Two fast-moving systems this weekend…January 27th, 2012 at 8:30 am by Jamie Jarosik under Weather
Quite the rainfall event, with a good soaking for most, as expected! Rainfall amounts were a little higher in spots than initially thought… here’s a look at the rainfall totals from around the region:
Area rivers, streams and creeks are running high, and some local roads are closed–mainly the ones that typically have high-water problems when we get a lot of rain. The only Flood Warning in our area is for the Little Miami River in extreme Southwest Greene Co & extreme Northeast Warren County.
Now we turn our attention to two fast-moving weekend systems. The first rolls in tonight, with a chance of snow as we head into the early morning hours of Saturday:
Accumulation looks light–generally an inch or less. But we’ll have to watch for slick spots, with temperatures falling into the upper 20s. Again on Sunday, some scattered light snow showers will be possible. I really feel like a broken record with our snow events lately. An inch here, an inch there. We never have cold air in place when a high-moisture content storm like yesterday’s moves through. I’ve been getting a lot of questions about WHY it’s been so mild this winter… and a couple reasons for this weather pattern include La Nina… but more importantly, the North Atlantic Oscillation (NAO).
Strong positive phases of the NAO are often associated with above-average temperatures in the eastern United States… something we’ve seen each month this winter. The NAO forecast for snow-lovers isn’t looking too promising. We have had one of the most positive on record, although just within the past few days it has dipped into negative status:
The graph above shows us the observed & current NAO. The red lines are from the GFS ensemble runs, forecasting out about two weeks. It looks like the negative phase will be short-lived by this… it is likely that we won’t see a big blast of cold air or a big snowstorm in the near future. There’s always hope for February, right? My thought right now is that mid-month is the period to watch. Stay tuned.