Western Pacific Tropical Analysis: October 18, 2017

Over the Tropical Western Pacific, the most potent monsoon trough setup of the year thus far has allowed Typhoon Lan to take center stage. Lan is a particularly large, sprawling system, and with favorable background conditions, is a system with a very high intensity ceiling. How much of this potential becomes realized depends largely on notoriously difficult to forecast inner core dynamics. Lan will move to the north, slowly at first but with a gradual increase in speed, and then to the northeast into the mid-latitudes. Prior to becoming a likely significant extratropical cyclone, Lan is expected to impact Japan with either a pass just offshore or direct landfall in about five days. An additional system or two may accompany Lan, but the impacts from Lan’s vast circulation should keep any additional systems in check concerning intensity.

***NOTE: While I would consider myself well-learned in meteorology, I am still a student with more to learn before becoming a degreed meteorologist. This forecast is not from an official source and should not be treated as such. For official information, please refer to your local weather agency.***

The 2017 Pacific Typhoon Season has largely been accompanied with a very weak or absent monsoon trough, so the season is unsurprisingly running well below seasonal activity. However, a high amplitude upward pulse from Madden Julian has ejected east from the Maritime Continent and overspread the western Pacific. Accompanying it has been a very impressive surge in monsoon southwesterlies extending into the Philippine Sea. As mentioned in the post’s lead paragraph, this is by far the most robust monsoon trough setup so far this year. Taking shape at the center of the Philippine Sea on the monsoon trough is Typhoon Lan. As of 03Z October 18, Typhoon Lan was located at 12.1ºN, 132.5ºW. Both JMA and JTWC assessed maximum sustained winds of 65 kt in their latest advisory packages.

As can be seen in the loop above, Lan is not the most visually striking typhoon. That is because it has yet to put together a respectable inner core, despite very favorable conditions. To me, this appears to be partly because of Lan’s size. Lan originally developed as a more normal sized system initially, but an additional surge of monsoon southwesterlies from the parent monsoon trough wrapped around and into the circulation, greatly expanding the system’s size. Lan featured an impressive CDO 12 or so hours ago and looked to be in the midst of core building, but the convection over the center has since collapsed. Conditions will remain particularly favorable for the next 72 hours prior to Lan’s passage of 20ºN, but considering the current state of the core (seen in a METOP-B pass from 0054Z October 18), it will probably take at least 24 hours for Lan to build a core and take advantage of the favorable conditions. Once a core is established, intensification is likely to be of the rapid variety. Most intensity guidance take Lan to category 4 intensity in 48 hours. Some guidance like the HWRF is probably consolidating the core too quickly, but forecasting a category 4 sometime in the next 48-72 hours does not appear unreasonable to me.

Lan will be moving north into a slight weakness in zonal subtropical ridge. Poleward outflow from Lan may actually help enhance the subtropical ridging to the east, which in turn will help draw Lan to the north with a gradual increase in speed. Lan should then begin to take on an easterly component to accompany the present northward motion once it begins to round the axis of the eastern ridge near 25ºN in 3-4 days. It is around this time when Lan will begin to interact with the right entrance region of a standing jet streak. The jet streak may temporarily increase upper divergence, but it will also begin shearing Lan as well as introducing dry air aloft into the circulation. The approach towards the mid-latitude flow in which the jet streak is embedded within will result in Lan’s acceleration towards the northeast. Lan is expected to pass near or just clip Honshu as a weakening, but still possibly significant system in slightly over 5 days. Lan could bring the potential for strong winds and impressive wave action along the coast, but rainfall may be the biggest threat to Japan from Lan. Due to Lan interacting with the right entrance region of the jet streak, heavy rain may extend well ahead of the main system.

Due to the track largely parallel with Japan, only a small difference in trajectory will exist between a direct strike and an offshore pass. At the moment, I am favoring a direct strike. Most guidance members are leaning towards the left of the two options. Probably the highest regarded member of guidance keeping Lan offshore is the HWRF. However, as mentioned earlier, the HWRF is probably consolidating Lan’s core too quickly, in turn ramping up Lan earlier than is likely. This may be impacting downstream depictions of subtropical riding and the jet streak, in turn steering the system further to the east. It’s a solution worth watching, but more the reliable guidance members remain to the west, landfalling in Honshu. Keep in mind that all the normal caveats for a 5+ day track forecast apply here. A Honshu encounter is just beyond JMA’s and JTWC’s 5 day forecasts, but an extrapolation from their 5 day forecast points appear to favor a direct strike as well.

Due in part to a busy schedule balancing college courses and a part time job, this is regrettably my first entry in over a month. I’m not sure I can keep a regular blog schedule like I was able to over the summer, but I will try to post when I can. Thank you all for reading! Until the next entry is up, updates will come in this entry’s comments section.

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North Atlantic Tropical Analysis: August 24, 2017 – Harvey Special

After dissipating in the eastern Caribbean Sea, Harvey has managed to redevelop in the Gulf of Mexico. Over the past 24 hours, Harvey has managed to strengthen from a tropical depression to a SSHWS category 1 hurricane. Harvey is continuing to strengthen as it heads towards the Texas coast, where it will bring the threat for strong winds, storm surge, and highly excessive rainfall.

***NOTE: While I would consider myself well-learned in meteorology, I am still a student with more to learn before becoming a degreed meteorologist. This forecast is not from an official source and should not be treated as such. For official information, please refer to your local weather agency.***

As of 18Z, Hurricane Harvey was located at 24.4ºN, 93.6ºW per NHC coordinates. Winds of 75 kts and a pressure of 976 mb were measured by aircraft recon, and this is the initial intensity to which Harvey is set. Harvey is located over very warm waters and in a good upper air environment, which has allowed a brisk strengthening over much of the past day. Final reports from the last recon mission indicate that Harvey may be leveling off in the near term. I do think this is temporary as the system transitions from a banding type structure to one more centralized around an eyewall. An eye has started to become more apparent on all bands of imagery over the past few hours.

Aside from the warm waters, a favorable upper level environment has been paramount to Harvey’s strengthening thus far. The system has developed an impressive divergent poleward outflow jet, allowing for good mass removal from the top of the tropical cyclone. The divergent nature of this outflow jet also extends just to the northeast of Harvey’s core where spiral bands have been able to consistently fire deep convection. Some light southwesterly shear has helped to keep outflow to the south and southwest of the system restricted, but the vigorous nature of the poleward outflow channel has been able to offset this up to this point.

Thus far, Harvey’s main steering mechanism has been the subtropical ridge to the system’s east. This ridge will push Harvey on a general northwestward trajectory for the next 48 hours, during which time it is expected to make landfall along the middle Texas coast. Because of the angle of approach towards the Texas coast, only a small change in angle could result in a landfall many miles further down the coast. At this time, I see little reason to differ from the NHC’s forecast, which has the track centerline making landfall not far north of Corpus Christi in just under 36 hours.

Every indication I am seeing is that Harvey will continue to strengthen up to landfall. Waters remain warm and heat laden, the upper air environment looks good, and the structure as revealed by a recent F-16 pass continues to improve (shown below). Harvey is also beginning to come into the range of the Brownsville radar, where an impressive eyewall is already showing up. Based on this, I think it is about 90% certain that Harvey will become a major hurricane. The NHC official forecast takes Harvey up to 110 kt just prior to landfall, which is a high end category 3 hurricane. That appears to be a good intensity estimate to me, although it is not impossible for the system to strengthen even slightly beyond that. With landfall, along with the high winds that will in all likelihood be above major hurricane intensity in the eyewall, the threat for a double digits of feet storm surge exists near and just to the right of the center at the landfall point.

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Even after landfall, Harvey will remain an impactful tropical cyclone, perhaps even more than at landfall itself. Once landfall occurs, steering is expected to break down. Harvey could be stuck drifting around near or just inland the Texas coast for a couple of days. Guidance begins to diverge at this point where exactly it will drift and how long it will remain quasi-stationary, but one thing that has been consistent is the monumental modeled rainfall totals. The WPC QPF forecast places a swath of over 20″ of rain along much of the Texas coast, and that is within an absolutely massive area that is expected to receive over 10″ of precipitation accumulation. As is the case with QPF forecasts, the rainfall will not be evenly distributed as the forecast graphic appears to indicate, but such mesoscale variations are nearly impossible to predict even in the short range. Regardless, much of south and southeast Texas should prepare for large scale flooding.

While there certainly is considerable spread, it does appear that the majority of guidance begins to trek Harvey to the northeast near or just off the coast after a few days of nearly stationary motion. Some guidance that brings the system offshore indicate that Harvey could intensify fairly quickly once more, but I expect the core to have taken a beating after moving inland, and do not think such solutions are very plausible. It is possible that it could take over five days from the time of this entry for Harvey to finally leave the vicinity of Texas.

For official, up to date information on Harvey and its expected impacts, please check out The National Hurricane Center. Updates from me will likely come in the comments section of this blog and/or on Twitter.

I usually post about the Western Pacific in my blog. For those interested, check out my post from earlier today, Western Pacific Tropical Analysis: August 24, 2017

Western Pacific Tropical Analysis: August 24, 2017

Typhoon Hato is now moving inland across southern China after making landfall near Macau as a category 3 typhoon. In its wake, Tropical Depression 16W has developed a little south, but near where Hato developed. It could end up taking a similar track as well. Elsewhere in the basin, no strong signal exists for tropical cyclone development over the next week.

***NOTE: While I would consider myself well-learned in meteorology, I am still a student with more to learn before becoming a degreed meteorologist. This forecast is not from an official source and should not be treated as such. For official information, please refer to your local weather agency.***

This is going to be a shortish entry today with a lot going on close to home.

Tropical Depression 16W has been designated today east of Luzon. As of 12Z, JMA placed the system at 16.4ºN, 126.5ºE. JTWC’s position was also nearby, but not exactly the same, which is not surprising considering the current state of organization. At this early point in development, 16W is experiencing some moderate easterly shear. That said, both JMA and JTWC are expecting 16W to gain enough organization to be classified as a tropical storm in about 24 hours. When this happens, it will be named “Pakhar.”

With a similar genesis and similar steering pattern to Hato, it should be unsurprising that 16W is expected to take a similar track to the one Hato took, towards Guangdong. However, unlike with Hato, 16W’s more southerly starting position means it will have to cross the Philippine island of Luzon. Because of this, I expect 16W to be a weaker storm than Hato, with lower odds that it will reach typhoon intensity. JTWC’s landfall intensity of around 65 kt appears reasonable to me, but I might hedge slightly lower. Regardless, 16W will be moving into the same regions recently affected by Typhoon Hato, bring additional impacts to the already storm weary areas.

Aside from 16W, not much else appears to have much development potential across the Tropical Western Pacific. Some potential development does appear possible along the weakening monsoon trough in the vicinity of the northern Marianas in about five days, particularly with American guidance. Any developing storm will likely move north and quickly into the mid-latitudes based on the active extratropical pattern.

My next Western Pacific entry will likely arrive Sunday. I am also doing a rare North Atlantic entry focusing on Harvey later today. Until the next WPac entry is up, updates will come in this entry’s comments section.

Western Pacific Tropical Analysis: August 17, 2017

Despite generally unfavorable conditions across most of the basin over the past week, a well organized disturbance was able to develop into Typhoon Banyan over the eastern portion of the basin. In Banyan’s wake, the Tropical Western Pacific is once again quiet, but it will likely not remain that way for long. A surge in the Southwest Monsoon is expected to sharpen the monsoon trough over the western Philippine Sea over the next couple of days, assisting in the development of a system to the east of Luzon and southeast of Taiwan. Additional tropical development may occur after the first system moves west.

One invest is currently designated in the Tropical Western Pacific. Invest 92W is located in the basin’s subtropical waters southeast of Japan. As of 18Z August 17, JTWC analyzed 92W’s center to be at 32.1ºN, 144.5ºE. 92W originates from a surface shear axis, which itself is the remnants of a decayed cold front. I was initially impressed with 92W’s convective cluster, but closer inspection revealed that the circulation center was well removed from this convection. I would be surprised if 92W ends up becoming a classifiable tropical cyclone. 92W is expected to move off to the northeast and into a baroclinic zone, where it will contribute to a new frontal wave in a couple of days.

No other invests are currently designated in the Tropical Western Pacific, but there is one more disturbance of note. An inverted surface trough exists just to the west of the Marianas in the eastern Philippine Sea. This disturbance is convectively active but poorly organized at the moment. Near-term development if any is expected to be slow. However, this disturbance will begin to interact with a tongue of monsoon southwesterlies that extends east of the Philippines in a couple of days. I expect this newfound monsoon trough environment to aid in the organization of a tropical storm in the western Philippine Sea by this time four days from now at the latest. The next name for a tropical storm on JMA’s naming list is “Hato.”

From its expected development near 20ºN to the northeast of Luzon and southeast of Taiwan, stout subtropical ridging to the north should keep this probable tropical storm on a primarily westward heading. Some easterly shear may be present to the south of this ridge, but a westward movement and a good outflow dump into the Tropical Easterly Jet may help offset the shear to a degree. At the moment, I am expecting the system to pass through the Luzon Strait and into the South China Sea, which is in good agreement with the ECMWF/EPS and UKMET solutions. However, a slight break between two cells in the subtropical riding could allow the system to track slightly more northerly and possibly impact Taiwan, which some of the GEFS and GEPS solutions indicate. I am favoring the European guidance at the time largely due to the consistency these solutions have displayed over the past few days. After entering the South China Sea, this system should continue to move primarily west towards the Chinese province of Guangdong. Depending on how much the system interacts with the higher terrain of Luzon and Taiwan, it is possible that it could intensify into a lower intensity typhoon.

In the wake of the previously discussed system, the monsoon trough is expected to remain established around 20ºN in the western Philippine Sea. Guidance is already alluding to a second developing system in 7-8 days in a very similar location to the first system. It’s too early to talk specifics on a system that might develop in the medium range, but the signal for such a system is fairly strong in spite of the range. Climatologically, activity seriously ramps up this time of year across the Tropical Western Pacific as well, which adds credence to the idea of additional development.

This will be my last blog for a week or so as I embark on a road trip to see the Solar Eclipse on August 21st. Until the next entry is posted, analyses and updates in forecast philosophy will arrive in the comments section.

Western Pacific Tropical Analysis: August 9, 2017

After about two and a half weeks, the Noru saga has come to a close at last. In the wake of the prolifically long lived typhoon, not much is left to be discussed as the basin has gone back into its slumber. Upper level subsidence has once again spread over the basin, and the monsoon southwesterlies have retracted back towards Southeast Asia, leaving little available focus for tropical development. The next period of significant tropical development is likely 10-14 days down the road, but as we approach the seasonal activity peak, it will become more and more difficult to keep down at least weak development for an extended period of time.

One coherent disturbance does currently exist over the Tropical Western Pacific. Located well to the east at approximately 14ºN, 174ºE, the disturbance features decent vorticity but lacking convective activity. The area this disturbance is traversing features high 500 mb heights and may be struggling with large scale subsidence. Considering the system’s present consolidation, tropical cyclogenesis cannot be ruled out with the system as it moves northwest and then north into a slight weakness between subtropical ridging, but subsidence and then shear north of 20ºN will likely prevent the disturbance from meeting requirements for a classifiable tropical cyclone. The system will likely be tagged as an invest, however.

Aside from the aforementioned disturbance, it is rather difficult to identify something with tropical cyclone potential over the next week or so. The belt of monsoon southwesterlies associated with last week’s reverse-oriented monsoon trough is now very far north and in the process of cutting off from the parent southwest monsoon. Large scale subsidence has also returned to the Tropical Western Pacific, and 500 mb heights are once again running abnormally high. Overall, conditions do not look favorable for tropical development.

In the medium range, there are some early hints that the monsoon trough may re-establish itself in the basin as subsidence begins to relax a little. Most guidance except American guidance show low level westerlies returning around day 10. I wouldn’t get hung up on American guidance failing to show a similar solution either, since it appears it gets Madden-Julian caught up in the Western Hemisphere, keeping a powerful downward pulse over the Tropical Western Pacific. This is a well-known bias in American guidance. Taking this into account, I’d say chances are rather good that the monsoon trough will make a return to the Philippine Sea, perhaps kicking off the next wave of activity around day 10.

Apologies for the missed post this past weekend as I was feeling rather poor. My next post is slated for this weekend. Until the next entry is posted, analyses and updates in forecast philosophy will arrive in the comments section.

Western Pacific Tropical Analysis: August 2, 2017

Typhoon Noru continues to spin across the Tropical Western Pacific, and the system has been joined by Tropical Storm Nalgae well to the east. Nalgae appears to be no threat to land, but the same cannot be said about Noru. Noru appears to be headed on a collision course for southern Japan and possibly South Korea. Noru has come back down to earth after a period of explosive intensification a few days ago, and some guidance solutions showing similar strengthening are likely overdone, but some strengthening remains possible before final landfall. Aside from the two active storms, no additional tropical activity appears likely over the next several days.

***NOTE: While I would consider myself well-learned in meteorology, I am still a student with more to learn before becoming a degreed meteorologist. This forecast is not from an official source and should not be treated as such. For official information, please refer to your local weather agency.***

The ever persistent Typhoon Noru is now approaching two weeks as a named system, an impressive feat. Noru has also generated the most ACE of any Pacific Typhoon since Goni and Atsani of 2015, and it will likely be passing them soon as well. As of 21Z August 2nd, the center of Noru’s now very large eye was located at 27.1ºN, 135.3ºE per JMA. JMA and JTWC’s latest intensities for the system are 85 kt and 95 kt, respectively. These are at or just below (respectively again) each agency’s T5.5 intensity. However, considering the particularly large eye and somewhat lackluster convective appearance, I have a suspicion that these intensities are perhaps a little generous. Regardless, Noru has come back down to earth after explosively intensifying into the first SSHWS category 5 tropical cyclone of 2017 a few days ago.

The defining feature of Typhoon Noru at the moment is the system’s massive eye. The eye both on infrared and microwave imagery measures about a degree and a half, or 90 nautical miles, in diameter. While not the largest tropical cyclone eye observed, it is in the upper percentile. This eye size is even more rare considering it lacks a remnant inner eyewall within it. With such a large core, the upper level outflow needs to be working overtime to properly vent the system. This has not been the case recently. Analyses have shown outflow to the system’s northwest restricted by a passing trough and associated PV streamer. This trough is now departing though, and there are already some early signs that the outflow is beginning to recover.

The aforementioned trough has been a major source of uncertainty in previous forecasts. Noru’s primary steering mechanism for the past several days has been a subtropical ridge to the north. The trough that is in the process of passing by weakened the ridge, and it was initially uncertain if enough of a weakness would be created to allow Noru to escape poleward. However, it now appears that Noru will not be escaping poleward. As the mid-latitude trough departs, the subtropical ridge should restrengthen some to Noru’s north, forcing the system slowly westwards towards the northern portion of Japan’s Ryukyu Islands. This west motion should continue for at least the next two days and at most three. After that, Noru is expected to be picked up by the next trough and recurve to the northeast. The exact recurve point is not yet known, but it does appear like it will occur either in the vicinity of the northern Ryukyus or in the East China Sea just to the west. This means landfall could still come in a variety of locations from anywhere on Kyushu to eastern South Korea, but considering that I expect Noru to continue maintaining an exceptionally large core, the worst of the typhoon could spread unusually far from the centerline. At the moment though, I expect a western Kyushu landfall, near the center of the guidance envelope.

As has been the case with Noru for all its life, the intensity forecast remains far from a walk in the park. Much of guidance has been blowing Noru back up into a very powerful system in the vicinity of the northern Ryukyus. American guidance in particular has been insistent on a system well below 900 mb. However, I continue to remain skeptical of such solutions, perhaps even more now than ever before. As mentioned previously, I expect Noru to maintain an exceptionally large core for the remainder of its life, which will need near perfect outflow for any strengthening to occur. Additionally, upwelling could become an issue for the large, slow moving storm. A strenghening signal does appear to be nearly unanimous in the vicinity of the Ryukyus, and this does seem to be in response to improving upper air conditions. The degree of strengthening is almost certainly overdone though. The HWRF more or less maintains the large cored Noru as a higher end SSHWS category 2 up until landfall, which appears to be a reasonable intensity forecast to me.

The other active system is Tropical Storm Nalgae, with formed from the reverse oriented monsoon trough well to the east of Typhoon Noru. In fact, the location of Nalgae’s birth is almost exactly the same as Noru’s. Nalgae is expected to strenghen some, perhaps nearly or just meeting the criteria for a minimal typhoon before being picked up by the same trough that just missed picking up Noru, sending the system north into the mid-latitude North Pacific.

Development over the rest of the Tropical Western Pacific looks unlikely over the next several days. There is an outside shot that Invest 98W, located to Tropical Storm Nalgae’s east, could organize enough to become classified, but considering the hostile conditions currently assaulting the invest, I do not expect this outcome to transpire.

My next post is slated for either Saturday or Sunday. Until the next entry is posted, analyses and updates in forecast philosophy will arrive in the comments section.

Western Pacific Tropical Analysis: July 30, 2017

Three systems are currently active across the Tropical Western Pacific, although two are currently inland. As it has done for over a week now, the long standing Typhoon Noru continues to spin over the Western Pacific waters, now meandering near the transition waters between the tropics and subtropics. Former Typhoon Nesat is now an entry level tropical storm over eastern China after crossing Taiwan. Tropical Storm Haitang is following closely on the heels of Nesat and now located inland over Taiwan. Some additional brief development may occur in the subtropical waters well east of Noru courtesy of a reverse-oriented monsoon trough, but the bulk of this entry will be dedicated to Typhoon Noru.

***NOTE: While I would consider myself well-learned in meteorology, I am still a student with more to learn before becoming a degreed meteorologist. This forecast is not from an official source and should not be treated as such. For official information, please refer to your local weather agency.***

In a season thus far of short-lived tropical cyclones, Typhoon Noru has stood out as a significant aberration. Noru is quickly closing in on ten days as an active tropical storm. With the system now positioned by JMA at 22.9ºN, 141.4ºE as of 12Z July 30, Noru is now south of the Tropic of Cancer for the first time in its life. This southward drop into the transition area between the tropics and subtropics is also accompanied by warmer, more heat laden waters and a more moist surrounding airmass, something Noru has been lacking the past several days. Coupled with light upper level winds, it should be no surprise to see Noru strengthening.

With 12Z intensity estimates of 80 kt and 95 kt from JMA and JTWC, respectively, the system has rapidly intensified from just under typhoon strength to 5 kt below each agency’s T5.5 intensity. On first glance, this sudden burst of intensification appears somewhat surprising, but perhaps it shouldn’t be. 37 GHz microwave imagery from about 48 hours previous to this post revealed good structure featuring a cyan eyewall ring, despite Noru struggling with the dry surrounding airmass at the time. In the presence of favorable conditions, a cyan ring on 37 GHz microwave imagery is usually an indication that rapid intensification is about to commence. Subsequent Coriolis and AMSR2 passes over the next 24 hours showed the continued presence of this cyan ring. Over the past 12-18 hours, Noru has moved into a more favorable environment, as mentioned in the paragraph above, and it appears that Noru’s surprisingly good structure has allowed for rapid intensification. I can’t quite place why Noru’s structure was able to consolidate while struggling with dry air and weakening below typhoon intensity, but if I were to speculate, the light to non-existant wind shear present over the system allowed the structure to remain undisturbed, despite the repeated and almost constant dry air intrusions. With newfound favorable conditions, Noru has intensified to its strongest yet. Constrains obviously come into play, but raw and instantaneous Data Ts are currently up near 7.0.

Noru’s drop to the south is in direct response to a subtropical ridge strengthening just to the system’s north, shoving the system south. This now-established ridge will be the primary steering mechanism for Noru over the next couple of days, although Noru will not be moving much. A slow westward motion is the primary expected motion for this period. After this, a passing mid-latitude trough will begin eroding the steering subtropical ridge, and Noru’s steering will again break down. A slow drift with a poleward component appears to be the preferred solution appears to be a common theme amongst guidance, but the degree of lateral movement at the same time is uncertain. Such motion could eventually make a big difference for Noru’s ultimate future, and a further westward positioning could eventually result in a trough capture that sends Noru into Japan. European guidance has consistently favored the western drift over an eastern one, and most of the strongest members amongst ensemble suites lie near the western side of their spreads. Considering Noru’s ongoing rapid intensification, I am biasing my track philosophy towards the left side of the guidance envelope, although the weak steering and large spread inherently leads to a low confidence forecast. My track would be a little left of, but very near both JMA’s and JTWC’s track forecasts.

Intensity forecasting is again tricky. Noru is and will be over waters warm enough to support a rather intense storm, but with the system’s slow movement, upwelling could eventually become an issue. Peak intensity may actually come in the near term with the current bout of rapid intensification, which may bolster Noru near or even surpassing the threshold for super typhoon intensity. Inner core dynamics may come into play following this bout of rapid intensification however, and it wouldn’t surprise me to see eyewall replacement begin in about 24 hours or so. Upwelling may come into the picture at this point, but I do expect other factors to remain favorable for Noru. At this point I expect Noru to be above SSHWS category three for the few days.

Tropical Storm Haitang has recently made landfall over Taiwan. The system was not particularly strong at landfall, but the system does feature some very deep convection. The one-two punch of Nesat and Haitang for Taiwan and eastern China could result in numerous flooding issues.

Extending to the south and east of Typhoon Noru is a reverse-oriented monsoon trough. Guidance has backed off considerably regarding the quantity of systems consolidating and emerging from the feature, but it still appears likely that at least one system will manage to develop well to the east of Noru. Considering the elevated latitude that the reverse-oriented monsoon trough is currently found at, any emerging system will likely remain on the weaker side before shooting off into the mid-latitudes.

My next scheduled post is slated for Wednesday. Until the next entry is posted, analyses and updates in forecast philosophy will arrive in the comments section.