Monday, November 28, 2011

Why no winter yet...

12-9 - Still no pattern change, although models aren't showing blowtorch warmth either.  Around the 19th, we may get some normal air masses to settle in, which by then is all we for some white stuff.  Three to Four storm possibilities between now and Christmas.  First obviously going to the lakes, but a normal progression is to bring each one further and further south.  See first model run with storm on Christmas

12-8  Still no pattern change.  The end of the period still shows return to neutral, but that return keeps getting pushed off.  How long can an AO remain positive?



12-5 - Yesterday's outlook looked favorable for a pattern flip, but out of caution, I didn't post. I'd like to see 3 or more days of a sustained cold, in at least 3 days of model runs before I am convinced the end of the warm pattern is near. This mornings runs have the cold remaning transitory, and while they have the nao and ao approaching neutral, this is much higher than what it was yesterday. The AO currently is 5 right now, the highest I've seen - keeps the cold bottled up in the artic. The PNA however, has been consistently forcasted to go positive since the 12-1 post below, so there will be some cold entering from Western Canada, but it moves fast and modifies as it exits over the Rockies. For the east to be cold, need the cold air coming in east of the Rockies. Lots of talk about storms for this week - just not seeing it though. One cuts west, the trailer goes off east. Possible flurries or quick changeover as front comes through, but doubtful it sticks.

noon disco- NAM does show a snow event wed nite into thurs. Normally the NAM runs a bit north of the other models, but its something to watch now. CMC and GFS both have storms, but a little to far out to sea. 0z UKMET has a storm going right over us bringing rain. Opening separat post on event as more data is coming in.

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12-1 update: this afternoon had ensembles for 12-15 with +pna, ao and nao heading -. GFS operational completely the opposite though. JB posted yesterday that "the ugliest pre dec 15 week in us since 2005 is on its way" HM posting that 60% of the country could be covered with snow and there will be an east coast storm next week. Now the models have been showing a storm in the dec 6-8 range, but its been cutting west of the Apps.

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Below are the major winter indices: Artic Oscilation (AO), Pacific North America (PNA) and North Atlantic (NAO) as forecast by the GFS today. Typical cold patterns have a postive PNA to set the ridge in the East Pacific so cold air comes into CONUS. AO as negative to release the cold air from the pole and NAO negative to keep the cold air around. While the PNA is currently positive, the NAO is really high and AO is really high. Then PNA goes negative. Also note the error pattern on the NAO and AO. The bold line is the actual, grey line is the consensus. When looking at the 10 and 14 day charts, the typical bias since Sept 1 is that the predicted consensus is lower than the actual and for today its much lower. So until we can change at least the AO to a strong negative, no real brutal or sustained cold air masses.

Friday, November 18, 2011

Analogs

Throwing an idea out there - we've had a wet early fall, so what other years have been wet or had a wet fall and how did the following winter turn out temp wise

Wettest Aug/Sept/Oct periods were:
1927 – 22.8 warmer
1933 – 21.46 cooler
1989 – 22.85 warmer 1c
2005 – 21.17 warmer 2c
1983 – 20.56 warmer .5c
1955 – 20.4
1934 – 17.55 (cooler .5)

Wettest years with over 60" of precip by October were:
1972 – 67.03 (Warmer 1c)
1975 – 61.21 (Warmer .5c)
1983 – 80.56 (Warmer .5c)
1989 – 65.11 (Warmer 1c)
1990 – 60.92 (Warmer 5c)
2007 – 61.7 (Warmer 3c)

Overwhelming indication that the DJF period will be warmer than normal

11-26 note: arguing against analogs is my three month cycle theory. JUN/JUL/AUG were below norm with SEPT/OCT/NOV above normal. This would lead to a below norm for DEC/JAN/FEB.

12-13 note:  as of right now, there is no snow in the long range models for the rest of the month.  Using Poughkepsie stats, here are some other years without snow in December and how they turned out:
2006 - Jan('07) 1.5; Feb 17.5; Mar 3.2  note Dxr had 8.3 in Feb
1994  - Jan ('95) 0;  Feb 4; Mar 0

And years with under 1.5 inches:
2004 - Jan(05) 22; Feb 11; Mar 16
1999 - Jan(00) 6.4; Feb 2.1; Mar 0
1998 - Jan (99) 15.9; Feb 1.5; Mar 1.9
1997 - Jan (98) 0; Feb 13; Mar 1.6

Out of those years, 98 and 99 were dry at POU, although other stations were closer to normal. 
There are no years to compare where we got 17 inches in October.

Monday, November 14, 2011

Winter??

11-26 While there are hints of at least a 3 day period of below normal temps at some point in second week, those hints are not yet consistent. Euro and CMC show very little cold air, with 540 lines right over us as the coldest. GFS still shows a trough digging in the eastern half of the country, but it lasts three days. Keep in mind normal temps for Dec are 45 to start 35 to end. It does look a bit closer to normal compared to what has happened lately though. With Nov, Oct and Sept being above normal, it should switch to colder soon. Unless you read my analog post.
No model has any threat of snow for next ten days. Will post again once trough becomes established or if storm threat arises.

11-22 Watching long range models which have been showing cold air invasion in week two, but keeps trending to splitting the trough and pumping warmth in. No evidence that even if the cold air gets here, that it stays for over a few days. Watching highs develop over OK/TX and moving NE over Mid Atlantic. Not a cold pattern. Will check in after Thanksgiving.

11-18

Still a borderline snow event for Tues, Wed before Thxgvg. Just a matter of whether the storm goes flat and underdeveloped, or if it amplifies and winds up (and where it deepens as well). Nothing very strong in any event.

11-14

Asided from a temporary cold blast or two from frontal passages, no colder than normal weather or snow is in the next two weeks. I am keeping an eye on the time period around Thanksgiving as there could be enough cold air aloft to bring some wet snow, but its not quite as impressive as the Oct. storms.

Tuesday, November 1, 2011

October snow results



Snow started in Danbury around 11am per facebook posts. Lasted until the middle of Saturday night. NWS official total was 17.2 inches for Danbury. Power went out at the airport around 3pm and went out at the weather station around 7:30. As of this writing three days later, power has not returned. At the peak, 850,000 CL&P customers (66%) lost power. All of New Fairfield, Ridgefield, Redding, over 95% of Bethel, Newtown and 66% of Danbury lost power. Those totals have only moved down slightly three days later. Temp in the house bottomed out at 48 degrees and has stayed there for the most part. The bedroom was heated to 59 using 15 candles last night. We lost limbs off the front maple, which crushed the forsythia, we lost a wygelia, spirea, butterfly bush, branches off a lilac, an entire lilac in the back, an entire dogwood, a third of another dogwood, prized rosebush, limbs off the back pine tree remain hanging. No damage to the house. There is a tree across Jefferson ave midway down the street, and powerlines cross the street further. Just about every property has trees down of some kind, although housing structures were not all that impacted. Restaurants and the mall are booming.


Other totals of note: http://forecast.weather.gov/product.php?site=NWS&format=CI&version=1&glossary=0&highlight=off&issuedby=OKX&product=PNS


Ridgefield - 17"; Shelton 12"; Greenwich 12"; Oxford 12"; N Caldwell, nj 12", W. Orange, 8"; W Milford 19"; Harriman 16"; Armonk 12"; CPark 3"; Mahopac 12"


Windsor Locks 20", Bristol 17", Coventry 10"; Ashfield, MA 25"; Plainfield Ma, 30.5"; Springfield 14"; Goshen Ma, 25"


Jaffrey NH 31.4"; Troy NH, 25"; New Ipswich ,26"


Bakersville CT 18", Winsted, 18" N Milford, 14"; Peru, MA 24"; Millbrook NY 21.6"; Halcott Ctr 11.5"; Phonecia 10"; Brattleboro 15"

Storm 3 - could be the one! (spoiler, it was)

 2/9  Set up is an upper low over TX that heads northeast into TN valley and then transfers off the coast. At the upper levels, there's ...