137
FXUS63 KABR 051144 AAA
AFDABR

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
644 AM CDT Tue May 5 2026

.KEY MESSAGES...

- High temperatures today and Wednesday will run around 15 to 20
degrees below normal ranging in the mid 40s to the mid 50s. Early
morning lows through Thursday will range in the mid 20s to the lower
30s (10 to 15 degrees below normal).

&&

.UPDATE...
Issued at 640 AM CDT Tue May 5 2026

The aviation discussion has been updated for the 12Z TAFS.

&&

.DISCUSSION...
Issued at 1243 AM CDT Tue May 5 2026

As of midnight, temperatures are ranging in the mid 30s to the lower
40s and winds fairly light around 5-10 mph out of the northwest.
Radar indicates light spotty returns on radar mainly over
southeastern ND and far northeastern SD as well as south central SD.
Due to ongoing dry air and large dewpoint depressions, these are not
hitting the ground. Other then below average temperatures through
Thursday morning, the overall forecast will remain dry.

The Northern Plains remains in west/northwest flow aloft on the
southwest side of an upper level low over Ontario and to the east of
an amplified ridge. Over the next several days, models indicate a
Fujiwara effect will occur between this closed low and the closed
low just to the east of it over Quebec. The now main closed low will
broaden and continue to spin and spin over the Hudson Bay
area/Quebec well into the weekend. This will leave us in ongoing
northwest flow as the ridge to our west hangs out over the western
CONUS before broadening towards the end of the week into the
weekend. Further out in time, Clusters agree on this +PNA pattern
with northwest flow over the CWA though at least the middle of the
week. However, low confidence on exact amplitude of the
ridge/position and trough/low out east as there are subtle
difference between the Cluster ensembles Day 6 and onward.

At the surface the Northern Plains is within this elongated ridge of
high pressure (with the center of the high north of
Saskatchewan/Alberta at 12Z). Through Wednesday evening we will
continue within this large area of high pressure keeping conditions
overall dry. However, in this northwest flow, few of the CAMs
(HiResW/NSSL-WRF) once again indicate the potential diurnal
heating/mixing very spotty showers this afternoon through sunset,
while the other CAMs show absolutely nothing. With ongoing inverted
V soundings, any popcorn shower that could form will be high based
and mainly virga (or sprinkles at most) as dewpoint depressions will
be on the order of 20+ degrees at the surface, similar to yesterday.
With very low confidence, did not add pops to the grids with ECAM
pops 10% or less. An area of low pressure swings down from Northwest
Canada (and its shortwave) and over the Northern Plains/Northern
Rockies for the end of the week bringing the return of rain chances
Thursday night/early Friday with pops of 20-40% along and west of
the Mo River. Additional chances for precip this weekend with
another clipper, with pops of 20-45%, mainly over central SD.
Confidence is low on track and amount of precip at this time.

With ongoing steep low level lapse rates/afternoon mixing, winds
will be breezy today and not as strong as yesterday with gusts of 25-
30 mph and up to 25mph Wednesday afternoon. With northwest flow/CAA
at 850mb, temps at this level today and Wednesday at peak heating
are only around zero to a few degrees below zero (10th to 20th
percentile) with highs only in the upper 40s and 50s. Wednesday and
Thursday morning 850mb temps will run to as low as -6C (4th to 8th
percentile) with surface lows only in the mid to upper 20s Wednesday
morning (our coldest morning of the week) and upper 20s to the lower
30s Thursday morning. Latest run of the NBM has dropped temps even
further a couple of degrees through Thursday morning. Overall highs
and lows through Thursday morning will be about 10 to 20 degrees
below normal with ongoing north to northwest flow at the surface.
Finally as this ridge broadens for the end of the week and weekend,
850mb temps will warm back up above zero to 12C, highest over the
western CWA with surface temps gradually warming up into the 60s by
Friday with possibly a few lower 70 readings by the weekend.
However, the 25-75th spread is still 7-10 degrees depending on exact
setup synoptically.

&&

.AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/...
Issued at 640 AM CDT Tue May 5 2026

Terminals KABR,KATY,KPIR,KMBG

VFR conditions will prevail through the next 24 hours. Mid level
clouds will develop and thicken by late morning and midday.
Northwest winds will increase by mid to late morning and remain
gusty through the afternoon between 20-25 knots.

&&

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

&&

$$

UPDATE...Vipond
DISCUSSION...MMM
AVIATION...Vipond