Storm Forecast
Valid: Tue 01 Dec 2009 06:00 to Wed 02 Dec 2009 06:00 UTC
Issued: Tue 01 Dec 2009 05:16
Forecaster: VAN DER VELDE
A level 1 was issued for Montenegro, southern Croatia and Bosnia-Herzegovina, Albania and western Greece mainly for excessive rainfall, as well as tornadoes.
A level 1 was issued for the Tyrrhenian sea for waterspouts.
SYNOPSIS
A trough filled with a cold unstable airmass produces widespread thundery conditions in the central Mediterranean region. On its east flank the cold front with a tongue of warm air moves very slowly eastward, affecting the southwestern Balkan coast with long lasting rainfall which is likely to have a significant convective contribution. Depressions near Ireland (late) and coastal central Norway can yield convection with sparse thunder. A frontal system approaching the Iberian peninsula is associated with some instability as well.
DISCUSSION
...Montenegro, southern Croatia and Bosnia-Herzegovina, Albania and western Greece...
Along the warm side of the cold front some hundreds of J/kg CAPE is predicted by GFS, and forcing should be significant and further enhanced by coastal convergence and forced ascent over higher terrain. Moisture is continuously transported into the region. Convective cells should augment local rain sums and pose a threat of severe gusts and possibly tornadoes given the shear and wind parameters (>12 m/s LLS, >25 m/s DLS, 200 mē/sē SREH). 0-3 km CAPE is also rather large. The center of heaviest rainfall is likely over Montenegro, possibly qualifying for level 2, shifting to southern Albania/W Greece during the night. The excessive rain may lead to floods and land slides.
...Tyrrhenian Sea and coasts...
The flat MSL pressure field filled with unstable airmass and steep near-surface lapse rates leads to slow-moving storms with an enhanced chance of waterspouts and perhaps an isolated flash flood on land. The same may apply to the African coast, but flow is stronger there reducing the chances.
