textproduct: Glasgow

KEY MESSAGES

- Some isolated patchy fog is possible across the lowest valleys tonight. There is a decent chance of rain and weak thunderstorms in the northeast this afternoon and tomorrow afternoon. - A slow warm up is expected going into Thursday before a small trough comes in and drops some rain.

- Another system will arrive around Thursday night with ample rain possible behind it through the weekend. A severe cell or two may be possible with this activity.

DISCUSSION

WEATHER PATTERN OVERVIEW: A low pressure system will linger just northeast of the area through tomorrow afternoon, so there is chance of showers and weak thunderstorms in the northeast part of the area this afternoon and tomorrow afternoon. With the winds calming tonight, there is a low chance of fog forming in the lowest valleys from about 4 AM to 8 AM. A weak ridge will build during the day Thursday to bring temperatures up to normal before a shortwave trough moves through in the evening. The best chance for a wetting rain is in the south going into Friday morning, and some locations have potential to see totals reach the quarter to half inch range with thunderstorms.

On Friday, an upper trough is expected to affect the area. There is a high chance of a Lake Wind Advisory being needed on Friday afternoon into early Saturday night, and then again for Sunday and Monday. From Friday through Monday, there is a high likelihood of most locations reaching at least four tenths of an inch of rain. Although there is moderate to high uncertainty on higher amounts, there is a low chance of some locations climbing over two inches of rain. Strong winds on Monday will likely inhibit rainfall from accumulating very much that day.

To start out July, the latest GFS and ECMWF ensemble have temperatures climbing warmer than normal and precipitation coming down, so the sprinklers may start coming in handy again.

FORECAST CONFIDENCE & DEVIATIONS: Made deviations to the afternoon winds by increasing them for this afternoon and tomorrow afternoon. Also increased PoPs and moved them a little further southwest for today and tomorrow.

There is high confidence in scattered showers and weak storms occurring in the northeast today, and moderate confidence for the same setup tomorrow.

There is high confidence of a shortwave trough moving through on Thursday evening, and then an upper trough affecting the area with rain, thunderstorms, and wind from Friday through Monday. There is high confidence of at least 4 tenths of rain falling in this timeframe, with low to moderate confidence on higher amounts occurring.

There is high confidence a Lake Wind Advisory will be needed for Fort Peck Lake on Friday, Sunday, and Monday.

AVIATION

LAST UPDATE: 1830Z

FLIGHT CAT RANGE: Mostly VFR. Some scattered MVFR cloud ceilings.

DISCUSSION: A trough northeast of the area will continue to influence the area with scattered MVFR cloud ceilings. There is moderate to high confidence in this occurring through tomorrow morning. VFR conditions are expected after 18Z Wednesday. There is low confidence in fog formation tonight into the morning tomorrow.

WIND: Northwest at 10 to 20 knots, becoming north at 5 to 10 knots from 03Z to 06Z, decreasing to light and variable after 06Z, becoming northeast at 5 to 10 knots after 18Z Wednesday.

GGW WATCHES/WARNINGS/ADVISORIES

None.