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TheForecast Post

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

Weather Trader Tropics MILEPOST 1004

August 10, 2026 Monday Tropical Update

70% chance of tropical wave in Atlantic becoming a depression. Hurricane Lala likely to form and impact Hawaii this weekend.

What the month did

August 2026 was the warmest August in the 132-year national record (1895–2026), at 75.6°F against a 1991–2020 normal of 73.1°F (+2.5°F).

August 2026 was the 22nd-driest August in the 132-year national record (1895–2026), at 2.3in against a 1991–2020 normal of 2.7in (-0.4in).

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.

We are still watching 3 areas of interest across the Atlantic basin this evening with a tropical wave along 30°W at 70% chance of tropical cyclone formation according to NHC.

However, the environment is hostile with dry air to the north with a Saharan dust layer. We have plenty of time to watch these systems as they travel around the sprawling Bermuda subtropical high.

ECMWF Ensemble 12z full-physics tracks next 15-days

Even if these waves don’t develop right away in the MDR, they still have opportunity to “catch fire” down the road closer to the Caribbean or in the western Atlantic. Plenty of ensembles show major hurricane potential with “survivors” that make it out of the MDR.

The AIFS Ensembles show this situation, too. Plenty of opportunity for a recurving major hurricane near Bermuda, and then more tropical waves coming off Africa into late August. The peak of the season is still a month away.

Central and Eastern Pacific —> Invest 93C —> Hurricane Threat to Hawaii

Still waiting on Tropical Depression 01C just within the Central Pacific basin —> and all indications that it will become TS & then Hurricane Lala.

Ensembles show the track of Lala right over the Hawaiian Island chain in 4-5 days.

And, the rest of the statistical + dynamic ATCF model suite —> consensus


African Dust —> Saharan Air Layer from Caribbean to the coast of Africa

North America Precipitable Water Next 6-days

Heavy rain around a building ridge from the Southwest through Rockies into the central Plains then southern Great Lakes into the Ohio River Valley.

Next 7-days Blend of Models Precipitation

Heat Dome —> High Temperatures Next 9-days to Wed August 19th

ECMWF HRES | Precipitable Water | My Favorite Parameter | Atlantic Tropics

2 strong tropical waves at lower latitudes being watched for development.

The SAL leads the way and in 4-5 days, we’ll have a potential TD/TS east of the northern Leeward Islands.

Then, another system comes off Africa and has a chance of developing. The waters are quite warm out here!

You can easily see Saharan Air Layers as giant frontal boundaries sweeping through the northern half of the Main Development Region with tropical waves to the south in the ITCZ/monsoon trough which is absolutely loaded with tropical moisture.

The cyclonic vorticity isn’t that exciting but probably enough for at least 1 named storm in the deep tropics.

The little area of vorticity north of Bermuda so far has not qualified as a named tropical system.

Flagship model: ECMWF AIFS 18z —> Integrated Vapor Transport next 8-days

  • A hurricane likely to form out of the ITCZ SE of Hawaii and threaten the islands by this weekend.

  • Multiple robust Atlantic tropical waves but not quite catching fire like they could in a more favorable environment sans El Niño.

Mid-Level 500 mb Height Anomaly next 10-days

Hudson Bay —> eastern Canada trough gives way to a “heat dome” centered on Texas and the Southeast


Atlantic Tropics showing some signs of life — NHC watching 3 areas

Tropical Waves — Lined up 6 deep from the Central Pacific to coast of Africa

2 of the waves in the parade in the Central/Eastern Pacific are now marked with 60% to 90% chance of development in next 7-days. And, 2 in the Atlantic at 10% and 70%.

Sea Surface Temperatures plenty warm now > 28°C (red)

The warmth in the MDR is quickly expanding to carve into the cool <26°C water from the cold Canary Current, so I think any tropical waves that stay below 20°N latitude will have sufficient warm water to develop.

NASA Dust (GEOS-5) — Saharan Air Layers continue to cruise across the Atlantic doing damage to tropical waves and stabilizing the tropical environment with warmth at lower levels. The SAL seems to tail off significantly into next week. Perhaps the end of the road for SAL.

Flagship AIFS Integrated Vapor Transport next 12-days —> tropical waves churn westward, and into second week of August, quite a few tropical waves in the MDR that look healthy enough, and we’ll have to watch into next week. I see at least 3 candidates with 2 better chance of survival. Even if they do not form or catch fire in the deep tropics, they need to be watched as they gain latitude and get closer to Bahamas, as the ECMWF ensembles showed.

Eastern Pacific Typhoon Basin

90% —> Invest 93C —> Hurricane Lala

ECMWF 18z takes Hurricane Lala around the Big Island and turns west on Sunday.

SST > 27°C around Hawaii — enough for a minimal hurricane

HAFS-A & B —> Hurricane Lala curving to the west of Big Island

Western Pacific Typhoon Basin

Quite a mess with the monsoon trough … multiple swirls with names but remaining relatively weak.

Integrated Vapor Transport from ECMWF AIFS 18z

Very busy basin with Chan-hom heading into Japan and then who knows how many more TCs will spawn out of the monsoon trough before it finally breaks down.

Global Tropical Cyclones for more ACE information, as well as my original climatlas.com/tropical site now with the beautiful Interstate Highway theme and full of interesting content!

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. Our own content is now sourced from hottestsince.com and weather.city and celsius.earth, and squall.cloud and weather.football and global-tropical-cyclones.com and precipitation.earth

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

Milepost
1004 · laid 2026-08-11T02:06:54.320000Z
Source
https://weather.substack.com/p/august-10-2026-monday-tropical-update
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