Tornado in Nevada, April 27, 2005

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RENO NV
240 PM PDT WED APR 27 2005

.SHORT TERM...
CONVECTION WHICH FIRED UP BEFORE NOON TODAY IN THE SOUTHERN ZONES
HAS BEEN SPREADING NORTHWARD DURING THE AFTERNOON. MANY LOCATIONS
HAVE REPORTED 1/4 INCH HAIL INCLUDING THE RENO WFO WHILE A RECENT
SLIGHTLY STRONGER CELL IN MINDEN PRODUCED 1/2 INCH HAIL. VIL VALUES
ASSOCIATED WITH THIS SMALL HAIL HAVE GENERALLY BEEN IN THE 15-20
RANGE. THE HEAVIEST RAIN REPORTED WITH A T-STORM WAS 1/3 INCH IN
YERINGTON. SNOW LEVELS HAVE REMAINED RELATIVELY HIGH...AROUND 8500
FT. PEAK OUTFLOW WIND GUST OF 51 MPH WITH BLOWING DUST WAS RECENTLY
REPORTED AT FALLON NAS WHILE OTHER WINDS HAVE GENERALLY BEEN IN THE
30-40 MPH RANGE.

SCATTERED TO NUMEROUS SHOWERS AND T-STORMS WILL CONTINUE OVER
MOST ZONES...ESPECIALLY IN THE NORTH AND EAST THRU THIS EVENING THEN
DIMINISH...EXCEPT IN MONO COUNTY AS THE UPPER LOW APPROACHES THE
PRECIP WILL INCREASE OVERNIGHT. AS WAS THE CASE OF THE UPPER LOW
PASSAGE LAST WEEKEND...THE CENTER IS LIKELY TO TRACK FARTHER SOUTH
THAN INDICATED BY THE MODEL DATA. AS A RESULT...THE SNOW LEVELS WILL
NOT DROP AS MUCH...PERHAPS TO NEAR 6000 FEET IN THE SIERRA BY EARLY
THURS MORNING WHILE PRECIP AMOUNTS WILL BE LESS IN THE TAHOE ZONE. A
FEW INCHES OF SNOW ARE LIKELY LATER TONIGHT THRU THURS MORNING IN
THE SIERRA FROM SONORA PASS SOUTH TO MAMMOTH MOUNTAIN...BUT AMOUNTS
ARE EXPECTED TO REMAIN BELOW ADVISORY LEVELS. MEANWHILE...STEADY
STRATIFORM RAIN BAND ASSOCIATED WITH THE EAST-WEST SURFACE BOUNDARY
CURRENTLY OVER SOUTHERN OREGON WILL DRIFT SOUTH TO THE THE NORTHERN
ZONES LATER TONIGHT. THESE AREAS MAY RECEIVE 1/2 INCH OF RAINFALL
THRU EARLY THURS MORNING WITH HOURLY RATES GENERALLY AROUND 0.10
INCH PER HOUR...RESULTING IN AREAS OF PONDING OR STANDING WATER IN
LOW LYING AREAS BUT SHOULD NOT BE A SERIOUS FLOOD THREAT.

THE STRATIFORM RAIN BAND WILL CONTINUE TO SAG SOUTHWARD ON THURSDAY
BUT WEAKEN AS IT APPROACHES RENO. EXPECTED RAINFALL AMOUNTS IN THE
SUSAN RIVER BASIN OF 1/4 TO 1/2 INCH WOULD NOT RAISE SIGNIFICANT
HYDROLOGIC CONCERNS. ELSEWHERE...ISOLATED TO SCATTERED SHOWERS ARE
EXPECTED WITH REDUCED COVERAGE IN MOST AREAS EXCEPT THE FAR SOUTH
ZONES WHERE A THUNDERSTORM REMAINS POSSIBLE BEFORE NOON. AIR MASS
BECOMES MORE STABLE IN THE AFTERNOON AS 500 MB FLOW BECOMES
NORTHWEST TO NORTH.

ACTIVITY WINDS DOWN ON THURS NIGHT AND FRIDAY SHOULD BE PARTLY
CLOUDY AND DRY OVER MOST AREAS...ALTHOUGH BOTH THE GFS AND NAM
PRODUCE A SMALL AREA OF INSTABILITY AND LIGHT QPF FROM RENO SOUTH TO
DOUGLAS COUNTY BY LATE FRIDAY AFTERNOON SO A SLIGHT CHANCE OF
THUNDER WAS ADDED TO THE RENO ZONE FOR THAT TIME PERIOD. NEXT SYSTEM
APPROACHES THE FORECAST AREA BY SAT AFTERNOON AND SAT NIGHT. OVERALL
IT LOOKS WEAKER THAN THE CURRENT UPPER LOW BUT MOISTURE DEPTH SHOULD
BE ADEQUATE TO PRODUCE SOME LIGHT PRECIP OVER THE FORECAST AREA.
THIS SYSTEM MAY ALSO EVENTUALLY TRACK FARTHER SOUTH BUT FOR NOW
GENERAL 20-30 PERCENT POPS WILL BE CARRIED OVER ALL ZONES UNTIL THIS
LOW COMES CLOSER. MJD

.LONG TERM...SUNDAY THROUGH WEDNESDAY...
LITTLE CHANGES MADE IN THE LONG TERM WITH CONTINUED UNCERTAINTY AS
TO TIMING OF SHORTWAVES. THE WAVE APPROACHING SATURDAY NIGHT HAS
BECOME MORE CONSISTENT IN TIMING AND POSITION THUS FIR SUNDAY HAVE
EXTENDED POPS FURTHER EAST INTO PERSHING AND CHURCHILL COUNTIES.
AFTER SUNDAY...BRIEF ZONAL FLOW RETURNS AHEAD OF A LOW APPROACHING
THE WASHINGTON/BRITISH COLUMBIA COAST. EXPECT TO SEE DECENT RIDGING
FOR TUESDAY AND WEDNESDAY WITH A TROF NEARING THE COAST ON THURSDAY.
JBONK
&&

.REV WATCHES/WARNINGS/ADVISORIES...
.NV...NONE.
.CA...NONE.
&&