Garrison, North Dakota 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

515
FXUS63 KBIS 261139
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
639 AM CDT Tue May 26 2026

.KEY MESSAGES...

- High temperatures about 20 degrees above average through the
  work week.

- Low shower/thunderstorm chances later this afternoon and
  overnight, otherwise mainly dry conditions through Friday.

- Critical fire weather conditions over far western North
  Dakota due to low humidity and gusty southeasterly winds.

&&

.UPDATE...
Issued at 638 AM CDT Tue May 26 2026

The isolated thunderstorm that moved through southwest North
Dakota very early this morning has now dissipated, with quiet
weather now in place. No changes needed at this time.


&&

.DISCUSSION...
Issued at 328 AM CDT Tue May 26 2026

Current surface analysis places low over the Northern Rockies
into the Great Basin, with high over Manitoba into the upper
Midwest. Upper level analysis places low along the Pacific
Northwest with ridging over our area, though a few weak waves
noted in the flow. Over our area, one of the weak waves has
produced a little weak convection over southwest North Dakota
in a narrow corridor of elevated instability. Expect this to
remain isolated and short lived.

For today, ridge in place will bring very warm conditions to the
area, with high temperatures running about 20 degrees above
average. Southeasterly winds will be on the increase given a
deepening surface low to the lee of the northern Rockies. This
will combine with low humidity values over far western North
Dakota to produce critical fire weather conditions (see Fire
Weather discussion below). Ahead of the aforementioned low a
boundary sets up over northwest through central North Dakota
late day into the evening, in line with an area of elevated
instability but little deep layer shear. This will bring low
shower/thunderstorm chances through the nighttime hours, but
severe threat remains limited given the lack of shear. With that
said, would not be surprised to see a few storms pulse up and
briefly approach severe limits.

As we go through the work week a rather similar pattern remains
in place with generally dry weather and high temperatures
continuing to hover around 15 to 20 degrees above average.

Latest guidance continues to bring question as to whether the
ridge holds into the area this weekend or whether it gets pushed
to the east. Either way temperatures look to hold above
average, the question is how much. Also, with the possibility of
the ridge pushing east and southwest flow setting up, chances
for precipitation enter the forecast.

&&

.AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/...
Issued at 638 AM CDT Tue May 26 2026

Isolated showers or thunderstorms are possible over northwest
and central North Dakota this evening and overnight. Otherwise,
VFR conditions are expected.


&&

.FIRE WEATHER...
Issued at 227 PM CDT Mon May 25 2026

Greatest area of fire weather concern continues to be over far
western North Dakota where the Fire Weather Watch has been
upgraded to a Red Flag Warning. This continues to be the area of
concern for the remainder of the work week with minimum
humidity values dropping into the lower 20s, and southeasterly
winds remaining elevated. Near critical fire weather conditions
remain possible over the remainder of western into north
central North Dakota. A variable in place, though, continues to
be the ongoing green up and how much the green conditions are
overtaking last years growth. Will continue to be in
communication with fuels personnel this week to keep track of
the green-up progression.

&&

.BIS WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning from 11 AM CDT /10 AM MDT/ this morning to 10
PM CDT /9 PM MDT/ this evening for NDZ001-009-017-031-032-040-
043.

&&

$$

UPDATE...JJS
DISCUSSION...JJS
AVIATION...JJS
FIRE WEATHER...JJS