Flash Flood Warning 14, NWS Reno, NV

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RENO NV
240 PM PDT SAT AUG 21 2004

.SHORT TERM...
CONVECTION BEGINNING LATER TODAY THAN YESTERDAY AND WITH LESS AREAL
COVERAGE. THE MAIN AREA OF CONCERN IS EAST OF THE SIERRA CREST FROM
SOUTH OF LAKE TAHOE TO MAMMOTH AND EXTENDING INTO WESTERN NV NEAR
HAWTHORNE. THE MORNING MODEL RUNS SHOWED THIS TREND TOWARDS LESS
ACTIVITY. THE ETA WAS TOO DRY AND TOO FAR EAST AND SOUTH WITH THE
CLOUDS AND PRECIPITATION AS HAS BEEN THE CASE FOR THE PAST SEVERAL
DAYS. WEST WINDS WERE INCREASING IN THE RENO AREA AND WILL HELP SET
UP LOW LEVEL CONVERGENCE TO THE EAST. FOR THE REMAINDER OF THE
AFTERNOON EXPECT SCATTERED THUNDERSTORMS MAINLY EAST AND SOUTH OF
RENO BUT WITH ONLY ISOLATED STRONG STORMS. A CHANGE IN THE WEATHER
PATTERN WILL TAKE PLACE OVER THE NEXT COUPLE OF DAYS. AN UPPER
TROUGH WILL DEVELOP OVER THE PACIFIC NORTHWEST AND BRING COOLER AND
LOCALLY WINDY WEATHER TO THE SIERRA AND WESTERN NV...ESPECIALLY THE
NORTHERN PORTIONS OF THE CWA. THE ETA MODEL WHICH HAS DONE SUCH A
POOR JOB HANDLING THUNDERSTORMS AND CONVECTION OVER THE PAST FEW
DAYS LOOKS MUCH MORE REASONABLE WITH THE INCOMING TROUGH. WINDS WILL
INCREASE DURING THE DAY SUNDAY WITH GUSTS OVER 30 MPH OVER MUCH OF
THE AREA FROM RENO NORTHWARD SUNDAY AFTERNOON AND EVENING.
TEMPERATURES WILL BE SEVERAL DEGREES COOLER THAN TODAY. SOME LIGHT
PRECIPITATION IS POSSIBLE IN FAR NORTHWEST NV AND NORTHEAST CA IN
THE AFTERNOON...INCREASING AND SPREADING SOUTH SUNDAY NIGHT AND
MONDAY. TEMPERATURES WILL CONTINUE TO COOL TUESDAY WITH EXPECTED
HIGHS IN THE 70S TO LOWER 80S ACROSS WESTERN NV VALLEYS. RC

.LONG TERM...WEDNESDAY THROUGH SATURDAY...
THE MEDIUM RANGE MODELS ARE IN FAIR AGREEMENT IN BRINGING THROUGH A
SHORT WAVE ON WEDNESDAY...WITH BELOW NORMAL HIGH TEMPERATURES AND
WINDY CONDITIONS EXPECTED. BY THURSDAY...I HELD HIGH TEMPERATURES
PRETTY MUCH THE SAME AS WEDNESDAY...AS MODEL DISCREPANCIES START TO
CREEP IN WITH THE TIMING OF THE EXITING TROUGH. THE UKMET/GFS/
CANADIAN HOLD THE  MEAN TROUGH BACK OVER THE WESTERN CONUS...WHILE
THE ECMWF PUSHES THE TROUGH A BIT FURTHER EAST OVER THE
INTERMOUNTAIN WEST.  WITH SUCH A TIGHT HEIGHT GRADIENT WITH THE
UPPER TROUGH...HEIGHT DISCREPANCIES BETWEEN THE MODELS ARE RUNNING
BETWEEN 573 DM (CANADIAN) AND 587 DM (ECMWF) NEAR RENO. WITH THE GFS
AROUND 580 DM...IT SEEMS TO BE A DECENT COMPROMISE AT THIS TIME...SO
I STUCK AROUND MEXMOS FOR MOST OF THE EXTENDED PERIOD. THIS WOULD
BRING STEADILY WARMING TEMPERATURES THURSDAY THROUGH SATURDAY WITH
RISING HEIGHTS. SNYDER

&&

.REV WATCHES/WARNINGS/ADVISORIES...
.NV...NVZ002-004 LAKE WIND ADVISORY SUNDAY AFTERNOON.
.CA...CAZ072 LAKE WIND ADVISORY SUNDAY AFTERNOON.
&&