Area Forecast Discussion
Issued by NWS Billings, MT
Issued by NWS Billings, MT
723 FXUS65 KBYZ 032038 AFDBYZ Area Forecast Discussion National Weather Service Billings MT 238 PM MDT Fri May 3 2024 .DISCUSSION... Tonight through Sunday night... The Northern Rockies region is under cyclonic, northwesterly flow at 500 mb this afternoon, with considerable cloud cover and a few isolated rain/snow showers. Changes are in store though, beginning tonight. Tonight into Saturday night, the 500 mb trough that has been affecting our weather the past few days will move eastward enough to allow shortwave ridging to move into our area from the west. This ridge will bring dry weather and partly to mostly sunny skies to the area. We will also experience some warming as surface high pressure moves into the northern/central Plains and low-level southeasterly winds on the western side of the surface high facilitate compressional warming and warm air advection. A corridor of wind gusts to 30-35 mph will exist from Wheatland County to southern Carbon County on Saturday. Sunday, a 500 mb low will move from the OR/CA/NV area to southern ID/northern NV. This system will bring clouds to the area, and an increasing chance of showers from west to east. For Sunday afternoon, PoP values are 20-90% over south central MT and western Sheridan County, WY. Isolated thunderstorms are possible as well (20% chance). The greatest PoP values are in the Crazy and Beartooth/Absaroka Mountains. Furthermore, continued low-level southeasterly flow will cause additional warming on Sunday. Over southeast MT and Sheridan County, WY, southeasterly winds will gust to 35-45 mph. Minimum relative humidity values should drop to around 20% Sunday afternoon. So, the combination of warm temperatures, gusty winds and low relative humidity will create elevated fire weather concerns Sunday in southeast MT and the lower elevations of Sheridan County, WY, wherever a greenup has not yet occurred. Sunday night, the 500 mb low will move into western WY and bring a 40-90% chance of showers (with a 20% chance of thunderstorms) to the area with the highest PoP values in the mountains and areas west of Billings. Models generally agree up to this point in the forecast (through Sunday night) that the greater precipitation amounts, generally 0.10 to 0.50 inches, will be west of southeast MT. In addition, a cold front will cross the area Sunday evening, bringing cooler air to the area but still warm enough to support rain in the lower elevations. Snow levels will fall from 9,000-10,000 feet Sunday evening to 6,000-8,000 feet by Monday morning. Low temperatures will generally be in the 20s to lower 30s tonight, then 30s-40s Saturday night and Sunday night, with Sunday night the warmer night. High temperatures will mainly be in the 60s Saturday and 60s-lower 80s Sunday (warmest in southeast MT and Sheridan County, WY). RMS Monday through Friday... By Monday, ensembles place an upper level low will over western Wyoming tracking east into eastern MT and western Dakotas by Monday night. This low will linger over the western Dakotas through Wednesday bringing multiple rounds of precipitation as well as strong northwest winds. There is still much spread amongst models on total QPF as well as the timing of the heaviest precipitation. Mon through Wed night, the region has about a 60-85% chance of getting at least a half an inch with about a 50-70% chance of at least an inch for southeast MT (areas east of Billings). For this same time period, the Absaroka/Beartooths and Bighorns have about a 40-60% chance of getting at least a foot of snow. Snow levels will generally be around 5000-6000 ft. With that, locations along the foothills could see a few inches of snow with Red Lodge at about a 40% chance of getting at least 3 inches. With regards to winds Monday, the strongest gusts will be off the western foothills along 1-90 as well as the high hills in southern Big Horn Co. These areas have about a 40-60% chance of getting wind gusts of at least 50 mph. Windy conditions will persist through Wednesday with gusts into the 30s and 40s. Precipitation chances start to diminish Thursday into Friday. Keep an eye on the forecast as placement of timing and amounts are likely to chance. Also be aware of changing cool and wet conditions for young livestock. High temperatures will be in the 50s through the week, possibly reaching the 60s by Friday. TS && .AVIATION... Isolated showers will be possible through this afternoon. VFR conditions will prevail through the period. TS && .PRELIMINARY POINT TEMP/POPS... Sat Sun Mon Tue Wed Thu Fri ----------------------------------------------------------- BIL 030/065 040/074 047/058 043/055 041/051 040/057 042/067 00/U 02/W 78/R 45/R 67/R 66/R 33/R LVM 028/063 042/066 040/053 037/050 036/048 036/052 036/062 00/B 17/T 98/T 46/O 67/O 55/O 23/R HDN 028/068 039/080 046/059 041/056 039/051 039/058 040/067 00/U 02/W 69/R 56/R 77/R 76/R 43/R MLS 028/063 041/081 050/060 042/052 038/052 041/061 042/067 10/U 01/N 59/T 76/R 78/R 75/R 32/R 4BQ 028/065 043/080 049/059 040/053 038/049 039/056 041/063 00/U 01/N 59/T 65/R 67/R 76/T 33/R BHK 025/060 038/074 048/060 038/050 034/051 037/058 037/063 10/U 01/N 59/T 87/R 77/R 65/R 33/R SHR 026/066 039/077 042/055 038/056 036/050 035/052 037/061 10/U 02/W 69/T 66/R 77/R 77/R 44/T && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...None. WY...None. && $$ weather.gov/billings