Cool, Canadian high pressure will build into the region through the course of the day today. An upper level disturbance will ride to the north of the region overnight tonight, bringing a cloud increase to the area. A scattering of rain and wet snow showers looks possible to the north and west of the Capital Region, closer to the Canadian border. Upon the passage of this system early Wednesday morning, high pressure rebuilds into the region.
Halloween trick-or-treaters will see a warm up, of sorts, for the collection of goodies. A warm front will be sweeping toward the region during the daytime hours, and the high pressure area mentioned above will be to our east. These two factors should cause the low level winds to shift into a southerly to southwesterly direction, helping to feed in some relatively milder air into the region. There will come a downside to this warmer air intrusion though, and that will be a chance for some showers during the peak trick-or-treat hours. A washout is by no means anticipated, however, the rain drops may have to be dodged from time to time.
The warm front passes through the area early Friday morning, followed in short order by a cold front. Both frontal boundaries are tied to a rather potent area of low pressure that is forecast to lift northward into southeastern Canada from the upper Great Lakes by Friday morning. As this low pressure system intensifies, the difference in atmospheric pressure between it, and the retreating high pressure area that brought us the fair midweek weather, will produce a rather healthy pressure gradient over our region. Thus, the expectation is for wind speeds to pick up beginning Halloween night, and to last through the day on Friday.
...Below is the official forecast for the Capital Region and vicinity...
Today: Mostly sunny and cool. High 45-50. North to northwest winds 5-10 MPH.
Tonight: Mostly clear to start, with increasing clouds late at night. Low near 30. Light southerly winds.
Wednesday: Morning clouds giving way to a mix of sun and clouds. High in the lower 50’s. West winds 5-10 MPH.
Wednesday Night: Mostly clear. Low in the mid 30’s. Light southerly winds.
Halloween: Partly sunny and a bit milder. A chance of showers late in the day. High 55-60. Southerly winds 5-15 MPH. Chance of rain is 40 percent.
Friday: Mostly cloudy, windy, and mild with a 50 percent chance of showers. High near 65 and low near 50.
Saturday: Partly sunny and breezy. Early high near 60 and low near 40.
Sunday: Mostly sunny and windy. High near 54 and low near 35.
Monday: Mostly sunny. High near 50 and low near 35.