Note: The 5-Day Outlook and the Severe Weather/Tropical pages were not updated today.
Last night ended up bringing moderate to heavy rain and thunderstorms to the area, focusing on central Long Island, Connecticut and northern New Jersey, though some places barely got any rain last night, including southern Bergen county.
Today so far was partly to mostly cloudy, which prevented temperaturs from reaching the mid 90s, however parts of the area are in the lower 90s. Tomorrow is going to be different, however, as warmer temperatures are possible, including thunderstorms.
Tomorrow’s Outlook / Severe Weather Potential
If there is less cloud cover than today, tomorrow could easily be the warmest day so far this year. The air mass is going to be very warm, with 850 mb temperatures near 20c. At this time, I am expecting tomorrow to start out mostly cloudy, with some clearing by the late morning/early afternoon and more clouds afterwards, leading to high temperatures reaching the lower to mid 90s. If there is enough sunshine, a few places in the immediate NYC area and further SW may reach the upper 90s.
Meanwhile, the cold front that will be producing severe thunderstorms for western NY/PA tonight will be moving through the area tomorrow. The parameters for severe weather are shown to be supportive for a widespread severe weather outbreak, which would support a 30%severe weather risk. There are, however, other factors that may affect tomorrow’s risk.
Thursday’s Severe Weather Potential: 15% Risk
As I previously mentioned, the cold front will be producing widespread severe weather and potentially a MCS for western NY and PA late tonight. The remnants of the severe weather may reach our area tomorrow early morning, leading to mainly cloudy skies and scattered showers or storms, though the shower/storm risk is higher to our north.
By the late morning, the cloud cover should start clearing some, though it is uncertain how much the sky clears up. If there are sunny to mostly sunny skies, then the atmosphere can destabilize, and the temperatures would rise into the mid to possibly upper 90s. If there are partly to mostly cloudy skies, the atmosphere will not destabilize as much, and temperatures would stay in the lower to mid 90s.
In the late afternoon, the cold front should move through. The parameters are favorable, with CAPE betwen 1500-2000, LI between -4 and -6, and wind shear between 35 and 50 knots. The models show a possible squall line moving through at that time, however the intensity of this squall line in the area depends on the cloud cover from earlier in the day, and where the best parameters are located. There is always the chance that a thunderstorm either to our north, in the area or to our south strengthens more and weakens the storms in between.
For now, I am going on the conservative side and expecting a 15% risk of severe weather for our area. If the scenario where there is more sunshine tomorrow and the best parameters stay near our area verifies, a 30% risk may be needed, however this is still uncertain. More details will come tomorrow, including a possible late morning update.
Friday And Weekend: Colder, Then Warming Up
Friday and Saturday should both be colder than Thursday, as a slightly colder air mass returns to the area. High temperatures should still remain near to slightly above average, in the mid to upper 80s, with mostly to partly sunny skies. By Sunday, however, temperatures should warm up ahead of the next storm, reaching the upper 80s to lower 90s.
Monday is a more interesting day, however. As an intense storm moves to our north, it brings through a cold front, but the air mass behind it is much colder. There is still uncertainty on how far north the storm is and its timing, however it is possible that Monday could bring a severe thunderstorm risk, along with temperatures rising well into the 90s again. Stay tuned for more details.
By Tuesday, there is a lot of uncertainty with the models, however it should be colder again. Temperatures are expected to return to below average levels again, but the extent of that is uncertain. The GFS and DGEX take this to the extreme, with high temperatures only in the 60s to lower 70s, well below the average for this time of the year. At this time, I am leaning towards a less extreme scenario, with high temperatures dropping into the upper 70s to lower 80s.