Storm Forecast
Valid: Fri 16 Jan 2009 06:00 to Sat 17 Jan 2009 06:00 UTC
Issued: Thu 15 Jan 2009 17:18
Forecaster: TUSCHY

SYNOPSIS and DISCUSSION

Weak pressure gradients prevail over Europe. The predominant airmass is cool and stable, which keeps thunderstorm chances low. A few fronts approach Spain/Portugal/Ireland from the west, but apart from a very isolated thunderstorm over the extreme E-Atlantic in conjunction with those fronts, no thunderstorm threat is forecast. However, the passage of a sharp upper trough around midnight will have enhanced attention, crossing Ireland from the west. The surface airmass, streaming into this feature has no good moisture connection to the south featuring low instability release, but forcing is intense. Severe wind gusts are possible but electrified, deep convection plays a menial role in this set-up and hence no level area was yet issued.

The most promising region for deep convection is west/north and east of Crete, as a weak upper trough lifts eastnortheastwards during the day. The environment is conducive to deep convection with low EL temperatures and moderate SBCAPE beneath the base of the upper trough, but no forcing at lower levels is seen in latest outputs, which could foster thunderstorm evolution. We therefore went for highlighting the W/SW-coast of Turkey, where LL wind field converges somewhat but also east of Crete where LL mixed-layer mixing ratio is maximized . Despite the possibility of lightning activity over a broad swath west/north and east of Crete, confidence is low that thunderstorm coverage will be high enough for a broad thunderstorm area. Instability and shear fields remain discrete so marginal hail and strong gusts are the main risk. The thunderstorm threat diminishes from the north during the night hours, as dry air filters in.