Aug 6, 2016

Weather Discussion for Saturday 6 August 2016

A cold front has stalled just to the northwest of us but it will still start to move toward the southeast during this afternoon. With the air heating up and the front moving through the region during this afternoon scattered showers and a few storms are possible. Greatest instability is to the S by SE of Albany with better shear and lift to the north. For now SPC has SE NY and Southern New England (mainly south of the MASS Pike) as having the better chance for severe storms.
This better chance is based on the assumption that this area will be "heating" for a longer time frame. BUT looking at the image below you can see that skies are mostly cloudy to the south and southeast of Albany, with a few breaks. The most sunshine and warming is occurring to the north and northwest but instability in this area is not too strong.
So I have to say that it's a low confidence forecast on today's severe threat. While I am not thinking that there is going to be a widespread severe threat, I feel that most of the #518wx area does have a chance for a strong or severe storm. Storms will be widely scattered if they do occur. For the weather geeks, the morning upper air sounding for Albany (modified for expected conditions at 1 PM this afternoon) is below. Analysis of this sounding shows moderate to strong CAPE (Convective Available Potential Energy) but the profile of this CAPE is somewhat "skinny". Instability indices are mostly weak ( one or two moderate); these mostly weak indices are probably due to a weak temperature lapse rate (change of temperature with height) between about 5 thousand feet and 12 thousand feet above the ground.
(8 AM EDT 6 Aug 2016  RAOB for Albany NY. Modified for expected afternoon conditions)
IF SEVERE storms happen, the main threat: strong wind gusts (wet downbursts) of 50-60 mph and very heavy rainfall. The chance for large hail is LOW. Best chance for storms/showers (40% probability) is between 1PM and 6PM today. Once again activity will be scattered, so not all of us will get wet. Also note that some storms could produce a quick 1" to 1.5" of rain in a short time, with an isolated 2-2.5 inches even a possibility. This heavy rainfall could cause local flooding in areas of poor drainage, even isolated flash flooding, as well as ponding fo water on the roads.