719
FXUS65 KGGW 071102
AFDGGW

Area Forecast Discussion
National Weather Service Glasgow MT
502 AM MDT Tue May 7 2024

.DISCUSSION...

KEY MESSAGES:

- High Wind Warning remains in effect for most locations south and
  west of Fort Peck Lake. Strongest winds which could lead to
  damaging impact are expected through today. Crosswind concerns
  and dangerous chop on Fort Peck Lake are heightened.

- Widespread periods of moderate to heavy rain will persist
  through Wednesday night. A Hydrologic Outlook as been issued for
  the area receiving the heaviest rainfall.

- Flood concerns increasing for small streams Tuesday and
  Wednesday, leading to rises along the Milk River late in the
  week.

WEATHER PATTERN OVERVIEW:

The slow-moving strong spring storm system will sit and spin over
the northern Plains for the next several days. Most of the
associated heavy rain will last through Wednesday morning. By the
weekend, a flat ridge will push from the Pacific Northwest across
the northern Rockies.

CONFIDENCE AND POTENTIAL DEVIATIONS FROM BASE FORECAST:

Persistent wind gusts of 50-60 mph have been occuring across
southwest Phillips County with occasional gusts over 50 mph across
other portions of the Warning area. Still looking at winds coming
up a bit over the ridge tops after sunrise, so will continue with
the warning.

Rainfall amounts for the region for today through Wednesday night
remain very high. Probability for an additional half inch is over
70% for the entire region. Confidence for 1 inch or more drops
off to 30-50% east of Opheim, Poplar and Glendive while staying at
60-90% for most of the area to the west. Probability for more
then 2 inches is highest across southern Phillips county at 40-70%.

With the widespread high precipitation amounts, flooding will
become a concern from midweek into the weekend. Updated RFC river
point forecasts are showing sharp rises for the Milk River at
Tampico and Glasgow by the end of the week. Small stream flooding
and impassable gravel roads are also expected mainly for
Phillips, Valley and Garfield counties.



&&

.AVIATION...

PATTERN: The unusually strong and slow-moving spring storm
system, will continue to push wave after wave of moderate to heavy
rain across the area today. A region of dry air will slightly
diminish rainfall near the Montana/North Dakota border today
before slowly spreading westward through Wednesday.

FLIGHT CONDITIONS: MVFR conditions will persist through most of
this TAF cycle. IFR is possible in the bands of heaviest rainfall,
with rises to VFR under the push of drier air.

WINDS: Gusty west to northwest winds will persist today for KGGW
and KGDV with weaker winds to the northwest. Winds will diminish
this evening and turn north to northeast overnight.


&&

.GGW WATCHES/WARNINGS/ADVISORIES...
High Wind Warning until midnight MDT tonight for Central and
Southeast Phillips-Central and Southern Valley-Garfield-
Petroleum-Prairie-Southwest Phillips.

&&

$$

weather.gov/glasgow