Brian McNoldy

3) another 7-8 inches is coming from persistent onshore winds generated by a stationary high pressure system near Bermuda

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The significant ongoing tidal flooding event in the #Miami area is caused by a few coincident components:
1) the full moon on October 6, which happens to be near perigee (October 8)
2) sea level rise adds ~8 inches to the baseline sea level used in NOAA tide predictions

#KingTide
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The closest one up that way that we have now is Lake Worth:
sfwmd.maps.arcgis.com/apps/dashboa...

Additionally, water levels have peaked above the moderate flooding threshold since Saturday morning and are forecast to continue into the weekend.
bmcnoldy.earth.miami.edu/tide/
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Peak water levels in the #Miami area have been above the minor flooding threshold for the past four days, and our tide forecasts show that continuing for at least the next ten days! #KingTide
bmcnoldy.earth.miami.edu/tide/
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Two areas of interest to watch in first week of October Updates and summaries on tropical Atlantic activity... including easterly waves, tropical storms, subtropical storms, and hurricanes.

As of today, 2025 has had more ACE accrued than 2024 did by now (and 2022, 2016, 2015, 2014, 2013, 2009, etc). Historically, roughly 20% of a season's activity still lies ahead.
bmcnoldy.blogspot.com/2025/10/two-...

Yikes... wait 'til you see it in another 5-7 days then!

Now that Imelda is an extratropical cyclone and there's a break in the activity, here's a look back at the tracks of all 9 named storms so far this season. Their peak intensity, minimum pressure, and total Accumulated Cyclone Energy are listed on the right.

The highest predicted tide of the year is coming up on October 8, but on top of that, forecast conditions in the atmosphere and ocean will boost it even more.

Southeast Florida: Expect several days of minor to moderate tidal flooding around every high tide beginning this week.

Hurricane #Imelda made a direct landfall on #Bermuda late Wednesday night at Category 2 intensity.
bmcnoldy.earth.miami.edu/tropics/radar/

As fellow binary interaction enthusiast, you might enjoy this, @michaelrlowry.bsky.social!

How about *only* hurricane pairings in the Atlantic and for the entire period of record (since 1851). What are the closest two hurricanes have ever been recorded? Humberto and Imelda right at the top. The nearest reliable contender was Easy and Fox back in 1951.

For reference, the exact values for each of the thresholds in 2025 (so far) are included below, with the annual number of hours averaged over the 1991-2020 "climate normal" period shown in parentheses.

≥47°F: 1651 (1620)
≥50°F: 1260 (1222)
≥55°F: 501 (558)
≥60°F: 52 (120)

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Now that #monsoon season is officially over in the #Albuquerque area and dewpoints are generally on the decline, here's a look at the amount of time spent above a few dewpoint (humidity) thresholds.

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I first shared this last October, and was really surprised at the feedback... it turns out far more people than you'd think have similar stories. Even if you aren't one of them, I guarantee you know several people.
drive.google.com/file/d/1CVSw...

Definitely relevant for #Imelda now!

and many others that lit up October in recent memory... Mitch '98, Joaquin '15, Matthew '16, Michael '18, Eta '20, Iota '20, Milton '24, etc, etc

The tropical Atlantic has now had 15 consecutive days of activity, and it's not over yet (Imelda will be around for another day or so). The Accumulated Cyclone Energy (ACE) climbed from 53% of average for the date to the current 93%. Climatologically, 20% of a season's ACE occurs after October 1.

The general rule of thumb is ~800 miles for an elastic interaction, but there's no hard number because of differences in size and intensity.

This interaction reminded me of Typhoons Della and Faye (1960) in the West Pacific as shown in Figure 3 of Dong and Neumann (1983): "On the Relative Motion of Binary Tropical Cyclones".
Humberto and Imelda got much closer together than Della and Faye did.
journals.ametsoc.org/view/journal...
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This style of plot is what we used to document the interaction and merger of Gil and Henriette in the East Pacific (2001) in a paper I co-authored, Prieto et al (2003): "A Classification of Binary Tropical Cyclone–Like Vortex Interactions". journals.ametsoc.org/downloadpdf/...
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On that figure, Humberto's track is in red and Imelda's track is in blue, with ∘ and x marks every six hours. Their geographic centroid is shown in a green dashed line, and faint red and blue lines connect the storm tracks to the centroid. A centroid-relative plot is shown in the inset.
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Here is a 4-day track summary of Hurricanes #Humberto and #Imelda, showcasing an example of the #Fujiwhara Effect. They approached and interacted with each other, coming within 465 miles, but did not complete an orbit around a common center or merge before moving back away from each other.
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What are the odds of this?!
Since starting daily precipitation measurements at the new house, the total over the past 5 months is extremely close to the average: 5.18 inches observed, 5.16 inches average.
#CoCoRaHS #CitizenScience #NMwx

Opinion | Trump Has No Mandate to Destroy America

Terrific column by @jamellebouie.net about Trump’s lack of mandate. Good reminder that Trump got 49.8% of the vote in 2024 to Harris’s 48.3%. Compare with 2020, when Biden got 51.3% of the popular vote to Trump’s 46.8%.
www.nytimes.com/2025/10/01/o...

Good question: I would say that 1) it would be useful to see the tracks plotted relative to their centroid and 2) there is a huge range of potential outcomes with the Fujiwhara effect (bsky.app/profile/bmcn...). Even if they get barely close enough to nudge each other's tracks...

I started this radar loop from #Bermuda early for #Imelda, but in the meantime, it's capturing some hefty rainbands from #Humberto! Latest loop is available at bmcnoldy.earth.miami.edu/tropics/radar/

Yes, most in my experience. How is China? :-)
bsky.app/profile/bmcn...

The centers of Hurricanes #Humberto and #Imelda are now just 480 miles apart, and they share a larger envelope of circulation. What a spectacular example of binary vortex interaction!

2025's Accumulated Cyclone Energy (ACE) could catch up to the climatological value somewhere around October 2. As of today, it's at 87% of average for the date. This is now more ACE that the recent 2024 and 2022 seasons had by this date.
bmcnoldy.blogspot.com/2025/09/high...