Area Forecast Discussion
Issued by NWS Billings, MT
Issued by NWS Billings, MT
380 FXUS65 KBYZ 131128 AFDBYZ Area Forecast Discussion...Updated National Weather Service Billings MT 528 AM MDT Fri Mar 13 2026 .KEY MESSAGES... - Pacific moisture moving into the region will interact with colder air through Saturday night to produce periods of wet snow. - Snowfall amounts of 1-4 feet forecast for area mountains. - Around 6-14 inches of snow expected across lower elevations with the highest north and northwest of Billings. The remainder of southeast MT and the foothills may see 4-8 inches. && .UPDATE... Updated forecast to lower temperatures along with updating the latest precipitation trends. Models were a bit too slow and not deep enough with the colder air building in overnight. Currently easterly winds have moved through all of the lower elevations outside of Livingston, but wouldn`t be surprised to see them get in there before sunrise this morning. Those easterly winds have dropped temperatures into the mid to upper 20s for most locations at 345am, which is certainly colder than models anticipated. With those colder temperatures road temperatures are currently at or below freezing, so the slushy/wet roads that were anticipated to persist overnight will likely ice up/become snow covered over the next several hours where snow is falling. Thus the morning commute will probably be a bit tougher than was anticipated as folks went to sleep last evening. Be sure to take it easy heading in to work this morning and allow extra time to get there safe. Snow measurements in Billings showed 2.8 inches here at the office and 3 inches at the airport as of midnight. A check of MT Mesonet snow measurement sites showed a lot of 1 to 3 inch amounts across the area, with 5.5 inches near Lame Deer, 5.2 inches near Judith Gap, and 4.4 inches near Ashland being the heaviest reports around 1am. Based on the models being a bit too warm overnight trended temperatures cooler by about 5 degrees today (NBM 50th percentile), especially areas in the main precipitation banding. This lines up better with the latest deterministic model blend. Also trended precipitation probabilities upward with the overnight model trends. No significant changes to snow totals from this morning onward with this update. Did go ahead and post a Winter Storm Watch for SE Montana in conjunction with the Dakotas offices, for Saturday through Sunday morning. Snow totals were already in the 4 to 8 inch range in this area so a watch seemed more than reasonable. Could end up being more of an advisory than a warning going forward, but will let the day shift take a look at the next model iteration to determine that. Rest of the forecast is in good shape. Models still showing a warm advection surge from the southwest today. Thinking this will be lessened by the cold air already being further south than previously forecast, but it could bring a change over to a mix of rain and snow or even all rain for a brief period this afternoon along and south of the I-90 corridor. This rain/snow line currently comes right up to Billings and could see the west end being a mix while the airport and heights stay snow. Chambers && .DISCUSSION... Today through Thursday... Current conditions reflect decreasing 700 mb winds across the area, generally sitting at 40-50 kts. With higher pressure filling in and precipitation in progress, these winds will no longer pose a threat and therefore all High Wind Warnings have been canceled. Conditions across the foothills will remain breezy overnight with gusts in the 30s and 40s mph. Additionally, a Winter Weather Advisory for the Sheridan foothills has been issued through noon today with 1 to 4 inches of snow expected (highest along the higher hills). Models generally show a break in precip Friday afternoon through Saturday morning, with more accumulations expected for Saturday afternoon through the night. This will have to be monitored for an extended or additional advisory. Pacific moisture will continue to stream in under westerly flow until troughing and a final cold front push through the area late Saturday. This is somewhat of a tricky forecast given the over running pattern and its tendency to have variable behavior in where the highest snowfall amounts will be. Additionally, given the wetbulb temperatures are hovering right around 32 degrees gives way to a rain/snow mix, especially along the river valleys. That being said there is confidence in a two and a half day period of accumulating snowfall. With that, Winter Storm Warnings are in effect for portions of south central MT for amounts of 6-14 inches of snow across the lower elevations. Keep in mind that elevation will play and important role in snowfall accumulations (valleys being rain/snow mix at times and higher hills getting higher accumulations). There is some differences in the models on just how much temps will warm for the day Friday, creating a little more uncertainty in accumulations. The better push of cooler air comes in Saturday afternoon and evening as a final cold front pushes through the region. As far as snowfall goes for the Absaroka/Beartooth foothills, areas like Livingston likely won`t get into the cold air until Saturday night, keeping rain as the main precip type. For areas like Red Lodge, a rain/snow mix will not accumulate to much, but look for chances or snow to increase tonight and especially Saturday as a more upslope pattern comes into play. Southeast MT can expect to see 4 to 6 inches through Saturday night with occasional rain mixing in during the day today. Sunday into Monday, heights begin to build back in with a brief disturbance under northwest flow. This will likely bring light snow to the mountains with ensembles bringing in a tenth o an inch or less for lower elevations. Temperatures will quickly rise through the week with highs expected to be in the 60s and 70s by Wednesday and Thursday. TS .AVIATION... 12Z TAF Discussion... Snow is ongoing over much of the forecast area as cold air has filtered into all but the far western foothills around Livingston (KLVM). Overall the forecast is consistent with previous iteration through most of the day today, with IFR or lower conditions under the main snowband bisecting the forecast area from NW-SE. On the periphery of this band VFR to MVFR conditions prevail with occasional IFR with transient pockets of snow expanding out away from the banding (KMLS/KSHR). Winds in Livingston are uncertain as models insist that westerly winds will prevail there, gusting in the 30 to 35kt range by mid day. However the easterly winds are not that far away and are slowly spreading west. Do think there will be a surge of westerly winds/warm advection kick in mid day into the afternoon, but extent of that remains a question mark. The aforementioned warm advection is beginning to show up in precipitation type for areas further north than earlier model runs. In Billings (KBIL) the RAP/HRRR/NAM are trying to switch over to rain this afternoon into the evening, then Freezing Rain/Ice Pellets in the evening to overnight. Even the GFS is starting to show signs in guidance for freezing rain after 04z tonight. Even Miles City is starting to show signs of mixed rain/snow or even all rain later today into this evening. This seems a bit far into the cold air to have that drastic a change but is something to keep an eye on. Leaned toward the latest GFS and NBM precipitation type for this taf run. Will be keeping a close eye on the precipitation type trends today. Chambers && .PRELIMINARY POINT TEMP/POPS... Tdy Sat Sun Mon Tue Wed Thu ------------------------------------------------------- BIL 033 026/034 011/032 016/047 040/065 044/073 047/076 +/O 9+/S 92/S 12/O 21/N 00/B 00/B LVM 050 033/044 013/036 024/052 044/062 045/069 047/072 9/R 9+/O 82/S 45/O 41/N 00/N 00/N HDN 034 025/037 010/031 011/047 035/065 039/075 041/078 +/O 9+/S 94/S 12/O 21/N 01/B 11/B MLS 035 024/031 010/023 006/037 030/057 039/067 041/070 8/S 99/S 82/S 02/O 11/B 00/B 01/B 4BQ 036 026/037 012/026 008/040 031/062 041/071 042/075 9/O 89/S 93/S 01/E 21/B 00/B 00/U BHK 034 020/029 005/021 002/033 023/055 036/065 040/066 7/S 89/S 92/S 02/S 22/W 00/B 00/B SHR 039 025/045 008/029 010/045 032/065 038/072 040/075 9/O 69/O +4/S 02/O 21/B 00/B 00/B && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...Winter Storm Warning in effect until 6 AM MDT Sunday FOR ZONES 29>31-34-36-42-57-58-63-67-68-138-141-171>173-228-235. Winter Storm Watch in effect from Saturday morning through Sunday morning FOR ZONES 32-33-37. Winter Storm Watch in effect from 3 PM MDT this afternoon through late Saturday night FOR ZONES 56-66. WY...Winter Storm Warning in effect until 6 AM MDT Sunday FOR ZONE 198. Winter Weather Advisory in effect until noon MDT today FOR ZONE 199. && $$ weather.gov/billings