July 9, 2011: Heat Returns Early This Week

As a low pressure started to develop close to the area yesterday, widespread showers and thunderstorms affected the region, including the NYC tri-state area. While the more widespread heavy rainfall amounts stayed to the south of the area, parts of the area saw locally heavy rainfall as well, with radar estimates showing amounts locally from 1 to 3 inches from NW NJ into SE NY and central Connecticut. Otherwise, most of the area saw 1/4 to 1/2 inch of rain.

With the low pressure out of the region, currently moving towards Newfoundland, today ended up with warmer temperatures than those of yesterday but without any significant heat, as temperatures reached the mid 80s inland and the mid to upper 80s in the immediate NYC area, Long Island, and southern Connecticut. Tomorrow will bring similar temperatures, but a brief yet intense heat spell will affect the area on Monday and Tuesday, with the potential for temperatures to reach the 95-100 degree range in parts of the immediate NYC area on Tuesday along with a risk of strong thunderstorms.


Tomorrow's Outlook:

Tomorrow will be another nice day across the area. With a high pressure still over the region, mainly sunny skies will continue through tomorrow with a light south wind expected. High temperatures will be slightly warmer than those of today, reaching the mid to upper 80s inland, upper 80s to lower 90s across most of the immediate NYC area except for coastal sections of NYC, and the lower to mid 80s across most of Long Island and southern Connecticut, with the warmest temperatures away from the immediate coast.


Monday - Tuesday: Hot, Humid, And Stormy

Over the last week, the potential was mentioned for a surge of heat early this week that could bring temperatures into the lower to potentially mid 90s. Yesterday's storm, which is currently moving towards Newfoundland, will fail to prevent this heat from reaching the region, with its only impact on the area being slightly delaying the entrance of the heat. As we have been under the same pattern through most of the summer, this surge of heat will be short lasting as well, as a storm moving from west to east in southern Canada will already bring a cold front through on Tuesday, but despite the short duration of the heat, hot temperatures are expected, which could end up close to those of the early June heat wave.

As previously mentioned, a weak low pressure is expected to move from west to east through southern Canada, ending up north of the Great Lakes on Monday and north of Maine on Tuesday. As this is a weak storm, most of the heat will shift towards the east as well without significantly weakening. The June 6-8 heat wave set up was also similar to this set up in some ways, as there was also a weak low pressure in southern Canada moving from west to east, allowing the heat to spread into the region without any significant moderation. With the heat moving into the region, Monday will bring warmer temperatures, reaching the upper 80s to mid 90s from NYC and further west along with partly sunny skies. An isolated thunderstorm cannot be ruled out west of NYC in the afternoon, but no significant storms are expected on Monday at this time.

The cold front will move through the area on Tuesday. With the previous update, there was some uncertainty with the exact timing, and as a result, I went conservative with the temperature outlook. With the latest expected scenario, however, it appears that the timing and cloud cover will be supportive enough to allow temperatures to rise into the 90s across parts of, if not most of the area. Lower to mid 90s are expected from NYC and further west on Tuesday, and a few upper 90s cannot be ruled out in parts of NE NJ should the warmer case scenario verify. Humid conditions are expected as well, and the heat index could reach the upper 90s to near 100 degrees on Tuesday. Scattered thunderstorms are possible once again in the afternoon and evening hours, with the potential for strong to severe thunderstorms as well.


Mid-Late Week: Sunny, Dry And Colder

A trough will move into the region behind Tuesday's cold front, bringing a relief from the brief heat spell. While Wednesday should still be very warm, with mid to upper 80s across most of the area with a west/WNW wind expected, the rest of the week will be colder as a high pressure moves over the region, bringing a cooler air mass along with sunny skies. Low temperatures on Wednesday night are expected to drop into the 50s away from NYC and the coastal areas, with sunny skies and highs in the upper 70s to mid 80s expected on Thursday. Similar conditions are expected for Friday as well.

By next weekend, another large ridge in the central US should begin to spread towards the region. The worst of the heat could stay to the west of the region once again as it has done so far this summer, but hot temperatures are likely to return into the region once again by the weekend, and temperatures may return into the 90s in parts of the area by the weekend or early next week. Stay tuned for more information on the longer range.