Snow Storm #8: Preliminary Verification

(updated below - Update2)

Preliminary storm-total snowfalls for Sunday and Monday from CDUS41...PNS...and CF6 bulletins.

Eight new daily records.
SUN...01 MAR 2009
ISP - 3.8" (2.1"; 2005)
ACY - 4.6" (1.7"; 1968)

MON...02 MAR 2009
ORH - 9.3" (7"; 1948)
PVD - 10" (7.1"; 1996)
BDR - 7.6" (4.5"; 2006)
BDL - 7.9" (7.9"; 1948)
ISP - 9.7" (5"; 1996)
PHL - 5.6" (5"; 1914)

CON snowfall was missing from CDUS41 at post time. GYXPNS bulletin carried a storm-total snowfall report of 9" as of 7:28 AM MON...02 MAR 2009 with 'Heavy Snow' in Remarks.

METAR P-group reported 0.17" liquid between 7:32 AM and 12:51 PM...after which light snow continued with no additional accumulations recorded by the tipping bucket. The 9" snowfall reported in the PNS bulletin had a liquid equivalent of 0.67" and a SN:H2O of 13.4:1. An estimated 2.3" of additional snow fell @ CON between 7:32 AM and 12:51 PM.

The 11.3" storm-total snowfall verification value for CON will be revised should WFO GYX get around to reporting the actual amount before the final results are posted.

Please report errors in Remarks.

Final results and storm summary Wednesday evening.

Update
WFO GYX published snowfall data in the F-6 for CON Tuesday afternoon.
3/1: 0.5"
3/2: 11"
STP = 11.5"

Update2
WFO BOX corrected the F-6 bulletin/s MAR 2 daily snowfall report for BOS. The corrected value is 6.9" for a two-day STP of 8.5".

WFO AKQ corrected the F-6 bulletin/s MAR 2 daily snowfall report for RIC. The corrected value is 2" for a two-day STP of 6.3".

Two more stations set new daily snowfall records on MAR 2.
EWR - 5.3" (4.3"; 1996)
BWI - 4.7" (3.7"; 1969)

Snow Storm #8: Aftermath Imagery

Note bay-effect streamer downwind of Delaware Bay/s mouth. Strong 850 mb cold air (9°F) advection over relatively warm (L30s) waters.

Courtesy NASA/s Earth Observatory Image of the Day. Hi-res version here.

Snow Storm #8: Gravity Wave

Tony Wood reporting for the Philadelphia Inquirer...

"Just before midnight Sunday, meteorologists said, a band of rapidly rising air - part of what is known as a "gravity wave" - developed in the upper atmosphere from eastern Virginia into eastern New Jersey. And this was a particularly potent one.

"For the next few hours, it generated heavy snow in South Jersey, with 10.5 inches in Hammonton by daybreak, and powerful wind gusts of 60 m.p.h. in Atlantic City and 59 m.p.h. in Cape May.

"Meanwhile, the wave temporarily would shut off snow to areas to the west, said Louis W. Uccellini, director of the National Center for Environmental Prediction..."

Snow Storm #8: The Forecasts

12 forecasters. 2 rookies and 10 veterans.
Forecasters are ranked in the table above by storm-total precipitation (STP)

Station forecasts here.



A real snow storm this go'round with all stations in play. Looks to be a good... old-fashion...and long overdue...I-95 corridor event from RIC to BGR.



What/s up with that conventional wisdom about -NAO and mid-Atlantic snow storms?



LOW pressure along the SE coast @ 12z...ready to hang a left for a run up the coast on its way toward 40N/70W.

Snow Storm #8: Call for Forecasts

Multi-day event at hand offering early spring snows to mid-Atlantic and coastal New England stations. HPC/s "Heavy Snow / Icing Discussion" indicated poor consensus on the details among the NWP solutions such that this event could go either way.

The forecast contest for Snow Storm #8 may be cancelled if forecasts from the next couple model runs suggest strongly the synoptics are unlikely to produce contest-worthy snows.

Cancellation notices will be posted on the web blog and the Contest/s web site only.

Deadline: 10:30 PM EST SAT...28 FEB 2009

Forecast element: storm-total snowfall
Verification begins: 12:01 AM EST SUN...01 MAR 2009

Enter your forecast here.
Follow the link from 'Enter Storm Forecast.'

Make the best forecast and you/ll win one month of FREE access to StormVista GOLD.
Details here.

More prizes will be awarded at the end of winter for the best over-all forecaster.
Details here.

As always...there/s no cost...or fee...or annoying requests for personal information to enter.

If you are making your first forecast this year 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) before entering a forecast.

Image: Winter on 5th Ave. (NYC) - Alfred Stieglitz (1892)

Sudden Stratospheric Warming - Effect on the Arctic Oscillation

Deep-layer above normal geo-potential heights (GPH) indicated by red shading in the plot area...began during the third week of JAN at the start of the long-duration SSW event.



Image courtesy CPC.

Snow Storm #8: Preview Redux

Today/s 12z NWP solutions in strong agreement with their depiction of cyclogenesis along the SE CONUS coast on SUN.

The image loops today/s 72-hour forecasts from the 12z runs of the ECMWF... UKMET...GFS...and GEM.

The upper LOW isn/t all that cold; however...strong HIGH pressure parked over eastern Canada will be needed to maintain low-level cold air. Synoptics also suggest a threat for freezing rain...especially coastal stations in New England and the mid-Atlantic/s inland stations.

NAM time-height x-sections suggest ~9 stations could be in play...more than enough to get #8 finally off the ground. After a healthy pace during the first two months of winter...FEB has turned out to be a big disappointment. Not a single contest-worthy storm. Snowfall climatology favors FEB as prime-time for most mid-Atlantic stations.

Should this scenario still seem likley tomorrow...a call for forecasts will come Friday evening with an entry deadline several hours earlier than usual Saturday evening so as to include snowfall in Pennsylvania.

Alps-like Mountain Range Under E. Antarctic Ice Sheet

"...the mountains the size of the European Alps but they also have similar peaks and valleys”... “...this adds even more mystery about how the vast East Antarctic Ice Sheet formed.”

"...“if the ice sheet grew slowly then we would expect to see the mountains eroded into a plateau shape. But the presence of peaks and valleys could suggest that the ice sheet formed quickly-we just don’t know. Our big challenge now is to dive into the data to get a better understanding of what happened” millions of years ago."

Full report here.

Cosgrove the Examiner

Blogging as Houston/s Weather Examiner.

Oriented toward KIAH / KHOU / KEFD / KGLS weather. Same detailed analysis...graphics..and imagery as his weekly newsletter (which is posted...too).

PDO - JAN '09

-1.40
17 continuous months below zero.



"The Pacific Decadal Oscillation (PDO) Index is defined as the leading principal component of North Pacific monthly sea surface temperature variability (poleward of 20N for the 1900-93 period)."

Image courtesy Joint Institute for the Study of the Atmosphere and Ocean

Cooler PAC favors more la Ninas and weaker el Ninos.