Wednesday, May 7, 2014

Cool, Stormy Weather To Give Way to Summery Warmth by Late May

I'm expecting some cool and stormy weather in mid-May to eventually give way to a shot of above-normal temperatures, before a cool spell returns for late May.

* A quick note, I have had at least 8 comments telling me that my late April-early May forecast was wrong, with more than a couple of these comments delivered with a less-than-enticing attitude. I've been receiving these comments for 2 weeks now- enough is enough. I don't expect myself to be correct 100% of the time, and I certainly hope no one else expects that of me, either.

Tropical Tidbits
The latest GFS Ensemble forecast above, valid on the evening of May 6th, shows troughing and cool weather present over Japan. By using the East Asia / Typhoon Rule, we can estimate that cool and stormy weather is can be expected around May 13-17th or so. Judging by the weak negative 500mb height anomalies, I'm only expecting a weak chill in the US, with the strongest cold weather allocated further north.

Tropical Tidbits
By the morning of May 9th, we see that the western portion of that elongated trough, seen in eastern China on the first image we analyzed, as now become a closed low and is progressing through Japan. If we once again apply this correlation, it is understood that a strong closed low may traverse the United States between a May 15-19th period. When this low comes through, I'm estimating we see it hit primarily the northern and central thirds of the nation, if you were to slice the US into thirds, horizontally. Cooler than normal temperatures can be expected with this, as well.

Tropical Tidbits
We finally do get relief in mid-late May, we a massive ridge of high pressure pumps up over Japan on May 11th, sticking around for a little while. This tells me we can then anticipate a period of anomalously warmer than normal weather in the United States around May 16-22nd or so.

Tropical Tidbits
Unfortunately, long range ensemble guidance supports the return of troughing and associated cold weather in Japan by May 16th, leading to potentially cooler and stormier weather in time for Memorial Day weekend.



gary said...

Just want to say I've enjoyed your work and have learned a lot. I disagree with critics who have little understanding of the weather and criticize every acre for being right or wrong! All my life I've learned to appreciate weather and have studied as much as an amateur can possibly get. I admire you folks a lot. Thank you much!!!!

gary said...

Just want to say I enjoy your work and have learned a lot. I've studied weather all my life as an amateur and have always learned to look at the big picture. I learn to avoid those folks who have to pick on what happened in every lousy acre and can't understand the multitude of variations and their causes. Good job! Thanks a lot!!!

Bree said...

I've always remembered Memorial Day Weekend to be cold & rainy!
So I never plan anything outside during that time frame!
Thank you Andrew for all your hard work that goes into this!
Keep em coming!!

Jason said...

Andrew-unfortunately I think that we have a part of our culture where tearing people down is fashionable. Anyone who thinks you should have everything perfect doesn't understand your work and shouldn't be reading this blog. Keep up the great work, I love this blog and learn a ton. I sound like a meteorologist to my wife and my friends. Very cool! Jason

Anonymous said...

I've been following this blog since last summer, and have noticed the "forecast bust" rate fairly high last fall, very low in the winter, and only moderate this spring. Let's face it, transition seasons are HARD. And in particular, the forecast time scale between 10 days and a month or so is known for having the least (currently understood) predictability. I appreciate what you're trying to do, and hope that we will be able to improve the tools you have to do it with.

Ace said...

Your work this last winter has been remarkable. I think that this is the future of forecasting beyond the model range of a week or so, at least for the foreseeable future. I am in awe.

Anonymous said...

Thank you - I've been an avid fan for several months now and I'm amazed how much better your forecasting is compared to my local forecasts. You're my "go to" for severe weather and we needed that this school year. We were able to plan ahead for snow days as far as a week in advance thanks to you!!

Mainemanstu said...

Thank you for your hard work and it is hard work. There is not one Met that is 100% correct. I love the weather--keep it up.

Anonymous said...

Your late April early May forecast was absolutely right for Lexington, KY!

Frank-o said...

I have never liked the fact that folks can post up using "Anonymous". This is a teaching site. I come here to learn, not tear people down.
To me this is a class room and "ALL" should be required to log in and use a real name.
I have no use for on line bullies......This is not the place for it.
Use the "DELETE" button and use it often!
Keep the trash posts off here!!!