Wednesday, December 31, 2008

New Year/s Eve Snow Storm

(updated below)

Snowfall was fairly intense there for a while this afternoon...with some northeastern stations reporting rates up to 2" / hour.

At times...VSBYs went below 0.25 SM beneath 100' ceilings. Network warning radars observed widespread banding signatures south of the mid-level deformation zone.

Cold columns and an energetic short wave made for extremely high SN:H2O (ALB @ 46:1...BGM @ 31:1...and BDR @ 17:1).

Turned out to be a marginal contest storm with the majority of stations reporting little more than nuisance amounts...although spotter reports from MA and NH were notably greater. Map shows preliminary snowfall reports from CDUS41 and PNS bulletins at post time.

UPDATE:
ALB - 7.2"; 55:1
BOS - 6.5"; 16:1
ORH - 6.4"; 16:1
BDL - 4.9"; 16:1
CON - 3.8"; 17:1
PVD - 4.9"; 19:1
CON - 3.8"; 17:1

New daily records @ BDL...BDR...BOS...ORH...and PVD.

In hindsight...this storm was probably contest-worthy.

Thursday, December 25, 2008

Interim Standings

After three snow storms...Emoran holds a slim 0.027 margin over donsutherland1 with dmcguriman in third.

Under the ‘two-thirds’ rule…forecasters who have entered at least two forecasts are included in this interim summary.

Full forecaster statistics table and charts here.

SUMSQ errors for each contest snow storm are normalized with a 'Z-score'...then averaged to compute the standings. Forecasters who have entered at least 2/3 of all snow storm contests are included in the standings.

If a forecaster has participated in more than two-thirds of all snow storm contests...then Z-scores from their 'best two-thirds' forecasts are used to calculate Interim and Final standings. Same idea as dropping the lowest quiz score before the final grade is computed.

Wednesday, December 24, 2008

Snow Storm #3: Results

Senior forecaster emoran made the best synoptic-scale forecast for NEWxSFC/s third snow storm. His forecast verified with 79.2 SUMSQ error points (Z-Score = -1.013).

He completed the trifecta with lowest Total Absolute Error (25.45") and Average Absolute Error (1.21"). His 90.2% R-SQ score...a measure of how well a forecast captures the variability of the observed snowfall... was also ranked first.

Emoran had the lowest station errors @ CAR BTV BDL MDT PHL BWI and made perfect forecasts @ BDL PHL BWI.

Congratulations emoran!

Emoran wins one FREE month of StormVista GOLD for his efforts.

2nd Place: donsutherland1 (90.8"; -0.880)
3rd Place: Raven (101.5"; -0.758)

Three forecasters came within 5% of the 97.7" " storm-total snowfall.

Full forecast verification and results summary here.

Tuesday, December 23, 2008

Snow Storm #3 - Coastal Frontogenesis


Click image to animate.

Note the sharp temperature gradient between PWM and Buoy 44005. The buoy is located 78 NM east of PWM.



Rapid deepening of -2.7 mb / hr at 00z concurrent with strongest horizontal temperature gradient of 0.372°F / NM. Strong temperature gradients initiate ageostrophic circulations across the boundary leading to pressure falls and upward vertical motion.

PWM observed a record 14.5" snowfall from this storm. The old record of 12.4" was set in 1933. Snow totals are often suppressed at PWM b/c of its proximity to the coast; however...in this case...the station remained on the cold side of the coastal front and all precipitation fell as snow.

WSI - DEC Update - Winter '08 / '09

From Reuters UK...
""Most of the East should be quite mild in January, before the pattern shifts again in February and March to allow for below-normal temperatures to return to the Northeast," WSI forecaster Todd Crawford said.

"Although February and March are expected to be colder than normal on average, the Northeast will experience greater temperature fluctuations than other regions, WSI said.

[...]

""Current oceanic and atmospheric indicators are quite similar to those observed during the winters of the early 1960s, when cold western U.S. winters were commonplace," Crawford said."
NE CONUS (relative to normal)
JAN - warmer
FEB - colder (except NJ/DE/MD)
MAR - colder

Snow Storm #3: Preliminary Verification

Preliminary storm-total snowfalls from CDUS41...PNS...and CF6 bulletins for Sunday and Monday.

Seven new daily records were set on Sunday.
PWM - 14.5" (12.4"; '33)
CON - 10" (7.9"; '14)
BGR - 9.7" (7"; '95)
BTV - 9.1" (7.8"; '10)
ORH - 8" (6"; '54)
ALB - 6.6" (5.7"; 1887)
BDL - 5" (2.6"; '75)

SN:H2O @ PWM and CON estimates derived from METAR 6///// and P///// groups.

Please report errors in Remarks.
Final results and storm summary Wednesday.

Monday, December 22, 2008

Snow Storm #2: Results


Journeyman forecaster Bruced39 made the best synoptic-scale forecast for NEWxSFC/s second snow storm. His forecast verified with 112.6 SUMSQ error points (Z-Score = -1.318). His 81.3% R-SQ score was also ranked first.

Bruced39 had the lowest station errors @ PWM BTV PVD BDR.

Congratulations bruced39!

Bruced39 wins one FREE month of StormVista GOLD for his efforts.

2nd Place: donsutherland1 (123.9"; -1.199)
3rd Place: emoran (125.9"; -1.179)

Five forecasters came within 5% of the 119.85" storm-total snowfall. Not only does the forecast need to get the storm-total snowfall right...but it has to be put in all the right places.

Intern / Rookie class: First-time forecaster Anthony placed first.

Full forecast verification and results summary here.

Sunday, December 21, 2008

Snow Storm #3: The Forecasts



11 forecasters for this week/s third snow storm. One additional entry than reported last night b/c our server delayed transmission of a timely entry. Never before has there been so many contest-worthy storms at one time.

Station forecasts here.



Bonus snows expected over northern forecast stations with respectable amounts farther south.



NAO and PNA closer to normal...but AO flying high near outlier territory.



Verification began last night @ midnight. Snowfall continues over the forecast area at post time and is expected to continue into Monday afternoon. Preliminary storm-total snowfalls will be posted early Tuesday with the final results available on the web site Wednesday.

Snow Storm #2: Preliminary Verification

Preliminary storm-total snowfalls from CDUS41...PNS...and CF6 bulletins for Friday and Saturday.

Five new daily records were set on Friday.
ORH - 11.6" (10"; '45)
BTV - 8.6" (5.2"; '96)
ALB - 7.8" (4.2"; '86)
PWM - 6.5" (4"; '61,'45,1885)
CON - 6.5" (5"; '85)

SN:H20 @ HYA...ABE...EWR are estimates derived from METAR 6///// and P///// groups.

Please report errors in Remarks.
Final results and storm summary Monday evening.

Friday, December 19, 2008

Snowfall Expected for Most of Shijiazhuang This Weekend

From the Handan Daily...
At 17 o’clock yesterday, provincial weather services in Shijiazhuang released warning of the coming strong winds and cold weather. The experts from the provincial weather services indicated that at the end of this weekend, the weather in the whole province will change into cloudiness from the cold winds and most of the areas will have snowfall.

Call for Forecasts: Snow Storm #3 - Winter '08 / '09

Don/t put those shovels and snow blowers away quite yet. More inventory on the way.

The third snow storm in less than a week is expected to affect the forecast area beginning Sunday. This one will approach from a lower latitude and undergo approximately 12+ hours of rapid deepening off the upper mid-Atlantic and southern New England coast. A moderately strong arctic HIGH progged to hold its position north of the LOW throughout the event...locking in lo-level cold air. Aloft...a more potent upper LOW with a forecast 100+ kt jet max at the base of the trof...will enhance the system/s dynamics and storm-total snowfall potential.

Make the best forecast and you/ll win one month of FREE access to StormVista GOLD. Details here.

Deadline: Saturday...20 December...2008 @ 10:30 PM EST

Forecast element: storm-total snowfall
Verification period begins: 12:01 AM EST Sunday...21 December 2008

Enter your forecast here.
Follow the link from 'Enter Storm Forecast.'

More prizes will be awarded at the end of winter for the best over-all forecaster. Details here.

As always...there/s no cost...or fee...or annoying requests for personal information to enter.

If you are making your first forecast this year...you/ll need to create an account (user name / password / valid e-mail...if you want a copy of your forecast sent to your Inbox) before entering a forecast.

------------------------------------------------------

The Northeast Weather Snowfall Forecast Contest (NEWxSFC) is celebrating its 10th anniversary this winter. The Contest began during the '99/'00 season on USENET/s ne.weather news-group. It/s the longest...continuously held snowfall forecasting contest for the NE CONUS on the Internet.

The Contest is open to any and all of the following:
Amateur and professional forecasters; broadcasters with or without trained Seals; weather-biz types and wanna-bees; wish-casters...astrologers...and other class of dreamers; Pollyannas or Cassandras; registered Nostradamusts; non-violent megalomaniacs; woolly-bear caterpillars or their agents; pest detectives...NE.Wx Usenet NG or GoogleGroup regulars and lurkers...refugees from EUSWx...StormVista...Golden Snowball...and meteorologists.

What is a contest-worthy event?

Snow Storm #2: The Forecasts



18 forecasters...including 2 new Rookies. Moderate snow occurring early this evening and more on the way this weekend.

Station forecasts here.



Forecaster consensus for a wide-spread New England event with heavy snowfalls expected at many stations.



What/s up with that CW about 'needing' -NAO...-AO...+PNA for a significant snow storm?



Verification began last night @ midnight. Snowfall continues over the forecast area at post time and is expected to continue into Saturday afternoon. Preliminary storm-total snowfalls will be posted early Sunday with the final results available on the web site Monday evening.

Thursday, December 18, 2008

Snow Storm #1: Results

Wxduff made the best synoptic-scale forecast for NEWxSFC/s inaugural snow storm. His forecast verified with 10.3 SUMSQ error points (Z-Score = -1.106).

He hit the trifecta with 1st place finishes for Total Absolute Error (9.05") and Average Absolute Error (0.57"). His 86.3% R-SQ score was second-highest of all entries.

Wxduff made perfect forecasts @ CON HYA EWR and had the lowest errors @ BGR PWM CON HYA EWR.

Congratulations Wxduff!

Wxduff wins one FREE month of StormVista/s GOLD for his efforts.

2nd Place: donsutherland1 (14.4"; -0.939)
3rd Place: dmcguriman (19.4"; -0.675)

Rookie forecaster 'weatherT' came within 0.7" of the 26.7" storm-total snowfall.

Full forecast verification and contest summary here.

Snow Storm #1: Preliminary Verification

Preliminary storm-total snowfalls from CDUS41...PNS...and CF6 bulletins for Wednesday.

No new daily records were set.

Please report errors in Remarks.
Final results and storm summary Friday evening.

Call for Forecasts: Snow Storm #2 - Winter '08 / '09

Round 2! After a slow start...we/re off the races.

Good prospects for a good dump as a second...stronger wave cruises into the forecast area on Friday for Snow Storm #2. Progs continue the idea of enhanced omega from coupled jet structure and strong...lo-level forcing courtesy warm-air advection.

Make the best forecast and you/ll win one month of FREE access to StormVista GOLD. Details here.

Deadline: Thursday...18 December...2008 @ 10:30 PM EST

Forecast element: storm-total snowfall
Verification period begins: 12:01 AM EST Friday...19 December 2008

Enter your forecast here.
Follow the link from 'Enter Storm Forecast.'

More prizes will be awarded at the end of winter for the best over-all forecaster. Details here.

As always...there/s no cost...or fee...or annoying requests for personal information to enter.

If you are making your first forecast this year...you/ll need to create an account (user name / password / valid e-mail...if you want a copy of your forecast sent to your Inbox) before entering a forecast.

------------------------------------------------------

The Northeast Weather Snowfall Forecast Contest (NEWxSFC) is celebrating its 10th anniversary this winter. The Contest began during the '99/'00 season on USENET/s ne.weather news-group. It/s the longest...continuously held snowfall forecasting contest for the NE CONUS on the Internet.

The Contest is open to any and all of the following:
Amateur and professional forecasters; broadcasters with or without trained Seals; weather-biz types and wanna-bees; wish-casters...astrologers...and other class of dreamers; Pollyannas or Cassandras; registered Nostradamusts; non-violent megalomaniacs; woolly-bear caterpillars or their agents; pest detectives...NE.Wx Usenet NG or GoogleGroup regulars and lurkers...refugees from EUSWx...StormVista...Golden Snowball...and meteorologists.

What is a contest-worthy event?

Wednesday, December 17, 2008

Snow Storm #1: The Forecasts



Twelve forecasters including three rookies for the inaugural event. Not much of a storm...but a good warm-up for Friday/s event.

Station forecasts here.



Forecaster consensus for a northern New England event.



No support from teleconnections. Just lucky to get a barely contest-worthy storm.



Verification began last night @ midnight. Snowfall has all but ended over the forecast area at post time. Preliminary storm-total snowfalls will be posted Thursday evening with the final results available on the web site Friday evening.

Tuesday, December 16, 2008

Coupled Jets



Good looking signature ahead of Friday/s snow storm.

Transverse...ageostrophic circulations in the entrance region of the polar jet advect cold air into the storm from the NW. Transverse...ageostrophic circulations in the exit region of the sub-tropical jet advect moist air into the storm from the SE. Enhanced omega occurs at the intersection of these circulations.

GooFuS also throws in some additional forcing with strong...low-level...warm air advection.

Could be a memorable event.

Monday, December 15, 2008

Call for Forecasts: Snow Storm #1 - Winter '08 / '09

The season has started!

Warm-advection snowfalls expected late Tuesday night and continuing into Wednesday across northern New England. Monday evening/s NAM forecast projections have reversed course from its earlier anemic trend and now suggest storm-total snowfalls will be contest-worthy.

Make the best forecast and you/ll win one month of FREE access to StormVista GOLD. Details here

Deadline: Tuesday...16 December 2008 @ 10:59 PM EST

Forecast element: storm-total snowfall
Verification period begins: 12:01 EST Wednesday...17 December 2008

Enter your forecast here.
Follow the link from 'Enter Storm Forecast.'

More prizes will be awarded at the end of winter to the best over-all forecaster. Details here.

As always...there/s no cost...or fee...or annoying requests for personal information to enter.

New and returning forecasters will need to create an account (user name / password / valid e-mail...if you want a copy of your forecast sent to your Inbox) before entering a forecast.

------------------------------------------------------

The Northeast Weather Snowfall Forecast Contest (NEWxSFC) is celebrating its 10th anniversary this winter. The Contest began during the '99/'00 season on USENET/s ne.weather news-group. It/s the longest...continuously held snowfall forecasting contest for the NE CONUS on the Internet.

The Contest is open to any and all of the following:
Amateur and professional forecasters; broadcasters with or without trained Seals; weather-biz types and wanna-bees; wish-casters...astrologers...and other class of dreamers; Pollyannas or Cassandras; registered Nostradamusts; non-violent megalomaniacs; woolly-bear caterpillars or their agents; pest detectives...NE.Wx Usenet NG or GoogleGroup regulars and lurkers...refugees from EUSWx...StormVista...Golden Snowball...and meteorologists.

What is a contesy-worthy event?

Synopti-scope® Detects Storm Signal

(updated below)

May not have too much longer to wait for this season/s inaugural snow storm.

Today/s 96-hour projection from the 12z GooFuS resolves a weak...warm advection event over northern portions of the forecast area mid-week.

The polar HIGH located north-northeast of the wave weakens slightly but holds its position as the LOW moves into the waters off Cape Cod and the Gulf of Maine.

Snowfall outlook...using 10:1 QFP...produces a 5 - 7" swath along and either side of a line from BGM - CON - BGR.

UPDATE:
Snow still seen as likely Tuesday night and Wednesday over northern New England; however...QPF has been trending lower today. Local NWS WFOs and HPC all leaning toward a nuisance-type event...all of which raises doubts about whether this storm will be contest-worthy.

GO / NO GO decision after this evening/s model runs.

Friday, December 12, 2008

First Nor'easter - Winter '08 / '09

First nor'easter to affect the forecast area this season was a dud.

Respectable storm-total snowfalls were scarce...
CAR - 4.1
BGR - 4
PWM - T
CON - 1
BTV - 9.2
ALB - 0.1
BGM - 3.6

NWP did a good job waving off this event by picking up on its predominate liquid / freezing character several earlier in the week.


Click image to animate.

Tuesday, December 9, 2008

Coastal Teaser #2 - DEC '08

(updated below - update II)

Healthy-looking nor'easter progged for end of the week...one that could affect about half the forecast area with this year/s inaugural contest storm. There/s a retreating HIGH as the storm gains latitude; however...cyclogenesis off the VA Capes would keep some of the cold air from escaping.

QPF @ 10:1 spits out 10"+ for ALB...CON...PWM...and BGR. Columns are currently depicted as cold enough for higher ratios...but let/s not get too far ahead of the story. Hard to tell where the cloud-tops are from GooFuS soundings b/c the moisture layers aloft are always depicted as being too deep.



Better get a snow storm in now while there/s cold air afoot b/c LR solutions have a decidedly 'mild' look to them well into Week 2.

If this scenario plays out...a call for forecasts would be made Wednesday evening with a late Thursday deadline.

UPDATE:
12/9/12z progs not all that encouraging for enough frozen precipitation at more than a handful of forecast stations nor are they in good agreement wrt timing. Yesterday/s GooFuS had the event Friday into Saturday...now it/s moved up a day.



HPC paints a 40% probability mainly over northern New England...with icing farther south across CT and MA.

GO / NO GO decision pending this evening/s model run(s).

UPDATE II:
12/10/00z NAM continues recent trend in its depiction of THU / FRI nor'easter as mainly a cold rain event over the forecast area with narrow band of IP / SN limited to northern edge of precipitation shield.

Potential appears marginal at this time for adequate conditions to warrant a call for forecasts.

Monday, December 1, 2008

Season-total Snowfall Forecast Contest - Winter '08 / '09

(updated below - Update II)

Deadline for entries has passed.

There were 30 entries this year...seven (7) of which came from Rookies. Welcome and good luck.

Good to see a strong turn out of Veteran forecasters...too. Last year/s contest winner 'duxpond' was a rookie back then and he/s back this year to defend his title.

Everyone/s forecast will be posted later today on the Contest/s web page.

Just for grins...this year/s forecasts were verified against last year/s snowfall totals with these results...ranked 1 to 10:
  • garymcm
  • TQ
  • bubbler86
  • Donald Rosenfeld
  • jackzig
  • weatherT®
  • duxpond©
  • Mitchel Volk
  • Raven
  • Don Rooney
® = rookie
© = defending champion

Update:


Click image to enlarge.

Update II:
Ranked by storm total precipitation.
Blue (red) cells indicate lowest (highest) tercile.



Period-of-record normal (PORN) snowfall: 916.9"
5 (26) forecasts below (above) PORN.
Consensus forecast: 18.9% above PORN
Minimum storm total precipitation (STP) forecast: 72% of PORN
Maximum STP forecast: 74% above PORN

All forecasts have been posted to the Contest/s web site.

Saturday, November 29, 2008

Deadline...

...for the 8th Annual 'Season-total' snowfall forecast contest is looming large in the window.

Forecasts must be entered NLT 11:59 PM EST...Sunday 30 NOV 2008.

You can submit your snowfall forecast for Winter '08 / '09 here.

You/ll need to create an account with a 'user name' and password...even if you/ve entered the Contest in year/s past. If you provide a valid e-mail address...a copy of your entry will be sent to your inbox.

Everyone/s forecast will be posted on the NEWxSFC/s web site within a day or two of Sunday/s deadline.

Next up...the regular snowfall forecasting season...where each storm is its own Contest. Every time you make the best forecast...you win...in addition to prestigious bragging rights...a month of free access to StormVista/s GOLD!

Friday, November 28, 2008

sCAST - Winter '08 / '09

AER/s sCAST has been released in past years in late NOV or early DEC. No sign of it yet...but while we wait...here/s a thumbnail sketch about how it works.

sCAST considers these elements when making its winter forecast:
  • Eurasia/s OCT snow cover
  • Sea level perssures
  • Air temperatures
  • Atmosphereic energy flux
  • ENSO state
  • Global warming trend
  • NAO / AO state
  • sCAST developer Dr. Judah Cohen explains...
    "...the link between October snow cover in Siberia and the Northern Hemisphere's winter temperatures, and snowfall.

    "October is the month when snow begins to pile up across Siberia. October is also the month that the Siberian high, one of three dominant weather centers across the Northern Hemisphere, forms.

    "In years when Siberian snow cover is above normal, a strengthened Siberian high and colder surface temperatures across Northern Eurasia develop in the fall.


    ""The result is a warming in Earth's stratosphere that occurs in January," said Cohen. "This eventually descends from the stratosphere to Earth's surface over a week or two in January, making for a warmer winter in Northern Hemisphere high latitudes. However, in mid-latitudes it turns colder, so winters in the northeastern U.S. and eastern Europe are likely to be colder and snowier than normal."
    Eurasia/s OCT 2008 snow cover of 8.88 km² was 13% below PORN (10.19 km²) this year... suggesting a generally mild winter b/c NAO/AO will be positive in JAN. Positive NAO/AO are a consequence of a strong polar vortex which keeps the coldest air at high latitudes.

    Wednesday, November 26, 2008

    How Much for Philly? - Scourge of Conventional Wisdom

    A question for the ages.

    John Bolaris...meteorologist for PHL/s FOX-TV affillite...issued his Winter '08 / '09 outlook today.
    "...December...expect below normal temperatures with above normal snowfall.
    ...January...above normal temperatures with below normal snowfall.
    February and March could be vicious, with below normal temperatures with (sic) above normal snowfall."
    Bottom line: group think.

    What is it with these TV-WX guys (gals) anyway? Begs the question about needing so many 'forecasters' when they all essentially parrot the same narrative.

    Of particular note...JB/s unsupported claim that "(a) negative NAO means more snow; a positive NAO means less snow."

    An analysis of PHL/s daily snowfall events since 1950 - a shortened period-of-record necessitated by data availability for AO...NAO...and PNA - finds there/s a greater probability for any amount of snow when NAO is positive and AO is negative.

    The only time -NAO is the preferred mode over +NAO is for events that produce 6" to almost 9" snowfalls.

    There are equal chances that a +NAO or -NAO drops at least 9" but less than a foot.

    By a 2:1 margin...+NAO and AO of either sign is the favored mode for snowfalls of 12" or more.

    It/s pretty obvious someone didn/t get the memo about NAO/s effect of snowfall in Philly.

    Snowfall data courtesy Utah University Climate Center.

    Tuesday, November 25, 2008

    WSI - NOV Update - Winter '08 / '09

    From PRWEB...
    "WSI expects the upcoming three-month period to average colder than normal across the northern and western US, with above-normal temperatures confined to the Southeast.

    In the NE...
    DEC: colder than normal

    "The WSI December forecast indicates colder-than-normal temperatures in key Northeast and North Central regions; much colder-than-normal temperatures are expected in New York, New England, and eastern portions of PJM.

    JAN: warmer than normal
    FEB: colder than normal

    "According to WSI seasonal forecaster Dr. Todd Crawford, "The current cold pattern in the northeastern US should persist through at least the first half of December. A temporary transition to a mild pattern should occur from January into early February, before the pattern reverts back to a much colder regime during the last weeks of winter. The current configuration of the very cold North Pacific ocean temperatures and wind patterns in the tropical Pacific should result in a cold winter in the Northwest and a warm winter in the Southeast. The Northeast will likely experience more subseasonal variability than other regions this winter.""
    WSI/s OCT outlook here.

    Sunday, November 23, 2008

    How Often is Frequently?

    Out of necessity...weather observations and forecasts apply a degree of smoothing to the chaos known as the atmosphere in order convey a sense of the 'prevailing' conditions at any one time.

    The answer to tonight/s musical question is informed less by the definition of 'frequently' than by its antonyms....
    Never
    Rarely
    Seldom
    Occasionally
    Uncommonly
    ...and by its usage in axioms such as "more often than not."

    "Nearly"..."several times"...and "almost" just don/t measure up. Scientific phenomena...such as hurricanes...severe wx...and blizzards...are described and categorized according to a well-defined classification scheme.

    Nobody ever said this was horseshoes.

    Saturday, November 22, 2008

    Blizzard Defined

    "A blizzard means that the following conditions are expected to prevail for a period of 3 hours or longer.

    (1) Sustained wind or frequent gusts to 35 miles an hour or greater;

    and

    (2) considerable falling and/or blowing snow (i.e., reducing visibility frequently to less than 1/4 mile).

    Although there is no set temperature requirement for blizzard conditions, the life-threatening nature of the low temperatures in combination with the other hazardous conditions of wind, snow, and poor visibility increases dramatically when the temperature falls below 20°F. "

    WSOM

    Let/s be careful out there this winter. Heavy snowfall does not a blizzard make. Blizzards are meso-beta scale (20 - 200 km) severe winter wx wind storms where visibility is restricted for at least three (3) hours.

    La Nina is Back

    So sayeth EBerry...

    "...tropical forcing does have a MJO component to it, projecting ~1.5 sigma in octant 5...~2 sigma in octant 4 with the interannual component left in. There has been eastward propagation of ~5-6 m/s along the equator for the past couple of weeks."
    [...]
    "Global relative AAM (plots updated through 20 November) is ~1 standard deviation (1 AMU) above the R1 data climatology, working with ~ plus 40 Hadley positive global tendency."
    [...]
    "At times, during the last several weeks, there have been well defined projections onto a positive phase of the Branstator (2002) circumglobal teleconnection (anomalous midlatitude ridges)."

    Who among us could argue anything but?

    Cold Start to December



    1052 HIGH coming into CONUS from Siberia for first week of meteorological winter as the AO experiences a bit of its version of the China Syndrome...free-falling to six (6) standard deviations below its mean.

    Thursday, November 20, 2008

    Arctic Oscillation Market Collapse

    Unless there/s been a big mistake in reporting the data...the AO took a steep...67% nose-dive today...as the index fell 1.456 points.

    Yesterday/s AO index value had soared to 2.187.... creeping toward outlier territory.

    Today...there must have been a strong 'sell' signal in the global teleconnection markets...b/c the index lost 2/3 of its value as it crashed-landed @ 0.730!

    Positive AO values trend to keep Arctic air bottled up at hi-latitudes. When the AO lurks below zero...the cold air often escapes into the Lower 48.

    By the looks of it...AO is heading downtown for an extended stay.

    CPC Outlook - Update - Winter '08 / '09

    CPC/s latest 90-day outlook for NEWxSFC/s forecast area this coming meteorological winter (D-J-F) continues with its 'equal chances' theme from last month/s outlook.

    Equal chances? Is that the best they can do?

    In other words...the odds are 50 / 50. The same odds you have when flipping a fair coin. For this we pay how much?

    Probability theory considers 50% as a 'good' chance of getting a desired outcome...so there/s no reason...yet...to abandon all hope for a memorable season.
    The Climate Prediction Center...located in the World Weather Building...SE of Washington...DC...uses many tools to develop the 90-day outlook. CPC forecasters...or maybe they/re known as 'outlookers' inside the WWB...consider ENSO...climatological departures from persistence trends in 10-year temperature and 15-year precipitation periods...Madden-Julian Oscillation voodoo(MJO)...teleconnection indexes such as the North Atlantic Oscillation (NAO)...Pacific-North American (PNA)...and Pacific Decadal Oscillation (PDO)...along with current soil moisture anomalies...razz-ma-tazz statistical tools...and last but not least...the dynamic Climate Forecast System (CFS) model.

    ENSO is seen currently as neutral by CPC and it/s expected to remain that way throughout the upcoming winter...even though...NCEP/s own SST forecasts maintain slightly negative anomalies in Nino 3.4.

    A much more detailed forecast discussion from the CPC is here.

    Tuesday, November 18, 2008

    AO and NAO - NHEMI Air Temperature Variability

    Winter Northern Hemisphere surface air temperature variability
    associated with the Arctic Oscillation and North Atlantic Oscillation

    "The paper shows that the NAO and the AO have different impacts on winter NH (surafce air temperature) SAT. The variability of other atmospheric variables related to the AO and the NAO is discussed."
    A bit wonkish...but a still a good read.

    GEOPHYSICAL RESEARCH LETTERS, VOL. 32
    Dongxiao Wang,1 Chunzai Wang,2 Xiaoyi Yang,1 and Jian Lu3
    Published 20 August 2005.

    AER - Winter Outlook '08 / '09

    sCAST modeler Judah Cohen of AER expects 'warm' temperatures in the east this winter. Cohen mentions the below normal snow cover in Siberia as a contributing factor in this year/s forecast.

    More...

    Italy/s Alps



    Beautiful dendritic patterns over Italy/s Alps as observed last Sunday from space.

    Note cloud cover to the north over Switzerland...Austria....France...and Germany.

    Map

    Sunday, November 16, 2008

    Coastal Teaser #1 - NOV '08



    If this outlier scenario from today/s 12z GooFuS comes to pass toward week/s end...it would be the earliest contest storm ever.

    Saturday, November 15, 2008

    Arctic Oscillation - October '08

    CPC posted OCT/s Arctic Oscillation (AO) index recently and it/s up...WAY-T-F up.

    OCT came in @ a monster +1.676...the 1st positive value since MAR '08.

    It/s only one data point but an important one b/c stratospheric and tropospheric circulations tend to be coupled during winter.

    The AO tends to be in its negative phase (weak...warm vortex) when the QBO is negative (easterly). A -AO favors arctic outbreaks over the eastern CONUS; whereas...+AO and QBO-W are associated with a strong...cold PV.

    +AO is famous for hording the coldest air over hi-latitudes.
    No cold...arctic air => weak baroclinicity.
    Weak baroclinicity => less cyclogenesis.
    Less cyclogenesis => fewer storms.
    Fewer storms => less chance of snow from migratory cyclones.

    Time to fold up the tents and go home?

    There/s no doubt QBO will be positive (westerly) for most of the '08 / '09 winter...until @ least late FEB / early MAR...which suggests D-J-F...as a whole...might not-be-so-cold-'n-wintry after all.

    Best AO analog years using a 'least-squares' method: '95 /'96...'73 / '74...'54 / '55...'75 / '76...and '72 / '73.



    R² value is down-right putrid (0.385) for 1st-choice analog year and they go down hill from there. None of the 'best' AO years match up well with 'best' QBO years...so there/s little-to-no confidence the AO analogs offer much insight this go 'round.

    Thursday, November 13, 2008

    Early Start - Winter '08 / '09

    Good reason to think winter/s getting a head start this year. Ski resorts on both sides of the Atlantic Ocean are opening early. There have been encouraging events recently in the 49th state...as well.

    "Mammoth Mountain in California and Bormio in Italy have both opened early for winter 2008-9." Mammoth opened 10 days early. Bormio a full month.

    Breckenridge Ski Resort...CO. Earliest opening in 30 years.

    "Baqueira Beret ski area in the Pyrenees will open a week earlier than planned, on Saturday November 22nd, rather than the 29th."

    "Marmot Basin in Canada opens...Saturday 15th November, its earliest ever opening."

    "Verbier has opened earlier than expected because of the heavy snowfall across the Alps in recent weeks."

    Meanwhile...Bill Steffen...Chief Meteorologist @ WOOD-TV 8 in Grands Rapids...MI... blogs about recent events in Alaska...
    "Barrow at the northern tip of Alaska had 21″ of snow in 28 days (they average 29″ per year…it’s a cold desert up there).

    "Fairbanks has only had two days warmer than average in the last month and a half. During October and early November, Fairbanks has been 8 degrees colder than average!

    "On the southern coast, Anchorage has only had one month this year that has been warmer than average. They haven’t reached 30 degrees since Oct. 22 and the last three weeks have been five degrees colder than average.

    "The water off Alaska is colder than average and the sun won’t be of any help until spring. That heavy, cold air will start building southward soon. The surface Arctic icecap grew this year and is now at its greatest areal extent since 2002."

    Wednesday, November 12, 2008

    D/Aleo Update - Winter Outlook '08 / '09

    Speaking with the Worcester Telegram & Gazette News today...Joe D/Aleo refined his outlook a smidge for the coming winter...
    "In a telephone interview yesterday from his New Hampshire home, Mr. D’Aleo said he is confident the rest of this month and December will be cold and potentially snowy. He said ice coverage in the Arctic has rebounded quickly and snow cover in that part of the world is at its usual depth for this time of year. He said that is important for this area, because air masses from the polar region head south toward Central Massachusetts in December.

    "“I suspect many of us will see snow on the ground before Thanksgiving,” he said.

    "Mr. D’Aleo, however, also noted that he is less confident now than he was three weeks ago about a warm-up in January and February."
    Ice coverage...


    Latest monthly Nino3.4 outlook from CFS...

    Almanac Outlooks - Winter '08 / '09

    FWIW...

    Tuesday, November 11, 2008

    Eurasia Snow Cover - OCT '08 - Part II

    October/s numbers for Eurasia areal snow cover are in and it ain/t pretty if you/re on the east coast and in the market for cold this winter.

    Eurasia snow cover...Siberia specifically...is correlated negatively to east CONUS winter temperature in AER/s sCAST model...so as Eurasia snow cover goes...so goes sCAST.

    Observed snow cover (L) Departures (R)

    The Global Snow Lab @ Rutgers U. reports Eurasia areal snow cover for OCT @ 8.88 km² (25th percentile)...which is 13% below the period-of-record average (1967-2008) of 10.2 km². This compares to an -8% departure in NHEMI snow cover.


    Eurasia/s OCT snow cover has been above average six (6) times during the past 10 years...most recently in 2006. Last year/s departure was -16%...which is not substantially different than this year. The '07 / '08 winter produced bonus snows across northern NE and disappointing totals elsewhere.



    Snowfall departure analysis courtesy NCDC.

    Other NEWxSFC posts about sCAST here.