[SWODY2] SWODY2

[SWODY2 at goshenarc.org]

ACUS02 KWNS 210548
SWODY2
SPC AC 210547

DAY 2 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1247 AM CDT TUE JUN 21 2005

VALID 221200Z - 231200Z

THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 45 NNW
ELO 40 NW BRD FAR JMS 50 W JMS 40 NW MBG PHP 20 N CDR 81V GCC 60 WNW
4BQ BIL BZN HLN 40 NNE HVR.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 15 SW FHU PHX EED 10
NE DAG BIH NFL 10 NNW OWY BOI 30 NNE CTB ...CONT... 60 ENE ELO 15
WSW DLH 10 N MSP LSE JVL MIE LUK CRW EKN CXY 10 N AVP ALB MPV 10 E
HUL ...CONT... 30 SSW PSX AUS ACT PRX TUL MHK LNK 35 NW GRI EAR GCK
50 SE AMA HOB 10 SSW P07.

...THERE IS A SLGT RISK OF SVR TSTMS WED/WED NIGHT ACROSS PARTS OF
THE NORTHERN PLAINS....

MODELS CONTINUE TO INDICATE THAT CLOSED LOW OFF THE CENTRAL PACIFIC
COAST WILL WEAKEN AND FINALLY LIFT NORTHEASTWARD.  MAIN ACCELERATION
IS FORECAST LATER TODAY INTO WEDNESDAY...AS UPSTREAM JET APPROACHES
FROM THE LOWER LATITUDE PACIFIC...AND ANOTHER CLOSED LOW BEGINS TO
EVOLVE OVER THE EASTERN PACIFIC...FARTHER TO THE SOUTHWEST.

LEAD SYSTEM IS PROGGED INTO THE NORTHERN U.S./CANADIAN ROCKIES BY
12Z WEDNESDAY...AHEAD OF ANOTHER SHORT WAVE TROUGH DIGGING ACROSS
NORTHERN/CENTRAL BRITISH COLUMBIA.  AS LATTER FEATURE CONTINUES TO
DIG INTO SOUTHERN BRITISH COLUMBIA/ALBERTA WEDNESDAY/WEDNESDAY
NIGHT...LEAD SYSTEM WILL PROGRESS INTO THE CENTRAL CANADIAN
PROVINCES...WHERE PRIMARY SURFACE CYCLOGENESIS WILL OCCUR.

IN RESPONSE TO UPSTREAM DEVELOPMENTS...CENTER OF BROAD CENTRAL U.S.
SUBTROPICAL RIDGE WILL SLOWLY SHIFT EAST OF THE CENTRAL
ROCKIES...WHILE RIDGE AXIS TO THE NORTH PIVOTS ACROSS THE NORTHERN
PLAINS AND BEGINS TO FLATTEN LATE IN THE FORECAST PERIOD.  VIGOROUS
DOWNSTREAM TROUGH WILL PROGRESS OFF THE NORTH ATLANTIC COAST...BUT
WEAK UPPER TROUGHING WILL PERSIST FROM THE SOUTHERN MID ATLANTIC
COAST INTO THE EASTERN GULF OF MEXICO.

...INTERMOUNTAIN WEST INTO UPPER MISSISSIPPI VALLEY...
DEEP LAYER SOUTHERLY FLOW TO THE WEST OF RIDGE AXIS IS ALREADY
MOISTENING MUCH OF THE INTERMOUNTAIN WEST AND ROCKIES. THIS WILL
CONTINUE INTO WEDNESDAY...AND HEATING/OROGRAPHIC FORCING SHOULD
SUPPORT NUMEROUS THUNDERSTORMS.  ALTHOUGH POTENTIAL FOR ORGANIZED
CONVECTIVE DEVELOPMENT ACROSS THE CENTRAL/SOUTHERN GREAT BASIN AND
ROCKIES APPEARS SLIM...VERY ISOLATED HAIL/DOWNBURST EVENTS ARE
POSSIBLE WHERE INSTABILITY BECOMES LOCALLY MAXIMIZED.

ON SOUTHERN PERIPHERY OF STRONG SOUTHWESTERLY MID/UPPER JET...SHEAR
PROFILES WILL BE BETTER...AND FLOW WILL AID PROPAGATION OF STORMS
OFF THE HIGHER TERRAIN INTO THE NORTHERN HIGH PLAINS.  ADDITIONAL
SCATTERED STORMS COULD INITIATE ALONG MID-LEVEL FRONTAL ZONE
PROGRESSING THROUGH CENTRAL MONTANA DURING PEAK HEATING.  DRYING
BOUNDARY LAYER IS EXPECTED IN WAKE OF PRE-FRONTAL SURFACE TROUGH
SHIFTING INTO THE WESTERN DAKOTAS/NEBRASKA PANHANDLE BY PEAK
HEATING.  HOWEVER...VERY DEEP MIXED BOUNDARY LAYER TO THE WEST WILL
BE SUPPORTIVE OF DAMAGING DOWNBURSTS IN STRONGER STORMS...AND CAPE
MAY REMAIN SUFFICIENT FOR MARGINAL HAIL THREAT.

ALONG/EAST OF SURFACE TROUGH...STRONG MID-LEVEL WARMING NORTH OF
UPPER HIGH CENTER WILL PROVIDE A STRONG CAP THROUGH MUCH OF THE
CENTRAL AND NORTHERN PLAINS.  BEST CHANCE FOR CONVECTIVE DEVELOPMENT
APPEARS TO BE NEAR THE BLACK HILLS...WHERE ENHANCED CONVERGENCE IN
THE VICINITY OF SURFACE TROUGH...HEATING/OROGRAPHY MAY PROVIDE
SUFFICIENT LIFT TO BREAK CAP WEDNESDAY AFTERNOON.  IF THIS
OCCURS...SHEAR IN ENVIRONMENT WITH MIXED LAYER CAPE IN EXCESS OF
3000 J/KG WILL BE SUPPORTIVE OF SUPERCELLS WITH LARGE HAIL/DAMAGING
WINDS.

OTHERWISE...FORCING TO BREAK CAP THROUGH THE REMAINDER OF THE
NORTHERN PLAINS IS MORE UNCERTAIN.  LATEST NAM...MORE SO THAN
GFS...SUGGESTS AN AREA OF ENHANCED LOW/MID-LEVEL WARM ADVECTION...
TO SOUTH OF LEAD CENTRAL CANADIAN SHORT WAVE...MAY LIFT ACROSS
WESTERN NORTH DAKOTA DURING THE LATE AFTERNOON HOURS.  IF LIFT IS
ABLE TO OVERCOME CAP...ISOLATED SEVERE STORMS ARE LIKELY...WITH
CONSOLIDATING/EXPANDING CONVECTION SPREADING WITH FORCING THROUGH
NORTHERN NORTH DAKOTA/NORTHWEST MINNESOTA WEDNESDAY NIGHT.

...MID MISSISSIPPI VALLEY...
LARGE CONVECTIVE CLUSTER SPREADING SOUTHEAST OF THE MID MISSOURI
VALLEY SHOULD BE WEAKENING BY/SHORTLY AFTER 12Z WEDNESDAY.  EVOLVING
UPPER FLOW PATTERN SEEMS LIKELY TO FAVOR NEW DEVELOPMENT DURING THE
DAY ALONG DEVELOPING WARM FRONTAL ZONE EXTENDING SOUTHEASTWARD
THROUGH THE MIDDLE MISSISSIPPI VALLEY. MODERATE INSTABILITY
ALONG/WEST OF THIS BOUNDARY COULD SUPPORT ANOTHER SMALLER CLUSTER OF
STORMS WITH AT LEAST MARGINAL POTENTIAL FOR HAIL/GUSTY WINDS...BUT
PROBABILITIES FOR THIS SEEM TOO LOW TO OUTLOOK A SLIGHT RISK AT THE
PRESENT TIME.

...MID ATLANTIC COAST STATES...
FLOW/SHEAR WILL GENERALLY REMAIN WEAK INTO WEDNESDAY...BUT
INSTABILITY BY WEDNESDAY AFTERNOON ALONG FRONT PROGRESSING INTO THE
NORTHERN MID ATLANTIC COAST/DELMARVA MAY SUPPORT STORMS APPROACHING
OR BRIEFLY EXCEEDING SEVERE LIMITS.  ADDITIONAL STORMS LIKELY WILL
DEVELOP NEAR/EAST OF LEE SURFACE TROUGH ACROSS VIRGINIA...AND ACROSS
THE MOUNTAINS OF NORTH CAROLINA...WHERE DIFLUENT UPPER FLOW COULD
ENHANCE ACTIVITY.

..KERR.. 06/21/2005

...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.