Temporary Relief to follow Heat Wave

Discussion: Right now we are caught between high pressure, near Bermuda, and a very positive-tilted approaching trough. The two players are generating a relentless S/SW flow of heat and humidity for New Jersey and this constitutes the reason for the current heat wave which began yesterday and will likely push through this Wednesday. Monday and Tuesday look like the hottest days of the heat wave with Tuesday likely being the hottest day. I have heat safety caveats for Mon, Tues, and Wed below and for good reason. Wednesday into Thursday looks transitional as a more comfortable air mass pushes out the current uncomfortable air mass from NW to SE. This should lead to relief for all of NJ away from the ocean on Thursday and all of NJ for Friday. The weekend then looks like a slow build back of heat and humidity, but not back to how disgusting today (Monday) and Tuesday will max to. So that’s the temperature profile of the week: Hazy, dangerously hot, and humid Monday-Wed afternoon. Transitional Wednesday afternoon-Thursday AM. Then more comfortable Thursday PM into Saturday morning. Regarding rain and thunderstorm potential, it looks like Wednesday will be the day that a frontal boundary approaches from the NW. This frontal boundary will separate the current air mass from the more comfortable air mass that will move in. Meteorological theory would suggest that the lifting from this frontal boundary will be adequate to produce downpours and thunderstorms, especially with how charged up NJ will be after Mon-Wed surface hearting and correlating instability. I doubt we’re looking at anything drought-busting and with the way linear stormfronts have broken up this year, not all will see rain. But we should at least see a broken stormfront with severe potential sometime in the Wednesday PM-Thrusday AM window. I will report accordingly as we closer approach. Again, on the other side of that stormfront/boundary will be a comfortable air mass for NJ for Thursday and Friday. Friday looks statewide but Thursday might be a “relief for all but coastal areas” kind of day if the boundary holds up before advancing further out to sea. The weekend the slowly rebuilds heat and humidity with traditional summertime feel (not excessive record-breaking heat) back by Sunday afternoon and into next week.

Monday (July 15) high temperatures should push well into the 90s and possibly reach or exceed 100 in some spots away from the ocean. Even the immediate coast has a shot at 90. Excessive humidity levels should push heat indices into a dangerous 105+ situation. A severe risk of dehydration, heat exhaustion, and heat stroke is in-place so please stay as cool as your situation allows for and as hydrated as possible. Skies should be mixed with more sun than clouds. Can’t rule out isolated pop-up showers and thunderstorms in this environment. Winds should be light out of the S/SW. Overnight lows should stay in the 70-75 range.

Tuesday (July 16) high temperatures should be similar to Monday, possibly even a degree or two higher. An even better chance for interior NJ to break 100 and for the immediate coast to break 90. Excessive humidity levels should again push heat indices into a dangerous 105+ situation. A severe risk of dehydration, heat exhaustion, and heat stroke is in-place so please stay as cool as your situation allows for and as hydrated as possible. Skies should be mixed with more sun than clouds. Can’t rule out isolated pop-up showers and thunderstorms in this environment. A slightly better chance of storms Tuesday than Monday. Winds should be light out of the S/SW. Overnight lows should stay above 70 statewide again.

Wednesday (July 17) high temperatures should push above 90 but not as dangerously hot as Monday-Tuesday. I would still adhere and acknowledge the safety concerns for heat and humidity to be safe. Coastal regions likely maxing in the mid-to-upper 80s. Skies should start with more sun than clouds but downpours and thunderstorms are possible for afternoon/evening hours. Storms could reach severe criteria at more than just an isolated level. Winds should remain out of the S/SW but breezier, especially for coastal SNJ open to the S (Delaware Bay and SENJ coasts). Overnight lows should fall back to near-70 for most NJ locations.

Thursday (July 18) high temperatures should only reach into the 80s with less humidity for most NJ locations. Some humidity might linger for coastal and SNJ/SENJ. Skies should be mixed with sun and clouds with thunderstorms around. Winds should be more out of the NW away from the ocean and up in NNJ. Coastal regions should see more of a S/SW wind. Overnight lows should range from 60-70 from NNJ elevations to SNJ coasts.

Friday (July 19) high temperatures should reach the mid-80s for most NJ locations. Coastal regions closer to 80. Skies should be mixed with more sun than clouds with a less humid feel. Low rain/storm chances. Winds should be light out of the N/NW. Overnight lows should range from upper-50s to upper-60s from NNJ elevations to SNJ coasts.

An early look at the weekend (July 20-21) indicates Saturday and Sunday capped in the 80s statewide with little-to-no rain. Regarding humidity, the front of the weekend should feel drier than the back of it as humidity slowly builds from “lower” to “average for summer.” 82-87 with average humidity will feel a lot better than 95-100 with excessive humidity though. Let’s confirm this in a few days. Thanks, and have a great week. Be safe! JC

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Jonathan Carr

Jonathan Carr (JC) is the founder and sole operator of Weather NJ, New Jersey’s largest independent weather reporting agency. Since 2010, Jonathan has provided weather safety discussion and forecasting services for New Jersey and surrounding areas through the web and social media. Originally branded as Severe NJ Weather (before 2014), Weather NJ is proud to bring you accurate and responsible forecast discussion ahead of high-stakes weather scenarios that impact this great garden state of ours. All Weather. All New Jersey.™ Be safe! JC