Area Forecast Discussion Issued by NWS Aberdeen, SD
000
FXUS63 KABR 151733 AAC
AFDABR
Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
1233 PM CDT Fri Mar 15 2024
.KEY MESSAGES...
- West winds of 25 to 40 mph and low afternoon humidity combine
for Red Flag conditions today in central/north central SD, and
a portion of the James valley.
- Cold front will shift winds to northwest tonight, with wind gusts
of 30 to 40 mph. These winds continue into Saturday.
- Mainly dry with near to above normal temperatures (Mon-Wed).
&&
.UPDATE...
Issued at 1225 PM CDT Fri Mar 15 2024
Updated discussion for the 18Z TAFs below.
UPDATE Issued at 1003 AM CDT Fri Mar 15 2024
As of 10AM, still some low clouds (1000-2000ft) over parts of
eastern SD into west central MN. They continue to push off towards
east/southeast slowly. Otherwise, wind gusts have been under
20mph this morning. A westerly wind will pick up through the day
along with daytime mixing/sunny skies will lead to gusts ranging
from 30-35kts with some areas possibly reaching 40kt gusts, with
the highest wind gusts across northern SD along the ND border. RH
values are forecasted to plummet to around 15-20% this afternoon
from the northern James River Valley to west of the Missouri
River, with the lowest values from Corson to Stanley counties.
With the gustier winds today along with low RH and ongoing dry
vegetation, a Reg Flag Warning remains in effect until 8pm. No
changes made to the forecast as it remains valid.
&&
.SHORT TERM /TODAY THROUGH SATURDAY AFTERNOON/...
Issued at 255 AM CDT Fri Mar 15 2024
An area of stratus over the central portion of South Dakota and
eastern North Dakota is forecast to progress east through the
morning. Should have minimal impact on sunshine, high temperatures
as model timing is between 12-15Z for passage out of eastern South
Dakota.
So, for today... high pressure will drift south while low pressure
deepens across the Western Lakes region. That puts us in westerly
low level flow, which will result in efficient mixing and dry fetch
off the higher terrain to the west. 1/2km winds increase from only
about 15kts this morning to between 30-40kts across the northern
tier of the CWA to 25kts south of highway 212. Mixing these winds
may be less efficient due to the fact that they are during a warm
advection push, so there is some uncertainty. BUFKIT mixed winds
show portions of the CWA along the ND state line well into the 30kt
range. For Pierre, it will be much more marginal, with lower
probabilities for exceeding 25mph. Unfortunately BUFKIT mixed tool
does support mid 20kts, so will err on the side of caution here.
Similar uncertainty exists with respect to dewpoints, which CAMS
show from the low range of single digits to upper teens in the
central portion of the CWA, and teens to low 20 degree range in the
eastern CWA. Sticking pretty close to the mean with this one, and
that still gets us below 20-25 percent RH for much of the CWA. As
such, will issue a Red Flag warning.
Pressure falls of 10mb/6 hours this evening are reversed with the
passage of a cold front tonight. Wind shift with this one is only
about 45 degrees (from west to northwest winds) so thankfully any
shifts in fire trajectories will not be so extreme. Cold advection
will mean winds stay up overnight and increase during the day
Saturday with a subtle surge in cold advection late in the day.
&&
.LONG TERM /SATURDAY EVENING THROUGH THURSDAY/...
Issued at 255 AM CDT Fri Mar 15 2024
A highly meridional and amplified pattern looks to continue through
most of the long term. That mid level pattern consisting of a block
over the western CONUS, and a deep trof over the eastern half of the
CONUS. This pattern should, overall, favor dry conditions for the
forecast area. However, that said, cold northwest flow aloft can be
tricky, especially on days where moderate sfc warming leads to steep
boundary layer lapse rates. Nonetheless, forecast will remain dry
until late next week. At that time, the pattern aloft begins break
down and allowing for more energy to cross the Rockies and enter the
Northern Plains. The long term starts off on Sunday with colder than
normal temps, as a cold airmass spreads over the region. However, by
Monday and for much of next week, the ridge/trof location aloft
allows for a milder airmass to advect/form over the High Plains and
then move into the Plains. So, after Sunday, temperatures will trend
back toward normal, and even above normal.
&&
.AVIATION /18Z TAFS THROUGH 18Z SATURDAY/...
Issued at 1225 PM CDT Fri Mar 15 2024
Terminals KABR,KATY,KPIR,KMBG
VFR cigs continue for the TAF period with the exception of KATY
which could see brief MVFR cigs between 13-16Z Saturday. A cold
front will swing from northwest to southeast over the forecast
area bringing a shift in winds from west to out of the northwest
behind it during the overnight hours. Winds will remain on the
breezy side this evening through the overnight hours and into much
of the day on Saturday before decreasing Saturday evening.
Sustained winds will range between 10-20kts with gusts 20-30kts
and up to 35kts Saturday afternoon.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...Red Flag Warning until 8 PM CDT /7 PM MDT/ this evening for
SDZ003>006-009-010-015>017-033>035.
MN...None.
&&
$$
UPDATE...MMM
SHORT TERM...Connelly
LONG TERM...TDK
AVIATION...MMM