Hurricane Oscar

[Normandy]

On 10/18/2024 at 11:20 AM, Windspeed said:

Just when everyone discards 94L to the compactor. That's an organizing mid-level vortex. A bit up in the mid-levels on the beam from San Juan, but it could be close to closing off at the surface. Shear is in the forecast, so I'm unsure how far a potential TC can intensify, but it does appear to be organizating in the short-term.

If @Windspeed can notice this yesterday morning, than the national hurricane center can to.  The “it’s a small system” isn’t an excuse this time.  The NHC’s policy of not naming something until recon gets there bit them in the ass time.  Got to use other data sources other than models and recon. Especially when it’s THIS close to land. No excuses.

hopefully Oscar doesn’t get too strong today because everyone in it’s path is unprepared.

[Boston Bulldog]

Current motion seems likely to have the tiny core miss Providenciales, which is fortunate. Grand Turk may not be so lucky

[Master of Disaster]

Not much larger than TS Marco. This may be one of the smallest hurricanes on record now. I seem to recall Marco having TS winds 11 miles from the center. 

[nycwinter]

i cannot remember the last time a system with very low probability even becoming a tropical depression all of a sudden becomes  a hurricane nhc missed the boat on this one..

[nycwinter]

16 minutes ago, Master of Disaster said:

Not much larger than TS Marco. This may be one of the smallest hurricanes on record now. I seem to recall Marco having TS winds 11 miles from the center. 

certainly bigger then marco for sure..

[SnoSki14]

8 minutes ago, nycwinter said:

i cannot remember the last time a system with very low probability even becoming a tropical depression all of a sudden becomes  a hurricane nhc missed the boat on this one..

This has been a bizarre season. Hell we might roundabout our way into hyperactivity after all. 

SSTs are still very warm pretty much everywhere, so it's not over yet. 

[Boston Bulldog]

Hard to tell with lack of quality radar, but looks like a direct strike on Grand Turk

[WxWatcher007]

Hurricane Oscar Discussion Number   3
NWS National Hurricane Center Miami FL       AL162024
500 PM EDT Sat Oct 19 2024

It is fair to say its been an unexpected day with regards to Oscar. 
After being upgraded to a tropical storm this morning, a 
resources-permitting Air Force Reconnaissance mission found that 
Oscar was much stronger than anticipated and in fact was a tiny 
hurricane, prompting the earlier special advisory at 18 UTC.  Having 
these critical in-situ aircraft observations has been invaluable to 
diagnosing the current intensity of the storm, and we thank the crew 
for flying this mission on short notice this morning. It is worth 
noting that remote sensing satellite intensity estimates are 
currently much lower, with the highest objective estimate at 55 kt 
from a DMINT AMSR2 pass at 1830 UTC. For what its worth, ASCAT-B/C 
also hit the small core of Oscar, only showing a peak wind retrieval 
of 42 kt from both passes and only a handful of other retrievals 
with tropical-storm-force winds. The last Air Force Reconnaissance 
leg through Oscar found peak 700-mb flight level winds of 77 kt. A 
dropsonde released in the northeast eyewall also had a 150 m layer 
mean average wind of 85 kt with a surface wind gust of 82 kt. A 
blend of the flight level and dropsonde data supports a wind speed 
of 75 kt this advisory. The wind field of Oscar is very small, with 
hurricane-force winds only extending out 5 n mi from the center, 
with a blend of aircraft and scatterometer data suggesting 
tropical-storm-force winds only extending about 30 n mi, primarily 
in the northern semicircle.  

Oscar has maintained a westward motion today, with recon fixes 
indicating an estimated motion of 275/9 kt. This motion, with a 
subtle shift a little more south of due west is anticipated over the 
next 24-36 h. On the current track, Oscar will pass very near 
portions of the Turks and Caicos Islands and Southeastern Bahamas 
this evening and tonight, where a hurricane warning is in effect. 
The narrow mid-level ridge that is currently steering the system is 
soon expected to become eroded by a longwave trough slowly sagging 
southward across the northwestern Atlantic Ocean, resulting in 
Oscar slowing down and bending a bit south of due west. Thereafter, 
as the trough produces a more pronounced weakness north of the 
hurricane, Oscar will likely execute a very slow but sharp turn to 
the north and then northeast. However, this is still expected to 
bring Oscar close to or over parts of eastern Cuba, before turning 
back northeastward. The latest NHC forecast track is a little 
further east of the prior forecast, blending the consensus aids TVCA 
and HCCA with the ECMWF model, which has been one of the few 
models that has depicted Oscar with much vertical coherence. 

The intensity forecast for Oscar is tricky, due to both the very 
small inner-core wind field associated with the hurricane, and the 
fact that none of the guidance (either global models, or 
hurricane-regional models) is depicting the current intensity right 
now. The last set of aircraft observations suggest the pressure is 
at least not rapidly dropping, with the final dropsonde providing an 
estimate of 987 mb. The NHC intensity forecast will show a bit more 
intensification, but I suspect the tiny hurricane will be quite 
susceptible to the increasingly negative environmental conditions. 
SHIPS guidance indicates that northwesterly vertical wind shear 
increases above 20 kt after 24 h and above 30 kt beyond 60 h. Very 
dry mid-level air exists in that region upstream of Oscar, and the 
storm could weaken rather quickly from 36-60 h. As we saw today, 
small systems like Oscar are often prone to rapid intensity 
changes, either up or down. After 96 h, most of the guidance that is 
able to depict Oscar shows it ultimately being absorbed by the 
deep-layer trough in the northwestern Atlantic, and the latest 
forecast still shows Oscar dissipating by that time.


Key Messages:

1. Oscar is expected to bring hurricane conditions to portions of 
the Turks and Caicos Islands and the southeastern Bahamas this 
evening and overnight, and could bring hurricane conditions to 
eastern Cuba during the next day or two. A Hurricane Warning is in 
effect for the Turks and Caicos and southeastern Bahamas, and a 
Hurricane Watch is in effect for portions of eastern Cuba. 

2. Oscar is expected to produce a dangerous storm surge on the
Turks and Caicos Islands beginning this evening. Minor coastal 
flooding is also possible along the north shore of Cuba later on 
Sunday. 

3. Locally heavy rainfall is possible across the Turks and Caicos
Islands and the southeastern Bahamas later today and tonight. These
rains are expected to spread to eastern Cuba on Sunday.


FORECAST POSITIONS AND MAX WINDS

INIT  19/2100Z 21.4N  71.1W   75 KT  85 MPH
 12H  20/0600Z 21.2N  72.6W   80 KT  90 MPH
 24H  20/1800Z 21.0N  74.1W   80 KT  90 MPH
 36H  21/0600Z 20.9N  74.9W   75 KT  85 MPH
 48H  21/1800Z 21.2N  75.6W   60 KT  70 MPH
 60H  22/0600Z 21.9N  75.3W   50 KT  60 MPH
 72H  22/1800Z 23.3N  74.2W   45 KT  50 MPH
 96H  23/1800Z 26.1N  72.1W   45 KT  50 MPH
120H  24/1800Z...DISSIPATED

$$
Forecaster Papin

[gallopinggertie]

38 minutes ago, Boston Bulldog said:

Hard to tell with lack of quality radar, but looks like a direct strike on Grand Turk

Does seem like it would be passing over or just to the south of Grand Turk now. Oscar’s track reminds me of Joaquin in 2015.

[Windspeed]

Yes, we may have just had a landfall. But the core is so tiny it's virtually impossible to tell via remote sensing. We'll have to see if there were any OBS to suggest as such in the ground.

[USCG RS]

6 hours ago, nycwinter said:

i cannot remember the last time a system with very low probability even becoming a tropical depression all of a sudden becomes  a hurricane nhc missed the boat on this one..

I mean, this thing came out of nowhere. Did any models even have anything like this remotely happening? 

[jbenedet]

18z GEFS now has ~50% tracks into the Caribbean. Big change from earlier runs. 
 

That’s actually the better bet to me vs the sharp recurve northeast after landfall in eastern Cuba.

 

 

[purduewx80]

3 minutes ago, USCG RS said:

I mean, this thing came out of nowhere. Did any models even have anything like this remotely happening? 

The HWRF had it as a cat 2 or 3 around this time off and on since early last week, but it was very inconsistent. 

[jbenedet]

#uncertainty
 

 

[GaWx]

On 10/14/2024 at 3:33 AM, GaWx said:

0Z UKMET: moving WSW underneath a deep high toward E Cuba:
   TROPICAL DEPRESSION 94L        ANALYSED POSITION : 17.3N  36.3W

     ATCF IDENTIFIER : AL942024

                        LEAD                 CENTRAL     MAXIMUM WIND
      VERIFYING TIME    TIME   POSITION   PRESSURE (MB)  SPEED (KNOTS)
      --------------    ----   --------   -------------  -------------
    0000UTC 14.10.2024    0  17.3N  36.3W     1013            24
    1200UTC 14.10.2024   12  17.2N  38.4W     1014            23
    0000UTC 15.10.2024   24  16.7N  40.3W     1012            23
    1200UTC 15.10.2024   36  16.4N  42.4W     1012            23
    0000UTC 16.10.2024   48  16.6N  45.2W     1011            24
    1200UTC 16.10.2024   60  16.8N  48.3W     1012            26
    0000UTC 17.10.2024   72  17.7N  51.8W     1011            29
    1200UTC 17.10.2024   84  18.6N  56.0W     1011            30
    0000UTC 18.10.2024   96  19.9N  59.3W     1011            29
    1200UTC 18.10.2024  108  21.4N  62.4W     1012            27
    0000UTC 19.10.2024  120  22.3N  65.3W     1012            28
    1200UTC 19.10.2024  132  22.5N  67.8W     1011            27
    0000UTC 20.10.2024  144  22.2N  70.1W     1010            29
    1200UTC 20.10.2024  156  21.4N  72.0W     1009            29
    0000UTC 21.10.2024  168  20.8N  73.5W     1007            25

Bump to show that as far back as this 0Z 10/14 (Sun evening) run, the UKMET (ignore strength because strength this far out is not a strength of the UK) was only just over 100 miles ENE of the actual 0Z 10/20 position. 
 Also, the ICON has been fairly good with a storm in the general area as far back as the 0Z 10/13 run.

 The NHC didn’t have its best with Oscar’s genesis. It had only a 10% chance in yesterdays 8AM EDT TWO! Not good. To compare I thought they did very well with Milton overall but not good with Helene’s projected track into GA as they kept the center in W GA instead of E GA like most of the main globals had. Up and down recently for them although they usually do well imo. This year I feel like they’ve been extra conservative in recognizing TCG.

[Floydbuster]

 

[gallopinggertie]

Hopefully Oscar’s tiny size prevents it from causing too many problems in Cuba. God knows they have enough going on at the moment as it is.

[NorthHillsWx]

Oscar is an extremely well-organized micro cane. Eye showing up nicely on radar now. Wish someone had known to chase this, would’ve been incredibly interesting watching that tiny eyewall move through 

https://www.metoc.navy.mil/fwcn/animate.html?icao=mugm&type=CMaxZH240

[purduewx80]

Looks like the AF will be in it a good part of the afternoon. I imagine there’s some concern at GTMO. Lightning taking off in line with the radar@NorthHillsWxposted. 

[WxWatcher007]

How long until landfall?

[Windspeed]

Looks like the AF will be in it a good part of the afternoon. I imagine there’s some concern at GTMO. Lightning taking off in line with the radar[mention=17109]NorthHillsWx[/mention]posted. 

Eastern eyewall is definitely cranking at the moment...

How long until landfall?

Perhaps 3, maybe 4 hours at most? Also, Oscar's tiny core will probably collapse fairly rapidly right at landfall. The mountainous terrain should disrupt inflow with haste.

[hawkeye_wx]

There is a recon plane out there, but for some reason it stopped flying through the center a few hours ago.

[NorthHillsWx]

I would bet good money with the radar/sat presentation at the moment that Oscar is at least a cat 2 

[NorthHillsWx]

It even looks like it might be starting to pop an eye

[hawkeye_wx]

Well, it appears we won't know Oscar's exact strength because recon is done and there is not another one on the way.  The eye will likely move into Cuba without more recon data.

[NorthHillsWx]

7 minutes ago, hawkeye_wx said:

Well, it appears we won't know Oscar's exact strength because recon is done and there is not another one on the way.  The eye will likely move into Cuba without more recon data.

I think some people in the eyewall are going to be surprised 

[jburns]

On 10/19/2024 at 11:31 AM, purduewx80 said:

Kinda hard to say NHC dropped the ball with minimal model support the last few days and all scatterometer data showing an open circulation. HWRF was the only model really showing much coming out of it. Even when it looked like a TC on satellite Thursday, recon found no westerly surface winds as ASCAT showed. Chalk it up to being a tiny circulation, I guess. Suspect we get RI into a hurricane today looking at the outflow in a light shear and warmer oceanic environment.

With all due respect, your post is more of a list of the reasons why they dropped the ball rather than a denial.  

[purduewx80]

7 minutes ago, jburns said:

With all due respect, your post is more of a list of the reasons why they dropped the ball rather than a denial.  

Semantics maybe, but I see it as a list of reasons there was insufficient data to classify it. 

[purduewx80]

29 minutes ago, hawkeye_wx said:

Well, it appears we won't know Oscar's exact strength because recon is done and there is not another one on the way.  The eye will likely move into Cuba without more recon data.

Yup, the other one coming out of Biloxi turned back. Probably too deep in Cuban airspace now. 

[WxWatcher007]