Veel neerslag in de komende dagen mogelijk (ma t/m do)
Update 27/5 7.15u
Gisteravond was er een felle buienlijn on NNO Nederland
Update 26/5 7.30u
SE-UK, Belgium, Luxembourg, parts of the Netherlands and parts of Germany ...
EZ, GFS, Euro4 and UKMO all offer a rather tight model solution regarding the placement of a pronounced low-tropospheric convergence zone. It should run from Belgium to CNTRL and SE Germany. WRF (especially with lower resolution) takes the convergence zone a bit more to the north.
Persistent convergence assists in moisture pooling and 850 hPa dewpoints of 8-10 C and BL mixed-layer mixing ratios in excess of 10 g/kg. Effective PWs exceed 20-25 mm during the evening and 25-30 mm during the overnight hours.
At least some modest deep layer shear exists over W-Germany and Benelux, where 0-3/6 km bulk shear of 10-15 m/s is forecast. BL shear strengthens during the late afternoon and evening hours with 10-15 m/s LL shear and 100-200 m^2/s^2 SRH-1 forecast. Shear drops to less than 5-10 m/s to the SE with Corfidi vectors of 5-10 kt or less (also fostered by local forecast soundings).
EZ and GFS both show similar MLCAPE peaks along the convergence zone with 500-1000 J/kg.Not much capping is present, so first storms probably evolve before noon (or continue from the night). Steady increase of thunderstorm coverage and intensity is expected thereafter and numerous clusters move along that convergence zone from SE to NW. Initial storms pose a large hail risk beside strong wind gusts. Rapid upscale growth of ongoing storms is forecast beneath upper divergence and increasing synoptic forcing. Numerous clusters move along that convergence zone from SE to NW. Excessive rain is a serious hazard with aforementioned parameters and a few places with either training or repeatedly crossing thunderstorm clusters could see rainfall amounts in excess of 50-80 mm/24h. This risk continues all night long!
A limited spatiotemporal overlap exists for a few tornado events over Benelux and W-Germany during the afternoon and evening hours with increasing BL shear and still uncapped/weakly capped conditions.
.gif)
Update 27/5 7.15u
Gisteravond was er een felle buienlijn on NNO Nederland
Update 26/5 7.30u
SE-UK, Belgium, Luxembourg, parts of the Netherlands and parts of Germany ...
EZ, GFS, Euro4 and UKMO all offer a rather tight model solution regarding the placement of a pronounced low-tropospheric convergence zone. It should run from Belgium to CNTRL and SE Germany. WRF (especially with lower resolution) takes the convergence zone a bit more to the north.
Persistent convergence assists in moisture pooling and 850 hPa dewpoints of 8-10 C and BL mixed-layer mixing ratios in excess of 10 g/kg. Effective PWs exceed 20-25 mm during the evening and 25-30 mm during the overnight hours.
At least some modest deep layer shear exists over W-Germany and Benelux, where 0-3/6 km bulk shear of 10-15 m/s is forecast. BL shear strengthens during the late afternoon and evening hours with 10-15 m/s LL shear and 100-200 m^2/s^2 SRH-1 forecast. Shear drops to less than 5-10 m/s to the SE with Corfidi vectors of 5-10 kt or less (also fostered by local forecast soundings).
EZ and GFS both show similar MLCAPE peaks along the convergence zone with 500-1000 J/kg.Not much capping is present, so first storms probably evolve before noon (or continue from the night). Steady increase of thunderstorm coverage and intensity is expected thereafter and numerous clusters move along that convergence zone from SE to NW. Initial storms pose a large hail risk beside strong wind gusts. Rapid upscale growth of ongoing storms is forecast beneath upper divergence and increasing synoptic forcing. Numerous clusters move along that convergence zone from SE to NW. Excessive rain is a serious hazard with aforementioned parameters and a few places with either training or repeatedly crossing thunderstorm clusters could see rainfall amounts in excess of 50-80 mm/24h. This risk continues all night long!
A limited spatiotemporal overlap exists for a few tornado events over Benelux and W-Germany during the afternoon and evening hours with increasing BL shear and still uncapped/weakly capped conditions.
Update 21.30u
Totaal berekende neerslag t/m donderdag (GFS)
KNMI: Lokaal kan er behoorlijk wat neerslag vallen (Harmonie komt met een brede strook van Winterswijk naar Den Helder met 40-70 mm), maar Hirlam (30 mm) en EC (5-10 mm) zitten fors lager. Over korte afstand kunnen morgen in ieder geval er grote verschillen optreden. Kans op onweer volgens INDECS groot in het midden en zuidoosten. Harmonie daarentegen komt een stuk noordelijker (gekoppeld aan hogere Tx) en komt soms met 40-60 ontl/5 min.
Zoals het er op zondag 25/5 nog uitziet
maar daarna.... 50-80/100 mm? (lokaal)
KNMI: Maandagochtend van het zuidoosten uit toenemende kans op regen. Aanvankelijk lijkt de opbouw stabiel gelaagd, maar in de middag wordt de atmosfeer in toenemende mate onstabiel, dankzij warmteaanvoer onderin en dagelijkse gang. In de middag kunnen de buien ook vanaf de grond ontstaan. Waar dat gebeurt is nog uitermate onzeker en detaillering is nog erg lastig. MuCape hoogste over het zuidoosten van het land, lokaal 1000-2000 J/Kg, windschering 0-3 km 30-35 kt (met name richtingsschering). Focering door zwakke PVA van de hoogtetrog maar vooral toch dagelijkse gang, Convectiemodus: multicel. Lokaal kan er behoorlijk wat neerslag vallen (Harmonie komt met een strook met 55-60 mm), maar Hirlam en EC zitten fors lager. Over korte afstand kunnen morgen in ieder geval er grote verschillen optreden. Kans op onweer volgens INDECS groot in het zuidoosten. Harmonie daarentegen komt een stuk noordelijker (gekoppeld aan hogere T) en komt soms met 80-160 ontl/5 min. Hagel behoort ook tot de mogelijkheden.
De conv.line trekt naar het Noorden in de loop van maandag/dinsdag
.gif)
De rest van de week is het met de regen nog niet gedaan lijkt het
Geen opmerkingen:
Een reactie posten