BULLETIN
Hurricane Hilary Intermediate Advisory Number 6A
NWS National Hurricane Center Miami FL EP092023
600 PM MDT Thu Aug 17 2023
…HILARY BECOMES A MAJOR HURRICANE…
Hurricane Hilary Discussion Number 6
NWS National Hurricane Center Miami FL EP092023
300 PM MDT Thu Aug 17 2023
www.nhc.noaa.gov/text/refresh/MIATCDEP4%20shtml/172056.shtml
Hilary has an impressive appearance on satellite imagery. The
eye, which is becoming better defined, is surrounded by very cold
cloud tops in the CDO. There are numerous convective banding
features, especially over the eastern semicircle of the
circulation. Upper-level outflow is well-defined over all but the
northwestern quadrant of the circulation. Recent objective Dvorak
T-numbers support an intensity of about 95 kt, which is used for
this advisory.
The hurricane continues to move on a west-northwestward track with
an initial motion estimate of 300/13 kt. Global models indicate
that a mid-tropospheric ridge currently situated to the north of
Hilary will shift eastward over the next few days while a cutoff
low remains near the California coast. This should result in a
steering pattern that will cause the system to gradually turn
toward the northwest, north-northwest, and north with increasing
forward speed during the next 72 hours. The official forecast
track has not changed much from the past few advisory packages, and
is a blend of the simple and corrected dynamical model consensus
solutions. Since the forecast track is roughly paralleling the
coastline north of the central Baja peninsula to the California
border, it nearly impossible to know at this point if the
center will remain just offshore or move over the peninsula before
reaching the southwestern United States.
Hilary is over very warm waters, near 30 deg C, with extremely
low vertical wind shear and a moist mid- to low-level atmospheric
environment. Therefore additional intensification is highly
likely for the next day or so. The various SHIPS rapid
intensification (RI) indices continue to show high probabilities of
RI during the next day or so. The most likely indicated intensity
increase is around 25 kt over the next 24 hours, which is also shown
in the NHC forecast. Later in the forecast period, cooler waters
and land interaction should result in some weakening. The official
wind speed forecast remain near or above latest HCCA guidance. The
surface circulation is likely to be dissipated by day 5, but a day 5
forecast point (as a remnant low) is still provided to maintain a
forecast track over the southwestern United States.
The latest cone
www.nhc.noaa.gov/refresh/graphics_ep4%20shtml/234623.shtml?gm_track#contents
It is almost certain at least one or more eyewall replacement cycles will occur before landfall.
This will greatly increase the area of the wind field.
A major disaster in the making.
You aint seen nothing yet.
www.tropicaltidbits.com/sat/satlooper.php?region=09E&product=ir
Hurricane Hilary a few minutes ago is still intensifying. I'm expecting it to reach close to Category 5 assuming another 6-12 hours of eye clearing and warming. pic.twitter.com/Y88BEX3sLm
— Ryan Maue (@RyanMaue) August 18, 2023
BULLETIN
Hurricane Hilary Advisory Number 8
NWS National Hurricane Center Miami FL EP092023
300 AM MDT Fri Aug 18 2023
…HILARY IS A LARGE AND POWERFUL CATEGORY 4 HURRICANE…
…SIGNIFICANT FLOODING IMPACTS POSSIBLE ACROSS PORTIONS OF THE
BAJA CALIFORNIA PENINSULA AND THE SOUTHWESTERN UNITED STATES EARLY
NEXT WEEK…
www.nhc.noaa.gov/text/refresh/MIATCPEP4%20shtml/180857.shtml
Hurricane Hilary Discussion Number 8
NWS National Hurricane Center Miami FL EP092023
300 AM MDT Fri Aug 18 2023
www.nhc.noaa.gov/text/refresh/MIATCDEP4%20shtml/180858.shtml
Hilary’s satellite presentation has continued to improve overnight,
with a solid ring of cold cloud tops surrounding a warming eye.
TAFB and SAB provided consensus Dvorak estimates of T6.0/115 kt
while objective estimates are a bit higher, between 125-135 kt.
The advisory intensity is therefore set at 125 kt as a blend
of the various estimates. Hilary has rapidly intensified by a
remarkable 65 kt over the past 24 hours. The hurricane remains
large, and the initial wind radii have been adjusted based on a
recent ASCAT-C pass. An Air Force Reserve Hurricane Hunter
aircraft is scheduled to investigate Hilary around midday and
should provide a more precise estimate of the hurricane’s intensity.
The hurricane continues to move toward the west-northwest, or 300/11
kt. However, with mid-tropospheric high pressure nudging eastward
from the Rocky Mountains into the Central Plains, and a cut-off low
off the California coast, Hilary is expected to turn northwestward
very soon and then turn northward and begin accelerating by 48
hours. The track guidance is more tightly clustered than usual
during the first 72 hours of the forecast, and therefore there is
relatively high confidence in the NHC track forecast, which is
essentially unchanged from the previous advisory. Since Hilary’s
forecast track parallels the coast from the central Baja California
peninsula northward to southern California, it is still nearly
impossible to predict an exact landfall location, not to mention
that Hilary’s exact landfall probably won’t make much difference
when it comes to the expected hazards and impacts in the region.
Hilary could strengthen a little more during the next 12 hours or
so. However, once hurricanes reach major hurricane strength, they
are prone to fluctuations in intensity, particularly if an eyewall
replacement begins. In addition, oceanic heat content will be
dropping significantly in 24-36 hours, and it’s likely that Hilary’s
large wind field will mix up cooler water ahead of the arrival of
the center. This colder water, as well as potential interaction
with the terrain of the Baja California peninsula, is expected to
induce faster weakening over the weekend, with Hilary likely to drop
below hurricane intensity some time on Sunday. Due to its
accelerating motion in 2 to 3 days, Hilary is still expected to be
producing tropical-storm-force winds when it reaches southern
California. The surface circulation is likely to dissipate soon
after moving into California, but a day 4 remnant low point is still
shown over the western U.S. for continuity purposes.
Trying to gauge the wind part of the equation with #hilary is difficult as we certainly don't have a large data set on which to go on nor any clear superior model in this category. Using the NAM FWIW and adding current 290 mile from center TS wind radii NAM shows a large… pic.twitter.com/LrxdsovQBI
— Jim Cantore (@JimCantore) August 18, 2023
LA Times is already blaming Hurricane Hilary on climate change (without evidence) and interviewing climate scientists about their feelings of dread and doom. Just too much happening all at once to manage. t.co/sAVa7DpasH pic.twitter.com/mBDk3DOe1l
— Ryan Maue (@RyanMaue) August 18, 2023
Hilary is now a category 4 Hurricane pic.twitter.com/iJKCYAyjsl
— Derek Schwartz (@derek_mafs) August 18, 2023
h/t DOORBERT