April 7: Say it ain’t Snow
We’re still looking at a major pattern change toward warm and mild weather for the second half of April. This weekend however looks cold and possibly snowy as indicated on the latest GFS (Saturday afternoon-evening):
The teleconnections are actually very favorable for Mid-Atlantic US snowfall. We have negative phases of AO and NAO with a positive PNA. That means cold air is available with some blocking and a W. US ridge. We have a closed-off upper level low swinging through the region with a neutral trough axis. If this was January, it would be a decent snow event. But it’s not.
We’re well into April and climatology is king. The sun angle is very high (similar to September) and the ocean surface is warming up (mid-to-upper 40s). The mid-to-upper levels of the atmosphere could certainly be cold enough for snow to develop and fall. The surface and lower-levels of the atmosphere however will likely be too radiant from daytime solar heating to allow snow to accumulate in most places. It could actually change snow into sleet or plain rain before reaching the surface, especially for CNJ and SNJ. Elevations would have the best chance of wet/slushy accumulations and mostly on natural surfaces. Add to that the uncertainty of an inverted trough and I’m not impressed. Therefore, I think snowfall is possible on Saturday but I think any level of ground disruption will be limited, especially if most snow falls during daylight hours. Another ghost storm of white rain for most. Conversational snow.
In English: Snow is possible this Saturday moreso for NNJ than SNJ. Everyone S of I-78 will likely see little to no accumulations and possibly just a wet mix and/or rain. N of I-78, especially NNJ elevations, have a chance for a slushy coating to a few inches on natural surfaces with only minor road/travel disruption. That’s how I’m seeing this play out…a cold nuisance before we carry on with spring. Be safe! JC