Winter '07 / '08 - Place Your Bets

Plenty-o-conventional wisdom underfoot this fall about a moderate-to-strong La Nina holding court over the upcoming winter. There/s even more CW obviously based on multi-event composites about how "warm 'n dry" it/s gonna be for the CONUS east of the much 'wetter' Lucky Ducks in OH / TN River valleys.

Too bad there/s no emoticon for skeptical chin-stroking with deep furrowed brow; otherwise...it might go here. Instead...take a look at the long-term composites for temperature and precipitation...

Temperature.................Precipitation

Mean temperature normal to 1°F above normal and mean precipitation '-2" to normal' extreme southern forecast area to 'normal to +2"' elsewhere.

The La Nina Analogs
The current MEI index 'trend match' has its best fit to '70 / '71...although the subsequent winter was almost over before the -ENSO event became strong. The latest numerical and statistical model output forecast a strong event (le -1.5°C) throughout all of met winter.


Note the highly ranked precipitation area (blue) across the GOM states and greater than median values along the EC and interior NE.

The next best MEI matches occurred prior to the non-Nina winters of '78 / 79 and '59 / '60. That leaves '88 / '89 as this winter/s runner-up MEI analog.


The '88 / '89 analog winter is closer to this year/s CW 'La Nina' winter forecast of 'warm and dry.'


Other Indices and MEI -- BFF or What?
PDO - '70 / '71 was 'warm' during its long-term 'cool' phase. This year/s PDO is 'cool' during a 'warm' phase. No benefits from these friends.

QBO...perhaps? The '70 QBO analog is ranked 5th; however...considering its 'E phase' in '70 / '71 flipped to W in March...two months earlier than the expected change in direction this winter. This flip/s timing could well be important this year b/c the QBO/s E phase is a leading indicator for a -AO and its associated increase in EC cold / storminess through the process of downward wave propagation.

AO...NAO...PNA...EP...and other like indices are thought to have skillful forecast ranges of about two weeks. There could be some utility in LR forecasting with these values if a multi-year trend is present.

The '70 / '71 analog demonstrates the variability of La Nina winters and suggests the coming winter won/t wind up 'warm and dry' in the NE or M-A.

ECHAM/s Winter '07 / '08 Outlook - September

The German Climate Model...known as ECHAM...extended forecast for NHEMI sea-level deviations in hPa (1 hPa = 1 mb) are shown below. Not sure when it was initialized -- best guess is September -- or how often it/s updated.


October
Main feature is the strong suggestion of a +AO...which doesn/t appear to be born out by its observed index; however...some of its physical features (HIGH over N Pole; broad trof across E CONUS and the ATL Ocean) are roughly in the right places.

November
Strong omega block along the International Dateline...which teleconnects to a trof W - ridge E L/W pattern over CONUS. E of the block...storm track over Siberia would favor enhanced snow pack and development of Siberian HIGH. Trof along W CONUS has connection to HI Is. and the so-called 'Pineapple Express.'

December
Weak +PNA pattern with positive anomaly over AK and broad trof across lower 48. Rex block in the E ATL and negative anomaly INVOF Azores suggests the presence of a -NAO variant.

January
The positive anomaly over W CN suggests +PNA and the negative anomalies W of Greenland and INVOF the Azores favors -NAO...which implies cold and stormy conditions for E CONUS. Strength of positive anomaly over Netherlands could result from a high-latitude block.

February
Pressure anomaly couplet in N ATL Ocean points decidely to +NAO. ATL ridge axis extends W across CONUS suggesting 'mild' mid-winter temperatures in the E.

First Snow Surprises Bulgaria

Closed LOW over the Bulgaria has dumped an early load of heavy snow on the region.

From Sofia News Agency...
"The first snowflakes for this winter season have started falling over Bulgaria's capital Sofia, the towns of Pernik and Dragoman on Saturday evening, surprising some and delighting others.
[...]
The thickness of the snow blanket in the mountains is expected to reach up to 70 centimetres (27")."


View Larger Map

The month of December is expected to be colder than last year with maximum temperatures between 3C and 8C.

Cyclone Drones

Updated below


Developed and intended for investigating the lower levels of tropical systems...it/s not a stretch to imagine these 28-pound unmanned aircraft by Aerosonde being flown someday into extra-tropical winter cyclones deepening off the SE coast.

Aerosonde Gallery

Update

In 1998...an Aerosonde MK 3 crossed the Atlantic Ocean in 27 hours...using only 1.5 gallons of fuel.


Aerosonde specs
Wing span: 2.9 m (9.5 ft)
Weight:15 kg (32.2 lb)
Engine: 24 cc fuel injected
Payload(s): Up to 5.3 kg (11.5 lb)
Fuel capacity: Up to 6 liters (1.6 gal)
Operation: Autonomous
Generator: 75W
Navigation: GPS

Performance
Cruise airspeed:75-110 kph (40-60 kts)
Endurance: 5 - 30 hr(subject to payload)
Range: ~2000 km (50 kts)
Streaming video
Global iridium satellite
Service ceiling: 4500 m (15,000 ft)

Brochure (.pdf)

CPC/s Winter '07 / '08 Outlook - October

Same general idea as last month/s long-lead outlook...although this month/s temperature POEs are higher - note strong increase and intrusion into TX - and zero line has expanded slightly. Southern extent of the positive precipitation anomaly has contracted from the northern GOM states into western KY. Dry tongue has advanced from VA / NC border onto the northern Delmarva peninsula.

sCAST - Winter '07 / '08

Met Winter '06 / '07 ------------- Met Winter '07 / '08

AER/s briefing slides (.pdf) about the sCAST model...this year/s forecast...and verification of last winter/s forecast.

Seems odd AER issued a forecast this early since an important model input is October snow cover across Siberia.

From the National Science Foundation (NSF)..."The model uses October Siberian snow cover, sea level pressure anomalies and recent temperature trends in its winter forecast."

AER/s rationale for its Winter '06 / '07 Forecast...
"October 2006 snow cover was observed to be above normal that coupled with a predicted negative winter Arctic Oscillation (a pattern that favors high heights in the Arctic and more cold air intrusions further south) produces the colder than normal temperatures in the East. The above normal snow cover also favors a stratospheric warming event this winter.

"A weak to moderate El Nino is currently predicted for the winter, which we anticipate will not have a strong impact on winter temperatures in the eastern US. However, if the El Nino turns out to be stronger than predicted, in the moderate to strong range, then the predicted temperatures in the East may be too cold. (Also the above normal snow cover in Siberia and observed atmospheric conditions in the North Atlantic during October once again favor a higher probability of a major East Coast snow storm this winter season).

"October is the month where snow cover undergoes its greatest expansion in the Eurasian region. During October, Eurasian snow cover can increase by as much as 10-15 million square kilometers, which is greater than the total land area of the United States, including Alaska. NSF-funded research has shown that variability in the extent of Eurasian snow cover can be used to predict cold or warm winters across the entire mid-latitudes of the Northern Hemisphere."

First Contact

Scattered reports of SN in the E are beginning to appear.

From KMWN (Mt. Washington, NH)
Oct. 12
122353Z 28054G62KT 1/16SM BLSN FZFG VV000 M04/M04 RMK SNB00E45

Oct. 13
132156Z 27025KT 1/16SM -SN FZFG VV001 M04/M04 RMK SNB15
132255Z 27031KT 1/16SM BLSN FZFG VV000 M04/M04 RMK SNE45 VRY LGT ICG

Today
140251Z 25030G34KT 1/16SM -SN DRSN FZFG VV000 M04/M04 RMK SNB05 VRY LGT ICG

140453Z 27046G51KT 0SM BLSN FZFG VV000 M04/M04 RMK SGE05SNE45 VRY LGT ICG

141059Z 29042G50KT 0SM -SN FZFG VV000 M07/M07 RMK SNB45 VRY LGT ICG

140351Z 27033G37KT 1/16SM -SGSN BLSN FZFG VV000 M04/M04 RMK SGB45 VRY LGT ICG
140453Z 27046G51KT 0SM BLSN FZFG VV000 M04/M04 RMK SGE05SNE45 VRY LGT ICG

140547Z 29032KT 1/16SM -SG BLSN FZFG VV000 M05/M05 RMK SGB35 VRY LGT ICG 60009 4/001 931008 11034 21049
140654Z 28049G56KT 1/16SM BLSN FZFG VV000 M06/M06 RMK SGE20 VRY LGT ICG

141255Z 28034G43KT 0SM -SGSN FZFG VV000 M07/M07 RMK SGB40 VRY LGT ICG
141350Z 30042G50KT 0SM BLSN FZFG VV000 M07/M07 RMK SGSNE15 VRY LGT ICG
141449Z 30041G47KT 0SM -SG BLSN FZFG VV000 M07/M07 RMK SGB30 VRY LGT ICG
141752Z 30041G49KT 0SM BLSN FZFG VV000 M06/M06 RMK SGE20 VRY LGT 60006 931007 11062 21077

141855Z 29045G49KT 0SM -SG BLSN FZFG VV000 M06/M06 RMK SGB40 VRY LGT ICG

Another report of snow from Snowshoe Mt...West Virginia during the afternoon of Oct. 11.

State of the Cryosphere

Kevin Myatt of the Roanoke (VA) Times has an interesting on-line article about the state of the NHEMI cryosphere in today/s Weather Journal.

The Arctic Ocean is largely unfrozen as of mid-October and its ice pack is a shadow of itself from one year ago. Kevin describes how cold air masses will be slow to develop as much of the cooling will go into replenishing the ice sheet.

The Cryosphere Today from the Department of Atmospheric Sciences at the University of Illinois is a good resource for more information.

Early Snowfalls

(Updated below - Update II)

Reports abound from around the globe of earlier than usual snowfall. Saw a story from Japan as well but lost the link.

Pocatello (Idaho) recorded its third-earliest seasonal snowfall Saturday

Snow Falls Early in South Iceland

Early snow surprises hikers, shuts down Yosemite pass

Sierra Nevada [dusted] with an usually early snowfall

[E]xpedition organizers had not anticipated the early snowfall and blizzards.

Not at all clear what it means or if it/s unusual. For all we know...snow falls earlier than usual somewhere every year.

Update
Early Snow @ Fort Collins,CO.

Update II
Hokkaido's Wakkanai city observes 1st snow in Japan

CPC/s Winter '07 / '08 Outlook - September

Seems a little odd for CPC to issue a 90-day outlook for meteorological winter (DJF) in early October based on mid-September data (2.5 month lead-time).

In the Northeast and the Mid-Atlantic...
"Temperatures are expected to be above average in response to the long-term warming trend.

Snowfall for the region will depend on other climate factors... which are difficult to anticipate more than one-to-two weeks in advance."



CPC/s winter outlook will be updated on Oct. 18 and again on Nov. 15.

QBO - September '07

QBO is six months into its negative phase where the index is currently well below its long-term average. First time in a while QBO will be east throughout the winter. Flip coming in the spring this time around.

Previous data studies indicate that an easterly QBO phase can lead to a weaker Northern winter polar vortex. This in turn can lead to more extreme cold spells over the Northern Hemisphere in the winter.

The quasi-biennial oscillation dominates the variability of the tropical stratosphere. Although the QBO is a tropical phenomenon...it affects the stratospheric flow from pole to pole by modulating the effects of extra-tropical waves.

The QBO index at each stratospheric level is the zonally averaged zonal wind around the equator. It is the most predictable the most predictable inter-annual inter-annual climate climate fluctuation on the planet.

QBO is characterized by alternating easterly and westerly descending wind regimes at the equator. The period of the oscillation varies from 20 to 36 months...with an average period of about 28 months...over the past half century.

The QBO determines the character of the early winter...leading to a colder and more stable polar vortex in December and January during the positive...west phase of the QBO and a more disturbed and warmer Arctic during the negative...east phase of the QBO.

Major winter stratospheric warmings preferentially occur during the easterly phase of the QBO, Holton and Tan (1980).

The solar cycle influences the latter part of the winters when a clear difference is observed between periods of high and low solar activity. During high solar activity the winters in the west (+) phase of the QBO tend to be disturbed and are often connected with Major Midwinter Warmings.

MET Office - NAO Prediction

From the UK Met Office...
"The figure below shows that the predicted winter NAO index for 2007/8 is weakly negative at -0.05 with a standard error of ±1.0. The near zero amplitude of the predicted index relative to the error bar means that the NAO prediction provides little signal for below- or above-normal European winter temperatures or precipitation. However, the prediction is consistent with a cooler, drier winter over northern Europe as a whole than experienced in winter 2006/7, when the observed index was +1.1."


The model does an OK job forecasting inter-annual variations...but not so much for an upcoming season. Its correlation coefficient (R) is an anemic 0.45. Enough to demonstrate some skill but not high enough to hint at which way it/s heading next.

Here/s the model/s loading pattern. The anomaly tri-pole along NOAM/S EC and the Saragossa Sea dipole are associated with anomalies @ 500 mb and a positive NAO.


Here/s the model/s SSTAs for this year. A strong signal NAO won/t be strong positive.


Forecasts for the previous two years/s have been good for sign and magnitude...however...past performance does not guarantee future rate of return. The error bars suggest 1) NAO won/t be stronger than last year and 2) the index has a 50/50 chance of going either way relative to zero.

Snow International

Global snow reporting from snow-forecast.com Updated weekly.

From their latest post...

North America
==========
"Over the past few days, our snow alert system has been busy sending
warnings of new snow for the Canadian Rockies - the first time this
season. With a strong La Nina, we would expect a steady stream of
Pacific storms pouring into the Pacific NW. This is just what the
forecast for the next 7 days shows with Whistler bearing the full
brunt on Saturday night and then again on Tuesday and yet again on
Friday. Too mild for snow at resort level this close to the coast and
this early in the season, but above mid-station we expect to see the
accumulation of another 50cm of fresh snow by Wednesday. As these
weather systems push deep into the continent on a NE track, many
resorts in the Pacific NW and the northern Rockies will enjoy
excellent early season snowfalls."

More...

Beware the Three-headed Dog

"...[T]hree major phenomena, which he likened to a "three-headed dog", influenced Australia's rainfall: El Nino events, the Indian Ocean Dipole, and the Southern Annular Mode, a weather pattern in the Southern Ocean..."

woof!

October's ENSO Anomaly Forecast - Winter '07 - '08

Latest CFS forecast for ENSO Region 3.4 SST anomaly of ~-1.6°C continues trend from previous model runs for La Nina conditions to be well established this winter. Each run has been stronger than the last. The current forecast for a 'strong' La Nina reflects a 1°C difference from last summer/s 'weak' forecast.


Previous DJF forecast values (°C)
April -0.6
May -0.6
June -0.8
July -0.9
August -1.1

Latest monthly temperature and precipitation anomalies reflect the model/s La Nina forecast for warm and dry in the SE.

7th Annual Season-total Snowfall Forecast Contest

NE.Wx/s annual ‘Season-Total Snowfall Forecasting Contest’ is your absolute best...biggest...and probably ONLY chance to be recognized for your long-range forecasting acumen; recognition you so richly deserve.

Not only that...but if you win the Contest...you get a copy of "The Snow Booklet"...by Nolan J. Doesken and Arthur Judson.

What other incentive could you possibly want to enter the Contest?

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

Trolls...goats...hat3-lsiters...and psests need not apply.

The reigning NE.Wx ‘Season-Total’ Snowfall Forecasting Champ-een is Raven2001.

Forecast element: sum-total season snowfall
Forecast period: December 1, 2007 through March 31, 2008
Verification: NWS preliminary climate reports (CLM or F6)

Deadline: Friday, November 30, 2007 @ 11:59 PM EST

Station list at the website.

WSI Energycast - OND

In the NE...
October - Colder than normal
November - Warmer than normal
December - Colder than normal

"According to WSI seasonal forecaster Dr. Todd Crawford, “The La Nina event continues to slowly strengthen and play a dominant role in temperature patterns, primarily via modulation of tropical convection patterns and their subsequent downstream impacts in the US. Typically, in the eastern US, La Nina means a warm October and a cold December, with the transition occurring in November. While we feel that December will indeed be cold in the East, the current ocean temperature patterns in the northern Pacific suggest that the early fall warmth may not be as certain as the La Nina signal suggests.” "

More...