####018005537#### FXUS63 KOAX 091142 AFDOAX Area Forecast Discussion National Weather Service Omaha/Valley NE 542 AM CST Tue Dec 9 2025 .KEY MESSAGES... - A brief warmup is expected into Tuesday, with highs warming into the mid 40s to mid 50s. - Strong winds likely (80%) Tuesday night into Wednesday morning with gusts 40 to 50 mph. - Snow chances late Wednesday into Thursday (20-30%), followed by a return of colder temperatures for the weekend. && .DISCUSSION... Issued at 430 AM CST Tue Dec 9 2025 The upper pattern has changed very little this week and is expected to remain much the same over the next seven days. A standing wave's ridge axis has set up along the West Coast with northwest flow over the High Plains streaking toward the eastern CONUS's general trofing. At the surface, we continue to experience a wide range of temps with mid 30s across most of Nebraska and mid-20s across eastern Iowa where the warm front has yet to pass. Westerly winds of only about 5 knots are trying to scour out the arctic air in place over the Corn Belt. It's tedious work. Valley's low of 20F on Monday was set at 12:14am. It took persistent southwesterly winds and most of twenty-four hours to drive temps up to 33 degrees by 11:56pm... which was the day's zenith. The drier westerly flow should be enough to preclude widespread fog, hopefully holding it off for all but sheltered low-lying spots. Temps will continue to improve today with the a mix of sun and clouds and continued westerly flow. MaxT's should range from near 40 in the Harlan, IA area to just shy of 60 at Fairbury, NE and Jefferson County. The warm temps are usually welcomed this time of year, but they're especially appreciated with the strong winds anticipated overnight. The sun and seasonal and super- seasonal temperatures should put a nice crust on any remaining snowfall and prevent blowing and lofting of snow cover. .TONIGHT... A shortwave zipping through the quick H5 flow brings likely PoPs to Minnesota, the Dakotas, and parts of central and eastern Iowa. Biggest impacts for this forecast area will be associated with the attendant cold front. NBM continues to struggle with the wind speeds. Believe the CAA associated with the front won't have trouble busting up the progged shallow inversion and should mix to almost 5kft. Mean values of momentum transfer suggest gust speeds of 50 mph in northeast Nebraska with some guidance pushing well over 60 mph. In collaboration with neighboring offices, have issued wind advisory from 9pm tonight to 9am Wednesday morning. Considered a high wind warning in far northeast Nebraska, but it is borderline. Wouldn't be surprised to see the day shift upgrade that advisory when we see the whites of the wind's eyes. The advisory may be a bit too long as confidence is best in the heart of the period when the CAA is maximized and the shortwave axis passes through the area. I woulnd't be surprised if the winds tapered quickly Wednesday morning with the redevelopment of the surface temp inversion. This could happen before the sun comes up... ending those winds 'prematurely'. Have also added a 10-15% chance of post-frontal sprinkles this evening. They won't last long enough to see them turn to snow. Eventually, though, we will fall into the twenties and low 30s. .THE REST OF THE WEEK... Temps will be notably cooler on Wednesday (30s) under the continued northwesterly upper (and surface) flow. A 20-30% chance of snow develops Wednesday night with the area in a baroclinic zone and warm air trying to make inroads from the west. Fewer ensemble members have been bringing snow this far south with the past two global model runs. (PoPs peak in the 30%s now instead of the 40%s). Current guidance keeps this upper pattern mostly unchanged through the work week with occasionally sharp temperature gradients draped directly across eastern Nebraska or at least within an afternoon's drive. This pattern leaves the forecast with a greater degree of uncertainty than normal. An undetected wiggle in the jet stream or a stronger lee cyclone, etc could have a 20 degree impact. The area could be subject to snow on any of these days with this baroclinicity in the vicinity. Let's hope this pattern resolves itself in a clearer way. Nobody likes an ambiguous forecast. Right now, snow chances look best (15-25%) over the northern tier of counties on Wednesday night and Saturday. && .AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/... Issued at 536 AM CST Tue Dec 9 2025 High clouds are streaming in from the northwest this morning with reasonable southwesterly winds. Northwesterly winds begin picking up speed this afternoon and evening and by midnight, they'll be gusting up to 40-55 mph. Wind speeds of 60-80 mph will be at FL030 at times. VFR conditions persist over the next 24 hours. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...Wind Advisory from midnight tonight to 8 AM CST Wednesday for NEZ033-034-042>045-050>053-065>068-078-088>093. Wind Advisory from 9 PM this evening to 6 AM CST Wednesday for NEZ011-012-015>018-030>032. IA...Wind Advisory from midnight tonight to 8 AM CST Wednesday for IAZ043-055-056-069-079-080-090-091. && $$ DISCUSSION...Nicolaisen AVIATION...Nicolaisen ####018010886#### FXUS63 KABR 091142 AAA AFDABR Area Forecast Discussion...UPDATED National Weather Service Aberdeen SD 542 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. && .UPDATE... Issued at 531 AM CST Tue Dec 9 2025 See below for an aviation forecast discussion for the 12Z TAFs. && .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 /12Z TAFS THROUGH 12Z WEDNESDAY/... Issued at 531 AM CST Tue Dec 9 2025 Terminals KABR,KATY,KPIR,KMBG Still dealing with a couple of pockets of fog/low clouds at KABR/KATY this morning. IFR fog/stratus should abate by 15Z, just in time to grapple with VFR/MVFR conditions in freezing rain. Temperatures should warm up enough for plain rain to take over at KABR/KATY by early afternoon, just in time to grapple with very strong northwest winds developing. Sustained winds over 30 knots, with gusts over 45 knots are expected. Low level wind shear potential will exist for much of the afternoon into this evening, as well. VFR conditions, to start, at KPIR/KMBG could have brush with MVFR visibility in rain (at KPIR) or freezing rain (at KMBG) this morning. Otherwise, VFR condition are expected at KPIR/KMBG from about 18Z to the end of the TAF valid period. Very strong northwest winds are expected at KPIR/KMBG, as well, by early this afternoon, with sustained winds over 35 knots and gusts over 50 knots. Low level wind shear potential will exist for much of the afternoon into tonight, as well. && .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 until 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. && $$ UPDATE...10 SHORT TERM...10 LONG TERM...BC AVIATION...10 ####018004832#### FXUS64 KHUN 091143 AFDHUN Area Forecast Discussion National Weather Service Huntsville AL 543 AM CST Tue Dec 9 2025 ...New AVIATION... .KEY MESSAGES... Updated at 1025 PM CST Mon Dec 8 2025 - Low to medium chances of freezing fog area-wide tonight into early Tuesday morning. - Subfreezing temperatures tonight, then a gradual warming trend through midweek. - Confidence is increasing in the potential of colder conditions early next week. && .NEAR TERM... (Today) Issued at 410 AM CST Tue Dec 9 2025 Satellite data and surface observations indicate that a layer of low stratus clouds (which has been in place for the past couple of days) is gradually eroding from NE-to-SW, with temperatures currently ranging from the m-u 20s in the northeastern portion of the CWFA (where skies have cleared) to the mid 30s in the southwestern portion (where skies remain cloudy). Although the presence of the cloud deck has thus far inhibited development of freezing mist/fog, it would not be surprising to see some develop between 10-14Z (especially to the N/E of Huntsville). Over the course of the day, a lengthy surface ridge extending from the northwest Gulf Coast into New England will shift southeastward. As the pressure gradient contracts between the ridge and a developing surface low dropping southeastward over the northern Plains, a modest increase in SSW flow will occur across our region. Although periods of scattered-broken high clouds can be expected as a weak mid-level wave shifts southeastward over the TN Valley, these should have only a minor impact on temperatures with afternoon highs still predicted to reach the 45-50F range (a few degrees cooler atop the Cumberland Plateau). && .SHORT TERM... (Tuesday night through Thursday) Issued at 1025 PM CST Mon Dec 8 2025 A deeper southerly flow should be in place for the mid week, as high pressure remains to our east. The southerly flow and higher heights/thicknesses will result in milder conditions. Lows should cool into the 30s (lower 30s east to upper 30s west) with light SE winds. A storm system forming over SW Canada will head eastward along the border, reaching the Great Lakes region on Wednesday. A cold front trailing south of this cyclone is forecast to move across this area Wed afternoon. Given that most of the energy should remain closer to the main storm, no precipitation is expected across this area. But with a SW-W flow and more sun, high temperatures for the mid week should rise into the mid to upper 50s. Cooler air west of the front filtering in will make for colder conditions Wed night with lows falling to around 30. Not as mild Thursday with highs in the mid 40s to around 50. && .LONG TERM... (Thursday night through Monday) Issued at 1025 PM CST Mon Dec 8 2025 Slightly cooler than seasonal temperatures are forecast Thursday night, with lows falling into the low/mid 30s. Closer to normal readings will return on Friday with highs into the mid/upper 50s under partly sunny skies. With cloud cover on the increase, lows Fri night should range in the 30s. Yet another storm system moving in from the WNW will bring lower end chances of showers across mainly the western areas Saturday afternoon. Rain chances should spread eastward across the Valley Saturday night, then end from west to east over our eastern areas Sunday morning. This system will bring colder air from up north to across the eastern CONUS early next week. Lows Sat night should cool from the upper 20s our Tennessee counties to mid 30s south of the Tennessee River. A chilly airmass will be more noticed Sunday, with highs only in the upper 30s north to mid 40s south. The start of the next work week, Monday will be on the cold side, with highs during the day into the mid/upper 40s. && .AVIATION... (12Z TAFS) Issued at 543 AM CST Tue Dec 9 2025 Although the stratus layer has gradually eroded from NE-to-SW since issuance of the previous aviation forecast, MVFR cigs will persist thru 15Z at MSL, with VFR conds at HSV. Beyond 15Z, sct- bkn mid and high-lvl clouds will spread across the region in WNW flow aloft, as sfc winds assume a SSW component and increase to 5-10 kts. Clouds layers aloft will continue to increase in both coverage and density this evening, and LLWS has been introduced beyond 4Z as models suggest that a WSW low-level jet will increase into the 45-55 knot range during this timeframe. && .HUN WATCHES/WARNINGS/ADVISORIES... AL...None. TN...None. && $$ NEAR TERM...70/DD SHORT TERM...RSB LONG TERM...RSB AVIATION...70/DD