{ "number": 765, "headline": "October 15, 2025 Wednesday Morning Weather", "standfirst": "Watching Caribbean in the 8-10 day range for tropical wave development", "desk": "tropics", "dateline": { "place": "Weather Trader", "state": null, "lat": null, "lon": null, "site_key": null, "site_name": null, "site_url": null, "accent": null }, "edition": "2025-10-15", "published": "2025-10-15T14:59:36.204000Z", "updated": null, "access": "free", "body_html": "

2025 Hurricane Season [Day 137]. My FORECAST for this year is 14 named storms, 7 hurricanes, and 3 major hurricanes (near average)

2025 Season to Date: 12 Named Storms, 4 Hurricanes, and 3 Majors | ACE = 100

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Good Morning! This is post 764 in this newsletter\u2019s 2-year history from Dr. Ryan Maue.

Winter is approaching, and we\u2019ll be transitioning to coverage of cold and snow.

Clear skies and warm temperatures across the South today (Wednesday)

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A powerful upper-level trough connected to the Canadian Arctic tropospheric polar vortex continues to spin over California.

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GFS Analysis 06z | California trough

The cut-off trough is remarkable for mid-October with very low geopotential heights at 500 mb \u2014 and cold temperatures in the mid-levels. The jet stream is highly amplified extending into southern California.

High Temperatures Today

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Only in the 60s across California today \u2026 with 80s and 90s in the Plains into the Southeast \u2014 quite warm for October 15. Lower 48 average high is 68.1\u00b0F

North Pacific Wave Train next 8-days | 850 hPa Wind

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I like showing this loop \u2014 so we\u2019ll do it again. All aboard the North Pacific \u201cwave train\u201d with multiple sequential \u201churricane force\u201d extratropical cyclones \u201cbombing\u201d out in the Aleutians and then decaying over Alaska or the Gulf of Alaska.

The typical extratropical cyclone forms as a shallow frontal wave NE of Japan and then phases with the upper-level jet stream often \u201crapidly intensifying\u201d with central pressures from the 930s to 960s mb. The entire lifecycle is 3-5 days, but may last longer if the mature or occluded stage becomes stationary or cuts off from the main storm track.

The result of these storms = atmospheric rivers into Alaska, Northwest Canada, and Pacific NW U.S. coast = mountain snowfall and heavy rainfall near sea level. We\u2019ll that in the \u201cIntegrated Vapor Transport\u201d maps.

North Pacific Jet Stream Next 10 Days > 200 knots

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North America Precipitable Water next 8-Days | 00z ECMWF

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Overview of the continent: Next 8-days

  1. A series of weak/moderate atmospheric rivers descend the west coast from WA/OR into California for a great start to the 2025-26 Water Year as a strong jet stream from North Pacific \u201cwave train\u201d sends repeated \u201churricane force\u201d cyclones into the Aleutian Low region.

  2. Weekend storm system for the central U.S. moves into Canada by Saturday and deepens to around 980 mb central pressure. Another storm then develops in the Great Lakes into Sunday and heads into the mid-Atlantic and Northeast for early next week \u2014 not quite cold enough for snowfall.

  3. Risk of severe weather along the tail end of the cold fronts with these central U.S. weather systems.

  4. Cool, dry Canadian air blasts through the Lower 48 behind these powerful storms this weekend and next week.

Look Ahead: Precipitation Type + MSLP | Next 8-days

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Current Temperature | RTMA 8:45 AM ET

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Current Temperature Anomaly | RTMA 8:45 AM ET

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Lower 48 is +2.7\u00b0F above normal with California remaining chilly

Low Temperatures Thursday Morning

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Lower 48 average low temperature of 46.9\u00b0F with 3.6 million at least freezing

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High Temperatures on Thursday

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Lower 48 average temperature of 68\u00b0F \u2026 with 90s in South Texas but only 2 Million population.

High Temperature Anomaly on Thursday

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ECMWF Next 6-Days Integrated Vapor Transport | 06z cycle

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Blend of Models 7-Day Precipitation through early next Tuesday

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Snowfall Next 7-days | Blend of Models

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

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Parade of troughs arriving from the North Pacific into the U.S. Northwest and then progressing across the northern tier of states = active pattern

Atlantic Basin Outlook | 8 AM ET Update

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Tropical Storm Lorenzo (12L)

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40 mph winds \u2014 poorly organized \u2014 and not expected to intensify further until dissipation within the next 24-hours.

Lorenzo did help the Atlantic ACE hit 100 for the 2025 season.

Central Atlantic GeoColor + IR Satellite Images

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Atlantic Basin | Integrated Vapor Transport | Next 12-days

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A tropical wave currently off the coast of Africa in the far eastern Atlantic will travel westward and could find more favorable environment conditions for development in the Caribbean in 8-10 days.

SST and Anomaly

NOAA Tropical Surface Analysis | 06z

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Atlantic Tropical Waves = 3 + nearly gone TS Lorenzo mixed in

ECMWF EPS 00z | Active Storm Tracks Day 10

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20% to 30% chance of development by Day 10 in the western Caribbean \u2014 extended range!

ECMWF EPS 00z | Active Storm Tracks Day 15

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About half of the ensemble members develop the tropical wave \u2014 eventually and create a powerful hurricane into late October, with a northward track thereafter.

The Caribbean is a favored region, of course, so we will keep a very close eye for the next several days to see how this trends.

AIFS ENS at Day 12 and Day 15 Comparison | Active Storm Tracks

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Much stronger signal today in the AIFS-ENS for the tropical wave development in the Caribbean.

GFS 00z Massive Category 5 Hurricane (one of many extended range solutions)

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GFS continues to blow up a Category 5 hurricane out of the Caribbean \u2014 way down the line at Days 10 to 15 \u2014way over the forecast predictability horizon. You\u2019ll probably see this bad boy on social media \u2014 until it [hopefully] disappears.

This is possible/plausible but beyond our capability to accurately/skillfully forecast.

NOAA GEFS 06z (31-members) | Through 10-days

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Active Caribbean from 06z GEFS ensemble members.

Summary:

We have low skill with location/intensity of tropical storm development more than 10-days into the future \u2014 BUT there are increasing signals for \u201csomething\u201d to develop \u2014 probably a coin flip based upon current guidance.

What do you do with this information? Monitor the situation daily to look for trends up/down in the risk of hurricane development \u2014 nothing new/different than what you\u2019d do during the rest of the season.

Eastern Pacific Tropical Weather Outlook | 8 AM ET

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60% chance of formation of another tropical cyclone (next name is Sonia) in the next several days. However, convection is limited and any development looks \u201cslow going\u201d as the Eastern Pacific hurricane season winds down.

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Winter is approaching, and we\u2019ll be transitioning to coverage of cold and snow .

Clear skies and warm temperatures across the South today (Wednesday)

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