Friday’s Tropical Update

1. Atlantic Basin: NHC still has a 10% chance up for the disturbance in the Gulf but time is running out. There appears to be a broad surface circulation. Models showing a more robust tropical wave in the central MDR next week.

2. Eastern Pacific Basin: Area SE of Hawaii could develop (50%) in deep tropics nearing Central Pacific. Another system likely next week well off southern Mexico.

3. Western Pacific Basin: Watching Tropical Storm Krosa (12W) for rapid intensification today.

Just scattered rain shower and storms in the far NW Gulf of Mexico.

Large Basin view of Simulated Water Vapor | ECMWF 00z

A wave that reaches the central MDR in 5-6 days showing signs in the ECMWF HRES and ensembles (down the road) for further development. Otherwise, the basin is under an onslaught of midlatitude and Saharan Air Layer influences - troughs and dry/stable air at low and mid-levels. Not a happy place for tropical storms.

Integrated Vapor Transport Next 10-days | Atlantic Basin

Sunday: tropical wave emerges into Atlantic and shows more significant moisture transport and circulation into Wed/Thurs next week as it reaches the central MDR. The prevailing flow takes this wave to the northern Caribbean / Bahamas in 10-days (August 3).

We need to closely watch these waves for gaining latitude and finding more hospitable environment in the subtropics for tropical cyclogenesis.

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’s coming. I’ll be using a variety of weather modeling output, some of it may be unfamiliar, but it’s state-of-the-art and industry leading standard.

Atlantic Basin Outlook

10% chance of development into weekend across the Northern Gulf of Mexico.

Eastern Atlantic Satellite Image

Only show in the town is the tropical wave just east of the Lesser Antilles.

Clear conditions from the Bahamas to Puerto Rico and the subtropical “warm pool”

NASA GEOS-5 | 00z DUST Aerosol Optical Depth (AOD) | 10-d Forecast

Tropical waves will need to deal with continued dust plumes into August.

Atlantic Ocean Surface Temperatures (SST) | Anomaly

Ocean temperatures plenty warm from African coast to the Lesser Antilles with 28°C corridor or warm pool extending into the western Atlantic around Bermuda. However, the anomaly (which doesn’t do anything) remains near-normal or slightly below in the Main Development Region (MDR) from Caribbean to Africa.

The “warm blob” around Bermuda is decreasing in magnitude.

Gulf of Mexico where the 10% wave spins is > 30°C — very warm — and evidence that you need more than “warm water” to form a tropical storm.

Tropical Atlantic Satellite Imagery

Convection with a tropical wave east of the Islands is maintaining vigor.

ECMWF Precipitation and MSLP | Next 6-days

ECMWF Vorticity Next 6-days

Better / more impressive collection of moisture / convection into the central MDR in 6-days … looks healthier than whatever we’ve seen in the past several weeks.

ECMWF | Precipitable Water Next 6-days

My favorite parameter … Huge amount of tropical moisture continues to rotate around a deep layer ridge anchored over the Southeast U.S.

And, we may see yet another repeat of this weather pattern that brings a blob of moisture from decaying front / backdoor trough into the Southeast.

The central MDR looks reasonably primed for development …

NOAA Tropical Surface Analysis | 06z

Atlantic Tropical Waves = 4 but not developing. The disturbance in the Gulf is still at 10% associated with an old frontal boundary.

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 00z | Next 12-days | Active Tracks

ECMWF Ensembles 00z | Next 15-days | Active Tracks

We do have hurricanes in the ensembles (EPS 00z) with 6/51 showing a powerful system in the western Atlantic. However, that is only 10%, so not a strong signal. We will monitor, of course.

Compare with AIFS Ensembles | Next 10-days | Active Tracks

Next 13-days | Active Tracks

Next 15-days | Active Tracks

The 10-14 day period lights up with the AIFS-ENS v1 showing many systems. This is a more coherent signal that deserves attention with the tropical wave in 6-days that reaches the MDR.

ECMWF Control (15-days)

GFS 06z | Next 16-days

Eastern Pacific Tropical Update

Area of convection well SE of Hawaii showing development but any storm formation will be slow. NHC has a 50% chance in next 7-days. Area south of Mexico is on tap for next week.

AIFS-Ensembles through 4-days

Weak lows in the far southern tropics along the ITCZ

Day 8 Active Tracks

Much higher chance of storm off Mexico going to die over cooler waters.

Western Pacific Tropical Update

Busy Western Pacific with multiple systems underway. I’m most interested in Tropical Storm Krosa (12W) for rapid intensification today.

ECMWF Control has 960s mb for Krosa (12W) at its peak intensity in 2-days suggestive of a Cat 2 Typhoon.

Tropical Storm 12W (Krosa)

A blob of intense convection is forming near the center … and wind shear will decrease allowing a brief window for faster intensification.

JTWC now shows a minimal typhoon in 36-hours. As it’s not forecast to affect land, we can watch Krosa (12W) develop and it may reach “major typhoon” status.

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.