We had our best weekend weather of the Spring season in central New York this past weekend but there are signs that it could be just as nice this upcoming weekend and you can thank another blocking pattern for the nice weather. It seems like whenever we talk about blocking patterns we are talking about doom and gloom. Just this past March/early April that we slipped into a blocking pattern that brought us below normal temperatures and above normal snowfall. This pattern set up as high pressure in the upper atmosphere anchored itself over Greenland. This time, however, the blocking high will be farther southwest, likely right over the Northeast, and that will translate to an extended period of sunny, dry and warm weather here in central New York. It is what we call an Omega Block in meteorology because the jet stream setup looks like the Greek letter omega.
At the end of last week there were still some questions as to how long the dry, sunny, warm weather would last but there are now strong signs that it will go through the upcoming weekend. The one model that was on the fence with this idea was the GFS. This model was the fastest in bringing the upper low to the east and breaking down the Omega block. Now, with today’s run, the GFS has shifted everything farther west.
This looks more like the European models forecast from last Friday. Certainly nothing is set in stone just yet, but if the end of week and weekend forecast pans out, it will be another victory for the European model. The list of ‘victories’ for the model over the last 6 months range from its handling of ‘Sandy’ in October to putting the brakes on warmth returning to the Northeast earlier this month. The European model isn’t always going to be right but when there are differences in the long range (6 to 14 days) we are more than likely going to side with the European model.
The bottom line for us is that as that high starts to develop later Tuesday/Wednesday over us, we will start to dry and clear out. This will start a stretch of sunny and warm weather taking us right through the upcoming weekend. During this time the winds will be light which means we won’t be importing warmer air but yet high temperatures will end up 5 to 10 degrees above normal. This will be a case of the strong early May sun doing the warming all by itself.
Trying to figure out when Omega blocking patterns break down can be tricky. We think it will start to happen early to mid week next week. Until it happens, our temperatures should remain above normal. We’ve got a low chance of showers and thunderstorms in for next Monday but it may be the middle of next week before our rain chances increase.