854 FXUS63 KFSD 161059 AFDFSD AREA FORECAST DISCUSSION National Weather Service Sioux Falls SD 559 AM CDT Tue Jun 16 2020 .SHORT TERM...(Today through Wednesday) Issued at 358 AM CDT Tue Jun 16 2020 As we remain sandwiched between a low pressure system off to our west and a high pressure system off to our east, warm and windy conditions remain across the area. As the low marches eastwards, the pressure gradient is expected to be at its strongest this afternoon and has thus prompted a wind advisory to be issued westward along a line from Brookings county to Charles Mix county. Sustained winds of 30-35 MPH are expected across the area for a couple hours, with gusts up to 50 MPH possible mainly across the MO River Valley where winds atop the boundary layer are pushing 50 knots. Thanks to a strong low level jet providing WAA across the area, maximum low temperatures were threatened on Monday although no records were set at our climate sites. This sets the stage for another warm day with temperatures in the mid to upper 90s. Heat index values will be restrained to the 90s, with relative humidity values down into the lower 30s providing some concern for fire weather conditions. As the cold front sweeps across central SD, there is a very minor chance that areas along the MO River Valley could see some rain or a thunderstorm overnight, but latest thinking is that the activity will remain off to our west. As the upper level low meanders eastwards across Canada, our area remains under southeasterly flow at the surface leading to another warm and windy day. Temperatures will again reach the mid 90s, with relative humidity values dropping into the lower 30s. The cold front will be knocking on our door out west by the late afternoon hours, and will provide our next chance at showers and thunderstorms. With ample daytime heating and dew points in the lower to mid 60s, CAPE values will be pushing 3000 J/KG along the MO River Valley. However, the stronger shear is farther west behind the front which means storms that are lifted up by the leading edge of the cold front will struggle a bit to remain organized. Elevated instability is present behind the front, so the threat for severe thunderstorms is there although the instability does decrease overnight. SPC's day 2 marginal/slight risk highlights the area nicely, and agrees well with the thoughts for large hail, damaging winds, and an isolated tornado being possible. .LONG TERM...(Thursday through Monday) Issued at 358 AM CDT Tue Jun 16 2020 The cold front will continue moving through the area on Thursday, looking like it will exit the area out east by early afternoon. Showers and thunderstorms will be likely as the front is passing through, ending from west to east into the morning hours on Friday. The cold front will limit temperatures to the upper 70s to mid 80s on Thursday and Friday, and will also bring a noticeable drop in wind speeds. Active weather continues into the weekend as the upper level trough axis moves overhead, leading to continued chances for showers and thunderstorms on Saturday with temperatures in the 80s. Northwesterly flow develops aloft on Sunday, looking to keep things active for the area into next week while limiting temperatures to the 80s. && .AVIATION...(For the 12Z TAFS through 12Z Wednesday morning) Issued at 558 AM CDT Tue Jun 16 2020 VFR conditions throughout the TAF period. Low level wind shear will remain present until 13-14Z when the boundary layer destabilizes, and gusty winds resume. Strong southerly winds will be present today, with strongest winds west of a line from Brookings to Mitchell to Lake Andes (all in SD) where gusts up to 50 mph will be possible. East of that line, gusts up to 40 mph are likely until the boundary layer stabilizes again after sunset and low level wind shear returns. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...Wind Advisory from noon today to 10 PM CDT this evening for SDZ038>040-050-052>055-057>060-063-064. MN...NONE. IA...NONE. NE...NONE. && $$ SHORT TERM...APT LONG TERM...APT AVIATION...APT