I dont even know what to call this season..NON SPRING SPRING ?
stardate 202204.07
I was afraid this is going to happen. After a fairly inconsequential winter that only featured one cold month January (and even that was mostly cold west of the Appalachian Mountains) and large areas of the country that saw below and much below normal snowfall for the season… we are now stuck in a pattern which is not winter and not spring. This kind of thing happens all the time when you have a moderate La Nina rampaging from the inter into the spring season. Moreover.. for the rest of the month there shows no sign of this changing.
The good news for people on the East coast is that as you will see in the pattern and the discussion there will at least be SOME days where it’s fairly warm (or if you are in New England fairly mild). Folks in the Midwest and the Deep South there are going to be several more really impressive long-lasting slow-moving weather systems along with increased severe weather chances. As this image shows we are already off to a record early start to the severe weather season across the Eastern portion of the US which is actually really common during a La Nina spring. The research shows that during a La Nina spring the vast majority of the severe weather events especially tornadoes seem to shift from the Midwest more to the Deep South and the southeastern states.
Here is the current upper air map for this Thursday and you can see this monstrous lie huge Upper LOW that is completely closed off from the main jet stream flow. The green white and purple colors Center over the Midwest are indicative of the anomaly that we are dealing with here and the number of 500 mb highlight lines show this system to be truly massive. In addition, if you look on the west coast of North America and into central Canada you will see a large area of dark red which represents the very strong Ridge and positive anomalies
Here is the Thursday midday surface map we can see what this enormous Upper Low in the jet stream looks like at the surface and it is pretty darn impressive. Notice how the front kicks out from the massive LOW north of Lake Huron as an occluded front where it then it becomes a cold front near Montreal then runs south through central New York and central Pennsylvania central Virginia to another area of LOW pressure in eAstern North Carolina. From there there is another cold front that extends from that low to Georgia end the Florida Panhandle.
The midday regional radar Shows numerous areas of Rain and snow showers across Wisconsin and Minnesota Northern Iowa rain showers in eastern Nebraska northeast Kansas Missouri Illinois Indiana southeast Wisconsin West Virginia Ohio and steady rain in Pennsylvania New York and interior New England.
And behind that massive system in the Great Lakes is a large Canadian HIGH pressure system almost 1040mb. The interaction of this large cold HIGH pressure area and the intense LOW in Wisconsin has produced a very strong pressure gradient bringing in the north winds and late season cold air from Canada into the Plains and the Upper Midwest.
This cold air will sweep eastward during the next 24 hours driving across the Midwest into the Appalachian Mountains and into the East coast and New England. As a result the rain showers in the eastern Great Lakes and the mountains of the Appalachians and northern New England will likely turn to snow showers Friday night into Saturday in many of these areas. Some of these snow and rain showers will make it east of the Appalachian Mountains and into portions of central Maryland central Virginia central North Carolina and eastern Pennsylvania during the day on Saturday.
Max temperature readings will stay in the upper 30s and 40s in the mountains of North Carolina Virginia West Virginia Western Maryland Western and central Pennsylvania New York State interior New England both days this weekend. And the wind will make you feel even colder.
Even more telling is the fact that Arctic Oscillation (AO) and the North American Oscillations/ NAO are both going to run persistently negative probably until theThe end of the month. This means there’s going to be a lot of blocking the Jetstream and Central in Eastern Canada and persistently deep troughs in the Eastern portion of the country.
Meanwhile the Pacific keeps sending in these strong pieces of energy in the jet stream that develop into these monster systems for the Plains and the Midwest. This image shows the upper air map for April 12th and we can see another massive trough swimming in the western part of the country and a car is finally Big Ridge on the East Coast. so the Midwest on the East Coast gets a chance to warm up significantly next week
By April 14th that massive system in California Nevada and the Great Basin moves across the Rockies then into the heart of the central Plains and Upper Midwest. This is going to be another huge LOW for the Midwest that will be trapped in the atmosphere. The Low will drag another strong cold front through the Deep South which will likely bring about another bout of severe weather to that area.
It is still warm on the East Coast through April 15th but it doesn’t last because once this LOW moves from e eastern Great Lakes into southeast Canada the cold front will move through and temperatures collapse once again to below much below normal levels for the entire eastern half of the country.
