148
FXUS63 KABR 310828
AFDABR

Area Forecast Discussion
National Weather Service Aberdeen SD
328 AM CDT Fri May 31 2024

.KEY MESSAGES...

- There is a 50-80% chance for showers and thunderstorms Sunday
afternoon and evening. Strong to severe thunderstorms will be
possible.

- Temperatures are forecast to rise above normal this weekend into
next week (highs in the 80s).

&&

.SHORT TERM /TODAY THROUGH SATURDAY AFTERNOON/...
Issued at 328 AM CDT Fri May 31 2024

The surface weather map at 08Z showed the exiting cold front/trough
across western MN and far southeastern SD. High pressure was set up
over much of western and central SD. While more persistent fog has
been seen off satellite imagery northeast of Traverse County in MN,
spotty fog has developed over eastern SD. This is where more rain
has fallen over the past 18 hours adding to the low level moisture,
and where winds remain light. A new daily record for precipitation
was reached yesterday at K8D3/Sisseton, with 1.35". We will keep
monitoring the latest visibility trends, like KATY/Watertown varying
between greater than 6 miles and 1/4 mile visibility between 0645-
0745Z.

Despite the area of high pressure at the surface, much of western SD
is under clouds and light rain. This is thanks in part to the 500mb
trough moving across the Northern Plains into Saturday morning. We
will continue the chance of light rain (around 20% chance) across
portions of the area through the day mainly from around Pierre
northeast to Redfield, Sisseton, and Watertown. These low chances
for precipitation will continue into this evening, before dry
weather returns through Saturday morning. Relatively light winds
will remain through the period.

&&

.LONG TERM /SATURDAY EVENING THROUGH THURSDAY/...
Issued at 328 AM CDT Fri May 31 2024

Saturday evening starts the long term with westerly flow aloft. This
will remain the pattern through Monday night. Tuesday, we get into
some southerly flow as a negatively tilted trough starts to move in
from the west. The GFS brings that trough in a bit faster than the
Canadian and EC, with the axis of the trough passing over the area
during the day Tuesday. The other two deterministic models are
slower and also bring the center of the low over the region
overnight Tuesday through Wednesday. The EC keeps the low
circulating over the Dakotas through the night Wednesday before
slowly moving southeast Thursday. The EC definitely has a stronger
and slower low, with shortwave energy remaining over eastern SD into
Friday morning. The Canadian and GFS both have northwesterly upper
level flow after the low moves off through the end of the period.

The best chance for some rain looks to be Sunday evening into early
Monday morning. NBM has PoPs ranging from 25% across central SD to
65% over northeastern SD Sunday evening and 15-25% west river to 75-
80% east of the James River Sunday night. With mid level lapse rates
around 7.5 C/km over eastern SD and MLCAPE between 1000 and 2000
J/kg, there looks to be a good probability of storms east of the
Missouri River with some possibly becoming severe. SPC has placed
the area in a slight risk (2 of 5) for severe storms already at Day
3. Another chance for rain would be Tuesday evening. NBM has PoPs in
the 25-45% range for areas east of the Missouri River. There also
looks to be a chance for some severe storms during this time frame
around and east of the James River with LR and CAPE values about the
same as Sunday evening.

With southerly winds and WAA, high temperatures for the first few
days of the period will be between 5 and 10 degrees above average,
in the upper 70s to low 80s. When the low moves in mid-week, winds
will be more northerly and bring CAA, which will bring temperatures
down to about average. Winds on Tuesday and Wednesday could become
strong during the afternoon hours mainly west river, with gusts of
30-35 mph possible.

&&

.AVIATION /06Z TAFS THROUGH 06Z FRIDAY/...
Issued at 1213 AM CDT Fri May 31 2024

Terminals KABR,KATY,KPIR,KMBG

VFR conditions for all terminals though KATY could see some fog
develop through the course of the morning hours.


&&

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

$$

SHORT TERM...KF
LONG TERM...KK
AVIATION...Connelly