iiinova — where your digital self keeps evolving

David Roth @drmetwatch.bsky.social · 20h

It was remarkable by 1984 standards and quite resilient in the decades since. The 2020s have not been kind. Each REHL version brings nMap2/nAWIPS — built upon GEMPAK — one step closer to the grave. I had to break free.

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David Roth @drmetwatch.bsky.social · 20h

GEMPAK is 42 years old. Bring it on. 🤣

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David Roth @drmetwatch.bsky.social · 20h

I know. I’ve jumped from the mid 1990s to the late 2000s decade. So proud. :)

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David Roth @drmetwatch.bsky.social · 20h

The first attempt to generate TC rainfall graphics via python solely. For Lala.

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David Roth @drmetwatch.bsky.social · 08/10/2026

Simon, elongating Isaias near a front, and the Caribbean disturbance. Isaias continues to resist the shear, but its synoptic environment is adapting/evolving towards its destination as a purely extratropical cyclone. We’ll see when the dry slot forms, which would be the next step in ET.

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David Roth @drmetwatch.bsky.social · 08/10/2026

After intensifying and looking more tropical during the day, there’s been a recent trend towards convective distortion and greater asymmetry. I’d say it’s starting extratropical transition, but it’s been near a frontal zone the whole time. ¯\_(ツ)_/¯

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David Roth @drmetwatch.bsky.social · 08/10/2026

I’m adding regional sectors when I can. Operational work has kept me busy. There will likely be a Southwest sector.

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David Roth @drmetwatch.bsky.social · 07/10/2026

An array of convective lows in the western part of the North Atlantic presently, all experiencing vertical wind shear. Both the Caribbean and subtropical Atlantic systems appear well defined and non-frontal. Stratus and outflow restriction is seen on the NNW/NW side of Isaias.

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David Roth @drmetwatch.bsky.social · 06/10/2026

Compare and contrast the current situation (“compact” TD 9 & its neighboring convective frontal wave) to the situation two years ago today with a more tropical-looking Milton and its companion convective frontal wave.

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David Roth @drmetwatch.bsky.social · 06/10/2026

Looks like Nolo switched from EP5 to CP2, which headed off the bin issue sooner. As CPHC has merged in with NHC, there’s a renewed effort to go to 10 bins in the northeast Pacific. It’s been needed since at least 1988, not long after the Eastern Pacific Hurricane Center was absorbed by NHC.

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David Roth @drmetwatch.bsky.social · 06/10/2026

It’s a 2-for-1 sale near the Isthmus of Tehuantepec this morning as frontal progression, coastal curvature, & divergence aloft have led to disturbances on both sides, likely with surface lows. Expect them to diverge with time as the frontal hybrid lifts E/ENE and the Pacific disturbance moves W.

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David Roth @drmetwatch.bsky.social · 05/10/2026

There are basic rules to follow concerning their movement. If there’s even a smidge of convection near the cyclone center, it will move parallel to 1000-500 hPa thickness lines. Model guidance still fails and tries to occlude convective lows unrealistically.

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David Roth @drmetwatch.bsky.social · 05/10/2026

The convective frontal hybrid slop is taking shape in the Gulf. There have been some truly hideous early October Gulf hybrids in the past. Sometimes they’ve been named, other times they have not. 🤞🐻⌚️

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David Roth @drmetwatch.bsky.social · 04/10/2026

The 22nd of Nolo quickly becomes the 23rd as it transits the International Dateline, shifting its title from major hurricane to typhoon. It remains 15E. It’s been advised upon or outlooked since September 8th. Nolo is forecast to approach Asia in five days or so. 🐻⌚️

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David Roth @drmetwatch.bsky.social · 30/09/2026

It’s possible. Keep in mind that the full range is roughly 892-1078 hPa, and unlike before there’s no plan to range fold the color scheme — it came up as an issue in the TC rainfall climo. Tying single color shade to single value would likely lead to minimal color variance, if done.

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David Roth @drmetwatch.bsky.social · 30/09/2026

There’s been a redesign of the Monthly Sea Level Pressure Records web page and the included maps. See what you think. www.wpc.ncep.noaa.gov/research/rot...

wpc.ncep.noaa.gov

Monthly sea level pressure records for the United States & Canada

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David Roth @drmetwatch.bsky.social · 30/09/2026

Post-TCs Fay, Hanna, & Gonzalo. On its 12th day, Fay is the most convective. Such a show off.

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David Roth @drmetwatch.bsky.social · 28/09/2026

Convection has remained shallow, with any deeper convection transient. The cyclone made landfall in NJ and moved back offshore while weakening. This was never a gimme for subtropical cyclone development.

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David Roth @drmetwatch.bsky.social · 27/09/2026

The buoy 215 miles southwest of Hilo has seen its pressure fall a bit as Nolo passes by. It eclipsed its September record by 5 hPa, the previous record wasset during Iniki. The period of record is since 1984.

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David Roth @drmetwatch.bsky.social · 26/09/2026

The nor’easter is getting more interesting cyclone phase-wise with shallow convection near the center. Central pressure is in the mid 980s. The warm conveyor belt circulation on sat pix is thinning. It has 1-2 days to develop organized deep convection to evolve into a Sub TC. 🍿

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David Roth @drmetwatch.bsky.social · 26/09/2026

The nor’easter remains extratropical. Highly asymmetric with a big dry slot. A convective comma head, sure. The occlusion itself surrounds a shallow warm core. No central convection. Central pressure in the mid 990s.

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David Roth @drmetwatch.bsky.social · 25/09/2026

Hurricane Nolo and the 24 hour rainfall totals on the Island of Hawai’i as of 1445z today. Getting towards 5” at Spencer.

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David Roth @drmetwatch.bsky.social · 25/09/2026

The nor’easter strengthens, with convection flaring up to its south under a pocket of cold air aloft. The model guidance is nudging towards moderate warm core with time. It has 2-3 days. 🐻⌚️

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David Roth @drmetwatch.bsky.social · 25/09/2026

Hello, Gonzalo. We’re getting to Josephine at this rate.

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Reposted by David Roth

Met Office - weather and climate @metoffice.gov.uk · 24/09/2026

Check out the impressive swirl of cloud produced by the mature low to the northwest of the UK, with its trailing cold front now sweeping into the northwest 🌀

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David Roth @drmetwatch.bsky.social · 24/09/2026

No. This is not a subtropical cyclone. It is an elongated frontal wave on the southeast side of a record strong high for September across southern Quebec. Thank you for your attention to this matter.

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David Roth @drmetwatch.bsky.social · 23/09/2026

Fay, reborn as a tropical depression

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David Roth @drmetwatch.bsky.social · 22/09/2026

Issues with Polo extend into the Southern High Plains, where its moisture contribution aloft aids a heavy rain event from today into Thursday. The model guidance has had a cohesive signal for this for at least five days.

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David Roth @drmetwatch.bsky.social · 21/09/2026

Breaking waves on Atlantic City Beach from about 25 hours ago. Towards the end of the clip a gull appears.

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David Roth @drmetwatch.bsky.social · 18/09/2026

This small low southwest of the Azores has gotten more interesting over the past couple days. NHC suddenly shot up its probability of formation today.

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David Roth @drmetwatch.bsky.social · 15/09/2026

What’s that, off to the left/west? 😉

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David Roth @drmetwatch.bsky.social · 06/09/2026

If you see Costco cookies on a conference call and welcome their input into the conversation, there’s someone I’d like you to meet. @mecookiemonster.bsky.social

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David Roth @drmetwatch.bsky.social · 03/09/2026

Edouard, degenerating as it moves farther inland and away from its main instability source, the Gulf. There’s no mysterious unknown process at play with how Edouard has behaved inland thus far. 🐻⌚️

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David Roth @drmetwatch.bsky.social · 02/09/2026

A mid to late morning report of 17.71”…

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David Roth @drmetwatch.bsky.social · 02/09/2026

If there’s anything to the brown ocean effect at all, it’s during afternoon heating when evapotransporation maximizes.

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David Roth @drmetwatch.bsky.social · 02/09/2026

For those claiming “brown ocean effect”, this is check and mate. Pre-existing drought. Inflow off the Gulf of Mexico continues since it’s not far inland. Non-sheared systems can survive inland for many days. See 1978-1994 inland TCs, Erin 2007, & Alberto 2018 for more examples.

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David Roth @drmetwatch.bsky.social · 02/09/2026

Edouard looks no worse for wear as it drifts farther inland

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David Roth @drmetwatch.bsky.social · 01/09/2026

Edouard early this morning offshore southwest Louisiana

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David Roth @drmetwatch.bsky.social · 31/08/2026

One of the better looking tropical depressions I’ve seen, with an interesting pit embedded. This is, by far, the best looking tropical cyclone in the North Atlantic Basin in 2026, and it hasn’t been named yet.

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David Roth @drmetwatch.bsky.social · 31/08/2026

A smidge bigger. In the order of Alicia 1983, Humberto 2007, and Bonnie 1986.

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David Roth @drmetwatch.bsky.social · 31/08/2026

It is meant to sort through the tropical cyclone rainfall climatology to ferret out analogs to ongoing systems. It failed during Lala — may have had to do with international Dateline crossing in its official track.

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David Roth @drmetwatch.bsky.social · 31/08/2026

Potential Tropical Cyclone Five looks decidedly better

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