000
FXUS63 KABR 291737 AAC
AFDABR

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
1237 PM CDT Mon Apr 29 2024

.KEY MESSAGES...

- Precipitation gradually ending today as low clouds erode from
  west to east. Passing cold front on Tuesday brings another
  round of showers and thunderstorms.

- Additional systems for late Wednesday, Thursday and Saturday
  though overall less moisture is expected with these systems.

- Below to near normal temperatures through the weekend.

&&

.UPDATE...
Issued at 1017 AM CDT Mon Apr 29 2024

Held clouds in longer over the region today. There`s only been a
very slow wobble east in the clearing so far. Also lowered highs a
couple of degrees to account for the expected persistent cloud
cover in the east.

&&

.SHORT TERM /TODAY THROUGH TUESDAY AFTERNOON/...
Issued at 344 AM CDT Mon Apr 29 2024

Still seeing areas of rainfall/drizzle across the CWA as the upper
low spins overhead. This low moves east through the day, gradually
bringing an end to the precipitation. Cloud cover will take its time
to erode as well, but should see a gradual clearing from west to
east through the day according to HRRR/HREF low-level cloud
products. Highs will remain cool across the east, where precip and
clouds are expected to hang on the longest. Here, highs are likely
to top out in the upper 40s to low 50s. Across central SD where
sunshine should emerge by this afternoon, 60s are forecast.

Return flow sets up overnight as warmer air aloft begins
overspreading the region. At the surface though, fairly light winds
and mostly clear skies initially should allow for temps to drop down
into the 30s for many locations before cloud cover eventually does
increase once again (at least across central SD) between about 09Z
and 12Z Tuesday. There is some potential for fog, mainly over
eastern areas where radiational cooling conditions look to persist
the longest. Did not insert into the forecast quite yet as
confidence isn`t overly high, but something for the day shift to
consider.

Focus then shifts to Tuesday as a cold front moves eastward across
the CWA. Mid-level shortwave energy associated with this as well, so
once again the stage is set for precipitation to move across the
region. Environment is characterized by high shear and low CAPE, so
thunderstorms definitely a possibility, but chances for
strong/severe storms seem somewhat limited. Better low-level
moisture and instability set up just to our south over southeast SD
into eastern NE and western IA, where better chances for severe
storms reside. That said, given the high shear environment (40-50
kts 10m AGL-500mb) and limited instability over the far southeast
CWA, would not be surprised if a few stronger storms get going. 1-hr
max 2-5km UH >75 showing up mainly over FSD CWA, but the northern
fringe of does flirt with the CWA border near Hamlin/Deuel counties.

&&

.LONG TERM /TUESDAY EVENING THROUGH SUNDAY/...
Issued at 344 AM CDT Mon Apr 29 2024

Showers and Thunderstorms in the far east will rapidly depart early
in the period (Tuesday evening) according to CAMS/NBM. Weak high
pressure follows for Tuesday night into Wednesday while a Colorado
low develops to the south. Upper flow is west/southwesterly, and
there is actually evidence in the GFS/NAM for one of these weak
embedded wave lifting into the western portion of the state during
the afternoon/evening Wednesday prior to the influence of this
Colorado low. The end result appears to be fast moving (in excess of
50-60kts) mid level showers. The rain associated with the Colorado
low then falls mainly on Thursday, with the low moving from Kansas
to Iowa before lifting across Minnesota and back into southern
Manitoba. This means, that while moisture will mostly come in one
wave Thursday, we`ll be stuck in a cool Canadian airmass wrapping
back across the Dakotas, with plenty of low level moisture to
generate clouds/light rain...and any sunshine will instantly
destabilized the low levels for additional shower activity...thus
the prolonged period of POPs that run through Friday even though the
system is lifting away.  With the upper low over North
Dakota/southern Canada, zonal flow develops for Saturday, with a
subtle wave crossing quickly, providing for another bout of mid
level warm advection/upglide related precipitation. The upper trough
is so persistent that it might take until late in the weekend or
early next week before temperatures shift back towards normal or
even a little above normal and we start to dry out.

&&

.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 1235 PM CDT Mon Apr 29 2024

Terminals KABR,KATY,KPIR,KMBG

The clearing line on the clouds and rain will progress slowly from
west to east through this evening. Until that moves through the
region, MVFR cigs are expected to prevail. MVFR cigs will push
back in with a fropa on Tuesday that will also bring more rain to
the area.

&&

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

$$

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