On Tuesday the Black Hills could experience dry lightning on what is expected to be the hottest day of the year so far. With temperatures above 100, relative humidity below 15 percent, and windy conditions, firefighters on Tuesday could be busy. In the southern Black Hills the 18 mph winds gusting to 28 could fan into life leftover lighting ignited fires from the mostly wet thunderstorms that passed through Monday afternoon and night.
The South Dakota State Fire Meteorologist, Darren R. Clabo, distributed this message Monday afternoon:
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A very warm and dry week is expected with excessively critical fire weather conditions expect for West River and the Black Hills on Tuesday. A few showers and thunderstorm (mostly wet) will pass over the region tonight. Unfortunately, this also means lightning strikes on the eve of a critical fire weather day. The hottest day yet this year will occur tomorrow as a large amplitude upper level ridge builds into the region: highs will be at or above 100 degrees with RHs below 15%. In addition, a strong pressure gradient will develop over western SD in the afternoon leading to gusty southwesterly winds. To add insult to injury, enough instability will be present to warrant a threat for dry lightning for the Black Hills and surrounding plains. Red Flag Warnings are in place for this region. East River will see cooler conditions with highs in the 80s and 90s and RHs from 30-40%. Conditions wills moderate on Wednesday as an upper level trough skirts the area. Temperatures will be in the 80s and 90s with RHs between 20 and 30%. Northerly winds are expected. Similar conditions will be seen Thursday but far southwestern SD may have minimum RHs drop below 15%. Temperatures in the 80s and 90s with RHs from 20-30% are expected Friday and through the weekend. To summarize, very hot and dry fire weather conditions, more representative of late July and August, have arrived. (Darren Clabo)
Helicopter 535 (San Bernardino NF) leaving on a pre-position order to the Black Hills National Forest (SD-BKF) on 06/26/2012 in the early morning.