Hilary Update First Ever Tropical Storm Warning For California Hardest Hit Sunday

Saturday Night Update August 18, 2023

There is no way to overstate this. A potential natural disaster is about to hit the Southwest United States. The first ever Tropical Storm Warning has been issued for Southern California. The once ‘major’ Hurricane has continued the expected weakening trend as it moves north across cooler water. As of 5 PM PDT/8 PM EDT, Winds were down to 100 mph, making this a Category 2 Storm.

It may cross parts of Baja California first but is still expected to reach California as a tropical system, below hurricane status.

In this report, I have new satellite loops, forecast maps, the reason I care so much about this, and live radar plus wind widgets to track right here.

Risk for:

• High winds
• Tornadoes
• Heavy rain
• Flash flooding
• Mudslides

This region is a desert and cannot handle the expected rainfall.

Tropical Storm Warning In The US

The FIRST TIME EVER Issued for California!

* California/Mexico border to Point Mugu

* Catalina Island

Continued Weather Report Below This …

My Personal Interest

I am an east coast meteorologist who has been spending a lot of time reporting on this storm. My personal interest is because I just visited this region back in May to hike a mountain in Palm Springs.

I understand there are a lot of weather headlines and hype across all media when there is a looming storm. Hurricane Hilary is historic due to the track it will take into the US, making it only the 3rd time a tropical system has made recorded landfall in southern California.

Palm Springs

This desert city is at the base of Mount San Jacinto. It reaches 10,834 Ft, which I know first hand as I hiked the famous Cactus to Clouds Trail to that altitude back in May. I found the two posts I made on Facebook to help share the idea of the terrain. It is desert cactus and rocky. That is dirt that simply cannot absorb heavy rain.

THIS IS THE AREA THAT MAY SEE THE MOST FLOODING!

I did this in two days since part of the route was closed due to snow and ice above 6,000 Ft.

My second day was from 8,000 Ft to the summit, where there was still 6 Ft of snow on the ground. This was higher than normal but at that elevation, they have a biome that is designed to deal with rain and snow.

The problem is that all of the heavy rain from Hilary will have to flow down.. to the desert, which will have its own heavy rainfall from the storm.

The streets do not have a drainage system to handle that.

Rainfall Forecast Map From NWS

Excessive Rainfall Risk Map

Live Radar Widget

NOTE: 

The Las Vegas Radar Is Offline

The KESX radar is currently down after being hit by lightning. Our technicians have been notified, but will not be able to head out for repairs until tomorrow morning due to ongoing inclement weather. There is currently no estimated repair time.#NVwx #CAwx #AZwx #VegasWeather pic.twitter.com/2ZeHIIgT59

— NWS Las Vegas (@NWSVegas) August 19, 2023

Forecast Focus From The National Hurricane Center

RAINFALL: 

Heavy rainfall in association with Hilary is expected to impact the Southwestern United States through next Wednesday, peaking on Sunday and Monday. Rainfall amounts of 3 to 6 inches, with isolated amounts of 10 inches, are expected across portions of southern California and southern Nevada. Dangerous to locally catastrophic flooding will be possible. Elsewhere across portions of the western United States, rainfall totals of 1 to 3 inches are expected, resulting in localized flash flooding.

Forecast Jet Stream And Humidity at 700mb

The dark green and purple show high amounts of moisture that will move into the desert southwest into Monday evening.

Hurricane Hilary IR Satellite

The colder colors are brighter and represent higher cloud cover.

The EYE WALL structure has become ragged as the storm weakens.

Satellite Snapshot

Hurricane Force Winds Extend: 45 miles from the center

Tropical Storm Force Winds Extend: 265 miles from the center

Official Status Report: 5 PM PDT (8 PM EDT) Advisory

• LOCATION…24.4N 114.2W
• ABOUT 240 MI…390 KM SSE OF PUNTA EUGENIA MEXICO
• ABOUT 600 MI…965 KM SSE OF SAN DIEGO CALIFORNIA
• MAXIMUM SUSTAINED WINDS…100 MPH…155 KM/H
• PRESENT MOVEMENT…NNW OR 345 DEGREES AT 17 MPH…28 KM/H
• MINIMUM CENTRAL PRESSURE…964 MB…28.47 INCHES

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

* Baja California peninsula north of Cabo San Quintin to the

California/Mexico border

* Mainland Mexico north of Guaymas

* California/Mexico border to Point Mugu

* Catalina Island

A Tropical Storm Watch is in effect for…

* Mainland Mexico from Huatabampito to Guaymas

Weaker Over Colder Water

The Sea Surface Temperatures along the path of Hilary highlight why it is beginning to weaken.

The region where it peaked at over 145 mph had temperatures of 86ºF. That is a lot of fuel for a tropical cyclone.

Farther north the water drops into the 70s, which is chilly and not enough to maintain the energy. That is why the storm is now losing intensity.

Hurricane Hilary Forecast Intensity

Saffir Simpson Scale

Ranking of Categories Based On Wind Speed

Wind Forecast: Map from NWS San Diego

The storm will be weakening, but there are mountains over 10,000 Ft that will still catch high winds over 80 mph. Most areas expect winds 40 to 65 mph.

Live Windy Widget

Use the controls to scroll through the timeline or zoom in closer.

Tropical Model Plots

HAFS-A Model Forecast

Snapshot Sunday Afternoon

History of Tropical Landfalls In Southern California:

Since 1900 there have been 2

1939 – The last landfall, 86 years ago!

Two significant storms from NWS San Diego

Taking a look back at our tropical landfall history…well my word, it’s been a long time! We have seen close encounters from previous systems, but the last time a tropical system made landfall in SoCal was back in 1939. A hurricane? 165 years ago in 1858! 📷 #CAwx #History pic.twitter.com/d0NtAkhaJ7

— NWS San Diego (@NWSSanDiego) August 18, 2023

LAST WEEK:  Maryland Trek 10 For These Kids

I will have a follow-up and recap on our amazing week shortly.

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RESTATING MY MESSAGE ABOUT DYSLEXIA

I am aware there are some spelling and grammar typos and occasional other glitches. I take responsibility for my mistakes, and even the computer glitches I may miss. I have made a few public statements over the years, but if you are new here you may have missed it: I have dyslexia, and found out during my second year at Cornell University. It didn’t stop me from getting my meteorology degree and being the first to get the AMS CBM in the Baltimore/Washington region. One of my professors told me that I had made it that far without knowing, and to not let it be a crutch going forward. That was Mark Wysocki and he was absolutely correct! I do miss my mistakes in my own proofreading. The autocorrect spell check on my computer sometimes does an injustice to make it worse. I also can make mistakes in forecasting. No one is perfect at predicting the future. All of the maps and information are accurate. The ‘wordy’ stuff can get sticky.  There has been no editor that can check my work when I needed it and have it ready to send out in a newsworthy timeline. Barbara Werner is a member of the web team that helps me maintain this site. She has taken it upon herself to edit typos when she is available. That could be AFTER you read this. I accept this and perhaps proves what you read is really from me… It’s part of my charm.

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