Sunday, January 31, 2010

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.

Friday, January 29, 2010

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.

Thursday, January 28, 2010

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.

Wednesday, January 27, 2010

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.

-----
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.

Monday, January 25, 2010

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.

Thursday, January 21, 2010

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.

Thursday, January 14, 2010

Monday, January 11, 2010

Winter '09 / '10 - Snow in Spain


"Snow fell in parts of Spain for the first time in half a century Monday as a wave of Arctic cold that has killed scores of people and caused billions of euros in damage to Europe's economy swept southwards.
 
"The southern Spanish city of Seville, which normally enjoys temperatures in January of around 15 degrees Celsius (59 degrees Fahrenheit), shivered under its first snowfall in half a century."
 
Elsewhere...
"Prague has had its heaviest snowfalls in 17 years and hundreds of homes across the Czech Republic were without electricity.

"Meanwhile Albania has been contending with a different type of extreme weather, as disastrous floods engulfed more than 10,000 hectares of farmland."
More...

Turning out to be a memorable winter after a long series of miserable seasons.

Winter '09 / '10 - December Snowfall - New Record for NOAM


Short 44 year period-of-record...

December snow cover over NOAM and the lower 48 rank #1 out of 44...as well as 10th for all months.  Second highest snowcover over the NHEMI.

Area units:  thousand sq. km

North America 
Rank Area Departure Mean
1/44 18137 1523 16615

Contiguous United States
Rank Area Departure Mean
1/44 4161 1292 2869

Canada
Rank Area Departure Mean
4/44 10277 221 10056

Northern Hemisphere
Rank Area Departure Mean
2/44 45862 2660 43202

Eurasia
Rank Area Departure Mean
7/42 27725 1138 26587

Source: Rutgers University Global Snow Lab