Winter '16 / '17 - Snow Storm #1: Preliminary Verification

Preliminary storm-total snowfalls for THU and FRI from CDUS41 and CXUS51 bulletins.  Good overall coverage.

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One new daily record.
29-DEC-16
CON - 8.3" (7.1"; 1956)

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Snow Storm #1 underperformed slightly with five stations reporting more than nuisance snowfall (>= 4").  BGM just couldn/t make it over the finish line.

A dozen stations reported snowfall greater than Trace.

No Snow-Liquid ratios for mixed precipitation conditions ... such as PWM ... where 1.84" liquid was measured.

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

Final results NLT SUN evening.

Winter '16 / '17 - Snow Storm #1: New Daily Record Snowfall @ KCON

SFC:  00Z FRI ... 30-DEC-16

Concord ... NH (KCON) set a new daily snowfall record on 29-DEC-2016.

New record:  8.3" (12.2:1 SLR)
Old record:  7.1" (1956)

Light snow began falling over the station shortly before noon on the 29th ... turning heavy and increasing to an inch to an inch and one-half per hour between 5 and 8 PM EST.

Winter '16 / '17 - Snow Storm #1: TSSN

On-set of convection heralded the change from liquid to frozen precipitation.
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KBED 300112Z 32011G19KT 1SM R11/6000VP6000FT -TSSN BR VV004 01/M01 A2941
RMK AO2 LTG DSNT SE AND S TSB06 P0001 T00061011

KBOS 300119Z 31015G25KT 3SM -TSSNGS SCT006 OVC015 01/01 A2938
RMK AO2 PK WND 32028/0056 RAE07SNB01GSB13 TSB10 LTGICCC W TS W MOV E P0007 T00110006

KPWM 300251Z 33013KT 1/2SM +TSSN FEW004 OVC010 M02/M02 A2929
RMK AO2 WSHFT 0154 RAE17SNB17 TSB49 PRESFR SLP918 LTGIC P0024 60079 I1002 I3002

K1P1 300255Z AUTO 00000KT 2 1/2SM -VCTSSN M03/M03 A2936 RMK AO2 P0001 60003 T10281031

Winter '16 / '17 - Snow Storm #1: The Forecasts!

Rookie 0
Intern 0
Journey 0
Senior 8
Official 1
TOT 9
Included NWS 'official' forecasts ... as of the deadline.
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Forecasts are ranked by their storm-total precipitation (STP).

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

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Heaviest snowfall (>= 4") consensus along and the right of CAR - BGR - ORH - BGM - ALB - CON - CAR
Lollypop expected at CAR.

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Teleconnection headwinds

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Everyone/s station-by-station forecast post to NEWxSFC/s web site @ http://www.newx-forecasts.com/

Winter '16 / '17 - Snow Storm #1: RAW FORECASTS

Here

Winter '16 / '17 - Snow Storm #1: Call for Forecasts!

Mill Pond ... ME
28-DEC-51

Borderline contest-worthy event relative to the number of forecast stations expected to observe more than nuisance accumulations given the SFC LOW/s progged proximity to the coast.

Today/s 12z NWP runs advertised rapid deepening of the SFC LOW along the SNE coast.  Strong UVM from dynamic cooling should cool columns enough to produce decent snows.

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Forecast element: storm-total snowfall
Deadline:
10:30 PM EST ... WED... 28-DEC-16
Verification period begins:
12:01 AM EST ... THU ... 29-DEC-16
Verification period ends:
11:59 PM EST ... FRI ... 30-DEC-16
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Enter your forecast at the NEWxSFC/s home page @ 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.
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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.
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Contest may be cancelled before deadline if storm appears to fizzle.

Winter '66 / '67 - White Christmas Eve

Classic Miller 'A'
Lived this one in SNJ :)

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23-DEC
- Cyclogenesis ovr LA
- Rapid movement east along stalled Arctic boundary INVOF GOM states
- Full latitude trof just east of MS river

SFC:  23-DEC-66

 24 - DEC
- LOW on the SC coast
- Light pre-dawn snow begins over southern mid-Atlantic
+TSSN (thunder snow) @ PHL and ILG between 4 and 8 PM


SFC:  24-DEC-66

25-DEC
LOW occludes ovr Cape Cod

Select mid-Atlantic storm-total snowfall
PHL:  12.6"  (1.09 liquid; 11.5:1 SLR)
ACY:  6.5"
BWI:  8.4"
ILG:  12.4"

SFC:  25-DEC-66

5H:  23-DEC-66
 

5H:  25-DEC-66

Winter '16 / '17 - Rare Snow in the African Desert

" ... snow on the edge of the Sahara Desert is rare. On December 19, 2016, snow fell on the Algerian town of Ain Sefra, which is sometimes referred to as the “gateway to the desert.”

"The town of roughly 35,000 people sits between the Atlas Mountains and the northern edge of the Sahara. The last recorded snowfall in Ain Sefra occurred in February 1979.

" ...  a review of several years of satellite data suggests that snow is also unusual in this section of the Saharan Atlas range.

"The snow fell in a region where summertime temperatures average 37°Celsius (99°Fahrenheit), though wintertime temperatures have been known to get down into the single digits Celsius (30s Fahrenheit). Such moisture is as rare as the cool temperatures, given that just a few centimeters (inches) of precipitation fall here in an entire year."

Source:  NASA Earth Observatory

Winter '16 / '17 - Arctic Oscillation: NOV

Winter '16 / '17 - North Atlantic Oscillation: NOV

Winter '16 / '17 - Snow Storm #1: Near Miss

ACY Boardwalk (1928)

The season/s first snow storm out-performed not only the numerical models but the professional meteorologists responsible for issuing the official forecasts.

Heaviest significant snowfall (>= 4") at first-order reporting stations was observed along and either side of a line from CON - BOS - BDR - BDL - ORH - CON.  In addition to these five forecast points ... PWM at 3.6" and CAR at 3.5" ended up being close enough to have warranted a 'call for forecasts' and a contest-worthy snow storm had the writing been on the wall Thursday evening.  As it was ... NE snowstorm legend Paul Kocin painted a large swath of 40% probability for at least 4" on WPC/s afternoon package.

Models were late catching on to this storm/s potential.  Similar circumstances plagued last year/s contests ... as well.

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Station / snowfall (")
BDL 6.5 (daily record)
ORH 6
BDR 5.3 (daily record)
CON 4.7
BOS 4.3
PWM 3.6
CAR 3.5
BGM 3.4
BGR 3.3
PVD 3.2
BTV ... ISP 3
EWR ... JFK 3 (daily records)
HYA 2.5 (est.)
ALB 2.4
ABE ... MDT ... PHL <1
ACY ... BWI ... IAD ... DCA T

Winter '16 / '17 - Eurasia Snow Cover

Winter '16 / '17 - 'Season-total' Snowfall Forecasts by Station

Winter '16 / '17 - 16th Annual 'Season-total' Snowfall Forecast Contest - Call for Forecasts!

NE.Wx's 16th annual ‘Season-total' Snowfall Forecast Contest is the absolute best ... biggest ... and probably ONLY chance to be recognized for your long-range forecasting acumen ;/

And it's easy.
All you have to do is forecast the season-total snowfall at 25 stations from RDU to CAR!

Deadline: WED ... 30-NOV-16 @ 11:59 PM EST

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Visit the Contest's website to enter your forecast.
Follow the link at the top of the page to 'Enter Season-total Forecast.'

1st place prize (delivered post-paid right to your front door):
"The Snow Booklet" by Nolan J. Doesken and Arthur Judson (paperback) and "Snow in America" by Bernard Mergan (hardcover)

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As always ... NO cost ... NO fees ... NO advertising ... NO annoying requests for personal information to enter the contest.  NEWxSFC is just a fun exercise for winter wx enthusiasts to see who can make the best season-total snowfall forecast.

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Forecast element: sum-total season snowfall @ each station
Forecast period: 01-DEC-16 through 31-MAR-17
Verification: NWS preliminary climate reports (CLM or CF6)

Error statistic: total absolute error [Σ abs(forecast - observed)]

Update your forecast as often as you want prior to the deadline.
Only your last entry gets verified.

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The reigning NE.Wx ‘Season-Total’ Snowfall Forecasting Champ-een is snowman
Last year's 'Season-total' forecast summary ... verification ... and final results ==> here

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The Contest is open to amateur and professional forecasters; broadcasters with or without trained Seals; any and all weather-biz types and / or wanna-bees; wish-casters ... astrologers ... along with any other universally recognized classes of dreamers; Pollyannas or Cassandras ... registered Nostradamusts ... non-violent megalomaniacs ... woolly-bear caterpillars or their agents ... pest detectives ... NE.Wx NG veterans and lurkers; refugees from AmericanWx and/or USWeather ... including self-imposed exiles from Eastern Wx ... and of course ... meteorologists.

In honor of USENET/s ne.weather/s patron saint Mr. Joseph Bartlo's final request (RIP) ... trolls ... goats ... hat3-lsiters ... and psests need not apply.

Winter '15 / '16 Regular Season Snowfall Contest Note

Great Blizzard of 1888 - Wilmington ... DE
Market St looking N from 10th St

17th Annual 'Regular Season'
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No FINAL standings
Two contest-worthy storms were too few for a valid contest.

Under the 'two-thirds' rule;
Forecasters are included in end-of-season rankings
if they entered at least two-thirds of all storm contests.

Given only two contest-worthy storms during the season ... forecasters with one entry only would not have been eligible.

In the interest of fairness; forecasters should have at least three opportunities to enter ... so three storms seems like the bare minimum to make certain a valid contest.

Winter '16 / '17 - Outlooks

Thread updated periodically as new outlooks and forecasts are issued from a variety of credible sources.

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AER ...

IRI ...

CPC ...

 

Read more »

Winter '16 / '17 - Arctic Oscillation (AO)

Winter '16 / '17 - Eurasia Snow Cover

Winter '16 / '17 - North Atlantic Oscillation (NAO)

Winter '16 / '17 - Multivariate ENSO Index (MEI)

Winter '16 / '17 - Pacific Decadal Oscillation (PDO)

Winter '16 / '17 - First Contact

 

 

Winter '15 / '16 - 15th Annual Season-total Snowfall Forecast Contest: FINAL Results

Snowman FTW!

The 'season-total' snowfall forecast contest/s error statistic is total absolute error.
For each forecast station ... the absolute value of (Forecast - Observed) is calculated ... then summed.

Forecasts with lower 'total absolute forecast' errors have more skill than those with higher 'total absolute forecast' errors.

CONSENSUS is the mean forecast of all forecasts computed for each station.
P-O-R-N is the 'Period Of Record Normal' or climatology.
Skillful season-total forecasts beat climatology.

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Table of lowest station errors.

  

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Table of the total absolute value of (total snowfall forecast - total snowfall observed).

 

If you finished higher in this table than the 'Total Absolute' table ... you did a better job of forecasting the sum total snowfall amount over the entire forecast area than the distribution of station-total snowfall amounts.

 

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Verified forecasts at NEWxSFC/s web site here.

Winter '15 / '16 - 15th Annual Season-total Snowfall Forecast Contest: Snowfall Totals (DJFM)

 

 

Green ==> 75th percentile

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

Red ==> 25th percentile

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Extremely slow start to the season.
Only CAR measured above normal snowfall in DEC.
Second highest monthly snowfall:  BGR at 67% normal.

Twelve stations above normal for JAN thanks to major event along the M-A at month's end.

BWI measured 526% normal.

 

Seven stations above normal in FEB.

SBY and BDR measured170% normal.

 

Thee stations above normal in MAR.

SBY measured 322%.

 

Season-total biggest losers: BTV (35%) ... BGM (30%) ... RDU (22%) ... and ALB (19%)

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Good year for the M-A.

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Season-total snowfall from all stations (720") came in 23% below the period-of-record normal (932").  Winter '15 / '16 ranks 3rd lowest among other Contest years since winter '04 / '05 ... the season when BGR and BGM were added to the station list. 

Winter '15 / '16 - Season-total Snowfall Forecast Contest: MAR totals

Station snowfall summary for MAR-16.
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:  0.280
NAO:  0.73
PDO:  2.40
QBO:  3.16
 SOI: -4.7

Winter '15 / '16 - Season-total Snowfall Forecast Contest: FEB totals

Station snowfall summary for FEB-16.
Rank ordered by percent of monthly normal.

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

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Teleconnection Indexes
AO:  -0.024
NAO:  1.58
PDO:   1.75
QBO:   6.79
SOI: -19.7

Winter '15 / '16 - VCP32: Procrastinating and Rationalizing

Winter '15 / '16 - Snow Storm #3 - Call for Forecasts!

E. Meadow - Hempstead Turnpike
Long Island ... NY
18-FEB-36

CANCELLED

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Not the greatest set of progs you/ll ever see but that/s been the story a couple times already this winter.

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Forecast element: storm-total snowfall

Deadline: 10:30 PM EST ... SUN ... 14-FEB-16

Verification period begins: 12:01 AM EST ... MON .... 15-FEB-16
Verification period ends: 11:59 PM EST ... TUE ... 16-FEB-16

 

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

Contest may be cancelled before deadline if storm appears to fizzle.

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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.

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 '15 / '16 - Snow Storm #2 - FINAL Results

Full forecast verification and summary at NEWxSFC/s home page.

	1st - TQ
	SUMSQ:	49.52
	SUMSQ Z:	-0.586
	STP:	17.8	(4)
	TAE:	28.2	(1)
	AAE:	1.04	(1)
	2nd - donsutherland1
	SUMSQ:	64.62
	SUMSQ Z:	-0.542
	STP:	25.4	(7)
	TAE:	32.7	(2)
	AAE:	1.31	(2)
	3rd - Herb @MAWS
	SUMSQ:	76.6
	SUMSQ Z:	-0.507
	STP:	9.1	(3)
	TAE:	34.6	(3)
	AAE:	1.39	(3)
	HM - Donald Rosenfeld
	SUMSQ:	77.7
	SUMSQ Z:	-0.504
	STP:	19.9	(5)
	TAE:	34.8	(4)
	AAE:	1.39	(4)

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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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Winter '15 / '16 - Snow Storm #2: Preliminary Verification

Preliminary storm-total snowfalls for TUE through THU from CDUS41 and CXUS51 bulletins.
Good coverage but some spotty reporting.

PWM
11-FEB climate bulletins reported 0.11" liquid but 0" snow.
METAR carried all snow during the period of precipitation.
Previous days' 13.1: 1 SN:H20 was applied to the reported 0.11" liquid for an estimated daily snowfall of 1.5"

HYA
P- and 6-groups carried all 0s throughout the event.
VSBY briefly 3/4 SM; otherwise ... ~2 SM.
Estimated STP no more then 0.1"

SBY
PNSAKQ carried a report from a city official of 1".
Daily climate data shows 1" snow and 0.02" liquid (SN:H20 = 50:1)

PNSPHI carried reports from neighboring Sussex county ... DE where MAX snowfall of 0.7" came from Delmar located five miles north of SBY.  SBY/s reported 1" snowfall appears reasonable but not the liquid equivalent.

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No new daily records.

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Snow storm #2 underperformed with only two stations observing more than nuisance snowfall (>= 4").
Most stations (23 of 27) reported snowfall greater than Trace.

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A 'Call for Forecasts' was not issued for what turned out to be the main event 08-FEB b/c NWP failed again to capture the storm's intensity until it was too late.

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Please report any errors in Comments along with a link to the correct data.
Final results SAT evening.

Winter '15 / '16 - Major Sudden Stratospheric Warming

Temperature change of -25°C over seven days & 10 mb flow reversal.



Images courtesy Japan Meteorological Agency.

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Previous post:

Winter '15 / '16 - Sudden Stratospheric Warming:  Watch #2 

Winter '15 / '16 - Season-total Snowfall Forecast Contest: JAN totals

Station snowfall summary for JAN-16.
Rank ordered by percent of monthly normal.

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

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Teleconnection Indexes
AO: -1.449
NAO: 0.12
PDO: 1.53
QBO: 9.34
MEI: 2.202
SOI: -19.7

Winter '15 / '16 - Snow Storm #2: The Forecasts!

Rookie 0
Intern 0
Journey 0
Senior 12
TOT 12

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

BLUE ==> 25th percentile.

RED ==> 75th percentile.
Grey and white STP cells are between the 25th and 75th percentile.

 

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Heaviest snowfall (+4") consensus along and the right of MDT - ABE -  PHL - BWI - MDT.

Lollypop expected at MDT.

 

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All above water.

Even during the heavier snowfall event on the 8th.

 

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