Tuesday, March 20, 2012

Incredibly Warm Weather in the Eastern U.S.

Yes, any place in the eastern continental U.S. will have an unseasonably warm day or two during the cold seasons, but not the entire eastern half at once and not more than a day or two.  What is happening now is unprecedented in over a century of record keeping:
First, consider the sheer number of daily record highs either tied or broken over the past 7-10 days. The counts below are courtesy of the National Climatic Data Center. This speaks to the widespread nature and longevity of this warm spell. The records from March 16 to March 19 have not been fully compiled at this time and will be added when they become available.

Day # of Records
Fri. Mar. 9 101
Sat. Mar. 10 105
Sun. Mar. 11 189
Mon. Mar. 12 138
Tue. Mar. 13 218
Wed. Mar. 14 457
Thu. Mar. 15 593

In a typical March, particularly in the nation's northern tier, you may see, perhaps, one or perhaps two days of record warmth before a sharp cold front bring that spring tease to a screeching halt. Not so in March 2012. 

Through March 19, International Falls, Minn., self-promoted as the "Icebox of the Nation", has set daily record highs 9 of the past 10 days! This includes Sunday's 79 degree high, which is the warmest day ever recorded during March in International Falls.
Jeff Masters at Weather Underground notes:
International Falls, Minnesota hit 78°F yesterday, 42° above average, and the 2nd hottest March temperature on record in the Nation's Icebox. The record of 79°F was set the previous day. Remarkably, the low temperature for International Falls bottomed out at 60°F yesterday, tying the previous record high for the date. I've never seen a station with a century-long data record have its low temperature for the date match the previous record high for the date. Yesterday was the seventh consecutive day that International Falls broke or tied a daily record. That is spectacularly hard to do for a station with a century-long weather record. The longest string of consecutive records being broken I'm aware of is nine days in a row, set June 2 - 10, 1911 in Tulsa, Oklahoma (with weather records going back to 1905.) International Falls has a good chance of surpassing nine consecutive records this week. (emphasis added)
Now this all is related to an extreme configuration of the jetstream brought on by an atypically strong La Nina and a strong positive phase of the North Atlantic Oscillation (which immediately followed a strong negative NAO that gave us excessively snowy winters in SE PA in in 2010 and 2011). But those are simply the proximate causes. Any large amplitude swings in oscillators in a complex require additional energy to be added or kept in the system.

I've only been in the SE Penn Piedmont region since '05, but I've noted an instability in the weather patterns since '08.  True that is only a unrepresentative anecdotal sample, but it jibes with the wild swings in weather and departure from normals that is well documented. This year we have forsythias blooming on St. Patrick's day, two years ago  the fireflies were out weeks earlier than usual.

But no, all of the above can't have anything to do with the data presented below, can it?

 131 years of global warming  in 26 seconds, NASA/Goddard Institute for Space Studies

No comments: