191
FXUS65 KPSR 112005
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
105 PM MST SUN MAY 11 2025
SYNOPSIS
TEMPERATURES WILL COOL THROUGH THE MIDDLE OF THE WEEK AS A DRY
WEATHER SYSTEM MOVES INTO THE REGION. ASSOCIATED WITH THIS WEATHER
DISTURBANCE, GUSTY WINDS WILL BE COMMON THE NEXT SEVERAL DAYS.
TEMPERATURES SHOULD SLOWLY REBOUND DURING THE LATTER HALF OF THE
WEEK EVENTUALLY HOVERING AROUND THE SEASONAL NORMALS.
DISCUSSION
A BLOCKING PATTERN WHICH HAS PREDOMINATED THE CONUS WILL SLOWLY OPEN
OVER THE NEXT SEVERAL DAYS AS A SERIES OF PROGRESSIVE PACIFIC
DISTURBANCES AND STRONG JET ENERGY DISLODGE CUTOFF NEGATIVE HEIGHT
ANOMALIES ACROSS THE LOWER MISSISSIPPI RIVER VALLEY. H5 HEIGHTS NEAR
585DM OVER THE SW CONUS WHICH HAVE SUPPORTED TEMPERATURES SOME 10F
ABOVE NORMAL WILL GRADUALLY ERODE CLOSER TO 572DM OVER THE NEXT 72
HOURS AS MODEST HEIGHT FALLS ENTER THE REGION. WHILE THE PRIMARY
COLD CORE/CIRCULATION CENTER AND STRONGEST FORCING WILL REMAIN NORTH
OF THE FORECAST AREA, SUFFICIENT JET ENERGY AND HIGHER MOMENTUM
WITHIN A SEASONALLY DEEP MIXING DEPTH WILL RESULT IN PERIODICALLY
GUSTY WINDS EARLY IN THE WEEK. WITH MODELS DEPICTING 25-35KT WINDS
DEVELOPING IN A H8-H7 LAYER CORRESPONDING TO THE INCOMING HEIGHT
FALLS AND WEAKENING FRONTAL BOUNDARY, CONFIDENCE IS VERY GOOD THAT
ENHANCED GUSTS WILL IMPACTS MUCH OF THE REGION BEGINNING IN SE
CALIFORNIA MONDAY, THEN MIGRATING EASTWARD TUESDAY. AN ENHANCED FIRE
DANGER AND LOCALIZED BLOWING DUST MAY BE THE MOST SIGNIFICANT
HAZARDS WITH THIS WEATHER SYSTEM PASSAGE.
ALTHOUGH THE CONUS PATTERN WILL REMAIN SLOWLY PROGRESSIVE DURING THE
LATTER HALF OF THE WEEK, SOME MEASURE OF BROAD CYCLONIC, OR QUASI-
ZONAL FLOW WILL SETTLE OVER THE SOUTHWEST. AS SUCH, FORECAST
CONFIDENCE IS GOOD THAT H5 HEIGHTS SHOULD HOVER IN A 576-579DM RANGE
WITH THE PATTERN CONFIGURATION PROHIBITING SIGNIFICANT HEIGHT RISES
OR RAPID WARMING. INSTEAD, NARROW GUIDANCE SPREAD SUGGESTS READINGS
RETURNING TO A NEAR NORMAL MID-MAY LEVEL PERSISTING INTO THE
WEEKEND. ENSEMBLE SPREAD STARTS GROWING NOTABLY TOWARDS THE END OF
THE PERIOD AS MEMBERSHIP IS SPLIT BETWEEN MAINTAINING NEGATIVE
HEIGHT ANOMALIES OVER THE SW CONUS, OR SHIFTING MEAN TROUGHING INTO
THE EASTERN CONUS AND ALLOWING BROAD RIDGING TO MATERIALIZE OVER THE
FORECAST AREA. CMC MEMBERS REMAIN THE MOST AMPLIFIED WITH NEGATIVE
ANOMALIES CENTERED OVER THE FORECAST AREA WITH TRENDS IN GEFS
MEMBERSHIP POINTING TOWARDS HIGHER PROBABILITIES OF AMPLIFIED
HEIGHTS AND/OR FLAT RIDGING. AT THIS TIME, THESE DISPARATE SOLUTIONS
FORM AN ENSEMBLE MEAN NOT FAR FROM A TYPICAL, DRY QUASI-ZONAL MAY
PATTERN.
AVIATION
UPDATED AT 1745Z.
SOUTH CENTRAL ARIZONA INCLUDING KPHX, KIWA, KSDL, KDVT:
EAST WINDS WILL RELAX TO AOB 10 KTS OVER THE NEXT COUPLE HOURS AS
THEY VEER OUT OF THE SSE AND THEN SW BY 21-23Z THIS AFTERNOON.
OCCASIONAL AFTERNOON AND EVENING SW/W GUSTS INTO THE MID TEENS ARE
ANTICIPATED. EXPECT SOMEWHAT TYPICAL TIMING FOR A NOCTURNAL E/SE
WIND SHIFT TONIGHT, BETWEEN 07-09Z. WITHIN A FEW HOURS AFTER SUNRISE
MONDAY MORNING, EXPECT WINDS TO PICK UP OUT OF THE SSE, CREATING A
LIGHT (6-10 KT) SOUTHERLY CROSS-RUNWAY WIND COMPONENT AT KPHX AND
KDVT, BEFORE DIRECTIONS SHIFT SW LATE MORNING. GUSTS TO BETWEEN 20-
25 KTS WILL BE COMMON MONDAY AFTERNOON. SKIES WILL REMAIN MOSTLY SCT-
BKN WITH CLOUD DECKS AOA 15 KFT AGL.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH:
GUSTY SOUTHWEST WINDS WILL BE THE PRIMARY AVIATION CONCERN THROUGH
THE TAF PERIOD UNDER SCT-BKN HIGH CLOUDS. WINDS WILL TEND TO SHIFT
FROM SOUTH/SOUTHEAST TO SOUTHWEST AT BOTH TERMINALS BY MID-LATE
AFTERNOON. ONCE WINDS SHIFT SOUTHWEST, EXPECT GUSTS TO AROUND 20 KTS
TO BECOME COMMON. WHILE GUSTS ARE EXPECTED TO CEASE AT KBLH
OVERNIGHT, THEY MAY REMAIN ELEVATED AT KIPL THROUGH THE OVERNIGHT
HOURS AND INCREASE FURTHER AFTER SUNRISE MONDAY MORNING.
FIRE WEATHER
AN ELEVATED FIRE DANGER WILL EXIST MONDAY AND TUESDAY AS WARM
TEMPERATURES, LOW HUMIDITY LEVELS, AND GUSTY WINDS BECOME JUXTAPOSED
WITH RECEPTIVE, DRY FINE FUELS. AFTERNOON HUMIDITY LEVELS IN THE
TEENS WILL BE COMMON THROUGHOUT THE WEEK FOLLOWING POOR TO FAIR
OVERNIGHT RECOVERY OF 20-50%. WIND SHOULD BE STRONGEST MONDAY AND
TUESDAY WITH GUSTS 25-35 MPH DURING THE AFTERNOON AND EARLY EVENING.
GUSTS WILL LIKELY BE MOST PRONOUNCED ACROSS RIDGE TOPS AND IN THE
TYPICAL DOWNSLOPING AREAS. SPEEDS SHOULD WEAKEN DURING THE LATTER
HALF OF THE WEEK, THOUGH STILL WILL RETAIN THE USUAL UPSLOPE
GUSTINESS. TEMPERATURES WILL ALSO COOL DURING THE MIDDLE OF THE WEEK
AS THE WEATHER SYSTEM MOVES INTO THE REGION, HOWEVER SHOULD REBOUND
CLOSER TO THE SEASONAL NORMAL BY THE END OF THE WEEK.
PSR WATCHES/WARNINGS/ADVISORIES
AZ...NONE.
CA...WIND ADVISORY FROM 5 AM MONDAY TO 5 AM PDT WEDNESDAY FOR CAZ562.
DISCUSSION...18
AVIATION...WHITTOCK
FIRE WEATHER...18
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page