983
FXUS63 KFGF 011948
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
248 PM CDT Mon Jul 1 2024

.KEY MESSAGES...

- There is a level 1 out of 5 risk for severe thunderstorms this
  evening for nearly the entire forecast area.

- A system is expected to bring numerous showers and
  thunderstorms to parts of the Northern Plains on Independence
  Day, with a low chance for severe thunderstorms.

&&

.DISCUSSION...
Issued at 248 PM CDT Mon Jul 1 2024

...Synopsis...
A decent low level jet will remain mainly east of the Red River
late this afternoon and into the evening. This has been the
primary forcing for the showers and thunderstorms across
northwest Minnesota. Precipitable water values have been very
high, around 1.70 inches, and the rainfall rates have been quite
impressive as well. Here at the NWS in Grand Forks, almost an
inch of rain fell in an hour or so. There could be another round
of showers/storms this evening, with another 700mb wave that is
moving into eastern Montana/western North Dakota right now. This
is where the weak surface front is as well. However, there is no
low level jet support out in that area tonight to help sustain
stronger convection too far into the evening. The 500mb low
will be located over southern Manitoba by 18z Tuesday, meaning
there is some support for redeveloping Tuesday afternoon
showers/storms. There should still be somewhat of a break on
Wednesday, before another stronger wave moves in for the July
4th holiday. Beyond that, northwest flow looks pretty well
entrenched, with a few additional waves possible.

...This Evening...
There is a weak surface boundary east of a Williston to
Dickinson line, but there has been extensive cloud cover across
that area most of the day. There has been some developing
convection across the western Dakotas with a little lightning
activity as well. There is ample effective shear out in that
region, but instability has been held down somewhat. As
mentioned in the paragraph above, there is no low level jet
support tonight for anything that does try to move into this FA.
CAMs do still show some sort of line of storms forming from
Minot to Bismarck by late afternoon, potentially moving into our
western FA by 7 pm or so (eastern North Dakota following that).
The HREF shows any UH tracks pretty much ending to the west of
this FA. Therefore think storms may continue to move into our FA
tonight, but on a weakening trend. However, these could still
be efficient rain producers, so will have to watch to see if any
of these move into areas that have seen highers totals up to
now. For the most part, the highest totals have been over the
northern Red River Valley into adjacent areas of northwest
Minnesota.

...Independence Day...
Have been watching this potential for a few days now. If
anything, have seen a slight shift southward with the heavier
precipitation axis in the latest ensembles. Yesterday at this
time, our FA was right in the middle, now it appears eastern
South Dakota into southern Minnesota (where they definitely
don`t need it) are more in the middle. Either way, will have to
keep an eye on this next system over the next few days.

&&

.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 1234 PM CDT Mon Jul 1 2024

Low clouds (MVFR to IFR) are creeping slowly to the east, and
will likely hold through most of the night. This will be the
main aviation impact outside of any thunderstorm activity. Most
of the current convective activity has shifted from KGFK into
northwest Minnesota. The visibility briefly dropped under 2SM as
the heavier rate rains moved through KGFK, otherwise
visibilities have been P6SM. This afternoon activity may clip
KTVF yet, but should mainly stay closer to the Canadian border.
CAMs still show additional thunderstorm development back along
the surface front over western North Dakota this afternoon, then
track it into this FA during the evening. If this activity does
develop, it could bring another period of about 2 hours of
showers or thunderstorms tracking through. After this passes,
clouds should slowly decrease, and it may clear or scatter out.
As far as winds, they have been all over the place this morning,
varying from light to gusting to 38 knots. It should stay on
the gusty side through the afternoon into evening, with some
decrease showing up late tonight into Tuesday morning.

&&

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

&&

$$

DISCUSSION...Godon
AVIATION...Godon