A wave of low pressure moved through the region today, producing widespread moderate-heavy rain in the morning, followed by a cold front in the late evening which produced additional scattered thunderstorms. The front will continue to clear the area tonight, with a cooler air mass bringing temperatures into the mid-upper 70s for highs and 50s-low 60s for lows for the rest of the week, with a gradual increase in temperatures and humidity going into next week. (Image credit: PSU e-Wall)
Monday, August 12 Observations:
Mostly cloudy skies were observed across the region with isolated thunderstorms affecting northern NJ, NYC and parts of Long Island in the morning; these showers produced very localized rain totals near/over 1/2 inch, with otherwise less than 1/4 inch of rain. Temperatures reached the low to mid 80s from NYC and further north/west, but were slightly cooler than expected in Long Island and coastal CT, reaching the mid to upper 70s. The highest temperature was 86 degrees in Teterboro, NJ, and the coolest high temperature was 73 degrees in Montauk, NY.
Tuesday, August 13 Observation:
A pre-frontal trough moved through the region this morning, producing widespread heavy rain and flash flooding in southern-central Pennsylvania, where totals were locally as high as 5-6 inches. Severe thunderstorms were observed in the southern end of this rain area, primarily producing gusty winds and flash flooding. These storms spread into New Jersey, but struggled to reach NYC, weakening as they moved in, with the heavy rain staying entirely south of Connecticut with much less rain than expected; the severe storms that fueled the morning heavy rain over PA collapsed while additional storms relocated slightly further south, over south-central NJ where a tornado was reported, with the northern end of the heavy rain shield collapsing as it shifted further south as well. The rain cleared the area by 11 AM to 1 PM, which was 2-3 hours earlier than expected, with partly to mostly cloudy skies continuing afterwards, with additional scattered thunderstorms affecting northern NJ, NYC and western Long Island between 8-11 PM.
Temperatures were cooler than those of Monday; highs reached the low to mid 70s in Long Island, mid to upper 70s in NYC, SE NY and south CT, and upper 70s to low 80s in northern NJ. The highest temperature was 82 degrees in Somerville, NJ, and the coolest high temperature was 71 degrees in Montauk, NY.