CONTEST STATUS - Updated: SUN...20-JUL-14 @ 7:35 PM EDT
Thursday, January 26, 2012
Monday, January 23, 2012
|Mid-Atlantic/s warm and runny 'nose-of-doom'|
STP: storm-total precipitation error
TAE: total absolute error
AAE: average absolute error
(number): category rank
Sunday, January 22, 2012
Preliminary storm-total snowfalls for Saturday from CDUS41...CXUS51...and PNS...as of noon Sunday.
The storm-total snowfall for HYA is an estimate derived from vicinity reports in Barnstable county carried in the PNSBOX bulletin.
Several stations in the data table do not have SN:H2O reported b/c their liquid totals included mixed precipitation.
Two new daily records.
PVD - 7.6" (6.6"; 1976)
BDR - 6.2" (6"; 2001)
Please report any errors and drop a link to the correct data in Comments.
Final results and storm summary Monday evening.
Saturday, January 21, 2012
Welcome back everyone.
The kick-off event was a l-o-n-g time coming. Here/s hoping it/s not the last!
6 Senior forecasters...including NEWxSFC/s Chief forecaster donsutherland1
WeatherT on being promoted to Senior forecaster
Roger Smith on being promoted to Journeyman forecaster
Brad Yehl on being promoted to Intern forecaster
NEWxSFC/s Chief forecaster is the winner of last year/s 'storm-total' contest.
Senior forecasters have a minimum of three years experience.
Journeyman forecasters have two years experience.
Intern forecasters have one year experience.
Rookie forecasters are rookies.
All forecasts have been posted to the Contest/s web site.
Follow the 'Winter '11 / '12 Storm Contest Forecasts Storm #1' link.
Entries are ranked by 'storm total' forecast.
Max: 78" (Mitchel Volk)
Thursday, January 19, 2012
A weak frontal wave rising out of the OH-TN river valley early Saturday morning will throw Atlantic moisture atop an arctic air mass parked over SE Canada.
Looks to be a borderline nuisance event but at this point in a rather disappointing season...we/ll take it.
The contest may be canceled prior to the deadline if NWP indicates a fizzling event.
Forecast element: storm-total snowfall
Deadline for entries: 10:30 PM EST FRI...20-JAN-12
Verification period begins: 12:01 AM SAT...21-JAN-12
Verification period ends: 11:59 PM SAT...21-JAN-12
Enter your forecast at the Contest's home page here.
Follow the link from 'Enter Storm Forecast.'
As always...there/s no cost...or fee...or advertising...or annoying requests for personal information to enter a forecast. It's just a fun exercise among winter wx enthusiasts to see who can make the best synoptic-scale snowfall forecast.
If you are issuing your first forecast this winter...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).
Want to be notified via e-mail when a 'Call for Forecasts' is issued?
Send your request to newx at newx-forecasts dot com.
Tuesday, January 17, 2012
GooFuS has been busy pumping out promising progs with shiny stellar dendrites dangling over the forecast area this weekend for what could turn out to be this winter/s season opener contest-worthy snow storm.
Sunday, January 15, 2012
The minor warming criterion (25°K increase over seven days at any level in the winter hemisphere) has almost reached the 30 mb level. A mere two or three degrees to go.
Major warming criteria is on the verge of being breached.
A major warming is defined as "...westerly winds at 60°N and 10 mb...become easterly [...]. A complete disruption of the polar vortex is observed and the vortex will either be split into daughter vortices, or displaced from its normal location over the pole."
Westerly winds at 85°N and above 10 mb have reversed.
'Complete' distruption is a stretch given the D+10 forecast. There's more blue (easterly mean zonal wind) in the several panels leading up to D+10; however...the PV is also expected to re-intensify.
...but a displaced 10mb PV is carried in the forecast.
Another important indicator of stratospheric warming is E-P flux. Apparently...when the flux vector field leans toward the pole...as shown in the analysis between 11-JAN and 13-JAN...stratospheric warming is underway.
Previous update here.
|NYC - East 46th St. near 2nd Ave.|
The polar vortex (PV) has been wicked strong until recently when it weaken slightly during the on-going minor stratospheric warming. Minor warmings are not known for their association with PV-reversals...so there's little expectation this event will be reflected at the surface in the form of a negative AO.
What a difference a year makes. Last December/s monthly AO was the second lowest (-2.631) during the period of record which began in 1950. JAN-11 didn't stand out in the historical record (ranked 14th) but it was strongly negative. This winter...December was the polar opposite at +2.221. January is on-track to finish...not unexpectedly positive...around +1.
Below is a time-series of the AO on winter's cusp throughout the 60+ year period of record (1950 - 2011). The blue line is a trace of the daily AO index on 15-JAN. The dark red line is a a trace of the same data after applying a nine-point binomial filter. The filter removes low frequency noise and highlights decadal trends.
Not sure what this says about the AO on 15-JAN other than there is a discernible cycle every nine years or so. It does have an interesting comparison to the cycles found in the 30-DEC data.
Thursday, January 12, 2012
NAO dips below zero for the first time in 55 days (-0.082 on 17-NOV-11).
Question now is will it last and if it does...how strong will it be? Current GooFuS and its ensemble forecasts hold out little hope...
Arctic Oscillation (AO) forecasts are another...more promising story...
For many NEWxSFC forecast stations...a negative AO plays a bigger role than a negative NAO for contest-worthy storms.
Going Negative - How Much for Philly
Going Negative - How Much for DC?
Going Negative - How Much for Dulles?
Daily teleconnection data here.
Tuesday, January 10, 2012
The initial minor warming event @10 mb...which began 25-DEC-11...is fading as a second warming gets underway on the opposite side of the globe (red shading lower left quadrant).
Note the weakening of the mean zonal wind in the upper 10 mb centered around 01-JAN-12 (upper right corner) which reflects dissipation of the initial minor warming event.
Elsewhere in the Ignorosphere...temperatures have been steadily warming at 30 mb over the North Pole and intersecting the long-term mean.
European NWP breaks down the polar vortex and reverses its flow @D+10 (blue shading = east flow) and depicts mean easterlies in the hi-latitude troposphere (lower right corner) which builds a deep anti-cyclone...
American NWP forecasts for the northern annular oscillations (AO / NAO) and the Pacific North American (PNA) indexes are all heading in a favorable direction...
Previous update here.
Monday, January 9, 2012
Friday, January 6, 2012
The latest monthly data from the Rutgers Snow Lab shows the observed areal snow cover over Eurasia was -- yawn -- average during December after being at or quite close to one standard deviation above the mean the past two years.
The month's ~26,642,000 km² coverage ranked 26th in the 46-year period of record (1966 - 2011) which is slightly less than the median December coverage of ~26,786,000 km².
Solid ORANGE line: period of record's AVERAGE areal snow cover.
Dashed YELLOW lines: + / - one standard deviation about the mean
RED line: nine-point binomial filter
Snowfall data courtesy Rutgers Snow Lab.
Earlier post about Novembers' Eurasia snow cover here.
Monthly Eurasian snow cover for 2011 (RED line; BLUE markers) and the 'period of record' median.
Thursday, January 5, 2012
Wednesday, January 4, 2012
Finally...the PV continues to lose strength...decreasing to less than 40 kts (20 m/s) by the end of the period. Also note 1) the mean zonal wind from the east throughout the depth of the polar troposphere...quite suggestive for a developing anti-cyclone and a long awaited return of the Arctic Oscillation to its negative state and 2) the robust 80kt (40 m/s) sub-tropical jet (STJ) INVOF 30°N latitude.
Tuesday, January 3, 2012
|Geo. Washington...Valley Forge...PA (1928)|
One measure of whether two events -- such as the AO for two months -- are independent of each other or whether a strong association exists between them is the chi-square test. The distribution of observed events (positive one month, negative the next or vice-versa) is compared to the distribution of the 'expected' events. Small differences between the 'observed' and 'expected' are interpreted as evidence of an association. Large differences mean they are independent.
No statistical testing was presented in Junker/s post; however...strong evidence for an association does exist...as shown in the table below at the intersection of DEC and JAN. The probability is 0...to three decimal places...the association between December/s and January/s AO state occurs by chance.
What about the other 'cool season' months? Can more predictive information be mined from these data? Is there a statistically significant association between the AO state lurking elsewhere?
Monthly AO data between 1950 and 2010 from CPC were analyzed using the 'chi-square' statistic to determine if there were statistically significant associations between months.
There is a fairly strong association between SEP/s AO state and that of FEB (a 5.5% probability the association occurs by chance) and a good association between JAN and FEB (8% probability)
What does AO state for SEP-11 'predict' for FEB-12? The SEP-11 AO was 0.665...so FEB-12 'should' follow suit and be positive.
What does AO state for JAN-12 'predict' for FEB-12? The JAN-12 AO is unknown but since JAN follows DEC....JAN-12 AO 'should' also follow suit...which implies FEB-12 will be positive.
Winter's where the AO ran hot between DEC and FEB have occurred nine times since 1950 (1972/3...1974/5...1975/6...1988/9...1991/2...1992/3...1998/9...1999/00...2007/08).
Not lookin'good for the home-team...altho all may not be lost this winter.
The so called 'Storm of the Century' roared out of the GOM and tore up the east coast in MAR-93 after +AO in D-J-F (1.627; 3.495; 0.184) and MAR was 0.764! There was a 'notable' NESIS storm in MAR-99 and the unforgettably infamous JAN-00 storm.
Sunday, January 1, 2012
Two to go...altho the Contest does run until the storms stop -- assuming they do get started.
As bad as it/s been for areal snow cover over the forecast area so far this winter...DEC-03 was worse with DEC-06 a close second.
December/s end-of-month snow cover between 2002 (upper left panel) and 2011 (lower right panel). Images courtesy NOHRSC.
Disappointed snow crows blame the villainous duo of la Nina...which favors a storm track west of the Appalachian mountains...and the persistently positive state of the Arctic Oscillation from a paucity of hi-latitude blocking.