Tuesday, August 28, 2012

Isaac Still Has Eyes On Arkansas


9:15 PM Tuesday Update... The Summer contest numbers are updated.  Amanda Paige is in the drivers seat to win the big prizes in contest #1.  To find out more about that and contest #2, click on "2012 Summer Contest" in the navigation bar above.  I'll have more on Isaac soon.

Do you know the meaning of "Isaac"?  It's Hebrew for "he will laugh".  How appropriate!  Let's be honest.  The forecasting of this system has been nothing short of horrible.  There were some saying this would hit the east coast of Florida, then Tampa, now the Louisiana coastline.  Most thought it would be a strong hurricane by now even possibly a major hurricane.  As of the time I write this, he is still a tropical storm, but should be upgraded to hurricane status soon.  So Isaac must be laughing at us!

Even just a few days out and the model guidance continues to shift with each and every run.  Some move it so far to the west that the center rides up through the Sooner state while others take it right through Arkansas.

I still think the main threat will be heavy rainfall in Arkansas so that raises the question about flooding.  Due to the recent drought, the ground will be able to absorb a large amount of water.  However, due to the hard nature of the ground and high rainfall rates, some of that will runoff.  The track of the storm is extremely important in determining who gets the highest amount.  As I have mentioned several times before, we need to look at the areas along and east of the center of circulation.  This is the right front quadrant.  The counterclockwise circulation will draw vasts amounts of Gulf moisture.  Bands of heavy rainfall will set up in this location and some of the embedded storms will have the ability to briefly rotate.  With any land falling tropical system, tornadoes are a possibility.  If any form, they should be isolated and brief.  Once Isaac makes landfall, the forward speed will increase and this should help limit the flooding potential.  I still expect most of the rainfall to exit by the weekend.

Check out the model maps below and the video.  5 years ago, I few through Hurricane Ike with the Hurricane Hunters in the Gulf of Mexico.  These dedicated men and women of the Air Force are working around the clock to give us vital information.  In 2005, they never left their jobs when many of their homes were destroyed by Katrina.  We should all be thankful for the work they do.  All of them undergo training right here at the Little Rock Air Force Base. I hope you enjoy the story below.

The overnight run of the European model has drastically shifted to the west and places the center over eastern Oklahoma.  This puts all of AR in the right front quadrant and raises the concerns for heavy rainfall.  This is valid late Friday
The UKMET brings the low into south central AR late Thursday with heavy rain overspreading the state from south to north.
The GFS places the center near Mt. Ida early Friday morning bringing heavy rain to about the eastern 2/3 of the state.
The HPC shows very high rainfall amounts along and east of the centers track.  This would bring widespread 2-5''+ amounts to much of central and eastern AR.  NOTICE THE SHARP GRADIENT IN THE AMOUNTS!  AREAS WEST OF THE CENTER WILL NOT SEE HIGH AMOUNTS COMPARED TO THOSE WHO ARE LOCATED EAST OF CENTER.
The official track from NHC shows Isaac going right through central AR early Friday morning as a tropical depression.  Notice the points are spaced at 24 hour intervals.  Those intervals get longer with each point.  This shows you the forward speed will increase once it moves northward.  This will hopefully prevent flooding, but we need to aware of high water!

1 comment:

Doug in HS said...

Isaac is laughing, sure enough.....laughing at his coverage from a certain channel dedicated to the weather.

The NEW Arkansas Weather Blog