[SWODY2] SWODY2

[SWODY2 at goshenarc.org]

ACUS02 KWNS 261712
SWODY2
SPC AC 261711

DAY 2 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1211 PM CDT MON JUL 26 2004

VALID 271200Z - 281200Z

THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM RRT
FAR ATY 10 SE YKN 20 N BUB MHN 10 ESE CDR 20 W RAP REJ DIK 65 NNW
DVL.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 20 SE IPL 30 E EED 20
N P38 ELY EKO 10 ESE TWF 10 SSE 27U 10 N PUW 35 NNW 4OM ...CONT...
10 N INL AXN OTG HSI RSL 15 SSE END FSI MWL 30 SW LFK 25 ESE ESF 20
NNW MEI HSV CSV 10 N JKL 10 W DAY 35 W TOL 35 SE OSC 160 NNW BUF
...CONT... 35 NNW BML 40 N AUG 15 SW BHB.

...THERE IS A SLGT RISK OF SVR TSTMS TUESDAY AFTN/EVE ACROSS PARTS
OF THE NORTHERN PLAINS....

WEAK...BROADLY CYCLONIC UPPER FLOW PATTERN WILL PERSIST THROUGH THIS
FORECAST PERIOD.  SEVERAL SMALLER SCALE TROUGHS/CLOSED LOWS ARE
EMBEDDED WITHIN THIS REGIME...AND MODELS SUGGEST THESE FEATURES WILL
REMAIN SLOWLY PROGRESSIVE.  MOST SIGNIFICANT SYSTEM MAY BE ONE NOW
DIGGING IN THE LEE OF THE CANADIAN ROCKIES.  THIS TROUGH/MID-LEVEL
CLOSED LOW IS PROGGED TO CONTINUE SLOWLY DIGGING SOUTHWARD TOWARD
THE NORTH CENTRAL CANADIAN/U.S. BORDER THROUGH LATE TUESDAY
AFTERNOON...BEFORE TURNING EASTWARD ACROSS THE CENTRAL CANADIAN
PROVINCES TUESDAY NIGHT.  AS THIS OCCURS...UPPER TROUGH IN WEAK
SUBTROPICAL WESTERLIES IS PROGGED TO DIG ACROSS THE FOUR CORNERS
STATES...WHILE A DOWNSTREAM CLOSED LOW/UPPER TROUGH LIFTS OUT OF THE
OHIO VALLEY INTO THE LOWER GREAT LAKES REGION.

...NORTHERN PLAINS...
PRE-FRONTAL LOW-LEVEL THERMAL RIDGE/SURFACE TROUGH IS EXPECTED TO
BECOME FOCUS FOR DESTABILIZATION TUESDAY AFTERNOON FROM THE CENTRAL
HIGH PLAINS INTO THE DAKOTAS.  WHILE RETURN FLOW OF MOISTURE WILL
NOT OCCUR...BOUNDARY LAYER MOISTURE ALREADY PRESENT...WITH LOWER/
MID 50S DEW POINTS...SHOULD BE SUFFICIENT FOR AT LEAST SCATTERED
THUNDERSTORM ACTIVITY.

STRONG DAYTIME HEATING WILL CONTRIBUTE TO A RATHER DEEP MIXED
BOUNDARY LAYER...WITH CAPE ON THE ORDER OF 1000 TO 1500 J/KG BY LATE
AFTERNOON.  WHILE THIS IS NOT PARTICULARLY EXCESSIVE...LARGE
LOW-LEVEL TEMPERATURE/DEW POINT SPREADS WILL CONTRIBUTE TO FAVORABLE
THERMODYNAMIC ENVIRONMENT FOR DOWNBURSTS.  DAMAGING WIND THREAT MAY
BE ENHANCED BY DOWNWARD TRANSFER OF MOMENTUM ASSOCIATED WITH 20 TO
30 KT SOUTHERLY LOW-LEVEL JET NEAR/JUST AHEAD OF SURFACE TROUGH
AXIS.

STRONGER MID/UPPER FORCING FOR UPWARD VERTICAL MOTION ASSOCIATED
WITH DIGGING TROUGH COULD SPREAD AS FAR SOUTH AS THE DAKOTAS LATE
TUESDAY AFTERNOON/EVENING...BUT PRIMARY FORCING FOR CONVECTIVE
DEVELOPMENT APPEARS LIKELY TO BE DAYTIME HEATING TO CONVECTIVE
TEMPERATURES.  THUS...IT APPEARS STORMS DEVELOPING IN SURFACE
TROUGH/JUST AHEAD OF COLD FRONT LIKELY WILL WEAKEN EARLY TUESDAY
EVENING WITH ONSET OF RADIATIONAL COOLING.  HOWEVER...AS LOW-LEVEL
WARM ADVECTION BECOMES ENHANCED ON NOSE OF SOUTHERLY LOW-LEVEL JET
ACROSS EASTERN SOUTH DAKOTA...ADDITIONAL CONVECTION IS POSSIBLE
BENEATH  WEAK DIFLUENT UPPER FLOW REGIME.  SHEAR WILL BE
LIMITED...BUT MID-LEVEL LAPSE RATES MAY BECOME STEEP ENOUGH TO
SUPPORT MARGINAL SEVERE HAIL THREAT INTO THE NIGHT.

...SOUTHERN GREAT BASIN INTO CENTRAL/SOUTHERN ROCKIES...
THUNDERSTORMS COULD BECOME FAIRLY NUMEROUS TUESDAY AFTERNOON AHEAD
OF SHORT WAVE TROUGH...ACROSS PARTS OF THE FOUR CORNERS REGION AND
CENTRAL/SOUTHERN ROCKIES.  WITH RELATIVELY COOL MID-LEVEL
TEMPERATURES CONTRIBUTING TO STEEP LAPSE RATES...THERMODYNAMIC
ENVIRONMENT MAY BECOME SUPPORTIVE OF A FEW VIGOROUS STORMS WITH
MARGINALLY SEVERE HAIL AND ISOLATED MICROBURSTS.

...EASTERN U.S...
SCATTERED CONVECTION WILL AGAIN BE POSSIBLE ALONG/AHEAD OF MID-LEVEL
TROUGH AXIS TRAILING FROM CLOSED LOW LIFTING INTO THE LOWER GREAT
LAKES REGION.  THOUGH FLOW FIELDS/SHEAR PROFILES WILL BE MODERATE IN
STRENGTH NEAR/EAST OF MID-LEVEL CIRCULATION... EXTENSIVE CLOUD COVER
AND POOR MID-LEVEL LAPSE RATES ARE EXPECTED TO MINIMIZE SEVERE
THREAT.  WARM MID-LEVEL ENVIRONMENT/WEAK LAPSE RATES WILL ALSO LIMIT
CONVECTIVE INSTABILITY SOUTHWARD INTO THE EASTERN GULF AND SOUTH
ATLANTIC COAST STATES.

..KERR.. 07/26/2004

...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.