Happy New Year - Contest # 4?

Sunday/s 12z progs suggest another contest-worthy event on New Year/s Day with cyclogenesis occurring in the Gulf of ME followed by an arctic outbreak.

Thermal profiles appear colder for this system..and like Storm # 3...it taps into hi-PW parcels from low latitudes.

Contest # 3 - Call for Forecasts

Fairly decent snows on the northern edge of the precipitation shield are expected to attend a deepening wave passing over the 40°N / 70°W ‘benchmark’ late Sunday into New Year/s Eve.

Deadline: 8:00 PM EST Sunday, 30 December 2007
Forecast verification begins: 8:00 PM EST Sunday, 30 December 2007

Enter your forecast via the Contest/s web site
Follow the link to 'Enter Storm Forecast.'

Please enter 0.05 for trace amounts instead of a 'T.'

All forecasts will be posted by the Contest Administrator to the NE_Wx Google Group before 11 PM EST Sunday, 30 December 2007 and to the Contest web site by Monday afternoon.

Contest subject to cancellation before the deadline…if forecast conditions warrant.

More information about the contest/s rules…forecast verification…and scoring can be found at the main web site.

Updates and announcement are posted on the Contest/s web log @ http://newxsfc.blogspot.com


<.boiler plate>
Forecasters need to register once before entering…even if they were registered last year.

Registration is simple… requiring only a user name and password. If you provide a valid e-mail address…a copy of your forecast will be sent to you. Please ensure your browser is enabled to accept first-party cookies.

Each contest must have a minimum of seven (7) forecasters for the results to be included in the end-of-season standings.

The NE.Wx Snowfall Forecast Contest (NEWxSFC) is a multi-month event that continues into late March or early April. In general…contests are held whenever a decent…synoptic-scale storm rears its head and threatens at least a half-dozen forecast stations with more than nuisance snowfall amounts. Forecasters are called to post their 'storm total' snowfall predictions…on deadline…for 27 NWS / FAA observing stations scattered about New England and the Mid-Atlantic regions. The Contest Administrator determines the deadlines for entries…verifies all forecasts…and publishes the final results to the Contest/s web site.

Please be sure to read the rules before entering the contest b/c your entry constitutes agreement to abide by them.

You can find the Contest Rules and additional information about error scoring…current monthly snowfall climatology from NCDC…daily CPC teleconnection indices…daily NESDIS N-Hemi snow cover…and NWS Daily Climate Bulletins (CDUS41) by pointing your browser here.
<./boiler plate>

Contest # 3 - Definite Maybe

12z NAM depicts a narrow band of 'hard to get excited about' nuisance snows on the nrn edge of a rain dominated precip shield. OTOH...GooFuS is back in the decent contest storm category after venturing off the reservation last night.

Final decision pending tonight/s 00z runs.

Contest # 3 - Unfriendly Trend

Friday/s 12z GooFuS solns for a 'contest-worthy' event come Monday were a darn sight better than tonight/s 'low and away' look. Latest GFS short-term output is now much more in line with the earlier 'contest-hostile' solns from NAM.

Given the unfriendly trend...Contest # 3 awaits another day.

For that matter...next two weeks don/t look all that promising either.

Happy New Year - One Step Closer

Today/s EC D+5 takes a big step closer toward a significant winter wx event for Northeast CONUS come New Year/s Day.

Note the depiction of greater amplitude to the wrn ridge and how the sfc LOW/s re-development off the mid-Atlantic coast is better defined than yesterday/s D+6 prog.

Whether it all gets there is still up on the air...but without a doubt...we be moving in the right direction.

Happy New Year

Today/s European model D+6 has real potential...despite the evolution and present placement of its major features.

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.

Is that soln reasonable given the how persistent the heat ridge has been to date...or might today/s soln be a tad too progressive? The implications for EC wx are significant if the soln truely is too progressive.

Also consider what/s progged to happen in the ern PAC where the model depicts deep layer WAA. Ordinarily...this would be expected to pump up or amplify the downstream S/W ridge.

In the event the SE heat ridge is not so progressive...and the wrn ridge b/comes more amplified by WAA...the wave length across CONUS would be shorter and the amplitude greater than presently progged.

Such an alternative scenario keeps the L/W trof closer to the EC where cyclogenesis would likely occur @ a latitude low enuf and a significant snowstorm is in play for much of the I-95 corridor.

NHEMI Snow Cover Inventory Up 10%...Cryosphere Busy Making Up for Lost Time

Over @ Global Warming heretic Joe D/Aleo/s blog...these NHEMI snow cover charts come courtesy of Dr. Bob 'CoolWx' Hart of FSU fame...

The graphic on the left depicts the areal NHEMI snow cover...which is now 10% > CLIMO (1996 - 2005)

The upper part of the chart on the right shows a comparison between 'CLIMO' and 'Observed' snow cover. Note the lines cross in the upper right corner. The lower part of the same chart shows the trend in magnitude of the snow cover/s deficit / surplus.

Dr. Joe expects hi-latitude arctic air masses to visit the Lower 48 come JAN '08 resulting in big forecast busts for NOAA and PWSPs.

NEWxSFC looks forward to his forecast verifying in spades.

That 70s Show

Made a post @ StormVista this evening about what to 'expect' next month based on inferences from this winter/s leading analog year 1970. You can find it here. If you/re a SV member...you/ll see graphics embedded in the post. OTRW...you/ll have to click links...so go ahead a sign up.

It made sense to make the post over there b/c their platform has far superior graphic handling and text formatting capabilities than Blogger.

Gist of the post:

• 1970 is a strong analog for this winter based on 'least squares' regression of MEI and QBO values.
  
• MSLP analysis for 12/9 - 12/18 show remarkable similarity between '07 and '70.
  
• Analysis of JAN 1971 5H Z and SFC T anomalies suggest a cold and stormy JAN '08 lay ahead.
  
• Analogs are fun but not very reliable.
  

Cold and stormy are our watch words @ NEWxSFC.

'49 / '50 Analog on Life Support

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.

Return of Hi-Latitude Easterlies

Note the ECMWF/s D+8 forecast for the return of deep tropospheric...hi-latitude easterlies over the pole suggesting a return of a negative AO index toward the end of DEC.

The time-height section also shows the 70mb mean zonal wind from the east over the Equator...indicating the negative QBO.

Negative QBO favors a negative AO...which is associated with a less stable...and slower polar vortex. These conditions present good opportunities for arctic outbreaks....storminess...and the potential for hi-latitude blocking.