Thursday, July 26, 2007

Steamy pattern through the weekend...

We enjoyed some delightful weather over the past weekend into the early portion of this week, with low dew points in the upper 40s and low 50s (meaning low humidity!). At this time of the year, that is absolutely terrific in Central Virginia and you knew it had to change. Dew points have been on the rise the last couple of days and we're in for some sticky conditions this weekend into early next week.

While we've seen a few showers and even thunderstorms scattered about the state, there hasn't been much rain over the last week (and the last month for that matter). If you're waiting for some rain, our chances will be going up over the weekend. We may get to see a few storms pop up before then, but a front arriving from the Midwest will be the main trigger for some widespread showers and thunderstorms. The period I'm focusing attention on is Sunday through Tuesday. Hopefully some beneficial rain will put a dent in the drought conditions now affecting parts of Virginia.

Looking ahead to next week...

This front will likely stall near or over us, leading to a continued threat for scattered showers and thunderstorms through at least Tuesday. There are signs that the high pressure ridge now over the Rockies and Plains (bringing days on end of triple-digit heat to places like Montana and the Dakotas) will begin to shift a bit to the east. This could lead to a drier but hotter spell heading into the first weekend of August.

The tropics...

Still nothing doing in the tropics! While a few clusters of thunderstorms have popped up over the Gulf of Mexico, nothing has been able to organize and it remains pretty quiet over the open Atlantic. It will be interesting to see if there is any development over the next couple of weeks, as we head into August. Remember the peak of hurricane season is in early to mid-September.

Friday, July 13, 2007

A break from the heat...

We've enjoyed a nice break from the heat the past two days, with afternoon temperatures in the 80s and comfortable levels of humidity. If you remember, last week I had talked about our longer range charts showing this pattern change for late this weekend...so it came a couple of days early! The clouds held back the temperature on Friday, but the sun will be back in full force to start the weekend. The humidity will be on the rise by Sunday, and while most of the weekend will be rain-free, there could be a few scattered thunderstorms popping up on Sunday afternoon.

Back to a steamy pattern next week...

It now looks like we'll have more of the typical July weather next week, so the temperatures and humidity will go back up. Afternoon temperatures will average in the low 90s with a blend of clouds and hazy sunshine. Each afternoon, there will be the risk for a few thunderstorms popping up. The storms should be rather isolated Tuesday and Wednesday, but more numerous Monday and Thursday, as a couple of fronts move through the region. The exact timing could change, as it is difficult to forecast exact details with a northwest flow aloft kicking weak disturbances through from time to time.

In the longer range...

The upper pattern looks like it may be rather flat next weekend heading into the week of July 23rd. This means our weather could be rather stagnant with fewer breaks in the heat. There's plenty of extreme heat out west and that might head east. Temperatures could be in the 90s for a prolonged period for the last two weeks of the month.

The tropics...

All is still very quiet in the tropics, with no development expected over the next couple of days. Don't be deceived though, it's still early in the season and activity usually doesn't pick up until August.

Friday, July 6, 2007

Intense summer heat on the way...

While temperatures here haven't been all that high for early July (upper 80s to around 90), a big dome of extremely hot air has been affecting the West. Here are some of the high temperatures from Friday:

Phoenix, AZ 113
Las Vegas, NV 115
Salt Lake City, UT 103
Boise, ID 105
Great Falls, MT 104
Rapid City, SD 105

Many of these were record highs, including Great Falls, where the temperature was way above the average high of 80 degrees!

Here in Central Virginia, temperatures will be on the rise through the weekend. The humidity won't be too bad on Saturday, with dew points in the somewhat comfortable low 60s. However, it will become quite steamy by Sunday afternoon, with temperatures in the mid 90s and the heat index around 100 degrees.

A extended spell of very hot weather next week...

Monday will likely be the hottest day here, with temperatures close to the century mark. We could flirt with 100 again on Tuesday, although there will be a risk for some scattered thunderstorms to develop in the afternoon. Temperatures in the 90s are likely again on Wednesday and Thursday, although there will be more cloud cover and an increasing threat for thunderstorms. The next front will move into the area by later Thursday, and should help to lower temperatures back into the 80s by Friday. Our longer range charts are showing the potential of a deeper East Coast trough developing by later next weekend. That could help keep our temperatures down a bit to start the week of the 16th.

The latest in the tropics...

Since our first two named storms of the season, the tropics have been very quiet. We don't see any potential development over the next couple of days. I previously mentioned that the favorable areas for development in June were in the Gulf and Caribbean. Now during July, we look farther into the Atlantic for possible development, including off the East Coast. As we get into August, activity usually increases, heading toward the peak of the Atlantic season, which is around September 10th.