July 31: Heat Returns Next Week

Blog Updates:

– Invest 90L now has a 60% risk of developing into a tropical depression or storm. For more information on 90L, as well as severe weather over the next 2 days, go to the Severe Weather / Tropics page.
– The latest 5-Day Forecast has been updated for the immediate NYC area and the interior area.


Today was another much needed cool day, with high temperatures again in the upper 70s to mid 80s. Today though was the last sunny and chilly day for a while, as clouds and rain return to the forecast tomorrow, with heat and humidity already returning by Tuesday.

Tomorrow’s Outlook:

Tomorrow should be cloudy across most of the area, with a SSE wind expected. High temperatures are expected to peak in the upper 70s to lower 80s across the area, though places that see more rain could end up slightly cooler.

Meanwhile, a disturbance approaching the area should bring widespread light to moderate showers and thunderstorms, with locally heavy rain possible. The rain should stay far west enough so that Long Island has a lower chance of rain for Sunday, but more rain is possible for Sunday night for Long Islands. The latest models, however, significantly backed away from the heavy rainfall amounts, only showing up to 1/4 inch. While I expect slightly higher rainfall amounts, I did slightly lower the forecast rainfall amounts for the area.

Next Week: Hot, Humid And Stormy

Monday will continue with the chilly temperatures and rain, however the rain should not be as widespread or as heavy as it should be on Sunday. High temperatures in the upper 70s to lower 80s are expected again. Tuesday will also bring partly to mostly cloudy skies with an isolated shower or two, however temperatures should be much warmer, in the mid 80s inland and in the upper 80s for the immediate NYC area.

By Wednesday, the next cold front approaches, however it is likely to be slow moving, with its effects lasting through Thursday. The models continue to be uncertain with the timing, however thunderstorms are likely for Wednesday and Wednesday night, with Thursday also potentially bringing some storms in the slower solution. Whether there is a severe weather potential or not, the models are showing high precipitable water values, over 2 inches, which combined with the slow moving cold front, could bring a heavy rain threat for that time frame. Wednesday should be the warmest day, with highs in the upper 80s inland and the upper 80s to lower 90s for the immediate NYC area, with Thursday slightly cooler.

Behind the cold front, the air mass is likely to stay relatively warm. High temperatures should continue to stay in the mid to upper 80s inland and the upper 80s to potentially lower 90s for the immediate NYC area.

Longer Range: Potential Heat Wave?

Beyond Days 5-7, especially in the summer, there is usually more uncertainty with the forecasts, though the models can give an idea of the expected pattern. For the last 3 days, the ECMWF and GFS models were relatively consistent in bringing yet another heat wave to the area starting next weekend, around Saturday/Sunday. The 18z GFS was the most extreme, with a 7-day heat wave with temperatures near 100 degrees, and while that solution is unlikely at this time, the models may be hinting that another heat wave may be on the way for the longer range. Stay tuned for more details on this potential should it reach the medium range.

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