427
FXUS63 KFGF 282330
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
630 PM CDT Sun Apr 28 2024

.KEY MESSAGES...

- 30 percent chance for an inch or greater of snow in north
  central Minnesota Monday morning bringing the chance for
  isolated minor impacts to travel.

- Multiple systems will continue to bring periods of rain to the
  region from Tuesday through the end of the week.

&&

.DISCUSSION...
Issued at 228 PM CDT Sun Apr 28 2024

Upper level low pressure system is centered over the central plains
tracking northeast into Minnesota and Iowa. Rain (moderate at times)
is situated along and north of the upper level low and is tracking
northward. This rain will continue to overspread eastern North
Dakota and northwestern Minnesota throughout the remainder of the
afternoon and into the evening hours. The low pressure system is
associated with the southwesterly flow aloft that will be stuck in
place through mid week before turning zonal/northwesterly end of the
week as represented by cluster analysis.

As the precipitation moves northward this evening and overnight snow
may mix in at times in eastern North Dakota and northwestern
Minnesota as temperatures near the surface cool to the low to mid
30s. Areas near Lake of the Woods and Beltrami (north central
Minnesota) reach the low 30s easily overnight bringing the chance
(30%) for rain to transition over to snow. Atmospheric soundings
differ in residence time, onset of snow, and growth within the DGZ.
30% of guidance has snow lasting longer, becoming moderate at times,
and longer time within the DGZ. This leads to accumulations of an 1
or more in north central Minnesota on elevated surfaces. There
exists a chance (30%) for isolated impacts to travel where snow
starts to accumulate on elevated surface. However, majority (70%) of
guidance has the rain/snow mix remaining, as saturation is through
the low and mid levels, temperatures hover above freezing/are
isothermal in the low levels, and DGZ growth is limited. This would
bring little to no impacts and up to an inch of new snowfall. Likely
(70%) QPF of 0.50 to 1.25 inches from this evening through Monday
evening. Temperatures quickly rewarm by Monday mid morning
transitioning all rain/snow back over to rain, with the system
exiting by the evening hours. Temperatures warm into the mid to
upper 40s for Monday afternoon. Dry conditions move in briefly
Monday night, with temperatures in the low to mid 30s.

An active pattern will continue beyond Monday, as a trough and
associated jet streak over the western US passes several waves
through the Northern Plains. The first shortwave arrives Tuesday. A
generally north to south oriented band of rain driven by weak
frontogenesis will propagate from west to east. Rainfall will last
longest across the north, as the trough becomes negatively tilted,
allowing rain showers to pivot along the International border. Along
the southern edge of the band in southeastern North Dakota and west
central Minnesota, small CAPE values foster the potential to see
thunder and locally heavier rainfall. A slight north or south shift
in the track of the low would correspondingly shift the heavier axis
of rainfall and the amount of instability to the south that is able
to work northward. Probabilities for at least a half inch of rain
are 50% north of Highway 2 during this period. Probabilities are 20%
in southeastern North Dakota.

The main trough will propagate east over the Rockies late in the
week. In turn, a larger wave will pass through the Northern Plains.
Cluster analysis clearly shows significant disagreements in the
track, timing and strength of this wave. At this time, it can be
deduced that while another system capable of bringing rain to the
region will be in the area, specifics are uncertain. What is more
consistent is that temperatures will be persistently near or below
average through next weekend, with highs generally in the 50s and
lows in the 30s.

&&

.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
Issued at 630 PM CDT Sun Apr 28 2024

Light rain continues to lift northward, with KFAR likely seeing
more showers than steady rain through much of the evening. Light
rain is currently being observed at KBJI, and will move into
KGFK and KTVF by around 03Z. A transition to a mix of rain and
snow remains possible heading into Monday morning, with little
to no impact expected from accumulating snow. Any snow will
transition back to rain by mid-morning. As for ceilings, a best
case scenario of MVFR is expected this evening, with the
expectation of more widespread IFR CIGs later tonight and into
Monday morning. Some guidance suggests LIFR CIGs are possible
around sunrise Monday; however, there is low confidence
regarding location, and consistency is minimal.

&&

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

&&

$$

DISCUSSION...Rafferty/Spender
AVIATION...Lynch