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KEY MESSAGES

- Much warmer and drier weather conditions will be the main focus for NE Montana now through Wednesday afternoon.

- Thunderstorms are expected later Wednesday evening.

- A strong cold front will bring much colder conditions and gusty winds, along with some accumulating snow near and north of US- Highway 2.

DISCUSSION

WEATHER PATTERN OVERVIEW:

The forecast for NE Montana over the next several days will be highly variable with strong swings in temperatures, precipiation amounts, and precipitation types. The 500-mb height field is characterized by a strong ridge of high pressure through the eastern Rockies and High Plains regions today through Wednesday. This is expected to bring near record high temperatures to many locations through Wednesday.

Later on Wednesday, an approaching strong low pressure storm system from the Great Basin and the Northern and Central Rocky Mountain Regions will provide enough of an unstable atmosphere to allow efficient rain showers and thunderstorms to develop. Convective outlook from SPC continues with just general thunderstorms, however the large temperature/dewpoint spread could support strong wind gusts. The limiting factor may actually be too large a T/Td spread, with the warm front lifting through during the day, and low level winds turning to a drier southwest direction.

Fire weather concerns are also increased with the dry and warm conditions especially on Wednesday. Greenup is underway and current timing of features suggest the strongest winds will come with quickly falling temperatures and rising RH on Wednesday evening.

As the system winds up and matures over our region, a strong cold front will sweep down from Saskatchewan and change some of the expected rain fall over to a rain/snow mix on Thursday.

By Thursday evening and through most of the upcoming weekend, behind this strong cold front, temperatures will be cold enough to allow for a complete change over to all snow, especially near and north of the Hi-Line. Gusty winds associated with this low pressure center will easily be sustained in excess of 30 mph with gusts in excess of 40 mph. Forecast will chills through this time range from 10 to 20 degrees above zero.

Overall, total precipitation is expected to be anywhere between 0.50 and 0.75 inch. Snowfall could be 1 to 3 inches for some favored northern locations.

FORECAST CONFIDENCE & DEVIATIONS: Blended NBM90 for winds through Thursday. Blended NBM75 with Max temp for today and Wednesday as we are expecting pre-frontal compressional warming.

AVIATION

VFR. Dry weather and high clouds are expected throughout the cycle ahead of the next low pressure system that will lower flight conditions by Thursday.

GGW WATCHES/WARNINGS/ADVISORIES

None.