gfs00...conferme su conferme, addio caldo!!

[Domenico G.]

Finalmente, per chi come me attendeva impaziente la fine del caldo peraltro spesso afoso...ecco che arriva il tracollo termico Adesso mi chiedo se oltre 10°C in meno rispetto ad oggi come possano influire sulle prp...ergo, i modelli non prevedono nulla in termine di precipitazioni, o cmq poca roba, ma secondo me i forti contrasti termici genereranno brevi ma localmente instensi fenomeni temporaleschi

[gabriele]

Re: gfs00...conferme su conferme, addio caldo!!

si credo di si.... specie sul confine... si toccheranno du masse d'aria con oltre 10°c di differenza... quindi su la linea dove si toccheranno,, mi sa che ci saranno temporali e credo anche abbastanza forti

[Toddy]

Re: gfs00...conferme su conferme, addio caldo!!

Qui da me martdì 31 saranno possibili minime al di sotto dei 10°C :))))))))))))))

[DonatoTragni]

Re: gfs00...conferme su conferme, addio caldo!!

Ottimo ragazzi finalmente!!

[thunder_mn]

Re: gfs00...conferme su conferme, addio caldo!!

Finalmente, per chi come me attendeva impaziente la fine del caldo peraltro spesso afoso...ecco che arriva il tracollo termico Adesso mi chiedo se oltre 10°C in meno rispetto ad oggi come possano influire sulle prp...ergo, i modelli non prevedono nulla in termine di precipitazioni, o cmq poca roba, ma secondo me i forti contrasti termici genereranno brevi ma localmente instensi fenomeni temporaleschi

Estofex http://www.estofex.org/ piazza a livello 2 Per il nord Italia per forti venti,grossa grandine e qualche tornado.

A level 2 was issued for N-Italy, parts of Slovenia and S-Austria mainly for large to very large hail, severe wind gusts and a few tornadoes.

SYNOPSIS

A potent upper trough over Ireland shifts towards the east and enters the North Sea during the latter part of the forecast. Around this base of this trough, numerous upper waves, embedded in a strong W-/SW-erly flow, cross W/central Europe, which fosters unsettled conditions over a broad area. Hot and stable conditions prevail for the Mediterranean.

As a side-note, environmental conditions northwest of the Azores become increasingly supportive for a potential subtropical development. A closed upper low NW of the Azores meanders to the east/northeast/north and models like GFS/EZMWF indicate a gradually developing warm core structure during the upcoming 48 h. However, subtropical development during the forecast period (24 h) seems unlikely due to the merging of a quasi-barotropic depression, with a baroclinically coined one from the north, so rapid strengthening of those morphing features is forecast with a pressure drop, justifying the term "explosive development". Despite the interesting synoptic background of this feature, it will also increase the blocking over the E-Atlantic, which is supported by the latest geopotential height gradient index forecast for the N-Atlantic.

DISCUSSION

... N-Italy, parts of Slovenia and most parts of Austria ...

A potent upper trough is about to cross the Alpine region around noon onwards with a sharp cyclonic kink seen in upper-level streamline pattern analysis. Despite some flattening of the amplitude during its NE-ward progression, still abundant PVA forecast to cross the area from the SW with a concentrated UVV maximum. BL airmass features Italian-style values for late summer, as dewpoints oscillate around 20°C. Yesterday's strong cap weakens with ongoing CAA, so initiation over N-Italy probably occurs around noon and onwards. Mid-level lapse rates remain modest, so MLCAPE will probably already peak at 1000 J/kg. Shear will be strong ( 30 m/s 0-6 km bulk shear, nearly the same magnitude in the lowest 3 km with strong directional shear signals). Storms, which move off the mountainous area tap into a very moist BL and supercells are well possible. Large hail and severe wind gusts will be the main risk with tornado chances increasing for discrete, long-lived supercells. Another concern is the augmented chances for bowing segments with a damaging wind gust risk, especially if storms line up due to the strong forcing/intense LL shear.

Thunderstorms move rapidly to the east/northeast with favorable conditions for organized, long-lived supercells over parts of Slovenia and S-Austria, moving along the gradually SE-ward dragging cold front. The passage of that cold front will also mark the end of the severe episode with model pool indicating the later afternoon/early evening hours, where CAPE values decrease. Till then, large to very large hail, severe wind gusts and an isolated tornado will be possible, if storms enter that area in a more discrete fashion. Another possibility is rapid clustering over NE-Italy, which would increase the severe wind gust risk (organized MCS with bowing segments) and decrease the tornado risk. Models still diverge, but mesoscale data currently support more discrete storm structures. Hence the level 2 was expanded well to the east. Locally heavy rainfall spreads eastwards and affects E-Austria, W-Hungary and parts of Slovakia during the evening/night hours although progressive nature of this event ought to limit the excessive rainfall risk.

Vedremo, c'è tempo fino alle ore 06.00 di Sabato.
Forse qualcosa potrà fare in Friuli, ciao