EPAC: HILARY - Post-Tropical - Discussion

[NDG]

Surprisingly at 2 PM ET they kept Hilary with winds of 115mph, I guess they want more evidence that it has weakened that much. Next pass should find pressure up into the 960s mb.

[Bocadude85]

Not only has she significantly weakened, she is also running west of the forecast track.

[mempho]

Not only has she significantly weakened, she is also running west of the forecast track.

This actually sounds a lot more forboding that the storm weakening. Not only does that put more of San Diego, Los Angeles and Orange Counties in the heavier preciptation bands, it's also likely to put the Coachella Valley and Death Valley into bands of consistently high precipitation.

[NDG]

Not only has she significantly weakened, she is also running west of the forecast track.

This actually sounds a lot more forboding that the storm weakening.

I agree, when it gets decoupled the LLC gets left behind so it gets steered by the winds closer to the surface instead of mid to upper levels.
I wouldn't be surprised if the LLC weakens out before making landfall over Baja or So Cal that it stays offshore to die.

[NDG]

Recon finds no hurricane force winds on the SE quadrant by SFMR.

[iorange55]

Not only has she significantly weakened, she is also running west of the forecast track.

This actually sounds a lot more forboding that the storm weakening.

I agree, when it gets decoupled the LLC gets left behind so it gets steered by the winds closer to the surface instead of mid to upper levels.
I wouldn't be surprised if the LLC weakens out before making landfall over Baja or So Cal that it stays offshore to die.

Are there any models showing this?

[Bocadude85]

Not only has she significantly weakened, she is also running west of the forecast track.

This actually sounds a lot more forboding that the storm weakening. Not only does that put more of San Diego, Los Angeles and Orange Counties in the heavier preciptation bands, it's also likely to put the Coachella Valley and Death Valley into bands of consistently high precipitation.

She wasn’t supposed to cross 114W until 24.6N, 12pm update had her at 22.8N and 113.9W. Will be interesting to see how much farther west she gets of 114 while still south of 24.6.

[NDG]

Unreal that they haven't downgrade it yet. People still think that there's a Major hurricane heading their way.

[Nimbus]

50 MPH winds take down power lines especially in areas where the power companies don't aggressively trim near the lines. If this comes in fast and stays offshore the power outages are going to be a problem as well as the flooding.

[Sciencerocks]

[bob rulz]

This area is much less accustomed to strong winds than almost anywhere in the eastern U.S., especially areas vulnerable to hurricanes. Widespread tropical storm-force winds are likely to do a lot of damage to that area, and as noted before, they are even less used to such high rainfall totals.

[Bocadude85]

I am currently in the Los Angeles area and people are certainly taking this seriously, the grocery stores are packed. Reminds me of being in South Florida when a hurricane was approaching.

[ConvergenceZone]

Not only has she significantly weakened, she is also running west of the forecast track.

This actually sounds a lot more forboding that the storm weakening.

I agree, when it gets decoupled the LLC gets left behind so it gets steered by the winds closer to the surface instead of mid to upper levels.
I wouldn't be surprised if the LLC weakens out before making landfall over Baja or So Cal that it stays offshore to die.

If that were to happen that would be an incredibly BIG BUST by the NHC. I think this will be a huge rainmaker for southern California. Potentially historic in nature in SOME areas.

[Evil Jeremy]

I am currently in the Los Angeles area and people are certainly taking this seriously, the grocery stores are packed. Reminds me of being in South Florida when a hurricane was approaching.

Yeah just swing by a Trader Joe’s, never seen it even remotely close to this busy. Staff was well prepped though. Water was pretty much sold out.

[cycloneye]

Hurricane Hilary Discussion Number 14
NWS National Hurricane Center Miami FL EP092023
300 PM MDT Sat Aug 19 2023

Hilary appears to be weakening quickly. The eye is filling
and the cloud tops in the eyewall and rainbands have been warming
during the past several hours. In addition, the hurricane has
become increasingly asymmetric with dry air continuing to wrap into
the western half of the circulation. The Air Force Hurricane
Hunters have been investigating Hilary during the past few hours and
found that the minimum pressure has risen to 959 mb. Blending the
aircraft flight-level wind and SFMR data, as well as some of the
satellite estimates yields an initial intensity of 95 kt, but that
could be a little generous. Areas of heavy rain are already
spreading across portions of the Baja California Peninsula and the
Southwestern U.S. Hilary is also producing a large area of high
seas along the coast of Baja California and the Gulf of California,
with maximum significant wave heights estimated to be higher
than 40 ft.

The hurricane is still moving north-northwestward, or 345/15 kt. The
steering currents are well established and consist of a strong
mid-level high pressure area over the south-central U.S. and a mid-
to upper-level low off the central California coast. The flow
between these features should cause Hilary to accelerate to the
north-northwest or north during the next day or two, with the core
of the system reaching the central portion of the Baja California
Peninsula tonight and southern California Sunday afternoon or
evening. The NHC track forecast is largely the same as the previous
one and near the middle of the guidance envelope. Users are reminded
that the exact details of the track forecast, including where Hilary
might make landfall, are of little overall importance since strong
winds and heavy rainfall will extend far from the center. These
hazards will also begin well in advance of the arrival of the
center.

Hilary is expected to continue weakening rather quickly while it
moves northward due to significantly cooler waters, drier air, and
an increase in vertical wind shear. However, Hilary is still
expected to be a hurricane when it makes landfall or moves very near
the central portion of the Baja California Peninsula. There is high
confidence that Hilary will move into southern California as a
tropical storm.


KEY MESSAGES:

1. Preparations for flooding impacts should be completed as soon as
possible, as heavy rainfall will begin well in advance of the
center. In the Southwestern U.S., the potentially historic
amount of rainfall is expected to cause flash, urban, and arroyo
flooding including landslides, mudslides, and debris flows.
Dangerous to locally catastrophic flooding impacts are expected late
tonight through early Monday.

2. Hurricane conditions are expected along the west-central coast of
the Baja California Peninsula within the hurricane warning area
tonight and Sunday morning, and are possible in the Hurricane Watch
area on Sunday.

3. Tropical storm conditions are expected to begin Sunday in
portions of the southwestern U.S. within the Tropical Storm
Warning area. Winds could be particularly strong and gusty in and
near areas of higher terrain. Gusty winds are expected to spread
well inland across the western U.S.

4. Large swells generated by Hilary will affect portions of the
Baja California Peninsula and southern California over the next
couple of days. These swells are likely to cause life-threatening
surf and rip current conditions.


FORECAST POSITIONS AND MAX WINDS

INIT 19/2100Z 23.8N 114.1W 95 KT 110 MPH
12H 20/0600Z 26.4N 114.8W 80 KT 90 MPH
24H 20/1800Z 30.8N 116.2W 60 KT 70 MPH
36H 21/0600Z 36.4N 117.6W 35 KT 40 MPH...POST-TROP/INLAND
48H 21/1800Z...DISSIPATED

$$
Forecaster Cangialosi

[arizona_sooner]

I have a feeling that Hilary will just flame out and not provide any moisture for central Arizona.

[NDG]

As mentioned on their latest update, the NHC is being generous with its strength, no way Hilary is a high end Cat 2 right now.

[Iceresistance]

As mentioned on their latest update, the NHC is being generous with its strength, no way Hilary is a high end Cat 2 right now.

https://i.imgur.com/b6wmgPx.jpg

They don't want to make people think that Hilary is going to be a goner by the time it gets to California, they want to make sure that the storm is weakening, but not fast enough to not cause severe impacts.

[iorange55]

Looks like the hi res models are dumping lots of rain on LA county. Geez.

[Cyclenall]

Hurricane Hilary Discussion Number 14
NWS National Hurricane Center Miami FL EP092023
300 PM MDT Sat Aug 19 2023

...

[b]There is high
confidence that Hilary will move into southern California as a
tropical storm.

Why? I'd be very surprised if there is still a surface llc left when she gets to SoCal. Its unraveling fast right now and it hasn't gotten far north yet.