From satellite, the whorl certainly looks convincing and the scale is right. GFS swallows it up by Monday in the southern zone of the Atlantic low over N Europe, but then as explained previously, the models are notoriously bad at forecasting their behaviour. Anything to note about surface windspeeds or sea conditions?

Nothing significant in wind speed terms. I reckon it was a tropical depression equivalent. We might have seen it develop into something more interesting if it hadn't been sheared to death so early on.

 

Nothing significant in wind speed terms. I reckon it was a tropical depression equivalent. We might have seen it develop into something more interesting if it hadn't been sheared to death so early on.

 

12" of rain reported in Livorno and flood alerts in Florence so even if they didn't get the wind, it was still a major event

Are we looking at a UKocane over the next 3 days?

With MetO warnings for 70mph gusts tues night/weds morning we aren't that shy.....

Are we looking at a UKocane over the next 3 days?

With MetO warnings for 70mph gusts tues night/weds morning we aren't that shy.....

Yeh but its baroclinic so I wouldn't call it a 'cane'. I'm actually flirting with the idea of doing a YouTube video on actual barotropic systems that came close to the UK.

 

Yeh but its baroclinic so I wouldn't call it a 'cane'. I'm actually flirting with the idea of doing a YouTube video on actual barotropic systems that came close to the UK.

 

Think "Debbie" hit Ireland didn't it?

 

Think "Debbie" hit Ireland didn't it?

 

Yeh Debbie is one of the best examples, but its by no means the only interesting case. I reckon hurricanes do hit the UK they are just ridiculously rare. I'd have to guess 1 in 1000 year event.

Small possibility of a medicane developing in the Adriatic tomorrow morning. Unlikely though. Models like trying to generate them in the Adriatic, but the reality is that Adriatic medicanes are extremely rare. 

I'd go with 20% chance of development. 

Quick discussion on Medicane potential over the next 2 or so weeks. Currently rating environmental conditions poor for Medicane development. Below is the ECM forecast for 192 hours.

The key ingredient for medicane formation is 'rossby wave breakage' or a upper level cold cutoff low over the med. We do see a region of anomalously low heights centred over the Adriatic (presumably this is why the models keep trying to spawn medicanes there) however we really want to see this either in the west med near the Baleric or much further south in the Ionian.  

So the cutoff low (when present) is in completely the wrong place, and the rest of the med is dominated by easterly winds. We really need to be seeing north westerly winds. 

Looks like this month is going to be pretty quiet for medicanes. I will write up that disturbance we had a few weeks ago though as a 'medistorm'. 

Wow. Convection has really organised over the last few hours. A system resembling a medicane, to my utter amazement has actually formed in the Adriatic.

Well that lasted all of 2 hours. 

Small chance of medicane genesis in the Ionian early next week. Unlike the Adriatic the Ionian is favourable for medicanes, and SSTs are unusually high there so if one does develop it might be strong.

Same picture on the 12Z. 

If a Medicane does develop then surface fluxes are going to be strong. SST anomalies are below:

You can view actual temps here http://www.ospo.noaa.gov/data/sst/contour/global.c.gif which are 25-26C which is very warm for Medicanes. 

Interesting times ahead.

Higher resolution WRF shows rapid intensification of Medicane system. This is a really interesting one to watch. 

Wind shear could really be a problem though. The Jet comes in pretty fast and would kill it off quick.

Q, you've said in the past that medicane seasons can last until January- this being driven by cold air aloft; interestingly, and on a broader scale, conditions for Atlantic hurricanes minimise after November. This contrast makes me wonder if Atlantic - Mediterranean - European atmospheric interactions might not give an indication of medicane intensity and occurrence in relation to the broader hurricane picture, possibly with a chronological pattern. Does this form part of your research, or is this a conjectural wildcard?

Q, you've said in the past that medicane seasons can last until January- this being driven by cold air aloft; interestingly, and on a broader scale, conditions for Atlantic hurricanes minimise after November. This contrast makes me wonder if Atlantic - Mediterranean - European atmospheric interactions might not give an indication of medicane intensity and occurrence in relation to the broader hurricane picture, possibly with a chronological pattern. Does this form part of your research, or is this a conjectural wildcard?

 

Hi bertwhistle. Its true that I've said that warm SSTs are not essential and Medicanes can form in very cold water indeed (15-18C is the benchmark). That being said warmer SSTs do mean stronger surface fluxes which, in turn, mean stronger storms. The upper cold core aloft is more a means of generating the medicane, once the tropical system is created they behave much more like conventional tropical storms and higher ocean heat content means greater potential intensification. Indeed model simulations with medicanes show that when you ramp up the SSTs the intensity goes up.         

I guess the TLDR of this is that it isn't going to affect formation probability that much, but it may well affect intensity.

As a point of note I've always said tropical cyclones that form well to the north in the Atlantic behave much more like medicanes. Even in the 2017 hurricane season I'd draw your attention to Tropical storm Arlene which formed in April. April is a bit late even for Medicanes but is less out of season than it is for conventional hurricanes, Arlene also formed in cold water and was meseo scaled like a medicane.

You can find countless examples of this sort of thing for example Hurricane Vince or Tropical storm Grace.  

 

Think "Debbie" hit Ireland didn't it?

 

Yep

From: https://www.intechopen.com/books/advances-in-hurricane-research-modelling-meteorology-preparedness-and-impacts/the-impact-of-hurricane-debbie-1961-and-hurricane-charley-1986-on-ireland

6Z is fun. Two medicanes at the same time, one in the Adriatic and one in the Ionian.

I don't expect anything to come of the Adriatic cane though. 

12Z Update: Both Medicanes are still visible. Again, I only think the Ionian one has a real chance of developing. ARPEGE is also on board with the Ionian medicane. I'd say development probability is around 40% now. 

HIRLAM model is very impressive. Massive intensification.

Now keep in mind, although this kind of Medicane is unusually strong and rare, the models showing this kind of thing is not rare. Models always tend to overestimate medicane development. 

Watching this one with interest; again, the prognostics are not handled well by the models so we need to keep an open mind as things evolve.

Addition: just noticed a rogue arm of the jet lying from Sicily to southern Greece. Now, if this was the Atlantic, lows would intensify just N of the jet. What influence is there on medicanes in relation to jet activity?