Hurricane Marco

[Orangeburgwx]

Wonder what that closed vort they found was... MLC?

Sent from my LML212VL using Tapatalk

[Superstorm93]

Recon not finding any impressive pressure readings so far. 

 

Still might be an open wave at this point. 

[Cheeznado]

Where NHC says the center is the plane found nothing even close to a circulation. I think maybe they jumped the gun in calling it a TD.

[yoda]

Tropical Depression Fourteen Advisory Number   2
NWS National Hurricane Center Miami FL       AL142020
500 PM EDT Thu Aug 20 2020

...AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT FINDS THE DEPRESSION
A LITTLE FARTHER SOUTH...
...TROPICAL STORM WARNINGS ISSUED FOR PORTIONS OF HONDURAS AND
NICARAGUA...


SUMMARY OF 500 PM EDT...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...14.3N 81.0W
ABOUT 155 MI...250 KM ESE OF CABO GRACIAS A DIOS ON NIC/HON BORDER
MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/H
PRESENT MOVEMENT...W OR 270 DEGREES AT 18 MPH...30 KM/H
MINIMUM CENTRAL PRESSURE...1007 MB...29.74 INCHES


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

The government of Honduras has upgraded the Tropical Storm Watch
to a Tropical Storm Warning from the Honduras/Nicaragua border
westward to Punta Castilla and for the Bay Islands.

The government of Nicaragua has issued a Tropical Storm Warning for
the coast of Nicaragua from Puerto Cabezas northward.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Tropical Storm Warning is in effect for...
* Honduras/Nicaragua border westward to Punta Castilla Honduras
* Bay Islands of Honduras
* Puerto Cabezas Nicaragua northward to the Honduras/Nicaragua
border

A Tropical Storm Warning means that tropical storm conditions are
expected somewhere within the warning area, in this case within the
next 12 hours.

Additional watches or warnings, including for the Yucatan Peninsula
of Mexico, may be required later this evening or tonight.

For storm information specific to your area, please monitor
products issued by your national meteorological service.


DISCUSSION AND OUTLOOK
----------------------
At 500 PM EDT (2100 UTC), the center of Tropical Depression Fourteen 
was located near latitude 14.3 North, longitude 81.0 West.  The 
depression is moving toward the west near 18 mph (30 km/h), and this 
general motion is expected to continue through tonight.  A turn 
toward the west-northwest and northwest with a decrease in forward 
speed is forecast on Friday, with a general northwest motion 
continuing through at least Sunday.  On the forecast track, the 
center of the system will move near or over extreme northern 
Nicaragua and northeastern Honduras, including the Bay Islands, on 
Friday and approach the east coast of the Yucatan Peninsula of 
Mexico on Saturday.  The center is then expected to cross the 
Yucatan Peninsula Saturday night and move into the south-central 
Gulf of Mexico on Sunday.

Maximum sustained winds are near 35 mph (55 km/h) with higher gusts.
Strengthening is forecast during the next couple of days, and
the depression is expected to become a tropical storm tonight.  The 
system could be near or at hurricane strength when it reaches the 
Yucatan Peninsula of Mexico late Saturday.

The estimated minimum central pressure is 1007 mb (29.74 inches).


HAZARDS AFFECTING LAND
----------------------
WIND:  Tropical storm conditions are expected to first reach the
coast within the warning area by tonight, making outside
preparations difficult or dangerous.  These conditions will spread
westward along the coast of Honduras within the warning area on
Friday.

RAINFALL:  The depression is expected to produce the following
rainfall accumulations through Sunday:

Eastern portions of the Mexican states of Quintana Roo and Yucatan:
3 to 6 inches, isolated maximum totals of 10 inches. This rainfall
may result in areas of flash flooding.

Honduras: 2 to 4 inches.

Jamaica and northern Nicaragua: 1 to 2 inches.


NEXT ADVISORY
-------------
Next intermediate advisory at 800 PM EDT.
Next complete advisory at 1100 PM EDT.

$$
Forecaster Berg

[yoda]

Tropical Depression Fourteen Discussion Number   2
NWS National Hurricane Center Miami FL       AL142020
500 PM EDT Thu Aug 20 2020

An Air Force Reserve Hurricane Hunter aircraft investigating the 
system found an area of lighter winds--likely where the center would 
be--farther south than previous estimates.  The highest flight-level 
wind measured by the aircraft was 30 kt at an altitude of 2500 feet, 
and although there were some SFMR measurements over 40 kt, these 
looked coincident with some heavy rain rates and thus are probably 
not reliable. Therefore, the initial intensity remains 30 kt.  
Structurally, the depression has a large cloud envelope with 
sporadic convective cells located in loose bands.

The updated initial position derived from the aircraft data 
indicates that the current motion is still westward, or 270/16 kt.  
This southward adjustment really only affected the first 36 hours 
or so of the forecast, with NHC's official track forecast being 
shifted southward during that period.  This ends up taking the 
cyclone's center over extreme northern Nicaragua and northeastern 
Honduras in 12-24 hours.  After 36 hours, model guidance remains in 
good agreement that the system should turn northwestward due to a 
deep-layer trough over the Gulf of Mexico.  The new set of model 
guidance has not shifted much from the previous cycle, and the NHC 
track forecast is very close to the morning forecast despite the 
initial position adjustment, with perhaps a slight eastward shift 
on days 4 and 5.  In general, the NHC forecast is closest to the 
GFS and HCCA model solutions.

The depression's farther-south position makes the intensity 
forecast more complicated with potentially more land interaction 
with parts of Central America.  Slight strengthening to tropical 
storm strength is expected before the center reaches Honduras and 
Nicaragua, with little change thereafter until the center 
re-emerges over the Gulf of Honduras.  Low shear and warm sea 
surface temperatures should then support further intensification up 
until it reaches the Yucatan Peninsula.  Since there is significant 
uncertainty in how land interaction will affect the cyclone's 
intensity, the forecast intensity has been flat-lined between day 2 
and day 4, with the understanding that the the winds could increase 
or decrease from the value shown.  Vertical shear is expected to 
increase by day 5, and some weakening is shown at that time.

Key Messages:

1. Tropical Depression Fourteen is expected to strengthen over the
northwestern Caribbean Sea through Saturday, and is likely to 
produce tropical-storm-force winds and heavy rainfall over portions 
of the coasts of Nicaragua and Honduras, including the Bay Islands, 
beginning tonight through Friday.  The system could be near or at 
hurricane strength when it reaches the Yucatan Peninsula of Mexico 
late Saturday, and watches could be required for a portion of that 
area tonight.

2. The system is expected to move into the south-central Gulf
of Mexico as a tropical storm on Sunday.  Some strengthening is
anticipated while it moves northwestward over the western Gulf of
Mexico early next week, but it is too soon to know exactly how
strong it will get or the location and magnitude of impacts it
will produce along the central or northwestern Gulf Coast.
Interests in that area should continue monitoring the progress of
this system over the next few days.

FORECAST POSITIONS AND MAX WINDS

INIT  20/2100Z 14.3N  81.0W   30 KT  35 MPH
 12H  21/0600Z 14.7N  83.0W   35 KT  40 MPH
 24H  21/1800Z 15.6N  84.7W   35 KT  40 MPH...INLAND
 36H  22/0600Z 17.0N  85.6W   45 KT  50 MPH...OVER WATER
 48H  22/1800Z 18.7N  86.6W   55 KT  65 MPH
 60H  23/0600Z 20.3N  87.9W   55 KT  65 MPH...INLAND
 72H  23/1800Z 22.1N  89.2W   55 KT  65 MPH...OVER WATER
 96H  24/1800Z 26.0N  91.5W   55 KT  65 MPH
120H  25/1800Z 28.5N  93.5W   50 KT  60 MPH

$$
Forecaster Berg

[Sam Kane]

Naztac reads 12zs pressure dropping, very interesting!

[Amped]

All the stronger solutions track further northeast.   Although recon found the center pretty far south, it is broad and weak enough that it can still reform.

[wizard021]

18z euro weaker. 

[yoda]

BULLETIN
Tropical Depression Fourteen Advisory Number   3
NWS National Hurricane Center Miami FL       AL142020
1100 PM EDT Thu Aug 20 2020

...DEPRESSION CLOSE TO BECOMING A TROPICAL STORM...
...HURRICANE WATCH AND TROPICAL STORM WARNING ISSUED FOR PORTIONS
OF EASTERN YUCATAN PENINSULA...


SUMMARY OF 1100 PM EDT...0300 UTC...INFORMATION
-----------------------------------------------
LOCATION...14.9N 82.2W
ABOUT 65 MI...110 KM E OF CABO GRACIAS A DIOS ON NIC/HON BORDER
ABOUT 310 MI...495 KM ESE OF ISLA ROATAN HONDURAS
MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/H
PRESENT MOVEMENT...WNW OR 285 DEGREES AT 14 MPH...22 KM/H
MINIMUM CENTRAL PRESSURE...1007 MB...29.74 INCHES


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

The government of Mexico has issued a Hurricane Watch and a
Tropical Storm Warning for portions of the eastern Yucatan
Peninsula from Punta Herrero northward to Cancun, Mexico.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Hurricane Watch is in effect for...
* Punta Herrero to Cancun Mexico

A Tropical Storm Warning is in effect for...
* Honduras/Nicaragua border westward to Punta Castilla Honduras
* Bay Islands of Honduras
* Puerto Cabezas Nicaragua northward to the Honduras/Nicaragua
border
* Punta Herrero to Cancun Mexico

A Hurricane Watch means that hurricane conditions are possible
within the watch area.  A watch is typically issued 48 hours
before the anticipated first occurrence of tropical-storm-force
winds, conditions that make outside preparations difficult or
dangerous.

A Tropical Storm Warning means that tropical storm conditions are
expected somewhere within the warning area, in this case within the
next 12 hours.

For storm information specific to your area, please monitor
products issued by your national meteorological service.


DISCUSSION AND OUTLOOK
----------------------
At 1100 PM EDT (0300 UTC), the center of Tropical Depression
Fourteen was located near latitude 14.9 North, longitude 82.2 West.
The depression is moving toward the west-northwest near 14 mph (22
km/h), and this general motion is forecast to continue through 
Friday morning.  A turn toward the northwest with a decrease in 
forward speed is expected by Friday afternoon and continuing through 
at least Sunday.  On the forecast track, the center of the system 
will move near or just offshore the coasts of northern Nicaragua and 
northeastern Honduras, including the Bay Islands, on Friday and 
approach the east coast of the Yucatan Peninsula of Mexico on 
Saturday.  The center is then expected to cross the Yucatan 
Peninsula Saturday night and move into the south-central Gulf of 
Mexico on Sunday.

Maximum sustained winds are near 35 mph (55 km/h) with higher gusts.
Strengthening is forecast during the next couple of days, and the 
depression is expected to become a tropical storm on Friday. The 
system is forecast to be near or at hurricane strength when it 
reaches the Yucatan Peninsula of Mexico late Saturday.

The estimated minimum central pressure is 1007 mb (29.74 inches).


HAZARDS AFFECTING LAND
----------------------
WIND:  Tropical storm conditions are expected to first reach the
eastern Yucatan coast within the warning area by Saturday afternoon,
making outside preparations difficult or dangerous.  Hurricane
conditions are also possible within the watch area by late Saturday.

Tropical storm conditions are expected to first reach the coasts of
northeastern Honduras and northern Nicaragua within the warning
area later tonight and early Friday, making outside preparations
difficult or dangerous.  These conditions will spread westward along
the coast of Honduras within the warning area during the day on
Friday.

RAINFALL:  The depression is expected to produce the following
rainfall accumulations through Sunday:

Eastern portions of the Mexican states of Quintana Roo and Yucatan:
3 to 6 inches, isolated maximum totals of 10 inches. This rainfall
may result in areas of flash flooding.

Honduras: 2 to 4 inches.

Jamaica and northern Nicaragua: 1 to 2 inches.


NEXT ADVISORY
-------------
Next intermediate advisory at 200 AM EDT.
Next complete advisory at 500 AM EDT.

$$
Forecaster Stewart

[yoda]

[yoda]

Tropical Depression Fourteen Discussion Number   3
NWS National Hurricane Center Miami FL       AL142020
1100 PM EDT Thu Aug 20 2020

The overall convective pattern has improved somewhat since the 
previous advisory, with a band of deep convection having developed 
near and just south of the low-level center. A pronounced mid-level 
circulation has been rotating westward to the north of the center of
the broader low-level circulation, which has likely prevented the 
cyclone from becoming a tropical storm by now, especially given the 
very impressive outflow pattern. However, NOAA buoy 42057 to the 
north of the center recently reported a sustained wind of 29 kt at 
4 meters elevation, which equals about a 32-kt 10-meter wind speed, 
which means that the cyclone isn't far from becoming a tropical 
storm. The intensity is being maintained at 30 kt until convection 
becomes more persistent.

The center has been reforming a little farther north and has also 
slowed down, with the initial motion now being west-northwestward 
or 285/12 kt. The slower and farther north initial position has 
required a slight northward shift in the forecast track for the 
next 24 hours and, as a result, the center of the cyclone is no 
longer expected to make landfall very far inland over Honduras or 
Nicaragua, if it makes landfall at all. By 36 hours, the new NHC 
forecast track shifts back closer to the previous advisory track 
due to a strong mid-level ridge extending westward across Florida 
and into the eastern and central Gulf of Mexico. That feature is 
expected to keep the cyclone moving in a general northwestward 
direction on days 2-5, resulting in landfall over the northeastern 
Yucatan Peninsula on Saturday, and be approaching the northwestern 
Gulf coast by the middle of next week. The official forecast track 
lies along the southern edge of the guidance envelope, close to the 
middle of the simple consensus models and a little south of the 
NOAA-HCCA corrected model.

Due to the northward shift in the new forecast track, the center 
and inner-core wind field of the cyclone will not be disrupted as 
much as previously expected, which has significant implications in 
the intensity forecast. The depression is now expected to reach 
hurricane strength just before it makes landfall on the east side 
of the Yucatan Peninsula in about 48 hours. Weakening is forecast 
in 60 hours while the cyclone moves across northeastern Yucatan, 
followed by gradual re-strengthening thereafter. Ocean temperatures 
along the path of the cyclone are forecast to be 30.0-30.5 deg C 
and the vertical shear is expected to remain low at less than 10 kt 
through 96 hours. Those conditions coupled with the impressive 
outflow pattern should allow for at least typical strengthening. By 
120 hours, the GFS- and ECMWF-based SHIPS models show the vertical 
wind shear increasing sharply from the southwest to 20-25 kt, which 
would normally induce weakening. However, it appears that those 
models are incorporating some strong jetstream winds of 60-70 kt 
well to the northwest of the center of the cyclone, which has 
resulted in high bias in the shear output. Therefore, the cyclone 
is forecast to be near hurricane strength when it approaches the 
Texas coast in 120 hours. The new intensity forecast is similar to 
but a little higher then the previous advisory due to less land 
interaction than previously expected, and is is a blend of the 
Decay-SHIPS and LGEM models, which are at the upper-end of the 
guidance envelope.

Key Messages:

1. Tropical Depression Fourteen is expected to strengthen over the
northwestern Caribbean Sea through Saturday, and is likely to
produce tropical-storm-force winds and heavy rainfall over portions
of the coasts of Nicaragua and Honduras, including the Bay Islands,
beginning tonight through Friday.  The system is expected be near 
or at hurricane strength when it reaches the Yucatan Peninsula of 
Mexico late Saturday where a Hurricane Watch and a Tropical Storm 
Warning are in effect.

2. The system is expected to move into the south-central Gulf
of Mexico as a tropical storm on Sunday.  Some strengthening is
anticipated while it moves northwestward over the western Gulf of
Mexico early next week, but it is too soon to know exactly how
strong it will get or the location and magnitude of impacts it
will produce along the central or northwestern Gulf Coast.
Interests in that area should continue monitoring the progress of
this system over the next few days.


FORECAST POSITIONS AND MAX WINDS

INIT  21/0300Z 14.9N  82.2W   30 KT  35 MPH
 12H  21/1200Z 15.5N  83.8W   35 KT  40 MPH
 24H  22/0000Z 16.8N  85.1W   45 KT  50 MPH
 36H  22/1200Z 18.2N  86.0W   55 KT  65 MPH
 48H  23/0000Z 19.8N  87.2W   65 KT  75 MPH
 60H  23/1200Z 21.4N  88.5W   40 KT  45 MPH...INLAND
 72H  24/0000Z 23.2N  89.8W   50 KT  60 MPH...OVER WATER
 96H  25/0000Z 26.7N  92.3W   65 KT  75 MPH
120H  26/0000Z 29.1N  94.3W   65 KT  75 MPH

$$
Forecaster Stewart

[NJwx85]

8 hours ago, WxWatcher007 said:

Very interesting discussion. Both tracks have hurricanes poised to make landfall around the same time. Just incredible to see. 

If those tracks verified, you might see a Fujiwara or the outflow from the larger storm might completely shear the other.

[Windspeed]

If those tracks verified, you might see a Fujiwara or the outflow from the larger storm might completely shear the other.

Yeah this is going to get interesting. I can see TD14 getting named first and may even pull off some faster intensification prior to landfall or interaction with the Yucatan. However, it may get sheared heavily in the GOM depending on interaction between upper trough and southerly flow on the western periphery of the large anti-cyclone positioned over the Bahamas in a few days. The exciting thing about this setup is the great amount of uncertainty even among the best tropical meteorologists. Everyone is in wait and see mode. TD13 may still reform a vortex and go bonkers if positioned just north of the GA. Then again it may do nothing and leave TD14 to go at it alone in the GOM. Then there is the public aspect of trying to make a forecast that creates awareness and yet leaves the possibility that one or both systems may not pan out.

[lakeeffectkid383]

2 minutes ago, WxWatcher007 said:

 

Less land interaction seems like it could be a big deal to me..

I know it’s very early but with Laura looking to be fairly significantly further south than previously thought and TD 14 now looking further NE than previously thought, any ideas how this may impact them If they land up even closer together than we thought they could in the Gulf? 

[lakeeffectkid383]

3 minutes ago, WxWatcher007 said:

It is too early but that could cause one to shear another and a slower track as they interact? Not sure at this point.

That’s what I figured but definitely an interesting thing to think about. If it did slow the storms down especially TD 14 it may land up interacting less with the trough to the north as it moves deeper into the Gulf thus creating less shear for it but either way it’s unique situation for sure. 

[Windspeed]

TD14's low-level vortex is fully exposed right now but very clearly defined on visible. If convection can go up over it this afternoon than strengthening will be in order and this can get named. However, if land-induced convection becomes dominate, there is the possibility of CS collapses and outflow boundaries adversely affecting it. We'll have to see how this evolves, but it definitely still needs work before I would expect Marco in the short-term.

[Windspeed]

000
WTNT44 KNHC 211456
TCDAT4

Tropical Depression Fourteen Discussion Number   5
NWS National Hurricane Center Miami FL       AL142020
1100 AM EDT Fri Aug 21 2020

An Air Force Reserve Hurricane Hunter aircraft flew into the
depression a few hours ago, and the plane made two center fixes
that were about 35 n mi apart, indicating that there are likely
multiple low-level swirls rotating around a common center.  A
well-defined swirl coincident with the second center fix has become
apparent in visible satellite imagery, but for now a blend of the
aircraft fixes is being used for the initial position until we can
be sure the satellite feature is in fact the one and only center.
Flight-level and SFMR winds, outside of heavy rainfall, indicate
that the maximum winds remain 30 kt.  Deep convection is still
lacking in organization, with the heaviest activity well to the
north near the Cayman Islands and along the Honduras coast.

The depression is moving northwestward, or 305/12 kt, along the
southwestern periphery of an Atlantic subtropical ridge and toward
a deep-layer trough over the Gulf of Mexico.  This northwestward
motion is expected to persist for the entire 5-day forecast period,
with a decrease in forward speed anticipated while the cyclone
approaches the Yucatan coast.  The track guidance has slowed down a
bit during that time, especially the GFS, and the new NHC forecast
is therefore a little slower than the previous forecast.  After
that time, an increase in forward speed is expected, and the NHC
forecast lies to the west of the TVCN model consensus, closer to
the GFS, ECMWF, and HCCA scenarios.

The structure of the depression aside, the environment still
appears conducive for strengthening while the system approaches the
Yucatan Peninsula.  Vertical shear over the depression is currently
less than 10 kt and is expected to remain low for the next 36-48
hours, and sea surface temperatures will be around 30 degrees
Celsius.  Therefore, steady intensification is shown in the official
forecast through 36 hours, and the NHC prediction lies near the
upper end of the guidance envelope between the HCCA and HWRF
solutions just before the center reaches the Yucatan coast.  After
some weakening while over the Yucatan Peninsula, re-intensification
is likely to occur over the central Gulf of Mexico between days 2
and 3 while vertical shear remains relatively low, and the cyclone
could become a hurricane during that time, as shown by the HCCA,
HWRF, and HMON models.  After day 3, southwesterly vertical shear of
30 kt or more is expected to develop over the northwestern Gulf, and
the official forecast follows the trend of all the intensity
guidance, showing weakening by day 4 as the cyclone approaches the
southeastern Texas or southwestern Louisiana coastline.  This
forecast remains highly uncertain, however, and users are urged to
continue monitoring changes to this forecast over the next couple
of days.


Key Messages:

1.  Heavy rainfall and gusty winds over portions of the coasts of
Nicaragua and Honduras, including the Bay Islands, are expected to
diminish today.

2. Tropical Depression Fourteen is expected to strengthen over the
northwestern Caribbean Sea through Saturday, and it is expected to
be near or at hurricane strength when it reaches the east coast of
the Yucatan Peninsula of Mexico late Saturday.  A Hurricane Watch
and a Tropical Storm Warning are in effect for portions of that
region.

3. The system is expected to move into the south-central Gulf of
Mexico as a tropical storm on Sunday.  Some strengthening is
anticipated while it moves northwestward over the central Gulf of
Mexico early next week, but it is too soon to know exactly how
strong it will get or the location and magnitude of impacts it will
produce along the central or northwestern Gulf Coast. Interests in
that area should continue monitoring the progress of this system
over the next few days.


FORECAST POSITIONS AND MAX WINDS

INIT  21/1500Z 16.6N  84.1W   30 KT  35 MPH
 12H  22/0000Z 17.4N  85.0W   40 KT  45 MPH
 24H  22/1200Z 18.6N  85.9W   50 KT  60 MPH
 36H  23/0000Z 20.0N  86.9W   60 KT  70 MPH
 48H  23/1200Z 21.5N  88.2W   50 KT  60 MPH...INLAND
 60H  24/0000Z 23.2N  89.7W   55 KT  65 MPH...OVER WATER
 72H  24/1200Z 25.1N  91.4W   65 KT  75 MPH
 96H  25/1200Z 28.7N  94.1W   60 KT  70 MPH
120H  26/1200Z 31.3N  95.5W   40 KT  45 MPH...INLAND

$$
Forecaster Berg

 

[wizard021]

I don't buy anything beyond a 45 mph system here.

[Orangeburgwx]

I don't buy anything beyond a 45 mph system here.

Got anything to back that up?

Sent from my LML212VL using Tapatalk

[NorthHillsWx]

Hot towers going up over the center. First time this system has looked like a TD. Let’s see if it can continue the organizational trend. 

[MUWX]

Certainly looks like TD 14 is starting to get its act together. 

[vortex95]

Really bizarre looking now.  Yesterday it was a large cluster of convection.  Now an exposed LLCC and a large band of convection well-removed to the NE.  This is what you'd expect a TS or min hurricane to look like after it moved over the Yucatan, not before (hollowed out center)!  Also, peripheral convection seems to be driven more by the deep trough to the NW.
 

[lakeeffectkid383]

6 minutes ago, vortex95 said:

Really bizarre looking now.  Yesterday it was a large cluster of convection.  Now an exposed LLCC and a large band of convection well-removed to the NE.  This is what you'd expect a TS or min hurricane to look like after it moved over the Yucatan, not before (hollowed out center)!  Also, peripheral convection seems to be driven more by the deep trough to the NW.
 

What’s causing the mass void in convection all around the western side of the center of circulation? Is it down sloping off the land or is it from the SW shear from the trough to its north or both, or neither?

[Amped]

The center did look pretty tight on visible earlier today. 

  Some convection around the center now. 

Hurricane models are showing  a 25-30mb pressure drop before it hits the Yucatan.  

I take these models more seriously in the near term with storms  over warm water in low shear, with a small core.   

Ernesto, Micheal and Harvey all experienced these kind of deepening rates when they were  near the Yucatan.  

Watch closely the next few hours if the burst over the center continues to grow, it could be an impressive 6-18hr RI event.

 

 

 

[Jackstraw]

I think it's in the final stages of mixing out dry air that's been prevalent to it's N and NW the last couple of days..  I would venture to guess that we see some fairly significant sustained convection during DMAX overnight.  If it misses the peninsula altogether there's not a lot in it's way until it hits potential forecasted shear in a few days.  Not saying RI or anything but I do think it will be Marco by 5am at the latest.  It sure is in a historical area to blow up  

[jpeters3]

FWIW, forecasted shear among dynamical models is generally in the 20-30 kt range upon entry into the gulf. 

 

[Amped]

Just now, WxWatcher007 said:

1005.3 mb extrapolated on that center pass, so we do have both a gradual pressure drop and increasing winds. Not a lot of convection elsewhere, but it’s solid where it matters.

4mb drop from the last pass. 

[Floydbuster]

I'd go ahead and name it. Can't be any worse than Hurricane Barry 2019. 

[yoda]

Marco at 11

[yoda]

BULLETIN
Tropical Storm Marco Advisory Number   7
NWS National Hurricane Center Miami FL       AL142020
1100 PM EDT Fri Aug 21 2020

...TROPICAL STORM MARCO FORMS OVER THE NORTHWESTERN CARIBBEAN...
...FORECAST TO MOVE NEAR THE YUCATAN PENINSULA ON SATURDAY...


SUMMARY OF 1100 PM EDT...0300 UTC...INFORMATION
-----------------------------------------------
LOCATION...18.7N 84.9W
ABOUT 180 MI...290 KM SE OF COZUMEL MEXICO
MAXIMUM SUSTAINED WINDS...40 MPH...65 KM/H
PRESENT MOVEMENT...NNW OR 330 DEGREES AT 13 MPH...20 KM/H
MINIMUM CENTRAL PRESSURE...1003 MB...29.62 INCHES


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

None.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Hurricane Watch is in effect for...
* Punta Herrero to Cancun Mexico

A Tropical Storm Warning is in effect for...
* Punta Herrero to Dzilam Mexico

A Hurricane Watch means that hurricane conditions are possible
within the watch area, in this case within 24.

A Tropical Storm Warning means that tropical storm conditions are
expected somewhere within the warning area, in this case within 24
hours.

For storm information specific to your area, please monitor
products issued by your national meteorological service.


DISCUSSION AND OUTLOOK
----------------------
At 1100 PM EDT (0300 UTC), the center of Tropical Storm Marco was
located near latitude 18.7 North, longitude 84.9 West. Marco is
moving toward the north-northwest near 13 mph (20 km/h). A slightly
slower northwestward motion is expected for the next day or so,
followed by an increase in forward speed by early next week. On the
forecast track, the center of Marco will approach the east coast of
the Yucatan Peninsula of Mexico on Saturday. The center will then
cross the northeastern part of the Yucatan Peninsula Saturday night
and move over the central Gulf of Mexico toward the northwestern
Gulf on Sunday and Monday.

Maximum sustained winds have increased to near 40 mph (65 km/h)
with higher gusts. Additional strengthening is forecast during the
next couple of days as the system approaches the Yucatan peninsula
and Marco could be near hurricane strength when it moves over the
central Gulf of Mexico on Sunday.

Tropical-storm-force winds extend outward up to 90 miles (150 km)
from the center.

The estimated minimum central pressure is 1003 mb (29.62 inches) 
based on reports from the Hurricane Hunter plane.


HAZARDS AFFECTING LAND
----------------------
WIND:  Tropical storm conditions are expected to first reach the
eastern Yucatan coast within the warning area by Saturday afternoon
and will spread northward and westward within the warning area
Saturday night, making outside preparations difficult or dangerous.
Hurricane conditions are also possible within the hurricane watch
area by late Saturday.

RAINFALL:  Marco is expected to produce the following rainfall
accumulations through Sunday:

Eastern portions of the Mexican states of Quintana Roo and Yucatan:
3 to 6 inches, isolated maximum totals of 10 inches. This rainfall
may result in areas of flash flooding.

Northeast Nicaragua and the Cayman Islands: 1 to 2 inches.


NEXT ADVISORY
-------------
Next intermediate advisory at 200 AM EDT.
Next complete advisory at 500 AM EDT.

$$
Forecaster Zelinsky