730
FXUS65 KVEF 180512
AFDVEF
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LAS VEGAS NV
1012 PM PDT WED SEP 17 2025
KEY MESSAGES
* INCREASING TROPICAL MOISTURE WILL MOVE INTO THE REGION THURSDAY
AND FRIDAY, BRINGING CHANCES FOR SHOWERS AND THUNDERSTORMS.
LOCALLY HEAVY RAIN AND HIGH RAINFALL RATES WILL LEAD TO AN
INCREASED RISK OF FLASH FLOODING.
DISCUSSION
THROUGH TUESDAY.
CURRENT SATELLITE IMAGERY SHOWS A BATCH OF TROPICAL MOISTURE MOVING
TOWARDS THE SOUTHERN CALIFORNIA COAST. THUNDERSTORMS ARE ONGOING IN
NORTHERN BAJA AND THE SAN GABRIEL MOUNTAINS IN CALIFORNIA. THIS
MOISTURE IS EXPECTED TO BE PUSHED INLAND BY AN EASTWARD MOVING
TROUGH OVER THE NEXT TWO DAYS, SENDING PWATS TO OVER 200 PERCENT OF
NORMAL FOR THIS TIME OF YEAR. MID AND HIGH CLOUD COVER WILL HINDER
WIDESPREAD CONVECTION ACROSS MUCH OF SOUTHERN NEVADA AND
NORTHWESTERN ARIZONA TOMORROW. HOWEVER, ENOUGH CLEARING BEHIND THE
CLOUD COVER COMBINED WITH AMPLE MOISTURE WILL CREATE A FAVORABLE
ENVIRONMENT FOR CONVECTION IN THE DESERTS OF SOUTHEASTERN
CALIFORNIA. STORM DEVELOPMENT BEGINS IN THE MORNING AFTER SUNRISE
AND WILL LAST THROUGHOUT THE DAY AND OVERNIGHT. MID AND UPPER
LEVEL SUPPORT AND SOME TRAINING POTENTIAL MEANS THAT RAIN RATES OF
1 TO 2 INCHES PER HOUR ARE POSSIBLE. THEREFORE, ISSUED A FLOOD
WATCH FOR SAN BERNARDINO COUNTY FROM 8 AM PDT THURSDAY TO 2 AM PDT
ON FRIDAY. FRIDAY SHOULD BE LESS ROBUST AS THE BEST FORCING EXITS
THE AREA, BUT LINGERING MOISTURE AND INSTABILITY WILL LEAVE AN
ACTIVE MONSOONAL ENVIRONMENT. THE AREA SHOULD GRADUALLY DRY OUT
OVER THE WEEKEND AND EARLY NEXT WEEK. TEMPERATURES WILL INCREASE
NEXT WEEK AND REACH ABOVE AVERAGE VALUES BY TUESDAY.
AVIATION...FOR HARRY REID...FOR THE 06Z FORECAST PACKAGE
LIGHT
SOUTHWESTERLY WINDS WILL BECOME LIGHT AND VARIABLE OVERNIGHT,
BEFORE PICKING UP AND SWINGING AROUND TO THE SOUTHWEST AS SHOWERS
AND THUNDERSTORMS BEGIN TO APPROACH THE VALLEY LATE TOMORROW
MORNING. VICINITY CONVECTION IS EXPECTED THROUGHOUT THE AFTERNOON
AND INTO THE EVENING HOURS. DURING THIS TIME VARIABLE GUSTY
OUTFLOW WINDS, LIGHTNING, RAIN, AND LOWERING CIGS WILL BE POSSIBLE
AT THE TERMINAL. STORMS WILL CLEAR OUT AND CONDITIONS WILL
IMPROVE DURING THE EVENING AND OVERNIGHT HOURS.
FOR THE REST OF SOUTHERN NEVADA, NORTHWEST ARIZONA AND SOUTHEAST
CALIFORNIA...FOR THE 06Z FORECAST PACKAGE... OUTSIDE OF ANY
CONVECTIVE INFLUENCE WINDS WILL REMAIN RELATIVELY LIGHT AND WILL
TEND TO FAVOR TYPICAL DIURNAL DIRECTIONAL TRENDS. THE EXCEPTION TO
THIS WILL BE THE WESTERN MOJAVE DESERT WHERE BREEZY WESTERLY
WINDS ARE EXPECTED THROUGH THE OVERNIGHT HOURS BEFORE DECREASING
EARLY TOMORROW MORNING. SHOWERS AND THUNDERSTORMS WILL BEGIN TO
PUSH INTO THE WESTERN MOJAVE DESERT FROM THE SOUTH DURING THE
EARLY MORNING HOURS. THESE SHOWERS AND THUNDERSTORMS WILL WORK
THEIR WAY NORTH THROUGH SOUTHEASTERN CALIFORNIA, NORTHWEST
ARIZONA, AND SOUTHERN NEVADA THROUGHOUT THE AFTERNOON AND INTO THE
EVENING HOURS. LOWERING CIGS, LIGHTNING, RAIN, AND VARIABLE GUSTY
OUTFLOW WINDS WILL BE POSSIBLE WITH ANY STORMS THAT DEVELOP ON
THURSDAY.
SPOTTER INFORMATION STATEMENT
SPOTTERS ARE ENCOURAGED TO REPORT
ANY SIGNIFICANT WEATHER OR IMPACTS ACCORDING TO STANDARD OPERATING
PROCEDURES.
DISCUSSION...MELTZER
AVIATION...STESSMAN
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