Area Forecast Discussion
Issued by NWS Billings, MT
Issued by NWS Billings, MT
632 FXUS65 KBYZ 291130 AFDBYZ Area Forecast Discussion National Weather Service Billings MT 530 AM MDT Sat Jun 29 2024 .UPDATE... Updates made to the Aviation Discussion. Rest of the forecast is on track. Matos && .DISCUSSION... Today through Sunday Night... Aside from a 10-30% chance for showers and maybe a few rumbles of thunder in the eastern areas this morning, drier and warmer conditions are in store today. Slightly cooler than normal high temperatures in the 70s with the chance for precipitation generally below 15% across the forecast area. Some breezy winds in the 10s-20s mph and gusts in the 20s to 30s mph will also be felt. Upper level ridging will continue building into the Northern Rockies into Sunday. Models show 850mb temperature anomalies of 8-12C will see surface temps in the 90s to 100F. The warmest temperatures are forecasted east of Billings, with highs near 100F for Sheridan, Broadus, and Forsyth. An mid-upper trough begin moving into the region Sunday afternoon, bringing a cold front and the chance for strong to severe weather. The latest SPC Day 2 Outlook has the entire forecast area in a Marginal Risk (level 1 out of 5) and a Slight Risk (level 2 out of 5) for the east- central MT region. The primary risks with this outlook will be wind and hail, with a secondary risk of heavy rainfall. The best instability will be east of Billings, due to greater diurnal heating. Models are showing 1000-2000 J/kg of MUCAPE, adequate deep layer shear values approaching 50-60 knots. Moisture availability shouldn`t be too much of an issue with PWATs between 1-1.25" east of Billings. The arrival of the cold front will provide needed forcing for storm development in the west, with storms becoming stronger as they move into the more favorable environment in the central-eastern areas. Isolated convective development ahead of the front is possible, however, numerous model soundings in the eastern areas show a notable cap in the lower levels. With some searching, you can find model soundings in the east that show an uncapped profile that would be indicative of what to expect for any isolated convection. Fairly straight line hodographs will favor hail development with the strongest storms. As for timing of the convection, isolated storm development is possible east of Billings beginning in the early-mid afternoon. The second round of convection will be associated with the cold front. The question on this round will be the strength and mode of storms as it progresses east, if deep convection is able to develop it has the potential to become an MCS in the far east before moving into the Dakotas. Cold frontal passage won`t be until early evening out west and after sunset in the far east. The chance for post-frontal showers and thunderstorms exists as well, with 30-80% probabilities, highest in the western mountains. With the frontal passage, breezy winds with gusts in the 20s-30s mph will be felt Sunday night into Monday morning. Matos Monday through Saturday... Moisture lingers as although Sunday nights, low-level jet is pushed east by a cold front, a surge of Pacific Moisture is brought in behind the front and its associated trough and will continue to impact south-central Montana and especially the mountains. While severe storms are not expected (though one or two cannot be ruled out), the main impact will be the large coverage of showers and storms, with the foothills and mountains having a 30-50% chance of getting at least half an inch of rain Monday through Tuesday morning. Tuesday through Wednesday has two potential solutions. One is broad cyclonic flow staying over the area and bringing about a small chance for continued storms and showers over the area, and the other is a brief period of ridging and drier air moving in and bringing about mild conditions and a slight rise in temperatures back into the mid 80s. Wednesday is looking to be another relatively better shot for stronger storms as a stronger shortwave and its associated cold front is progged to swing through southeast MT. The latter half of the week has high confidence in a broad upper ridge building into the western half of the country, which would bring about drier and hotter conditions to Montana. Vertz && .AVIATION... Low clouds, light rain, and local fog are producing reduced flight conditions, down to LIFR, at KMLS and KBHK this morning. Expect conditions to improve by late morning to early afternoon with diurnal heating. As for all other sites, VFR conditions will prevail through the period. Matos && .PRELIMINARY POINT TEMP/POPS... Sat Sun Mon Tue Wed Thu Fri ----------------------------------------------------------- BIL 048/077 052/090 060/080 056/077 054/081 055/077 053/081 10/U 03/T 57/T 64/T 23/T 34/T 22/T LVM 041/076 048/086 052/076 048/074 047/079 048/076 046/081 11/U 15/T 77/T 73/T 23/T 34/T 21/U HDN 046/078 052/095 059/081 055/078 051/083 052/078 051/082 10/U 02/W 57/T 74/T 13/T 34/T 22/T MLS 051/072 056/094 062/080 058/077 054/081 056/077 054/079 22/W 01/U 64/T 34/T 13/T 35/T 22/W 4BQ 049/075 055/096 062/080 057/077 053/082 056/077 054/078 11/B 01/U 35/T 54/T 12/T 34/T 22/T BHK 046/069 052/086 059/080 055/076 052/080 053/076 052/077 22/W 01/N 54/T 24/T 02/T 35/T 22/T SHR 043/078 051/099 057/078 050/075 047/081 049/077 047/080 10/U 02/T 27/T 73/T 12/T 34/T 22/T && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...None. WY...None. && $$ weather.gov/billings