626
FXUS63 KABR 152317 AAA
AFDABR

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
617 PM CDT Wed May 15 2024

.KEY MESSAGES...

- Precipitation and clouds will depart from west to east this
  evening, making way for warmer temps and less clouds on Thursday.
  Although, 20-30% chances for showers and thunderstorms exist across
  northern areas late Thursday afternoon and evening.

- Above average temperatures can be expected on Friday with highs in
  the 80s to perhaps some low 90s.

- A frontal boundary crossing the area late Friday afternoon and
  through the overnight hours into early Saturday will produce a 30 to
  60 percent chance for thunderstorms.

&&

.UPDATE...
Issued at 614 PM CDT Wed May 15 2024

Made a few tweaks to hourly pops to account for the slower than
expected exit of some sprinkles and showers west of the James
Valley. Otherwise, the forecast remains on track this evening.

&&

.SHORT TERM /THIS EVENING THROUGH THURSDAY NIGHT/...
Issued at 315 PM CDT Wed May 15 2024

Surface low is located near KATY this afternoon, and can be seen
rather nicely on satellite and surface obs. Clearing out ahead of
the surface low has led to some instability in the southeast corner
of the CWA, along with surface vorticity present and nearly 100 J/KG
of 0-3km MLCAPE. Atmospheric conditions are such that there could be
a brief landspout/funnel across the far eastern CWA (mainly
Deuel/Grant/Roberts counties as of this writing and into Big
Stone/Traverse counties through around 5PM CDT). Aside from this,
will be watching the departure of this surface low and associated
mid-level shortwave through the night, bringing an end to the precip
and cloud cover from west to east.

On Thursday, the day appears to start off mostly sunny with just
perhaps some linger low clouds over the far east and high clouds
approaching from the west. During the afternoon and evening hours,
we do get some weak instability (HREF mean CAPE <1000 J/KG)
developing over northern portions of the CWA, along with weak shear.
A couple perturbations in the WNW flow aloft move through, with a
few CAMs showing widely scattered/isolated convection moving
eastward along the ND/SD border. Forecast will feature 20-30%
chances for this potential, mainly over the northern CWA.

&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
Issued at 315 PM CDT Wed May 15 2024

The period begins Friday morning with an upper trough working
through the PacNW and Northern High Plains and southern Canada. This
will aid in developing an area of low pressure at the sfc east of
the Rocky Mtn chain. With sfc high pressure located of to the
southeast of our region, increasing southerly flow will draw in a
much warmer air mass into the Dakotas on increasing southerly winds.
Along with this, low level moisture increases as dew point
temperatures are progged to warm into the 50s to near 60 degrees.
Well above normal temperatures can be expected on Friday. 925mb
temperatures still look to top out around +25C and with 850mb temps
also approaching +20C, this supports the idea of a very warm day.
Highs could approach the upper 80s to low 90s in some of our zones.

This warm up will be brief as the aforementioned low pressure to our
west and an associated cold front are progged to swing into the CWA
by late Friday afternoon and Friday night. This system will touch of
some shower and thunderstorm chances in which some storms could turn
strong to severe. At this time, deep layer shear doesn`t appear it
will be lacking as it will be on the order of 30-40kts of magnitude.
With modest instability developing by the end of the day and the
approach of the frontal system, some strong to severe convection
could be possible Friday night. There still are some factors that
may limit this potential like a capping inversion that could be in
place. We`ll have to keep an eye on these trends over the next 24 to
36 hours.

This system will push east of our area by Saturday morning. Cooler
temperatures and dry conditions should be the rule for the first
half of the upcoming weekend before more of an unsettled pattern
returns. Quasi-zonal flow aloft will be the anticipated upper flow
pattern early next week with multiple weak waves traversing through
the region. This could give our forecast area on again, off again
chances for precip through the middle of next week.

&&

.AVIATION /00Z TAFS THROUGH 00Z THURSDAY/...
Issued at 614 PM CDT Wed May 15 2024

Terminals KABR,KATY,KPIR,KMBG

MVFR/IFR cigs are expected to improve to VFR this evening
everywhere except KATY which will improve Thursday morning. There
may be some fog development toward morning due to the recent rain,
but there is still too much uncertainty regarding extent to add to
the tafs at this time.

&&

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

$$

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