All eyes are on the tropical disturbance north of the Bahamas and a cold front over the Northern Plains. The combination of these two features will create some rather stormy weather conditions for the middle of this week, but is the Fourth of July weekend at risk?
The start of this short work week will feature departing high pressure off the Mid Atlantic coast which will lead to a developing southwesterly wind at 5 to 15 mph. Scattered cloud cover can be expected today through tomorrow with a threat for an isolated shower or thunderstorm. These thunderstorms will be capable of very heavy downpours, occasional lightning, and wind gusts over 30 mph. Humidity will be on the increase through tomorrow leading to rather humid conditions by tomorrow afternoon. Temperatures this afternoon will range from the lower to mid 80's along the coast and mid 80's over the Delaware River Valley. Low temperatures tomorrow morning will range from the upper 60's to lower 70's. Temperatures tomorrow afternoon will range from the mid to upper 80's along the immediate coast and upper 80's to lower 90's throughout the rest of the state for afternoon highs. The increasing humidity will make temperatures fall like the mid to upper 90's.
A cold front will slowly approach from the west with scattered showers and strong to severe thunderstorms. Meanwhile, a tropical disturbance will also lift northward toward the Mid Atlantic coastal waters. This disturbance by Wednesday evening may be a tropical depression or tropical storm. The moisture from this tropical low pressure system will help to enhance the showers and thunderstorms along and ahead of the cold front. The cold front will slowly press eastward through early Friday morning with showers and thunderstorms becoming widespread. The strongest thunderstorms will be capable of very heavy downpours, wind gusts over 40 mph, and occasional to frequent lightning. A very tropical air mass will be in place on Wednesday and Thursday with low temperatures in the lower to mid 70's and high temperatures in the upper 80's to lower 90's. I should note though that areas with persistent showers and thunderstorms will be limited to highs in the mid 80's.
The cold front will push off the New Jersey coast on Friday morning with clearing skies from west to east by late Friday morning. High pressure will be in control for Saturday and Sunday with a significant drop in humidity as a Polar air mass takes hold. Low temperatures will fall back into the upper 50's to lower 60's over northwestern New Jersey and lower to mid 60's along the New Jersey coast. High temperatures will range from the upper 70's to lower 80's on Friday and lower to mid 80's on Saturday and Sunday.
The timing and progression of the cold front and associated trough will be a key factor for Fourth of July. The faster the cold front moves off the coast, the faster skies will clear and humidity will crash throughout New Jersey.