####018005132#### FXUS64 KHUN 070256 AFDHUN Area Forecast Discussion National Weather Service Huntsville AL 856 PM CST Sat Dec 6 2025 ...New NEAR TERM, SHORT TERM, LONG TERM... .KEY MESSAGES... Updated at 855 PM CST Sat Dec 6 2025 - Low to medium chances of fog tonight with the potential for some to see it become freezing fog as temperatures drop to freezing below in several spots. - Low to medium (20-40%) chances of periodic light rain late Sunday afternoon through Monday morning. - Colder temperatures return early next week with sub-freezing lows Monday night, followed by a warming trend through midweek. && .NEAR TERM... (Tonight) Issued at 855 PM CST Sat Dec 6 2025 We had another below normal day where highs only got into the lower 40s when norms are in the upper 50s for early December. Low to medium chances for patchy fog is still expected tonight while the sky is pretty much clear. Obs are already observing light fog in a few locations. Will monitor trends to see if coverage there become dense, but coverage should be limited by cloud cover moving in after midnight or so. However, with temps falling into the lower 30s, fog in place will become freezing fog. Be sure to travel safely in fog, slow down and leave extra space between vehicles. Lowered overnight lows by a degree or two into the upper 20s to lower 30s based off of ob trends. Might have not gone low enough so will monitor obs to see if further adjustment is needed. && .SHORT TERM... (Sunday through Tuesday night) Issued at 855 PM CST Sat Dec 6 2025 Any lingering patchy fog/freezing fog issues will dissipate with sunrise. We will warm up to lower 50s on Sunday, much closer to seasonal values that we have been. That unfortunately, will be short lived. The trough's who center is located up in the Hudson Bay will amplify on Sunday and the associated sfc low in the eastern Great Lakes will pull a cold front into the region. The cold front will enter the TN Valley Sunday night and bring low to medium chances (20-40%) of rainfall with it that lingers into Monday. Lows Sunday night will be in the upper 30s. Behind the frontal passage, high pressure will build in and funnel in the colder air with a northwesterly wind. Drier air will decrease cloud cover, but highs on Monday will be back in the 40s. Monday night will be 10-15 degrees cooler than the night before with lows in the mid 20s under mostly clear skies. High pressure will shift eastward on Tuesday, allowing southerly flow to return. This will help daytime highs get back into the lower 50s. && .LONG TERM... (Wednesday through Saturday) Issued at 855 PM CST Sat Dec 6 2025 Wednesday may be the best day of the entire forecast as high pressure at the surface will promote dry and mostly sunny conditions. As a result, high temperatures will make a run at the 60 degree mark in some locations by the afternoon. A fast-moving trough over the Great Lakes will attempt to push a cold front south toward the region from the Ohio Valley Wednesday evening into Wednesday night. This front will probably struggle to make it all the way into the area, but a secondary shortwave will interact with this feature and generate some low chances (20-40%) chances for rain showers Thursday and Thursday night. In wake of this system, a cooler, drier air mass will settle into the area by Friday. A broad upper-trough situated over southern Ontario will become the dominant weather feature over the eastern CONUS late this week into the weekend. Several subtle shortwaves will traverse this feature, bringing additional reinforcing shots of cooler air into the region. Highs on Friday will peak in the mid to upper 40s, with overnight lows dropping into the lower 20s. Saturday looks to be even chillier as high temperatures will struggle to climb above the 40 degree mark -- with lows Saturday night in the Teens being common. Saturday night we may need to watch wind chills as readings in the single digits in a few locations may occur along the higher terrain. Regardless, it's important to recognize that a spill of colder weather and below normal temperatures will be favored late next week into the following week for mid-December. Make sure you review common sense safety rules for cold weather and make sure you're prepared. && .AVIATION... (00Z TAFS) Issued at 450 PM CST Sat Dec 6 2025 VFR conditions will prevail this evening underneath a clear sky. Patchy fog may develop late tonight into early Sunday morning at both terminals and have included a TEMPO to highlight the potential for localized MVFR to IFR conditions. Thereafter, VFR conditions will prevail through the remainder of the period with light southerly winds and a mostly clear sky. && .HUN WATCHES/WARNINGS/ADVISORIES... AL...None. TN...None. && $$ NEAR TERM...JMS SHORT TERM....JMS LONG TERM....AMP AVIATION...AMP ####018005874#### FXUS62 KCAE 070257 AFDCAE Area Forecast Discussion National Weather Service Columbia SC 957 PM EST Sat Dec 6 2025 .SYNOPSIS... Fog development is expected tonight into Sunday morning, potentially dense at times before mostly dry conditions are expected Sunday. The next round of rain moves in Sunday night and through Monday. Dry conditions are then anticipated for the mid to late week period while temperatures remain below normal. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... Key message(s): - Fog likely tonight with possibility of visibilities less than 1/4 mile, especially in the NW part of the area. As forcing from the right entrance region of an upper level jet streak pivots out of the area this evening, rain is coming to end across the FA. Dry mid-level air entering the mountains and Upstate is evident in water vapor imagery and this will continue progressing toward the Midlands tonight, dropping PWAT's to just under 0.50". Forecast soundings continue to indicate a very moist profile up to around 950-900mb trapped under this dry air and very little mixing occurring with weak wind profiles. Overnight lows are expected to drop into the mid to upper 30s generally and with crossover temps that were in the low to mid 40s, a robust signal for fog development is evident across the CWA tonight where dense fog is possible. Model guidance continues to show the highest confidence in potentially dense fog toward the Pee Dee and possibly northern Midlands where stratus has already eroded some and is the most likely area where some mid/high clouds can scatter out more in the coming hours. Have decided to hold off on a Dense Fog Advisory for now to monitor how cloud cover scours out in the coming hours, but one may be needed later tonight and into Sunday morning. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY NIGHT/... Key message(s): - Patchy dense fog Sunday morning - Increased chances of light rain on Monday - Drier and cold for Tuesday Patchy Dense Fog Sunday Morning... Low level moisture will remain trapped below a low level inversion, setting the stage for areas of fog, some of it locally dense. With the low level jet pulling away, it may take a few hours before it burns off completely, so I've extended the time in the grids until late morning. By afternoon, the fog should have lifted into a low overcast for most places. We may even see some breaks of sun over the Catawba/Pee Dee areas. Temps will remain several degrees below normal Areas of light rain Monday... The next shortwave passes through on Monday. We should have some decent lift sue to PVA, but the amount of rain that falls is less certain as there is a decent sized spread among the ensembles, ranging from very little to as much as an inch. Given the chances of PWs being 1/2 inch or more drop throughout the day from the ensembles, I think low end chance POPs are best. There will be cold advection at low levels as well, but model forecast profiles do not indicate any frozen precipitation in our CWA. We'll keep an eye on it, of course, but nothing to worry about at this time. Drier and Chilly Conditions Tuesday... Polar high pressure moves into the area by Tuesday. Cold advection will be king for a day, as morning temps go well below freezing, and highs are 10-15 degrees below normal. We should finally have a decent amount of sunshine, however. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... Key message(s): - Temperatures slowly moderate mid week - Next cold front moves through Friday Temperatures slowly moderate Wednesday and Thursday... Ensemble means show the jet stream migrating north for the middle of next week, allowing the air mass over the region to modify for a couple of days, although I wouldn't put on my bathing suit to take a dip in a lake anytime soon. High pressure at the surface will keep things dry. Next cold front moves through Friday... Models across the board are consistent with the next front moving through sometime on Friday, ranging from early morning to evening. This makes temperatures tricky on Friday as an earlier front would mean much colder conditions by afternoon, while a later front will allow things to stay mild most of the day. In either case, the chances for rain are not overly high as the air mass will continue to be rather dry. Things cool down significantly again for Saturday as another blast of arctic air moves into the U.S. && .AVIATION /00Z SUNDAY THROUGH THURSDAY/... Widespread fog will continue LIFR restrictions into Sunday morning. Following persistent rainfall across the area and clearing aloft, widespread fog and stratus have developed this evening. Temps should remain in the upper 30's for all TAF sites to avoid any freezing fog issues at this time. LIFR conditions are likely with a mix of low vsby and cig restrictions throughout much of the night and into the morning. This should continue through Sunday morning, lifting to stratus between 14-16z. Gradual improvement to IFR and then MVFR expected by late in the afternoon. EXTENDED AVIATION OUTLOOK...Lingering low level moisture may result in restrictions into Monday with drier air expected Tuesday through the end of the period. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...Dense Fog Advisory until 9 AM EST Sunday for SCZ016-018- 020>022-025>031-035-037-038-041-115-116-135>137. GA...Dense Fog Advisory until 9 AM EST Sunday for GAZ040-063>065- 077. && $$ SYNOPSIS... NEAR TERM... SHORT TERM... LONG TERM... AVIATION... ####018011294#### FXUS66 KPQR 070259 AAA AFDPQR Area Forecast Discussion...UPDATED National Weather Service Portland OR 659 PM PST Sat Dec 6 2025 .UPDATE... && .SYNOPSIS... A prolonged wet pattern continues through early next week as multiple frontal systems push inland. The most notable period continues to focus on Monday through midweek, when a prolonged atmospheric river may bring significant rainfall and rising rivers across southwest Washington and northwest Oregon. Today and Sunday bring lighter rainfall, while Monday is expected to produce the highest totals across southwest Washington and northwest Oregon. && .DISCUSSION...Now through Friday...Weather will remain active through at least the middle of next week. Upper level zonal flow will keep conditions dreary through Sunday with another shortwave disturbance passing this evening and overnight. This will bring a decent round of rain to the area as IVT values increase to between 250-500 kg/ms. Rainfall with this system is expected to be around 0.5-0.75 inches across the interior lowlands, 0.75-1.5 inches along the coast, 1.5-3.0 inches along the coast range and Cascades with the exception of the Lane County Cascades which will be lower at 0.75-1.5 inches. Widespread impacts are not anticipated through Sunday; however, if rainfall rates sustain around 0.2 to 0.3 inches per hour for several hours, a few faster-reponding basins, such as the Grays at Rosburg and the Willapa River, could rise quickly. Breezy southerly to southwesterly winds are expected at times with gusts typically 30-40 mph, strongest near exposed coastal and elevated terrain. This system will be a precursor to an active few days where several inches of rain could fall across NW OR and SW WA, increasing the potential for river and urban flooding. The synoptic set-up for the week starts with a ridge of high pressure centered over the Pacific between Hawaii and southern California. Clockwise circulation will advect sub-tropical moisture northward toward the PacNW in several round between Monday and Wednesday night. Mid level flow will predominantly be zonal as the top of the ridge extends northward along the West Coast. At the same time, several troughs will support surface lows and cold fronts that will provide lift over the region. The first slug of AR moisture enters the picture on Monday with IVT values along the coast peaking above 750 kg/ms and values inland peaking between 500-750 kg/ms. The heaviest rainfall with this first round is expected to fall between Monday and Tuesday morning. 45% of NCEP Ensemble members show rainfall totals between 4 pm Monday and 4 am Tuesday reaching or exceeding the 10 year Average Return Interval for the Portland area. This indicates that the expected rainfall totals during a 12 hour period has a 10% chance of occurring in any given year. This is notable given the expected widespread heavy precipitation and potential urban flooding impacts. This round of rain will be falling on already saturated soil which has prompted WPC to add a Day 3 Slight/Marginal ERO risk over the CWA. The slight risk covers all of SW WA, down the coast rang in OR and along the Cascades down to around Santiam pass. rainfall totals from 4 am Monday through 10 am Tuesday are expected to be 1.5-2.5 inches across the interior lowlands, 3.0-5.0 inches along the coast and coast range, and 3.0- 6.0 inches along the Cascades and Cascade Foothills. Amounts may be slightly lower farther south, mainly across Lane county. These rainfall amounts will lead to significant rises on area rivers, especially in the coast range. The second round of high IVT values is expected to impact the region Tuesday night into Wednesday. IVT values are expected to be slightly lower than the first wave, peaking around 500 kg/ms both inland and along the coast. However, the duration of these higher values is expected to be slightly longer. Rainfall totals from late Tuesday through Wednesday night are expected to be slightly lower across much of the area except for the Cascades where totals are forecast to be slightly higher. As it sits now, rainfall totals from early Monday through Wednesday night will significant and impactful. While the chances for widespread impacts are rather low, it is almost certain that localized impacts will occur somewhere within the CWA. Winds will be a concern Monday through Wednesday, with gusts up to at least 30 mph inland and up to at least 40 mph at the coast. There is a 10-20% chance for max wind gusts over 40 mph for inland areas, and a 20-40% chance for gusts over 50 mph along beaches and headlands. If wind gusts of this magnitude do materialize, expect scattered downed trees and power outages. Showery conditions will linger into Thursday and Friday as the flow gradually weakens and dries. Snow levels are expected to remain high (above 6000 ft) during this warm weather event, keeping most precipitation as rain in the Cascades. Forecast confidence in exact timing and magnitudes is still moderate given ensemble spread. Overall, the Monday through Wednesday time period remains the primary focus for potential high-impact hydrologic (see hydrology section below for more details) and wind concerns. -19/12 && .AVIATION...A showery weather pattern will give way to a warm front lifting northeastward across the area late tonight into Sunday morning, which will result in deteriorating flight conditions and steadier rain. In the meantime, expect a mix of mainly VFR and MVFR conditions through 06z Sunday. The probability for more persistent MVFR and even IFR conditions slowly rise between 06-18z Sunday as the weak front lifts across the region. For example, it appears there is 20-30% chance at any given hour of IFR conditions along the coast during this period with similar probabilities showing up in our statistical model guidance between 12-18z Sunday across much of the Willamette Valley. KPDX AND APPROACHES...Expect a mix of high-end MVFR and VFR conditions through 06z Sunday. Thereafter, a warm front lifting northeastward across the region will bring lowering ceilings and 50-70% chance for MVFR ceilings at any given hour between 06-18z Sunday. Light winds initially will also allow reductions in visibility to occur. There is 10-20% chance for conditions to drop into IFR thresholds at any given hour between 09-18z Sunday. With 30 kts of SSW wind at 2000 ft and 5-10 kt winds out of the SE to E at the surface, there will be a period of modest low level wind shear values as we approach 18z Sunday at KTTD and KPDX. && .MARINE...Seas will continue to slowly subside over the next 12-24 hours to less than 10 ft. A warm front will lift northeastward across the area late tonight into Sunday morning and result in southerly winds increasing across the waters. HREF and NBM guidance suggest there is at least an 80% chance that low end Gale Force wind gusts will occur across the waters south of Cape Falcon. Seas will temporarily rise and become more wind dominated due to these winds. Winds will then subside and result in decreasing seas late Sunday before the next warm front lifts northeastward across the waters. This suggests there is a 70% chance for stronger Gale Force winds to materialize across the waters Monday. This will push seas into the mid teens Monday afternoon with a 10-20% chance of seas climbing to at least 17-18 by 4pm Monday. Additional rounds of gusty southerly winds are in store across the waters next week, but there is around 40-50% chance for brief Gale Force wind gusts across the waters Tuesday and Wednesday. Southerly winds continue through the end of next week, but there is 10% chance or less of Gale Force winds materializing across the waters next Thursday, Friday and Saturday. && .HYDROLOGY...A series of frontal systems will keep conditions very wet through the weekend and much of next week. The most notable period will be late Monday through late Wednesday, when a prolonged atmospheric river will bring significant rainfall and the potential for widespread river flooding across southwest Washington and northwest Oregon. Total rainfall amounts from 4am Monday to 4am Thursday (72 hour total) will most likely be around 4 to 6 inches at the coast and interior lowlands, and 5.5 to 9.0 inches in the Coast Range and Cascades. Lane County Cascades will be an exception, with 4-6.5 inches expected. There is a 10% chance for rain amounts up to one foot in the Cascades and Coast Range, up to 8-9 inches at the coast, and up to 7 inches in the Willamette Valley, Portland metro and Cowlitz Valley. While rain amounts this high are unlikely to occur, they represent a reasonable worst case scenario. This outcome would result in widespread major flooding. Although rain will likely become lighter Thursday into Friday, the threat of flooding will linger along slow responding rivers. Rivers draining the Coast Range and Willapa Hills have a 30-60% chance of reaching moderate flood stage and a 20-40% chance of reaching major flood stage. Additionally, many Willamette River tributaries that drain from the Coast Range and Cascades have anywhere from a 40-70% chance of reaching minor flood stage and a 20-50% chance of reaching moderate flood stage. Flooding of the Willamette mainstem rivers is unlikely to occur (less than 5%). Probabilities for specific river points can be found at the National Water Prediction Service website. There is also increasing confidence in the potential for flooding along small creeks and streams as well as urban flooding, including roadway flooding. Periods of heavy rain will also increase the risk for landslides in areas of steep terrain and debris flows over recently burned areas. People, structures, and roads located below steep slopes, in canyons, and near the mouths of canyons may be at serious risk from rapidly moving landslides. Considering the probabilities of flooding for rivers and urban areas, a Flood Watch has been issued for all of southwest Washington and northwest Oregon from 4 AM Monday to 4 AM Friday. && .PQR WATCHES/WARNINGS/ADVISORIES... OR...None. WA...None. PZ...Small Craft Advisory until 4 PM PST Sunday for PZZ210-251. Gale Watch from Monday morning through Monday evening for PZZ210-251>253-271>273. Small Craft Advisory until 3 AM PST Sunday for PZZ252-253. Gale Warning from 3 AM to noon PST Sunday for PZZ252-253-272- 273. Hazardous Seas Warning until 7 PM PST this evening for PZZ271>273. Small Craft Advisory until 4 PM PST Sunday for PZZ271. Small Craft Advisory until 3 AM PST Sunday for PZZ272-273. && $$ www.weather.gov/portland Interact with us via social media: www.facebook.com/NWSPortland x.com/NWSPortland