Active weather approaching
After last week’s quiet introduction to autumn we get to pay the piper this week. A strong cold front is headed our way from the northwest and a developing surface low pressure system southwest of here near the Texas/Louisiana Gulf Coast will pump plenty of moisture northward over us. These two features will merge before they arrive in Virginia and provide the impetus for plenty of action over the next couple of days.
Monday (today) the clouds will lower and thicken as the day progresses. A weak warm front currently in North Carolina will get pushed northward courtesy of the developing surface low and a few showers will break out after sunset. Until then the ‘Burg will see light winds and high temperature in the mid-70′s (F). After dark the rain chances increase and overnight the area could see up to a quarter of an inch of rainfall, with higher totals closer to the Blue Ridge mountains.
After a relatively warm night with lows in the upper 60s Tuesday arrives with some potentially wild weather. During the early and mid-day hours the south winds will increase with gusts up to 30 mph, ushering in a steadier rain with another half-inch of accumulation or so. For the late afternoon – perhaps as early as 5:00 p.m. – a potentially explosive combination of abundant moisture, a bit of instability, and scads of wind shear (differences in speed and direction of the wind as one travels upward from the surface) has led the Storm Prediction Center to issue the following graphic for severe weather potential:
The main threat will be the chance of damaging winds as the cold front fires off a squall line, but with the abundance of wind shear a few rotating thunderstorms and tornadoes could easily form in the northern Virginia region. Tomorrow afternoon would be a good time to pay attention to the weather!