textproduct: Glasgow

KEY MESSAGES

- The next weather system will bring colder weather and mixed precipitation to the area Saturday night through Monday. Wetting rains are likely, with some areas seeing a mix with wet snow.

- Another system may bring precipitation chances as far west as the Yellowstone River Valley from Terry to Glendive Wednesday into Thursday.

DISCUSSION

A cold front will track through the region today with an upper trough digging into the pacific northwest. This will place NE Montana under southwest flow aloft initially with increasing chances for rain ahead of the trough Saturday night with a shortwave ejecting out ahead of the closed low and plenty of available moisture.

The low eventually cuts off as the shortwave gets absorbed in the northern stream over the Plains, resulting in a sort of split flow. That northern system will eventually translate east toward the Dakotas and Minnesota by Tuesday of next week. As this plays out look for rain to continue at times through Monday. As temperatures fall, look for a mix with or change to wet snow Sunday into Monday. Ground temperatures are still warm so expect little if any accumulation of snow, but there could be a couple of inches over the higher peaks of the Little Rockies. Meanwhile wetting rains will be widespread, with NBM mean solution now around and exceeding 0.50" QPF south of Highway 2 over the three day period. The system takes the exit by Tuesday with a northern stream ride setting up over the Northern High Plains while the closed low tracks south of the region. This low may track close enough to provide light precipitation as far west as the Yellowstone Corridor within our CWA from Terry to Glendive Wednesday into Thursday.

FORECAST CONFIDENCE & DEVIATIONS:

Confidence is increasing that the next system approaching on Saturday through Monday will bring beneficial amounts of precipitation, though given warm ground temperatures and marginal thermal profiles, below average confidence exists on snow as a precipitation type, timing of any changeover, or any accumulation, save for the higher terrain such as the Little Rockies.

Confidence is also below average on precipitation chances later in the week as ensembles show increasing spread at larger time scales. It is possible the low tracks too far to the southeast for anything significant, other than increasing clouds and light precipitation. Will be monitoring in the coming days for any trends.

AVIATION

LAST UPDATED: 0531Z

FLIGHT CAT RANGE: VFR, then MVFR over KGGW and KOLF

Discussion: VFR conditions through Saturday morning and afternoon before MVFR ceilings move eastward into the region during the evening and overnight hours. A cold front will move into Northeast Montana throughout the day and increase chances of precipitation Saturday evening through Monday in KGGW, KOLF, and KGDV.

Winds: Northwest winds and gusty conditions are expected to last for most of the cycle, especially in the afternoon and evening as the cold front passes through.

LLWS: Low level wind shear is likely around KOLF, KGDV, and KSDY during the morning hours on Saturday. Chances will decrease after 10Z and should move east out of the area by the afternoon.

KENZ

GGW WATCHES/WARNINGS/ADVISORIES

None.