680
FXUS65 KFGZ 041024
AFDFGZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
324 AM MST FRI SEP 4 2026
SYNOPSIS
THERE WILL BE A GRADUAL INCREASE IN SHOWER AND
THUNDERSTORM COVERAGE TODAY INTO THE WEEKEND, AS MOISTURE STARTS
TO PUSH NORTHWARD. THE HIGHEST CHANCES WILL BE IN EASTERN ARIZONA
TODAY, SHIFTING TOWARD NORTHWEST ARIZONA BY SUNDAY. EXPECT BREEZY
SOUTHWEST WINDS TO START EASING THIS WEEKEND, ALONG WITH SLIGHTLY
BELOW NORMAL TEMPERATURES CONTINUING INTO EARLY NEXT WEEK.
DISCUSSION
A LARGE UPPER LOW WILL REMAIN OVER THE NW UNITED
STATES THROUGH THE WEEKEND WITH HIGH PRESSURE TO OUR EAST. THIS
RESULTS IN CONTINUED SOUTH-SOUTHWESTERLY FLOW OVER OUR REGION.
SOME SHALLOW MOISTURE HAS BEEN PULLED NORTHWARD INTO GILA AND
SOUTHERN NAVAJO/APACHE COUNTIES, RESULTING IN A FEW SHOWERS. THIS
MOISTURE IS FORECAST TO SHIFT EASTWARD THROUGH THE DAY, WITH THE
HIGHEST CHANCES FOR ADDITIONAL SHOWERS AND THUNDERSTORMS (30-60%)
EAST OF A PAYSON TO FOUR CORNERS LINE, WITH ONLY LOW CHANCES
(5-15%) FARTHER WEST. A FEW STORMS COULD CONTAIN HEAVY RAINFALL
AROUND THE WHITE MOUNTAINS. BY SATURDAY, MOISTURE IS FORECAST TO
INCREASE FROM SOUTH TO NORTH THROUGH THE DAY WITH ISOLATED TO
SCATTERED SHOWERS AND THUNDERSTORMS. SOME OF THIS MOISTURE IS
SURGING NORTHWARD FROM DISTANT HURRICANE MARIE, WHICH IS FORECAST
TO BE AROUND 700 MILES WEST OF THE SOUTHERN TIP OF THE BAJA
PENINSULA BY SATURDAY AFTERNOON AND HEADING NORTHWESTWARD.
EXTENSIVE CLOUD COVER MAY LIMIT INSTABILITY FOR MANY AREAS, SO
STORM INTENSITY REMAINS UNCERTAIN. BY SUNDAY, A SHORTWAVE
DISTURBANCE IS SHOWN BY MUCH OF THE GUIDANCE MOVING ACROSS
SOUTHERN NV INTO UT WHILE EVEN DEEPER MOISTURE IS SHOWN IN THE
LATEST GRAND ENSEMBLE MOVING INTO NORTHWEST ARIZONA. MEAN PRECIPITABLE
WATER VALUES FROM THE 00Z ENSEMBLES ARE IN THE 1.00"-1.25" RANGE
FOR MUCH OF OUR AREA, HIGHEST IN NORTHWEST ARIZONA. THESE VALUES
ARE IN THE 85-95TH PERCENTILE, WITH VALUES AROUND THE 98TH
PERCENTILE IN NORTHWEST COCONINO COUNTY. EVEN WITH EXTENSIVE CLOUD
COVER, THE SHORTWAVE MAY PROVIDE ENOUGH LIFT FOR SOME HEAVIER
SHOWERS AND THUNDERSTORMS IN THE NORTHWEST CORNER OF THE STATE.
STORM CHANCES ARE UP TO 50-70% IN THIS AREA WHICH INCLUDES THE
GRAND CANYON/SUPAI. WPC HAS INCLUDED THIS AREA IN A SLIGHT RISK
FOR EXCESSIVE RAINFALL/FLASH FLOODING ON SUNDAY, AND THIS WILL
NEED TO BE MONITORED CLOSELY. THE PLACEMENT OF THE HEAVIER
RAINFALL RISK IS STILL NOT CERTAIN, AND COULD END UP BEING FARTHER
NORTHWEST INTO NV/UT. BY MONDAY AND TUESDAY, RAINFALL CHANCES
SHIFT TO MAINLY EASTERN ARIZONA. MID TO LATE NEXT WEEK ARE LOOKING
ACTIVE AGAIN AS A FAVORABLE MONSOON PATTERN SETS UP.
AVIATION...FRIDAY 04/12Z THROUGH SATURDAY 05/12Z
EXPECT MAINLY
VFR CONDITIONS. ISOLATED TO SCATTERED -SHRA/-TSRA ALONG/SOUTH OF
A KPAN-KRQE LINE TODAY, DIMINISHING BY 03Z. ONLY ISOLATED
-SHRA/-TSRA WEST OF THIS LINE 19Z-03Z. DAYTIME SFC WINDS SW 15-25
KTS GUSTING UP TO 30KTS, DECREASING TO 5-10 KTS AFTER 02Z.
OUTLOOK...SATURDAY 05/12Z THROUGH MONDAY 07/12Z...EXPECT MAINLY VFR
CONDITIONS. ISOLATED TO SCATTERED -SHRA/-TSRA FOR SATURDAY AND
SUNDAY. ACTIVITY MOST LIKELY WEST OF A KFLG-KPGA LINE, AND OVER
SOUTHERN APACHE COUNTY. DAYTIME SFC WINDS SW 5-15 KTS.
FIRE WEATHER...TODAY AND SATURDAY
MAINLY DRY AND BREEZY
CONDITIONS TODAY WEST OF A PAYSON TO FOUR CORNERS LINE WITH
SCATTERED SHOWERS AND THUNDERSTORMS ALONG AND EAST OF THIS LINE. ON
SATURDAY, ISOLATED TO SCATTERED ACTIVITY SPREADS AREA WIDE. WINDS
TODAY SOUTHWEST 10-20 MPH WITH GUSTS 25 TO 35 MPH, STRONGEST ACROSS
NORTHWEST ARIZONA. SATURDAY'S WINDS SOUTHWEST 10-15 WITH GUSTS TO 25
MPH. LITTLE CHANGE IN TEMPERATURES.
SUNDAY THROUGH TUESDAY...INCREASING MOISTURE WILL CAUSE SHOWER AND
THUNDERSTORM COVERAGE TO EXPAND. HIGHEST CHANCES FOR RAINFALL WILL
BE SEEN ON SUNDAY, ESPECIALLY IN NORTHWEST ARIZONA. WINDS SOUTH
THROUGH SOUTHWEST 5-15 MPH EACH DAY, THEN GENERALLY LIGHT AND
VARIABLE OVERNIGHT. LITTLE CHANGE IN TEMPERATURES.
FGZ WATCHES/WARNINGS/ADVISORIES
NONE.
PUBLIC...JJ
AVIATION...JJ
FIRE WEATHER...JJ
FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF
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