Storm Forecast
Valid: Sat 30 May 2009 06:00 to Sun 31 May 2009 06:00 UTC
Issued: Fri 29 May 2009 21:19
Forecaster: DAHL

A level 1 was issued across extreme NE Morocco ... NW Algeria ... SW Mediterranean Sea mainly for large hail and excessive rainfall.

SYNOPSIS

High-over-low block establishes over Europe during the period, with the cut-off cyclone being centered over the N Balkans and the anticyclone being centered over S Scandinavia. Main feature on the SFC map is a sturdy high-pressure area covering the northern half of the forecast area while quiescent SFC conditions prevail over the southern parts. A broad low-level baroclinic zone stretches from the Ionian Sea into the Ukraine along the E and S periphery of the upper low.

DISCUSSION

... N Algeria ... N Morocco ... W Mediterranean ...

It seems that high-based convection will (re-)develop in the Atlas mountains in the afternoon hours ahead of a weak short-wave trough over Iberia. Storms will experience increasingly strong shear in the afternoon/evening hours, so that tendency for upscale growth into one or more MCSs should exist. Though 20 m/s DLS will be present, convection may tend to become elevated during the overnight hours, limiting the effective shear. On the other hand, motion into open Sea waters may allow tapping of moist maritime boundary-layer parcels. Altogether, it seems that some severe threat will accompany this activity, mainly large hail and possibly excessive rainfall. Especially those parts of the system that are SFC-based may pose some severe-wind threat as well.