Severe Thunderstorm Warning 15, NWS Las Vegas, NV

MOJAVE DESERT/SOUTHERN GREAT BASIN AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LAS VEGAS NV
324 PM PDT WED JUL 30 2003

.SYNOPSIS...A MOIST AND UNSTABLE AIR MASS WILL REMAIN OVER THE
MOJAVE DESERT AND SOUTHERN GREAT BASIN THROUGH FRIDAY FOR A
CONTINUED THREAT OF AFTERNOON AND EVENING THUNDERSTORMS. THE BEST
CHANCES FOR SHOWERS AND THUNDERSTORMS WILL REMAIN OVER SOUTHERN
NEVADA AND NORTHWEST ARIZONA TONIGHT AND EXTEND INTO CENTRAL NEVADA
THURSDAY.

.DISCUSSION...CONVECTION WAS BECOMING ACTIVE THIS AFTERNOON ACROSS
MUCH OF THE AREA WITH SURFACE HEATING AND OROGRAPHICS THE MAIN
FORCING MECHANISMS. THIS MAY HELP THE ATMOSPHERE REALIZE MUCH OF ITS
POTENTIAL THIS AFTERNOON AND EVENING. SOME CELLS WERE REGENERATING
ON THE DOWNWIND SIDE OF TERRAIN AND THIS MAY LEAD TO MORE THAN JUST
ISOLATED FLASH FLOODING AS THE DAY GOES ON. CELLS OVER NYE AND
LINCOLN COUNTIES WERE DEVELOPING IN THE 850-700MB THETA E RIDGE WITH
THE HIGHEST VALUES IN SOUTHWEST UTAH WHERE FLASH FLOODING WAS
ALREADY IN PROGRESS BY EARLY AFTERNOON. JET DYNAMICS COULD BE AN
ADDITIONAL PLAYER TONIGHT OVER SOUTHERN NEVADA AND POINTS SOUTH AS A
SPEED MAX COMING OUT OF NORTHWEST MEXICO INTERSECTS THE JET ALREADY
IN PLACE OVER SOUTHERN CALIFORNIA. THE GFS SHOWS THIS FEATURE THE
BEST AND WATER VAPOR IMAGERY LENDS CONFIDENCE IN IT. THIS ALONG WITH
WHATEVER BOUNDARY INTERACTION COMES INTO PLAY COULD KEEP STORMS
GOING MUCH OF THE NIGHT OVER SOUTHERN NEVADA AND NORTHWEST ARIZONA.
WITH PRECIPITABLE WATER VALUES OVER 1.5 INCHES...PROLONGED HEAVY
RAIN IS POSSIBLE WITH STORMS AND WILL GO WITH A FLASH FLOOD WATCH
FOR SOUTHERN NEVADA/NORTHWEST ARIZONA AND POSSIBLE INYO COUNTY THIS
EVENING THROUGH TONIGHT.

IF THE GFS TURNS OUT RIGHT...A DISTURBANCE ROLLING UP INTO CENTRAL
NEVADA BY THURSDAY AFTERNOON WILL FAVOR CONVECTION OVER THE NORTHERN
HALF OF THE AREA THROUGH THURSDAY EVENING. SOUTHERLY FLOW IN PLACE
FRIDAY KEEPS LOW LEVEL MOISTURE OVER THE AREA WITH THE HIGHER
TERRAIN FAVORED FOR THUNDERSTORMS BUT POSSIBLY MOVING INTO THE LOWER
DESERTS. THE GFS CONTINUES TO INDICATE A SOUTHWEST COMPONENT
SATURDAY WHICH WOULD INCREASE SHEAR PROFILES WITH LOW LEVEL MOISTURE
STILL LIKELY IN PLACE. THUNDERSTORMS FORMING OVER THE HIGHER TERRAIN
WOULD BECOME WELL ORGANIZED AND NEED TO BE MINDFUL OF POSSIBLE
SEVERE ENVIRONMENT. SUNDAY THROUGH WEDNESDAY PERIOD APPEARS TO GIVE
WAY TO GRADUAL DRYING EACH DAY FOR DIMINISHING CHANCES OF
CONVECTION. NO SIGNIFICANT CHANGE WAS MADE.

.LAS...A FLASH FLOOD WATCH HAS BEEN ISSUED FOR NORTHWEST ARIZONA AND
THE SOUTHERN THIRD OF NEVADA UNTIL 4 AM PDT THURSDAY.

ADAIR

AZZ001>003-036-CAZ026>029-NVZ013>022-311400-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE LAS VEGAS NV
500 AM PDT WED JUL 30 2003

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHEAST CALIFORNIA/SOUTHERN
NEVADA/NORTHWEST ARIZONA

.DAY ONE...TODAY

A MOIST AND UNSTABLE AIRMASS WILL LEAD TO ISOLATED TO SCATTERED
SHOWERS AND THUNDERSTORMS TODAY. LOCALLY HEAVY RAIN IS POSSIBLE WITH
SOME STORMS.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH WEDNESDAY

MOISTURE WILL CONTINUE TO CIRCULATE AROUND THE MOJAVE DESERT
AND SOUTHERN GREAT BASIN THROUGH FRIDAY. ISOLATED TO SCATTERED
AFTERNOON AND NIGHTTIME THUNDERSTORMS WILL CONTINUE FOR PARTS OF THE
REGION. BEGINNING SATURDAY...MOISTURE WILL BECOME MORE LIMITED AND
THE CHANCES OF THUNDERSTORM ACTIVITY WILL DECREASE.

.SPOTTER INFORMATION STATEMENT...

SKYWARN ACTIVATION IS NOT ANTICIPATED BUT WEATHER SPOTTERS ARE
ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS ACCORDING TO
STANDARD OPERATING PROCEDURES.