611 FXUS65 KBYZ 280825 AFDBYZ Area Forecast Discussion National Weather Service Billings MT 225 AM MDT Sun Apr 28 2024 .DISCUSSION... Today through Monday... Satellite imagery shows a dynamic low in the central plains and a zonal flow moving thru the PacNW and northern Rockies. There are a couple of embedded weak shortwaves. The first is helping to produce scattered light showers over western areas currently, and is also associated with a shift to westerly winds. The other wave moving from WA/OR into ID will provide very modest ascent for shower activity later today. As surface winds turn to the NW over the next several hours, focus of showers from late morning til evening will evolve to our southern upslope areas. None of this precip will be heavy, and diurnal instability is too marginal for a mention of thunderstorms today. Mountains will pick up a little snow, on the order of a half inch to 2 inches. The probability of exceeding 2" over the next 24 hours is only 30% over the Beartooths. Temps today will again be seasonable with highs in the upper 50s to mid 60s. Before moving to Monday, we should point out there is advection of stratus approaching far southeast MT from western SD. Look for a fog/stratus combo in Carter County over the coming hours, and boundary layer moisture may even be deep enough to produce pockets of upslope drizzle over the hills. Something to watch if you're traveling in the Alzada and Ekalaka areas thru maybe 15z this morning. Downslope/pre-frontal warming will exist on Monday ahead of a stronger Pacific shortwave, and SW winds will become breezy (gusts 30-40 mph expected along western foothills). High temps should range from 60-70F, warmest over central and east parts. A few showers may spread over our western mountains/foothills in the morning, but the much better chances of showers (50-90%) will be in the afternoon as large scale ascent increases from the west. Dew points in the low-mid 30s will limit instability but sbcapes should reach 100-300 j/kg, so we may see a few weak thunderstorms near the cold front, which isn't expected to reach our west until close to 00z. The cold front/convection combo has the potential to produce gusty winds (up to 45 mph) by late in the day, starting in our west of course. Something to watch if you have outdoor plans late Monday afternoon & evening. JKL Monday evening through Saturday... An unsettled pattern with several shortwaves and troughing is in store for much of the week. Chances for precipitation are ubiquitous, the highest chances will be see on Monday as a cold front moves through Montana. The best chances for precipitation through Tuesday will be west of a Miles City to Sheridan line. Locations west of this line have a 50-80% chance of at least 0.1" of QPF in this period. The western mountains will have the highest precip probabilities through the extended forecast, with a few inches of snowfall expected. While precipitation for lower elevations will be mostly rain, snow levels are going to drop to around 3000ft Monday night bringing chances for some light snow accumulations. Locations such as Red Lodge have up to a 15% of an inch of snow, while the mountains will have a 50-80% chance of at least 2 inches. Models depict another wave pushing across the region Wednesday night, with some slightly increased moisture chances, 20-50% for lower elevations and 50-70% in the mountains. For the rest of the week, PoPs of 20-40% are in the forecast. From Monday night through Thursday night, the mountains have a 40-70% chance of picking up 6 inches of snow. With the passing cold front, breezy winds of 20-40 mph will be felt across the area through Tuesday. The highest gusts in the 30s-40s mph will be in the far east, along the Dakota borders. Highs in the 50s to low 60s through Friday, before potential 70s on Saturday. Matos && .AVIATION... Scattered light showers will impact areas west of KMLS-K00F today and tonight. VFR will be dominant, but local MVFR is possible especially near the foothills. Mountains will be frequently obscured in snow showers. There is also a moderate risk (50% chance) of fog/stratus in far southeast MT (KBHK-K97M) thru 15z this morning. Local MVFR-IFR is expected in this area. JKL && .PRELIMINARY POINT TEMP/POPS... Tdy Mon Tue Wed Thu Fri Sat ------------------------------------------------------- BIL 063 043/067 038/056 036/056 036/057 037/059 037/064 2/W 25/T 72/W 24/W 35/W 24/W 32/W LVM 059 039/061 029/049 028/049 030/054 033/055 034/061 5/W 29/T 84/J 35/W 34/W 25/T 32/W HDN 066 039/070 037/059 034/058 035/057 035/062 037/065 2/W 23/W 92/W 24/W 45/W 24/W 32/W MLS 065 039/068 040/057 036/056 036/055 036/060 038/061 1/B 01/B 81/N 13/W 23/W 23/W 32/W 4BQ 064 038/068 040/057 035/058 036/053 035/059 037/061 1/B 01/B 41/N 12/W 34/W 23/W 32/W BHK 058 033/068 037/057 033/056 033/053 032/057 034/058 0/B 00/U 61/N 13/W 24/W 23/W 32/W SHR 062 037/068 034/057 029/056 031/052 030/057 033/061 3/W 22/W 82/W 23/W 55/W 34/W 42/W && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...None. WY...None. && $$ weather.gov/billings