Storm Forecast
Valid: Tue 16 Feb 2010 06:00 to Wed 17 Feb 2010 06:00 UTC
Issued: Mon 15 Feb 2010 20:28
Forecaster: TUSCHY
A level 1 was issued for NW-Morocco mainly for locally heavy rainfall.
SYNOPSIS
Numerous waves, embedded in a SW-erly flow over the Mediterranean, cause regionally enhanced shower/thunderstorm activity, with the highest coverage probably along the W-coast of Greece and over NW-Morocco. Cold and dry conditions preclude deep convection over the rest of Europe.
DISCUSSION
.... West-central Mediterranean ....
An upper wave moves to the east and filters in some better moisture, so BL recovery will be in full swing. Strongest UVV max travels from NE Tunisia to the Ionian Sea and later on to Greece (during the morning hours). That's the area, where isolated to scattered thunderstorms are possible, especially along the W/NW coast of Greece during the night. Shear up to 6km is modest at best, but some directional shear develops in the lowest 1km AGL along the coast of Greece. Isolated large hail and a tornado report are possible although the overall risk looks conditional.
The complete west central Mediterranean could see isolated showers and thunderstorms although the forcing remains week. We highlighted the extreme western part for the overnight hours, as another trough approaches from the west. Nothing severe is forecast with that activity.
... NW-Morocco, S of Portugal and the Strait of Gibraltar ...
A strong vortex over the Iberian Peninsula sustains a strong west/southwesterly flow, which causes a moist, subtropical air mass to cover the area of interest during the forecast period. The main concern for anything severe encloses two areas:
a) NW-Morocco, due to the good connection to a high theta-e tongue and therefore repeated thunderstorm development with heavy rainfall. This could cause locally excessive rainfall, matching our criterion. Also, 20m/s DLS is enough for a few storms to gain better organization with strong to severe wind gusts.
b) The S coast of Portugal/SW coast of Spain and the Strait of Gibraltar, where augmented LL directional shear along the coast could cause a tornado event. The risk is too marginal for any level area.
