Winter '14 / '15 - Sudden Stratospheric Warming: Watch #2 - Update 4

Incoming!

 

Deep layer Easter easterlies.

 

 

PV displacement

 

Split vortices.

 

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Major SSW event has begun!

 

 

Winter '14 / '15 - Sudden Stratospheric Warming: Watch #2 - Update 3

ECMWF continues its forecast for a SSW event in the near-term.

Winter '14 / '15 - Sudden Stratospheric Warming: Watch #2 - Update 2

Complete break down of the Polar vortex at month's end.

Deep ... deep layer wind reversal (easterlies up and down the Polar atmosphere) 

 

Prediction:  cold spring in the east.

Winter '14 / '15 - Sudden Stratospheric Warming: Watch #2 - Update

Fookin' C-O-L-D a'comin.'

Winter '14 / '15 - Sudden Stratospheric Warming: Watch #2

ECMWF predicts a reversal by displacement of the Polar vortex beginning 24-MAR-15 ...

... and a deep ... icy trough INVOF Baffin Bay.

 

mid-to-late April could turn out quite interesting.

Winter '14 / '15 - VCP32: Nothing But Noses And Eyes

Winter '14 / '15 - Season-total Snowfall Forecast Contest: FEB Totals

Monthly station snowfall summary for FEB-15.
Rank ordered by percent of monthly normal.

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

 

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Teleconnection Indexes

AO:  +1.043
NAO:  +1.32
PNA:  +0.49
PDO:  +2.30 (monthly record)
QBO:  -28.62 (monthly record)
MEI:  +0.468 (JAN-FEB)

Winter '14 / '15 - Interim Standings: 5

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

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Complete interim statistics table and charts at the Contest/s web site here.
All verified forecast statistics from all forecasters for all Winter '14 / '15 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 '14 / '15 - Storm #7: FINAL Results

Full forecast verifications and summary for Storm #7 at the Contest/s web site.

	1st - Brad Yehl
	SUMSQ:	58.98
	SUMSQ Z:	-0.763
	STP:	14.3	(4)
	TAE:	24.8	(1)
	AAE:	1.08	(1)
	2nd - Herb@MAWS
	SUMSQ:	69.13
	SUMSQ Z:	-0.689
	STP:	15.1	(7)
	TAE:	27.9	(2)
	AAE:	1.27	(3)
	3rd - donsutherland1
	SUMSQ:	71.2
	SUMSQ Z:	-0.674
	STP:	8.0	(1)
	TAE:	30.6	(4)
	AAE:	1.22	(2)
	HM - Donald Rosenfeld
	SUMSQ:	81.4
	SUMSQ Z:	-0.599
	STP:	18.9	(8)
	TAE:	28.2	(3)
	AAE:	1.28	(4)

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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Click images to enlarge.

Winter '14 / '15 - Storm #7: Preliminary Verification

Preliminary storm-total snowfalls for THU from CDUS41 and CXUS51 bulletins.

Good coverage and reporting.

SBY/s STP interpolated from PNSAKQ vicinity reports.

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Six new daily snowfall records
THU ... 05-MAR-15
IAD - 9.5" (1.0"; 2001)
ACY - 7.0" (0.3"; 1960)
PVD - 6.3" (3.8"; 1931)
ISP - 6.3" (1.0"; 1993)
DCA - 4.8" (4.4"; 1888)
BDR - 4.0" (1.3"; 1981)

Record daily precipitation at ACY (2.4")

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Please report any errors in Comments along with a link to the correct data.

Final results SAT evening.

Winter '14 / '15 - Storm #7: The Forecasts!

Rookie 0
Intern 1
Journey 1
Senior 9
TOT 11

Forecasts are ranked by their storm-total precipitation (STP).

BLUE ==> 25th percentile.
RED ==> 75th percentile.
STP cells without color are between the 25th and 75th percentile.

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Heaviest snowfall (+6") consensus along and to the right of a line from PHL - ACY - DCA - IAD - BWI - PHL

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Opposite day.

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 Everyone/s station-by-station forecast at the Contest/s web site.

Winter '14 / '15 - Storm #7: RAW Forecasts

Here

Winter '14 / '15 - Storm #7: Call for Forecasts!

ACY Boardwalk - 1928

Pattern change may be coming but not before  there's another contest-worthy snow storm. 

Real mess of mixed precipitation types and Arctic temperatures in the offing will make for a challenging late-season forecast.

Contest for Storm #7 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: storm-total snowfall
Deadline for entries:  10:30 PM EST ... WED ... 04-MAR-15

Verification begins:  12:01 AM EST ... THU ... 05-MAR-15
Verification ends:  when the snow stops falling

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Enter your forecast at the NEWxSFC/s home page here.

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.

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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).

Winter '14 / '15 - VCP32: Like Any Other Day