Area Forecast Discussion
Issued by NWS Aberdeen, SD

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000
FXUS63 KABR 260141 AAB
AFDABR

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
841 PM CDT Thu Apr 25 2024

.KEY MESSAGES...

- Winds will remain breezy out of the southeast with gusts of 35 to
  near 45 mph, and slowly diminish from west to east into Friday
  morning.

- Marginal risk for severe storms with strong winds over 60 mph
  and small hail over portions of north central SD into this
  evening.

- Weak thunderstorms will remain possible through Friday night.
  Periodic soaking rains will continue into Saturday morning.
  Another round of rain showers will move in Sunday, with a focus
  over our southern and eastern counties.

&&

.UPDATE...
Issued at 839 PM CDT Thu Apr 25 2024

Have updated PoPs this evening to keep up with the latest trends
on radar. Rain should continue to push east and north through the
night, but especially on Friday as upper low gets closer to the
forecast area.

&&

.SHORT TERM /THIS EVENING THROUGH FRIDAY NIGHT/...
Issued at 401 PM CDT Thu Apr 25 2024

Elevated winds remain a concern over the next 1-3 hours, before
slowly diminishing. Several SD DOT and other locations have peaked
with wind gusts of 40-48 mph with a couple of locations briefly
around 50 mph. Winds will continue to be highlighted in our HWO and
other products through the evening hours.

Given the strong winds, the storms currently over
Meade/Perkins/Ziebach Counties (where winds are currently gusting
around 30 mph) will not take much to bring down near severe wind
gusts. We`ll continue to monitor the storms as they move into a less
favorable area. MLCAPE values near 1400J/kg will shift to central SD
by 00Z Thursday and diminish. While most storms will have a mainly
easterly component, any right moving supercells that could develop
would be shifting to the southeast. Bowing segments or outflows
still show up on the latest HRRR runs, and we will continue to
monitor for that potential with gusty winds pushing out away from
storms.

The main wave of precipitation, with embedded weak thunderstorms,
will shift overhead overnight. There is significant enough
differences in the CAMs and other models to reduce confidence in
overall rainfall totals. Friday may end up with significant dry
periods between the Missouri River and James River, especially
during the afternoon hours as rain bands rotate through. There end
up being a couple of maximums with this initial wave into Saturday,
over central SD and far eastern SD/west central MN.

Overall, the surface low will shift northeast from Colorado to
Kansas and Minnesota Saturday morning, pushing a wetting rain across
the region. The initial surge of rain showers will overspread the
area during the evening and overnight hours. While there will be
breaks in the showers they will continue through at least Friday
night. The rain showers may be accompanied by thunderstorms/mainly
just rumbles of thunder (after our initial storms this evening over
north central SD) through Friday evening.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
Issued at 401 PM CDT Thu Apr 25 2024

This period kicks off at 12Z Saturday with one low pressure system
departing while the next one organizes right on the heels of the
first one to our southwest. Lingering rain shower activity will be
possible Saturday morning, especially across our eastern zones as
the upper low circulation and its sfc reflection lift northeast
across MN into the western Great Lakes. Any additional rainfall will
be minimal with up to around a tenth of an inch of accumulation
possible during the morning. Otherwise, our forecast area could
sneek in a period of dry conditions at least by midday and afternoon
before the next surge of moisture moves into the region. Daytime
high temperatures will be on the cool side as we`re expecting
extensive cloud cover and 950mb temps between about +5C and +10C.
During the course of the day on Saturday, the 2nd in the series of
500mb low pressure systems will be organizing across the Four
Corners region of the CONUS.

Deterministic and ensemble guidance has a fairly good handle on this
system. They prog it to track northeastward out into the Central
Plains by Saturday night. It will continue to take a northeastward
track into NE during the day Sunday and end up somewhere around the
eastern SD/western MN border region by Sunday night before lifting
across northern MN and Ontario on Monday. The sfc low is expected to
be somewhat more displaced farther southeast from the upper features
compared to the first system that moves through tomorrow and
Saturday. Guidance takes this system`s sfc low through the Omaha, NE
area and central IA by midday Sunday and Sunday afternoon and then
on up toward the Twin Cities and western Great Lakes on Monday. The
first surge of moisture with this system is forecast to make it
northward into our forecast area by late Saturday night/early Sunday
morning. This activity should become more prevalent and widespread
during the daytime as the upper wave circulation moves closer into
our region. It appears at this time our far southern and eastern
zones will have the greatest potential to see the steadier rain
shower activity and higher rainfall potential by the time this
system winds down early Monday.

NBM QPF probabilities for seeing a quarter of an inch or more in a
24-hour period ending at 12Z Monday range from 30-70 percent with
this highest values(>50%) from the James Valley and east into west
central MN. Bumping up the probs to at least a half inch or more
within that same time frame prog our eastern zones(James Valley and
points east) between a 40-50 percent range. Farther west,
probabilities drop off considerably to between 10-30 percent. By 12Z
Monday, most of the PoPs associated with this system will be exiting
our far eastern zones. A dry period can be expected thereafter until
late Monday into early Tuesday with another mid-lvl wave traverses
the region from west to east. Only light rain shower activity and
minimal rainfall is expected at this time. Drier conditions will
return for the end of the period by the middle of next week.
Temperatures will remain rather cool on Sunday with highs struggling
to reach 50 degrees. It will be brief however as a warming trend is
expected during the course of the first half of next week.
Temperatures at or above normal will be possible with daytime
temperatures in the 60s and 70s and overnight lows in the 30s and 40s.

&&

.AVIATION /00Z TAFS THROUGH 00Z FRIDAY/...
Issued at 606 PM CDT Thu Apr 25 2024

Terminals KABR,KATY,KPIR,KMBG

As showers and thunderstorms gradually develop east and north
tonight, we can also expect lower cigs to form over the region,
likely becoming IFR after midnight. Showers may also bring
occasional MVFR vsbys.


&&

.ABR WATCHES/WARNINGS/ADVISORIES...
SD...None.
MN...None.
&&

$$

UPDATE...TDK
SHORT TERM...KF
LONG TERM...Vipond
AVIATION...TDK


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