GaWx

We’ll see. There has been video of catastrophic floodwaters coming off the mountains this afternoon in many places in Jamaica including Mandeville. Hurricane Mitch, the 2nd deadliest Atlantic basin hurricane on record, caused 11-18K fatalities, mainly from catastrophic flooding and landslides due to epic rainfall amounts.

Jeff P. is now witnessing a flooding catastrophe in Santa Cruz in his live feed:

Per Brad P live feed, Santa Cruz is now flooding. Also, large portions of many towns (homes and cars) are now being swept away by extreme flash flooding coming off the mountains. The way he is talking it sounds catastrophic. One town he mentioned is Mandeville.

Per Brad P. to the SE of the center in Santa Cruz, there are funnel clouds just now appearing:

SUMMARY OF 200 PM EDT...1800 UTC...INFORMATION ---------------------------------------------- LOCATION...18.2N 78.0W ABOUT 20 MI...35 KM SSW OF MONTEGO BAY JAMAICA ABOUT 230 MI...370 KM SW OF GUANTANAMO CUBA MAXIMUM SUSTAINED WINDS...165 MPH...270 KM/H PRESENT MOVEMENT...NNE OR 25 DEGREES AT 8 MPH...13 KM/H MINIMUM CENTRAL PRESSURE...899 MB...26.55 INCHES 165/899 There’s clearly NNE movement now.

Note that the 30C+ area around Jamaica did shrink a lot due to some cooling although unfortunately not nearly enough cooling to help. As Melissa was coming in, it was going over mainly 30+.

Here it is embedded (replace X with Twitter):

Even so, a nearby roof was just peeling off in Jeff P.’s feed due to >100 mph winds.

Jeff piotrowski live:

Jeff Piotrowski:

Before Melissa, the lowest SLP on record in Jamaica was 958 mb (1951’s Charlie) followed by 960 mb (Gilbert 1988).

ACE will likely exceed 122.5 by 18Z today.

I received 0.20” since last night bringing me to 2.75” MTD, which is only modestly below normal.

Today’s Euro Weeklies run mean has an even weaker SPV with only 8 of the 42 days’ mean stronger than normal, and it even includes 15% of members with a very early major SSW, by far the most yet of any run this season! Note that the progged mean Thanksgiving through Dec 11th of 2025 SPV is only ~20 vs normal of 31, which would be the weakest for that period since 2019-20: Compare the above to the prog at the same time last year: 40 of the 42 days’ mean stronger than normal along with ZERO members with a major SSW: Note that the mean Thanksgiving through Dec 12th of 2024 was up at ~37 (it verified to be way up at ~45) Now compare to the prog from the same time two years ago: 30 of the 42 days’ mean stronger than normal with only 2% with a major SSW: Note that the mean Thanksgiving through Dec 9th of 2023 was ~31 (it verified to be ~34): In summary, this post shows that the 100 member Euro Weeklies mean is suggesting a mainly weak SPV in late Nov and early Dec, which would compare to a very strong SPV for the same time in 2024 and a slightly stronger than normal SPV in 2023. Even if we assume that the 2025 prog is biased modestly too negative, a bias adjustment would still be progged pretty weak (~25) and would be way below 2024’s actual of 45 and significantly below 2023’s actual of 34. @mitchnick@snowman19

This epic modeling failure would be amazingly great news. Do you think this is a realistic possibility? Keep moving west!

The IOD will almost certainly still rebound sharply by winter as it did in those other 3 cases since 2010 as we’ve been in a +IOD regime in recent years and IOD almost always bottoms by this time of year:

1995-2005 did average ~160. But outside of those years, 10 seasons (1991-4, 2006-7, 2009, and 2013-5) were <80. If I were classifying what’s hyperactive, I’d add some years that were <175 during a much lower avg recorded ACE era such as 1886’s 166, 1899’s 151, 1906’s 162, 1916’s 144, 1932’s 170, and 1955’s 158. Even 1880’s 131 should be considered imho as it was way higher than all preceding years other than 1878 back to 1851.

2025 ACE: Through Sept 16th: 39 Sept 17th+: 74 and rising rapidly. The full season to date ACE is progged to get above the 1991-2020 full season avg of 122 by tonight and then go well above that within the next few days. This very active late season ACE has been the pattern especially in recent La Nina seasons. There have been 4 MH with 3 of them occurring since Sept 22!

That’s the nature of a solid +PNA as you know, especially without an accompanying -EPO. There has been a pretty strong +EPO in recent days. Often the coldest anomalies on average tend to be further SE with it often above normal in much of Canada. As the Euro Weeklies show, I also expect a warmup after the next 2 weeks. But, in the meantime, as mentioned the E 1/4 of the US is overall progged to have its coldest 10/27-11/9 since 2012 with coldest anomalies centered southern Mid-Atlantic states and SE US. Per the EW, a warmup follows but mainly to near normal rather than AN with only week 4 AN and it only slightly AN.

There are 3 Atlantic basin hurricanes on record on this date or later that were cat 5 and they had these lowest pressures/highest sustained winds: -Mitch of 1998: Oct 26-28; 905 mb/180 mph; but landfall was way down at 80 mph on Honduras. The extreme rainfall though was what made it so deadly. -Hattie of 1961: Oct 31; 914 mb/165 mph; it weakened slightly at landfall in Belize to 915 mb/150 mph (cat 4) -Cuba hurricane of 1932: Nov 5-8; 915 mb/175 mph; but it weakened some before hitting land as it was 150/cat 4 on landfall The latest on record cat 5 landfall was on Cuba on Oct 19 (in 1924) near its peak intensity of 165 mph. So, IF this were to hit Jamaica as a cat 5, it would become the latest on record to make landfall anywhere by 9 days.

This is very sad and terrifying to see knowing that Jamaica is in the crosshairs of this monster. Hopefully something unexpected will change things at least a little bit for the better before landfall. Any weakening would be quite welcome obviously.

It isn’t just upwelling that cools the waters at or near where a hurricane crosses: it also cools due to the conservation of energy (potential energy from warm water transitions to kinetic (wind) energy of the storm/heat engine), cooling from raindrops (I assume this factor is relatively minor), and cooling from cloudcover blocking the sun: Hurricanes cool the ocean by acting like "heat engines" that transfer heat from the ocean surface to the atmosphere through evaporation. Cooling is also caused by upwelling of cold water from below due to the suction effect of the low-pressure center of the storm. Additional cooling may come from cold water from raindrops that remain on the ocean surface for a time. Cloud cover may also play a role in cooling the ocean by shielding the ocean surface from direct sunlight before and slightly after the storm passage. All these effects can combine to produce a dramatic drop in sea surface temperature over a large area in just a few days. https://earthobservatory.nasa.gov/images/6223/passing-of-hurricanes-cools-entire-gulf#:~:text=Hurricanes cool the ocean by,pressure center of the storm