983
FXUS63 KBIS 170020
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
720 PM CDT Fri May 16 2025

.KEY MESSAGES...

- Rain and wind will continue to diminish through the evening
  and into the overnight hours. Patchy fog is possible overnight
  across the west.

- Near to sub-freezing overnight temperatures across western and
  north central North Dakota tonight, and all but far southwest
  North Dakota Saturday night.

- Rain chances return Sunday through Tuesday, highest southwest
  (as high as 90 percent) and lowest far north (around 30
  percent).

- Below normal temperatures expected through the middle of next
  week.

&&

.UPDATE...
Issued at 704 PM CDT Fri May 16 2025

Rain and winds will continue to diminish over the next several
hours. There are still a couple of sites seeing intermittent
advisory criteria wind gusts across the east, but we decided to
go ahead and let the Wind Advisory expire on time as winds
should dramatically improve over the next hour or two. Breezy
conditions may hang on across James River Valley overnight and
through the day on Saturday. With all of the recent moisture and
calming winds, patchy fog will be possible across the west
overnight. No major changes were needed for this update. Just
blended in the latest observations to the going forecast.

&&

.DISCUSSION...
Issued at 300 PM CDT Fri May 16 2025

An upper level low continues to move eastward this afternoon
shifting wrap around precipitation west to east. Strong pressure
gradient winds continue to descend on the backside of the low
leading to wind gusts around 40 to 50 mph across the state. A
few wind gusts around 55 to 60 mph have been observed in the
southwest. Rain continues across the western and central North
Dakota with wide spread 2 to 4 inch reports across the west and
central and a few isolated areas with 5 to 6 inch storm total
rain with it still raining. There has been some observed ponding
across the countryside by nothing major at this moment. As rain
tapers off to the east tonight surface high pressure will move
into the region. Thus, causing widespread freezing temperatures
across western and central North Dakota. Therefore, the Freeze
Watch has been upgraded to a Freeze Warning with a Frost
Advisory issued for portions of central North Dakota. Low
temperatures are forecast to drop down to the upper 20s out west
to mid 30s in the James River Valley. Recent rainfall and cold
temperatures are forecast to drop the temperature tonight to the
dew point resulting in patchy fog forming out west.

High temperatures tomorrow are forecast to warm back into the
upper 40s in the Turtle Mountains to the lower 60s in the
southwest. Much of the state is forecast to sit in the 50s.
Cyclonic flow aloft could bring some showers to eastern North
Dakota tomorrow afternoon. Breezy conditions are possible out in
the James River Valley as well. Tomorrow surface high pressure
will linger through the day resulting in some clearing of the
clouds across western and central North Dakota. Another round of
freezing temperatures is expected Saturday night for eastern
and central North Dakota as surface high pressure remains in the
region. Headlines are likely for frost freeze through Sunday
morning.

Another upper level low is forecast to dig across the Pacific
Northwest Sunday morning moving into the Rockies. This will
bring increased chances for showers and thunderstorms across the
west Sunday and into central North Dakota by the evening hours.
This upper level low is forecast to stall over the Central
Plains Monday leading to southern North Dakota remaining in the
deformation zone of the upper low through Tuesday. This will
lead to greater accumulations along the North and South Dakota
border. Much of Northern North Dakota will likely see less
precipitation. Temperatures will remain below normal through
Tuesday. Temperatures will begin to warm up by Wednesday
approaching near normal.

&&

.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 704 PM CDT Fri May 16 2025

Rain showers and winds will continue to diminish over the next
few hours. MVFR ceilings (and MVFR visibilities under the more
moderate showers) will remain in place across much of western
and central North Dakota overnight with improvement across the
west. Brief IFR ceilings will be possible tonight. Patchy fog
may also be possible across the west overnight but confidence
is low at this time. Conditions will then gradually improve
Saturday morning and Saturday afternoon over the central and
east. It will remain breezy through the day on Saturday across
the James River Valley with winds out of the north. Gusts to 25
knots or so will be possible at KJMS.

&&

.BIS WATCHES/WARNINGS/ADVISORIES...
Freeze Warning from 2 AM CDT /1 AM MDT/ to 10 AM CDT /9 AM
MDT/ Saturday for NDZ001>005-009>011-017>019-021-031>033-040-
041-043-044.
Frost Advisory from 2 AM CDT /1 AM MDT/ to 10 AM CDT /9 AM
MDT/ Saturday for NDZ012-013-020-022-034-035-042.

&&

$$

UPDATE...ZH
DISCUSSION...Johnson
AVIATION...ZH