Hurricane Francine | 100mph 972 mb peak | land ho!

[StretchCT]

This is basically a tropical storm without enough organization yet.  Should make it to the gulf coast in 3 days.  Mexico has TS watches out. 

DISCUSSION AND OUTLOOK
----------------------
At 400 PM CDT (2100 UTC), the elongated disturbance was centered 
near latitude 21.6 North, longitude 94.6 West. The system is moving 
toward the northwest near 5 mph (7 km/h) and a slow northwestward  
motion followed by a turn more northward is expected over the next 
day or two. On the forecast track, the disturbance is expected to 
move near the northern Gulf Coast of Mexico on Tuesday, and 
approach the Upper Texas and Louisiana coastline on Wednesday.

Air Force reconnaissance data indicate that maximum sustained 
winds are near 50 mph (85 km/h) with higher gusts. The system is 
expected to become a tropical storm on Monday, with more 
significant intensification forecast to occur on Tuesday.  The 
system is forecast to become a hurricane before it reaches the 
northwestern U.S. Gulf Coast.
* Formation chance through 48 hours...high...90 percent.
* Formation chance through 7 days...high...90 percent.

Tropical-storm-force winds extend outward up to 185 miles (295 km), 
primarily west of the center.

The estimated minimum central pressure is 1003 mb (29.62 inches).

  

Currently in a gap of radar

Do disco as of yet. But I think this could make it to Cat 1 or possibly 2.  Hurricane models aren't impressed - most have it interacting with land too much.  But the GFS takes it over water the entire time and in a rare event, forecasts this way over what the hurricane models have at a Cat 2.

A lot is going to rest on where that center forms. 

 

Edited September 12 by StretchCT

[Psu1313]

This one has me concerned for over performance. Sheer on the northern flank should lessen. If our system stays over water long enough to land in central Louisiana (see GFS), it will have a bit more time to collect strength. Between the very warm waters, a burgeoning storm that I don’t anticipate would have issues with its core, and just enough time, I could easily see this taking off. TS today, Hurricane by tomorrow and we just have to hope for lots of land interaction to limit the strength. 
 

sorry for the lack of charts this morning. I’m on my iPad. 

[StretchCT]

Still no center of circulation.  Discussion in spoiler. Progged to get to 80mph now.

Spoiler

Potential Tropical Cyclone Six Discussion Number   3
NWS National Hurricane Center Miami FL       AL062024
400 AM CDT Mon Sep 09 2024

Satellite imagery shows that the disturbance is producing 
considerable deep convection with cloud tops colder than -70 deg C. 
However, the cloud pattern is still in the organizing stage with not 
much evidence of banding features at this time.  Upper-level outflow 
is becoming established over the area.  Observations from an Air 
Force reconnaissance aircraft, data buoy 42055, and a partial ASCAT 
overpass suggest that the system has not yet developed a well- 
defined center of circulation.  The intensity is held at 45 kt for 
this advisory with the assumption of some undersampling of the winds 
over the western part of the circulation.  However, this could be 
generous.

Since the center is still not well defined, the initial motion is a 
rather uncertain, but slow, 340/4 kt.  During the next day or so, 
the system is expected to move along the western side of a mid-level 
ridge over the Gulf of Mexico.  This motion should keep the core of 
the system off the coast of northeastern Mexico and southern Texas 
for the next 24-36 hours.  Then, a shortwave trough over Texas is 
expected to induce a turn toward the northeast with an increase in 
forward speed, which would take the center of the system near and 
across the northwestern or northern Gulf coast late Wednesday.  The 
official track forecast has again been nudged eastward in the 48-72 
hour period, but not quite as far east as the ECMWF and corrected 
consensus model predictions.  It should be noted that confidence in 
the track forecast is lower than normal since the system lacks a 
well-defined center. 

Since the system is still not very well-organized and lacks an inner 
core structure, only slow strengthening is expected through this 
morning.  However, the disturbance is expected to soon become better 
organized while remaining over very warm waters, with high low- to 
mid-tropospheric humidity, and low vertical shear for the next 48 
hours.  Therefore steady strengthening is likely to begin by later 
today.  This is also shown by most of the numerical guidance.  When 
the system nears landfall, the global models show increasing 
upper-level westerlies near the northwestern Gulf coast, and this 
could lead to stronger vertical wind shear over the cyclone.  
Therefore the rate of strengthening could at least level off as the 
center nears the coast.  The official intensity forecast is similar 
to the previous NHC prediction, close to the Decay-SHIPS guidance, 
and continues to show the system as a hurricane at landfall.


KEY MESSAGES:

1. The system is forecast to become a tropical storm today as it
moves near the western Gulf of Mexico coast.  Tropical Storm Watches
are in effect for northeastern Mexico and extreme southern Texas.

2. The system is forecast to become a hurricane before it reaches
the northwestern Gulf Coast by the middle of the week.  While it is
too soon to pinpoint the exact location and magnitude of impacts,
the potential for life-threatening storm surge and damaging winds
are increasing for portions of the Louisiana and Upper Texas
coastlines beginning Tuesday night.  Hurricane and Storm Surge
Watches will likely be issued for a portion of that area later 
today, and residents should ensure they have their hurricane plan in
place.

3. Potential Tropical Cyclone Six is expected to bring heavy 
rainfall and the risk of considerable flash flooding along the coast 
of far northeast Mexico, portions of southernmost Texas, southern 
Louisiana, and southern Mississippi into Thursday morning.  A risk 
of flash and urban flooding exists across portions of the Mid-South 
from Wednesday into Friday morning.


FORECAST POSITIONS AND MAX WINDS

INIT  09/0900Z 22.2N  94.8W   45 KT  50 MPH...POTENTIAL TROP CYCLONE
 12H  09/1800Z 23.0N  95.3W   45 KT  50 MPH...TROPICAL CYCLONE
 24H  10/0600Z 24.1N  95.9W   55 KT  65 MPH
 36H  10/1800Z 25.2N  95.7W   60 KT  70 MPH
 48H  11/0600Z 26.8N  94.8W   65 KT  75 MPH
 60H  11/1800Z 28.5N  93.3W   70 KT  80 MPH
 72H  12/0600Z 30.7N  91.8W   50 KT  60 MPH...INLAND
 96H  13/0600Z 34.9N  90.2W   30 KT  35 MPH...POST-TROPICAL
120H  14/0600Z 37.5N  89.0W   20 KT  25 MPH...POST-TROPICAL

$$
Forecaster Pasch

Edited September 9 by StretchCT

[StretchCT]

Can see some trends east which will keep the storm over water.

[StretchCT]

Tropical Storm Francine

10:00 AM CDT Mon Sep 9
Location: 23.0°N 94.9°W
Moving: NNW at 5 mph
Min pressure: 1002 mb
Max sustained: 50 mph

The structure of the system on satellite imagery has improved this 
morning, with a large circular region of cold convection between -70 
to -85 near the estimated center. An Air-Force Reconnaissance 
Aircraft is sampling the system this morning and earlier found a 
cyclonic wind shift from southeasterly to northwesterly flow near 
the center of the mass of deep convection. This data provides enough 
evidence that a well-defined circulation now exists, and thus PTC 
Six has become Tropical Storm Francine with sustained winds of    
45 kt this advisory.

INIT  09/1500Z 23.0N  94.9W   45 KT  50 MPH
 12H  10/0000Z 24.0N  95.4W   50 KT  60 MPH
 24H  10/1200Z 24.9N  95.7W   55 KT  65 MPH
 36H  11/0000Z 26.3N  95.0W   65 KT  75 MPH
 48H  11/1200Z 28.0N  93.5W   75 KT  85 MPH
 60H  12/0000Z 29.7N  92.2W   75 KT  85 MPH...ON THE COAST
 72H  12/1200Z 32.4N  90.7W   35 KT  40 MPH...INLAND
 96H  13/1200Z 36.2N  89.6W   25 KT  30 MPH...POST-TROPICAL
120H  14/1200Z 37.5N  88.8W   20 KT  25 MPH...POST-TROPICAL

 

AI RI is showing chances for rapid intensification, mostly around 24 hrs. 

[StretchCT]

[NWOhioChaser]

It appears that strengthening is somewhat ahead of schedule. Also interesting to note that an eye feature now apparent on radar. So COC stacking is evidently occurring. 

[StretchCT]

37 minutes ago, NWOhioChaser said:

Also interesting to note that an eye feature now apparent on radar.

And sat

[StretchCT]

4:00 PM CDT Mon Sep 9
Location: 24.0°N 96.0°W
Moving: NNW at 7 mph
Min pressure: 996 mb
Max sustained: 65 mph

Disco highlights: Eyewall forming, pressure dropped significantly, mid level eye on radar. Poised to intensify in the short term with low shear, high water temps, ample moisture. Anticipated landfall as Cat 2

Spoiler

Tropical Storm Francine Discussion Number   5
NWS National Hurricane Center Miami FL       AL062024
400 PM CDT Mon Sep 09 2024

Since the prior advisory, Francine's structure has continued to 
improve. Curved bands are becoming more obvious on geostationary 
satellite imagery, even if the coldest cloud tops have warmed from 
earlier today. The last Air Force reconnaissance mission into 
Francine on its final center fix found a formative inner-core with a 
partial eyewall, 850 mb flight level winds up to 58 kt, and pressure 
down to 996 mb, a significant drop from this morning. These data 
were the basis for bringing the 18 UTC intensity up to 50 kt. Since 
then, a mid-level eye feature on the Brownsville radar has become 
apparent. Assuming some additional deepening, the initial intensity 
is set to 55 kt for this advisory. 

With the center becoming better established, the motion is a bit 
easier to estimate, currently at 340/6 kt. While the system has 
reformed a bit west of the previous track, the overall thinking has 
not changed much, as Francine will be moving around the periphery of 
a mid-level ridge centered over Cuba, and an upper-level trough 
propagating into Texas. This trough will ultimately shift the track 
of a more vertically deep Francine northeastward tomorrow with 
gradual acceleration until the storm makes landfall sometime between 
48 to 60 h. The track guidance this cycle has shifted westward, 
likely due to the more westward initial position, and is also a 
little faster. The latest NHC track forecast follows suit, showing a 
shift to the west and a faster motion, blending the prior forecast 
towards the reliable consensus aids TCVN and HCCA.

With the forming inner-core earlier observed by recon and still seen 
on radar currently, the tropical storm appears poised to intensify 
more significantly in the short term. Given the low vertical wind 
shear, ample moisture, and very warm sea-surface temperatures, a 
faster rate of intensification is shown over the next 36 h, and 
Francine is now forecast to become a hurricane tonight or tomorrow 
morning, and a Category 2 hurricane by Wednesday. In the final 
12-18 h before landfall, shear is expected to increase markedly, 
which will likely halt the intensification, though Francine is 
expected to be a Category 2 hurricane at landfall. Rapid weakening 
is expected after the system moves inland. The NHC intensity 
forecast is on the upper-end of the overall intensity guidance, but 
still is lower than some of the hurricane-regional model guidance 
(HAFS-B, HMON). 

Given the changes to the forecast, Hurricane and Storm Surge 
Warnings have been issued for a significant portion of the 
Louisiana coastline.

An experimental cone graphic that includes inland Hurricane and 
Tropical Storm Watches and Warnings in the U.S. is now available on 
the NHC website. Due to the time needed to compile the inland watch 
and warning information, the experimental cone graphic will not be 
available as quickly as the operational cone. Once it is available, 
the experimental cone graphic can be found from a red weblink above 
the operational cone graphic at 
www.nhc.noaa.gov/graphics_at1.shtml?cone#contents. Users are 
encouraged to take the experimental product survey found below the 
experimental cone.

KEY MESSAGES:

1.  Francine is expected to be a hurricane when it reaches the coast 
of Louisiana on Wednesday, and there is a danger of life-threatening 
storm surge for portions of the Upper Texas and Louisiana coastlines 
where a Storm Surge Warning is now in effect.  Residents in the 
warning area should follow advice, including evacuation orders, 
given by local officials. 

2. Damaging and life-threatening hurricane-force winds are expected 
in portions of southern Louisiana Wednesday, where a Hurricane 
Warning is now in effect. Preparations to protect life and property 
should be complete by Tuesday night since tropical storm conditions 
are expected to begin within this area early Wednesday.

3. Francine is expected to bring heavy rainfall and the risk of 
considerable flash flooding along the coast of northeast Mexico, 
the far lower and far upper Texas coasts, southern Louisiana, and 
southern Mississippi into Thursday morning.  A risk of flash and 
urban flooding exists across portions of the Mid-South from 
Wednesday into Friday morning.

FORECAST POSITIONS AND MAX WINDS

INIT  09/2100Z 24.0N  96.0W   55 KT  65 MPH
 12H  10/0600Z 24.8N  96.4W   65 KT  75 MPH
 24H  10/1800Z 25.9N  95.9W   75 KT  85 MPH
 36H  11/0600Z 27.4N  94.7W   85 KT 100 MPH
 48H  11/1800Z 29.4N  92.8W   85 KT 100 MPH
 60H  12/0600Z 31.8N  91.3W   45 KT  50 MPH...INLAND
 72H  12/1800Z 34.2N  90.8W   30 KT  35 MPH...INLAND
 96H  13/1800Z 36.9N  90.3W   25 KT  30 MPH...POST-TROPICAL
120H  14/1800Z 38.2N  89.1W   20 KT  25 MPH...POST-TROPICAL

 

[Psu1313]

2 hours ago, StretchCT said:

4:00 PM CDT Mon Sep 9
Location: 24.0°N 96.0°W
Moving: NNW at 7 mph
Min pressure: 996 mb
Max sustained: 65 mph

Disco highlights: Eyewall forming, pressure dropped significantly, mid level eye on radar. Poised to intensify in the short term with low shear, high water temps, ample moisture. Anticipated landfall as Cat 2

  Reveal hidden contents

Tropical Storm Francine Discussion Number   5
NWS National Hurricane Center Miami FL       AL062024
400 PM CDT Mon Sep 09 2024

Since the prior advisory, Francine's structure has continued to 
improve. Curved bands are becoming more obvious on geostationary 
satellite imagery, even if the coldest cloud tops have warmed from 
earlier today. The last Air Force reconnaissance mission into 
Francine on its final center fix found a formative inner-core with a 
partial eyewall, 850 mb flight level winds up to 58 kt, and pressure 
down to 996 mb, a significant drop from this morning. These data 
were the basis for bringing the 18 UTC intensity up to 50 kt. Since 
then, a mid-level eye feature on the Brownsville radar has become 
apparent. Assuming some additional deepening, the initial intensity 
is set to 55 kt for this advisory. 

With the center becoming better established, the motion is a bit 
easier to estimate, currently at 340/6 kt. While the system has 
reformed a bit west of the previous track, the overall thinking has 
not changed much, as Francine will be moving around the periphery of 
a mid-level ridge centered over Cuba, and an upper-level trough 
propagating into Texas. This trough will ultimately shift the track 
of a more vertically deep Francine northeastward tomorrow with 
gradual acceleration until the storm makes landfall sometime between 
48 to 60 h. The track guidance this cycle has shifted westward, 
likely due to the more westward initial position, and is also a 
little faster. The latest NHC track forecast follows suit, showing a 
shift to the west and a faster motion, blending the prior forecast 
towards the reliable consensus aids TCVN and HCCA.

With the forming inner-core earlier observed by recon and still seen 
on radar currently, the tropical storm appears poised to intensify 
more significantly in the short term. Given the low vertical wind 
shear, ample moisture, and very warm sea-surface temperatures, a 
faster rate of intensification is shown over the next 36 h, and 
Francine is now forecast to become a hurricane tonight or tomorrow 
morning, and a Category 2 hurricane by Wednesday. In the final 
12-18 h before landfall, shear is expected to increase markedly, 
which will likely halt the intensification, though Francine is 
expected to be a Category 2 hurricane at landfall. Rapid weakening 
is expected after the system moves inland. The NHC intensity 
forecast is on the upper-end of the overall intensity guidance, but 
still is lower than some of the hurricane-regional model guidance 
(HAFS-B, HMON). 

Given the changes to the forecast, Hurricane and Storm Surge 
Warnings have been issued for a significant portion of the 
Louisiana coastline.

An experimental cone graphic that includes inland Hurricane and 
Tropical Storm Watches and Warnings in the U.S. is now available on 
the NHC website. Due to the time needed to compile the inland watch 
and warning information, the experimental cone graphic will not be 
available as quickly as the operational cone. Once it is available, 
the experimental cone graphic can be found from a red weblink above 
the operational cone graphic at 
www.nhc.noaa.gov/graphics_at1.shtml?cone#contents. Users are 
encouraged to take the experimental product survey found below the 
experimental cone.

KEY MESSAGES:

1.  Francine is expected to be a hurricane when it reaches the coast 
of Louisiana on Wednesday, and there is a danger of life-threatening 
storm surge for portions of the Upper Texas and Louisiana coastlines 
where a Storm Surge Warning is now in effect.  Residents in the 
warning area should follow advice, including evacuation orders, 
given by local officials. 

2. Damaging and life-threatening hurricane-force winds are expected 
in portions of southern Louisiana Wednesday, where a Hurricane 
Warning is now in effect. Preparations to protect life and property 
should be complete by Tuesday night since tropical storm conditions 
are expected to begin within this area early Wednesday.

3. Francine is expected to bring heavy rainfall and the risk of 
considerable flash flooding along the coast of northeast Mexico, 
the far lower and far upper Texas coasts, southern Louisiana, and 
southern Mississippi into Thursday morning.  A risk of flash and 
urban flooding exists across portions of the Mid-South from 
Wednesday into Friday morning.

FORECAST POSITIONS AND MAX WINDS

INIT  09/2100Z 24.0N  96.0W   55 KT  65 MPH
 12H  10/0600Z 24.8N  96.4W   65 KT  75 MPH
 24H  10/1800Z 25.9N  95.9W   75 KT  85 MPH
 36H  11/0600Z 27.4N  94.7W   85 KT 100 MPH
 48H  11/1800Z 29.4N  92.8W   85 KT 100 MPH
 60H  12/0600Z 31.8N  91.3W   45 KT  50 MPH...INLAND
 72H  12/1800Z 34.2N  90.8W   30 KT  35 MPH...INLAND
 96H  13/1800Z 36.9N  90.3W   25 KT  30 MPH...POST-TROPICAL
120H  14/1800Z 38.2N  89.1W   20 KT  25 MPH...POST-TROPICAL

 

Not loving the trends. This storm can go boom. I almost feel like 115 at landfall is my low estimate. 

[Sentinel]

47 minutes ago, Psu1313 said:

Not loving the trends. This storm can go boom. I almost feel like 115 at landfall is my low estimate. 

Yeah, this is not great. However, I wonder if the storm becomes strong enough, will it bullseye Central LA, thus sparing more populated areas. 

[Psu1313]

45 minutes ago, Sentinel said:

Yeah, this is not great. However, I wonder if the storm becomes strong enough, will it bullseye Central LA, thus sparing more populated areas. 

My concern is that there is a potential route further east closer to New Orleans. I wouldn’t predict it at this moment, but it’s not a solution that is completely off the table. 

[StretchCT]

12z HMON not messing around with Cat 3. 18z backed off a little.  HAFS A from 18z also getting clost to if not over a Cat 3. This one goes to the east of NOLA, per PSU's concern. 

 

HAFS B 18z also at Cat 3. Goes just to the west of NOLA.  The hurricane models came to the party later than the GFS, but until that center formed, it was anyone's guess. 

 

[StretchCT]

There is some talk about dry air intrusion.  And it does look that way on the mid level WV sat. That air near the center isn't super dry though. 

But when you compare it to the models, they don't seem to have it going into the center.  A hint but not what is actually on the WV.  Hafs A, B, HWRF and GFS left to right

More importantly, they all even it out later on. GFS, HWRF, HafsA, B left to right

[StretchCT]

When you're living on the LA coast and you see yourself in the bright green area, you look at the scale and see that there's only a 20-30% chance of hurricane force winds during the next 72 hrs. And its the same all the way out to 120 hrs. 

Do you prep for a hurricane at this point? I mean it's a 20% chance. 

40-50% chance you see 50kt winds

Seems like a reasonable person would probably not do much to prep.  

[Sentinel]

7 minutes ago, StretchCT said:

When you're living on the LA coast and you see yourself in the bright green area, you look at the scale and see that there's only a 20-30% chance of hurricane force winds during the next 72 hrs. And its the same all the way out to 120 hrs. 

Do you prep for a hurricane at this point? I mean it's a 20% chance. 

40-50% chance you see 50kt winds

Seems like a reasonable person would probably not do much to prep.  

Honestly... Yes. With the Rocket Fuel in the Ocean, I would definitely have my city on alert. Could it be for nothing? Yes. Could it also protect the city? Yes. I would not call for evacuations, etc, but I would have my staff having things ready in case I need to move that way. 

[StretchCT]

8 minutes ago, Sentinel said:

Honestly... Yes. With the Rocket Fuel in the Ocean, I would definitely have my city on alert. Could it be for nothing? Yes. Could it also protect the city? Yes. I would not call for evacuations, etc, but I would have my staff having things ready in case I need to move that way. 

Let me rephrase. You meaning a local person who doesn’t follow the weather much. 

[Psu1313]

Dry air and sheer really did a number. High cloud tops are starting to boil around the center so this is not over, but a good sign for the moment that she is taking more time to organize .

[StretchCT]

4:00 AM CDT Tue Sep 10
Location: 24.4°N 96.2°W
Moving: NNW at 5 mph
Min pressure: 992 mb
Max sustained: 65 mph

 

FORECAST POSITIONS AND MAX WINDS

INIT  10/0900Z 24.4N  96.2W   55 KT  65 MPH
 12H  10/1800Z 25.4N  95.6W   70 KT  80 MPH
 24H  11/0600Z 27.1N  94.2W   80 KT  90 MPH
 36H  11/1800Z 29.0N  92.5W   85 KT 100 MPH
 48H  12/0600Z 31.4N  91.1W   50 KT  60 MPH...INLAND
 60H  12/1800Z 33.8N  90.5W   30 KT  35 MPH...INLAND
 72H  13/0600Z 35.7N  90.2W   25 KT  30 MPH...POST-TROPICAL
 96H  14/0600Z 37.0N  90.0W   20 KT  25 MPH...POST-TROPICAL
120H  15/0600Z...DISSIPATED

Moving slowly.

6z HAFS A and B backing off the strength back into the Cat 2 range.  They all seem to have the storm waiting until tonight to wind up. These don't update as quickly as I'd want, but still appreciate them. 

Edited September 10 by StretchCT

[StretchCT]

Firing up some new convection around the center.

[clm]

11 hours ago, Sentinel said:

Honestly... Yes. With the Rocket Fuel in the Ocean, I would definitely have my city on alert. Could it be for nothing? Yes. Could it also protect the city? Yes. I would not call for evacuations, etc, but I would have my staff having things ready in case I need to move that way. 

Exactly.  You're already prepared at that point.  If it doesn't pan out, let the bandwagon complain.  I'd rather have them complain about being prepared than not being prepared.

[clm]

11 hours ago, StretchCT said:

Let me rephrase. You meaning a local person who doesn’t follow the weather much. 

Wut is whethuh? 🤪

[Sentinel]

12 hours ago, StretchCT said:

Let me rephrase. You meaning a local person who doesn’t follow the weather much. 

They are not watching the weather anyway.. so.. Of course yes! 😁

[clm]

49 minutes ago, Sentinel said:

They are not watching the weather anyway.. so.. Of course yes! 😁

And then they'll complain and say why didn't you tell us or how were we supposed to know.

Edited September 10 by clm

[clm]

What are the chances Francine could be a rebel and go up through Texas?