The last several weeks has seen a lot of fluctuation between cold and warm spells with predominantly temperatures being below average overall. Due to the amount of cold In the pattern we have seen higher elevation snow showers bring accumulating snowfall To the higher elevations. This coming week Is going to see a continuation of the same general pattern. But There are changes that are going to be happening as we get closer to the end of April.
Here is a look at the 500 Millibar pattern over the Northern Hemisphere. Credit pivotal weather.
We can see that the polar vortex Has broken down as it continues through it's seasonal Adjustment.
Looking at the image we can see several areas with cold pockets that are rotating around the pole. Do this we can expect Our current pattern Of warm followed by cold followed by warmth is going to continue for the next 10-14 days So if you're waiting for any kind of Lasting warmth this spring You are going to have to be another patient.
The climate prediction center's 6-10 day outlook does support this idea of temperatures staying generally below average here in the eastern United States. These tall ridges And deep troughs are going to continue to keep the weather variable over the next couple weeks Including the chance for severe out Weather Outbreaks Across the plains, Midwest and Southeast US. For us here in the north east and northern midland we're going to continue to see bouts of rain and higher elevational snow continue to be an issue.
As the pattern continues to evolve We are going to see changes Develop that will bring more way of lasting warmth To our region. The CPC 8-14 day temperature outlook does support this idea of moderating temperatures as we approach the end of the month of April.
As I said a few days ago We have left the La Nina winter behind us As we are now officially in a neutral El Nino Southern Oscillation (ENSO).
The International research institute (IRI) has the ENSO Staying in neutral territory Through the Summer. Then potentially heading slightly back towards a La Nina Signal as we had towards winter. But based on what I'm seeing It could very well had the other direction heading towards a weak El Nino.
So far spring 2025 has been chilly with generally below average temperatures and it has been For at least parts of the region. Given that the neutral ENSO and other teleconnections (I've been talking about the last few weeks) are signaling not a lot of change in the overall pattern moving forward. I think this idea Of general coolness and wetness in the average precipitation pattern for our region will likely continue over the summer. So while well below average temperatures and feeling like winter at times type of pattern is generally behind us. I don't think this summer is going to be a super hot one. I think overall temperatures will be overall average to slightly below average for June through September. Likewise I think the region should generally see average to slightly above average precipitation over the summer . So while this is good news when it comes to overall drought conditions It also means it might not be the greatest summer for some of us.
The pattern that looks to be setting up for this summer Looks to favor quite a bit of heat in the central parts of the US, From Texas To the northern Plains. We all caught also could see above average temperatures in the Southeast US. This could allow for some severe weather outbreaks across the midwest across Pennsylvania into parts of the northern mid Atlantic. North of this area I think this summer severe weather risk should be more on the lines of average. There could also be a heightened Derecho risk, for parts of our region; as systems move along these heat ridges. So that's something we have to keep an eye on. For those who are new to the blog a Derecho is a Very fast type of thunderstorm called a Mesoscale convective system. The bold line can last for hundreds of miles producing widespread damaging winds of at least 58 mph. They can also bring flooding rains and isolated tornadoes.
I will touch on the 2025 hurricane season. The Sea surface temperatures (SST's) in the main development region of the Atlantic are much cooler than they were at this time last year With the idea of a neutral ENSO lasting through this summer Into at least the fall. These water temperatures and other teleconnections signal, the Atlantic hurricane season being around average as far as the number of Tropical Cyclones.
Based on what I see right now I think 2025 should end up seeing 13 to 16 named systems with 6 to 8 of these become hurricanes with winds of 74 mph or greater, and 3 to 4 of them becoming major hurricanes with winds of 111 mph or greater.
Right now I think the areas to watch the most Will be the eastern gulf, Northern Caribbean and along the in the Eastern seaboard of the US.
I will likely release a separate Atlantic hurricane outlook as we get closer to June.