By now you probably already know that a total solar eclipse will traverse North America during the afternoon of April 8, 2024. There have been many stories in the media and previous blog entries here at the CIMSS Satellite Blog: Will it be Cloudy on April 8th (2024)? and GOES Cloud Climatology on April 8th.

The Washington Post liked our previous GOES cloud climatology image so much they created their own version from our data and of course it looks fantastic! They know how to make good science look good! Please check out their story. Thank you to the Washington Post’s Lauren Tierney for reaching out to us and highlighting the work of the CIMSS cloud science team.

This presented an opportunity to update our GOES climatology figure. Enterprise Cloud Products were produced using NOAA’s Clouds from AVHRR Extended (CLAVR-x) processing framework at the University of Wisconsin, CIMSS. It turns out we have data that covers part of Atlantic Canada. New Brunswick and Nova Scotia to be specific, mostly cut out of the previous version unfortunately. One of the primary goals of the CIMSS Satellite Blog is to educate people and we usually learn new things along the way. For example, the author recently learned about the Atlantic Time Zone (note the final time marked on the map is in Atlantic Daylight Time or ADT). This also prompted the author to figure out how to put Canadian Province and Mexican State borders on maps in Matlab, so we can help our neighbors a bit.

Some people have expressed an interest in seeing these climatology data with a prettier color enhancement. The Washington Post version is really fantastic, but here’s the same data with a progressive colormap:

Notice the totality part of the eclipse goes by pretty fast, from the Pacific Ocean, across Mexico, across the contiguous USA, and past Canada into the Atlantic Ocean in about 25-30 minutes! It also will pass right over Newfoundland, which unfortunately is outside the coverage area of our data. For any given location, totality only lasts a few minutes though the eclipse event is much longer than that. The National Centers for Environmental Information (NCEI) has an eclipse page with an interactive map from which you can get both their cloud climate analysis and the time/duration of the eclipse for many towns and cities in the USA (it’s not helpful for our neighbors). Our friends in Canada are getting ready too of course and you can find more information about viewing the eclipse in Canada from Dan Falk (@danfalk on X) and this neat YouTube video he made. Mexico seems likely to get the best cloud-free views and also the spot with the longest view of totality. For our Spanish speaking audience, you can learn more about the eclipse and what to expect in Mexico (probably clear skies! Longer duration eclipse) from this UnoTV YouTube video featuring Primoz Kajdic of Universidad Nacional Autonoma de Mexico.

You might be wondering what the difference is between our cloud climatology product and the NCEI one or any others you might see on the web? Ours is generated solely from GOES observations, a few hours from every April 8 from 1995-2023 and averaged. Some other cloud climatologies may include satellite observations, some do not, and some include other satellite platforms.

Going to see the eclipse? Remember to be safe! Don’t look at the sun directly without suitable eye protection! You maybe can get away with it during totality, but remember it doesn’t last long and ends rather suddenly. Let the SUVI stare at the sun, it’s built for that! Follow NASA’s safety guidelines.

Disclaimer on cloud climatology: this is not a real forecast and past clear or cloudy skies do not guarantee anything for April 8, 2024! You should check your local forecasts which are probably starting to get pretty accurate for clouds around April 6 and will be most accurate the morning of the eclipse. The eclipse itself can impact the amount of certain types of clouds. Most local meteorologists along the path are going to be paying attention to cloud cover, where good open places to view it will be, and what local plans are for schools, parks, etc. Be safe traveling to your view area!

Don’t miss it if you can help it! While partial solar eclipses are not too rare, total solar eclipses that go through your country are. For most of us in the U.S., it’s going to be a long time before we see another one. Alaska will see one in March 2033. Montana and North Dakota will see one in August 2044. The rest of the lower 48 will have to wait until August 2045 when an eclipse will traverse the contiguous U.S. from Florida to California. NASA has more information about future and past eclipses.

Finally, if you can’t see the eclipse, don’t fret. The web will be full of pictures from those who get the best cloud-free views. Check back here at the CIMSS blog where we will post animations of GOES ABI imagery of the shadow crossing CONUS and hopefully some SUVI animations of the full eclipse. We enjoy making images of solar eclipse shadows! For fun, here’s what an eclipse in 1984 with a similar, but more southern, path looked like from GOES-5:

Thanks to Frank Espenak of NASA Goddard Space Flight Center (GSFC) for the prediction data on the eclipse path, including times.

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CIMSS Scientists who work with JPSS data had numerous presentations at the American Meteorological Society’s Annual Meeting held at the end of January in Baltimore. This blog post discusses two poster by Rich Dworak who (along with co-authors) investigated how JPSS data can define winds and ice properties in the Arctic.

Atmospheric Motion Vectors can be computed from polar-orbiting satellites, and these give better spatial resolution over the Poles compared to geostationary data. Additionally, because Suomi-NPP and NOAA-20 have similar orbits, data from multiple satellites can be used in tracking atmospheric features; it is the translation of those features that is used to infer atmospheric motion. (The addition of NOAA-21 to the mix will improve things further) ‘Polar Tandem’ winds in the poster below refer to winds computed using both Suomi-NPP and NOAA-20 data; a better forecast results when such winds are input into a numerical model (NAVGEM in this case). SWIR winds use observations from 2.25 um (that is, M11 on VIIRS) on Suomi-NPP and NOAA-20; these computed low-level winds lead to improved model forecasts as well.

Dworak and (different) collaborators also work on cryosphere products, detailed in the poster below. These operational products combine all-weather AMSR-2 information with high-resolution VIIRS observations of surface ice. In particular this results in better observations and predictions of the sea ice edge.

Satellite winds that are based on this work are available in real time at this link. An example the includes both Suomi-NPP and NOAA-20 data is shown below (0748 UTC on 22 February 2024). These winds were also discussed in this recent blog post.

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A sequence of daily NOAA-20 VIIRS Visible (0.64 µm) images from 01 November 2023 to 19 February 2024 (above) showed Iceberg A23a as it migrated northward away from the Antarctic Peninsula to east of the South Shetland Islands (days when dense cloud cover obscured A23a were omitted). Near the end of this time period, the iceberg — whose motion was driven by a combination of winds and ocean currents — performed a complete rotation, and reversed its path to begin drifting back toward the South Shetland Islands.

Daily NOAA-20 VIIRS Natural Color RGB images (excluding cloudy days) from 27 December 2023 to 15 February 2024 (below) also displayed the rotation of A23a, along with the change in direction of its drift within the Southern Ocean.

A toggle between Suomi-NPP VIIRS False Color RGB imagery and the Sea Ice Temperature product as viewed using RealEarth (below) showed A23a as it was located just east of Elephant Island and Clarence Island on 15 February. Sea Ice Temperature values were near or just below freezing.

GOES-16 (GOES-East) True Color RGB images (source) on minimally-cloudy days from 03 February to 19 February (above) also displayed the motion of A23a as it reversed course and drifted southwestward, back toward the South Shetland Islands (while performing part of its rotation).

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GOES-16 True Color RGB images from the CSPP GeoSphere site (above) showed multiple mesoscale vortices embedded within the exposed Low-Level Circulation Center (LLCC) of a Tropical Depression off the southeast coast of Brazil on 18 February 2024. This disturbance continued to organize and gradually intensify during the day and into the evening hours — with part of the LLCC being drawn beneath deep convection in the SW quadrant of the system — becoming Tropical Storm Akará at 0000 UTC on 19 February (surface analysis | warning text). Tropical Storms in the South Atlantic are relatively rare — the last was Tropical Storm Iba in 2019.

A sequence of Meteosat-10 Water Vapor images with an overlay of deep-layer wind shear from the CIMSS Tropical Cyclones site (below) indicated that Akará was located within a corridor of relatively low shear — a factor that favored intensification. Sea Surface Temperature values in the area where Akará first developed (near 25ºS latitude, 40ºW longitude) were around 27ºC.

A 6-day animation of the MIMIC Total Precipitable Water product — from 13-18 February (below) — showed that Akará first began to develop along the trailing edge of a stalled cold front that had been moving northward (surface analyses). Beginning on 15 February, a broad plume of moisture from the tropics began to move south along the coast of Brazil — which then fed into the circulation of the developing tropical disturbance (which formed as a subtropical depression on 16 February), helping it to intensify.

A closer view of the MIMIC Total Precipitable Water product (below) included plots of surface and ship reports from 13-18 February. Maximum TPW values within the circulation of Akará on 18 February were around 3.5 inches (brighter shades of white). The relatively compact system was far enough offshore to not have any adverse impacts (such as strong winds) that showed up in any of the surface/ship reports.

Surface wind information from Metop-B/C ASCAT and GCOM-W1 AMSR2 (below) showed the flow within portions of the developing tropical disturbance during the 17-18 February period (source). The circulation of Akará was well-sampled by Metop-B ASCAT at 0003 UTC on 19 February, just after it reached Tropical Storm intensity.

Significant Wave Height values derived by Sentinel-3A increased from 11.27 ft at 1216 UTC on 17 February to 14.98 ft at 0038 UTC on 18 February (below) — along the southern periphery of what was still a subtropical depression.

===== 19 February Update =====

GOES-16 True Color RGB images (above) showed that there was a notable lack of sustained deep convection near the exposed LLCC on 19 February — this was likely due to an increase in shear in the vicinity of Akará (below). The tropical storm had also moved far enough south to be located over colder water, where Sea Surface Temperature values were only around 25ºC.

===== 20 February Update =====

For the second consecutive day, sustained deep convection failed to develop near the exposed LLCC of Akará (above). The MIMIC TPW product (below) indicated that a ribbon of dry air had begun to wrap into the circulation of the tropical storm, beginning on 19 February.

Akará was then downgraded to a Tropical Depression as of 0000 UTC on 21 February (below).

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