Feb 5, 2015

February Shiver

The first four days of the month of February have been way below normal across a good part of the Northeast U.S. As shown on the map (to the left) from The Northeast Regional Climate Center. Some locations across the Northeast are 15°BELOW normal or lower for the month already (grant it we're not quite through the first week)! Some selected average monthly temperatures and departures from normal from across NY State and Western New England through the first four days of the month are as follows (average monthly temperature is given first; number in parentheses is the departure from normal): ALBANY: 11.4° (-12.1°); GLENS FALLS: 2.8° (-15.2°) (I'm actually amazed at the value for Glens Falls! They did drop to -27° on the 3rd and so far every night this month has been well BELOW 0°); BENNINGTON: 8.9° (-13.6°); PITTSFIELD: 11.1° (-10.1°)

Percentage of 105 analogs with Below (blue) or Above reds/oranges
The map to the right is from the CIPS Extended Analog web site, and it shows the percentage of 105 analogs that either had above or below temperatures. The map is for is for the period Feb 11-13 and it indicates that 65% or more of the analogs had BELOW normal cold for the Eastern U.S. Those same analogs indicate potential temperatures of 6° to 10° BELOW normal (map below). Also keep in mind ensemble data tends to average out or smooth atmospheric anomalies out so these temperatures could even be colder.                                                                                          
Forecast Temperature Anomaly for 2/11-13/2015

And if you're looking for any moderation or warmth forget it. The analog data (map to the right) for the period 17-19 February shows an even greater chance for below normal temperatures perhaps by as much as 12° or more colder than normal.

I'll have more on the expected snow this weekend into next week late tomorrow.

Feb 4, 2015

Expect More Snow and Frigid Weather

4 Feb 2015 11 AM Surface Map & Radar 
Expect a bit of thaw across the region for today but it will be short-lived as yet another arctic cold front currently extending from the Eastern Great Lakes to Missouri late this morning, blasts through the region by early Thursday AM. This front will be preceded and accompanied by some light snow or snow showers. The most persistent snow fall will occur during early Thursday morning. While the snowfall will be mostly light in intensity there will be a few pockets or briefly moderate and this will occur during the Thursday morning commute so count on some travel impacts.

Snowcast for Thurs 5 Feb 2015
The combination of colder air coming in behind the front on a WNW wind along with a weak wave of low pressure riding up along the front may allow from a few more inches of accumulation for folks across the Taconics and the higher spots in the Greens of Vermont and the Berkshires. But again it looks like a light snowfall not a big storm at all. The snow should taper off by around noon most places (early afternoon to the southeast of Albany). During the afternoon it will turn windy and colder along with falling temperatures. During Thursday morning, temperatures will range from the teens to some mid 20s to the southeast of Albany but by afternoon everyone will see them fall through the teens (into the digits to the northwest of Albany) along with moderate NW winds causing wind chill values between -10° and -20°. The winds will abate some Thursday night and with clear skies it looks like plenty of sub-Zero temperatures. Once again some locations across the Adirondacks to Glens Falls could drop to -20° to -25° by Friday morning. Friday will be sunny but cold throughout with temperatures generally in the teens.

During Saturday, yet another arctic cold front moves through accompanied by clouds and some snow showers. This front looks to have less moisture with it then the one on Thursday, so any snow accumulations that might occur will be even less. Unfortunately this front is expected to stall on Sunday to our south with low pressure riding along it through Monday. As shown on the maps below from the Weather Prediction Center. With arctic air to the north of the front and low "overrunning" is expected to develop, resulting in snow once again returning to the region by Sunday evening or night and continuing through Monday.
Forecast surface maps for 7 AM EST Sunday 8 Feb on left Monday 9 Feb on right
Various data sources including the GFS, GFS ensembles and CIPS Winter weather analog system are indicating the potential for a widespread moderate to marginally heavy snow accumulation across the region by Monday February 9, 2015, especially along and north of an approximate Buffalo to Albany to Boston line.

Percentage of COOP snowfall > 4 inches
Right now the potential for a widespread snowfall of  4 inches is high based on the CIPS analog map as shown to the left.

Percentage of COOP snowfall > 8 inches

Percentage of COOP snowfall > 12 inches

With a moderate chance for 8 inches or more of snow exists especially to the north of Interstate 90, as indicated on the map to the right

Meanwhile the potential for a very heavy snow appears to be very low, <30% from this storm, as shown by the CIPS analog map below.

So once again we'll have another end of the weekend/start of the work week snow threat to deal with. Then following this snow threat expect more of the same - BELOW normal temperatures for much of the remainder of next week.