Weak low east of the Lesser Antilles

[colbroe]

Intresting rotation at 15 N 55 west building some convection at the moment

[floridasun]

Intresting rotation at 15 N 55 west building some convection at the moment

saw it but getting hit by dry air

[AJC3]

I noticed on visible satellite over the past few days that the t-wave along which this weak low was located had only been crawling west toward the LA (it's still out there as I type)




So for grins, I calculated its approximate forward speed, using the NHC TWDs.

FRI 10/03 1815 UTC 54.0W moving W@5kt
SAT 10/04 0015 UTC 54.0W moving W@5kt
SAT 10/04 0615 UTC 54.5W moving W@5kt
SAT 10/04 1215 UTC 55.0W moving W@5kt
SAT 10/04 1815 UTC 56.0W moving W@5-10kt
SUN 10/05 0015 UTC 56.0W moving W@5-10 kt (1010 mb low near 15.0N)
SUN 10/05 0615 UTC 57.0W moving W@5-10 kt (1011 mb low near 16.0N)
SUN 10/05 1215 UTC 58.0W moving W@5-10 kt (1011 mb low near 16.0N)
SUN 10/05 1815 UTC 58.5W moving W@5-10 kt (1011 mb low near 15.5N)

The wave crept westward a total of 4.5 degrees in LON in 48 hours, whereas the average LON covered by an AEW in 24hr is typically about 6 (between 5-7) degrees.

4.5 degrees at 15N translates to about 260 nmi. So over the past 48hr, the forward speed of the wave was a paltry 5.4kt, right at what was given in the first 3 TWDs from the time this thread was started.

I assume the foward speed was bumped up on SAT because the mets at TAFB (I know several of them personally) aren't used to dealing with MDR waves moving that slowly.