Friday’s record high of 94 in Portland not uncomfortable enough for you? Try those same temps in the low to mid 90’s but with dew points at or over 70. That’s where we’re headed by Friday. The good news? That soupy air will have plenty of water in it to ease our drought if conditions are right. A welcome rainy period is likely for the weekend. Exactly how much rain falls, when it falls, were it falls, and how heavy it will fall are all questions that can’t be answered today but they’re questions that we hope to figure out over the next few days.
Tomorrow looks cool and dry once again and it’s not until Wednesday that we see the chance for some more showers. A cold front will be drifting into the area from the NW as a surge of tropical moisture gathers to our south. The cold front won’t make a ton of progress as the heat builds to the south and by Thursday, the front will be right on top of Northern New England and temps will be climbing. In terms of storm chances Wednesday, they look limited. Right now, it appears as though thunderstorms over Southern New England will rob our area of moisture and as the front weakens, there won’t be enough of a trigger to squeeze the remaining moisture out of the air. Some showers are possible across northern areas which will be closer to the better forcing.
The 12Z GFS paints a fairly good picture in terms of the overview for this week. Warming temps are in store with mainly sunny skies until Friday. Some clouds and the chance for a shower exists Wednesday but otherwise clear and warming will be the name of the game. Heat and humidity is at its worst Friday before clouds and rain move in and cool things off for the weekend. Off and on rain, sometimes possibly heavy, is likely until early next week. Details on that will become available in the coming days as things become more clear.
In terms of how today’s forecast went, the temps were just about right on but I underestimated how much moisture was left in the atmosphere for clouds and showers which ended up developing over the mountains and moving SE in a little cluster. They will slowly weaken and drift SE as daytime heating becomes less powerful. Clear skies are likely for viewing the Perseid meteor shower tonight. As an aside, it will be extra awesome this year because of Jupiter’s gravity warping the debris field. For more info, check out this article from space.com.