Winter '19 / '20 - Eurasian Snow Cover: AUG

Eurasia/s areal snow cover for AUG-19:  ~158,300 km2

-61% below 48-year P-O-R-N (~403,000 km2)
-46% below 48-year Median (~294,000 km2)
Rank: 39th

7th highest past 10 years
19 of past 20 years below median
 Last year:  ~140,800 km2

Analog years for winter '19 / '20

CORRECTION:  Second instance of 15/16 should be 16/17
---
Snow cover data courtesy Rutgers University Global Snow Lab
http://climate.rutgers.edu/snowcover/index.php

Winter '19 / '20 - Arctic Oscillation (AO): AUG

AUG AO:  -.722
Leading analog contenders ... as of AUG-19.

Consensus Outlook:  Winter '19 / '20 AO < 0

KEY
ENSO:  nada- (-0.5 < SSTa <  0); C- (weak La Nina); W- (weak El Niño); W (moderate El Niño); W+ (strong El Niño)
NAO:  sign of D-J-F average
PDO:  sign of O-N-D-J-F-M average
QBO:  + ==> west; - ==> east; +/- flipped west to east

---
Present state
ENSO: 0 < ONI < 0.5 trending lower
NAO < 0 past 5 months
QBO > 0 past 10 months.  Peaked JUN-19; trending lower.  Possible flip during upcoming winter
PDO (MAR-18 to OCT-19) < 0 No trend.

Winter '19 / '20 - North Atlantic Oscillation (NAO): AUG

AUG NAO:  -1.17
Leading analog contenders ... as of AUG-19.

Consensus Outlook:  Winter '19 / '20 NAO > 0

CORRECTION:  '50 / '51 ENSO should be 'C-'

KEY
ENSO:  nada- (-0.5 < SSTa <  0); C- (weak La Nina); C (moderate La Nina)
AO:  sign of D-J-F average
PDO:  sign of O-N-D-J-F-M average
QBO:  + ==> west; - ==> east

---
Present state
ENSO: 0 < ONI < 0.5 trending lower
QBO > 0 past 10 months.  Peaked JUN-19; trending lower.  Possible flip during upcoming winter
PDO (MAR-18 to OCT-19) < 0 No trend.

Winter '18 / '19 - North Atlantic Oscillation (NAO) Analog Verification

The analog forecasting technique seeks similarities to the NAO state in the run-up to the coming winter with NAO run-up states of winters past.  Presented here is the verification of NAO analogs for the '18 /'19 winter.

The NEWxSFC method ranks analog years by their the sum of square errors (SSE) statistic.
Lower SSE errors ==> stronger analog

Constraining the number of analog winters for analysis to five is arbitrary.

North Atlantic Oscillation (NAO) Index Analog Forecast Verification

In the run-up to Winter '18 / '19 ... '84 / '85 was the leading analog followed by '72 / '73 ... '59 / '60 ... '89 / '90 ... and '91 / '92.  Winter '18 / '19 NAO started weakly positive ... approached zero at meteorological winter's end ... then climbed above 1 in MAR.

A qualitative assessment of the analog forecast's accuracy would rate the analogs #2 or #5 as 'best' with #1 ... 3 ... and 4 'poor.'

A quantitative assessment of the other '72 / '73 and '91 / '92 teleconnections ... not so much.

Read more »

Winter '18 / '19 - Arctic Oscillation (AO) Analog Verification

The analog forecasting technique seeks associations to the AO state in the run-up to the coming winter with AO run-up states of past winters.  Presented here is the verification of AO analogs for the '18 /'19 winter.

The NEWxSFC method ranks analog years by their the sum of square errors (SSE) statistic.
Lower SSE errors ==> stronger analog

Constraining the number of analog winters for analysis to five is arbitrary.

In the run-up to Winter '18 / '19 ... '55 / '56 was the leading analog followed by '64 / '65 ... '84 / '85 ... '99 / '00 ... and '91 / '92.  Observed AO values for Winter '18 / '19 began neutral in DEC ... turned weakly negative in JAN ... then surged positive at meteorological winter/s end and into MAR.

A qualitative assessment of the analog forecast/s accuracy rates '84 / '85 as best.

A quantitative assessment of the other '84 / '85 teleconnections ... not so much.

Read more »

Winter '19 / '20 - NCDC Issues Updated Period-of Record Snowfall Climatology

Here

It's only been four years since the last update.

More NCDC climo data here

Winter '18 / '19 - 20th Annual 'Regular Season' Snowfall Forecast Contest: FINAL Results

After five snow storm forecasting contests ... under the ‘two-thirds’ rule … forecasters who entered at least FOUR forecasts are included in this season's FINAL standings.

Full table with all other error statistics at the Contest/s web site here (direct link).
Individual forecaster's storm statistics here (direct link).

Read more »

Winter '18 / '19 - 18th Annual 'Season-total' Snowfall Forecast Contest: FINAL Results

UPDATE (08-APR-19)
Forecaster verification table at the Contest web site (direct link)
Season-total snowfall v period-or-record normal trend chart

---
Original post:  (07-APR-19 @ 8:30 PM EDT)

Congratulations to Donald Rosenfeld for his 1st Place finish.
Donald also placed first in '05 / '06 and '12 / '13.

Forecasters ranked by their total absolute error.

---

Season-total snowfall from all stations (784") came in 14% below the period-of-record normal (914").
Winter '18 / '19 ranks 11th among other Contest years since winter '04 / '05 ... the season when BGR and BGM were added to the station list.

---
Apologies for the abbreviated recap.
Will add to the pile a little at a time this week including each forecaster's station-by-station verification.

Winter '18 / '19 - Season-total Snowfall Forecast Contest: Preliminary STP Verification

UPDATE (08-APR-19 @ 11:55 AM EDT)
Added links to monthly snowfall totals

---
Original post (06-APR-19 @ 6:42 PM EDT)

Preliminary sum-total season snowfalls for the verification period 01-DEC-18 though 31-MAR-19 collected from monthly climate bulletins (CLMxxx; CXUS51 ... CXUS52).

Seven forecast stations (28% of all stations) with bonus season-total snowfalls [more than Period-Of-Record-Normal (P-O-R-N)].

Rank ordered descending by percent of P-O-R-N.

Green ==> 75th percentile
White ==> Interquartile range (< 75th & > 25th percentiles)
Red ==> 25th percentile

---
Please report any errors in Comments along with a link to the correct data.
FINAL results expected NLT SUN evening.

---
Winter '18 / '19 monthly snow totals
DEC:  http://newxsfc.blogspot.com/2019/01/winter-18-19-season-total-snowfall.html
JAN:  http://newxsfc.blogspot.com/2019/02/winter-18-19-season-total-snowfall.html
FEB:  http://newxsfc.blogspot.com/2019/03/winter-18-19-season-total-snowfall.html
MAR:  http://newxsfc.blogspot.com/2019/04/winter-18-19-season-total-snowfall.html

Winter '18 / '19 - Season-total Snowfall Forecast Contest: MAR Totals

MAR-19 snowfall summary by Contest forecast station.
Rank ordered descending by percent of monthly period-of-record-normal (P-O-R-N).

---
Green ==> 75th percentile
White ==> Interquartile range (< 75th & > 25th percentiles)
Red ==> 25th percentile

---
MAR Forecast Station Highlights
Eleven stations above P-O-R-N
MA: 5
NE:  6

BDR ... NYC ... ABE ... MDT
At least 200% of monthly P-O-R-N

Biggest losers
Observed v P-O-R-N (% P-O-R-N)
RDU:  0" v 1.0"
ORH:  0" v 0.9"
RIC:  0" v 2.2"
SBY:  T v 1.8" (3%)
DCA:  0.3" v 2.1" (14%)