WEATHER CONDITIONS FOR THE GREAT

AMERICAN ECLIPSE 21 AUGUST 2017

based on the data SUNDAY MORNING 8/20/17

SUMMARY

Over the past SEVERAL days I have been issuing daily forecasts with regard to the great American eclipse on Monday August 21. If you do

not know by now Solar Eclipse will occur across much of the country with a spectacular long lasting totality sweeping across the country

from the Pacific Northwest to the Southeast US on the 21st. It will begin Monday late morning and last through the midday hours into the

afternoon. Obviously the main concern is going to be weather conditions. Some of you may be looking at various web sites on the Internet

or your smart phone or social media to get weather information. As a professional meteorologist of more than 25 years experience, I

can tell you that the weather information you get on your smart phone, social media or on various web sites which contain

temperatures, cloud cover, winds and precipitation beyond day 3 or 4 days is pretty much useless Crap. .

For those of you that did not know me .. I am a Grain or agricultural meteorologist. This means I deal in the commodity markets

quite extensively and if you know anything about the commodity markets or agricultural weather in general, then you know that

what matters is not the forecast for today or tomorrow. What matters is the forecast 3 days, 5 days, 8 days, 12 days 30 days out

into the future. As a result I spent my entire time forecasting behind the next 48 hours and I am very good at

This is important because the fact of the matter is that your local NWS forecast office gives the " extended forecast" the lowest priority

and effort of any of their forecast products . And the dirty little secret from the TV weather world is that most TV weather personalities and

meteorologists would rather not do 5 day or 7 day forecast. The only reason they do so because the news directors demand that they do

so. Most of TV weather folks (not all most) do not like making extended forecasts and they are not very good at it. (why exactly the

not very good at it is a whole different kettle of fish).

For this forecast I have divided the country up into several sections based upon geography and climate and the current weather

pattern. This makes it easier to break the forecast down into a readable format so that you, the average person, can understand what is

going to happen on August 21. Hopefully these forecasts will enable you and others to understand which areas of the country are likely to

see spectacular conditions for the solar eclipse , which areas are likely see so so conditions, and which areas are likely to have real

problems.

There are images and model data out there which can be presented which shows the overall cloud cover for Monday midday across the

continental US (conus) . However these are model projections from forecasts which are 8-9 days away and not very good. The model

guidance should be looked at but there is more to making a extended forecast than simply looking at whatever the model data is showing.

These forecasts rejections are based upon the model data from Sunday afternoon mainly the European model at 12 the but there is

some input from the Canadian GFS models.

We are now close enough to the event for the short range models to play a more important role in making the forecast. The SUNDAY

morning weather models are now showing some clear trends viewing conditions look worse for NEB KS MO and still iffy for portions

of SC and northeast GA. These next few maps will explain what the issues are with regard to the viewing conditions over various

portions of the country.

This first map represents the surface conditions on the morning of August 21 / 8am EDT- 5AM PDT. Overall there really is not much

to change in the SUNDAY morning report with regard to the HISTORIC solar eclipse event on August 21.

This first image represents the SURFACE map valid on Monday morning August 21. We still have two distinct / important features that

dominate this map. The first one is the area of LOW pressure associated with a weak cold front that is bringing significant rain and

thunderstorms to central and eastern portions of South Dakota . While the model data shows that the showers and thunderstorms are going

to pass north of the area of totality ... locations such as Nebraska ...South Dakota ....Iowa .. northern Missouri and much of Illinois are in

areas that is likely to see 80 to 90% of the sun covered by the Moon on Monday afternoon. The problem is that the clouds associated with

the cold front will interfere with much of THAT area seeing the solar eclipse.

The 2nd main or key feature is the HIGH pressure along the coast of the Middle Atlantic region. This HIGH will keep skies SUNNY

over most of the Southeastern and southern Middle Atlantic on Monday morning . However as the HIGH moves further off the coast

surface winds will become East then Southeast . This will cause low level humidity and dew points to rise significantly.

This next image shows the SURFACE map valid for Monday evening 8:00 PM EDT / 5PM PDT. When you compare this map to the

one above you will see that there was a significant increase in showers and thunderstorms across Nebraska ...Iowa and ...northern Illinois

...southwest Wisconsin and scattered showers across much of central and southern Kansas. Some of this activity will occur after the point of

Max solar totality but the problem is the cloud cover will be increasing rapidly Monday morning across the central Plains and into Missouri.

Over the Southeastern states there is a small increase and showers over South Carolina.

This image shows the TOTAL CLOUD COVER from the SUNDAY MORNING EUROPERPAN MODEL valid for 8AM EDT / 5AM

PDT Monday August 21 In this image the bright white represents heavy or complete out cloud cover and the gray color

represents partial cloud cover . The cause of the approaching cold front dropping southward from the upper plains into the central plains

on Monday morning and the southerly winds bringing moisture from the Gulf of Mexico there's a significant cloud cover problem covering

much of Eastern Colorado Nebraska Kansas and Missouri on Monday morning. We also have significant clouds along the coastal areas of

the Carolinas and Southern Georgia. The Pacific Northwest and they central Rockies are also in pretty good shape with justice thin band of

partial clouds over portions of Idaho

By 2:00 PM edt/ 1PM cdt Monday -which is when the hour of totality of the solar eclipse occurs... we still have significant clouds

across much of Kansas... southern and southeastern Nebraska ...central and northern Missouri ...and most of Illinois. The area I have

outlined in RED represents a significant portion of the path of totality which will be impacted by these clouds. The European model

over the Southeastern states has actually weaken the clouds so that much of the Carolinas and Northern Georgia are now forecast to by

the Euro model to see some clouds but also some breaks sun/ unobstructed skies. This is a significant proven what the data was

showing only few days ago.

Next we will look at the early Sunday morning GFS model and see its depiction of

cloud cover. Here we will use the clouds at 11:00 AM edt/ 10AM cdt and at

2PM EDT/ 1PM EDT. The color scales different here however for so keep that in

mind ( the dark gray color represents overcast skies the light gray represents

partial clouds and the white color represents generally clear skies)

Keeping that in mind we can see that the model is depicting cloud cover which is

very similar to what the European model showing.. This is a good sign and

increases our confidence in the actual cloud cover. Notice the GFS model shows

either mostly cloudy or overcast conditions over much of Kansas and Nebraska

and portions of southern Illinois and along the Carolina Coast. There are

significant clouds but not overcast over Southwestern and South Central Missouri.

And we have highlighted these areas in RED

By 2:00 PM the time of Max solar eclipse totality... the cloud conditions has

remained pretty much unchanged. Missouri is generally partly cloudy so things

should not be too bad there but southern Illinois looks overcast as does

significant portions of Nebraska ...and northern Kansas. Over the Southeastern

U.S. most areas are generally clear but the clouds have held along the coastal

areas of South Carolina which would impact person as trying to view the eclipse in

areas such as Myrtle Beach and Charleston .

Next we can take a look of the short range high resolution NAM / WRF Model.

This short range model of course specializes in handling thunderstorms and small

scale features and as such cloud cover depiction in a bit more specific detail.

Again I have highlighted the areas in RED which have the greatest risk of seeing

significant clouds during the time of the eclipse. Notice there continues to be

significant clouds and even some storms over much of central and eastern

Nebraska northern Kan