Severe Thunderstorms Early This Evening Possible

The Storm Prediction Center has been and will continue to monitor New Jersey and SW for a possible weather watch issuance within the next hour or two for severe thunderstorms.

The current surface analysis currently shows CAPE values of 1,000 j/g to 1,500 j/kg across much of Central and Southern New Jersey. Low-level lapse rates are around 8 c/km right now which is pretty steep. The lifted index values currently are in a range of -3 to -5. The supercell composite is suggesting values of 0.50 to 2 region wide. The significant hail composite is showing values of 0.50 to 1.50 across Southwestern New Jersey which the Derecho Composite showing values of 1 to 4.

What this all basically means is that there appears to be sufficient instability for thunderstorms to turn rapidly turn severe should there be any forcing mechanism to initiate them. What I think could do the trick is an area of thunderstorms that is beginning to redevelop over Maryland and Virginia. This could cause some very late afternoon and especially early evening scattered thunderstorms to form. These thunderstorms have the potential to form as line segments and supercells.

Most of the region has warmed well beyond the model guidance this afternoon with high temperatures so far in the 82 to 84 degree range. A localized sea breeze front may cool things down in portions of the coastal counties, but elsewhere it should remain quite warm and unstable until the sun begins to set this evening. The sea breeze front itself may serve as a focus for thunderstorm initiation if it begins to interact with the convection that should develop and transpire to our southwest.

Damaging Winds and Power Outages Likely By Evening

The Storm Prediction Center this morning placed most of Central and Southern New Jersey under a slight risk for severe weather. The Storm Prediction Center is not forecasting hail, but they are forecasting a probability of damaging wind gusts even an isolated tornado. The environment does have increasing shear, so a tornado concern would not be completely unwarranted by any means. But very severe winds aloft can easily be transported to the surface with any thunderstorm and therefore the risk of damaging winds is the primary concern.

The limiting factors for thunderstorms could be the real lack of sunshine. However, there still is some very modest instability with the warm sector now arriving in place. Temperatures will continue to increase, reaching the lower sixties to mid-sixties in most of Southern New Jersey. Dew points will also continue to increase and there will be rich moisture to work with.

Meanwhile, it will not take thunderstorms to produce very high winds this afternoon and this evening. A high wind warning is in effect for the potential of widespread damaging wind gusts as the front approaches and passes. Strong northwesterly winds are associated with an area of low pressure passing through Pennsylvania, which will eventually pass through New Jersey. It will be behind this low that we see the strongest gusts for a few hours. We received the heavy rain and some more heavy showers and thunderstorms could be on the way. Therefore, the ground will be saturated just in time for these strong winds increasing the chance of whole trees coming down, something the expected wind gusts in excess of 58 MPH will already be capable of doing with even a dry ground.

Widespread power outages are possible as a result of the high winds. This could be a situation that leads to outages that may be of long duration. Temperatures could fall more than 30 degrees across areas that get into the sixties in just three to four hours and with a driving wind, homes will cool down rapidly as the temperatures drop. This could cause some communities to enact shelter plans. More than 50,000 people could lose power in New Jersey if the worst case scenario is realized.