Winter '21 / '22 - Snow Storm #3: Preliminary STP verification

Boston Commons
Parkman Bandstand - 1933

CORRECTION:  daily snowfall record for BDR (had been listed as BGM) and BOS daily snowfall for 1/28/22 from 0.02" to 0.2".

h/t Roger Smith

---
Preliminary verification of storm-total snowfalls for FRI through SUN from CDUS41 (CLI) ... CXUS51 (CF6) ... METARs ... and PNS bulletins.  Several issues with coverage and reporting.

HYA
STP estimated from PNSBOX reports using inverse distance weighting of vicinity reports.
http://en.wikipedia.org/wiki/Inverse_distance_weighting

CAR
Resolved conflict between 29-JAN-22 daily snowfall reports carried by Daily Climatological Report (CLI) of 9.2" and Daily Climate Data (CF6) of 8.2" by comparing vicinity PNSCAR storm-total snowfall reports.  The 1" difference made no difference in final rankings of the forecasts; however ... minor differences noted in the SUMSQ Z-score statistic.

BGR
Liquid equivalent missing from Daily Climatological Report (CLI) and Daily Climate Data (CF6) reports for 29-JAN-22.  Amount estimated from METAR reports from AWOS at Hancock County-Bar Harbor Airport (KBHB) in East Surry ... ME.

Liquid equivalents recovered from METARS for several stations with missing data in climate bulletins.

---

Snow-to-liquid ratio (SLR) not reported for some stations with measurable snowfall b/c significant liquid and / or freezing precipitation also occurred during the verification period.

---
Stations observing >= Trace:  27 (100%)

Given stations had measurable snowfall ... stations observing at least:
4" - 17 (63%)
8" - 12 (44%)
12" - 7 (26%)
16" - 5 (19%)
20" - 2 (7%)
24: - 1 (4%)

Max snow melt-water (minimum SLR 10:1)
ACY - 1.60"
CAR - 0.92"
BGR - 0.82"

Max precipitation (frozen + freezing + liquid):
ACY - 1.60"
CAR - 0.92"
BGR - 0.82"

---
New daily record(s)
29-JAN-22
BOS - 23.6" (3.7"; 1957)
ISP - 23.2" (1.5"; 2014)
PVD - 18.8" (6.7"; 1912)
ORF - 14.7" (11.5"; 1973)
ACY - 14" (7.3"; 2014)
PWM - 11" (9"; 1957)
BDR - 9.6" (3.8"; 1973)
JFK - 9.3" (1"; 2014)
EWR - 6.6" (1.1"; 1986)
PHL - 5.8" (5"; 1904)

Orange cells indicate new daily record.
Trace amounts (0.05") are not included in STP.

---

Storm total snowfall
Image courtesy NOHRSC

---

SFC analysis:  18z ... 29-JAN-22
Image courtesy DOC / NOAA / NWS / NCEP / WPC

---
Please report any errors in Comments along with a link to the correct data.
FINAL results expected NLT TUE evening.

Winter '21 / '22 - Snow Storm #3: The Forecasts

BGR
01-JAN-63

Rookie      1
Intern      1
Journey      -
Senior      12
GOVT      1
PWSP      1
TOT      16

Forecaster table ranked ascending by storm-total precipitation (STP)

BLUE ==> 1st quartile
RED ==> 4th quartile
WHITE and GREY STP cells range between the 1st and 4th quartile

---

Heaviest snowfall (+12") consensus along and more-or-less to the right of BGR - PWM - BOS - HYA - PVD  - ISP - ACY - ISP - ORH - BGR.  Lollypop expected at HYA.

Teleconnections
Pretty impressive storm for such lousy indexes.

Everyone/s station-by-station forecast at the Contest/s web site.
Direct link to the forecast table.

Winter '21 / '22 - Snow Storm #3: RAW Forecasts

click Read more ...

NWS to follow.

Read more »

Winter '21 / '22 - Snow Storm #3: Call for Forecasts!

Knickerbocker Theatre
27/29- JAN-1922

High amplitude flow regime across CONUS ... courtesy RIDGE - WEST / TROF- EAST longwave configuration ... appears primed to deliver one heck of a contest-worthy snow storm for the last weekend of JAN.  It/s also the 100 year anniversary of the Knickerbocker Theatre fire.

- Enter your forecast at the NEWxSFC/s home page at http://www.newx-forecasts.com/

- Follow the top-of-page link from 'Enter Snow Storm Forecast'

---
Forecast element: each station/s storm-total snowfall

Deadline for entries: 10:00 PM EST ... THU ... 27-JAN-22

Verification begins: 12:01 AM EST ... FRI ... 28-JAN-22
Verification ends: 11:59 PM EST on the day when flakes stop accumulating.

You also get the chance to see how well your forecast stacks up against NWS Eastern Region Weather Forecast Offices. Turns out they/ve been fairly easy to beat!

Who Can Enter
Amateur and professional forecasters; broadcasters with or without trained Seals; any and all other weather-biz types and / or wanna-bees; wish-casters ... astrologers ... along with any other universally recognized class of dreamers; Pollyannas or Cassandras ... registered Nostradamuses ... non-violent megalomaniacs ... woolly-bear caterpillars or their Agents ... pest detectives ... ne.wx NG survivors; riders on the StormVista ... refugees from AmericanWx and/or USWeather free agents ... including self-imposed exiles from Eastern Wx ... and of course ... meteorologists.

Read more »

Winter '21 / '22 - Coastal Teaser #3

DC
24-JAN-1940

Persistent Ridge-West / Trof East mid-level flow regime looking to cough up another contest-worthy snow storm this coming weekend.

Progs pointing to a Miller 'A' type storm beginning its long climb up the east coast on FRI then exploding into a meteorological 'bomb' (and no ... not a so-called 'bomb cyclone'; a made-up term never used by Sanders and Gyakum 1980) during SAT.

A 'Call for Forecasts' expected WED ... 26-JAN-22.

All else equal ... deadline for entries would be 10 PM EST ... THU ... 27-JAN-22.

Winter '21 / '22 - 'Season-total' Snowfall Forecast Contest: DEC Snowfall Totals

DEC-21 snowfall summary by forecast station.
Rank ordered descending by percent of monthly period-of-record-normal (P-O-R-N).

Green ==> 4th quartile
White ==> less than 4h and greater than 1st quartile (inter-quartile range)
Red ==> 1st quartile

---
DEC Forecast Station Highlights
0 stations above normal monthly snowfall

Biggest Losers
ABE ... ACY ... BDR ... BOS ... BWI ... DCA ... EWR ... IAD ... NYC ... ORF ... PHL ... RDU ... RIC ... SBY observed less than 10% of normal monthly snowfall

---
Season-Total-to-Date
DEC P-O-R-N contributes 203.3" (22%) toward the season-total snowfall (D-J-F-M) of 929".
DEC-21 observed snowfall:  86" (42% of monthly P-O-R-N; 9% of season-total snowfall)

Image courtesy NOHRSC @ http://www.nohrsc.noaa.gov/nsa/

---

Teleconnections
AO / NAO / PNA data

Winter '21 / '22 - Snow Storm #2: FINAL Results and Storm Summary

Complete forecaster verification table and the FINAL Results / Storm Summary available at NEWxSFC/s home page.

SUMSQ:  sum of square error (")
SUMSQ Z:  Z-score
STP:  storm total precipitation error (")
TAE:  total absolute error (")
AAE:  average absolute error (")
(#):  category rank

Forecast by Observed Snowfall Scatterplots for Top Forecasts
Forecast/s dotted blue line below (above) the Observed snowfall/s solid red line ==> under (over) forecast bias.

Station by Station Comparison of Top 4 Forecasts and Observed Storm-total Snowfall

Forecast bias (average over/under per station) and skill score v. NWS ER WFOs.
For example ... Shillelagh's bias was on average a 1" under-forecast  The forecast was a 47% improvement over NWS ER WFOs.

Winter '21 / '22 - Snow Storm #2: Preliminary STP Verification

Preliminary verification of storm-total snowfalls for SUN through TUE from CDUS41 (CLI) ... CXUS51 (CF6) ... METARs ... and PNS bulletins.  Excellent coverage and reporting.

HYA
6- and 7-group precipitation data not carried in METARS.

---
Snow-to-liquid ratio (SLR) not reported for some stations with measurable snowfall b/c significant liquid and / or freezing precipitation also occurred during the verification period.

---
Stations observing >= Trace:  24 (89%)
Given stations with measurable snowfall ... stations observing at least:
4" - 5 (19%)
6" - 3 (11%)
8" - 2 (7%)
10" - 1 (4%)

Max snow melt-water (minimum SLR 10:1)
BGM:  1.18"
BTV:  0.57"

Max precipitation (frozen + freezing + liquid):
ORF:  1.97"
EWR:  1.87"
ISP:  1.60"

---
New daily record(s)
16-JAN-22
DCA - 2.6" (2.2"; 1965)

17-JAN-22
BTV - 8.1" (8"; 1909)

Orange cells indicate new daily record.
Trace amounts (0.05") are not included in STP.

---

Storm total snowfall
Image courtesy NOHRSC

---

SFC analysis:  12z ... MON ... 17-JAN-22
Image courtesy DOC / NOAA / NWS / NCEP / WPC

---
Please report any errors in Comments along with a link to the correct data.
FINAL results expected NLT THU evening.

Winter '21 / '22 - Snow Storm #2: Preliminary STP Verification

STATUS:  Preliminary STP table will be posted tomorrow ... WED ... 19-JAN-22 to account for snowfall observed today ... TUE ... 18-JAN-22.

The cyclonic circulation around the occluded MLK surface LOW near the mouth of the St. Lawrence River produced measurable 'lake effect' snowfall at BGM earlier today.

Winter '21 / '22 - Snow Storm #2: The Forecasts!

BWI
13-DEC-60

Rookie      2
Intern      1
Journey      -
Senior      12
GOVT      1
PWSP      1
TOT      17

Forecaster table ranked by ascending storm-total precipitation (STP)

BLUE ==> 1st quartile
RED ==> 4th quartile
WHITE and GREY STP cells range between the 1st and 4th quartiles.

Heaviest snowfall (+5") consensus along and to the right of CAR - CON - ALB - BGM - BTV - CAR  Lollypop expected at BTV.

PNA making a half-hearted effort but NAO and AO just not that interested.

Everyone/s station-by-station forecast at the Contest/s web site.
Direct link to the forecast table.

Winter '21 / '22 - Snow Storm #2: RAW Forecasts

 

NYC
12-27-47

click through for the listing ...

Read more »

Winter '21 / '22 - Snow Storm #2: Call for Forecasts!

HRW FV3 54-hr Forecast Valid 1 PM EST ... SUN ... 16-JAN-22

The long awaited and much anticipated mid-latitude cyclone arrives on the east coast SUN toting a steamer trunk brimming with mixed precipitation.  More than enough forecast stations for a contest-worthy snow storm.

- Enter your forecast at the NEWxSFC/s home page at http://www.newx-forecasts.com/
- Follow the top-of-page link from 'Enter Snow Storm Forecast'

---
Forecast element: each station/s storm-total snowfall

Deadline for entries: 10:00 PM EST ... SAT ... 15-JAN-22
Verification begins: 12:01 AM EST ... SUN ... 16-JAN-22
Verification ends: 11:59 PM EST on the day when flakes stop accumulating.

You also get the chance to see how well your forecast stacks up against NWS Eastern Region Weather Forecast Offices. Turns out they/ve been fairly easy to beat!

Read more »

Winter '21 / '22 - Coastal Teaser #2

 

Worst kept secret evah ...

Snow Storm #2 all but certain to affect most if not all forecast stations SUN into MON.  NWP models tease for a yuge event of mixed precipitation types makes for a challenging forecast.

Call for Forecasts likely FRI.

Deadline for entries would be 10 PM EST ... SAT ... 15-JAN-22

Winter '21 / '22 - Snow Storm #1: FINAL Results and Storm Summary

Complete forecaster verification table and the FINAL Results / Storm Summary available at NEWxSFC/s home page.

SUMSQ:  sum of square error (")
SUMSQ Z:  Z-score
STP:  storm total precipitation error (")
TAE:  total absolute error (")
AAE:  average absolute error (")
(#):  category rank

Forecast by Observed Snowfall Scatterplots for Top Forecasts
Forecast/s dotted blue line below (above) the Observed snowfall/s solid red line ==> under (over) forecast bias.

Station by Station Comparison of Top Forecasters

Winter '21 / '22 - Snow Storm #1: Preliminary STP Verification

Accumulation-weighted SN:H20 (SLR)

UPDATE 1/8 @ 1:15 PM EST:  fixed snow totals for IAD ... BGM.  Thanks to 'anonymous' in comments for the eagle-eye. 

---
Preliminary verification of storm-total snowfalls for THU from CDUS41 (CLI) ... CXUS51 (CF6) ... METARs ... and PNS bulletins.  Excellent coverage and reporting.

HYA
STP estimated from one report carried by BOSPNS within 2.2 SM of the station.  Station did not carry 6-and 7-group data.

SLR not reported for some stations with measurable snowfall b/c significant liquid and / or freezing precipitation also occurred during the verification period.

---
Stations observing >= Trace:  25 (93%)
Given stations with measurable snowfall ... stations observing at least:
4" - 14 (42%)
6" - 5 (19%)
8" - 2 (7%)

Max snow melt-water (minimum SLR 10:1)
ORH: 0.52"
BOS:  0.48"
BDL:  0.44"

Max precipitation (frozen + freezing + liquid):
ORH: 0.52"
BOS:  0.48"
BDL:  0.44"

---
New daily record(s)
None

---

Storm total snowfall
Image courtesy NOHRSC

---

SFC analysis:  09z ... 07-JAN-21
Image courtesy DOC / NOAA / NWS / NCEP / WPC

---
Please report any errors in Comments along with a link to the correct data.
FINAL results expected NLT SUN evening.

Winter '21 / '22 - Snow Storm #1: The Forecasts!

Central Park - NYC
09-JAN-1944

Rookie      -
Intern      1
Journey      -
Senior      10
GOVT      1
PWSP      1
TOT      13

---
Forecasters rank-ordered by ascending storm-total precipitation (STP)

BLUE ==> 1st quartile
RED ==> 4th quartile
WHITE STP cells fall between the 1st and 4th quartiles

Heaviest snowfall (+5") consensus along and to the right of a line from BOS - PVD - ISP - ORH - BOS.  Lollypop expected at BOS (6.4")

Teleconnections (AO ... NAO ... PNA) unavailable since 05-JAN-22.

Forecasters' station-by-station forecasts posted to the Contest/s web site here.
http://www.newx-forecasts.com/

Direct link to the table of forecasts here.
http://www.newx-forecasts.com/NEWxSFC_23/storms/storm1_forecasts_07JAN22.htm

Winter '21 / '22 - Snow Storm #1: RAW Forecasts

dc 03-07-41

 here ...

Winter '21 / '22 - Snow Storm #1: Call for Forecasts!

An initially flat ... open shortwave in fast moving semi-zonal flow offers an opportunity for the first snowfall forecasting contest of Winter '21 / '22.  

On a more optimistic note:  NWP expects the shortwave to amplify as it reaches the coast.

While the progs aren/t offering much hope for a contest-worthy snow storm ... the latest NWS WFO point forecasts issued by BOX ... GYX ... and CAR point to at least six stations more than a nuisance snowfall (>= 4") could be observed.

NOTE:  snowfall expected to begin over southern interior stations before the 10 PM EST deadline.  Forecasts should include amounts observed on THU.  This is non-standard verification period driven by events (verification usually begins a few hours after the deadline at the start of the next day).

The forecasting contest for Snow Storm #1 may be cancelled prior to the deadline if at least six-to-eight stations seem unlikely to observe at least a 4" storm-total snowfall.

---
Enter your forecast at the NEWxSFC/s home page at http://www.newx-forecasts.com/
Follow the top-of-page link from 'Enter Snow Storm Forecast'

---
Forecast element: each station/s storm-total snowfall

Deadline for entries: 10:00 PM EST ... THU ... 06-JAN-22
Verification begins: 12:01 AM EST ... THU ... 06-JAN-22
Verification ends: 11:59 PM EST on the day when flakes stop accumulating.

You also get the chance to see how well your forecast stacks up against NWS Eastern Region Weather Forecast Offices. Turns out they/ve been fairly easy to beat!

---
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).

---
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.

Winter '21 / '22 - Coastal Teaser #1

Hot on the heels of the 03-JAN snow storm comes the chance for a contest-worthy nor'easter and the first snowfall forecasting contest of the '21 / '22 winter.

Progs currently advertising cyclogenesis along the trailing end of an arctic cold frontal boundary draped across the central Gulf coast states attended by a negatively-tilted trough aligned along the MS river valley THU AM with snow beginning over the forecast area early FRI AM.

A 'Call for Forecast' would be issued WED evening with a deadline for entries @ 10 PM EST ... THU ... 06-DEC-22 should current model trends continue.