Area Forecast Discussion
Issued by NWS Billings, MT
Issued by NWS Billings, MT
328 FXUS65 KBYZ 172015 AFDBYZ Area Forecast Discussion National Weather Service Billings MT 215 PM MDT Fri May 17 2024 .DISCUSSION... Through Saturday night... Severe Thunderstorm Watch has been issue for Carter, Fallon, Custer and Powder River Counties through 02Z tonight. Main threats are damaging winds in excess of 60 mph, heavy rainfall and small hail. Also cannot rule out gusty winds or small hail with any thunderstorms over the area through this evening. There was 40-50 kt of Bulk Effective Shear moving E through the central zones into the E. MUCAPE/Surface CAPE was running 500-1000 J/kg over most of the forecast area. First cold front had sagged S through much of the area and was entering Sheridan to Carter Counties at 20Z. A second front will move into the western zones in the next hour or so. SPS was issued earlier for storms in Big Horn County, and latest SPS was over Custer County for a fast moving cluster of storms with gusty winds and small hail. Isolated to scattered showers were behind the cluster over the rest of the area. WSW flow was over the area with energy moving through the flow. A stronger shortwave will move in behind the second front through tonight. Used the CAMS for PoPs through tonight. PoPs will be 50-70% E of KBIL through 06Z, then PoPs decrease markedly overnight. Will continue wind highlights as winds have been increasing in the western zones this afternoon. KLVM has reach 52 mph thus far. Saturday still looked dry under westerly flow. It will be breezy and have blended gusts with NBM 90th percentile. Temps will be near normal. SW flow moves overhead Sat. night and a cold front will push SE into the area ahead of the next shortwave. Models were in decent agreement with 20-30% PoPs W of KBIL overnight, although soundings looked fairly dry. Lows will be in the upper 30s to mid 40s. A mix of rain/snow is not out of the question over KLVM/foothills due to lower dewpoints, but just have rain in there for now. Arthur Sunday through Friday... Sunday into Monday, ensembles have a shortwave trough moving into western MT, increasing chances for precip. Currently the chance for a quarter inch of rain/melted snow is best for the mountains and foothills, with about a 40-60% chance, decreasing north and east to around 20% for eastern MT. With snow levels predicted to drop down to around 6000 ft Sunday night, the foothills could see a rain/snow mix. The mountains will likely pick up a few inches of snow. As this low tracks southeast on Tuesday, most of the energy will stay over WY, allowing for mild and dry conditions. Dry conditions will continue into Wednesday as brief ridging builds in behind troughing. Ensembles then have another round of troughing moving through early Thursday into Friday, but are in some disagreement on the behavior of this low. Chances for precipitation increase across the region to 40-70% Thursday with a 40-60% chance Friday. High temperatures will generally be in the upper 50s to low 70s through the period. TS && .AVIATION... Scattered showers and thunderstorms will spread from west to east this afternoon and evening. When thunderstorms occur, brief MVFR/IFR conditions are possible along with gusts up to 45 kts. Beginning this afternoon, expect gusts up to 45 kts near KLVM, K6S0 and K1KM. Archer/TS && .PRELIMINARY POINT TEMP/POPS... Sat Sun Mon Tue Wed Thu Fri ----------------------------------------------------------- BIL 042/067 044/062 040/060 041/062 042/067 045/059 042/063 40/N 15/R 45/R 23/R 14/T 57/R 55/T LVM 035/066 041/058 035/057 036/061 039/063 040/057 039/061 10/N 28/T 47/T 34/T 16/T 68/T 55/T HDN 039/067 041/066 039/060 040/062 040/069 044/062 042/065 70/U 13/R 44/R 23/R 13/T 46/R 55/R MLS 042/065 042/068 042/060 039/061 041/067 044/062 042/062 50/N 11/B 32/R 12/R 12/R 34/R 44/R 4BQ 042/065 042/070 043/060 041/059 041/068 043/062 042/062 60/U 01/B 33/R 23/R 22/R 24/R 44/R BHK 039/063 039/070 040/061 037/059 037/065 040/060 038/059 70/N 11/B 42/R 12/R 12/R 24/R 44/R SHR 036/066 039/067 038/055 038/056 036/066 040/061 039/062 60/U 03/T 36/T 55/T 23/T 46/T 55/T && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...Severe Thunderstorm Watch 253 in effect until 8 PM MDT this evening FOR ZONES 32-33-36-37. High Wind Warning in effect until midnight MDT tonight FOR ZONES 63-141-172-228. Wind Advisory remains in effect until midnight MDT tonight FOR ZONES 65-66. WY...None. && $$ weather.gov/billings