Storm Forecast
Valid: Tue 15 Jul 2008 06:00 to Wed 16 Jul 2008 06:00 UTC
Issued: Mon 14 Jul 2008 20:45
Forecaster: TUSCHY

SYNOPSIS

An intense cyclonic vortex is placed east of Iceland and attendant strong polar jet affects the northern regions of Europe. A stationary and closed upper low is present over SW Europe and another one moves slowly to the east over SE Europe. Quite unstable but warm conditions prevail over eastern Europe with very hot conditions still present over SE Europe.

DISCUSSION

... Moldova, most parts of Romania and Bulgaria ...

Plenty of forcing present as upper trough shifts east / southeastwards and a cold front slowly pushes towards the east. BL moisture becomes better near the coastal areas of the Black Sea and a cooling atmosphere atop of this warm and moist BL results in strong instability release of up to 1000 J/kg MLCAPE, mainly over eastern Romania and Moldova. DLS of about 20m/s should result in multicell / isolated supercell development with an attendant large hail risk. BL is well mixed with large LL CAPE release over central / eastern Romania so as LCLs drop rapidly along the front, an isolated tornado can not be ruled out.

Further towards the south, over Bulgaria, shear gets stronger with up to 30 m/s DLS, but instability release weaker due to weaker lapse rates at mid - levels. However, dewpoints at the surface in the upper tens are present and scattered thunderstorms with a large hail risk will likely evolve during the afternoon and evening hours. Thunderstorms well inland will diminish in coverage / intensity after sunset but will likely keep going along the coastal areas and offshore.

... S / SE Spain, coastal areas of NW Algeria and the Alboran Sea ...

Closed and stationary upper low is present over the Iberian Peninsula. Very warm airmass at 850hPa should help to cap atmosphere during the day, but thunderstorms will start to develop during the night hours along the NW coast of Algeria and over SE Spain as models like GFS show stronger forcing, overspreading this area from the SW. Very strong DLS will be present with rapid storm organisation possible but some uncertainties like timing and coverage of storms are still present. No level area was yet issued but the region has to be monitored.

Futher to the west, over SW Spain, storms should also develop during the night hours, although storm coverage is isolated. Very steep mid - level lapse rates and weak to modest DLS could result in an isolated large hail risk but confidence is also too low to go with a level - 1.

... Extreme western Russia ( Vologda and central / eastern Kaleria ) ....

A strong surface depression moves northeastwards and so does the well evolved cold front. Modest shear mainly at mid and lower levels results in a strong to isolated severe wind gust risk. SRH - 1 gets maximized in the NE quadrant of the depression and a few tornadoes can occur. The svr. risk diminishes after sunset.




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