CONTEST STATUS - Updated: FRI ... 10-APR-15 @ 5:45 PM EDT

Winter '14 / '15 - Snowfall Forecast Contests

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16th Annual 'Regular Season'

FINAL Standings here
Forecaster summary data here

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14th Annual 'Season-total'
FINAL results here

Monday, May 4, 2015

Winter '14 / '15 - PDO: Variability Since 1661 CE

ABSTRACT:
"Climate in the North Pacific and North American sectors has experienced interdecadal shifts during the 20th century. A network of recently developed tree-ring chronologies for Southern and Baja California extends the instrumental record, and reveals decadal-scale variability back to AD 1661.


"The Pacific Decadal Oscillation (PDO) is closely matched by the dominant mode of tree-ring variability, which provides a preliminary view of multi-annual climate fluctuations spanning the past four centuries. The reconstructed PDO index features a prominent bidecadal oscillation, whose amplitude weakened in the late 1700s to mid-1800s.

"A comparison with proxy records of ENSO suggests that the greatest decadal-scale oscillations in Pacific climate between 1706 and 1977 occurred around 1750, 1905, and 1947."


"Reconstructed PDO since 1660.
Correlation between instrumental (dashed) and reconstructed PDO is 0.64 from 1925 to 1991.

"During warm periods, the eastern North Pacific is warmer than usual, and the central North Pacific
is cooler (viceversa during cool periods). Warm and cool PDO phases are qualitatively similar to warm
and cool ENSO events, but different because of slower temporal dynamics and stronger midlatitudinal responses."

More...

Winter '14 / '15 - Storm #7: NESIS

NESIS

Thursday, April 9, 2015

Winter '14 / '15 - Above Normal Snowfall and the MIA Northern Annular Oscillations

NYC
13-DEC-60

Number of days between 01-DEC and 31-MAR:  121
Number of days between 01-DEC and 31-MAR where

NAO <= 0:  9
NAO <= -1:  0

NAO >= 1:  50
NAO >= 1.5:  18
NAO >= 2:  2

AO <= 0:  28
AO <= -1:  9
AO <= -1.5:  2

AO >= 1:  60
AO >= 1.5:  48
AO >= 2:  32
AO >= 3:  11
AO >= 4:  4
AO >= 5:  3

PNA >= 0:  85
PNA >= 1:  11
PNA >= 1.5:  0

Number of NEWxSFC stations with at least
100% normal snowfall:  22
150% normal snowfall:  9
200% normal snowfall:  3
250% normal snowfall:  1


AO - NAO - PNA (daily)
Meteorological winter '14 / '15
AO - NAO - PNA (7-day moving average)
Meteorological winter '14 / '15
AO - NAO - PNA (30-day moving average)
Meteorological winter '14 / '15

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Something happenin' here.
What it is ain't exactly clear.

Wednesday, April 8, 2015

Winter '14 / '15 - 14th Annual Season-total Snowfall Forecast Contest: FINAL Results

Don Sutherland 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.
 
P-O-R-N is the 'Period Of Record Normal' or climatology.
Skillful season-total forecasts beat climatology.
 
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Lowest Station Errors
 
Forecaster STP Summary
 
Snowfall Totals (DJFM)
 
DEC Totals
 
JAN Totals
 
FEB Totals
 
MAR Totals
 
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Everyone's forecast has been verified and posted to the Contest/s web site here.
Hope to see y'all back again next winter.

Winter '14 / '15 - Season-total Snowfall Forecast Contest: Lowest Station Errors


Winter '14 / '15 - Season-total Snowfall Forecast Contest: Forecaster STP Summary

Forecaster season-total snowfall forecasts are ranked by their departure from the observed season-total snowfall.  It does not show forecasts ranked by their accuracy.  Forecast accuracy is determined by the sum of absolute errors for all stations.

Red ==> 67th percentile
White ==> Less than 75th and greater than 25th percentile
Blue ==> 33rd percentile

Winter '14 / '15 - Season-total Snowfall Forecast Contest: Snowfall Totals (DJFM)

Despite the slow start to the season ... winter quickly made up for lost time between late JAN and MAR.
Season-total snowfall for all stations (1,336") came in 43% above the period-of-record normal (934"). 
 
 
Green ==> 75th percentile
White ==> Less than 75th and greater than 25th percentile
Red ==> 25th percentile

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STP for winter '14 / '15 ranks 3rd among other Contest years since winter '04 / '05 ... the season when BGR and BGM were added to the station list.
 

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

Monthly station snowfall summary for MAR-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:  +1.837
NAO:  +1.45
PNA:  +0.49
PDO:  2.00
QBO:  -28.15 (monthly record)
MEI:  .650 (FEB-MAR)

Saturday, March 28, 2015

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!