Hurricane Nicholas

[Amped]

1 hour ago, GaWx said:

IF the 18Z Euro were to closely verify, Houston would have a huge flooding problem: this shows 12-20"+ amounts right in the city with most of this within just a 48 hour period and it still raining due to a near stalled Nicholas:

 

 

Am not liking this storm at all.  At least Harvey was a nice looking CAT4 when it hit the coast.  This will be an ugly mess and cause major flooding problems.

Also a lot of that precip falls in 18-24hrs over the Houston area.

[NorthHillsWx]

On radar, a little core looks like it could be coming together. Also, underneath deep convection. Do not give up on this one in the wind department. That’s a tight circulation and shear vector is not as detrimental as it could be and may also add to some ventilation as seen from the growing moisture stream north of the system. 

[WxWatcher007]

Tropical Storm Nicholas Discussion Number   3
NWS National Hurricane Center Miami FL       AL142021
1000 PM CDT Sun Sep 12 2021

Nicholas is not yet a well-organized tropical cyclone, with little 
evidence of convective banding features on satellite imagery.  
Observations from the Air Force Hurricane Hunter aircraft indicate 
that the center is still not very well-defined, and appears to have 
reformed again, this time farther south.  Data from the aircraft 
indicate that the central pressure has not changed much since 
earlier today, and the maximum winds remain near 35 kt.  This is 
above the latest Dvorak intensity estimates from TAFB and SAB.

Nicholas will be traversing very warm waters during the next day or 
so, and within a moist, unstable atmosphere.  These factors would 
favor strengthening.  However, moderate southwesterly shear 
associated with an upper-level trough over northern Mexico could be 
an inhibiting factor for strengthening.  In spite of the shear, 
the GFS model forecasts the system to strengthen while it nears 
the Texas coast.  The official intensity forecast is at the upper 
end of the current model guidance.  Given the uncertainties in the 
future strength of Nicholas, a Hurricane Watch is in effect for a 
portion of the Texas coast.

The current location of Nicholas is quite uncertain since the 
aircraft-reported center position is within a broad area of light 
winds and is well south of most of the deep convection.  Although 
the fixes show little motion this evening, based on the model 
predictions, it appears likely that the center will shift or re-form 
significantly northward as early as Monday morning.  This is at 
least partially accounted for in the latest NHC track forecast, but 
some northward adjustments are possible over night.  The storm 
is expected to move toward a weakness in the subtropical ridge 
during the next 36 hours or so.  The track guidance and the model 
consensus has shifted eastward somewhat since the earlier advisory 
package.  This has necessitated an eastward shift in the official 
track, and a northeastward extension of the watches and warnings.


Key Messages:

1.  Periods of heavy rainfall are expected to impact portions of the 
Texas and Louisiana coasts through the middle of the week.  
Significant rainfall amounts are possible, potentially resulting in 
areas of considerable flash and urban flooding, especially in highly 
urbanized metropolitan areas. Isolated minor to moderate river 
flooding is also expected.

2. There is the danger of life-threatening storm surge inundation
along the coast of Texas from Port Aransas to San Luis Pass.
Residents in these areas should follow any advice given by
local officials.

3. Nicholas is forecast to approach the middle Texas coast as a
strong tropical storm late Monday and early Tuesday, and could be
near hurricane intensity if it moves to the right of the forecast
track and remains over water longer. Tropical storm conditions are
expected along portions of the middle Texas coast beginning Monday
afternoon, with hurricane conditions possible from Port Aransas to
Freeport late Monday and Monday night.

4. Tropical storm conditions are expected along portions of the
northeastern coast of Mexico and the coast of south Texas beginning
Monday morning.


FORECAST POSITIONS AND MAX WINDS

INIT  13/0300Z 22.5N  95.5W   35 KT  40 MPH
 12H  13/1200Z 24.7N  96.5W   45 KT  50 MPH
 24H  14/0000Z 27.0N  96.5W   50 KT  60 MPH
 36H  14/1200Z 28.6N  96.1W   55 KT  65 MPH...NEAR THE COAST
 48H  15/0000Z 29.9N  95.4W   45 KT  50 MPH...INLAND
 60H  15/1200Z 30.4N  94.8W   40 KT  45 MPH...INLAND
 72H  16/0000Z 31.0N  94.0W   30 KT  35 MPH...INLAND
 96H  17/0000Z 31.7N  92.0W   20 KT  25 MPH...POST-TROP/REMNT LOW
120H  18/0000Z...DISSIPATED

$$
Forecaster Pasch

 

[Floydbuster]

I'm gonna say this tries to crank to a cane right at the coast. It may not make it but I think it'll try.

[Amped]

47 minutes ago, Amped said:

Am not liking this storm at all.  At least Harvey was a nice looking CAT4 when it hit the coast.  This will be an ugly mess and cause major flooding problems.

Also a lot of that precip falls in 18-24hrs over the Houston area.

Just noticed the Euro and UKMET are way slower than every other model to move the storm through Houston.   GFS CMC NAVGEM and ICON have the storm at the LA border at 72hrs.  EURO/UKMET have it stalled over San Antonio.

Assuming the more progressive solutions verify, the rainfall duration for Houston will be much shorter. Maybe just a 6-10 hr deluge which can easily drop 10" of rain. The 40" totals won't stand much of a chance though.

[WxWatcher007]

29 minutes ago, Floydbuster said:

I'm gonna say this tries to crank to a cane right at the coast. It may not make it but I think it'll try.

Agree. If the center is really reforming north along the edge of that convection as recon seems to be finding, that could help spur a period of more consistent organization. 

[WxWatcher007]

[Amped]

Clear NNE trend on the GFS.

 

[Floydbuster]

 

[MattPetrulli]

 

2 hours ago, MattPetrulli said:

I thought so earlier today, but recon and satellite show a rather very disorganized system and most intensity guidance has stayed in TS territory this evening. Could make it to a hurricane maybe, but I think it's rather unlikely at this time. Small size could help it spin up and intensify quickly, but it only has about 24-36 more hours over water at most so we'll see. 

 

Yeahhhhh may have to eat those words

[OKwx_2001]

Eye drop supports 1000mb. That's a 9mb drop since the last eye drop 2 hours ago. Yeah let's hope that doesn't continue 

[Normandy]

Watching closely for any convective burst occurring on the western flank of the circulation.  Radar suggests that the storm while deepening is still limited with respect to western Inflow

[SnowenOutThere]

It’s trying to form a core on radar.

[yoda]

Still 60mph and 1001mb at 5am

[yoda]

Just now, yoda said:

Still 60mph and 1001mb at 5am

Tropical Storm Nicholas Advisory Number   5
NWS National Hurricane Center Miami FL       AL142021
400 AM CDT Mon Sep 13 2021

...NICHOLAS FORECAST TO CAUSE FLASH FLOODING, DANGEROUS STORM SURGE
AND GUSTY WINDS LATER TODAY...


SUMMARY OF 400 AM CDT...0900 UTC...INFORMATION
----------------------------------------------
LOCATION...25.5N 96.6W
ABOUT 45 MI...75 KM SE OF MOUTH OF THE RIO GRANDE
ABOUT 200 MI...325 KM S OF PORT OCONNOR TEXAS
MAXIMUM SUSTAINED WINDS...60 MPH...95 KM/H
PRESENT MOVEMENT...NNW OR 345 DEGREES AT 14 MPH...22 KM/H
MINIMUM CENTRAL PRESSURE...1001 MB...29.56 INCHES


WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY:

None.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Storm Surge Warning is in effect for...
* Port Aransas to San Luis Pass Texas
* Aransas Bay, San Antonio Bay, and Matagorda Bay

A Hurricane Watch is in effect for...
* Port Aransas to Freeport Texas

A Tropical Storm Warning is in effect for...
* Mouth of the Rio Grande to High Island Texas
* Barra el Mezquital to the U.S./Mexico border

A Storm Surge Watch is in effect for...
* Mouth of the Rio Grande to Port Aransas Texas
* San Luis Pass Texas to Rutherford Beach Louisiana, including
Galveston Bay
* Baffin Bay and Corpus Christi Bay

A Tropical Storm Watch is in effect for...
* East of High Island Texas to Sabine Pass

[yoda]

Tropical Storm Nicholas Discussion Number   5
NWS National Hurricane Center Miami FL       AL142021
400 AM CDT Mon Sep 13 2021

Radar data from Brownsville shows that the center of Nicholas is on
the southwestern side of a large area of deep convection over the
western Gulf of Mexico.  While southwesterly shear continues to 
affect the storm, the radar presentation has recently improved, 
with what could be the start of a partial eyewall forming in the 
northern quadrant.  The initial wind speed remains 50 kt based on 
earlier aircraft flight-level winds of 59 kt, believable SFMR 
values up to 50 kt, along with radar winds at 5000 ft near 60 kt. 

The storm is moving north-northwestward at about 12 kt.  Nicholas is 
forecast to turn northward soon into a weakness in the subtropical 
ridge.  The track prediction is only nudged slightly westward from 
the previous one through landfall, consistent with recent model 
guidance.  Thereafter, there isn't good agreement among the models 
on how quickly the tropical cyclone will move northeastward out of 
Texas.  Generally the models are faster this cycle, which seems 
believable given the large northward re-formation earlier likely 
exposing Nicholas to stronger mid-latitude flow.  Thus the new NHC 
forecast is trended faster as well, but remains behind the model 
consensus.  Obviously the forward speed is important to the heavy 
rainfall forecast, and this trend will be one to watch.

Nicholas should continue to strengthen up until landfall due 
primarily to the very warm Gulf waters and the recent inner-core 
improvements.  Moderate southwesterly shear and some dry air are the 
main inhibiting factors and will hopefully keep the strengthening in 
check.  However, it is possible that Nicholas could become a 
hurricane before landfall, and that's the reason for the hurricane 
watch area.  Nicholas should weaken after landfall, diminish into a 
tropical depression within a couple of days, and degenerate into a 
remnant low in about 3 days.  No significant changes were made to 
the previous NHC wind speed prediction.


Key Messages:

1.  Heavy rainfall will impact portions of the Texas and Louisiana 
coasts through the middle of the week. Significant rainfall amounts 
are possible, potentially resulting in areas of considerable flash 
and urban flooding, especially in highly urbanized metropolitan 
areas. Isolated minor to moderate river flooding is also expected. 

2. There is the danger of life-threatening storm surge inundation
along the coast of Texas from Port Aransas to San Luis Pass.
Residents in these areas should follow any advice given by
local officials.

3. Nicholas is forecast to approach the middle Texas coast as a
strong tropical storm today, and could be near hurricane
intensity at landfall.  Tropical storm conditions are expected 
along portions of the middle Texas coast beginning by this 
afternoon, with hurricane conditions possible from Port Aransas to 
Freeport this afternoon and tonight.

4. Tropical storm conditions are expected along portions of the
northeastern coast of Mexico and the coast of south Texas beginning
during the next few hours.


FORECAST POSITIONS AND MAX WINDS

INIT  13/0900Z 25.5N  96.6W   50 KT  60 MPH
 12H  13/1800Z 27.3N  96.8W   60 KT  70 MPH
 24H  14/0600Z 29.2N  96.5W   45 KT  50 MPH...INLAND
 36H  14/1800Z 30.6N  95.8W   35 KT  40 MPH...INLAND
 48H  15/0600Z 31.5N  94.5W   30 KT  35 MPH...INLAND
 60H  15/1800Z 32.1N  93.0W   25 KT  30 MPH...INLAND
 72H  16/0600Z 32.5N  91.5W   20 KT  25 MPH...POST-TROP/REMNT LOW
 96H  17/0600Z...DISSIPATED

$$
Forecaster Blake

 

[NorthHillsWx]

Looks impressive on radar imagery. However, seems to have taken a NW jog. Time over water may be extremely limited now 

[weatherCCB]

Definitely developing a inner core. Hopefully land interaction will prevent it from taking off.

[SnowenOutThere]

41 minutes ago, weatherCCB said:

Definitely developing a inner core. Hopefully land interaction will prevent it from taking off.

Seems to have jogged East in the past hour or so, which gives it more time to strengthen.

[jconsor]

About Nicholas's wobbling... it is likely temporary.
 

 

[WxWatcher007]

The IR appearance looks impressive, but there's till a bit of disorganization near the surface. The current center is still on the edge of the deeper convection, and on radar you can clearly see a well defined area of spin within the deepest convection to the NE. Could be temporary, but worth watching. 

[NorthHillsWx]

Convection that had temporarily tried to become a formative core looks like it was sheared away from lllc, which may actually be reforming to the East. There’s clearly a strong MLC well to the northeast of the LLC, and this is becoming even more apparent on radar. May have to watch here for another center reformation. Pretty awesome process to watch on radar as the convection quite literally seems to be trying to drag the llc with it

[Windspeed]

Convection that had temporarily tried to become a formative core looks like it was sheared away from lllc, which may actually be reforming to the East. There’s clearly a strong MLC well to the northeast of the LLC, and this is becoming even more apparent on radar. May have to watch here for another center reformation. Pretty awesome process to watch on radar as the convection quite literally seems to be trying to drag the llc with it

About as clear a reformation as you're ever going to see and neat to have it visualized on quality radar. Interestingly, though shear is negative on the vortex due to tilt, in this case it will have bought Nicholas more time over water since the LLC that formed last night was very near to landfall. The new LLC forming under or closer to the MLC is going to be further NE. Still a sheared system though. The anticyclone is too far south of Nicholas. Whether a strong TS or minimal hurricane, this is still all about the heavy rain and flooding potential.

[Windspeed]

[NeonPeon]

It's really fascinating to be able to watch on radar.  This center seems a lot more stable and stacked, but it's not got enough time to digest that dry air, I wouldn't think, as its running out of water.

Edit: and as I say that, that central center is collapsing and its trying again out west. Wobbler.

[weatherCCB]

On Brownsville radar you can see a llc  moving N.E.   Just my observation.

[NorthHillsWx]

Good luck with the forecast on this one. This is something we usually don’t see on radar and is usually reserved for formative storms. There are 3 possible centers atm and I have no clue which one will take over. Assuming one does, I believe this storm will make a run at a hurricane before landfall given the eastward shifts, but good luck predicting that given current look

[NorthHillsWx]

What I *think* is going on here is there are two week sub vortices rotating around a larger vorticity maximum between them. I think the coc can likely be determined by the midpoint between these small circulation centers. Likely, this will consolidate into a larger single circulation as the smaller vortices will have a difficult time sustaining themselves within the larger circulation 

[STxVortex]

Nicholas looks to be probably making landfall around Port Aransas, Rockport to Mustang, Matagorda Islands, Port O'Connor, Palacios or maybe a smidge to the east. I'll figure it'll be a hurricane by then, the GOM water temperatures and heat index is just too hot.

I cleared out after securing the boat as best as I could over the weekend  [~Lat: 28.08°NLon: 97.05°W ,  Current conditions at Rockport Aransas County Airport (KRKP)  ].  It ain't gonna be a 'nuther Harvey but this stuff gets old.

I've amped up the WX monitoring now that I'm 'home', so FYI, some useful links :

Radar :

BRO radar

CRP radar

EWX [San Antonio] radar

Brownsville WFO

Corpus Christi WFO

EWX San Antonio WFO

Houston WFO

Current conditions at Port Isabel, Port Isabel-Cameron County Airport (KPIL)

Yeehaa, here we go ...

[Amped]

At this point, it's just trying to confuse us.