467
FXUS63 KFGF 171140
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
640 AM CDT Sat May 17 2025

.KEY MESSAGES...

- Near freezing temperatures are possible in portions of
  northeastern North Dakota this morning and a frost advisory is
  in effect. Additional freezing or near freezing temperatures
  are possible Saturday night into Sunday morning.

&&

.UPDATE...
Issued at 640 AM CDT Sat May 17 2025

Made a few minor tweaks to POPs to reflect recent radar and
observation trends. Most of the lingering rain (even some snow)
showers are along and east of the Red. Temps in northeastern ND
have fallen into the 32 to 33 range, so we seem to have hit the
temperatures for frost advisory even though not much to scrape.

&&

.DISCUSSION...
Issued at 353 AM CDT Sat May 17 2025

...Synopsis...

Upper low continues to pull through MN and WI, with wrap around
light rain and even a few snowflakes lingering across the Red
River Valley. No impacts expected. After some brief ridging into
tomorrow, another upper low will be coming out into the Plains
on Monday and Tuesday. Current ensemble runs have a few main
vort lobes rotating around each other as they come out, but all
track through SD and Nebraska into southern MN, so best
probabilities of wetting rain look like they will be along and
south of Highway 2. Another break for mid-week as ridging builds
in again, and then another weak shortwave could bring some
precip for Friday. Ensemble agreement goes downhill for next
weekend.

...Frost/freeze for this morning and tomorrow morning...

Cold air advection continues to bring lower temps and dew points
into the CWA. Cloud cover continues and wind has kept us well
mixed, but advection alone has dropped readings into the 34 to
35 range already. Looking upstream, temps may not fall much
below 33 degrees but that continues to fit well with the frost
advisory for northeastern ND. We will hit temperature criteria
even if clouds and winds keep the usual frost from happening.

The cold air advection will continue into today, then surface
ridging will extend into the Eastern Plains by tonight. Winds
will decrease and begin to shift to the northeast and east,
although it does not seem at this point it will go completely
calm. There is also the question of cloud cover as at least some
will still be hanging around. Likely will need another frost
advisory when the current one expires, and some spots may even
get below freezing. Probabilities of 32 or below range from 20
percent in northwestern MN to around 80 percent in the Langdon
area. With current headlines and some uncertainty on which
counties will hit freeze versus just frost, will hold off on
headlines for Sunday morning and let the day shift refine
things.

&&

.AVIATION /12Z TAFS THROUGH 12Z SUNDAY/...
Issued at 640 AM CDT Sat May 17 2025

MVFR conditions at most of the TAF sites, although KBJI is IFR
with some drizzle limiting vis down to 1SM or so. KTVF seeing a
bit of -SN, with vis down to 3 miles. Precipitation and
visibility limitations should end in the next hour or so.
However, the ceilings will stick around longer, with MVFR for
most locations and even some IFR at a few spots. Some recovery
to VFR by the end of the period. Winds that continue to gust
above 25 kts this morning will remain breezy for much of the
afternoon, then taper off this evening.

&&

.FGF WATCHES/WARNINGS/ADVISORIES...
ND...Frost Advisory until 10 AM CDT this morning for NDZ006>008-
     014>016-054.
MN...None.

&&

$$

UPDATE...JR
DISCUSSION...JR
AVIATION...JR