Hot, breezy and dry conditions the next two days has southern Minnesota, including Washington County, under a National Weather Service fire danger watch until Thursday night.
A high-pressure ridge over the state with result in highs in the lower 90s the next two days, 15 to 20 degrees above normal for late August, according to NWS meteorologist Lisa Schmit.
“Basically, we have a high-pressure ridge in the middle and upper levels of the atmosphere,” she said. “When we have those, that leads to hotter temperatures.”
Along with the heat, gusty southwest winds and low humidity are forecast Thursday, leading to the fire danger watch along a line from Renville, Minn., through the Twin Cities to Holcombe, Wis.
“Winds of 15 to 20 mph, with gusts in excess of 30 mph, along with minimum relative humidity near 20 percent, may lead to dangerous wildfire conditions across southern Minnesota and west-central Wisconsin,” said an NWS statement.
Although the hot, dry conditions boost the wildfire danger, Schmit said lower heat indices would offer some relief from the heat.
In addition, an approaching weak front moving led NWS forecasters to revise their Thursday forecast and call for highs slightly cooler than the 100 degrees predicted earlier this week.
“The reason for that is there’s a weak cold front moving down from the northwest and the main pocket of heat has shifted to southern Minnesota,” Schmit said.
Dry conditions will also continue across the St. Croix Valley through much of the Labor Day holiday weekend, Schmit said.
“We haven’t had much rain in a while. A lot of moisture is bottled up by (Hurricane) Isaac,” she said. “Our next chance of rain appears to arrive Sunday night into Labor Day.”
After highs of 91 today and 93 Thursday, the heat slowly moderates across the Valley for the weekend, Schmit said.
“We’re looking at highs in the low to middle 80s,” she said, adding those temperatures are still slightly above normal for the end of August and start of September.
Friday is expected to be sunny and warm with highs near 88. Highs Saturday and Sunday are forecast near 85, with lows falling to the low to middle 60s.