{ "number": 951, "headline": "June 4, 2026 Thursday Tropical Update", "standfirst": "Watching Caribbean and Gulf for tropical storm development later next week", "desk": "tropics", "dateline": { "place": "Weather Trader", "state": null, "lat": null, "lon": null, "site_key": null, "site_name": null, "site_url": null, "accent": null }, "edition": "2026-06-05", "published": "2026-06-05T01:32:08.436000Z", "updated": null, "access": "free", "body_html": "
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This is post number 951: Day 155 of 2026. Day 4 of Atlantic Hurricane Season. Good Evening! Welcome to all new and returning subscribers for another Atlantic hurricane season.

Author: Dr. Ryan Maue (X @RyanWeather X @weathertrader)

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Not expecting any tropical system out of the convection in the Gulf, just a rainmaker for TX/LA. Monsoon showers firing up in Mexico with moisture surging northward between two troughs \u2014 a strong one digging into Baja California, and \u2026

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\u2026 another massive trough off the East Coast of the United States with bone dry air dipping through Georgia into North Florida.

Weather Headlines for Thursday

ECMWF Flagship Ensemble Cyclone Tracks (12z)

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50-ensembles or realizations of the next 15-day forecast of sea level pressure (L\u2019s) tracked \u2026 and then plotted on top of each other.

Later next week, we\u2019re watching the Gulf of Mexico for medium chance of TS/Hurricane activity out of a large circulation/ gyre centered over Mexico + Central America that will spawn 2 Eastern Pacific tropical cyclones.

The remnants of an EPAC storm could cross into the Gulf. Still pegging June 15th (+12 days) signal for a TS/Hurricane in the Gulf > 50%. The overall environment will be hostile with strong wind shear (typical for mid-June) so we may looking at a fast-moving, asymmetric system.

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One scenario: ECMWF HRES 12z \u2014> Integrated Vapor Transport

Watch the large scale flow with the Central American Gyre pick up the remnants of an Eastern Pacific tropical storm into the Gulf \u2026 and then the very strong Caribbean \u2014> Gulf of Mexico moisture plume resumes around the westward extension of the Bermuda High. We\u2019ll be watching this pattern for the next 2-weeks, of course.

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Weather Patterns | Thursday Evening

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Weather Patterns | Friday

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ECMWF 18z | Precipitable Water | My Favorite Parameter

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Quite the moisture surge northward with the assistance of the two mid-level troughs!

ECMWF 18z | Precipitation Type + MSLP | Next 6-days

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Current Temperatures | RTMA | 7:30 PM ET

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Current Temperature Anomaly | RTMA | 7:30 PM ET

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Lower 48 was 2.7\u00b0F above normal

Relative Humidity \u2014> Bone Dry out West, and also rather dry across the entire Eastern U.S.

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High Temperatures Next 8-Days \u2014> Saturday June 13th.

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A lot more 90s building with 225 million population by next Friday

100s in the Plains mid-week

Low Temperatures Friday Morning

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High Temperatures on Friday

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Almost 100 million at least 90\u00b0F \u2026 and 304 million at least 80\u00b0F, so that\u2019s 90% of folks in the Lower 48

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Upper-Level Height Anomaly | AIFS-Single Next 10-days

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ALERT: Next week, a heat dome will form over the Great Lakes into the Mid-Atlantic and Northeast with potential for extreme heat.

ECMWF Flagship Ensemble Mean Temperature Anomaly next 15-days

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Week 1 \u2014> June 4-10th

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Week 2 \u2014> June 11-17th

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Whoa, that\u2019s a strong heat signal for Week 2 > 12\u00b0F anomaly for mid-Atlantic and Northeast

HRRR Radar Simulation Next 48-Hours \u2014> Saturday 2 PM ET

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Plenty of scattered storms in this very moist air mass surging northward out of the Gulf and tropical Pacific.

HRRR Precipitable Water Next 48-Hours

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NWS Precipitation Next 72-hours \u2014> Sunday Evening

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Blend of Models \u2014> Precipitation Next 10-days

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Atlantic Basin Satellite Channels

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Gulf of Mexico convection is associated with tail end of front connected to strong trough/storm off the East Coast

Infrared (Channel 13) colorized \u2014> showers and thunderstorms

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Still completely clear Caribbean

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Water Vapor (Mid-Level Ch. 9) - troughs + areas of dry air

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Major dry slot behind the mid-level trough

NASA GEOS5 (00z) \u2014> African dust plume forecast next 10-days

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African dust activity has really died down \u2026 decreased, but the Saharan Air Layers will still come across the basin even without dust.

North Atlantic Tropics | Quiet Next 7-days

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4 Tropical Waves \u2014 none developing in the Atlantic, but as they eventually reach the Eastern Pacific, could trigger formation.

My favorite parameter \u2014> Precipitable Water (PWAT) next 6-days

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Tropical storms and hurricanes are bundles of high moisture air > 2\u201d in the column (or more) so we look for areas of concentrated high PWAT air in the tropics \u2014> and we also can view frontal boundaries or dry air input from the middle-latitudes into the subtropics or tropics + Saharan Air Layers (dry)

Precipitation + MSLP Next 6-Days

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Integrated Vapor Transport \u2014> IVT next 12-days from ECMWF AIFS

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Eastern Pacific is busy with Amanda for a little while longer, and 2-more systems forming along Mexico/Central America within the gyre.

The moisture plume surges through the Caribbean into the Gulf and then northward through eastern U.S. \u2014 and we will watch for any tropical cyclone development in the Gulf in the 8-10 day time frame.

Eastern Pacific Tropics | 2026 Season | Tropical Storm Amanda 01E

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2 more systems on the way!

Amanda is hanging on, and may be bursting convection into the evening out there.

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Tropical Storm Amanda is way out in the Pacific \u2026 mixing some fish with 45 mph winds.

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2026 Names \u2014> Amanda, Boris, Cristina, Douglas, Elida

ECMWF Precipitable Water Next 6-days

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Relative Vorticity (Cyclonic) \u2014 interesting twin / elongated vorticity along Mexico + Central America \u2014> 2 named storms for the price of one, but both look weak without much time prior to landfall.

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ECMWF EPS | Next 15-days for Eastern Pacific

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Western Pacific Basin \u2014 Typhoon Season \u2014 Quiet next 7-days

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Global Ocean Temperatures \u2014> Sea Surface Temperature (SST)

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Tropical storms need at least 26\u00b0C SST to form and intensify \u2026 and hurricanes most often become major with 28\u00b0C SST (at least).

There are still rather cool (relative) areas in the Western Pacific and North Atlantic compared to the growing warmth along the Equator and off the western coast of Mexico with the oncoming El Ni\u00f1o. The recent 20-year climatology highlights much better than an older 1991-2020 baseline.

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Atlantic Ocean Temperatures | SST Analysis (June 5 00z)

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The Atlantic remains cooler than past 2-decades across the Main Development Region [MDR] from the Lesser Antilles (Caribbean) to the Canary Islands and coast of Africa. The North Atlantic off the East Coast and into the mid-latitudes is also quite cool.

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Thank you for reaching the end of this post! Hopefully you enjoyed the tour of the global tropics and what\u2019s coming in the weeks/months ahead in the tropics here on Weather Trader on Substack.

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 and AIFS, and NOAA GFS/GEFS, HRRR/RRFS and Blend of Models (NBM). NOAA WPC and SPC for fronts/convective outlooks.

For 2026 Hurricane Season: Every 6 or 12 hours, we get an update including these model output

My Atlantic Hurricane Season Forecast (2026)

From April 7, 2026: Atlantic Seasonal Hurricane Forecast: (11/5/2)

9-13 Named Storms (11 most likely)
4-7 Hurricanes (5 or 6 most likely)
1-3 Major Hurricanes (2 most likely)
Accumulated Cyclone Energy: 75-85 (well below normal)

NOAA 2026 Atlantic Hurricane Season Forecast

More details in Thursday, May 21, 2026 Tropical Update

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The Intertropical Convergence Zone (ITCZ) in the tropics along 5\u00b0N to 10\u00b0N is where moist air can ascend and form thunderstorms or like a convective pot boiling over = convection. In the coming weeks, especially into late June, we\u2019ll look for areas of disturbed weather \u2014 which means persistent convection \u2014 and potential formation of low pressure swirls along the ITCZ with tropical waves, in the Caribbean and Gulf of Mexico (America) with decaying frontal boundaries, and other pathways like tropical transition or subtropical cut-off lows. Lots of options/ways to form a tropical storm in the Atlantic in any given season.

The Bermuda High \u2014> Azores High in the subtropics usually keeps things quiet in the latitude around 30\u00b0N and suppresses the ITCZ to the south in late May into June. On the periphery of the Bermuda High, moisture plumes out of the Caribbean into the Gulf and then Texas + Southeast.

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Not expecting any tropical system out of the convection in the Gulf, just a rainmaker for TX/LA. Monsoon showers firing up in Mexico with moisture surging northward between two troughs \u2014 a strong one digging into Baja California, and \u2026

\u2026 another massive trough off the East Coast of the United States with bone dry air dipping through Georgia into North Florida.

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