[Swody1] SWODY1

[calvinfs at goshen.edu]

ACUS01 KWNS 060552
SWODY1
SPC AC 060549

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1249 AM CDT THU MAY 06 2004

VALID 061200Z - 071200Z

THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 25 SSW
JFK ABE AOO HLG MIE DNV PIA OTM 45 W LWD BIE HSI GRI OFK FOD LNR 35
N MKG 30 SSE OSC ...CONT... 30 WSW MSS 15 W MPV 10 ESE PSM.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 70 SSW GDP ALM 4CR 25
WNW TCC LHX CYS DGW SHR 10 SSE LVM 10 SE BTM LMT MFR RDM PDT 10 SSE
3TH GTF SDY BIS FAR HIB 125 NNE CMX ...CONT... 50 WNW 3B1 3B1 15 E
BHB ...CONT... 15 ESE NEL TTN CXY DCA 30 SSW NHK 30 WNW ECG FLO 35
NW CHS 40 ENE SAV SSI JAX GNV CTY MAI MGM AUO MCN AND PSK EKN PKB
DAY MTO UIN LWD CNK DDC PVW LBB 65 NNE ABI MWL ACT 10 SSE SAT 40 W
MFE.

...THERE IS A SLGT RISK OF SVR TSTMS FROM THE LWR GREAT LAKES REGION
INTO THE MID MISSOURI VALLEY....

SPLIT IN UPPER FLOW PATTERN WILL PERSIST ACROSS THE NORTHEAST
PACIFIC THROUGH THIS FORECAST PERIOD.  DOWNSTREAM OF BLOCK OFF THE
PACIFIC NORTHWEST/BRITISH COLUMBIA COAST...MERGING BRANCHES OF
STRONGER WESTERLIES WILL REMAIN GENERALLY ZONAL...EXTENDING EASTWARD
NEAR/JUST NORTH OF THE CANADIAN U.S. BORDER.

INTENSE MID/UPPER JET STREAK AND ASSOCIATED LOW AMPLITUDE WAVE ARE
EMBEDDED WITHIN THIS REGIME...AND PROGGED TO SHIFT OUT OF THE
CENTRAL INTO THE EASTERN CANADIAN PROVINCES.  AS THIS
OCCURS...LOW-LEVEL BAROCLINIC ZONE WILL TIGHTEN  IN EAST-WEST BAND
AND SHIFT SOUTHWARD ACROSS THE NORTH CENTRAL/NORTHEASTERN STATES. 
BY LATE THURSDAY NIGHT/EARLY FRIDAY...FRONTAL ZONE WILL EXTEND FROM
NEW ENGLAND INTO THE MID MISSOURI VALLEY AND CENTRAL HIGH PLAINS. 
THIS FEATURE IS EXPECTED TO BECOME FOCUS FOR EXTENSIVE CONVECTIVE
DEVELOPMENT THROUGH THIS PERIOD...SOME OF WHICH WILL BE SEVERE...
PRIMARILY WITH DAMAGING WIND GUSTS AND LARGE HAIL.

...GREAT LAKES REGION...
INCREASING CONVERGENCE/ISENTROPIC ASCENT AHEAD OF SURFACE FRONT IS
EXPECTED TO CONTRIBUTE TO MOISTENING/DESTABILIZATION THROUGH THE
DAYTIME HOURS FROM SOUTHERN LOWER MICHIGAN INTO NEW YORK STATE. MEAN
MIXED LAYER CAPE OF 1000 TO 2000 J/KG APPEARS LIKELY TO DEVELOP...AS
CAP SUPPRESSES CONVECTION EARLY AND ALLOWS A SUBSTANTIAL AMOUNT OF
SURFACE HEATING.  ALTHOUGH THERE ARE SOME DISCREPANCIES...MODELS
GENERALLY SUGGEST AREA OF STRONGER FORCING FOR UPWARD VERTICAL
MOTION WILL OVERSPREAD LOWER MICHIGAN AROUND/SHORTLY AFTER PEAK
HEATING.  THIS WILL BE IN ASSOCIATION WITH ZONE OF ENHANCED
LOW-LEVEL WARM ADVECTION BENEATH DIFLUENT UPPER FLOW FIELD...JUST
AHEAD OF BASE OF LOW AMPLITUDE TROUGH WHICH WILL SPREAD EAST OF THE
LOWER GREAT LAKES REGION TONIGHT.

GIVEN POTENTIAL INSTABILITY AND LARGE-SCALE FORCING...POTENTIAL
EXISTS FOR EVOLUTION OF FAIRLY SUBSTANTIAL MESOSCALE CONVECTIVE
SYSTEM.  RISK OF DAMAGING WIND GUSTS WILL BE ENHANCED BY 40 TO 50 KT
WESTERLY MEAN FLOW ENVIRONMENT...AND MAY PERSIST THROUGH THE EVENING
INTO THE OVERNIGHT HOURS AS ACTIVITY PROGRESSES EAST OF THE LOWER
LAKES INTO THE HUDSON VALLEY.

...UPPER MISSISSIPPI VALLEY INTO THE MID MISSOURI VALLEY...
WIDELY SCATTERED STRONG/SEVERE THUNDERSTORMS MAY BE ONGOING AT
06/12Z...JUST TO COOL SIDE OF SURFACE FRONTAL ZONE FROM PARTS OF
NORTHERN IOWA/SOUTHERN MINNESOTA INTO WISCONSIN.  THIS ACTIVITY IS
EXPECTED TO DEVELOP EASTWARD/DIMINISH DURING THE DAY...WITH FRONTAL
ZONE ADVANCING SOUTHWARD ACROSS NORTHERN ILLINOIS/SOUTHERN
IOWA/SOUTHERN NEBRASKA.  

MID-LEVEL CAP MAY SUPPRESS CONVECTION ALONG FRONT THROUGH MOST OF
THE DAY.  HOWEVER...LOW-LEVEL JET IS PROGGED TO PERSIST IN
ANTICYCLONIC ARC ACROSS THE CENTRAL PLAINS INTO VICINITY OF FRONT. 
ISENTROPIC ASCENT OF HEATED BOUNDARY LAYER AIR NORTH OF FRONTAL ZONE
MAY SUPPORT NEW CONVECTIVE DEVELOPMENT BY LATE AFTERNOON ACROSS
SOUTHERN IOWA/NORTHERN ILLINOIS. LARGE HAIL SHOULD BE PRIMARY THREAT
WITH THIS ACTIVITY...WHICH MAY PERSIST THROUGH THE EVENING
HOURS...WHILE DEVELOPING UPSTREAM ALONG INTENSIFYING LOW-LEVEL JET
AXIS INTO EASTERN NEBRASKA.

...MID/SOUTH ATLANTIC COAST STATES...
UPPER FORCING WILL BE WEAK BENEATH SUBTROPICAL RIDGE. 
HOWEVER...BOUNDARY LAYER WILL REMAIN MOIST ENOUGH...THAT WITH STRONG
SURFACE HEATING/WEAK WARM ADVECTION...WIDELY SCATTERED THUNDERSTORM
ACTIVITY WILL DEVELOP NEAR SURFACE TROUGH IN THE LEE OF THE
APPALACHIANS.

...SOUTHERN HIGH PLAINS/WEST TEXAS...
WEAK UPPER TROUGH IN SUBTROPICAL WESTERLIES MAY CONTRIBUTE TO 
SCATTERED THUNDERSTORM ACTIVITY ACROSS PARTS OF EASTERN NEW
MEXICO/WEST TEXAS.  THOUGH MID/UPPER FLOW FIELD WILL BE QUITE
WEAK...SHEAR PROFILES ARE PROGGED TO BECOME MODERATE IN STRENGTH ON
SOUTHWESTERN PERIPHERY OF CLOSED MID-LEVEL CIRCULATION...WHERE
SOUTHEASTERLY LOW-LEVEL FLOW WILL VEER TO NORTHWESTERLY AT
MID-LEVELS.  THIS MAY ENHANCE RISK OF AN ISOLATED SEVERE STORM OR
TWO NEAR DRY LINE...MAINLY SOUTH/EAST OF THE FORT STOCKTON AREA.

...NORTHWESTERN U.S...
LOW/MID-LEVEL BAROCLINIC ZONE MAY BECOME FOCUS FOR WIDELY SCATTERED
THUNDERSTORMS FROM THE LEE OF THE SOUTHERN CASCADES INTO  THE
NORTHERN ROCKIES...THOUGH LACK OF BETTER MOISTURE WILL LIMIT THIS
THREAT.  BEST POTENTIAL FOR LATE AFTERNOON/EVENING CONVECTIVE
DEVELOPMENT APPEARS TO EXIST ACROSS PARTS OF CENTRAL/NORTHEAST
OREGON...BENEATH DIFLUENT UPPER FLOW REGIME DOWNSTREAM OF CLOSED LOW
OFF THE PACIFIC NORTHWEST COAST.

..KERR.. 05/06/2004

...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.