228
FXUS63 KFGF 270306
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
1006 PM CDT Fri Jul 26 2024

.KEY MESSAGES...

- Heat concerns remain through the evening with heat indices in
  the upper 90s across the Red River Valley.

- There is a level 1/5 risk for severe weather late this
  afternoon and tonight and a level 2/5 risk for severe weather
  Saturday.

&&

.UPDATE...
Issued at 1006 PM CDT Fri Jul 26 2024

Still pretty humid across our south, but temps are coming down
so let the heat advisory go at 9 PM as scheduled.

Still getting thunderstorm activity along frontal boundary from
Jamestown area up towards Thief River Falls and Upper Red Lake
as another vort ejects out the southwesterly flow aloft into our
area. There is still quite a bit of elevated CAPE, but it is
mostly out ahead of the front where the dew points are still in
the 70s. Effective shear is around 40kts right along the frontal
boundary. There is a very small chance that everything could
line up to get a cell close to severe impacts. However, looking
at HREF updraft helicity tracks and SSCRAM guidance,
probabilities for severe look very low, less than 10 percent.
Will continue to monitor, but overall the main threats will be
locally heavy rain and lightning for the overnight activity.

UPDATE
Issued at 711 PM CDT Fri Jul 26 2024

Adjusted POPs for current trends as convection has developed
over northwestern MN. Cells so far have been staying strong but
sub-severe with a bit of small hail and lightning the main
threats so far. Will continue to monitor as the boundary pushes
a bit further east and then is expected to stall/wash out.
Further west, a few light rain showers are the only impacts over
the Devils Lake Basin.

&&

.DISCUSSION...
Issued at 242 PM CDT Fri Jul 26 2024

...Synopsis...
The 500mb ridging that is overhead today will shift eastward
tonight into Saturday, as a low over Alberta also tracks to the
east. This will serve to flatten the ridge and result in west or
southwest flow for the remainder of the forecast. There will be
periodic waves tracking through, so there are periodic chances
for showers and storms throughout as well. Overall, temperatures
will stay on the hot side and there may not be much of a break
from the high level smoke.

...The heat...
Starting to see some lower 90s temperatures across southeast
North Dakota with dewpoints in the low to mid 70s. No doubt it
is hot and humid. The surface boundary/cold front is poking into
the Devils Lake region, with noticeably cooler temperatures and
less humidity behind it. Unfortunately, the 500mb flow pattern
is pretty much paralleling it, so it will not be moving too much
further eastward. So only the Devils Lake region may see a
respite from the heat and humidity today and tonight. Will have
to keep an eye on these parameters again Saturday, but both
should be just a tad lower. Plus there may be Saturday morning
cloud cover around from any nocturnal convection, and the
seemingly continuous upper level smoke.

...Severe Weather...
The severe weather threat tonight is only a 1/5 risk due to the
low overall confidence in how it may unfold. At this point, the
above mentioned surface boundary is the main focus area. During
the heat of the day today, most activity should stay capped,
with 700mb temperatures of +12 to +14C. There has been a parade
of weak echoes tracking north-northeast into Canada along the
front, but only trace to a few hundredths of actual
precipitation has reached the ground. This may change by late
afternoon into tonight, as the low level jet increases slightly
again. However, CAMs seem to be backing off on much of anything
tonight, so confidence is pretty low overall.

How tonight unfolds will play into the severe weather potential
for Saturday, as there could be lingering clouds or outflows
associated with that. The northeast to southwest oriented
surface boundary will likely still be laying somewhere across
North Dakota, with plenty of moisture/humidity in place. Not
seeing any consistent signals for where and when any convection
will initiate again. CAMs are really not much help either,
showing something possible across the eastern FA in the
afternoon and another line of storms developing over western
North Dakota in the late afternoon, moving into our western FA
in the evening. So will have to see what later model runs have
in store.

&&

.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 711 PM CDT Fri Jul 26 2024

Storms impacting the KTVF area with some showers near KGFK and
KDVL. A stalling boundary will keep the convection in the
vicinity of these airports through the evening and into the
overnight, while KFAR and KBJI stay dry. Most ceilings and vis
should be VFR except for brief downpours if a heavier cell moves
over the airport. Low level wind shear will be an issue at some
of the southern and eastern sites as we decouple this evening
but winds aloft remain out of the south at 35 to 40 kts. The
frontal boundary will wash out and all sites will return to
southerly wind direction by the end of the period, with VFR
conditions expected.

&&

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

&&

$$

UPDATE...JR
DISCUSSION...Godon
AVIATION...JR