242
FXUS63 KFGF 162339
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
639 PM CDT Sun Jun 16 2024

.KEY MESSAGES...

- After a round showers Monday morning in southeastern North
  Dakota and west central Minnesota, stronger thunderstorms will
  develop over the area Monday evening and continue into the
  overnight. Primary threats will be heavy rainfall bringing
  flash flooding potential and hail up to golf ball sized, but
  some winds up to 60 mph will be possible.

- Thunderstorms will continue into Tuesday, with heavy rainfall
  and flash flooding possible, along with large hail and
  damaging winds.

&&

.DISCUSSION...
Issued at 359 PM CDT Sun Jun 16 2024

...Synopsis...

Upper low lifting into Manitoba is helping push out surface
trough/frontal boundary out our eastern CWA border, with most of
the winds already shifted to the west although some upper 60/low
70s dew points are lingering. The towering cumulus still has not
completely cleared our far eastern counties, but should be out
of the woods shortly for surface based convection in our east.
Could see a few sprinkles in our far south later this evening
from SD that CAMs are not catching onto, but impacts will be
very minor.

Later tonight there will be a fairly vigorous shortwave moving
from SD/Neb into WI. The model runs have been very inconsistent
with the precipitation set off by this shortwave. Previous model
runs, CAMs and large scale models alike, had heavy QPF over our
southern counties, but now are more over southern MN. We do get
some of the precipitation in our far south by tomorrow morning,
but not as much as previous forecasts. This sets up more
favorable conditions for late Monday into Monday night, with a
warm front lifting north into our CWA and a shortwave coming
from the High Plains into southeastern ND. CAPE will be elevated
at 1500-2000 J/kg and some 50 kts of deep layer bulk shear, so
hail up to golf balls and even some gusts up to 60 mph are part
of the impacts. Of greater importance will be heavy rain as with
the boundary lining up with the upper flow, storms will be
reforming on top of each other. The main shortwave will continue
into North Dakota but the boundary will not move too much until
late in the day on Tuesday. Thus, the chance for thunderstorms
and heavy rainfall will continue throughout the day on Tuesday.
Risk of flash flooding is high.

After a bit of a break on Wednesday with high pressure, the
southwesterly flow aloft continues, with signs in the ensembles
of another boundary lifting into the area on Friday. The trough
moves through Saturday before heading out into Great Lakes for
Sunday. Details, especially for severe impacts and heavy
rainfall, are uncertain at this point, but confidence in the
active pattern continuing is high.

&&

.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
Issued at 639 PM CDT Sun Jun 16 2024

VFR conditions are expected through tonight and tomorrow
morning. There are a line of light showers just south of KBJI so
there a little uncertainty as to whether the ceiling drop to
5000ft or not. The next round of showers are not expected until
after 0600z but may not affect KFAR until 18z as these are
expected to move North very slowly.

&&

.FGF WATCHES/WARNINGS/ADVISORIES...
ND...Wind Advisory until 7 PM CDT this evening for NDZ006-007-014-
     015.
MN...Flood Watch from Monday afternoon through Wednesday morning
     for MNZ024-028>032-040.

&&

$$

DISCUSSION...JR
AVIATION...MM