ATL: HANNA - Remnants - Discussion

[aspen]

15z microwave pass has a degraded partial eyewall, likely from the CONUS dry air that has been mentioned in earlier posts. It’s been several hours with a few thunderstorms popping in the NE quadrant, so the next pass could look better.

[FLpanhandle91]

Plenty of time for a run at Hurricane imo. Outflow boundary to the north is much more robust and it seems that a larger moisture envelope will assist in blocking dry air.

[Aric Dunn]

Dry air has essentially been cut off now.. things going to get interesting.. about 24 more hours to go..

[NDG]

NHC now calling for Hanna to become a Hurricane.

[HurricaneAndre2008]

ZCZC MIATCPAT3 ALL
TTAA00 KNHC DDHHMM

BULLETIN
Tropical Storm Hanna Advisory Number 8
NWS National Hurricane Center Miami FL AL082020
400 PM CDT Fri Jul 24 2020

...HANNA GETTING BETTER ORGANIZED OVER THE WESTERN GULF OF MEXICO...
...HURRICANE AND STORM SURGE WARNINGS ISSUED FOR PORTIONS OF THE
CENTRAL TEXAS COAST...


SUMMARY OF 400 PM CDT...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...27.3N 94.3W
ABOUT 195 MI...310 KM E OF CORPUS CHRISTI TEXAS
ABOUT 195 MI...315 KM ENE OF PORT MANSFIELD TEXAS
MAXIMUM SUSTAINED WINDS...50 MPH...85 KM/H
PRESENT MOVEMENT...W OR 275 DEGREES AT 10 MPH...17 KM/H
MINIMUM CENTRAL PRESSURE...999 MB...29.50 INCHES


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

A Hurricane Warning has been issued from Baffin Bay northward to
Mesquite Bay, Texas.

A Storm Surge Warning has been issued from Baffin Bay to Sargent,
Texas, including Corpus Christi Bay, Copano Bay, Aransas Bay, San
Antonio Bay and Matagorda Bay.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Storm Surge Warning is in effect for...
* Baffin Bay to Sargent Texas

A Hurricane Warning is in effect for...
* Baffin Bay to Mesquite Bay Texas

A Tropical Storm Warning is in effect for...
* Mouth of the Rio Grande to Baffin Bay Texas
* Mesquite Bay to San Luis Pass Texas

A Storm Surge Warning means there is a danger of life-threatening
inundation, from rising water moving inland from the coastline,
during the next 24 hours in the indicated locations. For a
depiction of areas at risk, please see the National Weather
Service Storm Surge Watch/Warning Graphic, available at
hurricanes.gov. This is a life-threatening situation. Persons
located within these areas should take all necessary actions to
protect life and property from rising water and the potential for
other dangerous conditions. Promptly follow evacuation and other
instructions from local officials.

A Hurricane Warning means that hurricane conditions are expected
somewhere within the warning area, in this case within the next 24
hours. Preparations to protect life and property should be rushed
to completion.

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

Interests elsewhere along the Texas and Louisiana coasts should
monitor the progress of Hanna.

For storm information specific to your area, including possible
inland watches and warnings, please monitor products issued by your
local National Weather Service forecast office.


DISCUSSION AND OUTLOOK
----------------------
At 400 PM CDT (2100 UTC), the center of Tropical Storm Hanna was
located near latitude 27.3 North, longitude 94.3 West. Hanna is
moving toward the west near 10 mph (17 km/h), and this motion should
continue through Saturday morning. A gradual turn toward the
west-southwest is expected Saturday night and that motion should
continue through Sunday. On the forecast track, center of Hanna
should make landfall along the Texas coast within the
hurricane warning area Saturday afternoon or early evening.

Maximum sustained winds are near 50 mph (85 km/h) with higher gusts.
Steady strengthening is forecast for the next 24 hours, and
Hanna is expected to become a hurricane before the cyclone makes
landfall. Steady to rapid weakening is expected after Hanna moves
inland.

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

The estimated minimum central pressure is 999 mb (29.50 inches)
based on nearby oil rig reports.


HAZARDS AFFECTING LAND
----------------------
Key messages for Hanna can be found in the Tropical Cyclone
Discussion under AWIPS header MIATCDAT3 and WMO header WTNT43 KNHC.

STORM SURGE: The combination of a dangerous storm surge and the
tide will cause normally dry areas near the coast to be flooded by
rising waters moving inland from the shoreline. The water could
reach the following heights above ground somewhere in the indicated
areas if the peak surge occurs at the time of high tide...

Baffin Bay to Sargent TX...including Corpus Christi Bay, Copano
Bay,
Aransas Bay, San Antonio Bay, and Matagorda Bay...2 to 4 ft
Mouth of the Rio Grande to Baffin Bay TX...1 to 3 ft
North of Sargent to High Island TX...including Galveston Bay...1 to
2 ft

The deepest water will occur along the immediate coast near and to
the right of the landfall location. Surge-related flooding depends
on the relative timing of the surge and the tidal cycle, and can
vary greatly over short distances. For information specific to your
area, please see products issued by your local National Weather
Service forecast office.

WIND: Hurricane conditions are expected in the warning area
Saturday afternoon. Tropical storm conditions are expected to begin
in the warning area tonight or Saturday morning.

RAINFALL: Hanna is expected to produce 5 to 10 inches of rain with
isolated maximum totals of 15 inches through Sunday night in south
Texas and into the Mexican states of Coahuila, Nuevo Leon, and
northern Tamaulipas. This rain may result in life-threatening flash
flooding, rapid rises on small streams, and isolated minor to
moderate river flooding in south Texas.

3 to 5 inches of rain is expected along the upper Texas and
Louisiana coasts.

SURF: Swells generated by Hanna are expected to increase and affect
much of the Texas and Louisiana coasts during the next few days.
These swells are likely to cause life-threatening surf and rip
current conditions. Please consult products from your local weather
office.

TORNADOES: A brief tornado or two will be possible, mainly
overnight, across portions of the upper Texas and Louisiana Coasts.


NEXT ADVISORY
-------------
Next intermediate advisory at 700 PM CDT.
Next complete advisory at 1000 PM CDT.

$$
Forecaster Stewart

NNNN

[galaxy401]

Hurricane Warnings issued.

[aspen]

Hanna’s “eye” that it’s had all day is being covered up by new hot towers. It looks like the actual center is a little further south, and with these new hot towers firing, it’s likely an actual eyewall is in development.

Hanna’s excellent outflow, development of an inner core, and placement in a high SST/low shear environment makes me believe this could be a storm that rapidly intensifies into a hurricane up until landfall, just like what the NHC is showing. I’m thinking it could be a low-end Cat 2 at most.

[1900hurricane]

It has the cyan ring.

[lrak]

Hurricane Warnings issued.

Ugh...

[Aric Dunn]

Hanna’s “eye” that it’s had all day is being covered up by new hot towers. It looks like the actual center is a little further south, and with these new hot towers firing, it’s likely an actual eyewall is in development.

Hanna’s excellent outflow, development of an inner core, and placement in a high SST/low shear environment makes me believe this could be a storm that rapidly intensifies into a hurricane up until landfall, just like what the NHC is showing. I’m thinking it could be a low-end Cat 2 at most.

As that convection built to the south side the center clearly has been pulled wsw to sw. doing a small cyclonic loop.. which is not typically a good sign.. RI typically happens after these types of drips.

[cycloneye]

Now forecast to become a hurricane.

24H 25/1800Z 27.3N 97.2W 65 KT 75 MPH

[drezee]

 https://twitter.com/andretrotter/status/1286768819554459653

[floridasun78]

hanna bet goz to be likely first hurr of season that surprise to some

[MississippiWx]

As great as models are in modern days, it’s amazing how poorly they handled the development of this very large and well-organized system. It’s baffling.

Hanna is a beautiful storm on satellite. It’s setting itself up for quick strengthening on approach to the coast. Frictional forces will only help. Brace for a high impact system, Texas.

[Hurricane Mike]

Video update on strengthening Hanna
https://www.youtube.com/watch?v=-tnsugh ... e=youtu.be

[Aric Dunn]

Cyclonic loops of the llc during this phase of a TC typically dont end well for any coastal areas in the way...

[Stormcenter]

Exactly, I just don’t think they’ll ever be able
to predict how strong these things will develop in advance
with even 50% accuracy. Obviously the computers are just not that good at doing that. IMO

As great as models are in modern days, it’s amazing how poorly they handled the development of this very large and well-organized system. It’s baffling.

Hanna is a beautiful storm on satellite. It’s setting itself up for quick strengthening on approach to the coast. Frictional forces will only help. Brace for a high impact system, Texas.

[Snowman67]

Fairly breezy outside right now. Is that a direct/indirect effect of Hanna?

[wx98]

Recon just left Tampa Bay heading toward Hanna. We should have a pass by 6:30 pm CDT

[aspen]

Another recon plane is heading out to Hanna. Let’s see if it finds a slightly stronger storm. Based on the latest organizational trends, I’m thinking it could be 50 kt and 994-998 mbar.