Estofex ćemo sigurno pratgiti češće slijedećih dana izgleda da je ovo nad Francuskom danas dobro predvidio
Valid: Tue 16 May 2006 06:00 to Wed 17 May 2006 06:00 UTC
Issued: Mon 15 May 2006 21:16
Over the Ern Atlantic, an intense upper-level trough continues to shift eastward, placing most parts of Europe under a southwesterly flow. This should set the stage for a possible active severe weather day over parts of France, Switzerland and Germany.
Development will be primarily ahead of a weak upper-level disturbance, which should cross Wrn Europe during the forecast period into central Europe. Another upper level-trough over SE Europe -although much weaker- should help for at least low-end instability release over parts of Bulgaria and Romania, but weak shear should preclude any severe weather threat.
...Central and Ern France, Switzerland, SW Germany...
Around 06:00 UTC, the aforementioned upper-level trough is expected to be located over the Bay of Biscay. Scattered elevated storms are expected to be ongoing in a zone of QG lift ahead of the system over southWrn and central France.
Models differ quite strongly about the timing and intensity of pressure falls ahead of the upper disturbance forming a trough over southern and Ern France that moves eastward during the day and should possibly develop into a surface cyclone tracking eastward over southern Germany early Wednesday morning. The intensity of pressure falls determines the intensity of a southWerly low level jet to develop through the Rhone-Valley and Jura mountains into southern Germany during the afternoon.
We will for now follow the scenario of GFS 12Z that presents a large area of 20 m/s SWly winds at 850 hPa atop 5 m/s Sly surface winds ahead of the surface trough. The resulting strong low-level shear will have a strong impact on the severity of the storms.
In response to solar heating, boundary-layer temperatures should rise to over 25 C south of the system, which with anticipated surface dew points in the 16-18 C range, may allow surface-based CAPE or the order of 1500 J/kg to build. However, insolation may initially be a problem due to residual cloudiness of Monday evenings' convective cluster over Spain.
Surface-based storms are expected to develop across northern parts of the level 2 area and nearby....and may gradually develop further southward down the Rhone Valley. Due to the strong shear and anticipated 300 m2/s2 0-3km SRH storms are likely to become quickly severe, some becoming supercells.
Large hail and damaging winds are likely to occur with the storms, the latter especially when the storms merge into a bow-echo systems that move northEward. Given the presence of strong low-level shear, there will be a chance of tornadoes as well, some of which could be strong.
During the evening and night, bowing convective systems are expected to track through Switzerland into southWrn Germany. As the available instability should be more limited there, they will likely become elevated quite rapidly. If more instability is present over southern Germany than currently expected, storms may make it as far E as Bavaria.