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KEY MESSAGES

- Warm, dry, and breezy today. A Red Flag Warning is in effect for areas east of HWY 24.

- A cold front arrives tonight to bring much cooler temperatures and isolated rain showers through Monday.

- Another slow warm up is expected by midweek with mostly dry conditions maintained.

DISCUSSION

WEATHER PATTERN OVERVIEW:

Synoptic upper ridging will allow for large scale subsidence and much warmer than average temperatures today. A cold front arriving tonight brings particularly warm/dry/breezy conditions ahead of it, with some prefrontal warming bringing highs as warm as the lower 80s.

After the cold front arrives tonight, a northwest flow aloft will bring much cooler highs in the 40s and 50s Monday with scattered showers (mostly virga for some). As another upper level ridge expands eastward, the pattern will rebound temperatures to seasonably warm levels with a continuation of limited moisture available for precipitation.

FORECAST CONFIDENCE & DEVIATIONS:

Increased winds/gusts through Monday to reflect expected enhancement from northwest flow and frontal passage. Also, increased temperatures and lowered RH accordingly today to counter recent NBM bias. There is high confidence some lower elevations to reach 80 degrees this afternoon with RH nearing 10 percent. Confidence is moderate or average for the extent of warming and further drying later this week based on advancement of upper ridging to the west.

-JEZ

AVIATION

LAST UPDATED: 0700Z

FLIGHT CAT RANGE: VFR

DISCUSSION: Dry weather with FEW to SCT mid to high level clouds today, then more overcast skies will develop tonight with isolated rain showers behind a cold front.

WIND: Increasing through the morning out of the west, becoming northwest at 20 to 25 kts gusting to 35 kts after 18Z.

FIRE WEATHER

Elevated to critical fire weather is expected today as winds across the eastern zones combine with fuels that are very dry from severe lack of precipitation this spring and a number of recent days with RH in the teens.

A cold frontal passage this evening will be preceded by mostly sunny and very dry conditions with widespread RH in the teens and temperatures as high as the lower 80s. This combined with a record dry year so far for some areas along the North Dakota border such as Sidney and forecast ERCs to near the 97th percentile supports critical fire concerns as winds increase this afternoon. A Red Flag Warning covers this area in zones 120 and 122. The wind is particularly concerning in the northeast with around 25-30 mph sustained likely for a period in the Plentywood area. Elsewhere, there will definitely be elevated fire weather today, just not as strong of winds or receptive fuels as the warned area. Much cooler conditions follow Monday while winds remain gusty out of the northwest, while there is near zero chance of a wetting rain from isolated rain showers.

Looking ahead, while another upper level ridge is favored to develop later this week, there is less concern at this time of stronger winds to develop coinciding with a dry pattern and RH down in the teens.

-JEZ

GGW WATCHES/WARNINGS/ADVISORIES

Red Flag Warning from 10 AM this morning to 9 PM MDT this evening for Dawson/McCone/Prairie/Richland/Wibaux Counties-Fort Peck Reservation and Daniels/Roosevelt/Sheridan Counties.