– Mild yet much warmer than average for the early week
– Very warm Wednesday/Thursday; 80+ degrees possible
– Cooler temperatures return by next weekend
– Another round of much shorter lasting warmth next week possible
With the second full day of the unusually strong and widespread warm air mass reflecting down to warm temperatures across the region, unlike the late week when a back door cold front kept temperatures much colder, slightly warmer temperatures were observed today, with highs reaching the upper 60s to lower 70s in northern NJ and SE NY, mid to upper 60s in the immediate NYC area, and the mid 50s to lower 60s across most of Long Island and southern CT. Cloudy skies were observed this morning; most areas already saw sunny skies by noon, although northeastern NJ was the last to break out of the cloud cover across the area, doing so by the early afternoon. Despite today’s temperatures ending up much warmer than average, even warmer temperatures were observed to the north; parts of New Hampshire even reached 80 degrees today, places that during warm spells would typically be colder than NYC.
After another unseasonably warm day tomorrow, temperatures will slightly cool down on Tuesday but remain much warmer than average. As a weak cool front begins to approach the region, however, the peak of the warm spell will affect the area on Wednesday and Thursday, when widespread mid to upper 70s are expected away from the coast, with places from NYC and north/west possibly passing the 80 degree mark on Thursday. The cold front will bring colder temperatures for Friday and next weekend, but no strong and sustained cold is expected.
**The graphic below shows an area of 75-80 degrees north of NYC; not all places in this zone are expected to reach 75 degrees, however.**
With slightly warmer 850mb temperatures, temperatures will warm up across the area tomorrow (Monday) once again. Mainly cloudy skies and areas of fog are expected through about 10 AM tomorrow, with skies becoming partly sunny from NYC and further north/west by the afternoon with mostly cloudy skies closer to the coast. With south winds expected, high temperatures will warm up into the lower to mid 70s in northern NJ and SE NY, passing 75 degrees in parts of northern NJ, upper 60s to lower 70s in NYC, and lower to upper 60s in most of Long Island and southern CT, with upper 50s near the immediate coast.
Tuesday – Thursday: Very Warm; 80-85 Degrees Possible
With the exception of Friday, Tuesday will be the coldest day out of the Saturday-Thursday warmth period, ending up relatively chilly compared to the rest of the region but still noticeably warmer than average. Partly to mostly cloudy skies are expected with the possibility of isolated showers, which along with east winds, will keep temperatures colder. There is some uncertainty with exactly how cold temperatures end up, as the GFS has highs near 70 degrees in NYC, the NAM has NYC barely touching 60 degrees, and the ECM has highs in the lower 60s. Considering the onshore wind, I am leaning towards the colder NAM, expecting highs in the mid 60s in most of northern NJ and SE NY, upper 50s to mid 60s in the immediate NYC area, and mid to upper 50s across most of Long Island and southern CT, with coastal areas in the lower 50s. It is still possible that temperatures may end up slightly warmer.
By Wednesday and Thursday, with winds shifting towards the southwest and the warmer air mass starting to move in, the much warmer temperatures will finally reach the area. As mentioned early in the post, parts of New Hampshire reached 80 degrees today with mainly sunny skies, dry conditions and 850mb temperatures near 12-14 degrees Celsius. With similar conditions moving into the area as the warm air mass sinks southeast, as long as there are no major changes in the set up, there is a better chance that temperatures would also reach and/or pass 80 degrees in parts of the area with the warmest air mass on Thursday. The 12z GFS run was posted to the left, from the NCEP Model Page (direct link to 12z GFS). This map, in addition to showing just how widespread the warm air mass is, which is unusual for this time of the year, more typical of May, it also shows widespread 850mb temperatures above 10C across the area ahead of the cold front, which along with WSW winds and mainly sunny skies, would easily be supportive of 80-85 degrees away from the coast.
The peak of this warm spell will begin on Wednesday, with mainly cloudy skies and perhaps some fog early in the day, especially closer to the coast, with otherwise partly sunny skies. High temperatures from NYC and further north/west are currently likely to reach the mid to upper 70s, with 60s to lower 70s likely further east towards most of Long Island and southern CT. Thursday, as previously mentioned, is expected to be the warmest day; highs are expected to reach the 70s across most of the area, again excluding parts of Long Island and southern CT, especially closer to the southern coasts, and assuming that no major change in the set up takes place, high temperatures are even expected to reach the lower 80s in parts of the immediate NYC area. Stay tuned for more updates on the late week warmth.
Friday – Next Week: Slightly Colder, But Not Cold
Unlike yesterday, when it appeared that Friday could be the warmest day, a stronger back door cold front is now apparently more likely to move through as a strong low pressure stalls near Newfoundland, which often translates to a trough over the northeastern US. As with most other storms under this year’s dry pattern, very little, if any rain is expected with this cold front, with dry conditions lasting through Friday. Due to the trough over the region, the cutoff low will also remain stuck well to the west of the area, and next weekend is likely to stay dry as well. There is still some uncertainty with the intensity of the back door cold front and as a result the temperatures, but high temperatures for Friday through Sunday are likely to return into the 60s, possibly near 70 degrees on Friday, which is much colder than this upcoming week but still warmer than average. Although uncertainty significantly increases going into next week due to the time range, it is a possibility that a much shorter lasting round of warmth affects the area for maybe 1-2 days next week, with the possibility of high temperatures returning to 70 degrees but not ending up anywhere near as warm as this week. More information on next week’s outlook will be posted over the next couple of days.