Heat, Humidity, and Storm Chances Peak Saturday: Five Things to Know
Happy Saturday, New Jersey! As promised, the 4th of July weekend has felt like stereotypical summer here in the Garden State. Every single day of July so far has featured at least one 90+ temperature reading somewhere in New Jersey. We'll almost certainly make it 6-in-a-row on Saturday, with some truly uncomfortable heat and humidity. And, thanks to an approaching cold front, a round of strong thunderstorms is likely later on too.
1.) An Excessive Heat Warning continues until 7 p.m. for the Philadelphia metro area. On the Jersey side of the Delaware River, this includes Mercer, northwestern Burlington, Camden, and Gloucester counties. As statewide high temperatures reach for about 90 degrees and dew points surge into the mid 70s, the heat index ("feels like" temperature) will be close to the 100-degree mark. Definitely uncomfortable, and right on the edge of "dangerous" heat. You need to cognizantly take care of yourself — stay extra hydrated, take frequent breaks in air conditioning, etc. Those who tend to melt in this brand of extreme heat will probably want to limit your time outside altogether.
2.) The Storm Timeline puts a few widely scattered thunderstorm cells over New Jersey after 1 p.m. Saturday. Given our warm, humid atmosphere, they may become strong or severe rather quickly. A more widespread line of showers and thunderstorms is expected after about 6 p.m. Once we get past sunset (about 8:30 p.m.) storm intensity should fizzle a bit. Rain should exit the Garden State shortly after Midnight.
3.) Flash Flooding will once again be our primary concern from any storms. The past two days have featured some stagnant isolated thunderstorms that produced heavy rain in localized areas. I believe Saturday's storms will be capable of the same (although individual storm cells will be less stationary, thankfully). A quick inch of rain, in a short period of time, is more than enough to inundate storm drains and cause flooding of even major roads.
4.) Severe Weather is possible, although the atmospheric parameters are not coming together for a widespread outbreak. Damaging wind gusts, in excess of 60 mph, are possible both from the initial round of discrete storm cells and the final cold front induced squall line. The threat for hail and a tornado is non-zero. It looks like the strongest storms of the day will be in the southern half of New Jersey, where the air will be "juiciest".
5.) Big Improvements arrive Sunday, with only isolated showers in the southwestern corner of the state. Humidity will slowly dial back as the day presses on, but it's still going to be a warm and sticky summer day with highs in the mid to upper 80s. Monday looks spectacular, with a welcome taste of truly low humidity. Temps will start to surge again midweek, but our next chance for widespread rain should hold off until about Thursday.
Be safe and make it a great Saturday! The CMDZ weather blog is going back on vacation until Monday.