Deep layer Easter easterlies.
PV displacement
Split vortices.
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Major SSW event has begun!
Saturday, March 28, 2015
Wednesday, March 25, 2015
Winter '14 / '15 - Sudden Stratospheric Warming: Watch #2 - Update 3
ECMWF continues its forecast for a SSW event in the near-term.
Monday, March 23, 2015
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.
Thursday, March 19, 2015
Tuesday, March 17, 2015
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.
... and a deep ... icy trough INVOF Baffin Bay.
mid-to-late April could turn out quite interesting.
Saturday, March 14, 2015
Wednesday, March 11, 2015
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
NAO: +1.32
PNA: +0.49
PDO: +2.30 (monthly record)
QBO: -28.62 (monthly record)
MEI: +0.468 (JAN-FEB)
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: +1.043NAO: +1.32
PNA: +0.49
PDO: +2.30 (monthly record)
QBO: -28.62 (monthly record)
MEI: +0.468 (JAN-FEB)
Monday, March 09, 2015
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.
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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.
Saturday, March 07, 2015
Winter '14 / '15 - Storm #7: FINAL Results
Full forecast verifications and summary for Storm #7 at the Contest/s web site.
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.
| 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.
Friday, March 06, 2015
Winter '14 / '15 - Storm #7: Preliminary Verification
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.
Thursday, March 05, 2015
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.
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.
Wednesday, March 04, 2015
Tuesday, March 03, 2015
Winter '14 / '15 - Storm #7: Call for Forecasts!
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| ACY Boardwalk - 1928 |
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).
