As we approach the last week of April and look back at the monthly average temperature anomalies to date, we see very clearly the warm east (especially the Great Lakes/Northeast) and the west is cooler.
Unfortunately for those who are enjoying the overall warmer pattern in the east (myself, me, everyone), a complete reversal is about to materialize.
Unlike the transient colder periods we’ve seen between recent warming, this change in pattern looks set to stabilize for a while – possibly for up to two weeks.
Our remote connections will work together to create a model coveted by cold and snow lovers during the winter months.
- The EPO becomes negative as a ridge amplifies over the Gulf of Alaska, combining with -AO and -NAO to bring cold air into Lower 48.
- The NAO remains completely negative, maintaining a high-latitude, westward-based ridge near Baffin Bay (between Greenland and Canada) and creating a “slowdown” below it, allowing time to stretch.
- The PNA will gradually become active, creating ripples on the West Coast and an elongated trench on the East.
- And finally, the ARRIVE remains negative, allowing cold air from the poles to flow south between the blocks created by -EPO and -NAO.
Simply put, the pieces to create a significant paradigm shift will gradually line up over the next few days. The result will be a period of sustained cooler than average temperatures in the eastern Rockies of the United States.
If it were still winter, this pattern would have the potential to generate significant cold snaps and possibly a winter storm or two for the East. However, as we are entering early May, 5 to 10 degrees below average temperatures will be chilly, but not cold. The flip side, of course, is that the West will eventually start to warm up. It will look like spring in the middle of next week when this pattern really settles down.
Want to see how cold or warm your area will be and for how long? Check 14-day trend forecast for your city here.
What you might be wondering at this point is: Can this forecast change?
Absolute. We saw how small changes in the forecast for these remote connections had a big impact in December. Due to the persistently negative PNA, the cold snap in the Eastern US was pushed further and further away. than. Finally, as Christmas approached, everything lined up to create a record cold snap.
As mentioned, this won’t be a record cold snap. After all, it’s almost May. However, late season frosts or freezes may occur. This possibility should be monitored, especially if you are working in the agricultural sector.
As evidenced by the map above, the flip I spent talking about this blog has started working behind the scenes of the latest cold front. If you get ahead of that, get out and enjoy your last day or so with really warm weather!
About the author
Meteorologist – ’22 Mississippi State Writer for Weather.us and Weathermodels.com. Focus on weather communication. BoyMom x1, CatMom x5. Twitter: @MegGulledgeWX