Tuesday, June 25, 2013

Coolest Opening To July In Years?


Wouldn't that be nice?  I'll get into the details in just a little bit, but as I said on the air last week, the first 100 degree day in Little Rock is on the table late this week.  The modeling has been very consistent with a high temperature in Little Rock of 99 degrees Thursday.  This burst of heat ahead of the cold front will ride in on strong southwesterly winds.  The good news is that temperatures AND humidity values will fall Friday into the weekend.  It will still be hot, but much easier to tolerate.

Now onto next week.  If you follow me on twitter, I mentioned this a couple of days ago about the unusual jet stream configuration going into the first of July.  The amplification simply means the jet stream has a highly north-south orientation to it.  That's unusual in itself this time of year.  It's also unusual to see it dive this far south.  Normally during the summer time, it retreats to the higher latitudes.  I'm not going to be upset about that!

Let's look at the first 4 days of July (temperatures) over he past 5 years.

2012: 112, 99, 103, 103
2011: 96, 98, 98, 94
2010: 92, 91, 90, 94
2009: 93, 92, 90, 93
2008: 89, 90, 93, 86

The first 4 days of 2008 to 2010 were not bad for July standards, but I think it's possible for us to beat that given the pattern.  Here are the charts below...

This is the 500mb pattern from the 00Z run of the European model valid next Tuesday.  Remember on the air last week I kept talking about the ridge building in the west and a downstream trough developing over us.  This looks very likely to happen.  You can see that ridge poking up in the western states.  Look how the black lines dive south and form the trough over us!!!!  This will help discharge cooler Canadian air and allow it to dive south into the trough.  This amplification (north to south) alignment to the jet stream is not something you see often in July!!!!
At 7PM July 1st, look how the heat has been suppressed to Texas and there are widespread  70s and 80s.  WOW!!! That's awesome for July 1st in the evening!
The below average temperatures last into the 2nd as well!!!!  This is valid again at 7PM
This is valid on the 4th of July at 7PM.  This gets much more complicated as this is 10 days out and unlikely to verify exactly.  See how cool it is over the northern half of the state?  This is due to the model seeing rainfall there.  DON'T PANIC YET.  This is 10 days out and unlikely to verify exactly.  I'll watch it for you.
NOAA's 8-14 day outlook (July 2nd through 8th) has a good chance for below average temperatures.  They are buying into the ridge out west and the trough here!!!!

2 comments:

Anonymous said...

Typo!! he instead of he

Anonymous said...

It looks like my hope for a massive cool front came to fruition!