{ "number": 749, "headline": "September 27, 2025 Saturday Tropical Update", "standfirst": "Humberto becomes Category 5 while other system (Imelda) slowly organizes", "desk": "tropics", "dateline": { "place": "Weather Trader", "state": null, "lat": null, "lon": null, "site_key": null, "site_name": null, "site_url": null, "accent": null }, "edition": "2025-09-28", "published": "2025-09-28T01:51:05.118000Z", "updated": null, "access": "free", "body_html": "
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2025 Hurricane Season [Day 119]. My FORECAST for this year is (still) 14 named storms, 7 hurricanes, and 3 major hurricanes (near average)

2025 Season to Date: 8 Named Storms, 3 Hurricanes, and 3 Majors | ACE = 70

Good Evening! This is post 749 in this newsletter\u2019s brief history (~2 years) on way to 750 tomorrow.

I really enjoy collecting the maps and typing up these posts \u2014 keeps me updated and engaged every day on the ongoing weather in the tropics and around the world. \u2014 Dr. Ryan N. Maue (*me)

Category 5 Hurricane Humberto putting on a show

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Potential for heavy rain accumulations along the Georgia - South Carolina - North Carolina coasts with Imelda nearby. Uncertainty in the track \u2014 but 10\u201d - 20\u201d likely with broad circulation of storm. We are hoping Imelda loops/stalls far enough away from the coast to limit direct impacts (winds, waves/rip currents, and rain).

7-Day Rainfall Totals

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Evening IR Satellite Loop | Caribbean

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Humberto reached T 7.1 on automated Dvorak technique (ADT) satellite intensity algorithm with a > 20\u00b0C eye and convection colder than -73\u00b0C \u2026 potential for Humberto to intensify a little bit more as it heads WNW over 29\u00b0C warm pool of the western Atlantic.

SST Analysis and Anomaly

SSTs are very warm along the path of both systems > 28.5\u00b0 to 29.5\u00b0C

NHC Track for Tropical Storm Humberto | 925 mb | 160 mph Winds

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Watching the 70\u00b0W longitude marker \u2014 as the farthest west that Humberto will get \u2014 as that would determine how much Imelda is pushed into the coast

Humberto ATCF Spaghetti

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ECMWF Ensemble 12z | Humberto Spaghetti

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Tropical Depression 09L \u2014> Imelda (09L) remains disorganized but should become a Hurricane by late Monday or early Tuesday as the forward motion slows to a crawl

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NHC still does NOT explicitly show a landfall of Hurricane Imelda through 5-days but there are ensemble members that show much closer approach

Tropical Depression 09L \u2014> Imelda | ATCF Track Spaghetti

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HAFS Maximum Intensity? Category 2 = pressure in the mid-970s

HAFS A Precipitable Water Next 126-hours

A trough from the north wipes out Imelda by Wednesday as Humberto exits into the North Atlantic

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HAFS B Precipitable Water Next 126-hours

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Imelda Spaghetti from the Google Deep Mind

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Imelda Spaghetti from ECMWF EPS 12z

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Note the members that DO directly landfall the coast \u2014 however, that is a minority solution < 30%

Atlantic Basin Outlook | 8 PM ET Update

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Medium and Range | AIFS 18z | 10-days Height Anomaly

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Steering Currents from the AIFS 10-day Heigh Anomaly loop: typical track NNW for Imelda \u2014 and then out-to-sea for Humberto until Day 7-8 when the blocking ridge strengthens to the north of Imelda.

Imelda is left behind and would likely be significantly weakened but not obliterated by combination of trough behind Humberto and then blocking ridge sequence.

ECMWF Next 10-Days Integrated Vapor Transport | 12z cycle

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Flagship model 12z solution out to 10-days shows Imelda lingering and potentially making a loop over/near the coast of North Carolina \u2014 uncertainty remains. Similar solution from the 18z Update:

ECMWF 18z Precipitable Water | Next 6-days

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ECMWF 18z | 850 hPa Wind Speed | Next 6-days

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NOAA Tropical Surface Analysis | 18z

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Atlantic Tropical Waves = 2 but neither flagged as development potential by NHC

One more tropical wave to watch coming off Africa tomorrow

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Easterly wave season ending soon into October.

Atlantic Satellite Imagery | IR and GeoColor (night time)

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Eastern Pacific Tropical Update | Hurricane Narda

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Hurricane Narda | Category 1 | 80 mph Winds \u2014> weakening quickly.

Western Pacific Tropical Update | Typhoon Bualoi

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JTWC landfall forecast of 80-knots for Bualoi into Vietnam

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Typhoon Neoguri still going \u2014 75 knot winds well into the central North Pacific with a nice eye

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Maps sourced from weathermodels.com designed and innovated by yours truly! Please subscribe there for real-time access to the newest maps, charts from all of the weather models including ECMWF.

", "body_key": null, "teaser_html": "

I really enjoy collecting the maps and typing up these posts \u2014 keeps me updated and engaged every day on the ongoing weather in the tropics and around the world. \u2014 Dr. Ryan N. Maue (*me)

Potential for heavy rain accumulations along the Georgia - South Carolina - North Carolina coasts with Imelda nearby. Uncertainty in the track \u2014 but 10\u201d - 20\u201d likely with broad circulation of storm. We are hoping Imelda loops/stalls far enough away from the coast to limit direct impacts (winds, waves/rip currents, and rain).

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