Weet niet of iemand er nog naar had gekeken, maar staat een vrij maffe voorspelling op. Vond het wel even de moeite waard die hier te posten:
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DISCUSSION
... Belgium, the Netherlands, Germany ...
Like during the CAA-events, which occured for the past few days, there is a concern regarding the thermodynamics. CAA is compact and occurs nearly simultaneous at all levels, but the long distance over the still warm North Sea helped to warm the low-levels and hence temperatures at 850hPa are not expected to fall below -5°C. Diurnal warming will be limited and surface temperatures over Germany are forecast to stay below or around 5-6°C . This in combination with the 850hPa temperatures results in weak LL lapse rates.
Cooling at mid-levels is way more significant and lapse rates steepen to 8°C/km.
Current thinking is that thermodynamic stratification still supports deep convection which can be seen in the expected EL temperatures, too.
Having a glance on the latest IR / WV images reveals an healthy postfrontal airmass with widespread convective activity and confidence is growing that we will see numerous thunderstorms over a broad area and we therefore decided to highlight quite a large area.
It looks like we have to deal with three different regions/mechanisms of enhanced thunderstorm chances:
a)
The first region is the coastal area of NW Germany and the Netherlands. SSTs are still well above 10°C and a well mixed BL is forecast to spread inland. LL lapse rates are enhanced and in combination with steep mid-level lapse rates, deep convection is possible. The main risk will be severe wind gusts as winds at 850hPa of 25-30m/s could be easily mixed down.
Another risk will be a tornado threat as surface friction takes its toll on the LL wind field and enhances shear and storm relative helicity (0-1km shear of 10-15m/s and SRH1 of up to 200 J/kg). This threat extends well inland and so does the level-1 .
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