textproduct: Glasgow

KEY MESSAGES

- A cold front will push east through the CWA this afternoon bringing gusty winds and rough conditions to Fort Peck Lake.

- Precipitation chances are expected over the northwestern half of the CWA this afternoon and evening. - Cooler and drier weather expected for the weekend continuing into early next week.

DISCUSSION

Today into Saturday: An upper low will begin to merge with a western Canada trough today. This will pull up Pacific moisture through the Desert SW while a surface low developing over southern MT and pulls NE, tracking showers across the western and northern CWA through Saturday morning. This will also allow NW winds to increase late today behind a cold front. The showers are expected to exit the CWA Saturday morning with significantly cooler high temps Saturday onward.

Rough conditions on Fort Peck Lake can be expected beginning this afternoon through Saturday afternoon. A Lake wind advisory has been issued for these times.

Rainfall amounts looked to be greatest over central Montana and the models have held steady since the last forecast run. Areas east of a line from Culbertson to Miles City are not expecting any QPF.

Saturday into Tuesday: Temps look to remain below to near normal as an upper ridge early next week moves east of the Pac NW.

Tuesday night onward: A trough swings through the Pac NW and become the focal point for newly developing showers mid week.

FORECAST CONFIDENCE & DEVIATIONS: NO changes to NBM.

High confidence on winds and temperatures this weekend. Moderate confidence on rain amounts through those periods.

Low confidence Tuesday onward where ensembles consensus breaks down. Expect many forecast changes from here onward.

/GAH

AVIATION

LAST UPDATED: 0430Z

FLIGHT CAT RANGE: IFR - VFR.

DISCUSSION: Increasing cloud cover is expected overnight with ceilings beginning to drop Friday afternoon due to the approaching storm. MVFR ceilings are expected to arrive Friday evening around 02-04Z and last through roughly 15Z Saturday morning. Rain will start around 00Z for KGGW first and last through the night expanding to the other terminals. Brief IFR ceilings will be possible near midnight/06Z, these may be accompanied by IFR visibility if rain transitions to snow around the same time at KGGW. Most other terminal should just expect rain.

WIND: East and light through Friday morning. Rapidly switching NW behind a front and increasing got 15 to 25 kts gust 40s kts Friday afternoon into the night. backing to the W and calming to 10 to 15 kts mid-day Saturday.

GAH

GGW WATCHES/WARNINGS/ADVISORIES

Lake Wind Advisory from noon Friday to noon MDT Saturday for Central and Southeast Phillips-Central and Southern Valley- Garfield-McCone-Petroleum.