Saturday 24 October 2015

Hurricane Patricia enters the record books

Think, "Storms of my grandchildren"
Patricia, Strongest Hurricane in History, Nears Mexico Landfall
Eric Holthaus


24 October, 2015

Over the past day or so, a phenomenal episode of strengthening has pushed Hurricane Patricia into the record books. Now, as the strongest hurricane ever measured—with 200 mph sustained winds—Patricia is just hours from making landfall in Mexico.

The National Hurricane Center, with official forecasting responsibility for the Atlantic and eastern Pacific, all but ran out of words to describe the storm’s ferocity, labeling it “potentially catastrophic” and “incredible.” On Twitter, professional weather watchers went a step furthermarveling at the storm’s record-breaking ability andfearing for Mexico’s coastal cities. Such a scenario—a quickly strengthening storm of unprecedented strength headed straight for land—is the stuff of meteorologists’ nightmares.

As of Friday morning, Patricia was a strong Category 5 hurricane—after strengthening from just tropical storm strength a day earlier. Still, calling Patricia a Category 5 underestimates just how ferocious this storm is.


Patricia is headed for a landfall between Manzanillo and Puerto Vallarta on Mexico’s southwest coast on Friday. The storm threatens to be the strongest ever to hit Mexico’s Pacific coast, surpassing a 1959 hurricane that also ranks as the deadliest in that part of the Pacific. As it moves inland, Patricia is expected to produce up to two feet of rain in Mexico’s coastal mountain range, creating a risk of flooding and mudslides over a vast area including Guadalajara, the country’s second-largest city.

As of Friday morning, Mexico is scrambling to prepare for Patricia. Three states—Jalisco, Colima, and Nayarit—have declared states of emergency. In Colima, officials handed out sandbags. Nearly 400,000 people are in the storm’s path.
Patricia has now surpassed 1997’s Hurricane Linda, which stayed safely off Mexico’s west coast, as the strongest known storm in the eastern Pacific, and 2005’s Hurricane Wilma, as the strongest known storm in the Western Hemisphere. It may have also surpassed 2013’s Typhoon Haiyan, which devastated the Philippines, as the strongest known storm in world history. It’s difficult to compare tropical cyclones in the western Pacific, called typhoons, and eastern Pacific hurricanes if only because routine aircraft measurements don’t exist in the western Pacific. Unlike Patricia, Haiyan was never directly measured by an aircraft, so we don’t know its true intensity.

from when it was named to this morning's no words 200mph/880mb status. Most strengthening past 30 hrs.

Over the past 30 hours, Patricia’s central pressure has fallen by 114 millibars, from 994 to 880—possibly beating the world’s record for fastest intensification. Since lower air pressure drives faster wind speeds, such a fast intensification has greatly increased the storm’s strength—Patricia strengthened by 100 mph in 24 hours, the most in the era of complete data coverage by weather satellites. This historic data was collected by a hurricane hunter aircraft flying through the center of Patricia, which departed the storm as it was still strengthening. Shortly after the research plane left, satellite estimates of Patricia’s intensity broke the Dvorak scale, peaking at 8.3 on the 8.0 scale.

In fact, Patricia is now very close to the theoretical maximum strength for a tropical cyclone on planet Earth.

20EPAccording to the Dvorak scale, a satellite-based estimate of hurricane intensity, Patricia is literally off the chats.    University of Wisconsin

If there is any good news, it’s that Patricia’s incredibly strong winds are concentrated into a narrow region near its core. The latest National Hurricane Center advisoryshows Patricia’s peak winds are confined to a span of just 15 miles across the center, which should help limit its impact at the time of landfall. Still, that’s little consolation for those in the storm’s direct path.

Patricia’s rapid intensification is linked to the current strong El Niño in the Pacific, which, along with global warming, has helped produce record-warm ocean temperatures in the region near where it formed.

Stunning, Historic, Mind-Boggling, and Catastrophic: Hurricane Patricia Hits 200 mph

Jeff Masters and Bob Henson 

5:04 PM GMT on October 23, 2015

Figure 1. GOES-East satellite image of Hurricane Patricia at 10:45 am EDT October 23, 2015. Image credit: NOAA Viz Lab.

23 October, 2015

Stunning, historic, mind-boggling, and catastrophic: that sums up Hurricane Patricia, which intensified to an incredible-strength Category 5 storm with 200 mph winds overnight. At 2:46 am EDT October 23, 2015 an Air Force hurricane hunter aircraft measured a central pressure of 880 mb in Patricia, making it the most intense hurricane ever observed in the Western Hemisphere. The aircraft measured surface winds of 200 mph, which are the highest reliably-measured surface winds on record for a tropical cyclone, anywhere on the Earth. The previous strongest Eastern Pacific hurricane was Hurricane Linda of 1997, with a pressure of 902 mb (estimated from satellite imagery.) The strongest Atlantic hurricane on record was Hurricane Wilma of 2005, with an 882 mb central pressure. Patricia does not beat the record-lowest pressure in the Western Pacific, though, which is held by Super Typhoon Tip of 1979: 870 mb.

Figure 1. GOES-East satellite image of Hurricane Patricia at 10:45 am EDT October 23, 2015. Image credit: NOAA Viz Lab.

Figure 2. Wind barbs from the early-morning October 23, 2015 Air Force hurricane hunter mission into Hurricane Patricia, off the Pacific coast of Mexico. The aircraft measured winds of Category 5 strength (dark pink colors) at their flight level of 10,000 feet across a 20-mile diameter region. Winds at the surface as measured by a dropsonde were 9% lower compared to winds measured at flight level, so we likely there was a region at least 15 miles in diameter of Category 5 winds at the surface. Image credit: Levi Cowan,

Patricia the fastest-intensifying Western Hemisphere hurricane on record

Patricia's central pressure dropped an astonishing 100 mb in 24 hours, making it the fastest-intensifying hurricane ever observed in the Western Hemisphere. Patricia's pressure at 5 am EDT Thursday, October 22, 2015 was 980 mb, and was 880 mb at 5 am EDT Friday. The previous record was a drop of 97 mb in 24 hours for Hurricane Wilma of 2005 (between 1200 UTC 18 October - 1200 UTC 19 October), according to the official 
NHC report for the storm. Patricia's intensification rate was very close to the WMO-recognized world record for fasting-intensifying tropical cyclone: 100 millibars in just under 24 hours by Super Typhoon Forrest in the Northwest Pacific in 1983.

Patricia is estimated to have intensified 85 knots (100 mph) in 24 hours, from a tropical storm to a Category 5 hurricane. In the Eastern Pacific, Hurricane Linda of 1997 is the only storm on record to have intensified at this rate. The Atlantic's record holder for largest wind increase in 24 hours is held by Hurricane Wilma of 2005, which intensified from a 60-knot tropical storm to a 150-knot Category 5 hurricane--an increase of 90 knots (105 mph). Air Force reconnaissance observations indicated that the eye of Wilma contracted to a diameter of 2 n mi during this time; this is the smallest eye known to National Hurricane Center (NHC) staff. Patricia's eye diameter was 8 miles at it's peak strength.

Figure 4. Infrared VIIRS images of Hurricane Patricia (top) and Super Typhoon Haiyan (bottom) near peak strength, showing the similarity in satellite presentations of the two storms. Image credit: Dan Lindsey, NOAAand NOAA/RAMMB.

Patricia the third strongest tropical cyclone in history (by wind)

Patricia's 200 mph sustained winds make it the 3rd strongest tropical cyclone in world history (by 1-minute averaged wind speed.) Officially, here are the strongest tropical cyclones in world history, according to the Joint Typhoon Warning Center and the National Hurricane Center (using 1-minute averaged sustained winds):
Super Typhoon Nancy (1961), 215 mph winds, 882 mb. Made landfall as a Cat 2 in Japan, killing 191 people.Super Typhoon Violet (1961), 205 mph winds, 886 mb pressure. Made landfall in Japan as a tropical storm, killing 2 people.Super Typhoon Ida (1958), 200 mph winds, 877 mb pressure. Made landfall as a Cat 1 in Japan, killing 1269 people.Super Typhoon Haiyan (2013), 195 mph winds, 895 mb pressure. Made landfall in the Philippines at peak strength.Super Typhoon Kit (1966), 195 mph winds, 880 mb. Did not make landfall.Super Typhoon Sally (1964), 195 mph winds, 895 mb. Made landfall as a Cat 4 in the Philippines.

However, it is now recognized 
(Black 1992) that the maximum sustained winds estimated for typhoons during the 1940s to 1960s were too strong. The strongest reliably measured tropical cyclones were both 10 mph weaker than Patricia, with 190 mph winds—the Western Pacific's Super Typhoon Tip of 1979, and the Atlantic's Hurricane Allen of 1980. Both storms had a hurricane hunter aircraft inside of them to measure their top winds. Haiyan's winds were estimated using only satellite images, making its intensity estimate of lower confidence.

Dr. Hugh Willoughby, former head of NOAA's Hurricane Research Division, had this to say about the winds measured in Super Typhoon Nancy and the other high-end typhoons from this list from the 1960s:

"I would not take the winds seriously because reconnaissance meteorologists estimated them visually. A decade later when I flew with the VW-1 hurricane hunters, we had the same Doppler system used to measure the winds of Typhoon Nancy. It tracked the aircraft motion relative to the (possibly moving) sea surface. It couldn't get a coherent signal in high winds because the beam reflected from both the actual surface (whatever that is) and blowing spray. Visual estimates are dubious because the surface (under the eyewall!) is hard to see unless you are flying below cloud base (200-300 m) and also because appreciably above 115 mph, it's completely white with blowing spray. We used to think that we could estimate stronger winds from the decreasing coverage of slightly greenish patches where the spray was thinner. I now think that we were kidding ourselves. In those days the distinctions among wind gust, sustained one-minute winds, etc., were less well defined than they are now. So we may never know the 1960s reconnaissance data really means!"

At the same time, we should keep in mind that not all hurricanes are sampled while at peak strength. Satellite methods of estimating intensity, such as the Dvorak technique, cannot capture the most extreme peak winds and central pressures found in storms such as Patricia and Wilma. It is possible that previous hurricanes, such as the 1935 Labor Day hurricane that devastated the Florida Keys, had intensification rates and peak winds on par with Patricia. The bottom line is that Patricia is at the very highest end of what we can expect in terms of a small, extremely intense hurricane.

The size of a hurricane also shapes its destructive power. Although Sandy was never a Category 4 or 5 hurricane, its longevity and size enabled it to move as much water in the form of waves and surge as Category 5 Katrina. We are lucky that Patricia is no larger than it is--although this is cold comfort for those who will be directly affected.

Figure 4. MODIS image of Hurricane Patricia as seen from NASA's Terra satellite on Thursday, October 22, 2015. At the time, Patricia was a Category 4 storm with 130 mph winds. Image credit: NASA.

Forecast for Patricia: Manzanillo at dire risk

Satellite loops early Friday afternoon showed that Patricia’s cloud tops had begun to warm, indicating weakening, and with wind shear now a moderate 10 - 20 knots and interaction with land beginning to occur, Patricia will likely weaken to 155 - 175 mph winds by landfall. The storm's expected turn toward the northeast has begun, and the storm is beginning to accelerate toward the coast of the Mexican state of Colima.

At particular risk is the city of Manzanillo, a regional center that straddles the back of a bay spanning several miles. On its current track, and with some acceleration in progress, it appears that Patricia could make landfall sometime between 5:00 and 9:00 pm EDT (4:00 - 8:00 local time, CDT] just to the northwest of Manzanillo--a trajectory that raises the odds of a catastrophic storm surge in or near Manzanillo. Patricia’s strongest winds are confined to a relatively small area, with hurricane-force winds only spanning a range of 30 miles from Patricia’s center. Category 5 winds of 156+ mph cover an area 15 miles across. Wherever those winds are focused, we can expect gigantic waves atop a devastating surge. An unnamed 
1959 hurricane--the deadliest in Northeast Pacific history, with an estimated 1800 direct and indirect fatalities--struck near Manzanillo on October 27 (see embedded YouTube newsreel footage below). In a Friday afternoon blog post, storm surge expect Dr. Hal Needham says he expects a storm surge of 16.5 ft (5 m), which will be accompanied by large, destructive waves. This would be the largest storm surge in the modern history of Western Mexico.

After landfall, Patricia will slam into very rugged terrain, triggering torrential rains with the risk of severe flooding and mudslides. The mountainous trek will shred Patricia’s low-level circulation quickly, but the hurricane’s upper-level circulation will proceed quickly northeastward, arriving near South Texas by Sunday. Models suggest that a nontropical or hybrid low-pressure center may develop near the upper-level center at that point. Patricia’s presence will exacerbate a multi-day rain/flood episode already under way across Texas, with 
widespread 4” - 8” rainfall amounts across the eastern half of the state expected between now and Monday. Localized totals well over a foot are quite possible.

iCyclone storm chasers in the path of Patricia

Storm chaser Josh Morgerman, who intercepted Super Typhoon Haiyan at landfall in Tacloban in the Philippines, is aiming to be in the path of Hurricane Patricia's eye at landfall in Mexico. From the iCyclone Facebook page:"7:30 am Friday (Jalisco): Erik and I are staring down the barrel of a gun. Incredible Hurricane PATRICIA-- possibly the most intense hurricane in recorded history-- is just offshore with winds of 175 knots (200 mph). The NHC forecast track takes the center right over our current location. To say we have conflicted feelings is an understatement. We want to see history unfold. We also don't want to die. Main task-- as soon as we have daylight-- is to find a really good building in Perula or nearby La Fortuna. We're thinking closer to the main road-- away from the water."

Other Links:
Manzanillo beach cam
Puerto Vallarta webcam

We'll have a new update this afternoon, after a NOAA hurricane hunter aircraft arrives in the storm.

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