956
FXUS65 KVEF 180904
AFDVEF
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LAS VEGAS NV
204 AM PDT THU SEP 18 2025
KEY MESSAGES
* INCREASING TROPICAL MOISTURE WILL MOVE INTO THE REGION TODAY AND
FRIDAY, BRINGING CHANCES FOR SHOWERS AND THUNDERSTORMS. LOCALLY
HEAVY RAIN AND HIGH RAINFALL RATES WILL LEAD TO AN INCREASED RISK
OF FLASH FLOODING, ESPECIALLY OVER SAN BERNARDINO COUNTY.
* SLIGHT CHANCES FOR SHOWERS AND THUNDERSTORMS WILL LINGER THROUGH
THE WEEKEND. DRIER AND WARMER WEATHER COULD RETURN NEXT WEEK.
DISCUSSION
THROUGH WEDNESDAY. EARLY MORNING SATELLITE LOOP SHOWED
MID AND HIGH LEVEL CLOUDS ASSOCIATED WITH THE REMNANTS OF MARIO
BLANKETING OUR CWA. SURFACE OBS SHOWED LIGHT WINDS, A VERY SHARP
DEWPOINT GRADIENT NEAR INTERSTATE 40, AND LIGHT RAIN NEARING OUR
SOUTHERN CWA BORDER. AS HAS BEEN THE CASE FOR A FEW DAYS NOW, THE
INCOMING RAIN IS THE PRIMARY FORECAST CONCERN. HIGH RESOLUTION
MODELS AND WPC PROJECTIONS STILL SHOW THE GREATEST CHANCES FOR HEAVY
RAIN IN SAN BERNARDINO COUNTY, SO WILL LEAVE THE FLOOD WATCH IN
PLACE THERE. LOWER, BUT NONZERO, RISKS FOR FLOODING STILL EXIST IN
THE REST OF OUR CWA, PRIMARILY INYO, CLARK, AND MOHAVE COUNTIES. THE
GREATEST RISK OF FLOODING SHOULD BE TODAY AND TONIGHT BEFORE THE
BEST FORCING EXITS FRIDAY MORNING. LEFTOVER MOISTURE AND MORE
SUNSHINE SHOULD FUEL THUNDERSTORM CHANCES FRIDAY AFTERNOON, THEN
LIMITED TO MAINLY OVER THE MOUNTAINS SATURDAY AND SUNDAY. MODELS
DISAGREE ON WHETHER ANOTHER CUTOFF LOW EARLY NEXT WEEK REMAINS
OFFSHORE OR MOVES INLAND AND TAPS INTO THE TROPICAL MOISTURE LURKING
TO OUR SOUTH. THE FIRST SCENARIO, WHICH LOOKS MORE LIKELY, WOULD
RESULT IN DRIER AND WARMER WEATHER. THE SECOND, WHICH CANNOT BE
RULED OUT, WOULD RESULT IN A ROUND OF MORE WIDESPREAD SHOWERS AND
THUNDERSTORMS.
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...MORGAN
AVIATION...STESSMAN
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