{"id":71366,"date":"2026-07-20T18:55:22","date_gmt":"2026-07-20T18:55:22","guid":{"rendered":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/?p=71366"},"modified":"2026-07-20T18:55:22","modified_gmt":"2026-07-20T18:55:22","slug":"dual-tropical-systems-in-the-eastern-pacific","status":"publish","type":"post","link":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/archives\/71366","title":{"rendered":"Dual Tropical Systems in the Eastern Pacific"},"content":{"rendered":"\n

We are starting to see the onset of an active period of tropical development in the eastern Pacific basin. Over the weekend of 18-19 July 2026, two separate systems were experiencing different stages of their life: Elida was dying out near the west coast of Mexico while Fausto was starting to consolidate into a tropical storm. The following satellite loops from GOES-18 (GOES West) show these systems. The first is the Band 2 visible product. Elida is in the western center of the animation while Fausto is in the south central part of the loop.<\/p>\n\n\n\n

\"Visible<\/figure>\n\n\n\n

Here’s the same loop as before, but from the Band 13 infrared perspective. Here, it is clear that Fausto represents deeper convection was the infrared imagery shows much colder cloud tops for that storm than it does for Elida. <\/p>\n\n\n\n

\"Infrared<\/figure>\n\n\n\n

Polar-orbiting satellites around this time provide some additional perspective on these storms. First, let’s look at some scatterometer data to evaluate near-surface winds. Here’s a view from OSCAT3 of Elida on Sunday the 19th. OSCAT tends to have more uncertainty in the wind vector retrievals than ASCAT does, but makes up for it with a wider swath and fewer gaps between swaths. (ASCAT was particularly unlucky with both storms on the 19th). Here we see clear evidence of a focused area of circulation with winds in the center maxing out at around 30-40 kts.<\/p>\n\n\n\n

\"OSCAT<\/figure>\n\n\n\n

Going further south to Fausto at roughly the same time in the 19th, we see a circulation that is not quite as refined as Elida. Winds are slower and the center of circulation isn’t as circular. <\/p>\n\n\n\n

\"OSCAT<\/figure>\n\n\n\n

Elida has propagated to the north, into the cooler waters of the midlatitude eastern Pacific. Between the 19th and the 20th, it lost its tropical storm status and is now officially post-tropical. However, Fausto is continuing to intensify and model tracks show that it may impact Hawaii in the coming days, so we’ll look at it a bit more. Here’s a frame from the CIMSS D-MINT<\/a> product from 1930 UTC on the 19th, approximately the same time as the animated loops above). D-MINT uses microwave and infrared observations to assess the intensity of tropical cyclones. The left three panels show three different microwave channels, and forecasters can use these to more easily identify the center of circulation when the infrared or visible images are cluttered with high-level cirrus shields. Here we see the circulation is likely centered around the lower-left hand corner of the microwave images. The rightmost panel depicts the mean surface wind of the system as estimated by the D-MINT algorithm, and in this case it is around 30 kts.<\/p>\n\n\n\n

\"D-MINT<\/figure>\n\n\n\n

We can use satellites to gauge how much Fausto improved from Sunday the 19th into Monday the 20th. We’ll start by looking at more recent scatterometer observations. In the ~25 hours between the OSCAT plot shown above and the more recent one below, Fausto’s circulation tightened up immensely and became much more circular. <\/p>\n\n\n\n

\"OSCAT<\/figure>\n\n\n\n

We also see the intensification in D-MINT. This prodcut relies on available microwave satellite observations and not all satellites contain the same set of channels, hence the difference in the images shown here. Regardless, the algorithm now projects a mean surface wind of 44 kts by 1524 UTC, about 20 hours later than the image above. <\/p>\n\n\n\n

\"D-MINT<\/figure>\n\n\n\n

NOAA’s National Hurricane Center projects that Fausto will become a hurricane <\/a>on the 20th. Model forecasts, including the GFS and Google’s DeepMind show Fausto continuing to the east-northeast, weaking to a tropical storm just before it passes to the north of Hawaii. However, the long-term forecasts also show additional Pacific tropical systems developing south of Mexico and continuing to the east, so eyes will be on the Pacific for some time to come. <\/p>\n","protected":false},"excerpt":{"rendered":"

We are starting to see the onset of an active period of tropical development in the eastern Pacific basin. Over the weekend of 18-19 July 2026, two separate systems were experiencing different stages of their life: Elida was dying out near the west coast of Mexico while Fausto was starting to consolidate into a tropical […]<\/p>\n","protected":false},"author":22,"featured_media":71390,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[89,10,114,2],"tags":[],"class_list":["post-71366","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-atms","category-general-interpretation","category-goes-18","category-tropical-cyclones"],"acf":[],"_links":{"self":[{"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/71366","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/users\/22"}],"replies":[{"embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/comments?post=71366"}],"version-history":[{"count":11,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/71366\/revisions"}],"predecessor-version":[{"id":71391,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/71366\/revisions\/71391"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/media\/71390"}],"wp:attachment":[{"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/media?parent=71366"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/categories?post=71366"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/tags?post=71366"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}