textproduct: Glasgow

KEY MESSAGES

- Expect temperatures to continue a gradual warming trend into Tuesday.

- Isolated showers and thunderstorms may produce gusty winds Monday afternoon.

- A cold front is expected on Tuesday with additional afternoon and evening thunderstorms.

- Near average temperatures return late in the week.

DISCUSSION

WEATHER PATTERN OVERVIEW:

Upper level northwest flow will remain anchored over eastern Montana today and Monday. A shortwave will drop southeast on Monday with a chance for showers thunderstorms in the afternoon, especially near the MT/ND border. HREF max ensemble wind gust guidance suggest this convection may lead to the downward transfer of higher momentum air, leading to isolated wind gusts of 40 to 50 mph.

For Tuesday, a cold frontal passage will result in enough low level convergence and lift to initiate afternoon and evening showers and thunderstorms. Initial forecast soundings look moist, so steady rainfall could result from some of this and persist into the middle of the week, along with cooler temperatures. Increasing west to northwest winds Tuesday night into Wednesday may also lend support to a Lake Wind Advisory for Fort Peck Lake.

Ensembles point to a warm up toward more seasonable conditions late in the week as a Pacific ridge begins to come ashore and translate eastward over the Rockies and Northern High Plains.

FORECAST CONFIDENCE & DEVIATIONS:

Tweaks were made to pops for consistency and collaboration, otherwise NBM landed well for the forecast period. Additional adjustments remain possible for Monday into Tuesday as thunderstorm chances get captured by convection allowing models and mesoscale analysis becomes more readily available.

Overall confidence is high on a cool and wet midweek, but would point out below normal confidence on gusty winds with thunderstorms on Monday due to the isolated or limited coverage expected.

AVIATION

UPDATED: Sunday June 14 at 0630Z

FLIGHT CAT RANGE: VFR.

DISCUSSION: Mid and high level clouds from time to time will give way to mostly sunny skies this afternoon.

WINDS: Northwest winds will range from 10 to 15 kts during the day, diminishing in the evening.

GGW WATCHES/WARNINGS/ADVISORIES

None.