Updraft: December 31, 2012 Archive

2012 Duluth Flood goes national; Why European model saw Sandy's path first

Posted at 4:55 PM on December 31, 2012 by Paul Huttner (7 Comments)
Filed under: Hurricanes

2012 Duluth Flood to be featured as one of the nation's top weather events at next week's national 2013 AMS Annual Meeting

Why did European Model (ECMWF) see Hurricane Sandy's path a full 3 days before USA models?

Sub zero start to the New Year 2013

10" ice thickness near shore in Excelsior Bay on Lake Minnetonka

Variable ice thickness as little as 5 to 6" in many lakes in southern Minnesota - still unsafe for cars & snowmobiles on many lakes

Top 5 weather stories of 2012

2012 ties for warmest year on record in Minnesota?

"January Thaw" in sight for next week - a shot at 40F+?

Image: Twin Cities NWS

Happy "Arctic" New Year!

2013 plays an arctic note to open the New Year.

Our 1st sub zero morning since February 21st (-5F) greets "Polar Plungers" in Excelsior and other other locations on New Year's Day.

I checked with organizers of the North American Pond Hockey Championships about ice thickness in Excelsior Bay Sunday. Steve Youngstedt tells me there is a good 10" of ice now.

By the end of this week's penetrating arctic cold that should increase to a good 12" to 14" in Excelsior Bay and smaller bays and ponds.

Keep in mind that the "main lake" and other southern Minnesota lakes have considerably less ice...and may not yet be safe for cars or snowmobiles in all areas. Ice is always thin near channels and points where water is flowing just underneath "dangerously" thin ice.

Image: MN DNR

The arctic chill eases Wednesday, and some light snow is possible as slightly milder air pushes in. Snowfall Wednesday should be under an inch in most areas.

Temps will recover into the 20s later this week, as we return to more "seasonable" cold levels.

Image NOAA/CPC

An early "January Thaw" in 2013?

The conventional wisdom usually includes a possible January Thaw along about the 3rd or 4th week of January. Our weather patterns have been anything but "conventional" the past few years.

All signs point to an early thaw in 2013. Both the European and GFS models shove a surge of milder Pacific air north into Minnesota by Friday...and then kick the thaw into high gear starting on Sunday. By next week temps could push into the 40s in southern Minnesota.

Image: Euro model from Norwegain Met Institute

38F on Sunday (GFS) and 41F+ next Wednesday? Don't rule it out.

Now where did I stash that bottle of windshield washer fluid?

2012: Tie for warmest year on record in Minnesota?

One of (if not the?) the biggest weather stories of 2012 has to be the record persistent warmth.

Now the Minnesota Climate Working Group estimates that 2012 will tie with 1931 as the warmest year on record for the Twin Cities.

Warm Year: 2012

2012 will finish in a tie with 1931 as the warmest year on record in the Twin Cities and will range from the warmest to third warmest on record depending on the location around the region.

For so long, it appeared like 2012 would be the warmest year on record for the Twin Cities, but then winter decided to arrive as if on cue on December 21 and since then temperatures have been mostly below normal. As a result, the average temperature for the Twin Cities for 2012 will wind up to be 50.8 degrees, the same as the 50.8 degrees recorded in 1931. The 1981-2010 average temperature for the year is 46.3 degrees so 2012 will finish 4.5 degrees above normal. Every month of 2012 was above normal except October which finished 1.4 degrees below normal. March 2012 was 15.5 degrees above normal and greatly assisted in lifting the average temperature for 2012.

The hottest day of 2012 in the Twin Cities was 102 degrees on July 6 and the coldest temperature of the year was -11 on January 19.

Twin Cities (1873-2012)

Rank Year Average
-----------------
1. 1931 50.8
2012 50.8 (tie with temperature estimate for December)
3. 1987 49.7
4. 2006 49.3
5. 1998 48.8

(1981-2010 normal: 46.3)

Hey 2013: 2012 called and says you better step it up if you want to get noticed.

2012 Duluth Flood gets a nod at 2013 Annual AMS Meeting

My partner in weather crime Craig Edwards highlighted the MN Climate Working Groups list of "Top 5" weather events in Minnesota published last week.

The Duluth Flood of 2012 is #2 on the list, but will be featured as one of the nation's highlighted weather events of 2012 during the 2013 AMS Annual Meeting "IMPACTS 2012" session next week.

I was asked by Climate Central's Andrew Freedman to speak about the "Great Duluth Flood of 2012" for the conference next week.

I will be reporting live for All Things Considered with Tom Crann from the 2013 AMS event in Austin, Texas next week.

Other major weather events of 2012 to be featured include:

-Hurricane Sandy with presentations and Town Hall Meeting from The Weather Channel's Bryan Norcross and Capital Weather Gang's Jason Samenow.

-The June 2012 Chicago to Washington D.C. Derecheo

-Impacts of the Record Arctic Sea Ice Minimum of 2012

-Weather Impacts on the June 2012 Colorado Waldo Canyon Fire Disaster

-Heat Waves & drought in the US during 2012

This is going to be a great week with some of the nation's top meteorology talent in the house. The Duluth Flood of 2012 is on the docket, and I'm looking forward to soaking up and reporting on the buzz from Austin next week.

Image: NASA Earth Observtory

Why the European model saw Hurricane Sandy first:

I first started working with the European (ECMWF) model in 1994 with Tom Skilling when I was the debut meteorologist with The WGN Morning News at WGN TV in Chicago. Tom had some unique ways to analyze the data, and you could see even back then that the ECMWF was a superior product.

The Euro is often the best model we have, which is why you see it used in this space often.

If you followed our coverage leading up to Hurricane Sandy, you know that I talked about growing concerns for the European Model's forecast path for Sandy into the Jersey shore as nearly a week in advance.

It turns out the "Euro" was right on the money from the start, and the other models including the NOAA's GFS played catch up all week.

Image: NOAA

Why did the Euro nail Sandy's path a full 2-4 days before the U.S. Models?

Better model physics and "initialization" and significantly more supercomputing power.

Scott K. Johnson from ars technica elaborates.

Seven days before Sandy made landfall in New Jersey, the atmospheric crystal ball was partly cloudy. The US National Weather Service forecast model showed a chance that Sandy might come ashore, but indicated that it was more likely the storm would spin off into the Atlantic. The European Centre for Medium-Range Weather Forecasts (ECMWF) model, however, definitely pointed the storm ashore. It would be about three days before the US model totally converged on the Europeans' forecast.

Forecast models require some serious computational horsepower, which can only be supplied by supercomputers. The ECMWF, for example, utilizes an IBM system capable of over 600 teraflops that ranks among the most powerful in the world, and it's used specifically for medium-range models That, fundamentally, is the reason their model frequently outperforms the American one. The US National Weather Service's modeling center runs a diversity of short-, medium-, and long-term models, all on a much smaller supercomputer. The National Weather Service has to do more with less.

This computational bottleneck limits the US model in two key ways. First, it runs at a coarser spatial resolution (about 25 kilometers, as opposed to 15 in the ECMWF model). Anything in the atmosphere that takes place at a smaller scale has to be approximated. In general, finer resolution models can directly simulate more processes, especially once you reach the scale of an individual storm cell.

Second, the way in which measurements are fed into the models differs. The US model takes "snapshots" of data, builds a global picture (the initial conditions), and then begins the forecast simulation. The ECMWF model, on the other hand, takes continuous observations spanning half a day, runs the model with that real data, and then sets it loose on the future. While computationally expensive, this can result in more realistic initial conditions, and is part of the reason why the ECMWF model is usually reliable a couple days further into the future then the US model.

Now you know whay the inside joke in the weather biz is that NOAA's GFS model has earned the... "Good For Speculation" tag.

The bottom line here? NOAA needs a serious shot in the arm to invest in supercomputers that can match or exceed the ECMWF capability.

Want to keep cutting budgets for NOAA?

We may want to rethink critical funding for upgraded NOAA supercomputers if we want the capability to see a devastating hurricane heading our way...days sooner than we can today. What is an extra 3 days of preparation, evacuation and staging emergency infrastructure worth before the next 100 billion dollar weather disaster?

PH

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