Area Forecast Discussion
Issued by NWS Aberdeen, SD

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000
FXUS63 KABR 171730 AAB
AFDABR

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
1230 PM CDT Sun Mar 17 2024

.KEY MESSAGES...

- Flurries this morning. Winds out of the north 20 to 30mph today.

- Warmer for Monday, with increasing winds out of the west in the
  afternoon. Afternoon humidity of 15 to 25 percent will result in
  high to very high Fire Danger.

- Mild on Tuesday then temperatures dropping below normal for Wednesday
  though Saturday. Precipitation chances increasing for Thursday. Snow
  possible at that time.

&&

.UPDATE...
Issued at 1227 PM CDT Sun Mar 17 2024

See the updated aviation discussion below.

UPDATE Issued at 1036 AM CDT Sun Mar 17 2024

Flurries or light snow showers have been noted across the region.
Coverage/intensity of showers is greater east of the James River
Valley. A few webcams are showing snow accumulation in grassy
surfaces, so did go ahead and bump wording from flurries to light
snow for this area. Light snow may linger longer into this evening
for that area as well. Otherwise models do continue to trend
toward breaks in the cloud cover for areas further west. Besides
this minor wording change, the current forecast looks to be on
track.

&&

.SHORT TERM /TODAY THROUGH MONDAY AFTERNOON/...
Issued at 243 AM CDT Sun Mar 17 2024

Northwest flow regime across the region will direct cold Canadian
air across the Dakotas/Minnesota today. Temperatures at 850mb bottom
out at 12-15Z this morning, between -10 to -17C, which will run us
about a standard deviation below climo. Mixed winds in BUFKIT with
steep low level laps rates translates into the mid 20 to low 30kt
range. Any daytime heating will provide enough impetus for some
weak/shallow convection and snow showers (flurries) as we have
already seen through the overnight hours.

Light winds tonight with a 1028-32mb high moving north to south
across the Dakotas. As this feature shifts to the south, and low
pressure develops across central Canada, the pressure gradient
increases to a peak of about 10mb across the state (from southeast
to northwest) along with pressure falls of 10mb/6 hours prior to
frontal passage. Strong warm advection will have a similar
inhibiting factor on peak winds as it did on Friday despite the
increased gradient, however mixed winds are still on the order of
30kts during that 21-00Z timeframe. Ensemble afternoon relative
humidity 25th-75th percentiles only show a range of 2-8 percent with
a general range between 20 and 30 percent, so for the afternoon we
may be looking at approaching Red Flag criteria. Will also see some
Coteau enhancement late with an inversion across the Sisseton hills,
southwesterly low level flow with continued strong northwesterlies
aloft.

&&

.LONG TERM /MONDAY EVENING THROUGH SATURDAY/...
Issued at 243 AM CDT Sun Mar 17 2024

As has been mentioned in previous discussions, an amplified
ridge/trof pattern aloft will continue through much of the long
term. Thus, mainly dry conditions are warranted until Thursday. On
Thursday a piece of mid-level energy tops the western CONUS ridge
and then slides southeast across the region, mainly North Dakota,
and then clipping the northeast part of South Dakota. There has been
decent consistency in this feature, although the most recent model
runs have trended slightly south with main pcpn axis. It looks to be
mainly a snow event with GEFS 24hr probs of an inch relatively high
(40-60%) along the border with ND and northeast SD. 24hr 3 inch
probabilities are fairly low at 20%. Looking toward the weekend,
forecast confidence is on the wane. The various models continue to
flip back and forth on whether the pattern will be progressive, or
will slow up and amplify over the central CONUS. The latest H5
height anomalies from the EPS/GEFS suggest some sort of trof over
the western/central CONUS by late weekend/early next week. The below
normal heights suggest below normal temps too from Wed-Saturday.

&&

.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 1227 PM CDT Sun Mar 17 2024

Terminals KABR,KATY,KPIR,KMBG

Flurries and MVFR CIGS can be expected at the KATY TAF site
through 00Z. For the rest of the region, VFR conditions will
prevail. Gusty northwest winds will gradually taper off this
evening as high pressure settles in.

&&

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

$$

UPDATE...Serr
SHORT TERM...Connelly
LONG TERM...TDK
AVIATION...Serr


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