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000
FXUS63 KFGF 171459
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
959 AM CDT Wed Apr 17 2024

.KEY MESSAGES...

- There is a 60 percent chance for light snow showers early
  Thursday morning into Friday, with highest chances near the
  US/Canada border. The chance for widespread impacts from snow
  is less than 10%.

- There is a 50 percent chance for daytime wind gusts to 45 mph
  Thursday and Friday, mainly west of the Red River Valley in
  North Dakota.

&&

.UPDATE...
Issued at 954 AM CDT Wed Apr 17 2024

Snow is mixing with or transitioning from rain near the
international border in northwest MN this morning. Impact are
not anticipated from this activity given warm temperatures above
freezing and rates light enough to limit visibility reduction
impacts.

Otherwise, light rain within a diminishing deformation band will
continue elsewhere in northwest and west-central MN through the
morning.

Gusty northwest winds up to 35 mph will spread into eastern
North Dakota this afternoon, with very low chance (less than
10% of reaching advisory criteria.

Scattered weak convective rain showers into eastern ND this
afternoon are also possible.

UPDATE
Issued at 650 AM CDT Wed Apr 17 2024

Deformation band of light to moderate rain continues to progress
west to east and will be clear of ND within the next hour or
two. Timing and rain rates are matching well with only minor
adjustments made. Behind this light fog and a few pockets of
drizzle have been reported but overal trend is dry. Cloud cover
seems to be redeveloping/filling back in upstream as the next
upper low to the northwest continues to progress eastward.
Warmest temps later today (near 60) are most likely in the
south where cloud cover may remain less/more sun while in the
north they may struggle to warm above 50 if low clouds persist.
I made some adjustments to cloud cover but held off on daytime
temperatures adjustments.

&&

.DISCUSSION...
Issued at 358 AM CDT Wed Apr 17 2024

The strong mid/upper low is now centered over southern MN, with a
mid level deformation zone still responsible for more organized
light to moderate rain over eastern ND/far northwest MN. Low level
moisture and at least some background forcing within cyclonic flow
is supporting areas of drizzle and a few showers elsewhere, though
there is a drier trend as winds shift to the west-northwest. This
area is expected to transition west to northeast following the track
progression of the synoptic low through midday and measurable
chances/coverage decrease substantially by this afternoon.
Additional rainfall of 0.1-0.25" (based on HREF PMM/NBM probs) can
be expected with this area of deformation it moves east early
this morning through this afternoon.

The next (colder) mid/upper low is to the northwest starting to
deepen over southern Saskatchewan this morning and this will tend to
keep CAA/cyclonic flow in place over the next several days. There is
a weak signal for light snow showers in this flow across our north
starting late tonight and continuing into Friday (may just be
flurries). On the back side of the departing mid/upper low there is
one last shortwave associated with a coupled jet structure that
could support better measurable snow chances along the US/Canada
border Thursday night into Friday but 95% of ensemble members show
less than 1" of snowfall and warm ground temps should further limit
impacts from actual accumulation (if any). Vis reductions may be
possible though if showers occur with stronger wind gusts.
Temperatures will be colder with nighttime lows below freezing,
however this is essentially within climate averages (28-32) for mid
to late April.

Regarding winds: Increasing gradient and BL winds increase as this
next system deepens and slowly tracks over southern Manitoba into
Ontario, and breezy to windy conditions are expected. There is a
signal with this w-sw flow pattern for daytime gusts near 45 mph with
favored areas west of the Red River Valley (NBM4.2 probs generally
30-50%). Despite these probs, mixing heights may not be deep
enough to fully tap into the strongest winds aloft lowering
confidence in wind advisory impacts. Snow shower activity could
help with momentum transfer though (where they track).

&&

.AVIATION /12Z TAFS THROUGH 12Z THURSDAY/...
Issued at 650 AM CDT Wed Apr 17 2024

Kind of a mixed bag of flight categories across the TAF sites but
KDVL, KGFK,and KFAR should float between MVFR and VFR by 1600z as
the sun starts to mix out these lower cloud layers. KBJI will be
MVFR/IFR the longest as this line of rain moves east. By tomorrow
morning(near sunrise) KDVL may be in MVFR/IFR conditions again as
another system moves across the international border.

&&

.FGF WATCHES/WARNINGS/ADVISORIES...
ND...None.
MN...None.

&&

$$

UPDATE...CJ/DJR
DISCUSSION...DJR
AVIATION...MM/DJR