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000
FXUS63 KABR 160143 AAB
AFDABR

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
843 PM CDT Mon Apr 15 2024

.KEY MESSAGES...

- Low pressure to generate strong/severe storms over northern
  Nebraska up into western/south central SD this evening. The
  main severe threats are hail/winds, although the farther north
  storms go the less favorable the environment for severe weather
  becomes. Tornado threat hinges on how much northward progress
  the warm front over Nebraska makes through ~03-04Z this evening.

- Windy conditions (15 to 30 mph with higher gusts) will persist
  through Tuesday night, all the while eventually switching around
  to the north-northwest from Tuesday afternoon through late
  Tuesday night. Precipitation expands/spreads north across the
  forecast area tonight, with off and on showers persisting
  Tuesday and Tuesday night.

- Cooler temperatures, around 10 to 15 degrees below normal, can
  be expected for the latter half of the week.

&&

.UPDATE...
Issued at 838 PM CDT Mon Apr 15 2024

Continue to watch convection moving into the far southwest CWA,
but activity is running into drier and a bit more stable air and
have seen a weakening trend. Still more to come as additional
activity moves north into Jones/Lyman counties over the next
couple hours. Made some adjustments to sky grids based on current
satellite trends. Also let the Red Flag Warning expire at 01Z.
Will also be making PoP adjustments to account for the activity
moving into the southwest CWA.

&&

.SHORT TERM /THIS EVENING THROUGH TUESDAY NIGHT/...
Issued at 236 PM CDT Mon Apr 15 2024

At 2 pm CDT, skies are partly to mostly sunny and southeast winds
are running 20 to 30 mph with gusts of 40 to 50 mph, easily.
Temperatures have warmed into the 60s and 70s for most locales.
Relative humidity values this afternoon have dropped into the 20 to
30 percent range. Conditions are close enough to Red Flag criteria
that will allow the Red Flag Warning to continue until 8 pm CDT
(currently scheduled expiration time).

Convection is expected to develop within the slight/enhanced risk
areas along or close to a warm front down over Nebraska, within the
envelope that is "peak heating" today, perhaps closer to the end of
the envelope around 23Z/00Z south and west of this CWA. Storm motion
moves convection northward rather quickly into the far
southern/southwestern forecast zones by ~03Z. All the while,
instability/shear progs suggest the better storm environment to the
south in northern/northwestern Nebraska may advect northward some
between 23Z and 04Z. It`s a rather low potential for happening,
given less than favorable LCL heights. But, most everything else
appears to become available, briefly, there in Jones/Lyman counties
for "all modes of severe" potential. 0-1km shear is progged right
now to increase to more than 25 knots and the available instability
increases as well from less than 500J/kg to potentially as much as
1500J/kg through 03-04Z timeframe as the warm front tries to work
northward a little bit. Otherwise, there remains a large hail threat
through, mainly, the late evening hours, before the core of
strongest PVA/mid-level WAA-forcing begins to overspread the region
later tonight through Tuesday. The upper low circulation is forecast
to be lifting out into western Kansas around 12Z Tuesday, tracking
over into the Minnesota/Iowa/Wisconsin tri-state area by 12Z
Wednesday. TROWAL-forcing should be taking over by the end of the
day Tuesday, with some areas of showery activity possible Tuesday
night into early Wednesday morning until the TROWAL-forcing region
shifts eastward away from the CWA. Ensembles-based qpf potential
still ranges from 0.50in to 1.50in of rain (30-80% chance of an inch
or more of rain over the CWA through 12Z Wednesday).

Winds will continue running at 15 to 30 mph with occasional higher
gusts overnight, especially where-ever there is a terrain-favored
downslope trajectory (north/west side of the Prairie Coteau for
example). Strongest corridor of low level winds (0.5km depth)
appears to swing around and focus over Minnesota on Tuesday. Wind
Advisory criteria may happen across the far eastern forecast zones
on Tuesday. Otherwise, should see Tuesday afternoon/evening lining
up as the transition zone from WAA-zone wind to CAA-zone wind when
direction shifts around to the north-northwest.

&&

.LONG TERM /WEDNESDAY THROUGH MONDAY/...
Issued at 236 PM CDT Mon Apr 15 2024

This period will continue a somewhat active trend from where the
short term left off. Low pressure that brought showers and
thunderstorms to the area prior to this period is progged to lift
northeast into WI and the Great Lakes on Wednesday. Back-side
showers will linger across our eastern zones Wednesday morning
before shifting out of area by day`s end. A tight gradient will be
maintained leading to gusty northwest winds of up to 25-35 mph. This
will help to draw in a cooler air mass. The coldest part of the air
mass will still hold off a bit longer however. An expansive upper
low will traverse across southern Canada in and close to the
International border region the latter half of this week. A quick
moving wave rounding the base of this feature could bring some light
rainfall to our far southern zones late Wednesday night into
Thursday morning. Overall though, a dry period is expected for the
end of the week and through the upcoming weekend. Cold air advection
processes will drive in the coolest portion of the air mass Friday
into Saturday. 850mb temperatures are progged to remain a 1-2
standard deviations below climo. Overnight lows will be back to
freezing or colder beginning Thursday morning and daytime highs
struggling to reach 50 will be possible Thursday through Saturday.

&&

.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
Issued at 639 PM CDT Mon Apr 15 2024

Terminals KABR,KATY,KPIR,KMBG

VFR conditions early in the period will give way to lowering CIGs
into MVFR/IFR overnight into Tuesday morning. SHRA/TSRA will also
be moving into the region, with reductions in VSBY expected.
Cannot rule out hail (GR) with any stronger storms, especially
near KPIR later this evening. Low-level wind shear (LLWS) will
also be a concern across the region, but more confidence in its
impacts at KATY, and have inserted mention of this into the TAF.
Although, there should generally be much stronger winds near 45 or
50 knots just off the surface across eastern SD tonight, and
perhaps as far west as central SD.


&&

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

$$

UPDATE...TMT
SHORT TERM...Dorn
LONG TERM...Vipond
AVIATION...TMT