Thursday, January 28, 2016
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
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]
Remarkably similar synoptics.
Parent HIGH over the upper Plains with an eastern extension over the NE.
Miller 'B' re-development off the Carolinas.
Please report any errors in Comments along with a link to the correct data.
Final results Tuesday evening.
Sunday, January 24, 2016
Winter '15 / '16 - Snow Storm #1: DCA STP #FAA_FAIL
24-JAN-16 The 2016 non-blizzard Blizzard |
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.
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Apparently ... DCA reported 17.8" STP (1.47 liquid) yet IAD and BWI measured 29.3" (2.63 liquid) and 29.2" (2.13 liquid) ... respectively.
This disparity has lead to questions about how much snow actually fell @DCA.
NWS vicinity reports in the PNS bulletin also suggest a possible under-measured of snow at Raygun/National.
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Reported snow liquid ratios (SLR)
DCA 12.1
IAD 11.1
BWI 13.7
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FAA contract personnel measure snowfall at many major airports. May be one reason why so many SLRs are 10:1.
That ... and not being able to find the snowboard when it's time to measure.
Friday, January 22, 2016
Winter '15 / '16 - Snow Storm #1: The Forecasts!
Rookie 0
Intern 0
Journey 0
Senior 13
TOT 13
Congratulations to snocat918 on achieving Senior forecaster status this season.
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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 (+12") consensus along and the the right of RIC - IAD - MDT - PHL - BWI - RIC.
Lollypop expected at IAD.
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Northern annular modes (AO / NAO) negative and rising. Evidence of amplifying long wave seen in PNA/s rising index.
Everyone/s station-by-station forecast at the Contest/s web site.
RAW forecasts here.
Winter '15 / '16 - Snow Storm #1: RAW Forecasts
Baltimore ... MD 28-JAN-22 |
All forecasts and summary statistics will be posted at the Contest web site and the web log ... respectively after lunch FRI.
Having issues with Excel this AM.
Thursday, January 21, 2016
Winter '15 / '16 - Season-total Snowfall Forecast Contest: DEC Totals
UPDATE: tele-connection index values
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Monthly station snowfall summary for DEC-15.
Rank ordered by percent of monthly normal.
Red ==> 25th percentile
NAO: 2.24
PNA: N/A
PDO: 1.01
QBO: 11.4
MEI: 2.123
Wednesday, January 20, 2016
Winter '15 / '16 - Snow Storm #1: Call for Forecasts
No question whether this is a contest-worthy storm. Couldn't ask for a better mid-latitude cyclone to kick-off the season other than its tardy arrival a week past winter's mid-point.
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Forecast element: storm-total snowfall
Deadline for entries: 10:30 PM EST THU ... 21-JAN-16
Verification begins: 12:01 AM EST FRI ... 22-JAN-16
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.
Monday, January 18, 2016
Winter '15 / '16 - Coastal Teaser #3
Decent inter - and intra-run-to-run consistency suggesting this season's first contest-worthy snow storm may be in the offing toward week's end.
Timing the on-set of precipitation remains a moving target. 18-JAN / 00z GFS pointing toward FRI AM over southern portions of the forecast area.
'Call for Forecasts' possible WED evening (20-JAN).
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There have been five previous winters without a contest-worthy storm in DEC ('99-'00, '06-'07, '11-'12, and '14-'15).
The first storms those winters were:
1/20/00
2/14/07
1/21/12
1/26/15
Total snowfall forecasting contests those winters:
'99-'00: 5
'06-'07: 5
'11-'12: 2
'14-'15: 6
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Hang in there forecasters.
All is (probably) not lost.
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NWP image courtesy meteocentre.com
Wednesday, January 13, 2016
Winter '15 / '16 - Coastal Teaser #2
A little past the halfway point of meteorological winter ... another coastal teaser lurks on the horizon.