####018008118#### FXUS63 KDLH 092212 AFDDLH Area Forecast Discussion National Weather Service Duluth MN 412 PM CST Tue Dec 9 2025 .KEY MESSAGES... - Snowfall associated with a clipper is moving into the Northland from the west now, and will continue spreading eastward this afternoon and evening. Greatest accumulations have shifted southward, with less than 2 inches now expected north of US-2. - A period of several hours of heavy snow with rates around 1 inch per hour is expected late this afternoon through this evening. - Cold temperatures and additional chances of precipitation are expected later this week into next week. && .DISCUSSION... Issued at 242 PM CST Tue Dec 9 2025 SUMMARY OF HEADLINE CHANGES: - Winter Weather Advisory for central St.Louis and southern Lake County areas has been cancelled. - Winter Weather Advisory for Itasca County remains in effect. - Winter Storm Warning for Carlton/South St. Louis, Douglas, Sawyer, and Price counties was downgraded to a Winter Weather Advisory. - Winter Storm Warning remains in effect for Cass, Aitkin, Crow Wing, Pine, Burnett, and Washburn counties. - Winter Weather Advisory remains in effect for Bayfield, Ashland, and Iron counties. ---------- Snowfall associated with the second clipper of the week has spread across portions of the Northland, with snow falling from the Brainerd Lakes region southeastward to the I-35 corridor. This area will continue to spread eastward this afternoon and evening, with snowfall ending early Wednesday morning with lake effects showers continuing through Wednesday for portions of northwest Wisconsin. The main axis of snowfall has shifted southward with the latest model guidance, leaving little to no accumulation north of US2. Several adjustments were made to headlines to reflect the southward shift in snowfall totals. See those changes above. The surface low associated with the clipper is now over southeast ND and will continue diving quickly to the southeast, crossing into southern WI tonight. The better forcing will clip our southwest and southern counties through this evening. Steep lapse rates aloft and saturated profiles through the column will allow for moderate to heavy snowfall, with rates of 1-1.5in per hour possible. There will likely be a swath of 5-6 inches somewhere from southern Cass County to Burnett County, and it might be a very narrow axis, with a dropoff northward to the US-2 corridor, where 1-3 inches is expected from Itasca County southeastward to the Twin Ports. Drier low level air behind yesterday's clipper has remained over the Arrowhead this afternoon, and coupled with the shift southward of the better forcing, this will further limit snowfall across the BWCA and Arrowhead. Winds have been slower to increase across the Northland and western Lake Superior, with the slightly weaker low and pressure gradient, and remain weak this afternoon. An increase in winds is expected as the surface low moves into west central MN this evening, but there will be less time for North Shore lake effect bands near the head of the lake. While it is still possible, winds will quickly turn to the northeast and then north, limiting the potential for enhancement from the Twin Ports up the North Shore. The snowfall totals in those area were adjusted downward this afternoon. Winds become northerly quickly early Wednesday, as the low is well to our south and mid level winds become northwesterly. Snowfall associated with the clipper will exit to the south and east, but could see lake effect showers on the South Shore linger through the day. A lobe of forcing within the backside of the upper trough will shift over western areas tomorrow, and light snow showers or flurries will remain possible through the day. There might an additional half inch of accumulation across the Brainerd Lakes area during the morning. Colder air arrives behind this clipper for Wednesday and Thursday, with temperatures 10-12 degrees below normal. Another clipper will bring light snowfall to the area Thursday afternoon into Friday, with light accumulations. More significant impact for the end of the week is the much colder air arriving for the weekend, with temperatures 20-25 degrees below normal. Highs on Saturday will likely remain below 0F, with wind chills in the -25 to -30F range. Cold weather headlines will likely be needed. && .AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/... Issued at 1141 AM CST Tue Dec 9 2025 A strong clipper will impact the Northland beginning this afternoon with snowfall arriving at BRD by 20Z, and spreading eastward through the late afternoon/early evening. For the next few hours, light flurries are possible, mainly where cigs are below 1kft with winds gradually increasing from the east to southeast. Some fluctuation in cigs are possible before the arrival of snow, with a mix of VFR down to IFR heights. Heaviest snowfall is expected in a band, south of US-2, mainly impacting BRD to south of HYR. At times, snowfall rates of 1-1.5"/hr are possible, reducing vis to less than 1 mile. Outside of this heavy snow band, snow chances reduce from south to north, with no mentionable snow chances at INL. Cigs will settle to MVFR at most terminals through the afternoon, and falling to IFR tonight at BRD, DLH, and HYR. Breezy easterly winds will back to the northeast as the surface low moves to our south, with gusts of 22-28kts, and back further to the north early Wednesday morning. Snowfall will end early Wednesday morning, with gusty north winds continuing through the end of the forecast period. && .MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/... Issued at 242 PM CST Tue Dec 9 2025 Another fast-moving clipper will pass to the south of the lake tonight through Wednesday afternoon. Winds will back northeasterly and strengthen this evening and will become hazardous for small craft. Gales of 35 to 40 knots are forecast from Taconite Harbor to Grand Portage where a Gale Warning is in effect. Small Craft Advisories go into effect at 10 pm tonight for the remainder of the waters. Wind gusts of 25 to 30 knots are expected. There is a 30-40% change of Gales spreading southward to the Outer Apostles and South Shore zones after midnight tonight, and the Gale Warning might need to be expanded. Additionally, waves will build to 3 to 7 feet over the southwest arm and along the waters of the South Shore. As the clipper departs on Wednesday winds will back northwesterly and diminish. Small Craft Advisories will likely be needed for portions of the North Shore from late Wednesday morning through Wednesday evening. Cold air moving over the high terrain will likely lead to katabatic winds from Silver Bay to Grand Portage. Wind and waves will then relax for Thursday before increasing again on Friday. For the open water discussion, refer to the NWS Marquette Area Forecast Discussion at weather.gov/mqt. && .DLH WATCHES/WARNINGS/ADVISORIES... MN...Winter Weather Advisory until 3 AM CST Wednesday for MNZ018- 026. Winter Storm Warning until 3 AM CST Wednesday for MNZ025- 033>036. Winter Weather Advisory until 6 AM CST Wednesday for MNZ037. Winter Storm Warning until 9 AM CST Wednesday for MNZ038. WI...Winter Weather Advisory until 6 AM CST Wednesday for WIZ001. Winter Weather Advisory until noon CST Wednesday for WIZ002>004-008-009. Winter Storm Warning until 9 AM CST Wednesday for WIZ006-007. MARINE...Small Craft Advisory from 10 PM this evening to 10 AM CST Wednesday for LSZ121-142>148-150. Gale Warning from 10 PM this evening to 10 AM CST Wednesday for LSZ140-141. && $$ DISCUSSION...HA AVIATION...HA MARINE...HA ####018007632#### FXUS65 KCYS 092212 AFDCYS Area Forecast Discussion National Weather Service Cheyenne WY 312 PM MST Tue Dec 9 2025 .KEY MESSAGES... - The long duration wind event continues, with wind gusts expected to peak Tuesday. While some breaks or lulls will occur, high winds will be a concern every day through Saturday. - A cold front will bring a banded rain and snow showers late Tuesday afternoon through the evening. This will also bring a brief reprieve from the wind into Wednesday morning. - High winds return Wednesday with another round of High Wind Watches in place for the southeast Wyoming wind prones and wind prone adjacent areas. && .SHORT TERM /THROUGH THURSDAY/... Issued at 307 PM MST Tue Dec 9 2025 High Wind Warnings are performing excellent with most zones consistently verifying throughout the day. Peak gusts have occurred in the usual wind prones with frequent gusts over 80 MPH. Wind prone adjacent areas have see gusts in the 70s and the high plains have seen 50 to 60+ MPH winds. High winds will continue through the afternoon hours as steep MSLP and height gradients keep winds aloft above 55 kts. A cold front moving into the CWA this evening will effectively shut off the winds as MSLP gradients weaken and winds turn more northwesterly. This break, however, will be short-lived as the next round of high winds is progged to start Wednesday morning. The incoming cold front will likely bring some precipitation to the CWA this evening and overnight. Based off Hi-Res guidance, precipitation looks scattered and almost convective in nature as weak pockets of instability exist. Given the instability and lingering strong winds, squall-like showers could be possible, especially overnight when precipitation is more likely to be snow. Some light snowfall could be possible for the high valleys west of the Laramie Range, but accumulations should generally stay under an inch. Winter Weather Advisories are in place for the Snowy and Sierra Madre this afternoon through Wednesday morning as the front will bring good mid-level moisture and upslope flow to the high terrain. Accumulations will be between 6 and 12 inches with the highest peaks expected to see more. High winds will return to the area once again on Wednesday as the the 250 mb jet streak continues to linger over the region. A series of weak upper-level disturbances will traverse the CWA throughout the day, allowing a surface trough to develop in lee of the Laramie Range. This surface trough will cause MSLP and height gradients along and west of the Laramie Range to steepen, increasing winds aloft. Luckily, the parameters for this event do not look as severe or as widespread as the event currently ongoing. However, the wind prone locations can still expect to see gusts over 70 MPH and wind prone adjacent areas could see gusts over 60 MPH. Winds will gradually begin to increase throughout the morning hours, with mixing helping to get some of these winds down to the surface during the afternoon. For now, decided to leave the High Wind Watches in place for this secondary event. Upgrades to these Watches are likely, however did not want to upgrade quite yet with High Wind Warnings currently in place for the ongoing event. High Wind Watches are in place for the usual southeast Wyoming wind prones and wind prone adjacent areas. High winds are likely to continue into Wednesday night as gradients remain steep and winds aloft remain strong. Subsidence should be more than sufficient to get these winds down to the surface. It comes as no surprise that high winds are likely to continue through the day Thursday. Gradients remain tight with roughly a 15 mb gradient expected over the CWA. This will allow winds aloft to remain in the 55 to 65 kt range with strong downward omegas. The biggest change to the forecast package came with the modification of ending times for this second high wind event. The GFS keeps the strong winds around longer than previous runs, so decided to extended the High Wind Watches through Thursday evening. Besides the never ending winds, Thursday will be quite warm thanks to a warm front that will move across the region late Wednesday night. Temperatures east of the Laramie Range will make it into the upper 50s and 60s! This will put temperatures about 20 degrees above average for mid-December! && .LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/... Issued at 307 PM MST Tue Dec 9 2025 As this high wind event finally begins to tail off into the weekend the wind prones will likely still need a warning for the better part of Friday and possibly Saturday as well. With the active jet once again impinging upon the area and the ridge getting nudged back west, 50-55+ kt 700mb flow will once again become entrenched over the southeast WY plateau. Given this low level wind max and pressure/height gradients remaining favorable, high winds are likely to persist into the early weekend (midday Saturday) in the wind prone areas of I-80 and I-25 near Bordeaux. With confidence still not quite there in terms of start/end timing combined with the warning soup that is the preceding few days will hold off on any additional headlines for now to try and avoid any confusion. Beyond what seems to be the unending high winds is a good downslope airmass which look to take hold (really starting today) and not let go well into next week as highs frequently climb into the 50s near the Colorado stateline for Friday/Saturday, and for all areas east of I-25 Sunday and beyond into the middle half of next week. Look forward to this weekend for some calmer December weather. && .AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/... Issued at 1025 AM MST Tue Dec 9 2025 MVFR cigs may sneak into RWL and LAR this afternoon into early tonight but the main story remains the anomalous high wind event. Gusts upwards of 60-70kts in the Wyoming terminals and 50kts in the Nebraska sites will linger through the evening with gusts dropping below 30kts for all sites by or around 12z. Much more tranquil for most tomorrow as winds turn SW outside the mountains and sustained winds under 15 mph. A few snow showers are possible mainly for Wyoming sites this afternoon as well and could briefly drop vis to 4-6sm in any heavier showers. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...High Wind Warning until 8 PM MST this evening for WYZ101-102- 104-105-108-109-119. High Wind Watch from Wednesday morning through Thursday afternoon for WYZ101-107. High Wind Warning until midnight MST tonight for WYZ103-106- 107-113>115-117-118. High Wind Watch from late tonight through Thursday afternoon for WYZ104-109. High Wind Watch from Wednesday morning through Thursday afternoon for WYZ105-113-115. High Wind Warning from 9 AM Wednesday to midnight MST Thursday night for WYZ106-117. High Wind Warning until 5 AM MST Friday for WYZ110-116. Winter Weather Advisory until 11 AM MST Wednesday for WYZ112- 114. High Wind Watch from Wednesday morning through Thursday evening for WYZ118. NE...High Wind Warning until 8 PM MST this evening for NEZ002-003- 019>021-054-055-095-096. && $$ SHORT TERM...SF LONG TERM...WFOCYS AVIATION...WFOCYS