731
FXUS65 KPSR 121027
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
327 AM MST FRI JUN 12 2026
KEY MESSAGES
- TEMPERATURES HOVERING AROUND 3 TO 8 DEGREES ABOVE DAILY NORMALS
WILL RESULT IN WIDESPREAD MODERATE HEAT RISK, WITH ISOLATED POCKETS
OF MAJOR HEAT RISK AT TIMES, THROUGH THE MIDDLE OF NEXT WEEK.
- AN INCREASE IN MOISTURE TODAY AND INTO THE WEEKEND WILL LEAD TO
SLIGHT CHANCES FOR SHOWERS AND STORMS, WITH BETTER CHANCES CURRENTLY
FOCUSED DURING MORNING AND OVERNIGHT PERIODS.
- OVERNIGHT LOW TEMPERATURES WILL BE NOTICEABLY WARMER AS A RESULT
OF THE INCREASED HUMIDITY, WITH MANY OF THE TYPICALLY WARMER LOWER
DESERT LOCALES STRUGGLING TO COOL BELOW 80 DEGREES.
SHORT TERM /TODAY THROUGH SUNDAY/
MOISTURE LEVELS HAVE RAPIDLY INCREASED ACROSS THE FORECAST AREA IN
THE LAST 12 HOURS, AS A PUSH OF SOUTHERLY FLOW ALOFT AND GULF SURGE
YESTERDAY EVENING HAVE WORKED IN TANDEM TO RAPIDLY MOISTEN THE LOWER
AND MIDDLE LEVELS OF THE COLUMN. DEWPOINT TEMPERATURES IN THE 50S
ARE NOW OBSERVED ACROSS MUCH OF THE LOWER DESERTS, WITH SOME
READINGS AS HIGH AS THE 60S IN THE IMPERIAL VALLEY AND YUMA AREA.
THE FORECAST REMAINS LARGELY ON TRACK, WITH THE FORECAST AREA
POSITIONED UNDER AN AREA OF EXCELLENT UPPER LEVEL DIVERGENCE BETWEEN
AN UPPER LOW OFF THE NORTHERN BAJA AND A SUBTROPICAL ANTICYCLONE
CENTERED SOMEWHERE CLOSE TO EL PASO/WEST TEXAS. AN INITIAL VORTICITY
LOBE EJECTED NORTHWARD ALONG THE LOWER CO RIVER VALLEY, WITH 500 MB
RAP ANALYSIS CURRENTLY PLACING IT NEAR THE CHOCOLATE MOUNTAINS IN
IMPERIAL COUNTY. AHEAD OF THIS FEATURE, A SHIELD OF WEAK RADAR
ECHOES HAS SPREAD OUT ACROSS THE AREA, STRETCHING FROM SOUTHEAST CA
TO AS FAR EAST AS THE PHOENIX METRO. A COUPLE EMBEDDED, WEAK
CONVECTIVE CELLS WERE OBSERVED AND PRODUCED A FEW STRIKES OF
LIGHTNING WITHIN THIS INITIAL SHIELD OF CLOUDS/RADAR ECHOES, AND
THIS ISOLATED THREAT FOR LIGHTNING WILL REMAIN THROUGH AT LEAST THE
REST OF THE MORNING. CAMS CONTINUE TO PROVIDE A CONSENSUS OF SPOTTY
(AT BEST) SHOWER ACTIVITY ACROSS THE AREA TODAY, WITH ALMOST ALL
AREAS SEEING NO MEASURABLE RAINFALL.
ON SATURDAY, THE MODEL CONSENSUS IS FOR MORE FAVORABLE
THERMODYNAMICS FOR DEEP, MOIST CONVECTION ACROSS PORTIONS OF AZ,
HOWEVER, BETTER SYNOPTIC ASCENT MECHANISMS BECOME DISPLACED TO THE
WEST AS THE SUBTROPICAL HIGH ASSERTS ITSELF CLOSER TO SONORA. NEAR-
SURFACE MIXING RATIOS BETWEEN 9-10 G/KG ARE SHOWN ACROSS SOUTHWEST
AND SOUTH-CENTRAL AZ SATURDAY, WITH GFS BUFR SOUNDINGS IN YUMA AND
PHOENIX INDICATING MUCAPE UPWARDS OF 250 J/KG TO AS MUCH AS 750
J/KG. LINGERING SYNOPTIC ASCENT, A SOMEWHAT SHALLOW, SATURATED LAYER
AROUND 650 MB, AND GRADUALLY STEEPENING LAPSE RATES, WOULD SUGGEST
THAT AT LEAST ISOLATED COVERAGE OF ELEVATED SHOWERS/STORMS WILL
DEVELOP SOMEWHERE ACROSS THE AREA SATURDAY MORNING AND BEGIN TO
TRACK NORTHEASTWARD AS FLOW ALOFT SHIFTS OUT OF THE SOUTHWEST. BY
THE AFTERNOON, SHOWER AND THUNDERSTORM ACTIVITY WILL BECOME
RELEGATED PRIMARILY TO THE NORTHERN AZ HIGH TERRAIN. IF AN ORGANIZED
OUTFLOW WERE TO DEVELOP AND BE STRONG ENOUGH AND PUSH DOWNHILL INTO
THE LOWER ELEVATIONS, IT IS CONCEIVABLE FOR SOME CONVECTION TO SPARK
OVER THE FOOTHILLS OF NORTHEASTERN MARICOPA COUNTY SATURDAY
EVENING, BUT AGAIN, RAINFALL POTENTIAL WILL BE FAIRLY LIMITED. THE
SUSTAINED SOUTHWESTERLY TO WESTERLY FLOW ALOFT WILL CONTINUE TO
DRY THE REGION SUNDAY, BUT NOT ENOUGH TO PRECLUDE THE POSSIBILITY
OF AFTERNOON SHOWERS AND STORMS ONCE AGAIN OVER THE HIGH TERRAIN
AND PORTIONS OF SOUTHEAST AZ.
AS THE SUBTROPICAL HIGH ASSERTS ITSELF CLOSER TO THE REGION THIS
WEEKEND, SLIGHTLY WARMER TEMPERATURES ARE LIKELY TO MATERIALIZE,
THOUGH H5 HEIGHTS WILL REMAIN LARGELY IN A 588-591 DAM RANGE THROUGH
THE WEEKEND. AS SUCH, ANTICIPATE TEMPERATURES TO REMAIN IN A 3F-8F
ABOVE NORMAL RANGE, WITH LOWER DESERT HIGHS MOSTLY BETWEEN 104F-111F
AND OVERNIGHT LOWS FROM THE MIDDLE 70S TO THE MIDDLE 80S. THIS
WEEKEND, THE OVERNIGHT LOWS WILL BE ABOVE THEIR NORMAL VALUES BY
AROUND THE SAME MAGNITUDE AS THE HIGHS, WHICH WOULD ALMOST NEVER BE
THE CASE IF CONDITIONS WERE SEASONABLY DRY FOR MID JUNE. THESE
TEMPERATURES WILL RESULT IN WIDESPREAD MODERATE HEATRISK; THOUGH
NOT MAJOR (EXCEPT FOR A FEW ISOLATED POCKETS), THIS IS A LEVEL OF
HEAT THAT CAN POSE A RISK TO ANYONE, ESPECIALLY IF NOT TAKING THE
PROPER PRECAUTIONS.
LONG TERM /MONDAY THROUGH THURSDAY/
ALTHOUGH UNCERTAINTY REMAINS IN THE UPPER LEVEL PATTERN NEXT WEEK
AND ESPECIALLY BY THE END OF THE WEEK, ENSEMBLES CONTINUE TO
ADVERTISE H5 HEIGHT ALOFT REMAINING FAIRLY STABLE THROUGH AT LEAST
THE FIRST HALF OF THE WEEK AND DRY (ALBEIT WEAK) WESTERLY OR
NORTHWESTERLY FLOW BEING MAINTAINED. TEMPERATURES MAY WARM A FEW
DEGREES TUESDAY AND/OR WEDNESDAY UNDER SLIGHTLY DRIER CONDITIONS
AND A PERIOD OF STRONGER SUBSIDENCE, AS SUGGESTED BY DEEPER
MIDLEVEL INVERSIONS IN MODEL SOUNDINGS, RESULTING IN SLIGHTLY
HIGHER COVERAGE OF MAJOR HEATRISK FOR A DAY OR TWO. EXTREME HEAT
PRODUCTS MAY NEED TO BE CONSIDERED FOR THIS TIMEFRAME, BUT
CONFIDENCE IS CURRENTLY LOWER THAN USUAL ON THE TEMPERATURE
FORECAST, AS IT HAS BEEN FLUCTUATING A FEW DEGREES UP OR DOWN WITH
EACH RUN OVER THE LAST FEW DAYS. REGARDLESS, TEMPERATURES 3F-8F
ABOVE NORMAL WILL PERSIST THROUGH AT LEAST THE MIDDLE OF NEXT
WEEK, AND MODERATE HEATRISK WILL BE WIDESPREAD.
AVIATION
UPDATED AT 0505Z.
SOUTH CENTRAL ARIZONA INCLUDING KPHX, KIWA, KSDL, AND KDVT:
WINDS WILL BE THE PRIMARY WEATHER ISSUE THROUGH FRIDAY NIGHT UNDER
PERIODS OF THICK MID/HIGH CIGS. CONFIDENCE IS GOOD THAT W/SW WINDS
WILL PERSIST WELL INTO THE OVERNIGHT BEFORE ATTEMPTING TO SWITCH TO
EASTERLY. HOWEVER, SOME LOCATIONS (SUCH AS KPHX) MAY NEVER TRULY
OBTAIN AN EASTERLY FETCH FRIDAY MORNING, BUT RATHER JUST BECOMING
VARIABLE BEFORE RAPIDLY SWITCHING BACK TO A WESTERLY COMPONENT BY
LATE MORNING. VIRGA MAY BE COMMON ACROSS THE AREA FRIDAY MORNING,
AND IT WOULDN'T BE IMPOSSIBLE FOR A FEW SHOWERS TO DEVELOP WITHIN
THE PHOENIX AIRSPACE. OTHERWISE, WIDESPREAD GUSTS ~20KT IS LIKELY
FRIDAY AFTERNOON/EVENING.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH:
THE CHANCE FOR SCATTERED SHRA FRIDAY MORNING WILL BE THE MAIN
WEATHER ISSUE UNDER PERIODS OF MID/HIGH CIGS. CONFIDENCE IS GOOD
THAT W/SW WILL REVERT BACK TO S/SE OVERNIGHT, AND MAINTAIN THOSE
HEADINGS INTO THE AFTERNOON. HAVE NOT INCLUDED A VCSH MENTION IN
THIS TAF PACKAGE, HOWEVER A FEW SHRA WILL BE POSSIBLE OVERNIGHT
THROUGH FRIDAY MORNING WITH PERIODS OF VIRGA COMMON. SOME ENHANCES
GUSTS 20-25KT ARE POSSIBLE AT KBLH LATE AFTERNOON.
FIRE WEATHER
TEMPERATURES 3-8 DEGREES ABOVE NORMAL WILL PREVAIL WITH LOWER
DESERT HIGHS NEAR 110F IN SOME OF THE HOTTER SPOTS, ESPECIALLY
OVER THE WEEKEND. IMPROVED HUMIDITY LEVELS WILL PREVAIL THROUGH
THE WEEKEND, WITH AFTERNOON MINIMUMS MOSTLY ABOVE 15% AND
OVERNIGHT RECOVERIES IN A POOR TO FAIR CATEGORY, WITH VALUES AS
LOW AS 25% IN THE FAR WESTERN DISTRICTS AND BETWEEN 35-50% FOR
MOST OTHER AREAS. WITH THE INCREASING MOISTURE WILL ALSO COME
SLIGHT CHANCES FOR ISOLATED SHOWER AND THUNDERSTORM ACTIVITY.
CHANCES WILL BECOME ALMOST ENTIRELY CONFINED TO THE HIGH TERRAIN
OF THE EASTERN DISTRICTS BY SATURDAY AFTERNOON. RAINFALL
POTENTIAL WILL BE LIMITED, SO LOCALLY GUSTY OUTFLOW WINDS AND DRY
LIGHTNING POTENTIALLY LEADING TO NATURAL FIRE STARTS ARE THE MAIN
CONCERNS. THE OVERALL WIND PATTERN WILL REMAIN DIURNAL WITH
SPEEDS AT OR BELOW 15 MPH AND AFTERNOON/EARLY EVENING UPSLOPE AND
UPVALLEY GUSTS UP TO 25 MPH.
PSR WATCHES/WARNINGS/ADVISORIES
AZ...NONE.
CA...NONE.
SHORT TERM...WHITTOCK
LONG TERM...WHITTOCK
AVIATION...18
FIRE WEATHER...WHITTOCK
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