MED: 02M/MASINISSA (DAVID) - ex-Tropical Storm

[Vince_and_Grace_fan]

It looks like that a recently formed extratropical cyclone near Italy (see here: https://hu.sat24.com/hu/it) could aquire subtropical characteristics on tomorrow and Sunday between Sicily and Tunisia as it will head southward. Models show symmetrical, but shallow warm core: http://moe.met.fsu.edu/cyclonephase/gfs/fcst/archive/20112006/29.html
The strength of the cyclone varies between a strong depression and moderate storm on the models, and it depend on how long will be the cyclone over water. The SST's are around 21-22 Celsius in that area.

Some cloud cover forecast which show nice the separation of the core of the cyclone from the frontal zone:

[underthwx]

Very interesting...it's my understanding that systems in the Mediterranean Sea, rarely reach Category 1 intensity?... Will be watching this to see what takes shape...

[wxman57]

Looks like the low center will be moving into Tunisia within 36-48 hrs.

[DanieleItalyRm]

Also Tropical cyclone formation probability sees a (low) possibility for tropical development over Med.. Now the system is definitely subtropical. warm core and convection over the LLCC. Still a little connected to the fronts. Too bad the landfall expected on Tunisia. I think it would have an interesting development if it can stay over open sea.

http://neige.meteociel.fr/satellite/anim_vis_it.gif

[Vince_and_Grace_fan]

The LLC is well-defined, but the convevtion weakened a bit since the morning hours. The ASCAT measured maximum winds near 30 kt at 09:35 UTC and Pantelleria's weathe station also reported 52 km/h (28 kt) 10-min sustained wind with 72 km/h (39 kt) gust at 09:50 UTC, so it probably produced storm-force winds, at least in small areas under the convection. The minimum pressure was 1007 hPa on Pantelleria, so he cyclone is not very deep, and much strengthening is not even expected until the landfall. https://www.infoclimat.fr/observations-meteo/temps-reel/pantelleria/16470.html

[underthwx]

The LLC is well-defined, but the convevtion weakened a bit since the morning hours. The ASCAT measured maximum winds near 30 kt at 09:35 UTC and Pantelleria's weathe station also reported 52 km/h (28 kt) 10-min sustained wind with 72 km/h (39 kt) gust at 09:50 UTC, so it probably produced storm-force winds, at least in small areas under the convection. The minimum pressure was 1007 hPa on Pantelleria, so he cyclone is not very deep, and much strengthening is not even expected until the landfall. https://www.infoclimat.fr/observations-meteo/temps-reel/pantelleria/16470.html

https://i.imgur.com/inqvaId.png

https://i.imgur.com/BYgOiqw.png

That's a cool picture, I like that...the system looks like it wants to be tropical one day, real bad, but it sounds as if it won't, which is a good thing...good morning

[Vince_and_Grace_fan]

Here are two animations from the daytime, one zoomed and an other with the frontal system around it. The convection isn't very susained and deep for now, so I don't know is it classifiable or not yet, but maybe it become more organized during the night. The latest model runs predict the landfall in Tunisia around 12-15 UTC tomorrow.

[DanieleItalyRm]

Most tropical now.https://mobile.twitter.com/PrometheiPlanum/status/1330416728199884800/photo/1

[Vince_and_Grace_fan]

Yes, the core of the cyclone became much more organized during the night hours and retained its well-defined, tropical-like structure until the landfall, an eye-like feature also developed after midday. On the other hand, it remained under the upper level trough which originated from the extratropical status and the yet streak to the southest also likely helped the convection with some baroclinic forces. But based on the sustained, organized and quite dep convecion (highest cloud tops were around -50,-55 Celsius), I say it probably was rather tropical than subtropical.
Sadly all 3 ASCAT instrument missed the cyclone in the morning (the SATSCAT pass show weaker winds then yesterday, but then was excessive with 40-50 kt wind), and the Tunisian meteorological stations reporting only 3 hourly, but the available data suggest the peak intensity likely was around 45 kt. In Mahdia, the closest city to the landfall the pressure was 1014.1 hPa a 12 UTC and 1012.6 at 15 UTC, and it reported 50 km/h (27 kt) 10-min sustained wind with 95 km/h (51 kt) gust at 15 UTC.

Animations:

[DanieleItalyRm]

I think tropical.
On November 21 was certainly subtropical. But November 22 showed too much convective activity insistence in the center. Although not very intense I compared it with Pablo's Oct 2019 when it was classified as a 40kt tropical storm. Both show -50°C in top clouds.
Ultimately I believe that this system can be considered tropical from 01.00 on November 22nd. I also believe this storm was about to intensify just before landfall (-54°C top cloud).
Tcfp-Noaa correctly predicted the possibility of tropical formation over soutern Mediterranean sea:

[DanieleItalyRm]

Conclusion: The images show the tropical cyclone that hit Tunisia on November 22. The small storm was born from a cold core depression on November 20 over Tyrrhenian Sea, which proceeding southwards then transited into a hybrid cyclone (subtropical) over the Sicily Channel-Pantelleria and subsequently into a tropical cyclone (warm core and convection in the center ) close Linosa is. Recall that more times the tropical transition has allowed the formation of tropical cyclones at medium latitudes and on waters below 23 ° C (Grace 2009, Pablo 2019 etc.). The development of the system has produced excessive rainfall throughout southern Italy and Tunisia, with flood events. In Italy the 450mm in 48 hours of Cirò Marina and the 331mm in 24 hours of Crotone stand out in Calabria, as well as the 148mm in 72 hours on eastern Sicily. In Tunisia, Tunis-Carthage accumulated 117.6mm in 72 hours of which 97mm in 48h. Mahdia 84mm in 48 hours. Wind gusts that affected Tunisian coast reached 45-50kt (90 km/h). Fortunately, the not excessive diameters of these storms bring the most intense winds on fields within 50-100km in diameter. The Ascat satellite did not pass on the morning of November 22nd, at the peak of the system's intensity. However, the gusts of 51kt (94 km/h) recorded in Mahdia during the landfall are consistent with a storm of intensity T2.5/T3.0 on Dvorak scale. In Gafsa, although weakened and in the semi-desert hinterland, the system still carried gusts of 45kt (83 km/h).

CIRA-JPSS images: two images (00:42 AND 02:20) beginning of the initial tropical nocturnal phase. Note the lights of part of south Italy and Tunisia cities.



CIRA-JPSS images:Just before landfall over Tunisa, 13:32. Note the eye of the storm


Kachelmannwetter image: during the landfall over Tunisia, 15:00

[Vince_and_Grace_fan]

Here is my preliminary intensity estimate and satellite animations:



[youtube]https://youtu.be/cojfhP0_zA4[/youtube]

[DanieleItalyRm]

Here is my preliminary intensity estimate and satellite animations:

https://i.imgur.com/Y961rwH.png

https://youtu.be/cojfhP0_zA4

I really admire what you do Vince_and_Grace. It would be nice if you put your transaction- conclusion graphs system also at the end of the satellite loop videos. I also recommend visible loop satellite witouth regions confine, where the shape of the system is more appreciable

[Nancy Smar]

Looks like none of us here knew about this. Based on the image, this system was officially designated as Tropical Storm 02M.

[Vince_and_Grace_fan]

Looks like none of us here knew about this. Based on the image, this system was officially designated as Tropical Storm 02M

I saw it a week or two ago, but forgot to share it here.