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TheForecast Post

A chronicle of American weather and climate  ·  Wednesday, 16 September 2026

Weather Trader Tropics MILEPOST 755

October 3, 2025 Friday Tropical Update

Confidence increasing for Tropical Storm Jerry forming next week

What the month did

October 2025 was the 7th-warmest October in the 131-year national record (1895–2025), at 57.0°F against a 1991–2020 normal of 54.5°F (+2.4°F).

October 2025 was the 56th-wettest October in the 131-year national record (1895–2025), at 2.3in against a 1991–2020 normal of 2.5in (-0.2in).

NOAA/NCEI Climate at a Glance, contiguous United States. This is the observed record for the month, not a score of anything said in this piece — the forecast ledger begins 2026-08-17 and cannot reach earlier posts.

2025 Season to Date: 9 Named Storms, 4 Hurricanes, and 3 Majors


Mid-Level Water Vapor Loop

The Atlantic is currently quiet in terms of potential tropical storm development but a tropical wave in the far Eastern Atlantic off the coast of Africa will slowly organize in the coming days. NHC has a 40% chance of development in 7-days.


ECMWF Next 12-Days Integrated Vapor Transport | 00z cycle

Large view centered on North America shows the development of [Eastern Pacific] Hurricane Priscilla with moisture heading into the U.S. Southwest — also absorbing what’s left of Octave, and then being followed by Raymond.

Today’s flagship 00z model run from ECMWF shows a hurricane (Jerry) developing near the Northeast Caribbean in 7-days — middle to late next week. The system them stalls and heads quickly north out to sea. This is a great outcome — similar to our previous major hurricanes (Erin, Gabrielle, Humberto).

Tropical storm development in not imminent —but increasing chances now up to 40% chance of a far Eastern Atlantic tropical wave developing into a TD in 7-days

Medium Range | AIFS 06z | 10-days Height Anomaly

North America will see the rebuilding of a strong high pressure ridge over the central U.S. = warmth again for the middle of the country. However, on either side, troughs will dominate including in the Pacific Northwest and Southeast.



NOAA WPC 7-Day Precipitation

Atlantic Basin Outlook | 8 AM ET Update

NHC is watching a tropical wave (40%) for a MEDIUM chance of development — and increasing

A non-tropical frontal boundary has a low yellow hatching over Florida (10%)

ECMWF 06z Precipitable Water | Next 6-days

Low latitude tropical wave showing some signs of development perhaps into early next week — 40% according to NHC

ECMWF 06z Relative Vorticity | Next 6-days

The updated 06z model spins up the tropical wave slowly but surely into next week.

NOAA GFS 06z | Integrated Vapor Transport

Similar solution with GFS 06z — and the GEFS 06z Ensembles through 10-days with high likelihood of (major) Hurricane Jerry.

SST Analysis and Anomaly | 12z

Ocean temperatures remain plenty warm for any category of hurricane in the tropics up to about 30°N with 28°C and above SSTs.


Atlantic Satellite Image | IR and GeoColor Visible

Limited convection over water … we are watching a wave coming in the far Eastern Atlantic

NOAA Tropical Surface Analysis | 06z

Atlantic Tropical Waves = 2 but neither are flagged as development potential by NHC. The ORANGE 40% hatching is for a wave that NHC didn’t put on the map yet.


Eastern Atlantic Visible Satellite Image

ITCZ/monsoon trough shows up well + area of convection just off African coast

ECMWF EPS 00z | Active Storm Tracks Day 7

~50% chance of development of tropical wave with a curious member already at 925 mb (Category 5) in 7-days. However, that is only 1 out of 50.

ECMWF EPS 00z | Active Storm Tracks Day 10

The Northeast Caribbean will need to closely monitor this tropical wave!

ECMWF EPS 00z | Active Storm Tracks Day 15

This is “over the predictability horizon” after 2-weeks … but there’s little doubt that the Atlantic hurricane season remains activated even if we don’t know exactly where a particular system will be.

This is typical for mid-October as our focus shifts westward into the Gulf of Mexico and Caribbean.


Eastern Pacific Tropical Weather Outlook | 8 AM ET

2 more systems coming online in the next 7-days = Priscilla and Raymond

Tropical Storm Octave | NHC Cone

Octave will take a clockwise loop for the next 5-7 days and may interact with Priscilla well down the road.

Burst of convection with Octave — the next disturbance likely a TD/TS by this weekend off coast of Mexico (90%) = Priscilla

Eastern Pacific Current Satellite

PWAT Next 6-days for Octave and Priscilla — then Raymond!

Western Pacific Typhoon Season

Typhoon Matmo has moved across Luzon into the South China Sea and will intensify to 85-knots (JTWC) before making landfall in China in 2-3 days.

Another Typhoon likely to develop in the NW part of the basin between Taiwan and Japan.

7-day Active Cyclones | Ensemble Spaghetti (50-members) | ECMWF 00z


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.

Milepost
755 · laid 2025-10-03T12:42:38.673000Z
Source
https://weather.substack.com/p/october-3-2025-friday-tropical-update
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