question à propos de Bonnie

[castor028]

Bonjour...

 

J'me pose une tite question: On dit que Bonnie va apporter beaucoup de pluie à Montréal entre Jeudi soir et Vendredi. On est Jeudi soir, et Bonnie affecte le nord de la Floride, coment va-t-elle parcourir une aussi grande distance en si peu de temps, ça m'intrigue... A mon avis, ça devrait prendre au moins 2 jours pour être affecté au Québec

 

Eric

[Pierre]

En fait le front stationnaire juste à l'est du sud du Québec permet de canaliser l'humidité tropicale en provenance du sud des ÉU. Regardez l'imagerie radar nord Américaine pour plus de détail.

 

Une première pulsion affecte déjà l'Estrie et la Beauce ainsi que le Vermont , les vestiges de Bonnie atteindront vraisemblablement le sud du Québec tard cette nuit et nous affecteront vendredi à différents degrés.

 

Voici l'explication Américaine:

 

Area forecast discussion

National Weather Service Burlington Vermont

420 PM EDT Thursday Aug 12 2004

 

 

Short term (tngt-sat)...

significant rafl event unfolding across forecast area through Friday evening as heavy rain associated

with frontal boundary affects parts of forecast area through tonight then remnants of

Bonnie brings more heavy rain to the region Friday. Hoisted flood watches

for all forecast area except St law valley.

 

 

Surface cold front along spine of Green Mountains is serving as a focus for showers

and thunderstorms as strong low level moisture convergence acts on hi precipitable water airmass.

GFS has a good handle on area of convergence with front and indicates

that front and low level convergence will move back westward across nny tonight

shifting heavy rafl threat to the west.

 

 

Models in pretty good agreement lifting remnants of Bonnie across middle

Atlantic region Friday and across forecast area Friday evening. Official track brings it very

close to btv. Based on this track...heaviest rafl would be across

western Vermont and adrndcks. GFS actually tracks low further S and east and

targets southern and eastern Vermont with heaviest rafl. The combination of current

rafl associated with frontal boundary and remnants Bonnie during Friday will likely

result in widespread rafl amts of 1-3" through Friday night with locally 4-5"

possible in areas that receive heaviest rain through tonight. Based on this

potential rafl we issued Flood Watch for all but St law valley through

Friday night. Left St law valley out as it appears this area will be west of

heaviest rafl and ffg numbers are quite hi in the region.