Arizona Snowbowl

000
FXUS65 KFGZ 312350
AFDFGZ

Area Forecast Discussion
National Weather Service Flagstaff AZ
450 PM MST Sat Oct 31 2026

.SYNOPSIS...Isolated to scattered showers continue through this 
afternoon, then become more widespread tonight through Sunday. Heavy 
rain is expected with flash flooding possible across the entire 
region. This is a serious situation. Stay tuned to your favorite 
weather source and find a way to receive warnings. Stay away from 
waterways. Turn around, don't drown.

&&

.DISCUSSION...A soggy Halloween weekend is expected overall but 
Halloween night is shaping up to be dry in most places. 

Moisture continues to surge northward ahead of an approaching trough 
this afternoon. The trajectory of the moisture combined with some 
shallow instability, will allow for upslope showers to develop and 
continue into this afternoon, especially along and south of the 
Mogollon Rim. 

The deepening west coast trough will be the catalyst for the next 
round of heavy rainfall from late tonight through Sunday. As we head 
into this evening, moisture continues to increase and with the mid-
level flow strengthening and rain becoming more widespread across 
the region. Expect increased activity with moderate to heavy rain to 
continue from late tonight into Sunday. On Sunday, the trough starts 
to push to the east. This will drag a strong cold front through the 
area, further enhancing the heavy rain into Sunday evening, plus 
adding a marginal severe risk for Sunday. Main severe hazards will 
be a damaging wind threat. While conditions are not ideal for 
rotating storms, we cannot rule out an isolated tornado, mainly 
across the southern most parts of our forecast area. Models continue 
to hit the precipitation aspect of the event hard, especially along 
and south of the Mogollon Rim. PWATs remain well above normal with 
values ranging between 1.0"-1.5" through much of the region. The 
already saturated grounds will exacerbate flooding concerns and in 
some areas we may see sharp rises on creeks and streams with what we 
would normally consider relatively light rainfall amounts. Rainfall 
totals remain highest along and south the Mogollon Rim, with totals 
between 3"-6". Other areas may see 1"-3" with locally 4"+ possible. 
The Flash Flood Watch remains in effect through late Sunday night 
for the entire forecast area. It is not often we see a moderate 
excessive rainfall outlook across our area from the Weather 
Prediction Center, so please heed all warnings and road closures 
throughout the event. 

** There is potential for significant hydrological issues to 
continue due to the very wet antecedent conditions. Both flash 
flooding and river flooding will be a problem, with some area 
waterways remaining elevated for days beyond the main event. Be 
prepared in case you need to take action or need to head to higher 
ground. Have a way to receive warnings and always remember, TURN 
AROUND, DON'T DROWN! **

In addition to the rain, there is the potential for a period of 
strong, gusty winds from late tonight through Sunday, especially 
along and east of the Mogollon Rim. The pressure gradient really 
tightens up in advance of the approaching trough and winds may gust 
30-40 mph at times. Event through the winds look to largely remain 
below advisory levels, with the very wet conditions some trees may 
be at risk of uprooting/falling.  

The trough finally moves out of the area on Monday, with a few 
lingering showers possible across eastern Arizona. Conditions 
quickly dry out but with colder air arriving, some areas may see 
rain turn to snow before all is said and done. Best chances for any 
accumulating snow looks to be across the Kaibab Plateau, San 
Francisco Peaks, and Buffalo Pass/Chuska Mountains. 

A ridge tries to build in behind the departing trough but a low 
remaining off to our north helps to flatten out the flow through the 
middle of the week. Overall, looks like to may be a brief period of 
warming and drying out before the next trough/cur-off low moves 
towards our area. 

&&

.AVIATION...Sunday 01/00Z through Monday 02/00Z...WDSPRD MVFR/IFR 
overspreads the region from south to north through 06Z, and remains 
through the TAF period. Periods of IFR/LIFR possible in +RA and lows 
CIGS over the higher terrain. Winds SE-SW 5-10 kts through 15Z, then 
becoming S/SW 10-20 kts with gusts 30-40 kts.

OUTLOOK...Monday 02/00Z through Wednesday 04/00Z...WDSPRD MVFR/IFR 
in +RA/RA through 12Z-16Z Monday, then VFR. Areas of LIFR possible 
in FG/low CIGS over the higher terrain. Winds W/NW 5-15 kts Monday, 
becoming NW-NE Monday night into Tuesday.

&&

.FIRE WEATHER...Rest of today through Monday...Isolated showers 
expected mainly along and south of Mogollon Rim through the late 
afternoon hours of today, then steadily increasing through the 
evening and then expanding northward. By tonight, a major rainfall 
event will begin. Expect an extended period of moderate to heavy 
rainfall, along with embedded thunderstorms. lasting through Monday 
morning. Southerly winds today, 10 to 20 mph. Winds increase Sunday, 
especially over the eastern zones, with southwest winds 15 to 25 mph 
and gusts around 30 to 35 mph, potentially reaching as high as 35 to 
45 mph in the higher terrain. A cold front will push most of the 
precipitation out of the region late Monday morning or early Monday 
afternoon. Winds are also expected to shift west through northwest 
around 10 to 20 mph, with gusts around 25 mph in eastern Arizona.

Tuesday through Thursday...A drier weather pattern is expected 
through this period. Easterly winds 5 to 15 mph Tuesday, turning 
back southwesterly 5 to 15 mph for Wednesday. Winds are then 
expected to become light Thursday.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...
Flood Watch from 11 PM MST /midnight MDT/ this evening through 
late Sunday night for AZZ004>018-037>040.

&&

$$

PUBLIC...Meola
AVIATION...Humphreys
FIRE WEATHER...Schank

For Northern Arizona weather information visit
weather.gov/flagstaff