472
FXUS63 KABR 021528 AAB
AFDABR

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
1028 AM CDT Sun Jun 2 2024

.KEY MESSAGES...

- A slight risk of severe weather (level 2 on a scale of 5) will
  develop this afternoon through the evening hours as a cold front
  sweeps across the area. All severe weather hazards are
  possible, including large hail, damaging winds, and tornadoes.

- There is around a 50% chance of showers and thunderstorms Monday
  night through Tuesday, mainly focused over eastern SD/west
  central MN. Some storms could become strong to severe.

&&

.UPDATE...
Issued at 1026 AM CDT Sun Jun 2 2024

Overhauled the pops through this afternoon to better reflect
current radar trends and latest hi-res model runs. That
substantially increased pops across the east this morning and
decreased pops across most of the area this afternoon.

&&

.SHORT TERM /TODAY THROUGH MONDAY AFTERNOON/...
Issued at 355 AM CDT Sun Jun 2 2024

Showers and thunderstorms are ongoing east of the Missouri
River to the James River this morning. Radar indicates that a few
have been capable of producing small hail. While most will remain
below severe limits, we will continue to monitor them as they are
borderline in this marginal atmosphere. The supercell composite
parameter in this area is between 2-4. Additional storms are over
southwestern SD, and will need to be monitored later this morning. A
stronger line of storms is expected to develop this evening
weakening the cap, ahead of a frontal boundary shifting across the
region. All severe weather hazards will be possible, including
damaging winds, large hail, and tornadoes. There is a level 2 out of
5 risk for severe storms to develop in this line. These storms
should exit into Minnesota late tonight into the early overnight
hours Monday. Dry weather should then dominate our weather after 08Z
Monday through mid afternoon when additional showers move into
central SD.

&&

.LONG TERM /MONDAY EVENING THROUGH SATURDAY/...
Issued at 355 AM CDT Sun Jun 2 2024

Monday evening we will be in generally west to southwest flow aloft
as a trough moves towards the region. This trough will sweep across
the area from west to east Tuesday through Wednesday morning.
Deterministic models show the trough elongating and widening
Wednesday with the northwest flow pattern remaining through
Thursday. Models start to disagree after this. The EC shows the low
at the center of the trough continuing to circulate over the Great
Lakes region with several more lows dipping south out of Canada to
enlarge the trough and spread it further west back into our area
through the end of the period. The GFS and Canadian however, show
the trough becoming more concentrated around the low and our area
transitioning into more of a straight northerly flow pattern as a
ridge forms to our west with a high over the Four Corners region.

Tuesday looks like the best chance for some showers/storms. Along
the ND/SD border NBM is showing 30-50% PoPs Tuesday morning as the
cold front moves across. Tuesday afternoon and evening, rain chances
increase east of Hwy 281 along the cold front (30-50%). MLCAPE east
of the James River Valley Tuesday afternoon is around 1000 to 1500
J/kg with bulk shear between 40 and 50 kts. Lapse rates are low,
between 5.5 and 6.0 C/km. Given this, storms are possible, but it is
hard to say if any will become severe. There is a 15 to 20% chance
for some light showers over far northeastern SD and west central MN
Wednesday as the low continues to circulate. Afterwards, the rest of
the period is expected to be dry.

Temperatures through the period will remain around normal with
highs in the 70s. Lows will also be around normal, in the low 50s.
with CAA on Wednesday we could get some higher winds with gusts of
40+ mph possible west river. This looks to be the strongest winds of
the period.

&&

.AVIATION /12Z TAFS THROUGH 12Z MONDAY/...
Issued at 704 AM CDT Sun Jun 2 2024

Terminals KABR,KATY,KPIR,KMBG

VFR ceilings and visibility will be interrupted by showers and
thunderstorms through this evening, with the strongest storms
expected as early as 20Z today to 01Z Monday at MBG and similarly
at PIR. However, most storms are expected to stay northeast of
PIR later today. For ABR the timing will be between 23Z today and
02Z Monday, with ATY generally between 02-05Z Monday. MVFR
ceilings are forecast at ATY after 05Z. Large hail of over 2
inches in diameter and damaging winds of 70-80 mph will be the
main concern with the strongest storms late this afternoon through
this evening.


&&

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

$$

UPDATE...Wise
SHORT TERM...KF
LONG TERM...KK
AVIATION...KF