This is my first winter outlook for the area, and other regions close to us. Most of
the year's featured, a near neutral ENSO (discounting 2008, which had a
weak La Nina), a negative PDO (discounting 1993-1994), and
had teleconnection patterns that matched with this years.. I could not
find a single year that even came close to matching with this year's
teleconnections. In the past fifty years, there hasn't been a single
instance where the NAO and AO fluctuated as much as it has. This is
telling me that something is up with the observed wind patterns over the
North Atlantic. For the teleconnections, the closest fits were
2008-2009, 1993-1994, and 1977-1978. As for precipitation patterns, the
best fits were 2006-2007, 2008-2009, and 1977-1978.. I don't want to
sound like I'm "wishcasting" (that's what happened last year), so I'll
give you my first thoughts. These years were also checked for correlations in the AO and NAO, and there were only two years that corresponded, and those were 1993-1994 and 1977-1978. Some of you who are older, probably remember the winters of 93'-94' and 77'-78'. During the winter of '77-'78, the area saw temperatures about 10 degrees Fahrenheit below the normal average temperature. In the winter of 1993-1994, we saw temperatures about 4-6 degrees below average, mainly in the month of January. This may have biased my winter forecast, so don't expect it to be as cold as those years.
I'll start with storminess and precipitation. In actuality, this could go either way this year. In my personal opinion though, I believe that El Nino will be non-existent by the time December comes around. If this occurs, then I expect precipitation to be above normal in the Ohio Valley, all the way into the Eastern United States. Any place south of Indiana or west of Indiana will likely see below normal precipitation. The jet stream will likely be directed across the southern and central United States this year. The biggest storms will occur when the NAO dips to negative values, and the PNA also goes negative, forcing a large trough into the Midwest. For right now, I'm going to go out on a limb, and state that snowfall may be slightly above normal for the winter season.
I don't believe we will see another split flow jet stream, which will allow for a stronger jet stream, more dynamic storm systems, and colder weather for areas north of the jet stream. From Southern California into the Southeast, I expect above normal precipitation for the first part of the winter season, but near normal precipitation for the rest of the winter. In the east, coastal storms will be frequent so precipitation should be well above average. As for temperatures, the analogue years are nearly "black and white", meaning that some of the analogue years clearly show above normal temperatures across the Ohio Valley, Northeast, Upper Midwest, and other parts of the Northern United States, while the other half of the analogues show below normal temperatures across the Northern United States. When they were averaged, most of the United States should end up cooler than normal east of the Rockies. West of the Rockies, due to the strength of the western ridge, I expect above normal temperatures. In other words, there is a very good chance that we end up with below normal temperatures for the winter, but I will keep the original forecast at equal chances for above or below normal temperatures.
I'll start with storminess and precipitation. In actuality, this could go either way this year. In my personal opinion though, I believe that El Nino will be non-existent by the time December comes around. If this occurs, then I expect precipitation to be above normal in the Ohio Valley, all the way into the Eastern United States. Any place south of Indiana or west of Indiana will likely see below normal precipitation. The jet stream will likely be directed across the southern and central United States this year. The biggest storms will occur when the NAO dips to negative values, and the PNA also goes negative, forcing a large trough into the Midwest. For right now, I'm going to go out on a limb, and state that snowfall may be slightly above normal for the winter season.
I don't believe we will see another split flow jet stream, which will allow for a stronger jet stream, more dynamic storm systems, and colder weather for areas north of the jet stream. From Southern California into the Southeast, I expect above normal precipitation for the first part of the winter season, but near normal precipitation for the rest of the winter. In the east, coastal storms will be frequent so precipitation should be well above average. As for temperatures, the analogue years are nearly "black and white", meaning that some of the analogue years clearly show above normal temperatures across the Ohio Valley, Northeast, Upper Midwest, and other parts of the Northern United States, while the other half of the analogues show below normal temperatures across the Northern United States. When they were averaged, most of the United States should end up cooler than normal east of the Rockies. West of the Rockies, due to the strength of the western ridge, I expect above normal temperatures. In other words, there is a very good chance that we end up with below normal temperatures for the winter, but I will keep the original forecast at equal chances for above or below normal temperatures.
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