Storm Forecast
Valid: Tue 18 Nov 2008 06:00 to Wed 19 Nov 2008 06:00 UTC
Issued: Tue 18 Nov 2008 02:22
Forecaster: VAN DER VELDE

SYNOPSIS

A blocking high pressure system lies over the Atlantic. Two troughs enter Europe with the northwestern flow, connected by a cold front. The strongest ascending QG motions are forecast over Denmark, Germany, Czech Republic and Poland, and over the southern half of France sliding into the western Mediterranean area. Another trough with a more unstable airmass affects the area around Greece and Turkey.


DISCUSSION


...Crete, Aegean Sea, southwestern Turkey...

Relatively large CAPE (>1000 J/kg) and moderate vertical shear (15-25 m/s) offer potential for strong multicell clusters or MCS storms with a chance of large hail. While SREH is not strong, some storms may exhibit rotation. Flash flooding may occur.


...Denmark, Germany, Czech Republic, western Poland...

An area of some CAPE, ELs to -15°C and strong shear follows after the cold front during the evening. SREH >200 m2/s2 and LLS > 10 m/s in combination with CAPE require alertness for isolated tornadoes. However, the GFS model predicts a heavy inversion between 2 and 4 km altitude and unfavorable positioning to QG ascent, and a strong convergence zone is absent, so chances for severe weather seem too marginal.

...Mediterranea Sea...

Waterspouts may occur, especially where the combination of strong LL buoyancy, moisture, convergence and weak winds are present.