ATL: NATE - Post Tropical - Discussion

[Aric Dunn]

Take for instance harvey( though nearly every hurricane does this before and eye clears out) after a series of large convective burst and the sirrius canopy expands the convection quickly dies revealing the low to mid level eye then you get a series of hit towers that form in multiple quads that rotate up heat the core and an eye finally clears out.. some hurricane its happens faster some take longer.

https://www.youtube.com/watch?v=oSAEzwYCQ4E

[Shell Mound]

Yes, Nate's southern quadrant and inner core are definitely experiencing south-southwesterly shear. The reason for the apparent weakening can be seen on satellite imagery. Nate has left the protective shield of its upper-level anticyclone and has outrun it. That is why convection near the inner core has decreased while outer bands have intensified. Note that upper-level winds from the southwest are converging over and just northwest of Nate. You can see that winds over Nate's inner core are from the south-southwest, while winds just to the west and northwest are from the southwest. Had these winds been diverging over a distance, they would have favored an expansion of Nate's outflow to the north and west, allowing an outflow channel to develop. That would be a jet exit region, hence divergence. However, what we see with Nate is a jet entrance region (convergence). The upper-level trough axis over the Midwest is to the northeast of Nate, not to its northwest, so the flow behind the trough axis is converging, not spreading apart. This pinches Nate and causes it to experience shear as it nears land. Also, upper-level convergence not only indicates shear, but also allows drier mid-level continental air to enter Nate from the north. This explains the arc clouds and outflow boundaries on Nate's northwestern quadrant. So Nate probably has peaked and will now weaken rather than strengthen up until landfall, which is common for late-season (October) storms that near the northern Gulf Coast (i.e., Lili of 2002), as opposed to storms that occur earlier in the year, in August and September, when continental troughs are weaker and the trough axis is sometimes farther west, allowing outflow expansion and moister low-level air, as with Camille and Harvey.

Aircraft data show that the shear and dry air have taken a toll, with SFMR supporting 70 to 75 knots at most. Flight-level winds of 87 knot in the strongest quadrant are probably less representative of the surface winds in a weakening system, and SFMR may lose some of its accuracy as a system enters shallower, shelf waters near the shoreline. So Nate has probably weakened to 70 to 75 knots at this point. Probably it will be a low-end Category-1 hurricane as it impacts southeastern Louisiana, which is manageable. The fast movement and relatively small size should reduce impacts from rain and storm surge, which are the deadliest factors in tropical cyclones. All in all, good news for the Gulf Coast, but any hurricane or strong tropical storm should still be taken seriously.

I think we are all probably a bit skittish; we tend to be during active seasons. When conditions tend to be conducive and produce numerous destructive storms, we tend to think that *every* storm could be a potential catastrophe. Fortunately, that does not appear to apply to Nate. Everyone needs a break: Texas, Florida, Puerto Rico, the Bahamas, Central America, the Virgin Islands, and all rest of the Lesser Antilles...this season has been active and destructive, and that's enough.

[AdamFirst]

This storm has less than 6 hours to landfall...I also agree it has peaked. Maybe a chance for marginal intensification, perhaps to cat 2, but it's moving too quickly and there are multiple factors - i.e. cooler shelf water, forward speed & wind shear - that are preventing it from truly bombing out.

The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or STORM2K. For official information, please refer to products from the National Hurricane Center and National Weather Service.

[tolakram]

Wxman57, what do you see Nate doing? You always shoot straight and I respect your opinions/forecasts. I had to turn our local Nola news off until my favorites come back on the air.

Might want to put this in the discussion thread, the model thread, at this point, is about over.

[Javlin]

Water in Back Bay which is 1/4mile N of me water already covering both private/public peers that are now under about 1:30PM

[AdamFirst]

Just saw that WWL (CBS affiliate in New Orleans) will be airing the LSU-Florida game as scheduled...not even a hurricane can disrupt their football

[psyclone]

That leading outer band sure looks spicy. Tornado warning now in southwester Baldwin County AL for a waterspout on approach to the coast.

[CaneCurious]

Wxman57, what do you see Nate doing? You always shoot straight and I respect your opinions/forecasts. I had to turn our local Nola news off until my favorites come back on the air.

Might want to put this in the discussion thread, the model thread, at this point, is about over.

Thanks! I've been going back and forth between the 2 so much today that I forgot which one I was in.

[CaneCurious]

Just saw that WWL (CBS affiliate in New Orleans) will be airing the LSU-Florida game as scheduled...not even a hurricane can disrupt their football

Hell no! They are switching over to their other channel WUPL for continuous coverage

[psyclone]

Water in Back Bay which is 1/4mile N of me water already covering both private/public peers that are now under about 1:30PM

The MS coast in such a bad spot for water rises...and is frequently in the path of storms...not a good combo. Hopefully Nate weakens and moves quickly enough to mitigate the hazard to some extent.

[Bamagirl2408]

Is it showing a more northerly componant yet? (I can never tell) Any chance Mobile moves out of Hurricane Warning at 4? Mets in New Orleans and Mobile saying different things.

[Big Easy Breeze]

Just saw that WWL (CBS affiliate in New Orleans) will be airing the LSU-Florida game as scheduled...not even a hurricane can disrupt their football

Got that right. That's how we roll. But seriously, we have this hurricane "stuff" down pat. Calm and controlled.

At this time, Nate would need to stop immediately its current movement, and hook NNE to hit Biloxi.

[CaneCurious]

Is it showing a more northerly componant yet? (incan never tell) Any chance Mobile moves out of Hurricane Warning at 4? Mets in New Orleans and Mobile saying different things.

I had to turn off the Nola local news. They were driving me crazy. What is Mobile saying?

[dukeblue219]

Any chance Mobile moves out of Hurricane Warning at 4? Mets in New Orleans and Mobile saying different things.

I highly doubt it. The stronger winds are on the E side of the storm and a downgrade in the warning would carry a message of "you can relax" which the NHC will want to avoid. Here's the current hurricane-force wind probability over the next 36 hours. As you can see, Mobile has a good chance of experiencing hurricane force winds.

Per NHC: Hurricane Warning: An announcement that hurricane conditions (sustained winds of 74 mph or higher) are expected somewhere within the specified coastal area. Because hurricane preparedness activities become difficult once winds reach tropical storm force, the hurricane warning is issued 36 hours in advance of the anticipated onset of tropical-storm-force winds.

[CaneCurious]

Just saw that WWL (CBS affiliate in New Orleans) will be airing the LSU-Florida game as scheduled...not even a hurricane can disrupt their football

Got that right. That's how we roll. But seriously, we have this hurricane "stuff" down pat. Calm and controlled.

At this time, Nate would need to stop immediately its current movement, and hook NNE to hit Biloxi.

That's what I keep saying. I'd much rather get my forecast from Storm2K than the local media. They are strictly towing the NHC line and I just can't see that happening.

[Bamagirl2408]

Is it showing a more northerly componant yet? (incan never tell) Any chance Mobile moves out of Hurricane Warning at 4? Mets in New Orleans and Mobile saying different things.

I had to turn off the Nola local news. They were driving me crazy. What is Mobile saying?

Still sticking with w MS landfall and 80-90 gusts @ midnight in west Mobile.

[Bamagirl2408]

Is it showing a more northerly componant yet? (incan never tell) Any chance Mobile moves out of Hurricane Warning at 4? Mets in New Orleans and Mobile saying different things.

I had to turn off the Nola local news. They were driving me crazy. What is Mobile saying?

I live in very west Mobile. Closer to Pascagoula near Grand Bay. Just started raining.

Still sticking with w MS landfall and 80-90 gusts @ midnight in west Mobile.

[Javlin]

Is it showing a more northerly componant yet? (incan never tell) Any chance Mobile moves out of Hurricane Warning at 4? Mets in New Orleans and Mobile saying different things.

I had to turn off the Nola local news. They were driving me crazy. What is Mobile saying?

Still sticking with w MS landfall and 80-90 gusts @ midnight in west Mobile.

You can see the air getting compressed to the NW and everything starting to point NNE this is what the NHC has been seeing and saying

http://www.ssd.noaa.gov/goes/east/eaus/flash-vis.html

even the clouds structure show it in the WV loop

http://www.ssd.noaa.gov/goes/east/eaus/flash-wv.html

New Orleans is relatively safe some winds not much even if a Cat 1 xame through they still play ball I was there during Juan/Saints in the dome

[artist]

000
UZNT13 KWBC 071918
XXAA 57192 99243 70883 08148 99005 26430 17523 00044 26436 18025
92732 23233 21036 85468 19441 21535 70118 10830 21537 50586 03156
23027 40759 14734 23029 30971 27926 22009 25100 37956 17018 20249
507// 15010 88999 77999
31313 09608 81846
61616 NOAA9 WE16A NATE OB 05
62626 SPL 2438N08824W 1901 MBL WND 20032 AEV 33460 DLM WND 21526
004177 WL150 18528 082 REL 2429N08831W 184623 =
XXBB 57198 99243 70883 08148 00005 26430 11977 26442 22850 19441
33772 15227 44706 11456 55698 10823 66682 10056 77673 09429 88638
06817 99624 06457 11609 05037 22578 03050 33562 01865 44555 01250
55546 00632 66539 00660 77521 01161 88506 02750 99466 06543 11459
06957 22391 15931 33322 23932 44283 31322 55264 34557 66221 45157
77177 577//
21212 00005 17523 11981 20034 22892 21038 33850 21535 44725 22035
55652 20531 66532 23527 77382 23030 88333 27517 99317 26013 11303
22509 22286 18012 33245 17018 44221 15016 55205 15510 66177 25502
31313 09608 81846
61616 NOAA9 WE16A NATE OB 05
62626 SPL 2438N08824W 1901 MBL WND 20032 AEV 33460 DLM WND 21526
004177 WL150 18528 082 REL 2429N08831W 184623 =

[Sanibel]

Still NNW and Euro is turning it only after it glances just to the east of New Orleans...