Severe Thunderstorm Warning 4, NWS Reno, NV

000 
WWUS55 KREV 312313
SVSREV

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE RENO NV
412 PM PDT THU MAY 31 2007

CAC003-312330-
/O.CON.KREV.SV.W.0004.000000T0000Z-070531T2330Z/
ALPINE CA-
412 PM PDT THU MAY 31 2007

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 430 PM PDT
FOR EAST CENTRAL ALPINE COUNTY...

AT 406 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A SEVERE THUNDERSTORM CAPABLE OF PRODUCING NICKEL SIZE
HAIL...AND DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS 
LOCATED JUST SOUTHWEST OF MONITOR PASS...OR ABOUT 8 MILES SOUTHWEST 
OF TOPAZ LAKE. THIS STORM WAS MOVING AROUND 5 MPH TO THE SOUTH 
SOUTHEAST.

TRAVELERS ALONG STATE ROUTES 89 AND 4 IN ALPINE COUNTY ARE NEAR THIS 
STORM...AND MAY EXPERIENCE HAIL AND STRONG WIND GUSTS. SINCE THIS 
STORM IS MOVING SLOWLY...LOCALLY HEAVY RAINFALL IS POSSIBLE NEAR 
THIS STORM.

LAT...LON 3856 11979 3857 11960 3872 11960 3869 11976

$$
CS

000 
WWUS55 KREV 312328
SVSREV

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE RENO NV
427 PM PDT THU MAY 31 2007

CAC003-312337-
/O.EXP.KREV.SV.W.0004.000000T0000Z-070531T2330Z/
ALPINE CA-
427 PM PDT THU MAY 31 2007

...THE SEVERE THUNDERSTORM WARNING FOR EAST CENTRAL ALPINE COUNTY
EXPIRES AT 430 PM PDT...

THE THUNDERSTORM NEAR MONITOR PASS HAS WEAKENED CONSIDERABLY AND 
SEVERE WEATHER IS NO LONGER EXPECTED IN THE AREA. EXPECT LOCAL HEAVY 
RAIN TO CONTINUE NEAR MONITOR PASS THROUGH 5 PM

LAT...LON 3856 11979 3857 11960 3872 11960 3869 11976

$$

JHW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RENO NV
300 PM PDT THU MAY 31 2007

.SHORT TERM...
UPPER HIGH CENTER OVER NW NV WITH CONVECTION FIRING AROUND PERIPHERY
OF HIGH CIRCULATION FROM SRN MINERAL COUNTY NNW ALONG SIERRA CREST
THIS EVENING. HIGH CLOUD BASES AND VERY WARM TEMPS FAVORABLE FOR
DOWNBURST WINDS WITH VIRGA AND FAIRLY SMALL RAIN CORES. AIRMASS
FORECAST TO REMAIN UNSTABLE INTO SATURDAY WITH WEAK UPPER VORT OR
LOW MOVING TO CENTRAL CA CST BY FRIDAY AFTERNOON ADDING MORE
DYNAMICS AND FOCUSING TO MIX. THUS HAVE SCT TSTM COVERAGE OVR ENTIRE
CWA FRIDAY EXCEPT ISOLATED IN WEST CENTRAL. BY SATURDAY BETTER
FOCUSING EXPECTED IN WEST CENTRAL NEVADA AS SSW FLOW INCREASES OVER
AREA. BY SUNDAY MODELS INDICATING DRIER SWLY FLOW PUSHING CONVECTION
OFF SIERRA CREST ESPECIALLY N OF HIGHWAY 50 INTO LASSEN COUNTY.
HAVE KEPT SLIGHT CHC POPS IN FOR NRN SIERRA ZONES SUNDAY IN CASE
CONVECTION POPS EARLY BEFORE WLYS KICK IN. TEMPS REMAINING WELL
ABOVE NORMAL WITH HIGHS IN THE UPPER 80S TO MID 90S IN WRN NV
VALLEYS THROUGH SUNDAY WITH SOME LOCAL RELIEF FROM ANY AFTN
AND EVE CLOUDS AND THUNDERSHOWERS. CYLKE

.LONG TERM...MONDAY THROUGH THURSDAY...

OVERALL LOOKS LIKE A DRY BUT INCREASINGLY BREEZY PERIOD NEXT WEEK...
THOUGH THERE ARE SOME MEANINGFUL DIFFERENCES BETWEEN LATEST NCEP ENS
MEAN AND ECMWF.

NCEP ENS SHOWS RIDGE OVER THE INTERMOUNTAIN WEST BREAKING DOWN
AROUND TUESDAY IN RESPONSE TO APPROACHING TROF OVER NE PACIFIC...
THIS LEADS TO A MORE ZONAL FLOW OVER THE CWA DURING THE BALANCE OF
THE LONG TERM. HOWEVER ECMWF BRINGS THIS UPPER TROF IN FULL FORCE
OVER THE REGION TUESDAY. OVERALL HAVE COOLED TEMPS IN THE EXTENDED
PAST MONDAY...BASED ON LOWERING HEIGHTS ALOFT...BUT IF ECMWF
VERIFIES READINGS MAY NEED TO BE COOLED SLIGHTLY MORE. INTERESTING
TO NOTE THAT TELECONNECTIONS WITH NEGATIVE ANOMALIES OVER SIBERIA
SHOW COOLER THAN NORMAL TEMPS OVER GREAT BASIN... AGREEING MORE WITH
ECMWF SOLN.

AFTN CONVECTIVE CHANCES SEEM SLIM...WITH PRIMARY POSITIVE PW
ANOMALIES IN THE ENS MEAN EITHER WELL NE OF THE CWA OR OFF THE CA/OR
COASTLINES. SOME OF THAT MOISTURE FCST TO APPROACH THE CWA THURSDAY
WHICH MAY LEAD TO BETTER CHCS FOR TS...BUT NOT CONFIDENT ENOUGH TO
INCLUDE ATTM. WIND SPEEDS SHOULD INCREASE GIVEN APPROACH OF UPPER
TROF/TIGHTENING HEIGHT GRADIENT...HAVE INCREASED FCST WINDS IN
RESPONSE TO THIS. SOME SIERRA RIDGE TOPS COULD SEE GUSTS AOA 50KTS
SOMETIME DURING THE MON-THURS PERIOD.

CS

.FIRE WEATHER...
CONVECTION STARTING OVER THE SAME GENERAL AREAS TODAY AS YESTERDAY
HOWEVER A FEW HOURS EARLIER. THUNDERSTORM CHANCES CONTINUE TO
INCREASE FRIDAY AS MOISTURE AND INSTABILITY INCREASE. WITH DECENT
MOISTURE AMOUNTS AND SLOW CELL MOVEMENT...NOT EXPECTING WIDESPREAD
CRITICAL DRY LIGHTNING. CWRS ARE RELATIVELY HIGH AS ANY
THUNDERSTORMS ARE EXPECTED TO PRODUCE AT LEAST A TENTH OF AN INCH OF
PRECIP AT THE CORE. MAIN CONCERN WILL BE LIGHTNING OUTSIDE OF RAIN
CORES AND ALSO GUSTY OUTFLOW WINDS AS HIGH AS 50 MPH.

THERE DOES CONTINUE TO BE POTENTIAL PROBLEMS OVER THE WRN NEVADA
ZONES FRIDAY AND SATURDAY AS THUNDERSTORMS FORM FURTHER OFF THE
SIERRA CREST IN AREAS WITH CRITICALLY DRY FUELS. ONCE AGAIN...WILL
WAIT TO SEE WHAT KIND OF RAIN RATES OCCUR TODAY AND THEN DECIDE
WHETHER OR NOT TO BOOST LALS OVER THOSE AREAS. JORDAN

&&

.AVIATION...
VFR CONDITIONS WITH THE EXCEPTION OF ISOLATED TO SCATTERED
SLOW-MOVING THUNDERSTORMS THROUGH ABOUT 04Z. STORMS LIKELY TO FIRE
EARLIER WITH MORE COVERAGE GIVEN BETTER LIS AND PWS COMPARED TO
YESTERDAY...AND ARE CAPABLE OF PRODUCING SMALL HAIL...MODERATE
RAIN...AND DOWNBURST/OUTFLOW WINDS AOA 45KTS. HAVE INCLUDED VCTS AT
TRK/TVL/RNO AND WILL HANDLE ANY SPECIFIC STORMS WITH TEMPOS...THOUGH
BEST CHCS ARE AT TVL/TRK.

COULD SEE SOME VSBY RESTRICTIONS BETWEEN 11-13Z/FRI AT TRK BASED ON
PERSISTENCE AND DECENT LOW LVL MOISTURE.

CS

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

HTTP://WEATHER.GOV/RENO