####018007060#### FXUS63 KDVN 090955 AFDDVN Area Forecast Discussion National Weather Service Quad Cities IA IL 355 AM CST Tue Dec 9 2025 .KEY MESSAGES... - Freezing rain possible during evening commute today, especially across northwest Illinois and extreme eastern Iowa mainly along/north of Hwy 30. - Vigorous snow showers and the possibility of snow squalls will accompany a strong cold frontal passage overnight/early Wednesday morning. - Windy conditions tonight/Wednesday with peak gusts possibly 45-50+ mph timed for a several hour period after a cold front moves through. - Additional clipper systems will likely result in periods of accumulating snow Thursday through Sunday. - Temperatures will drop for the weekend with wind chills well below zero Friday and Saturday night. && .SHORT TERM /THROUGH WEDNESDAY/... Issued at 341 AM CST Tue Dec 9 2025 Initial clipper system and attendant WAA wing of light snow has moved off to the east early this morning. Lingering low stratus extends across parts of NE Iowa and N Illinois and monitoring for any freezing drizzle potential in continued WAA. However, saturation depth is in question and higher ceilings generally show to where this potential seems very low, but non-zero at this time. Meanwhile, upstream the next clipper system is diving southeast toward the Northern Plains early this morning. This system will deepen as it dives through the Upper Midwest tonight/early Wednesday with ensemble and deterministic guidance in decent agreement on a sub 990 mb surface low tracking from MN through WI. There remains continued uncertainty with how warm temps will get today given the snow cover and cloud cover, particularly across the north. Have continued to follow toward cooler raw models for highs today versus warmer NBM, especially across the northern counties. Thus, have temps only into the lower 30s there, but low to mid 40s far south. WAA wing of precipitation is anticipated to push through the cwa late today through this evening, with soundings generally supportive of limited ice to where the bulk of the precipitation is expected to fall in the form of rain. Surface temps will be critical for freezing rain potential, and with the freezing line anticipated to be in our north this would support areas near/north of Hwy 30 with the best chance for a transient period of freezing rain leading to potential for some slippery travel for the evening commute. Thus, have opted for a Winter Weather Advisory for much of the area north of Hwy 30. Ahead of the clipper this evening we'll see south winds turn more westerly and turn gusty with gusts over 30+ mph and temperatures continuing to warm ahead of an attendant cold front, thus the freezing rain potential looks to be rather fleeting at only a couple hours at any one location across our northern counties. Overnight into Wednesday morning we'll see a strong cold front sweep across the area. Some of the hi-res guidance is supporting the potential for some robust snow showers and possibly snow squalls accompanying the front given some weak surface based instability and saturation coupled with with lapse rates reaching well into the DGZ. Momentum transfer supports potential for some gusty winds possibly over 40-45+ mph leading to sharply reduced visibilities and possibly a quick minor coating of snow. After the front and snow showers sweep through, the signal remains for at least advisory criteria winds through the morning on Wednesday with strong CAA and impressive 50+ kt winds at 850 mb along with a unidirectional profile and steep lapse rate environment. Question is what's the best approach for a headline given the complex nature of the setup between transient short period of impactful snow showers/squalls, and concerns for ground blizzard - mainly with neighbors north/west. In terms of the ground blizzard the feeling is age of recent added snow (3 days) coupled with warming at or above freezing all locations briefly this evening/tonight and also some light rain/freezing rain may work in tandem to limit this potential in our region. Bottom line, since we've still got some time wanted to allow for that to continue to assess and nail down the risk and appropriate headline(s). && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... Issued at 341 AM CST Tue Dec 9 2025 The pattern looks to remain active throughout the period with clipper systems bringing precip chances about every couple of days or so. With that, the deterministic models and ensembles are starting to converge on the next clipper and snow chance arriving by Thursday night. Amounts look to be light with this system. Arctic air will follow by the weekend. There is a signal for a stronger clipper system potentially on Saturday, which combined with colder SLRs in the arctic airmass may result in the potential for several inches of accumulation for parts of the area. Blustery winds will also accompany the arctic air and could result in wind chills potentially nearing -25F at times across our northern counties over the weekend. && .AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/... Issued at 1135 PM CST Mon Dec 8 2025 Warm advection band of flurries and light snow is pushing east of the river terminals. In the wake I have added LLWS next several hours at MLI and BRL attendant to LLJ where VWP show 40+ kts near 2kft agl. Otherwise, anticipate lower MVFR to IFR conditions settling in at DBQ early this morning and stayed pessimistic in maintaining these lower conditions throughout the day at DBQ with strengthening low level inversion and potential for mist/fog. At CID and MLI, potential exists for a period of lower MVFR early this morning. Can't rule lower conditions persisting beyond with development of mist/fog possibly as warmer/moist air advects over snowpack, but confidence is low. At BRL where less snow cover is noted the potential is greatest for predominantly VFR for much of the period. Another band of light WAA precipitation attendant to a clipper system will translate across the terminals late Tuesday afternoon and evening. Soundings would support mainly light rain/freezing rain, but can't rule out some sleet as well with evaporative cooling with even a brief bout of snow at DBQ possible. This will be on the nose of an impressive 50-60 kt LLJ that will be accompanied by LLWS mention at all sites Tuesday evening. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...Winter Weather Advisory from 6 PM this evening to midnight CST tonight for IAZ040>042-051>054. IL...Winter Weather Advisory from 6 PM this evening to midnight CST tonight for ILZ001-002-007. MO...None. && $$ SHORT TERM...05 LONG TERM...05 AVIATION...05 ####018007522#### FXUS63 KARX 090957 AFDARX Area Forecast Discussion National Weather Service La Crosse WI 357 AM CST Tue Dec 9 2025 .KEY MESSAGES... - This afternoon into Wednesday morning brings multiple winter weather hazards to the region. Heavy snow is expected north of I-94 this evening with up to 6 inches falling in 4-6 hours. South/west of I-94, a period of light freezing rain and cold rain is expected this evening followed by a short break until, between midnight and 6 AM Wednesday, strong winds and a brief burst of intense snow showers is expected. Along I-94, largely snow will occur but a glaze of ice may also occur as well. - Very cold temperatures for the end of the week. Highs will struggle to climb out of the single digits Friday and Saturday. Morning wind chills of -25 or lower possible. && .DISCUSSION... Issued at 357 AM CST Tue Dec 9 2025 Winter storm this afternoon into Wednesday morning 08z WV satellite shows a shortwave over western British Columbia with a broad upper jet on the equatorward side of this feature extending over WA/OR east to ND/SD. Surface lee cyclogenesis has begun in southern Alberta as a result. Across our CWA, patchy FZDZ has occurred overnight ahead of an exiting shortwave. Wind field across the northern Plains and Upper Midwest has begun responding to the deepening surface low in southern Alberta, becoming southwesterly, advecting in warmer air, as evidenced by slowly rising temperatures overnight. This afternoon into tonight, surface cyclone deepens as it races southeast toward our CWA which looks to become under the left exit region of the upper jet. Low level wind fields ramp up in response, with warm advection continuing. As the upper wave approaches, widespread precip will develop. North of I-94, confidence is high that precip will fall as all snow around 5 to 10 PM this evening with snow rates above 1" per hour expected given strong forcing from the upper wave and an axis of 700/850mb frontogenesis developing on the northern periphery of the warm advection. While totals may not quite reach 6" (only about a 30% chance per 09.00z LREF/HREF/NBM), expected impacts from the high snow rate are sufficient to continue the Winter Storm Warning. For areas south/west of I-94, progged soundings suggest warm advection will have been sufficient enough for a warm nose to develop, leading to a period of freezing rain. While this freezing rain should end after a couple of hours as surface temperatures continue to climb, cold pavement temps and widespread snow cover may lead to additional droplets continuing to freeze even as 2m temperatures reach above freezing. Thus, a light glaze of ice to a few hundreths in accumulation is expected. Have therefore expanded the ongoing Winter Weather Advisory to cover the remainder of the CWA. For areas right along I-94, uncertainty in the exact source of impacts - snow and/or freezing rain - remains stubbornly high. Global models, as evidenced by the 09.00z LREF, are a bit farther south with their axis of high probability to reach 3" of snow compared to high resolution ensembles, as evidenced by the 09.00z HREF and particularly the 09.00z REFS. For example, 09.00z LREF shades potential for 3" of snow close to La Crosse while the HREF keeps 60% probabilities close to I-94. Overall run to run trend in LREF has been toward the north, however, so continue to think cutoff of appreciable snow impacts will reside around or just south/west of I-94. As for ice, areas along I-94 are favored to only receive a light glaze as warm advection looks to end before an appreciable warm nose develops. Moving ahead to the overnight hours, 09.00z NAM/RAP soundings suggest the presence of strong near surface lapse rates with saturation at the top of this conditionally unstable boundary layer immediately following the passage of the surface cold front. Therefore, there will be potential for a short burst of intense snow showers following the passage of the cold front. Progged low level lapse rates are steepest in areas west of the Mississippi, so will need to watch this area closest. Finally, surface winds will be on the increase overnight outside of the aforementioned snow showers as a 55 knot 850mb jet overspreads NE IA, far SW WI, and parts of SE MN in the presence of strong CAA aloft. 09.00z HREF wind probabilities suggest a 50 percent chance for winds to top 30 mph with a 70% chance for 45+ mph gusts. While the gust probabilities may be inflated due to the presence of the ARW in this ensemble, this suggests close consideration will be needed for a Wind Advisory overnight into Wednesday morning. Surface snow conditions will also need to be monitored - while the period of freezing rain and rain described in NE IA and SE MN described above should lead to a crust developing on the surface of the snow pack, if the top of the snow pack remains susceptible to blowing, very low visibilities could result and a pivot toward blizzard headlines would need to be considered. Very cold Saturday and Sunday After another upper trough swing southeastward over the Great Lakes, an even colder air mass invades the region. Lows Saturday and Sunday mornings are favored to be below zero with wind chills of -25 or lower possible. Will focus on the details of this upcoming cold snap in the coming days. && .AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/... Issued at 1146 PM CST Mon Dec 8 2025 Light snow continues to move east into central Wisconsin. Behind this snow, lowered CIGS and visibilities have been noted and will likely continue through the overnight. With these lowered CIGS, freezing drizzle may be possible (20 to 30%) during the overnight period. Flight categories look to improve to VFR conditions briefly during the mid morning to early afternoon hours until the round of rain/snow arrives this afternoon/evening. At this time, the flight categories dip back down into the IFR range. Precipitation type will be a problem with this system. Snow is expected for areas along and north of I-94 the entire time while areas to the south will see a mix of rain and snow and potentially some freezing rain, mainly in late afternoon/early evening for the freezing rain. Later on during the evening, the precipitation type will turn to all snow. Predominant southerly winds expected through much of the TAF period. There is a brief window of some west to northwest winds during the mid morning. After a cold front pushes through between 03 and 06Z, winds shift to the northwest and will become quite breezy, with gusts of 30 to 40 mph by the end of the TAF period. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...Winter Weather Advisory from 3 PM this afternoon to 6 AM CST Wednesday for WIZ032>034-041>044-053>055-061. Winter Storm Warning from 3 PM this afternoon to 6 AM CST Wednesday for WIZ017-029. MN...Winter Weather Advisory from 3 PM this afternoon to 6 AM CST Wednesday for MNZ079-086>088-094>096. IA...Winter Weather Advisory from 3 PM this afternoon to 6 AM CST Wednesday for IAZ008>011-018-019-029-030. && $$ DISCUSSION...Ferguson AVIATION...Cecava ####018010003#### FXUS63 KABR 090959 AFDABR Area Forecast Discussion National Weather Service Aberdeen SD 359 AM CST Tue Dec 9 2025 .KEY MESSAGES... - Approaching clipper system will (60-95% chance of occurrence) generate a period of light freezing rain today, starting out early this morning across north central South Dakota, before shifting over into northeast South Dakota and west central Minnesota by mid morning through early afternoon. Temperatures warm above freezing from west to east throughout the morning into early afternoon today. A Winter Weather Advisory remains in place this morning for the freezing rain potential. - Northwest winds this afternoon through tonight are expected to gust in excess of 50 to 65 mph across central and north central South Dakota. Gusts in excess of 50 mph are also expected over northeast South Dakota and west central Minnesota by early this evening, persisting into the early morning hours on Wednesday. A High Wind Warning is in effect for these dangerously strong winds. - By the end of the week, colder air is expected to move in. High temperatures will be in the single digits above 0, with overnight lows as low as the teens below zero. Wind chill values Friday and Saturday morning could be as low as -20 to -30 degrees. - Multiple rounds of snow will be possible late this week. Northeastern South Dakota into western Minnesota has a 30-50% chance of 2" of snow Thursday through Friday. A band of snow may impact the area over the weekend, although there is still a lot of uncertainty in the tracks and amounts. && .SHORT TERM /TODAY THROUGH WEDNESDAY AFTERNOON/... Issued at 357 AM CST Tue Dec 9 2025 At 3 AM CST, there was a pocket of freezing fog in the James River valley (mainly Brown County), although, Watertown briefly dropped visibility into some fog as well. It is cloudy over the CWA this morning, with temperatures west of the James River valley predominantly in the mid 20s to upper 30s (warmest out along and west river). Within and east of the James River valley, temperatures were mainly in the teens to mid 20s. Precipitation is overspreading the northern high plains of Montana and far western North Dakota, heading in this direction. Only adjustments to the Winter Weather Advisory for freezing rain was to add a couple more tiers of counties for a few hours for the early part of this morning when WAA-forced precipitation (rain) reaches north central South Dakota (expected prior to 12Z). The MRMS Sfc Probability of subfreezing road temperatures over the next 60 minutes supports this brief expansion of the freezing rain headline over to Corson/Dewey counties from 11Z to 16Z this morning. Did break off a piece of the pre-existing "northeast SoDak" wint wx headline area in order to create a "between the MO and James River valleys" hazard segment to include Campbell, Walworth, Potter and Faulk counties, running from 12Z to 18Z. Otherwise, the rest of the Winter Weather Advisory is basically the same, timing/coverage-wise, and the High Wind Warning remains in place, unchanged from what the Monday day-shift crafted when they issued the High Wind Warning. Should be looking at a corridor of time this morning when freezing rain is happening from west to east across the CWA, predominantly throughout and north of the U.S. Highway 212 corridor. Strong post- cold frontal 0.5km mixing winds on a 16+hpa 6-hourly pressure rise bubble should be able to produce sustained winds at 40 mph for an hour or more, or gusts well in excess of 60mph sometime between late this afternoon and late tonight. Regarding post-clipper system snowfall on the backside of the system late tonight into Wednesday morning, there is now a small section of terrain-influenced "near blizzard"-type blowing snow being produced by the blowing snow model across a portion of Marshall and Roberts counties tonight between roughly 05Z and 10Z when winds and temperatures and upslope on the Prairie Coteau may be able to overcome the general lack of any sort of meaningful snowfall-rates to produce some localized/isolated rather poor visibility in falling/blowing snow. A new wrinkle for the next shift to debate. Despite the warming process coming to an abrupt halt yesterday at the James River valley (temperatures did warm up quite a bit west of the James River valley yesterday), still going with a significant warm-up today, CWA-wide. So, after two days of snowmelt, topped with several hours of rainfall potential, there should be no blowing snow concerns across central/north central South Dakota. Once temperatures fall back below zero this evening, the remaining modified snowfield should transition into blocks/sheets of ice. Similar outcome expected across northeast SoDak and west central Minnesota this afternoon/evening, although CAMS/deterministic GSM's do hint at there being some falling snow (generally less than an inch except up on the far northern portion of the Prairie Coteau) potential later tonight into Wednesday morning across far northeast South Dakota and west central Minnesota. After how warm it will be today, Wednesday will feel like quite a shock to the system, when high temperatures will only be in the upper teens to low 30s over the CWA. && .LONG TERM /WEDNESDAY EVENING THROUGH MONDAY/... Issued at 357 AM CST Tue Dec 9 2025 The pattern of the Northern Plains remaining on the front side of the upper-level ridge over the western CONUS. With this setup, a couple of jet streaks will move over the area, providing enough divergence aloft to support precipitation Thursday through early Friday. Model soundings indicate that snow is the most likely precipitation type through the event, but there will be chances for rain and freezing rain as well. The latter precip types could occur with a de-saturation of the DGZ aloft during the event, which could transition from ice formation to liquid formation aloft depending on how cold temperatures at the top of the saturated layer remain. Latest ensemble medians have broad coverage of 0.10"-0.20" in liquid totals through Friday morning, with the highest totals over north central into northeastern South Dakota. This will translate to around 1"-2" across much of the forecast area, although varying snow to liquid ratios (~10:1 over north central South Dakota ranging to ~15:1 over northeastern South Dakota) may create a disparity between the highest liquid equivalent and highest snowfall locations. Latest probability of at least two inches peaks over northeastern South Dakota, ranging from 30 to 50 percent. With this setup, a strong blast of cold air is expected to move into the region Friday into Saturday. 850mb temperatures by Saturday morning are expected to be in the teens below 0 Celsius, which is below the 10th percentile for this time of year. The presence of this cold air will lead to overnight lows at the surface below zero Fahrenheit Friday and Saturday mornings. At these temperatures, wind chills are expected to reach -20 degrees Fahrenheit in most of north central and northeastern South Dakota, and potentially even approach the Cold Weather Advisory Criteria of the northern counties of -30 degrees Fahrenheit. Friday morning is of particular concern, because while temperatures are slightly warmer than Saturday morning, northwesterly winds of 20-25 miles per hour gusting to 35 overnight will counteract that difference. The latest long-range ensemble guidance put the probability of hitting -30 degrees Fahrenheit for the minimum overnight wind chill in northeastern South Dakota at 20- 40% on Friday morning, easing up to around 10-20% Saturday morning. Yet another round of snow may impact the region this weekend, this time being more banded with a swath of heavier precipitation totals. There is still a lot of uncertainty remaining, but it is worth noting that forecast snow totals have jumped up over the latest forecast cycle. The latest NBM currently puts a band of 50% probability to see 2" of snowfall accumulations, with a band of 20- 30% chance for up to 4". && .AVIATION /06Z TAFS THROUGH 06Z TUESDAY/... Issued at 1116 PM CST Mon Dec 8 2025 Terminals KABR,KATY,KPIR,KMBG Conditions will deteriorate late tonight through Tues morning as MVFR/IFR cigs spread over the region with the next winter storm. Frza will be a concern east of the Missouri in the morning before temps rise. Then westerly winds increase with gusts of 40 to 50 kts at KMBG and KPIR. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...High Wind Warning from 3 PM this afternoon to 6 AM CST Wednesday for SDZ006>008-011-018. Winter Weather Advisory until 9 AM MST this morning for SDZ003- 015. High Wind Warning from 11 AM this morning to 2 AM MST Wednesday for SDZ003-015. Winter Weather Advisory until noon CST today for SDZ004-005-009- 010-016-017. High Wind Warning from 3 PM CST /2 PM MST/ this afternoon to 3 AM CST /2 AM MST/ Wednesday for SDZ004-005-009-010-016-017- 033>037-045-048-051. Winter Weather Advisory from 7 AM this morning to noon CST today for SDZ006>008-011-018>023. High Wind Warning from 6 PM this evening to 6 AM CST Wednesday for SDZ019>023. MN...Winter Weather Advisory from 9 AM this morning to 3 PM CST this afternoon for MNZ039-046. High Wind Warning from 3 PM this afternoon to 6 AM CST Wednesday for MNZ039-046. && $$ SHORT TERM...10 LONG TERM...BC AVIATION...20