Weather systems are slowing down over the Eastern United States as blocking pattern, or what we call in meteorology an “Omega Block,” sets up. In this situation, two areas of low pressure are separated by an area of high pressure. Thus, creating what looks like the Greek letter “Omega” in the mid and upper levels of the atmosphere (or jet stream level).
Once this pattern sets up, it only very slowly breaks down, resulting in very little or no change in weather for several days. For areas located on either side of the high, or on the east/west side of the blocking pattern, this means an extended period of cool and unsettled weather. These are areas where low pressure dominates. Here in Central New York we will end up close to high pressure as this block forms.
Once the blocking is underway, there will be increasing amounts of sunshine and temperatures will warm quickly into the 70s today and through the rest of the week. It won’t be so much that we are ‘importing’ warmer air into Central New York as much as we will be creating this warm air mass in place due to the strong May sun.
If there is any potential for a change from the sun and warmth it comes from one of the areas of low pressure mentioned above. It will be off the New England coast at the end of the week and will dive south just off the coast Friday. While it will never move inland toward us here in Central New York, it may turn our winds into the east just enough to cause our temperatures to ‘dip’ a bit Friday. There could even be a few extra clouds Thursday night and Friday. Stay tuned.
With that low moving away from us Saturday, high pressure will re-establish itself over us so we see no reason to shift away from a forecast of dry, sunny and warm weather this Saturday, Sunday and Monday. Tuesday we expect that low pressure from the west side of the Omega block will start to have an effect on our weather, bringing rain to CNY. We are keeping an eye on the timing of the change as this is still a week away.