687
FXUS65 KGGW 300838
AFDGGW

Area Forecast Discussion
National Weather Service Glasgow MT
238 AM MDT Tue Apr 30 2024

.DISCUSSION...

KEY MESSAGES:

- Rain will move northeast across NE Montana this morning and exit
  to the north this afternoon.

- Strong west winds develop this morning with gusts to 40 to 50
  mph possible south and 30 to 40 mph north. Lake Wind Advisory is
  in effect for Fort Peck Lake.

- Low RH south of MT200 today will create critical fire weather
  mainly in the southeast.

- Cooler temperatures and frequent chances for precipitation
  continues for the rest of the week.


WEATHER PATTERN OVERVIEW:

A slow moving upper level low will be along the Montana/Canada
border until Friday. Look for cool temperatures with frequent
chances for precipitation. Strong west winds are expected today
but wind speeds will remain below High Wind Warning criteria of 40
mph sustained with gusts to 58 mph.

The strong winds and RH as low as 20 percent will create critical
fire weather in the southern portion of FWZ 122 (Dawson, Prairie,
and Wibaux Counties) which received little or no rain overnight.
While FWZ 136/137 (CMR Refuge, Fort Peck Lake, Southern Petroleum
and Southern Garfield Counties) will also have low RH, that area
received wetting rain overnight. Will keep FWZ 136 and 137 out of
the Red Flag Warning and limit the Warning to FWZ 122.

A dry slot moves in during the day today as the rain moves to the
north. The dry slot will remain over the area tonight with mainly
dry weather.

An upper trough will rotate around the south side of the upper low
across Montana Wednesday and Wednesday night. This will bring
more rain mixed at times with snow to NE Montana Wednesday night
and Thursday. Precipitation chances continue on Friday as the low
moves to the east.

Upper ridge this weekend will allow for mainly dry weather and
warmer temperatures. The next trough/low is expected early next
week.
CONFIDENCE AND POTENTIAL DEVIATIONS FROM BASE FORECAST:

High confidence on the rain moving to the northeast today and the
dry slot moving in with gusty west winds today.

Moderate confidence of more precipitation moving in during the day
on Wednesday and continuing through Thursday. Low confidence of
precipitation amounts in some variation showing up in the
ensembles.

Moderate confidence on the dry weather this weekend. There is
uncertainty in the timing of the weather system early next week at
this time.


&&

.AVIATION...

LAST UPDATED: 0820Z

FLIGHT CAT RANGE: IFR-MVFR-VFR this morning, VFR this afternoon
and tonight.

DISCUSSION: Showers and low clouds this morning will bring a
variety of flight conditions to the TAF sites. The low clouds
clear in the late morning or early afternoon with either mid
level clouds or mostly clear skies expected this afternoon and
evening. Mostly clear skies are expected late tonight.

WIND: West to NW 10 to 20 knots early increasing to 20 to 30 knots
this morning with gusts to 40 knots continuing through this
afternoon. West winds diminish to 5 to 10 knots late tonight.



&&

.FIRE WEATHER...

Showers will move to the northeast this morning.
Gusty west winds 20 to 35 mph with gusts 40 to 50 mph will develop
this morning. Skies will clear south MT 200 this morning with
a sharp drop in humidity values. The southern part of Fire Weather
Zone is expected to have critical fire weather conditions today.
Will issue a Red Flag Warning from 11 am to 8 pm today for Fire
Weather Zone 122 which includes Prairie, McCone, Dawson, Richland
and Wibaux Counties.

While Fire Weather Zones 136 (Fort Peck Lake and CMR Refuge) and
137 (Southern Petroleum and southern Garfield Counties) will also
have strong west winds and low RH, that area received wetting
rain overnight so no warning will be issued there.

&&

.GGW WATCHES/WARNINGS/ADVISORIES...
Lake Wind Advisory until 9 PM MDT this evening for Central and
Southeast Phillips-Central and Southern Valley-Garfield-McCone-
Petroleum.

Red Flag Warning from 11 AM this morning to 8 PM MDT this
evening for Dawson/McCone/Prairie/Richland/Wibaux Counties.

&&

$$

weather.gov/glasgow