####018004803#### FXUS65 KTFX 241455 AFDTFX Area Forecast Discussion National Weather Service Great Falls MT 855 AM MDT Wed Apr 24 2024 .SYNOPSIS... It will be a bit on the warm side today, with afternoon temperatures in the 70s for many lower elevation locations. Do expect a few late day showers though over Central and Southwest MT. On Thursday, a cooling trend starts, with a few thunderstorms possible over Southwest MT. By Friday, widespread lower elevation rain and mountain snow develops over much of Central MT. The cool and wet conditions will continue through at least Saturday. && .UPDATE... Overall, the forecast is mostly on track so far this morning. The one change I made was to tweak POPs to be more in line with the latest Hi-Res guidance, which has been honing in on the Bridgers and Gallatin Mountains a bit more. Ludwig && .AVIATION... 525 AM MDT Wed Apr 24 2024 (24/12Z TAF Period) VFR conditions will prevail across all terminals during this TAF period. Wednesday night into early Thursday morning there is a 40% chance of rain at the KEKS and KBZN terminals which could reduce ceilings down to low VFR/high MVFR levels and so a PROB30 group was included for it. The rain at the KBZN terminal will reduce ceilings down to low VFR levels at the very end of the TAF period. At the KHLN, KGTF, and KLWT terminals there is a 20% chance of rain Wednesday night into early Thursday morning. There wasn't enough probabilistic support to include a PROB30 group for those TAFs. In the middle of this TAF period at the KGTF and KCTB terminals there will be winds gusting up to 20 kts and 28 kts respectively. Wednesday afternoon there will be isolated instances of mountain wave turbulence across North-central and Central Montana. -IG Refer to weather.gov/zlc for more detailed regional aviation weather and hazard information. && .PREV DISCUSSION... /ISSUED 525 AM MDT Wed Apr 24 2024/ Today through Thursday...It will be a quiet morning over the CWA, with just some passing clouds. Do expect increasing clouds once again this afternoon. With good mixing and dry air in place, afternoon temperatures were raised just a few degrees above NBM for today. There will be a few late afternoon/evening showers over Central and Southwest MT as an upper level disturbance moves through. On Thursday, expect similar conditions, expect it will be a bit cooler, and with slightly more instability, there will be a chance for thunderstorm over Southwest MT. Friday through Sunday...A split upper level trof develops over the western half of the US from Friday into Saturday. One piece of energy goes into the Southwest US, while another piece of energy moves into the Pacific Northwest, before dissolving as it moves towards the West Yellowstone area. The end result is widespread lower elevation rain and mountain snow to affect much of the CWA from Friday into Sunday. The GFS continues to vary in the location of the heavier precipitation, but most models are agreeing that the mountains of Southwest MT will have periods of accumulating snowfall. Overall, snow levels will generally be near/above 6000 feet this weekend. Some of the heavier snowfall is expected in the mountains around Pony and Big Sky. Generally a 4 to 8 inch snowfall is expected on Friday and again on Saturday in these areas. With impacts being confined mostly to mountain areas, and spread out over 2+ days, I think a winter weather advisory will be the best way to handle the upcoming snowfall. However if snow amounts increase a bit or snow levels lower, a winter storm watch/warning might need to be issued. Otherwise, all models agree that temperatures will be slightly below normal for Friday and Saturday, before trying to go slightly above normal for Sunday. Monday through Wednesday...The flow aloft will generally be westerly next week, but also unsettled. Expect several upper level disturbances to move from west to east through the CWA early next week. This will result in periods of lower elevation rain and mountain snow showers. Overall, temperatures next week look to be close to seasonal averages for this time of year. Brusda && .PRELIMINARY POINT TEMPS/POPS... GTF 76 44 67 40 / 10 20 0 10 CTB 70 38 60 37 / 0 0 0 0 HLN 76 45 67 42 / 10 20 20 20 BZN 74 39 64 38 / 0 30 70 70 WYS 64 32 54 32 / 0 30 90 80 DLN 70 40 62 39 / 10 30 50 50 HVR 76 44 69 40 / 0 10 0 0 LWT 71 41 61 39 / 0 20 20 40 && .TFX WATCHES/WARNINGS/ADVISORIES... None. && $$ http://www.weather.gov/greatfalls ####018005365#### FXUS64 KCRP 241458 AFDCRP Area Forecast Discussion National Weather Service Corpus Christi TX 958 AM CDT Wed Apr 24 2024 ...New UPDATE... .UPDATE... Issued at 948 AM CDT Wed Apr 24 2024 Expect mostly cloudy, warm and humid conditions across South Texas today as a mid level ridge builds overhead. The onshore flow will gradually increase to moderate levels through the afternoon as low pressure deepens over the Central Rockies. This will draw mid 70 dewpoints into the region resulting in more humidity. The strong capping inversion at the H85 level will keep clouds around much of the day. Although by late afternoon skies should become partly cloudy as some drier air seen on visible satellite mixes in at low levels. It should be noticibly warmer today -vs- yesterday with temperatures warming into the mid 80s (east) to mid 90s (west). This is about 5-10 degrees higher than yesterday. Current forecast is on track and no changes are anticipated. && .SHORT TERM... (Today through Thursday) Issued at 331 AM CDT Wed Apr 24 2024 Deterministic models predict a slowly progressive pattern over the CONUS during the period, with an upper level ridge (with N-S axis) is expected to move eastward across the central CONUS (including TX) today, while an upper level disturbance enters the west coast tonight then approaches the Four Corners region Thursday. Although above normal PWAT values are expected to persist over the CWA during the period, no significant precipitation expected owing to significant CIN/subsidence today, and greater CIN Thursday. In response to the foregoing upper disturbance to the west, breezy/windy conditions are expected over the CWA Thursday afternoon. Yet, Elevated fire weather conditions are not expected due to elevated relative humidity values. The nearness to the full moon and increasing onshore wind speeds will contribute to a Moderate risk of rip currents Thursday. Will retain the NBM maximum temperatures today/Thursday over the CWA, which are slightly warmer than both the HREF and SREF ensemble mean values. && .LONG TERM... (Thursday night through next Tuesday) Issued at 331 AM CDT Wed Apr 24 2024 Key Messages: - Medium to high chance of patches of Wind Advisory conditions Thursday night into Friday. - Very warm on Saturday with highs nearing the triple digits out west. Not much of a change from previous Extended forecast package. A series of mid to upper level disturbances will combine with pockets of above normal moisture to provide a slight chance (20-30%) for showers and thunderstorms Friday and again Sunday through Tuesday. A few frontal boundaries will also accompany the upper level systems Friday and Sunday, but these will generally only make it into portions of the Rio Grande Plains. Aside from this, the main hazard through the long-term range is a strong southeasterly flow developing and leading to brief periods of Wind Advisory conditions over portions of the Brush Country Thursday night and across the Coastal Bend and Victoria Crossroads on Friday. Winds are also forecast to be elevated across the coastal waters through the entire cycle leading to SCEC to SCA conditions. Otherwise, expect increasingly warmer temperatures into the weekend with a medium chance (50%) of maximums exceeding 100 degrees across the west on Saturday, or 95 degrees or above daily through Tuesday. && .AVIATION... (12Z TAFS) Issued at 641 AM CDT Wed Apr 24 2024 Expect a mixture of MVFR and VFR ceilings this morning through early afternoon, followed by prevailing VFR conditions. Expect an approximately 03-06z Thursday transition to predominate MVFR ceilings. Weak to moderate onshore flow this morning/early afternoon followed by breezy conditions during the late afternoon/early evening hours. A transition to weak to moderate flow expected overnight. && .MARINE... Issued at 331 AM CDT Wed Apr 24 2024 Weak to moderate onshore flow expected today and tonight. Generally moderate onshore flow will develop Thursday afternoon, as an upper level disturbance approaches the southwestern United States. Onshore flow is forecast to strengthen to moderate to strong levels Thursday night, with periods of Small Craft Advisory or Caution conditions persisting through Sunday. Winds will weaken into more moderate levels Sunday night and into weak to moderate by Monday. Isolated showers and thunderstorms will be possible daily Sunday through Tuesday as a weak disturbance moves over the area. && .PRELIMINARY POINT TEMPS/POPS... Corpus Christi 86 72 85 73 / 0 0 0 0 Victoria 85 70 84 72 / 10 0 0 0 Laredo 93 72 94 74 / 0 0 0 10 Alice 88 71 90 72 / 0 0 0 0 Rockport 83 72 82 73 / 0 0 0 0 Cotulla 92 73 95 74 / 0 0 0 10 Kingsville 87 72 87 74 / 0 0 0 0 Navy Corpus 83 74 83 75 / 0 0 0 0 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...None. GM...None. && $$ SHORT TERM...JM/75 LONG TERM....NP/92 AVIATION...JM/75