De atmosfeer staat op ontploffen #259 Regen-droog-regen

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Storm Forecast
Valid: Tue 12 Aug 2008 11:00 to Thu 14 Aug 2008 06:00 UTC
Issued: Tue 12 Aug 2008 11:30
Forecaster: GROENEMEIJER

SYNOPSIS

Not much changes ahead as major upper trough is still in place over NW-Europe. Numerous disturbances rotate around this trough, resulting in unsettled conditions over most parts of central and N-Europe. Still hot and stable conditions over the Mediterranean and SE/E-Europe.

DISCUSSION

A low pressure area over British isles is the most prominent feature on the weather maps. Around an associated mid/upper-level low over Ireland, a strong cyclonically-curved jet extends across northern Iberia via central France into NW Germany.

N France, SE Benelux, NW and N Germany...

Within the section of the jet over western continental Europe, a speed maximum/jet streak over NE France should move northeastward during the remainder of the day. In the lower troposphere, a baroclinic wave has developed. At 11 UTC, the surface cold front of the wave was located near a line from Amsterdam to Luxembourg to Dijon.

Ahead of the surface cold front, surface winds are generally between south and southeast, which creates 100-250 m2/s2 of 0-3 km storm relative helicity. About 500-1000 J/kg of surface-based CAPE is expected here. Strong deep-layer (0-6 km bulk) shear of 25-35 m/s should create an environment conducive to updraft rotation. Relatively high near-surface buoyancy release for surface parcels will probably support low-level rotation as well.

Rotating storms have already been observed by Doppler radar across NE Belgium and SE Netherlands. Further development of a number of small supercells capable of producing tornadoes, possibly including a few strong ones (F2/F3) are expected across the SE Benelux, Lorraine, the Rhineland, Northrhine-Westphalia and Lower Saxony, before moving to north-central parts of Germany later today. Additionally, isolated large hail and some strong/severe straight-line winds are expected.

E Denmark, S and SE Sweden...

These areas will likely be affected by the aformentioned frotnal wave overnight. As it appears as though kinematics will remain favourable for rotating updrafts throughout the night, a few tornadoes may occur here as well even though less buoyancy will be available for surface parcels.

SE France ...

About 25 m/s of 0-6 km bulk shear and 1000-2000 J/kg CAPE should produce an environement conducive of a few, possibly rotating, storms. The main threat of these storms appear to be large hail and excessive rainfall.

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Op dinsdag 12 augustus 2008 12:45 schreef Prowl het volgende:
Midden Limburg meld een klein onweersbuitje met veel regen

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(ZEER) ZWARE WINDSTOTEN
In de kustprovincies en op het IJsselmeer komen windstoten voor tot 90 km/uur overeenkomend met windkracht 10.
dinsdag 12 augustus 2008 15.24 uur

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Op dinsdag 12 augustus 2008 13:53 schreef IkWilbert het volgende:
update van estofex zojuist
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Op dinsdag 12 augustus 2008 15:37 schreef Fredo55 het volgende:

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Op dinsdag 12 augustus 2008 17:47 schreef viagraap het volgende:

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Het waait hard idd. Maar sinds wanneer komt 90km/u overeen met windkracht 10?

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Op dinsdag 12 augustus 2008 17:47 schreef viagraap het volgende:

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Het waait hard idd. Maar sinds wanneer komt 90km/u overeen met windkracht 10?

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Op dinsdag 12 augustus 2008 19:59 schreef kebabkever het volgende:
er gaat momenteel een supercel over noord-limburg... en het westen krijgt vanacht zeer zwaar weer..

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Op dinsdag 12 augustus 2008 13:53 schreef IkWilbert het volgende:
update van estofex zojuist
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Op dinsdag 12 augustus 2008 20:17 schreef -CRASH- het volgende:
De supercel gezien van de achterkant
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Op dinsdag 12 augustus 2008 20:41 schreef kepler het volgende:


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