Storm Forecast
Valid: Sat 06 Jul 2013 06:00 to Sun 07 Jul 2013 06:00 UTC
Issued: Fri 05 Jul 2013 17:01
Forecaster: PISTOTNIK

No threat levels were issued.

SYNOPSIS

Weak geopotential gradients with very warm conditions prevail across most of the continent. A large surface high is centered over England and the North Sea, supported by subtropical upper-level ridging from the Southwest. Over Central and Eastern Europe, cooler upper levels allow a daily buildup of low to moderate instability in many regions.
Slightly stronger dynamics are confined to Ireland and Scotland, which get grazed by a strong Atlantic depression, and to Finland, where an upper-level trough slowly moves southeastward while cutting off. Along with the latter, cooler and drier low-level air starts to move southward and to displace the moist and warm air mass over the continent.

DISCUSSION

... high probability thunder areas ...

Rather widespread thunderstorm activity will form again in response to diurnal heating. Slow (and partly erratic) storm motions and high precipitable water values (regionally more than 30 mm) point to a slightly enhanced risk of heavy precipitation. However, a lack of pronounced cnvergence zones does not allow to detect ¨hot spots¨. Other severe weather threats (large hail with the strongest pulse storms, localized severe downbursts where cold pools form, and an isolated landspouts where outflow boundaries collide in a favourable way) are even more marginal. Hence it was decided to go without any level 1 area despite expected high coverage of storms.

... Finland ...

QG lift overspreads Finland with the passage of the upper-level trough. Towards the North, deep-layer shear increases to around 15 m/s, but at the same time the CAPE signals fade out. Scattered storms will form in the afternoon and could organize into (rather low-topped) multicells, but instability seems too low to promote an enhanced severe weather risk.

... Morocco, Portugal, N Spain ...

Forecast models indicate localized CAPE maxima up to 1000 J/kg where rich low-level moisture gets deep enough with onshore breezes. However, strong capping under the ridge axis will likely suppress any convective initiation.