808
FXUS65 KFGZ 280910
AFDFGZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
210 AM MST MON SEP 28 2026
SYNOPSIS
RADAR IMAGERY SHOWS STRATIFORM RAIN AND EMBEDDED
SHOWERS ARE DEVELOPING IN WESTERN ARIZONA AND SPREADING ACROSS THE
REST OF NORTHERN ARIZONA THIS MORNING. THE RISK FOR EMBEDDED
THUNDERSTORMS WILL INCREASE DURING THE DAY DUE TO LIMITED DAYTIME
HEATING AND AS A TROUGH NEAR CALIFORNIA CONTINUES TO MOVE
EASTWARD TOWARD THE LOWER COLORADO RIVER VALLEY AND INTERACTS
WITH TROPICAL MOISTURE BEING LIFTED NORTHWARD. HEAVY RAINFALL,
STRONG THUNDERSTORMS AND FLASH FLOODING ARE POSSIBLE TODAY AND
TUESDAY. A FLOOD WATCH REMAINS IN EFFECT THROUGH TUESDAY EVENING.
SHOWER AND THUNDERSTORM CHANCES WILL THEN DECREASE WEDNESDAY AND
WEDNESDAY NIGHT, WITH MILD AND DRY CONDITIONS TO START OFF
OCTOBER.
DISCUSSION
MOISTURE FROM POLO AND THE REMNANTS OF ODALYS
CONTINUE TO OVERSPREAD THE AREA, WITH STRATIFORM RAIN AND
EMBEDDED SHOWERS SPREADING ACROSS NORTHERN AZ AS THE MID/UPPER-
LEVEL TROUGH NEAR CALIFORNIA CONTINUES TO MOVES INTO THE LOWER
COLORADO RIVER VALLEY, WITH AN CLOSED UPPER-LEVEL LOW DEVELOPING
AT THE BASE OF THE TROUGH, THEN SLOWLY MOVING ACROSS THE REGION
TUESDAY. THE RISK FOR EMBEDDED THUNDERSTORMS WILL INCREASE LATER
TODAY AND INTO TUESDAY DUE TO LIMITED DAYTIME HEATING, ALONG WITH
IMPROVED UPPER-LEVEL SYNOPTIC SUPPORT ASSOCIATED WITH THE TROUGH
AND CLOSED LOW. SOME OF THESE THUNDERSTORMS COULD BECOME STRONG TO
SEVERE AT TIMES WITH HEAVY RAIN, STRONG WINDS, AND LARGE HAIL.
WPC CONTINUES TO MESSAGE A MODERATE RISK FOR EXCESSIVE RAINFALL
FOR MOST OF THE REGION FOR TODAY AND THEN SHIFTING FOCUS FOR THE
EASTERN PART OF THE STATE TUESDAY AS THE TROUGH AND CLOSED UPPER-
LEVEL LOW MOVE EASTWARD. A FLOOD WATCH REMAINS IN EFFECT THROUGH
TUESDAY EVENING. WIDESPREAD RAINFALL AMOUNTS OF 1 TO 2 INCHES
FORECAST ACROSS THE HIGH DESERTS OF NORTHEAST ARIZONA HAVE AN
AVERAGE RETURN INTERVAL OF 5 TO 10 YEARS, MAKING THIS AT LEAST AN
UNCOMMON EVENT THERE. LOCALLY HEAVY RAINFALL FROM THUNDERSTORMS,
ALONG WITH UPSLOPING AND OTHER TERRAIN-EFFECTS COULD ALSO LEAD TO
LOCALIZED RAINFALL OF 2-3 INCHES, ESPECIALLY OVER THE HEAVIER
TERRAIN AND EASTERN AZ. HIGH TEMPERATURES ACROSS THE REGION TODAY
AND TUESDAY WILL BE QUITE COOL DUE TO THE CLOUD COVER AND
RAINFALL, 10 TO 20 DEGREES BELOW AVERAGE. BY WEDNESDAY NIGHT,
PRECIPITATION CHANCES START WINDING DOWN IN THE FAR EASTERN PARTS
OF THE STATE AS THE TROUGH SWEEPS EAST AND TAKES THE MOISTURE
PLUME WITH IT.
CONTINUING NOTE: WHILE THE TROPICAL MOISTURE IS ASSOCIATED WITH
TROPICAL SYSTEMS, ODALYS HAS DISSIPATED OVER THE OPEN OCEAN AND
THE CIRCULATION ASSOCIATED WITH POLO WILL NOT ACTUALLY MAKE IT UP
INTO ARIZONA. POLO IS EXPECTED TO MAKE LANDFALL IN BAJA
CALIFORNIA TODAY, CROSS THE GULF OF CALIFORNIA AND BREAK APART TO
OUR SOUTH WHEN IT MAKES LANDFALL AGAIN IN MAINLAND MEXICO.
BY THURSDAY ONWARD DRY AIR FROM THE WEST AND NORTH WILL TAKE OVER
AND LIMIT THE POTENTIAL FOR PRECIPITATION THROUGH THE REST OF THE
WEEK. SOME RIDGING WILL MOVING IN TOWARDS THE END OF THE WEEK
LOOK FOR A PLEASANT START TO OCTOBER AS HIGH TEMPERATURES RECOVER
TO A FEW DEGREES ABOVE AVERAGE.
AVIATION...MONDAY 28/06Z THROUGH TUESDAY 29/06Z
VFR CONDITIONS
TO START THE PERIOD, LOWERING TO MVFR BETWEEN 09Z-12Z. SHOWERS
AND THUNDERSTORMS WILL BECOME MORE NUMEROUS AS THE NIGHT
PROGRESSES BECOMING AREA WIDE DURING THE DAY MONDAY. WINDS
SOUTH 5-15 KTS DAYTIME, LIGHT AND VARIABLE OVERNIGHT. GUSTY AND
ERRATIC WINDS NEAR STORMS.
OUTLOOK...TUESDAY 29/06Z THROUGH THURSDAY 01/06Z...EXPECT SCATTERED
TO NUMEROUS SHOWERS AND THUNDERSTORMS AREA WIDE THROUGH TUESDAY
AFTERNOON WITH THE FOCUS OF PRECIPITATION THEN SHIFTING TOWARDS
EASTERN ARIZONA HEADING INTO WEDNESDAY. LOOK FOR AREAS OF MVFR
CONDITIONS WITH BRIEF IFR CONDITIONS IN HEAVIER SHOWERS AND
THUNDERSTORMS. DAYTIME WINDS VARIABLE AT 5-15 KTS TUESDAY, WEST TO
NORTHWEST AT 5-15 KTS WEDNESDAY. LIGHT AND VARIABLE AT NIGHT.
FIRE WEATHER...TODAY THROUGH TUESDAY
PRECIPITATION CHANCES WILL
PEAK TODAY THROUGH TUESDAY WITH WIDESPREAD WETTING RAIN AND EMBEDDED
THUNDERSTORMS ACROSS THE REGION TODAY AND BECOMING MORE FOCUS
OVER EASTERN ARIZONA BY TUESDAY EVENING. THIS WILL PRESENT A
MODERATE FLOOD AND FLASH FLOOD RISK. WINDS S 5-15 MPH ON TODAY, N-NE
10-20 MPH ON TUESDAY.
WEDNESDAY THROUGH FRIDAY...SOME LINGERING PRECIPITATION CHANCES IN
FAR EASTERN ARIZONA WEDNESDAY, DRYING OUT ELSEWHERE. DRY WITH NO
PRECIPITATION ACROSS THE STATE THURSDAY AND FRIDAY. WINDS NW-N 5-15
MPH ON WEDNESDAY, LIGHT AND VARIABLE 5-10 MPH THURSDAY, LIGHT AND
VARIABLE MOST AREAS FRIDAY WITH THE EXCEPTION OF SOME WINDS E 5-15
MPH ALONG THE RIM.
FGZ WATCHES/WARNINGS/ADVISORIES
FLOOD WATCH THROUGH TUESDAY EVENING FOR AZZ004>018-037>040.
PUBLIC...SCHANK
AVIATION...MCCOLLUM
FIRE WEATHER...SCHANK
FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page