Thursday, October 15, 2009

Double Dip of Record Cold Highs

The high temperature for Thursday of 54 degrees set a new record for the coldest low, or what is called a record low maximum. The old record low maximum was 56 set in 1939. It's very likely that tomorrow's high will set another record, making it back-to-back record-setting days. The record low maximum for tomorrow is 54 set in 1940, and we are forecasting a high of just 49. Those 70s next week can't get here too soon.

Late Fall-Early Winter Outlook

Today, the Climate Prediction Center issued its long-range forecast for November through January, based primarily on the El Nino-Southern Oscillation trend.
Here's the Temperature Trend, where blue shades indicate cooler-than-average temperatures, and the orange shades warmer-than-average:


And the Precipitation Trend, where green shades indicate wetter-than-average conditions expected, and the tan shades indicate drier-than-average conditions:


The equatorial Pacific west of South America has been in El Nino conditions (meaning warmer-than-average ocean surface temperatures) for months now, and looks like it will continue through the North American winter months as well. This has meant in previous El Nino Winters that the Southeast tends to be a little cooler-than-average. Here is an example of a strong El Nino event occurring during Winter (January-March):


So based on this information, it appears that the Commonwealth can expect a cooler-than-average start to Winter this year, and when you combine that with precipitation...well, that can mean more winter weather precipitation events in our future! As mentioned in the previous blog entry, today just to our north, New York and Pennsylvania are getting a slightly early start on their winter weather season with a heavy wet snow falling today into Saturday. Could this be a sign of things to come for us as those colder temperatures creep farther South over the next month? We'll be keeping you ahead of the storm.

Periods of Rain Thursday

After a drizzly early Thursday morning, periods of showers will continue to overspread Central Virginia today as an upper-level storm system tracks through the Midwest. This same system is also overriding much colder air at the surface in other parts of the country, bringing snow and winter mix precipitation from North Dakota to northern Minnesota and Wisconsin. As this storm progresses east, it may also bring a heavy, wet snowfall to parts of Central Pennsylvania today and Friday. Winter Weather advisories and warnings are in effect for that region to our north.
Up to a foot of snowfall accumulation is possible by Saturday!
For us in Central Virginia, though, we'll merely continue with this overcast, cool, drizzly weather into the weekend. However, the highest elevations of western Virginia may get a few wet snowflakes Saturday.