GaWx

12Z UKMET: strongest run yet and SW of prior run with LF near Tampa area: TROPICAL STORM IAN ANALYSED POSITION : 14.7N 74.5W ATCF IDENTIFIER : AL092022 LEAD CENTRAL MAXIMUM WIND VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS) -------------- ---- -------- ------------- ------------- 1200UTC 24.09.2022 0 14.7N 74.5W 1007 26 0000UTC 25.09.2022 12 14.2N 77.0W 1005 25 1200UTC 25.09.2022 24 14.9N 79.2W 1004 27 0000UTC 26.09.2022 36 15.4N 81.4W 1003 25 1200UTC 26.09.2022 48 17.0N 82.8W 1002 30 0000UTC 27.09.2022 60 18.9N 84.2W 1001 30 1200UTC 27.09.2022 72 20.9N 85.1W 998 34 0000UTC 28.09.2022 84 23.0N 85.6W 996 42 1200UTC 28.09.2022 96 24.5N 85.8W 994 42 0000UTC 29.09.2022 108 25.6N 85.1W 993 51 1200UTC 29.09.2022 120 26.6N 84.1W 991 55 0000UTC 30.09.2022 132 27.0N 83.2W 986 54 1200UTC 30.09.2022 144 28.3N 82.5W 987 47

@WxWatcher007 is if I'm not mistaken.

12Z UKMET 168 is ~100 miles WSW of Tampa heading NNE to NE. Extrapolating this would lean toward it coming ashore a little north of Tampa.

Euro 168 landfalls SC/NC border.

That UKMET track is from the 0Z as the 12Z is a good bit further west (along 85W through 144).

That's my educated guess.

12Z GEFS mean is significantly west of the last GEFS run and has the largest number of members well to the west in the central GOM since yesterday's 12Z run.

12Z UKMET a big shift back to the SW vs the 0Z run with it nearly stalling at the 85W longitude 200 miles west of Naples: TROPICAL DEPRESSION 09L ANALYSED POSITION : 14.4N 69.4W ATCF IDENTIFIER : AL092022 LEAD CENTRAL MAXIMUM WIND VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS) -------------- ---- -------- ------------- ------------- 1200UTC 23.09.2022 0 14.4N 69.4W 1009 24 0000UTC 24.09.2022 12 15.1N 71.6W 1008 26 1200UTC 24.09.2022 24 15.0N 74.1W 1007 29 0000UTC 25.09.2022 36 15.0N 76.2W 1005 28 1200UTC 25.09.2022 48 15.8N 78.5W 1004 31 0000UTC 26.09.2022 60 17.3N 80.4W 1002 33 1200UTC 26.09.2022 72 19.1N 82.1W 1000 34 0000UTC 27.09.2022 84 21.2N 82.8W 998 40 1200UTC 27.09.2022 96 23.4N 84.1W 997 38 0000UTC 28.09.2022 108 24.5N 85.0W 995 42 1200UTC 28.09.2022 120 25.2N 85.1W 996 44 0000UTC 29.09.2022 132 25.9N 84.9W 996 48 1200UTC 29.09.2022 144 26.1N 84.8W 996 50

Interestingly, Gaston has restrengthened some per the latest NHC discussion: Tropical Storm Gaston Discussion Number 13 NWS National Hurricane Center Miami FL AL082022 300 PM GMT Fri Sep 23 2022 Gaston is improving in satellite presentation this morning. Convection is re-forming and wrapping around the northern and western sides of the circulation. A recent scatterometer pass showed that Gaston was slightly stronger than the previous advisory and the initial intensity has been increased to 55 kt. The tropical-storm-force wind field was also expanded, especially in the northwestern quadrant based on these data.

From the NHC discussion: "The initial wind speed is set to 30 kt, perhaps conservatively since the eastern side of the circulation has not been sampled by scatterometer or aircraft data." "The depression has about a day over warm water in light to moderate shear before all the models blast the system with strong upper- level southwesterly winds. Most of the guidance shows this system becoming a tropical storm before weakening significantly by late this weekend and dissipating early next week. The official wind speed prediction is near the NOAA corrected-consensus guidance HCCA."

From the 11 AM EDT NHC discussion: The latest NHC track forecast lies near the center of the guidance envelope and closely follows the IVCN and HCCA aids. This prediction is very similar to the previous one, with only slight westward adjustments at days 3-5 to reflect the latest model consensus trends. The moderate to strong deep-layer northeasterly shear over the cyclone is expected to persist through tonight, so only slight strengthening is forecast through early Saturday. But once the shear decreases to less than 10 kt this weekend, more significant intensification is forecast as the cyclone moves over SSTs in excess of 30 deg C. The latest NHC intensity forecast has been increased from the previous one and explicitly calls for rapid intensification as the cyclone crosses the northwestern Caribbean Sea. The system is forecast to approach the Cayman Islands and Cuba as a strengthening hurricane, with additional intensification likely once it emerges over the warm waters of the southeastern Gulf of Mexico. In fact, this forecast calls for the system to approach the Florida peninsula as a major hurricane by day 5, which is supported by the latest IVCN and HCCA aids.

In reality per the NHC discussion, #10 is quite possibly already a TS and it is forecasted to be upgraded to one later today. In contrast, #9 is still undergoing strong shear though it also is forecasted to be upgraded later today. #10: "The initial wind speed is set to 30 kt, perhaps conservatively since the eastern side of the circulation has not been sampled by scatterometer or aircraft data." "The depression has about a day over warm water in light to moderate shear before all the models blast the system with strong upper- level southwesterly winds. Most of the guidance shows this system becoming a tropical storm before weakening significantly by late this weekend and dissipating early next week. The official wind speed prediction is near the NOAA corrected-consensus guidance HCCA." They could both be upgraded at the next regular advisory. If so, it would seemingly come down to minutes since it would probably be dependent on which one has the earlier issued advisory. If we base it on the just released ones, TD #10 would have the better chance to be called Hermine because TD #10's package was released about 10 minutes earlier than the 11AM for TD #9.

0Z UKMET: 150+ miles further SE track vs 12Z with landfall near Ft Myers at 132 (vs aimed at Big Bend on prior run) and then NE into the peninsula: TROPICAL DEPRESSION 98L ANALYSED POSITION : 13.3N 67.3W ATCF IDENTIFIER : AL982022 LEAD CENTRAL MAXIMUM WIND VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS) -------------- ---- -------- ------------- ------------- 0000UTC 23.09.2022 0 13.3N 67.3W 1007 29 1200UTC 23.09.2022 12 14.2N 69.3W 1009 27 0000UTC 24.09.2022 24 14.6N 71.1W 1008 26 1200UTC 24.09.2022 36 14.7N 73.6W 1007 26 0000UTC 25.09.2022 48 15.1N 75.4W 1005 30 1200UTC 25.09.2022 60 15.8N 77.4W 1004 32 0000UTC 26.09.2022 72 17.6N 79.2W 1002 37 1200UTC 26.09.2022 84 20.2N 81.1W 1000 38 0000UTC 27.09.2022 96 22.5N 82.3W 996 32 1200UTC 27.09.2022 108 24.1N 83.2W 994 40 0000UTC 28.09.2022 120 25.4N 83.0W 992 52 1200UTC 28.09.2022 132 26.7N 82.9W 993 45 0000UTC 29.09.2022 144 27.5N 82.0W 996 45

The UKMET is almost always very conservative on forecasted storm strength especially during the early stages. This run actually never has it stronger than a TS and it's near its strongest during hours 132-168 of this run. So far, it hasn't had it stronger than 992 mb on any run. So, I consider the UKMET track much more informative than the intensity in most cases including now.

What a concentration over and just SE of S FL on the 12Z EPS! Note that those that cross S FL pretty much don't get further west than 84W in the NW Caribbean. Those that miss FL to the SE don't get past about 81W in the NW Carib.

That is quite the SE shift of the mean track to across far SE FL, where the mode also is now. Note that the mean member speed is quicker thus allowing for more members to be taken NE early with the trough. The mode on the 0Z was further NW near a Ft. Myers to Melbourne track.

12Z UKMET is fairly similar to its 0Z run with it moving due north along the 85W longitude at 144 with a most likely later hit per extrapolation on or near the FL Big Bend: NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER 60 HOURS FORECAST POSITION AT T+ 60 : 15.5N 75.0W LEAD CENTRAL MAXIMUM WIND VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS) -------------- ---- -------- ------------- ------------- 0000UTC 25.09.2022 60 15.5N 75.0W 1006 29 1200UTC 25.09.2022 72 16.5N 77.6W 1004 30 0000UTC 26.09.2022 84 18.7N 79.7W 1002 38 1200UTC 26.09.2022 96 20.7N 81.4W 1000 40 0000UTC 27.09.2022 108 23.0N 83.2W 998 34 1200UTC 27.09.2022 120 24.2N 84.2W 996 44 0000UTC 28.09.2022 132 25.2N 84.9W 995 47 1200UTC 28.09.2022 144 26.3N 85.0W 997 50

Here's how I see it. Late Sept climo does not favor the good number of EPS members going NE across the S half of FL. That's more like mid Oct and later climo. But there's an Octoberlike upper trough coming into the E US days 4-6 before lifting out. Notice that the faster EPS members are mainly the ones that turn NE across S FL. So, it appears that a big key will be speed of 98L. If it goes faster, it will have a better chance to get caught by the upper trough and move NE over the S half of FL. But, if not fast enough, it very likely won't and would instead likely hit the N Gulf coast anywhere from the FL Big Bend westward to LA and probably at a slower speed.

The 6Z EPS mean at 144 looks to me like it shifted slightly NE of the 0Z EPS at 150.

0Z Euro is west of the last two runs. 0Z EPS mean seems to be similar to the 12Z. The spread seems a bit tighter (fewer extremes like Yucatan and Bahamas).

0Z GEFS mean is the furthest west of any recent run.

Regarding TCs that were born in the Caribbean during 9/21-30 1851-2015, climo says Gulf LA eastward to FL is easily the most likely destination although a pretty good number also go WNW into MX after either crossing the Yucatan or going just N of it. https://www.nhc.noaa.gov/climo/images/sep_21_30.png

It is to a large extent although the 0Z ICON, which doesn't go past 180 hours, was then moving WNW just NW of the NW corner of the Yucatan headed for the western Gulf. Also, the 0Z UKMET though in the SE GOM moving NNW was over 200 miles west of its prior run along with the US E coast H5 trough pulling out.

0Z GFS slams LA! 0Z UKMET at 144 is in SE GOM moving NNW after NW just before: TROPICAL DEPRESSION 98L ANALYSED POSITION : 9.8N 64.4W ATCF IDENTIFIER : AL982022 LEAD CENTRAL MAXIMUM WIND VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS) -------------- ---- -------- ------------- ------------- 0000UTC 22.09.2022 0 9.8N 64.4W 1007 23 1200UTC 22.09.2022 12 11.2N 64.3W 1008 29 0000UTC 23.09.2022 24 12.5N 66.4W 1007 30 1200UTC 23.09.2022 36 13.9N 68.7W 1007 30 0000UTC 24.09.2022 48 14.5N 70.5W 1006 28 1200UTC 24.09.2022 60 14.8N 72.9W 1005 33 0000UTC 25.09.2022 72 15.1N 75.2W 1003 32 1200UTC 25.09.2022 84 16.3N 77.6W 1000 36 0000UTC 26.09.2022 96 18.1N 79.5W 997 41 1200UTC 26.09.2022 108 20.3N 81.6W 993 42 0000UTC 27.09.2022 120 21.7N 83.2W 992 42 1200UTC 27.09.2022 132 22.9N 84.4W 994 46 0000UTC 28.09.2022 144 24.0N 85.1W 992 51

We already have had 3 hurricanes this month. There will very likely be at least a 4th from 98L. If Gaston were to become a H, there would then very likely be 5 this month. If we get to 5, that would tie for the most in Sept. since the active era started in 1995!