142
FXUS63 KFGF 240429
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
1129 PM CDT Thu May 23 2024

.KEY MESSAGES...

- Heavy rain tonight into Friday over portions of the Red River
  basin may bring additional rises on area rivers.

- Patchy frost could form Saturday early morning in the Devils
  Lake basin, although will depend on cloud cover and wind.

&&

UPDATE
Issued at 1005 PM CDT Thu May 23 2024

Showers continue to move across the region this evening. A few
embedded thunderstorms remain possible, as well as locally heavy
rain. Minimal adjustments needed this update, but will be
monitoring for localized ponding and overland flood potential
associated with the heavier showers.

UPDATE
Issued at 832 PM CDT Thu May 23 2024

Severe threat has diminished across much of the area this
evening. Widespread showers and embedded thunderstorms will
continue to move northward through the overnight period, with
moderate to heavy rain possible at times.

&&

.DISCUSSION...
Issued at 337 PM CDT Thu May 23 2024

Main upper low is still coming out from the northern Rockies
into the western Dakotas. Some convection firing in northeastern
SD on the leading edge of the 850mb jet and in uncapped 2000
J/kg SB CAPE has mostly been unorganized and not severe.
However, the CAMs still break out some more impressive
convective cells later on this afternoon and evening.
While the main wind shift with the warm front is still mostly down
in SD, there is some 55 dew points pooling further north near
the I-94 corridor where winds are from the east. That could make
some cells moving in that area interesting and could bring some
rotation in addition to the main hazards of hail up to two
inches and winds to 70 mph. Will continue to monitor how the
mesoscale features develop in the next few hours, but it still
seems that we will see some good chances for isolated to
scattered severe storms during the 21 to 03Z time frame.

As the instability decreases tonight, the main upper low will
still be coming out into the Northern Plains and the surface low
lifting into the Red River Valley. This time the main
deformation band sets up more over our northern counties, with
the Devils Lake Basin and northern Red River Valley seeing the
best probabilities of over an inch of rain. There is even some
50 to 60 percent probability of over 2 inches of rain by Friday
evening. The precipitation will continue to wrap around the low
pressure system as it lifts off into Canada Friday night. Some
colder temperatures start to come down the backside of the
system, with some of the models showing a few flakes mixing in
the far northwestern counties as early as Friday morning. No
accumulations or impacts expected. More cold air coming down as
the system pulls east Friday night, although there is some signs
of a reinforcing shortwave bringing some clouds that could
prevent frost formation.

The active pattern continues into the holiday weekend as flow
becomes southwesterly, although the bulk of the energy on Sunday
seems like it will be to our south. Northern branch shortwave
coming through Monday will dig into the Great Lakes Tuesday,
allowing ridging to build in and a warming trend for
Wednesday/Thursday.

&&

.AVIATION /06Z TAFS THROUGH 06Z SATURDAY/...
Issued at 1130 PM CDT Thu May 23 2024

VFR to MVFR conditions prevail outside of showers and
thunderstorms tonight, with IFR CIGs expected during showers and
embedded storms. Ceilings will slowly fall during the remainder
of the overnight period as an upper low traverses the region.
Some guidance brings ceilings as low as 600 feet heading into
Friday morning before a slow improvement takes shape during the
day. Winds are expected to be gusty along a strong pressure
gradient associated with the upper low, with sustained winds of
20 knots and gusts to near 30 knots at times. Shower activity
will remain in the forecast through at least midday Saturday
before slowly moving off to the north and east during the
afternoon and evening.

&&

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

&&

$$

UPDATE...Lynch
DISCUSSION...JR
AVIATION...Lynch