FXUS63 KABR 262334 AAA

AFDABR



Area Forecast Discussion...UPDATED

National Weather Service Aberdeen SD

634 PM CDT Thu Jun 26 2025



.KEY MESSAGES...



- Severe storm chances return Friday afternoon through Friday

  night, with a slight risk (level 2 of 5) for severe weather 

  across the entire forecast area. Main threat includes large 

  hail, potentially 2" in diameter or larger, wind gusts between 

  60-70 mph, and a few tornadoes.



- Additional chances for severe weather continue Saturday/Saturday

  night with a slight risk (level 2 of 5) for severe weather 

  mainly along and south of Highway 12.



- Temperatures will remain rather warm along with higher levels of

  humidity on Friday through the weekend. Drier conditions will be

  possible early next week as warm temperatures continue.



&&



.UPDATE...

Issued at 626 PM CDT Thu Jun 26 2025



See below for an aviation forecast discussion for the 00Z TAFs.



&&



.DISCUSSION...

Issued at 302 PM CDT Thu Jun 26 2025



The main concern in the forecast package will be the scattered 

severe storms possible Friday and Saturday over the forecast area 

and the return of summer like temperatures these days. As of 3pm, 

radar indicates light to moderate rain continuing to fall mainly 

east of the Coteau with the last of the rain forecasted to exit the 

far northeastern CWA this evening. We are seeing some clearing over 

western SD and portions of central SD on the backside of this 

system. The ongoing low level moisture and post-rain will lead to 

more fog overnight into early Friday morning. EC meteograms 

highlight this well with Conshort indicating a bit more broader in 

coverage than what we saw this morning, mainly along and east of the 

Mo River. Some of this fog could be dense at times especially over 

the James River Valley and Coteau. This has been added to the grids 

and an advisory may be needed if we see visibilities drop to less 

than 1/4 mile.



The shortwave and its associated low pressure system will be off to 

our east this evening with zonal to slight northwest flow aloft as a 

low amplitude ridge moves in over the area this evening and shifting 

eastward into MN on Friday, bringing a relief to the soggy weather. 

A weak amplitude trough sets up and extends over the Pacific 

Northwest this evening through Friday. Within this trough, a 

stronger shortwave will push east/northeast on the downwind side of 

the trough. The axis of this shortwave is forecasted to be over 

MT/WY and western Dakotas into Canada by 00Z Saturday. Winds will be 

increasing to 40-50kts from 300-500mb and 700mb winds increasing to 

25-35kts with these winds highest over MT/ND. By Friday evening, its 

center of the low looks to hover the Saskatchewan/Manitoba border 

with central to portions of northeastern SD within the warm sector 

between the warm front and cold front, will will be over western SD 

along with a lee low. So with upper air support and lift from the 

front will aid in convection, however, the better lift looks to be 

over ND and northward, closer to the low.



Within the warm sector, return flow at 850mb will bring in more low 

level moisture and warmer air with winds between 20-30kts and 

dewpoints rising between 10-15C by the afternoon and evening with 

temperatures 20-25C in this area. With this WAA, surface temps are 

expected to rise in the 80s the lower 90s, warmest over central SD, 

with dewpoints in the mid to upper 60s to possibly the lower 70s. 

This will lead to moderate to strong instability (and help break the 

daytime cap as 700mb temps range from 9-12C) as HREF Surface/MUCAPE 

will increase between 1000-3000j/kg, with the 2-3K values over 

central SD. The potential max values could be up to 4000-5000 j/kg 

in this area! EC EFI highlights values 0.6-0.8 for CAPE and CAPE-

shear over central SD for this enhanced threat. With the increased 

winds aloft, bulk shear will run between 30-40kts and mid level 

lapse rates between 7-8C. STP values between 1-2 run from north 

central SD through southeastern SD where we see the greatest 0-1km 

SRH (up to 100m2s2). HREF 2-5 UH>75m2s2 paintballs indicate 

organized convection could fire up as early as late afternoon (~22Z) 

but more in two areas to start. One area over north central SD into 

ND and the other area over central/south central SD into southern 

SD/northern NE. This northern convection, per HREF, becomes more 

numerous as it pushes eastward. UH>150m2s2 indicates these cells 

could be right moving supercells over central to northeastern parts 

of SD. So if we can get convective initiation, it will not take much 

for these storms to become severe with what was mentioned for severe 

parameters. The SPC has expanded the slight risk (level 2 out of 5) 

and now covers the entire CWA. The main threats include large hail 

with a 10% hatched area along and west of a line from Aberdeen 

through Redfield, meaning 10% or greater chance for hail to be at 

and over 2" in diameter within 25 miles of a point (due to this 

supercell potential). There is also the threat for a few tornadoes 

with any supercells with a 2% chance within 25 miles of a point 

along and west of the James River to the Mo River. Winds gusts 

between 60-70 mph is also a threat.



The embedded shortwave will be over the southern portions of 

Canada/Northern CONUS by Saturday afternoon and evening with the 

surface low/boundary shifting eastward. Temperatures are expected to 

rise into the upper 80s to the lower 90s and dewpoints in the upper 

60s into the lower 70s with similar instability/shear setup as 

Friday. EC EFI has a larger area of 0.6-0.8 for CAPE from southern 

SD through northeastern SD into MN with a shift of tails of zero.

With this ongoing instability, severe storms are possible again 

as SPC has a slight risk (2/5) mainly along and south of Highway 12.



Lastly, we continue in this moist setup as PWAT values will still 1-

2 standard deviations above climo Friday and Saturday with values up 

to 1.25" along and east of the Mo River Saturday and along and east 

of the James River Sunday. Mean specific humidity still ranges about 

2 standard deviations above climo from 850-925mb. So with any 

thunderstorm that forms, it does have the potential to produce heavy 

downpours. Any training of these storms could lead to an increase 

potential for flooding.



Overall dry weather expected Sunday into early next week with temps 

in the 80s to lower 90s.



&&



.AVIATION /00Z TAFS THROUGH 00Z FRIDAY/...

Issued at 626 PM CDT Thu Jun 26 2025



Terminals KABR,KATY,KPIR,KMBG



All four terminals should be precipitation-free through the TAF

valid period. While KPIR/KMBG are VFR right now, low clouds/fog

are forecast to return after 06Z tonight and persist until a few

hours after sunrise on Friday. KABR/KATY remain socked in under an

MVFR stratus layer. Guidance suggests that later tonight, ceilings

will lower and/or fog will develop (as it has the previous two

nights...persistence), resulting in a period of IFR conditions at

KABR/KATY through appx 15Z Friday before there is any potential

for flying weather conditions to improve at those two terminals.



&&



.ABR WATCHES/WARNINGS/ADVISORIES...

SD...None.

MN...None.

&&



$$



UPDATE...10

DISCUSSION...MMM

AVIATION...10

