607
FXUS65 KVEF 201142
AFDVEF
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LAS VEGAS NV
442 AM PDT TUE OCT 20 2026
KEY MESSAGES
* AN INCOMING TROUGH BRINGS WIDESPREAD RAIN AND MOUNTAIN SNOW
CHANCES, GUSTY WINDS, AND COOLING TEMPERATURES THIS WEEK.
* INCREASING CONFIDENCE FOR A DRY CONDITIONS AND SEASONABLE
TEMPERATURES THIS WEEKEND.
DISCUSSION
THROUGH MONDAY.
OUR NEXT SYSTEM BEGINS TO ENCROACH ON THE REGION TODAY IN THE FORM
OF A CLOSED LOW SPINNING OFF THE CA COAST. OVER THE REMAINDER OF
THE WORK WEEK, IT WILL SLOWLY MOVE THROUGH THE FORECAST AREA,
EVENTUALLY TRANSITIONING TO AN OPEN WAVE AS IT PHASES WITH A PACNW
SHORTWAVE. NORTHWARD MOISTURE ADVECTION AND UPPER-LEVEL
DIVERGENCE IN THE LEFT EXIT REGION OF A JET STREAK WILL SPUR
ISOLATED TO SCATTERED SHOWERS AND STORM TODAY. BEST CHANCES
(25-50%) ARE GENERALLY NORTHWEST OF I- 15 AND IN MOHAVE COUNTY.
THE SLOW-MOVING NATURE OF THE SYSTEM RESULTS IN A SIMILAR SETUP ON
WEDNESDAY. PRECIPITATION CHANCES ARE HIGHER ACROSS THE BOARD
(+25%) ON WEDNESDAY DUE TO ADDITIONAL MOISTURE AND COLDER AIR
ALOFT, BUT THE SAME PLACES WILL BE FAVORED. FINALLY, THE MAIN VORT
MAX ASSOCIATED WITH THE LOW SWINGS THROUGH ON THURSDAY, BRINGING
THE BEST POTENTIAL FOR WIDESPREAD PRECIPITATION (60-90% IN MOST
LOCATIONS). HOWEVER, THE PHASING WITH THE PACNW SHORTWAVE SENDS A
SECONDARY VORT MAX DOWN THE BACKSIDE AND KEEPS THE TROUGH OVERHEAD
THROUGH THE END OF THE WORK WEEK. AS A RESULT, ISOLATED TO
SCATTERED SHOWER CHANCES LINGER ON FRIDAY.
OVERALL, BEST ODDS OF PRECIPITATION IMPACTS ARE IN THE SOUTHERN
GREAT BASIN, INYO COUNTY, AND NORTHERN MOHAVE COUNTY WHERE CHANCES
OF 1"+ RANGE FROM 25-50%. THUNDERSTORM DEVELOPMENT WILL AID THIS
POTENTIAL, BUT TRAINING CONVECTION IS GOING TO BE REQUIRED GIVEN
THE FLOW ALOFT. THE BIGGEST "BUST" POTENTIAL IS IN THE SOUTHERN
MOJAVE DESERT (THINK OF THE AREA BOUNDED BETWEEN TWENTYNINE PALMS,
BARSTOW, LAS VEGAS, KINGMAN, AND LAKE HAVASU), WHERE MODELS HAVE
THIS ZONE KIND OF CAUGHT IN A DRY SLOT BETWEEN THE TWO MAIN
PRECIPITATION REGIMES. THIS AREA HAS A 40-70% CHANCE OF 0.10" OR
LESS. THERE IS A MINOR WINTRY COMPONENT OF THIS SYSTEM AS SNOW
LEVELS BOTTOM OUT AROUND 8KFT IN THE SIERRA. HOWEVER, AS THEY DO,
PRECIPITATION WILL LARGELY BE DONE, SO ANY IMPACTS ARE EXPECTED TO
BE CONFINED TO ELEVATIONS ABOVE 9KFT WHERE FORECAST SNOW TOTALS
RANGE FROM 3-10" (THE HIGHER AMOUNTS NEAR THE CREST). LASTLY,
GUSTY SOUTH-SOUTHWEST WINDS (20-40 MPH) WILL ACCOMPANY THIS SYSTEM
AS WELL, BUT ANY IMPACTS SHOULD BE CONFINED TO THE LOCAL LAKES.
BY SATURDAY, ENSEMBLE GUIDANCE HAS OUR AREA FIRMLY ON THE BACKSIDE
OF THE TROUGH. WE WILL SEE A DRY NORTHERLY FLOW THAT QUICKLY
SCOURS OUT MOISTURE AND PRECIPITATION CHANCES, AND PRODUCES SOME
GUSTY NORTH WINDS. ON SUNDAY AND MONDAY, THE FLOW WEAKENS AND
BECOMES MORE ZONAL/SOUTHWESTERLY, KEEPING US DRY WITH LIGHT WINDS
AND SLIGHTLY BELOW-NORMAL TEMPERATURES.
AVIATION...FOR HARRY REID...FOR THE 12Z FORECAST PACKAGE
WINDS
WILL CONTINUE FOLLOWING TYPICAL DAILY DIRECTIONAL PATTERNS WITH
SOME VARIABILITY, REMAINING LIGHT EXCEPT DURING THIS AFTERNOON
WHEN SOUTHEASTERLY WINDS INCREASE TO AROUND 8KT. FEW-SCT CLOUDS
AROUND 10KFT ARE EXPECTED THROUGH THE PERIOD, WITH ISOLATED
AFTERNOON AND EARLY EVENING CONVECTION OVER THE HIGHER TERRAIN
THAT IS NOT EXPECTED TO IMPACT THE TERMINAL. VFR CONDITIONS WILL
CONTINUE.
FOR THE REST OF SOUTHERN NEVADA, NORTHWEST ARIZONA AND SOUTHEAST
CALIFORNIA...FOR THE 12Z FORECAST PACKAGE...ACROSS THE REGION,
WINDS WILL CONTINUE FOLLOWING TYPICAL DAILY DIRECTIONAL PATTERNS,
WITH SPEEDS AROUND 5-10KT. ONE EXCEPTION TO THIS IS ACROSS THE
WESTERN MOJAVE DESERT/KDAG WHERE EASTERLY WINDS THIS AFTERNOON ARE
EXPECTED TO INCREASE TO 12-15KT WITH GUSTS TO 20-25KT THROUGH
SUNSET. ADDITIONALLY, KBIH IN THE NORTHERN OWENS VALLEY WILL
EXPERIENCE GUSTY UP-VALLEY SOUTHEASTERLY WINDS LATE MORNING INTO
TONIGHT, WITH GUSTS PEAKING AT AROUND 25-30KT THIS AFTERNOON
THROUGH LATE EVENING. ISOLATED TO SCATTERED THUNDERSTORMS ARE
EXPECTED ACROSS THE REGION THIS AFTERNOON AND EVENING, ESPECIALLY
OVER HIGHER TERRAIN. HAVE INCLUDED VCTS MENTION FOR KBIH THIS
EVENING FOR THUNDERSTORMS EXPECTED TO DEVELOP OVER SURROUNDING
MOUNTAINS, HOWEVER, CONFIDENCE IS TOO LOW AT THIS TIME TO INCLUDE
TS ELSEWHERE. VFR CONDITIONS PREVAIL OUTSIDE OF THUNDERSTORM
ACTIVITY WITH CEILINGS EXPECTED TO REMAIN AT OR ABOVE 10KFT.
SPOTTER INFORMATION STATEMENT
SPOTTERS ARE ENCOURAGED TO REPORT
ANY SIGNIFICANT WEATHER OR IMPACTS ACCORDING TO STANDARD OPERATING
PROCEDURES.
DISCUSSION...WOODS
AVIATION...PHILLIPSON
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