Area Forecast Discussion
Issued by NWS Glasgow, MT
Issued by NWS Glasgow, MT
954 FXUS65 KGGW 021513 AFDGGW Area Forecast Discussion National Weather Service Glasgow MT 913 AM MDT Thu May 2 2024 .DISCUSSION... Not too much to update this morning. Will be addressing rainfall expected early next week with probabilities/amounts trending up with each model run. TFJ Previous Discussion... KEY MESSAGES: - *** Winter Weather Advisory remains in effect for the higher elevations of the Little Rocky Mountains in southwest Phillips County through 4 PM Friday. - Cold front this morning brings rain and snow showers with isolated thunderstorms. The chances for rain and snow showers continue through Friday. - Northwest winds 15 to 25 mph today will result in a Lake Wind Advisory for Fort Peck Lake. - Nighttime temperatures will drop below freezing in many areas tonight through Friday night. - Another round of rain showers are expected next week, starting late Sunday. Some places could receive an inch or more of rain Monday through Wednesday. WEATHER PATTERN OVERVIEW: A slow moving upper level low pressure system near the US/Canada border will finally lift northeast away from the area late Friday. This will allow for a break in the action before another upper low moves in on Sunday. Look for rain and snow showers and isolated thunderstorms to move into NE Montana this morning. It will be a cool day, and cool enough that snow levels will lower for mostly snow in the Little Rockies of southwest Phillips County, and a mix of rain and snow showers over the remainder of Phillips and along the Canadian Border today. Temperatures will be cold enough tonight and Friday morning for snow showers in most areas. Areas along the Canadian Border could see up to an inch of snow through Friday while higher elevations of the Little Rockies could see up to 5 inches of snow. Upper ridge moves through the area on Saturday with dry and warmer weather. Sunday will be the warmest day as the ridge moves to the east and the next system approaches from the west. This next system moves in from the west Sunday night and becomes a stacked low over the region on Monday. Models and EC/GFS/CMC ensemble mean have decent agreement in the low meandering along the Montana/Dakota border on Tuesday before weaken into an upper trough on Wednesday. It will be a widespread rain event that could last several days. Probability of at least one inch of rain between Sunday night and Wednesday is 40-60% at this point and the probability of at least 2 inches of rain is 10-30%. CONFIDENCE AND POTENTIAL DEVIATIONS FROM BASE FORECAST: Confidence is high on the showers behind the cold front today but whether it will be rain or snow showers at a given point and time will depend on temperatures. High confidence on 2-5 inches of snow in the Little Rockies today through Friday. Low confidence on the possibility of thunderstorms today and snow accumulations outside of the Little Rockies. Medium confidence the rain/snow showers continuing through Friday. High confidence on the dry weather on Saturday and rain that starts Sunday night and lingers through at least Thursday. Lower confidence on rainfall amounts. && .AVIATION... LAST UPDATED: 1515Z (9:15 AM) FLIGHT CAT: VFR early, becoming MVFR/IFR this morning at KGGW and KOLF, and becoming a mix of VFR-MVFR this afternoon and evening at KSDY and KGDV. A mix of MVFR-IFR late tonight. DISCUSSION: A cold front will move through the area this morning. A mix of rain and snow showers are expected today and tonight with low clouds that will vary from MVFR-IFR at KGGW and KOLF and low VFR to MVFR at KSDY and KGDV. Thunderstorms are possible again at times today and this evening. Isolated to scattered snow showers are expected tonight and Friday. WIND: From the west and southwest at 5 to 10 kts early. Then from the northwest at 15 to 20 kts during the afternoon and evening hours, and northwest 5 to 15 kts late tonight. && .GGW WATCHES/WARNINGS/ADVISORIES... Lake Wind Advisory until 8 PM MDT this evening for Central and Southeast Phillips-Central and Southern Valley-Garfield-McCone- Petroleum. Winter Weather Advisory until 4 PM MDT Friday for Southwest Phillips. && $$ weather.gov/glasgow