Damaging Wind in Wyoming, September 5, 2002

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
135 PM MDT THU SEP 5 2002

FORECAST STILL ON TRACK AS MOISTURE FROM THE REMNANTS OF HURRICANE
HERNAN ARE BEING DRAWN NORTHWARD THROUGH SOUTHERN CALIFORNIA AND AS
FAR NORTH AS EXTREME SOUTHERN UTAH. AT LEAST THATS THE EXTENT OF
THE DEEP LAYERED MOISTURE. THE LEADING EDGE OF THE MID AND UPPER
LEVEL MOISTURE IS ALREADY SPREADING INTO SOUTHWESTERN WYOMING. GOES
PW SOUNDER SHOWS 1.5 INCH PLUME HAS MOVED NORTHWARD INTO SOUTHERN
NEVADA ALREADY WHICH IS ABOUT A HALF INCH MORE THAN THE MODELS WERE
FORECASTING. PLUME SEEMS TO BE AIMED RIGHT AT US AND SEE NO REASON
TO CHANGE THE FORECAST MUCH. IT APPEARS A WEAK DISTURBANCE OVER
SOUTHERN NEVADA OR SOUTHWEST UTAH WILL LIFT NORTH ACROSS OUR WESTERN
ZONES OVERNIGHT KEEPING THE THREAT OF STORMS. IDEA OF SCATTERED FOR
OUR WESTERN ZONES STILL LOOKS GOOD WITH WIND RIVER BASIN ON EDGE OF
THIS SYSTEM.

PLUME BECOMES BETTER ENTRENCHED OVER THE WEST ON FRIDAY WITH FIRST OF
SPEED MAXES ROTATING ACROSS THE AREA. PLUME GRADUALLY SHIFTS EASTWARD
FRIDAY NIGHT AND SATURDAY WITH WIDESPREAD RAIN DEVELOPING ACROSS
CENTRAL WYOMING. FRONTAL BOUNDARY SAGGING SOUTH OUT OF MONTANA SHOULD
ALSO BE A FOCUS FOR POTENTIALLY HEAVY RAIN SATURDAY AND SUNDAY.
GENERALLY FOLLOWED THE AVN AGAIN TODAY WITH WHAT I BELIEVE IS A
BETTER DEPICTION OF BOTH THE CURRENT AND FUTURE MOISTURE PLUME. IN
ADDITION TO THE PLUME...A SERIES OF SPEED MAXES SHOULD PROVIDE
PERIODS OF ENHANCED RIGHT ENTRANCE REGION DYNAMICS DURING THIS ENTIRE
EPISODE. IT APPEARS THIS PLUME WILL CAMP OUT OVER OUR AREA THROUGH AT
LEAST SUNDAY BEFORE UPPER LOW LIFTS NORTHEAST ACROSS OUR AREA ON
MONDAY. ONE DAY OF POTENTIALLY MORE SERIOUS CONVECTION POSSIBLE AS
UPPER LOW PASSES BY...FOLLOWED BY GRADUAL CLEARING MONDAY NIGHT OR
TUESDAY. MID CREW ADDED IN SOME WRAPAROUND PRECIPITATION FOR TUESDAY
MORNING BUT BASED ON CURRENT AVN TIMING THIS MAY BE GONE BY THEN.
WILL NOT FLIP FLOP BUT LET MID CREW EXAMINE THIS ONE MORE TIME. AM
STILL COUNTING ON SHORTWAVE RIDGING WEDNESDAY AND THURSDAY FOR SLOW
WARMUP AND DRY CONDITIONS. A SPECIAL WEATHER STATEMENT WILL BE
ISSUED WITH THE AFTERNOON PACKAGE CONCERNING THE DRASTIC CHANGE TO
WETTER AND COOLER WEATHER.

.RIW...NONE.

SKRBAC

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE RIVERTON, WY
242 PM MDT THU SEP 5 2002

TIME(MDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0223 PM    RIVERTON                  WY   58 MPH TSTM WIND GUST
09/05/02   FREMONT                        WIND GUST RECORDED AT
                                          RIVERTON AIRPORT
                                          ASOS.REPORTED BY OTHER

RAM

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE RIVERTON, WY
242 PM MDT THU SEP 5 2002

TIME(MDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0223 PM    RIVERTON                  WY   58 MPH TSTM WIND GUST
09/05/02   FREMONT                        WIND GUST RECORDED AT
AT                                        THE RIVERTON AIRPORT ASOS.

RAM

WYZ001>020-022>028-061100-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE RIVERTON WY
300 PM MDT THU SEP 5 2002

...COOLER AND WETTER WEATHER HEADED FOR WESTERN AND CENTRAL WYOMING
WITH THE POTENTIAL FOR HEAVY RAIN...

A VERY MOIST WEATHER PATTERN IS IN THE EARLY DEVELOPMENT STAGES OVER
THE SOUTHWESTERN UNITED STATES. A DEVELOPING LOW PRESSURE SYSTEM OFF
THE WEST COAST WILL DRAW MOISTURE FROM THE REMNANTS OF HURRICANE
HERNAN NORTHWARD INTO WYOMING BEGINNING FRIDAY AND CONTINUING THROUGH
THE WEEKEND.

THE FIRST DISTURBANCE IN THIS SOUTHWEST FLOW WILL MOVE ACROSS
WESTERN WYOMING TONIGHT SPREADING SCATTERED SHOWERS AND
THUNDERSTORMS. MOISTURE FROM THE REMNANTS OF HURRICANE HERNAN WILL
DEEPEN ACROSS THE WESTERN PORTION OF THE STATE ON FRIDAY AND SPREAD
ACROSS THE ENTIRE AREA BY SATURDAY. WIDESPREAD SHOWERS AND
THUNDERSTORMS ARE EXPECTED WITH LOCALLY HEAVY RAIN POSSIBLE. SHOWERS
AND THUNDERSTORMS ARE EXPECTED TO CONTINUE THROUGH SUNDAY AND
POSSIBLY INTO MONDAY BEFORE THE ASSOCIATED UPPER LEVEL LOW PRESSURE
SYSTEM MOVES EAST.

RAINFALL AMOUNTS AT THIS TIME ARE STILL UNCERTAIN BUT EARLY
INDICATIONS POINT TO BETWEEN ONE HALF AND ONE INCH ACROSS MANY LOWER
ELEVATION LOCATIONS WITH 1 TO 2 INCHES IN THE MOUNTAINS BETWEEN
FRIDAY AND MONDAY.

FARMERS...RANCHERS AND OTHERS WITH OUTDOOR INTERESTS SHOULD BE
PREPARED FOR THIS DRASTIC CHANGE TO COOLER AND WETTER WEATHER.
STAY TUNED TO YOUR FAVORITE MEDIA OUTLET FOR FURTHER STATEMENTS ON
THIS DEVELOPING WEATHER SITUATION.

SKRBAC