####018004881#### FXUS63 KLSX 091716 AFDLSX Area Forecast Discussion...Updated Aviation National Weather Service Saint Louis MO 1116 AM CST Tue Dec 9 2025 .KEY MESSAGES... - Today will be the warmest day of the week with highs in the 40s & 50s. Temperatures then plummet behind multiple cold fronts with highs in the teens forecast for some on Saturday. - Wednesday will be blustery with wind gusts of 30 - 40 mph and wind chills up to 10 degrees below the air temperature. && .SHORT TERM... (Through Late Wednesday Afternoon) Issued at 300 AM CST Tue Dec 9 2025 Warm air advection has begun in the region and will only become stronger today as the surface pressure gradient tightens ahead of our next cold front. This influx of warmth in addition to insulating cloud cover has caused temperatures to climb this morning, which will serve as a nice launching pad for the seasonably mild temperatures this afternoon. Increasingly strong warm air advection along southwest flow is expected to rocket temperatures into the 50s for areas without snow and that see the most sun, namely southeast/central/east-central Missouri. East-central Missouri will get an additional boost in highs from downsloping off the Ozarks. The warmth will be short-lived. The aforementioned cold front will pass through the area overnight Tuesday, bringing with it strong northwest winds and much cooler air. The strongest wind gusts are expected to occur Wednesday morning as the ~50 kt winds topping the boundary layer begin to mix down. This will result in a brief period of 40 - 45 mph gusts in our far northern counties, on the cusp of Wind Advisory criteria. Elsewhere, the day will still be windy with sustained winds upwards of 25 mph and gusts of 30 - 40 mph. Strong low-level winds will result in strong cold air advection as well, with temperatures remaining steady or falling through the day. Aside from far southwest Illinois and southeast Missouri which will see ample sunshine and less cold air advection, highs on Wednesday will be about 10 degrees cooler than Tuesday. Jaja && .LONG TERM... (Wednesday Night through Monday) Issued at 300 AM CST Tue Dec 9 2025 Our next chance for precipitation will come Thursday into Friday and will only exist along our northeastern CWA border (think Quincy, IL - Salem, IL give or take). Although LREF probabilities show a high likelihood of measurable precipitation falling in these areas during this period (60 - 70%), amounts are confidently slim. Probabilities of less than 0.05" of precipitation falling are also 60 - 70%. Obviously the interpretation of this changes based on precipitation type, which is uncertain. The freezing line is expected to be in the vicinity of our northern border, with ensembles trending warmer at least in the past 24 hours. If these locations do see precipitation, it may start off as light rain with only a flake or two present overnight. Then again, if temperatures are cooler than forecast, they may see light snow on the order of a trace. More impactful will be the cold this weekend, that's coming in a little later than previously forecast. The cold will still begin Friday night, but it is now centered around Sunday instead of Saturday and ends Monday. There is still uncertainty regarding how cold it will get as this is tied to how far south in the CONUS the Arctic airmass spills. The heart of the airmass has been trending away from our region, and the NBM has warmed in response. However, given the anomalous 10th climatological percentile cold, the pre- existing snowpack, and a 90th climatological percentile incoming surface high, I suspect the NBM has warmed a little too much. The latest 01z 12/9 NBM run has cooled a bit, but its forecasts on Sunday, when we'll be closest to the surface high, are still above the 50th percentile. This trend is expected to continue as the NBM continues to catch on over the next few days. In the case of any nighttime radiational cooling, however, it'll very likely still be too warm. Jaja && .AVIATION... (For the 18z TAFs through 18z Wednesday Afternoon) Issued at 1111 AM CST Tue Dec 9 2025 South/southwest winds will veer more to the west ahead of an approaching cold front. Behind the front, winds swing to the northwest and increase in speed/gusts. Highest gusts of near 40 knots are forecast Wednesday morning at KUIN and the metro terminals. There may be a period of MVFR stratus at well impacting KUIN, but chances are higher further to the north/northeast so left mention out for now. Gosselin && .LSX WATCHES/WARNINGS/ADVISORIES... MO...None. IL...None. && $$ WFO LSX ####018004321#### FXUS64 KBRO 091716 AFDBRO Area Forecast Discussion National Weather Service Brownsville TX 1116 AM CST Tue Dec 9 2025 ...New DISCUSSION, AVIATION, MARINE... .KEY MESSAGES... Updated at 1111 AM CST Tue Dec 9 2025 - Ridging aloft keeps very low (less than 10%) probabilities of precipitation (PoPs) today through Friday. - Average temperatures today and tonight become above average tomorrow through the majority of the 7 day forecast as winds generally return out of the south-southeast, with highs in the 80s and lows in the 50s and 60s. - Low chances of rain (15-30%) are possible over the weekend as several cold fronts arrive near to or pass through the County Warning Area (CWA). && .DISCUSSION... Issued at 1111 AM CST Tue Dec 9 2025 Persistent ridging aloft is expected to maintain dry (less than 10% PoPs) conditions and plentiful sunshine across Deep South Texas today through Friday. Northerly winds gradually veer to southerly by late tonight as a surface high pressure shifts from the Deep South US to to the Southeast coast. A weak cold front approaches the northern ranchlands tomorrow afternoon and possibly moves southward into portions of the CWA overnight, briefly shifting winds out of the north late tomorrow night into Thursday morning before returning out of the south-southeast by Thursday evening. Another cold front moving into central Texas on Friday may lead to weak coastal troughing with a low (15-20%) chance of rain along the coast Friday night into Saturday afternoon. Low (15-30%) chances of rain may return on Sunday across the entire region as yet another cold front approaches and possibly passes through Deep South Texas, with coastal troughing keeping a low (15-30%) chance of rain near the coast, lingering into Tuesday. However, uncertainty remains in timing, location and strength of these upcoming cold fronts, so chances of rain and forecast temperatures (below) are subject to chance. Near average temperatures are expected today and tonight with daytime highs reaching the low to mid 70s and overnight lows falling to the 50s inland and 60s across the barrier islands. Above average temperatures return tomorrow and into the rest of the forecast period as winds become mainly southeasterly to southerly, with highs in the 80s tomorrow, 70s and 80s on Thursday and 80s Friday through Sunday. Following the cold front on Sunday, average temperatures are possible next Monday (in the 70s), but warm again with 80s possible on Tuesday. Overnight lows generally remain in the 50s and 60s. A low risk of rip currents continues today through the afternoon tomorrow. && .AVIATION... (18Z TAFS) Issued at 1111 AM CST Tue Dec 9 2025 Light to gentle north-northeasterly winds gradually veer to easterly this afternoon and southeasterly by this evening, followed by calm to light and variable winds overnight. VFR conditions continue into the afternoon tomorrow along with light southeasterly to southerly winds. && .MARINE... Issued at 1111 AM CST Tue Dec 9 2025 Favorable marine conditions are anticipated over the next 7 days across the Lower Texas coastal waters as gentle to moderate southeasterly to southerly winds and slight to moderate (2-3 ft) seas prevail through at least Saturday. Small Craft Exercise Caution conditions are possible on Sunday as a cold front possibly moves through, leading to potentially moderate to fresh easterly winds and moderate seas, followed by moderate easterly winds and seas by Monday, becoming southeasterly again next Tuesday. && .PRELIMINARY POINT TEMPS/POPS... BROWNSVILLE 74 58 81 62 / 0 0 0 0 HARLINGEN 74 52 82 57 / 0 0 0 0 MCALLEN 75 56 84 59 / 0 0 0 0 RIO GRANDE CITY 74 52 82 54 / 0 0 0 0 SOUTH PADRE ISLAND 69 64 76 67 / 0 0 0 0 BAYVIEW/PORT ISABEL 72 57 80 60 / 0 0 0 0 && .BRO WATCHES/WARNINGS/ADVISORIES... TX...None. GM...None. && $$ SHORT TERM...65-Irish LONG TERM....65-Irish AVIATION...65-Irish ####018007135#### FXUS62 KRAH 091719 AFDRAH Area Forecast Discussion National Weather Service Raleigh NC 1219 PM EST Tue Dec 9 2025 .SYNOPSIS... Arctic high pressure will build across the region today. The high will settle across the Southeast ahead of a strong, clipper low pressure system that swing across the Great Lakes tonight and Wednesday. A moisture-starved cold front trailing the clipper low will move across NC Wednesday night. && .NEAR TERM /TODAY AND TONIGHT/... As of 320 AM Tuesday... * Sub-freezing temperatures will allow any snow or moisture on area roads and sidewalks to freeze, producing hazardous travel through mid to late morning. * Cold today with highs 15 to 20 degrees below normal In the wake of exiting shortwave trough, a migratory Arctic high pressure will weaken while building over the area today before shifting offshore tonight. Light snow/flurries have ended across the area, leaving behind widespread low clouds early this morning. However, dry low-level air advection from the north, combined with increasing subsidence aloft, should lead to NE to SW clearing/partial clearing through mid to late morning. Across the area that received 1-2 inches of snow across the northern Piedmont and northern coastal plain, morning lows in the lower to mid 20s will support slick spots and patchy black ice, especially on shaded secondary roads, bridges and overpasses. Temperatures rising above freezing by late morning, combined with increasing solar radiation, will reduce the risk of slippery conditions. Temperatures will be unseasonably cold for early December, with highs ranging from mid/upper 30s north to lower 40s south --about 15 to 20 degrees below normal. After the low stratus scatters out, expect periods of broken/overcast cirrus and cirrostratus, some of which may become orographically-enhanced, through tonight. Lows tonight will fall into the 20s area-wide. && .SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/... As of 320 AM Tuesday... * Windy conditions will develop ahead of a dry cold front. The large-scale mid/upper trough over the central and eastern US will be reinforced by several digging shortwave troughs, including a clipper-type perturbation and it's accompanying dry cold front that will sweep through the mid-Atlantic states late Wednesday and Wednesday night. The primary weather impact will be the development of windy conditions within the pre-frontal regime. SWLY winds will increase after daybreak and peak during the afternoon/max heat, with sustained winds of 15 to 20 mph and frequent gusts between 25 to 35 mph, occasionally reaching 35 to 40 mph at times. Residents should secure outside items and holiday decorations. Expect considerable cloud cover, consisting of mid and high level clouds, ahead of the cold front. Temperatures will moderate closer to normal for early December, with highs ranging from near 50 north to mid 50s south. Following the dry cold frontal passage Wednesday night, CAA will ensue. Skies will clear and gusts will diminish. Overnight lows will fall into the lower 30s north to mid 30s south. && .LONG TERM /THURSDAY THROUGH TUESDAY/... As of 1215 PM Tuesday... * Temperature roller coaster, below normal Thursday and Friday, moderating to near/above normal Friday night through Sunday, then falling back to below normal Sunday night through Tuesday. * Highest chance (slight) for precipitation will be Saturday night into Sunday. Aloft, a s/w traversing the base of the longwave trough will move across the region on Thu, while the parent low tracks ewd across the Northeast US/srn Quebec. In the wake of the s/w, the flow will become gradually more zonal Thu night through Sat. A weak s/w disturbance may track across the mid-Atlantic late Fri/Fri night. The longwave trough will again amplify over the central CONUS Sat/Sat night as a low tracks esewd across Ontario and a nrn stream s/w tracks esewd from the nrn Rockies to the mid MS/OH Valley. As the low continues its ewd progression toward the Northeast US, the s/w will continue ewd across the Appalachians and mid-Atlantic on Sun, then offshore Sun night. The longwave trough will linger over the ern US on Mon, with another nrn stream s/w swinging through it and across the region Mon night/Tue. At the surface, high pressure will modify as it builds ewd across the region in the wake of the front Thu and Fri. Meanwhile, a low pressure system will develop off the central Rockies and move ewd across the Plains and into the mid MS Valley Thu and Fri. As the low moves east across the region, a warm front may lift across the area. A trailing, secondary low may track ewd or newd across the region along the front late Sat/Sat night, though the track and strength varies between the available guidance. Regardless, as the low moves out, the attendant cold front will quickly move across the area, with Arctic high pressure building in behind it. The center of the high will track east from the mid/upper MS Valley and across the OH Valley/Great Lakes Sun night-Tue. Precipitation: There is a non-zero chance of rain perhaps clipping central NC counties along the VA border, but for now will keep the forecast dry. The better chance for rain will be Sat night/Sun, however chances are slight given the model variability, with a chance the rain could split central NC entirely (GFS). Temperatures: Highs mainly in the 40s on Thu, with lows mainly in the mid to upper 20s. Some moderation could start Fri, with the potential for highs to reach low/mid 50s across the south. Sat and Sun will be the warmest days, with temps near to above normal. Temperatures will drop in the wake of the cold front, with a return to below normal for Sun night through Tue. && .AVIATION /11Z TUESDAY THROUGH SATURDAY/... As of 600 AM Tuesday... Dry low-level air advection from the north and increasing subsidence aloft should support a return to VFR condition from NE to SW through mid to late morning(still some uncertainty on the exact timing). Thereafter, expect periods of broken/overcast cirrus clouds, especially across the northern terminals. Light northerly winds this morning will shift to SWLY into the afternoon. A 45-50 kt LLJ will result in a period of LLWS late tonight into early Wednesday. Outlook: A 45-50 kt LLJ will result in a period of LLWS early Wednesday, followed by turbulent conditions Wednesday with frequent SWLY gusts of 25 to 35 mph. Otherwise, predominately VFR is expected through late week. && .RAH WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory from 7 AM Monday to noon EST Tuesday for NCZ007>011-021>028-041>043. && $$ SYNOPSIS...MWS NEAR TERM...CBL SHORT TERM...CBL LONG TERM...10 AVIATION...CBL