Area Forecast Discussion
Issued by NWS Billings, MT
Issued by NWS Billings, MT
678 FXUS65 KBYZ 190154 AFDBYZ Area Forecast Discussion National Weather Service Billings MT 754 PM MDT Tue Jun 18 2024 .UPDATE... Rain continues at Baker, at the tail end of the wave departing to the northeast, and this precip will end by 03z. To the west, we are still seeing isolated to scattered showers in an area with steep lapse rates and hints of PV advection west of Billings. This activity may linger for a bit longer but overall it is dissipating slowly. Have made a few pop/wx adjustments, including the removal of TS for the duration of the night. The overnight will be chilly and dry with mid 30s to around 40F for lows most places. As previously noted, each of our climate stations has the potential to reach a daily record for June 19. The other issue tonight (remarkably for so close to the solstice) could be fog. HRRR is hinting at it in our east and along the Musselshell. That said, dewpt depressions are quite low, and in fact dewpts remain in the low-mid 40s in our east as of 745pm. With clearing skies and light winds, some valley fog seems plausible (we`ll give it a 20% chance for now). JKL && .DISCUSSION... Rest of Today through Thursday Night... Satellite and radar imagery showed an upper trough axis across eastern Montana with wrap around precipitation spilling into our central and western zones while the southeast corner of MT was being dry slotted. Precipitation coverage was greatest from Billings south and southwest into the foothills aided by upslope flow. The only lightning noted was in north central MT at this time. We may see a few isolated embedded lightning strikes over our northern tier zones through evening, with enough instability still out there to produce some groupel (Story, WY reported some) this afternoon. Otherwise, as the upper trough slowly exits to the Dakotas by evening we will see precipitation winding down. Some trailing energy in the SW flow may produce some lingering showers in our west until after midnight, but these should be hit and miss showers at best. For tonight, we should see partial clearing late. Overnight lows will be in the 30s to lower 40s. Our current forecast is for record lows... Forecast Low Record Low Billings 39 42 1946 Livingston 34 34 2007 Sheridan 34 36 1985 Miles City 37 41 2020 For Wednesday, relatively benign W/SW flow will mean mostly sunny skies. We may see a few showers/thunderstorms develop in our eastern border counties, as well as around the Belts and Snowies, but for the most part dry conditions will prevail. The pattern will favor a low level jet (850mb) developing Wednesday night which may result in persistent isolated showers along the eastern border counties overnight. Highs Wednesday will be in the upper 60s west to mid 70s east. Lows Wed night will be in the lower 40s west to around 50 east. Not much overall change for Thursday as southwest flow continues aloft. We may see a few showers develop over the mountains by midday, but more significantly, isolated showers and thunder developing in a low level convergent zone (Rosebud County vicinity) over the plains. MUCAPE may get over 500 J/kg in this area with a 90% chance of effective bulk shear over 35kts. Thus, a few strong storms are possible in the east Thursday afternoon and early evening, though not a severe risk for now. Highs Thursday will range from mid 70s west to lower 80s east. Showers could linger again Thursday night over the eastern plains. Lows will be in the 50s. BT Friday through Tuesday... Friday, the region will be ahead of Pacific troughing bringing increased chances for precipitation early Friday morning through Saturday morning. Models generally have forcing being the strongest over northern MT, but our region still has a good chance of getting at least a quarter inch of rain (50-70% Billings north and east). SE flow in the low levels will stream in warm air and moisture ahead of the frontal passage Friday night. PWATs will be around 0.8-1.3 inches (highest in the east). This will give way to good instability across the region and allow for thunderstorms to develop. Ridging will build in the latter half of Saturday through Sunday allowing for hot and dry conditions. Ensembles and clusters then bring in slight troughing or westerly flow late Monday into Tuesday, but generally keep most energy to the north keeping PoPs at 20% or lower. High temperatures will be in the 70s Friday, 70s/80s Saturday, 80s/mid 90s Sunday and 80s for Monday and Tuesday. TS && .AVIATION... Showers will begin to dissipate late this evening. Fog is likely to form after 06Z for SE MT (KMLS and KBHK) dropping conditions back down to MVFR/IFR. Fog is also possible for KBIL, but confidence is lower. Conditions will clear up after sunrise with VFR prevailing for most sites tomorrow. Mountain obscurations will continue through the evening. TS/LT && .PRELIMINARY POINT TEMP/POPS... Wed Thu Fri Sat Sun Mon Tue ----------------------------------------------------------- BIL 039/073 050/078 057/075 055/081 056/094 060/087 056/083 30/U 01/B 47/T 62/W 00/U 11/U 11/U LVM 034/071 041/075 049/077 049/082 051/091 054/086 049/082 41/U 01/B 37/T 51/U 01/U 11/N 11/U HDN 037/076 049/081 057/077 054/083 054/095 058/089 054/085 21/U 02/T 57/T 72/W 00/U 10/U 11/U MLS 037/074 051/078 057/074 055/078 054/092 061/086 056/082 21/U 12/T 57/T 73/W 10/U 10/U 21/U 4BQ 036/074 052/078 059/077 057/079 055/094 064/088 057/084 02/T 22/T 56/T 72/W 10/U 10/U 10/U BHK 035/072 050/075 054/072 054/077 051/089 059/087 053/083 32/T 22/T 57/T 73/W 10/U 10/U 21/U SHR 034/074 046/080 054/078 052/080 052/094 058/089 053/085 21/U 11/B 46/T 62/W 00/U 10/U 10/U && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...None. WY...None. && $$ weather.gov/billings