textproduct: Great Falls

KEY MESSAGES

- Flood advisory issued for portions of Glacier County until Noon on Wednesday.

- Periods of rain over North Central MT today, with precipitation becoming more isolated on Wed.

- A good chance for showers/thunderstorms on Thu.

- Temperatures are warm on Sat, but cool a bit for Sunday, with scattered showers/thunderstorms both days.

DISCUSSION

- Meteorological Overview: A slow moving upper level low will continue to spin over southern Canada today, resulting in periods of rain over North Central MT today. A few showers are possible across Southwest MT. Snow levels are a bit higher today, generally around 7000 feet this morning. Some patchy fog is also possible through about 9 AM or so. Temperatures will continue to be cool today, especially over North Central MT, with Southwest MT seeing temperatures closer to normal the further south you go.

For Wednesday, the upper level low is going to slowly start to pull away, thus showers will be ending, with temperatures starting to climb back towards normal for most areas.

On Thursday, the next upper level trof approaches. This trof is now progged to move through the CWA a bit earlier in the day. This will keep the threat for stronger storms to mainly just the far eastern portions of the CWA. Otherwise, there will be a good chance for showers/thunderstorms across the CWA as the trof moves through.

For Friday through Sunday, a southwesterly flow aloft will reside over the CWA for Fri/Sat...resulting in warm temperatures and a chance for mostly late day thunderstorms on Sat. On Sunday, a few showers/thunderstorms will be around, along with cooler temperatures.

For Mon/Tue of next week, the forecast models differ, with one model having a brisk westerly flow, while another model has another upper level low moving through the CWA. Thus confidence is low in the forecast for early next week at this time.

- Forecast Confidence & Scenarios: The main concern today is the additional rainfall over North Central MT that might lead to additional flood statements. For now, most areas will receive less than 0.50 inches of rainfall, with Glacier County possibly receiving another inch.

For Thursday, the potential for severe storms looks to be limited to just the far eastern portions of the CWA, as the upper level trof is now progged to move through the CWA a bit earlier in the day. Brusda

AVIATION

02/12Z TAF Period

Periods of rain will affect North Central MT today, with showers becoming more isolated as you go southward through Southwest MT. Some morning fog could affect portions of Southwest MT. Showers will be on the decrease overnight over North Central MT. Mountains/passes will be obscured over North Central MT through the period. Brusda

HYDROLOGY

A flood advisory has been issued for a portion of Glacier County. Generally it is the southwestern portion of the county. 2 to 3 inches of rainfall have fallen in the area over the past few days, with up to another inch possible by later today.

The main concern right now is Badger Creek and Two Medicine River south of Browning. Both streams are near/at bankful and water could start going over its bank at any time.

Further north, the St Mary River from Babb to US/Canadian border continues to rise, but it is expected to remain below flood stage, thus no statement will be issued at this time for this river.

Elsewhere, Cascade, Teton and Pondera counties reported no flooding as of early this morning. Some creeks are near bankful, but are not expected to exceed bankful at this time, thus no flood statements for these counties at this time. Brusda

PRELIMINARY POINT TEMPS/POPS

GTF 56 42 68 46 / 100 10 10 20 CTB 50 37 65 43 / 100 20 0 10 HLN 62 42 74 49 / 50 10 0 30 BZN 65 38 75 44 / 10 10 0 20 WYS 65 31 73 38 / 0 0 0 0 DLN 68 38 76 45 / 0 10 0 10 HVR 55 40 68 42 / 100 50 20 0 LWT 56 37 67 42 / 70 10 0 10

TFX WATCHES/WARNINGS/ADVISORIES

Flood advisory issued for portions of Glacier County.