Severe Thunderstorm Warning 33, NWS Las Vegas, NV

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LAS VEGAS NV
1010 AM PDT SAT SEP 18 2004

.SYNOPSIS...MOISTURE ASSOCIATED WITH HURRICANE JAVIER WILL COME UP
FROM THE SOUTH THIS WEEKEND BRINGING A CHANCE OF SHOWERS AND
THUNDERSTORMS MAINLY TO NORTHWEST ARIZONA. MEANWHILE A STRONG LOW
PRESSURE SYSTEM WILL MOVE OVER THE AREA FROM THE PACIFIC NORTHWEST.
THIS WILL RESULT IN BREEZY TO WINDY CONDITIONS WITH TEMPERATURES
COOLING AT LEAST 5 DEGREES EACH DAY.
&&

.UPDATE...12Z ETA AND GFS RUNS ALONG WITH CURRENT OBSERVATIONS
INDICATE ANY SHOWERS AND THUNDERSTORMS ASSOCIATED WITH NORTHWARD
SURGE OF MOISTURE FROM HURRICANE JAVIER TODAY REMAINING CONFINED TO
THE FAR SOUTHEAST PORTION OF THE FORECAST AREA. INDICATIONS ARE THAT
SOME MOISTURE IS/WILL SPILL OVER THE SIERRA CREST TO THE EAST SLOPES
IN FAR NORTHWEST INYO COUNTY TODAY. UPDATED FORECAST TO ADD A SLIGHT
CHANCE OF SHOWERS TO THE SIERRA NORTH OF INDEPENDENCE OR LONE PINE
AND TO REMOVE THE CHANCE OF THUNDERSTORMS FOR CLARK AND LINCOLN
COUNTIES...INCLUDING THE LAS VEGAS VALLEY.

.PREVIOUS DISCUSSION...240 AM PDT SAT SEP 18...SHORT TERM...MOISTURE
CURRENTLY SEEMS A LITTLE HARD TO COME BY. WOULD LIKE TO SEE A FEW
MORE SIGNS OF A SURGE THAN CURRENTLY IN PLACE. KYUX VWP WAS
SOUTHERLY AROUND 20 KTS THROUGH 4K FEET BUT IS NOW ONLY 2K FT DEEP.
HOWEVER LOWER 70 DEWPOINTS EXIST AT YUMA SO MOISTURE IS NEAR AND
WOULD EXPECT IT TO GET PUMPED UP RATHER QUICKLY INTO MOHAVE COUNTY
ONCE THE WINDS PICK UP. BECAUSE THE MOISTURE IS SLOW IN COMING I
LOWERED THE MORNING POPS IN THE GRIDS AND LEFT THE AFTERNOON ALONE.
THINK THAT FLASH FLOOD THREAT IS LOW SINCE STORM MOTION WILL BE
FAIRLY BRISK. ORGANIZED STORMS ARE UNLIKELY AS WELL AS 0-6 KM SHEAR
VALUES ARE ONLY IN THE 5-10 KT RANGE. SO ANY SEVERE THREAT WOULD
LIKELY BE RESTRICTED TO COLLAPSING PULSE STORMS.

FEEL THAT WITH TEMPS A LITTLE COOLER TODAY THAT RED FLAG CONDITIONS
ARE NOT A CONCERN IN THE NORTH TODAY AS WE DIDNT QUITE REACH IT
YESTERDAY EITHER. WINDS WILL PICK UP TODAY AHEAD OF THE COLD FRONT
BUT SHOULD REMAIN JUST BELOW ADVISORY CRITERIA. SUNDAY MAY SEE
STRONG ENOUGH WINDS TO NECESSITATE AN ADVISORY...BUT WILL LET THE
NEXT SHIFTS LOOK INTO IT SINCE IT IS STILL A WAYS OUT.
&&

.LONG TERM...MEDIUM RANGE MODELS NOW ALL STRONGER WITH UPPER HIGH
OVER THE EASTERN U.S. WHICH IN TURN SLOWS MOVEMENT OF UPPER TROUGH
EAST ACROSS UTAH AND THE ROCKIES NEXT TUESDAY AND WEDNESDAY. DRY
WITH WELL BELOW NORMAL TEMPERATURES TUESDAY AND WEDNESDAY AS AREA
REMAINS UNDER COOL CYCLONIC FLOW. WARMING TREND IN STORE THROUGH THE
END OF THE WEEK AS MID LEVEL RIDGE BUILDS OVER THE WESTERN U.S.
&&

.AVIATION...TAF ADEQUATELY COVERS ALL SIGNIFICANT WEATHER EXPECTED
AT KLAS.
&&

.VEF WATCHES/WARNINGS/ADVISORIES...
.NV...NONE.
.AZ...NONE.
.CA...NONE.
&&

HARRISON