180
FXUS65 KFGZ 041639
AFDFGZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
940 AM MST SUN MAY 4 2025
SYNOPSIS
A LARGE AREA OF LOW PRESSURE WILL BRING COOLER
TEMPERATURES AND INCREASED CHANCES FOR PRECIPITATION TODAY THROUGH
WEDNESDAY. WARM AND DRY WEATHER FORECAST TO RETURN THURSDAY ONWARD.
DISCUSSION
A DEEP AND COLD UPPER LOW (FOR MAY) IS NOW NEAR PALM
SPRINGS AND WILL MOVE EASTWARD TODAY AND TONIGHT, BEFORE SLOWING
DOWN AND SPLITTING ON MONDAY. THE LOW THEN RECONSOLIDATES NEAR THE
FOUR CORNERS MONDAY NIGHT AND TUESDAY, WHILE FILLING AND WARMING. A
TRAILING LOW MOVES INTO THE TROUGH POSITION OVER ARIZONA ON
WEDNESDAY.
THIS IS A COMPLICATED PATTERN, WITH MANY DIFFERENT ASPECTS TO LOOK
AT. CONVECTION AHEAD OF THE LOW TODAY MAY PRODUCE A FEW STRONGER
THUNDERSTORMS, WHILE PRECIPITATION TONIGHT MAY ENHANCE ALONG A COLD
FRONT. THEN, WRAPAROUND PRECIPITATION AFFECTS THE AREA MONDAY AND
MONDAY NIGHT, WITH CONVECTIVE ELEMENTS CONTINUING INTO TUESDAY. THE
TRAILING LOW WILL MOVE INTO A MOIST AIR MASS WEDNESDAY, WITH MORE
POTENTIALLY SIGNIFICANT CONVECTION BREAKING OUT.
ADDITIONALLY, WE WILL HAVE GUSTY PRE-FRONTAL WINDS TODAY, BUT OUR
RELATIVE HUMIDITY LEVELS AND WIND SPEEDS AVOIDS THE NEED FOR ANY
HEADLINES. SNOW LEVELS IN THE CORE OF THE LOW LATER TONIGHT AND
MONDAY WILL PRODUCE AREAS OF SNOW ABOVE 6500-7500 FEET, WITH A FEW
BRIEF TROUBLE SPOTS POSSIBLE FROM FLAGSTAFF WESTWARD.
WHEN THIS IS ALL SAID AND DONE, MANY AREAS THROUGH WESTERN AND
CENTRAL ARIZONA MAY SEE QPF AMOUNTS FROM 1-2". ANOTHER LATE SEASON
GIFT THAT MAY ALLOW US TO AVOID A DANGEROUS FWX SEASON BEFORE THE
MONSOON ARRIVES IN LATE JUNE.
ALL THIS IS COVERED IN THE CURRENT PACKAGE, WE WILL EXAMINE SNOW
LEVELS A BIT CLOSER THIS AFTERNOON PACKAGE. NO SHORT TERM UPDATES
NEEDED.
AVIATION...SUNDAY 04/12Z THROUGH MONDAY 05/12Z
ISOLD -SHRA ARE
MOVING NORTHWEST ACROSS WEST OF KSEZ-KGCN LINE. -SHRA/-TSRA WILL
INCREASE ACROSS THE AREA AFTER 16Z THROUGH AROUND 02Z. MVFR
POSSIBLE IN HEAVY SHOWERS. SHOWERS WILL CONTINUE THEREAFTER,
BEGINNING TO TURN TO -SHSN AT HIGH ELEVATION SITES AROUND 03-06Z.
WINDS BECOMING S 15-25 KTS WITH GUSTS UP TO 35 KTS 16Z-02Z. GUSTY
AND RAPIDLY CHANGING WIND ARE POSSIBLE NEAR SHOWERS.
OUTLOOK...MONDAY 05/12Z THROUGH WEDNESDAY 07/12Z...CONTINUED
AREAS OF -SHRA/-SHSN AND SOME ISOLATED -TSRA THROUGHOUT THE
PERIOD, WITH THE BEST CHANCES AFTER 12Z MONDAY. CONDITIONS MAY
DROP TO MVFR/IFR IN HEAVIER SHOWERS. WINDS ARE SW 10-15 KTS ON
MONDAY, THEN W 5-10 KTS ON TUESDAY. GUSTY AND RAPIDLY CHANGING
WIND ARE POSSIBLE NEAR SHOWERS.
FIRE WEATHER...TODAY THROUGH MONDAY
COOLER WITH SHOWERS AND
THUNDERSTORMS AT TIMES. ACCUMULATING SNOW POSSIBLE ABOVE 6500-7000
FEET LATE TONIGHT AND MONDAY. SOUTHERLY THROUGH SOUTHWEST WINDS
INCREASING TO 15 TO 20 MPH, WITH GUSTS TO 25 TO 35 MPH TODAY.
SOUTHWEST WINDS DECREASE TO 10 TO 15 MPH ON MONDAY.
TUESDAY THROUGH THURSDAY...COOL AND SHOWERY WEATHER CONTINUES
TUESDAY, WITH DECREASING COVERAGE WEDNESDAY. BECOMING DRY AND MUCH
WARMER THURSDAY. SOUTHWEST THROUGH WEST WINDS 10 TO 15 MPH TUESDAY.
WINDS MORE WEST-NORTHWESTERLY ON WEDNESDAY, LIGHT AND VARIABLE TO
NORTHEAST ON THURSDAY.
FGZ WATCHES/WARNINGS/ADVISORIES
NONE.
PUBLIC...PETERSON
AVIATION...MAS
FIRE WEATHER...JJ
FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF
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