{ "number": 698, "headline": "August 10, 2025 Invest 97L High Chance of Development", "standfirst": "Sunday: tropical wave in East Atlantic expected to be long-lived 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": "2025-08-11", "published": "2025-08-11T00:22:23.136000Z", "updated": null, "access": "free", "body_html": "
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2025 Atlantic Hurricane Season [Day 71]. My FORECAST for this year is 14 named storms, 7 hurricanes, and 3 majors. 2025: 4 named storms, 0 hurricanes, and 0 majors

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Good evening! Area of thunderstorms in the eastern Gulf off the Florida peninsula coastline looked quite impressive today, but has since waned leaving behind a low-level swirl on visible satellite imagery. This shower activity is associated with a trough and not expected to develop \u2014 NHC not watching.

Invest 97L is underway in the far eastern Atlantic over the Cabo Verde Islands, and is puffing impressive convection within a moisture rich environment \u2014 just behind a Saharan Air Layer. Another strong tropical wave is on its heels still over Africa, but it is not expected to develop in the MDR.

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Sunday Evening Tropical Update

  1. Central North Atlantic (20%) Invest 96L: low chance of something weak developing on its way into north Atlantic well away from land.

  2. Invest 97L: main event \u2014> over cool waters in the far eastern Atlantic but billowing convection. A tropical depression or storm could develop right away if the convective activity sustains, otherwise, it may be within the next 48-72 hours once it reaches warmer water > 26\u00b0C \u2014 then rapid intensification episode could happen to get it up to Major Hurricane Intensity in 7-8 days. UNKNOWN impacts to the East Coast of the USA.

  3. Eastern Pacific Basin: Henriette (08E) is back as a hurricane over cool SSTs but within low vertical wind shear environment. The little system may actually reach major hurricane status north of Hawaii.

  4. Western Pacific Typhoon Update: Tropical Storm Podul (16W) heading westward toward Taiwan but intensity uncertainty is high (TS \u2014> Typhoon)

ECMWF 12z | Precipitable Water Next 10-days

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My favorite parameter: Invest 97L comes into the picture on a track northeast of the Caribbean where it then recurves NW to a position off the Carolinas in 10-days. This is a more westward solution among the ensemble members but consistent with the large envelope of uncertainty (cone) at 9-11 days.

Note, the tropical wave on the heels of Invest 97L (Erin?) is further to the south and reaches the Caribbean in 10-days. Atlantic hurricane season is still several weeks from peaking.

ECMWF 12z | Simulated Satellite Next 10-days

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The tropical waves and Saharan Air Layers are all moving in tandem generally westward \u2026 and interacting along the way. As Invest 97L tracks W, it will need to content with this dry, stable/warm layer.

ECMWF 12Z | Integrated Vapor Transport Next 12-days | Atlantic Basin

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+Moisture transport vectors from the 12z flagship solution. The ECMWF 12z control shows a East Coast \u201cclose call\u201d similar to Erin (2001) almost 25-years ago.

ECMWF 12z Flagship Solution | Sunday for next 13-days

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Atlantic Basin Outlook

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Atlantic Satellite Imagery | Infrared

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Significant flare up of convection with Invest 97L.

Eastern Atlantic & Tropical Africa | Satellite Image

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Another tropical wave is on its heels over Africa, then another in eastern Nigeria.

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Invest 97L is over chilly SSTs ~25.5\u00b0C

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NASA GEOS-5 | 00z DUST Aerosol Optical Depth | 8-day Forecast

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Plumes of Saharan dust coming off African continent to north of tropical wave and monsoon trough/ITCZ and any tropical waves must contend with this negative influence on its trek westward across the Atlantic MDR.

Atlantic Ocean Surface Temperatures (SST) + Anomaly (vs. last 20-years)

Eastern Atlantic SSTs are not impressive compared to the past 2-years but seem to be plenty enough for 97L.

NOAA Tropical Surface Analysis | 18z

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Atlantic Tropical Waves = 2 including Invest 97L (90%) and another wave that is being stretched N/S by a trough. The top half is a weak low w/20% chance of development in the north central Atlantic.

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ECMWF AIFS-Single Consistently Develops a Major Hurricane | 12z Cycle

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AIFS-Single is back today with landfall solutions \u2026 just keeping these for the records as we do not know how the A.I. trained systems perform \u2014 but it seems they have the same issues/pitfalls as conventional / fully physics systems.

Previous 06z | AIFS-Single

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Previous 00z | AIFS-Single

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These tracks at/past 10-days are \u201cway over the horizon\u201d of predictability and only possible/plausible track scenarios that exist in every hurricane season in August and September since 1995.

NOAA GFS Extended Range | 18z

Well out-to-sea!

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Previous 12z solution | GFS

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GEFS Ensembles 12z | All Tracks through Day 9

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GEFS Ensembles 12z | All Tracks through Day 15

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Powerful major hurricane tracks off the Florida and Southeast/East Coast by Day 15 \u2014 but vast majority are off the coast \u2014 although GEFS is underdispersive.

Canadian Machine Learning Trained + Conventional Full Physics

Checking on our friends in Canada with their world-class modeling systems.

ECMWF ensemble model outlook | Invest 97L

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

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The black solid open-circle line is the \u201censemble mean\u201d position every 6-hours but that is NOT a solution itself, just a statistic to show the average equally weighted track points through the next 12-days. Many Category 4+ solutions are west of that line so we can\u2019t discount a near-coastal impact or landfall.

ECMWF Ensembles 12z | Day 10 All Tracks

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ECMWF Ensembles 12z | Day 15 All Tracks

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Very intense solutions with a few threats to the US (STILL low %) but still too far out (10-13 days) and vast majority are not affecting land.

AIFS Ensembles 12z | Day 10 All Tracks

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AIFS Ensembles 12z | Day 15 All Tracks

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Eastern and Central Pacific Tropical Update

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Hurricane Henriette could reach Category 3 status \u2014 small but impressive!

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Henriette is over 25\u00b0C water but it\u2019s increasing on track to the Northwest.

Another system could form well off the coast of Mexico in 7-10 days.

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Western Pacific Typhoon Update

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Tropical Storm Podul (16W)

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Podul forecast to become a typhoon \u2014 and if it heads a bit further south, then it could escape the worst impacts of vertical wind shear and become quite intense \u2014 landfall over Taiwan is possible.

Ryan\u2019s notes from August:

Heading into mid-August with a more active period in the Atlantic basin \u2014> remember that we have many models updating every 6-12 hours, and many show catastrophic or historic solutions e.g. major hurricanes near land including the U.S.

HOWEVER, nothing is imminent or set in stone. We only use models to show the \u201cplausible\u201d scenarios of systems that could/may develop. We have 100s of solutions generated daily \u2014 1000s per week. Digesting this information is the job of responsible meteorologists and media \u2014 to process the data, assess the risks, and add value.

The models cannot consistently and/or skillfully look over the predictability horizon e.g. 8-10 days especially with tropical cyclones. The convection / storm clusters are not resolved by the full physics weather models at their current resolution (9 km to 25 km). Also, the A.I. models do not provide that much of an additional skill gain for individual tropical cyclones that have not yet formed.

As we watch tropical waves come off Africa in the coming days, each/every has the potential to develop especially heading into August. However, when/where and what impacts are unknown.

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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Invest 97L is underway in the far eastern Atlantic over the Cabo Verde Islands, and is puffing impressive convection within a moisture rich environment \u2014 just behind a Saharan Air Layer. Another strong tropical wave is on its heels still over Africa, but it is not expected to develop in the MDR.

Central North Atlantic (20%) Invest 96L: low chance of something weak developing on its way into north Atlantic well away from land.

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