2021 Atlantic/Pacific Hurricane Season

In the past few minutes recon measured 928.1 hPa.

115530 2830N 08932W 6964 02566 9281 +226 +039 129016 023 033 002 00

An intermediate NHC discussion has it at 130 knots and possible Cat 5 at landfall.

An intermediate NHC Discussion at 12Z has it at 130 knots but possible 135 (Cat 5) or higher at landfall. Hurricane Ida Special Discussion Number  13
NWS National Hurricane Center Miami FL       AL092021
700 AM CDT Sun Aug 29 2021

Recent reports from both NOAA and Air Force Reserve Hurricane Hunter
aircraft indicate that Ida has continued to strengthen since the
0900 UTC advisory and the maximum winds are estimated to be 130
kt. This intensity is based on peak 700-mb flight-level winds of
146 kt that have been reported by both aircraft and believable SFMR
winds of around 130 kt. The NOAA aircraft very recently reported 
that the minimum pressure has fallen to around 933 mb.  This special 
advisory is issued to raise the 12-hour forecast intensity to 135 
kt, but it is possible that Ida could peak slightly above that 
before landfall occurs.

The initial motion estimate is 320/13 kt, slightly faster than 
the previous forecast.  Therefore, the 12-hour forecast point has
also been adjusted slightly.  No other changes were made to the 
track or intensity forecasts.

The initial and forecast 64-kt wind radii were adjusted outward in
the northeast and southeast quadrants based on aircraft data.

Note that this Special advisory replaces the regular 1200 UTC (700
AM CDT) intermediate public advisory.

Key Messages:

1. Extremely life-threatening storm surge inundation of 9 feet or 
greater above ground level is imminent somewhere within the area 
from Burns Point, Louisiana, to Ocean Springs, Mississippi. 
Overtopping of local levees outside of the Hurricane and Storm 
Damage Risk Reduction System is possible where local inundation 
values may be higher. Interests throughout the Storm Surge Warning 
area should follow any advice given by local officials.

2. Catastrophic wind damage is likely where the core of Ida moves 
onshore along the southeast coast of Louisiana in the next few 
hours. Hurricane-force winds are expected today within the Hurricane 
Warning area along the Louisiana coast, including metropolitan New 
Orleans. 

3. Damaging winds, especially in gusts, will spread inland near the 
track of the center of Ida across portions of southeastern Louisiana 
and southwestern Mississippi today through early Monday. These winds 
will likely lead to widespread tree damage and power outages.

4. Ida will produce heavy rainfall today through Monday across the 
central Gulf Coast from southeastern Louisiana, coastal Mississippi, 
to far southwestern Alabama resulting in considerable to life- 
threatening flash and urban flooding and significant river flooding 
impacts. As Ida moves inland, significant flooding impacts are 
possible across portions of the Lower Mississippi, Tennessee, and 
Ohio Valleys through Wednesday.

FORECAST POSITIONS AND MAX WINDS

INIT  29/1200Z 28.5N  89.6W  130 KT 150 MPH
 12H  29/1800Z 29.2N  90.4W  135 KT 155 MPH
 24H  30/0600Z 30.6N  91.1W   70 KT  80 MPH...INLAND
 36H  30/1800Z 32.2N  91.0W   45 KT  50 MPH...INLAND
 48H  31/0600Z 33.8N  90.0W   30 KT  35 MPH...INLAND
 60H  31/1800Z 35.4N  87.9W   25 KT  30 MPH...INLAND
 72H  01/0600Z 36.7N  85.2W   20 KT  25 MPH...INLAND
 96H  02/0600Z 38.9N  78.9W   20 KT  25 MPH...POST-TROP/INLAND
120H  03/0600Z...DISSIPATED

On a par with 1856 and 2020.

13Z update:

130 kts (150 mph), 930 hPa.

No change at 14Z. It seems to have peaked as it has moved off that warm eddy.

SUMMARY OF 900 AM CDT...1400 UTC...INFORMATION
----------------------------------------------
LOCATION...28.7N 89.8W
ABOUT 40 MI...65 KM SSE OF GRAND ISLE LOUISIANA
ABOUT 90 MI...145 KM SSE OF NEW ORLEANS LOUISIANA
MAXIMUM SUSTAINED WINDS...150 MPH...240 KM/H
PRESENT MOVEMENT...NW OR 320 DEGREES AT 14 MPH...22 KM/H
MINIMUM CENTRAL PRESSURE...930 MB...27.46 INCHES

...900 AM CDT POSITION UPDATE... 
...NORTHERN EYEWALL OF IDA APPROACHING THE COAST OF SOUTHEASTERN 
LOUISIANA...

An elevated NOAA C-MAN station at Southwest Pass, Louisiana, 
recently reported a sustained wind of 102 mph (165 km/h) and a wind 
gust of 116 mph (187 km/h). Another elevated NOAA C-MAN station at 
Pilot's Station East near Southwest Pass recently reported a 
sustained wind of 97 mph (156 km/h) and a gust to 121 mph (194 
km/h). 

A NOAA National Ocean Service observing site at Pilottown, 
Louisiana, recently reported a sustained wind of 52 mph (84 km/h) 
and a gust of 77 mph (124 km/h). 

Southwest Pass, anemometer height 38 metres, 102 mph.

Pilot Station East, anemometer height 20 metres, 97 mph.

21Z, now down to 130 mph, 938 hPa.

Hurricane Ida Discussion Number  15
NWS National Hurricane Center Miami FL       AL092021
400 PM CDT Sun Aug 29 2021

NWS Doppler radar imagery and data from an Air Force Reserve
Reserve Hurricane Hunter aircraft showed that Ida made landfall
around 1655 UTC along the southeastern coast of Louisiana near
Port Fourchon with estimated maximum winds of 130 kt and a minimum
pressure around 930 mb.  Since that time, Ida made a second 
landfall southwest of Galliano, Louisiana, and with the eyewall now
onshore weakening has begun.  Based on the latest Doppler
velocities the initial wind speed has been conservatively reduced
to 115 kt for this advisory.  As Ida's circulation moves farther
inland this evening and overnight a faster rate of weakening is
expected, and Ida is forecast to become a tropical depression over
Mississippi by late Monday.  Although weakening is forecast, 
damaging winds, especially in gusts, are expected to spread inland 
over southeastern Louisiana and southwestern Mississippi through 
Monday morning.  To account for this, the gust factor in the 
Forecast/Advisory has been adjusted accordingly.  By 72 hours, Ida 
is predicted to merge with a frontal zone over the eastern United 
States and become an extratropical low, and this low is forecast to 
strengthen into a gale center near Atlantic Canada by the end of 
the forecast period.

Radar fixes indicate that Ida's forward motion has slowed and the
initial motion estimate is 325/9 kt.  The hurricane should turn
northward tonight around the western periphery of a deep-layer 
ridge near the southeastern United States coast.  Ida is forecast 
to turn northeastward and recurve over the eastern United States as 
it enters the mid-latitude westerlies.  The GFS is a bit faster in 
ejecting the post-tropical cyclone northeastward on days 3 through 
5, and the NHC forecast follows a blend of the various consensus 
models and the GFS ensemble mean.

Key Messages:

1. Extremely life-threatening storm surge inundation of 9 feet or
greater above ground level will continue through early this
evening along portions of the coast between Burns Point, Louisiana,
to Ocean Springs, Mississippi. Overtopping of local levees outside
of the Hurricane and Storm Damage Risk Reduction System is possible
where local inundation values may be higher.

2. Catastrophic wind damage will occur near the core of Ida as
it moves inland over southeastern Louisiana during the next few
hours.  Hurricane-force winds and damaging wind gusts are expected
through tonight within the Hurricane Warning area in southeastern
Louisiana, including metropolitan New Orleans.

3. Damaging winds, especially in gusts, will spread inland near the
track of the center of Ida into southwestern Mississippi tonight
and early Monday. These winds will likely lead to widespread tree
damage and power outages.

4. Ida will continue to produce heavy rainfall through Monday across 
the central Gulf Coast across southeast Louisiana, coastal 
Mississippi, and southwestern Alabama, resulting in considerable 
to life-threatening flash and urban flooding and significant 
river flooding impacts. As Ida moves inland, significant flooding 
impacts are possible across portions of the Lower Mississippi 
Valley, Tennessee Valley, Upper Ohio Valley, Central Appalachians, 
and Mid-Atlantic through Wednesday.

FORECAST POSITIONS AND MAX WINDS

INIT  29/2100Z 29.5N  90.6W  115 KT 130 MPH...INLAND
 12H  30/0600Z 30.7N  90.9W   65 KT  75 MPH...INLAND
 24H  30/1800Z 32.4N  90.7W   35 KT  40 MPH...INLAND
 36H  31/0600Z 34.0N  89.4W   25 KT  30 MPH...INLAND
 48H  31/1800Z 35.6N  87.2W   25 KT  30 MPH...INLAND
 60H  01/0600Z 37.1N  84.2W   20 KT  25 MPH...POST-TROP/INLAND
 72H  01/1800Z 38.6N  80.5W   20 KT  25 MPH...POST-TROP/EXTRATROP
 96H  02/1800Z 41.3N  72.5W   30 KT  35 MPH...POST-TROP/EXTRATROP
120H  03/1800Z 43.8N  67.0W   35 KT  40 MPH...POST-TROP/EXTRATROP

Hard she blows

It's on the cusp of becoming a hurricane. 60 knots at 21Z. An eye did show up later on satellite and now in the most recent 87 GHz scan at 2054Z.

The latest NHC forecast conservatively forecasts it reaching 105 knots (Cat 3) before encountering dry air and later some increased shear but warmer seas. Interesting one to watch develop.