Winter '16 / '17 - Today's Unworthy Snow Storm

NYC
Alfred Stieglitz (1870s)

UPDATE (11-MAR-17 @ 11:30 EST)
Yesterday's system turned out to be more of a nuisance than anything else and certainly not contest-worthy.

Plowable snowfall (inches):
HYA - ~7
ABE - 4.5
PVD - 4.4
BDR, ISP - 4

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Yesterday afternoon, NWP models and operational weather forecasters finally caught on to today/s marginally contest-worthy snow storm over the northern M-A and coastal SNE.  This coming after several days and multiple runs suggesting skimpy snowfall totals i.e., less than plowable ... and unwelcome liquid precipitation over the forecast stations.

Not the first time this has happened this season nor seasons in the past; however ... it does point to a significant lack of consistent ability to forecast snow storms where the storm-total may or not be plowable and whether the event is contest-worthy.

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Some have suggested issuing a 'Call for Forecasts' whenever it appears there's a chance for a contest-worthy snow storm.  If were only that simple!

A fair amount of work comes with issuing a 'Call for Forecasts'.

Hundreds of email invitations have to been sent (50 at a time ... 30' apart so as not to be flagged as spam by your ISP or blocked by my ISP).
The contest/s web site has to be updated.
The contest/s web log has to be updated.
The contest/s Facebook page has to be updated.

Then it becomes a judgment call deciding whether the storm was contest-worthy (six to eight stations with more than nuisance storm-total snowfall i.e., >= 4").

Collecting surface ... upper air ... and remote sensing data used in the final analysis and storm summary reporting takes time while the event is unfolding. All for naught if the storm fizzles.

Believe you me ... no one is more disappointed when a snow storm slips through the cracks.

Bottom line: a contest-worthy storm has to be reasonably well predicted by the numerical models and WPC 24-to-36 hours before the first flakes fall for a 'Call for Forecasts' to be issued.

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Final thought:
The number of forecast stations affected with more than nuisance snow totals is one of several criterion for deciding whether a snow storm is contest-worthy.  The number ranges between six and eight.

In this case ... the number of stations would have been eight instead of six.
The reason:  EWR ... BDR ... JFK .. and ISP are relatively close together as are PVD and HYA and there'd likely be relatively small variations in the storm-total snowfalls between stations.

Winter '16 / '17 - Season-total Snowfall Forecast Contest: FEB totals

Station snowfall summary for FEB-17.
Rank ordered by percent of monthly normal.

 

Station snowfall summary for Winter '16 / '17 - Season-to-date through FEB

Green ==> 75th percentile
White ==> Less than 75th and greater than 25th percentile
Red ==> 25th percentile

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Teleconnection indexes and month-over trend (updated as they become available)
AO:  0.340⇩
NAO:  1.00⇧
PDO:  0.70⇩
QBO:  14.78⇩
SOI:  -2.2⇩

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Winter '16 / '17 - Caressing Snow by Adolf Fassbender (NYC 1947)

Winter '16 / '17 - Sudden Stratospheric Warming: Watch #2 - UPDATE 1

Displacement event/s peak progged for early next week.

 

PV displaced SW by warm pulse.

Center of anticyclone does not advance as far south as 31-JAN/s event.

 

 

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Strong anticyclonic couplet above 10 mb

Winter '16 / '17 - Interim Standings: 1

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

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Complete interim statistics table and charts at the Contest/s web site here.
Forecaster verification statistics for Winter '16 / '17 contest storms here.

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SUMSQ errors for each contest snow storm are normalized 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 '16 / '17 - VCP32: Criticizing the Lowbrows

Winter '16 / '17 - Season-total Snowfall Forecast Contest: JAN totals

Station snowfall summary for JAN-17.
Rank ordered by percent of monthly normal.

 

Station snowfall summary for Winter '16 / '17 - YTD JAN

Green ==> 75th percentile
White ==> Less than 75th and greater than 25th percentile
Red ==> 25th percentile

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Teleconnection indexes and month-over trend (updated as they become available)
AO:  0.942 ⇩
NAO:  0.48 ⇔
PDO:  0.77 ⇩
QBO:  14.92 ⇩
SOI:  1.3 ⇩

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Winter '16 / '17 - Forecaster Storm Data

Here

Winter '16 / '17 - Sudden Stratospheric Warming: Watch #2

Could be the season/s final stratospheric warming event.
Images from 15-FEB-17 ECMWF run.


Weak high-altitude zonal flow returns after the recent SSW event.

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Flow above 30 mb reverses and strengthens as the PV is once again displaced.
Flow throughout the depth of the troposphere (evidence of the downward propagation from the previous SSW?) also reverses.

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Cold pool from previous SSW event progged to settle above the NOAM/s Arctic Circle near month/s end.

Stratosphere Diagnostics courtesy Freie Universität Berlin

Winter '16 / '17 - Snow Storm #3: FINAL Results

Forecaster verifications and storm summary at NEWxSFC/s home page.
http://www.newx-forecasts.com/

	1st - donsutherland1
	SUMSQ:	172
	SUMSQ Z:	-0.885
	STP:	6.2	(2)
	TAE:	40.4	(2)
	AAE:	2.25	(3)
	2nd - WeatherT
	SUMSQ:	184
	SUMSQ Z:	-0.814
	STP:	24.3	(6)
	TAE:	43.1	(4)
	AAE:	2.27	(4)
	3rd - Brad Yehl
	SUMSQ:	186
	SUMSQ Z:	-0.805
	STP:	17.3	(5)
	TAE:	42.0	(3)
	AAE:	2.21	(2)
	HM - TQ
	SUMSQ:	224
	SUMSQ Z:	-0.591
	STP:	3.3	(1)
	TAE:	38.9	(1)
	AAE:	2.16	(1)

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

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