{ "number": 740, "headline": "September 21, 2025 Sunday Hurricane Season", "standfirst": "Hurricane Gabrielle may rapidly intensify with Humberto on the way", "desk": "tropics", "dateline": { "place": "Weather Trader", "state": null, "lat": null, "lon": null, "site_key": null, "site_name": null, "site_url": null, "accent": null }, "edition": "2025-09-22", "published": "2025-09-22T00:07:38.152000Z", "updated": null, "access": "free", "body_html": "
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Good Evening!

Hurricane Gabrielle was upgraded at 5 pm \u2014 and may be rapidly intensifying tonight as the eyewall wraps deep convection more tightly around a nascent eye. The hurricane has improved anticyclonic outflow. All systems go for at least a major hurricane and I would not be surprised to see Category 4 (115-knots).

There is no direct threat to land as Gabrielle will slide safely east of Bermuda on ENE course. However, the remnants could impact Europe in a week.

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Monster Super Typhoon Ragasa + Typhoon Neoguri | Sunrise

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Ragasa is a massive typhoon w/145-knot winds and still has room to run up to 155-160 knots as the eye should contract heading through Taiwan Strait.

Atlantic Basin Outlook | 8 PM ET Update

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Two more areas being watched by NHC including a new 30% yellow hatchling based upon ensemble guidance from the A.I. models.

The 60% orange will be our next Invest and likely to develop into Humberto in next 5-7 days. Models also show it becoming a major hurricane on a similar course as Gabrielle.

Hurricane Gabrielle

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NHC keeps Gabrielle east of Bermuda \u2014 with maximum intensity of 100 knots (Category 3 \u2014Major ) within 36 to 48 hours. I think the storm will reach at least 115-knots based upon the recent HAFS mesoscale guidance (18z)

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2025 Hurricane Season [Day 113]. My FORECAST for this year is (still) 14 named storms, 7 hurricanes, and 3 major hurricanes (near average)

2025 Season to Date: 7 Named Storms, 2 Hurricanes, and 1 Major | ACE = 44

Hurricane Gabrielle (07L) ATCF Spaghetti

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ECMWF Ensembles 12z | Gabrielle

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HAFS Mesoscale Models in 30 hours for Gabrielle

Central pressure in the 950s with 130-knots winds at 850 hPa more than sufficient for a Category 4 intensity

ECMWF 12-Days Integrated Vapor Transport | 12z cycle

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Flagship model ECMWF 12z now develops Humberto north of the Caribbean in 5-6 days \u2026 but not seeing the yellow hatchling catching fire (NHC 20%)

Atlantic Satellite Imagery | Infrared

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NOAA Tropical Surface Analysis | 12z

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Atlantic Tropical Waves = 2

Sea Surface Temperature + Anomaly | ECMWF 12z Analysis

Anomalously warm water centered upon Bermuda

Global SST Anomaly: tropics generally cooler than normal while the North Pacific surface marine heat wave continues

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Eastern Atlantic and Africa Infrared Satellite

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African wave train lined up on the tracks \u2014 we\u2019ll see if background environmental conditions are more favorable in the next 1-2 weeks for tropical storm formation.

ECMWF EPS 12z Ensemble | All Cyclone Tracks Through 7-days

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ECMWF EPS 12z Ensemble | All Cyclone Tracks Through 12-days

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I see Humberto \u2014 and there are a few more tracks that randomly extend westward presumably from a leftover tropical wave \u2014 but low chances < 10%


ECMWF EPS 12z Ensemble | All Cyclone Tracks Through 15-days

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Gabrielle and Humberto but small chance of something else (< 10%) through 15-days (October 6)

AIFS-ENS Comparison at 12z | All tracks at Day 7

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The A.I. trained ensembles also show Humberto \u2026 and if we look at the MSLP contours at Day 10 \u2014 a bunch of members show a TS or Hurricane from the Gulf to Bahamas.

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AIFS-ENS Comparison at 12z | All tracks at Day 12

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Meanwhile \u2014 AIFS blows up more member tracks w/ TS/Hurricane west of Humberto in the Gulf and out of the Caribbean

AIFS-ENS Comparison at 12z | Active Tracks at Day 15

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I\u2019ve decided to keep showing the extended range (15 day) AIFS-ENS tracks since they may indicate potential tropical storm formation areas and favorable tracks \u2014 which apparently means the Gulf and off the U.S. Southeast coast.

However, I still suspect these are FALSE ALARMS as the AIFS-ENS has been way too eager to develop every tropical wave \u2014 likely a bias/problem with the lower resolution (0.25\u00b0) model \u2014 but I really don\u2019t know. This model was just launched into the wild for everyone to use w/o much feeling for the quality of tropical storm formation forecasts in the medium and extended range.

Eastern Pacific Tropical Update | Tropical Storm Narda

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Tropical Storm Narda (14E) underway \u2014 should become a hurricane in 36-48 hours and head westward over warm enough waters for steady intensification to near a major hurricane.

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Western Pacific Typhoon Season Update

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Morning GeoColor Imagery of Super Typhoon Ragasa

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Super Typhoon Ragasa (24W) | 145 knots | Category 5

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HAFS-A 18z at 06z on Monday

917 mb with 177 knot winds at 850 hPa = solid Category 5 Super Typhoon

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HAFS-A 18z forecast +51 Hours Valid on Tuesday 21z

Ragasa retains its inner-core and does not appear to weaken much at all \u2026 without and land interference through the Taiwan Strait. While JTWC has Ragasa sliding south of Hong Kong, the typhoon is massive and significant impacts are possible on Tuesday regardless of a direct hit or landfall over the city.

Tropical Storm Neoguri (25W) has slightly weakened to 110-knots (Category 3)

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Neoguri did reach 125-knots \u2014 so NOT quite Super Typhoon status (130 knots) well east of Japan

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Maximum 125-knots at 00z earlier on Sunday

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Hurricane Gabrielle was upgraded at 5 pm \u2014 and may be rapidly intensifying tonight as the eyewall wraps deep convection more tightly around a nascent eye. The hurricane has improved anticyclonic outflow. All systems go for at least a major hurricane and I would not be surprised to see Category 4 (115-knots).

There is no direct threat to land as Gabrielle will slide safely east of Bermuda on ENE course. However, the remnants could impact Europe in a week.

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