01:18 2014 Hurricane Season in a Nutshell Meteorologist Ari Sarsalari looks back at the 2014 hurricane season.

Typhoon Hagupit has gained strength again as it closes in on a Philippines landfall this weekend, according to the latest update from the U.S. military's Joint Typhoon Warning Center (JTWC). Preparations are underway for potentially life-threatening winds, storm surge and flash floods in the Philippines, where the typhoon has been named Ruby.

(MORE: Philippines Prepare for Typhoon)

For days, major disagreements between American and European computer forecast models had created major questions about whether Hagupit would even make it to the Philippines. However, on Thursday, the models began to converge on an ominous forecast track that could take Hagupit on a slow, agonizing path across the heart of the island nation. Among the areas at risk is Tacloban, a city devastated by Super Typhoon Haiyan (Yolanda) just 13 months ago.

(MORE: On the Ground After Typhoon Haiyan)

<img class="styles__noscript__2rw2y" src="https://i.imwx.com/images/maps/truvu/map_specnewsdct-03_ltst_4namus_enus_160x90.jpg" srcset="https://i.imwx.com/images/maps/truvu/map_specnewsdct-03_ltst_4namus_enus_160x90.jpg 400w, https://i.imwx.com/images/maps/truvu/map_specnewsdct-03_ltst_4namus_enus_160x90.jpg 800w" > Hagupit: Infrared Satellite

On Wednesday night U.S. East Coast time, JTWC estimated Hagupit's maximum sustained 1-minute wind speed at 180 mph, putting it in a tie with Super Typhoons Vongfong and Nuri in October as the most powerful typhoon of 2014.

As of 9 a.m. EST Friday, JTWC raised its estimate of Hagupit's top winds to 150 mph, making it once again a "super" typhoon, the equivalent of a Category 4 hurricane.

However, at 10 p.m. EST Friday, JTWC reduced its estimate of the typhoons top winds to 140 mph, which means the typhoon is just under the "super" criteria. It remains the equivalent of a major Category 4 hurricane.

The Japan Meteorological Agency (JMA) earlier declared Hagupit a "violent" typhoon, the highest classification on its scale, with 10-minute sustained winds of 130 mph and gusts to 190 mph. That ties Vongfong for the highest wind speeds of 2014 in JMA's bulletins. Hagupit has since been downgraded to a "very strong" typhoon on JMA's scale with winds of 115 mph and gusts to 160 mph as of 4 a.m. EST Friday.

Hagupit moved into the waters east of the Philippines early Thursday local time, prompting that country's weather agency (PAGASA) to give it the name Ruby. The Philippines has its own alphabetical list of names, separate from the international list, for tropical cyclones passing near or over its territory.

Forecast: Increasing Danger for Philippines

<img class="styles__noscript__2rw2y" src="https://image.weather.com/images/maps/truvu/map_specnews09_ltst_4namus_enus_320x180.jpg" srcset="https://image.weather.com/images/maps/truvu/map_specnews09_ltst_4namus_enus_320x180.jpg 400w, https://image.weather.com/images/maps/truvu/map_specnews09_ltst_4namus_enus_320x180.jpg 800w" > Hagupit Forecast Path

PAGASA has issued public storm warning signals for 36 geographic areas, spanning from southeastern portions of Luzon (the main northern island) through the Visayas (central Philippines) and northeastern parts of Mindanao (the main southern island).

The island of Samar in the Visayas nearest the initial arrival of the landfall was raised to Public Storm Warning Signal No. 3, meaning winds of 100-185 kph (62 to 115 mph) are expected "in at least 18 hours."

PAGASA also placed a large part of this region in Public Storm Warning Signal No. 2, meaning 61 to 100 kph (38 to 62 mph) are possible "in at least 24 hours." Metro Cebu, the second-largest metropolitan area in the country after Metro Manila, is included in Public Storm Warning Signal No. 2.

(FORECAST : Tacloban | Cebu | Manila)

First, the typhoon is expected to approach the eastern shores of the central Philippines (Eastern Visayas Region) on Saturday evening local time (Saturday morning U.S. time).

While it still remains a bit uncertain whether the center of Hagupit will technically "make landfall", the most intense eyewall winds will arrive in Samar Island (particularly northern and eastern parts of the island), and perhaps also affecting northern Leyte Island (including Tacloban City) Saturday evening, continuing into Sunday, local time.

During this initial period of contact with land, Hagupit will likely unleash its most powerful winds. It should be at least a Category 4 equivalent tropical cyclone by that time, but may possibly be a Category 5 storm.

In areas where the wind blows onshore, dangerous storm surge is likely. Philippine officials have issued storm surge advisories for a number of communities at risk. Some communities on the islands of Samar and Leyte are at risk of storm surge up to 4 meters (13 feet) according to the alerts, equivalent to the height of a one-story home.

(MORE: List of Storm Surge Advisories from ABS-CBN TV)

<img class="styles__noscript__2rw2y" src="https://i.imwx.com/images/maps/truvu/map_specnewsdct-93_ltst_4namus_enus_160x90.jpg" srcset="https://i.imwx.com/images/maps/truvu/map_specnewsdct-93_ltst_4namus_enus_160x90.jpg 400w, https://i.imwx.com/images/maps/truvu/map_specnewsdct-93_ltst_4namus_enus_160x90.jpg 800w" > Model Rainfall Forecast (The latest rainfall forecast from WSI's RPM computer model. This high-resolution computer model accounts for local terrain, which can greatly enhance rainfall in typhoons.) (The latest rainfall forecast from WSI's RPM computer model. This high-resolution computer model accounts for local terrain, which can greatly enhance rainfall in typhoons.)

As Hagupit grinds west-northwest across the Philippines, the danger will gradually transition from one of wind damage and storm surge to one of heavy rainfall.

Again, there is some uncertainty in Hagupit's path and forward speed, but in general its center should move in the general direction of Metro Manila. The process is expected to be agonizingly slow -- potentially taking 48-72 hours to move from the eastern Philippines to Metro Manila.

We expect Hagupit's winds to have weakened considerably upon nearing Manila, however, some downed trees/tree limbs, power outages, and structural damage is still possible, there, Monday.

In general, a tropical cyclone's rainfall potential depends on how slowly it moves, not its intensity. Hagupit will be moving along very slowly over an area with rugged terrain. As a result, rainfall totals could be extraordinarily high -- locally exceeding 2 feet -- leading to landslides, debris flows, and life-threatening flash floods.

Just three years ago in December 2011, Tropical Storm Washi (Sendong) dumped tremendous rainfall on the island of Mindanao, causing massive floods that killed 1,268 people. Winnie was only of tropical depression strength when it triggered deadly flooding in late Nov. 2004.

Over the past 10 years, six separate tropical cyclones have claimed over 1,000 lives in the Philippines, including:

- Haiyan/Yolanda Nov. 2013: Over 7,300 killed (AP)

- Bopha/Pablo Dec. 2012: 1,901 killed

- Washi/Sendong Dec. 2011: 1,268 killed

- Fengshen/Frank Jun. 2008: 1,410 killed

- Durian/Reming Nov./Dec. 2006: 1,399 killed

- Winnie Nov. 2004: 1,593 killed

(WUNDERGROUND BLOG: Philippines Typhoon History {Written in Nov. 2013})

Storm Spares Small Pacific Islands

Earlier in its lifetime, Hagupit made its closest approach to the Yap Islands Wednesday evening, local time (15 hours ahead of U.S. EST), passing about 60 miles to the south of the islands. Given its relatively small wind field at that time, only tropical storm-force wind gusts (peak gust to 43 mph) were recorded at Yap International Airport as of late Wednesday evening.

The center passed north of the Republic of Palau Thursday morning, local time (Wednesday afternoon and evening, mainland U.S. time).

Closest to the center of Hagupit was Kayangel, a cluster of three atolls making up the northernmost state of Palau. It is not immediately clear how intense Hagupit's winds were in Kayangel, which like Tacloban was also heavily damaged by Haiyan in 2013.

Winds peaked at only 21 mph to the south in Koror, the more heavily populated state of the republic.

Typhoon and tropical storm warnings have been discontinued for Yap and Palau.

Hagupit began to undergo a period of rapid intensification late Wednesday morning (U.S. East Coast time). According to the U.S. military's Joint Typhoon Warning Center, Hagupit became a super typhoon as of 2 p.m. EST Wednesday when its maximum sustained winds reached 150 mph -- a sharp increase from 115 mph just six hours earlier. Another six hours later, Hagupit's winds reached an estimated 180 mph.

The rapid intensification was the result of impressive upper-level "outflow channels," basically air flow in the upper levels of the atmosphere spreading apart, or away from, the center of Hagupit. Those outflow channels near the top of the typhoon force air to rise more vigorously within its core circulation, allowing the central pressure to plummet and the typhoon's winds to increase.

Hagupit is the seventh Western Pacific cyclone to reach super typhoon status in 2014.

Incidentally, December tropical cyclones in the western Pacific are a typical occurrence. On average, 1-2 tropical cyclones form in the western Pacific basin each year.

Check back with us at weather.com and The Weather Channel for the latest on Typhoon Hagupit and its potential impacts.

MORE ON WEATHER.COM: Super Typhoon Haiyan - Aerial Photographs (Nov. 2013)