Tropical Storm Matthew to Threaten U.S. Gulf Coast

[donsutherland1]

My post earlier today highlighting the potential for Louisiana landfall has proved incorrect.

At this point in time, the system has become Tropical Storm Matthew and it is centered at 24.0°N 93.8°W, or 120 miles east of the position outlined this morning.

Overall, the synoptic situation has not changed much, only Matthew's position is farther to the east than I had anticipated relative to the setup. Therefore, I still expect Matthew to turn to the north-northeast as opposed to its due east movement. However, given his position, this will take a little time. Hence, a track farther to the east appears more likely.

Nevertheless, I still believe Matthew will be tracking close to north-northeast immediately prior to landfall.

My estimated track follows:

24.5N 92.7W
25.0N 91.8W
26.0N 90.0W
27.5N 89.0W
30.0N 87.6W
31.5N 87.2W

Given its environment, I still lean against Matthew's becoming a hurricane prior to its landfall on Sunday.

[rainstorm]

thanks

[TS Zack]

This little East movement looks more like the LLC trying to follow the blob of convection.
Wait and see is the Hurricane Phrase of the Year

[donsutherland1]

Corrected Track:

I had inadvertently estimated the track based on a position of 24.0N 93.8W. In fact, Matthew was at 24.2N 93.8W.

The correction follows:

24.5N 93.1W
25.0N 92.3W
26.0N 91.0W
27.5N 89.9W
30.0N 89.0W
31.5N 88.6W

I apologize for the error.

P.S. Thanks to the member for e-mailing me the error of my initial position. The impact was increasingly large on the later positions.

[donsutherland1]

Overnight, Tropical Storm Matthew tracked at a 25° angle or north-northeastward. Although I had expected Matthew to make such a turn to the north-northeast, I believed it would happen a little later at roughly 26°N.

On another interesting point, its movement suggests that perhaps Matthew's easterly track at the time the storm was declared a tropical storm was less an easterly track than the relocation of its center, or some share of movement and eye relocation.

In any case, through the day and until landfall, I expect Matthew to continue to track toward the north-northeast.

Consequently, I have adjusted last night's idea of a track farther to the west, with the all-important landfall point being shifted from 30.0N 89.0W to 30.0N 90.0W.

24.5N 93.1W; Actual: 24.5N 93.6W
25.0N 92.3W; Actual: 25.0N 93.2W

Estimated Track:
26.0N 92.6W
27.5N 91.7W
30.0N 90.0W
31.5N 89.4W

[donsutherland1]

As I believe it might be helpful in showing where my early error occurred, I offer additional explanation.

After having examined Matthew's behavior from last evening to the present, I increasingly believe that the 10 mph eastward trajectory reported yesterday in the first public advisory was in fact, not entirely the result of an eastward movement. Rather, at least in part, it was the result finding the actual location of the center. In other words, the Invest95 position I had relied on at the very beginning (24.0N 95.7W) probably placed what became Matthew farther to the west than his developing center actually was.

Consequently, when I factored in the reported motion, my estimated track--and I'm referring to the corrected one, not the one I accidentally posted based on an incorrect initial position that I had inputted--was too far to the east.

Now, taking into consideration what actually has happened, and assuming my hypothesis holds water, I expect less need for revision.

Interestingly enough, as the early part of the outlined track still places greater reliance on the recent movement of Matthew, those positions might well wind up farther east relative to the actual track than the latter positions. If so, that will add credence to my hypothesis that Matthew's motion was not 10 mph to the east but less (with part of the difference being the result of obtaining the true location of its center).

We'll see what happens.

What does seem evident is that Matthew will not take a Josephine (1996)-like track but one more like Hurricane #5 (1948) as discussed previously based on the synoptic situation.

[donsutherland1]

Throughout the day, Tropical Storm Matthew has moved erratically, drifting to the east--even a little southward when heading east--and now back to the north over the past few hours.

Over the next 12-18 hours, I expect Matthew to track generally to the north-northeast.

Hence, at this point in time, I have little change in my thinking from this morning.

Estimated Track:
26.0N 92.6W; Actual: 26.0N 92.8W
27.5N 91.7W; Actual: 27.5N 91.3W
30.0N 90.0W
31.5N 89.4W

Overall, Matthew should make landfall as a minimal tropical storm later Sunday morning or possibly very early Sunday afternoon. It will be remembered more for its rain than its winds.

[rainstorm]

thanks don

[mikey mike]

Do you expect any blow-up of thunderstorms around the circulation center,as happens sometimes whenever these type systems near landfall?

[donsutherland1]

Mikey mike,

I believe you might see some flareups in convection as Matthew moves toward landfall. However, I don't see him becoming significantly stronger prior to landfall.

[donsutherland1]

You're welcome, Rainstorm.

[Steve]

Good work Don. I'm hoping (obvious reasons) that you hit your position #3 (90/30) because that will mean we'll get the center of circulation. Those are usually pretty fun and not really dangerous. You have done a good job with this storm as has Sean in New Orleans. The UKMET, CMC and GFDL (interesting alliance) were the earliest models I saw to come to what appears to be the closest conclusion (still remains to be seen).

Steve

[donsutherland1]

Steve,

Thanks for the kind words. Matthew's turn to the north-northeast was a little sharper than what my idea had implied. I believe he will be passing a little to the west of 30.0N 90.0W.

[donsutherland1]

Tropical Storm Matthew has moved ashore in Terrebonne Parish, which is a little to the east of what the initial synoptic snapshot seemed to suggest.

Overall, the estimates from approximately 24 hours ago were reasonable. I will modify the final two positions but will score both sets at the end.

Estimated Track for Saturday (10/9) Morning:
26.0N 92.6W; Actual: 26.0N 92.8W
27.5N 91.7W; Actual: 27.5N 91.3W
30.0N 90.0W
31.5N 89.4W

Final Estimates:
30.0N 90.6W
31.5N 90.2W