875
FXUS63 KABR 142031
AFDABR

Area Forecast Discussion
National Weather Service Aberdeen SD
331 PM CDT Tue May 14 2024

.KEY MESSAGES...

- Areas of showers and thunderstorms tonight and Wednesday as low
  pressure moves through the region. Severe storm threat
  (marginal) confined to southwest and south central SD.

- Light precipitation returns Thursday afternoon and evening (15-
  30%).

- Temperatures to remain seasonal for next several days.

&&

.SHORT TERM /THIS EVENING THROUGH WEDNESDAY NIGHT/...
Issued at 331 PM CDT Tue May 14 2024

Starting to see convection firing within the surface trough across
southwest/south central SD, some of which is building/moving into
the far southwest CWA. Instability and shear are low/marginal, so
there is a small possibility some of these storms could be strong to
marginally severe. Upper circulation is nicely noted on water vapor
imagery over southwest SD.

The surface trough/low moves into the eastern CWA during the day
Wednesday, with continued chances for showers and thunderstorms.
Instability is lacking once again, so don`t really expect much of a
severe storm threat. Chances wane across central SD by afternoon as
the entire system pushes east. Highest chances (60-90%) for precip
Wednesday afternoon is confined to the eastern CWA, mainly east of
the James River.

An area of high pressure at the surface then moves in Wednesday
night, bringing drying conditions. Various cloud products suggest
clearing of the lower cloud cover expected during the day Wednesday.

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
Issued at 331 PM CDT Tue May 14 2024

The long term period will remain active with shower and
thunderstorms chances through early next week. Starting off
Thursday, Clusters are in agreement with the shortwave trough over
the Northern Plains, with the axis from ND/MN border southward then
southwestward into the central Plains, leaving our area in zonal to
northwestern flow behind it. This will push east through the day
with another weak shortwave behind it, following the same path. By
Friday, models get messy and all over the place but show a trough
developing over western Canada with a broad area of low pressure
from 850mb to the surface positioned over Canada into the northern
CONUS. The general idea is that this low and upper level low/wave
slowly moves east across Canada/northern CONUS through the weekend.
Another trough moves in over the Pacific Northwest with a -PNA
pattern setting up early next week. With such variation on the
actual timing and intensity of the mid level to surface features
between the Clusters, confidence remains low in our long range
forecast Friday through early next week.

With this next shortwave and surface trough, this looks to bring the
chance of some light moisture with the latest NBM pops showing a
general 20-30% Thursday afternoon and evening, mainly across our
northern/northeastern CWA with the "highest" pops staying along the
ND/SD border. Friday afternoon and evening, moisture returns with
NBM pops ranging from 20-40%, with most of the moisture staying to
our north for now. For the weekend, very broad slight pops ranging
from 15-25% for now with additional moisture possible into early
next week. We will have to wait closer to time to narrow down
timing/locations.

NBM has a spread of 4-6 degrees between the 25-75th percentile
across the CWA with highs ranging in the 70s for Thursday. That
spread increases quite a bit Friday to a 7-10 degree difference,
with forecasted highs much warmer (behind a warm front)in the upper
70s to the mid 80s. The spread increases for the weekend as temps
look to cooldown a bit back into the upper 60s to the mid 70s by
Sunday.

&&

.AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/...
Issued at 1234 PM CDT Tue May 14 2024

Terminals KABR,KATY,KPIR,KMBG

VFR conditions will prevail to start the TAF period, with MVFR
CIGs forecast to move in late in the period as a storm system
moves through. There is some potential for IFR CIGs also during
the day Wednesday but will take a closer look at this for the 00Z
TAFs. -SHRA/SHRA and -TSRA/TSRA also expected to affect the region
through the period as this storm system moves through. Potential
for MVFR VSBY in areas of heavier precipitation.


&&

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

$$

SHORT TERM...TMT
LONG TERM...MMM
AVIATION...TMT