textproduct: Glasgow

KEY MESSAGES

- Hot temperatures continue though at least Friday with highs in the mid 80s to low 100s. A Heat Advisory is in effect for today and Wednesday for most parts of the area as a result. - Gusty southeast winds starting today will lead to critical fire weather in areas of dry fuels in the east and a hazard to small craft on Fort Peck Lake.

- Isolated thunderstorms are expected by Tuesday evening, with additional chances through the week. Some of the storms could be strong, with isolated severe gusts for today.

DISCUSSION

WEATHER PATTERN OVERVIEW: Temperatures are expected to climb into the 90s and low 100s as an upper ridge sets up from now through Friday. The lowest temperatures will be in the locations with the highest elevations, or in a river if you feel like swimming. There will be sufficient heating and enough moisture at the surface to help generate isolated thunderstorms this afternoon, mainly between 3 PM and 10 PM. The most likely threat is strong winds up to 60 mph since a wide dewpoint depression (around 45 degrees) is expected. There will be low wind shear (less than 30 knots from 0 to 3 km) in the environment, so any storm that occurs will likely just spread out in all directions as it hits the ground and will not move in any particular direction. There is a chance of thunderstorms like these in the southwest part of the area as well. Wednesday and Thursday are expected to be similar to today, with most convection confined to the western part of the area though. There is critical fire weather, strong winds over Fort Peck Lake, and intense heat over the area the next few days, so various weather products have been issued for all these hazards.

For Saturday, high PWAT values (1 to 1.3 inches) are expected in the atmosphere over the area, so thunderstorms that occur this day will be prone to heavy downpours. So far, the deterministic GFS has these values dropping back down below one inch by Sunday afternoon. Overall, there are at least isolated thunderstorms possible each day through June 3rd, and temperatures will drop into the 70s and 80s for highs thankfully.

FORECAST CONFIDENCE & DEVIATIONS: Only deviation was to increase PoPs to reflect CAMs through late Tuesday evening.

There is high confidence in temperatures hitting the 100 mark through Friday for at least a few locations. Low temperatures will struggle to drop below the mid 60s as well, so adequate water intake will be important.

There is moderate confidence in thunderstorms bringing strong wind gusts to a few locations today, and low confidence for these type of gusts on Wednesday. There is moderate to high confidence in isolated to scattered thunderstorms occurring somewhere in the area from Thursday through early June.

There is high confidence in the Red Flag Warnings, the Heat Advisories, and the Lake Wind Advisory products.

AVIATION

LAST UPDATED: 0630Z.

FLIGHT CAT RANGE: VFR, MVFR possible in the afternoon.

DISCUSSION: Some high clouds will move through the area during this TAF cycle. Northeast Montana will be on the edge of an upper trough starting tomorrow, so there is low to moderate confidence of isolated thunderstorms bringing erratic winds and brief MVFR conditions from 21Z today through 01Z Wednesday.

DENSITY ALTITUDE: Will be high due to near 100 degrees temps creating thinner air in the afternoons through Thursday. Temperatures of around 104 are expected to occur near KOLF.

WIND: Southeast at 6 to 15 knots, increasing to 15 to 25 knots with gusts to 35 knots after 18Z.

LLWS: South to southeast at 40 knots through 14Z with wind heights around 1900-2000 feet.

EQUIPMENT: KSDY obs are unavailable and will be AMD NOT SKED.

GGW WATCHES/WARNINGS/ADVISORIES

Lake Wind Advisory from 9 AM this morning to 6 AM MDT Thursday for Central and Southeast Phillips-Central and Southern Valley- Garfield-McCone-Petroleum.

Heat Advisory from noon today to 9 PM MDT this evening for Central and Southeast Phillips-Central and Southern Valley- Daniels-Dawson-Eastern Roosevelt-Garfield-McCone-Northern Phillips-Northern Valley-Petroleum-Prairie-Richland-Sheridan- Western Roosevelt-Wibaux.

Heat Advisory from noon to 9 PM MDT Wednesday for Central and Southeast Phillips-Central and Southern Valley-Daniels-Dawson- Eastern Roosevelt-Garfield-McCone-Northern Phillips-Northern Valley-Prairie-Richland-Sheridan-Western Roosevelt-Wibaux.

Red Flag Warning from noon today to 9 PM MDT this evening for Dawson/McCone/Prairie/Richland/Wibaux Counties-Fort Peck Reservation and Daniels/Roosevelt/Sheridan Counties.

Red Flag Warning from noon to 10 PM MDT Wednesday for Dawson/McCone/Prairie/Richland/Wibaux Counties-Fort Peck Reservation and Daniels/Roosevelt/Sheridan Counties.