July 4, 2012: Heat Continues Through Saturday

Forecast Highlights:

- Heat continues through Saturday, approaching 100 degrees on Sat

- Cooler temperatures to return for next week

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Today's Observations:

The heat in place since last Thursday continued once again, with a hot 4th of July for most of the area. Temperatures reached the lower 90s inland, lower to mid 90s in the immediate NYC area except for JFK, mid to upper 80s in southern CT, and the mid 80s in most of Long Island. Temperatures verified across most of the area but were cooler than expected in Long Island.

The heat wave continued in Newark which observed its 7th consecutive 90+ degree day, with the rest of northern NJ and parts of NYC on track to record another heat wave with the heat expected to stick around through Saturday. Following nearly 100 degree heat on Saturday, a cold front will move through the entire region, bringing an end to the heat wave that has been stuck over the region for the last week.


Thursday - Saturday Outlook: Still Hot


The heat wave will continue through Saturday from NYC and further north/west, with temperatures on Thursday and Friday reaching the lower to mid 90s in the immediate NYC area and the upper 80s to lower 90s inland. A NW flow on Thursday will likely bring slightly warmer temperatures into Long Island/S CT, reaching the mid 80s to lower 90s, while the sea breeze will have more influence on Friday, keeping temperatures slightly cooler in the mid to upper 80s for most of Long Island/S CT, staying below 85 degrees closer to the immediate coast.

By Saturday, the last surge of heat associated with the week-long heat wave affecting a large part of the US will move into the region, ahead of a cold front that will push the heat out. There is still slight uncertainty with the exact timing of the front, but the air mass is easily capable of producing 100+ degree heat, especially south of I-80 where widespread 100+ degree heat is likely. Temperatures are a bit more questionable for the area, with widespread 90s generally likely except for immediate coastal areas, although at least in NE NJ and parts of NYC, temperatures are expected to surge into the upper 90s, possibly reaching 100 degrees or a bit higher in parts of NE NJ in the warmer case scenario.

Warm overnight/morning temperatures will increase the potential for hot temperatures as long as the front's timing remains slow enough so that any rain/cloudy skies don't move in until at least the late afternoon hours, which is the current expectation; by 8 AM (12z), temperatures are expected to warm into the lower-mid 80s in the immediate NYC area, reaching the lower-mid 90s by 11 AM. If this warming trend remains uninterrupted into the rest of the afternoon hours, temperatures will have a chance to reach the lower 100s in parts of NE NJ, although for now upper 90s are more likely. With dew points perhaps approaching 70 degrees, heat index values may reach the 100-105 degree range. Scattered thunderstorms are expected for the late afternoon/evening hours, but at this time a widespread severe storm outbreak does not appear to be likely. Stay tuned for more information on Saturday's outlook.


Sunday - Next Week: Cooling Down


Following Saturday's cold front, a cooler air mass will move into the region, but no strong cool air mass is expected to move in, with temperatures generally staying close to average. The GFS is currently showing widespread rain/storms for Sunday; although some storms are possible, I am siding with a drier scenario, with temperatures generally reaching the mid 80s to lower 90s with partly cloudy skies and a risk of an isolated thunderstorm. For the rest of next week there appears to be little change in the air mass, with temperatures generally staying in the 80s. Although there could be a warming trend towards the end of next week, there isn't any hot or strong cool air mass on the way through at least late next week.