FXUS63 KFSD 242351

AFDFSD



Area Forecast Discussion

National Weather Service Sioux Falls SD

651 PM CDT Fri Apr 24 2026



.KEY MESSAGES...



- Showers and very isolated thunderstorms expected tonight into

  Saturday (80-90 percent chance near and north of I-90). 



- Scattered to numerous (80-100%) showers and storms expected 

  again Sunday into Monday. Areas of heavier rainfall are 

  possible but for now flooding and flash flooding chances 

  remain low (less than 20 percent).



- A very small chance the severe weather could creep north 

  towards northwest IA and the Mo River Valley Sunday night, but

  confidence is very low.



- Seasonable temperatures expected through mid next week, with

  highs mostly in the mid 50s to mid 60s.



&&



.DISCUSSION...

Issued at 1243 PM CDT Fri Apr 24 2026



Upper level low pressure well to the north of the area will swing a 

smaller piece of energy into the area tonight into Saturday. Fairly 

strong mid level frontal forcing develops in response to this wave, 

with some of the stronger forcing in the 700-750mb layer. Late 

tonight into Saturday morning the front closer to 800-850 mb looks 

to be more active and could shift some of the better precipitation 

closer to I-90. Overall amounts within this band of rainfall will 

likely be about a quarter to three quarters of an inch. Instability 

is minimal so other than a few rogue lightning strikes this will 

mainly be a welcome rain event. 



Weak upper level support and low to mid level warm advection 

continues through most of Saturday and given some very weak 

instability in the soundings, scattered showers will remain likely 

through the day. Some isolated thunderstorms will also be possible, 

but severe weather is not expected tonight through Saturday. The 

better chances for rain should remain mostly north of I-90 but could 

be a little more spread out across the area with isolated to 

scattered activity and more disorganized forcing.



Weak upper level ridging builds ahead of a stronger wave Saturday 

night into Sunday morning. This could be a period where activity is 

the most isolated. 



Upper level support rapidly increases Sunday afternoon into Sunday 

night, leading to the areas best chance for some heavier rain Sunday 

night into Monday. Marginally steep elevated lapse rates along with 

strong low level moisture convergence will lead to showers and 

thunderstorms for much of the area. The trends to watch for on Sunday 

night will be the potential for the better forcing to produce 

heavier rainfall west of I-29 towards central into northeast SD and 

another area closer to northwest IA and points south where deeper 

instability could produce an MCS with that activity shifting more 

eastward. A very small threat for severe weather in northeast NE and 

northwest IA Sunday night, although model soundings and Ensemble 

output indicate only a very small chance for CAPE values above 1000 

J/kg.



Low pressure aloft deepens over southeast SD Sunday night and slowly 

drifts east through Monday. This will continue the threat for rain 

into Monday afternoon, likely ending Monday evening most locations.



Rainfall amounts continue to trend higher with the latest NAM 

producing a fairly large area of 2-4" of rain for most of southeast 

SD through tonight through Monday. The latest GFS is very similar, 

just a touch lower on amounts with the Canadian and RRFS a little 

farther north and west with the heavy rain amounts. The latest 50th 

percentile from the GEFS gives the area 1-2" with the higher amounts 

north of I-90. The Canadian ensemble parks the higher 2" amounts 

across most of southeast SD. The 6z EC Ensemble very similar to this 

output as well.



Once this system finally exits, mainly north to northwest flow aloft 

is expected Tuesday into Friday which will keep seasonally cool 

temperatures close to normal in place each day. While there will be 

a few chances for showers and maybe an isolated thunderstorm the 

activity looks to remain fairly isolated and fairly light.



&&



.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...

Issued at 650 PM CDT Fri Apr 24 2026



An area of rain over western South Dakota is beginning to move 

into our area to start the period. This activity will bring MVFR to 

locally IFR ceilings for areas mainly near and west of the James 

River tonight before spreading eastward to the I-29 corridor through 

the daytime morning hours Saturday. 



Activity looks to be a bit more scattered in nature down by 

KSUX during the day Saturday, so only added PROB30 groups there

for now. However, guidance is also indicating that a couple of 

thunderstorms may develop by the Highway 20 corridor Saturday 

afternoon, but confidence was not high enough in location and 

coverage of -TSRA to warrant mentioning in the TAF at this time.



Winds look to be light and variable for the most part tonight 

into tomorrow morning, with a slight uptick in east-

northeasterly winds Saturday afternoon. 



&&



.FSD WATCHES/WARNINGS/ADVISORIES...

SD...None.

MN...None.

IA...None.

NE...None.



&&



$$



DISCUSSION...08

AVIATION...Samet