WASHINGTON — High pressure that has been keeping us dry and unseasonably warm (it got to above 90 degrees at Reagan National on Sunday) will remain in control of our weather, but some interactions with Hurricane Maria will bring some caveats.
For one thing, a change in wind direction will pump in even more humidity off the ocean and the bay. However, in that process, the extreme summer-like temperatures will be trimmed somewhat. In terms of comfort level, it may end up like “six of one, half dozen of the other” if it cools down but gets more humid. At any rate, as Maria makes its closest approach to the mid-Atlantic coast, we will certainly see some clouds blowing off the top of the storm system. By midweek there could even be a few showers here at home, but we would just be on the westernmost fringe and aren’t expecting the showers to add up to much.
It looks like the dry spell will continue, even with a strong cold front on the way for the end of the week. This front will kick Maria out to sea for good. But it will also finally bring autumnal weather back to our area. During this stretch of warm weather in the East, it’s been very cool in the western U.S. and Canada, especially in the mountains. Some of that weather is simply spreading east.
The pattern is pretty well established and confidence is pretty high on the details. The only wild cards this week are how much cloud cover we get on Tuesday from Maria (that would have an effect on high temperatures) and if any showers will even produce measurable rainfall. Also, the timing of the cold front for Thursday has some variability: if it’s faster we’ll end up cooler; if it’s slower we’ll be warmer and unstable enough perhaps for a thunderstorm or two.
• A mild and sticky start, some patchy fog in the river valleys
• Lots of sunshine with a hint of haze and high level clouds
• Hot in the afternoon, especially for late September
• Clouding over from the southeast to northwest
• Easterly breezes make it more humid
• Slight chance of some drizzle or light showers, mostly east of I-95 and toward the Chesapeake Bay
• Still feeling like summer but not as hot
• Mostly cloudy
• Warm and very muggy
• A chance of light showers or drizzle, mostly east of I-95
• Mix of clouds and sun
• Breezy & warm
• Still humid
• Watching possibility of showers or a thunderstorm
• Lowering humidity later in the day
• Mix of clouds and sun
• Breezy, more seasonable, and more comfortable
Editor’s Note: The WTOP Workweek Weather Blog is intended as an in-depth yet plain language summary of the business week’s weather potential in the D.C. area along with an explanation of the contingencies and uncertainties that exist at the time of publication. For the latest actual Storm Team 4 forecast, check out the link on the main WTOP Weather Page.