Damaging Wind in Wyoming, July 27, 2001

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
246 PM MDT FRI JUL 27 2001

WEAK THUNDERSTORMS PULSING ACROSS SW THIS AFTERNOON. STORMS MAINLY
TRAINING ALONG DEW POINT BOUNDARY NEAR CO/UT BORDER.  SHORTWAVE JUST
NORTH OF RNO AT 20Z TO MOVE ACROSS N UT INTO SW WY THIS EVENING.
NOCTURNAL TS SHOULD BE CONFINED NEAR VORT CENTER AND AGREE MORE WITH
AVN SOLUTION TAKING VORT ACROSS SOUTHERN WY BORDER THAN FURTHER NORTH
POSITION OF ETA.  WILL KEEP ISOLD TS THROUGH FIRST PERIOD FOR SW
ZONES.  OTHERWISE CLEAR NIGHT WITH GOOD RADIATIONAL COOLING.  MAIN
FOCUS TURNS TO CRITICAL FIRE WX SITUATION DEVELOPING OVER WEEKEND.
110 KNOT JET DIGGING TROUGH OFF B.C. COAST TO ROUND BASE TONIGHT WITH
SHORTWAVE SHEARING ACROSS MONTANA SATURDAY.  DYNAMICS AND MOISTURE
NORTH WITH CWFA IN HOT AND WINDY DRY SLOT.  ASSOCIATED SURFACE FRONT
TO HIT NW CORNER AROUND 00Z SUNDAY AND STRETCHES ACROSS MT/WY BORDER.
SOUTHWARD PROGRESS WILL DEPEND LARGELY ON PUSH FROM CONVECTIVE
OUTFLOWS TO THE NORTH. WINDY SITUATION SETTING UP WITH PRESSURES
FALLING EAST OF DIVIDE IN ADVANCE OF FRONT AND FORECAST SOUNDINGS
SHOWING GRADUAL INCREASE IN WIND WITH HEIGHT UP TO 50 KT AT H5.  LND
AND CPR MAY COME CLOSE TO RECORD HIGHS 96 AND 97 RESPECTIVELY...ALL
OTHER RECORDS SAFE.  ON SUNDAY...INITIAL SHORTAVE CARVES BROAD TROUGH
FROM NW INTO DAKOTAS WITH CWFA UNDER DRY SW FLOW.  THOUGH POST FROPA
SURFACE GRADIENT WEAK WITH RISING PRESSURES TO NORTH...FORECAST
SOUNDINGS CONTINUE TO SHOW GOOD HOOKUP WINDS WITH LITTLE SPEED
SHEAR.  SO CONTINUED WINDY AND HOT EXCEPT FOR NORTH CENTRAL WHERE
SOME RELIEF LIKELY FROM WEAK FROPA.  IN EXTENDED...DRY SW FLOW
PREVAILS WITH MEAN TROUGH POSITION REMAINING OVER NW U.S. AND UPPER
HIGH OVER S PLAINS.  QUASI-STATIONARY FRONT MAY DIP DOWN INTO N
ZONES OCCASIONALLY DEPENDING MAINLY ON CONVECTIVE OUTFLOWS.

.RIW...RED FLAG WARNING THIS EVENING AND SATURDAY FOR ALL
MOUNTAIN ZONES...AND WEST...SOUTH AND CENTRAL LOWER ELEVATIONS.

AEM