How do you make a five month out forecast?
The honest answer is you can’t. But what you can do is look at the dominate weather patterns in April and show what can happen. I will start by saying that April is a bad month for cloud cover in the United States. Clouds can ruin the plans you made years in a advance to see this incredible astronomical sight. This article will show you the general weather patterns and take a look back at where the clouds and even storms were the past seven years on April 8.
High pressure is good, low pressure is bad:
The major problem with the month of April is large areas of high pressure are not over the United States. Dominate high pressure areas bring cloud free skies because of sinking air. Air has weight, and high pressure is “heavy” inhibiting clouds from building up. In August of 2017 a large area of high pressure brought great weather with clear skies over much of the U.S. Usually large high-pressure areas are over the Pacific and Atlantic Oceans. The path of the total solar eclipse is outlined.
Tracking three lows:
With high pressure not having a major influence our weather, it creates an opening for areas of low pressure to take over. Three different lows can all bring clouds and rain. Low pressure air is “light.” Light air lifts and condenses creating clouds and sometimes rain. Lows act as cloud shields and can ruin eclipse viewing. Springtime storms can also bring severe weather and tornadoes.
Tracking two lows:
A big issue for Mexico, Texas and the southeastern United States is the sub-tropical jet stream. During the spring months this jet stream can bring thick clouds and rain or high clouds. You can still see the eclipse under high thin cirrus clouds, but viewing is muted just a touch. Our best hope is this jet stream is far south of Texas on this day. The polar jet stream can ventilate storms from low pressure areas and create strong storms along the central and eastern paths.
Here are the odds:
I’m sure you’ve heard the saying, “Climate is what you expect, weather is what you get.” The image below is the average cloud cover for the entire month of April. Along the eclipse path, the chances of getting clouds from the mid-west to northeast is 80%. Not a good climate forecast. But also not a guarantee clouds or storms will impact the eclipse. No matter where you’ll be, the time to check the forecast is 10-days out. Three to five days out the forecast will be more accurate, and you’ll have a good idea what the skies will look like on April 8.
For us in Texas:
The state of Texas is split between a 30% to 50% chance of clouds. Central and west Texas has the best chance to be cloud free on April 8 with higher chances of clouds from Waco to Texarkana. My concern is a cold front happening this day. That will not only bring clouds but could also bring severe weather. Timing is everything so a cold front at 4 pm may still have clear skies during the eclipse. We’ll put out an eclipse forecast two weeks before April 8 giving a general idea what to expect in our state. It will be more accurate seven days out. A note about Mexico: it’s the dry season and has the best chance for mostly clear or clear skies on this day.
Past 7-years weather:
April 8, 2023:
What I’ve done here is taken the GOES-East satellite images from April 8 at 1:30PM Central Time. What you want to see is a clear view of the ground. The bright white clouds are overcast skies. The grayer colors are high cirrus clouds. Cirrus clouds reduce the sharpness of the eclipse, but it is still visible. You’ll miss everything under overcast skies. April was a rainy month this year. Nearly an inch of rain fell in Houston April 7. Cloudy skies covered most of the eclipse path in the next day. Only a few spots were cloud free. Northeast Texas was a good spot. Besides high clouds the rest of the country had good eclipse weather with the exception of the far northeastern U.S.
April 8, 2022:
Yikes! Once you get out of Texas thick clouds covered most of the eclipse path through the United States.
April 8, 2021:
This was another pretty good day for the state of Texas. You can also see how a large area of low pressure created thick clouds for the Midwest. Maine also had mostly cloudy skies.
April 8, 2020:
Here is an example of the sub-tropical jet stream carrying clouds to Mexico and west Texas. The rest of the eclipse path saw mostly clear skies until you get to northeastern United States. Later in the day storms from the Great Lakes moved south and brought severe weather. There were 31 tornado reports along the eclipse path. The concern with this set up is that traffic would be so bad with people trying to get back home, they would get stuck on the roads during the storms.
April 8, 2019:
This was another great day for central and west Texas. The rest of the eclipse path was terrible. The brighter the white, the thicker the clouds.
April 8, 2018:
Here is another example with most of the eclipse path under cloudy skies. Central and west Texas is clear with Ohio under mostly sunny skies.
April 8, 2017:
My final example is from 2017. East Texas is cloudy with clear skies from Arkansas to Ohio. The northeastern United States is cloudy. Did you notice that the farther east you go, the better the chance of not seeing the eclipse. Texas usually had good weather. Usually...
One last note about this day:
If you are looking forward to this day and have plans, prepare for the worst weather. There will be some spots where it will be cloudy. And because April is severe weather season, please make sure you don’t get stuck on the roads if severe weather is forecasted. If you have a car and it’s cloudy, make sure you have a way to see where the clouds are. There is a chance you can simply travel a few miles to clear skies.