Heavy snows fell across northern portions of the forecast area...yet so-called 'critical heavy snowfall' teleconnection indices are all on the wrong side of zero for this event.
Today/s EC D+5 takes a big step closer toward a significant winter wx event for Northeast CONUS come New Year/s Day.
The SE heat ridge has shifted its position once this winter...when it retrogressed about two weeks ago and widespread snows were observed in the NE. This time...a progressive planetary wave regime shoves the heat ridge well offshore by D+10 into the south-central ATL.
The graphic on the left depicts the areal NHEMI snow cover...which is now 10% > CLIMO (1996 - 2005)
Accu-Wx/s Winter '07 / '08 outlook is heavily weighed by the '49 / '50 analog where cold temperatures @ the start of DEC flipped to abnormal warmth mid-month and stayed above normal through FEB.
The northern polar stereographic view for the same nine days @ 5H depicts one similar feature...the weak trofs off the west CONUS coast...and several that are at markedly @ odds with each other. Note the analog year trof INVOF the Azores and a ridge in the observed. There/s an analog year trof in the GOM and ridging in the observed. There/s a ridge INVOF the Hawaiian Is. in the analog year and an observed trof.
On the afternoon of December 16...a rapidly deepening secondary LOW had moved to a position over Lower NY Bay... having advanced NE hugging the shorelines of VA...MD...and NJ during the morning.
Preliminary storm-total snowfalls from CDUS41...CF6...and PNS bulletins for Saturday...Sunday...and Monday.New daily records
12/16
BOS - 7.6" (5"; 1896)
ORH - 8.4" (6"; 1896)
12/17
CAR - 9.2" (7.3"; 1978)
Contest Storm #2 got no help from the PNA index as it was negative during the period. Positive PNA is frequently cited as an important ingredient for decent snowfalls in the NE CONUS. A positive PNA index doesn/t hurt b/c it oft times favors cyclogenesis off the SE CONUS coast...but it/s not an absolutely necessary ingredient.
The deadline for Contest #2 is Saturday evening but in hindsight...it should have been Thursday evening given the respectable amount of snow that fell across SNE today.
12z solns from the ECMWF and GooFuS suggest there/s a nor'easter...possibly a Miller 'B'...in the chamber for early next week.
Preliminary storm-total snowfall based on final CDUS41 bulletins from Sunday...Monday...and Tuesday.
"First, and curiously, the snow cover in other seasons (summer, fall and winter) hasn't shown big changes, Robinson says.
"Second, after falling off in the late 1980s, reaching a record low in 1990, the snow cover rebounded - until three years ago. So the decreases in complete calendar years 2004, 2005 and 2006 could constitute an anomaly.
"Third, Robinson, who contributed to the blue-ribbon Intergovernmental Panel on Climate Change (IPCC) reports, says that one could make the interesting argument that the world is warmer because of less snow.
"It's a chicken-egg question," he says.
"The physical mechanism isn't fully understood, Cohen says, but fall snow coverage evidently affects air pressure patterns that influence other changes: An above-normal snowpack in Siberia in October correlates with below-normal temperatures in the United States in winter.
"October is the key, Cohen believes, because when the sun is strongest (summer), the snow is scarce; when the snow cover peaks (winter), the sun is absent. October has both."
(updated below)
The first week of DEC has been a good period for snow storms in the NE the past half-decade. The table shows the number of contest stations reporting snow by year and day of week.
The season starts when the storms start and continues until it/s obvious winter is over. The season runs normally from early December through the middle of March; however, IIRC, the earliest contest storm occurred in late November and the latest storm was in April. Most years there have been ten contest storms.
Not every snowstorm that affects the forecast area will trigger a contest. The criteria used to decide whether a storm is contest-worthy are loosely defined as one that/s expected to:
"...(F)orecaster Joe Bastardi of AccuWeather on Tuesday reiterated his forecast for a warm winter in the Northeast, although the weather has been running colder than normal since Nov. 1. In an interview with MarketWatch, he said it will stay cold until the middle of December and then run about four degrees above normal in the northeastern U.S."
Rather BOLD prediction given December/s temperature departures during past -ENSO events. Much of NE has been one-half to one standard deviation below normal...the same being true for large portions of the M-A.
Temperature.................Precipitation
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