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000
FXUS63 KABR 221527 AAB
AFDABR

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
1027 AM CDT Mon Apr 22 2024

.KEY MESSAGES...

- Elevated fire danger today has led to the issuance of a Red Flag
  Warning for the combination of gusty northwest winds and low
  humidity for parts of central and northeast South Dakota.

- 10 to 20% chance of sprinkles/very light rain, mainly across
  portions of northern and northeastern SD this morning through
  the midday.

- Near to above normal temperatures through much of the 7-day
  forecast.

- There are PoPs covering the extended forecast starting Thursday
  for the upcoming active weather pattern.

&&

.UPDATE...
Issued at 1023 AM CDT Mon Apr 22 2024

Frontal boundary is making its way through the James River valley
as winds have switched to the northwest. Starting to see the drier
air and windy conditions develop across central SD behind the
front. May need to consider a Wind Advisory for north central SD.
Will leave the Red Flag Warning in place as humidity values will
drop down to around 20 percent along with the gusty winds
developing. Greenup is progressing, especially for southern areas,
so perhaps not quite a heightened concern with the Red Flag this
go-around, but still windy and dry nonetheless.

&&

.SHORT TERM /TODAY THROUGH TUESDAY AFTERNOON/...
Issued at 405 AM CDT Mon Apr 22 2024

Short term models continue to show a quick shortwave moving in from
the west/northwest, associated with a closed low in Canada. Winds
aloft will be increasing to around 50-60kts out of the
west/northwest through the day. The 850mb and weak surface
trough/front will push quickly west to east over the CWA this
morning through the early afternoon. CAMs indicates some light
returns across parts of our northern/northeastern counties but will
that even reach the ground? Several RAP Bufkit soundings in this
area continue to show very dry low levels so this could be more of a
sprinkle or virga situation with maybe some light rain at most along
the ND/SD border, closer to the low. Pops run from around 10-20% to
show for this.

Behind the front, drier air moves in with NBM indicating RH values
tanking this afternoon, dropping into the upper teens to the lower
20 percentile for most of the CWA. A steepening pressure gradient
will lead to winds picking up out of the west/northwest as soundings
show the classic inverted V look to them with steep low level lapse
rates, mixing well into the 700mb range (30-40kts) over much of the
CWA with higher speeds across north central to south central SD this
afternoon. Soundings indicate surface winds-925mb, ranging from 20-
30kts, highest over north central SD. NBM shows this well with both
sustained wind and gusts, with gusts ranging from 20-45kts, again
highest over north central SD. Winds will continue to be breezy
overnight (20-30kts gusts) into Tuesday (25-35kts gusts) as a
secondary cold front swings through (and 850mb winds increasing to
30-40kts). Winds will decrease west to east Tuesday evening.

The combination of low RH and gusty winds this afternoon leads to a
fire weather concern. The Fire Weather Watch has been upgraded to a
Red Flag Warning from north central to central SD along with a few
of the northeastern SD counties. The rest of the counties I have
dropped the Fire Weather Watch and replaced with an SPS for elevated
fire concern. Previous shift did mention it is looking much more
green across our southern/southeastern counties which is why I
decided on an SPS for here. However, this will need to be monitored
through the day for a possible upgrade.

&&

.LONG TERM /TUESDAY EVENING THROUGH SUNDAY/...
Issued at 405 AM CDT Mon Apr 22 2024

High pressure at the surface and aloft has a hold over the CWA at
the start of the period. Dry and cool conditions Tuesday night give
way to dry and warm conditions Wednesday into Thursday. By Thursday,
the high pressure ridge aloft has moved east of the region, placing
the CWA underneath southwest steering flow. Models are depicting
some pockets of precipitation possibly getting going as early as
Thursday afternoon, but in rather sparse coverage. Better
coverage/increasing PoPs are in place by Friday morning through
Friday night when a large chunk of energy is progged to lift out of
Colorado and head northeast toward the region. At this point, it
appears the low will occlude Friday night somewhere between northern
Nebraska and southeast South Dakota, with TROWAL-forced
precipitation chances potentially hanging on into the first part of
Saturday. There is another low pressure system progged to lift out
of the western CONUS longwave trof, but not before a lull in
precipitation potential from ~the middle of Saturday through the
first half of Sunday. Models still have some work to do, to get on
the same page for timing/track of this second low pressure system
scenario out at the end of the forecast period.

Winds will need to be monitored closely for Thursday, as current
guidance suggests (at least) wind advisory strong southerly winds
will be in play.

With the GFS/GEFS no longer forecasting markedly cooler low level
air (compared to ECMWF/Canadian counterparts) in the days 3 through
5 timeframe, the in-house ensemble-based temperature guidance is
closing in on some warmer temperatures for the mid to late week
timeframe. Expect highs in the 60s and 70s (potentially warmer than
that over portions of the Missouri River valley and points west).
Even on Saturday, there is currently a 25 to 65 percent
chance of seeing daytime highs 60 degrees or higher.

&&

.AVIATION /12Z TAFS THROUGH 12Z TUESDAY/...
Issued at 637 AM CDT Mon Apr 22 2024

Terminals KABR,KATY,KPIR,KMBG

VFR conditions are forecast through the TAF period. Winds will
shift to the west/northwest today and become gusty. A passing
shower/sprinkle is possible, mainly this morning, at the KMBG and
KABR terminals.


&&

.ABR WATCHES/WARNINGS/ADVISORIES...
SD...Red Flag Warning until 8 PM CDT /7 PM MDT/ this evening for
     SDZ003>011-015>018-033>037-045.

MN...None.
&&

$$

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