362
FXUS65 KPSR 182057
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
157 PM MST SAT APR 18 2026
KEY MESSAGES
- HIGH PRESSURE OVER THE SOUTHERN PLAINS WILL CAUSE BREEZY TO
WINDY CONDITIONS FOR PORTIONS OF SOUTH CENTRAL ARIZONA SUNDAY
MORNING, WITH THE STRONGEST GUSTS OVER HIGHER TERRAIN EAST OF
PHOENIX.
- TEMPERATURES WILL WARM THIS WEEKEND THROUGH THE BEGINNING OF THE
UPCOMING WEEK, REACHING 5 TO 10 DEGREES ABOVE DAILY NORMALS,
WHICH TRANSLATES TO WIDESPREAD LOWER DESERT HIGHS IN THE
NINETIES.
- PERIODS OF BREEZY TO LOCALLY WINDY CONDITIONS AND COOLER
TEMPERATURES ARE EXPECTED BY THE MIDDLE OF THE UPCOMING WORK
WEEK.
SHORT TERM /TODAY THROUGH MONDAY/
IT IS A CRISP SUNNY START TO THE WEEKEND ACROSS MUCH OF THE DESERT
SOUTHWEST, WITH SHORTWAVE RIDGING PROGRESSING ACROSS THE AREA. THE
SUNSHINE AND HIGH PRESSURE HAS ALREADY CONTRIBUTED TO A 24-HR
SURFACE TEMPERATURE CHANGE OF AROUND +4-7F. THE WARMING TODAY WILL
LEAD TO AFTERNOON HIGH TEMPERATURES REACHING THE LOWER 90S ACROSS
MOST LOWER DESERT COMMUNITIES, WHICH IS AROUND 5 DEGREES ABOVE
NORMAL. WINDS ARE MUCH LIGHTER TODAY ACROSS SE CA AND SW AZ, AS
THE SURFACE PRESSURE ALONG THE LOWER COLORADO RIVER WEAKENED WITH
THE SHIFTING EASTWARD OF THE GREAT BASIN SURFACE HIGH. WINDS ARE
ALSO FAIRLY LIGHT ACROSS SOUTH- CENTRAL AZ FOLLOWING SOME MORNING
NORTHEASTERLY BREEZES.
A STRENGTHENING SURFACE HIGH IN THE SOUTHERN PLAINS TONIGHT WILL
SET UP A STRONG PRESSURE GRADIENT ACROSS PARTS OF SOUTHERN NM AND
AZ AND LEAD TO ENHANCED EASTERLY WINDS. COMPARATIVELY, ENSEMBLE
GUIDANCE IS PREDICTING A WEAKER GRADIENT THAN THE VERY STRONG ONE
THAT SET UP BACK ON MARCH 28TH, WHICH SAW WIND GUSTS MEASURE UP
TO AROUND 40-45 MPH IN THE HIGH TERRAIN EAST OF PHOENIX IN THE
MORNING, WITH 25-35 MPH MEASURED IN THE LOWER DESERTS OF SOUTH-
CENTRAL AZ. THE MARCH 28TH GRADIENT WIND EVENT ALSO PRODUCED A LOT
OF LOFTED DUST THAT BECAME APPARENT AFTER SUNRISE. SIMILAR
CONDITIONS ARE A REASONABLE EXPECTATION WITH TONIGHT/TOMORROW
MORNING'S GRADIENT WIND EVENT ALTHOUGH IT IS EXPECTED TO BE A
DEGREE OF MAGNITUDE WEAKER THAN THE MARCH 28TH EVENT. HI-RES
MODELS AND THE NBM SUPPORT LOCALIZED MOUNTAINTOP WIND GUSTS UP TO
45-50 MPH, WITH UP TO 35-45 IN SOME HIGHER TERRAIN COMMUNITIES,
LIKE SAN CARLOS AND GLOBE/MIAMI, WHILE LOWER ELEVATIONS OF SOUTH-
CENTRAL AZ CAN REASONABLY ANTICIPATE UP TO 25-35 MPH GUSTS AFTER
SUNRISE TOMORROW. A WIND ADVISORY HAS BEEN ISSUED FOR MOST HIGH
TERRAIN AREAS EAST OF PHOENIX FROM 3 AM - 11 AM MST TOMORROW. WIND
GUSTS SHOULD ABATE THROUGH THE AFTERNOON AS THE GRADIENT RELAXES.
AS IS COMMON WITH ELEVATED BREEZES DURING THE OVERNIGHT AND
MORNING HOURS, MORNING LOW TEMPERATURES WILL LIKELY BE WARMER THAN
THE NBM DETERMINISTIC FORECAST. AS A RESULT, LOWS WERE BOOSTED UP
A FEW DEGREES ACROSS SOUTH-CENTRAL AZ AND BRING RECORD WARM LOW
INTO THE PICTURE FOR PHOENIX (CURRENT RECORD: 73F). AFTERNOON HIGH
TEMPERATURES TOMORROW ARE EXPECTED TO WARM ANOTHER FEW DEGREES
COMPARED TO TODAY, UNDER CONTINUED HIGH PRESSURE AND SOUTHERLY
MID-LEVEL FLOW. LOWER DESERT HIGHS WILL PUSH INTO THE MID-90S,
WHICH IS AROUND 10 DEGREES ABOVE NORMAL FOR THIS TIME OF YEAR.
THERE WILL ALSO BE AN INCREASE IN HIGH CLOUDS AND SOME HIGH-BASED
CUMULUS DOWNSTREAM OF A VERY WEAK SHORTWAVE TROUGH. A FEW ECHOES
OF VIRGA AND A BRIEF LIGHT SPRINKLE SHOWER CANNOT BE RULED
TOMORROW EVENING, WITH WEAK MID-LEVEL ASCENT, IN PARTS OF SOUTH-
CENTRAL AND SOUTHEAST AZ.
WHILE A PRONOUNCED EASTERN PACIFIC CUTOFF LOW WILL NEAR THE
NORTHERN CA COAST MONDAY, HIGHER PRESSURE AND WARM SOUTHERLY FLOW
WILL PERSIST ACROSS AZ AND SOUTHEAST CA. AS A RESULT, TEMPERATURES
WILL AGAIN WARM INTO THE MIDDLE 90S ACROSS THE LOWER DESERTS AND
THE CLOUDS WILL CLEAR UP AS THE VERY WEAK SHORTWAVE DEPARTS.
ALTHOUGH, SOME LINGERING MIDLEVEL MOISTURE MAY BE ENOUGH FOR A FEW
AFTERNOON CONVECTIVE SHOWER ACROSS THE EASTERN AZ HIGH TERRAIN,
MAINLY IN THE WHITE MOUNTAIN. THE EASTERLY GRADIENT WIND WILL BE
MUCH WEAKER TOMORROW NIGHT INTO MONDAY, AS THE SOUTHERN PLAINS
SURFACE HIGH SHIFTS FURTHER EAST, WITH NO IMPACTFUL WIND GUSTS
EXPECTED.
LONG TERM /TUESDAY THROUGH FRIDAY/
BY THE MIDDLE OF THE UPCOMING WORK WEEK, THE PATTERN WILL BEGIN
TO SHIFT. THE UPPER LOW OFF THE WEST COAST WILL PUSH INLAND OVER
THE WESTERN US, ALBEIT IN A WEAKENING PHASE. ENSEMBLES ARE IN GOOD
AGREEMENT ON THIS EVOLUTION, BUT DETAILS SUCH AS THE N/S
DISPLACEMENT OF THE LOW AND THE EXACT TIMING/SPEED OF ITS EASTWARD
PROGRESSION REMAIN UNCLEAR. ON A LARGE SCALE, A BROAD AREA OF
POSITIVE MIDLEVEL HEIGHT ANOMALIES LOOKS TO ESTABLISH OFF THE
PACIFIC NORTHWEST/BRITISH COLUMBIA WITH NEGATIVE HEIGHT ANOMALIES
TO ITS SOUTH AND EAST. THIS IS IN RESPONSE TO A SPLIT JET REGIME,
WHERE MUCH OF THE WESTERN AND CENTRAL CONUS FALLS UNDER THE BROAD
CYCLONIC FLOW OF THE POORLY DEFINED SOUTHERN STREAM. AS A RESULT,
WE CAN EXPECT COOLER TEMPERATURES (LIKELY CLOSER TO SEASONAL
LEVELS, IN THE 80S ACROSS THE LOWER DESERTS) WEDNESDAY ONWARD
ACROSS THE FORECAST AREA, AND PERIODS OF BREEZY TO LOCALLY WINDY
CONDITIONS AS SHORTWAVES PROGRESS THROUGH THE DESERT SOUTHWEST.
THE FIRST PERIOD OF INCREASED WINDS WILL LIKELY BE TUESDAY INTO
WEDNESDAY, ESPECIALLY FOR THE WESTERN CWA, AS THE INITIAL, BROAD
UPPER LOW MOVES INLAND AND PACKS HEIGHTS FIELDS OVER THE SOUTHWEST
U.S..
AVIATION
UPDATED AT 1744Z.
SOUTH CENTRAL ARIZONA INCLUDING KPHX, KIWA, KSDL, AND KDVT:
NO MAJOR AVIATION CONCERNS ARE EXPECTED THROUGH THE TAF PERIOD.
GUSTY, EASTERLY WINDS WILL CONTINUE THROUGH THE MORNING INTO THE
EARLY AFTERNOON HOURS, WITH GUSTS BETWEEN 15-20 KTS, BEFORE
RELAXING AND SWITCHING OUT OF THE WEST BY 22-23Z. A LATE SHIFT
BACK TO EASTERLY NEAR MIDNIGHT TONIGHT, AND IS EXPECTED TO REMAIN
THROUGH THE REMAINDER OF THE TAF PERIOD WITH A WESTERLY SHIFT
TOMORROW AFTERNOON CURRENTLY UNLIKELY. GUSTY CONDITIONS WILL
RETURN FOR THE LATE MORNING HOURS TOMORROW, SIMILAR TO THIS
MORNING. MOSTLY CLEAR SKIES THROUGH THE TAF PERIOD, WITH FEW-SCT
HIGH CLOUDS ENTERING THE REGION LATE TONIGHT.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH:
NO MAJOR AVIATION CONCERNS ARE EXPECTED THROUGH THE TAF PERIOD.
AT KIPL, WINDS WILL FAVOR A W/N DIRECTION WITH SPEEDS AOB 6 KTS.
AT KBLH, EXPECT A GRADUAL TRANSITION FROM E TO NW, WITH PERIODS OF
S'RLY DURING THE TRANSITION. SPEEDS AT BOTH TERMINALS WILL BE AOB
6 KTS. SKIES WILL REMAIN MOSTLY CLEAR BEFORE FEW-SCT HIGH CLOUDS
BEGIN TO OVERSPREAD SE CALIFORNIA BY THIS AFTERNOON.
FIRE WEATHER
DRY AND OCCASIONALLY BREEZY CONDITIONS WILL PREVAIL THROUGH THE
NEXT WEEK. WINDS WILL BE LIGHT TODAY, GENERALLY BELOW 15 MPH, AND
THEN A STRONG EASTERLY WIND WILL DEVELOP ACROSS SOUTH-CENTRAL AZ
TOMORROW MORNING. THE STRONGEST WINDS WILL BE OVER THE HIGHER
TERRAIN OF THE EASTERN DISTRICTS, WITH WIND GUSTS PUSHING UP TO
35-45 MPH, BUT SHORTLY AFTER SUNRISE, GUSTS UP TO 25-35 MPH ARE
LIKELY TO BECOME COMMON ACROSS THE LOWER ELEVATIONS. GIVEN THE
TIME OF DAY OF STRONGEST WINDS, RH VALUES WILL BE ABOVE CRITICAL
LEVELS. STILL, SOME LOCALLY ELEVATED FIRE WEATHER CONDITIONS MAY
EXIST ACROSS SOUTH- CENTRAL AZ MIDDAY THROUGH EARLY AFTERNOON
TOMORROW. AFTERNOON MINRHS BELOW 15% AND AT TIMES IN THE SINGLE
DIGITS WILL BE COMMON THROUGH THE NEXT 7 DAYS, WITH MINOR DAY TO
DAY VARIATIONS. OVERNIGHT RECOVERIES WILL ALSO VARY THROUGH THE
NEXT WEEK, BUT FALL MOSTLY IN THE 30-50% RANGE.
PSR WATCHES/WARNINGS/ADVISORIES
AZ...WIND ADVISORY FROM 3 AM TO 11 AM MST SUNDAY FOR AZZ547-552-555-
557-558-560>563.
CA...NONE.
SHORT TERM..BENEDICT
LONG TERM...WHITTOCK
AVIATION...RYAN
FIRE WEATHER...WHITTOCK/BENEDICT
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