####018008411#### FXUS65 KBYZ 042045 AFDBYZ Area Forecast Discussion National Weather Service Billings MT 145 PM MST Thu Dec 4 2025 .KEY MESSAGES... - Gusty to locally strong winds (35-50mph) over the foothills west of Billings continue into tonight (Livingston, Nye, Big Timber, Harlowton). - Periods of moderate to heavy snow in the mountains continue through Saturday. Total accumulations over a foot forecast, greatest on west and northwest facing slopes. - Light precipitation possible (20-40% chance) tonight through Friday morning lower elevations. Mainly snow but could mix with rain through early this evening. - Better precipitation chances (30-60%) arrive late Friday through Saturday. Increasing chances for mixed precipitation during this period has lowered potential snow accumulations, but could still make travel difficult in a few locations. - Confidence is above average for warm and potentially very windy weather pattern for early next week. && .DISCUSSION... This afternoon through Wednesday... No changes planned to current winter weather highlites for area mountains with this forecast package. Active weather pattern through the weekend as the area remains in northwesterly flow on the western edge of a persistent trof. Waves of energy dropping southwest into this trof are bringing glancing blows of cold air into the area while aloft a fairly constant stream of Pacific moisture provides moisture for precipitation when these disturbances move through. One disturbance is beginning to impact the area now and will bring a chance for mainly light snow to the area tonight into tomorrow morning. Initially snow potential will be more widespread from west to east as the system moves through the area, but will subside southward into primarily the Bighorn mountains and foothills going into tomorrow morning. Probabilities for an inch or more of precipitation over the lower elevations tonight into Friday morning are less than 10% for most locations, but in those favored Bighorn foothills locations probabilities increase to around 40% for the Wolf mountains and the Aberdeen hill area. Mountains will see persistent light to moderate snowfall through Friday with periods of heavier snow on west facing slopes. Tonights system exits the area tomorrow morning with a break in precipitation chances for the lower elevations. The next disturbance arrives by late afternoon/early evening, and this system has stronger forcing associated with it. Yesterdays model runs sagged the cold front this system pulls down from Canada further south into our area than the current model runs do. As a result the latest guidance is suggesting less snowfall for the lower elevations. In fact, Friday night may see temperatures rise above freezing in the middle of the night as an area of warmer air pushes through in the low-mid levels. NBM shows snow Friday evening turning to a mix of rain/snow and possibly some pockets of freezing rain/sleet in the middle of the night before transitioning back to snow around sunrise. This warm advection scenario is dampening snow ratios and cutting snow accumulations down significantly from yesterdays runs over central and eastern areas, from 2 to 4 inches down to a Trace to 2 inches for areas along and east of a Harlowton to Billings to Crow Agency line, with probabilities for 2+ inches below 30%. Given this change not planning on any winter highlites for the lower elevations for Friday night-Saturday at this point, but will have to watch how the mixed precipitation potential evolves over the next 24 hours. For the mountains periods of moderate to heavy snow will continue with probabilities of over a foot sitting at 60 to 80 percent in the higher elevations of the Beartooth/Absaroka/Crazy mountains. The heaviest accumulations will be on west and northwest facing slopes. Winds through the weekend...Gusty conditions have been ongoing along the western foothills since sunrise this morning with a few gusts over 50 mph being reported, and gusts as high as 40 mph spreading as far east as eastern Golden Valley and Stillwater counties. Expect winds to remain gusty over the western foothills through the night tonight, with peak gusts dropping about 10 mph from current peak values, closer to 40 mph. Another period of gusts in the 50 mph range arrives Friday night as the stronger mid level flow/warm advection pushes over the divide and strengthens the gap wind ingredients there. The strength of the winds looks to stay below wind highlite thresholds, but that will depend on the disturbance and how far west the cold front makes it. If the front drops further southwest than currently forecast winds could be weaker, if it stays further northeast than currently forecast winds could get closer to needing wind highlites. Winds should weaken and become less impactful Saturday afternoon. Extended forecast continues to trend warmer and mainly dry for the lower elevations Sunday through Wednesday as a ridge develops along the Pacific coast and pushes over the Northern Rockies. Pacific moisture will continue to flow over the mountains through this period producing fairly continuous but mainly light snowfall for west facing mountain slopes, along with a good amount of daily cloud cover. Downslope winds will push temperatures well above average for much of the area by Tuesday with forecast highs in the mid to upper 40s, a few lower 50s possible. Ridge flattens on Wednesday with falling heights aloft and a more direct flow of Pacific moisture flowing over the area, taking the edge off of temperatures though still staying above normal for this time of year. The potential exists for a prolonged period of strong winds along the western foothills from late Sunday through Tuesday night, which may push into the plains during the afternoon hours Monday and Tuesday. Chambers .AVIATION... 18z Discussion... Strong west/southwest winds are forecast for KLVM/K6so through the daytime hours today (through 00z). Gusts up to 45kts should be expected. Winds at KBIL are forecast to be sustained around 15kts out of the WSW with gusts up to 25-30kts. The next round of wintry precipitation enters between 22-02z (NW- SE) which will start as mixed precip and then transition to snow. KBIL may be on the very edge of this rain/snow line and thus frequent transitions back and forth after 06z should be expected. Also note that if the wind direction changes a little off of the forecast, the showers at KBIL may start as early as 00z. VFR conditions wil prevail through 06z when lower VIS and CIGs are possible. While most sites will likely prevail MVFR conditions, IFR and LIFR conditions at any site could briefly occur. Mountains will be partially to fully obscured for the entire period. WMR && .PRELIMINARY POINT TEMP/POPS... Fri Sat Sun Mon Tue Wed Thu ----------------------------------------------------------- BIL 027/037 026/037 022/040 030/043 032/047 031/041 031/043 34/S 65/S 20/B 10/B 14/R 54/O 43/O LVM 026/039 030/040 027/041 028/043 032/048 031/044 031/047 78/S 85/S 21/B 20/N 25/R 55/O 43/O HDN 026/037 022/035 017/040 024/043 027/046 027/040 026/043 62/S 77/S 40/B 10/B 14/R 65/O 43/O MLS 025/032 017/025 009/031 020/039 028/043 024/036 023/038 41/E 64/S 40/B 10/B 24/R 43/O 42/O 4BQ 028/033 020/033 015/037 024/042 028/046 027/039 026/041 42/S 33/S 31/B 00/B 13/O 53/O 32/O BHK 021/031 010/025 003/030 017/038 023/040 019/032 017/033 54/S 44/S 41/E 10/N 24/O 32/S 32/S SHR 023/036 018/038 019/041 022/045 024/050 025/041 023/044 65/S 55/S 30/B 10/B 13/R 64/O 43/O && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...Winter Storm Warning in effect until 2 PM MST Saturday FOR ZONES 67-68. Winter Weather Advisory in effect from 5 PM this afternoon to 2 PM MST Friday FOR ZONE 171. WY...None. && $$ weather.gov/billings ####018005017#### FXUS64 KHUN 042046 AFDHUN Area Forecast Discussion National Weather Service Huntsville AL 246 PM CST Thu Dec 4 2025 ...New NEAR TERM... .KEY MESSAGES... Updated at 1014 AM CST Thu Dec 4 2025 - Periods of rain start this afternoon and continue through late tonight with rainfall amounts up to 0.25-0.50 inches. - Fog development tonight into Friday morning and again Saturday morning may cause travel delays. && .NEAR TERM... (Tonight) Issued at 246 PM CST Thu Dec 4 2025 Large swath of stratiform rain is right on our doorstep at the MS/AL border spreading northeastward into southern middle Tennessee. This area of rainfall will continue to shift eastward over the next few hours, with all of north Alabama and southern middle Tennessee expected to see some rainfall by tonight. Rainfall amounts will most likely be around 0.25 inches areawide and flooding issues are not a concern. High-end scenario rainfall totals where more moderate rainfall rates set up this evening could see up to 0.5 inches. Embedded lightning activity is not expected as no instability is present. Rain exits from west to east overnight with everyone in the TN Valley dry by sunrise. Unfortunately, that does not mean clear skies by sunrise as overcast, low clouds hang on into Friday. With light winds and the ground sufficiently saturated, dense fog development will become a concern going into the morning tomorrow, impacting the morning commute. Temps should remain above freezing so freezing fog causing slick surfaces is not the main concern so much as just the sudden visibility reductions on area roadways. && .SHORT TERM... (Friday through Saturday) Issued at 1014 AM CST Thu Dec 4 2025 Any fog that develops overnight behind the areas of rain will have the potential to linger as late as noon in sheltered valleys. Early morning commuters should allocate extra time just in case the fog becomes dense. A dense fog advisory is not expected at this time, but subsequent shifts will continue to monitor the potential. Weak high pressure at the surface settles into the Ohio River Valley, so limited subsidence will keep skies overcast throughout Friday. As a result, high temperatures will peak in the upper 40s, similar to today. Moisture will remain trapped underneath the overcast skies and not wicked away because of light winds. As a result, fog remains a concern for Friday night into Saturday morning. Drier air in the mid levels moves in late Saturday, allowing skies to finally clear heading into Saturday night. && .LONG TERM... (Saturday night through Tuesday) Issued at 1113 PM CST Tue Dec 2 2025 Some clearing Saturday night, but guidance shows mostly cloudy conditions returning around midnight and continuing through the overnight hours. Lows in the 35 to 40 degree range look reasonable. The main feature to watch through the long term forecast will be the passage of a 500 MB trough through the eastern CONUS. Through the weekend, the trough will amplify and move from the Plains into the eastern CONUS. In association a surface low pressure system looks to pass through the area from Sunday and Sunday night. Deterministic models maintain high uncertainty regarding if any precip will be present with the frontal passage. As such, stuck with blended guidance that reflects the low chances of rain (~20%) from Sunday night. If we do receive precip, especially near daybreak Monday morning, we will have to keep an eye on temps as they will likely near or just below freezing which could produce brief and hopefully non-impactful wintry precip. We have very low confidence in this however, just an interesting (non-impactful) tidbit to keep an eye on. Through the beginning of the work week, zonal flow aloft paired with high pressure influence will promote non impactful weather. Temps will have the opportunity to warm slightly with highs in the 40s and 50s. The forecast becomes slightly more uncertain from Wednesday forward as models struggle to resolve our next system. && .AVIATION... (18Z TAFS) Issued at 1117 AM CST Thu Dec 4 2025 Main impact for aviation today will be associated with rain moving in from the southwest this afternoon. Ceilings will drop heading into the evening down to IFR. With more persistent rain areas, could see vsby lower to 3 SM. Rain tapers off early Friday morning but low clouds and fog will remain. While flight categories were only lowered to IFR, there is a low chance (20-30%) that LIFR cigs linger until 12-15Z. Conditions gradually improve heading into tomorrow afternoon and should return to VFR just after this TAF period. && .HUN WATCHES/WARNINGS/ADVISORIES... AL...None. TN...None. && $$ NEAR TERM...KG SHORT TERM....30 LONG TERM....RAD AVIATION...30 ####018002547#### FXUS63 KUNR 042046 AFDUNR Area Forecast Discussion For Western SD and Northeastern WY National Weather Service Rapid City SD 146 PM MST Thu Dec 4 2025 .KEY MESSAGES... - Light snow returns tonight into Friday, with another chance on Saturday into Sunday. - Warmer and breezy conditions early next week. && .DISCUSSION...(This Evening Through Thursday) Issued at 127 PM MST Thu Dec 4 2025 An upper air analysis shows northwest flow continues over the northern plains today, with a weak disturbance over eastern MT. Surface chart depicts low pressure over western SD, with warm frontal boundary now through the forecast area, towards central SD. Temperatures currently sit in the mid 30s to low 40s, with light to breezy westerly winds. Clouds will increase this evening ahead of the next wave as it drops down from eastern MT. Light precipitation arrives tonight, late enough that it should remain as snow. Expect little to no accumulations with this wave, however upslope over the northern Black Hills will bring minor accumulations of 1-3 inches. Light precipitation will taper off Friday morning, with dry conditions expected the latter half of the day, and similar temperatures to today. Another disturbance moves in late Friday and associated cold front will drop down from MT/SD. Expect a slight decrease in temperatures for Saturday, and another chance for light precipitation during the day into Sunday morning. Some areas in the western SD plains could see 1-2 inches, with the higher elevation Black Hills perhaps seeing slightly higher amounts. Unsettled pattern will bring more chances for light precipitation early next week, however low-level warmer air moving in will bring mild (but breezy) days for Monday and Tuesday, with highs for some areas climbing into the 50s. && .AVIATION...(For the 18Z TAFS Through 18Z Friday) Issued At 1040 AM MST Thu Dec 4 2025 VFR conditions continue this afternoon into early this evening. Breezy northwest winds are expected north of Interstate 90. An incoming system will bring light snow to northern and western portions of the area around 03Z tonight. Increasing MVFR/IFR conditions are expected, especially across northeast Wyoming, the Black Hills, and through northwest South Dakota overnight into Friday morning. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...None. WY...None. && $$ DISCUSSION/KEY MESSAGES...Dye AVIATION...15 ####018008009#### FXUS61 KOKX 042048 AFDOKX Area Forecast Discussion National Weather Service New York NY 348 PM EST Thu Dec 4 2025 .SYNOPSIS... Strong high pressure builds in from the west tonight into Friday. The high will pass east Friday night as weak low pressure passes well to the south Friday night and heads well out to sea on Saturday. A cold front moves through Sunday night. Behind it, high pressure builds in from the west, remaining in control through Tuesday. Low pressure may impact the area mid next week as it passes to the north. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... Key Points: * Low wind chills and record low temps possible at some spots tonight. Temperatures plummet tonight thanks to arctic high pressure building in behind the cold front, reaching the single digits in some spots well inland, teens most elsewhere, and the lower 20s in/just outside NYC and out by Montauk. Some record low temps may be approached or set. NW flow 20-25 mph gusting to 25-35 mph this evening after cold front passage. Winds then quickly diminish late tonight as high pressure starts to build in. By midnight or thereafter, winds should be northerly around 10 mph or less. Tonight's winds in combination with falling temps will lead to wind chills in the single digits and teens as early as this evening. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/... Key Points: * Cold conditions continue, especially daytime Friday. * Weak low pressure passing well south may brush the area with some light snow/rain Friday night into Saturday. Temps on Fri as the high builds across will only reach the mid/upper 20s inland, lower 30s most elsewhere, and the mid 30s across eastern Long Island. Still maintaining a 30-40 PoP as the precip shield with a southern stream low passing off Hatteras and moving nearly due E out to sea skirts the area. Precip type should be mostly light snow with little to no accumulation Fri night, then light rain or a rain/snow mix on Sat as temps warm and mid levels dry out. The best chance for precipitation looks to be after midnight Friday night as an inverted trough extending from the low moves into the region. Low temps Fri night will be in the teens to 20S, with lower 30s expected in NYC. Lows Saturday night into Sunday morning will be a couple of degrees warmer. Highs on Sat will be in the upper 30s/lower 40s. && .LONG TERM /SUNDAY THROUGH THURSDAY/... Key Points: * Some of the coldest air of the season so far moves in early next week. High temperatures Monday and Tuesday likely in the upper 20 and 30s region-wide, with morning wind chills in the single digits and teens. * A period of precipitation is possible Sunday night into Monday, and could bring light snow to portions of the area should it occur, mainly north of the I-95 corridor. Troughing aloft across much of the Eastern US to start the period. A cold front moves across the area Sunday night that ushers in a modifying arctic air mass through early next week. While the frontal passage, at this time, appears moisture starved, still have to monitor this period as there are differences amongst guidance handling two separate shortwaves traversing east. The 12Z GFS/GEFS depicts more interaction with these waves, inducing surface low development off the New England coast on Monday, and bringing a period of light rain and snow to the region. Other guidance is much more separated and drier as a result, and this wetter solution is being considered an outlier with this update. Still a period to watch though over the next couple of days as these differences resolve. Regardless thereafter, 1030 mb surface high builds east over the Mid Atlantic into Tuesday, keeping conditions cold and dry locally. Daytime highs both Monday and Tuesday look to remain mostly in the 30s, or even 20s inland, and a gusty NW flow behind the front will add to the cold. Morning wind chills Tuesday could fall into the single digits to near 0 inland, and teens along the coast, which would not warrant any cold headlines. A clipper system may move through the Northeast on Wednesday, bringing the next chance for precipitation. && .AVIATION /20Z THURSDAY THROUGH TUESDAY/... A cold front moves through late this afternoon through early this evening. High pressure then builds in from the west through tonight and settles over the area Friday morning before weakening and moving away late in the day. VFR prevails. Any light snow showers this afternoon should be confined to KSWF, where a PROB30 is in place for -SHSN and stronger winds for a short time with and just behind the cold frontal passage. The winds will gradually go more WNW, then NW through the evening push. Peak winds will likely occur over the next few hours. Winds and gusts begin to decrease some around 00Z this evening with the gusts ending late tonight, mainly by 04-06z. ...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty... There may be some peak gusts a few kt higher than what is currently in the TAF over the next few hours, potentially up to around 35 kt. .OUTLOOK FOR 18Z FRIDAY THROUGH TUESDAY... Friday afternoon: Primarily VFR. Low chance of brief MVFR and light snow during the late afternoon/night, especially for southern and eastern terminals. Saturday: Low chance of MVFR and light rain in the morning, mainly E of the NYC metros, otherwise VFR prevails. Sunday through Tuesday: VFR. Detailed information, including hourly TAF wind component forecasts, can be found at: https:/www.weather.gov/zny/n90 && .MARINE... NW gales continue on the ocean and the eastern Sound/bays of Long Island this evening following a cold frontal passage, with winds gusting to 30 kt on the Harbor/wrn Sound/south shore bays. Seas should peak at 5-8 ft on the ocean E of Fire Island Inlet, 4-7 on the ocean W of there, and 5 ft on the Long Island side of the central/ern Sound. Blowout tides may be possible on the western Sound with the low tide early this evening, with water levels approaching 2 ft below MLLW. Any gales will be replaced by SCAs late tonight and quickly ramp down, with quiet cond through Saturday. Small Craft Advisory (SCA) conditions likely return to all waters Sunday night into Monday as NW flow increases behind a cold frontal passage. Gusts near or above 25 kt look to persist into Monday evening before subsiding, then sub SCA conditions expected on all waters once again into midweek. && .HYDROLOGY... No hydrologic impacts are expected. && .TIDES/COASTAL FLOODING... Water levels may touch minor flood thresholds at the Bridgeport and Stamford CT tide gauges with the midday high tide on Sat as low pressure passes well south. && .CLIMATE... Low temps Fri morning may reach daily record lows at KJFK/KBDR, and may also get close at KLGA. High temps Fri may also be close to daily record low maxes at KLGA/KJFK. Record Low Temperatures: KEWR: 15/1935 KBDR: 17/1989 KNYC: 11/1926 KLGA: 21/1942 KJFK: 20/1966 KISP: 13/1966 Record Low Maximum Temperatures: KEWR: 31/2002 KBDR: 28/2002 KNYC: 22/1886 KLGA: 32/2002 KJFK: 33/2007 KISP: 30/2002 && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...Gale Warning until midnight EST tonight for ANZ331-332-340-350- 353-355. Small Craft Advisory until midnight EST tonight for ANZ335-338- 345. && $$ SYNOPSIS...JP/DR NEAR TERM...JP SHORT TERM...JP LONG TERM...DR AVIATION...JE MARINE...JP/DR HYDROLOGY...JP/DR TIDES/COASTAL FLOODING... CLIMATE...