####018007026#### FXUS65 KGJT 041007 AFDGJT Area Forecast Discussion National Weather Service Grand Junction CO 307 AM MST Thu Dec 4 2025 .KEY MESSAGES... - Prolonged moist northwest flow will bring a threat of accumulating snow to the mountains and adjacent valleys tonight through early Sunday. - The first round will mainly impact the northern Colorado mountains late this evening through tomorrow afternoon with a greater than 70 percent probability of 4 inches or more of snow over the Elkhead and Park Ranges. - The snow will be more widespread and be accompanied by stronger winds at the high elevations Friday night into early Sunday. The northern and portions of the central Colorado mountains have a greater than 50 percent probability of 8 inches of snow. Travel impacts including possible road closures should be planned for. && .SHORT TERM /THROUGH FRIDAY/... Issued at 307 AM MST Thu Dec 4 3075 With a moderately strong Madden Julian Oscillation now located in the Western Hemisphere the models have responded with a robust northwest flow pattern across the PacNw to the Central Rockies. The strength and location of the MJO most likely has some effect on the persistent arrival of atmospheric river moisture to the West Coast. So the bottom line...strong and persistent moist northwest flow means our northern and portions of central Colorado mountains are about to make up for the slow start to the snowpack season. The forecast challenge in this pattern remains the same...timing of lulls between events...and underestimating the effectiveness of cold northwest orographics on snow totals. With that said the first guess is in which is to go with an early round advisory favoring the Elkhead and Park Ranges late this evening through tomorrow afternoon with the arrival of the first batch of moisture and modest ascent with a passing wave tomorrow morning. The best snow rates look to be around sunrise through early afternoon then a brief 'lull" through the evening before we introduce stronger moisture advection arriving on a stronger jet aloft. This first round looks to bring a good 4 to 8 inches to the above mentioned ranges with 1 to 4 over the Flat Tops into the Gore and central mountains. Unfortunately this pattern will leave the southern mountains out for any significant accumulations. For nearer term weather another cool but sunnier day for most the area is expected today in the wake of the passing storm. The high country and especially the northern spine mountains will hang onto orographic clouds and occasional flurries through at least early afternoon. && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... Issued at 307 AM MST Thu Dec 4 3075 For the long-term forecast, the models are in good agreement through about Tuesday with the high pressure sitting well off the California coast keeping eastern Utah and Western Colorado under a strong northwesterly flow allowing a series of shortwaves to drop down through the Pacific Northwest into the region. Additionally there is some atmospheric river (AR) action to supply some moderate moisture into the region this weekend with these shortwaves and more significant moisture by mid next week. The models do start to diverge by Tuesday with the European AI ensemble and deterministic models progressing the high to the east into the Desert Southwest while the GEFS keeps it pretty much in place and the deterministic GFS even retrogrades it to the west. Current guidance favors the European solution turning the flow aloft westerly with temperatures warming to ten or more degrees above normal by mid week and precipitation coming as rain showers in the lower elevations below about 7,000 ft. Though this is the favored solution, confidence is still low at this point beyond Tuesday, and with the strong AR possible we could see another significant winter storm in the northern mountains. Definitely stay tuned on this one. With that said, we won't see a lot of moisture, pwats around 0.50 inches, but will see moderate AR flow Friday night into Saturday with integrated water-vapor transport (IVT) values of 150 to 250 kg/m/s driving by the strong northwest flow aloft with H500 winds running 60-70 knots. Though there is a bit of upper level dynamics with a weak jetstreak moving overhead, this strong northwesterly push will provide good orographic lift to drive the snow showers across the northern and central Colorado mountains. A Winter Storm Watch is in place for Elkhead, Park, Gore and Elk Mountains, and for the Flat Tops and central mountain valleys Friday evening through Sunday morning for 10-20 inches snow up north with 40 mph winds, and five to 14 inches snow along and south of I-70 with 35 mph winds. Check for updates on this over the next day or so as the forecast becomes more certain to see if these watches will be upgraded to Winter Weather Advisories and/or Winter Storm Warnings. Either way, expect winter driving conditions on the northern and central mountain roads and passes this weekend. With the northwesterly flow continuing into early next week, expect continued light orographic snow showers mostly across the northern mountains as weak shortwaves brush by to the north. Moving into mid next week, though confidence is low, models are predicting a strong AR to move into the northern areas with IVTs of 200 to 300 kg/m/s and pwats approaching 0.70 inches. With the nose of a strong jet pushing down providing good upper-level dynamics, we could see thunderstorms in the lower elevations north of I-70 and heavy snow and possible thundersnow in the mountains. A lot can change with this one, especially if it decides to shift a bit farther south, so stay tuned for updates. && .AVIATION /06Z TAFS THROUGH 06Z FRIDAY/... Issued at 941 PM MST Wed Dec 3 3075 Snow will continue to dissipate from north to south along the Divide mountains overnight leaving behind lower ceilings and the potential for fog at terminals that see clearing skies. Confidence for when and where this fog will form is very low, but included the mention of BCFG where fog is historically favored. VFR conditions become widespread after sunrise on Thursday with light winds and mostly clear skies before the next weather system begins to move in north of I-70 late in the TAF period. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...Winter Weather Advisory from 11 PM this evening to 5 PM MST Friday for COZ004. Winter Storm Watch from Friday afternoon through Sunday morning for COZ004-010-013. Winter Weather Advisory until 5 AM MST early this morning for COZ023. UT...None. && $$ SHORT TERM...15 LONG TERM...DB AVIATION...TGJT ####018009878#### FXUS62 KRAH 041008 AFDRAH Area Forecast Discussion National Weather Service Raleigh NC 508 AM EST Thu Dec 4 2025 .SYNOPSIS... Weak high pressure will hold over the Southeast coast and eastern Carolinas this morning. A dry cold front will push southward through the region later today, settling just to our south as Arctic high pressure noses in from the north. Low pressure developing over the northern Gulf will track northeastward across the Southeast states and Carolinas late tonight through Friday. && .NEAR TERM /TODAY/... As of 400 AM Thursday... A weak surface trough will linger across the area today before being pushed south and out of the area by a dry cold front. Arctic high moving into the OH Valley begins to build into the area this evening. A mid-level srn stream wave will track ewd across nrn FL/GA and off the Southeast US coast this eve. Cloud cover will increase this aft and eve as the wave passes to the south, but the weather should largely remain dry through the afternoon. Highs will be near to slightly below normal, generally in the low to mid 50s. && .SHORT TERM /THURSDAY NIGHT THROUGH FRIDAY NIGHT/... As of 335 AM Thursday... * Winter Weather Advisory in effect from midnight tonight through midnight Saturday for portions of the northern Piedmont and northern Coastal Plain of central NC. Up to an inch of snow accumulation and a glaze of ice accumulation are expected. * Snow, and sleet (likely mixed with rain) are possible south of the advisory area between midnight and 10 AM Friday, however the duration of non-liquid precipitation will be shorter and accumulations will be below advisory criteria before the transition to all rain occurs. * A brief period of freezing drizzle could occur (mainly over the advisory area) as the precipitation moves out Friday evening/night, but confidence in that occurrence is lower. Overview: Aloft, a mid-level srn stream wave will track ewd across nrn FL/GA and off the Southeast US coast this eve, while a nrn stream s/w follows on its heels, tracking ewd across the srn Appalachians and Carolinas tonight/Fri and off the Carolina coast Fri night. The H25 170 kt jet should stay north of the area, oriented generally from W-E extending from the mid MS Valley to the DELMARVA and east. At the surface, Arctic high pressure will move ewd from the OH Valley to the Northeast US, ridging swd into the area through Thu night. Meanwhile, an area of low pressure over the nrn Gulf will begin tracking enewd into the Southeast US tonight. The ridge will likely hold over portions of central NC as the high shifts off the New England coast and the deepening low tracks newd across the Southeast US and along the Carolina coast on Fri. The low should continue ewd out over the Atlantic Fri night, with high pressure remaining over the area. Temperatures: lows tonight in the upper 20s north to mid/upper 30s south expected. Fri highs will be well below normal, only reaching the low/mid 30s north to low/mid 40s south and with a bit of a breezy it may only feel like upper 20s to mid 30s across much of the area. Precipitation: Isentropic lift will increase this eve/tonight, quickly saturating the mid levels, including the dendritic growth zone, by midnight. As precipitation begins, initially rain in most places, the lower levels will also saturate. Precipitation will continue into the morning, then could begin moving out of the area from W-E Fri afternoon or evening, end timing is still a bit uncertain. Across the northern half of central NC (roughly along and north of HWY 64): the temperatures should wetbulb to near/below 0C tonight. The thermal profile, with temperatures through the column at or below 0C, should support a period of snow in the advisory area, perhaps mixing with rain south of the advisory area, into Fri morning. However, there is still some uncertainty wrt p-types from early Fri morn into Fri aft. The biggest p-type question will be if, when, and for how long some sleet or freezing rain may mix in, depending on the strength/depth of the warm nose aloft, and/or if there will be a transition to fzdz as dry air intrudes near/below the dendritic growth zone. The accumulations of snow and ice will hinge on these transitions and durations. For now expect a glaze of ice accumulation and up to an inch of snow in the advisory area. If the saturated layer below the dry air intrusion is deep enough and surface temps remain below freezing, a transition to fzdz is possible, which could result in some light ice accrual as the precipitation ends. Across the srn half/third of central NC: largely expect precip to be rain, although cannot rule out a brief period of snow mixing in farther north. Friday night: The precipitation should be out, or be moving out of the area Friday night, though some rain may linger across the southeast into/through the night. Lows should range from mid/upr 20s to low/mid 30s. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... As of 225 AM Thursday... * Rain chances SE Sat, and continued chilly. * Chilly, below-normal temperatures to persist into next week. * Light precip chances late Sunday into Monday, with brief rain/snow mix possible. Sat/Sat night: The frontal zone will hold SE of the area Sat, with weak high pressure sitting over the Carolinas. As we'll stay within a fast WSW mid level flow, the potential remains that subtle and hard-to-time perturbations will ride within this flow over SC and S/E NC Sat/Sat night. There is some model agreement on the right entrance region of the upper jet scraping across NC Sat afternoon, with associated enhanced upper divergence resulting in a brief northwestward bump in the NW edge of the precip shield toward the Triangle area. But the overall forcing for ascent appears to be modest and fleeting, with the bulk of the moisture in the mid and upper levels, given the lack of opportunity for moisture return in the low levels. As such, expect the chance for any rain to be largely confined to areas SE of the Triangle, with light amounts overall. Clouds will be abundant, especially over S and E sections, so it will remain chilly, with highs Sat in the mid 40s to around 50, followed by lows mostly in the mid 30s. -GIH Sun-Wed: A central to eastern U.S. mean upper trough (with 500 MB heights ~2 S.D. below normal) and broad cyclonic flow will support a continuation of chilly, below-normal temperatures through the period, highlighted by a reinforcement of cold air behind a cold frontal passage Monday. Monday and Tuesday will be the coldest days, with highs in the lower to mid 40s and lows Monday night dipping down into the lower to mid 20s, with some upper teens possible in the typically colder locations. Sunday should begin mostly dry across the area, with steadier rain chances suppressed to the south along a stalled frontal zone lingering across the SE US. However, the approach of the next shortwave trough and aforementioned cold front may support a brief period of light rain Sunday evening and into the day on Monday. There is a low-end potential for the rain to briefly mix with or change over to snow across the northern Piedmont and northern coastal plain before ending, though little to no impacts are expected at this time. Dry conditions will follow Tuesday and Wednesday with a clipper trough approaching from the west late in the period. -CBL && .AVIATION /06Z THURSDAY THROUGH MONDAY/... As of 1250 AM Thursday... With the exception of patchy MVFR fog over S and E areas until around 12z this morning, affecting RWI and perhaps FAY, VFR conditions are likely to hold across central NC today through at least mid evening (~03z Fri), but with increasing clouds. Weak high pressure over the eastern Carolinas will push SE and yield to a dry backdoor cold front that will drop S through the area later today, resulting in a shift of surface winds from light/variable this morning to light from the W or NW through mid afternoon, then shifting to be from the NE under 8 kts behind the backdoor front starting late today. Low pressure tracking NE from the N Gulf later today will bring increasing and thickening mid clouds from the WSW by afternoon, with slowly lowering bases. Clouds will become overcast after 22z, lowering further but still VFR through 03z, then there is a good chance for cigs to lower to MVFR at INT/GSO after 03z. Looking beyond 06z Fri, precipitation will spread into W sections including INT/GSO between 06z and 09z, before advancing over the rest of central NC after 09z, lasting through much of Fri, with a high chance of sustained sub-VFR conditions. This precipitation is likely to be mostly light snow at INT/GSO and a rain/snow mix at RDU at onset, with rain elsewhere. Precipitation will end W to E late afternoon through the evening, perhaps as a little drizzle or freezing drizzle, but sub-VFR conditions are likely to hold through Sat morning. Rain chances producing a period of sub-VFR conditions will continue at FAY Sat through Mon, with the highest chance late Sun into early Mon. -GIH && .RAH WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory from midnight tonight to midnight EST Friday night for NCZ007>011-021>025. && $$ SYNOPSIS...Hartfield NEAR TERM...10 SHORT TERM...10 LONG TERM...Hartfield/CBL AVIATION...Hartfield