GaWx

Thanks. So, since this pattern of this offshore low and associated cooler air in the E US is likely indirectly related to the very strong Nino, is this possibly a sign of things to come this winter?

Is the offshore E US strong low bringing down the cool air into the E US this entire week likely related to the very strong Nino? 0Z 10/12 GEFS forecast for 6Z 10/21: no offshore storm and thus no cool air pinned in E US: 0Z 10/18 GEFS forecast for 6Z 10/21: much cooler E US in reality associated with offshore strong storm working in tandem with 3 Canadian highs keeping cool dry Canadian air pinned in E US: Cool air this week E US thanks to the above pattern consistent with Euro Weeklies’ significantly cooler change: (had been warm on runs from Oct 12-13 when no offshore storm)

^Further to the above: illustrates the E US cooling power of the offshore storm this week!

1. Temps: Euro Weeklies 10/12 run for 10/19-25: warm E US because there was no offshore storm on model yet 10/18 run for 10/19-25 is much cooler E due to strong offshore storm: thank you storm! ——————- 2. Precip for 10/19-25: 10/12 run: no offshore storm 10/18 run: strong offshore storm keeping it cool in E US!

The non-tropical low now forming gas gone orange: Tropical Weather Outlook NWS National Hurricane Center Miami FL 800 PM EDT Sun Oct 18 2026 1. Off the East Coast of the United States: A storm-force non-tropical low pressure area is developing along a frontal boundary tonight off the southeast coast of the United States. This low is likely to move slowly and erratically over the next couple of days while it initially remains non-tropical. Later this week, if the system stays over the Gulf Stream, environmental conditions could become more conducive for the low to develop some subtropical characteristics. A subtropical cyclone could form over the second half of this week as the system begins moving generally northeastward, offshore of the eastern United States. Regardless of development, this system will cause high winds, coastal flooding, and dangerous surf along portions of the U.S. East Coast. Please consult statements and warnings from local National Weather Service offices and the Weather Prediction Center for more information, along with High Seas Forecasts and Storm Warnings issued by the National Weather Service. * Formation chance through 48 hours...low...near 0 percent. * Formation chance through 7 days...medium...40 percent.

Thanks. Do you know whether or not it’s normal for +AAM to be prevalent within 30-50N at any point during a strong El Niño? Or does it tend to stick closer to the equator? Have you seen any actual data? The only other El Niño for which I can see latitude based relative AAM from this site’s data is 23-4 because it only goes back to 2022. Reviewing 23-4, the 30S to 30N region had the main +AAM only during Dec 1st-Jan 15th and it never exceeded +3 SD for any latitude. That paled in comparison to Sept 14th-Oct 3rd of ‘26, when it exceeded +4 SD in portions of 15S to 15N!

POSSIBLE LOW LEVEL INVEST NEAR 36.0N 71.0W FOR 20/1800Z.

Ray et al, A similar theme to what Ray emphasized last month remains even nearly a month later where the really impressive +AAM emphasis is mainly 30S to 30N: Is it normal during El Nino for the +AAM (atmosphere rotating faster than the solid earth as I understand it), which we know is characterized as El Niñoish, to usually be strongest mainly in the 30S to 30N latitudes (with the highest near the equator) since that is nearer to the Nino regions than latitudes outside of that region? If so, do the regions outside of 30S to 30N normally get consistently positive during strong El Niños? Do they ever consistently average +AAM for long periods or is that typically relegated to 30S to 30N even during the subsequent N hem. winter? ———————— By the way, the relative AAM by lat. above is not surprisingly still supporting a very strong global relative mean +AAM with it back >+3 since Oct 12th:

The many upcoming chilly nights throughout the SE that have started will accelerate the autumn leaf changes everywhere, even where it’s too warm for frost. Is anyone seeing significant colors yet? I expect higher elevations almost certainly are, but what about those at 1,000 feet or lower? Here, the deciduous trees are almost all still green. By the end of the week, however, I wouldn’t be surprised to see a few starting to change even this far SE near sea level.

About as beautiful and comfortable a full late Oct week as is possible for outdoor activities is in the cards this week for a large portion of the SE away from coastal NC with lots of sunshine, high temps in the 60s-70s, mainly 15 mph or lower winds after today, and dewpoints down in the 30s-40s. We can thank persistent mainly N to NE winds resulting from three sprawling areas of Canadian high pressure centered to our NE, helped by persistent low pressure offshore the E coast especially the first half of this week. Enjoy it while you can, especially with the amount of rainfall expected Nov-March due to the very strong Nino.

Thanks, Adam. I’m certainly not worried about a persistent SE ridge this winter!

Tropical Weather Outlook NWS National Hurricane Center Miami FL 800 PM EDT Sat Oct 17 2026 For the North Atlantic...Caribbean Sea and the Gulf of America: 1. Off the East Coast of the United States: A strong non-tropical low pressure area is expected to form by Sunday night off the southeast coast of the United States. This low is likely to move slowly and erratically through the middle of next week, and some subtropical development is possible during this time. Regardless of development, this system will cause high winds, coastal flooding, and dangerous surf along portions of the U.S. East Coast. Please consult statements and warnings from local National Weather Service offices and the Weather Prediction Center for more information, along with High Seas Forecasts issued by the National Weather Service. * Formation chance through 48 hours...low...near 0 percent. * Formation chance through 7 days...low...30 percent.

To add to the above, the ‘23 Jul-Sep MJO was much more MC/IO oriented than the nonexistent MC/IO of ‘26: ’23: ‘26:

Doldrums lead to ‘23 FL Keys coral disaster as it wasn’t just due to GW…it was warming of several degrees from the doldrums superimposed on background ocean warming of several degrees due to GW: Sea-surface temperatures in the Coral Sea off northern Queensland often increase during periods known as the "doldrums," characterized by weak winds, reduced cloud cover and dry, descending air. These conditions are unusual for the humid tropics, where we would typically expect plenty of cloud cover, thunderstorms and rainfall.

12Z UK: H in N ATL: NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER 36 HOURS FORECAST POSITION AT T+ 36 : 32.7N 70.7W LEAD CENTRAL MAXIMUM WIND VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS) -------------- ---- -------- ------------- ------------- 0000UTC 19.10.2026 36 32.7N 70.7W 1007 44 1200UTC 19.10.2026 48 33.7N 71.3W 1004 43 0000UTC 20.10.2026 60 35.0N 71.2W 1002 41 1200UTC 20.10.2026 72 36.0N 70.5W 1001 39 0000UTC 21.10.2026 84 36.0N 70.0W 1001 45 1200UTC 21.10.2026 96 36.0N 70.2W 998 42 0000UTC 22.10.2026 108 36.2N 70.5W 996 45 1200UTC 22.10.2026 120 36.9N 69.2W 992 42 0000UTC 23.10.2026 132 38.1N 66.5W 987 48 1200UTC 23.10.2026 144 40.9N 61.1W 978 67 0000UTC 24.10.2026 156 45.8N 56.8W 977 55 1200UTC 24.10.2026 168 47.9N 58.0W 996 43