Jump to content
  • Member Statistics

    16,988
    Total Members
    7,904
    Most Online
    Dankles
    Newest Member
    Dankles
    Joined

Major Hurricane Sam


Jtm12180
 Share

Recommended Posts

Going to be very close if the Euro pans out.  Cut-Off Low to the west with a ridge to the east implies a due north track after the run.  Which of the two features becomes the dominant steering element likely dictates whether or not landfall occurs on the East Coast.  Stronger low seems like it would send it more west, stronger ridge seems like it would send it slowly north before ejecting NE when the next trough comes in.  On the next cycle!

Link to comment
Share on other sites

19 minutes ago, OSUmetstud said:

500mb is just all wrong for a US landfall. Theres a trough where you'd want a ridge and a ridge where'd you want a trough. So much has to change for it to happen. I'd put it at less than 10 percent...and that might be generous. 

Can you explain this a little more?  That's not how I am reading this and want to be schooled on how I am interpreting this.  See tweet below for what I am seeing:

https://twitter.com/andretrotter/status/1441137766515937280?ref_src=twsrc^tfw|twcamp^tweetembed|twterm^1441137766515937280|twgr^|twcon^s1_c10&ref_url=http%3A%2F%2Fstorm2k.org%2Fphpbb2%2FEmbedTweet.html1441137766515937280

Link to comment
Share on other sites

Just now, Normandy said:

Can you explain this a little more?  That's not how I am reading this and want to be schooled on how I am interpreting this.  See tweet below for what I am seeing:

https://twitter.com/andretrotter/status/1441137766515937280?ref_src=twsrc^tfw|twcamp^tweetembed|twterm^1441137766515937280|twgr^|twcon^s1_c10&ref_url=http%3A%2F%2Fstorm2k.org%2Fphpbb2%2FEmbedTweet.html1441137766515937280

Every single member of the eps didn't make landfall. I'm not surprised that Eric compared a single op run to a hugo plot...and the storm still missed...

Most of the guidance has the trough sitting on the east coast not cutting off that far southwest...and a trough in the position makes sense with a massive ridge over Ontario. 

 

Link to comment
Share on other sites

DISCUSSION AND OUTLOOK
----------------------
At 500 PM AST (2100 UTC), the center of Tropical Storm Sam was 
located near latitude 11.1 North, longitude 39.7 West. Sam is moving 
toward the west near 16 mph (26 km/h) and a general west to 
west-northwest motion is expected to continue over the next several 
days, with a gradual slowdown in forward motion.

Maximum sustained winds have increased to near 60 mph (95 km/h) with
higher gusts. Rapid intensification is forecast during the next
several days. Sam is forecast to become a hurricane tomorrow morning
and could become a major hurricane by Saturday.

Tropical-storm-force winds extend outward up to 60 miles (95 km)
from the center.

The estimated minimum central pressure is 1000 mb (29.53 inches).
  • Sad 1
Link to comment
Share on other sites

Tropical Storm Sam Discussion Number   5
NWS National Hurricane Center Miami FL       AL182021
500 PM AST Thu Sep 23 2021

Sam could be in the beginning stages of developing a small 
inner-core this afternoon as a central dense overcast is beginning 
to take shape. On geostationary visible satellite imagery, the storm 
has occasionally exhibited a clear area, though this feature has 
been tilted a bit southeast of the estimated low-level center 
position. In addition, overshooting convective cloud tops have been 
recirculating cyclonically around this feature, suggesting 
convective symmetrization that may help shield the low-level vortex 
from dry-air intrusion as seen earlier on the northwest side of Sam. 
Unfortunately, I have not received a high resolution microwave pass 
over Sam in 9-12 hours, so there remains some uncertainty on the 
structure underneath the cirrus canopy. The latest subjective Dvorak 
estimates from SAB and TAFB were 55-kt and 45-kt respectively. 
Taking a blend of these intensity estimates yields 50-kt for this 
advisory.

Sam's estimated motion is nearly identical to this morning, moving 
north of due west at 280/14 kt. A large and anomalously strong 
mid-level ridge is located poleward of Sam and should maintain the 
current west to west-northwest heading over the next 2-3 days. 
However, this ridge-axis is forecast to build in to the northwest 
ahead of Sam, which is likely to gradually slow down this forward 
motion over the next few days. In fact, Sam is forecast to move 
unusually slow for a tropical cyclone in the deep tropics east of 
the Lesser Antilles. Afterwards, a weakness in the ridge to the 
northwest is forecast to gradually develop as a broad deep-layer 
trough parks itself just offshore of the eastern United States by 
early next week. This could potentially allow Sam to gain a bit more 
latitude at a somewhat faster forward motion as the ridge axis 
shifts back east. The track guidance this cycle has slowed down a 
bit compared to this morning and is also a bit further south in the 
early portion of the forecast. The NHC official track will follow 
suit this advisory, though is not quite as slow as the GFS model. It 
is interesting to note that both the GFS and ECMWF ensemble guidance 
this afternoon shows a significant spread in track solutions by day 
5 in the cross-track direction, so this track forecast is a bit more 
uncertain than usual.

With the apparent improvement in inner-core structure inferred
on satellite today, Sam appears poised to rapidly intensify in the
short-term. In fact, the latest GFS-SHIPS guidance is now explicitly
forecasting rapid intensification over the next 24-48 hours. This
seems feasible given that the guidance is forecasting 5 kt or less
vertical wind shear over the next 60 hours as the cyclone traverses
over warm 28-29 C sea-surface temperatures. Thus, the intensity
guidance in the short-term has been raised once again, now showing a
50-kt increase in intensity over the next 48 hours taking Sam to
major hurricane intensity by Saturday afternoon. Remarkably, this
rapid intensification is still below the latest HCCA and LGEM
guidance over this time span. After this period, Sam is likely to
start undergoing inner core fluctuations, related to eyewall
replacement cycles that are challenging to forecast far in advance.
A modest increase in southwesterly vertical wind shear could also
occur in the day 3-5 period. Thus, the NHC intensity forecast still
tops off Sam as 110-kt hurricane by the end of the forecast period,
which is on the high end of the intensity guidance envelope.


FORECAST POSITIONS AND MAX WINDS

INIT  23/2100Z 11.1N  39.7W   50 KT  60 MPH
 12H  24/0600Z 11.5N  41.9W   60 KT  70 MPH
 24H  24/1800Z 11.9N  44.2W   75 KT  85 MPH
 36H  25/0600Z 12.3N  46.0W   90 KT 105 MPH
 48H  25/1800Z 12.6N  47.4W  100 KT 115 MPH
 60H  26/0600Z 13.1N  48.7W  105 KT 120 MPH
 72H  26/1800Z 13.7N  50.0W  110 KT 125 MPH
 96H  27/1800Z 15.2N  52.5W  110 KT 125 MPH
120H  28/1800Z 17.5N  55.5W  110 KT 125 MPH

$$
Forecaster Papin
  • Weenie 1
Link to comment
Share on other sites

14 minutes ago, OSUmetstud said:

Every single member of the eps didn't make landfall. I'm not surprised that Eric compared a single op run to a hugo plot...and the storm still missed...

Most of the guidance has the trough sitting on the east coast not cutting off that far southwest...and a trough in the position makes sense with a massive ridge over Ontario. 

 

Appreciate the input.  Lets see what the subsequent model cycles show

Link to comment
Share on other sites

Regardless of the eventual track, it’s going to be very cool to watch this thing take off over the next two days in the MDR. For all those that have been waiting for this part of the MDR to look like the peak periods of yesteryear, get your popcorn ready. 
 

  • Like 3
  • Weenie 1
Link to comment
Share on other sites

1 hour ago, OSUmetstud said:

500mb is just all wrong for a US landfall. Theres a trough where you'd want a ridge and a ridge where'd you want a trough. So much has to change for it to happen. I'd put it at less than 10 percent...and that might be generous. 

Exactly. Like a landfall is definitely gonna happen as long as everything that every model plays out in the exact opposite way they are forecasting. I've only been tracking weather for a handful of years. Has there been another time recently when the models would be this wrong?

Link to comment
Share on other sites

15 minutes ago, cptcatz said:

Exactly. Like a landfall is definitely gonna happen as long as everything that every model plays out in the exact opposite way they are forecasting. I've only been tracking weather for a handful of years. Has there been another time recently when the models would be this wrong?

I mean the storm is still 200 hours out . People are hyping it because of the big high pressure in the Atlantic. 

Link to comment
Share on other sites

1 hour ago, cptcatz said:

Exactly. Like a landfall is definitely gonna happen as long as everything that every model plays out in the exact opposite way they are forecasting. I've only been tracking weather for a handful of years. Has there been another time recently when the models would be this wrong?

 

The models had Florence turning out well east of Bermuda.....every system is different but yeah models were very wrong with Florence even up to landfall there were fairly significant changes.....

Tracking Hurricane Florence l Cone, Spaghetti Models, Satellite, Radar  Images | wltx.com

 

Hurricane Florence Could Hit The Carolinas This Week - Charlotte Stories

  • Like 1
Link to comment
Share on other sites

5 minutes ago, downeastnc said:

 

The models had Florence turning out well east of Bermuda.....every system is different but yeah models were very wrong with Florence even up to landfall there were fairly significant changes.....

Tracking Hurricane Florence l Cone, Spaghetti Models, Satellite, Radar  Images | wltx.com

 

Hurricane Florence Could Hit The Carolinas This Week - Charlotte Stories

That one was a really extraordinary turn of events. From an easy recurve pattern (modeled) to stalling over NC.  

1 hour ago, cptcatz said:

Exactly. Like a landfall is definitely gonna happen as long as everything that every model plays out in the exact opposite way they are forecasting. I've only been tracking weather for a handful of years. Has there been another time recently when the models would be this wrong?

This far out, the operational runs are just weenie fodder IMO. Fun to look at but that's about it. The ensembles will really give you a sense of where things stand in terms of modeled track, though it should be noted these will shift and can shift dramatically one way or another at this range too.

I wouldn't look at the long term stuff on the models, 6+ days out, as whether a model is right or wrong. At this stage, I'd watch for the larger steering environment players and short to medium term environment for potential intensification to get a sense of what's possible with regard to track and intensity. 

  • Like 5
Link to comment
Share on other sites

28.5-29°C SSTs, negligible shear, has a core per MW, CBs rotating that eyewall feature; all signs point to Sam reaching hurricane status in the AM if at least by Noon AST. No wonder the SHIPs is so pronounced for an RI phase. Only we appear to already be ahead of schedule by 24 hours. Sam will be a classic Cape Verde major hurricane by Saturday, if not sooner.
0d341b43e3c303fe9ea0fd69226ca575.jpg
fb500e48bff17cfbe43a636cb54aad0b.gif

  • Like 3
Link to comment
Share on other sites

7 hours ago, Intensewind002 said:

Were you there for Gloria? My dad is from North Babylon and suffolk got hit really hard wind damage (wind was worse than Sandy according to him). Not sure but I think the Nassau Suffolk border was also the border between who got hurricane force winds and who didn’t on LI. I’m only 21 so Sandy is the worst storm I’ve ever witnessed

In the Navy, pre-internet days, heard about Gloria after the fact.

  • Like 1
Link to comment
Share on other sites

  • Jtm12180 changed the title to Major Hurricane Sam

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

  • Recently Browsing   0 members

    No registered users viewing this page.

×
×
  • Create New...