textproduct: Glasgow

KEY MESSAGES

- Elevated SE winds are anticipated Monday.

- There is potential for precipitation this week, with chances beginning overnight Thursday.

DISCUSSION

Zonal flow over Montana will gradually build into an upper-level ridge. Although minor perturbations moving through the flow will produce elevated SE winds Monday, primarily fair weather is anticipated through Wednesday.

By Thursday, an upper-level low off the coast of central California will meander eastward over the Great Basin, enabling the associated upper-level trough to begin digging over Montana. The combination of trough-driven frontogenesis and moisture advection will produce chances for precipitation beginning overnight Thursday.

As of the most recent NBM run, precipitation is anticipated to end by Saturday morning. However, model agreement deteriorates substantially beyond this point. Forecast confidence is uncertain through the end of the week.

FORECAST CONFIDENCE & DEVIATIONS:

- Confidence in weather conditions is moderate to high through Wednesday.

- Confidence in precipitation late this week is low.

- The GFS and ECMWF begin to exhibit significant discrepancies by Friday morning. Both indicate upper-level troughing persisting through Friday night, but orientation and strength vary.

DON

AVIATION

LAST UPDATED: 0530Z

FLIGHT CAT RANGE: VFR

Discussion: The weather will be largely benign over the next 24 hours. Expect fair skies with FEW/SCT clouds at various levels through the forecast period. A BKN ceiling is anticipated over KGGW this morning.

Wind: W-NW winds at 08 to 12 knots, with gusts to 20 kt at KSDY, diminish overnight, becoming light and variable by early this morning.

LLWS: Low level wind shear at all stations will diminish and cease early this morning.

GGW WATCHES/WARNINGS/ADVISORIES

None.