-- Discussion containing changed information from previous version are highlighted. --
589
FXUS63 KFGF 240133
AFDFGF

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

.KEY MESSAGES...

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- 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.
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&&

.UPDATE...
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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.
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&&

.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 /00Z TAFS THROUGH 00Z FRIDAY/...
Issued at 630 PM CDT Thu May 23 2024

Clusters of thunderstorms have developed across southeastern
North Dakota, with KFAR likely seeing the greatest chances of
VCTS for the next several hours. For KGFK and KTVF, scattered
shower activity could produce lightning briefly; however, the
more persistent rain is not likely to arrive until closer to
06Z. VFR conditions are generally being reported outside of
shower/thunderstorm activity, with MVFR to intermittent IFR
ceilings/visibility within heavier showers and storms. The
probability of IFR ceilings, however, will increase through the
late evening and overnight period across much of the area. Winds
are still expected to increase, with gusts up to 25 knots. Wind
direction prevails out of the east; however, there are many
outflow boundaries associated with thunderstorms that will cause
sporadic wind shifts through much of the afternoon and evening.

&&

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

&&

$$

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