Archive for May 20, 2014

WARMER WEATHER ARRIVES BUT SO DOES A CHANCE OF SHOWERS AND THUNDERSTORMS… THE EXTENDED FORECAST LOOKS LIKE SEASONAL TEMPERATURES WILL RETURN ALONG WITH MOSTLY DRY CONDITIONS

Temperatures the past couple of days were a little on the chilly side, especially during the morning hours. That’s all about to change as warmer air tries to move into our region from the west and southwest. There is a complicating factor that may result in an increase in the chance of showers and thunderstorms beginning late tonight and continuing through Thursday. A northwesterly flow aloft is expected to contain disturbances that may trigger showers and storms every once in a while. In a weather pattern like this, it is nearly impossible for meteorologists to nail down the timing of any rain that develops. I don’t think we are going to see a widespread rain event over the next few days, but there could be isolated areas that do get a decent shower or storm. The highest rain chances that I saw are 30% during this period.  Temperatures today (Tuesday) should top out in the upper 70’s and some spots may see the lower 80’s. Wednesday should be warmer, but that will depend on the cloud cover and any potential showers/storms that develop. Rain chances should decrease on Friday and as it looks right now, the Memorial Day weekend looks okay, with just a small chance of a shower or thunderstorm. Note that we are approaching the time of year when you can’t rule out a shower or thunderstorm during the afternoon and evenings on certain days. This is due to the fact that our humidity levels normally increase at this time of year and it doesn’t take that much of a trigger to cause a shower or thunderstorm to develop. By trigger, I am referring to a sea breeze boundary, upper-level disturbance, cold pocket of air aloft, frontal boundary, etc., etc. The heating from the sun is very strong at this time of year, and this sometimes causes the atmosphere to become quite unstable during the afternoons and evenings. The sun heats the land which causes the air at the surface to rise into the cooler air aloft. (Warm air is lighter and less dense than cooler air). This results in condensation, which causes clouds and sometimes precipitation. The process of condensation releases latent heat which makes the air rise even further into the atmosphere. That’s what makes those huge cumulonimbus clouds that we frequently see during the spring and summer. That’s it for now. Have a great day!

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