Saturday 7/2 Update

Hope your Fourth of July weekend is going well so far.  No complaints about today's weather, as we had plenty of sunshine to enjoy, and the worst of the heat and humidity stayed just to our west (St. Louis and Springfield, MO, both reached 99). 

Looking ahead to the rest of the holiday weekend, the big variable/question mark in the forecast for Sunday & Monday will be the influence of a weak cold front dropping in from the south.  This front should provide enough moisture and lift to generate at least a few scattered storms over the next couple of days.  Here's a peak at the NAM forecast model for 7PM Sunday:

The purple coloring over parts of IL & MO is estimated accumulated rainfall over 6 hours...indicating the chance for scattered storms during the afternoon & early evening.  That is where I think the best chance of scattered storms will be Sunday, although it's not out of question that something could pop up elsewhere.  No organized severe weather is anticipated, although a storm or two could produce some marginally severe hail or wind.  Officially, I'm putting the rain chance at 20% for Sunday, with the rest of us seeing sunny to partly cloudy skies.  Sunday should be the warmest day of the weekend too...with highs in the mid 90's. 

Looking ahead to Independence Day, a couple of forecast models are indicating the potential for an MCS (mesoscale convective system...or simply a thunderstorm cluster) to move through late Sunday night/early Monday morning.  I'm not sold on this yet, and many times these are extremely difficult to predict more than 12 hours out, so stay tuned.  Regardless, an overnight storm shouldn't disrupt many plans.  As for Monday afternoon, it's a similar setup to Sunday...only I believe the chances for scattered storms are a little higher area-wide.  Here's what the NAM looks like for 7PM:

Notice that there is a little broader coverage on the rain there...so officially I'm going with a 40% chance of scattered storms during the afternoon and early evening, but I think as the peak heating of the day diminishes, we'll see most of the storms die down in time for fireworks displays.

Heading into the rest of next week, the same front that will drop in from the south later tomorrow will waffle back and forth this week, leading to an up and down swing in temperatures and rain chances.

On Tuesday, the front pushes back to the north, leading to more heat and diminishing rain chances.  Then Wednesday & Thursday, the front drops back to the south, upping scattered storm chances, and eventually leading to a slight cool down (perhaps), by the end of the week.  However, as we continue on into the July, the frequency of cold fronts actually making it through our area decreases, so this forecast is certainly subject to change.

A couple of quick extras, I found a couple of interesting tidbits on spaceweather.com today.  First of all, the International Space Station will be visible from our area tonight and Sunday night.  Tonight, it will be visible in the WNW sky (47 degree elevation), between 9:28-9:31 PM....then again Sunday night in the NNW sky (68 degrees), between 8:30-8:34 PM.  To see the specifics on how to view the ISS from your backyard, check out http://www.spaceweather.com/flybys.

A second thing from that site...a rare type of clouds, called noctilucent clouds, invaded parts of the northern U.S.  Check out this picture from Washington state: 

To read more on these clouds, click here.