As we move toward autumn, low pressure systems will begin to boot Juneau’s unusually warm and dry summer out of the way.
The National Weather Service says July was not quite as warm and dry as June, when the average temperature was more than three degrees above normal.
In fact, temperatures were in the 80s for three days in June and in the 70s for 12 days, according to meteorologist Rick Fritsch. June precipitation was below normal.
July started off cooler, with daytime highs in the upper 50s and 60s. But just when it seemed summer was over, the weather got better.
July, Fritsch says, “recovered in fine form on the 28th through the 31st, [with temperatures of] 77, 81, 79, 75. In terms of averages for the month, those warm days kind of over-powered that spell of time when we were in the 50s. We finished the month, July, just a hair under a full degree above normal,” he says.
Precipitation in July was just about normal.
The summer’s warm temperatures are helping feed Nugget Falls at the Mendenhall Glacier. The amount of water coming over the falls is remarkable.
“And it’s all because we’ve had these warm temperatures, the snow level is so high, a lot of ice way up high melting and feeding Nugget Falls, the Taiya River, and various other places that are fed from sources way up in the mountains,” he says.
The Taiya River near Skagway actually reached minor flood stage from melt last week, but is back down, Fritsch says.
Juneau has not had anything even close to a glacial outburst this summer, known as a Jökulhlaup (Yo-ko-laup). Even a release from Suicide Basin above the glacier was weak.
Hydrology graphs on the Weather Service website show Mendenhall Lake and Mendenhall River levels have been dropping since August first.