ATL: FLORENCE - Models

[SouthFLTropics]

Ridge is flexing its muscle at 102 hrs. Florence further South. I’m on my phone and can’t post images. Maybe someone can throw a trend image up.

[NC_Cyclone]

Ridge is flexing its muscle at 102 hrs. Florence further South. I’m on my phone and can’t post images. Maybe someone can throw a trend image up.

For the life of me I can’t figure out how to post an image.

But the last 5 runs have trended south significantly

[Hurricane Andrew]

Who's ready for...questionable relevance intensity comparisons?

Yes, of course you are!

Lead times are 0, 24, 48, 72, 96, and 120 hours from 06z 9/7. Measurements in MB.

9/7 06z GFS: 995, 987, 985, 972, 949, 943
9/7 00z GFS: 991, 982, 971, 956, 950, 941
9/6 06z GFS: 982, 973, 954, 936, 942, 930

As you can see, 06z GFS holds off on deep restrengthening until the D3-D5 period, something I am inclined to agree with (as is the NHC). Earlier runs had more rapid re-intensification. Also notable is that the new GFS shows a more compact storm, something the 00z HWRF also suggested. As we know, compact hurricanes have upsides and downsides; the upside is that they might effect a smaller area; the downside, they can re-intensify far faster.

[xtyphooncyclonex]

At 132, Flo looks to be aiming the Carolinas

[SouthFLTropics]

132 hours on the 06z is significantly SW of the 00z run. Fartherest SW I’ve seen it yet I believe.

[northjaxpro]

The UKMET, as has been the case all week, continues to consistently show the Southeast U.S. coast under the gun! As time progresses eithin 5-7 days upon the event, the UKMET just may indeed be handling the level of ridging l 0u0around Florence better than the other reliable models and that makes me feel really uncomfortable.

[Hurricane Andrew]

938mb Cat 3/4 (adjusting for GFS-ism) into the OBX at HR 150...surge would be pushed into the Chesapeake, again, that's just verbatim. What's interesting is that by the D5-D6 lead period, the intensity differential is quite normalized (5-10mb, rather than the 30-40 it was at D2-D3). So it seems to me that the GFS is merely correcting for overly rapid re-intensification in earlier runs, as well as an underestimation of how much the shear would weaken Florence. By the time we get to D4, D5, D6, she's in bathwater with relatively low shear and moderate OHC, as GCANE posted in the discussion thread. Lots going on with this storm, anything beyond D2/3 is all but a coin toss, it seems.

[BobHarlem]

6Z GFS GFS landfall @ Cape Hatteras Thursday morning.

[plasticup]

Well that's disturbing.

[SouthFLTropics]

The UKMET, as has been the case all week, continues to consistently show the Southeast U.S. coast under the gun! As time progresses eithin 5-7 days upon the event, the UKMET just may indeed be handling the level of ridging around Florence better than the other reliable modrls and that makes me feel really uncomfortable.

I hear you...considering your location I’d be a bit uneasy. Right now my initial thoughts are that we could get the rare Georgia coast strike from the East. I think anyone between Daytona and the Delmarva are initially in the crosshairs. Don’t think it will get as far south as my location but I’m not taking my eye off her either.

[SouthFLTropics]

938mb Cat 3/4 (adjusting for GFS-ism) into the OBX at HR 150...surge would be pushed into the Chesapeake, again, that's just verbatim. What's interesting is that by the D5-D6 lead period, the intensity differential is quite normalized (5-10mb, rather than the 30-40 it was at D2-D3). So it seems to me that the GFS is merely correcting for overly rapid re-intensification in earlier runs, as well as an underestimation of how much the shear would weaken Florence. By the time we get to D4, D5, D6, she's in bathwater with relatively low shear and moderate OHC, as GCANE posted in the discussion thread. Lots going on with this storm, anything beyond D2/3 is all but a coin toss, it seems.

Into the Outer Banks and right up the gut of Chesapeake Bay. DC would likely see hurricane conditions on this run.

[Hurricane Andrew]

Slowly making the turn from NW to NE over the Delmarva as a TS on Friday...this would be a very bad outcome for the Mid Atlantic. Much of the area has already seen above average precipitation over the last few months, and the GFS dumps 6-8" over portions of Delaware and Maryland, with widespread 2-5" over wider swaths of the Mid Atlantic.

You know, I don't want to beat a dead horse, but if you want an example of how uncertain forecasting could be, here was the NWS forecast for me this morning:

A slight chance of showers before 1pm. Mostly cloudy, with a high near 73. North wind 3 to 7 mph. Chance of precipitation is 20%.

It is raining on the upper end of moderate, for the last 20 minutes or so, with no sign of stopping.

My point is, almost anything can happen at this point. A LOT of factors at play here, GCANE touched on several of them in the other thread.Anyone from Miami to Maine should be watching this.

[Hurricane Andrew]

Due east from 192-198 just south of NYC.

[ronjon]

The UKMET, as has been the case all week, continues to consistently show the Southeast U.S. coast under the gun! As time progresses eithin 5-7 days upon the event, the UKMET just may indeed be handling the level of ridging around Florence better than the other reliable modrls and that makes me feel really uncomfortable.

I hear you...considering your location I’d be a bit uneasy. Right now my initial thoughts are that we could get the rare Georgia coast strike from the East. I think anyone between Daytona and the Delmarva are initially in the crosshairs. Don’t think it will get as far south as my location but I’m not taking my eye off her either.

Starting to think central and north Florida might not be out of the woods yet. Aric has been spot on with the underdoing of the ridge strength. Could this storm eventually track into Daytona Beach or Melbourne? Its still likely SC but any further south shifts by the models will have my attention.

[Hurricane Andrew]

Stupid thing just sits off the LI coast from D8-D9, as a weak TS or TD...waters are a lot colder there, 22º to 25º, not really conducive for restrengthening. The lead-up to that first landfall is another story...nice toasty 29º to 30º.

[Hurricane Andrew]

FV-3 GFS coming in massively weaker, only 995mb at HR 66. A bit further S as well.

We really need recon in this storm; I wouldn't be surprised to see today's POD bump up the beginning of 12-hour fixes to tomorrow or the day after.

[Hurricane Andrew]

New HWRF keeps this as an absolute mess through 48 hours. At HR45, she is 40mb weaker than the 18z proved her to be. I am starting to see consensus in that, if little else.

[AutoPenalti]

Not good, a weaker Florence keeps her moving west along the strengthening ridge.

[gatorcane]

Wow a number of Euro ensembles (orange lines) take this into Florida now which represents a significant shift south on the 00Z run. Models also show a more pronounced SW dip the next couple of days which was nowhere to be seen a couple of days ago. Are the west shifts done?

[NC_Cyclone]

Well.. HWRF initialized very close to reality on strength this time and still ends up with a MONSTER


https://www.tropicaltidbits.com/analysis/models/?model=hwrf&region=06L&pkg=satIR&runtime=2018090706&fh=108