Wednesday, April 27, 2011

Tornado Watch Until 8PM Wednesday

A Tornado Watch is in effect until 8PM for all of the counties highlighted in red, which includes much of central and western Virginia.

Isolated tornadoes, damaging winds to 70 mph, and large hail up to 2" in diameter (larger than golf balls) are all possible this afternoon and early evening with any thunderstorms that become severe.

Instability is rapidly increasing in the area as a result of ample moisture, wind shear aloft, and peak afternoon temperatures rising into the low to mid 80s. Scattered thunderstorms are developing across the area, producing heavy downpours, frequent lightning, and gusty winds. We'll be tracking the severe threat today. For the latest information, please go to the Storm Room here. Stay with CBS 6, we'll keep you ahead of the storm!

Severe Threat Again Today For Many States Including Virginia

Significant severe weather is likely again today through the Deep South and Ohio Valley region ahead of a potent storm system that has a history of producing tornadoes, hail and wind damage, and flooding through the Plains and Midwest. Here is today's Severe Weather Outlook for the eastern half of the U.S.:

In Virginia this afternoon, a few of our scattered heavy thunderstorms that should develop during the peak afternoon heating in a moist environment (just like on Tuesday afternoon) could be severe. Our primary threats in central Virginia include damaging wind gusts and hail, but southwest Virginia will have the additional threat for isolated tornadoes.

The cold front associated with this potent upper storm system will finally sweep through the East Coast Thursday, with a squall line likely advancing through central Virginia Thursday morning ahead of it. As a result, we'll have the slight risk for damaging wind gusts from that line Thursday:

Here's the time-line based on our data this morning for Thursday's squall line and cold frontal passage:

After sunrise Thursday, the squall line should be nearing I-95:

I expect strong wind gusts, heavy downpours, frequent lightning, and hail out of this line Thursday morning as it sweeps through our area:

It looks like the rain and storms will be forced out of the Commonwealth to the east by mid-afternoon as the cold front sweeps through, ushering in drier air.
This is great news for those of you with outdoor plans Thursday evening!

Rainfall accumulations look like they will range from half an inch to an inch in most of central Virginia from the squall line, with isolated higher totals possible from the embedded strongest storms. Stay with CBS 6, we'll keep you ahead of the storm.
--Meteorologist Carrie Rose ("Like" Carrie on Facebook by clicking here)

Monday, April 25, 2011

Rain & Storms Mid-Week, Nice Weekend Ahead

If you were outside Sunday for various Richmond activities, including Monument Avenue's traditional Easter on Parade, you probably thought it was Summer instead of Spring! Officially at Richmond International Airport Sunday the high temperature was 88 degrees. That's well above the average high for this time of year of about 72 degrees, but not quite to the record high for yesterday's date of 94 degrees in 1925.

Monday will be nearly identical to Sunday, perhaps a degree warmer up to 89 degrees! High pressure off the Carolinas coast is keeping us mostly sunny and allowing a steady south to southwest wind to bring in warmer, moist air. Today's record high is 96 degrees, also from 1925. So the beginning of this week feels like July's average highs (upper 80s), but we're still not breaking any records from this Summer preview. However, the morning temperatures today in central Virginia were close to being record-warm lows for today's date! This morning's low temperature was 66 degrees, just one degree shy of the record warm low for April 25th of 67 degrees from 1976!

With that steady stream of moisture gradually infiltrating the Commonwealth from the south, we should get scattered showers both Tuesday and Wednesday, especially in the afternoons when we are the warmest and can get scattered convection. But our best chance for heavy rainfall (which we need: current year-to-date deficit is about 2.5" below normal) will arrive Thursday ahead of a strong cold front. The exact timing of this front is still not set in stone, but it does appear that a squall line should advance into all of the Mid-Atlantic ahead of the front Thursday morning into early afternoon. Some of these storms could be severe with damaging wind gusts. As with any thunderstorm, threats will also include lightning, hail, and downpours. We'll be tracking the development of that system and its progression toward us over the next several days.

Once that cold front exits east Thursday, the end of the week looks dry with typical Spring weather settling into the region with afternoon highs in the 70s and comfortably cool mornings in the 40s and low 50s. This is great news for the big race events at Richmond International Raceway from Thursday night through Saturday! Click here for the RIR event schedule. Stay with CBS 6, we'll keep you ahead of the storm. --Meteorologist Carrie Rose