Fire weather this weekend

Widespread rain was seen over a large portion of SD over the past two days. However, southwestern SD stayed relatively dry (precipitation images below). Thus this forecast will focus on the issues over southwestern SD through the weekend.

Saturday:
High temperatures will be in the mid-80s with minimum RH in the 8-18% range. Westerly winds from 5-15 mph are expected with some gusts to 25 mph possible. Look for mostly clear skies although some altostratus or cirrus are possible. The GFS is showing a very dry lower troposphere and nearly unidirectional westerly winds up the column. There are some 30-knot winds just above the mixed layer and if we can tap into that momentum, we may see some strong gusts at the surface.

Saturday night:
Minimum temperatures will range from 45-55 across the lower elevations and from 55-65 over the higher elevations (yes, it will be warmer over the higher elevations of the Black Hills). Maximum RH recovery will range from 40-50% over those cooler lower elevations and only from 15-25% over the warmer higher elevations. This will precondition the fuels for Sunday.

Sunday:
This will be a pre-cold front day and the forecast will depend on the timing of the frontal passage. But for now, it looks like the front won’t pass southwestern SD until Sunday night which will lead to hot and dry conditions during the day. The forecast as of now calls for temperatures to range from 85-95, minimum RH from 8-18%, and southwest winds from 10-20 mph while gusts to 25+ mph are possible.  Red Flag Conditions are possible. A deep well-mixed layer is forecast which may transport some higher momentum to the surface bringing stronger wind gusts.

Just because we’ve seen drizzle and rain over the past two days over much of SD does not mean it has been wet everywhere! Keep your situational awareness up through the weekend.