101
FXUS63 KFGF 251135
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
635 AM CDT Tue Jun 25 2024

.KEY MESSAGES...

- There is a level 1 out of 5 risk for severe thunderstorms over
  the Devils Lake basin Thursday evening, and a lower chance for
  severe thunderstorms elsewhere Thursday night into Friday.

&&

.UPDATE...
Issued at 635 AM CDT Tue Jun 25 2024

Clear skies and light southwest winds are prevailing across
eastern ND and northwest MN this morning. Winds are still
expected to increase from the west-northwest with increasing
daytime mixing under mostly sunny skies as winds aloft increase.
There are a few showers that have been developing but quickly
dissipating near our far southeast CWA border (near the ND/SD
state line). Much more stable air is in place as the main
instability axis is now south of us and drier BL conditions are
in place, resulting in these showers struggling to hold
together as they approach. I could still see a few sprinkles or
a light shower in the far southern RRV this morning. This update
was to capture near term trends, otherwise forecast is on
track.

&&

.DISCUSSION...
Issued at 356 AM CDT Tue Jun 25 2024

...Synopsis...

Westerly flow aloft is in place today, and while there will be a
series of progressive troughs and ridges, the main pattern will tend
to resemble zonal/quasi-zonal. Height falls behind the trough
passages should bring a period of below average temperatures at
times, though actual highs are complicated by timing of frontal
zones and precipitation in this pattern. There is strong
consensus regarding the mean evolution of the pattern, with
variance in the smaller details common to progressive patterns
like this.

...Today-Tonight...

The main frontal zone is almost completely out of our
area with much lower Tds and drier air aloft helping stabilize
conditions. However, near the frontal zone there is still an axis of
500-1000 J/KG elevated instability near the ND/SD through mid
morning which may support a few elevated showers/non severe
thunderstorms in our far southern RRV. Westerly BL flow ahead of the
next mid level wave keeps an axis of warm 850 temps in place so we
should see some recovery in temps (once again warmer than average),
despite the post frontal air mass in place. Lower Tds and marginal
lapse rates keep potential instability minimal in our area ahead of
this next shortwave rough later in the day. HREF supports a period
of elevated light showers (maybe a rumble of thunder) this evening
through Wednesday morning.

...Thursday-Friday Severe Threat/Rain...

A more organized trough develops
out of the Pacific northwest with a brief amplification of
shortwave ridging over the Northern Plains. This allows a period
of SW flow to build back into the northern plains. The warm
sector/instability axis favored to our west based on latest
ensemble clusters, and this region would favor initiation/better
severe potential. However, as the mid/upper trough moves east
Thursday this axis will begin to slide east and depending on the
timing, may support an elevated severe risk into our west
Thursday evening. Widespread showers/embedded thunderstorms then
overspread our region, while the frontal zone shifts south and
east through Friday. Depending on cloud cover/daytime
destabilization, this could act as a focus for new severe
thunderstorm development, but highly conditional on
clearing/frontal timing. GEFS CSU machine learning (and NBM
CWASP) highlight the low (5%) severe potential late Thursday
mainly in our west and in our far east-southeast Friday.

Regarding rain amounts: Within more organized convective elements
probs for 1"+ total rainfall will be expected with favored
region in global ensembles near the US/Canada border. There
isn`t currently a signal for more organized higher totals that
would create concerns for more than localized runoff issues.

&&

.AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/...
Issued at 635 AM CDT Tue Jun 25 2024

VFR conditions are expected to prevail through this evening
across eastern ND and northwest MN, with increasing winds from
the west-northwest midday. These winds should start to shift
more to the north and decrease (less than 10kt) as the sun sets.
Isolated showers are expected in far southeast ND this morning,
but confidence is low they will move within the vicinity of
KFAR. Better shower chances arrive with a disturbance this
evening/overnight tonight but coverage/chances (20-30%) are too
low for TAF inclusion. As this system passes all guidance is
showing a signal for MVFR ceilings to develop in the 6-12Z
period tonight/Wednesday morning northwest to southeast, with a
low chance for IFR.


&&

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

&&

$$

UPDATE...DJR
DISCUSSION...DJR
AVIATION...DJR