108
FXUS63 KFGF 160814
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
314 AM CDT Mon Sep 16 2024

.KEY MESSAGES...

- There is a level 1 out of 5 risk for severe storms over the
  western Devils Lake region early this morning, with the main
  hazards being lightning, hail, and localized heavy rain.

- There is a level 2 out of 5 risk for severe storms over
  portions of eastern North Dakota and northwest Minnesota this
  afternoon and evening.

- There are multiple chances for rain this week, with a low
  probability for severe storms and heavy rain.

&&

.DISCUSSION...
Issued at 314 AM CDT Mon Sep 16 2024

...Synopsis...

The pattern remains very active, with a western trough and
eastern ridge. With the Northern Plains in southwest flow,
periodic shortwaves are expected to track through. However, the
overall predictability is much more uncertain beyond about a
day or two.

...Severe potential early this morning...

There are quite a few areas of storms early this morning. There
is scattered activity moving through the arrowhead of Minnesota,
another broad area over western South Dakota, and a line of
storms just south of Minot. The surface flow is very moist and
weak, with a few stations reporting lower visibilities in fog.
This seems to be from the Lake of the Woods region down toward
Grafton and Grand Forks. Will consider a Special Weather
Statement for fog in these areas through sunrise. The line of
storms just south of Minot is the closest to the FA, and seems
to be associated with the 850mb jet and good 850mb moisture
transport. The strongest portion of the 850mb jet is focused
into southwest North Dakota, and is much more broad and a bit
weaker into this FA. CAMs are not in the best agreement, but
some have the activity between Rugby and Minot brushing western
portions of the Devils Lake region through sunrise. The HREF
shows a few longer UH tracks in this area, so will be keeping a
watch on this area over the next few hours. The area of storms
over western South Dakota seems to show a better area of
rotation, which may be a MCV, which would bear watching for
later in the day too as it moves north to northeast. So not sure
if there will be a break after sunrise, before more activity
fires up again, or the activity will just weaken a bit before
strengthening again. Any storms early this morning have been
slow moving and will likely drop heavy amounts of rain in a
short duration. Will have to keep an eye on where this morning
rain falls in case there are more rounds across the same areas
this afternoon and tonight.

...Severe potential this afternoon and tonight...

High levels of moisture remain over the FA this afternoon and
tonight, with precipitable water values rising up to around 2
inches (pretty good for mid September). Will have to see how
long and where the morning clouds hang around, to see where the
best instability develops by this afternoon. It doesn`t look
like there are any surface boundaries that set up this
afternoon, but it is hard to say for sure with remnant or dying
morning convection around. The 0-6km shear stays on the lower
end, but could be increase a bit by 00z Tuesday. The biggest
parameter that jumps up again this evening is the low level jet.
The 06z model runs are showing it even stronger by 00z Tuesday,
potentially as high as 50 to 60 knots, focused into the
northern Red River Valley and southeast Manitoba. Precipitable
water values remain around 2 inches across northeast North
Dakota and northwest Minnesota. The HREF shows longer UH tracks
picking up in the mid to late afternoon (across northeast North
Dakota and northwest Minnesota) and continuing through about 9
to 10 pm. SPC has updated the Day 1 Severe Weather Outlook to go
a slight risk (level 2 out of 5) for this area. So maybe after
a mid to late morning lull, convective activity may be on the
uptick again by mid to late afternoon into the evening. Hard to
time waves beyond this, but the pattern remains active.

&&

.AVIATION /06Z TAFS THROUGH 06Z TUESDAY/...
Issued at 1141 PM CDT Sun Sep 15 2024

Look for a chance of showers and thunderstorms overnight and
into Monday. The best chances will occur after 10Z at KDVL, then
progress east through the remainder of the day. VFR ceilings are
expected to prevail at all TAF sites outside of thunderstorm
activity. Winds tonight remain light and variable before
increasing slightly just before sunrise. Broken to overcast cloud
cover prevails in the vicinity of showers and thunderstorms,
with SCT clouds elsewhere.

&&

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

&&

$$

DISCUSSION...Godon
AVIATION...Lynch