Extended Forecast
Valid: Mon 10 Mar 2008 06:00 to Tue 11 Mar 2008 06:00 UTC
Issued: Sat 08 Mar 2008 22:50
Forecaster: SCHLENCZEK

SYNOPSIS

Upstream of an occluding 950hPa surface low over Ireland, another baroclinic wave is forecast to develop. Its warm front will stretch from western Ireland via the Bay of Biscay towards northern Spain on Tuesday morning. The upper trough, associated with the surface low over Ireland, should move from Ireland to the North Sea during the period.

An upper level trough over western Mediterranean will translate eastward, affecting the Tyrrhenian Sea and central Mediterranean. Another upper trough over the Aegean Sea will move northeastward while weakening.

DISCUSSION

Western UK

The trough axis is forecast to cross Ireland in the early afternoon and strong gradient flow will lead to mostly non-convective severe gusts. Showers and isolated thunderstorms may develop in the post-frontal airmass but lightning should occur too sporadic to issue a thunderstorm area. Apart from the aforementioned gusts, severe weather is not expected.

Central Mediterranean

As the cold upper airmass overspreads the central Mediterranean, some hundred J/kg of CAPE should be created. Best overlap of shear and instability is expected between Sicily and Greece where 20 to 25 m/s deep layer shear are forecast. Multicellular storms could produce marginally severe hail and gusty winds. Low LCL heights as well as good LL buoyancy may allow an isolated funnel / waterspout.

Western Turkey and Bosporus region

A few hundred J/kg of CAPE should remain over that particular region and thunderstorms will likely persist during the day. Recent GFS runs predict good LL buoyancy in a weakly sheared environment and an isolated funnel / brief tornado is not ruled out. 0-6 km deep layer shear should stay below 15 m/s and therefore severe hail / gusts are rather unlikely. Thunderstorms should diminish after sunset.