Saturday, January 28, 2023

Winter '22 / '23 - Snow Storm #1: FINAL Results and Storm Summary

Richmond ... VA
Broad St (uphill from Shockoe Bottom)
Presidents Day 18-FEB-79

Complete forecaster verification table and the FINAL Results / Storm Summary available at NEWxSFC/s home page.

SUMSQ:  sum of square error (")
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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Forecast Skill Score (measured against NWS ER WFOs)

 

Positive skill values indicate a forecast/s improvement over the NWS forecasts.

Bias is the arithmetic difference between the average Forecast snowfall and the average Observed snowfall (avgForecast - avgObserved).

Friday, January 27, 2023

Winter '22 / '23 - Snow Storm #1: Preliminary STP Verifications

NYC
East 88th St. (1952)

Preliminary verification of storm-total snowfalls for WED and THU based on reporting found in CDUS41 (CLI) ... CXUS51 (CF6) ... METARs ... and PNS bulletins issued by NWS.

Excellent coverage and reporting.

HYA
Trace amounts derived from METARs.

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Snow-to-liquid ratio (SLR) not reported for some stations with measurable snowfall b/c liquid and / or freezing precipitation also occurred during the verification period.


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Stations observing >= Trace:  19 (70%)
Given stations had measurable snowfall ... stations observing at least:
4" - 2 (7%)

MAX snow melt-water (minimum SLR 8:1)
CAR - 1.05"
BTV - 0.54"
BGM - 0.30"

MAX precipitation (frozen + freezing + liquid)
PWM - 2.60"
PVD - 1.84"
ACY - 1.58"

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New daily snowfall record(s)
none

Orange cells indicate new daily record.
Trace amounts (displayed 0.05") are not included in STP.

Distribution of storm-total snowfall
Image courtesy NOHRSC

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SFC analysis:  09z ... 26-JAN-23
Image courtesy DOC / NOAA / NWS / NCEP / WPC

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Please report any errors in Comments along with a link to the correct data.
FINAL results expected NLT SAT evening.  

Wednesday, January 25, 2023

Winter '22 / '23 - Snow Storm #1: The Forecasts!

NYC
43rd St and Broadway (1937)

Rookie      -
Intern      1
Journey      1
Senior      10
GOVT      1
PWSP      -
TOT      13

Forecaster table ranked ascending by storm-total precipitation (STP)

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

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Heaviest snowfall (+4") consensus along and to the right of CAR - BGR - CON - BGM - BTV - CAR.  Lollypop expected at CAR.

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Teleconnections

 

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Everyone/s station-by-station forecast at the Contest/s web site.
Direct link to the forecast table.

Tuesday, January 24, 2023

Winter '22 / '23 - Snow Storm #1: RAW Forecasts

PHL
Broad Street (1899)
Published in order of receipt.

Monday, January 23, 2023

Winter '22 / '23 - Snow Storm #1: Call for Forecasts!

NYC - Queens
Woodside Station (1872)

Today/s 12z NWP suggests the WED/THU storm will produce more than nuisance snows (>= 4") over almost half the Contest/s forecast stations with the M-A stuck once again holding the bag.

Closed LOW analyzed over SW CONUS today progged to open up and lift east along the Gulf of Mexico coast on TUE then track NE through the TN/OH river valleys and spawn 2ndary cyclogenesis over interior M-A before heading up the NE's coastal plain.

System is primarily a rain-maker carrying a broad shield of frozen precipitation to its NW.

Winter '22 / '23 storm tracks to-date ... plagued by La Nina's persistent fatty ridge over the SE ... have treated the far northern reaches of the forecast area with modest snows but measly amounts elsewhere.

This winter/s 1st snowstorm won/t be the latest start to the snowfall forecasting season.  That honor remains with Winter '06 / '07 when the 1st contest-worthy storm made its debut on 12-FEB-07.  That was the 1st of two FEB storms ... followed by two storms in MAR ... and one more in APR; so all hope of salvaging this season is not yet lost.

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- Enter your forecast at the 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: 10:00 PM EST ... TUE ... 24-JAN-23

Verification begins: 12:01 AM EST ... WED ... 25-JAN-23
Verification ends: 11:59 PM EST on the day when flakes stop accumulating.

By entering ... you also get the chance to see how well your forecast stacks up against NWS Eastern Region 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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The 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.

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.

Saturday, January 7, 2023

Wolf Moon

RE-POST
Much the same for JAN-23.

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January/s full moon was supposedly named the 'wolf' moon by native Americans living in the NE b/c there were hungry wolves roaming outside their camps.

Color me skeptical but that/s the story.

Even so ... the name does conjure up some dark imagery -- dead of winter ... cold ... lifeless ... short days ... cemeteries.

So ... if the wolves are hungry for food ... then it follows snow crows can be hungry for snow.

Wolf Moon seems like a good description this year even if its origins may not be genuine. The first full moon of '07 comes early this month. Not likely to see any halos portending a snowstorm in the E tonight; although ... it may be a different story later in the month.

If winter/s first Contest storm slips into early February ... it would be just in time for the Snow Moon.

Friday, January 6, 2023

Winter '22 / '23 - 'Season-total' Snowfall Forecast Contest: DEC Snowfall Totals

Valley Forge ... PA
16-DEC-70

DEC-22 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 4h and greater than 1st quartile (inter-quartile range)
Red ==> 1st quartile

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DEC Forecast Station Highlights
Stations with above normal monthly snowfall
BGM:  113% (13% above normal)

Biggest Losers
RDU ... SBY ... DCA ... EWR ... ACY ... BWI ... PHL ... IAD ... NYC ... ORF ... and RIC observed less than 10% of normal monthly snowfall.

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Season-Total-to-Date
DEC P-O-R-N contributes 203.3" (22%) toward the season-total snowfall (D-J-F-M) of 936".
DEC-22 observed snowfall:  104" (51% of monthly P-O-R-N; 11% of season-total snowfall)

Images courtesy NOHRSC @ http://www.nohrsc.noaa.gov/nsa/

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Teleconnections


AO / NAO / PNA data