Second Named Storm to Impact Garden State in 2020

For the second time during this 2020 Atlantic Hurricane Season, a named storm impacted the Garden State.  On August 4th, Tropical Storm Isaias, which battled dry air and a hostile upper level environment before becoming a strong Category One Hurricane, moved into New Jersey.  After lashing the Carolinas with maximum sustained winds as high as 85 mph, Isaias came through Virginia, and took more of a westerly track across Delaware, Southwestern New Jersey, and Southeastern Pennsylvania.

The track, similar to the path taken through the Mid-Atlantic by Tropical Storm David on September 7, 1979, resulted in several forms of wicked weather for different parts of the state.  For the Western portion of New Jersey, it meant heavy rains.  At the Jersey Shore, it meant gusty winds, tornadoes, rough surf, and coastal flooding.  For areas in between, it meant tornadoes, gusty winds, downed trees and power lines.  Although the storm had lost much of the strength it had when it came ashore in Southern North Carolina, its more westward track put much of New Jersey in the more dangerous eastern half.

Coupled with a fast forward motion reminiscent of Hurricane Gloria in 1985, and a transition to more of an extratropical system, the storm still managed to pack quite a punch.  Here at Greg’s Weather Center in South Plainfield, NJ winds gusted as high as 50 mph.  The barometric pressure only dropped to 29.39 inches, but the fall was quite dramatic in only a short period of time.  From about 9:22 AM in the morning to about 1:35 in the afternoon, the pressure fell some 0.46 inches, or a little more than 15 millibars.  A rate of approximately 0.11 inches or 3.63 millibars per hour.

Rainfall at GWC was only 0.72 inches with a maximum rainfall rate of 2.49 inches at 2:45 AM in the morning.  The real story here was the wind, and between 11:30 AM and about 1:00 PM, the winds were at their strongest.  According to footage taken outside during some of that period, an apparent funnel cloud developed around the time of 12:50 PM.  

While the funnel didn’t touch the ground, it did cause the winds to pick up and make a bit of a racket on the side of my house.  A number of locations around South Plainfield were damaged including downed trees on Cedarbrook Ave, Van Fleet Avenue, Ralph and Willow Avenues, Wells Drive, Geary Drive, and Tompkins Avenue.  Many of these streets were closed off to traffic.

By 3:34 PM, things had completely changed at GWC.  The winds had shifted direction, the clouds moved out, and the sun reappeared.  In a span of just under an hour and a half, the pressure had risen 0.13 inches, or 4 millibars to 29.52 inches.  At 5:03 PM, the barometer had risen back up to 29.71 inches.  A rise of 0.32 inches over a span of just under 3.5 hours, which translated to a rate of 0.09 inches or approximately 3 millibars per hour.

There was a lot of damage around Central Jersey including downed trees in Basking Ridge, Bound Brook, East Brunswick, Holmdel, Howell, Linden, and South Brunswick.  Isaias caused the third largest power outage in the history of New Jersey behind two other recent landfalling Garden State tropical systems:  Sandy (October 2012) and Irene (August 2011).  Some 1.4 million New Jersey residents were left in the dark immediately after the storm.  

Isaias did produce a number of tornadoes around the state and the Mid-Atlantic.  One tornado was confirmed in Strathmere in Cape May County while another was also verified in Ship Bottom on Long Beach Island.  In addition, a wind gust of 110 mph was reported on Long Beach Island.  Several more twisters touched down across the region including one in Doylestown, Pennsylvania that turned cars over as if they were toys.  

Another occurred in Queen Anne’s County in Maryland while two more touched down in Delaware.  A total of 6 were confirmed in the Mid-Atlantic while the Storm Prediction Center received reports of 33 twisters from North Carolina to New Jersey.  Even Mount Washington in New Hampshire got in on the act with the highest wind gust ever recorded in the month of August at 146 mph.  

Maximum sustained winds reported around the region included 54 mph at JFK Airport, 53 mph at LaGuardia Airport, 69 mph in Islip, NY (Long Island), and 48 mph at Farmingdale, New York.  Highest wind gusts reported included:  Battery Park at 78 mph, Farmingdale, NY at 78 mph, Barnegat Light on the north end of LBI at 75 mph, Rutgers University in New Brunswick at 70 mph, and Island Heights at 69 mph.  

Eastern Pennsylvania also dealt with heavy rainfall from the system.  Lehigh Valley Airport near Allentown, PA received 4.92 inches of rain that came with a rainfall rate as high as 1.5 inches per hour.  Rainfall estimates were as high 6 inches across portions of Western New Jersey.  Rainfall amounts ranged from 0.19 inches in Oceanport in Monmouth County, NJ to 5.41 inches in Logan Township in Gloucester County.  The highest rainfall amount in Middlesex County was 1.63 inches in Woodbridge Township to the east of GWC.

Isaias was the 2nd named storm to affect New Jersey this season.  Tropical Storm Fay was the first storm to impact the Garden State when it struck on Friday, July 10th.  The storm dumped 1.99 inches of rain on GWC that day, which was about 23.5 percent of the total rain for the month of July.  Maximum rainfall rate in Fay at GWC was 5.01 inches.  Barometer dropped from 29.96 to 29.66 inches or about 10 millibars before the storm passed.  The last time two named storms affected New Jersey in the same season was 1996 (Bertha in July and Fran in September).