Hurricane Hilary

[olafminesaw]

Just now, WxWatcher007 said:

Still on approach to the eye. Nothing surprising showing up yet. Spotty data coming in. 

Seems the inner core is still quite small

[WxWatcher007]

1 minute ago, olafminesaw said:

Seems the inner core is still quite small

Yeah, SFMR of 64kt only came in last few obs

[WxWatcher007]

Not all the way through but 957.0mb extrapolated pressure with peak FL wind of 110kt and SFMR of 93kt.

[WxWatcher007]

947.4mb extrapolated in the center. They’re circling in the eye so unclear which quadrant they exit toward.

[WxWatcher007]

Went from the eye into the NW quad, where they have found max FL of 96kt and SFMR of 85kt.

[WxWatcher007]

Looking at IR, the best stuff may be in the southern half of the hurricane. We’ll see.

[WxWatcher007]

First VDM 

Product: Air Force Vortex Message (URPN12 KNHC)
Corrected: This observation corrected a previous observation.
Transmitted: 18th day of the month at 18:37Z
Agency: United States Air Force 
Aircraft: Lockheed WC-130J Hercules with reg. number AF96-5300 
Storm Name: Hilary
Storm Number & Year: 09 in 2023 (flight in the Northeast Pacific basin)
Mission Number: 1
Observation Number: 08 ( See all messages of this type for this mission. )

A. Time of Center Fix: 18th day of the month at 18:02:30Z
B. Center Fix Coordinates: 18.16N 111.94W
B. Center Fix Location: 352 statute miles (567 km) to the SSW (202°) from Cabo San Lucas, Baja California Sur, Mexico.
C. Minimum Height at Standard Level: 2,664m (8,740ft) at 700mb
D. Minimum Sea Level Pressure: 948mb (28.00 inHg)
E. Dropsonde Surface Wind at Center: From 200° at 11kts (From the SSW at 13mph)
F. Eye Character: Closed
G. Eye Shape & Diameter: Circular with a diameter of 32 nautical miles (37 statute miles)
H. Estimated (by SFMR or visually) Maximum Surface Wind Inbound: 93kts (107.0mph)
I. Location & Time of the Estimated Maximum Surface Wind Inbound: 18 nautical miles (21 statute miles) to the ENE (61°) of center fix at 17:57:00Z
J. Maximum Flight Level Wind Inbound: From 143° at 113kts (From the SE at 130.0mph)
K. Location & Time of the Maximum Flight Level Wind Inbound: 19 nautical miles (22 statute miles) to the ENE (60°) of center fix at 17:56:30Z
L. Estimated (by SFMR or visually) Maximum Surface Wind Outbound: 85kts (97.8mph)
M. Location & Time of the Estimated Maximum Surface Wind Outbound: 18 nautical miles (21 statute miles) to the NW (310°) of center fix at 18:16:00Z
N. Maximum Flight Level Wind Outbound: From 57° at 96kts (From the ENE at 110.5mph)
O. Location & Time of the Maximum Flight Level Wind Outbound: 21 nautical miles (24 statute miles) to the NW (311°) of center fix at 18:17:00Z
P. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 8°C (46°F) at a pressure alt. of 3,051m (10,010ft)
Q. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 18°C (64°F) at a pressure alt. of 3,048m (10,000ft)
R. Dewpoint Temp (collected at same location as temp inside eye): 8°C (46°F)
R. Sea Surface Temp (collected at same location as temp inside eye): Not Available
S. Fix Determined By: Penetration, Radar, Wind, Pressure and Temperature
S. Fix Level: 700mb
T. Navigational Fix Accuracy: 0.02 nautical miles
T. Meteorological Accuracy: 0.02 nautical miles

Remarks Section:
 

Maximum Flight Level Wind: 113kts (~ 130.0mph) which was observed 19 nautical miles (22 statute miles) to the ENE (60°) from the flight level center at 17:56:30Z

[Kevin Reilly]

1 minute ago, WxWatcher007 said:

First VDM 

Product: Air Force Vortex Message (URPN12 KNHC)
Corrected: This observation corrected a previous observation.
Transmitted: 18th day of the month at 18:37Z
Agency: United States Air Force 
Aircraft: Lockheed WC-130J Hercules with reg. number AF96-5300 
Storm Name: Hilary
Storm Number & Year: 09 in 2023 (flight in the Northeast Pacific basin)
Mission Number: 1
Observation Number: 08 ( See all messages of this type for this mission. )

A. Time of Center Fix: 18th day of the month at 18:02:30Z
B. Center Fix Coordinates: 18.16N 111.94W
B. Center Fix Location: 352 statute miles (567 km) to the SSW (202°) from Cabo San Lucas, Baja California Sur, Mexico.
C. Minimum Height at Standard Level: 2,664m (8,740ft) at 700mb
D. Minimum Sea Level Pressure: 948mb (28.00 inHg)
E. Dropsonde Surface Wind at Center: From 200° at 11kts (From the SSW at 13mph)
F. Eye Character: Closed
G. Eye Shape & Diameter: Circular with a diameter of 32 nautical miles (37 statute miles)
H. Estimated (by SFMR or visually) Maximum Surface Wind Inbound: 93kts (107.0mph)
I. Location & Time of the Estimated Maximum Surface Wind Inbound: 18 nautical miles (21 statute miles) to the ENE (61°) of center fix at 17:57:00Z
J. Maximum Flight Level Wind Inbound: From 143° at 113kts (From the SE at 130.0mph)
K. Location & Time of the Maximum Flight Level Wind Inbound: 19 nautical miles (22 statute miles) to the ENE (60°) of center fix at 17:56:30Z
L. Estimated (by SFMR or visually) Maximum Surface Wind Outbound: 85kts (97.8mph)
M. Location & Time of the Estimated Maximum Surface Wind Outbound: 18 nautical miles (21 statute miles) to the NW (310°) of center fix at 18:16:00Z
N. Maximum Flight Level Wind Outbound: From 57° at 96kts (From the ENE at 110.5mph)
O. Location & Time of the Maximum Flight Level Wind Outbound: 21 nautical miles (24 statute miles) to the NW (311°) of center fix at 18:17:00Z
P. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 8°C (46°F) at a pressure alt. of 3,051m (10,010ft)
Q. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 18°C (64°F) at a pressure alt. of 3,048m (10,000ft)
R. Dewpoint Temp (collected at same location as temp inside eye): 8°C (46°F)
R. Sea Surface Temp (collected at same location as temp inside eye): Not Available
S. Fix Determined By: Penetration, Radar, Wind, Pressure and Temperature
S. Fix Level: 700mb
T. Navigational Fix Accuracy: 0.02 nautical miles
T. Meteorological Accuracy: 0.02 nautical miles

Remarks Section:
 

Maximum Flight Level Wind: 113kts (~ 130.0mph) which was observed 19 nautical miles (22 statute miles) to the ENE (60°) from the flight level center at 17:56:30Z

So, looks like Hilary has already peaked at 939 mb but that was an estimate from satellite imagery.  Now with that said Hilary will not intensify any further moving NW into dry air, cooler waters, and eventual shear. It will just maintain then slowly start weakening over the next 24-36 hours. 

[Normandy]

The recon passes thus far show a very broad wind field and loose gradient around the center, which makes sense considering the storm is in the process of undergoing an ERC.  Further strengthening would be tough since it’s already pretty deep of a system and broad, however the storm is very well ventilated aloft and is drawing moisture from the south and Baja of California.  Therefore I wouldn’t rule it out.  

bottom line is the broad windfield will make it such that TS winds and heavy rains will arrive well before the center will.  There won’t be time for this to spin down because of cold waters as impacts will be felt while the center is still 300 (or more) miles south. 

[WxWatcher007]

Not a lot of time in the storm. Already done. No sampling of the southern half. 

[Nibor]

IR presentation significantly improving. 

[TheDreamTraveler]

Another thing I don't see people mentioning is that even with Hilary weakening on its approach to California it's going to have a MASSIVE wind field just due to how big of a storm it is and how strong it originally was. That wind field will stretch well out from the center. This won't be no small tropical storm at approach. This isn't a tropical storm that was weak all its life coming in but a almost category 5 with an impressive core and size weakening and coming in

[yoda]

BULLETIN
Hurricane Hilary Advisory Number  10
NWS National Hurricane Center Miami FL       EP092023
300 PM MDT Fri Aug 18 2023

...HILARY REMAINS A POWERFUL CATEGORY 4 HURRICANE...
...LIFE-THREATENING AND POTENTIALLY CATASTROPHIC FLOODING LIKELY 
OVER MUCH OF BAJA CALIFORNIA AND SOUTHERN CALIFORNIA THIS WEEKEND 
AND EARLY NEXT WEEK...


SUMMARY OF 300 PM MDT...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...18.7N 112.2W
ABOUT 80 MI...125 KM W OF SOCORRO ISLAND
ABOUT 325 MI...525 KM SSW OF CABO SAN LUCAS MEXICO
MAXIMUM SUSTAINED WINDS...130 MPH...215 KM/H
PRESENT MOVEMENT...NW OR 315 DEGREES AT 12 MPH...19 KM/H
MINIMUM CENTRAL PRESSURE...948 MB...28.00 INCHES


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

The government of Mexico has upgraded the Hurricane Watch to a
Hurricane Warning on the west coast of Baja California northward
to Cabo San Quintin and upgraded the Tropical Storm Watch to a 
Tropical Storm Warning north of Loreto on the east coast of Baja 
California and north of Guaymas in mainland Mexico.

A Tropical Storm Watch has been extended westward from the 
Orange/Los Angeles County Line to Point Mugu.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Hurricane Warning is in effect for...
* Baja California peninsula from Punta Abreojos to Cabo San Quintin

A Hurricane Watch is in effect for...
* Baja California peninsula north of Cabo San Quintin to Ensenada

A Tropical Storm Warning is in effect for...
* Baja California peninsula from Punta Abreojos southward
* Baja California peninsula entire east coast
* Mainland Mexico north of Guaymas

A Tropical Storm Watch is in effect for...
* Mainland Mexico from Huatabampito to Guaymas
* Baja California north of Ensenada to the California/Mexico border
* California/Mexico border to Point Mugu
* Catalina Island

 

[yoda]

 

[yoda]

WTPZ44 KNHC 182046
TCDEP4

Hurricane Hilary Discussion Number  10
NWS National Hurricane Center Miami FL       EP092023
300 PM MDT Fri Aug 18 2023

Hilary remains a large and powerful major hurricane.  The Air Force 
Hurricane Hunters sampled the northern portion of Hilary and found a 
higher minimum pressure than expected of 948 mb, 700 mb flight-level 
winds of 113 kt, and peak SFMR surface winds of 93 kt. However, the 
aircraft did not sample the southern half of the circulation, which 
currently has some of the deepest convection. Blending the available 
aircraft data and latest satellite intensity estimates yields an 
initial intensity of 115 kt.

Hilary continues to slowly bend to the right, and the initial motion 
is northwestward or 315/10 kt.  A general north-northwest to north 
motion with a steady increase in forward speed is expected tonight 
and through the weekend as the system is steered by pronounced 
steering flow between a strong subtropical ridge over the 
south-central U.S. and a mid- to upper-level low off the central 
California coast.  The models have trended faster this cycle, and 
the NHC forecast has followed suit.  Based on the latest forecast, 
the core of Hilary is expected to be very near the central portion 
of Baja California Saturday night and move inland over southern 
California by Sunday night. It should be noted that strong winds and 
heavy rains will occur well ahead of the center.

Fluctuations in the hurricane's strength are expected through 
tonight, but Hilary is expected to begin weakening on Saturday as it 
moves over progressively cooler SSTs and into an environment of 
increasing shear and drier air.  The NHC intensity forecast is lower 
than the previous one, partially due to the lower initial intensity, 
and a little higher than the HCCA and IVCN models.


KEY MESSAGES:

1. Heavy rainfall associated with Hilary will begin well in advance 
of the center, from the Baja California Peninsula into the 
Southwestern United States. Preparations for the impacts of flooding 
from rainfall should be completed as soon as possible, as heavy rain 
will increase ahead of the center on Saturday. In the Southwestern 
United States, flash, urban, and arroyo flooding is expected, with 
the potential for dangerous and locally catastrophic impacts.

2. Hurricane conditions are expected within portions of the
hurricane warning area along the west-central coast of the Baja
California Peninsula Saturday night and are possible in the
Hurricane Watch area.

3. Tropical storm conditions are possible by late Sunday in 
portions of southern California where a Tropical Storm Watch is in 
effect.

4. Large swells generated by Hilary will affect portions of the 
coast of southwestern Mexico, the Baja California peninsula, and
south California over the next few days. These swells are likely
to cause life-threatening surf and rip current conditions.


FORECAST POSITIONS AND MAX WINDS

INIT  18/2100Z 18.7N 112.2W  115 KT 130 MPH
 12H  19/0600Z 20.3N 113.2W  115 KT 130 MPH
 24H  19/1800Z 22.6N 114.1W  105 KT 120 MPH
 36H  20/0600Z 25.6N 115.0W   85 KT 100 MPH
 48H  20/1800Z 29.4N 116.1W   65 KT  75 MPH
 60H  21/0600Z 34.1N 117.3W   45 KT  50 MPH...INLAND
 72H  21/1800Z 39.3N 117.7W   30 KT  35 MPH...POST-TROP/INLAND
 96H  22/1800Z...DISSIPATED

$$
Forecaster Cangialosi

[olafminesaw]

Isla Socorro, which is about 80 miles East of where the center passed, recorded sustained winds of 45 mph and gusts of 70 mph

[yoda]

Time sensitive 

 

 

[schoeppeya]

Looks like there another aircraft en route, should be great timing to capture whatever peak this thing is going for after the ERWC. Looks great on sat. 

[olafminesaw]

53 minutes ago, schoeppeya said:

Looks like there another aircraft en route, should be great timing to capture whatever peak this thing is going for after the ERWC. Looks great on sat. 

May just miss peak. It's about to move over much cooler waters.

[Amped]

The eye just cleared out again.   My guess is recon finds pressure in the 935mb-940mb range. Should be able to hold on with cooler waters for another 12-18hrs given the extent of the moisture.

[hlcater]

Not in the cooler waters yet. Probably by tomorrow AM though.

 

[olafminesaw]

Already flash flooding in southern Nevada

[WxWatcher007]

One of the best threads yet on why a historic rainfall event is likely.

 

[NorthHillsWx]

Once again, historic rainfall over the “perma” drought. Get away from the runoff areas and waterways and let this storm fix 15 years of drought in a few days. This is the absolute best thing that could have happened for the southwest, I’m tired of everyone putting a negative spin on something that (when the rain ends) will be the best thing that’s happened in a decade to help the local environment 

[WxWatcher007]

13 minutes ago, NorthHillsWx said:

Once again, historic rainfall over the “perma” drought. Get away from the runoff areas and waterways and let this storm fix 15 years of drought in a few days. This is the absolute best thing that could have happened for the southwest, I’m tired of everyone putting a negative spin on something that (when the rain ends) will be the best thing that’s happened in a decade to help the local environment 

I didn’t think the thread had any particular slant, but wanted to share the meteorology to those following. I’m actually a little more skeptical today that this’ll be beneficial to anything other than major basins, but I really have no knowledge of what’s needed out there and how it should fall. 

[Toro99]

26 minutes ago, NorthHillsWx said:

Once again, historic rainfall over the “perma” drought. Get away from the runoff areas and waterways and let this storm fix 15 years of drought in a few days. This is the absolute best thing that could have happened for the southwest, I’m tired of everyone putting a negative spin on something that (when the rain ends) will be the best thing that’s happened in a decade to help the local environment 

Lake Mead ftw

[Nibor]

[NorthHillsWx]

2 minutes ago, Nibor said:

Beastmode

[WxWatcher007]

Hurricane Hilary Discussion Number  11
NWS National Hurricane Center Miami FL       EP092023
900 PM MDT Fri Aug 18 2023

Hilary's cloud pattern has not changed much since earlier today.  
The hurricane continues to exhibit a large 30-35 n mi wide eye with 
a surrounding ring of deep convection with clouds tops around -75
degrees Celsius. The latest subjective Dvorak intensity estimates
from TAFB and SAB support an initial intensity of 115 kt. The next
Air Force Reserve reconnaissance mission is currently en route, and
it should provide a better assessment of Hilary's intensity and
structure overnight.

Hilary has turned north-northwestward with an initial motion
estimate of 335/12 kt. The track forecast reasoning is unchanged
from before.  Hilary is forecast to turn northward and begin to
accelerate on Saturday as it is steered by deep-layer southerly flow
between a strong subtropical ridge over the south-central United
States and an upper-level low off the coast of central California.
The models have again trended slightly faster, and the NHC foreast
has been adjusted accordingly.  The NHC track forecast brings the
center near the west-central coast of the Baja California Peninsula
in about 36 hours, and along the northwestern coast of the peninsula
in 48 hours.  This is near the middle of the tightly clustered
guidance envelope.  Users are reminded to not focus on the exact
details of the track forecast as strong winds and heavy rainfall 
will extend far from the center.  These hazards will begin well in
advance of the arrival of the center.

Hilary has likely peaked in intensity, and weakening is expected to
begin on Saturday as it moves over cooler SSTs.  A faster rate of
weakening is likely to begin by 24 hours as Hilary moves over
SSTs less than 26C and the vertical wind shear begins to increase.
However, Hilary is forecast to be a large hurricane when it passes
near the west-central coast of the Baja Peninsula, and a
tropical storm when it nears the U.S./Mexico border.  The NHC
intensity forecast is similar to the previous advisory, and lies
close to the IVCN consensus model.

KEY MESSAGES:

1. Heavy rainfall associated with Hilary will begin well in advance
of the center, from the Baja California Peninsula into the
Southwestern United States. Preparations for the impacts of flooding
from rainfall should be completed as soon as possible, as heavy rain
will increase ahead of the center on Saturday. In the Southwestern
United States, flash, urban, and arroyo flooding is expected, with
dangerous and locally catastrophic impacts likely.

2. Hurricane conditions are expected within portions of the
hurricane warning area along the west-central coast of the Baja
California Peninsula Saturday night and are possible in the
Hurricane Watch area.

3. Tropical storm conditions are expected to begin on Sunday in 
portions of southern California where a Tropical Storm Warning is in 
effect.

4. Large swells generated by Hilary will affect portions of the
coast of southwestern Mexico, the Baja California peninsula, and
southern California over the next few days. These swells are likely
to cause life-threatening surf and rip current conditions.


FORECAST POSITIONS AND MAX WINDS

INIT  19/0300Z 19.7N 112.7W  115 KT 130 MPH
 12H  19/1200Z 21.4N 113.6W  110 KT 125 MPH
 24H  20/0000Z 24.2N 114.4W   95 KT 110 MPH
 36H  20/1200Z 27.6N 115.4W   80 KT  90 MPH
 48H  21/0000Z 32.1N 116.8W   55 KT  65 MPH...INLAND
 60H  21/1200Z 37.8N 117.8W   30 KT  35 MPH...POST-TROP/INLAND
 72H  22/0000Z...DISSIPATED

$$
Forecaster Brown

[hlcater]

4 minutes ago, WxWatcher007 said:

Hurricane Hilary Discussion Number  11
NWS National Hurricane Center Miami FL       EP092023
900 PM MDT Fri Aug 18 2023

Hilary's cloud pattern has not changed much since earlier today.  
The hurricane continues to exhibit a large 30-35 n mi wide eye with 
a surrounding ring of deep convection with clouds tops around -75
degrees Celsius. The latest subjective Dvorak intensity estimates
from TAFB and SAB support an initial intensity of 115 kt. The next
Air Force Reserve reconnaissance mission is currently en route, and
it should provide a better assessment of Hilary's intensity and
structure overnight.

Hilary has turned north-northwestward with an initial motion
estimate of 335/12 kt. The track forecast reasoning is unchanged
from before.  Hilary is forecast to turn northward and begin to
accelerate on Saturday as it is steered by deep-layer southerly flow
between a strong subtropical ridge over the south-central United
States and an upper-level low off the coast of central California.
The models have again trended slightly faster, and the NHC foreast
has been adjusted accordingly.  The NHC track forecast brings the
center near the west-central coast of the Baja California Peninsula
in about 36 hours, and along the northwestern coast of the peninsula
in 48 hours.  This is near the middle of the tightly clustered
guidance envelope.  Users are reminded to not focus on the exact
details of the track forecast as strong winds and heavy rainfall 
will extend far from the center.  These hazards will begin well in
advance of the arrival of the center.

Hilary has likely peaked in intensity, and weakening is expected to
begin on Saturday as it moves over cooler SSTs.  A faster rate of
weakening is likely to begin by 24 hours as Hilary moves over
SSTs less than 26C and the vertical wind shear begins to increase.
However, Hilary is forecast to be a large hurricane when it passes
near the west-central coast of the Baja Peninsula, and a
tropical storm when it nears the U.S./Mexico border.  The NHC
intensity forecast is similar to the previous advisory, and lies
close to the IVCN consensus model.

KEY MESSAGES:

1. Heavy rainfall associated with Hilary will begin well in advance
of the center, from the Baja California Peninsula into the
Southwestern United States. Preparations for the impacts of flooding
from rainfall should be completed as soon as possible, as heavy rain
will increase ahead of the center on Saturday. In the Southwestern
United States, flash, urban, and arroyo flooding is expected, with
dangerous and locally catastrophic impacts likely.

2. Hurricane conditions are expected within portions of the
hurricane warning area along the west-central coast of the Baja
California Peninsula Saturday night and are possible in the
Hurricane Watch area.

3. Tropical storm conditions are expected to begin on Sunday in 
portions of southern California where a Tropical Storm Warning is in 
effect.

4. Large swells generated by Hilary will affect portions of the
coast of southwestern Mexico, the Baja California peninsula, and
southern California over the next few days. These swells are likely
to cause life-threatening surf and rip current conditions.


FORECAST POSITIONS AND MAX WINDS

INIT  19/0300Z 19.7N 112.7W  115 KT 130 MPH
 12H  19/1200Z 21.4N 113.6W  110 KT 125 MPH
 24H  20/0000Z 24.2N 114.4W   95 KT 110 MPH
 36H  20/1200Z 27.6N 115.4W   80 KT  90 MPH
 48H  21/0000Z 32.1N 116.8W   55 KT  65 MPH...INLAND
 60H  21/1200Z 37.8N 117.8W   30 KT  35 MPH...POST-TROP/INLAND
 72H  22/0000Z...DISSIPATED

$$
Forecaster Brown

With the way things are going on satellite, I am not convinced that we have peaked in intensity. Think we make another run at 125-130kts tonight. Recon will tell.