Thursday, February 11, 2016

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 - 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

Tuesday, February 09, 2016

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.

Sunday, February 07, 2016

Winter '15 / '16 - Snow Storm #2: Call for Forecasts

MDT
07-FEB-67
Riding the 18z NAM and GFS.
Minimum number of stations in play.
A few more are close enough.

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Forecast element: storm-total snowfall
Deadline: 10:30 PM EST ... MON ... 08-FEB-16
Verification period begins: 12:01 AM EST ... TUE ... 09-FEB-16
Verification period ends: when the snow stops falling

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.

Friday, February 05, 2016

Winter '15 / '16 - Phantom Storm #1


Today/s poorly-forecast nor'easter turned out to be a decent contest-worthy snow storm over coastal portions of southern New England.

Insufficient lead time to issue a 'Call for Forecasts.'

Near-blizzard conditions on Cape Cod.
Who knew?

Storm-total snowfall (")
ORH - 12.5
ISP - 9.8
PVD - 8.8
BDR - 8
BGR - 7.8
BDL - 6.6
CON - 5.1
PVD - 5.1
BOS - 4.6
JFK - 4.6
EWR - 2.8

Monday, February 01, 2016

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

UPDATE (01-FEB-18):
As advertised ...

 
 
Looks yuge.

Beat the rush.
Start laying in supplies now.

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10 mb Temperature Anomalies
GFS Ensembles 10-JAN-16

"The models are now coming into better consensus for a stronger pulse of energy transfer beginning next week that is predicted to initiate a sudden stratospheric warming (SSW) at the end of the month."

 -  AER Arctic Oscillation Analysis and Forecasts (time sensitive)

Progs expect PV displacement v. PV split.

Thursday, January 28, 2016

Winter '15 / 16 - Snow Storm #1: NESIS

Rank:  4
NESIS:  7.66
Category:  4
Description:  Crippling

Large format image here.

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The storm covered ~434,000 square miles and affected ~103 million people.

Of those, ~1.5 million people had more than 30" of snowfall; ~24 million had over 20".
- NOAA

Tuesday, January 26, 2016

Winter '15 / '16 - Snow Storm #1: FINAL Results

Full forecast verification and summary at NEWxSFC/s web site.

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 1st - Donald Rosenfeld 
 SUMSQ:1152.22  
 SUMSQ Z:-1.946  
 STP:14.0 (1) 
 TAE:135.8 (1) 
 AAE:5.22 (1) 
     
 2nd - TQ 
 SUMSQ:1802.59  
 SUMSQ Z:-0.968  
 STP:108.6 (6) 
 TAE:143.9 (3) 
 AAE:6.00 (3) 
     
 3rd - Mitchel Volk 
 SUMSQ:1942.0  
 SUMSQ Z:-0.759  
 STP:127.3 (7) 
 TAE:156.5 (5) 
 AAE:6.80 (6) 
     
 HM - donsutherland1 
 SUMSQ:2151.8  
 SUMSQ Z:-0.443  
 STP:142.2 (9) 
 TAE:160.7 (6) 
 AAE:6.70 (5) 
     

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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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Click images to enlarge.

Monday, January 25, 2016

Winter '15 / '16 - Snow Storm #1: Preliminary Verification

Preliminary storm-total snowfalls for Friday though Sunday from CDUS41 and CXUS51 bulletins.  Good coverage and reporting.

DCA STP in question.
Vicinity reports suggest an under-measurement.
Sensitivity analysis on forecasts with a 30" verification shows no impact on top three finishers (HM flips) with minor shuffling in the pack's middle.
Note the SLRs are similar at IAD and BWI.

AP reporting on the controversy.
The two vicinity sites mentioned in the article are ~3 miles NNW (Adams Morgan neighborhood) and ~5 miles NW (Dalecarlia Reservoir) distant from DCA.

Meanwhile ... ~2 miles across the river to the east in Anacostia ... MD ... a trained spotter reported 19" and about the same distance to the SSE a 17" report from National Harbor ... VA

Reporting issues continue at SBY.
SBY/s 6" STP comes from a 'media' report carried in AKQ/s Public Information Statement (PNS).

HYA/s 14" STP comes from an 'amateur radio' report carried in BOX/s Public Information Statement (PNS).

Stations with STP but no SN:H2O had mixed freezing ... frozen ... and liquid precipitation.

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Boatload of new daily records for SAT ... 23-JAN-16
JFK - 30.3" (3.6"; 2005)
ABE - 30.2" (7.7"; 1966)
EWR - 27.5" (4.5"; 2005)
MDT - 26.4" (9.5"; 1982)
BWI - 25.5" (11.5"; 1935)
ISP - 23.4" (4.2"; 2005)
IAD - 22.1" (1.7"; 1982)
PHL - 19.4" (11.9"; 1935)
BDR - 12" (7.1"; 1965)
DCA - 11.3" (11"; 1935)
ACY - 10.1" (1.2"; 1948)
RIC - 5.3" (2.7"; 1908)
ORF - 1.2" (1"; 2000)
RDU - 1.2" (1.2", 1954) [22-JAN-16]

Areal coverage - The Great non-blizzard Blizzard JAN 2016
 
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Several new daily records exceeded those set in 1935.

Remarkably similar synoptics.
Parent HIGH over the upper Plains with an eastern extension over the NE.
Miller 'B' re-development off the Carolinas.
 
STP (liquid)
DC - 2.85"
BWI - 2.68"
RIC - 2.88"
 
 
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Please report any errors in Comments along with a link to the correct data.
Final results Tuesday evening.