547
FXUS65 KVEF 192150
AFDVEF
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LAS VEGAS NV
ISSUED BY NATIONAL WEATHER SERVICE FLAGSTAFF AZ
250 PM PDT MON MAY 19 2025
SYNOPSIS
THIS WEEK WILL SEE A SIGNIFICANT WARMING TREND THAT
WILL RESULT IN WHAT IS LIKELY TO BE THE FIRST 100 DEGREE DAY OF
THE YEAR IN LAS VEGAS ON THURSDAY. THURSDAY WILL BE THE HOTTEST
DAY OF THE WEEK, BEFORE A SLOW, GRADUAL COOLING TREND HEADING INTO
NEXT WEEKEND. A WEAK DISTURBANCE IS EXPECTED TO BRING INCREASED
WINDS TO THE REGION OVER THE WEEKEND, BUT CURRENTLY, THE FORECAST
REMAINS DRY.
SHORT TERM
THROUGH TUESDAY.
SUNNY SKIES AND NORTHERLY BREEZES ARE THE RULE FOR MOST OF THE
REGION TODAY AS THE TROUGH RESPONSIBLE FOR THE UNSETTLED WEATHER
OVER THE WEEKEND TRANSLATES EASTWARD ACROSS THE ROCKIES, LEAVING
SOUTHEASTERN CALIFORNIA, SOUTHERN NEVADA, AND NORTHWESTERN ARIZONA
BENEATH NORTHWEST FLOW ALOFT. MID-LEVEL MOISTURE IS TEMPERING OUR
WARM-UP SOMEWHAT THIS AFTERNOON, THOUGH IT IS STILL UNDERWAY,
WITH TEMPERATURES ON TARGET TO TOP OUT AT LEAST A FEW DEGREES
WARMER THAN YESTERDAY, BUT STILL SLIGHTLY BELOW NORMAL FOR THE
MIDDLE OF MAY. WINDS WILL DIE DOWN LATE THIS AFTERNOON THROUGH
THIS EVENING WITH THE LOSS OF MIXING AND AS THE SURFACE PRESSURE
GRADIENT SLACKENS, WITH LOWS RANGING FROM THE 40S IN THE MOUNTAINS
TO 60S AND 70S IN THE VALLEYS. HEADING INTO TUESDAY, THE WARMING
TREND WILL CONTINUE AS RIDGING DEVELOPS OVER THE SOUTHEASTERN
PACIFIC, AND FLOW ALOFT TRANSITIONS TO QUASI-ZONAL. INCREASING
THICKNESSES WILL LEND TO HIGHS REBOUNDING ABOVE NORMAL INTO THE
80S AND 90S FOR MOST, WITH TRIPLE DIGITS IN DEATH VALLEY AND 70S
CONFINED TO THE HIGHER TERRAIN. AS TO BE EXPECTED IN THIS REGIME,
CLEAR SKIES AND DRY CONDITIONS WILL CONTINUE.
LONG TERM
WEDNESDAY THROUGH SUNDAY.
THE RIDGE WILL CONTINUE TO BUILD OVER THE SOUTHWEST US THE SECOND
HALF OF THE WEEK. TEMPERATURES THROUGH THE WEEK WILL WARM EACH DAY
IN RESPONSE TO BUILDING HEIGHTS. THE RIDGE IS KNOCKED DOWN SLIGHTLY
ON THURSDAY AS A WEAK SHORTWAVE MOVES THROUGH THE PACIFIC NORTHWEST,
BUT ANOMALOUSLY HIGH HEIGHTS WILL REMAIN OVER THE AREA. THIS
COMBINED WITH A SLIGHT INCREASE IN WINDS TO ADD IN MIXING MEANS
THURSDAY WILL LIKELY BE THE WARMEST DAY OF THE WEEK. THE PROBABILITY
OF REACHING 100 DEGREES IN LAS VEGAS ON THURSDAY IS 75 PERCENT,
AND THERE IS A 25 PERCENT CHANCE FOR DEATH VALLEY TO REACH 110
DEGREES. WEDNESDAY AND THURSDAY, EXPECT WIDESPREAD MODERATE (LEVEL
2) HEATRISK ACROSS THE DESERT VALLEYS, A LEVEL OF HEAT THAT
AFFECTS ANYONE SENSITIVE TO HEAT, ESPECIALLY THOSE WITHOUT
ADEQUATE COOLING OR HYDRATION. THERE IS ALSO THE POTENTIAL FOR
SOME MAJOR (LEVEL 3) HEATRISK ALONG THE COLORADO RIVER AS WELL AS
DEATH VALLEY, WHICH AFFECTS ANYONE WITHOUT EFFECTIVE COOLING OR
HYDRATION. KNOW WHERE TO FIND THE NEAREST COOL LOCATION AND BRING
PLENTY OF WATER IF PLANNING ON SPENDING TIME OUTDOORS.
FORECAST UNCERTAINTY INCREASES FRIDAY INTO THE WEEKEND AS MODELS TRY
TO RESOLVE HOW THE RIDGE BUILD BACK INTO THE RIDGE AND HOW IT
INTERACTS WITH ANOTHER MORE POTENT PACIFIC NORTHWEST SHORTWAVE.
FRIDAY SHOULD CONTINUE TO BE WARM AS MOST MODELS SHOW SOME FLAVOR
OF A RIDGE REMAINING OVER THE AREA. HIGH TEMPERATURES ON FRIDAY
SHOULD ONLY COOL A FEW DEGREES, THUS SIMILAR HEATRISK IMPACTS ARE
EXPECTED ON THURSDAY AS MENTIONED ABOVE. AFTER THAT, THERE IS TOO
MUCH MODEL VARIANCE TO DETERMINE POTENTIAL IMPACTS AND SPECIFICS.
WILL CONTINUE TO MONITOR FOR WIND AND OTHER POTENTIAL IMPACTS AS
CONFIDENCE IS TOO LOW TO DETERMINE DETAILS GIVEN THE HIGH
UNCERTAINTY.
AVIATION...FOR HARRY REID...FOR THE 00Z FORECAST PACKAGE
GUSTY
NORTHERLY WINDS ARE EXPECTED TO CONTINUE EARLY IN THE FORECAST
PERIOD, WITH SOME VARIABILITY BETWEEN 340-020. SUSTAINED SPEEDS
WILL REMAIN UNDER 15KT, WITH INTERMITTENT GUSTS TO 18-22KT
EXPECTED. WINDS WILL DECREASE RAPIDLY BETWEEN 01-03Z, WITH LIGHT
AND VARIABLE WINDS THEREAFTER UNTIL WINDS SETTLE OUT OF THE
SOUTHWEST PRIOR TO DAYBREAK. BY MID MORNING, WINDS RETURN TO THE
EAST, AHEAD OF A SOUTHEASTERLY SHIFT EARLY AFTERNOON WHEN WINDS
ARE EXPECTED TO INCREASE TO AROUND 10KT. AROUND 22-23Z, A
SOUTHWESTERLY WIND SHIFT LOOKS TO PUSH INTO THE VALLEY, WITH
SUSTAINED SPEEDS AROUND 10KT EXPECTED, WITH ONLY A BRIEF WINDOW
FOR POTENTIAL GUSTS THROUGH EARLY EVENING. VFR CONDITIONS WITH
CLEAR SKIES WILL PREVAIL.
FOR THE REST OF SOUTHERN NEVADA, NORTHWEST ARIZONA AND SOUTHEAST
CALIFORNIA...FOR THE 00Z FORECAST PACKAGE...GUSTY NORTHERLY/NORTH-
NORTHWESTERLY WINDS WILL CONTINUE AT ALL TERMINALS EXCEPT KDAG
THROUGH EARLY THIS EVENING. GUSTS TO 20-25KT ARE EXPECTED ON AT
LEAST AN INTERMITTENT BASIS, WITH WINDS DIMINISHING QUICKLY AFTER
SUNSET AREAWIDE AS SPEEDS DROP TO 6-8KT AFTER 03-04Z. AT KDAG,
WINDS GENERALLY REMAIN WESTERLY TO NORTHWESTERLY FOR THE DURATION,
WITH SPEEDS AROUND 10KT THROUGH LATE THIS EVENING BEFORE AN
UPTICK TO AROUND 12-15KT OVERNIGHT THOUGH MID MORNING. ELSEWHERE,
WINDS WILL REMAIN VARIABLE OR SETTLE OUT OF TYPICAL DIURNAL
DIRECTIONS THROUGH TUESDAY MORNING. SIMILAR TO KLAS, KHND IS
EXPECTED SEE A SOUTHWESTERLY WIND SHIFT LATE IN THE PERIOD, THOUGH
THIS SHIFT LOOKS TO HOLD OFF UNTIL OR JUST AFTER 21/00Z FOR KVGT.
VFR CONDITIONS PREVAIL AREAWIDE.
SPOTTER INFORMATION STATEMENT
SPOTTERS ARE ENCOURAGED TO REPORT
ANY SIGNIFICANT WEATHER OR IMPACTS ACCORDING TO STANDARD OPERATING
PROCEDURES.
SHORT TERM...PHILLIPSON
LONG TERM...NICKERSON
AVIATION...PHILLIPSON
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