####018004562#### FXUS65 KVEF 111657 AFDVEF Area Forecast Discussion National Weather Service Las Vegas NV 857 AM PST Thu Dec 11 2025 .KEY MESSAGES... * Warmer than normal temperatures will continue through tomorrow, and another period of breezy northerly winds is expected down the Colorado River Valley this afternoon. * Temperatures will gradually cool over the weekend and early next week, but conditions will remain dry across most areas. && .DISCUSSION...through next Thursday. High pressure will remain in place across the region into the weekend, maintaining well above normal temperatures and clear skies. See the climate section below for additional details on potential record temperatures today and Friday. Winds will be light over most of the area, except in the lower Colorado River Valley where a tightened pressure gradient will maintain breezy north winds, generally near and south of Davis Dam. Waves of 1 to 2 feet will still be possible today from Laughlin/Bullhead City to Needles, and any outdoor recreation and marine interests should continue to exercise caution. The pressure gradient will weaken by the weekend, allowing winds to decrease. Over the weekend and early next week, the ridge will flatten as a series of shortwaves embedded within the mean flow track across southern California and northern Mexico. No precipitation is anticipated with this system, but an increase in high cloud cover is expected, which will help lower temperatures by several degrees. A slight increase in moisture moving into central California next week may bring a few light snow showers to the higher elevations of the Sierra in far northern Inyo County. However, at this point, snow amounts are expected to be light (a few inches), and no significant impacts are anticipated. && .AVIATION...For Harry Reid...For the 18Z Forecast Package...Winds will remain under 8 knots, and will follow typical daily directional trends. VFR conditions will persist through the TAF period. For the rest of southern Nevada, northwest Arizona and southeast California...For the 18Z Forecast Package...With the exception of the Colorado River Valley, winds across the region will remain under 10 knots and will follow typical daily directional trends. Winds in the Colorado River Valley will favor a more northerly direction through the TAF period, with 20 to 25 knot gusts continuing into the evening hours before dropping off overnight. VFR conditions will continue through the TAF period. && .CLIMATE...Numerous climate locations across the region have a forecast high temperature and/or forecast warm low temperature within 3 degrees of the daily record today and Friday. The table below shows the daily record maximum temperature and the year the record was last set. An asterisk (*) denotes which records are in jeopardy (within 3 degrees of the forecast). A double asterisk (**) denotes which sites have forecast values that will tie or break the existing record. MAX THU, DEC 11 FRI, DEC 12 Record(Yr) Record(Yr) Las Vegas 72(1939)** 74(1958)* Bishop 78(1958) 74(1953) Needles 78(1958)** 80(1958)* Daggett 79(1958) 83(1958) Kingman 77(1950) 72(1950)** Desert Rock 68(2010)** 72(1988)** Death Valley 81(1914)* 79(1924)** The table below shows the daily record warm minimum temperature and the year the record was last set. An asterisk (*) denotes which records are in jeopardy (within 3 degrees of the forecast). A double asterisk (**) denotes which sites have forecast values that will tie or break the existing record. WARM MIN THU, DEC 11 FRI, DEC 12 Record(Yr) Record(Yr) Las Vegas 50(2014)** 51(1995)** Bishop 36(2016) 44(1956) Needles 54(2014)* 59(1995) Daggett 53(2016) 51(1995)* Kingman 47(1981)* 51(1934) Desert Rock 47(1996)** 53(1995) Death Valley 58(1914)* 60(1914)* && .SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report any significant weather or impacts according to standard operating procedures. && $$ DISCUSSION/CLIMATE...Planz AVIATION...Stessman For more forecast information...see us on our webpage: https://weather.gov/lasvegas or follow us on Facebook and Twitter ####018006279#### FXUS65 KRIW 111658 AFDRIW Area Forecast Discussion National Weather Service Riverton WY 958 AM MST Thu Dec 11 2025 .KEY MESSAGES... - Gusty winds will gradually decrease today with afternoon high temperatures 20 to 30 degrees above normal. - A cold front approaches northern Wyoming and bring mainly light snow, especially north of a Powell to Buffalo line. - Most locations will see a continuation of above normal temperatures into next week with little to no precipitation chances. && .DISCUSSION... Issued at 210 AM MST Thu Dec 11 2025 If there is one thing that Wyoming is known for weather-wise, it is the wind. The wind has been rather fierce around here for the past couple of days, with a few gusts in the triple digits. Thank you to a tight pressure gradient and the right front quadrant of an 140 knot jet passing overhead. We still have a few gusts over 75 mph, mainly around Chief Joseph Highway. But the wind has backed off a few ticks in most areas early this morning. But this is by Wyoming standards, this would be very windy by most areas standards. And that is the main forecast predicament we find ourselves this morning. The High Wind Warnings will expire at 5 am this morning. General trends are for the wind to continue decreasing, as the jet is moving further north and the pressure gradient is beginning to relax somewhat. The 700 millibar winds are finally beginning to decrease, with all locations seeing them fall under 50 knots by around noon today. Probabilistic guidance also shows this trend, with chances of wind gusts over 50 mph falling to less than 1 out of 4 for most populated areas by noon. The exceptions are the usual suspects, mainly the south side of Casper and near Cody. Some of the deterministic MOS guidance does have a brief period of high wind around Casper this morning before decreasing in the afternoon. There could be a few stray high wind gusts at some of the mesonet sites, but these tend to be on high rock bluffs away from populated areas and have little impact. We will likely let the warnings expire, but this will be a game time decision as we still hold the right to extend them. The second enigma (a problem, not the German new-age band popular in the 90s), is what will happen tonight and tomorrow across northern Wyoming. A cold front will sag southward toward the area from Montana and likely bring some snow or rain turning to snow across this location. I do get nervous when I see a boundary with some jet energy here. Just about all guidance keeps the best forcing over Montana and away from Wyoming. As for snowfall amounts, Johnson County will be the most impacted as far as the lower elevations. Chances of advisory amounts of snow are low though. At Buffalo, there is only a 1 out of 6 chance of 3 inches or more with around a 1 out of 3 chance of 2 inches or more. As for the mountains, the most would likely fall in the western Bighorn Range. A few locations have a 1 in 2 chance of 6 inches of more, but these are the highest elevations away from the mountain passes. A small part of the northern Absarokas has a 1 in 2 chance of 6 inches of snow or more. However, this is also in a remote area and Beartooth Highway is closed for the season. So, no advisory here as well. The steadiest snow will fall from late tonight through Friday morning before gradually ending Friday afternoon. There is one more notable thing, high temperatures today. This will especially be the case across central Wyoming. The MOS guidance has high temperatures in the 60s in Riverton and in Casper. If it occurs at the Riverton Airport, it would only be the fourth sixty degree high in December in almost 30 years, and the latest by nine days. In Casper, which has records back to 1939, it would only be the fourteenth time in station history. Most locations across the area will be 20 to as much as 30 degrees above normal for high temperatures. It will cool off on Friday behind the front, but most locations, except for where snow will be falling will remain above normal. Following that, it looks like we will enter into a quieter period. Flat ridging will build across the area and bring mainly dry conditions through Monday night. The next system looks to approach the state on Tuesday or Wednesday from the west. With this pattern, it would mean snow across the western mountains with favorable upslope westerly flow with mainly dry conditions to the east with downsloping. We could have another high wind event though, as the pressure gradient looks rather tight and a powerful jet, possibly over 150 knots, might be in place over Wyoming. It is still a long way out, but the potential is here. With the westerly flow, temperatures look to remain above normal with no signs of arctic air masses for the next seven days. && .AVIATION /12Z TAFS THROUGH 12Z FRIDAY/... Issued at 345 AM MST Thu Dec 11 2025 SCT-BKN FL200-250 skies across the area through 00Z. VFR ceilings at KJAC are expected to scatter out toward the beginning of the forecast this morning. Wind gusts of 25 to 45kt are still in place at KCOD, KCPR, KJAC and KRKS and will continue through the day. These winds will finally decrease and subside after 00Z. Wind gusts of 20 to 25kt will occur at some of the remaining terminals in the afternoon. A cold front will drop south across areas east of the Divide during this time, turning winds to the NNE in its wake first at KCOD after 03Z and KCPR after 05Z. Snow showers will be in the vicinity at KCOD with the frontal passage, along with MVFR ceilings. MVFR ceilings will also occur at KCPR. These ceilings are expected to lift by the end of the TAF period. Please see the Aviation Weather Center and/or CWSU ZDV and ZLC for the latest information on icing and turbulence forecasts. && .RIW WATCHES/WARNINGS/ADVISORIES... High Wind Warning until 5 PM MST this afternoon for WYZ019-020- 022-030. && $$ DISCUSSION...Hattings AVIATION...LaVoie/Lowe ####018003225#### FXUS66 KSGX 111659 AFDSGX Area Forecast Discussion National Weather Service San Diego CA 859 AM PST Thu Dec 11 2025 .SYNOPSIS... Weakening offshore flow will transition to weak onshore flow with slow deepening of the marine layer through the weekend with a greater return of low clouds and fog to coastal areas for the weekend. Gradual cooling will spread inland through the weekend, but with weekend high temperatures still as much as 15 to 20 degrees above average for portions of the inland valleys and lower coastal slopes of the mountains. There will be slight warming on Monday followed by slight cooling for Tuesday and Wednesday. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... Morning Update... No change from previous update. Weak offshore winds have kept the marine layer largely offshore with clear skies and abundant sunshine expected today. From previous discussion... .SHORT TERM (Today through Saturday)... High pressure aloft will slowly weaken into the weekend with weakening offshore lower-level flow becoming weakly onshore with slow deepening of the marine layer for Friday into the weekend. Early this morning, satellite imagery shows low clouds and fog remain well off the coast and beyond the offshore islands. Some patchy low clouds and locally dense fog could return near the coast tonight into Friday morning. However, increasing coverage and greater spread into coastal areas is more likely for Friday night into Saturday morning. Gradual cooling will spread inland for today into the weekend with Saturday high temperatures still as much as 15 to 20 degrees above average for portions of the inland valleys and lower coastal slopes of the mountains. High temperatures on Saturday will range from around 70 near the coast to around 80 for the Inland Empire with the lower to mid 80s for the lower deserts. && .LONG TERM (Sunday through Wednesday)... Not much change in high temperatures for Sunday. High temperatures may warm slightly on Monday with weak offshore lower- level flow, then cool slightly for Tuesday and Wednesday. Night and morning low clouds and fog will become patchier and not extend as far inland into coastal areas for the early and middle part of next week. && .AVIATION... 111630Z...Clear skies and VFR conditions at all sites through 02Z this evening. Chances for Patchy fog and low cloud development from the coast up to 15 SM inland will increase after 03Z for Orange County and after 05Z for San Diego County. Ceilings around 100-500 ft and visibilities less than 1 SM will be possible through 18Z. && .MARINE... There is a 30-60% chance for fog development this evening through Friday morning. Should fog develop, visibilities below 1 nautical mile will be possible. Otherwise, no hazardous marine conditions are expected today through Monday. && .SGX WATCHES/WARNINGS/ADVISORIES... CA...None. PZ...None. && $$ PUBLIC...Munyan AVIATION/MARINE...Villafane