Winter '17 / '18 - Snow Storm #6: RAW FORECASTS

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Winter '17 / '18 - Temperature Departure From Normal: Progress Report - February

Winter '17 / '18 - Snow Storm #6: Call for Forecasts!

Boston Commons
MAR-1933

Miller B cyclogenesis off the Carolina coast at the start of the forecast period expected to saunter leisurely up the coast and deepen through FRI.  Marginal vertical temperature profiles near the coast will make for a challenging forecast.

NWP suggests additional accumulations may be observed over extreme northern stations after the verification period ends; however ... amounts should be relatively minor.

The forecast contest for Snow Storm #6 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 EST ... TUE ... 06-MAR-18
Verification period begins:  12:01 AM EST ... WED ... 07-MAR-18
Verification period ends:  11:59 PM EST ... FRI ... 09-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 has been off-line going on two weeks with no estimated return-to-service date
which means in all likelihood ... forecasters will not have a copy of their forecast emailed to them.  Apologies for the inconvenience. 

Winter '17 / '18 - Coastal Teaser: #2

Snow Storm #6 may be in the cards mid-week at the start of NEWxSFC/s fourth quarter.

Upper LOW currently over the PAC NW ejects to the east ... then deepens as its progression b/comes retarded by high-latitude blocking.  Miller 'B' cyclogenesis progged off the VA Capes followed by a slow crawl up the coast suggesting a long duration event.

Should the present trend in NWP output continue ...
Call for Forecasts:  MON ... 05-MAR-18
Deadline for entries:  10:30 PM EST ... TUE ... 06-MAR-18
Verification period:  12:01 AM EST ... WED ... 07-MAR-18 till TBD

NEWxSFC/s email client has been off-line for over a week with no estimated return-to-service date.

Watch this space.

Winter '17 / '18 - Regular Season Interim Standings: 3

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.

Winter '17 / '18 - Snow Storm #5: FINAL Results

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

	1st - HWSNBN
	SUMSQ:	63
	SUMSQ Z:	-1.524
	STP:	5.2	(4)
	TAE:	29.9	(1)
	AAE:	1.30	(1)
	2nd - NWS ER WFOs
	SUMSQ:	73
	SUMSQ Z:	-1.062
	STP:	5.8	(5)
	TAE:	30.4	(2)
	AAE:	1.32	(2)
	3rd - donsutherland1
	SUMSQ:	84
	SUMSQ Z:	-0.630
	STP:	8.6	(8)
	TAE:	33.0	(6)
	AAE:	1.43	(6)
	HM - Brad Yehl
	SUMSQ:	86
	SUMSQ Z:	-0.538
	STP:	30.8	(12)
	TAE:	32.9	(5)
	AAE:	1.43	(5)

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

Winter '17 / '18 - Snow Storm #5: Preliminary STP Verifications

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

Exceptions:
PWM / CON
17-FEB CLI and CF6 bulletins carried 'MM'.
STP based on ASOS reports carried in PNSGYX.

HYA
METARs and vicinity reports carried in PNSBOX.

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 - 23 (85%)
4" - 8 (35%)
6" - 4 (17%)
8" - 0

Melt-water
ORH - 0.54"
PWM - 0.53"
BOS - 0.52"

New daily records:
None

Surface analysis:  03z ... 18-FEB-18
   
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Please report errors in Comments along with a link to the correct data.
FINAL Results post expected TUE evening ... 20-FEB-18

Winter '17 / '18 - Snow Storm #5: The Forecasts!

Rookie   -
Intern   1
Journey  -
Senior   9
GOVT    1
PWSP    1
TOT  12

All forecasts posted to the Contest/s web site.
http://www.newx-forecasts.com/NEWxSFC_19/storms/storm5_forecasts_17Feb18.htm
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) and PWSP (Private Weather Service Provider) forecasts derived from public issuances current at the deadline.

Heaviest snowfall (>= 4") consensus along and to the right of BOS - PVD - BDR - BDL - ORH - BOS with an isolated action center INVOF ABE.  Snow cone expected at PVD.

Tele-connection indexes (sigh).  AO racing to catch the bus (or not).

Median station forecasts (Power Map - Excel 2013)

Winter '17 / '18 - Snow Storm #5: RAW FORECASTS

Here

Winter '17 / '18 - Snow Storm #5: Call for Forecasts

Apologies for the truncated notice.

Sad looking area of LOW pressure progged to ride the STJ into the forecast area on SAT and lay down a stripe of frozen precipitation along the NW edge of the precipitation shield as it deepens off the SNE coast near the 40/70 benchmark.

Synoptics seem all wrong for a contest-worthy snow storm but hate to be left at the alter this late in the season after seeing the broad brush of plowable snow forecast currently by ER WFOs.

Whatever happened to those blockbuster nor'easters around Presidents Day?

The forecast contest for Snow Storm #5 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 EST ... FRI ... 16-FEB-18
Verification period begins:  12:01 AM EST ... SAT ... 17-FEB-18
Verification period ends:  11:59 PM EST ... SUN ... 18-FEB-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.

---
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).