August 2017: Looking Back at Harvey 5 Year Later

[brooksgarner]

Jeesh. That 00z GFS...

Keep in mind that accumulations happen over 3-6 days, but still... rivers/bayous, oh my.

There is also a period where it shows ~8 inches in 6 hours. Obviously that will change but shows that fast accumulations will happen.

Yes. Certainly in the cards!

[jasons2k]

In the last three runs, the GFS has had me from 20" to a little over 3" to now almost 25." Ping pong. Wow.

[mcheer23]

NAVY model major shift north.

[Belmer]

This is such a troubling situation on so many aspects. I don't get headaches often, but two days in a row I've been taking Advil and I blame Harvey for it all.

While I'm very concerned about the rainfall totals, I am also concerned about RI once this nears the coast. For those who remember Humberto, which I know has been brought up I believe on this forum, but for those who aren't... Humberto formed about 100 miles south of Galveston in 2007 as a Tropical Depression (35mph). In 24 hours it strengthened to 90mph (strong Category 1 Hurricane, close to a Category 2) and hit just East of Galveston. Many models (if any?) did not pick up on that and many were caught off guard. Harvey has thrown so many wrenches at us in the forecast, I won't trust how strong this gets until we are hours away from landfall.
With that said, only voluntary evacuations have been ordered. If Harvey were to ramp up to say a Category 2-3 Hurricane, it will almost be too late for people to leave or even board up their home. Between that, storm surge and flooding, I'm getting gravely concerned with the potential loss of life.

I know it can be exciting to see a storm, but we really need to pray and hope for not only these rainfall totals to not prove accurate, but Harvey doesn't significantly strengthen before making landfall. Could really be a devastating and sad situation! Not to mention, Harvey is the same tropical wave that moved off the coast of Africa and caused a lot of flooding in Sierra Leone where last I checked, over 300 people died.

Hoping Euro doesn't show what the GFS did (or worse).

[jasons2k]

Recon found center has shifted north again, tucking under the convection.

[Scott747]

Well recon is showing a healthy reformation to the n. Looks closer to 22.5 which was the 12 hr northern most location.

If confirmed this will have some impact on track with the 6z initializations.

[mcheer23]

Well recon is showing a healthy reformation to the n. Looks closer to 22.5 which was the 12 hr northern most location.

If confirmed this will have some impact on track with the 6z initializations.

Confirmed. 22.6

[Andrew]

Well recon is showing a healthy reformation to the n. Looks closer to 22.5 which was the 12 hr northern most location.

If confirmed this will have some impact on track with the 6z initializations.

Makes sense the LLC reformed closer to the convection. Convection is really going off tonight. Still see some mid level shear but not as bad. Tomorrow night is when I would really worry about fast intensification.

[Scott747]

Well recon is showing a healthy reformation to the n. Looks closer to 22.5 which was the 12 hr northern most location.

If confirmed this will have some impact on track with the 6z initializations.

Makes sense the LLC reformed closer to the convection. Convection is really going off tonight. Still see some mid level shear but not as bad. Tomorrow night is when I would really worry about fast intensification.

Correct. Just enough shear to hold it off for the next 12/18 hrs.

Of interest is with the reformation that folks don't mistake it for a directional heading. It simply reformed and should continue its nw motion.

However it could change the tracks we saw from the 0z runs. Extrapolated out it may be as much as 20/25 miles up the coast. Doesnt sound like much but that's a decent shift.

Also the euro will be initilized with the 10 pm location. Something to keep in mind for its run.

[Andrew]

ECMWF took a pretty good jump north into Corpus.

Also interesting to note that due to the curvature of the Texas coastline, a little extra jog north could result in a pretty good amount of extra time in the gulf.

Edit to add: Stalls north of corpus/SE of San Antonio. Would be a pretty bad scenario for us in SE Texas.

[Scott747]

With euro being initialized with the 10pm location. Extrapolate this run and it's closer to Aransas and San Antonio Bay, and not Corpus.

I think there will be a shift slightly up the coast with the 4 am package.

[javakah]

I wish I knew what to expect in the area between Katy and Sugar Land. Did fine on Memorial/Tax Days, but I don't think we got as much as other parts of the Houston metro. Seeing us keep coming up for 20+ inches sure makes me nervous.

[Andrew]

I wish I knew what to expect in the area between Katy and Sugar Land. Did fine on Memorial/Tax Days, but I don't think we got as much as other parts of the Houston metro. Seeing us keep coming up for 20+ inches sure makes me nervous.

Rain, lots of rain. A good estimate at this point is ~10 inches, but some locations will see much more than that. Really depends on where/when this storm stalls

[don]

Latest 0z Euro still showing widespread 10-15+ inches of rain across the area... I've never seen the models show this much consistency for rainfall amounts this high here.

[Belmer]

Latest 06z model guidance. Less of a shift SW into Mexico as the 00z showed. Back onto the eastward shift into the Gulf...

[Belmer]

Harvey looking mean this morning! Recon looks to have found 999mb pressure. Winds up to 45mph. See what the 4am update provides.

[Scott747]

Just released ships output gives a 66% chance Harvey hits 105kt. Concerning.

Also with the reformation n i think the track will be adjusted towards Matagorda Bay. 6z guidance is already way off.

[Belmer]

Looks like recon is even finding lower pressure... 996mb. Harvey is definitely strengthening quickly tonight. Models not picking up on this or the further north movement.

[Andrew]

Looks like recon is even finding lower pressure... 996mb. Harvey is definitely strengthening quickly tonight. Models not picking up on this or the further north movement.

I mean, I guess the 3km NAM did

[Belmer]

Looks like recon is even finding lower pressure... 996mb. Harvey is definitely strengthening quickly tonight. Models not picking up on this or the further north movement.

I mean, I guess the 3km NAM did

Fair... hmm, better wording? Most reliable models didn't pick up on this! Definitely lower pressure and further north though than what models had for at this time. 12z model runs should be interesting.