NE.Wx Snowfall Forecast Contests: Regular Season

Showing posts with label Regular Season. Show all posts

Tuesday, February 18, 2025

Winter '24 / '25 - Snow Storm #4: FINAL Results and Storm Summary

BOS - Morrissey Boulevard
FEB-78

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

SUMSQ: sum of square errors (")
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 4 Forecasts

- Forecast/s dotted BLUE line below (above) the Observed snowfall/s solid RED line ==> under (over) forecast error.

- R^2: how well the forecast 'explained' the variability of the observed snowfall (i.e., an R^2 of 0.710 means the forecast explained 71% of the observed snowfall's variability).

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

---
Forecast Skill Score (measured against NWS ER WFOs)

- Positive (negative) skill values indicate the degree of a forecast/s improvement (degradation)
compared to NWS forecasts.

- Bias: the arithmetic difference between the average Forecast snowfall and the average Observed snowfall (avgForecast - avgObserved).

Monday, February 17, 2025

Winter '24 / '25 - Snow Storm #4: Preliminary STP Verifications

by TQ @ 7:17 PM

Presidents Day
19-FEB-79

UPDATED 18-FEB @ 10:30 AM ET to include snowfall for CAR ... BGR ... and BGM plus trace amounts for several other stations on 17-FEB.

h/t RS

---
Preliminary verification of storm-total snowfalls based on reporting from CDUS41 (CLI) ... CXUS51 (CF6) ... METARs ... and PNS bulletins issued by NWS.

Good coverage and reporting.

---
HYA
STP derived from an inverse distanced-weighting technique using vicinity STP reports
from Barnstable county carried in the BOXPNS bulletin as inputs.

Summary SLR value is quantity-weighted.
Station SLRs < 8 are not reported b/c of probable contamination from liquid and/or freezing precipitation.

Winter '24 / '25 - Snow Storm #4: The Forecasts!

by TQ @ 5:03 PM

Flatiron Building
NYC (c.1905)

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

Rookie      -
Journey    1
Senior      9
Chief        1
GOVT      1
PWSP      -
TOT       12

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

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

---

Heaviest snowfall (+6") forecast consensus along and to the right of CAR - BGR - CON - BTV - CAR. Lollypop expected at CAR.

---
Teleconnections

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

Friday, February 14, 2025

Winter '24 / '25 - Snow Storm #4: RAW Forecasts

by TQ @ 10:38 PM

Click on 'Read more >>' to see RAW forecasts.

NWS ER WFO forecasts to follow

---

Winter '24 / '25 - Snow Storm #4: Call for Forecasts!

by TQ @ 6:44 PM

Beacon St.
Boston ... MA (FEB-1901)

Another in a series of mid-latitude cyclones predicted to deepen as it translates east from the lee of the Rockies toward and through the St. Lawrence River valley this weekend. Contest-worthy snows expected across northern stations of the forecast area.

- Enter your forecast from 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 PM ET FRI ... 14-FEB-25
Verification period BEGINS: 12:01 AM ET SAT ... 15-FEB-25
Verification period ENDS: 11:59 PM ET the day snow stops accumulating

The forecasting contest for Snow Storm #4 may be cancelled prior to the deadline if at least 6
to 8 stations are unlikely to observe at least 4" of storm-total snowfall.

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

Winter '24 / '25 - 26th Annual 'Regular Season' Snowfall Forecast Contest: Interim Standings #1

by TQ @ 6:57 PM

DC
20-MAR-1924

After 3 contest-worthy snow storms ... under the ‘two-thirds’ rule … forecasters who have entered at least 2 forecasts are included in Interim Standings #1.

Complete interim statistics tables and a chart at the Contest/s web site (direct link)
Forecaster statistics for Winter '24 / '25 contest snow storms (direct link)

---
SUMSQ errors for each Contest snow storm are normalized / standardized) by computing a 'Z-score' ... then averaged ... and ranked 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.

Tuesday, February 11, 2025

Winter '24 / '25 - Snow Storm #3: FINAL Results and Storm Summary

by TQ @ 4:05 PM

14.3"
DC (07-FEB-36)

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

SUMSQ: sum of square errors (")
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 4 Forecasts

Forecast/s dotted BLUE line below (above) the Observed snowfall/s solid RED line ==> under (over) forecast error.

R^2: how well the forecast model 'explained' the variability of the observed snowfall (i.e., an R^2 of 0.710 means the forecast model explained 71% of the observed snowfall's variability).

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

---
Forecast Skill Score (measured against NWS ER WFOs)

- Positive (negative) SKILL values indicate the degree of a forecast/s improvement (degradation)
compared to NWS forecasts.
Bias: the arithmetic difference between the average Forecast snowfall and the average Observed snowfall (avgForecast - avgObserved).

Monday, February 10, 2025

Winter '24 / '25 - Snow Storm #3: Preliminary STP Verifications

by TQ @ 4:46 PM

Knickerbocker storm
DC (28-JAN-1922)

Preliminary verification of storm-total snowfalls for FRI and SAT based on reporting from CDUS41 (CLI) ...CXUS51 (CF6) ... METARs ... and PNS bulletins issued by NWS.

Good coverage and reporting.

---
HYA
STP derived from inverse distance-weighting technique using vicinity STP reports from Barnstable county carried in the BOXPNS bulletin as inputs.

Summary SLR value is quantity-weighted.
Stations with SLR < 8 are not reported b/c of probable contamination from liquid and/or freezing precipitation.

---
Stations observing >= Trace: 25 (93%)
Stations observing > Trace: 18 (67%)

Given a station had measurable snowfall; stations observing at least:
4" - 10 (37%)
6" - 1 (4%)
8" - 1 (4%)
10" - 1 (4%)

MAX snow melt-water (minimum SLR 8:1)
BDR - 0.58'
ORH - 0.51"
PVD - 0.46"

MAX precipitation (frozen + freezing + liquid)
JFK - 0.72"
JFK - 0.69"
EWR - 0.64"

---
New daily snowfall record(s)
None

---
Daily snowfall data table

ORANGE: new daily record
GREY: STP derived from PNS or METARs or inverse distance weighting

Trace amounts (displayed as 0.05") are not included in STP or SLR calculations.

---
Areal distribution of storm-total snowfall

Image courtesy NOHRSC
https://www.nohrsc.noaa.gov/

---
SFC analysis: 06z ... 09-FEB-25

Image courtesy DOC / NOAA / NWS / NCEP / WPC
https://www.wpc.ncep.noaa.gov/html/avnsfc.shtml

---
Please report any errors in Comments along with a link to the correct data.
FINAL results expected NLT TUE evening on or about 9 PM ET.

Sunday, February 09, 2025

Winter '24 / '25 - Snow Storm #4: Call for Forecasts!

by TQ @ 7:45 PM

Dutch Reformed / Bay Ridge Church
2nd Ave Ridge Blvd 80th St
Brooklyn ... NYC (c.1900)

UPDATE: 1:30 PM ET MON ... 10-FEB-25

THIS 'CALL FOR FORECASTS' FOR SNOW STORM #4 HAS BEEN CANCELLED.

TOO FEW STATIONS IN PLAY FOR A CONTEST-WORTHY SNOW STORM.

Contest Status

by TQ @ 1:14 PM

PHL - Broad and Chestnut
early 1930s

Winter '24 / '25
NE.Wx Snowfall Forecast Contests

26th Annual 'Snow Storm' Snowfall Forecast Contest

UPDATE: 8:15 PM ET - TUE ... 18-FEB-25

Snow Storm #5
Synoptiscope in VCP32

Snow Storm #4: 15-FEB-25

FINAL Results and Storm Summary here

Snow Storm #3: 08-FEB-25

FINAL Results and Storm Summary here

Snow Storm #2: 19-JAN-25

FINAL Results and Storm Summary here

Snow Storm #1: 05-JAN-25
FINAL Results and Storm Summary here

---

Deadline for entries: 10 PM ET. Typically ~24 hours before the leading edge of a contest-worthy snow storm is predicted to enter the forecast area.

Enter your forecast here.

---

24th Annual 'Season-total' Snowfall Forecast Contest

UPDATE: 4:30 PM ET - FRI ... 14-MAR-25

Deadline for entries has passed.
Details and Forecasts here

Monthly snowfall totals

DEC here

JAN here
FEB here

MAR here

---

Winter '23 / '24 - Snowfall Forecast Contests

25th Annual 'Snow Storm' Snowfall Forecast Contest

FINAL results here

23rd Annual 'Season-total' Snowfall Forecast Contest
FINAL results here

Saturday, February 08, 2025

Winter '24 / '25 - Snow Storm #3: The Forecasts!

by TQ @ 2:07 PM

4th Ave
NYC (c.1908)

Everyone/s station-by-station forecast on the Contest/s web site. NOTE: Some forecasts for 'Trace' (0.05) display as 0.1 but are recorded in the database as 0.05.

Direct link to the forecast table.

---
Rookie      -
Intern         -
Journey      1
Senior      14
Chief           1
GOVT        1
PWSP         -
TOT         17

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

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

---

Heaviest snowfall (+6") forecast consensus along and to the right of BOS - PVD - BDL - ALB - ORH - BOS. Lollypop expected at ORH.

---
Teleconnections

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

Winter '24 / '25 - Snow Storm #3: RAW Forecasts

by TQ @ 9:30 AM

Click on 'Read more >>' to see RAW forecasts.

Winter '24 / '25 - Snow Storm #3: Call for Forecasts!

by TQ @ 1:31 PM

Grand Army Plaza
Brooklyn ... NY (FEB-1929)

LOW pressure coming ashore over northern CA on THU predicted to re-organize in the lee of the Rockies on FRI then enter the forecast area as a contest-worthy storm SAT PM.

- Enter your forecast from 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 PM ET FRI ... 07-FEB-25
Verification period BEGINS: 12:01 AM ET SAT ... 08-FEB-25
Verification period ENDS: 11:59 PM ET the day snow stops accumulating

The forecasting contest for Snow Storm #3 may be cancelled prior to the deadline if at least 6
to 8 stations are unlikely to observe at least 4" of storm-total snowfall.

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

Winter '24 / '25 - Snow Storm #2: FINAL Results and Storm Summary

by TQ @ 3:29 PM

BWI - Mount Vernon Place (1938)

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 4 Forecasts

Forecast/s dotted blue line below (above) the Observed snowfall/s solid red line ==> under (over) forecast error.

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

---
Forecaster Skill Score (measured against NWS ER WFOs)

- Positive (negative) skill values indicate the degree of a forecast/s improvement (degradation) compared to NWS forecasts.
- Bias: the arithmetic difference between the average Forecast snowfall and the average Observed snowfall (avgForecast - avgObserved).

Tuesday, January 21, 2025

Winter '24 / '25 - Snow Storm #2: Preliminary STP Verifications

by TQ @ 7:23 PM

NYC - West Broadway at Spring Street
(1983)

Preliminary verification of storm-total snowfalls for SUN and MON based on reporting from CDUS41 (CLI) ... CXUS51 (CF6) ... METARs ... and PNS bulletins issued by NWS.

Good coverage for station snowfalls but spotty/questionable reporting of melt water.

---
Missing/questionable melt-water values precludes accurate SLR calculations for some stations

HYA
STP derived from inverse distanced-weighted scheme based on vicinity reports from PNSBOX.

---

Summary SLR value is quantity-weighted.
Stations with SLR < 8 are not reported b/c of contamination from liquid or freezing precipitation.

Winter '24 / '25 - Snow Storm #2: The Forecasts!

by TQ @ 7:57 PM

DC
N St ... NW (2007)

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

Rookie     -
Intern       -
Journey   -
Senior      14
Chief      1
GOVT    1
PWSP    1
TOT       17

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

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

---

Heaviest snowfall (+6") consensus along and to the right of BGR - PWM - ORH - BDL - CON - BGR. Lollypop expected at BGR.

---
Teleconnections

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

Saturday, January 18, 2025

Winter '24 / '25 - Snow Storm #2: RAW Forecasts

by TQ @ 10:15 PM

Click through on the 'Read more >>' link to see the forecasts.

Winter '24 / '25 - Snow Storm #2: Call for Forecasts!

by TQ @ 4:41 PM

NYC
27-JAN-1937

On SUN ... surface LOW pressure predicted to undergo explosive development -- deepening ~25 mb in 24 hours -- as it moves early in the period from western NC toward the NE along the eastern seaboard then on to the CN maritime provinces by the wee hours of MON morning.

Contest-worthy storm-total snowfalls expected mainly over the northern two-thirds of the forecast area.

- Enter your forecast from 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 PM ET SAT ... 18-JAN-25
Verification period BEGINS: 12:01 AM ET SUN ... 19-JAN-25
Verification period ENDS: 11:59 PM ET the day snow stops accumulating

The forecasting contest for Snow Storm #2 may be cancelled prior to the deadline if at least 6
to 8 stations are unlikely to observe 4" or more storm-total snowfall.

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

Winter '24 / '25 - Snow Storm #1: FINAL Results and Storm Summary

by TQ @ 7:17 PM

NYC
26-DEC-47

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

Forecast/s dotted BLUE line below (above) the Observed snowfall/s solid RED line ==> under (over) forecast bias.

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

---
Forecaster Skill Score (measured against NWS ER WFOs)

- Positive skill values indicate the degree of a forecast/s improvement over NWS forecasts.
- Bias: the arithmetic difference between the average Forecast snowfall and the average Observed snowfall (avgForecast - avgObserved).

Tuesday, January 07, 2025

Winter '24 / '25 - Snow Storm #1: Preliminary STP Verification

by TQ @ 7:41 PM

Smithstonian - 1920s

Preliminary verification of storm-total snowfalls for SUN and MON based on reporting from CDUS41 (CLI) ... CXUS51 (CF6) ... METARs ... and PNS bulletins issued by NWS.

Good coverage and reporting.

Exceptions
SBY
NWS Climatological Report (Daily - CLI) carried 'MM' for SAT snowfall-total and 0.53" liquid.

NWS WFO Monthly/Daily Climate Data (CF6) carried 8.5" and 'M' for liquid.

STP derived by an inverse distance weighting scheme with AKQ and PHI vicinity reports carried in their PNS bulletins for Sussex county ... DE and Worcester and Wicomico counties in MD came to 8.5".

---