textproduct: Glasgow

KEY MESSAGES

- Today and tomorrow will be warm with above to much above normal temperatures.

- A cold front early Saturday will bring wind and a return to cooler, near normal temperatures this weekend.

- Gusty Winds are expected Friday afternoon ahead of the front and Saturday morning behind the front. A Lake Wind Advisory is in effect for these times.

DISCUSSION

Synoptic Setup: Forecast begins with a large ridge hot high pressure running from the Intermountain West into western Montana and a Trough of cooler pacific air dropping down from northern British Columbia to off the coast of the Pacific Northwest. Between these two features SW flow has setup with pacific moisture and minor disturbance ridding in from off the coast of Northern California to northern Idaho.

Today through Friday: Ridge moving over the area will provide for dry conditions and warm temperatures with highs in 80s. As the trough to the west approaches and high pressure exits east Friday the Pressure gradient will lend to gusty winds Friday afternoon out of the S to SE.

Friday night into Saturday night: This will last till the front moves through that evening and switches the gusts to the west to northwest. There is some question on to whether the gusts will sty up overnight behind the front leading to lower confidence. A Lake Wind Advisory has been issued from 8AM Friday morning 9AM Saturday morning for these gusts. Also, expect cooler temps with highs int he 60s from here onward.

Sunday through Monday: Current model data suggests a disturbance moving through southern/southeastern Montana on entering SW flow will generate some rain showers across the area as it passes through. An isolated thunderstorm may be possible during this time. Currently the bulk of QPF is over the Yellowstone Valley of the GGW CWA, but confidence is low as the track appears to be shifting SE and totals are lowering quickly with the last few forecasts.

Monday night onward: Forecast in general looks to become semi- zonal with a minor trough embedded in it. However, ensembles are in disagreement with strength which is reducing confidence in the forecast from here onward.

FORECAST CONFIDENCE & DEVIATIONS: No changes from NBM.

AVIATION

LAST UPDATED: 1800Z

FLIGHT CAT RANGE: VFR

DISCUSSION: Fog across the area has ended for the day. It is not expected to occur again tonight. Expect SKC to FEW mid to high clouds across the area through the majority of the cycle. mid level clouds will appear again from south to north Friday afternoon.

LLWS: There is a small chance(10-30%) for Low level wind shear across the area from 06-14Z tonight due to a developing Low Level Jet. This is too low of a chance to include in the TAFs directly.

SFC WIND: S or Variable at 5 to 10 kts through mid-morning Friday. Then turning S to SE and increasing to 5 to 15 kts late Friday Morning. Further increasing to 15 to 20 gust 35 kts in the afternoon Friday.

GAH

GGW WATCHES/WARNINGS/ADVISORIES

Lake Wind Advisory from 8 AM Friday to 9 AM MDT Saturday for Central and Southeast Phillips-Central and Southern Valley- Garfield-McCone-Petroleum.