Tropical Update

Quieter weather regime is in place for the Philippines this week with the northerlies affecting Luzon and easterlies affecting Visayas and Mindanao. Eastern Asia is also mostly quiet and cold with chances for snow showers especially in NE China and the Korean Peninsula. Western areas of Honshu, as well as Hokkaido, in Japan will experience sea-effect snow. As for the tropics, we are currently watching two tropical disturbances: one in the South China Sea, and another in the Philippine Sea. This IR Image from NRLMRY depicts the numerous weather systems discussed in this update.

IR image from NRLMRY

The first tropical disturbance is Invest 98W which is located approximately 300km south of Vietnam in the South China Sea. An ASCAT pass earlier today suggests a developing low-level center with winds of 20 to 30kph. Wind shear is low to moderate (10-20kt). Sea surface temperatures are somewhat favorable. The system is embedded in the wind convergence that is producing showers across the South China Sea. 98W is moving westward at around 20kph and could approach the Thai-Malay Peninsula this weekend. The system has a low chance of development as noted by JTWC, as well as having little model support. Nevertheless, we do expect the disturbance to bring rains across Malaysia, Thailand, and even Cambodia and Singapore over the weekend.

VIS Image from NRLMRY showing the location of Invest 98W

The next system is 99W which is located approximately 400km southeast of Davao City. It, too, is embedded along a weak convergence that is bringing showers into Yap and Palau. While 99W's chances for development is low, it could potentially bring heavy rains across Southern Mindanao, depending on the track it takes. Right now, we have two scenarios: a tracks towards Western Papua/North Moluccas and North Sulawesi of Indonesia. The other potential track is towards the northwest into Southern and Central Mindanao. Either way, we expect rain showers to affect Davao Region starting tonight and will continue for the next 3 days. We will give you more updates with regard to the progress of this disturbance.

Finally, we have the 3-day weather forecast for cities in the Philippines. As said at the top, we expect quieter weather in the northern half of the Philippines with only slight chances for rain showers. Much of the precipitation will occur in the Southern Visayas/Mindanao region due to the wind convergence as well as the developing 99W. Please note that this is NOT OFFICIAL.

We'll have our next update on Monday, January 2, unless there's a significant development to either 98W or 99W. So this is potentially our last post for 2011. Until our next update, we hope you all have a wonderful and SAFE NEW YEAR!
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Issued (09 UTC) 5pm PhT 123011

Tropical Update

Heavy rain continues to dominate the Southern Philippines, rubbing a salt in the wound as they say. More than 200mm have fallen in the past 24 hours alone in some locations in Mindanao. Areas in Region X (near CDO and Iligan) have also recorded 150 to almost 200mm. Furthermore, places in Visayas such as Cebu, Negros and Leyte Provinces have also reported heavy rains. We have created a simple graphic below showing the rainfall accumulations in the past 24 hours. Data were collected from PAGASA, the World Meteorological Organization (WMO), and NASA's TRMM. Please do note that there may be discrepancies with the data so please use them with caution.

The heavy rains that the region have been experiencing is due to the combination of ITCZ and a weak tropical disturbance (LPA) that moved through Mindanao yesterday. This batch of showers will continue to move slowly to the west and will eventually affect Indochina by the end of the week.Furthermore, a cold front continues to trigger scattered rain showers across Southern Luzon and parts of Visayas.

IR Image from NOAA

We expect rainfall amounts to be around 100 to 200mm for much of Visayas and Northern Mindanao. Palawan will also have light to moderate rains that could amount up to 150mm. Luzon will see less rain although amounts of up to 100mm could still bring minor flooding. We do have this rainfall forecast map for the Philippines which shows accumulation for the next 24 hours. This is NOT OFFICIAL and should not be used in life or death situations.

The NE Monsoon behind this front is also bringing cooler temperatures across Northern Luzon. Places like Laoag have dipped into the upper teens last night. Baguio City have dropped to 12C on Christmas morning. Higher elevations in Central Luzon such as Antipolo and Tagaytay have also reported mid to upper teens within the past 2 nights.

Finally we have our 3-day Weather Forecast for Baguio, Manila, Cebu, and Davao. As always, THIS IS NOT OFFICIAL. We'll have another update on December 30.

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Issued (09 UTC) 5pm PhT 122711

Tropical Update

All is well across the Western Pacific today, except of course the Southern Philippines where people are still trying to recover from the flooding disaster brought by Washi. Right now there are no tropical cyclones in the region although we are watching some interesting weather, as noted by our analysis below:

IR Image from NRLMRY

Cold temperatures prevail across much of Eastern Asia with some cities not climbing out of the freezing mark. Weather here is pretty dry, though, except with some passing snow showers. Meanwhile in Japan, a snowstorm is currently affecting Hokkaido and Eastern/Northern Honshu bringing with it heavy snow (up to 50cm in some areas) and strong winds. The LOW will be moving slowly eastward so expect improving conditions by next week, except in the northern portions of Japan.

As for the Philippines, the tail end of the cold front will be moving southwards, bringing cooler weather for much of Northern Luzon. In fact, we could see the coldest temps of the month so far this coming Sunday. Places like Laoag and Aparri could see temps as low as 19C. Northern islands such as Basco and Itbayat will see temps go down to almost 16C. Mountainous areas including Baguio City could get down to as low as 12C come Sunday morning and even Monday morning. This cold surge won't extend farther south though so places like Cebu and Davao will remain mild with temperatures ranging from 22 to 32C. Furthermore, eastern sections of the country will experience increased chances for precipitation due to wind convergence. Expect rains across the Bicol Region and Eastern Visayas and Mindanao.

ITCZ is bringing rain showers across Palau and Yap today. There is also a weak circulation embedded although we are not expecting this to strengthen. Nevertheless, the ITCZ is forecast to move westwards in the coming days and could approach Mindanao by Sunday or Monday. Cities here will have scattered light to moderate rains.

We have released a 3-day Graphic Forecast for four cities in the Philippines. Please note that these forecasts are NOT OFFICIAL.

Next update will be on December 26, 2011. Until then, have a safe and happy Christmas!
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Issued (08 UTC) 4pm PhT 122311

TD Washi Update #13 [FINAL]

Tropical Depression Washi is now rapidly disintegrating in the South China Sea, just east of Vietnam. The storm was last located approximately 340km east of Ho Chi Minh. Maximum sustained winds are around 45kph gusting to 70kph. It is moving westward at 20kph.

The system is now weakening with convective activity almost gone. The circulation center is also becoming less defined, as seen on an ASCAT pass. A new surge of the NE Monsoon is bringing moderate wind shear and drier air. JTWC and JMA have both given their respective final warnings for the storm. As such this will also be our final update for TD Washi.

IR Image from NRLMRY

Washi's remnants could affect Southeastern Vietnam with scattered rain showers. Rainfall amounts should generally be light, however.

As the Tropical Season is nearing its end, we will revert back to giving 3x a week updates regarding the weather in the region. As always, we'll keep monitoring the Pacific for possible cyclone development.
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Issued (2130 UTC) 530am PhT 122011

Tropical Depression Washi Update #12

Washi is now beginning to weaken over the South China Sea and has been downgraded to a Tropical Depression by both the JTWC and JMA. The storm was last located on satellite approximately 570km east southeast of Ho Chi Minh, Vietnam. Maximum sustained winds are now down to 55kph with gusts of up to 80kph. TD Washi is moving west southwestward at 20kph.

Latest satellite image shows the system is becoming less organized as the system begins to encounter unfavorable conditions. Central convection is still strong although the low level circulation center is now partly displaced to the southeast. Nevertheless, the system continues to hold much moisture and has actually brought heavy rains in the Spratly Islands. An islet called the South West Cay (currently occupied by Vietnam) recorded nearly 180mm of rain in the past 24 hours.

VIS Image from NRLMRY

As the system "unravels", we expect rain showers to affect extreme Southern Vietnam, tonight and into tomorrow, amounts should be light. Washi should continue moving southward and could dissipate as early as tomorrow night. Its remnants could affect the Malay Peninsula by Wednesday.

Personal Forecast (NOT OFFICIAL)

Meanwhile, the NE Monsoon continues to affect Luzon in the Philippines. Expect on and off showers with occasional downpours, specially in the afternoon hours. Casiguran, Aurora recorded more than 200mm of rain in the past 24 hours alone. Rains should taper off by Wednesday as the front lifts out. However, another cold front is forecast to dive down into East Asia by this weekend, bringing another round of precipitation and cold air with it.

We'll have more updates tomorrow, stay safe!
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Issued (09 UTC) 5pm PhT 121911

Tropical Storm Washi Update #11

Tropical Storm Washi has now moved away from the Philippine Area of Responsibility. It was last located approximately 820km east southeast of Ho Chi Minh, Vietnam. Maximum sustained winds remain at 85kph gusting to 110kph. Washi has slowed down and is currently moving west southwestward at 15kph.

IR Image below shows the location of Washi. The core remains intact despite the increasing wind shear.

Washi will continue moving southwestward, avoiding Vietnam. It is forecast to begin to weaken as it approaches the Malay Peninsula by the middle part of this week.

Another update later this afternoon.
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Issued (2130 UTC) 530am PhT 121911

TS Washi (Sendong) Update #10

Tropical Storm Washi (Sendong) continues to move away from Palawan and Mindanao and is beginning to exit the Philippine Area of Responsibility. The center of the storm was last located approximately 400km west northwest of Puerto Princesa City or about 940km east southeast of Ho Chi Minh in Vietnam. Maximum sustained winds remain at 85kph gusting to 110kph. Washi has also begun to turn to the west southwest and is moving at 30kph.

All signal warnings have now been dropped by PAGASA. Even though Washi is now moving away from the country, the death toll in Mindanao continues to climb and has already surpassed the 500 people-mark today. The Philippine Red Cross estimates that as many as 400 people are still unaccounted for. We haven't really received any casualty reports out of Palawan yet and let us hope it stays that way.

As we have forecast yesterday, weather conditions are now beginning to improve for much of Mindanao, allowing rescuers to do their job in finding the victims. However, there will still be some scattered rain showers, particularly in the Eastern Sections of Visayas, Southern Luzon, and Northern Luzon as the NE Monsoon continues to affect the said areas. The Visual Satellite Image from NRLMRY below shows the last location of Washi as well as a long convergence line that has set up over the South China Sea. This line of thunderstorms indicate a clash of windflow as the NE Monsoon surge and easterlies meet. The line stretches from as far south as Malaysia, northeast towards Luzon. Expect light to moderate rains for the next 24 hours. Rainfall out of Luzon and Visayas today range from 50 to 100mm, expect the same amounts for at least the next 2 days.

VIS Image from NRLMRY

Going back to TS Washi, the storm has begun to reorganize a little bit as it moves over the open waters of South China Sea. However, we expect intensification to be limited due to increasing wind shear and drier air brought by the monsoon surge. Additionally, sea surface temperatures in the SCS will decrease as Washi moves westward.

As far as the track, we have shifted our forecast southward to account for the recent turn, as well as latest computer guidance. Hence, the track is now aligned with most weather agencies in the basin. We forecast Washi to continue moving west southwestward, moving south of Vietnam. It will be approximately 400km south of Ho Chi Minh come Tuesday morning. Washi will then start to weaken as conditions become unfavorable. It is forecast to become a Tropical Depression by Tuesday and will likely dissipate by Wednesday. Its remnants will likely move into the Malay Peninsula, north of Singapore.

Personal Forecast (NOT OFFICIAL)

We'll have another update tomorrow morning.
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Issued (0930 UTC) 530pm PhT 121811

TS Washi (Sendong) Update #9

Tropical Storm Washi (Sendong) is beginning to move away from the Philippines, after moving through Palawan last night. It was last located approximately 70km northwest of Puerto Princesa City, moving west northwestward at 25kph. Maximum sustained winds have decreased slightly to 75kph gusting to 100kph.

Washi has weakened as it crossed the Palawan Island. The center has become somewhat disorganized and elongated. We are still waiting reports out of Palawan although initial rain amounts range from 50 to 100mm. Meanwhile, in Mindanao, the death toll continues to climb and is now more than 400 people, with hundreds more missing. Again, the main culprit here are the flash floods, particularly in Iligan and Ozamiz. Right now though, Washi is moving away so we expect improving conditions.

There is still Signal Warning #2 for Palawan and Signal #1 for Cuyo and Coron Group of Islands, this is as of 5am from PAGASA.

Areas mentioned will still have rain showers throughout today, particularly in Palawan. Much of Mindanao and Visayas should get clearing skies with small chances of showers and thunderstorms. The rains brought by the NE Monsoon will continue to affect Central and Southern Luzon, particularly the Bicol Region.

Forecast track for Washi has not changed and we'll have more info regarding this later in our afternoon update.
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Issued (2130 UTC) 530am PhT 121811

TS Washi (Sendong) Update #8

Tropical Storm Washi (Sendong) is now reorganizing over the Sulu Sea and is moving towards the province of Palawan. This after moving through Mindanao last night and leaving more than 150 people dead. Most casualties were reported near Iligan due to flash floods that hit overnight, catching many residents off guard. It is feared that that number could rise as authorities try to find more people from affected communities. 100 to 200mm of rain has also fallen across parts of Mindanao and Visayas. Even Central and Southern Luzon are reporting light rains due to converging winds brought by Washi and the NE Monsoon.

This surge in the monsoon will bring strong northeasterly winds across Northern Luzon together with light rain showers with isolated thunderstorms.

Washi was last located approximately 240km east southeast of Puerto Princesa City or about 290km northwest of Zamboanga City. Maximum sustained winds have weakened a little bit to 85kph gusting to 105kph. Our wind estimates are lower than that of JTWC based on latest satellite data. TS Washi is currently moving westward at 20kph.

As of 5pm today, PAGASA has raised Signal Warning #2 Palawan and Signal #1 for Cuyo, Coron Group of Islan, and Negros Island. All other warnings elsewhere have now been dropped.

Latest IR Image shows a new hot tower (yellow colored) erupting near the center which could suggest that Washi is trying to reorganize over the open waters. Wind shear have increased in the past 12 hours which left the center partially exposed this afternoon; it has since improved as new convection tries to fire off.

IR Image from NRLMRY

TS Washi will be moving in to Palawan tonight, particularly near Puerto Princesa City. We are looking at a landfall of time of around 9pm tonight. Expect heavy rains, strong winds, and storm surges, particularly along the northern half of the island. Rainfall amounts could vary from 100 to 200mm. Washi is then forecast to exit into the South China Sea tomorrow morning.

Long term forecast takes Washi into the Eastern South China by early next week. JTWC is showing a sharper recurve towards Malay Peninsula. Our forecast is somewhat north of that and we are expecting Washi to make skirt the Southern Coast of Vietnam, near Ho Chi Minh very early Tuesday. It will then weaken due to land interaction, lower sea temperatures, and increasing wind shear. Washi could approach the Malay Peninsula by Wednesday as a weak Tropical Depression.

Personal Forecast (NOT OFFICIAL)

We'll have another update tomorrow morning, stay safe!
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Issued (0930 UTC) 530pm PhT 121711

TS Washi (Sendong) Update #7 [LANDFALL]

Tropical Storm Washi (Bagyong Sendong) is now moving into Sulu Sea after affecting Mindanao last night. The storm center was last located approximately 30km north northwest of Dipolog City or about 50km south southwest of Dumaguete City. Maximum sustained winds are still around 85kph gusting to 105kph. Washi is moving westward at 25kph.

As of 5am today, PAGASA still have Signal #2 warnings for Misamis Occidental, Lanao del Norte, Lanao del Sur, Zamboanga Provinces. Signal #1 for Palawan, Bohol, Siquijor, Southern Cebu, Negros Oriental, Southern Negros Occidental, Camiguin Island, Misamis Oriental, Bukidnon, North Cotabato, and Maguindanao. 

A recent microwave image shows an inner core that is intact and very organized--almost showing an eye, hence we kept the intensity at 85kph.

Image from NRLMRY

Western Mindanao (Zamboanga Peninsula) and Central Visayas (Particularly Negros Island) will continue experiencing stormy conditions with heavy rain and strong winds. Latest rainfall reports out of Mindanao range from 100 to 150mm with some locations like Cagayan de Oro reporting nearly 200mm of rainfall. We expect another 100mm to fall today across these parts. However, weather should begin to improve for most of Mindanao beginning this afternoon. TS Washi will then move into Palawan later this evening as a strong Tropical Storm. The warm waters of the Sulu Sea, coupled with weak wind shear, will allow Washi to regroup and perhaps intensify a little bit more before affecting the Province.

TS Washi is forecast to exit the Philippine Area of Responsibility by Sunday morning. After that, computer models begin to diverge as to the future track of the storm. For now, we forecast Washi to move westward into Southern Vietnam, affecting the country as early as Tuesday.

We'll have another update later this afternoon. Stay safe!
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Issued (22 UTC) 6am PhT 121711

TS Washi (Sendong) Update #6 [LANDFALL]

Tropical Storm Washi (Bagyong Sendong) is now making landfall along the Eastern Mindanao Coast, particularly along the Surigao del Sur/Davao Oriental Provinces. It has strengthened a little bit just before moving into land with maximum sustained winds now around 85kph with gusts of up to 105kph. TS Washi has also slowed down and is currently moving westward at a speed of 20kph. The center of the storm was last located approximately 140km northeast of Davao City.

As of 5pm today, PAGASA has raised Signal Warning #2 for the provinces of Surigao Del Norte, Siargao Island, Surigao Del Sur, Dinagat Province, Agusan Provinces, Bukidnon, Davao del Norte, Davao Oriental, Compostela Valley, and Camiguin. Signal #1 for Misamis Occidental, Lanao del Norte, Lanao del Sur, North Cotabato, Samal Island, Maguindanao, Davao del Sur, Zamboanga Provinces, Negros, Cebu, Bohol, Southern Leyte, Siquijor, and Palawan.

IR Image from NRLMRY showing the storm beginning to move into Mindanao. Bright colors mean stronger convective activity. The yellow circle represents the center of the storm (CDO) and is a sign of intense convection which could bring very heavy rainfall along with strong winds.

These areas will receive heavy rainfall along with strong winds overnight. We expect rainfall amounts of 150 to 250mm with isolated amounts of up to 350mm along the mountainous areas of Mindanao. The threat of landslides and flashfloods are very high, please coordinate with the authorities for evacuations! Stormy conditions will persist for at least 10 hours; weather should begin clearing out tomorrow for most areas in Mindanao.

Outer rain bands will also affect Cenral Visayas particularly Negros, Cebu, Bohol, and Panay. These rain showers may bring up to 150mm over night. Scattered thunderstorms, enhanced by Washi, may also affect Southern Luzon.

TS Washi will continue moving westward passing near Cagayan de Oro and Iligan City tonight. It will exit into Sulu Sea tomorrow morning as a weak storm. The interaction with the topography of Mindanao will be crucial for the future intensity of Washi. It may or may not have a chance of redeveloping over the water. Palawan will also be affected starting Saturday afternoon and into the night as Washi moves in from the east. The storm is expected to exit the Philippine Area of Responsibility by Sunday afternoon. Computer models then take Washi along the South China Sea and into Southern Vietnam by Tuesday next week.

Personal Forecast (NOT OFFICIAL)

Invest 96W south of Guam has dissipated and no longer has a chance for development.

We'll have more updates tomorrow morning. Stay safe.
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Issued (10 UTC) 6pm PhT 121611

Tropical Storm Washi (Sendong) Update #5

Tropical Storm Washi (Bagyong Sendong) is now strengthening at a quicker pace as it moves closer towards the Philippines. The storm was last located approximately 250km west of Palau or about 750km east northeast of Davao City. Maximum sustained winds are now at 65kph gusting to 90kph. TS Washi is moving westward at 30kph.

As of posting time, PAGASA has now released Signal Warnings in anticipation of Washi (Sendong). Signal #1 is in effect for Eastern Samar, Western Samar, Leyte Provinces, Camotes Island, Bohol, Surigao Del Norte, Siargao Island, Surigao Del Sur, Dinagat Province, Agusan Provinces, and Misamis Oriental.

TS Washi moved over Palau earlier today, bringing breezy conditions along with rain showers. The storm was not that strong then; Koror only reported maximum winds of around 40-50kph and a minimum pressure of around 1002mb. During the past 6 hours though, the system has really gotten itself together. Infrared satellite shows cloud tops continue to cool and a central dense overcast beginning to become organized. The image below is what we call a microwave satellite image which looks through the clouds (like an xray). In this particular image, we can see that Washi seems to have begun forming an ill-defined eyewall. While it has a small chance of becoming a typhoon due to very fast movement, it could still rapidly intensify within the next 12 to 24 hours.

Again, due to fast forward speed, TS Washi has roughly 24 hours left before it begins to interact with Mindanao. We have not changed our forecast significantly and are still expecting a landfall to occur sometime tomorrow afternoon or early evening. TS Washi is forecast to move near Surigao and then cross into the Central Visayas, affecting Bohol, Cebu, and Negros. Washi will then move into Sulu Sea by Saturday morning. It should then begin affecting Palawan by late Saturday night. Medium-term forecast shows that Washi could exit the PAR by Sunday morning.

Personal Forecast (NOT OFFICIAL)

A new low pressure area was also spotted today. Invest 96W is located well southeast of Guam and does not pose any immediate threat to land. It has a LOW chance of developing into a storm although we'll continue monitoring this system.

We'll have more updates tomorrow, please stay safe!
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Issued (09 UTC) 5pm PhT 121511

Tropical Storm 27W Update #4

Tropical Storm 27W remains a weak TS as it nears Palau. It was located approximately 150km east of the island, moving westward at 30kph. Maximum sustained winds are still at 65kph with gusts reaching up to 85kph. A Tropical Storm Warning remains in effect for Palau while the Tropical Storm Watch for Yap has now been cancelled.

VIS Image from NRLMRY

Latest reports out of Koror indicate increasing winds with gusts reaching up to 45kph. Moderate rain showers are also being reported from the area. Expect stormy conditions to persist for another 6 hours. Since 27W is moving at a fairly quick pace of about 18kts, weather should improve in the Palau/Yap area by later tonight.

We are expecting Tropical Storm 27W to enter the Philippine Area of Responsibility later today; PAGASA will assign the name "Sendong" for 27W once it enters the PAR. Forecast track still takes 27W towards Northern Mindanao/Eastern Visayas by Friday. 27W could still intensify although as mentioned last night, we don't expect this system to become a typhoon.

More updates later this afternoon.
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Issued (2330 UTC) 730am PhT 121511

Tropical Storm 27W Update #3

27W has strengthened into Tropical Storm today. It was last located approximately 500km east southeast of Palau, moving westward at 25kph. Maximum sustained winds are now at 65kph gusting to 85kph.

Latest IR image shows that the low level circulation that was fully exposed this morning has begun to be cloud covered again as a new cluster of convection forms over the center. Cold cloud tops continue to form closer to the circulation which might indicate weaker wind shear. However, this batch of storms is still displaced somewhat northwest of the center; combined with the fast forward speed of 27W, we might see a slow rate of intensification for at least 12 to 24 hours.

IR Image from NRLMRY

TS 27W is forecast to move close to Palau later tonight which is why a Tropical Storm Warning is now in effect for Palau and a TS Watch for Yap. Expect winds to increase in the coming hours, combined with widespread light to moderate rains. Rainfall amounts could vary from 100 to as much as 200mm in 24 hours. There will also be increased surf as the storm approaches. Conditions should improve by tomorrow afternoon.

TS 27W will then continue moving westward and could be inside the Philippine Area of Responsibility by tomorrow morning. Due to the conditions remaining favorable throughout the forecast period, TS 27W should intensify further before impacting the Philippines. Timeline for TS 27W would be around Friday morning for Northern Mindanao. It will then cross into Central Visayas and exit into Palawan by Saturday. JTWC is forecasting this to become a typhoon, we're not. However, that could change.

Personal Forecast

We'll have more updates by tomorrow.
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Issued (09 UTC) 5pm PhT 121411

Tropical Depression 27W Update #2

Tropical Depression 27W has strengthened slightly as it moves westward across the Pacific. It was last located approximately 780km east of Palau. Maximum sustained winds are now at 55kph gusting to 75kph. TD 27W is moving westward at 25kph.

TD 27W gained strength overnight because of the favorable conditions in the region. There is, however, a slight increase in wind shear where 27W currently is situated. Because of this, the system does not look as organized as last night. Despite this setback, the main convection remains intact and there are still some cold cloud tops emanating from the cluster. Overall environment should remain favorable enough to allow 27W to strengthen to Tropical Storm strength, perhaps as early as today.

IR Image from NRLMRY

TD 27W is forecast to continue moving westward and could approach Palau by later tonight/early tomorrow. The National Weather Service (NWS) has issued Tropical Storm Watches for Palau and Yap for strong winds beginning today. TD 27W will then continue moving westward, and could enter the Philippine Area of Responsibility early tomorrow morning (Thursday). The Joint Typhoon Warning Center is very bullish in terms of development. Banking on improving outflow, weak wind shear, and high SSTs, JTWC is forecasting 27W to become a typhoon before moving into Northern Mindanao by Friday morning.

While the conditions do look good for continued development, we are forecasting a somewhat weaker peak wind. Depending on the rate of intensification, it is likely 27W will remain as a Tropical Storm and not become a typhoon. Of course, the forecasts can (and do) change.

IR Image from NOAA showing the locations of both 26W and TD 27W.

We have put out the final warning for 26W, for more info, please refer to our separate post.
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Issued (22 UTC) 6am PhT 121411

Tropical Depression 26W Update #4(FINAL)

Tropical Depression 26W is now beginning to dissipate south of Vietnam. It was last located approximately 350km south east of Ho Chi Minh. Maximum winds are now only around 35 to 55kph. 26W is moving southwestward at 15kph.

As forecast, increasing wind shear and cooler sea temperatures in this part of the South China Sea have blocked any development regarding 26W. Current IR image depicts fragmented and very weak convection; the center of circulation is barely recognizable as well. Rain clouds associated with 26W may try to move into Southern Vietnam today which could bring scattered rain showers, although amounts should generally be less than 100mm.

IR Image from NRLMRY

Due to the weakening trend and the dissipation forecast, this will be our last update for TD 26W. For updates on the other depression--27W, please refer to our separate post.
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Issued (22 UTC) 6am PhT 121411

Tropical Depression 27W Update #1

The Joint Typhoon Warning Center has just upgraded Invest 95W into Tropical Depression 27W. This system is located approximately 790km south of Guam. It is moving westward at 20kph. Maximum sustained winds are currently around 45kph gusting to 65kph.

We've been talking for days about Invest 95W and its chances of developing; now here we are warning it as a TD. Conditions have been, and continue to be, favorable for development and the system has made improvements over the past 24 hours. Center of circulation continues to intensify and consolidate as evident on a microwave image. Furthermore, convective activity continues to increase and become more organized. Weak wind shear, moist air, and warm sea surface temperatures will continue to persist which will likely help 27W to strengthen further. In fact, JTWC is forecasting this system to become a Typhoon by Thursday!

VIS Image from NRLMRY

As far as the forecast goes, we expect TD 27W to remain in a generally westward movement. Based on its current speed, it is likely to enter the Philippine Area of Responsibility late tomorrow; if it does PAGASA will give the name "Sendong". As mentioned before, 27W will probably intensify further, given the favorable environment. It is forecast to become a Tropical Storm tomorrow morning and will move just south of Palau. By Thursday, it would be moving inside PAR and has a chance of becoming a typhoon by then--it all depends on the rate of intensification. If it continues to move on its present trajectory, we expect Mindanao to begin feeling the effects from 27W by as early as Friday afternoon.

We'll have more updates tomorrow morning.
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Issued (09 UTC) 6pm PhT 121311

Tropical Depression 26W Update #3

Tropical Depression 26W is now weakening in the waters south of Vietnam. It was last located approximately 550km southeast of Ho Chi Minh. Maximum sustained winds remain at 45kph gusting to 65kph. TD 26W is moving west southwestward at 15kph.

The system currently has a very weak convective activity despite having low wind shear. The dry-air from the NE Monsoon is what's inhibiting development. The center of circulation is still intact although winds around it have weakened significantly.

VIS Image from NRLMRY

Tropical Depression 26W is forecast to continue moving southwestward, avoiding landfall in Vietnam. However, still expect light to moderate rain showers for the next 1 to 2 days. The system will likely dissipate by as early as tomorrow as wind shear increases in the area.

Meanwhile, a new tropical depression formed in the Pacific today. For more info on this system, please check out our separate post: Tropical Depression 27W Update
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Issued (09 UTC) 6pm PhT 121311

Tropical Depression 26W Update #2

Tropical Depression 26W remains a weak system as it continues to move westward towards Vietnam. Maximum sustained winds are still at 45kph gusting to 65kph. 26W is moving westward at 15kph. The system briefly strengthened last night but then weakened earlier this morning. Shear continues to inhibit development of this cyclone.

Forecast remains generally the same for 26W. We don't expect any significant intensification due to unfavorable conditions that will return in the next 12-24 hours. Nevertheless, we do think rain will begin affecting Southern Vietnam today, particularly those near the coast. Due to the waning convective activity, rains will generally be light to occasionally moderate.

More updates for 26W later this afternoon.

Meanwhile, Invest 95W in the Western Pacific continues to consolidate while moving westward. It is approximately 950km south southeast of Guam. Microwave image shows convective banding with well-defined cyclonic turning at the lower and mid-levels. Conditions are favorable for continued development although computer models are not that bullish. JTWC has upgraded 95W's chances to "MEDIUM" and will continued to be monitored in the coming hours.
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Issued (00 UTC) 8am PhT 121311

Tropical Depression 26W Update #1

Invest 94W has just been upgraded by the Joint Typhoon Warning Center into a Tropical Depression. The center of 26W was last located approximately 450km west of Southern Palawan or about 750km east of Ho Chi Minh in Vietnam. Maximum sustained winds are estimated to be around 45kph gusting to 65kph. TD 26W is moving westward at 15kph.

Significant improvements in the upper-air environment in the past 24 hours have really helped the recent organization of 26W. Wind shear in the area is currently sitting at around 15 to 20 knots with sea surface temperatures somewhat favorable. Dry air from the north easterlies (monsoon) are being offset by a surge of south westerlies that JTWC is attributing to a MJO event. These conditions should help 26W strengthen a little bit or at least maintain its current intensity for another 24 to 48 hours. Computer models bring 26W westward and eventually southwestward under the ridge and could begin to affect Southern Vietnam by Tuesday.

Satellite image below (from NRLMRY) shows the partially exposed low-level circulation center as well as the blow-up of strong convection (brighter white clouds) west and northwest of the circulation. The eastern side of the storm is "empty" due to the presence of shear.

Meanwhile, nother area of low-pressure was spotted in the middle of the Western Pacific. Invest 95W is located about 700km west of Pohnpei in Micronesia. Cyclonic turning is evident on the satellite loop as well as a recent microwave image. 95W is located in an area of light to moderate wind shear (10 to 20kts) with favorable sea temperatures. Computer models are not showing any development and most of them keep it as a weak tropical wave moving westward. Nevertheless, we'll continue to watch this little system as it could definitely evolve into something more than a LPA.

IR image from NRLMRY

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Issued (09 UTC) 5pm PhT 121211

Tropical Update

The Tropical Cyclone Formation Alert issued by the Joint Typhoon Warning Center yesterday was allowed to expire this morning, hence Invest 94W was never upgraded into a depression by the said agency. We should note, however, that the JMA has still is classifying 94W as a Tropical Depression although not releasing special TC Warnings.

As predicted, the strong wind shear in the South China Sea is taking its toll on 94W's development. Its center (located approximately 400km west of Southern Palawan, around Spratly Islands) has become fully exposed today with weaker winds than yesterday as seen from an ASCAT pass. However, the most recent satellite images shows a new band of deep convection displaced southwest of the center which might suggest improvements with regard to 94W's development. With that said, latest models are still not showing development for 94W. Almost all of the computer models keep it as a weak tropical wave that could bring rain showers once it gets into Southern Vietnam. Wind shear across South China Sea remains very strong and that is significantly inhibiting 94W's chances of becoming a cyclone. Still, we'll continue updating you with this system.

As for the Philippines, rain showers continue to fall across Central and Northern Luzon. Rainfall amounts these past 24 hours is somewhat lower with most stations reporting "only" 50 to 100mm. As we have forecast yesterday, this batch of precipitation is slowly moving north and northeast (also weakening in the process). As the front in East Asia lifts out this Tuesday, we expect drier conditions together with warmer temperatures. Another front is forecast to dive into Korea/NE China by late next week which could bring another round of cool weather across the Philippines.
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Issued (08 UTC) 4pm PhT 121111

Tropical Update

Invest 94W continues to slowly consolidate over the South China Sea. It is located approximately 400km northwest of Palawan. Its low level circulation center has become better defined today and winds have increased somewhat based on an ASCAT pass. Convective activity associated with this LPA continues to blossom as well. Because of the latest developments, JTWC is now putting out a Tropical Cyclone Formation Alert for 94W signifying a "HIGH" chance of cyclone development within the next 24 hours.

As far as computer models go, 94W is not forecast to become a strong cyclone mainly due to the strong wind shear in the area. Furthermore, we are also expecting 94W to slowly move away from the Philippines in the next 24 to 36 hours. Nevertheless, showers from 94W are still possible especially along Palawan.

Meanwhile, converging winds east of the Philippines is bring scattered rain showers across Luzon and Visayas. Another 100 to 200mm of rain fell in 24 hours triggering isolated landslides and minor flooding. This batch of showers should slowly lift north in the coming days.
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Issued (09 UTC) 121011

Tropical Update

A Low Pressure Area has been spotted in the South China Sea, approximately 360km west of Palawan. An ASCAT pass earlier today reveals a disorganized low level circulation center with winds of 15 to 30kph. Some convection is also associated with the said LPA and is bringing scattered showers across Western Visayas and Luzon. Not much is expected with this disturbance due to the strong wind shear in the South China Sea. However, models do keep this batch of showers just west of the Philippines for at least 24 more hours before slowly moving westward.

IR image from NOAA

The bigger weather maker for the Philippines today is the ITCZ and the Northeasterlies (Amihan) which are affecting much of Luzon and Visayas. Both systems have already brought 100 to 200mm of rain this past two days across parts of Southern Luzon, Bicol Region, and Visayas Islands. Mindanao (particularly western sections) will also be experiencing scattered to widespread showers for the next 2 days. Models show the precipitation to slowly die beginning Sunday.

Apart from the rains, the northeasterly winds from East Asia is also bringing in colder air towards the country. We expect to continue seeing low temperatures in the middle 20's (celsius) in urban areas and possibly some teens in mountainous areas (eg Baguio). A slight warmup is projected to occur by the middle of next week.
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Issued (09 UTC) 5pm PhT 120911

TD 25 Update #2 (FINAL)

Tropical Depression 25W is now beginning to dissipate in the waters east of Vietnam. It was last located approximately 630km east of Ho Chi Minh City. Maximum sustained winds are estimated to be around 45kph. JTWC has given their final warning for 25W this morning.

This short lived system never really got it going as it had to battle moderate wind shear and cooler sea surface temperatures. Nevertheless, there is still some convective activity associated with the circulation and still has the chance to bring scattered showers across portions of Eastern Vietnam; although rainfall amounts should not be that heavy.

Satellite image from NRLMRY

This will also be our final update for TD 25W. Rest of the Western Pacific is quiet.
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Issued (10 UTC) 6pm PhT 120511

Tropical Depression 25W Update #1

Invest 93W has been upgraded into a Tropical Depression early this morning by the Joint Typhoon Warning Center (JTWC). The system is located in the South China Sea, approximately 600km east of Vietnam.

Latest update from the JTWC shows an estimated sustained winds of around 45kph with gusts of up to 65kph. An ASCAT pass last night picked up the low level circulation center with winds of somewhere around 30 to 50kph. However, convective activity has weakened and the depression has become a bit disorganized these past 6 hours. Based on the trends there is a chance 25W could dissipate sometime today. Nevertheless, the train of showers associated with this depression could still move towards Vietnam over the next couple of days.

Stay tuned for our afternoon update for more on 25W.
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Issued (22 UTC) 5am PhT 120511

Tropical Update

Invest 93W is slowly developing over the South China Sea and has the potential to become a Tropical Depression over the next 24 hours. The low pressure area was last located approximately 280km northwest of Brunei or about 500km southwest of Palawan.

An ASCAT pass earlier today shows 35 to 50kph winds coming from the south and a clear indication of the existence of a low level circulation center. Convective activity is strong despite the moderate easterly wind shear in the area.

JTWC has upgraded the chances to HIGH so we will be closely monitoring this system if it does become a Depression. The forecast takes 93W towards the north and eventually to the northwest--towards Vietnam.

Visible Satellite from NRLMRY

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Issued (10 UTC) 6pm PhT 120411