{ "number": 633, "headline": "June 8, 2025 Tropical Update Sunday", "standfirst": "Tropical Storm Barbara forecast to become a hurricane", "desk": "tropics", "dateline": { "place": "Weather Trader", "state": null, "lat": null, "lon": null, "site_key": null, "site_name": null, "site_url": null, "accent": null }, "edition": "2025-06-08", "published": "2025-06-08T15:10:22.823000Z", "updated": null, "access": "free", "body_html": "
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2025 Atlantic Hurricane Season [Day 8]. My expectation for this year is 14 named storms, 7 hurricanes, and 3 majors. So far, 0 named storms, 0 hurricane, and 0 majors.

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Sunday\u2019s Tropical Weather Headlines

  1. Atlantic tropical update: No areas being watched through the next 7-days (June 15) by NHC and the ECMWF ensembles are blank for 10-days (June 18).

  2. Eastern Pacific tropical update: Tropical Storm Barbara (02E) forecast to become a Category 1 hurricane. Invest 91E to the SW may interact down the road. (Now Tropical Depression 03E)

Thank you to readers continuing into this Hurricane Season. My goal is to keep you informed about ongoing extreme weather events inside and outside of the tropics, but also a week (hopefully) heads up on what\u2019s coming. I\u2019ll be using a variety of weather modeling output, some of it may be unfamiliar, but it\u2019s state-of-the-art and industry leading standard.

Weather Trader is a reader-supported newsletter. To receive new posts via email, consider becoming a free or paid subscriber.

ECMWF 00Z | Integrated Vapor Transport | Next 10-days

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Eastern Pacific: Barbara (02E) and Invest 91E very close together off the southern coast of Mexico. The former may become a hurricane briefly before reaching cooler waters. After these two, another named storm is likely in 5-days or so.

Gulf and Caribbean are under influence of strong subtropical high keeping moisture flowing out of the deep tropics with trades or easterlies. This is keeping the eastern U.S. wet and unsettled as Canadian troughs continue to dip into the Midwest and Northeast.

No tropical cyclone formation likely in the Atlantic basin in the next 10-days+

Precipitable Water Next 5-days | Atlantic Basin

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We need > 2\u201d PWAT to fire up a tropical storm or a hurricane.

PWAT remains under 2\u201d in the Gulf and Caribbean w/o a trigger for tropical cyclone development. The ITCZ/monsoon trough is flat with a sharp gradient south of the Saharan Air Layers.

Tropical Atlantic | Precipitation and MSLP Next 10-days

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Same story as yesterday typical for early June \u2014 Strong 1028-1030 mb High Pressure across the Atlantic basin at 35\u00b0N (Azores High) eventually breaks down because of cold fronts / Canadian troughs. Until then, the strong Azores high will shove the ITCZ in the Atlantic slightly south of climatological position.

Atlantic Basin

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Nobody home for next week \u2014 good news.

Eastern Atlantic Satellite Image

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Dust layer in between two bands of clouds. The northern side is shallow stratocumulus over cooler waters while the ITCZ/monsoon trough has some convection. Tropical waves over Africa are quite close to the Equator.

NASA-GEOS-5 00z DUST Aerosol Optical Depth (AOD) | 8-days Forecast

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Dust now approaching the Lesser Antilles but will disperse into the Caribbean and Gulf.

Atlantic Ocean Surface Temperatures (SST) | Anomaly

This depiction uses ECMWF SSTs with a recent 20-year model hindcast climatology.

Comparison Tropical Cyclone Heat Potential 2024 and 2025

Left (2024) and Right (2025) \u2014 considerable heat potential difference as of June 6th compared to last year especially outside of the Caribbean.

Tropical Atlantic Satellite Imagery

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Only point of discussion is Saharan dust \u2014 lack of convection is noticeable as a result from Africa to the Caribbean.

Tropical Surface Analysis | 06Z

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Atlantic Tropical Waves = 1 but no development expected [plausible or possible] over Suriname / Brazil.

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GFS Model Update

Days 0 to 10 Relative Vorticity

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We can look at the GFS every day for weeks and see a modeled tropical storm or hurricane in the Caribbean or Gulf especially after Day 10. However, this is a known bias/false alarm problem with spurious convective \u2014 vorticity spin-ups due to the convective parameterization or estimation of vorticity generation due to intense diabatic heating. Perhaps it\u2019s worthwhile to show what will not happen.

And, yet again a major hurricane develops out of the Caribbean gyre across the Yucatan into the Gulf of Mexico by Tuesday, June 17 +9 days. The vorticity originates from the Eastern Pacific and southern Caribbean.

However, this is still highly unlikely w/o ensemble support from the more trusted model \u2014 ECMWF EPS.

The binary interaction between Invest 91E and Barbara looks quite interesting.

Medium range ensemble model outlook

These are 51-realizations of the same model with different initial conditions. Each ensemble gets equal ~2% weight in a mean calculation.

ECMWF Ensembles | 10-Days | All Storm Tracks

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Blank slate through June 17.

Eastern Pacific Tropical Update

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Barbara is underway (02E) and Cosme is highly likely to form later today or tomorrow. Then, another area to be watched in 4-5 days along the southern coast of Mexico.

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Barbara expected to become a minimal hurricane later this evening.

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ECMWF 00z Ensembles | Eastern Pacific

30-Hours active storm tracks

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Barbara (right) and Invest 91E (Cosme to the left)

7-Days Active Storm tracks

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Another storm by next weekend possible.

Western Pacific Tropical Update

JTWC watching Invest 92W over the Philippines but Low Chance of development in the next 24-hours

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Disorganized convection in the monsoon trough across the South China Sea and Philippines.

Integrated Vapor Transport Next 5-days

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A large circulation consolidates somewhat into a low pressure center or oblong gyre with a lot of moisture into southern China.

Day 5 Active Cyclone Tracks

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The ensembles are all in the 980-990 mb pressure category = minimal typhoon if it can consolidate further.

Day 15 All Tracks

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Amazingly, nothing else in the Western Pacific aside from the current Invest 92W.

SST and Anomaly

Water temperatures are cooler than normal west of the Philippines due to the continued mixing from the elongated monsoon circulation. The 26\u00b0C isotherm is well south of Japan.

Ryan\u2019s Notes:

June 2025: We use the ECMWF for medium-range prediction because the GFS can\u2019t be trusted due to false-alarm bias, and unrealistic intensification of tropical convection into spurious (ghost) storms. I don\u2019t agree this is a good thing like CNN.

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.

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Atlantic tropical update : No areas being watched through the next 7-days (June 15) by NHC and the ECMWF ensembles are blank for 10-days (June 18).

Eastern Pacific tropical update : Tropical Storm Barbara (02E) forecast to become a Category 1 hurricane. Invest 91E to the SW may interact down the road. (Now Tropical Depression 03E)

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