Thursday, August 17, 2017

How the eclipse may affect temperatures

It will be interesting to see what happens with temperatures on the afternoon of the eclipse.

Forecasters at the National Weather Service in Indianapolis pulled up data from the last annular eclipse to take place in 1994.  The temperature dropped 4° in an  hour when the maximum eclipse occurred over Lafayette.  The moon appears smaller in an annular eclipse, so it does not cover all of the sun.  So it is conceivable the temperature may drop 5° to 7° during the peak of the eclipse.

Right now we are forecasting a high of 90° for Monday.  Since the eclipse is happening during the peak heating of the day I'm curious to see if that keeps the temperatures from reaching their full potential.

Wednesday, August 16, 2017

Solar Eclipse: Closer look at cloud cover projections

We are now less than five days away from the much anticipated Solar Eclipse.  In the Weather Department our eyes are focused on what the weather will be like for the day.

As we get closer computer models usually come in to better agreement as to what cloud cover and precipitation will be.  So far, the two medium-range computer models we use are at odds.
GFS's cloud cover and precipitation rate projection at 2pm ET Monday.

ECMWF's cloud cover and precipitation rate projection at 2pm ET Monday.

The two computer models we are looking at is NOAA's global forecast model (GFS) and the European Forecast Agency's global forecast model (ECMWF).

The best viewing of the solar eclipse will be with less cloud cover.  For that we want to the total cloud cover percentage as close to 0% as possible.  While you may be able to see some of the eclipse through the clouds, the more clouds overhead, the less you will see.

As you can see in the images above both computer models project clouds around in the Midwest on the afternoon of the 21st.

Here's a more specific look at the projected total cloud cover percentage at 2pm Monday, August 21 around central Indiana.

Bloomington, In:
  • GFS - 78%
  • ECMWF - 40%
Cape Girardeau, Mo:
  • GFS - 45%
  • ECMWF - 64%
Carbondale, Il:
  • GFS - 56%
  • ECMWF - 34%
Columbus, In:
  • GFS - 79%
  • ECMWF - 66%
Farmington, Mo:
  • GFS - 83%
  • ECMWF - 39%
Indianapolis, In:
  • GFS - 79%
  • ECMWF - 81%
Kokomo, In:
  • GFS - 98%
  • ECMWF - 52%
Lafayette, In:
  • GFS - 95%
  • ECMWF - 78%
Muncie, In:
  • GFS - 90%
  • ECMWF - 58%
Paducah, Ky:
  • GFS - 43%
  • ECMWF - 83%
St. Louis, Mo:
  • GFS - 99%
  • ECMWF - 29%
Understand that there are another 35 computer model runs to go before the eclipse gets here.  And that's just for these two computer models.  Once we get within 72-hours of the event, additional computer models will chime in with what they think will happen with the weather conditions.

Sunday, August 13, 2017

Updated cloud cover projection for Solar Eclipse

I continue to look over computer model data for the Solar Eclipse coming Monday, August 21.  Specifically, I'm watching how much cloud cover could be in the sky for the eclipse.

This morning's computer model runs are on two ends of the spectrum for cloud cover.  NOAA's global forecast model (GFS) continues its bullish run on clouds.  The European forecast agency's ECMWF keeps skies much more clear.

It is interesting to note that the GFS has been very consistent suggesting clouds over much of the Midwest for several days.

Remember, for the best viewing experience we want less clouds.

Total cloud cover projections for 2pm ET/1pm CT:

Bloomington, In:
  • GFS - 98%
  • ECMWF - 38%
Cape Girardeau, Mo:
  • GFS - 89%
  • ECMWF - 36%
Carbondale, Il:
  • GFS - 93%
  • ECMWF - 18%
Columbus, In:
  • GFS - 90%
  • ECMWF - 51%
Farmington, Mo:
  • GFS - 94%
  • ECMWF - 27%
Indianapolis, In:
  • GFS - 97%
  • ECMWF - 52%
Lafayette, In:
  • GFS - 100%
  • ECMWF - 29%
Muncie, In:
  • GFS - 98%
  • ECMWF - 58%
Paducah, Ky:
  • GFS - 76%
  • ECMWF - 20%
Peru, In:
  • GFS - 100%
  • ECMWF - 20%
St. Louis, Mo:
  • GFS - 92%
  • ECMWF - 3%
Terre Haute, In:
  • GFS - 99%
  • ECMWF - 34%
It just so happens I will be in Missouri the day of the eclipse.  Better yet, where I am going to be is in the area of totality.  Here's hoping the cloud cover projections keep going lower and lower!

Saturday, August 12, 2017

Early look at sky conditions for the 2017 Solar Eclipse

The buzz around the Solar Eclipse on August 21 is starting to increase as we get closer to the day.  While it is still many days away, computer models are beginning to take a stab at what sky conditions will be for the day.

There are two computer models that can reach far enough in to the future to project cloud cover for the 21st.  The National Oceanic and Atmospheric Administrations global forecast model (GFS) and the European forecast agency’s global forecast model (ECMWF).

For several days the GFS has suggested there will be a lot of clouds and rain in the Midwest for the 21st while the ECMWF is more bullish on sunshine.

Sunday morning’s computer model total cloud cover projections* at 2pm ET:

Bloomington, IN:
  • GFS - 99%
  • ECMWF - 45%
Cape Girardeau:
  • GFS - 100%
  • ECMWF - 31%
Carbondale:
  • GFS - 98%
  • ECMWF - 36%
Columbus, IN:
  • GFS - 100%
  • ECMWF - 24%
Farmington, MO:
  • GFS - 98%
  • ECMWF - 19%
Indianapolis:
  • GFS - 100%
  • ECMWF - 40%
St. Louis:
  • GFS - 95%
  • ECMWF - 18%
*Higher number equates to more clouds obscuring the sky/sun.  The lower the number the better for viewing the solar eclipse.
Between those two computer models there are 55 more computer models runs to go before the solar eclipse happens.  The cloud cover projection will likely flip flop many times between now and then.  With luck we'll see the numbers drop to 0%.

Do you plan to view the solar eclipse?  If so, let me know where you'll be watching it by leaving a comment on this post!