Severe Thunderstorm Warning 17, NWS Reno, NV

WESTERN NEVADA AND EASTERN CALIFORNIA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RENO NV
200 PM PDT FRI AUG 1 2003

UPPER LOW OVER NORTHERN BAJA COAST WILL MOVE INTO THE SIERRA AND
CENTRAL NEVADA BY SATURDAY NIGHT...SLOWLY BRINGING A DRIER SW FLOW
TO THE REGION BY MONDAY.  WATER VAPOR SHOWS AN IMPULSE LIFTING NORTH
FROM SOUTHERN NEVADA WHICH WILL BRING UPPER DIVERGENCE TO WESTERN
NEVADA AND NE CALIFORNIA THIS EVENING AND TONIGHT.  WILL SPREAD THE
FF WATCH TO NORTHERN AREAS UNTIL MIDNIGHT...AND END IT IN THE SOUTH
AT 9 PM AS THE THREAT OF SHOWERS AND LOCALLY STRONG THUNDERSTORMS
CONTINUES.

TOMORROW FLOW TURNS MORE SOUTHERLY AHEAD OF THE TROF.  PLENTY OF
UPPER DIVERGENCE AVAILABLE OVER NE CALIFORNIA INTO CENTRAL AND
NORTHERN NEVADA FROM LINGERING IMPULSE.  ALSO...THETA-E RIDGE REMAINS
OVER THE SIERRA...AND IN MOIST AND UNSTABLE ATMOSPHERE...STRONG
SHOWERS AND THUNDERSTORMS AGAIN LIKELY.  UPPER SUPPORT DROPS OFF
OVERNIGHT AS THE TROF MOVES INTO CENTRAL NEVADA...BUT NOT BEFORE
THUNDERSTORMS CONTINUE INTO SATURDAY NIGHT...ESPECIALLY ACROSS
THE BASIN AND RANGE.

SUNDAY FLOW FINALLY TURNS MORE SOUTHWEST...BUT BEING RELATIVELY
LIGHT IT WILL TAKE ANOTHER DAY TO DRY OUT EVEN WESTERN PORTIONS OF
THE CWA.  WILL LEAVE A CHANCE OF SHOWERS AND THUNDERSTORMS IN FOR
SUNDAY...AND INDICATE A DRYING TREND BEGINNING IN THE WEST ON
MONDAY.  SG

IN THE EXTENDED...TUESDAY THROUGH FRIDAY... MODELS IN GOOD AGREEMENT
WITH ERN PACIFIC TROF JUST OFF THE WEST COAST ON TUESDAY AND
DEVELOPMENT OF LOW PRESSURE CENTER IN GULF OF ALASKA BY WEDNESDAY.
00Z GFS AND 12Z ECMWF DROP LOW CENTER FURTHER SOUTH TO JUST OFF THE
PAC NW COAST BY THURSDAY WHILE CANADIAN AND UKMO KEEP LOW FURTHER
NORTH. POSITIONING OF LOW FURTHER SOUTH WOULD PRODUCE A TIGHTER
PRESSURE GRADIENT ACROSS OUR CWA BETWEEN TROF AND HIGH SITUATED WELL
EAST OVER NM. IN ANY CASE... LOOKS LIKE ONLY UNCERTAINTY WILL BE
STRENGTH OF AFTERNOON WIND IN THE EXTENDED. DRY AND STABLE SOUTHWEST
FLOW WILL DEVELOP BY TUESDAY ACROSS THE AREA... ONLY CHANCES LEFT
FOR PRECIP WILL BE IN FAR NRN ZONES AHEAD OF ANY WEAK UPPER LEVEL
DISTURBANCES THAT EJECT NORTHEAST AROUND BASE OF TROF. THEREFORE
LEFT SLIGHT CHANCE OF THUNDERSTORMS IN NRN WASHOE... NRN LASSEN AND
ERN MODOC COUNTIES TUESDAY AND WEDNESDAY AND LEFT REST OF CWA DRY.
EXPECT BREEZY AFTERNOONS AND EVENINGS DUE TO SOUTHWEST GRADIENT FLOW
PATTERN AND WEAK UPPER DISTURBANCES. MAX TEMPS WILL REMAIN UP TO 5
DEGREES BELOW NORMAL THRU THURSDAY... THEN BEGIN TO APPROACH CLIMO
BY FRIDAY AS HIGH BEGINS TO BUILD BACK WEST. BENINATO

.REV...FLASH FLOOD WATCH UNTIL 9 PM
       CAZ072-073-NVZ001-002-003.

       FLASH FLOOD WATCH UNTIL MIDNIGHT
       CAZ070-071-NVZ004-005.

CAZ070>073-NVZ001>005-031400-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE RENO NV
645 AM PDT FRI AUG 01 2003

THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN NEVADA...THE EASTERN
SIERRA AND NORTHEASTERN CALIFORNIA.

.DAY ONE...TODAY

MOIST AND UNSTABLE CONDITIONS OVER WESTERN NEVADA AND EASTERN
CALIFORNIA WILL PRODUCE SHOWERS AND THUNDERSTORMS THIS AFTERNOON AND
EVENING.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH SATURDAY

THE MOIST AND UNSTABLE CONDITIONS WILL CONTINUE THROUGH EARLY IN THE WEEK
WITH DRIER CONDITIONS RETURNING ACROSS THE REGION BY MIDWEEK.

.SPOTTER INFORMATION STATEMENT...

SKYWARN ACTIVATION MAY BE REQUIRED FOR THE FLASH FLOOD THREAT THIS
AFTERNOON.  WEATHER SPOTTERS ARE ASKED TO REPORT SIGNIFICANT WEATHER
CONDITIONS TO THEIR LOCAL NATIONAL WEATHER SERVICE OFFICE.