Friday, January 17, 2025

Winter '24 / '25 - Snow Storm #2: Call for Forecasts!

NYC
27-JAN-1937

On SUN ... surface LOW pressure predicted to undergo explosive development -- deepening ~25 mb in 24 hours -- as it moves early in the period from western NC toward the NE along the eastern seaboard then on to the CN maritime provinces by the wee hours of MON morning.

Contest-worthy storm-total snowfalls expected mainly over the northern two-thirds of the forecast area.

- Enter your forecast from NEWxSFC/s home page at http://www.newx-forecasts.com/

- Follow the top-of-page link from 'Enter Snow Storm Forecast'


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Forecast element: each station/s storm-total snowfall

Deadline for entries:  10 PM ET SAT ... 18-JAN-25
Verification period BEGINS:  12:01 AM ET SUN ... 19-JAN-25
Verification period ENDS:  11:59 PM ET the day snow stops accumulating

The forecasting contest for Snow Storm #2 may be cancelled prior to the deadline if at least 6
to 8 stations are unlikely to observe 4" or more storm-total snowfall.

By entering ... you also get the chance to see how well your forecast stacks up against NWS Eastern Region's Weather Forecast Offices. Turns out they/ve been easy to beat!

Who Can Enter

Amateur and professional forecasters; broadcasters with or without trained Seals; any and all other weather-biz types and / or wanna-bees; wish-casters ... astrologers ... along with any other universally recognized class of dreamers; Pollyannas or Cassandras ... registered Nostradamuses ... non-violent megalomaniacs ... woolly-bear caterpillars or their Agents ... pest detectives ... ne.wx news group survivors; riders on the StormVista ... refugees from AmericanWx and/or USWeather free agents ... including self-imposed exiles from Eastern Wx ... and of course ... meteorologists.

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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).

As always ... there/s no cost ... no fee ... no advertising ... or annoying requests for personal information to enter a forecast. It/s just a fun exercise for snow crows and winter wx enthusiasts to see who can make the best synoptic-scale snowfall forecast.

Monday, January 13, 2025

Winter '24 / '25 - 'Season-total' Snowfall Forecast Contest: DEC Snowfall Totals

DC
Connecticut Ave and Chevy Chase Circle - 1942


DEC-24 snowfall summary by forecast station.

Rank ordered descending by percent of monthly period-of-record-normal (P-O-R-N).

Green ==> 4th quartile
White ==> less than 4th and greater than 1st quartile (inter-quartile range)
Red ==> 1st quartile

'Obs' reporting '0.05' denote 'Trace' amounts (observed but not measurable).

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DEC Forecast Station Highlights

1 station observed at least 100% of its monthly climo snowfall (BGM).

Biggest Losers
9 stations with less than 10%.
2 stations observed trace amounts (displayed as 0.05").
3 stations not a single flake ... ice pellet ... or hailstone observed.

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Season-total-to-Date
DEC P-O-R-N contributes 207" (22%) toward the season-total (D-J-F-M) snowfall of 936".
DEC-24 observed snowfall:  130" (63% of monthly P-O-R-N; 14% of P-O-R-N season-total snowfall).

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Teleconnections

AO / NAO / PNA data

Wednesday, January 8, 2025

Winter '24 / '25 - Snow Storm #1: FINAL Results and Storm Summary

NYC
26-DEC-47
Complete forecaster verification table and the FINAL Results / Storm Summary available at NEWxSFC/s home page.

SUMSQ:  sum of square errors (")
SUMSQ Z:  Z-score
STP:  storm total precipitation error (")
TAE:  total absolute error (")
AAE:  average absolute error (")
(#):  category rank

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Forecast by Observed Snowfall Scatterplots for Top 4 Forecasts
Forecast/s dotted BLUE line below (above) the Observed snowfall/s solid RED line ==> under (over) forecast bias.

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Comparison of Top 4 Forecasts and Observed Snowfall by Station

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Forecaster Skill Score (measured against NWS ER WFOs)

- Positive skill values indicate the degree of a forecast/s improvement over NWS forecasts.
- Bias:  the arithmetic difference between the average Forecast snowfall and the average Observed snowfall (avgForecast - avgObserved).

 

Tuesday, January 7, 2025

Winter '24 / '25 - Snow Storm #1: Preliminary STP Verification

Smithstonian - 1920s
Preliminary verification of storm-total snowfalls for SUN and MON based on reporting from CDUS41 (CLI) ... CXUS51 (CF6) ... METARs ... and PNS bulletins issued by NWS.

Good coverage and reporting.

Exceptions
SBY
NWS Climatological Report (Daily - CLI) carried 'MM' for SAT snowfall-total and 0.53" liquid.

NWS WFO Monthly/Daily Climate Data (CF6) carried 8.5" and 'M' for liquid.

STP derived by an inverse distance weighting scheme with AKQ and PHI vicinity reports carried in their PNS bulletins for Sussex county ... DE and Worcester and Wicomico counties in MD came to 8.5".

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Sunday, January 5, 2025

Winter '24 / '25 - Snow Storm #1: The Forecasts!

BWI - Park Avenue (1948)

Rookie  0
Intern    0
Journey  0
Senior  13
Chief      1
GOVT    1
PWSP    1
TOT      16
 
Forecaster table ranked ascending by the forecast storm-total precipitation (STP)



BLUE ==> 1st quartile
RED ==> 4th quartile
WHITE STP cells range between the 1st and 4th quartile

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Saturday, January 4, 2025

Winter '24 / '25 - Snow Storm #1: RAW Forecasts

 Click through on 'Read more>>' to see forecasts.

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Friday, January 3, 2025

Winter '24 / '25 - Snow Storm #1: Call for Forecasts!

BWI - Chesapeake Bay (1976)
Short wave impulse coming ashore in the PAC NW on FRI expected to excite lee-side cyclogenesis late SAT before moving across central portions of the M-A.  No consensus among NWP models as yet to the N/S location of the E/W oriented band of contest-worthy snowfall.

- Enter your forecast from NEWxSFC/s home page at http://www.newx-forecasts.com/

- Follow the top-of-page link from 'Enter Snow Storm Forecast'

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Forecast element: each station/s storm-total snowfall

Deadline for entries:  10 PM ET SAT ... 04-JAN-25
Verification period BEGINS:  12:01 AM ET SUN ... 05-JAN-25
Verification period ENDS:  11:59 PM ET the day snow stops accumulating

The forecasting contest for Snow Storm #1 may be cancelled prior to the deadline if at least 6
to 8 stations are unlikely to observe 4" or more storm-total snowfall.

By entering ... you also get the chance to see how well your forecast stacks up against NWS Eastern Region's Weather Forecast Offices. Turns out they/ve been easy to beat!

Who Can Enter
Amateur and professional forecasters; broadcasters with or without trained Seals; any and all other weather-biz types and / or wanna-bees; wish-casters ... astrologers ... along with any other universally recognized class of dreamers; Pollyannas or Cassandras ... registered Nostradamuses ... non-violent megalomaniacs ... woolly-bear caterpillars or their Agents ... pest detectives ... ne.wx news group survivors; riders on the StormVista ... refugees from AmericanWx and/or USWeather free agents ... including self-imposed exiles from Eastern Wx ... and of course ... meteorologists.

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Contest Status

PHL - Broad and Chestnut
early 1930s
Winter '24 / '25
NE.Wx Snowfall Forecast Contests
 
26th Annual 'Snow Storm' Snowfall Forecast Contest
UPDATE:  4:40 PM ET - FRI ... 17-JAN-25
 
Snow Storm #2
Call for Forecasts
Details here
 
Snow Storm #1
FINAL Results and Storm Summary here

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Deadline for entries:  10 PM ET.  Typically ~24 hours before the leading edge of a contest-worthy snow storm is predicted to enter the forecast area.
 
Enter your forecast here.
 
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24th Annual 'Season-total' Snowfall Forecast Contest 
UPDATE:  3 PM ET - MON ... 13-JAN-25

Deadline for entries has passed.
Details and Forecasts here

Monthly snowfall totals
DEC here
JAN here
FEB here
MAR here
 
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Winter '23 / '24 - Snowfall Forecast Contests
25th Annual 'Snow Storm' Snowfall Forecast Contest
FINAL results here

23rd Annual 'Season-total' Snowfall Forecast Contest
FINAL results here

Wednesday, December 11, 2024

Winter '24 / '25 - 24th Annual 'Season-total' Snowfall Forecast Contest: The Forecasts!

19-OCT-1940
All forecasts at the Contest/s web site. (direct link to forecast data table here).

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Welcome and Good Luck to All 🍀🍀🍀

Senior NEWxSFC forecaster WXCHEMIST ... having made the best 'season-total' snowfall forecast for Winter '23 / '24 ... returns this year to defend his 'Chief Season-total Forecaster' title.

Forecasters also compete against the Period-of-Record Normal (P-O-R-N) and CONSENSUS.

Table below rank-orders forecasts by ascending season-total snowfall.



BLUE - Quartile 1
RED - Quartile 4
ORANGE - Winter '24 / '25 Chief 'Season-total' forecaster

P-O-R-N - Period-Of-Record Normal
CONSENSUS - median forecast for each station

Forecasts submitted with decimal values have been recorded as such for verification;  however ... rounding was applied for display purposes only.

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Forecasters:  20
Total station forecasts:  500 (excluding P-O-R-N & CONSENSUS)
 
Station forecasts for:
ABV normal:  66%
Normal:  5%
BLO normal:  30%


All forecasts at the Contest/s web site. (direct link to forecasts here).

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Last SIX winter's have birthed below-normal season-total snowfall.  Probably fair to say we're due; although we said the same ting last year :(

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The 26th annual individual snow storm forecast contests start when the flakes from a contest-worthy storm start flyin'.

'Call for Forecasts' announcements issued on this fine blog ... web site ... Facebook ... and via email.