Wednesday, May 31, 2006

Climate: Summer 2006 Temperature Analogs

This is from the National Weather Service in Philadelphia


IN SPITE OF A COOL START TO MAY, MAY 2006 WILL BE WARMER THAN NORMAL IN PHILADELPHIA.
GOING BACK TO 1872, THERE WERE 17 INSTANCES IN WHICH BOTH APRIL AND MAY WERE WARMER
THAN THE LONG TERM NORMAL (IN THE UPPER THIRD OF ALL APRILS AND MAYS). BELOW ARE WHAT
OCCURRED IN PHILADELPHIA DURING THE ENSUING SUMMERS. WE DID CROSS REFERENCE ENSO
STATES AND REMOVED THE TWO THAT WERE TRENDING TOWARD LA NINA CONDITIONS DURING THE
SUMMER. THE CURRENT ENSO STATE IS NEUTRAL. THE SUB SURFACE WATER IS WARMER THAN
NORMAL THROUGHOUT MOST OF THE TROPICAL PACIFIC. WE ARE NOT ENSO EXPERTS, BUT THIS
SHOULD PRECLUDE A LA NINA FROM RE-EMERGING. THE FIFTEEN REMAINING ANALOG YEARS ARE
BELOW. IN THE FOR WHAT ITS WORTH DEPARTMENT 1933 HAS MIRRORED 2006 WITH RESPECT TO
TEMPERATURES CLOSER THAN ANY OF THE OTHER ANALOG YEARS SO FAR. IT ALSO WAS A VERY
ACTIVE HURRICANE SEASON.



YEAR.... JUNE AVG..JULY AVG..AUGUST AVG...SUMMER AVG...SUMMER PCPN

1896......70.4.......77.6.......76.6.......74.9........7.80
1922......73.6.......75.5.......73.0.......74.0........9.54
1933......74.4.......76.6.......76.0.......75.7.......19.32
1941......71.6.......76.1.......73.1.......73.6.......15.62
1942......72.5.......77.2.......73.1.......74.3.......15.86
1959......72.2.......75.9.......76.5.......74.9.......16.49
1965......73.4.......75.1.......75.2.......74.6.......10.12
1977......68.6.......77.8.......76.2.......74.2.......15.50
1980......70.6.......78.5.......80.0.......76.4........9.11
1985......68.8.......75.4.......74.1.......72.8........9.36
1991......75.7.......79.0.......79.0.......77.9.......12.01
1993......74.4.......81.4.......78.9.......78.2........8.68
1995......74.3.......81.5.......79.9.......78.6........4.69
2001......75.2.......75.4.......79.9.......76.8........8.20
2004......71.8.......76.3.......75.0.......74.4.......16.65


AVG.......72.5.......77.3.......76.4.......75.4.......11.93
NML.......72.3.......77.6.......76.3.......75.4.......11.50


Additional reading: How the first heat wave compares to summer temperature averages, based on El Nino/La Nina conditions (pdf)

What does the above mean? Simply put, based on the years that have a similiar conditions regarding El Nino/La Nina and temperatures, the type of summer we will have may end up being close to average. While some of these types of summers, such as 1993 and 1995, were scorchers for Philadelphia, 1933 was pretty close to normal outside of a hot June (which is something that some meteorologists are forecasting).