Friday, September 23, 2016

Arkansas Leans Euro

You see all these political polls nowadays with states leaning GOP and leaning DEM.  My forecast usually leans Euro over the GFS.  I hate saying that, but the European model does an overall better job.

I want to show you how drastic a change the forecast for Monday is undergoing because the GFS is now catching up to the European's slower frontal boundary movement.  While the end result is about the same between the two models, cooler air next week, forecasting the boundary location is the big question for Monday!

Remember, the European model has shown highs in the 80s and 90s Monday consistently.  Here are the past two 12Z runs.

The following maps are from EuroWX.com and Weatherbell.com
The 12Z run of the Euro today shows a HUGE temperature contrast from north to south Monday for highs.  70s north behind the front with 80's and 90s ahead of it.  This makes more sense given the upper pattern with the trough going to the SW U.S and another piece going to the Great Lakes.  This would push the front in from north to south and the Ozarks would slow the southward push allowing for another hot day before the cool down Tuesday.

The 12Z run Thursday had the same idea as todays run.
The 12Z run of the GFS Thursday showed high temperatures next Monday only in the 50s and 60s as it pushed the front through too rapidly.  It took most of its upper level energy north of the state instead of leaving some behind in the southwest U.S. 

Today's run (Friday) now has highs in the 70 and 80s.  It's getting warmer with each run for Monday!  This is due to the slower frontal movement.

Why am I posting this?  Just an illustration as to why I like to look at the Euro so much.  Not always right, but if I was a betting person, I'd put money on it.

Thursday, September 22, 2016

Pumkin Spice Cold Front

Friday morning update... No surprise, the GFS is now looking like the Euro at 500mb.   The super cool air, I warned about forecasting, looks less likely.  With that said, IT WILL TURN SIGNIFICANTLY COOLER.  However, the temperatures forecast by the GFS will likely turn out to be wrong.  Look at the two models and their latest versions.

The GFS midday Monday shows the trough moving into the Great Lakes.  This helps drive a cold front through the state.  But look how different it looks in the southwest U.S.  A piece is left behind which is different than previous runs.

The Euro at the same time looks very close to the GFS now.  It's worth noting the Euro has been fairly consistent which is another reason why I have liked this model.  It's not run 4 times a day and comes up with 4 different solutions.

The GFS numbers now have temperature highs in the upper 70s Monday and Tuesday compared to previous runs which had it in the 50s and 60s.  The Euro is also a bit slower pushing the front through the state.  This brings in big differences in the forecast for Monday.  The Euro says we go into the 90s Monday which the GFS has 70s.  However, by Tuesday, both show a better feeling air mass across much of the state.

So there are still challenges in the forecast, but I would continue to hedge my bets on the slower Euro, BUT continue to hope the GFS can beat it only because I want cooler weather faster. LOL.

Also, I don't expect the cooler air to last by a few days.  It will warm up again, maybe not into the 90s, but the cooler air will modify.

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FINALLY,  a change in the weather!  We're getting a turn to fall, but there are two questions that can't be answered yet.  How cool and how long will it last?  The two main models (GFS and Euro) continue to show differences, but both models do cool us down significantly. As I always say in the long range, I would hang my hat more on the Euro than the GFS in most situations and this is no different.

Some of the maps are courtesy of Weatherbell.com and EuroWx.com 

At 500mb, about 20K feet up, we see significant difference between the models. You can clearly see the Euro cuts off a low over the southwestern United States and leaves it behind with the main trough (all the red) moving through the Great Lakes.  That will help drive the front into the state.  This would lead to cooler temperatures, but not as cool as the GFS which brings the whole trough through.

The GFS brings the whole thing though Monday into Tuesday.  See that big area of red north of Arkansas?  Nothing is left behind. This solution would send a surge of VERY cool air into the state.   However, at this time, I think it would be best to consider this a bit too strong.

Just for fun, the GFS temperatures behind the front Tuesday at 1PM are only in the 50s.  This is due to the colder push of air behind the front, but more importantly, because of cloud cover.
The GFS Tuesday at 1PM, shows extensive cloud cover keeping temperatures quite cool.  Again, at this time, I would hedge my bets against this at this time.

The Euro shows highs in the 60s north, 70s central, and 80s south Tuesday.  This looks more realistic.

In summary, it will cool down!  The question is, does the Euro or GFS have the right idea?  Many times, it's something in between, but I would bet it will be closer to the Euro.

Wednesday, August 31, 2016

Goodbye Summer, Hello Fall!

ALL NUMBERS ARE PRELIMINARY AND OFFICIALS WILL NOT BE AVAILABLE UNTIL THURSDAY.

Today (August 31st) is the last day of meteorological summer.  When the final numbers come in, we'll see temperatures were above average and rainfall was well above average.  The number of 100° plus days was close to average with a total of 5.  Average is 6.

By average high temperature (assuming a high today of 94°) it was 92.88° which is NOT in the top 10.

By average low temperature, we ended up at 75.27° which is the 2nd warmest in Little Rock weather history.

By average seasonal temperature, it was 84.07° which is the 6th warmest on record.

What explains these wacky numbers?  MOISTURE!!!!   High levels of humidity kept lows from dropping much at night which gave us that 2nd warmest by low temperature.  That high moisture level also prevents daytime highs from getting out of hand and that explains why we didn't crack the top 10 in that category.  HOWEVER, that elevated low temperature average boosted this summer to #6 by average seasonal temperature.

In summary, it was NOT your imagination, it was a very humid summer with very high heat index readings and many days with heat advisories!

Assuming NO rainfall today through midnight, and there is a slight chance today, August 2016 will end up being the 8th wettest in Little Rock weather history which dates back to the 1870s.

The summer of 2016 will be the 9th wettest in Little Rock weather history with 16.76''.  By the way, our yearly total so far is 45.95'' and that's 14.63'' above average.  We still have 4 months to go and November is typically the wettest month of the year according to 30 year climo.


Let's roll into September and see what it can bring...


  • We will lose 1 hour and 2 minutes of daylight.
  • hottest state temperature was 114 degrees at Waldron on Sept. 8, 1922
  • lowest state temperatures was 28 degrees at several locations
  • Highest daily rainfall was 12.25'' at Crystal Valley on the 13th, 1978
  • Highest monthly rainfall was 21.95'' at Moore in 1898
  • Little Rock hottest September temperature was 106 on Sept. 1, 1947
  • Little Rock coldest temperature was 37 degrees on the 22nd, 1942
  • Wettest in Little Rock was 10.23'' in 1898
  • Driest was .27'' in 1917 in Little Rock.