518
FXUS63 KABR 140459 AAC
AFDABR

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
1159 PM CDT Sat Jul 13 2024

.KEY MESSAGES...

- Potential for strong to severe storms tonight (low confidence
  and less coverage) and again Sunday evening through Sunday
  night (higher confidence and storm coverage).

- Hot conditions continuing Sunday, with highs in the upper 80s
  to upper 90s and heat indices from 90 to perhaps 100 degrees.
  Hottest conditions expected across central SD.

- Temperatures will moderate with lower humidity for the first
  half of next week before readings warm back up toward the end
  of the week.

&&

.UPDATE...
Issued at 801 PM CDT Sat Jul 13 2024

Allowed the heat advisory to expire as most sites have fallen
below "feels-like" temperatures of 100 degrees with actual
temperatures back down in the 80s. Continuing to monitor ongoing
severe weather in southeast ND this evening as it moves south and
could clip Traverse county.

&&

.SHORT TERM /THIS EVENING THROUGH SUNDAY NIGHT/...
Issued at 311 PM CDT Sat Jul 13 2024

Still a rather complex forecast scenario in the short term in
regards to convection chances and heat indices, which unfortunately,
leads to a low confidence forecast this go-around. As for the heat
indices and headlines, will leave the current Heat Advisory in place
until 01Z this evening. The shortwave moving across the state right
now is still bringing quite a few mid and high level clouds for some
areas, and those spots are struggling a bit to realize maximum
temps/heat indices. Although, as central SD clears out from this
system, places like Pierre are finally starting to warm into the low
90s. Latest look at obs across the area does reveal quite a few
locations with 100+ heat indices, but it could be much more without
these clouds. That said, the number of 100+ obs have been increasing
a bit, and still several hours left of warming, so the headline
should work out OK, with potential for some areas to stay a bit
"cooler" where cloud cover hangs on the longest. Temps on Sunday
came in a touch cooler this forecast cycle, so headline potential
seems a bit more marginal and will let the overnight shift take a
closer look at possible heat headlines. If anything, it appears to
be the western/southwestern CWA in line for a possible headline.

Turning to convection, it is still a complex forecast and not real
confident in overall coverage this afternoon/tonight. This current
weak wave moving across the area this afternoon may actually
generate convection across the eastern CWA in the next few hours,
which a few CAMs have been trying to show. Speaking of CAMs, they
have kind of been all over the place in terms of storm placement,
timing, and overall coverage. What seems a bit more likely is
activity sliding southeast into the western CWA from whatever
becomes of the thunderstorm complex in southern Canada and northern
MT associated with a weak wave moving along the International
border. But again, coverage of storms is in question. Strong to
severe storms certainly possible, with CAMs indicating bowing
segments and high wind potential. SPC has upgraded to Enhanced Risk
for a portion of the northwest CWA.

We`ll rest the mechanism tomorrow into tomorrow night with continued
chances for strong to severe storms as we remain in a hot/humid and
unstable air mass. CAMs suggesting a bit more storm coverage late
afternoon and more so into the overnight hours over ND and parts of
our CWA. Chances in the forecast are generally 50-60% at its
highest, which is now over the eastern half of the CWA.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
Issued at 311 PM CDT Sat Jul 13 2024

The main theme in this period will be the return of a drier, cooler
air mass into the region behind a departing convectively producing
disturbance early in this term. Mid level flow across our region
will remain quasi-zonal early at the start of this period Monday
morning as an expansive mid level anticyclone remains centered over
the Four Corners region. Guidance continues to prog embedded mid
level shortwave energy tracking through our region early Monday.
Combining this with the passage of a cold front will lead to
scattered convection across the region and in our forecast area.
Monday morning should continue to feature leftover convection that
will be departing the eastern fringes of our forecast area. Can`t
rule out additional isolated convection later in the day as the
frontal boundary sags farther south through the CWA. Some hi-res
guidance suggests this scenario as favorable instability and deep
layer shear will remain present. However, at this time blended
guidance is going with dry conditions by Monday afternoon, so we`ll
stick with that trend.

The deeper upper trough axis will work through the Upper Midwest and
western Great Lakes on Monday. This will help to shove the sfc
frontal boundary farther south and east with sfc high pressure
building in across the Dakotas by Monday afternoon and Monday night.
Cold air advection will take over driving in a much cooler and drier
air mass. The center of the high will shift southeastward across the
central and eastern Dakotas on Tuesday and looks to remain fairly
persistent trough at least midweek, perhaps even a bit longer than
that. The aforementioned mid level anticyclone over the Four Corners
is progged by longer range guidance and the clusters to amplify
northward across the Northern Rockies/Northern High Plains into
Western Canada. This will lead to mainly dry and relatively cool
northwesterly flow aloft across our region until the end of the
week. Parts of our region will likely get into return flow once the
sfc high shifts farther east of our area late in the week. Warmer
temperatures and perhaps a touch more humidity will return late in
the period.

&&

.AVIATION /06Z TAFS THROUGH 06Z SUNDAY/...
Issued at 1153 PM CDT Sat Jul 13 2024

Terminals KABR,KATY,KPIR,KMBG

VFR conditions are expected through Sunday evening. A line of
thunderstorms may move through or near KMBG and KPIR through 9z
before exiting.

&&

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

$$

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