A Tale of Two Models: Which do you believe?

by Landon Aydlett, Warning Coordination Meteorologist, Weather Forecast Office (WFO) Guam

A Tale of Two Models:

Which do you believe?

And which do you share on social media?

(Preferably neither)

For over a week now, I’ve received many anxious calls and messages, on a daily basis, concerned about “the next storm” that is expected to hit on May 2…may 4….or May 6….may 9?? Or may 11. Or May 7. And the graphics are there to go along with the fear.

Look at the first two images- 2 different model forecasts, both set for early morning on May 6. One has a tropical storm/typhoon sitting over saipan at that time. The other has….well, trade winds.

Which do you believe and take as pure fact, at TEN DAYS out? Hopefully neither. But which do you think is going viral on social media and in WhatsApp chat groups? I can give you one guess.

At 10 days out - the amount of uncertainty in a single model forecast is HUGE. This long range (long range being anything, really, beyond 5 days) forecast is subject to a significant amount of change.

And there’s been a lot of change. Just in the last few days, the variations of these outlooks ranged from 0 to 3 tropical cyclones ranging from everywhere between May 2 and May 12, with hits to Guam, saipan, the Philippine Sea, or none of the above. A scenario several days ago had something forming in Chuuk and spinning up TODAY near Yap. But what is near yap right now? A ton of sun.

These long range model threats and spin-ups are things we’ve seen in the weather business for years. These things we don’t propagate to the public due to the high uncertainty and the lack of credible concerns that far out. However, the ease of weather info and models to everybody everywhere all the time puts this Information at anyone’s finger tips. Yes, a great, and visual tool; but one the user must know how to interpret and use.

Unfortunately, there’s an endless supply of social mediarologists out there who use these tools, some with solid meteorological backgrounds, who make YouTube videos and reels to propagate these things “out of an abundance of concern and early communications” but really for likes and clicks. Such early speculations cause fear, anxiety and concern. A trend that has really developed in the region since Super Typhoon Hiayan (Yolanda) in the Philippines, and the spread and influence of social media. And don’t get me wrong - some of these guys are right on point with the meteorology, and you have to focus on what they’re saying vs some of what they’re showing (those long range images).

The last two images - JTWC home page and the CPC long range outlook. Neither we, nor JTWC, are monitoring any suspect areas for development or disturbances at this time. However- we are looking at heightened probability for TC activity in the broad region to our east in the coming weeks. Something may, or may not, spin up in this region. Either solution is very possible. Chances are - we could see something spin up in the next week or so, but the timing, location and direction of motion is still far from realization.

Rest assured, if- and when, something that starts to form in our region and poses a threat to any of our islands, I and the NWS will be communicating broadly.

For now - all the focus in the CNMI should be on disaster response and recovery, and making use of every waking moment to get back to normal, so that if and when something does threaten, everyone can be maximally prepared.