Heavy Rain & Gusty Winds This Evening, Very Cold Air Arrives Late Tonight &Tomorrow

First batch of steady rain is moving through early this morning.  Rain will become lighter and intermittent late this morning and early this afternoon. Before another batch of steadier and heavier rain arrives later this afternoon with a weak triple-point low passing just northwest of the area. The warm front with low, to push from SE to NW this afternoon, causing temperatures to rising through 40s and into 50s this afternoon. Some parts of Long Island and New Jersey Shore may briefly get into the warm sector with temperatures in the lower 60s.  Before a strong cold front from west approaches this evening. A strong southwesterly LLJ, will be passing overhead this evening. This will enhance lift and moisture along the cold front coming and cause more rain, heavy at times over the Tri-State area.

6z NAM showing 925mb winds 50-70kts for the coastal areas
6z NAM showing 925mb winds 50-70kts for the coastal areas

Winds late this afternoon and evening will increase to 15mph to 25mph with higher gusts up to 35mph, near the coast. An inversion layer around 925mb is forecast to keep much stronger winds will the low-level jet from mixing down to surface. However, elevated instability will be on the increase tonight in the warm sector. This can produce some isolated thunderstorms that may contain wind gusts over 50mph. Especially over parts of Long Island and the New Jersey coast. Rain and isolated thunderstorms should end, after the cold front passage later tonight.

6z NAM showing elevated instability
6z NAM showing MUCAPE values increasing 250-500 J/kg over Long Island and New Jersey shore by 5pm
6z 4km WRF showing convection with heavy rainfall in the NYC Metro this evening
6z 4km WRF showing convection with heavy rainfall in the NYC Metro this evening

Coldest air of the fall season will arrive later tonight. This is some unusually cold air for the middle of November. This type of airmass is more what you expect in late December or January.  Despite lots of sunshine, 850mb temperatures decreasing to -16C will keep temperatures mostly in middle 20s to lower 30s tomorrow.  Wednesday morning temperatures may in the lower 20s or even the teens in across over much of the area.  Temperatures on Tuesday and Wednesday may as much as 20 degrees below normal for this time of year.

6z NAM 850mb temperatures dropping to near -16C tomorrow
6z NAM 850mb temperatures dropping to near -16C tomorrow afternoon
6z 4km NAM showing temperatures in the teens on Wednesday morning
6z 4km NAM showing 2-meter temperatures in the teens on Wednesday morning

Southwest winds will allow temperatures to rise back into 40s on Thursday. Before another cold shot of air arrives on Friday and last into Saturday. High temperatures will likely be upper 30s to lower 40s. However, it also looks mainly dry. As the flow becomes too progressive for trough amplification or northern and southern streams to phase along the east coast.A moderating trend will begin Sunday again, as trough start dig over Central US and ridge start build over the East Coast. Temperatures may once again to return near or above normal going into early next week. The next storm system during this period will likely track to well to our west and bring only rainfall to our region.

Leave a comment