...PARTICULARLY FROM EASTERN
NEBRASKA INTO PARTS OF SOUTHWEST SOUTH DAKOTA AND WESTERN
IOWA...WILL BE SUFFICIENT FOR SUPERCELLS WITH LARGE HAIL/DAMAGING
WIND GUSTS...POSSIBLY TORNADOES.

WITH ONSET OF SURFACE COOLING IN WARM SECTOR AND NOCTURNAL
STRENGTHENING OF LOW-LEVEL JET...PRIMARY CONVECTIVE DEVELOPMENT INTO
THE OVERNIGHT HOURS IS EXPECTED TO OCCUR NORTH OF RETREATING SURFACE
FRONT. STRONGEST LIFT AND DESTABILIZATION ABOVE FRONTAL INVERSION
APPEAR LIKELY ACROSS PARTS OF NORTHERN IOWA/SOUTHERN MINNESOTA BY
LATE EVENING...SPREADING EASTWARD INTO THE GREAT LAKES OVERNIGHT.

...NORTHERN INTERMOUNTAIN REGION...
MOISTURE CONTINUES TO INCREASE ACROSS THE NORTHERN INTERMOUNTAIN
REGION...AHEAD OF CLOSED LOW OFF THE PACIFIC NORTHWEST COAST. 
MODELS SUGGEST ANOTHER SHORT WAVE WILL ROTATE AROUND SOUTHERN/
EASTERN PERIPHERY OF LOW...ACROSS THE NORTH CENTRAL PACIFIC COAST BY
LATE AFTERNOON.  THIS FEATURE SHOULD ENHANCE CONVECTIVE
POTENTIAL...PARTICULARLY FROM PARTS OF SOUTHEAST OREGON/NORTHWEST
NEVADA INTO CENTRAL IDAHO...WHERE THERMODYNAMIC ENVIRONMENT WILL BE
SUPPORTIVE OF ISOLATED MICROBURSTS.

..KERR.. 05/07/2004

...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.