Aberdeen, South Dakota 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

187
FXUS63 KABR 160557 AAC
AFDABR

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
1257 AM CDT Fri May 16 2025

.KEY MESSAGES...

- West to northwest winds will gust to 45 to 60 mph across central
  and northeastern South Dakota through Friday.

- The probability of low temperatures falling to 36F degrees or
  colder Saturday night is 60 to 90 percent in areas along and
  north of the US Highway 212 corridor.

- Another round of showers and thunderstorms will impact the area
  Sunday through Tuesday. The probably of seeing 0.75 inches of
  rain over a 24 hour period, ending at 7 am Tuesday, is 40 to 70
  percent.

&&

.UPDATE...
Issued at 1255 AM CDT Fri May 16 2025

See below for an aviation forecast discussion for the 06Z TAFs.

UPDATE Issued at 723 PM CDT Thu May 15 2025

The Wind Advisory for far eastern SD (mainly eastern slopes and
just east of the Sisseton Hills/Prairie Coteau) has been upgraded
to a High Wind Warning for the rest of the overnight hours.

UPDATE Issued at 637 PM CDT Thu May 15 2025

Strong winds will continue to be the main concern over the next
12-24 hours, with several locations gusting in the 45-60mph range.
Steady rain remains for much of the area, while returning for
portions of far northeastern SD and west central MN over the next
couple of hours. Few changes are currently needed to the ongoing
forecast.

&&

.SHORT TERM /THIS EVENING THROUGH TONIGHT/...
Issued at 225 PM CDT Thu May 15 2025

A strong upper level and surface low is driving the current weather
across the area, with the upper low centered between KABR/KMBG as of
19Z, with a 986mb surface low in southeast ND. A shortwave rotating
around the east side of the upper low has led to convection over
eastern SD and west central MN today, but that is nearly out of the
CWA as of this time. Once that lifts north over the next 60 minutes,
that will bring an end to the severe threat over our CWA.
Northwesterly winds around the low are bringing in much colder
temperatures to the area, with current temperatures in the low-mid
50s, or about 25 to 35 degrees colder than yesterday at 2pm. The
combination of the tight pressure gradient and colder air moving
into the area, has led to winds gusting to 45 to 60 mph over central
SD early this afternoon.

Primary focus through tonight is the strength of the winds and the
timing/location of the precipitation rotating around the low. The
strong low of around 986mb, which is a minimum in the CFSR climo
from 1979-2009 for the 3 weeks around today, will pivot and
strengthen slightly (low 980s) over southeastern ND tonight, leaving
a tight pressure gradient in place over the region through the
overnight hours and into Friday. With light cold air advection
continuing tonight, leading to low level lapse rates trying to stay
high enough to enable mixing (6-8 C/km from 0-0.5km), expect the
winds and gusts to stay up through the night. 0.5km winds are around
45-50kts and 850mb winds around 50-55kts (around top of mixed
layer), which would support solid advisory wind gusts this afternoon
into the first part of the overnight period. Do think there is
around a 6 hour period this evening, as the sfc low strengthens in
southeast ND, where we could see occasional gusts of 50kts over the
central part of SD. In addition, NBM 24hr Max Wind Gusts through 06Z
tonight have a 50-80% chance of a gust reaching 60mph for areas to
the west of Brown/Spink counties. Utilized that info and the
corridor of the strongest winds aloft to expand the High Wind
Warning northward to Dewey/Corson counties, although I do feel like
it may need to be pushed a tier of counties or two eastward this
evening, based on some of the latest CAM solutions. That eastward
expansion will likely depend on the strength of the surface low, as
those that have it in the 978mb range show the stronger gusts. In
addition, expanded the wind advisory northeastward to include the
rest of SD for this afternoon into tonight as the winds increase.
The winds are out of a favorable downslope direction on the east
side of the Coteau, so increased the gusts to near 60mph in that
area and highlighted that potential in the text product. Will have
to see how the obs trend and may need to upgrade the downslope areas
to a high wind warning too. Both of these headlines will continue
into Friday.

Now for precipitation through tonight. While there`s a little bit of
a lull right now, there will be plenty of moisture wrapping around
the low, leading to a decent sized precipitation shield that will
shift south and cover a good portion of the CWA tonight. Utilized
the CAMs to help nudge the NBM timing/coverage of the precipitation,
with the lowest chances over northeast SD and closer to the sfc low.
Models fairly consistent in the corridor of heaviest precipitation
producing 0.75-1.5" of rain between 00-12Z on Friday, although there
are differences in the exact location for it. The consensus has it
stretching from south central ND through north central SD and then
potentially somewhere east between US-12 and US-212 area towards the
James River valley. There may also be some upslope assistance over
the Coteau to produce some higher amounts by Friday morning.
Instability is largely reduced on the cold side of the low, but did
linger slight chances of thunder near the low (along the ND/SD
border) for tonight.

&&

.LONG TERM /FRIDAY THROUGH THURSDAY/...
Issued at 225 PM CDT Thu May 15 2025

The period begins on Friday with an anomalously strong surface low
pressure system near eastern ND or western MN. West-northwesterly
winds will continue impacting the forecast area throughout Friday,
with a 40-75 percent chance gusts exceed 45 mph west of the James
River valley. A wind headline may be need on Friday. High
temperatures on Friday will definitely be cold with readings in the
40s and low 50s. The NBM probability of seeing highs under 50
degrees is 30 to 75 percent, with the highest potential over the
western half of the CWA. These readings will be 15 to 25 degrees
below average for this time of year.

The storm system departs the region by Friday night, leaving behind
cool temperatures and diminishing winds. Low temperatures Saturday
morning may drop into the 30s, with frost possible. Temperatures
remain cool Sunday morning with a large portion of the CWA seeing a
50 to 85 percent chance of lows below 36 degrees. Increasing cloud
cover and rain chances may limit the frost potential over the
southwest CWA, or the Pierre and Murdo area.

Another storms system will cross the Plains into the midwest with
additional showers and thunderstorms expected, mainly Sunday
afternoon through Tuesday. The slow moving nature of the storms
should produce plentiful rainfall. The probably of seeing 0.75
inches over a 24 hour period, ending at 7 am Tuesday, is 40 to 75
percent. With cool temperatures, highs mostly in the 50s and low
60s, along with limited instability, severe weather is not expected
with this storm system.

&&

.AVIATION /06Z TAFS THROUGH 06Z FRIDAY/...
Issued at 1255 AM CDT Fri May 16 2025

Terminals KABR,KATY,KPIR,KMBG

MVFR to IFR ceilings and strong winds gusting 40-50kt will continue
through the overnight hours before slowly diminishing through the
day, with gusts weakening to 25-35kts Friday evening.

&&

.ABR WATCHES/WARNINGS/ADVISORIES...
SD...High Wind Warning until 7 PM CDT /6 PM MDT/ this evening for
     SDZ003-015-033-045.

     High Wind Warning until 7 AM CDT this morning for SDZ004-005-
     007>011-016-017-020>023-034>037-048-051.

     Wind Advisory from 7 AM this morning to 7 PM CDT this evening
     for SDZ004-005-007>011-016-017-020>023-034>037-048-051.

     Wind Advisory until 7 PM CDT this evening for SDZ006-018-019.

MN...None.
&&

$$

UPDATE...10
SHORT TERM...SRF
LONG TERM...SD
AVIATION...10