Evening Zones Update: Showers Wednesday, Cooler End of Week, T-Storms Easter Sunday?

Good evening, everyone! Another lovely day was had today thanks to even more southwest flow than on Monday. High temperatures reached the mid 80s across much of the state of New Jersey! Areas further east were generally a bit cooler due to micro-scale breezes and large-scale synoptic southerly and southwesterly winds having more of a cooler, marine component for areas further east. EWR and TEB actually saw a bay-breeze as winds shifted SE off the Bay and cooled temperatures off in parts of Urban E NJ. Regardless, though, Newark still managed to reach a high of 82 degrees and NYC had a high of 80 degrees. JFK, however only had a high of 66 degrees and most of Long Island was generally in the upper 60s to around 70 degrees. 

Dewpoints have already risen into the upper 40s to low to mid 50s in some spots thanks to the southwest flow. When combined with an increase in high clouds out ahead of some storms in Central PA associated with a pre-frontal trough ahead of a cold front, should lead to low temperatures holding in the 50s to even around 60 or higher in the warmer urban locations.

Some of these showers and weak thunderstorms will attempt to reach the area on Wednesday morning. However, they will be outrunning the best synoptic forcing and will thus weaken before they reach the area, as the main shortwave and positive vorticity advection will generally remain well off to the northwest.

The above image is the Q-Vector convergence valid at 11:00am Wednesday morning —  a good indicator of the synoptic forcing for lift. While the best synoptic forcing is clearly to the north, there is a small uptick in Q-Vector convergence may be enough to reinvigorate some of the showers near the area during this time. It’s still nothing too impressive, but there is enough mid-level instability for a few of these showers to contain a rumble of thunder. But generally, low-level stability combined with the showers outrunning the best forcing and the Q-Vector convergence not being all that impressive will prevent these from being a big deal. But again, a quick moderate burst of rain and a rumble of thunder cannot be ruled out, which has a slight chance to cause a brief early delay in the Yankee game. We do think any showers that do form should clear the area by 1:00 or 2:00pm, at the latest. New England will have a better combination of Q-Vector convergence and daytime heating to be able to generate low and mid-level instability as well as forcing to generate showers and thunderstorms, so coverage should be a bit more numerous there. 

After the front comes through, we will actually have a brief quick warming spike as the sun comes out and we get downsloping flow — look at the west-northwest flow in the streamlines. This will allow temperatures to potentially rise into the mid 70s for much of the area from 2-5pm on Wednesday, with upper 70s to around 80 in SE NJ. Thus, the weather for most of the Yankee game looks great, though some breezy conditions with winds gusting up to 20-25mph as the downsloping causes mixing is certainly possible.

But notice the cooler 850mb temperatures on the bottom right. Those will come through later Wednesday night and allow temperatures to cool nicely. We thus expect temperatures to plummet into the low 40s for a lot of the area, but closer to 50 in more urban areas.

Mostly sunny and chiller weather with highs in the low 60s are likely on Thursday and Friday. The clear skies and calm winds thanks to high pressure will allow for more cold nights — upper 30s are possible in inland locations, with generally 40s elsewhere. It may be downright chilly for the Yankee games on both nights — a jacket will certainly be recommended! Temperatures will start in the 50s and then fall into the upper 40s late in the game.

As far as the weekend is concerned, it looks like a warm front will move through the area on Saturday evening, allowing for more southwest flow and moisture. This may trigger some showers on Saturday night as we transition from the cool sector into the warm sector. A rumble of thunder is also possible with elevated instability.

Most of Easter Sunday looks like a nice, warm day with high temperatures in the upper 70s to around 80 with even a slight uptick in humidity, but still comfortable. In this warm sector, it looks like there will be enough precipitable water and instability to form strong to severe thunderstorms — the above image shows sufficient CAPE, 1″ PWATs, and 500mb bulk shear generally around 30 knots. However, the main synoptic forcing will be well off to the northwest, and that is also why the best wind shear still remains in those areas. There’s also a stout cap in the forecast soundings for NYC. But notice how above the cap, there is actually plenty of mid-level instability — a pretty stout EML. So if we can get a small shortwave to break out ahead of the main trough and serve as a small trigger to break the cap, the atmosphere is certainly ripe for strong thunderstorms on Sunday evening. But given the zonal pattern expected, it may be hard to get any of the good forcing to make it southeast of the Adirondacks, keeping most of the organized activity well west and north of the area. The better threat of rain may come around April 20th as better NAO blocking forces a system further south, with more synoptic rains possible.