799
FXUS65 KPSR 162127
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
225 PM MST FRI OCT 16 2026
KEY MESSAGES
- WIND ADVISORIES CONTINUE ACROSS PORTIONS OF THE REGION THROUGH
SATURDAY MORNING WITH GUSTS OCCASIONALLY OVER 35 MPH RESULTING IN
AREAS OF BLOWING DUST AND DIFFICULT TRAVEL FOR HIGH PROFILE
VEHICLES.
- A SLIGHT CHANCE OF LIGHT RAIN WILL ARRIVE INTO PARTS OF SOUTH-
CENTRAL ARIZONA OVER THE WEEKEND WITH THE BETTER CHANCES FOCUSED
OVER HIGHER TERRAIN LOCATIONS.
- A PACIFIC LOW PRESSURE SYSTEM MOVING INTO THE SOUTHWEST DURING THE
MIDDLE OF NEXT WEEK WILL LEAD TO MUCH BETTER RAINFALL CHANCES WITH
THE POSSIBILITY OF A FEW EMBEDDED THUNDERSTORMS, AS WELL AS COOLER
TEMPERATURES
SHORT TERM /TODAY THROUGH SUNDAY/
AS FULL LATITUDINAL TROUGHING DEEPENS OVER THE EASTERN CONUS, A
MATURE HIGH AMPLITUDE REX BLOCK REMAINS ESTABLISHED OVER THE WESTERN
HALF OF THE COUNTRY. THIS PATTERN CONTINUES TO PROMOTE STRONG SFC
HIGH PRESSURE OVER THE CENTRAL ROCKIES/HIGH PLAINS, AND COMBINED
WITH INVERTED LOW PRESSURE EMANATING FROM THE GULF OF CALIFORNIA, AN
INTENSE PRESSURE GRADIENT HAS DEVELOPED ACROSS THE CWA. AN H9-H8 30-
50KT EASTERLY LLJ HAS WEAKENED EARLY THIS AFTERNOON AS THE THERMAL
ENHANCEMENT HAS DETERIORATED, BUT LINGERING GUSTY WINDS AND LOFTED
DUST WILL CONTINUE TO IMPACTS MANY AREAS THROUGH THE OVERNIGHT.
WHILE LOWER ELEVATIONS WILL EXPERIENCE PARTIAL DECOUPLING AND MUCH
WEAKER WINDS AFTER SUNSET, RIDGE TOPS AND THE TYPICAL WIND PRONE
AREAS WILL LIKELY CONTINUE TO RECORD GUSTY WINDS PUSHING ADVISORY
CRITERIA THROUGH THE OVERNIGHT. THE COMBINED EFFECT OF A
SIGNIFICANTLY LOOSENED PRESSURE GRADIENT AND THICKER CLOUDS
COMPROMISING MECHANICAL MIXING WILL PRECLUDE ADVISORY CRITERIA
BEYOND SATURDAY MORNING.
THE AFOREMENTIONED REX BLOCK WILL SLOWLY OPEN THIS WEEKEND WITH THE
NEGATIVE HEIGHT ANOMALY PROPAGATING FROM SOUTHERN CALIFORNIA INTO
NORTHERN ARIZONA. THIS PLACES SOUTH-CENTRAL ARIZONA WITHIN A VERY
FAVORABLE LEFT FRONT JET QUADRANT WITH A WEAK COLD CORE SKIRTING THE
FORECAST AREA INDICATIVE OF PERIODS OF ROBUST ASCENT. THE UNDERLYING
SOUTHWEST FLOW WILL ALSO CONCURRENTLY IMPORT THICK MOISTURE THROUGH
THE H7-H5 LAYER SUCH THAT TOTAL COLUMN PWATS REACH 1" BY SATURDAY
AFTERNOON. WHILE THESE PARAMETERS WOULD GENERALLY SUPPORT WIDESPREAD
LIGHT RAIN, A VERY DRY SUB-CLOUD LAYER RESULTING FROM THE PERSISTENT
DOWNSLOPING EASTERLY WINDS WILL BATTLE THE ABILITY FOR PRECIPITATION
REACHING THE GROUND. NEVERTHELESS, GIVEN THE ASCENT STRUCTURE AND
MAGNITUDE OF MIDLEVEL MOISTURE, SOME LIGHT SHOWERS SHOULD REACH THE
SURFACE SATURDAY AFTERNOON THROUGH SUNDAY MORNING WITH THE BEST
CHANCES OVER HIGHER TERRAIN AREAS EAST OF PHOENIX WHERE SFC TO CLOUD
BASE DEPTHS ARE MINIMIZED. OTHERWISE, PARTIAL CLEARING WILL SLOWLY
ADVANCE THROUGH THE FORECAST AREA SUNDAY WITH MOISTURE AND ASCENT
LIFTING INTO NORTHERN ARIZONA.
LONG TERM /MONDAY THROUGH THURSDAY/
THE RIDGE COMPRISING THE NORTHERN PORTION OF THE REX BLOCK WILL PUSH
EASTWARD EARLY NEXT WEEK AS THE UPPER LOW WEAKENS INTO AN OPEN WAVE
AND BECOMES ABSORBED INTO THE MEAN SOUTHWEST FLOW. LINGERING LIGHT
SHOWERS MAY CONTINUE TO AFFECT OROGRAPHICALLY FAVORED AREAS OF THE
EASTERN CWA MONDAY AIDED BY THE NEXT PIECE OF SUBTROPICAL JET ENERGY
ROUNDING TOWARDS THE SOUTHWEST FROM THE EASTERN PACIFIC. IF ACTIVITY
DOES DEVELOP, TOTAL ACCUMULATIONS ARE EXPECTED TO BE FAIRLY MINIMAL.
BY TUESDAY, DEEP TROUGHING AND STRONG NEGATIVE HEIGHT ANOMALIES WILL
AMPLIFY AND INTENSIFY ALONG THE WEST COAST, HOWEVER CONFIDENCE IS
EXACT THE TIMING AND DEPTH OF THIS FEATURE REMAINS LOW TO MODERATE.
AS A RESULT, NOTABLE FORECAST TEMPERATURE SPREAD EXISTS DURING THE
MIDDLE OF NEXT WEEK, IN ADDITION TO UNCERTAINTY IN RAINFALL TIMING
AND AMOUNTS. AT THIS TIME, THE PREPONDERANCE OF MODEL EVIDENCE
POINTS TOWARDS WEDNESDAY AND THURSDAY AS THE MOST LIKELY TO
EXPERIENCE SHOWERS AND EMBEDDED THUNDERSTORMS AHEAD OF THE TROUGH
PASSAGE AND THE INTRODUCTION OF MUCH COOLER, BELOW NORMAL AUTUMNAL
TEMPERATURES.
AVIATION
UPDATED AT 1805Z.
SOUTH CENTRAL ARIZONA INCLUDING KPHX, KIWA, KSDL, AND KDVT:
STRONG GUSTY E'RLY WINDS AND SLANTWISE VISIBILITY REDUCTIONS DUE TO
LOFTED DUST WILL PERSIST THROUGH THE REST OF THE DAY. E'RLY WINDS
WILL CONTINUE TO GUST CONSISTENTLY UP TO 20-30 KTS, WITH OCCASIONAL
STRONGER GUSTS UP TO 35 KTS, THROUGH THIS AFTERNOON. STRONG
GUSTINESS SHOULD SUBSIDE TONIGHT AT MOST TERMINALS, BUT ELEVATED
SURFACE SPEEDS IN THE TEENS WILL LIKELY PREVAIL THROUGH THE
OVERNIGHT HOURS, WITH AN OCCASIONAL GUST INTO THE 20S. GUSTS TO 30
KTS WILL STILL BE POSSIBLE AT KSDL AFTER MIDNIGHT. ALL TERMINALS
WILL SEE A RESURGENCE OF GUSTS UP TO 23-30 KTS SATURDAY MORNING, BUT
THEN WINDS WILL GRADUALLY SUBSIDE THROUGH SATURDAY AFTERNOON.
SLANTWISE VISIBILITY IMPACTS ARE LIKELY THROUGH AT LEAST SATURDAY
MORNING. THICK MID AND HIGH CLOUD DECKS WILL SPREAD INTO THE AREA
THROUGH THE DAY SATURDAY.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH:
BREEZY CONDITIONS THROUGH THIS AFTERNOON WILL BE THE MAIN AVIATION
CONCERN. NORTH-NORTHEAST FLOW WILL BE COMMON THROUGHOUT THE PERIOD,
WITH PERIODIC GUSTS UPWARDS OF 25 KTS (OCCASIONALLY HIGHER) AT KBLH
AND SLIGHTLY WEAKER AT KIPL. MOSTLY CLEAR SKIES WILL GIVE WAY TO
INCREASING MID TO HIGH CLOUDS THROUGH THE AFTERNOON AT KIPL AND BY
THIS EVENING AT KBLH. AN ISOLATED SHOWER CANNOT BE RULED OUT
OVERNIGHT, BUT CHANCES ARE TOO LOW FOR INCLUSION IN THE TAF.
FIRE WEATHER
STRONG EAST WINDS WILL CONTINUE THROUGH SATURDAY ACROSS SOUTHERN
ARIZONA WITH THE MOST PRONOUNCED GUSTS OVER MOUNTAIN TOPS OF EASTERN
DISTRICTS DURING THE OVERNIGHT AND EARLY MORNING HOURS. GUSTS 40-45
MPH MAY BE COMMON OVER THESE LOCATIONS WITH A PORTION OF THESE WINDS
BUILDING INTO LOWER ELEVATIONS BY LATE MORNING. SPEEDS WILL SLOWLY
DECREASE THROUGH THE DAY WITH EVEN WEAKER WINDS SUNDAY THROUGH THE
MIDDLE OF NEXT WEEK. LIGHT SHOWERS ARE POSSIBLE THIS WEEKEND, AND
PARTICULARLY OVER EASTERN DISTRICTS, BUT THE CHANCE FOR WETTING
RAIN IS LOW (~10%). THE STRONG EAST WINDS WILL RESULT IN MINIMUM
HUMIDITY LEVELS 20-30% SATURDAY, BUT INCREASING CLOSER TO A 30-50%
RANGE THEREAFTER. OVERNIGHT RECOVERY SHOULD BE GOOD TO EXCELLENT. A
PACIFIC WEATHER DISTURBANCE WILL BRING INCREASED CHANCES OF WETTING
RAINFALL, BREEZY WINDS, AND COOLER TEMPERATURES DURING THE LATTER
HALF OF NEXT WEEK.
PSR WATCHES/WARNINGS/ADVISORIES
AZ...WIND ADVISORY UNTIL 11 AM MST SATURDAY FOR AZZ547-552-553-555-
557-558-560>562.
WIND ADVISORY UNTIL 3 PM MST THIS AFTERNOON FOR AZZ531>534-536-
538-539-554-559.
WIND ADVISORY FROM 8 AM THIS MORNING TO 3 PM MST THIS AFTERNOON
FOR AZZ537-540>546-548>551.
CA...NONE.
SHORT TERM...18
LONG TERM...18/RYAN
AVIATION...BENEDICT
FIRE WEATHER...18/RYAN
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