419
FXUS65 KVEF 161742
AFDVEF
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LAS VEGAS NV
1042 AM PDT TUE SEP 16 2025
KEY MESSAGES
* WARM AND DRY WEATHER WILL CONTINUE THROUGH WEDNESDAY.
* CHANCES FOR SHOWERS AND THUNDERSTORMS WILL SPREAD OVER THE REGION
FROM SOUTH TO NORTH WEDNESDAY NIGHT THROUGH FRIDAY, WITH SLIGHT
CHANCES LINGERING THROUGH THE WEEKEND. THURSDAY AND FRIDAY WILL BE
THE MOST LIKELY PERIOD FOR WIDESPREAD RAINFALL AND IMPACTS.
DISCUSSION
THROUGH MONDAY. CLEAR SKIES AND LIGHT WINDS AGAIN
EARLY THIS MORNING. THE MAIN CONCERN FOR THIS FORECAST IS STILL THE
REMNANTS OF MARIO AND HOW MUCH RAIN COULD FALL. SATELLITE IMAGERY
FROM MONDAY EVENING SHOWED THE TROPICAL STORM LOOKING VERY POOR,
ALTHOUGH A NEW BURST OF CONVECTION OVERNIGHT SUGGESTS MARIO IS NOT
QUITE DEAD YET. REGARDLESS OF WHETHER IT IS A TS, TD, OR REMNANT
LOW, TROPICAL MOISTURE WILL BE SURGING NORTH ACROSS OUR AREA FROM
WEDNESDAY EVENING THROUGH THURSDAY NIGHT. PRECIPITABLE WATER SHOULD
REACH ONE INCH OVER NEARLY ALL OF OUR CWA, WITH UP TO AN INCH AND A
HALF IN THE LOWER ELEVATIONS OF THE COLORADO RIVER VALLEY AND
POSSIBLY DEATH VALLEY. MODELS HAVE HONED IN A LITTLE ON RAINFALL
TIMING SINCE YESTERDAY, AND AMOUNTS HAVE GENERALLY RISEN. THE BEST
CHANCES FOR HEAVY RAIN SEEM TO BE FOCUSED ON THURSDAY AND FRIDAY.
25TH PERCENTILE RAIN AMOUNTS NOW SHOW ABOUT ONE TENTH OF AN INCH
OVER MOST OF THE MOJAVE DESERT AND TWO TO FOUR TENTHS IN THE
MOUNTAINS (THESE NUMBERS WERE NEARLY ZERO YESTERDAY), AND 75TH
PERCENTILE AMOUNTS SHOW HALF AN INCH TO ONE INCH FOR MOST OF THE
MOJAVE DESERT AND UP TO TWO AND A HALF INCHES IN THE MOUNTAINS, BOTH
OF WHICH ARE UP ROUGHLY 30 PERCENT SINCE YESTERDAY. NOT ENOUGH
CONFIDENCE IN THE DETAILS TO ISSUE A FLASH FLOOD WATCH YET, ALTHOUGH
IF MODEL TRENDS CONTINUE, ONE MAY BE NEEDED LATER TODAY OR EARLY
TOMORROW MORNING. THE MOST LIKELY "FAILURE MODE" FOR FLASH FLOOD
POTENTIAL WILL BE OVERCAST SKIES INHIBITING INSTABILITY AND CAUSING
RAIN TO BE MORE STRATIFORM THAN CONVECTIVE. ONCE WE GET PAST FRIDAY,
THERE IS A LOT OF MODEL DISAGREEMENT ON HOW MUCH INSTABILITY AND
FORCING WILL BE AVAILABLE, SO LOW CONFIDENCE IN POPS OVER THE
WEEKEND AND INTO EARLY NEXT WEEK. THE FORECAST WILL REFLECT SLIGHT
CHANCES FOR SHOWERS AND THUNDERSTORMS, MAINLY IN THE AFTERNOONS,
WHICH IS A GOOD MIDDLE GROUND ASSUMING MOISTURE DOES NOT GET SCOURED
OUT (MODERATE TO HIGH CONFIDENCE) AND THERE IS NO SYNOPTIC FORCING
(LOW TO MODERATE CONFIDENCE).
AVIATION...FOR HARRY REID...FOR THE 18Z FORECAST PACKAGE
GENERALLY LIGHT WINDS OF 10-12 KNOTS OR LESS ARE EXPECTED THROUGH
THE PERIOD. WINDS TO SHIFT FROM NORTHEAST TO SOUTHEAST BY
19Z-20Z, THEN SHIFT SOUTHWEST THIS EVENING. A FEW HIGH CLOUDS TO
STREAM NORTHWARD INTO THE REGION BY EARLY WEDNESDAY. TEMPERATURES
ARE NOT EXPECT TO REACH 100 DEGREES, BUT WILL CLIMB TO THE UPPER
90S BETWEEN 22 AND 00Z.
FOR THE REST OF SOUTHERN NEVADA, NORTHWEST ARIZONA AND SOUTHEAST
CALIFORNIA...FOR THE 18Z FORECAST PACKAGE...A MOSTLY DIURNAL WIND
PATTERN IS EXPECTED AT AREA TERMINALS. WINDS GENERALLY 10 KNOTS
OR LESS OUTSIDE OF KBIH AND KDAG, WHERE SPEEDS AND/OR GUSTS TO 15
KNOTS CAN BE EXPECTED AT TIMES. HIGH CLOUDS WILL GRADUALLY LIFT
NORTHWARD ACROSS SOUTHERN CALIFORNIA, NEVADA AND CENTRAL ARIZONA
OVERNIGHT INTO WEDNESDAY. LOW CHANCES FOR SCATTERED SHOWERS/STORMS
WILL ENTER THE PICTURE JUST BEYOND THE TAF PERIOD 18Z WED TO 06Z
THURS MAINLY FOR KDAG, KEED AND KIFP. HOWEVER, CONFIDENCE REMAINS
RATHER LOW IN ANY TERMINAL BEING DIRECTLY IMPACTED.
SPOTTER INFORMATION STATEMENT
SPOTTERS ARE ENCOURAGED TO REPORT
ANY SIGNIFICANT WEATHER OR IMPACTS ACCORDING TO STANDARD OPERATING
PROCEDURES.
DISCUSSION...MORGAN
AVIATION...AUSTIN
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