####018003790#### FXUS66 KSGX 100425 AFDSGX Area Forecast Discussion National Weather Service San Diego CA 825 PM PST Tue Dec 9 2025 .SYNOPSIS... Warm and dry conditions with periods of weak Santa Ana winds this week. Above average temperatures expected into next week, with the most significant departure from normal expected today through Thursday. Mostly clear skies are expected through at least Thursday, with low clouds and fog returning to coastal areas as early as Friday or Saturday morning. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... Evening update... Skies remain clear this evening under weak offshore flow. Several high temperature records were broken today, the warmest of which was Escondido, which tied their daily of 86 degrees. The most impressive was Big Bear, which after a low of 27 degrees this morning made it up to 72 degrees this afternoon, breaking their previous daily high record of 65 degrees. See LAXRERSGX for a complete list of records. Weak offshore flow will continue into Wednesday afternoon. Peak gusts of around 25-35 mph is expected through the typical wind-prone passes, canyons, and foothills. The upper level ridge of high pressure over the East Pac will continue to shift eastward on Wednesday bringing additional warming across the region with highs as much as 15-20 degrees above normal in the valleys and foothills and around 10-15 degrees above normal elsewhere. Little change in high temperatures on for Thursday for the mountains and deserts, but weakening offshore flow will be overtaken by the sea breeze Thursday afternoon, helping spread a little cooling into the coastal areas and valleys. The upper high then weakens on Friday, bringing minor cooling to the entire region on Friday. Previous discussion... Skies are expected to remain mostly clear through Thursday. Chances of low clouds and fog returning to the coast begin to increase Friday with higher chances over the weekend. High resolution guidance is showing the development of a coastal eddy Thursday night into Friday, which would increase the chances of low clouds and fog returning to coastal areas. The first night or two that marine layer low clouds and fog return, the fog has the potential to be dense especially as ridging aloft remains over the area. Highs for the weekend into early next week will remain above average, but not quite as warm as this week. Highs along the coast through Monday will be about 5 degrees above average and 8 to 12 degrees above average for inland areas. For the early to middle part of next week there starts to become some uncertainty in the upper level pattern. By next Tuesday, 65% of ensemble clusters are showing the ridge continuing over the West Coast, with 20% showing the ridge weakening due to an incoming trough, and 15% showing the ridge present but over the Eastern Pacific. && .AVIATION... 100400Z...Clear skies with VFR conditions will continue through the TAF period at all sites. Breezy northeast winds in the foothills and locally into the adjacent valleys with gusts up to 25-30 kts will be possible through 18Z Wednesday with winds beginning to trend down after 20Z. && .MARINE...No hazardous marine conditions are anticipated through Sunday. && .SKYWARN... Skywarn activation is not requested. However weather spotters are encouraged to report significant weather conditions. && .SGX WATCHES/WARNINGS/ADVISORIES... CA...None. PZ...None. && $$ PUBLIC...SS/CO AVIATION/MARINE...Westerink ####018003733#### FXUS64 KOHX 100426 AFDOHX Area Forecast Discussion National Weather Service Nashville TN 1026 PM CST Tue Dec 9 2025 ...New SHORT TERM, LONG TERM... .KEY MESSAGES... Updated at 1008 PM CST Tue Dec 9 2025 - Look for warmer temperatures and breezy conditions on Wednesday. - There are low to medium rain chances (20-50%) tomorrow mainly across portions of northern Middle Tennessee as a cold front sweeps through the mid state. - Another cold front will impact the region this weekend, with low precipitation chances Saturday night. The coldest air of the season is expected Sunday night, with widespread lows in the teens. && .SHORT TERM... (Tonight through Thursday Night) Issued at 1008 PM CST Tue Dec 9 2025 Surface and low-level winds are increasing in advance of a strong cold front that looks to sweep across Middle Tennessee tomorrow. Temperatures on Wednesday will be quite pleasant in spite of the breezy conditions, but colder air will soon return to the mid state. The deepest moisture associated with the cold front will remain to our north. There are low to medium rain chances across portions of northern Middle Tennessee tomorrow as a result of the cold front, but QPF values are anemic. There is a very low chance of light wintry weather affecting portions of the Upper Plateau late tomorrow, but, again, any significant impacts will likely remain outside of the OHX county warning area. && .LONG TERM... (Friday through next Wednesday) Issued at 1008 PM CST Tue Dec 9 2025 Friday should turn out to be somewhat pleasant temperature-wise, although another cold front will rotate through the mid state during the afternoon, so the warmth will be short-lived; indeed, the weekend weather is going to be frigid as an Arctic air mass settles into the region. Although Friday's fropa should come through dry, we do expect low precipitation chances Saturday night as an upper trough swings through the area. Some of the precipitation may be frozen, but QPF values are below 0.15" most locations, so there aren't currently any concerns except for frigid conditions on Sunday (highs mainly in the 30s) and Sunday night (lows mainly in the teens). Next week, look for better rain chances as temperatures warm up nicely. && .AVIATION... (00Z TAFS) Issued at 515 PM CST Tue Dec 9 2025 Surface high pressure has moved off to the east, and return flow has kicked in across Middle Tennessee. Winds are expected to increase overnight as the surface pressure gradient tightens up ahead of an approaching cold front. We also expect LLWS to develop later tonight and Wednesday morning as near-surface winds increase prior to fropa, which will take place from late morning through tomorrow afternoon. It is unlikely that any of the terminals will be impacted by precipitation. Mostly we will see just some additional mid and high cloudiness. Surface winds will remain gusty through the day tomorrow. && .PRELIMINARY POINT TEMPS/POPS... Nashville 40 55 29 43 / 0 10 0 0 Clarksville 39 51 27 41 / 10 10 0 0 Crossville 33 48 24 36 / 0 20 10 0 Columbia 37 54 26 44 / 0 10 0 0 Cookeville 36 49 27 37 / 0 30 10 0 Jamestown 35 47 25 35 / 0 40 10 0 Lawrenceburg 37 54 26 44 / 0 10 0 0 Murfreesboro 38 54 27 42 / 0 10 0 0 Waverly 38 52 26 42 / 10 10 0 0 && .OHX WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...Rose LONG TERM....Rose AVIATION.....Rose ####018005366#### FXUS65 KPIH 100428 AFDPIH Area Forecast Discussion National Weather Service Pocatello ID 928 PM MST Tue Dec 9 2025 .KEY MESSAGES... - Abnormally warm temperatures will continue - Rain and snow shifts north tonight and Wednesday - Breezy to windy conditions will persist && .SHORT TERM /THROUGH TONIGHT/... Issued at 1236 PM MST Tue Dec 9 2025 For some folks, it is wet and windy this afternoon. For many, it is just windy. There hasn't been much of any rain across the Snake Plain and Magic Valley today, and that trend will continue until everything shifts north of us tonight and tomorrow. That said, we are seeing light rain pushing through the Treasure Valley that should move across the Magic Valley and as far east as Craters and Pocatello. There are some spots hitting WIND ADVISORY criteria as the winds are peaking with this round of stronger wind. However, we aren't seeing widespread conditions hitting threshold...so we are going to be issuing any headline at the moment. Looking at wind tonight and Wednesday, we should see them drop off a little bit this evening...but pick up again later tonight and tomorrow. We could see a few spots again hitting advisory thresholds, but nothing that is worthy of issuing a headline. In reality, while it will remain pretty breezy out there...overall wind speeds should be a bit lower that today. Meanwhile, plenty of moisture is falling across the central mountains. We are seeing a lull across the rest of the highlands for now. The trends show the next surge arriving late this evening continuing into tomorrow morning. There are two issues here to watch. The first is a brief surge of colder air crossing into Idaho for a few hours. Right now, we have snow levels with this push down to 6000-7000ft in the Challis and Pahsimeroi Valleys. We also expect snow levels to drop down between 5000-6000ft from Island Park and Monida into the far north end of the Snake Plain. Probability forecasts for snow levels drop them another 500-1000ft in those areas. This will produce 1-4" of snow in the Island Park area and around Monida Pass, with higher amounts well up into the backcountry. If they drop lower we could see another inch or so of snow in those areas, and maybe at least snowflakes falling north of the INL and toward Dubois. The rest of the area by sunrise will see snow levels rapidly increasing by sunrise...between 8000-9500ft and eventually all locations during the day tomorrow. The overall pattern is not much in the way of moisture accumulations except for the Sawtooths, Frank Church, the eastern highlands and Bear River Range. In those areas, we should see additional amounts up to 0.70" in the mountains and up to 0.40" down low. There is a 30-70% chance of more than 0.70" for the highest elevations around Island Park and the Big Holes. For the Sawtooths and Frank Church, there is a 45-75% chance exceeding that threshold. The models so far seem to be overforecasting amounts that far south in the central mountains, so we feel more confident in amounts under 0.70" even with fairly strong upslope conditions. The other trend is how quickly precipitation shifts northeast after midnight. Some of the models have the main push already back into western Montana and northern Idaho by sunrise, while some also hold it longer over central and eastern Idaho. Even if it holds a bit longer in our area, it will rapidly be out of here tomorrow evening. && .LONG TERM /WEDNESDAY THROUGH TUESDAY/... Issued at 1236 PM MST Tue Dec 9 2025 Once again the long term period Thursday through next Tuesday is dominated by extremely warm and mainly dry conditions. High temperatures for the most part will range from the upper 30s to mid 40s mountains and upper 40s to mid 50s lower elevations. Thursday and Friday will be the warmest with some upper 50s in the low elevations. Lows generally 20s and 30s throughout. The general average forecast through the period is around 15 to as much as 20 degrees above normal. Upper ridge slides west to east Thursday through Saturday and will be overhead Saturday. Will see only slight cooling when the ridge moves east Sunday through Tuesday. Will have mainly dry conditions Thursday through Sunday with only a slight chance of mountain showers. A more zonal pattern may allow a better chance of precipiation Monday into Tuesday as a return to Pacific moisture is in play. Have some chances everywhere by Tuesday with still very elevated snow levels at over 6 thousand feet. && .AVIATION /06Z TAFS THROUGH 06Z THURSDAY/... Issued at 928 PM MST Tue Dec 9 2025 Winds have weakened this evening will likely remain relatively light overnight. Expect winds to become gusty once again by Wednesday afternoon. SUN will once again turn west-southwesterly in the afternoon as opposed to the standard upvalley south- southeast wind. Showers continue to pour through DIJ for the remainder of the night and there are indications that IFR conditions will develop there by morning. && .PIH WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...Keyes LONG TERM...GK AVIATION...13 ####018003430#### FXUS63 KUNR 100428 AFDUNR Area Forecast Discussion For Western SD and Northeastern WY National Weather Service Rapid City SD 928 PM MST Tue Dec 9 2025 .KEY MESSAGES... - High Wind Warning remains in affect for much of western SD. Expect wind gusts up to 65 mph. - Winter Weather Advisory is now in affect for northwestern SD from tomorrow night through Thursday morning. - Potential for a winter storm to impact the area on Friday through Saturday. && .DISCUSSION...(This Evening Through Tuesday) Issued at 1249 PM MST Tue Dec 9 2025 Rest of today...Winds picked up a little later than anticipated but widespread wind gusts in the 55-65 mph range have been observed over the past hour. Localized stronger wind gusts over 65 mph are occurring in areas where precipitation has developed. Expect this trend to continue through the rest of the afternoon. Winds will quickly diminish through the overnight hours but we will hang on to the scattered precipitation across the region. Immediately behind this current system that has brought the winds to region, the next system is following closely behind. An area of low pressure over the MT Rockies on Wednesday will slide SE, arriving to the CWA on Thursday. Strong overrunning will support 700mb frontogenesis/isentropic lift on Wednesday, bringing widespread light snow in the morning, then becoming rain through the day as warmer air advects in from the west. he broad band of snow over central South Dakota could become freezing rain as warmer air aloft noses in. Ice accumulations have increased slightly in this latest forecast package, especially across northwestern SD. With the combination of snow, rain/snow and then freezing falling in the same locations with ice accumulations approaching a tenth of an inch, the Winter Weather Advisory was issued. Additionally ice conditions may continue even after the precipitation has stopped as wet roads and power lines may flash freeze with the strong CAA expected across these areas as we progress into the evening hours on Thursday ahead of the next storm system. Models are beginning to agree on the end of the week system in terms of targeting northwestern SD for the potential for some accumulating snows around 6". With locations to the south seeing only 1-2", with this sharp gradient we need to continue to monitor the evolutions and tracks the models show to pinpoint just where the heaviest snows will fall. && .AVIATION...(For the 06Z TAFS Through 06Z Wednesday Night) Issued At 927 PM MST Tue Dec 9 2025 Local MVFR/IFR conditions due to lower clouds/-sn will end in/near the Black Hills by 10/09z. VFR conditions will prevail through Wednesday morning as gusty northwest winds wane. MVFR/IFR conditions will redevelop over northeastern WY/northwestern SD Wednesday afternoon/evening as mixed precipitation develops. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...High Wind Warning until 2 AM MST /3 AM CST/ Wednesday for SDZ001- 002-012>014-025>027-030>032-041>044-046-047-049-072>078. Winter Weather Advisory from 5 PM Wednesday to 11 AM MST Thursday for SDZ001-002-012>014-032-078. WY...High Wind Warning until 2 AM MST Wednesday for WYZ060. && $$ DISCUSSION/KEY MESSAGES...Woodward AVIATION...Helgeson