####018004579#### FXUS65 KBOI 090402 AFDBOI Area Forecast Discussion National Weather Service Boise ID 902 PM MST Mon Dec 8 2025 .DISCUSSION...This evening's 00Z sounding from Boise revealed a very moist air mass for mid December: the measured precipitable water value of 0.66 inches is around the 95th percentile for the time of year. Mild, moist, and strong west-northwest flow aloft will continue to transport moisture into our area through Wednesday, with precipitable water values climbing to around the 99th percentile on Tuesday. The strong flow will aid orographic lift and produce moderate to heavy precipitation amounts in the mountains north of the Snake Basin, where 1-2 inches (locally 3+ inches on higher peaks) of precipitation will fall. Snow levels of 6500-9000 feet will confine snow to the highest peaks, and rivers, creeks, and streams will rise as a result. However, mainstem river flooding is not expected in our area. Light rain will fall off and on through Tuesday in portions of the Snake Plain, especially the Upper Treasure Valley near the foothills, including Boise where some upsloping will occur. The axis of the moisture plume will remain just north of our area, preventing rainfall totals from becoming more impactful across our area. Winds will be breezy, especially in the higher terrain, and temperatures will remain well above normal. && .AVIATION...Precipitation continuing through Tuesday across far E Oregon and much of SW Idaho. VFR expected in light rain. MVFR to LIFR ceilings/vis in heavier rain and high elevation snow, mainly north of Snake Plain. Mtns obscured. Snow levels oscillating between 6.5k-9k feet MSL, lowest to the NE. Low level wind shear threat through Tue AM. Surface winds: SW-SE 5-15 kt. SW gusts to 20-35 kt for higher terrain and open areas, not including Treasure Valley. Winds aloft at 10kft MSL: increasing to W-NW 40-55 kt overnight. KBOI...Persistent light rain through Tuesday evening, but a 90% chance of remaining VFR. Threat of low level wind shear through Tue morning. Surface winds: SE 5-12 kt, transitioning to northerly 3-10 kt Tuesday afternoon. && .PREV DISCUSSION... SHORT TERM...Tonight through Wednesday night...An impressive atmospheric river is lined up across the Pacific Ocean extending past Hawaii and is impacting the Pacific NW. Precipitation will become widespread north of a line from Burns OR to Jerome ID late this afternoon and last through Tuesday night. This will bring 1-2 inches of liquid equivalent precipitation to the central ID mountains. Heavier precipitation will be just north of our area. Rivers, creeks and streams will see notable rises over the next few days. Snow will be confined to the highest peaks above 7000-8000 feet. LONG TERM...Thursday through Monday...The active weather takes a break Thursday. The ridge supporting the atmospheric river will move inland, pushing most of the moisture north of our area. Precipitation tapers off through the day Thursday with only a 20-30% chance of precip in the mountains that evening. Winds also come down as the strong flow aloft shifts north with the AR. Temps remain 10- 15 degrees above normal, with partly cloudy skies each day through Sunday. The main hazard Thursday through Sunday will be mixing heights less than 2 kft AGL in the afternoons, an indicator of inversion development. Saturated soils from the recent rain will make fog and low stratus likely, especially if a strong inversion forms. Thursday and Friday would be the warmest days with a slight cool down Saturday and Sunday with highs dropping from near 60 in the Snake Plain to the lower 50s. Low confidence in temperature forecasts as the effect of inversions and fog/stratus tend to not be captured well by models. Speaking of models, after Sunday there is disagreement in the arrival of our next system. Most if not all hint at the ridge weakening and the storm track moving back south over the area, but differ on when that first storm moves through. Monday would be the earliest shot at our next round of precipitation, with chances increasing further into next week. && .BOI WATCHES/WARNINGS/ADVISORIES... ID...None. OR...None. && $$ www.weather.gov/Boise Interact with us via social media: www.facebook.com/NWSBoise www.x.com/NWSBoise DISCUSSION...ST AVIATION.....SH SHORT TERM...KA LONG TERM....JM ####018005618#### FXUS66 KLOX 090402 AFDLOX Area Forecast Discussion National Weather Service Los Angeles/Oxnard CA 802 PM PST Mon Dec 8 2025 .SYNOPSIS...08/644 PM. A warming trend will continue this week with well above normal temperatures through Friday, peaking Tuesday through Thursday. Offshore flow will produce locally gusty canyon winds in the mornings. && .SHORT TERM (MON-THU)...08/745 PM. ***UPDATE*** A 591 MB ridge of high pressure is centered about 700 miles west of Los Angeles, and will remain nearly stationary (while weakening some) through midweek. At the surface, high pressure centered west of the Bay Area extends inland over central California and the Great Basin. With lower pressure over the southern California Bight, offshore pressure gradients have set up over the region. At 700 PM this evening, the LAX to Daggett gradient was -4.3 MB. This gradient is forecast to strengthen some overnight, and again Tuesday night into Wednesday morning. This will maintain weak to locally moderate Santa Ana Winds over portions of the area, from the Santa Lucias to the Santa Susana Mountains and the San Gabriels. Peak wind gusts will be between 25 to 40 mph in the Santa Ana wind-prone areas, with occasional gusts up to 45 mph possible. Along with the breezy winds, warm and dry conditions will persist through the week, with highs peaking Tuesday and Wednesday. Expect highs to be in the 70s to mid 80s, with upper 80s in the warmer valleys. By Thursday, some cooling is expected as the upper ridge begins to weaken over the area. ***From Previous Discussion*** Weak Santa Ana conditions associated with weak to moderate offshore flow across the region will persist through Wednesday under a quite strong ridge aloft for this time of year. The result will be dry, warm, and breezy conditions with widespread highs in the 70s to mid 80s with the warmest valleys nearing 90 degrees. These types of temperatures may bring increased concerns for heat illnesses for vulnerable people or those who are outside for a prolonged period of time. The dry air mass and long nights this time of year will support temperatures dropping off quickly in the evening, especially where winds drop off. The ridge begins breaking down with offshore flow weakening or reversing onshore Thursday, kicking off a decent cooling trend. A Wind Advisory continues for the Santa Lucias with marginal wind advisory possible for the most prone Santa Ana wind areas of Ventura/Los Angeles County. Fortunately, fire weather concerns are still limited due to the significant rainfall we experienced earlier this season. .LONG TERM (FRI-MON)...08/239 PM. Seasonably warm conditions are anticipated this weekend with night to morning low clouds potentially returning to coastal areas along with afternoon to evening breezy onshore to northwest winds. Rain free conditions look to continue well into next week. There is a 30-40 percent chance of a strong ridge rebuilding overhead into the middle part of next week with weak to moderate Santa Ana conditions at times. In this scenario, widespread highs in the 70s to mid 80s would return for most coasts and coastal valleys. If the ridge is weaker or offshore flow doesn’t materialize (40-50 percent chance), more seasonably warm temperatures (60s and 70s) would be common. && .AVIATION...09/0056Z. At 0010Z at KLAX, there was a surface- based inversion up to 900 feet with a temperature of 25 C. Moderate to high confidence in KPRB, KSMO, KLAX, and KLGB TAFs. High confidence in remaining TAFs. There is a 15% chance of VLIFR to LIFR conditions at KPRB, KSMO, KLAX, and KLGB sometime between 10Z-17Z Tue. KLAX...Moderate to high confidence in TAF. There is a 15% chance of 1/2SM FG to 1SM BR and BKN002-004 cigs sometime between 10Z-17Z Tue. Any easterly winds will remain less than 7 knots. KBUR...High confidence in VFR TAF. && .MARINE...08/800 PM. For the outer waters, Small Craft Advisory (SCA) conditions are likely through at least Wednesday morning, with a 30-40% chance of winds lingering through the rest of the week. SCA winds are mostly likely north of San Nicolas Island during the afternoon and evening hours. For the inner waters south of Point Conception and the nearshore waters along the Central Coast out to 10 NM offshore, there is a 60% percent chance of local northeast SCA level wind gusts from Ventura to Santa Monica and a 60-70% chance of northeast SCA winds from near Pismo Beach to Point Piedras Blancas late tonight though Tuesday morning. There is a low-to- moderate (20 to 40 percent) chance of SCA level NE winds once again for the aforementioned areas Tuesday night into Wednesday morning. Otherwise, winds and seas should remain below SCA levels. && .LOX WATCHES/WARNINGS/ADVISORIES... CA...Wind Advisory remains in effect until 10 AM PST Tuesday for zone 342. (See LAXNPWLOX). PZ...Small Craft Advisory in effect until 11 AM PST Tuesday for zone 645. (See LAXMWWLOX). Small Craft Advisory in effect until 3 AM PST Wednesday for zones 670-673. (See LAXMWWLOX). && $$ PUBLIC...Munroe/Ciliberti AVIATION...Schoenfeld MARINE...Lund/Schoenfeld SYNOPSIS...Gomberg/Ciliberti weather.gov/losangeles Experimental Graphical Hazardous Weather Outlook at: https://www.weather.gov/erh/ghwo?wfo=lox ####018004666#### FXUS64 KTSA 090403 AFDTSA Area Forecast Discussion National Weather Service Tulsa OK 1003 PM CST Mon Dec 8 2025 ...New AVIATION... .KEY MESSAGES... Updated at 1000 PM CST Mon Dec 8 2025 - Patchy fog is possible late tonight into Tuesday morning mainly near and south of the Ouachitas, especially in the valleys. - Above average temperatures are expected Tuesday to Thursday before another cold front brings below average temps to close out the week. - Precipitation chances remain very low over the next 7 days. && .UPDATE... Issued at 708 PM CST Mon Dec 8 2025 Evening surface analysis depicts an area of high pressure over the lower Mississippi Valley with lee side troughing over the central High Plains. An east to southeast wind will prevail tonight in most areas, keeping temps from cratering overnight. The latest data indicates development of low cloud and possibly some fog from the Ouachitas down to the Red River Valley in a low level moisture return regime. Sky grids have been updated with the latest short term data, and some patchy fog has been inserted into the grids. Lacy && .SHORT TERM... (Through tonight) Issued at 1150 AM CST Mon Dec 8 2025 Skies will finally clear this afternoon for all locations with temperatures warming to near seasonal averages in the mid to upper 40s. The surface ridge axis will shift southeastward by afternoon, allowing a return of light southerly winds which will stay constant or gradually increase overnight with Lee troughing developing over the High Plains. This will keep overnight lows from falling too much tonight. Lows generally in the low to mid 30s are expected, though some more sheltered, generally cooler valley locations will likely dip into the 20s. Bowlan && .LONG TERM... (Tomorrow through Monday) Issued at 1150 AM CST Mon Dec 8 2025 The upper air pattern over the next week will lead to mostly a temperature forecast through this forecast period as a series of dry cold fronts pass through the area. The pressure gradient will tighten further on Tuesday leading to breezy southwesterly (downslope) flow spreading over the region. This regime is conducive to a quick warmup over eastern Oklahoma and western Arkansas for tomorrow. Temperatures will rise into the 60s for most locations under mostly sunny skies. The breezy winds, relatively dry air, and warm temperatures could locally raise some fire weather concerns as we are about two weeks removed from any kind of appreciable rainfall over the area. Leaned on the warmer end of guidance for highs tomorrow as the NBM is generally too low in these quick transition periods. A weak front pushes through the region on Wednesday knocking temps back a bit, though still above average. Temps will rise again on Thursday ahead of a stronger, Arctic front scheduled to arrive on Friday. Guidance has trended warmer with temperatures behind this front as the upper air pattern is not conducive for a significant Arctic intrusion into the Southern Plains. The stronger push of Arctic air appears to stay north and east of the local region. Still, a glancing blow will lead to colder temperatures through the weekend. Given the uncertainty and range of guidance, stuck with the NBM blend for temps during this period. No precipitation is forecast through the next week with predominately dry northwest flow aloft over the region. Bowlan && .AVIATION... (06Z TAFS) Issued at 1002 PM CST Mon Dec 8 2025 VFR conditions will prevail through the forecast period. Expect some passing high cloud. Short term models still forecast low clouds and fog to stay south of the Ouachitas and away from KMLC and KFSM. Removed sct mention of low cloud at KFSM. Sfc winds will increase by midday out of the south to southwest with gusts 20 to 25 kts across E OK and far NW AR. Lacy && .PRELIMINARY POINT TEMPS/POPS... TUL 33 61 42 56 / 0 0 0 0 FSM 31 61 40 59 / 0 0 0 0 MLC 33 61 42 59 / 0 0 0 0 BVO 29 62 40 56 / 0 0 0 0 FYV 32 58 41 55 / 0 0 0 0 BYV 32 58 43 52 / 0 0 0 0 MKO 32 60 42 57 / 0 0 0 0 MIO 32 57 41 54 / 0 0 0 0 F10 33 62 42 59 / 0 0 0 0 HHW 31 60 40 60 / 0 0 0 0 && .TSA WATCHES/WARNINGS/ADVISORIES... OK...None. AR...None. && $$ UPDATE...30 SHORT TERM...04 LONG TERM....04 AVIATION...30