520
FXUS63 KABR 101938
AFDABR

Area Forecast Discussion
National Weather Service Aberdeen SD
238 PM CDT Fri May 10 2024

.KEY MESSAGES...

- Above normal temperatures (about 10-15 degrees Saturday/5-10 degrees
  Sunday) with dry conditions through the weekend.

- Precipitation chances return to the area Tuesday with the
  highest probability of rainfall occurring Tuesday afternoon
  through Wednesday morning (30-60%).

&&

.SHORT TERM /THIS EVENING THROUGH SATURDAY NIGHT/...
Issued at 205 PM CDT Fri May 10 2024

Passage of weak cold front has resulted in gusty north/northwest
winds with a few spots in excess of 40mph, but aside from an
exception or two, below wind advisory criteria. These winds will
subside this evening with loss of daytime heating, a surface ridge
moves overhead and gradient weakens.  Aloft, its a northwest flow
regime as an upper trough moves out of the eastern
Dakotas/Minnesota, with dry air aloft spilling over a northwest
Pacific/western Canada ridge. This will provide ideal conditions for
auroral viewing tonight.

As the ridge heads east for Saturday, low level flow becomes
westerly, which will enhance mixing under 850mb warm advection. Will
lean towards the NBM 75th percentile for highs/temperatures and
anticipate better mixing out of dewpoints in the afternoon.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
Issued at 205 PM CDT Fri May 10 2024

Clusters agree on continuing split flow for the start of the long
term as the ridge axis will be over western Canada and pushing
eastward through the evening. Through the day Monday, this ridge
becomes more positive tilted as it moves overhead. There is a
difference on how amplified the ridge will be by Monday evening as
Clusters 1 and 3 (made up of mostly EC) keep it more amplified than
Clusters 2/4 (made up of majority GEFS/GEPS). Following this ridge
will be our next system as a trough sets up over the northwestern
U.S into western Canada and pushes east over the Northern Plains
Tuesday night into Wednesday, along with its surface low. The
Clusters made up of mostly EC seem to show a little faster movement
into the Northern Plains than GEFS/GEPS, with GEFS/GEPS indicating
this trough being a bit deeper and positive tilted. Through the day
Wednesday we really see differences in the Clusters with overall
timing and intensity as this wave pushes east. Day 7 and onward is
split 50/50 on either a ridge over the western CONUS or
zonal/another trough moving in.

With this setup, a surface trough/weak cold front will pass over the
CWA, associated with a low moving east over Ontario/Hudson Bay area
on Sunday. Main indicator will be a wind shift behind it out of the
northeast as low levels remain dry. However, some shortwave energy
riding down the ridge could support very isolated chances of rain
showers. GEFS seems to be more aggressive on this shortwave energy
than EC/GEPS. Latest NBM indicates a 14% chance or less Sunday late
afternoon and evening. 15-20% pops are in the grids over the Coteau
for this time. With this next low moving in Monday night, ensembles
show moisture increasing from northwest to southeast over the CWA
through Tuesday morning (20-40%), becoming widespread with our
highest chances of rains Tuesday afternoon and evening (40-60%
pops). Rain chances continue Wed as the front pushes east (20-40%),
highest over our eastern CWA. No organized severe weather is
expected but there is enough CAPE and some shear for some thunder
chances during the afternoon through even hours on Tuesday.

Highs will remain above average for Sunday ranging in the mid to
upper 70s to the lower 80s. Slightly cooler air moves in Monday with
highs in the 60s to lower 70s with a bit of a rebound on Tuesday.
Temps look to cool again midweek.

&&

.AVIATION /18Z TAFS THROUGH 18Z SATURDAY/...
Issued at 1128 AM CDT Fri May 10 2024

Terminals KABR,KATY,KPIR,KMBG

VFR conditions for all terminals. Winds are peaking, will remain
around current speeds through the afternoon and early evening,
diminish and shift to west/southwest tonight/Saturday.


&&

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

$$

SHORT TERM...Connelly
LONG TERM...MMM
AVIATION...Connelly