Noreaster IV Odds Growing Uncertainty Also Increasing

I think at this point it is fairly safe to say that we will be dealing with another coastal storm next week beginning late Tuesday. It looks to be a long duration event as it could last into Wednesday night or early Thursday morning which would mean a prolonged period of northeast winds (coastal flooding). From the standpoint of strength (pressure) this storm won’t be crazy strong but the pressure gradient will tighten some so it will be windy along the coast. From the standpoint of precipitation type that looks to be anyone’s guess. Rain or snow or possibly both. However as far as nailing down anything really specific it is way too soon. There are too many moving pieces to this puzzle and models are going to change some more over the weekend.

EUROPEAN MODEL TUESDAY 8PM MARCH 21, 2018

The jet stream profile Tuesday evening on the European model illustrates the dilemma here in figuring out any sort of specifics. You have the blocky nature of the pattern which is not super strong but strong enough with a low at 50N 50W. This forces a broad trough to develop to our west but as the red lines show there are multiple short waves here and they keep interacting with each other differently with every model run. All the models have a coastal low to our south.

GFS MODEL TUESDAY MARCH 21, 8PM

EUROPEAN MODEL SURFACE FORECAST TUESDAY EVENING MARCH 21, 2018

This once again will be a case of a dying primary low and a developing secondary. Cold air will be to the north. How much colder air drains down remains to be seen. In each one of these storms cold air has become more important as we drew closer to the actual event so I’m going to guess that it won’t be much different in this case. How much cold air drains southward will depend on the low that is out near New Foundland (the 50-50 low) and how long it sits there before it begins to pull out. If it pulls out faster the trough would sharpen west of of us and cold air would be less important. Im leaning away from this idea right now. If it holds its own or hangs around a bit longer it will mean another big snowstorm for somebody though exactly where is unanswerable at this point.

At least we have today through Monday to enjoy with relative nice weather however today looks to be rather windy and cold with temperatures in many areas only in the upper 30s and lower 40s. Saturday Saint Patrick’s Day looks good with sunshine with some high clouds; more clouds as you go south into Southern New Jersey & Southeastern Pennsylvania. Sunday and Monday look nice and sunny though cold. We will more specifics on the weekend forecast coming up shortly.