Winter '18 / '19 - Regular Season: Status

Philly

Winter '18 / '19 getting long in the tooth for another contest-worthy snow storm; although ... it/s happened four times previously in April ('02 ... '03 ... '07 ... and '11) which works out to a five-year 'return period' so maybe we get lucky.

Winter '18 / '19 - Regular Season Interim Standings: #3

CORRECTED (09-MAR-19)
Don Sutherland had been identified incorrectly as the Chief 'Regular Season' forecaster when that honor belongs to Brad Yehl.  We regret the error and thank Don Sutherland for bringing it to our attention.

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After five snow storm forecasting contests ... under the ‘two-thirds’ rule … forecasters who have entered at least FOUR forecasts are included in interim standings #3.

Complete interim statistics table and chart at the Contest/s web site HERE (direct link)
Forecaster statistics for Winter '18 / '19 contest snow storms HERE (direct link)

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SUMSQ errors for each contest snow storm are normalized (i.e., standardized) with a 'Z-score' ... then averaged to compute the standings. If a forecaster has issued forecasts for more than two-thirds of all snow storm contests ... then Z-scores from their 'best two-thirds' forecasts are used to calculate the Interim and Final standings.

Similar idea as dropping the lowest test score before computing the final grade.

Winter '18 / '19 - Snow Storm #5: FINAL Results

Forecasters' station verifications and the storm summary available at NEWxSFC/s home page.
http://www.newx-forecasts.com/

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

Forecast by Observed Snowfall Scatterplots for Top Forecasts
Dotted blue line below (above) solid red line ==> under (over) forecast

Station by Station Comparison of Top Forecasters

Winter '18 / '19 - Snow Storm #5: Preliminary STP Verification

Preliminary storm-total snowfalls for SUN and MON from CDUS41 (CLI) ... CXUS51 (CF6) ... METARs ... and PNS bulletins.  Good coverage and reporting.

Exceptions
CON
No daily snowfall reported in CF6 or CLI bulletins for 03-MAR-19.
PNSGYX carried 5.8" ASOS
STP may be amended if official data reported prior to posting of FINAL results.

HYA
STP estimated by inverse distance weighting of Barnstable county vicinity reports within 10 miles of the station carried in PNSBOX.

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Stations observing >= Trace - 22 (81%)
Given stations with measurable snowfall ... stations observing at least:
4" - 14 (64%)
6" - 8 (36%)
8" - 3 (14%)
10" - 1 (5%)

Max snow melt-water (minimum SLR 10:1)
BOS:  1.06"
ORH - 0.88"
BDL - 0.65"

Max precipitation (frozen + freezing + liquid):
HYA:  1.53"
PVD - 1.20"
BDR - 1.08"

New daily record(s)
04-MAR-19
BDR - 6" (1.5"; 1971)
ISP - 0.5" (0.05"; 1971, 2010)

Image courtesy NOHRSC

SFC analysis:  06z ... 04-MAR-19
Image courtesy 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 WED evening.

Winter '18 / '19 - Season-total Snowfall Forecast Contest: FEB Totals

FEB-19 snowfall summary by Contest forecast station.
Rank ordered descending by percent of monthly period-of-record-normal (P-O-R-N).

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Green ==> 75th percentile
White ==> less than 75th and greater than 25th percentile (inter-quartile range)
Red ==> 25th percentile

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FEB Forecast Station Highlights
CAR
56% > monthly P-O-R-N

Biggest losers
Observed v P-O-R-N (% P-O-R-N)
RDU:  T v 2.4"
ORH:  T v 2.9"
RIC:  0.1" v 4" (3%)
NYC:  2.6" v 8.9" (29%)
SBY:  1" v 3.4" (29%)

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Season-to-Date
On average ... FEB contributes 257" (28%) toward the average season-total snowfall (D-J-F-M) of 914".

FEB-19 observed snowfall:  220" (24% of season-total snowfall)

Bonus snows in the M-A may seem like a distant memory; however ... five of the seven forecast stations with at least 95% of the annual average snowfall are in the M-A at this point in the season.

Winter '18 / '19 - Snow Storm #5: The Forecasts

Rookie      -
Intern      -
Journey  1
Senior      11
GOVT      1
PWSP      -
TOT      13

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

BLUE ==> 25th percentile.
RED ==> 75th percentile.
WHITE and GREY STP cells range between the 25th and 75th percentile.

Heaviest snowfall (+6") consensus along and to the right of BGR - PWM - BOS - BDL - ORH - CON - BGR.  Lollypop expected at ORH.

Teleconnections still on vacay.

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

Winter '18 / '19 - Snow Storm #5: RAW Forecasts

HERE

Winter '18 / '19 - Snow Storm #5: Call for Forecasts! Take 2

Boston Commons
MAR-33

Snow Storm #5 ... a late season nor'easter ... takes aim at most of the forecast area to open the season/s final quarter.

Rapid deepening of the mid-latitude cyclone during its approach and transit near 'Teh Benchmark' (40N/70W) typically produces bonus snows over SNE/s I-95 corridor.  Lack of Arctic air anchored north of the LOW could play a important role defining the RN / SN transition zone.

NOTE:  Any snowfall observed over extreme northern forecast stations (e.g., CAR ... BGR ... etc.) from the exiting storm during the first few hours of SUN should not be included in your forecast.

The forecasting contest for Snow Storm #5 may be cancelled prior to the deadline if at least six-to-eight stations are unlikely to observe at least a 4" storm-total snowfall.

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Forecast element: each station/s storm-total snowfall

Deadline for entries: 10:00 PM EST ... SAT ... 02-MAR-19
Verification begins: 12:01 AM EST ... SUN ... 03-MAR-19
Verification ends: 11:59 PM EST ... MON ... 04-MAR-19

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Enter your forecast at the NEWxSFC/s home page HERE. (http://www.newx-forecasts.com/)
Follow the top-of-page link from 'Enter Storm Forecast.'

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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 winter wx enthusiasts to see who can make the best synoptic-scale snowfall forecast.

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 fairly easy to beat!)

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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).