June 16, 2012: 95+ Degrees Later This Week

Forecast Highlights:


- Slightly Cooler Than Normal Temps Through Tuesday
- Heat Surge, 95+ Degrees For Wednesday/Thursday
- Colder Temperatures Return Next Weekend


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Today's Observations:

Mostly sunny skies were observed again across most of the area as a high pressure continues to remain spread out across the region, with temperatures ending up similar to those of yesterday, in the upper 70s to lower 80s from NYC and further north/west and the mid to upper 70s across most of Long Island/S CT, although Montauk in far eastern Long Island reported a high of 69 degrees.

Temperatures will slightly cool down tomorrow and on Monday with increased cloud cover and the potential for an isolated shower in the far western parts of the area, although with a surge of heat moving into the region, the hottest temperatures of the year so far will be observed on Wednesday and Thursday, with widespread 90+ degrees covering the area, getting as high as the 96-100 degree range along the Washington DC-NYC corridor.


Sunday - Tuesday: Slightly Cooler, A Bit Cloudier


With a SE flow developing for Sunday and Monday, slightly cooler temperatures are expected. Highs will reach the mid to possibly upper 70s from NYC and further north/west, although the biggest impact will be felt in Long Island/S CT, where most places will reach the upper 60s to lower 70s for highs. Areas closer to the coast may see highs in the mid 60s. Partly cloudy skies are likely on both days, especially further east on Sunday, and further west on Monday ahead of a weakening cold front that will produce some clouds but very little, if any rain. Temperatures on Monday will be similar to those of Sunday, possibly a little warmer. Temperatures will begin to warm up on Tuesday as a warm air mass approaches, with high temperatures in the mid 70s to lower 80s across the area.


Wednesday - Beyond: Big Heat, Then Cooling Down


As mentioned over the last few days, the first potential heat wave of the season will take place on Wednesday and Thursday, possibly extending into Friday. With 850mb temperatures up to 20-22C moving into the region with a west wind developing, temperatures will easily surge above 90 degrees for both days across most of the area, excluding the immediate coast, with temperatures from NYC and further north/west reaching the mid to upper 90s. In the warmer case scenario, parts of the immediate NYC area may even get very close to 100 degrees. Mostly to partly sunny skies are expected for both days with no rain.

The next cold front will move through the region on Friday, ending the heat. The exact timing is uncertain, as the ECM has the frontal passage closer to Thursday while the GFS brings the front through on Friday. At this time, I am leaning with the slower timing for the passage, with highs again reaching the 80s, although the timing will determine whether highs reach 90 degrees in NYC or not, thus determining whether the heat surge meets the requirement for a heat wave, which is 3+ consecutive days of 90+ degrees. There is the potential for thunderstorms with the cold front on Friday, possibly extending into early Saturday should the front end up slower although at this time Friday is more favored for the storm potential. Afterwards, there are increasing signals for another trough to build into the region, bringing the area back to the same chilly, occasionally cloudy and wet pattern observed during the first half of the month.