Stuck In The Seventies

Other than a few showers on Saturday afternoon and evening, the last several days have been almost identical to each other.  It's been a relative rarity this year to cobble together three or four nice days in a row but since Sunday we have been able to do just that thanks to a blocking pattern out in the Atlantic, which helps keep us in the "nice" pattern on the dry side of the upper level low in the Atlantic.   Knowing that we have not always been the beneficiaries of such nice weather in May before as upper lows have been cruelly parked overhead, this stretch of nice weather has been beneficial for farmers who have been able to work their fields, beneficial for outdoor enthusiasts who have been tired of being cooped up indoors, and beneficial for pollen producing trees and flowers as allergy levels have been miserably high.

Daily high temperatures have changed little over the past five days, with only Allentown's 69 degree high on Saturday the one exception from a "stuck in the seventies" pattern that the region has seen.   High temperatures have varied little of late, a rare exception to a Spring that would feature 30 and 35 degree temperature swings from one day to the next as warm fronts would bring a tease of warmth and cold fronts would slap March back in our face -- all in the course of 18-30 hours in several instances this year.   These temperatures are generally where we should be at this time of the year -- Philadelphia has been one or two degrees above average each day since Saturday while Allentown has averaged exactly to "normal" each day.

In May, being average is not a bad place to be!

Philly Rides The Coaster

It wouldn't be April in Philadelphia without having temperature forecasting headaches -- and hangovers -- from the afterglow of an 80 degree day in the city.   Temperatures have been on an impressive roller coaster ride -- jumping 25 degrees from Tuesday to Wednesday in Philadelphia, only to see the "official" daytime high drop another 15 degrees from yesterday to 1 AM this morning in Philadelphia.   Philly has been the home to impressive swings in temperature as of late -- we've shown larger bounces just a week ago.   However, unlike last week this week's bounces were really the most significant in Philadelphia.

Allentown and Reading had smaller, less impressive, hikes in temperature between Tuesday and Wednesday -- Reading bouncing up 21 degrees, Allentown just 16 as cooler air held much later in the afternoon in the Lehigh Valley and Berks and prevented larger temperature climbs from taking place.   Likewise, Millville climbed 14 degrees between Tuesday and Wednesday as they were able to avoid showers for a longer period of time on Tuesday and were in the warm sector for a while before winds nudged off of the Atlantic and cooled them off.

If anything, this pattern shows how fickle frontal boundaries can be at this time in the year as winter chill gasps for its last signs of life and the strengthening of the Southeast ridge can help negate cold air pushes...or stall them out into fickle boundaries that can screw up forecasts and cause large day-to-day temperature fluctuations.

Flip Of A Switch

Just 24 hours ago we were basking in near universal 80 degree weather, except for oceanic-influenced areas of Southern New Jersey that were in the 60's and 70's.   Today, however, is a different and colder story thanks to a cold front that slipped south this morning and rains that have chilled us through the day.  Millville's 19 degree drop is mere peanuts compared to the 32 degree drop in temperature from this time yesterday in Allentown.

Philadelphia is 27 degrees colder than this time yesterday and is 12 degrees colder than 6 AM this morning, when the city was basking in mid 60's and it was good running weather.   Hope the runners got out and got their run in before the rains moved in.

For those keeping score, the high in Philadelphia occurred at 1:36 AM at 73 degrees.   Today will still go in the books as "above average" but it is an inverse day...almost an introduction to the opposites...

So Much For Spring

From morning temperatures around 70 degrees in many parts of the Delaware Valley to sleet mixing in with rain during the early afternoon in the northern and western suburbs...a six hour swing of temperatures that was rather wild and an abrupt reminder that Spring doesn't arrive easily and permanently.   Temperatures in Philadelphia dropped about 20 degrees from 6 AM to Noon today, hitting the upper 40's before settling in the mid 40's late in the afternoon.  

Round one of the stormy weather today came in the predawn or dawn hours -- generally impacting Chester County with gusty winds that were as high as 65 mph before the first band of rain and wind weakened as it hit Philadelphia.   A second round of wind and rain developed around 8 AM across Central Pennsylvania and Maryland, marching east and crossing the Philadelphia area around 10 AM (see below).   This second line was the main front and meant business, dropping temperatures 15 degrees between 10 and 11 AM in Philadelphia and similar levels elsewhere.   In addition to gusty winds, a quick shot of heavy rain accompanied the frontal boundary passage as well.   Winds gusted to 56 mph in Philadelphia and 55 mph in Wilmington with the front as it crossed through.

Now that "calmer" weather has moved in, expect a return to more typical April temperatures tomorrow with highs generally in the 50's.  Unfortunately, calmer doesn't mean tons of sunshine...the coming days will feature a battle between southern warmth and northern chill as a frontal boundary lingers across the Mid Atlantic.