Maar hier de tekst ook nog ff dan :
Intense long-wave trough is placed over Nern Europe. At its Sern edge, strong jet extends from Iceland to Great Britain, NEern Central Europe and further to NEern Europe. Embedded vort-maxima are present over Eern Poland, Scotland, and Iceland by late Wednesday evening and continue rotating along the edge of the main trough. Over the Mediterranean ... well developed cut-off migrates from Tunisia to Greece. At lower levels ... unseasonably cold airmass affects Nern Europe, while relatively warm maritime airmass enters NWern Europe in the warm sector of intensifying surface low. To the south ... well developed frontal boundary extends from west-central Russia to Nern Balkans and central France.
DISCUSSION
...Nern Europe ...
Several vort-maxima will be the focus of convective activity over Nern Europe. Over NEern Europe, a well developed short-wave trough migrates NEward leaving the forecast region till Thursday. However ... thunderstorms that form underneath the upper trough may be affected by deep vertical wind shear at the cyclonal flank of the upper jet ... and organized convection is not ruled out. Overall threat seems to be too low to warrant a slight risk. To the west ... another strong vort-max will reach Nern Central Europe ... and well developed surface low moves from Nern Great Britain to Sern Scandinavia. The cold front of this low pressure system is expected over Benelux and NWern Germany at 12Z. To the E ... warm sector airmass may destabilize due to surface heating: Upstream, Wednesday 12Z Brest sounding shows moist and warm boundary-layer airmass underneath an inversion that should be advect NEward into Central Europe. If mid-level cooling will be present due to the approaching upper trough, CAPE should build during the day. Strong forcing due to DCVA will be present and showers and thunderstorms are likely along and east of the cold front. 20+ m/s deep layer wind shear and 10+ m/s low-level wind shear are forecast and organized thunderstorms /short bows and shallow mesocyclones due to relatively weak instability/ may form. Strong or severe wind gusts should be the main threat. The chance for tornadoes will be significantly enhanced due to low LCL heights and locally enhanced low-level helicity in the afternoon when instability should reach its maximum. If supercells will form, isolated large hail is not ruled out. Although amount of instability is not certain ATTM, we decide to issue a slight risk for the affected region. An update may be warrant if instability will be lower than expected. West of the cold front ... showers and thunderstorms are forecast in the range of the upper trough. Strong low-level winds S of the surface low and strong vertical wind shear will be present, and organized convection is not ruled out. However ... instability will be weak due to latest GFS model output, and best chances for convection should exist over the Nern parts of the region. Small hail, severe wind gusts, and a tornado or two are not ruled out if thunderstorms will form. Further W ... a third vort-max will reach Great Britain late in the day. GFS does not indicate significant instability in the range of this vort-max. However ... if showers and thunderstorms will form, strong vertical wind shear over Nern Great Britain will be sufficient for organized convection. ATTM, it seems that thunderstorms will not form over the affected region.
Intense long-wave trough is placed over Nern Europe. At its Sern edge, strong jet extends from Iceland to Great Britain, NEern Central Europe and further to NEern Europe. Embedded vort-maxima are present over Eern Poland, Scotland, and Iceland by late Wednesday evening and continue rotating along the edge of the main trough. Over the Mediterranean ... well developed cut-off migrates from Tunisia to Greece. At lower levels ... unseasonably cold airmass affects Nern Europe, while relatively warm maritime airmass enters NWern Europe in the warm sector of intensifying surface low. To the south ... well developed frontal boundary extends from west-central Russia to Nern Balkans and central France.
DISCUSSION
...Nern Europe ...
Several vort-maxima will be the focus of convective activity over Nern Europe. Over NEern Europe, a well developed short-wave trough migrates NEward leaving the forecast region till Thursday. However ... thunderstorms that form underneath the upper trough may be affected by deep vertical wind shear at the cyclonal flank of the upper jet ... and organized convection is not ruled out. Overall threat seems to be too low to warrant a slight risk. To the west ... another strong vort-max will reach Nern Central Europe ... and well developed surface low moves from Nern Great Britain to Sern Scandinavia. The cold front of this low pressure system is expected over Benelux and NWern Germany at 12Z. To the E ... warm sector airmass may destabilize due to surface heating: Upstream, Wednesday 12Z Brest sounding shows moist and warm boundary-layer airmass underneath an inversion that should be advect NEward into Central Europe. If mid-level cooling will be present due to the approaching upper trough, CAPE should build during the day. Strong forcing due to DCVA will be present and showers and thunderstorms are likely along and east of the cold front. 20+ m/s deep layer wind shear and 10+ m/s low-level wind shear are forecast and organized thunderstorms /short bows and shallow mesocyclones due to relatively weak instability/ may form. Strong or severe wind gusts should be the main threat. The chance for tornadoes will be significantly enhanced due to low LCL heights and locally enhanced low-level helicity in the afternoon when instability should reach its maximum. If supercells will form, isolated large hail is not ruled out. Although amount of instability is not certain ATTM, we decide to issue a slight risk for the affected region. An update may be warrant if instability will be lower than expected. West of the cold front ... showers and thunderstorms are forecast in the range of the upper trough. Strong low-level winds S of the surface low and strong vertical wind shear will be present, and organized convection is not ruled out. However ... instability will be weak due to latest GFS model output, and best chances for convection should exist over the Nern parts of the region. Small hail, severe wind gusts, and a tornado or two are not ruled out if thunderstorms will form. Further W ... a third vort-max will reach Great Britain late in the day. GFS does not indicate significant instability in the range of this vort-max. However ... if showers and thunderstorms will form, strong vertical wind shear over Nern Great Britain will be sufficient for organized convection. ATTM, it seems that thunderstorms will not form over the affected region.