[SWODY2] SWODY2

[SWODY2 at goshenarc.org]

ACUS02 KWNS 210552
SWODY2
SPC AC 210551

DAY 2 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1251 AM CDT SUN AUG 21 2005

VALID 221200Z - 231200Z

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 75 ESE YUM IGM DRA
RNO SVE 4LW PDT 30 N 63S ...CONT... 70 NE ISN 10 ESE Y22 35 ESE GRI
TOP TBN 10 SE POF MKL 10 E MSL RMG AVL HKY 15 NE ORF ...CONT... 20 S
DRT AUS ACT ABI FST 80 WNW MRF.

...NO SVR TSTM AREAS FORECAST...

ALTHOUGH DISCREPANCIES EXIST AMONG MODELS/MODEL RUNS WITH REGARD TO
EVOLUTION OF SMALLER SCALE FEATURES...LATEST NAM/GFS AND SHORT-RANGE
ENSEMBLE FORECASTS SUGGEST AMPLIFIED WAVES WITHIN SPLIT BELTS OF
POLAR WESTERLIES WILL REMAIN SLOWLY PROGRESSIVE THROUGH THIS
FORECAST PERIOD.  LEAD TROUGH...WITH EMBEDDED CLOSED LOW...WILL
CONTINUE TO GRADUALLY SHIFT EAST SOUTHEASTWARD TOWARD NORTH ATLANTIC
COASTAL AREAS MONDAY.  BROADER-SCALE UPSTREAM TROUGH IS STILL IN THE
PROCESS OF EVOLVING...IN ASSOCIATION WITH NORTHEAST PACIFIC SHORT
WAVE MIGRATING INTO THE CANADIAN ROCKIES...AND ANOTHER DIGGING
STRONGLY OUT OF ALASKA.  LATTER FEATURE IS PROGGED TO DIG ACROSS
BRITISH COLUMBIA DURING THE DAY MONDAY...INTO THE PACIFIC NORTHWEST
COAST STATES BY EARLY TUESDAY...AS FORMER LIFTS INTO NORTHERN
SASKATCHEWAN/MANITOBA.

IN RESPONSE TO DEVELOPMENTS IN MID-LATITUDE WESTERLIES...
SUBTROPICAL RIDGING ACROSS THE U.S. WILL CONTINUE TO BE SUPPRESSED. 
SUBSTANTIAL COOLING/DRYING IN LOWER-LEVELS EAST OF THE ROCKIES WILL
CONFINE THUNDERSTORM ACTIVITY TO SOUTH ATLANTIC/GULF COASTAL AREAS
AND THE SOUTHERN PLAINS.  IT WILL REMAIN WARM ACROSS THE WEST...BUT
COOLING AT MID-LEVELS IS EXPECTED TO CONTRIBUTE TO FAIRLY EXTENSIVE
CONVECTIVE DEVELOPMENT...MAINLY ACROSS THE HIGHER TERRAIN OF THE
GREAT BASIN...AND THE ROCKIES.

...MONTANA...
MODELS SUGGEST EVOLVING UPPER FLOW PATTERN WILL SUPPORT DEVELOPMENT
OF SURFACE CYCLONE IN THE LEE OF THE ROCKIES MONDAY...WITH LOW
DEEPENING AND MIGRATING INTO EASTERN MONTANA MONDAY NIGHT INTO EARLY
TUESDAY.  FORCING ASSOCIATED WITH THIS FEATURE MAY BECOME A FOCUS
FOR CONVECTIVE DEVELOPMENT...PARTICULARLY ACROSS CENTRAL
MONTANA...NEAR/SHORTLY AFTER PEAK HEATING.  ALTHOUGH LAPSE RATES
SHOULD BECOME RATHER STEEP...LIMITED LOW-LEVEL MOISTURE SEEMS LIKELY
TO MINIMIZE MAGNITUDE OF DESTABILIZATION.  COUPLED WITH WEAK SHEAR
PROFILES...SOUTH OF STRONGER BELT OF FLOW TO THE NORTH OF THE
CANADIAN BORDER...RISK OF SEVERE STORMS APPEARS SMALL AT THE PRESENT
TIME.

...SOUTH CENTRAL HIGH PLAINS THROUGH GULF COAST STATES...
SEASONABLY MOIST/UNSTABLE ENVIRONMENT WILL PERSIST...AND WEAK
IMPULSES EMBEDDED WITHIN FLATTENING SUBTROPICAL WESTERLIES SHOULD
AID CONVECTIVE DEVELOPMENT MONDAY.  FORCING MAY BECOME SUPPORTIVE OF
 ONE OR MORE STORM CLUSTERS...WHICH COULD BE ACCOMPANIED BY STRONG
GUSTY WINDS...DESPITE PRESENCE OF WEAKLY SHEARED ENVIRONMENT. 
HOWEVER...TOO MUCH UNCERTAINTY EXISTS WITH REGARD TO THE PROGRESSION
OF THESE FEATURES TO CONFIDENTLY DELINEATE LOW PROBABILITY SEVERE
THREAT AREA.

..KERR.. 08/21/2005

...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.