Area Forecast Discussion
Issued by NWS Las Vegas, NV

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000
FXUS65 KVEF 070557
AFDVEF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LAS VEGAS NV
1057 PM PDT MON JUL 6 2015

.SYNOPSIS...LINGERING MOISTURE COMBINED WITH DAYTIME HEATING WILL
TRIGGER SHOWERS AND THUNDERSTORMS ACROSS THE AREA THIS EVENING AND
AGAIN TUESDAY. AN AREA OF LOW PRESSURE OFF THE CALIFORNIA COAST WILL
GRADUALLY MOVE INLAND WEDNESDAY THROUGH FRIDAY. THIS WILL BRING
DRIER CONDITIONS TO THE AREA ALTHOUGH IT MAY SPARK A FEW SHOWERS
ACROSS THE SIERRA AND MOUNTAINS OF SOUTHERN NEVADA ON THURSDAY AS
THE SYSTEM MOVES THROUGH.  MUCH COOLER CONDITIONS ARE EXPECTED WITH
TEMPERATURES AVERAGING SEVERAL DEGREES BELOW NORMAL THROUGH THE
WEEKEND.
&&

.UPDATE...FIRST OFF, A FYI, OUR RADAR WILL BE DOWN THROUGH AT LEAST
TOMORROW MORNING DUE TO A WEATHER-RELATED COMMUNICATIONS ISSUE.
PLEASE USE THE ADJACENT WSR-88D RADARS AS WELL AS THE TERMINAL
DOPPLER RADAR (TLAS) FROM MCCARRAN AIRPORT FOR ANY RADAR MONITORING.

RADAR SHOWS A FEW SHOWERS AND THUNDERSTORMS DRIFTING EAST TOWARD THE
SOUTH END OF THE LAS VEGAS VALLEY AND THESE MAY CROSS BETWEEN NOW
AND 1 AM. GRIDS WERE UPDATED TO INCREASE POPS FOR THIS. THE
ENVIRONMENT SHOULD BE RELATIVELY WORKED OVER FROM THE EARLIER
CONVECTION THAT ROLLED THROUGH AND THUS SHOULD ACTIVITY SHOULD NOT
BE ABLE TO CRANK UP IN INTENSITY TOO MUCH.

WE ARE ALREADY PASSED OUR LOW TEMP FOR TONIGHT AND THUS I ALSO
TWEAKED LOW TEMPS DOWN FOR LAS VEGAS. DEWPOINTS WERE ALSO ADJUSTED
UP IN MANY AREAS OVERNIGHT.

ANOTHER ACTIVE DAY IS EXPECTED AGAIN FOR THE AREAS THAT REMAIN ALONG
AND EAST OF THE MOIST-DRY INTERFACE. I WILL BE ANALYZING POPS AGAIN
FOR THE MORNING PACKAGE.
&&

.AVIATION...FOR MCCARRAN...A FEW SHRA MAY DRIFT ACROSS THE SOUTH END
OF THE VALLEY THROUGH 08Z AND BRING GUSTY WINDS AND LOWER CIGS TO
AREAS IN AND AROUND THE AIRPORT COMPLEX. OTHERWISE EXPECT WINDS TO
FAVOR TYPICAL DIURNAL DIRECTIONAL TRENDS THE REST OF THE NIGHT AT 10
KTS OR LESS INTO TUESDAY MORNING. MAINLY SCT-BKN CLOUDS AOA 12K-18K
FEET. CLOUDS SHOULD TRANSITION TO THE FEW-SCT RANGE BY DAYBREAK
TUESDAY. ONCE AGAIN ON TUESDAY SHRA/TSRA ARE EXPECTED TO DEVELOP IN
AND AROUND THE LAS VEGAS VALLEY AND IN THE APPROACH CORRIDORS MAINLY
AFTER 20Z. THIS ACTIVITY SHOULD DECREASE BETWEEN 03Z AND 05Z
WEDNESDAY. STORM MOVEMENT WILL BE NORTHEAST TO EAST AND THUS
ACTIVITY MAY MAKE IT INTO THE VALLEY ONCE AGAIN AND POTENTIALLY
IMPACT THE AIRPORT COMPLEX ITSELF.

FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...SHRA/TSRA IN AND AROUND THE AREA SHOULD DECREASE
OVERNIGHT BUT STILL CAUSE GUSTY AND ERRATIC WINDS IN AND NEAR IT.
OTHERWISE LOOM FOR TYPICAL DIURNAL WINDS OVERNIGHT AT 10 KTS OR
LESS. SHRA/TSRA SHOULD DEVELOP BETWEEN 18Z AND 21Z TUESDAY AND
DIMINISH BETWEEN 03Z AND 07Z WEDNESDAY WITH THE GREATEST ACTIVITY
NORTH OF A LINE FROM KIYK-KLAS-KIGM. ONCE AGAIN GUSTY AND ERRATIC
WINDS AND CIGS AND VSBY REDUCED TO MVFR OR LOWER ARE POSSIBLE IN AND
NEAR SHRA/TSRA ACTIVITY. OTHERWISE EXPECT WINDS FAVORING TYPICAL
DIURNAL DIRECTIONAL TRENDS. GUSTS OF 20-25 KTS IN THE AFTERNOON AND
EVENING IN THE OWENS VALLEY AND IN AND NEAR KDAG.
&&

.PREVIOUS DISCUSSION...
ISSUED AT 636 PM PDT MON JUL 6 2015

.UPDATE...MASSIVE THUNDERSTORM FIRED UP IN THE NORTHWEST PART OF LAS
VEGAS WITH ANTHER STORM ALSO FIRING NEAR THE LAKES NEIGHBORHOOD.
THIS ACTIVITY WAS ALL MOVING SOUTHEAST AND SHOULD SWEEP ACROSS THE
REST OF THE VALLEY AND SOUTHERN CLARK COUNTY. AS A RESULT, POPS WERE
INCREASED FOR CENTRAL AND SOUTHERN CLARK COUNTY FOR THE REST OF THIS
EVENING. PLEASE FOLLOW OUR FACEBOOK AND TWITTER FEEDS FOR DETAILED
UPDATES.
&&

.PREVIOUS DISCUSSION...
ISSUED AT 200 PM PDT MON JUL 6 2015

.SHORT TERM...THROUGH WEDNESDAY NIGHT.

DRIER AIR WILL BEGIN TO PUSH EAST ACROSS THE REGION TOMORROW THANKS
TO AN APPROACHING PACIFIC LOW PRESSURE SYSTEM. HOWEVER...LOW LEVEL
MOISTURE WILL BE SLOW TO PUSH EAST SO SCATTERED SHOWERS AND STORMS
WILL AGAIN BE POSSIBLE MAINLY ACROSS NORTHWEST ARIZONA...SOUTHERN
NEVADA...AND EXTREME EASTERN CALIFORNIA. DRIER CONDITIONS ARE
EXPECTED ACROSS THE WESTERN MOJAVE DESERT WHERE CONDITIONS WILL BE
MORE STABLE AND PRECIPITABLE WATER VALUES DROP FROM DAYS PRIOR...BUT
SOME ISOLATED ACTIVITY MAY STILL DEVELOP IN THE INYO COUNTY
MOUNTAINS.

BY WEDNESDAY...DRIER AND MORE STABLE AIR WILL INVADE THE ENTIRE
FORECAST AREA WITH MUCH CALMER CONDITIONS EXPECTED. SOME ISOLATED
CONVECTION WILL BE POSSIBLE ACROSS THE SIERRA AND NORTHERN INYO
COUNTY WHICH WILL BE IN CLOSER PROXIMITY TO THE APPROACHING
LOW...BUT ELSEWHERE DRY CONDITIONS WILL PREVAIL.

.LONG TERM...THURSDAY THROUGH MONDAY.

RATHER STRONG PACIFIC TROUGH WILL PUSH INTO THE REGION ON THURSDAY
AND TAKE ON A SLIGHT NEGATIVE TILT AS IT DOES SO. MODELS HAVE
TRENDED STRONGER AND FURTHER SOUTH WITH THIS SYSTEM THE PAST COUPLE
OF DAYS WHICH WILL MEAN COOLER TEMPERATURES...BREEZY
CONDITIONS...AND SOMEWHAT BETTER CHANCES FOR SHOWERS ACROSS OUR INYO
AND SOUTHERN NEVADA ZONES. TEMPERATURES THURSDAY WILL AVERAGE TEN
DEGREES OR MORE BELOW NORMAL WITH SHOWERS AND ISOLATED THUNDERSTORMS
POSSIBLE MAINLY ACROSS THE MOUNTAINS OF INYO COUNTY AND THE SOUTHERN
GREAT BASIN...BUT A FEW SHOWERS MAY ALSO DEVELOP ACROSS THE SPRING
AND SHEEP RANGE IN FAR SOUTHERN NEVADA. I HAVE INCREASED POPS INTO
THE SLIGHT CHANCE CATEGORY FOR THE ABOVE MENTIONED AREAS...AND
FUTURE SHIFTS CAN TWEAK THEM AS NECESSARY.

THE TROUGH WILL LIFT NORTHEAST BY FRIDAY WITH HIGH PRESSURE SLOWLY
REBUILDING ACROSS THE FOUR CORNERS OVER THE WEEKEND. THIS WILL ALLOW
TEMPERATURES TO CLIMB UPWARDS AGAIN AND MONSOON MOISTURE TO BEGIN
SEEPING BACK INTO ARIZONA. TEMPERATURES WILL REMAIN A FEW DEGREES
BELOW NORMAL THROUGH THE WEEKEND BUT RETURN TO NEAR NORMAL BY
MONDAY.

&&

.SPOTTER INFORMATION STATEMENT...SPOTTERS ARE ENCOURAGED TO REPORT
ANY SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING
PROCEDURES.
&&

$$

UPDATE/AVIATION...STACHELSKI
DISCUSSION...OUTLER

FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:

HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER



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