Monday, October 17, 2011

Mid-week rain will result from merging storm systems

Two storm systems will merge over Virginia Wednesday, producing a washout in the Commonwealth that day, bringing windy conditions, and also ushering in much cooler air for the end of the week. Parts of Virginia could get their first frosts Friday and Saturday mornings! Let's talk about where the two storm systems are right now.

One is still organizing in the Gulf of Mexico just northeast of Mexico's Yucatan Peninsula. Here's the morning color-enhanced infrared satellite image of this yet unnamed system:

And for your perspective, here's a broader infrared satellite view of the Gulf of Mexico Monday morning:

An Air Force Reconnaissance Plane is scheduled to investigate this system Monday afternoon. If it is deemed organized enough with sufficient tropical cyclone characteristics, it may become a Depression or named Tropical Storm Rina (pronounced REE-nuh). You can check back for updates on the tropics using our Hurricane Tracker Tool by clicking here.

The next system to affect us will arrive from our west as a digging trough over the central U.S., enhancing the potency of the approaching (potentially tropical) low from Florida. This will bring rain and windy conditions to Virginia Wednesday and Thursday. A strong surface cold front will sweep through the Mid-Atlantic by early Thursday as the merged upper trough and low pressure system from the Gulf lift north of Virginia. Here's what the jet stream creating the digging upper trough will look like by Wednesday morning, just as it is about to merge with the southern low:

After that merged storm system lifts north of Virginia Thursday, much cooler, drier air will surge into the Mid-Atlantic for the end of the week from central Canada. This could lead to the first frost for parts of central Virginia by Friday and Saturday morning, with lows dipping into the 30s. We'll keep you posted on that frost potential through the week as the potency of this storm system becomes clearer! For your reference, the average first Fall freeze (low temperature of 32 degrees F) for Richmond is October 29th, so a frost around October 21st would not be unusual.

Stay with CBS6, we'll keep you ahead of the storm.
--Meteorologist Carrie Rose