Area Forecast Discussion

DISCUSSION

KEY MESSAGES:

- Patchy fog expected Sunday morning.

- Warm, dry week ahead for the region.

- Showers return late next week or early next weekend.

The recent rainfall combined with decreasing cloud cover and stable conditions the next few days will cause patchy fog in many of the valleys of central Idaho and western Montana Sunday morning. The fog is expected to clear out by Sunday afternoon due to drier air from aloft mixing down in the afternoon.

As the cutoff low over the region moves out, another is moving into the U.S. West Coast and heading south of the desert southwest. There's also a broad trough established across the northern Pacific Ocean. The two features combined will setup a southwest, split flow pattern into the northern Rockies region. As a result, the region will see warm and mild conditions most of the week. Afternoon temperatures will be about 10 degrees above season averages with light winds and partly cloudy skies.

As the broad trough over the northern Pacific starts to progress eastward, it will start to bring showers back to the region late next week or early next weekend. With the southwest flow pattern, the snow levels will remain very high and mountain snow isn't a concern yet, however, as we get into the week after if the trough continues to progress eastward it would bring some cooler air into the region. So the bottom line is expect a warm, mild week with some showers moving in next weekend and the potential for more mountain snow a week or more away.

AVIATION

Recent rain fall combined with stable conditions will cause some patchy fog across the region Sunday morning. Terminals KMSO, KHRF, and KSMN are most likely to be impacted. Some patchy fog near terminal KGPI is also possible due to the high dew points, though they did not receive any precipitation in the last 24 hours, so much less coverage is expected there. Otherwise, warm and mild conditions are ahead for the next week.

MSO WATCHES / WARNINGS / ADVISORIES

MT...None. ID...None.