'Medicane' 7/8 November 2014

[Simon Culling]

A compact and strong storm system formed in the western Mediterranean Sea during yesterday (Fri 7th November) which allegedly had shared characteristics of a tropical storm and an extra-tropical depression. It hit the islands of Malta and Lampedusa with storm force winds and is currently drenching southern Italy with plenty of rain. The SST's in this part of the Med (22-24*C) are too low for a true hurricane to form, but they might have some influence on the development of the low pressure systems that regularly form here in the autumn as part of the 'Mediterranean Monsoon'.

The W'undergorund Blog of Dr Jeff Masters carries a good explanation as does the Wikipedia page:

http://www.wunderground.com/blog/JeffMa ... rynum=2854

http://en.wikipedia.org/wiki/Mediterran ... al_cyclone

[03Stormchaser]

I like the term Medicane, is this often used in setups like this?

[Simon Culling]

Hello Steve, severe events like this are not frequent occurrences, but these appear to be quite distinct systems. depressions often form in the Mediterranean (especially in the lee of the Alps) but these so-called 'Medicanes' appear to be smaller more dynamic systems. Good pdf on a recent one below:

http://www2.mmm.ucar.edu/people/rotunno ... eather.pdf

[Simon Culling]

METARS from Malta Airport:

LMML 072145Z 28011KT 9999 -SHRA BKN027 14/14 Q1002 TEMPO VRB20G40KT 2000 TSRA BKN014CB
LMML 072115Z 27015G29KT 9999 SCT012CB BKN015 BKN040 15/15 Q1002 RETSRA TEMPO 2000 TSRA BKN012CB
LMML 072045Z 27018G32KT 220V290 9999 -TSRA SCT013CB SCT020 15/15 Q1001 RESHRA TEMPO 2000 TSRA BKN012CB
LMML 072015Z 31021KT 9999 SHRA SCT025 14/14 Q1001 TEMPO 8000 SHRA BKN014TCU
LMML 071945Z 30020KT 9999 -SHRA FEW005 BKN020 14/14 Q1000 TEMPO 8000 SHRA BKN014TCU
LMML 071915Z 30016KT 9999 -SHRA SCT004 BKN025 14/14 Q1000 TEMPO 8000 SHRA BKN014TCU
LMML 071845Z 32021G31KT 9999 -SHRA SCT015 14/14 Q0999 TEMPO 8000 SHRA BKN014TCU
LMML 071815Z 31025G37KT 6000 SHRA SCT005 BKN015 15/14 Q0997 TEMPO 3000
LMML 071745Z 31037G53KT 7000 SHRA BKN011 15/14 Q0993 NOSIG
LMML 071739Z 31041G57KT 9999 SHRA BKN011 16/14 Q0992 NOSIG
LMML 071715Z 30033G56KT 9000 BKN008 FEW012CB SCT015 17/15 Q0986 NOSIG RMK LIGHTNING TO NW
LMML 071645Z 25017G30KT 220V280 8000 BKN012 17/17 Q0985 NOSIG
LMML 071634Z 23016G31KT 180V270 6000 -RA SCT006 BKN027 17/17 Q0984 NOSIG
LMML 071615Z 20031G56KT 170V230 2000 -RA BKN005 16/16 Q0986 NOSIG
LMML 071545Z 19028G43KT 160V220 4000 RA SCT015 16/13 Q0991 NOSIG
LMML 071535Z 19026G44KT 5000 RA BKN015 16/13 Q0993 BECMG 7000
LMML 071515Z 20024G43KT 7000 BKN021 17/12 Q0995 NOSIG
LMML 071445Z 19018G31KT 160V220 8000 BKN016 16/13 Q0997 NOSIG
LMML 071415Z 20017G29KT 8000 -RA BKN016 15/12 Q0998 NOSIG
LMML 071345Z AUTO 21011KT 9999NDV -RA SCT053/// 15/12 Q1000
LMML 071315Z 24014KT 8000 RA SCT019 15/12 Q1000 NOSIG
LMML 071245Z 21010KT 6000 -SHRA FEW006 BKN025TCU 16/12 Q1000 BECMG 5000 SHRA BKN015TCU
LMML 071234Z 20011KT 7000 SCT020TCU 16/12 Q1001 BECMG 5000 SHRA BKN015TCU

You can see two wind peaks - in the SW winds initially and then when they have veered NW as the low moved away. Note the pressure rise of 11mb in one hour between 17:15 ND 18:15.

[NZstorm]

Interesting storm given the sharp pressure falls and rises. It did develop within the diffluent zone of a mid latitude jet stream, so traditional in that sense. Buts its mesoscale intensification is unusual and no doubt the warm seas will be the big factor.

I notice the European did a better job at indicating the deepening than the GFS.

[Tornado Tim]

I notice the European did a better job at indicating the deepening than the GFS.

If your meaning ECMWF, then yes, it usually always does a better job than any other model.
My work uses it all the time, even though it costs quite a bit, its well worth it as it has a much richer data ingestion than other global models.

[NZ Thunderstorm Soc]

If your meaning ECMWF, then yes, it usually always does a better job than any other model.

I agree.

[Simon Culling]

The island of Lampedusa (an Italian administered island to the west of Malta) also saw some very strong winds associated with this storm:

LICD 071150Z 25043G64KT 1500 1200W RA FEW020 OVC040 14/14 Q995
LICD 071206Z 26046G73KT 240V300 3800 RA SCT030 16/13 Q994
LICD 071250Z 28041G62KT 6000 -RA FEW020 BKN040 16/12 Q994

However, it did not see such large pressure rises after the system moved away. There do not appear to be any other reports of strong winds in the Med, although this system did bring a lot of rain to southern Italy. This type of weather system seems to form and weaken very quickly.