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Another off season tropical depression has formed, this time about 400 miles east-northeast of Chuuk. 02W has winds of 25kts according to JTWC. The depression has some modest convection over the LLCC, with some curved banding features wrapping in. 02W is forecast to strengthen, as shear is low to moderate, waters warm (for now) and outflow good. JTWC expect a peak of 60kts before shear rises and waters cool along track. The track forecast is uncertain and fairly complex. Currently, motion is slow due to competing steering influences, between a ridge to the northeast and another to the northwest. The northeastern ridge is currently favoured to win out, allowing an eventual acceleration in speed northwestwards. Thereafter, there is disagreement in the models, with some forecasting a recurve northeast, and others forecasting a westward turn. JTWC favours the recurve scenario in a few days time.

A tropical depression has formed east of the Philippines, with winds of 25kts. Deep convection is currently displaced from the LLCC by moderate shear. Shear is not expected to ease significantly over the next few days, but favourable outflow should allow at least some slow intensification regardless. A general westwards track towards the Philippines is expected, with eventual landfall looking likely, though not certain. Because of the marginal environment, 01W will unlikely be a typhoon at landfall, probably a moderate to strong tropical storm instead.

A tropical depression with 30kt winds has formed 575 nautical miles southeast of Manila, Philippines. The depression has some moderately deep convection obscuring the LLCC, with some fairly well developed banding features flanking it. The environment is favourable, with low shear, good outflow and warm waters beneath the depression. However, landfall in the Southern Philippines is imminent, so short term strengthening will be limited by this. As 23W moves over the warm waters in between the islands of the southern Philippines, it has the potential to reintensify, and JTWC expect a peak of 45kts at this point. Thereafter, once 23W moves out into the South China Sea, a surge of cold northeasterly winds aloft will increase shear and drive cold, dry air into the system, causing weakening to occur as 23W continues westwards under the sreering influence of ridging to the north.

A tropical depression has formed from a low lattitude disturbance out in the east of the basin, 255 nautical miles south-southeast of Chuuk. Winds area at 25kts. 22W has a strong mid level centre, but a weaker circulation at the surface. With the plentiful deep convection associated with the system, it won't be long before the surface circulation strengthens. A strong ridge to the north will keep 22W on a west-northwestward track for the next 3-4 days. Thereafter, model disparity increases significantly, with some models forecasting a recurve northeastwards and others maintaining a continued westerly track towards the Philippines. One thing appears very likely however; 22W is likely to become a strong typhoon as the environment ahead is highly favourable. EDIT: JMA have upgraded the system to Tropical Storm Hagupit, with winds of 35kts.

After 3 weeks of inactivity, the Western Pacific has churned out a new tropical depression in resumption of what has been a relatively quiet season. 21W is moving through the southern islands of the Philippines, with winds of 30kts. Whilst 21W is interacting with land, the depression will struggle to strengthen. Strong ridging to the north will push 21W westwards back over water in the southern half of the South China Sea (SCS). Shear is low, and waters warm in the SCS, which favours intensification into at least a strong tropical storm before eventual landfall in Southern Vietnam. If 21W gets it's act together more quickly than expected once it clears the Philippines, then it has a shot at becoming a typhoon.

Tropical Depression 20W has formed a couple hundred miles northwest of Yap, and several hundred miles east of the Philippines. 20W has winds of 30kts. The depression already has well defined banding features and increasing convection over the LLCC. Given this satellite presentation, it won't be long before 20W is a tropical storm. Going by JTWC's forecast, it won't be long before 20W is a typhoon either. Shear is low, waters are very warm and outflow is good. This could produce some rapid intensification over the next few days. 20W is expected to head west-northwestwards, then northwest then north-northeastwards as it rounds the southern and western sides of the subtropical ridge loacted to the north. On the north-northeasterly leg of the track, shear could increase, causing some weakening at days 4 and 5.

Another tropical storm has formed, about 100 miles northeast of Pohnpei. 19W has winds of 35kts. 19W is expected to take a path similar to Typhoon Phanfone, albeit from a starting point further southeast. Strengthening is expected, as shear should remain low and outflow good. 19W could become quite an intense typhoon, just like Phanfone.

Tropical Storm 18W has formed well south of Japan and well east of the Philippines. Winds are at 35kts. Conditions are favourable for intensification throughout the next 5 days, with low shear and warm sea temps expected to persist. A generally northwestward track is expected through this time as ridging to the northeast remains in control. 18W is expected to be a significant typhoon southwest of Iwo To in 5 days time.

A new tropical storm has formed well southeast of Iwo To, Japan. The storm is named Kammuri, with winds of 35kts according to JMA. Kammuri is expected to strengthen as shear is relatively low and waters warm. Kammuri is expected to move slowly northwestward towards Iwo To, in a weak steering environment. Beyond this time, there is some uncertainty, but current thinking is that Kammuri will recurve to the northeast south of mainland Japan, as a trough creates a weakeness in the subtropical steering ridge to the north. The timing of this turn is uncertain. As poleward outflow continues to improve, Kammuri should strengthen into a typhoon, before weakening occurs by day 4/5 as sheat increases and waters cool along track.

The sixteenth tropical depression of the season has formed east of the Philippines. Winds are at 30kts. The depression has building convection over the LLCC, and formative banding features. The environment ahead is very favourable for intensification, with low shear, very warm waters and strong outflow. In fact, JTWC forecast rapid intensification to occur at some point over the next few days. Track wise, 16W looks to recurve northeastwards before reaching the Philippines, which is good news after the country has just been affected by Typhoon Kalmaegi. Having said that, some heavy rains are still likely as 16W passes by. Ridging to the north should break down as a trough pushes in from China. This should send 16W northeastwards through the islands southwest of Japan and ultimately into Japan itself. At this point, 16W should be an extratropical storm, but a pretty deep one nonetheless.

A new tropical depression has formed in the Western Pacific, well east of the Philippines. Winds are at 25kts. Convection is wrapping well on the western quadrant of the depression, although is a little thin on the northeast side. Conditions support some strengthening over the next few days, as waters are very warm and shear is low. A general west-northwesterly track is expected on the south side of ridging to the north. This puts Luzon at risk of impact from 15W in 4-5 days time, at which time JTWC expect 15W to be a 100kt typhoon. Track forecasts can change as ever, but this system is pretty concerning for the Philippines.

After a very long lull in new named storms (the last one to form was Super Typhoon Halong on July 27th! It is believed to be the first time on reliable record that there was no new named storms in August), we have newly formed Tropical Storm Fengshen, just south of Western Japan. Fengshen has winds of 40kts, according to JMA. Some persistant deep convection has developed over the LLCC, with some limited banding features too. Fengshen is forecast to move quickly east-northeastwards along the northern flank of subtropical ridge throughout the next few days. Fengshen is expected to strengthen a little, as, for now, shear is low, waters, again, for now, are warm and Fengshen has good poleward and equatorward outflow channels. As Fengshen continues east-northeastwards, it will reach higher shear as it interacts with the mid-lattitude westerlies, and move over colder waters. These two factors will cause Fengshen to become extratropical to the south of Eastern Japan, before finally exiting the tropics into the North Pacific.

A tropical depression has formed in the northern South China Sea, from invest 90W. 14W is located just southeast of Hainan Island and has winds of 25kts. 14W is currently being affected by shear, and the majority of the system's convection is being sheared away from the LLCC, to the northwest. Because of this environment, no change in strength is expected prior to landfall on eastern Hainan, in a little over 12 hours. 14W will then make a second landfall over the adjacent portion of southern China, and fully dissipate.

Tropical Storm Genevieve has formed in the far west of the basin, a long way out to sea. Winds are at 40kts. Genevieve has probably peaked, as shear is increasing over the storm, already displacing convection from the LLCC. Even stronger shear lies on Genevieve's generally westwards path, which will cause Genevieve to weaken soon, as it moves into the Central Pacific.

Tropical Depression 11W formed yesterday to the southeast of Guam, and has since strengthened into a 50kt tropical storm named Halong. Halong has deep convection over the LLCC, with banding features taking shape nicely in the southern quadrant. Halong is in an area of low shear and has well developed equatorward outflow, but poleward outflow is being surpressed by troughing to the north. This troughing is expected to lift out over the coming days, allowing Halong to further intensify, into a typhoon. Halong is expected to pass north of Guam in a northwesterly direction, before veering north as the storm reaches the western extent of the steering ridge to the north.

Invest 96W, that formed nearly 2 weeks ago, has finlly been declared a tropical storm, and is located just east of the Philippines. JMA estimate the winds at 35kts. JTWC haven't upgraded the system yet. The precursor to Nakri was a huge monsoon depression with two LLCC's orbiting around each other in a broad cyclonic gyre. The eastern LLCC has lost definition and convection has consolidated near the western LLCC, which is where Nakri's position has been located. Nakri's broad nature, along with some moderate shear, will probably only allow Nakri to strengthen slowly over the next couple of days as it moves towards Taiwan on a northwesterly track.

The tenth tropical depression of the season has formed about 175 nautical miles west-northwest of Yap, and is well east of the Philippines. The depression has some deepening convection over the LLCC, and some banding features taking shape. Shear is low, and waters warm, so intensification is expected. The steering pattern is quite complex. 10W is currently stuck between a ridge to the northeast and another to the southeast. The competing steering influence means that 10W is expected to move little over the next day or so. The ridge to the northeast is expected to win out beyond this time, allowing 10W to track northwestwards towards Taiwan. Luckily for the Philippines, it looks like this new system should not affect them as much as Rammasun did, as 10W should pass to the northeast. Taiwan need to keep a close eye on 10W however, as the depression is likely to be at typhoon strength near Taiwan by day 5, barring any track changes.

A new tropical depression has developed in the Western Pacific basin, the ninth of the 2014 Western Pacific Typhoon season. As Somerset Squall noted in the Western Pacific invest thread, conditions look favourable for development. The JTWC forecasts the system to reach 75 kt in 5 days, with a general westward track toward the Philippine islands. Confidence in the JTWC forecast is currently rather low. JTWC forecast track of 09W. A review on the fact that many models1 had multiple lows assessed within the area of 09W, from the Western Pacific invest thread: The JTWC answers this question, by stating that: In summary: It seems to be the poor initialization, combined with, and probably caused by the small size of the cyclone, that are causing this problem. EDIT: Deleted sentence that system would unlikely hit the Philippines as it is becoming more plausible that the Philippines will be hit by this system Sources: http://forum.netweather.tv/topic/80549-west-pacificnorth-indian-ocean-investseason-thread-2014/ http://www.usno.navy.mil/JTWC/ 1: http://moe.met.fsu.edu/cyclonephase/

Invest 90W has become the Western Pacific season's first tropical depression, a couple hundred miles south of Guam. Winds are at 30kts. The depression is in it's formative stages, and currently is quite broad. 08W is in an area of low shear, but there is not much outflow in a poleward direction. Because of the lack of outflow and broad structure, strengthening could initially be quite slow. Over the next few days, poleward outflow is expected to improve as the system heads northwestwards. With shear remaining low and waters warm aswell, a much quicker rate of strengthening is forecast be JTWC to occur beyond 72hrs. JTWC are currently forecasting 08W to become the strongest West Pacific system so far, forecasting a peak of 105kts. Track wise, the subtropical ridge anchored to 08W's north will be the primary steering influence. This should steer 08W northwestwards, between Guam and Yap. Thereafter, the ridge is expected to weaken due to an advancing trough from the west, sending 08W northwards east of Taiwan, ultimately bringing the system towards Okinawa. The timing of this turn is uncertain, and could change in the coming days.

After a lull of a month and a half (besides Tropical Storm Mitag south of Japan earlier this week, which really was blink and you'll miss it), the Western Pacific has re-awoken with the formation of Tropical Storm Hagibis, located southeast of Hong Kong, China. Hagibis is a large, sprawling storm with large rainbands flanking the consolidating LLCC. Winds are at 35kts. The storm is in an area of low shear and over warm water, so some intensification is expected, however, this will be limited by the fact that Hagibis only has about 24hrs over water before landfall east of Hong Kong. Primary concern here is some very large rainfall totals in southeastern China and Taiwan.

A new tropical depression has formed in the western Pacific, just to the southeast of Guam. The JMA (Japan Meteorological Agency) has started issuing advisories on the system, without classifying it as of yet. The JTWC has issued a tropical cyclone formation alert on the system, and that agency currently has designated the system as 99W. Current structure Over the last few hours (as of 11:00 UTC), inner convection has weakened markedly, with a circular area of convection rapidly weakening into a weakly defined banding structure. The weakening of the inner convection can be seen below: DVORAK satellite imagery loop of 99W (courtesy: NOAA) Despite the apparent disorganization of the convection, a clear circulation is apparent near 146.5E, 10.5N. This circulation has become better defined over the last day or so. Forecast Currently, the system is moving northeastward. The JMA forecasts a slow curve back toward the northwest with some slight intensification. Meanwhile, the GFS forecasts a track directly northward without any strengthening. However, it appears as if the GFS has badly initialized the system, which indicates that this track forecast might not be very reliable. The track forecast from GFS is indicated below: Once the system becomes better defined, a more clear picture of the track of 99W will become apparent. Sources: http://www.usno.navy.mil/JTWC/ http://www.jma.go.jp/en/typh/ http://www.ssd.noaa.gov/PS/TROP/floaters/99W/99W_floater.html http://www.nrlmry.navy.mil/TC.html

As Sommerset Squall and others noted in the thread of Haiyan, another invest has developed in the West Pacific, which could strike the Philippines. The invest is currently rather disorganized, and only broad cyclonic rotation is noted in the IR loop below. http://www.ssd.noaa.gov/PS/TROP/floaters/90W/flash-vis-long.html As the system is not yet recognized on the CIMSS web site, the analysis will be done by charts of the complete West Pacific. Current shear levels are low around the system, as an anticyclone is directly overhead (or just to the west of the system). The system itself is currently located near 2.0N, 144.0E. The anticyclone can be found as the area where the wind vectors spiral out of that particular point. (around 2N, 142E) Shear tendency over the past 24 hours shows that the shear is decreasing to the west of the cyclone, but increasing to the east of the cyclone. (Cyclone Haiyan is the cyclone indicated with the red cyclonic shape, this is not the area I'm discussing right now). Concluding, shear levels are quite favorable around the cyclone, improving the chances on development. Next is the 850 hPa vorticity. The vorticity map shows that there is currently some pronounced vorticity at the area of the invest, though slightly west of the position the JTWC is indicating. An overview of the West Pacific in Water Vapor imagery does show high levels of dry air directly to the north of 90W, but because this system is at such low latitude, I don't think it will be a big impediment to development. Because the area hasn't been initialized as an invest yet, there are also no direct TC forecast tracks available. Because of that, the GFS full WPAC charts will be used to make a forecast. Below is a forecast of the MSLP (minimum surface level pressure) at T84, based on the GFS output. It shows a weak TC making landfall just to the south of the area Haiyan hit yesterday. This could lead to even more heavy rainfall and consequently flash floods to the already soaked middle and southern Philippines. It would be a very bad scenario if this pans out. And finally, the NAVGEM model (it doesn't seem to be very reliable). It also shows a weak cyclone making landfall right at the spot Haiyan made landfall (T96hr) Currently, the available models aren't showing a real monster to develop. As the system becomes more pronounced and gets initialized by the models, we'll get a better assessment and forecast of the system, and how much it could impact the Philippines. Let's hope a disaster like Haiyan won't repeat itself with this system. Sources: http://www.ssd.noaa.gov/PS/TROP/floaters/31W/31W_floater.html http://tropic.ssec.wisc.edu/ http://www.wetterzentrale.de/topkarten/fsfaxsem.html http://tc.met.psu.edu/wpac/indexwpac.html http://www.usno.navy.mil/JTWC/