Bastardi Bold

"...(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.

Nieves de La Nina

Take your pick.



D-J-F snowfall maps for seven La Nina Years Selected by Climate Predition Center using ocean criteria (1942-43...1950-51...1955-56...1970-71...1973-74...1975-76...1988-89)

Make your own.

November/s ENSO Anomaly Forecast

Latest consensus ensemble mean forecast for ENSO Region 3.4 this MET winter (D-J-F) is ~-1.8°C...indicating 'strong' La Nina conditions are expected. Five of the six latest model runs are less than or equal to the forecast ensemble mean. Forecast values have delined each month since May (-0.6°C). Last month/s forecast was -1.6°C.

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.