textproduct: Billings

KEY MESSAGES

- There is daily potential for thunderstorms through the coming weekend; some severe thunderstorms are possible. Monitor the forecast.

- High elevation snowmelt will allow flows on rivers and streams to increase into the second half of this week. No flooding is expected at this time.

DISCUSSION

Through Thursday night...

Showers and a few weak thunderstorms were tracking across north and eastern areas early this morning as a weak shortwave slides into the Dakotas. Smoke from Canadian wildfires was bringing visibility reductions to northeast MT, but thus far, the smoke has remained mainly north of us.

Another shortwave will track through the area from southwest to northeast today into Thursday bringing widespread shower and thunderstorm chances. Temperatures will be a few degrees cooler than yesterday, with highs in the 70s to middle 80s. Breezy southeast winds can be expected over eastern areas, where locations near the Dakotas border could see wind gusts into the 30s mph. The southeast winds will transport moisture into the area from the Plains, and precipitable water values will increase to near to over an inch by this afternoon. Ample moisture, along with MUCAPE values of 500-1000 J/kg and deep layer shear of 25-40 kts will combine to bring a threat of strong to severe thunderstorms across the area this afternoon and evening. Thunderstorms are expected to form over the mountains by midday, spreading east into the evening. Showers and thunderstorms will persist into the overnight hours over northern and eastern areas. Strong wind gusts, hail and heavy rain are possible with the strongest thunderstorms. The Storm Prediction Center currently has a marginal risk of severe thunderstorms over the entire area this afternoon and evening. If you have outdoor plans, monitor the forecast and make sure you have a way to receive warnings should severe weather approach.

Shower and thunderstorm chances continue into Thursday as the wave lifts off to the north and east. Severe thunderstorms are not currently expected on Thursday with less instability and shear over the area. Temperatures are forecast to range from the middle 60s over the north, to the middle 70s over southern areas. STP

Friday through Wednesday...

An active pattern continues into next week as shortwaves move through the upper level flow, leading to daily chances for showers and thunderstorms.

PWATs are expected to be around 1 inch, or 100-140% of normal, for much of the region through the weekend. Coupled with CAPE values greater than 1000 J/kg (Friday) to greater than 2000 J/kg (Saturday and Sunday), there is potential for strong to severe thunderstorms to develop. This will be something to keep an eye on.

For Monday into midweek, PWATs are expected to remain near normal, with enough daytime heating/instability to continue to bring showers (40-60% chance) and thunderstorms (20-40% chance) to much of the region.

High temperatures will be mostly in the 80s for Friday through the weekend, decreasing to 70s to low 80s for Monday into midweek. Archer

AVIATION

Isolated to scattered showers, and a few weak thunderstorms will gradually shift east through northeastern areas into the morning hours. A disturbance lifting through the region will bring another round of more widespread showers and thunderstorms this afternoon into tonight. While VFR conditions will prevail during this time, MVFR conditions are possible under the stronger showers and thunderstorms. Otherwise, smoke will continue to reduce slant range visibility at times for locations east and north of KBIL. Archer/STP

PRELIMINARY POINT TEMP/POPS

Tdy Thu Fri Sat Sun Mon Tue ------------------------------------------------------- BIL 084 057/074 053/077 056/084 058/083 055/079 056/078 5/T 75/T 13/T 42/T 32/T 43/T 43/T LVM 078 050/077 050/077 051/084 051/081 049/078 049/078 8/T 95/T 35/T 32/T 23/T 23/T 43/T HDN 087 057/075 052/079 056/086 057/084 055/079 055/078 4/T 85/T 23/T 42/T 42/T 53/T 54/T MLS 084 056/065 052/074 056/084 060/083 057/079 055/078 2/T 98/T 32/T 51/B 52/T 63/T 54/T 4BQ 084 058/073 053/075 056/084 058/083 057/077 055/075 3/T 96/T 22/T 51/U 42/T 53/T 54/T BHK 078 051/062 047/070 051/078 054/081 054/077 052/074 2/W 89/T 41/E 41/B 52/T 62/T 54/T SHR 083 052/075 049/079 054/085 055/082 053/078 051/075 6/T 94/T 25/T 32/T 23/T 44/T 55/T

BYZ WATCHES/WARNINGS/ADVISORIES

MT...None. WY...None.