####018011260#### FXUS65 KRIW 082107 AFDRIW Area Forecast Discussion National Weather Service Riverton WY 207 PM MST Mon Dec 8 2025 .KEY MESSAGES... - Persistent moderate snowfall is expected across the northwest WY mountains beginning tonight. Snow continues through Thursday, with greatest amounts (1 to 2 feet) across the Absarokas, Pitchstone Plateau, and near Togwotee Pass. - Strong to high wind is likely (greater than a 90% chance) across much of central and southern Wyoming late Monday night through Tuesday. Strongest winds (60 to 70+ mph) will be along the South Pass to Casper Corridor and along the Absarokas and Wind River Mountains Tuesday morning. - Temperatures will remain 10 to up to 20 degrees above normal across much of the region through Thursday. && .UPDATE... Issued at 205 PM MST Mon Dec 8 2025 There was not much change to the overall forecast with snowfall amounts and winds remaining generally on track. Regarding snowfall amounts, there was an uptick across the Tetons and also across the northern Bighorns with the latest forecast. Given that, have opted to hoist an Advisory for the Bighorns and have upgraded the Watch to a Warning for the Tetons. The combination of wind and snow will be the main concern for both locations, more so than amounts. This will be a long-duration event, with snow lingering well into Thursday (beyond the ending of the hazards), however, winds will decrease by Wednesday late afternoon, as will snowfall rates, hence keeping with the 5 PM Thursday timing for ending the highlights. The other Watch areas (Wind River Mountains and Salt/Wyoming Ranges) will likely see Warning amounts, but given the long-duration of the event (over 48 hours) and the limited travel concerns (no impacts to travel corridors) have opted for Advisories for those zones. Regarding wind, the only notable change from the previous forecast was to add a High Wind Warning for the upper Wind River Basin to include Dubois. This area favors west-northwest flow and as the jet moves through tonight, it is looking likely that they will see gusts around 50 to 60 mph, with locally stronger gusts possible. Notably, latest NAM model indicates a period of 70 to 80kts at 700mb Tuesday late morning into the early afternoon. Though not expecting that to fully mix to the surface, it is significant enough of a signal to warrant the Warning. Winds do not look to be as strong on Wednesday for that area, so have only kept the Warning through Tuesday afternoon, rather than Wednesday afternoon with the other High Wind highlights. && .DISCUSSION... Issued at 306 AM MST Mon Dec 8 2025 Sometimes I think the weather is like a rubber band. Basically, you can have a long stretch of quiet weather, but each day builds up tension in the band. Eventually, it ends up snapping. And this is the case over the next few days. Much of November was very quiet and tranquil weather wise. And we are now in one of the more active periods we have had in a while. And a rather complex one, with most threats including wind and snow. In a bit of a change in format, we will hit each one of these individually followed by a general outlook of aspects of the forecast that are less impactful as well as the weather past Wednesday night. SNOW DISCUSSION...We continue to have some mainly light snow falling over the western mountains as I write this around 2 am. It is beginning to let up in the Tetons, so we will likely expire the advisory around 5 am. There should then be a lull in the snow for around 12 to 24 hours before the next round of snow moves in from north to south as a boundary sags southward and a potent 140 knot jet sags southward toward the area, enhancing upper level divergence. The highest confidence for heavy snow continue to be in the Absarokas where there will be some orographic enhancement to go along with the jet energy. Many locations here have greater than a 9 in 10 chance of a foot of new snow with some of the southern portions of the range having nearly a 1 in 2 chance of 2 feet or more. This, combined with some strong wind, looks to be the most impacted area. So, we have issued a Winter Storm Warning here starting tonight and continuing through Wednesday afternoon. Southern portions of Yellowstone Park also have a greater than 3 out of 5 chance of a foot of new snow, but lesser amounts elsewhere. As a result, we had more questions about a warning here, but with the strong wind we went ahead and issued and also to match up with our neighbors to the north. Northern portions of the Park will likely only see advisory amounts though. Further south there are more questions, as the dynamics are not as favorable here with the jet being further away. Nevertheless, a decent portion of the Tetons, Wind Rivers and Salt and Wyoming Range have at least a 1 in 2 chance of a foot of new snow. I'm not completely convinced yet though. Since the bulk of the snow here would not fall until at least Tuesday, we have elected to go with watches and let future shifts decide between warnings, advisories or even nothing. As for the Bighorns, there is at least a 3 out 4 chance of greater than 6 inches of new snow, but the chance of a foot is generally less than 1 out of 3. Any impactful snow would hold off until Tuesday afternoon or evening, so we still have time to decide on any highlights here. As for the lower elevations, impacts look minimal. Warmer air will try to push into the area, especially on Wednesday. With 700 millibar temperatures expected to rise as high as minus 2 by Wednesday, snow levels may rise as high as 7500 feet, keeping the valleys a rain / snow mix and even all rain at times. Chances of 3 inches of snow or more are basically zero because of this. As for the lower elevations East of the Divide, there could be some light snow in the Big Horn Basin and Johnson County. But, with the warmer air moving in, especially on Wednesday, any accumulation would be negligible. One caveat is that there is still some spread in the details of timing of the periods of heaviest snow. The deterministic runs have a lot of differences as well, with the European much wetter than the GFS for example. WIND DISCUSSION...We are already starting to see some gusty wind develop in places like Casper this morning. There has been a bit of a change in that the jet has moved a bit further north, and this brought some of the strongest wind gusts down a bit. However, we still have a good set up for strong wind much of southern and central Wyoming in the right front quadrant of the jet, a tight pressure gradient and strong winds at 700 millibars. The strongest 700 millibar winds are now down to around 60 to 65 knots as opposed to the 80 knots yesterday, guidance does tend to be a bit bold a few days out. Nevertheless, we still have a very good chance of high wind across much of the area. Much of the southwestern wind corridor from Kemmerer to Rock Springs to Casper has at least a 3 in 4 chance of wind gusts past 55 mph sometime between Monday night and Wednesday night. With this, we have upgraded the High Wind Watch to warning for all of the zones starting at 11 pm tonight. The most prolonged high wind will be across southern Lincoln and Sweetwater County, this includes Interstate 80 as well. In Natrona County, Tuesday looks like the most impactful day with a greater than 4 out of 5 chance of wind gusts past 55 mph. Chances drop a bit on Wednesday, but not enough confidence to drop it for this day. There are two other areas of concern. One is in northern Johnson County, which could see a brief period of high wind Wednesday afternoon as flow turns northwest, with some areas having a greater than 1 in 2 chance of wind gusts past 50 mph. The other is the Upper Wind River Basin, which has a similar set up. Again, this would likely not be until Tuesday, so there is still time to decide. Gusty winds are possible elsewhere, but changes of high wind are 1 out of 4 or less. REST OF THE FORECAST...It will be fairly mild outside of the mountains, with some areas seeing highs into the 40s and even the 50s, especially on Wednesday as flow becomes southwesterly. We are also watching another piece of energy that could bring some precipitation to northern Wyoming later Thursday into Friday. There is a large spread in guidance though so confidence remains rather low. Looking ahead to next weekend, at this point to looks largely dry with a gusty wind and above normal temperatures, but confidence remains rather low. && .AVIATION /18Z TAFS THROUGH 18Z TUESDAY/... Issued at 1010 AM MST Mon Dec 8 2025 VFR conditions across all terminals to start the TAF period. The main concern this period will be increasing winds across nearly all terminals. This afternoon KCOD, KCPR, and KRKS are expected to see periodic gusts of 30 to 40 knots. These winds will begin to increase at the start of the period gusty winds likely persisting through much of the overnight into Tuesday morning. Other terminals will see increasing winds but at a lesser magnitude with only periodic gusts of 15 to 25 knots this afternoon and evening. Precipitation returns to KJAC this evening with temperatures likely too warm for all snow, so a mix of snow/rain or all rain is expected. Showers will be possible at KJAC through the overnight with prevailing precipitation likely to arrive by the late morning on Tuesday. Winds increase furthermore at KJAC around this time with gusts around 30 knots through the end of the period. Other terminals are forecast to stay mainly dry with a few VCSH at KCOD and KPNA. Winds increase furthermore by the late morning hours at nearly all terminals. The strongest gusts will be at KCPR, KRKS, and KCOD where gusts of 35 to 45 knots will be possible. Other terminals will see gusts of 20 to 35 knots with a few terminals not seeing these winds till shortly after the end of the TAF period. Mountain obscuration is possible for the start of the period but it is likely to only worsen by the late evening through the rest of the TAF period. Please see the Aviation Weather Center and/or CWSU ZDV and ZLC for the latest information on smoke, icing, and turbulence forecasts. && .RIW WATCHES/WARNINGS/ADVISORIES... Winter Storm Warning until 5 PM MST Wednesday for WYZ001-002. Winter Weather Advisory from 5 AM Tuesday to 5 PM MST Wednesday for WYZ008-014-015-024. Winter Storm Warning from 5 AM Tuesday to 5 PM MST Wednesday for WYZ012. High Wind Warning from 8 PM this evening to 2 PM MST Tuesday for WYZ016. High Wind Warning from 11 PM this evening to 5 AM MST Thursday for WYZ019-020-022-027>030. && $$ UPDATE...Hensley DISCUSSION...Hattings AVIATION...Dziewaltowski ####018010022#### FXUS61 KPHI 082107 AFDPHI Area Forecast Discussion National Weather Service Mount Holly NJ 407 PM EST Mon Dec 8 2025 .SYNOPSIS... A cold front moves through the region early this morning. High pressure then builds into the region later today before building overhead tonight, then moving offshore on Tuesday. Low pressure passes through the region Wednesday, followed by several strong cold fronts. Arctic high pressure builds into the region for the end of the week and next weekend. && .NEAR TERM /THROUGH TUESDAY/... The region will be embedded within relatively weak flow aloft through tonight between enhanced flow associated with a closed upper- low over Quebec and a shortwave axis passing to the south. On Tuesday, another shortwave associated with the upper-low will pass just to the north of our area ahead of a more significant trough approaching from the northwest. At the surface, high pressure will continue to settle into the region through tonight as an area of low pressure tracks eastward off the coast of the Carolinas. High pressure will begin to depart to the east on Tuesday. The far northern edge of the precipitation shield associated with the area of low pressure to the south of the region has tried to make its way into parts of the Maryland eastern shore and southern Delaware today, but dry air has kept most of this from reaching the ground. With that said, some flurries or very light snow will remain possible into the early evening hours across the aforementioned areas before chances diminish. No accumulation is expected. Breezy north-northeasterly winds will quickly diminish as we head into the evening and overnight hours. Clouds will clear from northwest to southeast tonight, with the entire region expected to be mostly clear by dawn. The mostly clear skies and light winds will allow for effective radiational cooling, so a very cold night is in store. Temperatures are expected to bottom out in the single digits across the Poconos and into far northwestern NJ, and perhaps into the Lehigh Valley. Mid-upper teens are expected for the remainder of eastern PA and most of NJ. Where clouds clear the latest across southern DE and far southern NJ, temperatures could remain in the mid 20s. Tuesday will feature increasing mid and high clouds from west to east, particularly in the mid to late afternoon hours. High temperatures look to be in the upper 20s to near 30 northwest of the fall line, mid 30s in the vicinity of I-95, and near 40 for the Delmarva and into southeastern NJ. Some CAMs feature snow showers across our far northern zones associated with the shortwave passing to our north during the afternoon and evening hours. Even though this cannot be entirely ruled out, forecast soundings indicate quite a bit of dry air below the DGZ which should make it hard for anything to reach the ground. This leads to confidence in occurrence being too low to include mentionable PoPs at this time. && .SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY NIGHT/... A clipper system will dive into the Great Lakes and Ohio Valley Tuesday night and will pass through northern New York and northern New England late Wednesday, departing Wednesday night. A cold front will follow through behind the departing low Wednesday night, and then cold air advection will be underway. Temperatures return closer to normal on Wednesday with highs generally in the low to mid 40s, and possibly near 50 in Delmarva. Precipitation develops across most of the area, with snow across the southern Poconos and northwestern New Jersey, a wintry mix just northwest of the I-95 corridor into the Lehigh Valley and northern New Jersey, and rain across the heart of the I-95 corridor into central and southern New Jersey and Delmarva. The rain/snow line will gradually lift north throughout the day Wednesday, with precipitation changing to plain rain as far north as the Lehigh Valley, and snow may mix with rain in the southern Poconos and northern New Jersey. During the transition period, particularly during the morning hours, snow may mix with sleet and freezing rain. In terms of overall snowfall accumulation, can expect generally 1 to 3 inches in the higher elevations of the southern Poconos and northwestern New Jersey, and less than an inch for areas southeast of there. For areas that receive any ice accumulation, currently a light glaze of less than a tenth of an inch is forecast. Rain and snow tapers off late in the day Wednesday. Dry Wednesday night with lows mainly in the mid and upper 20s across northern areas and in the low to mid 30s elsewhere. && .LONG TERM /THURSDAY THROUGH MONDAY/... Several reinforcing cold fronts will pass through the region through the end of the week, with an Arctic airmass building overhead this weekend. Thursday looks to be mostly dry, though some flurries may be possible with the passage of a strong cold front. Highs return to below normal levels, generally in the upper 30s to low 40s. Lows Thursday night drop into the 20s across much of the area, and in the teens in the southern Poconos. Temperatures will drop by a few degrees on Friday, generally topping off in the upper 30s to around 40. A clipper-like system may pass through the region Friday night into Saturday morning. Models are not in good agreement in terms of the timing and placement of this system, and latest runs are trending a bit drier. Will use NBM guidance for this time with PoPs generally 35 to 45 percent, and mostly snow. An Arctic airmass then builds into the region for the weekend. Gusty winds may develop on Saturday afternoon. Highs on Saturday and Sunday will struggle to reach the freezing mark for most of the area, though should be in the mid 30s or so in southern Delmarva and along the Jersey Shore. Highs will be a few degrees cooler on Sunday compared to Saturday. Lows Saturday night will be in the teens and low 20s. && .AVIATION /20Z MONDAY THROUGH SATURDAY/... The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY and surrounding areas. Through 00Z...VFR. BKN high clouds. North-northeast wind 10-15 kt with gusts 20-25 kt, decreasing to around 10 kt by 20-22Z. High confidence. Tonight...VFR. SCT/BKN high clouds, decreasing late. North-northeast wind around 10 kt becoming LGT/VRB 03-05Z, though a north-northeast direction will still be favored. High confidence. Tuesday...VFR. A few high clouds to start, with increasing mid-level clouds by late afternoon. Light wind in the morning becoming south to south-southwest at 5-10 kt after 16-17Z. High confidence. Outlook... Tuesday night...VFR. NSW. Wednesday through Wednesday night...Sub-VFR in RA and/or SN, though SN is most likely at KRDG/KABE. Conds lift to VFR Wednesday night. Thursday through Thursday night...VFR. Gusty west winds possible on Thursday. Friday through Saturday...Sub-VFR conds possible with RA and/or SN, most likely Friday night. Gusty westerly winds possible on Saturday. && .MARINE... A Small Craft Advisory is currently in effect for all coastal waters as well as the Delaware Bay. It is set to expire at 6 PM for the Delaware Bay and for coastal waters from Sandy Hook to Manasquan NJ, 1 AM Tuesday from Manasquan to Little Egg Inlet NJ, and 6 AM Tuesday for the remaining coastal waters. Northeast wind initially 20-25 kt with gusts to 30 kt for the coastal waters and 15-25 kt for the Delaware Bay, will gradually diminish through this evening and into tonight. By daybreak Tuesday, winds are expected to be northeast at 15-20 kt. Winds will become southeasterly at 15-20 kt by Tuesday afternoon. Seas 4-6 feet will diminish to 2-4 feet around daybreak Tuesday, and remain in that range through the day. Outlook... Tuesday night...SCA conditions develop. Winds increase to 15 to 20 kt with gusts up to 25 kt. Wednesday through Wednesday night...Strong SCA conds likely, with gale force winds possible. S to SW winds 20 to 30 kt. Gusts up to 35 kt possible. Winds turn W Wednesday night, generally at 20 to 25 kt with gusts up to 30 kt. Thursday through Thursday night...SCA conds Thursday subside to sub-SCA criteria Thursday night. W winds 15 to 20 kt with 25 to 30 kt gusts, diminishing to 10 to 15 kt with gusts to 20 kt. Friday through Friday night...SCA conds possible. W winds 15 to 20 kt. Saturday...Strong SCA conditions likely with gale force winds possible. Westerly winds 20-30 kts with gusts up to 35 kts possible. && .CLIMATE... Very cold temperatures are expected tonight into Tuesday morning. At this point, do not anticipate any climate site to break its daily record low, however it is certainly possible that a few come within a few degrees of doing so. Below are the record lows for December 9. SITE RECORD/YEAR Allentown (ABE) 7/2002 AC Airport (ACY) 6/1968 AC Marina (55N) 5/1876 Philadelphia (PHL) 6/1876 Wilmington (ILG) 13/1960 Reading (RDG) 0/1989 Trenton (TTN) 12/2002 Mount Pocono (MPO) -1/1902 Georgetown (GED) 10/1976 && .PHI WATCHES/WARNINGS/ADVISORIES... PA...None. NJ...None. DE...None. MD...None. MARINE...Small Craft Advisory until 6 PM EST this evening for ANZ430- 431-450. Small Craft Advisory until 1 AM EST Tuesday for ANZ451. Small Craft Advisory until 6 AM EST Tuesday for ANZ452>455. && $$ SYNOPSIS...AKL/MPS NEAR TERM...Cooper SHORT TERM...AKL/MPS LONG TERM...AKL/MPS AVIATION...AKL/Cooper MARINE...AKL/Cooper CLIMATE...WFO PHI ####018009901#### FXUS61 KPHI 082108 AFDPHI Area Forecast Discussion National Weather Service Mount Holly NJ 408 PM EST Mon Dec 8 2025 .SYNOPSIS... High pressure builds overhead tonight, then moving offshore on Tuesday. Low pressure passes through the region Wednesday, followed by several strong cold fronts. Arctic high pressure builds into the region for the end of the week and next weekend. && .NEAR TERM /THROUGH TUESDAY/... The region will be embedded within relatively weak flow aloft through tonight between enhanced flow associated with a closed upper- low over Quebec and a shortwave axis passing to the south. On Tuesday, another shortwave associated with the upper-low will pass just to the north of our area ahead of a more significant trough approaching from the northwest. At the surface, high pressure will continue to settle into the region through tonight as an area of low pressure tracks eastward off the coast of the Carolinas. High pressure will begin to depart to the east on Tuesday. The far northern edge of the precipitation shield associated with the area of low pressure to the south of the region has tried to make its way into parts of the Maryland eastern shore and southern Delaware today, but dry air has kept most of this from reaching the ground. With that said, some flurries or very light snow will remain possible into the early evening hours across the aforementioned areas before chances diminish. No accumulation is expected. Breezy north-northeasterly winds will quickly diminish as we head into the evening and overnight hours. Clouds will clear from northwest to southeast tonight, with the entire region expected to be mostly clear by dawn. The mostly clear skies and light winds will allow for effective radiational cooling, so a very cold night is in store. Temperatures are expected to bottom out in the single digits across the Poconos and into far northwestern NJ, and perhaps into the Lehigh Valley. Mid-upper teens are expected for the remainder of eastern PA and most of NJ. Where clouds clear the latest across southern DE and far southern NJ, temperatures could remain in the mid 20s. Tuesday will feature increasing mid and high clouds from west to east, particularly in the mid to late afternoon hours. High temperatures look to be in the upper 20s to near 30 northwest of the fall line, mid 30s in the vicinity of I-95, and near 40 for the Delmarva and into southeastern NJ. Some CAMs feature snow showers across our far northern zones associated with the shortwave passing to our north during the afternoon and evening hours. Even though this cannot be entirely ruled out, forecast soundings indicate quite a bit of dry air below the DGZ which should make it hard for anything to reach the ground. This leads to confidence in occurrence being too low to include mentionable PoPs at this time. && .SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY NIGHT/... A clipper system will dive into the Great Lakes and Ohio Valley Tuesday night and will pass through northern New York and northern New England late Wednesday, departing Wednesday night. A cold front will follow through behind the departing low Wednesday night, and then cold air advection will be underway. Temperatures return closer to normal on Wednesday with highs generally in the low to mid 40s, and possibly near 50 in Delmarva. Precipitation develops across most of the area, with snow across the southern Poconos and northwestern New Jersey, a wintry mix just northwest of the I-95 corridor into the Lehigh Valley and northern New Jersey, and rain across the heart of the I-95 corridor into central and southern New Jersey and Delmarva. The rain/snow line will gradually lift north throughout the day Wednesday, with precipitation changing to plain rain as far north as the Lehigh Valley, and snow may mix with rain in the southern Poconos and northern New Jersey. During the transition period, particularly during the morning hours, snow may mix with sleet and freezing rain. In terms of overall snowfall accumulation, can expect generally 1 to 3 inches in the higher elevations of the southern Poconos and northwestern New Jersey, and less than an inch for areas southeast of there. For areas that receive any ice accumulation, currently a light glaze of less than a tenth of an inch is forecast. Rain and snow tapers off late in the day Wednesday. Dry Wednesday night with lows mainly in the mid and upper 20s across northern areas and in the low to mid 30s elsewhere. && .LONG TERM /THURSDAY THROUGH MONDAY/... Several reinforcing cold fronts will pass through the region through the end of the week, with an Arctic airmass building overhead this weekend. Thursday looks to be mostly dry, though some flurries may be possible with the passage of a strong cold front. Highs return to below normal levels, generally in the upper 30s to low 40s. Lows Thursday night drop into the 20s across much of the area, and in the teens in the southern Poconos. Temperatures will drop by a few degrees on Friday, generally topping off in the upper 30s to around 40. A clipper-like system may pass through the region Friday night into Saturday morning. Models are not in good agreement in terms of the timing and placement of this system, and latest runs are trending a bit drier. Will use NBM guidance for this time with PoPs generally 35 to 45 percent, and mostly snow. An Arctic airmass then builds into the region for the weekend. Gusty winds may develop on Saturday afternoon. Highs on Saturday and Sunday will struggle to reach the freezing mark for most of the area, though should be in the mid 30s or so in southern Delmarva and along the Jersey Shore. Highs will be a few degrees cooler on Sunday compared to Saturday. Lows Saturday night will be in the teens and low 20s. && .AVIATION /21Z MONDAY THROUGH SATURDAY/... The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY and surrounding areas. Through 00Z...VFR. BKN high clouds. North-northeast wind 10-15 kt with gusts 20-25 kt, decreasing to around 10 kt by 20-22Z. High confidence. Tonight...VFR. SCT/BKN high clouds, decreasing late. North-northeast wind around 10 kt becoming LGT/VRB 03-05Z, though a north-northeast direction will still be favored. High confidence. Tuesday...VFR. A few high clouds to start, with increasing mid-level clouds by late afternoon. Light wind in the morning becoming south to south-southwest at 5-10 kt after 16-17Z. High confidence. Outlook... Tuesday night...VFR. NSW. Wednesday through Wednesday night...Sub-VFR in RA and/or SN, though SN is most likely at KRDG/KABE. Conds lift to VFR Wednesday night. Thursday through Thursday night...VFR. Gusty west winds possible on Thursday. Friday through Saturday...Sub-VFR conds possible with RA and/or SN, most likely Friday night. Gusty westerly winds possible on Saturday. && .MARINE... A Small Craft Advisory is currently in effect for all coastal waters as well as the Delaware Bay. It is set to expire at 6 PM for the Delaware Bay and for coastal waters from Sandy Hook to Manasquan NJ, 1 AM Tuesday from Manasquan to Little Egg Inlet NJ, and 6 AM Tuesday for the remaining coastal waters. Northeast wind initially 20-25 kt with gusts to 30 kt for the coastal waters and 15-25 kt for the Delaware Bay, will gradually diminish through this evening and into tonight. By daybreak Tuesday, winds are expected to be northeast at 15-20 kt. Winds will become southeasterly at 15-20 kt by Tuesday afternoon. Seas 4-6 feet will diminish to 2-4 feet around daybreak Tuesday, and remain in that range through the day. Outlook... Tuesday night...SCA conditions develop. Winds increase to 15 to 20 kt with gusts up to 25 kt. Wednesday through Wednesday night...Strong SCA conds likely, with gale force winds possible. S to SW winds 20 to 30 kt. Gusts up to 35 kt possible. Winds turn W Wednesday night, generally at 20 to 25 kt with gusts up to 30 kt. Thursday through Thursday night...SCA conds Thursday subside to sub-SCA criteria Thursday night. W winds 15 to 20 kt with 25 to 30 kt gusts, diminishing to 10 to 15 kt with gusts to 20 kt. Friday through Friday night...SCA conds possible. W winds 15 to 20 kt. Saturday...Strong SCA conditions likely with gale force winds possible. Westerly winds 20-30 kts with gusts up to 35 kts possible. && .CLIMATE... Very cold temperatures are expected tonight into Tuesday morning. At this point, do not anticipate any climate site to break its daily record low, however it is certainly possible that a few come within a few degrees of doing so. Below are the record lows for December 9. SITE RECORD/YEAR Allentown (ABE) 7/2002 AC Airport (ACY) 6/1968 AC Marina (55N) 5/1876 Philadelphia (PHL) 6/1876 Wilmington (ILG) 13/1960 Reading (RDG) 0/1989 Trenton (TTN) 12/2002 Mount Pocono (MPO) -1/1902 Georgetown (GED) 10/1976 && .PHI WATCHES/WARNINGS/ADVISORIES... PA...None. NJ...None. DE...None. MD...None. MARINE...Small Craft Advisory until 6 PM EST this evening for ANZ430- 431-450. Small Craft Advisory until 1 AM EST Tuesday for ANZ451. Small Craft Advisory until 6 AM EST Tuesday for ANZ452>455. && $$ SYNOPSIS...AKL/MPS NEAR TERM...Cooper SHORT TERM...AKL/MPS LONG TERM...AKL/MPS AVIATION...AKL/Cooper MARINE...AKL/Cooper CLIMATE... ####018007808#### FXUS63 KFGF 082109 AFDFGF Area Forecast Discussion National Weather Service Grand Forks ND 309 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. && .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. && .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. && $$ DISCUSSION...JR AVIATION...JR