CONTEST STATUS - Updated: SUN ... 07-DEC-14 @ 6:30 PM EST

Winter '14 / '15 - Snowfall Forecast Contests

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16th Annual 'Regular Season'
STORM #2
Synoptiscope in VCP32

STORM #1 (26/27-NOV-14):
FINAL results here

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14th Annual 'Season-total'
Forecasts here.
.

Monday, January 31, 2011

Winter '10 / '11 - Snow Storm #6 - Call for Forecasts

Boston...MA
02-FEB-61
NESIS:  7.06 (crippling)
Potent winter storm heading east today from the central plains is packed to the gills with dynamic and thermo-dynamic forcing elements.

Models advertising coupled upper-level jet streaks...100+ kt speed-max at 5H...tight thermal gradient bent into an 'S-shape' at 85H indicating strong WAA on 60 kt winds loaded with 1"+ PWs from the GOM.

The intensity of initial wave crossing the forecast area this evening looks to be a contest-worthy event; however...it was not well-modeled with enough lead time to issue a 'call for forecasts.'

The contest may be canceled prior to the deadline if NWP indicates a fizzling event.

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Deadline for entries: 10:30 PM EST TUE...01-FEB-11
Forecast element: storm-total snowfall

Verification period begins: 12:01 AM WED...02-FEB-11
Verification period ends: 11:59 PM WED...02-FEB-11

Enter your forecast at the Contest's home page here.
Follow the link from 'Enter Storm Forecast.'

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As always...there/s no cost...or fee...or advertising...or annoying requests for personal information to enter a forecast. It's just a fun exercise among 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).

Want to be notified via e-mail when a 'Call for Forecasts' is issued?
Send your request to newx at newx-forecasts dot com.

Sunday, January 30, 2011

Winter '65 / '66 - On This Day in NESIS History

A MAJOR (NESIS 5.05 5.93) snowstorm affected the northeast between January 29 and 31...1966. This storm ranks 12th out of 66 since 1948.


Originating in the GOM on 29-JAN...the storm marched up the coast to a position off the Delmarva Peninsula on the 30th where a 930-ish central pressure was observed.  The strong cyclonic circulation threw high PW air into an arctic air mass where dew points were in the single digits.  Little doubt there was a coastal front involved...altho it/s not shown in the SFC analysis.  The 7 AM temperature in Birmingham...AL was 1°F and 3°F in Atlanta...GA.

Snowfall records were established that still stand today at...
ABE - 9.6"
BDL - 6.2"
BDR - 5"
BGM - 14.5" (1.01" liquid)
BOS - 5.7"
EWR - 5.6"
JFK - 5.2"
ORH - 8.5" (1.4" liquid)
PHL - 5.6"
PVD - 5.2"

NAO for D-3...D-2...D-1...and storm day
-1.654-1.739-1.622-1.402

AO
-3.510-2.929-2.853-3.053

PNA
0.002-0.0340.2500.565

Daily Wx Map
(click to enlarge)
The Northeast Snowstorm Impact Scale (.pdf) was developed by Paul Kocin and Dr. Louie Uccellini in 2004 to "...convey a measure of the impact of heavy snowfall in the Northeast urban corridor, a region that extends from southern Virginia to New England.

"The NESIS differs from the Fujita tornado scale and the Saffir–Simpson hurricane scale in that NESIS focuses on the amount of snow that falls, mapped onto the population density that experiences the snow, rather than focusing on wind as the major impact agent."

Winter '10 / '11 - Interim Standings - #3

After five snow storms...



Under the 'two-thirds' rule...the best 'two out of three' z-scores are used to compute the interim standings. After Snow Storm #4 5...your top four z-scores were used to calculate these standings. Data used to compute the standings are posted at the Contest web site here.

Z-scores are used to standardize / normalize forecast errors for each snow storm so at the end of the season...the 'equalized' scores can be averaged.


An expanded data table with higher resolution graphics and additional measures of forecaster skill at the Contest's home page.

Saturday, January 29, 2011

Winter '10 / '11 - Forecaster Master Database

The forecaster master database through Snow Storm #5 has been updated here.

The database (.html) has each forecast verification element by forecaster...such as Sum of Square Errors (SUMSQ)...Total Absolute Error (TAE)...Average Absolute Error (AAE)...and the Coefficient of Determination (RSQ). These 'measures of skill' are described at the Contest's web site here as part of the interim 'regular season' standings (scroll down).

Winter '10 / '11 - Snow Storm #5 - Final Results

1st - nnjwxguy78
SUMSQ: 327.44
SUMSQ Z: -1.369
STP: 5.00 (1)
TAE: 70.70 (2)
AAE: 2.83 (4)

2nd - Mitchel Volk
SUMSQ: 377.41
SUMSQ Z: -1.086
STP: 38.40 (5)
TAE: 73.00 (4)
AAE: 2.70 (2)

3rd - donsutherland1
SUMSQ: 436.72
SUMSQ Z: -0.750
STP: 45.65 (8)
TAE: 70.15 (1)
AAE: 2.70 (1)

Honorable mention - ejbauers
SUMSQ: 448.55
SUMSQ Z: -0.683
STP: 55.55 (9)
TAE: 71.65 (3)
AAE: 2.76 (3)

SUMSQ: sum of square errors
STP: storm-total precipitation error
TAE: total absolute error
AAE: average absolute error
(rank)

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Full forecast verification and summary at the Contest/s home page.

Friday, January 28, 2011

Winter '10 / '11 - Snow Storm #5 - Preliminary Verification

Preliminary storm-total snowfalls for Wednesday and Thursday from CDUS41...CXUS51...and PNS...as of noon Friday.

No updated snowfall report was carried in the NWS PNSBOX bulletin for HYA. Verifying storm-total snowfall of 3.5" was estimated from vicinity reports.

SBY/s Daily Climate Bulletin did not carry a snowfall report.  Verifiying storm-total snowfall came from PNSAKQ.

PHL/s record-setting snowfall on Wednesday piled-up over the course of six hours!

Many stations in the data table do not have SN:H2O reported b/c their totals included mixed precipitation.
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Fourteen new daily records!

Wednesday...26-JAN-11
PHL - 14.2" (4.4"; 1963)
ABE - 11.3" (5.3"; 1994)
EWR - 11" (5.8"; 1994)
BWI - 7.8" (6.9"; 1966)
MDT - 6.4" (6.1"; 1904)
BDR - 6" (3.6"; 1949)
JFK - 6" (3.3"; 1994)

Thursday...27-JAN-11
ORH - 11" (6.1"; 1963)
ISP - 9.6" (1.1"; 2004)
BDL - 9.1" (5.2"; 1963)
BOS - 8.8" (8"; 1894)
BDR - 7" (3.8"; 1963)
PVD - 6.7" (3"; 1963)
JFK - 4.3" (2.7"; 2004)

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Please report any errors and drop a link to the correct data in Comments.
Final results and storm summary Saturday evening.

Wednesday, January 26, 2011

Winter '10 / '11 - Snow Storm #5 - Snow Gun

(Updated below)

Tonight's 00z rawindsonde flight launched from OKX observed some major-league instability atop deep low-level moisture.


- Note the strong deep-layer iso-thermal WAA through ~600 mb beneath a layer of CAA near 500mb.
- Snow is indicated b/c the entire column is below zero.
- Specific gravity peaks close to 5g/kg near 750 mb.
- Baroclinic instability indicated with strong increase in wind speed with height.

More importantly is the observed instability AOA 700 mb as indicated by the theta-E plot shown below.  Strong instability is indicated when the trace goes straight up as it does ~700 mb and in the layer between 650 and 500 mb.


Snowfall rates at IAD earlier this evening were quite intense...where less instability was observed.  If I'm the duty forecaster at OKX this evening...I'd be preparing for snowfall rates in excess of 2"/HR over my CWA.

Sounding images courtesy SPC.

UPDATE:
METAR KISP 270656Z 02025KT 1/4SM R06/1800V2200FT +SN BLSN BKN003 OVC008 M01/M03 A2950 RMK AO2 SLP988 SNINCR 5/019

5" / hour!

Winter '10 / '11 - Snow Storm #5 - TSSN

SPECI KIAD 262021Z 34007KT 1SM -TSSN BR BKN004 OVC010CB 01/M01

METAR KFDK 262051Z AUTO 35010KT 1SM -TSSN OVC009 01/01


METAR KBWI 270154Z 34009KT 3/4SM R10/3500V4500FT -TSSN BR OVC003 01/00

Winter '10 / '11 - Snow Storm #5 - The Forecasts

EDIT:  a double-entry for Roger Smith was removed.  The forecast data table at the Contest's web site has been updated.

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14 13 entries

1 Rookie
4 2 Intern forecasters
1 Journeyman forecasters
7 Senior forecasters including Chief forecaster Ira Libov.

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All forecasts have been posted to the Contest's home page.
Follow the link from Storm #5.

Entries are ranked in ascending order by 'storm-total' snowfall.
Please check you entry for accuracy.


Larger than usual range of expected storm-total snowfall...
Min: 56" (Roger Smith) Min: 67" (Donald Rosenfeld)
Max: 188" (iralibov)
Avg: 120" Avg: 125"
Median: 123" Median: 124"
STD: 35" STD: 31"


Heaviest snowfall axis expected to fall inside ORH - BOS - PVD - ISP -EWR - ORH

Tuesday, January 25, 2011

Monday, January 24, 2011

Winter '10 / '11 - Interim Standings - #2

After four snow storms...


Under the 'two-thirds' rule...the best 'two out of three' z-scores are used to compute the interim standings. After Snow Storm #4...your top three z-scores were used to calculate these standings.  Data used to compute the standings are posted at the Contest web site here.

Z-scores are used to standardize / normalize forecast errors for each snow storm so at the end of the season...the 'equalized' scores can be averaged.


An expanded data table with additional measures of forecaster skill at the Contest's home page.

Winter '10 / '11 - Snow Storm #5 - Call for Forecasts

East Side...NYC
24-JAN-1908
Large-scale disagreement between today/s 12z NAM and GooFuS runs. HPC discounted the NAM solution as a 'slow outlier' in its afternoon discussion.

GooFuS keeps the LOW closer to the coast putting enough stations in play for a contest-worthy event.

The contest may be canceled prior to the deadline if NWP indicates a fizzling event.








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Deadline for entries:  10:30 PM EST TUE...25-JAN-11
Forecast element: storm-total snowfall

Verification period begins:  12:01 AM WED...26-JAN-11
Verification period ends:  11:59 PM THU...27-JAN-11

Enter your forecast at the Contest's home page here.
Follow the link from 'Enter Storm Forecast.'

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As always...there/s no cost...or fee...or advertising...or annoying requests for personal information to enter a forecast. It's just a fun exercise among 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).

Want to be notified via e-mail when a 'Call for Forecasts' is issued?
Send your request to newx at newx-forecasts dot com.

Winter '10 / '11 - WSI Expects Warm FEB

"“The end of the recent long-lived and extreme North Atlantic blocking episode, along with a return to more dateline blocking typical of late winter La Nina regimes, should result in a return of colder weather to the western half of the US in February while the eastern US finally experiences more moderate temperatures,” said WSI Chief Meteorologist Dr. Todd Crawford."

FEB - warmer
MAR - colder
APR - colder
More...

Winter's seasonal forecast for the northeast from WSI...
DEC - colder
JAN - warmer
FEB - warmer

"“The recent behavior of the North Atlantic Oscillation, along with the fact that current and recent atmospheric/oceanic patterns have closely resembled those from the 1950s-1970s period, has reinforced our hypothesis that there may have been a fundamental climate shift in 2008 that will result in weather patterns more similar to those found 40-60 years ago,” Dr. Crawford added."

Crawford/s reference to the NAO's recent behavior may be related to the index's 5-year moving average falling below zero for the first time in more than two decades. This chart shows the historical tendency for the NAO's moving average for meteorological winter (D-J-F) to remain positive or negative once the shift occurs.

Winter '10 / '11 - Stratospheric Warming - Take 4

Meant to post this over the weekend. Subsequent runs of the ECMWF have continued with the idea of a weakening polar vortex by month/s end suggesting a warming in the stratosphere with implications for cold temperatures toward the end of meteorological winter.















Note how the strong 85 m/s (~170 kts) PV in the left panel weakens to 35 m/s (~70 kts) by D+10 where the deep-layer blue highlights near 90°N indicates an east wind.  Favorable conditions are indicated for the Arctic Oscillation to fall well below zero in late February.

Not that significant warmth is expected anytime soon as the NAO ridge retrogrades toward Greenland and PNA remains positive with the most northern extension of the ridge reaching well above the Arctic Circle.  Short-wave energy migrating from this hi-latitude into the base of a deep eastern trough brings great potential to spin-up strong coastal storms off the SE CONUS.



Winter '10 / '11 - Snow Storm #4 - Final Results - UPDATED

The final results for Snow Storm #4 have been updated to include a forecast issued after the deadline.  Technical difficulties with the Contest's web site were experienced by Senior forecaster Mitch Volk Friday evening around 9:30 PM.  These difficulties prevented him from issuing a forecast before the deadline.

When I learned of this problem...I asked Mitch to send me the forecast he tried unsuccessfully to enter.  His forecast was included and verified along with the other forecasts.  Forecaster skill scores have been re-computed and posted to the Contest's web site.

Mitch has participated in the NEWxSFC every winter since its inception in 1999...issuing a timely forecast for almost every snow storm and every season-total contest.  Under the circumstances...accepting his forecast after the deadline is the right thing to do.
 
1st - Brad Yehl
SUMSQ: 75.76
SUMSQ Z: -1.032
STP: 7.50 (4)
TAE: 26.50 (2)
AAE: 1.10 (3)

Bride's Maid - Shillelagh
SUMSQ: 79.91
SUMSQ Z: -0.976
STP: 0.80 (2)
TAE: 26.90 (3)
AAE: 1.08 (2)

3rd - TQ
SUMSQ: 95.25
SUMSQ Z: -0.770
STP: 11.50 (7)
TAE: 27.90 (4)
AAE: 1.16 (4)

Honorable Mention - donsutherland1
SUMSQ: 100.19
SUMSQ Z: -0.703
STP: 17.60 (9)
TAE: 24.50 (1)
AAE: 1.07 (1)

SUMSQ: sum of square errors
STP: storm-total precipitation error
TAE: total absolute error
AAE: average absolute error
(rank)

Sunday, January 23, 2011

Winter '10 / '11 - Snow Storm #4 - Final Results

SFC Analysis
12z 21-JAN-11
1st - Brad Yehl
SUMSQ: 75.76
SUMSQ Z: -0.945
STP: 7.50 (3)
TAE: 26.50 (2)
AAE: 1.10 (3)

Bride's Maid - Shillelagh
SUMSQ: 79.91
SUMSQ Z: -0.890
STP: 0.80 (2)
TAE: 26.90 (3)
AAE: 1.08 (2)

3rd - TQ
SUMSQ: 95.25
SUMSQ Z: -0.686
STP: 11.50 (6)
TAE: 27.90 (4)
AAE: 1.16 (4)

Honorable Mention - donsutherland1
SUMSQ: 100.19
SUMSQ Z: -0.621
STP: 17.60 (8)
TAE: 24.50 (1)
AAE: 1.07 (1)

SUMSQ: sum of square errors
STP: storm-total precipitation error
TAE: total absolute error
AAE: average absolute error
(rank)

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Full forecast verification and summary at the Contest/s home page.

Saturday, January 22, 2011

Winter '10 / '11 - Snow Storm #4 - Preliminary Verification

Preliminary storm-total snowfalls for Friday from CDUS41...CXUS51...and PNS...as of 8 AM Saturday.

No snowfall report was carried in the NWS PNSBOX bulletin for HYA. Verifying storm-total snowfall of 0.5" was estimated from HYA/s Pxxxx METAR data.

A field formatting error in the data table shows ACY and IAD with 0.1".  Actual STP was a 'trace' (0.05") at both locations.
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Three new daily records.
FRI...21-JAN-11
BDR BGR - 17.3" (4.3"; 1946)
BOS - 7.3" (6.4"; 2001)
EWR - 4.5" (4.2"; 2001)

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Please report errors and drop a link to the correct data in Comments.
Final results and storm summary on Sunday.

Winter '10 / '11 - Snow Storm #4 - The Forecasts

11 entries

1 Rookie
2 Intern forecasters
2 Journeyman forecasters
6 Senior forecasters

Snow storm #4...while tame compared to the first three events...put down down respectable storm-total snowfalls over several New England stations.

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All forecasts have been posted to the Contest's home page.
Follow the link from Storm #4.

Entries are ranked in ascending order by 'storm-total' snowfall.
Please check you entry for accuracy.


Broad range of expected storm-total snowfall...
Min: 72" (donsutherland1)
Max: 147" (MarkHofman)
Avg: 95"
Median: 90"
STD: 21"


Heaviest snowfall axis expected to fall inside BGR - PWM - BOS - PVD - BDL - ORH - CON - BGR

Thursday, January 20, 2011

Winter '10 / '11 - Snow Storm #4 - Raw Forecasts

Raw forecasts here.

Winter '10 / '11 - December Snow Cover

From NCDC...

"The Northern Hemisphere snow cover extent during December 2010 was much above-average, marking the fourth largest December snow cover extent on record — behind December 2009, 1985, and 1970."


"During December 2010, the North American snow cover extent was above average, ranking as the seventh largest on record. This marks the fourth consecutive December with above-average snow cover extent for the continent."


Global Snow Report here.
National Snow and Ice Report here.

Wednesday, January 19, 2011

Winter '10 / '11 - Snow Storm #4 - Call for Forecasts

Union...Maine
JAN-1926
Miller-B (.pdf) cyclogenesis forecast to occur off the Delmarva peninsula early FRI morning.

Progs aren/t all that juiced nor are the powerhouse dynamics we/ve seen with previous storms evident until the system lifts out to the NE.

Even so...the storm appears to be contest-worthy.

The contest may be canceled prior to the deadline if NWP indicates a fizzling event.

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Deadline for entries: 10:30 PM EST THU...20-JAN-11
Forecast element: storm-total snowfall

Verification begins: 12:01 AM EST FRI...21-JAN-11
Verification ends: 11:59 PM EST FRI...21-JAN-11

Enter your forecast at the Contest's home page here.
Follow the link from 'Enter Storm Forecast.'

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As always...there/s no cost...or fee...or advertising...or annoying requests for personal information to enter a forecast. It's just a fun exercise among 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).

Want to be notified via e-mail when a 'Call for Forecasts' is issued?
Send your request to newx at newx-forecasts dot com.

Winter '10 / '11 - Northeastern Snowfall Impact Scale - Return Periods

The heavy snowfall of late December scored a 4.92 on the Northeastern Snowfall Impact Scale (NESIS).  It ranked 59th out of 76 events.

How often can a storm of this impact be expected to affect the NE?

Plotting the Gumbel distribution curve for the 76 NESIS events...we can estimate the return period of a 4.92 magnitude snow storm as 3.72 years.

What about the estimated return periods for the 'Top-5' NESIS storms?
Was the March-93 'Superstorm' really the 'Storm of the Century?' The Great Blizzard of JAN-96...ranked 2nd highest NESIS...was another memorable storm of the late 20th century.

How often can storms of such extreme impact be expected?

'Top-5' NESIS Events and Index...
12/14-MAR-93: 13.20
6/8-JAN-96: 11.78
2/5-MAR-60: 8.77
15/18-FEB-03: 7.50
2/5-FEB-61: 7.06

Gumbel distribution for 76 NESIS events
Return period...in years...for the 'Top-5' NESIS events...
12/14-MAR-93: 340
6/8-JAN-96: 153
2/5-MAR-60: 28.5
6/7-FEB-03: 14.2
2/5-FEB-61: 11.2

The return period for the MAR-93 Superstorm is more than twice as long as its nearest neighbor...the Great Blizzard of JAN-96.  Consider yourself lucky to have been alive when these genuinely historic storms occurred b/c it'll likely be a long...long time before a snow storm will have such a severe impact on the NE again.

Monday, January 17, 2011

Winter '10 / '11 - Interim Standings - #1

After three snow storms...


Under the 'two-thirds' rule...the best 'two out of three' z-scores are used to compute the interim standings.  After Snow Storm #4...your top three z-scores will be used.

Z-scores are used to standardize or normalize the errors from each storm so at the end of the season...the scores can be averaged.


An expanded data table with other measues of forecaster skill at the Contest's home page.

Saturday, January 15, 2011

Winter '10 / '11 - Forecaster Master Database

The forecaster master database has been updated here.

The database (.html) has each forecast verification element by forecaster...such as Sum of Square Errors (SUMSQ)...Total Absolute Error (TAE)...Average Absolute Error (AAE)...and the Coefficient of Determination (RSQ).  These 'measures of skill' are described at the Contest's web site here as part of last year's interim/final 'regular season' standings (scroll down).

Friday, January 14, 2011

Winter '10 / '11 - Snow Storm #3 - Final Results

12z 12-JAN-11 
1st - emoran
SUMSQ: 423.59
SUMSQ Z: -1.115
STP: 1.20 (2)
TAE: 76.80 (2)
AAE: 2.84 (2)

2nd - donsutherland1
SUMSQ: 430.73
SUMSQ Z: -1.091
STP: 39.75 (6)
TAE: 72.35 (1)
AAE: 2.68 (1)

3rd - Donald Rosenfeld
SUMSQ: 430.92
SUMSQ Z: -1.090
STP: 4.40 (3)
TAE: 84.70 (5)
AAE: 3.14 (5)
00z 13-JAN-11

Honorable Mention - Brad Yehl
SUMSQ: 484.58
SUMSQ Z: -0.908
STP: 42.15 (7)
TAE: 84.05 (4)
AAE: 3.11 (4)

SUMSQ: sum of square errors
STP: storm-total precipitation error
TAE: total absolute error
AAE: average absolute error
(rank)

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0.19" SUMSQ error difference between 2nd and 3rd place forecasts.

Mark Hofmann came within 0.1" of the observed storm-total snowall (214.9") for all stations.

Full forecast verification and summary at the Contest/s home page.

Winter '10 / '11 - North Atlantic Oscillation at Winter/s Crest

Meteorological winter has reached the half-way mark.  Coldest time of the year in the Northern Hemisphere...yet for much of the first half...temperatures have been much below normal...an unexpected oddity during la Nina.

This Hovmöller diagram from CPC shows the 5-day running mean of 5H anomalies above 65°N.

The strong action center along 60°W shows strength and persistence of the NAO over the past 90 days. 

The blocking HIGH over Greenland has weaken in recent days with a subsequent rise in the index to minus 2...heading for positive territory this weekend.

NAO is forecast to fall below zero later in the week as the PNA index rises to about 3...suggesting a favorable environment for coastal storms to develop off the SE coast.




Thursday, January 13, 2011

Winter '10 / '11 - Going Retro

Three-wave pattern forecast for 23-JAN-11 implies a retrogression of plantery low long waves.


This flow-regime evolution would claw the 5H anomaly westward to a position over Greenland...return the NAO to negative territory where it belongs...and reprise the currently cold temperatures over the eastern CONUS.

Winter '10 / '11 - Snow Storm #3 - Preliminary Verification

Preliminary storm-total snowfalls for Tuesday and Wednesday from CDUS41...CXUS51...and PNS...as of 8 AM Thursday.

No snowfall data in the NWS climate bulletins for SBY. Verifying storm-total snowfall of 0.05" was estimated from SBY/s METARs

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Twelve new daily records.

WED...12-JAN-11

BDL - 24" (10.3"; 1996)
ORH - 21.1" (10"; 1996)
CON - 18.3" (8.6"; 1901)
BDR - 15" (3"; 2004)
BOS - 14.6" (6.7"; 1976)
ISP - 14" (2.1"; 2004)
PWM - 13" (10.2"; 1905)
ALB - 12.8" (10.2"; 1891)
BGR - 10.4" (5.7"; 1954)
BTV - 9.3" (5.9"; 1976)
EWR - 6.4" (3.2"; 1994)
JFK - 4.2" (1.6"; 1970)

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Please report errors and drop a link to the correct data in Comments.

Final results and storm summary Friday evening.

Winter '10 / '11 - Snow Storm #3 - Teleconnections


Arctic Oscillation continues its long run at well below zero as a minor warming event takes hold in the stratosphere...shown below by the hi-latitude...above normal geo-potential heights (GPH).


Also note the AO/s classic tri-pole configuration...in this case with strongly positive 5H anomalies over the Bering Sea and a secondary maxima over NE Canada.


Tuesday, January 11, 2011

Winter '10 / '11 - Snow Storm #3 - The Forecasts

12 entries

1 Rookie
3 Intern forecasters
2 Journeyman forecasters
6 Senior forecasters including Chief forecaster Iralibov

Another 'true' snow storm unlike some years where we try to forecast what is little more than a narrow stripe of snow under the northern edge of a mainly rain storm's comma cloud.

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All forecasts have been posted to the Contest's home page.
Follow the link from Storm #3.

Entries are ranked in ascending order by 'storm-total' snowfall.
Please check you entry for accuracy.


Broad range of expected storm-total snowfall...
Min: 112" (TQ)
Max: 216" (emoran)
Avg: 176"
Median: 174"
STD: 31"


Heaviest snowfall axis expected to fall inside BOS - ORH - BDL- ISP - PVD - BOS.

Winter '10 / '11 - Snow Storm #2 - Final Results

Daily Wx Map
08-JAN-11
1st - Donald Rosenfeld
SUMSQ: 115.75
SUMSQ Z: -0.945
STP: 15.60 (10)
TAE: 37.60 (1)
AAE: 1.39 (1)

2nd - Donsutherland1
SUMSQ: 116.46
SUMSQ Z: -0.937
STP: 4.80 (2)
TAE: 39.70 (3)
AAE: 1.47 (3)

3rd - Mitchel Volk
SUMSQ: 121.70
SUMSQ Z: -0.874
STP: 14.10 (9)
TAE: 39.40 (2)
AAE: 1.46 (2)

HM - Emoran
SUMSQ: 129.88
SUMSQ Z: -0.775
STP: 7.80 (5)
TAE: 40.70 (4)
AAE: 1.51 (4)

SUMSQ: sum of square errors
STP: storm total precipitation error
TAE: total absolute error
AAE: average absolute error
(number): category ranking

Full forecast verification and summary at the Contest home page.

Monday, January 10, 2011

Winter '10 / '11 - Snow Storm #3 - Raw Forecasts

The raw forecasts have been posted to the NEWx GoogleGroup.

Winter '10 / '11 - Snow Storm #2 - Preliminary Verification

Preliminary storm-total snowfalls for Friday through Sunday from CDUS41...CXUS51...and PNS.

No snowfall data in the NWS climate bulletins for SBY. Verifying storm-total snowfall of 0.5" was estimated using a SN:H2O ratio of 12.5:1...the same as RIC.

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One new daily record.

SAT...08-JAN-11
ACY - 7.7" (6.6"; 1988)

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Please report errors and a link to the correct data in Comments.

Final results and storm summary TUE evening.

Sunday, January 9, 2011

Winter '10 / '11 - Snow Storm #3 - Something Happenin' Here

30+ kts of warm'n moist being ingested into the nascent LOW via cold conveyor belt.
Strong baroclinicity given the skinny-digit arctic dew points over land.

Winter '10 / '11 - Snow Storm #1 - NESIS

NESIS:  4.92
Category:  3 (Major)
Rank:  18th


More...

Winter '10 / '11 - Snow Storm #3 - Call for Forecasts

Main Street
Camden...ME
1901
One storm exits stage left...new storm enters stage right.

I-95 corridor in the cross-hairs for its second heavy snowfall and high wind event this winter.  Progs indicate rapid deepening of a slow moving cyclone along the NJ and SNE coastline.

The contest may be canceled prior to the deadline if NWP indicates a fizzling event.

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Deadline for entries: 10:30 PM EST MON...10-JAN-11
Forecast element: storm-total snowfall

Verification begins: 12:01 AM EST TUE...11-JAN-11
Verification ends: 11:59 PM EST WED...12-JAN-11

Enter your forecast at the Contest's home page here.
Follow the link from 'Enter Storm Forecast.'

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As always...there/s no cost...or fee...or advertising...or annoying requests for personal information to enter a forecast. It's just a fun exercise among 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).

Want to be notified via e-mail when a 'Call for Forecasts' is issued?
Send your request to newx at newx-forecasts dot com.

Saturday, January 8, 2011

Winter '10 / '11 - Snow Storm #2 - The Forecasts

17 entries

2 Rookies
3 Intern forecasters
1 Journeyman forecasters
11 Senior forecasters including Chief Forecaster Iralibov

Another great turn-out and a difficult storm for the season's second act.

All forecasts have been posted to the Contest's web site.
Follow the link from Storm #2.

Entries are ranked in ascending order by 'storm-total' snowfall.
Please check you entry for accuracy.

Broad range of expected storm-total snowfall...
Min: 28" (Roger Smith)
Max: 128" (albwxexaminer)
Avg: 70"
Median: 64"
STD: 23"




Consensus heavy snowfall axis (+4") between EWR - BGM - ALB - ORH - ISP - JFK - EWR.

Thursday, January 6, 2011

Winter '10 / '11 - Snow Storm #2 - Raw Forecasts

Times Square...NYC
16-JAN-1965
This evening/s early NWP solutions don/t appear to expect much of an exciting synoptic snowfall event QPF-wise; however...there may be some surprise station STPs given there are v-e-r-y cold columns capable of creating copious crystal dendrites with uncharacteristically high SN:H2O.

The raw forecasts have been posted to the NEWx GoogleGroup here.

Wednesday, January 5, 2011

Winter '10 / '11 - Snow Storm #2 - Call for Forecasts

Times Square...NYC
13-JAN-1954
Tonight/s 00z NAM consistent with earlier runs in its depiction of dynamically driven... meso-scale contest-worthy snowfall event over the northern mid-Atlantic and coastal New England regions.

Game on...at least for now.

Contest may be canceled prior to the deadline if NWP indicates a fizzling event.

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Deadline:10:30 PM EST THU...06-JAN-11
Forecast element: storm-total snowfall
Verification begins: 12:01 AM EST FRI...07-JAN-11
Verification ends: 11:59 PM EST SUN...09-JAN-11

Enter your forecast at the Contest web site here.
Follow the link from 'Enter Storm Forecast.'

---
As always...there/s no cost...or fees...or advertising...or annoying requests for personal information to enter a forecast.  It's just a fun exercise among 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).

Want to be notified via e-mail when a 'Call for Forecasts' is issued?
Send your request to newx at newx-forecasts dot com.