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000
FXUS63 KABR 240217 AAB
AFDABR

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
917 PM CDT Tue Apr 23 2024

.KEY MESSAGES...

- Winds out of the south to southeast between 35-45 mph will be
  possible Thursday into Thursday night, strongest across SD.

- A more active and wet pattern develops by the end of the week
  into early next week as a couple of low pressure systems move
  through the region delivering rainfall to most of the forecast
  area.

&&

.UPDATE...
Issued at 915 PM CDT Tue Apr 23 2024

No major updates planned for this evening.

&&

.SHORT TERM /THIS EVENING THROUGH WEDNESDAY NIGHT/...
Issued at 246 PM CDT Tue Apr 23 2024

The current surface weather map shows the exiting area of low
pressure over the Upper Great Lakes, and a broad area of high
pressure from central Canada through MT and the western Dakotas. A
tight pressure gradient between these features has help keep winds
out of the north to northwest at 20-25 mph with gusts of 25 to 35
mph. Winds are slowly beginning to diminish over central SD as
the surface ridge nears.

The surface ridge will shift into the eastern Dakotas by 00Z and
push into MN Wednesday morning. Dry air will remain in place for
much of the area Wednesday, with relative humidity values falling to
25 to 35 percent. Winds out of the south to southeast will be on the
increase during the day Wednesday, with gusts nearing 35 mph west of
the Missouri River late Wednesday afternoon into Wednesday evening.
While little to no precipitation is expected, several CAMs do hint
at evening showers developing across eastern SD. The chances for
precipitation of 0.01" or more were generally kept at or below 20%
with the increasing low level winds and weak 500mb wave ahead of the
apex of the ridge shifting overhead Thursday morning.

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
Issued at 246 PM CDT Tue Apr 23 2024

The main focus in this period will be on the upcoming pattern shift
that will turn our dry and warm conditions into a more wet, cool one
by the end of the week into this weekend. Starting Thursday at 12Z,
we see an upper ridge still in place and overhead controlling our
weather for one more day. Most of the day Thursday will feature dry,
windy and warm conditions. A tight pressure gradient develops
between sfc high pressure across the western Great Lakes and low
pressure across the lee of the Rockies and northern High Plains.
Strong south to southeast winds develop during the day with expected
gusts by afternoon between 35-45 mph. In fact, probabilities of
seeing wind gusts reaching or exceeding 40 mph are high across most
of our forecast area, except for our far eastern zones. Most of our
SD zones stand a 60-90 percent chance of seeing wind gusts of this
magnitude. 950mb temperatures will climb to between +15C and +20C by
the afternoon which should translate into highs well above normal.
We`re still going conservative at this point with deterministic NBM
closer to the 25th percentile, but it`s possible we may have to bump
these values up before Thursday approaches.

As referenced, the upper flow pattern is going to turn more active
by Friday and remain that way right through the weekend into early
next week. An upper trough/low working through the 4-corners region
will shift northeast into the central Plains by late Thursday into
Friday. Sfc low pressure is well progged by deterministic and
ensemble solutions to organize in the lee of the Rockies and shift
northeast into the northern Plains on Friday into Saturday. Lead s/w
activity could kick off showers and some thunderstorms as early as
Thursday evening before pcpn expands and spreads across our forecast
area overnight Thursday night into Friday and Friday night.
Probabilities of seeing a half inch of rain in a 24-hr period for
our CWA are high in the 50-70 percent range for most of our zones.
This would be associated with just the first of the two systems
Thursday night through the first half of Saturday. We expect a break
in the rainfall by Saturday evening as the first system lifts
northeast into the Great Lakes.

A secondary, follow-on low pressure system is progged to lift out
into the Plains by the end of the weekend through Monday, in perhaps
similar fashion to Friday`s system. Guidance does seems to have a
decent grip at this point on track and timing of this one. Rainfall
chances are expected to increase across our forecast area on Sunday
and linger into Monday morning before curtailing as the system pulls
away. There still remains differences in placement of QPF with this
disturbance, but latest trends hint at the steadier or higher values
could be across our eastern zones once again. Something to watch in
the coming days and iron out. Temperatures will be trending downward
as expected with all the clouds and rainfall around. Daytime reading
are expected to cool from the 50s and 60s on Friday to the 40s to
around 50 degrees on Sunday. A bit of rebound will be possible early
next week with temperatures climbing back to near to above normal
values for late April.

&&

.AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/...
Issued at 604 PM CDT Tue Apr 23 2024

Terminals KABR,KATY,KPIR,KMBG

VFR skies/vsbys are expected regionwide through tonight.


&&

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

$$

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