textproduct: Glasgow

KEY MESSAGES

- The next chance for isolated to scattered thunderstorms is expected this afternoon and Friday afternoon. Accumulation is possible in central Montana for Friday into Saturday.

- There are elevated to critical fire weather conditions expected in the eastern part of the area on Friday afternoon.

DISCUSSION

WEATHER PATTERN OVERVIEW: Northeast Montana is expected to remain situated between an upper trough and upper ridge. With cool 500 millibar temperatures expected to stay over the area through Saturday (around -20 Celsius) and northwest flow aloft, there is a low to moderate probability of thunderstorms occurring on Thursday and Friday. A cold front on Friday afternoon and shortwave trough are expected to move through central Montana to bring an opportunity for accumulating rain. So far the base NBM suggests a few hundredths up to a tenth of precipitation accumulation, with isolated higher amounts in the Little Rockies from Friday afternoon through Saturday afternoon.

There is very little accumulation of rain expected in the east part of the area on Friday, but the chance of thunder and passing front will make fire weather conditions a bit on the higher end based on the current forecast. We expect there to be low relative humidity and strong winds on Friday afternoon, and based on the fact it has been fairly dry there as of late, a Fire Weather Watch has been issued from noon Friday through 8 PM Friday for fire weather zone 120 and 122.

FORECAST CONFIDENCE & DEVIATIONS: Made deviations to bring PoPs up to around 50 percent for Thursday afternoon and Friday afternoon. Also dropped the relative humidity manually for Friday afternoon.

There is low to moderate confidence of thunderstorms occurring this afternoon and Friday afternoon, as well as precipitation accumulating a tenth of an inch of precipitation on Friday evening into Saturday morning west of Fort Peck Lake.

There is high confidence of critical fire weather conditions occurring on Friday afternoon for fire weather zones 120 and 122.

AVIATION

LAST UPDATED: May 7th at 0620Z

FLIGHT CAT RANGE: VFR - MVFR

DISCUSSION: The Glasgow county warning area is on the the edge of an upper trough, so mid to high cloud conditions will give way to scattered thunderstorms from 18Z Thursday to 03Z Friday. There is therefore moderate (40 percent) confidence of MVFR conditions occurring with these storms.

WINDS: Southeast at 5 to 13 knots, becoming northwest at 7 to 17 knots after 20Z Thursday, becoming light and variable after 03Z Friday.

GGW WATCHES/WARNINGS/ADVISORIES

Fire Weather Watch from Friday afternoon through Friday evening for Dawson/McCone/Prairie/Richland/Wibaux Counties-Fort Peck Reservation and Daniels/Roosevelt/Sheridan Counties.