Saturday, February 25, 2012

Weather History: How To Go From 8 To Near 80 In Ten Days

In the near 130 years of daily weather records in Philly, we've only busted the 70 degree mark 17 times in February, not having reached that mark since 2002.  It's a tough mark to crack in the cold season.    A majority of those 17 (11) have occurred in the last eight days of the month, including our warmest day in February record...and our closest approach to 80 in Philadelphia during February.

February 25th, 1930 is our warmest February day on record at 79 degrees.  It was part of a stretch of six days where Philly hit 70 three times, including 70 and 72 on the 20th and 21st...and a stretch of eight days where the high was 60 or warmer.  A legitimate spring fling of torch proportions.  The root cause was a high pressure center in the Atlantic and a storm system that rode up through the Midwest and Great Lakes.  The high was strong for February -- wouldn't even call it a wintertime "Southeast Ridge" because it was bringing near summer-time warmth northeastward -- and came on the heels of a sharp cold snap that I'll touch on in a moment.  A "weak" backdoor front on the 22nd nudged highs back into the 60's for a couple of days before the warmest of the stretch kicked in on the 25th.  

It helps the morning low that day was just 54, tying for the warmest low on record in Philadelphia in February as well.

Highs on the 25th were 30 to 35 degrees above average for this time of the year, depending on location.  While nobody locally cracked 80 degrees, Washington and Baltimore did...both reaching 84 and 83, respectively.   70's occurred as far north as New York City, 60's up to Boston.  All of those locations above set daily records and in the case of Philly, Baltimore, and Washington -- all set monthly records and records for the warmest so early in the season.

While the vast majority of us weren't around for this warm spell 82 years ago, the cold mongers among us would take solace in knowing that the high in Philadelphia six days after that all-time February record was just 30 degrees and the highs on February 16th and 17th, 1930 (right before the warm stretch started) were 22 and 28 degrees, respectively with a low of 8 on the 16th.    Putting all this together -- temperatures went from 8 to 79 in a span of nine days.  One could argue that this is the ultimate temperature roller coaster.

Sometimes February, not April, can be the cruelest month to those who like temperature constancy but it does show that extremes sometimes happen in very close proximity to each other.