GaWx

Per 12Z Euro 240, it appears to be aiming for the FL Panhandle 9/29-30 as a MH.

It made it to lemon status on the 2 PM NHC TWO: A tropical wave located several hundred miles east of the Windward Islands is producing an area of disorganized showers and thunderstorms. Some gradual development of this system is possible during the next several days while the system approaches the Windward Islands toward the end of the week and moves over the eastern Caribbean sea over the weekend. * Formation chance through 48 hours...low...near 0 percent. * Formation chance through 5 days...low...20 percent. Edit: The 12Z Euro has the most impressive 850 vorticity for this AEW in many runs at 72 hours. The 12Z Euro at 120 hours is the most organized for this of any Euro run at that point since the 0Z 9/14 run. 12Z Euro: TS at 168 moving NW in W Car. H at 192. Nearing MH SE GOM 216!

This will very likely be lemoned and Invested soon. Meanwhile, the 12Z GEFS is quite active with this in the Caribbean and about as active as any run so far.

The UKMET (12Z) has this as a TC per the textual output for the second time* as it was also on the 12Z 9/14 run: NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER 144 HOURS FORECAST POSITION AT T+144 : 13.6N 76.4W LEAD CENTRAL MAXIMUM WIND VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS) -------------- ---- -------- ------------- ------------- 1200UTC 25.09.2022 144 13.6N 76.4W 1006 26 *Corrected to say this is the 2nd UKMET run with it rather than the first run

I'm bumping this for the record since now nearly all models have this developing to some extent and the 6z GFS has this as a TC within 4 days as well as a MH in the W Car. The Euro had this as an active AEW per the above as far back as the 0Z 9/13 run, way ahead of the GFS. The 240 hour map of the 0Z 9/14 Euro run even had this as a TS SW of PR moving WNW on 9/24 (see image below). Actually, the ICON and CMC had this active though to a lesser extent by the 0Z 9/14 run. So, if this turns out to be something significant in the Caribbean, the GFS will have in retrospect been way behind the Euro. (The just released 12Z GFS is similar to the 6Z GFS with a TC at the Windwards.) Here is the 0Z 9/14 Euro at 240:

This has hardly weakened to this point and the center is going to be over water soon.

There are a significant number (nearly 25%) of 12Z EPS members landfalling on the CONUS 9/29-10/2 as hurricanes or as a strong TS from TX through NC with also a couple of still offshore threats. At least half of these hit the FL Gulf coast, which is my #1 risk area this season based on third year cold ENSO analogs. Being that this was a more active EPS run than prior ones, I wouldn't be surprised if most of the next ones over the next few days aren't as active. Regardless, this will more than likely be the next potential threat period on the CONUS.

With 12 days still to go, Sept is far from a done deal after Fiona, which itself may become a MH. Keep in mind that as recently as September 10th (just 4 days before the Fiona TC formed on 9/14), people here including myself were considering the possibility of no new TC through 9/20 based on then still very quiet models as even the precursor to Fiona was temporarily quieter. Furthermore, the models including EPS are now making some late Sept W Car noise largely from the AEW now near 43W. Especially with the W Car peak season climo already getting started by then, a TC there then wouldn't be the least bit surprising. On 9/10, even Andy Hazelton said this: "Not a whole lot to look at at the climo peak of hurricane season, behind #Earl. 95L fizzled due to shear. The low riding wave is struggling with SAL (EPS refuses to give up on it but color me skeptical). The proverbial #nextwave coming off is already trending weaker on models."

This AEW is now near 42W (very weak low probably ~11N) continuing westbound and has been pretty inactive the last 2 days as dry, stable air has been interacting with it. There's only scattered convection with it now. The 12Z Euro does have this as a weak low in the W Caribbean 9/26, which then moves NW to the Gulf of Honduras on 9/28. By then, the W Caribbean season is already starting to get into full swing climowise. So, something to keep an eye on. Edit: A good number of 12Z EPS members active with this in W Caribbean 9/26-8.

Looking at the prior 10 years, the average number of hurricanes from storms born in Sept is only two. So, Sept of 2022 has already exceeded that mark with three. Of the last 10 years, only 2020 had more with four and 2022 still has another 12 days to go. Fiona's ACE is likely going to end up quite impressive.

Now a hurricane officially at 70 knots.

Much of the eastern half of PR is getting blasted with very heavy rain along with solid TS force winds. Fiona is quite possibly a hurricane now. Waiting on official confirmation.

The 18Z EPS 144 has fewer left outliers vs the 12Z EPS 150.

12Z UKMET goes NW over far E PR and then moves WNW for short time followed by NW...so quite a shift E from prior run at PR! MET OFFICE TROPICAL CYCLONE GUIDANCE FOR NORTH-EAST PACIFIC AND ATLANTIC GLOBAL MODEL DATA TIME 1200UTC 17.09.2022 TROPICAL STORM FIONA ANALYSED POSITION : 16.3N 63.6W ATCF IDENTIFIER : AL072022 LEAD CENTRAL MAXIMUM WIND VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS) -------------- ---- -------- ------------- ------------- 1200UTC 17.09.2022 0 16.3N 63.6W 1005 35 0000UTC 18.09.2022 12 17.2N 64.9W 1003 33 1200UTC 18.09.2022 24 18.4N 65.8W 1001 44 0000UTC 19.09.2022 36 19.0N 67.7W 999 45 1200UTC 19.09.2022 48 20.0N 68.6W 999 46 0000UTC 20.09.2022 60 21.4N 69.9W 996 53 1200UTC 20.09.2022 72 22.4N 70.5W 995 51 0000UTC 21.09.2022 84 23.9N 70.5W 987 57 1200UTC 21.09.2022 96 25.8N 70.0W 978 54 0000UTC 22.09.2022 108 27.8N 69.3W 969 63 1200UTC 22.09.2022 120 30.6N 68.6W 961 73 0000UTC 23.09.2022 132 33.9N 66.5W 953 84 1200UTC 23.09.2022 144 38.7N 61.4W 942 99

Is the 0Z EPS drunk? About 30% of the members landfall on the SE US coast after only 8% at 12Z! Also, fwiw since not a good model, the 0Z CFS hits FL and then skirts the coast up to NC. Earlier runs were OTS. And keep in mind the 12Z JMA's sharp left turn from 168 to 192.

Horrible flooding reported in Guadeloupe. Look out Virgin Islands and PR this weekend and DR Sunday. This has been a very wet storm. And it is going to slow down, a very lethal combination.

Today this looks less impressive as of DMIN although it is starting to refire convection near 11N, 30W. Still watching as quite a few ensemble members still keep this intact near the Caribbean.

A safe miss of the CONUS is easily the best bet on the 12Z EPS. However, fwiw, it has 6 of the 51 members (only 12%) hit the CONUS as a TS+: 2 ME, 1 SC, and 3 FL (2 far south and 1 Melbourne) that then go into the Gulf.

With regard to the CONUS, a safe recurve is clearly the best bet as of now. That has the support of the Euro, GFS suite, UKMET, and CMC. But on the 12Z JMA (slower) from 168 to 192, it gets blocked and turns west at least for a short time from a new high to its north. Also, fwiw, many of the 12Z CMC ensemble members (GEPS) hit the CONUS (2 in NE US, handful FL, and good number Gulf coast). The JMA and GEPS both bigtime suck vs the more credible Euro, GFS, and UKMET, of course. But I thought it was worth mentioning.

This only waned a little after I last posted about this near midday. Now, check it out as we start to head toward DMAX, which is still 5-6 hours away in the E MDR. Convection has again blossomed in a circular pattern and is centered on 11N, 24W. It looks even more impressive than it looked early today. This has the makings of a sleeper as the NHC doesn't mention this in the TWO.

Per NHC, Fiona dropped another 0.2 of latitude between the 5PM (AST) and 8PM positions, which is south of the NHC track. It is now down to 16.1N vs 16.6N at the 11AM position during a period in which it was forecasted to be at 16.6N now. So, it is now 35 miles south of where the 11AM track had it for now.

Headed for NC?

Happy Hour GFS is way west vs 12Z!

12Z EPS implies ~30% risk of a CONUS TS+ landfall based on ~15 of TS+ members landfalling there. Per NHC, Fiona lost 0.3 degrees of latitude the last 6 hours.

I think that is more likely a cat 1 H landfall at WPB on the 12Z Euro (near 990 mb). Look for the 12Z EPS mean to shift SW.