I Can’t Speak to Snowfall, but Winter Is On the Comeback Trail for a While to ComeDecember 23rd, 2013 at 9:56 pm by Don Paul under 4 Warn Weather
After the rain, the power outages from the ice storm, and the still-in-progress Tonawanda Creek flooding (at the time of this posting), the return to wintry weather will prove to be relatively benign…at least at the outset. Some limited lake snow will develop toward Tuesday morning and into Tuesday across Chautauqua County and western Cattaraugus County, with moderate to marginally heavy amounts on some hills. Thanks to a synoptic trough, snow showers will flare up over much of WNY on Tuesday, giving many parts of WNY a shot at a White Christmas, albeit a thin coating.
What is the bigger story is the return of our oft-discussed “indices” to having a role in our longer term pattern. That’s opposed to the cold weather which has resulted from a ridge over the north Pacific and an eastern trough which encouraged a polar flow from NW Canada (not Siberia). For the first time this cold weather season, the PNA will be slightly positive/cold phrase, the NAO will trend to slightly negative/cold phase, and the AO looks to trend sharply negative, as it had been earlier in the autumn. The 500mb ensemble means in the ECMWF, GFS, and Canadian GEM all support a ridge closer to the US west coast and an eastern trough–with no signs of a return to any lasting period of mild weather. We’ve already had those symptoms, but our indices were out of phase–which is quite unusual. There will be some quick ups, but undoubtedly the downs will outweigh and outnumber the ups over the next couple of weeks, minimally.
Lake Erie has bounced back to 36. That won’t last long. There are no signs of any major synoptic snowstorm in the next 6-7 days, but ski resorts will be able to make new snow and get some occasional help from nature.