Image credit: PSU Ewall

Occluded front with showers this afternoon, Strong T-storms possible tomorrow

After a little sunshine to start early this morning, it has turned more dreary and dismal. A warm front south of region, has more clouds to increase and thicken over the area with few scattered showers and drizzle. An occluded frontal boundary will move through region later today, with more showers increasing in coverage this afternoon. Skies will remain mostly cloudy with south to southeast winds, ahead of this boundary and keep temperatures mostly the in the 60s this afternoon.

Heaviest showers are most likely with forcing along the shortwave trough be northwest of the region. Precipitable water values range from 1.50″ to 1.75″. So heavy downpours with localized flooding is possible. Some elevated instability this afternoon with MUCAPE values near 500 J/KG. So there is also chance for some rumbles of thunder. But models are also showing a marine stable layer with CINH, that could cause any thunderstorms to weaken as they approach the coast.


Occluded frontal boundary to west this morning with warm over Mid-Atlantic region.

Any showers and thunderstorms should come to end during the early evening hours with the frontal and shortwave trough passage. Skies will clear later tonight with higher mid-level heights building over region. Temperatures will fall into the lower to middle 50s.

Saturday will start with plenty of  sunshine during the morning and into early afternoon hours. Then the cold front and shortwave trough will come through with some more clouds and another chance of showers and thunderstorms late tomorrow  afternoon and early tomorrow evening. There is still potential for some strong or borderline severe thunderstorms with stronger wind fields and steeper mid-level lapse rates. The Storm Prediction Center continues with a marginal risk for western sections of region  tomorrow afternoon 

The 12z NAM showing line of showers of thunderstorm late tomorrow afternoon approaching the region.

The 12z/13 NAM model showing line of showers of thunderstorm late tomorrow afternoon approaching the region.

Temperatures tomorrow afternoon with deeper mixing and west-southwest winds will reach into the lower to middle 70s again. Except southerly winds off the waters tomorrow will keep Long Island and Coastal Connecticut in middle to upper 60s. This cold front and shortwave trough moves east later Saturday night with high pressure building into region. This was clearing skies and temperatures to drop into upper 40s to lower 50s overnight.

Sunday will be cooler, with the region underneath a anomalous cold upper-level low. It will not feel very much like May.  But it will be beautiful day with partly sunny skies. A tightening pressure gradient will also cause breezy conditions. High temperatures will be in the upper 50s to lower 60s. Which around 10 to 15 degrees below normal.