NE.Wx Snowfall Forecast Contests

Tuesday, March 20, 2018

Winter '17 / '18 - Snow Storm #8: Front-end +TSSN

Blacksburg ... VA
INVOF Roanoke (ROA)

METAR KBCB 210135Z AUTO 05007KT 1/2SM +VCTSSN OVC006 00/00 A2959 RMK AO2 LTG DSNT SE

Monday, March 19, 2018

Winter '17 / '18 - Snow Storm #8: Call for Forecasts!

by TQ @ 7:20 PM

19-MAR-56
Carmine St ... NYC

Not the 1st time the progs indicated an out to sea solution in the medium range ... then hang a hard left and roar up the coast as its VT approaches.

Should Snow Storm #8 come to pass ... MAR will have at least three contest-worthy snow storms for only the third time in NEWxSFC/s history.

Other years with three MAR snow storms happened in 2001 and 2014 (return period 9.5 years; probability during any given winter: 11%).

The forecast contest for Snow Storm #8 may be cancelled prior to the deadline if fewer than six stations are likely to observe at least a 4" snowfall.

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Forecast element: each station's verification period snowfall

Deadline for entries: 10:30 PM EDT ... TUE ... 20-MAR-18
Verification period begins: 12:01 AM EDT ... WED ... 21-MAR-18
Verification period ends: 11:59 PM EDT ... THU ... 22-MAR-18

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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. See how well your forecast stacks up against NWS Eastern Region Weather Forecast Offices.

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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).

NEWxSFC/s email client is permanently off-line.
Forecasters may no longer have a copy of their forecast emailed to them.
Some are getting thorugh. Some are not.
The Contest/s email address newx (at) newx-forecasts (dot) com remains unreachable.
Apologies for the degraded service which is beyond my control.

Saturday, March 17, 2018

Winter '17 / '18 - Snow Storm #7: FINAL Results

by TQ @ 8:15 PM

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


1st - iralibov
SUMSQ:	328
SUMSQ Z:	-1.379
STP:	31.6	(5)
TAE:	66.3	(1)
AAE:	2.46	(1)

2nd - donsutherland1
SUMSQ:	365
SUMSQ Z:	-1.041
STP:	29.7	(2)
TAE:	67.0	(2)
AAE:	2.48	(2)

3rd - TQ
SUMSQ:	394
SUMSQ Z:	-0.787
STP:	47.5	(8)
TAE:	75.0	(4)
AAE:	2.78	(4)

HM - Brad Yehl
SUMSQ:	400
SUMSQ Z:	-0.735
STP:	45.8	(7)
TAE:	67.8	(3)
AAE:	2.51	(3)

SUMSQ: sum of square errors (")
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

Snowfall analysis courtesy National Operational Hydrologic Remote Sensing Center
http://www.nohrsc.noaa.gov/interactive/html/map.html

Friday, March 16, 2018

Winter '17 / '18 - Snow Storm #7: Preliminary STP Verifications

by TQ @ 7:33 PM

Table of preliminary storm-total snowfall by station for WED and THU from CDUS41 (CLI) ... CXUS51 (CF6) and ... SAUS41 (METAR) bulletins.

Exceptions: none

SLR not available for some stations reporting measureable snowfall b/c liquid and / or freezing precipitation also occurred during the verification period.

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Stations observing at least:
Trace - 27 (100%)
4" - 14 (52%)
8" - 10 (37%)
12" - 6 (22%)
16" - 3 (11)
20" - 2 (7%)

Melt-water
ORH - 1.6"
PWM - 1.28"
BTV - 1.19"
BGR, BOS - 1.16"

Max precipitation: ORH - 1.6"

New daily records: 13-MAR-18
ORH - 21.8" (14.8"; 1993)
BOS - 14.5" (12.3"; 1993)
PVD - 9.5" (7"; 1993)

SFC analysis: 15z ... 13-MAR-18

13-MAR-93: the last Storm of the Century for the 20th century.

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Please report errors in Comments along with a link to the correct data.
FINAL Results post expected SAT evening ... 17-MAR-18

Thursday, March 15, 2018

Winter '17 / '18 - Regular Season Interim Standings: 4

by TQ @ 7:45 PM

Under the ‘two-thirds’ rule … forecasters who have entered at least FOUR forecasts are included in the interim standings.

Complete interim statistics table and chart at the Contest/s web site here (direct link)
Forecaster statistics for Winter '17 / '18 contest snow storms here (direct link)

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SUMSQ errors for each contest snow storm are normalized (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.

Same idea as dropping the lowest quiz score before computing the final grade.

Wednesday, March 14, 2018

Winter '17 / '18 - Snow Storm #6: NESIS

by TQ @ 7:18 PM

CAT 2
NESIS 3.45

inter '17 / '18 - Snow Storm #2: NESIS

by TQ @ 7:15 PM

CAT 1
NESIS 1.71

Monday, March 12, 2018

Winter '17 / '18 - Snow Storm #7: The Forecasts!

by TQ @ 7:39 PM

UPDATE: 17-MAR-18 @ 12:40 PM EDT
Corrected 'Consensus Forecasts and Extremes' chart.

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Rookie -
Intern 1
Journey -
Senior 8
GOVT 1
PWSP -
TOT 10

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

Forecasts ranked by their verification period storm-total precipitation (STP).
BLUE = 25th percentile
RED >= 75th percentile
White STP and 4cast cells range between the 25th and 75th percentile

NWS ER WFOs (GOVT) forecasts derived from public issuances current at the deadline.

Heaviest snowfall (>= 12") consensus along and to the right of CAR - BGR - PWM - BOS - PVD - ORH - PWM - CAR. Snow cone expected at BGR.

AO FTW! (again).

Sunday, March 11, 2018

Winter '17 / '18 - Snow Storm #7: RAW FORECASTS

by TQ @ 10:41 PM

Here

Winter '17 / '18 - Snow Storm #6: FINAL Results

by TQ @ 1:16 PM

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


1st - Donald Rosenfeld
SUMSQ:	200
SUMSQ Z:	-1.171
STP:	16.1	(8)
TAE:	53.2	(1)
AAE:	2.22	(1)

2nd - Herb @MAWS
SUMSQ:	220
SUMSQ Z:	-1.005
STP:	4.7	(4)
TAE:	53.3	(2)
AAE:	2.32	(3)

3rd - NWS ER WFOs
SUMSQ:	249
SUMSQ Z:	-0.772
STP:	11.1	(6)
TAE:	56.4	(3)
AAE:	2.45	(5)

HM - Roger Smith
SUMSQ:	253
SUMSQ Z:	-0.745
STP:	22.9	(10)
TAE:	58.4	(5)
AAE:	2.24	(2)

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