Changement dans le pattern météo?

[meteodave]

Le pattern météo semble vouloir changer d'ici 7 à 10 jours.

En effet, la plupart des modèles indiquent une vague de chaleur avec du temps moins instables pour le fin de semaine prochaine (commençant entre jeudi et samedi prochain). (il n'y a que les modèle canadiens qui semblent résister, pour l'instant, à cette poussée de chaleur)

 

Pour le sud du Québec, vous avez eu une certaine chaleur depuis quelques jours et pour demain aussi, mais pour les régions plus au nord (Saguenay, entre autre) ça n'a pas été le cas. Aujourd'hui par exemple, ça été entre 15 et 18 degrés toute la journée et demain ce sera aussi frais avec de la pluie avec un vent d'est sympathique.

 

Alors c'est à surveiller.

 

David

 

P.S. Pour ce que est des gens de la région de Mtl, vous avez eu droit, cette semaine, à vos premiers orages intéressants depuis, je crois, 2 ans.

[meteodave]

Western Cooling Possible Next Week

Friday, June 30, 2006

As I'm sure everyone who follows the weather (and reads this column) knows, June has been hotter than normal in the western part of the country, especially in areas away from the coast; however, the weather pattern might change significantly during the second half of next week. The upper-level high pressure system, which has, on average, been farther to the west and stronger than normal this month, might shift eastward into the Plains. That would allow the jet stream to dip weakly along the West Coast, opening the door to the possibility of cooler-than-normal weather.

 

This will not happen in time for the Fourth of July holiday, however. In fact, the high pressure system, which has recently shifted to the east and weakened a little, will expand westward once again over the next couple of days, gaining some of its lost strength as it does so. As a result, it will remain hotter than normal in interior parts of the West through at least Tuesday. The heat will not be as intense as it was last weekend or early this week, and the hot weather will not expand into coastal areas; however, temperatures will be a little higher than current levels across the interior.

 

As far as the southward dip in the jet stream is concerned, it will not begin until around Wednesday of next week, and the dip will be strongest along the West Coast around Friday of next week. Here are a couple of upper-level forecast charts to indicate the possible change. The first is a forecast chart for Sunday afternoon, and the center of the high pressure system is near Salt Lake City. The second is for around midday next Friday. The center of the high pressure system is forecast to be over the Texas panhandle, with a noticeable dip in the jet stream along the West Coast.

 

 

 

 

 

If this long-range computer model were to verify, then temperatures would be several degrees below normal in interior California and a few degrees below normal in interior parts of the Pacific Northwest and in Nevada. I tend to believe that the computer model might be over-forecasting the strength of this southward dip in the jet stream; however, even a weaker version of this pattern would bring a welcome and noticeable reduction in heat, which would be appreciated by most after a June in which temperatures averaged 2.5 to 8.0 degrees above normal.

 

 

Un creux dans l'Ouest du continent signifie souvent crête dans l'Est et une porte ouverte pour l'air chaud.

 

À suivre.

 

David