textproduct: Glasgow

KEY MESSAGES

- Gusty chinook winds expected today, with west to northwest wind gusts as high as 60 mph over the Little Rockies.

- The next cold front will drift through the area tonight with rain/snow chances and rapidly falling temperatures. A Winter Weather Advisory for 1-3 inches is in place over the Little Rockies.

- Another chinook with strong winds followed by a cold front is Expected Wednesday night into Thursday.

DISCUSSION

WEATHER PATTERN OVERVIEW: Synoptic Setup: Forecast begins with a weak ridge over the northern Plains and southern Canadian Prairie Provinces embedded in otherwise zonal flow. The nose of this ridge has dipped off the front range to generate a Chinook down the Plains through today which is butting up against a cold frontal boundary at the International Border.

Today: Strong gusty winds will be in charge for today with higher than normal temps courtesy of downsloping from the chinook. The front itself has already moved a little south of the international border and is providing a light inversion this morning in the far northeast which could lead to low level wind shear before sun-up when the inversion will be eaten away and wind shear disappears.

Tonight: As the chinook shuts off the cold front will advance south generating an area of lift just north of it which will begin wringing out rain transitioning to snow especially across the far west. Snow totals going into Monday Morning will reach upward and possible above 2 inches over the Little Rockies due to some upslope. Therefore a Winter Weather Advisory for snow was issued.

Monday through Wednesday: Cooler pacific airmass will press into the region for a cold start to Monday but should slowly warm/modify by Wednesday. Isolated chances for rain or snow are possible Tuesday afternoon and evening.

Wednesday night into Thursday: Another Chinook overnight followed by a cold front That afternoon is looking likely and a quick ridge/trough couplet moves through the region. Strong winds are already building themselves into the forecast and a persistent monitoring for possible High Winds is taking place over these time periods.

Friday onward: Post cold front it looks like a more Arctic airmass moves in rather than Pacific airmass. This will drop temps closer to normal for the area through the weekend.

FORECAST CONFIDENCE & DEVIATIONS: Deviations from NBM were focused on the first 30 hours with hourly PoPs being redone in a 33/33/33 blend of NPoP SREF, NPoP Consshort, NBM PPI01 to increase hourly totals. At the same time, WPC QPF was used over these same areas to show a more spread out gradient as well.

Confidence is HIGH in high winds across the Little Rockies today.

Confidence is MODERATE to HIGH for placement and totals for snow tonight.

Confidence is HIGH for another ridge/trough couplet to cause a chinook followed by a cold front mid to late work week. Though confidence is MODERATE to LOW in the exact timing.

GAH

AVIATION

LAST UPDATE: 0600Z

FLIGHT CAT RANGE: VFR - MVFR

DISCUSSION: A chinook will bring higher than average wind speeds through the cycle. Cloud heights and ceilings will begin dropping later this afternoon with isolated rain and then snow showers impacting the terminals around 00-02Z. This may reduce visibility briefly but currently is not expected to drop below MVFR. All snow should clear from the terminals by Monday evening if not earlier.

LLWS: Low level wind shear returns tonight from 02-16Z IF an inversion is able to set up at any given location. However, confidence in this is moderate, highest for KSDY and KOLF.

WIND: West at 10-15 gust 25 kts tonight. Slowly veering NW and increasing to 20-25 gust 35 kts after sunrise through Sunday afternoon. Further veering N and decreasing to 10 kts or less by midnight.

GAH

GGW WATCHES/WARNINGS/ADVISORIES

High Wind Warning until 9 PM MST Sunday for Southwest Phillips.

Winter Weather Advisory from 6 PM Sunday to 6 AM MST Monday for Southwest Phillips.