####018002665#### FXUS65 KFGZ 121645 AFDFGZ Area Forecast Discussion National Weather Service Flagstaff AZ 945 AM MST Fri Dec 12 2025 .SYNOPSIS...High pressure will continue to bring well above normal temperatures and dry weather to the region into next week. && .DISCUSSION...For today, an anomalously strong high pressure system will remain in place across northern Arizona, leading to another round of dry weather and near record warmth. High temperatures are expected to be between 10-20 degrees above average. Yesterday, a high temperature of 68 degrees was observed at the Flagstaff Airport. This tied the daily record set in 1950. Flagstaff may tie or break today's daily high temperature record of 64, set all the way back in 1921. This unusually strong high pressure system will largely dominate northern Arizona's weather through next week, with fair weather and near record warmth forecast to continue. On Sunday and Monday, high temperatures may dip a couple of degrees due to passing high clouds and influences associated with a weak shortwave trough forecast to overtop the ridge. Otherwise, light winds are forecast through Tuesday. On Wednesday, the ridge flattens, resulting in breezier southwest winds with speeds in the 10-20 mph range. && .AVIATION...Friday 12/18Z through Saturday 13/18Z...VFR conditions and light/variable winds expected through the period. Localized NE breezes 10-20 kts possible 06Z-16Z downwind of higher terrain in Yavapai County. OUTLOOK...Saturday 13/18Z through Monday 15/18Z...VFR conditions expected, with increasing high clouds Saturday evening through Sunday. Light and variable winds forecast for most areas through the weekend. Localized NE breezes 10-20 kts possible 06Z-16Z each day downwind of higher terrain in Yavapai County. && .FIRE WEATHER...Friday and Saturday...Dry and warm conditions continue with temperatures reaching 10-20 degrees above average. Light and variable daytime winds around 5 to 15 mph each day. Minimum RH values 15-35% each afternoon. Sunday through Tuesday...Dry and warm conditions will continue into next week with temperatures 10-15 degrees above average Sunday and Monday and 10-20 degrees above average on Tuesday. Light and variable daytime winds around 5 to 15 mph each day. Minimum RH values between 20-35% Sunday and Monday, and 15-25% on Tuesday. && .FGZ WATCHES/WARNINGS/ADVISORIES...None. && $$ PUBLIC...RR AVIATION...JJ FIRE WEATHER...RR For Northern Arizona weather information visit weather.gov/flagstaff ####018007109#### FXUS63 KDTX 121648 AFDDTX Area Forecast Discussion National Weather Service Detroit/Pontiac MI 1148 AM EST Fri Dec 12 2025 .KEY MESSAGES... - Bitter cold temperatures for the weekend into Monday. - The coldest period looks to be Saturday night and Sunday morning, when wind chill readings are forecast to drop to 5 to 15 degrees below zero. - A couple opportunities to get a little light snow, particularly this evening/tonight and on Monday. Otherwise, localized snow along the southern Michigan border Saturday afternoon, and along the eastern Thumb shoreline Sunday. - A dramatic warmup is then forecasted Tuesday-Thursday next week, as temps likely push aoa 40 degrees, setting the stage for potential rain. && .AVIATION... Sfc high pressure over Se Mi and dry ambient airmass has caused a general erosion of the stratus across much of Se Mi. Developing southwest flow in advance of an approaching cold front will focus the stratus deck across the MBS and FNT region this afternoon. Forecast expansion of the low clouds late this afternoon evening will increase chances for low cloud re expansion across the remainder of the terminals later in the day. The cold front is forecast to track across Se Mi between 06Z and 12Z Saturday morning. Frontal convergence and enhancement off Lake Mi will support an area of light snow showers along/in advance of the front. The overall brief period of stronger forcing will keep snow accums less than an inch. For DTW...The window of opportunity for snow showers will be between 06Z and 10Z. A forecast weakening of the forcing as the front moves across Se Mi suggests just a potential for a dusting of accumulation overnight DTW THRESHOLD PROBABILITIES... * Low in ceilings below 5000 feet this afternoon. Moderate tonight and low Sunday. && .PREV DISCUSSION... Issued at 248 AM EST Fri Dec 12 2025 DISCUSSION... A shortwave tracking through far southern Lake Michigan has helped sustain clouds over much of southern Lower Michigan, holding temps in the low to mid 20s at press time. Areas which cleared out, northern Thumb region, tanked into the single numbers. Inversion heights are forecasted to lower slightly, thus still opportunity for low clouds to scour out and temps to dip, but there is also some high clouds noted across the area. Strong PV Anomaly over the Central Canada with additional upper level energy coming out of the Gulf of Alaska on track to move through the Central Great Lakes Saturday and Saturday night. Bitter cold arctic airmass will overspread Lower Michigan, with -30 to -32 C advertised at 700 MB, with Lake Michigan modified 850 MB temps of -20 C or slightly colder for second half of the weekend. Meanwhile, aggressive height falls tracking through the northern Great Lakes this evening, tapering off toward the southern Michigan border. None- the-less, with west-southwest flow coming off Lake Michigan and the low level convergence/fgen of the arctic front moving through, a period of scattered-numerous snow showers looks likely as 1.75-2.0 g/kg of 850 MB specific humidity tracks through Saturday evening- night. With short lived forcing at any given location (<3 hrs), would expect accumulations of a dusting to less than an inch. Excellent drying and subsidence to follow frontal passage, with mean 850-700 MB dew pts depressions of 25 C taking hold over the bulk of southeast Michigan. This will be key, as very strong Jet streak (90- 100 knots at 500 MB) and another impressive 500 MB height fall center tracks through the northern Ohio Valley during Saturday/Saturday evening. Locations along and especially south of I- 94 could get clipped with the northern fringe of the snow shield, but the forcing/airmass is colder than the DGZ, and snowflakes should be fine, and thus would only expected another dusting to perhaps an inch right along the border. As usual with the very dry arctic airmass, tough to gauge how much lake clouds/light snow showers/flurries make it eastward Saturday night, as surface dew pts of -15 to -20 F spread into Wisconsin. Even if skies do in fact clear out, looks like surface winds will not be able to fully decouple, with light surface winds preventing temps from cratering much below zero. Euro ensembles indicating 40- 50 percent chance of 2M temps dropping at or below zero over central sections of the CWA at 12z Sunday. None-the-less, that will place wind chills in the 10 to 15 below zero range. Will have to keep a close eye on the eastern Thumb shoreline on Sunday as winds do look to veer around to the north-northwest as the mid level cold pool/wave exits the Central Great Lakes. Shortwave coming over the top of the upper level ridge over the Rockies swings through Lake Huron on Monday. Pretty good isentropic ascent progged with just enough moisture to support light snow showers, epsecially as one heads north. Right now, 00z Canadian looks to be one of the more aggressive solutions, with 5 hundreths to a tenth of an inch of qpf. NBM pops have at least increased to more solid chance pops. Warm air breaking off from the upper level ridge off the West Coast next week as the upper level flow transitions to the zonal over the northern Conus by mid week. NBM temps indicating low to mid 40s by Thursday with a good chance of rain as next deepening low pressure system enters the picture. MARINE... Elongated area of high pressure remains centered over the region today before sliding southward into the Ohio Valley this evening into tonight. This will provide a brief period of lower winds and wave heights today which ramp back up tonight in advance of the next low pressure system. This low will track across Ontario Friday night while pulling an arctic front across the region. This very cold airmass will again bring increased westerly winds across the area with wide spread gusts to 30 knots across much of Lake Huron and sporadic gusts to gales possible during the weekend as 850 MB temps plummet to -20 C. At a minimum, another round of Small Craft Advisories will need to be issued at some point for tonight through much of the weekend as the arctic air holds over the region. This cold airmass and elevated winds will also lead to potential snow squalls and freezing spray as well. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...None. Lake Huron...Small Craft Advisory from 10 PM this evening to 4 AM EST Monday for LHZ421-441. Small Craft Advisory from 10 PM this evening to 4 PM EST Saturday for LHZ422. Lake St Clair...None. Michigan waters of Lake Erie...None. && $$ AVIATION.....SC DISCUSSION...SF MARINE.......DRK You can obtain your latest National Weather Service forecasts online at www.weather.gov/detroit.