040 FXUS65 KGGW 080220 AFDGGW Area Forecast Discussion National Weather Service Glasgow MT 820 PM MDT Mon Apr 7 2025 .DISCUSSION... KEY MESSAGES: 1) Scattered light rain showers will move into the region from the west overnight. 2) Gusty west to northwest winds Tuesday and Wednesday afternoon and evening will impact early season recreation out on Fort Peck Lake. A Lake Wind Advisory for Fort Peck Lake has been issued for Tuesday from 10 am to 8 pm. WEATHER PATTERN OVERVIEW: Evening update: Short term models this evening are showing higher wind speeds for Tuesday afternoon. The RAP and HREF Grand Ensemble are showing west winds 15 to 30 mph over the western half of the forecast area which is strong enough to issue a Lake Wind Advisory for Fort Peck Lake. The main update to the forecast will be to increase wind speeds on Tuesday. Previous Discussion: Upper ridging will give way to the upper trough off the Pacific Northwest moving onshore. The next round of light rain showers looks to occur tonight and Tuesday, with total QPF amounts remaining under 0.10" for most places. On Tuesday afternoon, gusty winds and low RH may elevate fire weather concerns for a time but not for widespread or prolonged enough exposure to merit issuing headlines at this time. HREF and NBM show CAPE/Shear profiles supportive of an isolated thunderstorm or two on Wednesday. The main concern operationally will be developing west to northwest winds ranging from 15 to 25 mph with gusts to 35 or 40 mph, resulting in the potential for the First Lake Wind Advisory for the season for Fort Peck Lake. Upper ridging will resume warm and dry conditions over the region late week before the next rough arrives for the weekend. FORECAST CONFIDENCE & DEVIATIONS: NBM was used for much of the forecast period, but NBM 90 was blended in for Tuesday afternoon. Confidence is high on gusty weather conditions for a time that afternoon with more widespread gusty west winds on Wednesday. Lower confidence exists on showers tonight and Tuesday as well as thunderstorm potential on Wednesday given marginal support and isolated coverage. && .AVIATION... VFR conditions will prevail into tonight though lower ceilings will move in this evening from the west. Showers are also possible overnight and Tuesday. SE winds 5 to 15 knots tonight will become west Tuesday morning and increase to 15 to 25 knots Tuesday afternoon. && .GGW WATCHES/WARNINGS/ADVISORIES... Lake Wind Advisory from 10 AM to 8 PM MDT Tuesday for Central and Southeast Phillips-Central and Southern Valley-Garfield- McCone-Petroleum. && $$ weather.gov/glasgow