textproduct: Glasgow

KEY MESSAGES

- Hot temperatures with highs in the 90s west and north and 100 to 105 east are expected today. A Heat Advisory is in effect today for parts of the east where highs of 100 to 105 are expected. - Isolated to scattered storms are expected this afternoon through Thursday night SPC has a Slight Risk of severe storms in the east today and a Marginal Risk in all areas Thursday.

- Thursday will be not as hot but the heat returns Friday and Saturday with upper ridge. Saturday is expected to be the hottest day before a strong cold front Saturday night bring cooler temperatures Sunday and Monday.

DISCUSSION

WEATHER PATTERN OVERVIEW:

Upper ridging over the western U.S. will remain in place in varying degrees through at least Saturday. Hot weather will continue into the weekend. Today will be somewhat hotter with many areas in the east between 100 and 105 for highs and heat impact reaching into major in some of the 100+ areas. Will issue a Heat Advisory for several zones in the east today.

Smoke from western Montana and Pacific NW wildfires will continue to be over the area today and tonight with unhealthy air quality at times and variable visibility.

Weak waves will move through the ridge at various times through Thursday night with chances for showers and thunderstorms over parts of the region. Models are showing increased instability and higher dew points this afternoon and evening with a cool front moving through that could lead to a few severe thunderstorms. SPC has a slight risk mainly east of the Yellowstone River today with a threat of large hail and damaging winds. Additional chances for showers and thunderstorms continue late tonight through Thursday night over eastern Montana with a surface low over the area.

High on Thursday will be 5 to 10 degrees lower before the ridge strengthen Friday and Saturday. At this point, Saturday looks like it will be very hot with highs above 100 in most areas.

Ridge moves east Saturday night and upper trough moves for Sunday and Monday. A strong dry cold front on Sunday is expected to bring gusty NW winds followed by much cooler temperatures on Monday.

FORECAST CONFIDENCE & DEVIATIONS:

High confidence in the hot weather continuing through Saturday. Low confidence in timing any showers and thunderstorms.

Deviated from the NBM to tweak pops at times this afternoon through Thursday to provide better hour to hour consistency and better match SPC Outlooks for convection.

AVIATION

FLIGHT CATEGORY: VFR - MVFR.

DISCUSSION: Upper ridging will continue to provide hot temperatures to the region. Smoke and haze will impact visibility through the TAF period with MVFR conditions possible at times. There will be varying amounts of mid and high clouds across the region today and tonight. A cold front will bring chances for showers and thunderstorms this afternoon and tonight with strong and erratic winds possible.

DENSITY ALTITUDE: Increased density altitude is expected today with temperatures near or over 100 in the afternoon and evening. Extra power and longer runway will be needed for takeoffs.

GGW WATCHES/WARNINGS/ADVISORIES

Heat Advisory from 11 AM this morning to 7 PM MDT this evening for Dawson-Eastern Roosevelt-McCone-Prairie-Richland-Western Roosevelt-Wibaux.