336
FXUS65 KPSR 141021
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
321 AM MST THU MAY 14 2026
KEY MESSAGES
- RELATIVELY STABLE TEMPERATURES WITH AFTERNOON HIGHS 4 TO 8
DEGREES ABOVE NORMAL WILL PREVAIL THROUGH SATURDAY, THEN COOL
CLOSER TO THE DAILY NORMALS SUNDAY INTO EARLY NEXT WEEK.
- BREEZY CONDITIONS WILL RETURN TO THE AREA OVER THE WEEKEND WITH
THE STRONGEST GUSTS ACROSS SOUTHEAST CALIFORNIA AND THE ARIZONA
HIGH TERRAIN.
- CRITICAL FIRE WEATHER CONDITIONS WILL BE POSSIBLE THIS WEEKEND,
PARTICULARLY ON SUNDAY FOR THE EASTERN ARIZONA HIGHER TERRAIN.
SHORT TERM /TODAY THROUGH FRIDAY/
EARLY MORNING MIDLEVEL WATER VAPOR IMAGERY REVEALS SOUTHWESTERLY
FLOW STILL ENTRENCHED OVER AZ, WITH SOME LINGERING MOISTURE OVER THE
EASTERN HALF OF THE STATE SCOURING OUT, RESULTING IN CLEARING SKIES.
THE BULK OF SUBTROPICAL JET ENERGY HAS SHIFTED EAST OF THE FORECAST
AREA, AND SO EXPECT A RETURN TO LIGHTER WINDS WITH ONLY MARGINAL
AFTERNOON BREEZINESS. TO THE WEST OF THE AREA, 500 MB RAP ANALYSIS
INDICATES THE PRESENCE OF A SW-NE ORIENTED, ELONGATED WEAK TROUGH
STRETCHING FROM OFF THE SOCAL COAST NORTHWARDS TOWARDS A MORE POTENT
SYSTEM PROGRESSING EASTWARD ALONG THE CANADA/US BORDER OVER MONTANA.
WHILE THE ELONGATED DISTURBANCE TO OUR WEST APPEARS CONNECTED WITH
THE MORE PROGRESSIVE NORTHERN STREAM, ENSEMBLES REMAIN IN EXCELLENT
AGREEMENT THAT IT WILL REMAIN LARGELY IN PLACE THROUGH THE END OF
THE WORK WEEK, HELPING TO HOLD H5 HEIGHTS STEADY NEAR 582 DAM OVER
THE FORECAST AREA. THIS SHOULD RESULT IN A NEAR PERSISTENCE
TEMPERATURE FORECAST, WITH AFTERNOON HIGHS AROUND 4F-8F ABOVE DAILY
NORMALS AND ONLY FLUCTUATING A FEW DEGREES DAY TO DAY INTO THE
WEEKEND, NEAR 100F FOR THE TYPICALLY WARMER LOWER DESERT
COMMUNITIES. HOWEVER, THE DRY AIRMASS IN PLACE COUPLED WITH CLEAR
SKIES WILL PROMOTE EFFECTIVE OVERNIGHT RADIATIVE COOLING RESULTING
IN COMFORTABLE MORNING LOWS, NEAR THEIR NORMAL VALUES FOR MID MAY.
LONG TERM /SATURDAY THROUGH WEDNESDAY/
THE MAIN CONCERN IN THE LONG TERM WILL BE INCREASED WINDS ACROSS THE
REGION THIS WEEKEND LEADING TO ELEVATED TO LOCALLY CRITICAL FIRE
WEATHER CONDITIONS. ENSEMBLES SHOW GOOD AGREEMENT THAT A TROUGH IN
THE NORTHERN STREAM WILL MOVE ONSHORE ALONG THE PACIFIC NORTHWEST
COAST EARLY SATURDAY, FOLLOWED BY A PERIOD OF AMPLIFICATION AND
STRONGLY NEGATIVE MIDLEVEL HEIGHT ANOMALIES BECOMING ESTABLISHED
OVER THE INTERIOR WEST. HOWEVER, WPC CLUSTER ANALYSIS DOES STILL
SHOW DISCREPANCIES IN HOW STRONG THIS TROUGH WILL BE AND THE PRECISE
TIMING, RESULTING IN SOME UNCERTAINTY IN HOW MUCH REGIONAL PRESSURE
GRADIENTS WILL TIGHTEN, AND THUS THE TIMING AND PEAK MAGNITUDE OF
WINDS. SEVERAL DISTURBANCES ARE LIKELY TO ROTATE ABOUT THIS LARGER
SCALE TROUGHING FEATURE, AFFECTING THE DESERT SOUTHWEST THIS WEEKEND
INTO EARLY NEXT WEEK. THE CURRENT TIMING OF THE STRONGER WINDS (AND
ASSOCIATED AREAS OF FIRE WEATHER CONCERNS) FAVORS SOUTHEAST
CALIFORNIA AND SOUTHWEST ARIZONA SATURDAY, THE EASTERN AZ HIGHER
TERRAIN SUNDAY, AND POTENTIALLY THE LOWER CO RIVER VALLEY ON MONDAY.
WIND AND/OR FIRE WEATHER HEADLINES WILL LIKELY NEED TO BE CONSIDERED
IN FUTURE UPDATES.
ASIDE FROM WINDS AND FIRE WEATHER CONCERNS, THE PATTERN THIS WEEKEND
WILL PROMOTE COOLER TEMPERATURES BY SUNDAY. LATEST NBM
PROBABILISTIC TEMPERATURE GUIDANCE SHOWS SPREAD INCREASING, WITH
IQRS OF AT LEAST 5F SUNDAY ONWARD. HOWEVER, MONDAY IS SHAPING UP
TO BE THE COOLEST OF THE NEXT 7 DAYS, WITH MANY LOWER DESERT AREAS
STRUGGLING TO REACH THE MIDDLE 90S. NEGATIVE MIDLEVEL HEIGHT
ANOMALIES APPEAR TO DEPART TO THE NORTH AND EAST DURING THE MIDDLE
OF NEXT WEEK, ALLOWING H5 HEIGHTS TO REBOUND CLOSER TO 580 DAM.
ANTICIPATE AFTERNOON HIGHS TO WARM IN RESPONSE THROUGH THE MIDDLE
OF THE WEEK, LIKELY NEARING 100F ONCE AGAIN FOR THE TYPICALLY
WARMER SPOTS ACROSS THE LOWER DESERT. HOWEVER, THE OVERALL
PATTERN/FLOW ALOFT DOES NOT SUBSTANTIALLY CHANGE, WITH ENSEMBLES
GENERALLY SHOWING RIDGING OFF THE WEST COAST AND BROAD
ANTICYCLONIC FLOW OVER THE WESTERN/CENTRAL CONUS.
AVIATION
UPDATED AT 0505Z.
SOUTH CENTRAL ARIZONA INCLUDING KPHX, KIWA, KSDL, AND KDVT:
NO MAJOR AVIATION WEATHER CONCERNS UNDER GENERALLY CLEAR SKIES CAN
BE EXPECTED THROUGHOUT THE TAF PERIOD. THE OVERALL WIND PATTERN
WILL FOLLOW THE TYPICAL DIURNAL TENDENCIES WITH SPEEDS GENERALLY
AOB 10 KTS, WITH OCCASIONAL AFTERNOON GUSTS INTO THE MID TO UPPER
TEENS.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH:
NO MAJOR AVIATION WEATHER CONCERNS UNDER GENERALLY CLEAR SKIES CAN
BE EXPECTED THROUGHOUT THE TAF PERIOD. AT KIPL, WINDS WILL
GENERALLY BE OUT OF THE WEST WHILE AT KBLH, WINDS WILL GENERALLY
FLUCTUATE OUT OF THE SOUTH TO SOUTHWEST. WIND SPEEDS WILL
GENERALLY BE BETWEEN 8-12 KTS THROUGHOUT THE PERIOD. ANOTHER ROUND
OF PEAK GUSTS UPWARDS OF 20-25 KTS WILL BE POSSIBLE AT KIPL
DURING THE LATE AFTERNOON/EVENING HOURS.
FIRE WEATHER
SLIGHTLY ABOVE NORMAL TEMPERATURES, DRY CONDITIONS, AND LIGHTER
WINDS WITH TYPICAL AFTERNOON UPSLOPE/UPVALLEY BREEZINESS WILL
PREVAIL THROUGH FRIDAY. A WEATHER SYSTEM WILL MOVE ONSHORE ALONG
THE PACIFIC NORTHWEST EARLY SATURDAY AND DEEPEN OVER THE WESTERN
US RESULTING IN INCREASED WINDS ACROSS THE AREA THIS WEEKEND. THE
STRONGEST WINDS ARE ANTICIPATE IN SOUTHEAST CA INTO SOUTHWEST AZ
ON SATURDAY, THEN OVER THE EASTERN AZ HIGH TERRAIN SUNDAY, AND
THIS WILL LIKELY RESULT IN ELEVATED TO LOCALLY CRITICAL FIRE
WEATHER CONDITIONS. AFTERNOON MINRHS WILL COMMONLY FALL IN AN
8-15% RANGE THROUGH EARLY NEXT WEEK, WITH OVERNIGHT RECOVERIES
RANGING FROM 25-45% ACROSS THE AREA AND IMPROVING ONLY SLIGHTLY
FROM THERE ON SATURDAY AND SUNDAY NIGHTS.
PSR WATCHES/WARNINGS/ADVISORIES
AZ...NONE.
CA...NONE.
SHORT TERM...WHITTOCK
LONG TERM...WHITTOCK
AVIATION...LOJERO
FIRE WEATHER...WHITTOCK
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page