WEATHER BLOG: Cinco De Mayo

We have one low pressure exiting the mid-Atlantic coast Saturday morning with a front trailing westward across Virginia and into Kentucky and Illinois. So although we have this weak front to the south, there is another low pressure area up over New Brunswick that has a secondary front stretching from Maine to southeast New York and back into south-central Pennsylvania. This second ill-defined front will press southward and more or less merge with the southern front as high pressure up over James Bay noses southward. The high is not pushing quickly southward, and the gradient/flow around this high centered near James Bay will end up having an easterly component to it later which only adds low level cool and somewhat moist air from the Atlantic this time of year.

Between the merging fronts Saturday there can be a shower in parts of the area, especially the farther west and south you go in the viewing area where they will likely get clipped by the precip with and behind the first front as seen on radar now across West Virginia and Virginia. Cloud cover is kind of a crap shoot Saturday with more clouds than sun, but probably a few breaks. The light northeasterly flow will certainly not help it dry out.

We took temperatures down a few degrees from continuity from Thursday, but if it stays cloudy most of the heating hours Saturday midday and afternoon we will still be a few degrees too high. Whatever partial sun there happens to be or not to be Saturday afternoon into Saturday evening, the clouds will fill back in with the light northeasterly flow and the low level moisture condensing into the clouds again.

For Sunday, we expect a better chance that we break into appreciable sun in the afternoon as a piece of the high pressure to the north breaks off and sinks southward.