NJ’s May heat wave ends with a bang: 90s then strong storms Wednesday

The Bottom Line

Wednesday is the grand finale of New Jersey's May heat wave, the fourth consecutive day in a row with widespread 90s in the state. The day will start sunny, breezy, and hot. But as a strong cold front approaches, we will have to watch for strong thunderstorms to develop, from late afternoon through Wednesday evening. Torrential downpours, damaging winds, small hail, and frequent lightning are possible. As the heat breaks and that front stalls just south of New Jersey, we face an extended period of unsettled weather. Scattered rain and clouds will make for an iffy Thursday, with highs only around 60 degrees — a full 30 degrees cooler than the day before. Friday will be better and drier. But Saturday looks quite wet, cloudy, and miserably cool, as temperatures will barely make it into the 50s to start the Memorial Day Weekend. Blech.

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Weather Hazards

Yet again, a Heat Advisory has been issued for most of inland New Jersey, in effect through 8 p.m. Wednesday. With high temperatures in the lower 90s and a heat index in the upper 90s, heat illnesses such as heat exhaustion and heat stroke become more prevalent and more dangerous. You know the drill by now: Dress for the heat, stay hydrated, and stay as cool as possible.

Strong to severe thunderstorms are also a concern Wednesday. The Storm Prediction Center has posted a Marginal Risk for damaging wind and hail in New Jersey. While not everyone in New Jersey will see a storm, the ingredients will be there for nastiness. If watches or warnings are issued for your area, be prepared to seek shelter and/or change outdoor plans accordingly.

The only other thing I am watching is the potential for heavy rain on Saturday. We could reach the 1-inch mark, which could be enough for some ponding and minor flooding issues. I am not ringing those alarm bells just yet — it is only something to watch.

Normal high temperatures range from 73 to 74 degrees now throughout New Jersey. Normal lows are 53 to 55 degrees.

On average, May is the 5th warmest, 5th driest, and 8th snowiest month of the year.

Wednesday

This is going to be an active weather day, as we start steamy and end stormy.

First of all, it is going to be sunny and hot one more time. Expect 70s in the morning, then lower 90s on average in the afternoon. The heat index will probably push into the upper 90s once again. So far, little change from the rest of the week.

All the ingredients will be present for strong to severe thunderstorms: Energy in the form of heat, moisture in the form of humidity, and a spark or lift from an approaching cold front.

It looks like storms are possible as early as 3 or 4 p.m. with peak thunderstorm activity in the early evening (dinnertime) hours. The juiciest atmosphere looks to be around central and southwestern New Jersey, where temperatures will be hottest and the trajectory of the storms will be just right. (Having said that, I think everyone should stay "weather aware" for potentially stormy weather later on.)

Any storms that do form will have the potential of producing pockets of heavy rain and gusty winds. Small hail and frequent lightning are possible too.

Storm intensity should generally pulse down after sunset (8:15-ish), although the chance for showers and thunderstorms will continue overnight. We will start to taste cooler, drier air too — low temperatures will dip into the upper 50s by morning.

Thursday

Thursday will be 30+ degrees cooler than Wednesday. But not a very nice day, as our weather stays unsettled — an effect of that cold front stalling just to our south.

High temperatures will only reach about 60 degrees, give or take. What a difference! How refreshing!

Skies will stay cloudy, with a persistent pocket of rain hanging over the state throughout the daytime hours. I hesitate to call it a washout for any given location, but it could be a pretty damp day overall.

Friday

Friday's weather will trend drier than Thursday's, especially during the day. We should see a mix of clouds and sun, allowing temperatures to climb into the 60s. Still cooler than normal for late May, but better.

Rain chances will start ramping up again starting in the Friday late afternoon and evening hours, as our next storm system rolls in from the west.

Memorial Day Weekend

Folks, I think it's time to face facts: Saturday is not going to be a nice weather day. At all.

Yes, we need rain. And we are looking at 1 to 3 inches of total rainfall over the next week. But why oh why does the wettest, cloudiest, most miserable weather have to coincide with one of the most important holiday weekends of the year?

Saturday does look wet, with periods of rain from early morning through late night. Rain could be heavy at times. It will be overcast and quite cool, with high temperatures barely touching the 50s. That is a full 20 degrees below normal highs for this time of year — actually closer to our normal low temperatures. Blech.

Sunday will be slightly better, with showers in the morning. The forecast still shows a cloudy and cool day with highs in the lower 50s.

The best of the bunch is Memorial Day Monday, with only hit or miss showers and a chance for glimmers of sun. If all goes well, high temperatures will push into the 60s. Not quite beach or pool weather, but it should feel less damp and miserable.

Then long-range models show we will warm right back into the 70s and 80s again next week, as soon as the Memorial Day Weekend is over. Mother Nature is really cruel sometimes.

Dan Zarrow is Chief Meteorologist for Townsquare Media New Jersey. Follow him on Facebook for the latest forecast and realtime weather updates.