532
FXUS63 KABR 092022
AFDABR

Area Forecast Discussion
National Weather Service Aberdeen SD
322 PM CDT Sun Mar 9 2025

.KEY MESSAGES...

- Wind and fire weather headlines in place on Monday to highlight
  potential for gusts 45-60mph and critical fire weather
  conditions due to low humidity (20% or less) windy conditions,
  along with dry fuels.

- Record highs possible on Monday with much above normal
  temperatures (upper 60s to low 70s) moving in.

- A potential storm system could be affecting the region for the
  end of the week. Uncertainty surrounding system track, timing,
  precipitation type and change-over and strength of wind
  components, just to name a few, are all making this a complex
  system for Friday night and Saturday.

&&

.SHORT TERM /THIS EVENING THROUGH MONDAY NIGHT/...
Issued at 321 PM CDT Sun Mar 9 2025

Over the past hour or two, several observations across the region
are showing humidity around 20 percent or less with wind gusts
around 25 mph, give or take. Will therefore leave the Red Flag
Warning in place until its expiration time of 00Z this evening.
Temperatures are currently in the 60s across the region and have not
noticed anyone hit 70 yet, but it`s certainly not out of the
question as we have a few more hours of heating left.

Focus then shifts to Monday afternoon/evening with warm and dry air
surging eastward into the CWA. 925mb temps tomorrow are a few
degrees warmer than today, with readings topping out around +17C to
+20C across the CWA. So, likely adding a handful of degrees onto
Monday`s highs compared to what we saw today. This will bring most
areas into the upper 60s and low 70s. HREF cloud cover ensemble mean
does not suggest an overly abundant coverage of cirrus. Combine this
with good mixing, and the stage is set for near maximum heating
potential. Upped highs a few degrees and could easily see some/many
areas rising into the low 70s, perhaps even some areas around 75
degrees. After examining the new wind/RH numbers for Monday
afternoon, decided to add the rest of the CWA into the Red Flag
Warning. Also expanded the warning until 02Z as the wind shift with
the front moving south into the evening hours will be problematic
for any fires that start.

Strong winds still look like a good possibility across at least
northern SD by late afternoon Monday. 3hr pressure changes on the
order of 8 to 10mb showing up across northeast SD Monday evening.
Would like to see this coincide a bit better with daytime mixing,
but there is an opportunity for this perhaps over north central SD
by late afternoon into early evening, even further east across the
northern tier of counties. Things setting up more nicely over ND,
but still see some potential for high winds with gusts approaching
60 mph immediately in the wake of the frontal passage. Will stick
with the High Wind Watch for now and have mid shift take one final
look at how things are shaping up before any possible upgrades to a
warning. At the very least, a Wind Advisory is likely needed for
parts of the CWA.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
Issued at 321 PM CDT Sun Mar 9 2025

Northwest to zonal flow aloft expected for the middle of the work
week, with ridging Thursday in response to a trough deepening over
the western CONUS. Flow becomes diffluent aloft Friday as this wave
continues through the Rockies ahead of the upper low development
late Friday/early Saturday. This Colorado Low type setup continues
through Saturday as the upper low makes a curved track up to the
northeast through Minnesota.

At the surface, the long term starts with a departing 1016-1018mb
high pressure system. There is an about 10mb gradient across the
state for late Tuesday/early Wednesday so a brief stiff southerly
breeze before the pressure gradient relaxes during the day Wednesday.
Low level warm advection will get rid of the Canadian airmass from
earlier in the week. Continued, though light return flow means
slowly moderating temperatures through the end of the work week. At
00Z-06Z Friday, 850mb temperatures peak around +14C between the main
deterministic members, however ensembles/ensemble means are a bit
cooler with the EC ensemble only bringing the +12C line as far north
as Omaha, while the NAEFS has +12C up into south central South
Dakota. These represent a standard deviation to maybe about 2
deviations above climo. Deterministic members suggest later in the
day we see the wrap around cold airmass begin to actually impact the
CWA, with easter portions remaining in the milder air even into the
00Z-12Z Saturday timeframe.  PWATS are a little underwhelming as
well, only about a standard deviation over South Dakota despite the
fact we`re still in mid-March, say as in comparison to when we`re
mainly getting our Colorado lows between April and May. GFS
deterministic does go as high as 1" over towards Minneapolis, but
the values overhead are nothing earth-shattering at this point.

What is impressive at this point is how similarly the output between
deterministic members are at this point, with fairly similar surface
low placement through the surface low progression, though the
Canadian is a little slower. Surface pressure, and an estimated 25mb
gradient across the state translates into extremely windy
conditions on the backside of the system. Thus will leave the
blowing snow aspect of this system in the forecast.  850mb
temperature gradients are also fairly similar in timing, though the
Canadian is a little slower on the colder air migration, while the
EC is, as expected a little lower resolution so the gradient in
temperatures isn`t as extreme as the other two models. Still though,
there is still a lot of uncertainty between even GEFS members, with
QPF ranges of only around 0.1 to in excess of 2 inches likely the
result in slight shifts of the backside deformation zone and TROWAL
plus slight displacements in the thermal gradient/snow line.

&&

.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 1237 PM CDT Sun Mar 9 2025

Terminals KABR,KATY,KPIR,KMBG

VFR conditions are forecast through the TAF period.


&&

.ABR WATCHES/WARNINGS/ADVISORIES...
SD...Red Flag Warning from noon CDT /11 AM MDT/ to 9 PM CDT /8 PM
     MDT/ Monday for SDZ003>011-015>023-033>037-045-048-051.

     Red Flag Warning until 7 PM CDT /6 PM MDT/ this evening for
     SDZ003>006-009-010-015>018-033>037-045-048-051.

     High Wind Watch from Monday afternoon through Monday evening for
     SDZ003>011-015.

MN...Red Flag Warning from noon to 9 PM CDT Monday for MNZ039-046.

&&

$$

SHORT TERM...TMT
LONG TERM...Connelly
AVIATION...TMT