####018006285#### FXUS62 KCHS 090049 AFDCHS Area Forecast Discussion National Weather Service Charleston SC 749 PM EST Mon Dec 8 2025 .SYNOPSIS... High pressure will extend across the region for much of the week. A cold front will push offshore Thursday morning with another cold front possibly moving south through the area over the weekend. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... A surface low will continue to develop north of the region and offshore under a stronger shortwave, with surface high pressure building behind it. This will result in a dry conditions locally, with a heightened surface pressure gradient resulting in slightly breezy conditions along the coast where gusts into the teens are expected to continue into the overnight period. Ahead of surface high pressure, cooler air is expected to advect south into the region while stratus begins to erode due to a substantial amount of dry air aloft. The setup is likely to lead to noticeably colder temps than the previous night, with overnight lows generally in the upper 20s/lower 30s inland to lower/middle 30s near the coast. These temps combined with breezy coastal winds could produce wind chills into the low-upper 20s, lowest in the Tri-County Area. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/... The Tuesday through Thursday period will offer much improved conditions compared to the rainy and foggy weather that has been observed for the past several days. A broad west to northwest flow will dominate aloft as a large area of high pressure pressure gradually shifts offshore of the Southeast U.S. coast. A broad trough is forecast to dig across the eastern CONUS Wednesday into Thursday which will help drive a weak cold front offshore Thursday night. Moisture return ahead of the front looks meager at best with a dir airmass progged to hold over much of the Gulf. PWATs are forecast to surge somewhat right ahead of the front itself, but will remain well below the 1" mark. This lack of moisture coupled with the corridor of great quasi-geostrophic forcing progged to remain displaced well to the north, suggests the front will pass through dry with little prospects for measurable rainfall. Temperatures will moderate ahead of the front with highs reaching the upper 40s/lower 50s Tuesday and lower-mid 60s Wednesday into Thursday. Lows Wednesday morning will drop into the upper 20s well inland to the lower 40s at the beaches with upper 30s/lower 40s inland with upper 40s/near 50 at the beaches Thursday morning. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... Quiet weather will generally prevail into the weekend as high pressure slides east across the Southeast U.S. and eventually offshore. A cold front is forecast to backdoor in from the north on Sunday as as the beginnings of a cold air damming/wedge take shape. There are considerable timing differences noted with the southward moving wedge front Sunday. The timing of the front will closely tied to any possible surface cyclone that develops along the front. For now, both the GFS and ECMWF ensembles, including any AI counterparts, keep any surface low weak and tracking well to the north. The area may be fully wedged in on Monday with cloudy and cool conditions prevailing. There was no reason to deviate from the 08/13z NBM at this time given the uncertainty, although NBM-based temperatures Sunday and Monday may end up being too warm depending on how the wedge evolves. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/... MVFR cigs will prevail at CHS/JZI terminals this evening and overnight, primarily through about 13Z Tuesday. A brief window for IFR cigs is possible at CHS/JZI terminals overnight as well, but guidance has trended higher and dry air filtering into the region from the west should eventually erode cloud cover near or shortly after daybreak Tuesday. VFR conditions are then expected at CHS/JZI terminals through 00Z Wednesday. At SAV, MVFR cigs should prevail for the next few hours, but clouds begin to erode earlier, thus have indicated a transition to TEMPO MVFR cigs between 01Z-03Z tonight. There is a risk for MVFR cigs to temporarily impact the SAV later tonight, but confidence remains too low to include in the latest TAF issuance. VFR conditions should prevail at SAV during the second half of the night through 00Z Wednesday. Extended Aviation Outlook: There are no high confidence concerns. && .MARINE... Tonight: Northerly winds gusting up to 15-20 kt early evening will strengthen further overnight into early morning hours, resulting in gusts around 25 kt, highest in the nearshore waters from South Santee down to Edisto Beach, SC, and in the outer Georgia waters from Savannah to Altamaha Sound. Seas will also build to 4-6 ft, largest across the outer reaches of the nearshore waters from South Santee down to Edisto Beach, SC and across the outer Georgia waters from Savannah to Altamaha Sound tonight. Small Craft Advisories will therefore remain in effect for these marine zones (AMZ350 and AMZ374) through the night. Tuesday through Saturday: Winds and seas will diminish below advisory levels across the South Santee-Edisto Beach nearshore and Georgia offshore waters by mid-morning Tuesday. Otherwise, winds will turn more southerly for Wednesday and more westerly Thursday into Saturday as high pressure slides offshore and a cold front pushes offshore. Winds and seas could surge to Small Craft Advisory levels Wednesday night/Thursday morning immediately ahead and just behind the cold front. Advisories at the most likely over the South Santee-Edisto Beach and the Georgia offshore legs where the latest LREF probs for gusts >25 kt is running 50-80%. Otherwise, winds and seas will remain below Small Craft Advisory thresholds. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. MARINE...Small Craft Advisory until 10 AM EST Tuesday for AMZ350-374. && $$ NEAR TERM... SHORT TERM... LONG TERM... AVIATION... MARINE... ####018009712#### FXUS63 KFGF 090054 AFDFGF Area Forecast Discussion National Weather Service Grand Forks ND 654 PM CST Mon Dec 8 2025 .KEY MESSAGES... - A brief period of moderate to heavy snow will bring a quick 1 to 3 inches across northeastern North Dakota and northwestern Minnesota this afternoon and evening. - Very difficult travel conditions are expected Tuesday from accumulating snow and ice, blowing snow, and very strong winds. Some uncertainty in the track of the system exists, which will determine where snow transitions to freezing rain. In the snow area, expect 3-5 inches with some some areas receiving 6 or more inches of snow. - Strong winds will come in late Tuesday into Tuesday night behind the precipitation, with gusts up to 60 mph in southeastern North Dakota. Blowing snow across portions of northeastern North Dakota and far northwestern Minnesota will bring very difficult travel conditions with low visibility in addition to ice and snow. - Much colder temperatures will arrive late week, with a 70 percent chance for winds chills to drop to -30 or colder. && .UPDATE... Issued at 650 PM CST Mon Dec 8 2025 Conditions will continue to improve as snowfall spreads east of the region. Behind this, low clouds will keep temperatures above zero for the most part, although pockets of clearing may allow drops to just below zero in northwest Minnesota. No other weather impacts are expected until the next system pushes in tomorrow morning. && .DISCUSSION... Issued at 309 PM CST Mon Dec 8 2025 ...Synopsis... Shortwave trough currently digging from southwestern Manitoba into ND will continue diving into our northern counties tonight. This will bring a quick shot of snow and winds briefly shifting to the northwest before they return back to the south tomorrow morning ahead of the next system. The shortwave tomorrow is expected to be more vigorous, with a deeper surface low and strong cold air advection behind it. The strong shortwave will continue to be pretty fast moving, moving off into southern MN/northern IA tonight and then the next reinforcing shortwave coming down on Wednesday. North to northwest flow with periodic clipper systems continues through the rest of the period, with lower heights and colder air coming in on Friday. Some variation on where exactly the baroclinic zone ends up over the weekend, but decent agreement between ensemble members on northwesterly flow and another clipper moving in Monday. ...Brief moderate to heavy snow through this evening... First shortwave today has a fair amount of 850mb frontogenesis with it as seen on SPC mesoanalysis. Snow currently moving through northeastern ND has been showing fairly impressive rates, with 1 to 2 inches per hour in some locations. Fortunately the system is fast moving, so residence time will be short and most likely snow amounts are a quick 1 to 3 inches. Not out of the question that some spots could see more than 3 inches, but probability of that is around 10 to 20 percent. Expect larger impacts tomorrow. ...Accumulating snow and ice tomorrow... The stronger shortwave will dig into the northern Red River Valley tomorrow. There are still minor differences in the track of the surface low, with a difference of less than 50 miles making a big difference in temperature profiles. It is still unknown where exactly the rain/freezing rain/snow line will be, along with the band of heaviest snow. However, probabilities of at least a glaze of freezing rain are 60 to 90 percent along our western and southern counties. Best chances for at least 4 inches of snow are mostly across the eastern Devils Lake Basin into the Northern Red River Valley and northwestern Minnesota, with a 40 percent chance for 6 inches or more in some spots. While exact amounts are still uncertain, travel impacts are highly likely with at least some ice and snow accumulation across the area. Portions of the Devils Lake basin and northern Red River Valley look to have the best convergence of a bit of freezing rain, up to 6 inches of snow, and blowing snow later in the day to go ahead and put out a winter storm warning through Tuesday and Tuesday night. Further east into MN, there will be a strong 2 to 4 inches of snow but less wind and lower chances for ice, so kept it advisory. Western Devils Lake basin will see a bit less snow, and southeastern ND into far northwestern MN mostly freezing rain and then rain. The icing impacts in southeastern ND will be affecting by rising temperatures, with some melting of ice and even crusting of snowpack possible with temps rising into the mid to upper 30s. However, for simplicity kept advisory through 00Z and later shifts can cancel early if needed. ...High winds Tuesday night... Very strong cold air advection and pressure rises on the backside of the departing low will bring good confidence in high winds Tuesday night behind the precipitation. BUFKIT soundings for KFAR have a strong mixed layer up to 780mb and momentum transfer as high as 55 kts Tuesday evening. Probabilities for 60 mph gusts or higher are 50 to 60 percent across southeastern ND. Not sure how long the high gusts will last into the overnight beyond the initial push of cold air advection, but elected to go high wind warning all the way from 00Z to 12Z Wednesday in the interests of headline simplicity. ...Cold temperatures Friday into the weekend... Upper low/trough digging into the Upper Midwest and Great Lakes Friday will help bring a reinforcing surge of cold air into the Northern Plains. This looks to be coldest of the season so far, with lows in the teens and 20s below zero over the weekend and highs on Saturday not even getting to the positive numbers. Mean apparent T values around around -40 Saturday and Sunday mornings. Likely will need some cold headlines of some sort, but too early to exactly determine advisory or warning. .AVIATION /18Z TAFS THROUGH 18Z TUESDAY/... Issued at 1152 AM CST Mon Dec 8 2025 A bit of light snow or flurries reducing vis down to 2 miles at a few spots. Ceilings are mostly MVFR but a few have broken up to VFR or gone down to IFR. Some vis down to 1 mile or even lower at times is not out of the question, with IFR conditions for a while this afternoon and evening. After a bit of a break back to MVFR/VFR overnight as this first round of snow, visibility and ceilings will go down again towards the end of the period as the next round of precipitation arrives. That system will have the potential for FZRA as well as snow particularly at KDVL and KFAR, so have a mention going at those sites. Winds will be shifting around from the southeast to the west, then back to the southeast before going north with the cold front coming down. Speeds look like they will stay mostly in the 10 to 15 with gusts up to 20 kts during the TAF period, but will be ramping up quickly afterwards when they shift northwest for Tuesday afternoon. && .AVIATION /18Z TAFS THROUGH 18Z TUESDAY/... Issued at 531 PM CST Mon Dec 8 2025 Snow will continue to push eastward through the evening towards BJI, clearing out for the most part in eastern North Dakota and far northwest Minnesota. Associated with the approaching band of snow will be periodic visibility reductions to 1/2SM at times (potentially even 1/4SM), with prevailing 1-2SM. MVFR to IFR ceilings will continue to linger on the backside of this snow. There are signals for a brief push to VFR in the Red River Valley. Confidence is low in the extent of VFR ceilings and the cutoff could be sharp so anticipate some amendments as necessary depending on how things shake out. Looking ahead to tomorrow, conditions will deteriorate from northwest to southeast through the morning and afternoon hours. Heavy snow in northwest Minnesota and northeast North Dakota will contribute to visibility reductions to 1/4SM at times, particularly with the blowing snow accompanying it. Additionally, freezing rain is likely to develop across eastern North Dakota into west-central Minnesota, particularly impacting FAR for a long duration. Eventually, all sites will shift to primarily snow, and with the winds approaching 40-50 knots (again particularly at FAR), blowing snow should cause visibility reductions to continue to linger once falling snow ends. MVFR to IFR ceilings will also accompany this system. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...Winter Storm Warning from 6 AM Tuesday to 6 AM CST Wednesday for NDZ007-008-015-016-026-027-029-030-054. Winter Weather Advisory from 6 AM to 6 PM CST Tuesday for NDZ024-028-038-039-049-052-053. High Wind Warning from 6 PM Tuesday to 6 AM CST Wednesday for NDZ024-028-038-039-049-052-053. Winter Weather Advisory from 6 AM Tuesday to 6 AM CST Wednesday for NDZ006-014. MN...Winter Storm Warning from 6 AM Tuesday to 6 AM CST Wednesday for MNZ001-002-004-007-008-013>015. Winter Weather Advisory from 6 AM to 6 PM CST Tuesday for MNZ003-029. High Wind Warning from 6 PM Tuesday to 6 AM CST Wednesday for MNZ003-029. Winter Weather Advisory from noon Tuesday to 6 AM CST Wednesday for MNZ005-006-009-016-017-022>024-027-028- 030>032-040. && $$ UPDATE...Perroux DISCUSSION...JR AVIATION...Perroux