textproduct: Glasgow

.KEY MESSAGES

- Fairly quiet weather is expected today, and precipitation chances begin early tomorrow morning and go through Tuesday.

- An isolated severe storm is part of the story tomorrow into tomorrow night. - The most significant rainfall totals are expected to occur on Sunday night into Monday.

DISCUSSION

WEATHER PATTERN OVERVIEW: A cold front has brought temperatures down a bit today, and some low to mid level clouds have helped keep it cooler as well. The trend toward cooler temperatures is expected through Tuesday as the main Pacific trough makes its way in. The rainfall totals have decreased a tad for Sunday through Tuesday, but the overall pattern continues to show rainfall amounts over half an inch in the north up to 1.6 inches; this area includes Phillips, Valley, Daniels, Sheridan, and Roosevelt counties. Garfield, Petroleum, McCone, Dawson, Richland, Wibaux, and Prairie counties are suggested to see a few hundredths up to 1 inch. The southeast counties have the lowest forecast rain amounts. Most of the rain is expected to occur on Sunday night.

An airmass on the humid side is expected to move in from the east tomorrow to bring showers and isolated strong thunderstorms to the area. SPC has a marginal risk of severe weather that may be upgraded to a slight risk at some point.

Although there is some uncertainty on how much wind there will be as the system departs to the east, strong winds with gusts over 45 mph appears likely for the entire area on Tuesday. This is because as the Fall season makes its way in, the polar jet stream typically starts strengthening again. Increases in differential heating (difference between cold and warm air) occur as temperatures in the north decrease, especially with shorter days and lower sun angles. If you are interested, a few terms used in meteorology are geostrophic wind, ageostrophic wind, and thermal wind. Each one has a specific meaning and are helpful in understanding weather systems. Anyway, a lake wind advisory will most definitely be needed for Monday night into Tuesday.

FORECAST CONFIDENCE & DEVIATIONS: Made slight increase in PoPs through tomorrow morning.

There is moderate to high (50 to 80 percent) confidence in rain amounts from Sunday through Tuesday, and winds for Tuesday.

There is low confidence in the location of severe thunderstorm activity tomorrow evening into the overnight.

AVIATION

LAST UPDATED: 1830Z

FLIGHT CAT RANGE: VFR - MVFR

DISCUSSION: Surface moisture that has moved in from the east has aided in low cloud development at MVFR levels this afternoon. There is moderate confidence these clouds will persist through 00Z before dissipating. Southwest flow aloft will help bring in some upper level moisture, so rain and thunderstorm chances are expected to move in tonight after 09Z for all sites. There is moderate to high confidence of MVFR conditions at times after 09Z through the day tomorrow.

WINDS: North to northeast at 7 to 16 knots.

GGW WATCHES/WARNINGS/ADVISORIES

None.