Saturday, December 05, 2009

Regular Season Contest Overview


DC 1917
Here/s the sequence of events whenever there/s a contest-worthy snow storm.

A 'Call for Forecasts' is made ~24 hours before the deadline for entries. The deadline is usually 10:00 PM ET the day before snowfall is expected.

The 'verification period' begins @midnight on the day snow is expected to begin over any forecast station. The period continues until snow has stopped falling over the entire forecast area or a hard deadline for the Contest/s end has been set.

Once the snow has stopped and the NWS has reported the snowfall amounts in their daily climatological bulletins ... a 'preliminary verification' data table with the storm-total snowfall amounts is posted to the web log. These numbers are subject to challenge and / or modification for ~24 hours ... if they are found later to be in error and / or new information becomes available.

All forecasts are then verified and ranked. The forecaster with the smallest sum of squared-errors (SUMSQ) is the winner.  Storm summary statistics and individual station forecast results are posted to the Contest/s web page. Forecasters are notified by e-mail when the final results are posted.

Summary
Day 1 - Call for Forecasts
Day 2 - Deadline - 10:00 PM Eastern (edited:  15-NOV-18)
Day 3 - Snow happens.  Forecasts posted to web site.  Forecast summary posted to web log.
Day 4 - Preliminary snowfall totals posted to web log ... if storm duration is one day.
Day 5 - Verified forecasts and Final Results posted to web site. Brief storm wrap-up posted to web log.

Complete contest rules and more information here.

Friday, December 04, 2009

Thursday, December 03, 2009

Winter '09 / '10 - Pattern Change - Part Deux

ECMWF 100-mb forecast advertising a split and dramatic shift in the polar vortex (PV) over the next 10 days...with a minor stratospheric warming thrown in for good measure.

PV is forecast to move from its present position in the eastern HEMI north of Siberia...



...to extreme NW Canada in the western HEMI.


Winter '09 / '10 - Coastal Teaser CANCEL

FORECAST


OBSERVED

Winter '09 / '10 - NHEMI Snowcover - November

Could be better.  Much better.  Not only is much of Canada still below normal but so is a fair chunk of the Upper Plains and mid-West.



Orange (blue) areas are below normal (above).  White areas are normal.



Late OCT rally lasted through early NOV before fading rapidly.



State of the cryosphere at month/s end and the start of meteorological winter shows there/s a lot of ground to be made up.  Good hi-latitude snow pack is an important element for creating polar and arctic air masses.

Wednesday, December 02, 2009

9th Annual 'Season-total' Snowfall Forecast Contest - The Forecasts

Welcome rookie forecasters and welcome back veterans to the start of another NE.Wx snowfall forecasting season.  19 entries this year.  Only three expecting below-normal snowfall.

Forecasts in the table below are ranked in ascending order by sum-total snowfall for all stations.

Sum-total period-of-record normal (PORN) snowfall for all stations during D-J-F-M is 916.9".
The percentage displayed next each forecaster/s 'season total' snowfall forecast is its PORN percentage.

Forecasts colored in BLUE (RED) indicate the 25th (75th) percentile.



Minimum sum-total forecast is 576.6" (63% of PORN).
Maximum sum-total forecast is 1,298" (42% above PORN)

Forecaster average is 1,042" (14% above PORN)
Average of all 25-station forecasts is 16% above PORN.

Consensus station forecasts for snowfall at least 25% above PORN:
BGR - 139%
BDR - 135%
SBY - 133%
PHL - 132%
ACY - 128%

® = rookie
© = defending champion

Detailed forecasts here.

Tuesday, December 01, 2009

9th Annual 'Season-total' Snowfall Forecast Contest - UPDATE

Deadline for entries has passed.  Thanks to all who submitted a forecast.
 
Expected to have the forecasts posted this evening but that will have to wait until tomorrow.

Saturday, November 28, 2009

Winter '09 / '10 - 9th Annual 'Season-total' Snowfall Forecast Contest - Last Call!

Deadline:  Monday...November 30 2009 @11:59 PM EST

Full details here.

Hope to have forecaster summary posted Tuesday evening...01 December.

Thursday, November 26, 2009

Winter '09 / '10 - WSI - November Update

"WSI expects the upcoming period (December-February) to average cooler than normal in the eastern and south-central US, with above-normal temperatures common across the western and north-central US. The WSI seasonal outlooks reference a standard 30-year normal (1971-2000).

"The combination of the current El Nino event, abundant Eurasian snow cover, and a favorable pattern of ocean temperatures in the Atlantic Ocean suggest that this winter will be a cold one in the eastern US, especially after the New Year" said WSI seasonal forecaster Dr. Todd Crawford.

"There are even indications that a significant pattern change will occur in late November and that December may be colder than we are currently forecasting.

"In December, WSI predicts...
Northeast - Warmer than normal

"In January...
Northeast - Colder than normal

"In February...
Northeast - Colder than normal"
More...

NOAA Stays Put in World Wx Building

"The National Oceanic and Atmospheric Administration has extended its lease at its World Weather Building in Suitland, providing an alternative for space as its legal dispute over a new College Park location drags on with the bankrupt Opus East, according to Grubb & Ellis Co., which represents the current landlord.

"The agency will remain for an unspecified time at its longtime home of the National Centers for Environmental Prediction and the National Weather Service. NOAA occupies the 137,004-square-foot facility at 5200 Auth Road.

"Opus East stopped work this summer and sued the General Services Administration for back payments on the College Park project, which was nearly completed. Opus said it put more than $36 million into the complex but that the GSA held up payments over disputed add-on work. The resulting liquidity crunch contributed to Opus Corp. of Minneapolis declaring bankruptcy for Opus East of Rockville."
Source...