While winds with the system do not breach gale force, the wind field has become defined enough that a closed low has potentially formed just off of Andros Island in the Bahamas. ASCAT data revealed 25kt winds in the eastern quadrant with westerlies to the south of the pressure center. Convection with the system has been blossoming because it is currently stacked underneath an upper-level anticyclone. This has formed in conjunction with a few other upper-level features, including two upper-level lows, one over the southeastern Gulf of Mexico and a stronger one north of Puerto Rico, and an upper-level trough over the Carolinas. Weak ridging has developed in the middle, which is also where 94L is also located. This area of favorability is rather small, however, so the system itself is not particularly large, but this may allow it to intensify with more earnest than it otherwise would.

In the short-term, 94L will likely to continue to intensify through tomorrow, as sea surface temperatures are extremely warm, shear is low, dry air is not present, and the upper low over the Gulf may allow for some slight baroclinic assistance. Regardless of how strong 94L becomes, it will not have very long to intensify. It has already started a gradual northwest turn in response to a cold front moving southward across the eastern U.S., bringing relief from this weekend’s intense heat. As the front approaches 94L, the invest should begin a northward turn along or just off the east coast of Florida, potentially as a tropical depression or weak tropical storm. As this point, conditions will become increasingly unfavorable for the storm. Because the system is not officially a tropical cyclone, its vertical extent into the troposphere is not very high, and the dominant southwesterly frontal flow is based within the surface. All of those weaker upper-level features will likely remain in place throughout the storm’s life, which will bring 94L out of its cocoon of favorability. As the front approaches, its parent trough will kick into the Great Lakes region, which will enhance the southwesterly flow in the upper-levels, inducing an increasing speed shear over 94L as it starts to turn northeast off the South Carolina coast by Tuesday night. At this point, it’s possible that the system may merge with the frontal boundary, completely reducing its chances of becoming a tropical cyclone, or dissipating whatever tropical entity is present.

However, even if 94L develops, the impacts from the system are expected to remain minimal. Rainfall totals from the system itself will likely not breach 2 inches, as the storm itself is small, quick-moving, and likely will be offshore. So unlike Barry, this is unlikely to produce flooding rains. If the system moves onshore, then rainfall and gusty winds may become more of a problem, but should still remain minimal. In fact, more rain is expected from the cold front in Florida rather than 94L. The front will beat 94L to the Carolinas, so even less of an impact is expected there.

Even though the impacts from 94L are expected to be minor, please still listen to advice from local officials and news outlets for the latest information for your specific area. If this system does become a tropical storm, it would gain the name “Chantal”. Remember that it’s only late July, so the majority of the season is still to come. Stay tuned to Force Thirteen for updates on 94L and all things tropics related.

The post New Invest Quickly Developing near Florida, Could Become a Brief Depression or Storm appeared first on Force Thirteen.

As of now, the system is still rather disorganized and not yet classifiable as a tropical cyclone despite the warnings and near guaranteed chance of it becoming one. PTC 02L is rather broad and remains decoupled, as the northerly shear from a ridge centered over northern Mississippi. In fact, the most intense thunderstorm activity is currently over southeastern Louisiana. The mid-level vortex is displaced to the south of the low-level center as a result, not allowing for rapid organization at this stage, as was expected. The low-level center is also quite difficult to discern, as multiple vorticity maximums continuously form and dissipate about a center of rotation, the location of which is unclear. However, as the diurnal maximum approaches, more convection is expected to fire in the vicinity of the surface vortex. This will more than likely allow for further strengthening into a tropical cyclone by tonight or tomorrow.

The forecast for PTC 02L remains rather murky at this point given uncertainties between the models in regards to both track and intensity. Steering currents over the system are weak for now, but a ridge building over the Four Corners region will cause the system to move slowly westward with time. Meanwhile, as a trough dips through the Great Lakes region, it will drag a cold front through the eastern U.S. It in tandem with a ridge near the Bahamas will act to tug the storm northwards this weekend, likely somewhere along the Louisiana Gulf Coast.

A big question mark going into this system is how strong it will become. The majority of the guidance suggests that will peak as a strong tropical storm, but there are also plenty of models that suggest that PTC 02L could become a hurricane and a select few saying a pretty powerful one at that, namely the UKMET and previously the HWRF. If the storm remains weaker, as in a tropical storm, it will curve north earlier into southeastern Louisiana. This is because the SWerly flow initiated by the frontal boundary is based towards the surface, and a weaker storm would not extend as high up into the troposphere as a more intense storm would. If the storm is a stronger hurricane, then it may slip farther west before turning north along the Upper Texas Coast or far western Louisiana as the Bahamas ridge will shift closer to Florida and would ultimately cause the storm to turn north. Either of these solutions remain on the table, but it is uncertain which solution will prevail.

At this point, the National Hurricane Center is splitting between the two extremes and is forecasting a landfall in western Louisiana as a category 1 hurricane with winds of 85mph on Saturday evening. It should be noted, however, that the cone extends as far west as Houston and as far east as New Orleans, so anywhere between those two points is likely to receive the eventual landfall of this storm.

Regardless of where the system makes landfall and how strong it is, very heavy rains are certain to fall. New Orleans has already suffered from flash flooding this morning, and the system is not even a tropical cyclone yet. Areas near and east of the landfall point should expect anywhere from 8-12 inches of rain with isolated totals potentially as high as 20 inches east of the landfall point, which is still not yet known. Given that the Mississippi River is already much higher than normal due to heavy rains all throughout the river basin, heavy rains from this system will only exacerbate issues. Rainfall is by far the biggest threat from this system, much more so than wind and even storm surge, but those threats will become clearer as the forecast track and intensity becomes more certain. Even areas inland into Mississippi, Alabama, northern Louisiana, Arkansas, and Missouri can also expect heavy rains and potential flash flooding from this system as well. The rainfall threat for Texas is lower given that the landfall is expected to be east of the state and the western side will be drier, but a further west landfall would shift the heavy rains towards them.

In the meantime, an aircraft reconnaissance mission is scheduled to investigate the system this afternoon, which will give us a better idea of the internal structure of the storm. If this storm does gain a name, which is almost a certainty at this stage, it will be named “Barry”. Please make sure you have your hurricane and flooding preparations ready if you are in the path of this storm, and always listen to the information given to you by your local NWS office or outlets for the latest information regarding this potentially damaging system. Stay tuned here to Force Thirteen for more up-to-date information regarding this system.

The post Future of Newly Designated Potential Tropical Cyclone 02L still Uncertain, but Heavy Rains are Coming to the Gulf Coast appeared first on Force Thirteen.

Over the past several weeks, there has been large-scale subsidence across most of the Atlantic and Eastern Pacific that has prevented the development of convection, as subsiding air cools and dries out. This has been the result of a convectively decoupled phase of the Madden-Julian Oscillation (MJO) remaining over the basin for the majority of the month, promoting less convective activity. When convective activity is suppressed, then the pressures are allowed to rise. High wind shear from upper-level troughs across the basin has also not been allowing for thunderstorms to persist and bundle, which is a key ingredient for a disturbance to have a chance of development. In addition, Saharan dust embedded within the Saharan Air Layer (SAL) has been dominating most of the tropics recently, although this is quite typical during the early part of the summer. All of these factors combined have not allowed for disturbances to flourish and develop into tropical cyclones. however, this will likely soon change.

Right now, the El Nino has been weakening substantially due to the persistence of easterly wind bursts and the lack of warm ocean anomalies in the subsurface. Rather, cooler anomalies have been upwelled due to the lack of westerly wind bursts to force the warmer anomalies eastward across the equatorial Pacific. The Pacific Decadal Oscillation (PDO) signature to the north is also fragmented, as there exists a region of cooler anomalies off the West Coast of the U.S., which is not allowing for the classic +ENSO signature. As a result, the anomalies within the ENSO 3.4 region are dropping and the highest SSTAs are currently located in the equatorial Central Pacific, west of the typical Nino regions. This could be allowing for the formation of a Modoki El Nino, but as of now, it will likely be very weak, possibly not going above the typical threshold for an El Nino (+0.5 SSTA). It appears likely that this pattern may persist into the remainder of the summer and into the heart of the hurricane season.

As for the Atlantic itself, the configuration is not quite ideal at the moment, as the Atlantic Multidecadal Oscillation (AMO) signature does not concentrate the warmest anomalies within the tropical Atlantic, but rather farther north into the subtropics, especially closer to North America where ridging is stronger. The waters in the tropical Atlantic and south of western Africa are cooler than average at the moment, but a lot of those lower anomalies are due to increased heat energy input into the West African Monsoon, which is stronger than average this year. Cooler anomalies are also focused near and east of Maritime Canada as a result of a higher abundance of non-tropical storm activity. However, the warm anomalies are not as far north as it once was and has been progressively pushing southward with time. This is a typical phase of a 2nd EOF AMO, where the warmest anomalies are centered between the tropical and the polar waters. The somewhat neutral but slightly negative North Atlantic Oscillation (NAO) pattern is allowing only slight movement of the warm anomalies southward. However, the NAO is expected to become progressively more negative as a result of less ridging over the subtropical eastern Atlantic. According to climate models and past analog years, these warm anomalies will be centered over the tropical Atlantic, which will likely prove more favorable for a busier hurricane season, as tropical waves should develop more frequently in the deep tropics. This would set up the basin into a 1st EOF AMO, which is the most optimal setup for an active hurricane season. It will be difficult to determine how this will hold as the peak of the hurricane season approaches, but it will likely bode well for yet another above average year.

Climate models are taking all of these factors into account and forecasting lowering shear and increased precipitation across the tropics, but not until the second half of July, which is also when the MJO comes back into a favorable configuration for tropical development across the basin. As a result, activity will likely remain quiet until the middle to end of July, when we may finally start seeing activity ramp up. This will also more than likely begin at the end of the train of storms forecast by some of the models in the EPAC basin within the next few weeks, of which Alvin may just be the start of. Nevertheless, always have a hurricane plan ready just in case a storm comes knocking on your door later this season.

The post When Will the Atlantic Start Seeing Activity? appeared first on Force Thirteen.

The Southwest Indian Ocean had its costliest season and deadliest season ever reliably recorded in the modern period, as well as one of the most active ever seen. A total of 15 namable storms existed within the basin with 11 cyclones and 10 major cyclones. All of these numbers were all-time records since reliable records began. In addition, the number of Intense Tropical Cyclones, based on the scaling from Meteo France, was also at an all-time high, at 10. The season began with an unnamed moderate tropical storm in mid-September and ended with Tropical Cyclone Lorna at the end of April. Cyclone Cilida became the strongest storm of the season as a 135kt category 4 (category 5 by F13 analysis), and briefly threatened the Mascarene Islands in late December. January featured 2 moderate tropical storms, Desmond and Eketsang, in the Mozambique Channel, causing moderate damage. Cyclones Funani and Gelena were twin category 4 cyclones that remained out-to-sea in February. March was the most active season, featuring 4 named storms, all of which were Intense Tropical Cyclones. One of those storms was Cyclone Idai, by far the most destructive storm of the season and the costliest and one of the deadliest ever seen in the basin, causing over $2 billion USD in damages and likely over 1000 fatalities. Idai struck southern Mozambique near Beira as a category 2 in mid-March after meandering in the Mozambique Strait for about a week, where it caused massive destruction. A major humanitarian crisis occurred following the storm in both Mozambique and Zimbabwe, which were devastated by flooding and mudslides from Idai’s extreme rains. A severe cholera outbreak also ensued in the weeks following the disaster, which likely increased the death toll, which is never expected to be known. In all, Idai was one of the most destructive storms to have ever struck both Africa and the Southern Hemisphere. In April, Cyclone Kenneth struck northern Mozambique as a category 4 storm. While not as severe as Idai, Kenneth still brought severe impacts to northern Mozambique and Comoros.

The Australian Region was also quite active during the season, but not to the extent of the Southwest Indian Ocean. 12 tropical storms were present within the basin, 6 of which were cyclones, and 3 of which were major cyclones. December featured Cyclones Owen and Penny, both striking the Cape York Peninsula, with Owen striking it as a category 1-equivalent storm. The basin was pretty quiet during January and February, with only 2 named storms present within the basin. Like the SWIO, March was the most active month, when all 3 of the basin’s major cyclones formed, or category 4s on the Australian Scale. Cyclone Trevor struck Australia as a category 3 on the SSHWS scale twice, but damage was relatively minor. Cyclone Veronica was the strongest and most significant storm of the season, which, at one point, threatened to strike Western Australia as a category 5 cyclone on their scale. Veronica was notable for its extremely quick intensification, and at one point, it was reported to have strengthened 50kts in only 6 hours. After the storm weakened, and re-intensified, Veronica slowed down and rapidly disintegrated on approach to landfall, which it briefly made around Karratha before turning sharply west and fizzling completely. Veronica caused significant flooding around Port Hedland, which had its port shut down throughout the duration of the storm. In all, Veronica caused $1.6 billion USD in damages, but no fatalities were reported. Cyclone Lili formed in early May near East Timor, causing moderate damage.

The South Pacific actually featured below-average activity throughout the season, producing only 5 namable storms and 2 cyclones, neither of which hit major cyclone status. The turn of the year featured Cyclone Mona, which only brought heavy rains and minimal impacts to Fiji. Cyclone Oma was the most impactful storm of the season, which was a minimal, but long-lasting, cyclone. Oma meandered around Vanuatu and New Caledonia in February, causing moderate damage and no fatalities. Cyclone Pola, the strongest storm of the season, peaked as a category 2 on the SSHWS and a category 4 on the Australian scale in late February, but did not significantly impact any islands. March and April featured no activity, a very unusual event, with only minor levels of activity happening in May.

In addition to the abundance of activity in the main Southern Hemisphere Basins, a rare tropical cyclone formed in the South Atlantic Ocean, named Iba, during late March. Iba was unusual for a South Atlantic storm in that it was fully tropical, as most storms that form in that region are subtropical, and lasted for over 3 days. The activity within the Southern Hemisphere is winding down, as the prime focus for tropical cyclogenesis now begins to shift towards the Northern Hemisphere, but another weak tropical cyclone or two may try to develop before the season officially ends at the end of June.

The post A Recap of the 2018-19 Southern Hemisphere Cyclone Season appeared first on Force Thirteen.

Trevor developed from a broad area of low pressure that was previously located over the Solomon Sea. Since then, the system split over the Papuan Peninsula, and the southwestern circulation became dominant, developing into Trevor. Currently, the storm is gaining organization as it slowly progresses westward. The storm has developed well-defined outflow and inflow channels and is tightening its central dense overcast. As of now, it remains only a minimal tropical storm, but intensification is expected as it approaches the Cape York Peninsula.

Trevor is currently under relatively weak steering currents, as it is far enough south of the monsoon trough that the flow isn’t overwhelmingly westward, but there also aren’t any synoptic bodies, such as a ridge or trough, in the vicinity of the storm. As a result, the general easterly trade flow is dominant, which will slowly push Trevor into the Cape York Peninsula by Tuesday evening local time. The Bureau of Meteorology is currently forecasting the storm to be a category 2 cyclone, which corresponds to a strong tropical storm or weak category 1 TC on the Saffir-Simpson scale, when it makes landfall south of Lockhart River. This is because the environment ahead of Trevor is favorable for intensification, as sea surface temperatures are warm, vertical wind shear is quite low, and dry air has been far removed from the system. Trevor is then forecast to weaken over land and emerge into the Gulf of Carpentaria by Wednesday afternoon as a tropical low. Past this point, the forecast track appears to take the storm west across the northern GoC while a ridge develops over the continent, likely making landfall somewhere along the coastline of the Northern Territory from Nhulunbuy to the border with Queensland sometime around Friday and Saturday. The uncertainty mainly lies with the intensity. Some models bring the storm in as a tropical storm while others bring it in as a powerful cyclone. At this point, it still remains a bit too far out to determine where and how strong Trevor will be after it crosses the Cape York Peninsula, so please stay tuned to your local authorities and the Bureau of Meteorology for the latest information for your specific area.

The primary threats associated with Trevor with its first landfall will be heavy rainfall, as the storm is relatively slow-moving and is quite broad. Rainfall has just begun along the Cape York Peninsula and will likely persist into the next several days as Trevor crawls westward. Rainfall totals exceeding 30cm in some areas cannot be ruled out, which can lead to dangerous flash flooding. Gusty winds will also be a concern, especially for coastal communities. These can cause localized power outages and downed trees. Rough seas will be an issue as well, with some minor coastal flooding possible south of the landfall zone. As for areas in the Northern Territory, it remains to be seen what the main threats will be from Trevor, if any, but those with interests in this part of Australia should be vigilant to the forecast over the next several days. Have a plan ready just in case the storm comes toward you.

The post Cyclone Trevor Set to Impact the Cape York Peninsula appeared first on Force Thirteen.

Idai’s center is currently situated about 95mi off the coast of Madagascar, delivering intermittent squalls with heavy rainfall and gusty winds, along with rough seas. Idai was rapidly strengthening earlier today, strengthening from 80mph to 120mph in 18 hours, but has since leveled off and has potentially weakened slightly. This is most likely due to upwelling, as the storm has been sitting over the same general waters for about 2 days due to weak upper-level steering currents. As a result, convective tops have cooled and the eye has become less defined with time.

The storm has slowly begun to move towards the southwest as a ridge to the south begins to build once more. As the storm moves away from the Madagascan coastline, it will begin to encounter a more favorable environment, featuring warmer ocean waters and low wind shear. The only potential hinderance to the storm could be dry air brought in off the African Continent, which could disrupt the inner core. Intensification over the next several days is likely to be gradual as a result as Idai moves towards the west. By Thursday, the cyclone is likely to make landfall along the central Mozambique coast north of Beira as a category 3 cyclone with winds of between 120mph (195kph), after peaking as a moderate category 4 cyclone. Afterwards, the storm would move inland and weaken, but some longer-range forecast models indicate it could reemerge over the Mozambique Channel and possibly restrengthen as it dives southwards, but this would not occur for another week.

If Idai were to make landfall as the forecast indicates, then it would rival some of the strongest storms to ever impact the country. Along the immediate coastline to the south of the center, high storm surge on the order of 5 to 8 feet (~1.5-2.5 meters) could occur in some areas. This would inundate multiple coastal structures and cause flooding well inland. Strong winds will likely knock out power and down trees across a wide swath of land. However, heavy rainfall and flooding are the primary threats. In most locations, rainfall totals could exceed 25cm, with isolated areas possibly receiving 40-50cm. This can create flash flooding that is both dangerous and life-threatening. The primary areas of concern are areas in and around central Mozambique, but surrounding areas should watch out for possible impacts by this weekend.

If you live in this area, have an evacuation plan ready. Listen to your local authorities for the most accurate information for your specific location. Stay tuned to ForceThirteen for the latest on Cyclone Idai.

The post Cyclone Idai Remains a Big Threat to Mozambique appeared first on Force Thirteen.

Officially, Michael peaked (and made landfall) with wind speeds of 135kts, or 155mph, and a minimum central pressure of 919mb. This ranks the storm on the upper-end of category 4 on the Saffir-Simpson Hurricane Wind Scale. If the storm’s winds were about 2kts higher, Michael would rank as a category 5, the highest ranking on the scale. So naturally, when a storm is this close to reaching such a feat, storm trackers like to go in-depth into the storm to see whether or not it truly was a category 5 or not. There exist factors that may either prove or debunk the thought of Michael being a category 5 hurricane.

One of the first things may storm trackers use to analyze a storm’s intensity is satellite imagery, more specifically infrared satellite imagery. There’s no question that Michael’s satellite presentation was incredible, but was it good enough for category 5? Dvorak imagery is one method to use when determining intensity, and is usually considered the most accurate. For Michael’s peak satellite presentation (1645 UTC 10 Oct), the storm features cold-medium gray cloud tops within the southern CDO and an eye temperature near +9C. Subjective Dvorak estimates for Michael reached T6.5, or about 127kts, and the CIMSS ADT value reached T7.2, or about 145kts. However, ADT is used more for real-time analysis, and many data points are considered erroneous based on exact center positioning. Using this, satellite estimates suggest that Michael was a 130-135kt hurricane, comfortably within the category 4 range.

However, satellite observations were not the only thing readily available to us to analyze Michael’s intensity. Because the storm was approaching landfall, aircraft reconnaissance intersected the center of the hurricane dozens of times throughout the day. The planes recorded wind and pressure data during their flights, giving us direct observations into the storm. The final mission into Michael was from AF301 from the US Air Force, which flew into Michael upon landfall, observing maximum flight level winds of 151kts, or about 175mph, within the southeastern quadrant. Generally, the northeastern quadrant is the strongest part of the storm, but because this part of the storm was already over land at the time, the plane was not allowed to measure wind speeds there (and winds at the surface would not have been any stronger because of frictional forcing on land). In addition, the plane released a dropsonde into the center of Michael’s eye, recording pressure and wind data along the way. The dropsonde itself recorded a minimum surface pressure of 922mb with a wind speed of 34kts, meaning that it missed the exact center. When extrapolating this data, it is likely that the pressure within the exact center was 919mb +/-1mb. Because there is no set adjustment for flight level winds to surface winds, it is difficult to determine the surface winds based on this data. However, SFMR surface readings recorded 120kt winds, but these are generally considered to be too low based on all other data observed, likely due to proximity to land.

Another thing we can use to determine the strength of Michael is to observe what happened on the ground. This can vary from storm chaser observations to damage surveys. Storm chaser Josh Morgerman recorded a pressure of 939.7mb in central Panama City, which was just 3.7nmi away from a 923.2mb reading in Callaway, which was located in the western edge of the eye at the time. Both observations were taken at 1745 UTC Oct 10. Pressure gradience always decreases by a factor of 4 within the eye, which was about 9.4nmi away from the exact center of the hurricane. This would mean that the exact center pressure was likely near 917mb, 2mb lower than the operational NHC number.

The last thing we can use to get a grip on the true wind speed is damage assessments. In a case like this, the damage from the hurricane can be used to determine how strong the winds could have been, similar to how a tornado’s top wind speeds within a certain area are estimated. At this time, there have yet to be any damage surveys publicly released, but using a subjective view at images from Mexico Beach, where the winds were estimated to have been the highest, it’s safe to say that maximum sustained winds were likely somewhere between 130 and 145kts, equivalent to that of a high end EF4 tornado. This range is so wide because there exists uncertainty with the exact winds due to the lack of any official estimates. This estimate is subjective, however.

In conclusion, I believe that the most likely outcome was that Michael reached maximum sustained wind speeds of 138kts, which barely reaches the threshold for category 5. However, we will not have a definitive number from the NHC until they release their Tropical Cyclone Report on the storm during early 2019. Regardless of whether or not it was a category 4 or 5, Michael was a truly historic storm that will be in the minds of storm trackers and Floridians for years or decades to come.

The post Hurricane Michael: Category 4 or Category 5? appeared first on Force Thirteen.

However, the remainder of the season remains a big mystery. There are a lot of conflicting factors at the moment, either suggesting we will end up having a below or even above average season. The first factor most people look at to determine the future of activity in the Atlantic basin (or any basin, for that matter) is the state of the ENSO, or the El Nino Southern Oscillation. This is defined as a variation in trade winds and therefore, sea surface temperatures across the equatorial Pacific west of South America. The strength of this is usually confined to the Pacific Walker Circulation. A stronger PWC would result in stronger trade winds and would cool the sea surface temperatures, resulting in a La Nina pattern. A La Nina is typically favorable for Atlantic tropical cyclogenesis because it weakens convection over the Pacific through tropospheric descent, which results in rising motion and reduced wind shear across the Atlantic. The opposite of this is an El Nino, where the trades are weaker and any subsurface heat in the form of a Kelvin wave would rise up and result in warmer sea surface temperatures. This enhances Pacific convection, and the shear of which and surrounding vertical descent reduces tropical cyclone activity in the Atlantic. Currently, sea surface temperature anomalies are warmer than normal, but not quite enough to qualify as an El Nino. Climate models suggest a weak-to-moderate El Nino is likely to form by the autumn, which could result in a lessening of Atlantic activity. Recently, Southern Oscillation Index values, which measure the strength of the Walker Circulation, have trended negative, meaning that the environment is more conducive for an El Nino to develop.

In addition to the ENSO, the tropical Atlantic has gone through a multitude of changes over the past several months. SSTAs were significantly cooler than average in May and June, almost record cold. But since the beginning of July, the trade winds have subsided and the West African Monsoon has amplified, resulting in more tropical wave activity in the past 2 weeks. One of these waves developed into Hurricane Beryl. However, there is still more Saharan dust in the atmosphere than usual, which is choking off convection to these tropical waves. Beryl was able to develop into the storm that it did because it was located at a very low latitude within the moisture shield of the InterTropical Convergence Zone, had an incredibly small gale radius, and was in an environment boosted in favorability by a convectively coupled Kelvin wave. Had Beryl formed a few days earlier and about 3 degrees of latitude farther north, it would’ve likely remained either a wave or a weak TC. But the warming of the tropical Atlantic is likely to result in more tropical cyclones in the region than initially thought, which could cause more long-tracked hurricanes to develop.

Finally, the subtropical Atlantic is still warmer than the tropical Atlantic, anomalously speaking. When this is the case, more convergence is focused in the region, resulting in more convection. This causes the air to rise over the region and sink around it, in the tropical regions. This serves as a reversal of the regular Atlantic Hadley Cell, which allows air to rise in the tropics and sink farther north. This can cause more activity to be focused farther north or have tropical cyclones peak in the region. Climate models suggest that this pattern will remain, but might not cause too big of an issue as perviously thought, but can still inhibit activity. This could also cause the Madden-Julian Oscillation to have more negative phases than positive ones for the Atlantic, but if the positive phases arise in August and September, then activity will blossom more towards the peak of the season.

Right now, the most likely outcome is a near average season. An average season usually contains 12 named storms, 6 hurricanes, and 3 major hurricanes (category 3 or greater), along with an ACE value near 100. Most analog years, such as 1989, 2000, 2002, and 2014 are conflicting. The first 2 years were above average while the latter 2 were below average. This recent burst of July activity is likely over now, and due to the MJO configuration for the next few weeks, it likely won’t pick up again until early or mid-August. However, remember that it only takes one storm to make it a bad season for you. Hopefully, the storms can stay away from regions severely impacted last year, such as Puerto Rico, Texas, Florida, Costa Rica, and all of the Lesser Antilles, but always have a plan ready just in case one comes your way. Even if the storm is relatively weak, it can still produce flooding rains that can cause more damage than the high winds of a major hurricane. Take every storm seriously, and try not to make the hurricane’s category dictate your actions regarding the storm.

The post The 2018 Atlantic Hurricane Season: Where do we Go from Here? appeared first on Force Thirteen.