textproduct: Glasgow

KEY MESSAGES

- Tuesday morning will be cold across northeast Montana, with chances for near record lows if clouds clear out overnight.

- Warm weather returns mid week. The next chance for showers returns Wednesday.

DISCUSSION

WEATHER PATTERN OVERVIEW:

A strong upper trough will keep cool conditions through tonight before weakening and allowing temperatures climb closer to normal by Wednesday. Tonight low temperatures look to drop below freezing with clearing skies and light wind. With these cooler temperatures, make sure to protect sensitive vegetation.

By mid week upper level ridging over the west coast will allow quick moving shortwave troughs to sneak through the overall quasi- zonal flow, bringing some isolated thunderstorm chances through the end of the week. The best chance for thunderstorms will be Wednesday. Model plumes continue to suggest weak instability in the ~300 J/kg MLCAPE range during Wednesday evening. GEFS forecast RH and dewpoint for Wednesday evening continue to rise.

FORECAST CONFIDENCE & DEVIATIONS: No changes to NBM.

AVIATION

LAST UPDATED: 1900Z

FLIGHT CAT RANGE: MVFR-IFR through daytime. MVFR-VFR by Tuesday.

DISCUSSION: Overcast conditions with isolated rain showers will persist over the region through the afternoon and evening. Clouds begin to clear out sometime overnight from west to east, and any clouds that do remain should be right around the MVFR threshold. Temperatures could be below freezing for many locations Tuesday morning.

WINDS: Winds will be north to northwest through this evening at 10-15kts. By close to midnight, expect a transition to light and variable winds which should remain through midday Tuesday.

Cliff

GGW WATCHES/WARNINGS/ADVISORIES

None.