Storm Forecast
Valid: Sun 08 Jun 2008 06:00 to Mon 09 Jun 2008 06:00 UTC
Issued: Sat 07 Jun 2008 21:03
Forecaster: SCHLENCZEK
SYNOPSIS
An upper level cut off low over the Bay of Biscay will move to the Balearic Islands during the period. Over the western and central / eastern Mediterranean, a westerly upper jet streak with 40 m/s at 300hPa will translate eastward. Apart from the region southwest of Iceland and southern Finland, weak pressure gradients prevail over large portions of Europe. Another 45 m/s jet streak with an embedded shortwave trough over northern Sweden / southern Finland will translate eastward.
DISCUSSION
...Southern Finland, Baltic Sea, western Russia...
In the early afternoon, an upper shortwave trough will move across southern Finland. A few hundred J/kg of CAPE may form and QG forcing should be sufficient for deep convection. Deep layer shear around 20 to 25 m/s may support organized multicells and perhaps a few mesocyclones, capable of producing isolated large hail and severe gusts. Enhanced (15 m/s) low level shear and low LCL heights suggest that an isolated tornado is not ruled out. Thunderstorm activity will likely diminish after sunset.
...Central Europe...
In an unstable environment with some hundred J/kg of almost uncapped CAPE, diurnally driven convection will evolve. Deep layer shear below 10 m/s suggests that severe weather will be rather unlikely. Nevertheless, weakly organized multicells could be accompanied by isolated large hail and an isolated severe gust. Given a large area with marginal severe threat, a categorical threat level is not warranted. As the wind field is rather weak, especially orographically induced storms may persist for a few hours and torrential rainfall may lead to local flooding.
...Aegean Sea, northwestern Turkey...
Some hundred J/kg will likely form during the day when an upper level vort max will overspread the region. Given 20 m/s deep layer shear, organized multicells and some mesocyclones with large hail and isolated severe gusts will likely develop. In the late afternoon, storms will leave the forecast area.
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