textproduct: Glasgow

KEY MESSAGES

- Very warm, dry, and breezy conditions today will raise fire weather concerns for areas generally south of the Missouri River. Red Flag Warning continues through 8 PM tonight.

- A chance for showers or an isolated thunderstorm late tonight, especially along the Canadian border.

- A more active and wetter weather pattern is expected for the week ahead with shower and thunderstorm chances to increase.

- Cooler temperatures by the middle of next week.

DISCUSSION

WEATHER PATTERN OVERVIEW:

Upper ridging remains firmly established over the western U.S. for today as a surface low pressure system tracks across southern Montana. This will lead to warm temperatures, low humidity, and breezy conditions, with a Red Flag Warning in effect for locations south of the Missouri River until 8pm.

An initial shortwave looks to flatten the ridge late tonight into tomorrow morning with a shower or thunderstorm along the Canadian border, and continues along the MT/ND Border later in the day. Zonal flow with various shortwaves look to continue at times through the remainder of the week as a trough begins to set up over the Pacific Northwest. This will lead to cooler temperatures but more active chances for showers and thunderstorms each day.

FORECAST CONFIDENCE & DEVIATIONS:

Lowered day 1 RH blending in ADJMAV, increased HiRes guidance for winds using Fv3 and wind gusts using NBM90, as well as hand edits to better match with neighbors. Continued using HRRR for day 1-3 smoke/haze.

AVIATION

LAST UPDATE: 1830Z.

FLIGHT CAT RANGE: VFR.

DISCUSSION: Clear skies through the early evening, increasing to SCT - FEW mid clouds overnight. Haze from upstream wildfire smoke will be present but not enough to restrict visibility.

WIND: Frequent wind shifts through the TAF period. Light winds between 5 and 15 kts this afternoon, shifting northeast to east tomorrow mid morning as low pressure tracks through and increasing to a range of 10 to 20 kts with occasional stronger gusts. Winds return NNW in the afternoon tomorrow.

FIRE WEATHER

Critical fire weather conditions continue today with warm temperatures, min RH values between 10 and 20%, and developing frequent wind shifts with speeds ranging from 10 to 20 mph with gusts to 30 mph. A Red Flag Warning remains in effect for FWZs 122, 135, 136, and 137 until 8 pm today. While breezy conditions are likely to continue Saturday night, relative humidity readings are likely to recover, resulting in improving fire weather conditions.

GGW WATCHES/WARNINGS/ADVISORIES

Red Flag Warning until 8 PM MDT this evening for Dawson/McCone/Prairie/Richland/Wibaux Counties-Southern Petroleum and Southern Garfield Counties-The Little Rockies-The Lower Missouri River Breaks including the Charles M Russell National Wildlife Refuge.