Severe Thunderstorm Warning 10, NWS Reno, NV

000 
WWUS55 KREV 272341
SVSREV

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE RENO NV
441 PM PDT WED MAY 27 2009

CAC035-272347-
/O.EXP.KREV.SV.W.0010.000000T0000Z-090527T2345Z/
LASSEN CA-
441 PM PDT WED MAY 27 2009

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN LASSEN COUNTY
WILL EXPIRE AT 445 PM PDT...

THE STORM THAT EARLIER PROMPTED THE SEVERE THUNDERSTORM WARNING HAS
WEAKENED...THEREFORE THE WARNING WILL BE ALLOWED TO EXPIRE. 
HOWEVER...DEADLY LIGHTNING AND BRIEF HEAVY RAIN IS STILL POSSIBLE 
NEAR HIGHWAY 299 WEST OF BIEBER UNTIL 5 PM.

IF YOU OBSERVED ANY WIND DAMAGE...LARGE HAIL...OR FLOODING FROM THE
STORM EARLIER...REPORT IT TO THE NATIONAL WEATHER SERVICE IN RENO.
CALL OUR OFFICE AT 775-673-8100. YOUR REPORTS HELP US IMPROVE OUR
WARNING PROCESS.

LAT...LON 4118 12132 4119 12129 4118 12121 4098 12120
      4091 12133 4092 12133 4094 12132 4108 12133
TIME...MOT...LOC 2337Z 225DEG 11KT 4106 12127

$$

SNYDER

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RENO NV
218 PM PDT WED MAY 27 2009

.SHORT TERM...
ISOLATED TO SCATTERED THUNDERSTORMS DEVELOPING JUST WEST OF THE
SIERRA CREST AS EXPECTED THIS AFTERNOON. HIGH CENTER HAS MOVED
INTO W CNTRL NV THIS AFTERNOON WITH UPPER FLOW FROM THE EAST OVER
MONO COUNTY...LIGHT OVER RENO-TAHOE WITH SW FLOW IN LASSEN TO NW
NV. WITH SFC GRADIENT STILL FROM THE EAST...THIS WOULD FAVOR MOST
CONVECTION STAYING NEAR THE CREST THIS EVENING. HOWEVER...WITH THE
CONVECTION ALONG THE CREST A BIT MORE WIDESPREAD...COULD SEE SOME
OUTFLOWS GENERATING SOME CONVECTION A BIT FURTHER EAST. RIGHT
NOW...THERE IS ENOUGH OF A CHANCE OF THIS OCCURRING TO KEEP AT
LEAST A MENTION OF ISOLD STORMS NEAR AND WEST OF A GERLACH-
FERNLEY-HAWTHORNE LINE. BEST CHANCES LOOK TO BE NORTH OF
SUSANVILLE WHERE UPPER LEVEL FLOW IS MOST FAVORABLE AS STORMS WILL
MOVE TO THE NORTHEAST. EXPECT STORMS TO DIE THIS EVENING SHORTLY
AFTER SUNSET.

TOMORROW...WITH HIGH CENTER IN ERN NV...UPPER FLOW BECOMES MORE SE
ACROSS THE AREA. NOT A SIGNIFICANT INCREASE IN MOISTURE...BUT
UPPER FLOW WILL SUPPORT THERMAL TROUGH MIGRATING TO THE CREST OR
EVEN INTO EXTREME WRN NV. THIS WILL BE MORE FAVORABLE FOR
THUNDERSTORM FORMATION EAST OF THE CREST. ALSO EXPECT SOME STORMS
IN CNTRL NV THAT COULD MOVE NWWD INTO THE FALLON-LOVELOCK AREAS.
BEST COVERAGE NEAR AND WEST OF HWY 395 WITH GNLY ISOLD STORMS
ELSEWHERE. AGAIN...WITH NO MESO OR SYNOPTIC SCALE FORCING...EXPECT
STORMS TO DIE SHORTLY AFTER SUNSET.

FRI APPEARS TO BE BEST DAY RIGHT NOW AS BOTH NAM/GFS SHOW A WK
WAVE AT TROP LEVEL MOVING INTO TAHOE-RENO-FALLON AREAS BY 00Z.
THIS WL LIKELY INCREASE FORCING AND WITH SLIGHTLY MORE MSTR
FORECAST BY MODELS...EXPECT SCT STORMS JUST ABOUT EVERYWHERE.
STORMS MAY CONTNIUE OVERNIGHT NORTH OF I-80 IF WAVE IS STG ENOUGH.
BY SAT...REALLY UNCERTAIN AND DEPENDS ON HOW MUCH CONVECTION
OCCURS FRI. RIGHT NOW WILL CONTINUE SCT COVERAGE OF STORMS...BUT
IT MAY BE MORE ISOLATED WITH SCT SHOWERS IF ATMO IS TOO WORKED
OVER OR THERE REMAINS A TON OF DEBRIS CLOUDS.

MAIN THREAT FROM THE CONVECTION WILL LIKELY BE LCLLY HVY RAIN
WITH SLOW MOVING STORMS. DEPENDING ON STRNGTH OF STORMS A LCL SVR
WIND GUST OR MARGINAL HAIL THREAT NOT OUT OF THE QUESTION...MOST
LIKELY ON FRI. WALLMANN

.LONG TERM...SUNDAY THROUGH WEDNESDAY...
COOLED HIGHS TUESDAY AND WEDNESDAY...OTHERWISE LITTLE TO NO CHANGE
TO THE EXTENDED PACKAGE. WESTERN RIDGE TO BREAK DOWN NEXT WEEK FOR
MUCH COOLER TEMPS AND THE CHANCE FOR PRECIPITATION.

THE GFS AND ECMWF HAVE GENERAL AGREEMENT ON ONE THING...AN UPPER
TROUGH/LOW WILL IMPINGE ON THE REGION AROUND TUESDAY-WEDNESDAY.
THEREFORE...I EASED DOWN HIGHS TO AROUND AVERAGE TUESDAY AND
WEDNESDAY. DEPENDING ON THE STRENGTH OF THE LOW AND CLOUD COVER...
TEMPS COULD EVEN FALL BELOW AVERAGE. POP-WISE...THERE IS LITTLE
DETAIL THAT CAN BE GLEANED AT THIS POINT AS FAR AS CONVECTIVE
LOCATIONS GIVEN THE SMALLER-SCALE NATURE OF CONVECTION AND ITS
INITIATION. HOWEVER...IN A GENERAL SENSE...BEFORE THE UPPER LOW
COMES IN THERE WILL BE DIURNAL CONVECTION AND THEN A COMBINATION OF
CONVECTION AND LARGER-SCALE PRECIPITATION WITH THE LOW. THEREFORE...
A BROAD CHANCE OF SHOWERS AND THUNDERSTORMS WAS THE BEST WAY TO
HANDLE THE WEATHER WORDING FOR NOW. SNYDER
&&

.AVIATION...
THUNDERSTORMS WEST OF THE SIERRA CREST ARE EXPECTED TO RE-DEVELOP
FURTHER EAST ON MID TO LATE AFTERNOON SW-W WINDS. THIS WILL BRING THE
HIGHEST THREAT FOR THUNDERSTORM EFFECTS (MAINLY GUSTY OUTFLOW WINDS
TO 35 KTS BUT A DIRECT HIT WOULD MEAN +TSRA AND BRIEFLY LOWER VSBYS)
TO KTVL AND KTRK THROUGH 04Z. ANY THUNDERSTORMS SHOULD DIE OUT BY
04Z.

FOR THURSDAY AFTERNOON AND EVENING...THE THREAT FOR THUNDERSTORMS
WILL SPREAD A BIT EAST OF THE SIERRA FOR A BIT BETTER CHANCE AT KRNO
(5% TODAY AND 10-15% THURSDAY). GUSTY OUTFLOW WINDS TO 45 KTS PSBL
AT KRNO WITH ANY STORMS IN THE VCNTY ON THURSDAY. SNYDER

&&

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

HTTP://WEATHER.GOV/RENO

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE RENO NV
714 AM PDT WED MAY 27 2009

CAZ070>073-NVZ001>005-280215-
SURPRISE VALLEY CALIFORNIA-LASSEN-EASTERN PLUMAS-
EASTERN SIERRA COUNTIES-GREATER LAKE TAHOE AREA-MONO-
MINERAL AND SOUTHERN LYON COUNTIES-GREATER RENO-CARSON CITY-
MINDEN AREA-WESTERN NEVADA BASIN AND RANGE INCLUDING PYRAMID LAKE-
NORTHERN WASHOE COUNTY-
714 AM PDT WED MAY 27 2009

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

.DAY ONE...TODAY AND TONIGHT

HIGH PRESSURE WILL BEGIN TO MOVE EAST AND ALLOW SCATTERED
SHOWERS AND THUNDERSTORMS TO INCREASE ALONG THE SIERRA THIS
AFTERNOON AND EVENING. A FEW STORMS WILL BE CAPABLE OF GUSTY WINDS
TO 45 MPH AND SMALL HAIL.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

MOISTURE AND INSTABILITY WILL CONTINUE TO INCREASE ALONG THE
SIERRA AND SPREAD TO NORTHEAST CALIFORNIA AND MUCH OF WESTERN
NEVADA. AS A LOW PRESSURE SYSTEM DEVELOPS OFF THE WEST COAST...
THUNDERSTORMS WILL BECOME BETTER ORGANIZED. STORMS ARE EXPECTED TO
BE STRONG AND CAPABLE OF PRODUCING LOCALLY HEAVY RAIN...HAIL AND
STRONG WIND GUSTS. THE ACTIVE PATTERN WILL LIKELY PERSIST INTO
EARLY NEXT WEEK.

.SPOTTER INFORMATION STATEMENT...
SPOTTERS SHOULD BE PREPARED FOR LIMITED ACTIVATION BEGINNING
THURSDAY AFTERNOON. SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT
WEATHER TO THE NATIONAL WEATHER SERVICE OFFICE.

HTTP://WEATHER.GOV/RENO