Contest # 2 - Early Obs

The heavy snowfall over IAD / DCA / BWI earlier today was missed by all forecasters. PNS from LWX reported 2.9" at DCA with IAD and BWI each picking up 4.5". SN:H2O about 8:1 in the DC area...~10:1 at BWI.

Forecast soundings had depicted a relatively deep layer from ~1500 to 3500' AGL where the temperature was right at 0°C. 85H WAA ordinarily would have pushed the temperature trace to above freezing causing the snow to melt. Add to that the SE SFC wind with temperature at or slightly above 32°F should have spelled doom for snowfall...as well.

Strong UVM associated with the passage of the diffluent mid-level trof could have been reponsible for the dynamic cooling that keep the precipitation frozen all the way to the ground.

Contest # 2 - The Forecasts

Forecasters: 12
New: 3
Veterans: 9

Always good to see new forecasters along with the old hands. Good luck to all.


The consensus heavy snow axis runs from MDT - BGM - ISP - EWR - MDT with a max of 6" at ABE.

All individual forecasts have been posted to the NEWxSFC web site. Follow the link to 'Latest Forecasts.' The forecasts are ranked from minimum to maximum storm total snowfall (STP) for all stations.

Minimum STP: 22.45" - Donald Rosenfeld
Maximum STP: 116" - edhoffman503
Average STP: 58.95"
Median STP: 52.75"
10th percentile: 43.1"
90th percentile: 86.1"

Verification snowfall amounts will be posted Tuesday evening. They are considered preliminary and subject to change / challenge for 24 hours.

Contest # 2 - Call for Forecasts

The flat wave under-cutting the long wave ridge along 80W is expected to gin-up fair to good snowfalls across the northern M-A and SNE this weekend. Since beggars can/t be choosers this winter…this storm/s on deck for Contest #2.

Entry Deadline: Saturday, 24 February 2007 @ 10:30 PM EST.

Verification begins 12:01 AM EST Sunday, 25 February 2007 and ends 11:59 PM EST Tuesday, 27 February 2007.

Your forecast must be entered via the Contest/s web site. Follow the link to ‘Enter Storm Forecast.’

Forecasters will need to register once before entering, even if they were registered last year. Registration is simple, requiring only a user name and password. If you provide a valid e-mail address, a copy of your forecast will be sent to you immediately after your entry is submitted. Please ensure your browser is enabled to accept first-party cookies.

All forecasts will be posted to the NE_Wx Google Group by the Contest Administrator before 11 PM EST Saturday, February 24, 2007 and to the Contest/s web site by Sunday evening.

Contest updates are posted on the Contest/s web log.

The NE.Wx Snowfall Forecast Contest (NEWxSFC) is a multi-month event that continues into late March or early April. In general, contests are held whenever a decent, synoptic-scale storm rears its head and threatens at least a half-dozen forecast stations with more than nuisance snowfall amounts. Forecasters are called to post their 'storm total' snowfall predictions, on deadline, for 27 NWS / FAA observing stations scattered about New England and the Mid-Atlantic regions.

You can find the Contest Rules and additional information about Error Scoring, current monthly snowfall climatology from NCDC, daily CPC teleconnection indices, daily NESDIS N-Hemi snow cover, and NWS Daily Climate Bulletins (CDUS41) by simply pointing your browser @ NEWxSFC

March of Winter/s End

Meteorological winter...defined as the three coldest months (DJF)...comes to a close in a few days but winter wx can and does continue throughout March over much of New England.

The latest monthly temperature outlook from the Climate Prediction Center (CPC) indicates above normal mean temperatures over the western quarter of the CONUS. The warm anomaly suggests the expected position of the mean long wave ridge axis.

If there/s a ridge in the west...then it follows there/ll be a trof in the east...which is good news for squeezing another storm or two out of this otherwise disappointing winter.

Coastal Teaser #5

MR progs depict active southern stream next week and the possibility for a coastal storm passing near the 40°N / 70°W 'benchmark.' Storms passing over the 'benchmark' generally produce respectable snows over SNE.

Latest GooFuS point forecasts suggest low levels would be cold enough to support frozen precipitation over interior portions of the M-A and NE.


Click image to animate loop.

Big Changes @ High Latitudes

The ECMWF/s 12z forecast from Friday shows an atmosphere quite different than the one observed all winter. The deep layer flow near the pole for much of the winter has been westerly except for the past few weeks when the weather turned bitterly cold in the E.


The ECMWF progs show a troposphere and stratosphere bathed in easterlies and the stratosphere warmed 20°C by February 24.

A warm stratosphere comes about when the troposphere is cold (lower heights in the troposphere means lower and therefore warmer heights in the stratosphere).


Deep easterlies mean the pole is dominated by HIGH pressure. Easterlies weaken the polar vortex (PV) or shift its position and leads to an increase in general storminess in the mid-latitudes.

Broad HIGH pressure at the poles is observed during the negative phases of the Northern Atlantic (NAO) and Arctic oscillations (AO). The negative phase favors arctic outbreaks in the E CONUS.

Taken together...deep easterlies...-AO...and -NAO suggest a good potential for additional winter wx along the EC toward the end of the month.

Click on cross-section images to animate.

Contest # 1 - Final Results

Full verification table and summary @ the Contest web site. Follow the links to 'Latest Forecasts' and 'Latest Results.' Finally...a contest snowstorm! Never in the eight-year history of the NE.Wx Snowfall Forecast Contest has the first storm formed so late in the season. In every other year...the first storm appeared no later than the end of December.

This storm was worth the wait. Ever changing progs in the medium range carried into the short-range period making this a difficult forecast. Loaded with sub-tropical moisture...a frisky short wave...and deep enough arctic air...record daily snowfall were observed across portions of central NY and VT. Arctic air lost out closer to the coast where strong maritime influences kept snowfall to a minimum.

1st Place - TQ
SUMSQ Error: 197.1”
SUMSQ - Z: -0.460
STP: 156.6” (4th)
TAE: 52” (2nd)
AAE: 2.08” (1st)

2nd Place - bruced
SUMSQ Error: 216.1”
SUMSQ - Z: -0.450
STP: 165.5” (6th)
TAE: 54.4” (3rd)
AAE: 2.27” (3rd)

3rd Place - donaldsutherland1
SUMSQ Error: 226.6”
SUMSQ - Z: -0.445
STP: 150.25” (1st)
TAE: 54.5” (4th)
AAE: 2.37” (4th)

Honorable Mention - noreasterjer07
SUMSQ Error: 253.5” (4th)
SUMSQ - Z: -0.427
STP: 188” (13th)
TAE: 49.1” (1st)
AAE: 2.23” (2nd)

SUMSQ: sum of square errors
STP: storm total precipitation
TAE: total absolute error
AAE: average absolute error

Contest # 1 - Verification

(Update 1) (Update 2)



Tracking down snowfall reports needed to verify forecasts sure ain/t what it used to be. The latest F6 and CDUS41 reports are now readily available through IWIN. Hot links take you directly to the latest bulletin.

Nothing like it used to be.

Many stations filed their final snowfall reports with yesterday/s CDUS41 reports. Additional snowfall reports are expected tonight from stations along the northern tier of the forecast area.

This post will be updated tomorrow morning with preliminary storm-total snowfall reports for the forecast verificaton. Snowfall totals are subject to challenge and may change...where appropriate.

Update 1
Preliminary Snowfall Totals
CAR 14.30
BGR 5.20
PWM 9.90
CON 9.50
BTV 25.70
BOS 2.50
HYA 0.00
ORH 10.30
PVD 0.50
BDR 2.00
BDL 2.40
ALB 16.80
BGM 18.50
ISP 0.50
JFK 1.50
ABE 7.60
MDT 6.00
PHL 4.30
ACY 0.80
EWR 3.40
BWI 2.70
IAD 3.00
DCA 2.20
SBY 0.50
RIC 0.00
ORF 0.00
RDU 0.00
TOT 150.10

Update 2
The preliminary storm-total snowfall amounts will become final on Saturday morning if there are no challenges. Final results will be posted Saturday evening.

Contest # 1 - The Day After

GOES12 1615z Visible - click to enlarge

Contest # 1 - Teleconnections

AO nice and low...NAO about normal - not that there/s anything wrong with that --...and PNA running a little hot.