Sunrise 6:05 AM   Sunset 8:46 PM Moonrise 1:05 PM   Moonset 2:12 AM

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FXUS63 KFSD 160334 AFDFSD

Area Forecast Discussion National Weather Service Sioux Falls SD 1034 PM CDT Wed May 15 2024

KEY MESSAGES

- Scattered showers and thunderstorms will end late this evening.

- Well above normal temperatures are expected Friday and Saturday with high confidence (>70%) on Friday.

- A more active southern stream jet is expected next week which could bring a better chance for increased shower and thunderstorm coverage.

DISCUSSION
Issued at 212 PM CDT Wed May 15 2024

A small ribbon of instability ahead of an incoming mid and upper level wave and surface cool front, generally along a pre frontal trough, should allow for a few thunderstorms near and east of I-29 from about 2 pm through the evening. Surface based CAPE should be around 1500 J/kg, but a closer inspection of the 100mb mixed layer CAPE drops this down to 1000 J/kg or less. So while severe weather is possible it should remain very isolated and on the lower end. The better chances will be east of I-29 late afternoon and evening.
Otherwise more stable air will spread into the area as the upper level wave moves by tonight. This should push the showery activity out of the area by about midnight. One more thing to watch will be the chance for a few funnel clouds or possibly a landspout with the better chances in southwest MN and parts of northwest IA along the incoming cool front where about 100-150 J/kg of 0-3km CAPE has developed.

Thursday should be warm and dry with westerly flow. While a small amount of instability will be possible at this time it should remain capped. The weakest cap will be in central SD, but right now that should still hold and even if something did develop impacts would be pretty low. Highs generally mid and upper 70s.

While Friday and Saturday will see some small chance for showers and thunderstorms overall each day should be mostly dry. With faster flow aloft off to the north and west, warm conditions are expected.
We should see highs in the 80s most locations on Friday, then 70s on Saturday as a cool front moves through.

Sunday will see the next slightly more organized threat for showers and thunderstorms as southwest flow aloft strengthens and a mid level wave moves through. Temperatures will be seasonally warm with highs in the 70s.

Monday appears to be the next better chance for showers and thunderstorms as a fairly strong southern stream low level jet drives northward. This should bring some additional low level moisture northward bringing a bit of an increase in instability. At least a chance to see some 60+ surface dew points. The latest GEFS indicating about a 30-50% chance for a half an inch or more of rainfall Monday into Tuesday with a 20 % chance for an inch or more.

Tuesday into Wednesday will see an upper level wave move through with a shortwave ridge building behind. This should bring a better chance for showers and thunderstorms Tuesday vs. Wednesday. However there may be another wave moving through Wednesday night which could bring more chances for showers and storms. Both days should be seasonally mild with lows in the 50s and highs in the 70s.

AVIATION /06Z TAFS THROUGH 06Z FRIDAY/
Issued at 1032 PM CDT Wed May 15 2024

Showers and isolated thunderstorms will exit the area around 06Z. Otherwise, VFR conditions are expected through the TAF period. Winds will be light west/northwesterly through Thursday, then begin to turn more southwesterly on Thursday night.

FSD WATCHES/WARNINGS/ADVISORIES
SD...None.
MN...None.
IA...None.
NE...None.

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Sioux falls, SD,