A large ridge of high pressure continues to dominate the weather across the Eastern Region. This has resulted in some unseasonably warm weather, which will continue today. Most temperatures should climb into the mid-80s this afternoon, except in some of the highest terrain.
Tonight, a back-door cold front tonight currently located in eastern Canada will be pressing southward. However, the effective cooling, resulting in much lower temperatures tomorrow, will take place across New England. Therefore, the Greater Baltimore Area, as well as the rest of the mid-Atlantic states, should still encounter a warm afternoon, at least by mid-October’s standards. Most temperatures will wind up in the mid and upper-70s — and the slight reduction will have nothing to do with a frontal passage, or a “change in the air mass.” Instead, this can be attributed to the arrival of high, thin clouds. These cirrus clouds, associated with a developing wave of low pressure in the Southeast, will dim the sun and hold temperatures down a bit. Clouds should then thicken tomorrow night, and it will be followed by some rain starting VERY LATE TOMORROW NIGHT and lasting into Wednesday.
We’re still allowing for a couple of showers on Thursday, although some of these forms of guidance (led chiefly by the European and Canadian medium-range models) are indicating that there may be a “lull” here on Thursday, as we find ourselves “in between systems.” By and large, a departing wave of low pressure will be leaving behind a relatively warm air mass. The “gridded data,” which includes most forms of temperature guidance, is implying that temperatures around here on Thursday afternoon will be no lower than the middle-70s, because by early in the afternoon, there may be nothing more than a passing shower, and clouds may actually try to break for a little sunshine.
As a vigorous parcel of energy in the Tennessee Valley on Thursday begins to pivot to the north and east on Thursday night and Friday, there will probably be a few more showers occurring — and these will be accompanied by a cooling trend. Most temperatures by the start of next weekend will be no higher than the upper-60s. However, that is actually pretty “typical” for mid-October.
Have a good day !!!