A look at the time series above suggests that this past week is indeed quite an outlier and one of only 5 such September periods going back to 1874 with a mean temperature above 70ºF (note that the records above are a composite of observations collected in the Salt Lake Area as the airport didn't exist back then!).
An unfortunate aspect of this hot dry weather is a loss of moisture from the big rains we had from September 14–16. As shown in the chart below for the Mill D North SNOTEL in Big Cottonwood Canyon, those big rains greatly increased the soil moisture content of the soils at both 2 and 8 inch depths.
Data Source: NRCS |
In the mountains, if that moisture is not replaced before the first snows, the soils will be the first place that the snowmelt goes in the spring (rather than to the rivers and streams). That might be a good thing if we end up having a huge snow year, but if our run of meager winters continues, it would exacerbate the crappy runoff situation even further. As we have discussed previously (see Wasatch Weather Weenies Survival Guide for El Nino), the current Super El Nino doesn't really load the dice one way or the other for us, so at this point, we have to have a wait-and-see approach to what happens between now and the first snows, as well as during the winter.
From what I can find online, the Great Salt Lake is currently near 70 F which I assume is above average. If the forecast of a cool and moist trough late this week actually pans out, maybe that will contribute to some lake enhanced precipitation locally.
ReplyDeleteEven an average winter would be a welcome change!
ReplyDeleteIt's also been extremely warm (and dry) all month here on Colorado's Front Range. I suspect it will be a near-record warm September for Boulder/Denver.
ReplyDeleteQuestion: What is the URL for the tool you used to generate the time-series plot at the top of the post?