-- Discussion containing changed information from previous version are highlighted. --
345
FXUS63 KFGF 210619
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
119 AM CDT Fri Jun 21 2024

.KEY MESSAGES...

- Scattered showers and thunderstorms are forecast tonight
  through Sunday, although the heavier precipitation looks to
  stay just to the south of this FA.

- Unsettled weather continues into next week, with potentially
  strong to severe storms Monday.

&&

.UPDATE...
-- Changed Discussion --
Issued at 118 AM CDT Fri Jun 21 2024

Radar continues to show the main rain and t-storm area well
south of the forecast area and likely the pops in our southeast
ND/west central MN area too high. Thus trimmed them back rest of
the night into Friday morning.


UPDATE
Issued at 947 PM CDT Thu Jun 20 2024

Updated POP grids for the southern Valley into tomorrow morning
in coordination with neighbors. Clouds continue to be on the
increase, but are more mid-level. Forecast remains on track.

UPDATE
Issued at 635 PM CDT Thu Jun 20 2024

Mid-level and upper level clouds are streaming into the area
this evening. Precipitation can be seen on radar to our south in
MN and SD, but our shower chances won`t begin until tomorrow
morning for the southern Valley. Forecast remains on track.
-- End Changed Discussion --

&&

.DISCUSSION...
Issued at 326 PM CDT Thu Jun 20 2024

...Synopsis...
Surface high pressure over Lake Superior continues to push
slowly to the east, with return flow across this FA. This has
helped to scour out the higher moisture values here, with most
of the FA seeing comfortable dewpoints in the low to mid 50s and
precipitable water values less than 1 inch. However there is a
pretty sharp moisture gradient to the south of the FA, where
dewpoints are closer to 60F and precipitable water values rise
up to 1.70 inches. A 700mb short wave will push across portions
of the Northern Plains tonight, as a surface warm front orients
from east to west across southern South Dakota into southern
Minnesota by Friday morning. This surface set up lingers through
the day Friday into Friday night, while several short waves
track just to the south of the FA. By Saturday, one short wave
tracks across southern Minnesota, while a closed 700mb low drops
into our northern FA. This 700mb system will slowly track
southeast through the FA Saturday night into Sunday, followed by
brief 500mb ridging Monday. At this point, Monday looks like
the warmest day of the 7-day forecast period. Another short wave
will try to force some ridge-riding storms mainly along and
north of the highway 2 corridor on Monday, although there is
quite low confidence on when or where this might be. The rest
of the period looks to feature a building western United States
ridge and eastern trough, putting this FA in northwest flow.
There could be sporadic precipitation chances, but the signal is
pretty weak at this point.

...Tonight through Sunday...
So far any light precipitation this mid afternoon has remained
either north or south of this FA. Went ahead and removed any
lingering precipitation chances for the rest of the afternoon,
which were mainly along the Dakotas border into west central
Minnesota.

Will see increasing precipitation chances tonight, generally for
areas along and south of I-94 in North Dakota and highway 10 in
Minnesota. There will be a decent low level jet, 850mb warm
advection, and elevated instability north of the warm front that
is expected to set up across southern South Dakota into
southern Minnesota. This should keep the best chances for rain
to the south of this FA. Would expect weakening convection
during the day Friday to shift into western Wisconsin, with more
activity developing over eastern South Dakota associated with
the next wave. Some of this South Dakota activity may brush our
far southern FA on Saturday, but nothing too substantial.

The low level jet cranks up again Friday night. Along with the
shortwave, another night of steady storms looks likely, but
again, just to the south of this FA.

By Saturday, some precipitation will linger across southern
Minnesota associated with the eastward moving nocturnal
convective remnants. The 700mb wave dropping southeastward out
of southern Saskatchewan and southern Manitoba will then keep
some showers and storms in the forecast for this FA from
Saturday afternoon through Sunday afternoon. The probability for
severe storms during this period is low.

...Into next week...
Monday looks like the warmest day of the period, with highs
reaching the 80s to around 90 (depending on residual cloud cover
of course). Not seeing a very consistent signal for convection
associated with the ridge-riding wave on Monday. Some ensembles
are faster than others, showing a late Sunday into early Monday
solution, while others are later Monday afternoon into Monday
evening potential. There does appear to be a pretty substantial
cap in place, with 700mb temperatures ranging from around +10C
around Winnipeg to around +15C along the Dakotas border.
However, if the wave is strong enough, and depending on the
timing, strong to potentially severe storms could form during
this period. There is very low predictability for this event
though, as it is still several days out. Beyond that, confidence
is even lower.

&&

.AVIATION /06Z TAFS THROUGH 06Z SATURDAY/...
Issued at 1026 PM CDT Thu Jun 20 2024

Winds will continue to be light and variable into Friday
morning. RA will slowly work north, in addition to MVFR and IFR
ceilings. As winds steady themselves in the easterly direction
around 5 - 10 knots, RA and TSRA and the low ceilings will be
more of a concern for aviation through early Saturday morning.

&&

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

&&

$$

UPDATE...Riddle
DISCUSSION...Godon
AVIATION...AH