High Wind in Wyoming, November 28 to 29, 2003

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
156 AM MST FRI NOV 28 2003

.SHORT TERM...
MAIN FORECAST PROBLEM OF THE DAY IS HIGH WIND POTENTIAL.  00Z
GUIDANCE CONTINUES TO PAINT A FAVORABLE PICTURE FOR HIGH WINDS
ACROSS SOUTHEAST WY BUT HAS HELD BACK THE ONSET BY SOME 3 TO 6
HOURS.  EVENING RAOBS SHOWED AXIS OF UPPER JET FROM CENTRAL ALBERTA
TO THE PLAINS OF EASTERN WY/CO...ROUGHLY FROM THE TOP OF THE UPPER
RIDGE DOWN THE EAST SIDE.  THAT UPPER RIDGE SHOULD GET FLATTENED AS
AN UPPER TROF MOVES ACROSS THE EASTERN NORTH PACIFIC INTO THE
INTERMOUNTAIN REGION LATER TODAY.  AT THE SURFACE...PRESSURE
GRADIENT REALLY TIGHTENS UP AS PRESSURE FALLS IN EXCESS OF 15 MB
ACROSS SOUTHWEST SD INTO THE NEBRASKA PANHANDLE AND 1040+ MB SURFACE
HIGH OVER UT WEAKENS ONLY SLIGHTLY.  DIFFERENCES IN 700 MB HEIGHTS
BETWEEN CASPER WY AND CRAIG CO EXCEED 60 METERS BY 00Z AND PERSIST
THROUGH THE NIGHT. THE DIFFERENCE OF 850 MB HEIGHTS BETWEEN CASPER
AND CRAIG REACHES A MAX OF 95 METERS ABOUT 29/06Z. ALSO LIKE THE
STABLE LAYER THAT DEVELOPS ROUGHLY MOUNTAIN TOP LEVEL LATER THIS
AFTERNOON AND EVENING WEST OF CHEYENNE.  ALL THIS LENDS ENOUGH
SUPPORT TO UPGRADE EXISTING HIGH WIND WATCH TO HIGH WIND
WARNING...THOUGH WILL DELAY THE START OF THE WARNING UNTIL
AFTERNOON. DAY SHIFT CAN LOOK AND SEE IF WARNING NEEDS TO BE
EXTENDED INTO SATURDAY.  BUMPED DOWN HIGH TEMPS THIS AFTERNOON A BIT
AFTER LOOKING AT EVENING UPPER AIR DATA AND SEEING THE BEST THERMAL
GRADIENT WELL BACK ACROSS UT/AZ.

.LONG TERM...FOR SATURDAY SHORTWAVE ENERGY SHEARS AS IT MOVES
SOUTHEASTWARD ACROSS THE AREA. HOWEVER...ENOUGH MOISTURE/OROGRAPHICS
DEPICTED TO INCLUDE A CHANCE OF AFTERNOON SNOWSHOWERS ACROSS
SOUTHERN CARBON COUNTY. WARMER GUIDANCE HIGHS LOOK BEST PER LOW
LEVEL TEMPERATURE PROGS. SAT NIGHT/SUNDAY...LOW AMPLITUDE SHORTWAVE
RIDGING MOVES SLOWLY EASTWARD. WITH DEEP MOIST OROGRAPHIC WESTERLY
FLOW...WILL KEEP SNOW SHOWERS ACROSS CARBON COUNTY/SNOWY RANGE. WITH
EXTENSIVE CLOUD COVER...WILL STAY CLOSE TO GFS HIGHS. SUNDAY NIGHT...
WITH DEEP MOISTURE WILL EXPAND SNOW COVERAGE FURTHER EAST BUT
AMOUNTS SHOULD BE LIGHT DUE TO WESTERLY FLOW ALOFT AND LIMITED
DYNAMICS. SHORTWAVE RIDGING PREVAILS MONDAY. WITH DOWNSLOPE FLOW AND
FORECAST LOW LEVEL TEMPERATURES...GFS HIGHS ARE TOO COOL. TUESDAY...
GFS SHOWS A PROGRESSIVE SHORTWAVE TROUGH PASSAGE EARLY IN THE DAY.
WILL NOT INSERT PRECIPITATION FOR NOW AS THIS IS DAY 5 AND MODEL
CONFIDENCE IS LOW. DRY WSW FLOW PREVAILS ON WEDNESDAY. WITH MEAGER
MOISTURE/DYNAMICS WILL KEEP IT DRY. THURSDAY...GFS SHOWS A COLD
FRONTAL PASSAGE WITH A PASSING SHORTWAVE TROUGH ACROSS THE NORTHERN
PLAINS. IF THIS SCENARIO OCCURS...LOSS OF DOWNSLOPE AND COOLER LOW
LEVEL TEMPERATURES WILL DROP HIGHS BACK CLOSER TO NORMAL. STILL DRY
WITH LACK OF MOISTURE/DYNAMICS.

.CYS...
WY...HIGH WIND WARNING THIS AFTERNOON AND TONIGHT ZONES
61>64..66..67.
NE...NONE.

BANN/RUBIN

NEZ001>003-019>021-054-055-WYZ059>070-281245-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE CHEYENNE WY
118 PM MST THU NOV 27 2003

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHEASTERN WYOMING AND THE
WESTERN NEBRASKA PANHANDLE.

.DAY ONE...TODAY AND TONIGHT

TODAY WILL BE BREEZY TO WINDY ACROSS SOME AREAS WITH WEST TO
NORTHWEST WINDS OF 15 TO 30 MPH. WINDS WILL DECREASE TONIGHT.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

STRONG WINDS WILL OCCUR FRIDAY THROUGH FRIDAY NIGHT ACROSS THE
SOUTHEAST WYOMING MOUNTAINS AND THE LOWER ELEVATIONS OF CARBON COUNTY
AND THE EASTERN SLOPES OF THE LARAMIE RANGE.  WEST WINDS OF 30 TO 40
MPH WITH GUSTS OVER 60 MPH WILL LIKELY OCCUR THROUGH FRIDAY NIGHT.
WIND GUSTS ACROSS THE MOUNTAINS COULD REACH 70 MPH FRIDAY AND FRIDAY
NIGHT. A HIGH WIND WATCH HAS BEEN ISSUED FOR PORTIONS OF THE AREA FOR
FRIDAY AND FRIDAY NIGHT.

A CHANCE OF SNOW SHOWERS WILL EXIST OVER THE WEEKEND OVER MUCH OF
CARBON COUNTY AND THE SNOWY RANGE...AND ALSO LATE IN THE DAY ON
TUESDAY.

RUBIN/DAUGHERTY