Area Forecast Discussion
Issued by NWS Flagstaff, AZ
Issued by NWS Flagstaff, AZ
Versions:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
390 FXUS65 KFGZ 131054 AFDFGZ Area Forecast Discussion National Weather Service Flagstaff AZ 354 AM MST Thu Nov 13 2025 .SYNOPSIS...Above normal temperatures and dry conditions continue through Friday. An approaching storm system will then bring cooler temperatures, gusty winds, and chances for rain and mountain snow over over the weekend. Continued cooler, and unsettled conditions look to continue into the next week. && .DISCUSSION...Today and Friday...Heights begin to gradually fall over the next couple of days as high pressure shifts eastward ahead of an approaching low off the Pacific. As such, temperatures begin to cool each day along with increasing cloud cover. Dry conditions look to prevail for the vast majority, however a few isolated showers can not be totally ruled out over western Arizona late Friday. Saturday and Sunday...The low off the Pacific begins to break off from the jet and become more a closed-low by Saturday. Southerly flow begins to increase, leading to an increase in moisture advection across the state with areas of precipitation developing in the later half of the day as a result. As the low ejects off the Pacific late Saturday and early Sunday, frontogenetic forcing should lead to an area of moderate to heavy precipitation developing early Sunday. This area of precipitation is then expected to move west to east across the state as it continues through the day. Overall QPF amounts have not change too much with recent runs, outside of a slight uptick. Guidance seems to continue to favor about 0.50-1.00 inches along and south of the higher terrain, with some locally higher amounts in the typical upslope areas. North of the Rim, QPF amounts look to taper off greatly, with generally around to tenth to a quarter of an inch of liquid expected. Guidance continues to favor a warmer solution with this storm. Thus, much of the precipitation will fall as rain, at least through the first part of the storm with 700 mb temperatures largely above 0C. As cold air advection increases behind the front late in the day Sunday, temperatures aloft begin to fall back to around -1C to -3C. This would support snow levels falling from an initial 8000-8500 feet down to around 7000 feet. Thus, some light snowfall is possible Sunday night, however any accumulations will be minimal. The best shot at accumulating snow will be elevations at or above 8000 feet; namely the San Francisco Peaks, Kaibab Plateau, Chuska Mountains, and the White Mountains. Strong, gusty south/southwest winds are also expected as the storm approaches. As of now, the strongest gusts are forecast to occur on Sunday for much of the area. Gusts upwards of 30-40 mph look probable, mainly along and downwind (north) of the Mogollon Rim. Monday through Wednesday...Heights briefly rise on Monday, given a brief reprieve a more active pattern. Although, it does appear that some showers will likely linger through the day. A secondary cut-off low looks to move into the southwest, which looks to keep cooler temperatures and increased precipitation changes through at least the start of the week. Guidance continues to waver on exactly how much colder air is introduced with this system. Of the 00Z guidance, the CMC favors a warmer (all rain) solution, while the ECMWF has a deeper, colder low (better chances for snow) over northern Arizona. The GFS seems to fall in the middle of the pack, but still favors snow levels being on the higher side. As a result, uncertainty near the end of the forecast period still remains high. && .AVIATION...Thursday 13/12Z through Friday 14/12Z...Look for VFR conditions with the exception of local haze/smoke due to prescribed burns. Light/variable winds through 17z, becoming south 5-10 kts with gusts up to 20 kts through 01Z, then light/variable overnight. OUTLOOK...Friday 14/12Z through Sunday 16/12Z...VFR conditions are forecast. Isolated rain showers developing Friday evening through Saturday morning, along and west of a KPAN-KPGA line. Rain chances increase and spread eastward from Saturday afternoon through Sunday, with areas of MVFR and local IFR conditions. Winds south at 5-10 kts gusting to 20 kts on Friday increasing to 10-15 kts gusting to 25 kts on Saturday. && .FIRE WEATHER...Today and Friday...Dry with temperatures 10 degrees above average today, around 5 degrees cooler for Friday. By Friday evening, there is a low chance of rain west of I-17/US89. Afternoon winds S-SW 10-15 mph with gusts up to 20 mph. Minimum afternoon RH 15-25% Thursday, increasing to 20-35% Friday. Saturday through Monday...Colder and unsettled weather is expected. The highest precipitation chances are from late Saturday through Sunday, primarily in the form of rain with snow levels down near 8000 feet by Sunday. Precipitation chances decrease to 10-40% Monday. Winds SE-S 10-20 mph on Saturday, SW 15-20 mph gusting up to 30 mph Sunday and SW 10-15 mph on Monday. && .FGZ WATCHES/WARNINGS/ADVISORIES...None. && $$ PUBLIC...Humphreys AVIATION...JJ FIRE WEATHER...JJ For Northern Arizona weather information visit weather.gov/flagstaff