Monday afternoon

It’s hot, but at least the humidity isn’t too bad.  Current dew point is 65, right on the bottom end of when humidity starts adding discomfort.  General rule is that dew points below 65 cause little problem for the majority of the population.  However, when the dew point rises above 65, the humidity really gets noticeable.  For this area, Dew points at 70 or above can make the air feel oppressive.  The dew point, by the way, is the temperature to which the air must drop for the air to be 100% saturated.  So, dew points are an absolute way to express moisture in the air.  The higher the dew point, the more moisture is in the air.  Relative humidity, a more familiar term, is highly variable and values change widely during most days.  I know you’re not supposed to define a word by using, but relative humidity really is “relative” (to the air temperature).  More on this at a later date, if anyone is interested – or even if you aren’t!

Back to the weather…there’s a large, weak upper air disturbance over the deep south that is bringing scattered showers/t-storms from the Gulf Coast as far north as Tennessee and east as far as the Carolinas.  This system has been cut-off from the normal wind patterns over the northern U.S.  As a result it is just drifting aimlessly.  Forecast models continue a general weakening trend with a WSW direction.   Thus, higher moisture will be trapped by this system and discourage northward movement.

That becomes the big question mark for our midweek chance for rain.  As usual, the NAM family and the GFS have their differences.  But, once again, none of the models is expecting much rain.  The NAMs are faster and stronger but bring in rain/t-storms during  the morning – the worst time for significant rain.  Meanwhile, the GFS holds off the rain/t-storms until about 4-10PM.  That allows time for more heating, but thunderstorms also need moisture.  That’s being trapped by the southern system.  Neither system holds out much hope for a decent amount (say, .50″ or more) of rain.

As I’ve mentioned before, beyond a day or two the GFS seems to be better.  So it looks like tomorrow and Wednesday should both reach the lower 90’s with a good chance of late day thunderstorms on Wednesday.

Commentary (and a bit of bragging)

As I write this, my wife and 12-year old granddaughter (Holly) are downstairs in the sewing room.  My wife sews a lot (quilt-maker) and Holly has always been fascinated and has been learning for years.  Today they are working on a charitable project called Dresses for Africa.  The original idea used pillow cases to make a quick and easy dress for young girls in Africa.  They made five a few weeks ago and are back at it again.  Here’s a picture of Holly’s first efforts.         If you sew or know people might be interested, you can get all the information at www.littledressesforafrica.org.