Storm Forecast
Valid: Sat 03 Jan 2009 06:00 to Sun 04 Jan 2009 06:00 UTC
Issued: Fri 02 Jan 2009 21:16
Forecaster: DAHL

SYNOPSIS

A deep and extensive upper trough persists over the northeastern half of Europe and over Russia, maintaining advection of cold/dry air across most of Europe except the Iberian Peninsula and the southern Mediterranean. A secondary, southern frontal zone is stretching across the N African States and the S Mediterranean. Main features this period will be two southern-stream short-wave troughs, one off the Iberian W coast, and the other farther downstream over the W Mediterranean, as of Friday evening. Ahead of these features, weak cyclogenesis is anticipated over Iberia and the central Mediterranean on Saturday.

DISCUSSION

... Iberian Peninsula ... extreme western Mediterranean ...

Though CAPE is simulated - and currently observed - to be quite meager, 20 to 25 m/s DLS should be present over the extreme southern parts of Iberia on Saturday. Deep-layer forcing also appears to be rather robust, which may allow for some organization of the storms. Expect the strongest cells to produce isolated marginally severe hail/winds. Still, minimal thermodynamic support should limit the allover severe threat, and coverage of severe thunderstorms is currently anticipated to be too low for a categorical risk.

... central Mediterranean ... southern Aegean ...

Farther downstream, low-level cyclogenesis seems to be slightly stronger, but the associated upper trough will de-amplify, so that the vertical-motion regime will become increasingly less focused. Also, regions of positive - but quite weak - CAPE seem to remain displaced from the favorably sheared areas, so that the allover severe threat seems to be quite low. A few waterspouts cannot be discounted, though low-level thermodynamic support is somewhat marginal, so that the coverage should be quite low.