Winter '09 / '10 - Snow Storm #3 - Final Results

NEWxSFC Senior forecaster ilibov has won this season/s third snowfall forecast contest with a SUMSQ error of 85.3"...a 52% improvement over the average SUMSQ error of 176". Ilibov/s Z-score was a very strong -1.711.

Ilibov also placed 1st in every other categoory. 'Total absolute error' 25.9" (Z-score: -1.850)...'average absolute error' of 1.08" per station (24 stations forecast)....'storm total precipitation' error 3.1"...and an R-SQ of 67.7%.

Ilibov had the lowest station errors @BWI and DCA.

Congratulations Ilibov!

2nd Place: Shillelagh (SUMSQ error: 137.4"; Z-score: -0.727)
3rd Place: millersville_bauers* (140.6"; -0.668)
Honorable Mention: nnjwxguy78 (150.3; -0.483)

*Rookie

Full forecast verification...storm summary...and final results at the Contest web site here.

Winter '09 / '10 - Stratospheric Warming Event - II

Warming underway at 10mb...portends a cold end of month as hi-latitude blocking returns.

Imagery courtesy Climate Prediction Center.

Winter '09 / '10 - Snow Storm #3 - Preliminary Verification

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

No climate report for SBY at post-time. The Salisbury CO-OP observer's 220 PM report carried in AKQNS was used.  Value may be revised if CDUS41 or CF6 bulletins are issued before final verification.

Two new daily records.

SAT...30-JAN-10
ACY - 7.6" (3.6"; 1966)
ORF - 6.1" (5"; 1965)

Please report errors and a link to the correct data in Comments.

Final results and storm summary Monday evening.

Winter '09 / '10 - Snow Storm #3 - The Forecasts

12 entries...including three Rookies...two Interns...and seven Senior forecasters issued 151 station forecasts for this winter/s third contest snow storm.

Forecasts are ranked by storm total precipitation (STP) in ascending order. Blue (red) values are in the 25th (75th) percentile.

Forecasts at the Contest web site.

Consensus for a southern mid-Atlantic event.

Arctic Oscillation heading quickly south while NAO and PNA flat-line.

Surface LOW over LA FRI evening forecast to exit stage left late Saturday and kick-out into the western Atlantic off the coastal Carolinas.

Verification period ends 11:59 PM EST...SAT...30-JAN-10.
Preliminary storm-total snowfall totals will be posted the evening of SUN...31-JAN-10.

Winter '09 / '10 - Snow Storm #3 - Raw Forecasts

Raw forecasts here.

All forecasts will be posted to Contest web site and summary information on the web log by FRI evening.

This snow storm appears to be a marginally contest-worthy storm given its potential impact on a limited number of forecast stations.

Then again...there's an added wrinkle to the forecast with the likelihood of accumulating snowfall over a few northern forecast stations during the verification period.

Winter '09 / '10 - Imminent Stratospheric Warming Event

End of FEB temperature outlook: C-C-COLD!

Winter '09 / '10 - Snow Storm #3 - Call for Forecasts

January's second contest snow storm combines juiced-up southern stream energy and bitter arctic cold from the snowfields of northern Canada.

Precipitation coming from weak low-level warm-advection and jet level divergence...with less than impressive mid-level dynamics as streams phase in confluent zone off the mid-Atlantic coast.

Models have been trending farther south past the few runs such that the bare minimum of stations for a contest-worthy storm are expected to be affected.

Last-minute contest cancellation possible if NWP consensus for the frozen precipitation shield dips below the DC metro area. Cancellation notice will be posted to the Contest web site and web log.

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Deadline: 10:30 PM EST THU...28-JAN-10

Forecast element: storm-total snowfall

Verification begins: 12:01 AM EST FRI...29-JAN-10
Verification ends: 11:59 PM EST SAT...30-JAN-10

Enter your forecast at the Contest web site here.
Follow the link from 'Enter Storm Forecast.'

As always...there/s no cost...or fee...or annoying requests for personal information to enter. Just a fun exercise to see who can make the best synoptic-scale snowfall forecast.

If you are issuing your first forecast this year...or you entered the 'season-total' forecast contest...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 submitting your entry.

Winter '09 / '10 - Coastal Teaser #3

NWP model solutions have been advertising a coastal storm late in the week with GooFuS starting the event a day sooner than the ECMWF.

PNA is forecast to peak near +2 STD...AO currently below -1 STD and decreasing...and the NAO is expected to rise sharply from -3 STD ahead of an event that could turn out to be a fair test of Archambault cool-season regime transition and its impact on NE precipitation (.ppt 3.5 mb)

A 'Call for Forecasts' may be issued late Wednesday with a 10:30PM EST deadline on Thursday...if shorter-range progs indicate a contest-worthy snow storm is likely to occur.

Stratosphere is showing signs of another warming during early FEB as the PV shifts away from the pole to a position over Great Britain where it splits in half with an anti-cyclone centered over extreme NE Alaska / NW Canada.

Oft times...it takes ~3 weeks for these signatures to work their way into the troposhere...heralding a return to bitter cold in the east by month's end featuring arctic air mass intrusions from the north pole.

Winter '09 / '10 - Cold Expected to Return in February

From Bloomberg...

"A strengthening El Nino pattern in the Pacific Ocean may lead to a colder February than some forecasters are predicting, according to Bastardi.

“El Nino has broken into moderate territory,” Bastardi said. “February could be brutal in the Northeast.”

"Jim Rouiller, the senior energy meteorologist with Planalytics Inc. in Wayne, Pennsylvania, said he expects cold to make a comeback with the arrival of February.

"Most of northern Europe, from the U.K. to Scandinavia, will be colder than average in February and March, said Andover, Massachusetts-based forecaster WSI Corp.

“Winter will be coming back with a vengeance in February,” Todd Crawford, WSI’s chief meteorologist..."

WSI/s NE CONUS forecast issued in November called for above-normal temperatures in DEC and below-normal in JAN.

Bastardi piles on...

"February is going to go down in memory as a month that was as cold and stormy as December,” predicts Joe Bastardi, chief long-range meteorologist for Accuweather. “It might turn out to be one of the coldest Februaries in the last 115 years.”"

Joe D'Aleo adds...

"“The latest GEM [Global Environmental Multiscale] and ECMWF [European Center for Medium Range Weather Forecasts] model runs are showing colder weather for the remainder of the winter. By the last week of January, we should see cold filling into Canada and then diving back down into the states,”..."

WSI  expects the same in Europe...

"WSI expects temperatures for the approaching period (February-April) to average colder than normal across Scandinavia, UK and most of the mainland, with the exception of parts of Iberia and the Mediterranean states.


"After a brief respite from the bitter cold in late January, this rather extreme winter appears to be gearing up for an encore in February," said WSI Chief Meteorologist Dr. Todd Crawford. "All of the important weather and climate factors that we monitor suggest winter will be coming back with a vengeance in February. This transition back to much colder temperatures is already showing up in two-week forecasts from our computer models, lending more confidence to the colder forecast trend."

True enough...models have been suggesting strong infusions of arctic air from Siberia as February rolls in.

Caveat Consensus.

VCP32 - Now She Says Come In