810
FXUS65 KPSR 041200
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
500 AM MST WED JUN 4 2025
UPDATE
UPDATED 12Z AVIATION DISCUSSION.
KEY MESSAGES
- SCATTERED SHOWERS WILL REMAIN POSSIBLE MAINLY ACROSS SOUTH-
CENTRAL ARIZONA THIS MORNING AND OVER THE HIGHER TERRAIN THROUGH
THIS AFTERNOON.
- A RETURN TO A MORE TYPICAL JUNE WEATHER PATTERN EXPECTED BY
THURSDAY INTO FRIDAY WITH SEASONABLY DRY AND HOT CONDITIONS
FORECAST FOR THE WEEKEND INTO NEXT WEEK.
- MODERATE HEATRISK WILL DEVELOP STARTING THIS WEEKEND WITH HIGH
TEMPERATURES PEAKING NEAR 110 DEGREES ACROSS THE LOWER DESERTS
ON SUNDAY AND MONDAY.
DISCUSSION
THE LAST SEVERAL HOURS HAVE BEEN MUCH MORE ACTIVE THAN ANTICIPATED
WITH WIDESPREAD THUNDERSTORMS IMPACTING MUCH OF EASTERN RIVERSIDE
AND LA PAZ COUNTIES RESULTING IN POCKETS OF HEAVY RAINFALL OF OVER
AN INCH. GUIDANCE REALLY UNDERESTIMATED HOW MUCH MOISTURE AND
INSTABILITY WOULD BE AVAILABLE AS THIS NEXT UPPER LEVEL LOW ENTERS
THE REGION FROM THE WEST. FOR THE REST OF THE MORNING HOURS,
SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED TO IMPACT
PORTIONS OF SOUTH-CENTRAL ARIZONA WITH GUIDANCE LIKELY AGAIN
UNDERESTIMATING THE COVERAGE AND THE POTENTIAL FOR DECENT
RAINFALL. IT WOULD NOT BE SURPRISING TO SEE A FEW THUNDERSTORMS
PRODUCE 0.5" OR SO WITHIN OR NEAR THE PHOENIX METRO THROUGH
SUNRISE. POPS HAVE BEEN RAISED TO AT LEAST ALLOW 20% CHANCE OF
SHOWERS AND THUNDERSTORMS FOR THE REST OF THE OVERNIGHT, BUT THAT
MAY BE UNDERDONE. THE UPPER LEVEL LOW IS NOW ENTERING SOUTHWEST
ARIZONA AND IT WILL GRADUALLY WEAKEN AS IT LIFTS NORTHEASTWARD
THROUGH SOUTHERN AND CENTRAL ARIZONA THROUGH THE REST OF THE
MORNING. BY THIS AFTERNOON, MOST OF THE ENERGY FROM THE EXITING
LOW WILL BE CONFINED TO THE ARIZONA HIGH COUNTRY LEAVING JUST
LINGERING CHANCES FOR SHOWERS AND MAYBE A FEW THUNDERSTORMS TO THE
NORTHEAST AND EAST OF PHOENIX.
BROAD TROUGHING WILL PERSIST ACROSS THE BULK OF THE WESTERN U.S.
INCLUDING WESTERN PORTIONS OF THE DESERT SOUTHWEST ON THURSDAY,
BUT BY FRIDAY WE WILL SEE THE SUB-TROPICAL RIDGE CENTERED TO OUR
SOUTHEAST NUDGING INTO ARIZONA. H5 HEIGHTS ARE SEEN RISING FROM
580-582DM LATER TODAY, TO 584-586DM FRIDAY, BEFORE PEAKING
SOMEWHERE AROUND 590DM OVER THE WEEKEND. DRYING CONDITIONS WILL
OVERTAKE THE REGION THROUGH FRIDAY AS HEIGHTS ALOFT INCREASE
ALLOWING FOR A CONSISTENT WARMING TREND. NBM FORECAST TEMPERATURES
SHOW HIGHS TOPPING 100 DEGREES ON THURSDAY AND AROUND 105 DEGREES
FRIDAY. AS THE PEAK OF THE HEIGHTS AFFECT THE REGION THIS WEEKEND
INTO EARLY NEXT WEEK, TEMPERATURES ARE LIKELY TO PEAK AT OR JUST
BELOW 110 DEGREES ON SUNDAY AND MONDAY. MODERATE HEATRISK WILL
DEVELOP OVER THE REGION BY THE WEEKEND, BUT IT SEEMS TEMPERATURES
WILL NOT REACH EXTREME HEAT LEVELS. GUIDANCE THEN MOSTLY FAVORS A
WEAK QUASI CUT-OFF LOW MOVING FROM JUST OFF THE CALIFORNIA COAST
OVER THE WEEKEND INTO OR NEAR OUR REGION BY AROUND NEXT TUESDAY.
THIS FEATURE IS NOT LIKELY TO BRING MUCH CHANGE FOR OUR REGION AS
IT LOOKS QUITE DRY, BUT IT MAY BE ENOUGH TO DROP DAYTIME HIGHS
BACK INTO THE NORMAL RANGE BY THE MIDDLE OF NEXT WEEK.
AVIATION
UPDATED AT 1158Z.
SOUTH CENTRAL ARIZONA INCLUDING KPHX, KIWA, KSDL, KDVT:
NO MAJOR AVIATION CONCERNS THROUGHOUT THE TAF PERIOD AS THE STORMS
THAT DEVELOPED IN THE OVERNIGHT HOURS HAVE MOVED TO THE NORTH OF
THE TERMINALS. HOWEVER THERE ARE STILL SOME SCATTER SHOWERS
DEVELOPING TO THE SW THAT MAY CONTINUE TO BRING VCSH OVER THE
NEXT SEVERAL HOURS BUT CURRENTLY LIGHTENING IS NOT A CONCERN. BY
13-15Z THE ACTIVITY SHOULD BE THROUGH THE TERMINALS. THIS MORNING
EXPECT VRB WINDS AND SHIFTING OUT OF THE WEST TO SW BY EARLY THIS
AFTERNOON AOB 10KTS. FEW-SCT CLOUD COVERAGE WILL CLEAR BY THIS
EVENING.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH:
NO MAJOR AVIATION CONCERNS THROUGHOUT THE TAF PERIOD. AT KIPL
WINDS WILL BE OUT OF THE E TO SE AND AT KBLH WINDS WILL CONTINUE
TO BE PRIMARILY OUT OF THE SSW ESPECIALLY LATER TONIGHT. WIND
SPEEDS AT BOTH TERMINALS ARE EXPECTED TO BE GENERALLY AOB 10KTS
WITH THE EXCEPTION AT KBLH LATE TONIGHT POTENTIALLY SEEING 1-2KTS
ABOVE 10KTS FOR A FEW HOURS. FEW-SCT CLOUD COVERAGE IS EXPECTED
TO CLEAR BY THIS AFTERNOON.
FIRE WEATHER
A WEATHER SYSTEM WILL EXIT THE REGION LATER TODAY WITH LINGERING
CHANCES FOR SHOWERS AND ISOLATED THUNDERSTORMS INTO THE AFTERNOON
ACROSS THE ARIZONA HIGHER TERRAIN. DRYING CONDITIONS AND HOTTER
TEMPERATURES ARE THEN EXPECTED THROUGH THE REST OF THE WEEK.
MINRHS WILL REMAIN ELEVATED TODAY AT MOSTLY ABOVE 20-25% BEFORE
LOWING TO 10-15% BY FRIDAY. WINDS SHOULD FOLLOW FAIRLY TYPICAL
DIURNAL TENDENCIES WITH PERIODIC AFTERNOON UPSLOPE GUSTINESS.
THE DRY WEATHER PATTERN IS EXPECTED TO CONTINUE THROUGH THE
WEEKEND INTO EARLY NEXT WEEK WITH TEMPERATURES RUNNING 5-10
DEGREES ABOVE NORMAL AND DAILY MINRHS MOSTLY IN A 5-10% RANGE.
PSR WATCHES/WARNINGS/ADVISORIES
AZ...NONE.
CA...NONE.
DISCUSSION...KUHLMAN
AVIATION...RYAN
FIRE WEATHER...KUHLMAN
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