628
FXUS63 KABR 302033
AFDABR

Area Forecast Discussion
National Weather Service Aberdeen SD
333 PM CDT Tue Apr 30 2024

.KEY MESSAGES...

- Showers and scattered thunderstorms end by early evening across
  northeast South Dakota and west central Minnesota. Still can`t
  rule out a strong storm or two south and east of the Watertown
  area through late afternoon/early evening.

- At least 3 or 4 notable wave will move through the region,
  providing rainfall chances. Thunderstorm chances (including
  potential for severe storms) overall, look rather low through the
  period.

- Near to below normal temperatures early in the period potentially
  warming to near or above normal beginning Sunday into early next
  week.

&&

.SHORT TERM /THIS EVENING THROUGH WEDNESDAY NIGHT/...
Issued at 331 PM CDT Tue Apr 30 2024

At mid-afternoon, sfc low pressure and an associated cold front are
tracking their way eastward across eastern South Dakota. Showers and
thunderstorms have developed and advanced in a northeast fashion in
conjunction with this system. A robust, negatively tilted s/w trough
is currently shifting northeast across our region with strong
southwesterly flow aloft of about 45-55 kts helping to kick off the
convection observed across eastern SD this afternoon. Ingredients
for severe weather is just lacking for the most part in our CWA
compared to locales farther south of our forecast area. BUFKIT
profiles at Watertown continue to indicate steepening mid level
lapse rates prior to the fropa with some skinny CAPE developing late
this afternoon. Our southeast zones remain on the northern fringe of
the plume of instability. MUCAPE values off the HREF top our around
500j/kg late this afternoon across our far southeast zones before
shifting east out of our area by 00Z. SPC continues to highlight
portions of Deuel and Hamlin Counties for a marginal risk for severe
weather the remainder of today. Mid/upper lvl clouds are quickly
shifting off toward the northeast exposing the lower agitated CU
across our eastern zones, so we are expecting some heating to take
place still with the help of a little sunshine. CAMS do continue to
initiate surface based convection in our eastern forecast zones this
afternoon before it moves into western Minnesota. So, still can`t
rule out a strong or two in our far southeast that may produce some
hail and a localized strong wind gust or two.

For the most part, the convection is all over and done with by early
this evening. Increasing west to northwest winds on the backside of
this disturbance will continue to gust on the order of about 25-
40mph into tonight before beginning to relax by late evening. Wind
prone areas of the Sisseton Hills will hold onto the stronger winds
until after midnight. High pressure briefly moves through the area
during the first half of Wednesday. By the afternoon, it`s already
east of the CWA and we begin to pick up southerly low-lvl flow once
again. A persistent mid-level low poised northwest of our region
will maintain southwest flow aloft over our area. Mid level warm
advection kicks in once again by Wednesday afternoon helping to kick
off more shower development across NE and lifting north into central
and northeast SD Wednesday afternoon and Wednesday night.

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
Issued at 331 PM CDT Tue Apr 30 2024

The long term portion of the forecast begins on Thursday with an
area of low pressure and upper level trough crossing the region,
bringing yet another around of showers. According to the grand
ensemble, the probability of seeing a quarter of an inch of QPF is
35 to 55 percent. As of now, some of the deterministic models are
indicating a possible dry period on Friday, before more showers
cross the central and southern northern plains Friday night. The
latest NBM is also trending drier on Friday.

Ridging aloft begins to build across the area for the weekend,
bringing a period of dry and warmer conditions. High temperatures in
the 70s may finally return to the forecast area by Sunday.
Unfortunately, increasing southerly winds are also expected with the
NBM showing a 40 to 90 percent chance of gusts exceeding 30 mph
Sunday afternoon. Beyond Sunday, there are some differences among
models with the timing and evolution of the next upper level trough
and associated surface low pressure system. Some models suggest
showers will move back into the area as soon as Sunday night, while
others suggest Monday through Monday night. The NBM has high pops,
30 to 40 percent Monday into Tuesday.

&&

.AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/...
Issued at 1242 PM CDT Tue Apr 30 2024

Terminals KABR,KATY,KPIR,KMBG

Rain showers with embedded thunderstorms will continue to push
across portions of northeast South Dakota through the afternoon
affecting the KABR and KATY terminals. Occasional lighter showers
will be possible at KPIR and KMBG through the afternoon. KATY will
have the best chance to see a few -TSRA/TSRA with tempo vsby
reductions to MVFR. Lower cigs will be possible through the
majority of the afternoon hours at KABR and KATY before improving
to VFR this evening. Gusty west to northwest winds between 25-35
kts will be possible at KPIR and KMBG through the afternoon into
the evening before relaxing by mid to late evening.

&&

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

$$

SHORT TERM...Vipond
LONG TERM...SD
AVIATION...Vipond