Update for TS Siony (Atsani) as of 5 AM November 6, 2020

THE CENTER OF SEVERE TROPICAL STORM “SIONY” IS LIKELY TO PASS VERY CLOSE OR OVER ITBAYAT ISLAND WITHIN THE NEXT 2 TO 3 HOURS.
 
Track and intensity outlook:
 
• Track: “SIONY” is forecast to make landfall or close approach over Batanes (more likely in the vicinity of Itbayat Island) within the next 2 to 3 hours as it continues to move west-northwestward. It is forecast to exit the Philippine Area of Responsibility (PAR) tonight. It will then turn southwestward tomorrow morning over the sea to the southwest of Taiwan and move over the West Philippine Sea towards the Paracel Islands area.
 
• Intensity: “SIONY” is forecast to either maintain its current strength or slightly intensify to 100 km/h within the next 24 hours. Beyond this 24-hour window, the storm is forecast to significantly weaken due to increasingly unfavorable conditions associated with a surge of the northeasterlies over the West Philippine Sea. It may be downgraded to a Low Pressure Area on Monday.
 
 
Location of eye/center: At 4:00 AM today, the center of Severe Tropical Storm “SIONY” was estimated based on all available data at 60 km East Northeast of Basco, Batanes or 70 km East of Itbayat, Batanes (20.7°N, 122.5°E).
 
Strength: Maximum sustained winds of 95 km/h near the center and gustiness of up to 115 km/h.
 
Movement: Moving Westward at 20 km/h.
 
Forecast Positions
• 24 Hour (Tomorrow morning): 265 km West Northwest of Itbayat, Batanes (OUTSIDE PAR) (22.1°N, 119.7°E)
• 48 Hour (Sunday morning): 570 km West of Basco, Batanes (OUTSIDE PAR) (20.9°N, 116.5°E)
• 72 Hour (Monday morning): 770 km West of Laoag City, Ilocos Norte (OUTSIDE PAR) (18.2°N, 113.3°E)
 
 
TROPICAL CYCLONE WIND SIGNAL
TCWS #2 (61-120 km/h winds prevailing or expected in 24 hours)
Luzon:
Batanes and Babuyan Islands
 
 
TCWS #1 (30-60 km/h winds prevailing or expected in 36 hours)
Luzon:
The northern portion of mainland Cagayan (Santa Ana, Gonzaga, Lal-Lo, Allacapan, Santa Teresita, Buguey, Camalaniugan, Aparri, Ballesteros, Abulug, Pamplona, Sanchez-Mira, Claveria, Santa Praxedes),
 
The northern portion of Apayao (Santa Marcela, Luna, Calanasan),
 
The northern portion of Ilocos Norte (Adams, Pagudpud, Bangui, Dumalneg, Burgos, Vintar, Pasuquin, Bacarra)
 
 
Other tropical systems being monitored (as of 4:00 AM today)
• The Low Pressure Area outside the PAR was estimated at 1,515 km East of Mindanao (10.1°N,139.3°E). It is forecast to move generally west-northwestward or northwestward and may enter the PAR this afternoon or evening. It is heading towards the direction of Eastern Visayas and may likely reach the area tomorrow afternoon or evening. This weather disturbance may develop into Tropical Depression “TONYO” within the next 48 to 72 hours.
 
 
 

SEVERE WEATHER BULLETIN #5
FOR: TROPICAL STORM “#SionyPH” (ATSANI)
ISSUED BY DOST PAGASA AT 11:00 AM, 03 November 2020

“SIONY” SLIGHTLY INTENSIFIES AS IT MOVES SLOWLY OVER THE PHILIPPINE SEA EAST OF EXTREME NORTHERN LUZON.

NO TROPICAL CYCLONE WIND SIGNAL

Track and intensity outlook:
• Track: “SIONY” is forecast to move slowly or almost stationary in the next 24 hours. Afterwards, the tropical storm will move generally westward towards Extreme Northern Luzon. A landfall scenario over Batanes-Babuyan Islands area around Friday remains likely. However, due to the projected quasi-stationary state of this tropical storm, there remains a high degree of uncertainty in the forecast track.

• Intensity: “SIONY” is forecast to intensify into severe tropical storm in the next 24 to 36 hours. Intensification into Typhoon is likely on Thursday prior to close approach or landfall over Extreme Northern Luzon.

Location of eye/center: At 10:00 AM today, the center of Tropical Storm “SIONY” was estimated based on all available data at 565 km East of Basco, Batanes(20.2°N, 127.4°E).

Strength: Maximum sustained winds of 85 km/h near the center and gustiness of up to 105 km/h.

Movement: Moving East Northeastward Slowly

Forecast Positions
• 24 Hour (Tomorrow morning): 740 km East of Calayan, Cagayan (19.7°N, 128.5°E)
• 48 Hour (Thursday morning):445 km East of Calayan, Cagayan (19.2°N, 125.7°E)
• 72 Hour (Friday morning): 160 km West Southwest of Basco, Batanes (20.0°N, 120.5°E)
• 96 Hour (Saturday morning):625 km West of Basco, Batanes (OUTSIDE PAR) (20.4°N, 116.0°E)
• 120 Hour (Sunday morning):995 km West of Extreme Northern Luzon (OUTSIDE PAR) (19.6°N, 112.0°E)

Update for TS Siony (Atsani) as of 11:00 PM, November 2, 2020
Valid until the next bulletin to be issued at 11 AM, November 3, 2020

“SIONY” CONTINUES TO DECELERATE NORTHWARD OVER THE PHILIPPINE SEA EAST OF EXTREME NORTHERN LUZON.
NO TCWS raised

Track and intensity outlook:
• Track: “SIONY” is forecast to gradually enter into a quasi-stationary state in the next 36 hours. Afterwards, the tropical storm will move generally westward towards Extreme Northern Luzon. A landfall scenario over Batanes-Babuyan Islands area around Friday remains likely. However, due to the projected quasi-stationary state of this tropical storm in the next 36 hours, there remains a high degree of uncertainty in the forecast track.

• Intensity: “SIONY” is likely remain within tropical storm category within the next 36 hours. Intensification into a severe tropical storm is likely on Wednesday and into a Typhoon on Thursday prior to close approach or landfall over Extreme Northern Luzon.

Location of eye/center:
• At 10:00 PM today, the center of Tropical Storm “SIONY” was estimated based on all available data at 605 km East of Basco, Batanes (19.8°N, 127.7°E).

Strength:
• Maximum sustained winds of 65 km/h near the center and gustiness of up to 80 km/h.
Movement:
• Moving Northward Slowly

Forecast Positions:
• 24 Hour (Tomorrow evening): 705 km East of Basco, Batanes (20.1°N, 128.7°E)
• 48 Hour (Wednesday evening): 665 km East of Calayan, Cagayan (19.3°N, 127.8°E)
• 72 Hour (Thursday evening): 225 km East of Calayan, Cagayan (19.3°N, 123.6°E)
• 96 Hour (Friday evening): 360 km West of Basco, Batanes (OUTSIDE PAR) (20.4°N, 118.5°E)
• 120 Hour (Saturday evening): 830 km West of Extreme Northern Luzon (OUTSIDE PAR) (20.2°N, 114.0°E)

SEVERE WEATHER BULLETIN #2
FOR: TROPICAL STORM “#SionyPH” (ATSANI)
ISSUED BY DOST PAGASA AT 11:00 PM, 01 November 2020
(Valid for broadcast until the next bulletin to be issued at 11 AM tomorrow)

“#SionyPH” SLIGHTLY WEAKENS BUT REMAINS WITHIN TROPICAL STORM CATEGORY OVER THE PHILIPPINE SEA.

Track and intensity outlook:
• Track: The center of Tropical Storm “SIONY” is forecast to continue moving west-northwestward tonight through tomorrow evening before slows down significantly and becomes almost stationary tomorrow evening through Tuesday evening.
Afterwards, “SIONY” will begin tracking west-southwestward or westward towards Extreme Northern Luzon.
Due to the projected erratic movement of this system in the next 48 hours, there is high degree of uncertainty in the forecast track.

• Intensity: “SIONY” is likely remain within tropical storm category within the next 36 to 48 hours. It may intensify to severe tropical storm category during the period when it becomes almost stationary on Tuesday.

Hazards affecting land areas and coastal waters:
“SIONY” remains less likely to directly affect the weather and coastal water conditions in the country over the next 2 to 3 days. However, the public and disaster managers, especially those situated in Northern Luzon, are advised to continue monitoring for updates on this tropical cyclone.

Location of eye/center: At 10:00 PM today, the center of Tropical Storm “SIONY” was estimated based on all available data at 990 km East of Northern Luzon (17.0°N, 131.0°E).

Strength: Maximum sustained winds of 65 km/h near the center and gustiness of up to 80 km/h.

Movement: Moving West Northwestward at 30 km/h.

Forecast Positions:
• 24 Hour (Tomorrow evening): 770 km East of Aparri, Cagayan (18.9°N, 128.9°E)
• 48 Hour (Tuesday evening):780 km East of Aparri, Cagayan (18.6°N, 129.0°E)
• 72 Hour (Wednesday evening): 415 km East of Aparri, Cagayan (17.7°N, 125.5°E)
• 96 Hour (Thursday evening):85 km West Northwest of Laoag City, Ilocos Norte (18.4°N, 119.8°E)
• 120 Hour (Friday evening):670 km West of Calayan, Cagayan (OUTSIDE PAR) (19.7°N, 115.1°E)

NO TROPICAL CYCLONE WIND SIGNAL

SEVERE WEATHER BULLETIN #1
FOR: TROPICAL STORM “#SionyPH” (ATSANI)
ISSUEDBY DOST PAGASA AT 11:00 AM, 01 November 2020
(Valid for broadcast until the next bulletin to be issued at 11 PM today)
 
TROPICAL STORM “SIONY” SLIGHTLY INTENSIFIES AND IS NOW INSIDE THE PHIILIPPINE AREA OF RESPONSIBILITY (PAR).
 
• “SIONY” entered the PAR at 8:00 AM today.
• It is forecast to move generally northwestward until Monday evening, then slowly west-southwestward by Tuesday.
• It remains less likely to affect any portion of the country over the next 2 to 3 days.
 
Location of eye/center: At 10:00 AM today, the center of Tropical Storm “SIONY” was estimated based on all available data at 1,365 km East of Central Luzon(16.0°N, 134.3°E).
 
Strength: Maximum sustained winds of 75 km/h near the center and gustiness of up to 90 km/h.
 
Movement: Moving West Northwestward at 30 km/h.
 
Forecast Positions
• 24 Hour (Tomorrow morning): 895 km East of Aparri, Cagayan (18.0°N, 130.1°E)
• 48 Hour (Tuesday morning):785 km East Southeast of Basco, Batanes (18.9°N, 129.3°E)
• 72 Hour (Wednesday morning): 780 km East of Calayan, Cagayan (18.4°N, 128.8°E)
• 96 Hour (Thursday morning):530 km East of Aparri, Cagayan (17.7°N, 126.6°E)
• 120 Hour (Friday morning):40 km Southwest of Calayan, Cagayan (19.0°N, 121.2°E)
 
NO TROPICAL CYCLONE WIND SIGNAL