Accu-Wx went into a defensive crouch today with a
missive by WxMatrix/s Jesse Ferrel where he advanced the arguments 'winter hasn/t started yet' and 'it/s not over...until it/s over'.
Both arguments are silly on their face.
If winter has yet to begin...then why does AW/s Winter Outlook include details about early and mid-DEC. Ferrel then argues their outlook covers NOV through MAR. So which is it?
The 'A forecast hasn/t busted until the event has come and gone' maxim is true altho that/s a mighty thin reed given the current state of winter to date and trends in LR NWP.
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 time series shows 5H geo-potential heights (left two images) and SLP (right two images) from the pole to 10°N during the first nine days of DEC for 1949 and 2007. Hard to see anything other than weak correlations.
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.
In the mass fields...both years have HIGH SLP over Siberia...altho it/s much stronger in the analog. Evidence of a GOM LOW in the analog is missing in the observed where a broad area of LOW pressure is centered along the International Date Line.
Not looking too good ATTM for our friends at Accu-Wx. They/ve made a lot of noise and thumped their chests since October hawking the near-certain expectation for a sudden...and dramatic about face in temperatures that would occur mid-DEC. At this point...the '49 / '50 analog might need to be placed on life support.
Calling Doctor Howard...Doctor Fine...Doctor Howard.Had intended to post the analog / observed comparisons last week...but a good contest snow storm came along...and seeing how that/s the reason why we/re here...it was delayed. Will post an update with a look at the period that/s passed since then.
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.
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