MED: DANIEL - Post-Tropical/Aftermath

[Vince_and_Grace_fan]

Some accumulated precipitation data from yesterday to 17:30 today (in Greek time, which means 14:30 UTC) in the area of Volos and Zagora from Meteo.gr, WU and Netatmo.
Unfortunately some stations didn't report since the midday hours, one of them is Zagora, where already fell 780 mm rain by 13:10 and it could be close to 1000 mm by now.

[underthwx]

Some accumulated precipitation data from yesterday to 17:30 today (in Greek time, which means 14:30 UTC) in the area of Volos and Zagora from Meteo.gr, WU and Netatmo.
Unfortunately some stations didn't report since the midday hours, one of them is Zagora, where already fell 780 mm rain by 13:10 and it could be close to 1000 mm by now.

https://i.imgur.com/uTtc2Vv.png

That's an incredible amount in a relatively short amount of time, I've heard reports of as much as 2286 mm of rainfall accumulations are possible??? I'm not familiar with the topography of the affected areas, and how well the region can accommodate such an amount of rainfall?, I also read that parts of Greece have been affected by wildfires recently, so the rainfall is welcome to be sure, but not so much all at once! With the activity in the Western Pacific, Eastern Pacific, the Atlantic and the Mediterranean Sea....Mother Nature once again reminds us of her power....

[DanieleItalyRm]

Some accumulated precipitation data from yesterday to 17:30 today (in Greek time, which means 14:30 UTC) in the area of Volos and Zagora from Meteo.gr, WU and Netatmo.
Unfortunately some stations didn't report since the midday hours, one of them is Zagora, where already fell 780 mm rain by 13:10 and it could be close to 1000 mm by now.

News from models from the possible development?

[Vince_and_Grace_fan]

That's an incredible amount in a relatively short amount of time, I've heard reports of as much as 2286 mm of rainfall accumulations are possible??? I'm not familiar with the topography of the affected areas, and how well the region can accommodate such an amount of rainfall?, I also read that parts of Greece have been affected by wildfires recently, so the rainfall is welcome to be sure, but not so much all at once! With the activity in the Western Pacific, Eastern Pacific, the Atlantic and the Mediterranean Sea....Mother Nature once again reminds us of her power....

Some models showed accumulated precipitation around that value earlier, but it seems overestimation, however, locally 1000-1500 mm rain possible.
A smaller mountain range lies directly along the coast of the Aegean Sea in the affected area (yellow arrow), which generate excess precipitation on the eastern side in case of easterly winds like now, and this effect also occure further west, along the higher mountains.

Daniele: Most of the models don't show much development right now until the landfall in Libya, maybe thereafter if the cyclone could emerge into the Eastern Mediterranean Sea.

[ChrisH-UK]

A satellite loop from Meteosat 10. It's dragging a lot of convection over Greece.

[underthwx]

I'm reading some updates, which include heartbreaking news of at least one confirmed fatality in Greece, from the flooding, as the Prime Minister of Greece urges residents to heed the warnings and instructions from authorities....

[Europa non è lontana]

Massive flooding in Makrinitsa
https://twitter.com/amhelakos/status/1699021437980270679

Flooding on Skiathos
https://twitter.com/meteogr/status/1699085198116176068

Waterspout/tornado in Limnionas (Euboea)
https://twitter.com/meteogr/status/1699104640841695575

In terms of model output:

JMA is the most intense 12z model with landfall in the eastern Gulf of Sidra as a 992mb TS in 136 hours. CMC has a weaker landfall, earlier, and north of Benghazi. ICON also has a weaker landfall in the north of Libya, but moves the storm parallel to the coastline, where it would have potential for redevelopment north of Egypt. UKMet has landfall as a minimal TS in the eastern Gulf of Sidra in 120 hours.

[kevin]

Satellite image of Daniel earlier today:

[Sciencerocks]

Subtropical at most...

I think it has a chance to become tropical once the upper level low washes out and it can develop convection over the core during the next couple of 3-4 days. I thank a tropical storm is likely.

[AJC3]

I’m confused… who has named this Daniel?

Put me down as confused too, where does the name "Daniel" come from?...

 https://twitter.com/TONYGam43718746/status/1699104385178206314

[Vince_and_Grace_fan]

The convection is increasing near the center, it looks more and more subtropical.

[AJC3]

Incredible radar loop from Greece. The major port city of Volos (pop. ~140,000) got absolutely inundated by Daniel's rainfall

https://i.imgur.com/a8jntuS.mp4

A few news articles...

https://www.foxweather.com/weather-news ... ember-2023

https://www.weatherzone.com.au/news/sto ... ce/1489771

[Vince_and_Grace_fan]

The top 8 daily rain amounts yesterday (only up to 20:45 local time) in Greece: https://www.meteo.gr/article_view.cfm?entryID=2913
The 754 mm in Zagora broke the last daily record (set by Hurricane Ianos in 2020).

[Europa non è lontana]

Most global models have clustered on a TS making landfall along the Gulf of Sirte, between Sirte and Benghazi - Daniel could become a significant threat for flooding in Libya if this pans out, especially if it makes landfall near a major city, as the entirety of the area is arid and typically sees little rainfall. Many models show over 100mm of rain within 24 hours for some areas.

[Vince_and_Grace_fan]

The morning ASCAT pass indicated well-defined, subtropical-like wind field with maximum winds of 25-30 kt farther NW from the center.

The LLC is clearly visible also on the satellite images and the convection continues to organise on its western and northern side with cloud top temperature around -45, -50 °C, while outer bands started to affect South Italy, East Sicily and Malta.

[Sciencerocks]

 https://twitter.com/zoom_earth/status/1699377347365916972

[doomhaMwx]

I’m confused… who has named this Daniel?

Put me down as confused too, where does the nane "Daniel" come from?...

FU-Berlin

[Vince_and_Grace_fan]

The most rain (locally up to 300-400 mm) fell today in the western parts of Thessaly according to Meteo.gr network, where Ianos also produced significant floods in 2020.
Also the weather stations in Zagora and Portaria is back, and according to the current data the total rain reached 895 and 884 mm (I dont't know if some data lost ot not).
https://penteli.meteo.gr/stations/zagora/
https://penteli.meteo.gr/stations/portaria/

[AJC3]

Here is there current ESTOFEX notice for Storm Daniel

Storm Forecast
Valid: Wed 06 Sep 2023 06:00 to Thu 07 Sep 2023 06:00 UTC
Issued: Tue 05 Sep 2023 18:53
Forecaster: GROENEMEIJER

A level 2 was issued across parts of Greece for exceptionally heavy rainfall, and to a lesser extent for tornadoes.

A level 1 was issued across an area surrounding the level 2 area for the same hazards, and for large hail across the southwestern Aegean Sea and the Peloponnese.

A level 1 was issued around the Caucasus mountains for large hail and heavy precipitation.

A level 1 was issued for Southwest England and western Brittany for large hail and locally heavy precipitation.



DISCUSSION

Greece...

For most of the forecast period, the strong easterly flow across the Aegean Sea and Greece should continue with further thunderstorm development across the East coasts of Thessaly, Evia, and the Sporades, leading to very high accumulations. The storms will continue to spread inland as elevated convection, creating very hazardous conditions there as well. Numerical weather prediction models call for another 150 - 400 mm of additional rain during the forecast period before quasigeostrophic forcing for upward motion weakens.

Because of the strong buoyancy near the surface and the existence of various convergence zones, a number of waterspouts and tornadoes may occur in coastal areas.

Across the southwestern Aegean Sea, steeper lapse rates and moisture are advected northward, while about 15-20 m/s of deep-layer shear should be available. This suggests a few supercells with large hail may be possible there.


England and Brittany...

Ahead of a subtle wave in the southerly flow across the far eastern North Atlantic Ocean, sufficient lift for the initiation of mostly elevated thunderstorms may be present. With modest CAPE and shear values, the severe threat should be limited, but a low risk of marginal flooding or an isolated large hail report will be present, warranting a level 1.


Caucasus...

Abundant and moderate instability will be present south and north of the main Caucasus range, respectively. Isolated and widespread convective storms are predicted to develop. Given the presence of 20-25 m/s of 0-6 km bulk shear, these storms may include a few supercells with large hail. North of the mountain range, upslope flow will likely enhance the heavy rainfall risk.

[Europa non è lontana]