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000
FXUS63 KABR 212320 AAA
AFDABR

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
620 PM CDT Sun Apr 21 2024

.KEY MESSAGES...

- Elevated fire danger on Monday due to the combination of gusty
  northwest winds and low humidity.

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

- Increasing rain potential for the second half of the upcoming work
  week.

&&

.UPDATE...
Issued at 614 PM CDT Sun Apr 21 2024

The forecast remains on track this evening. No major changes are
planned.

&&

.SHORT TERM /THIS EVENING THROUGH MONDAY NIGHT/...
Issued at 325 PM CDT Sun Apr 21 2024

We`ll keep southerly winds in place overnight with mild air aloft
out ahead of the approaching surface frontal boundary. Therefore,
don`t expect temps to drop much below 40 degrees for much of the
area. Will be watching the frontal boundary and weak mid-level wave
moving through the area on Monday. Still appears lower levels of the
atmosphere are rather dry on Monday, so it may be difficult to get
much more than some areas of virga/sprinkles or a couple light
showers. Low PoPs/sprinkles are in the forecast to cover this
passing weak wave.

More focus will revolve around the elevated fire danger on Monday in
the post-frontal air where northwest winds will begin gusting from
30 to 45/50 mph during the afternoon hours. Best mix down potential
for strongest gusts off Bufkit look to be across central/north
central SD where advisory-level gusts are possible, so something to
consider for the overnight shift - the possibility of needing a
headline for wind. With all this wind, comes a dry air mass, with
forecast humidity values falling to around 20 to 25 percent over a
good chunk of the CWA, maybe even a tad lower than 20 percent over
central SD. The fuels status are the big question, as we are
progressing through greenup, at least in the beginning stages.
Whether or not we are to a point where we can call portions of our
CWA "not critical" anymore is a struggle, and tried to err on the
side of caution even while using what guidance/evidence for
greenness is given to us. Decided to issue a Fire Weather Watch from
18Z to 01Z tomorrow, and mid shift can decide how they want to
proceed. Web cams seem to hint that southern portions of the CWA
have progressed into greenup perhaps a bit further than areas across
the north.

Models then show a cold front dropping south across the area Monday
night. A shot of cold air advection at the low levels gets going
Monday night as we start off around +14C to +15C at 925mb, but by
12Z Tuesday we are down to about +4C to +6C.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
Issued at 325 PM CDT Sun Apr 21 2024

Tuesday morning we have quite a lot of shortwave energy over the
area that will move east through the day and allow an upper level
ridge to become dominant. This ridge moves east through the next few
days. Friday, we have a low come up from CO/WY bringing our next
chance for some precipitation. This moves northeast and out of our
region by Saturday evening. Another low starts to move towards the
region at the end of the period.

The Canadian ensemble is showing the most intense rainfall at the
moment with around a 50-70% chance of more than half an inch of rain
in 24 hours ending Friday night (00Z Saturday) for areas east of the
James River. The EC ensemble isn`t far behind, with 70-80% chance of
more than a half an inch in 24 hours for the same area but ending at
midnight Friday night (06Z Saturday). The most the NBM gives at the
moment is 50-60% chance of a half an inch in 24 hours ending Friday
night (00Z Saturday), but its area is east of a line from Aberdeen
to Murdo. The EC and GFS are giving some good mid level lapse rates
Friday afternoon, around 7.5 to 8 C/km for areas east of the James
River. CAPE isn`t looking as great so not expecting strong to severe
storms at this time. Things could change throughout the week. Rain
chances continue through the weekend.

Winds on Tuesday could get a bit strong with gusts of 35+ mph not
out of the question as that low moves off to our east. Expect much
the same for Thursday as the low approaches for Friday. Temperatures
will be right around normal for this time of year with Thursday
being the warmest.

&&

.AVIATION /00Z TAFS THROUGH 00Z MONDAY/...
Issued at 614 PM CDT Sun Apr 21 2024

Terminals KABR,KATY,KPIR,KMBG

VFR conditions are expected through Monday evening. A mostly dry
front will move through the region on Monday bringing a wind shift
to the northwest and breezy winds.

&&

.ABR WATCHES/WARNINGS/ADVISORIES...
SD...Fire Weather Watch from Monday afternoon through Monday evening
     for SDZ003>011-015>022-033>037-045-048-051.

MN...None.
&&

$$

UPDATE...Wise
SHORT TERM...TMT
LONG TERM...KK
AVIATION...Wise