Tropical Depression 9 forms

TD # 9 has formed in the Bay of Campeche. It is still disorganized, and it moving to the east very slowly.ir_enhanced_storm1_1 Before it moves onshore, it could become Tropical Storm Hanna. The short term forecast is simple, but the log term becomes more complicated. As it moves into the Western Caribbean, a piece of it may be left behind.trackmap_storm1 So keep it right here for the very latest.

Invest 93L Attempts to Organize Near the Yucatan Peninsula; Extended Wet Period for South Florida

Invest 93L attempts to organize as it near the Yucatan peninsula Tuesday. The odds of development per the NHC sit at 50% by Thursday afternoon and 50% over the next five days. Hurricane Reconnaissance Aircraft found a small well defined center this afternoon but convection isn’t organized enough for Invest 93L to be upgraded to a tropical cyclone. Moderate westerly shear pushes the deepest convection towards the Yucatan but a huge slug of tropical moisture brings pockets of heavy rainfall up towards south Florida (especially over the Keys). Models generally bring Invest 93L east-northeast in the coming days. The question remains if the area of low pressure lingers in the northwest Caribbean for a while or it gets picked up by a trough and carried out to the open western Atlantic this weekend. The bottom line is regardless of development an extended wet periods is expected for the Yucatan, Cuba, and south Florida.

Fly to Gulf Disturbance

Invest 93L Models

The GFS model brings 7+ inches of rainfall to Key West and about 6″ to Miami by Saturday afternoon. These totals may be a little overdone as recent model runs keep Invest 93L further south. The Weather Prediction Center estimates t 5+” is possible in Key West by next Tuesday in their 7 day outlook. Areas south of Tampa Bay will also see enhanced rainfall but the hefty totals stay south of Ft Myers. The further south Invest 93L stays the less rainfall south Florida will see.

GFS-Precip Acc

The 0Z ECMWF and 06Z GFS are in pretty good agreement through Friday. Deep moisture brings steady rainfall to south Florida and west Cuba into Friday afternoon. The area of low pressure stays weak/possibly just broad in nature near the Florida Straits and northwest Cuba. With a stalled frontal boundary nearby enhanced wind shear will make it tough for Invest 93L to deepen significantly.

ECMWF vs GFS MSLP and Precip Rate

Tropical moisture looks to exit south Florida early Saturday. By early Sunday morning both the 0Z ECMWF and the 06Z GFS track low pressure northeast into the open western Atlantic. The Euro does keep a small “piece” of low pressure behind in the western Caribbean. If this is valid tropical downpours could linger in the western Caribbean into next work week.

ECMWF vs GFS MSLP and Precip Rate.png 2





Watching the Gulf for Potential Development

The models have continued to hint at the potential development of an area of low pressure in the southwest Gulf for the last couple of weeks. However, there is very little run to run consistency and hence, plenty of uncertainty with this scenario. A look at the enhanced satellite picture shows a disorganized area of showers and storms in the Bay of Campeche. These showers are being fueled at least partially by the leftovers of Trudy, which made landfall on the Pacific coast of Mexico earlier this weekend.

Floater IR Enhanced 2

The National Hurricane Center gives this area a low chance (10%) of developing by Tuesday evening, but a higher chance of slowly developing by later in the week as it traverses eastward. After this disturbance begins to move eastward, that’s where the models differ on their respective solutions. The ECMWF (Euro) has a deep trough that digs into the Gulf and develops this system just west of Florida, eventually taking it up through the Peninsula early next weekend. While this scenario is certainly possible, it would likely be some sort of hybrid system and not fully tropical. Another caveat is that the Euro ensembles are farther east with their development of this system, impacting South Florida instead of the Big Bend.


Meanwhile, the GFS model is more in line with the Euro ensembles. It develops this hybrid system across the Florida Straits and brings it up through extreme southern Florida before curving out to sea. Many of the other models we look at fall somewhere between these two solutions. With this much uncertainty, anything is possible but the forecast is far from set in stone. Be sure to check back here throughout the week for the latest.

GFS MSL and Precip Rate


Gonzalo Continues to Strengthen; Ana Still Eyes Hawaii

After dropping back to a Category 3 strength storm Wednesday night, Gonzalo has re-strengthened into a strong Category 4 storm. Maximum sustained winds as of 11am Thursday were at 145mph and the minimum central pressure was down to 940mb. The storm exhibited an impressive-looking eye structure after completing an eyewall replacement cycle Wednesday night. The satellite picture showed a very symmetrical looking storm with a classic convective structure.

Florida Visible-Tropical Moisture

Sea surface temperatures are fairly warm under Gonzalo, which has allowed it to maintain intensity (and even strengthen). Those sea surface temperatures will start to drop off a bit as the storm approaches Bermuda, but will still likely remain warm enough to support major hurricane intensity. In addition, the wind shear is favorable for the intensity of the storm. An analysis of the wind shear below (courtesy University of Wisconsin) shows Gonzalo in an area of 15kt northwesterly shear, which is moderate. However, the wind shear at the mid-levels of the atmosphere (second image below) is much lower, closer to 5kts or so and is likely helping to intensify Gonzalo.

Upper Wind Shear

Mid level shear

In addition to the lower mid-level shear, the shear tendency downstream of Gonzalo is favorable for a storm of this intensity (image via University of Wisconsin). Shear tendency measures the pattern of wind shear over the last 24 hours (lessened or strengthened) and shows Gonzalo moving into an environment that has seen the wind shear decrease by 5kts in the last 24 hours. At the same time though, notice how wind shear has increased over Bermuda, as well as over the Eastern seaboard (thanks to a frontal system). Therefore, while conditions will remain favorable for Gonzalo in the short term, beyond 24-36 hours the shear should increase significantly enough (and the sea surface temperatures should cool down enough) to allow Gonzalo to weaken.

Shear Tendency

While it is increasingly evident at this point that Gonzalo will be a major hurricane as it passes near Bermuda, the key for the island will be the exact track. The current forecast calls for the storm to pass just 20 nautical miles to the west of Bermuda, putting the island on the dangerous east side of the storm and well within striking distance of the powerful winds in the eyewall. However, just a slight shift west or east in track would make a huge difference.

Gonzalo Wide Trackpng

Gonzalo Close Up Track

There are several major effects that a storm track like this would have on Bermuda. First and foremost, winds will be intense. Hurricane force winds extend outward up to 45 miles from the eye of Gonzalo, and tropical storm force winds extend outward up to 150 miles. The latest advisory from the NHC gives Bermuda a 74% chance of seeing hurricane force winds from Gonzalo and this number may go up as we get closer to these potential effects. Tropical storm force winds will likely begin by Friday morning, and will intensify to hurricane force by Friday afternoon/evening as the storm passes by the island.

Wind Radii 1

Wind Radii 2

Another effect from Gonzalo will be wave heights and storm surge. On the eastern side of the storm, Bermuda will experience the worse of the storm surge. Elsewhere, high wave heights will be a big issue. Maximum wave heights from the storm may approach 50 feet in areas, and even the East Coast of the US will see increased swells and a higher rip current risk.

Max Wave Heights

The final impact will be significant rainfall. With Gonzalo moving fairly slowly at the moment, rainfall amounts on Bermuda may be 3″-6″+. The latest run of the 12km RPM model shows upward of 6″ of rain across the entire island by Friday night.

RPM 12km Futurecast-Precip Acc Bermuda

With most of the attention on Gonzalo, we can’t lose sight of another dangerous storm, Ana in the Central Pacific. As of 11am Thursday, Ana was a tropical storm with maximum sustained winds of 60mph. Ana has suffered from higher wind shear over the last couple days. However, the latest enhanced satellite imagery shows a slightly improved structure to Ana, along with some deeper convection near the center.

Ana Enhanced Satellite

The official track for Ana takes it to the northwest, eventually curving it just southwest of the Big Island as a Category 1 storm Friday night. It then recurves it back toward the islands, taking it very close to Oahu, Kauai, and Niihau. This would be the 3rd tropical storm this season to come close to or impact the Islands (Iselle and Julio). It is important to note, however, that track errors for storms in the East and Central Pacific is much higher than for those in the Atlantic.

Tropical Track Pacific

Gonzalo Now A Category 4-Aims For Bermuda; Ana Almost A Hurricane-To Impact Hawaii

It’s official. Hurricane Gonzalo becomes the first category four hurricane in the Atlantic since Hurricane Ophelia in 2011. As of 11 AM EDT max sustained winds reach 130 mph, pressure is down to 949 mph, and Gonzalo tracks northwest at 12 mph. The eye structure is better visible on enhanced satellite imagery in recent hours (likely due to the completion of an eye wall replacement cycle early this morning). Recon data estimates the inner eye is only 2 NM wide, a sign of a very strong hurricane. The major hurricane could fluctuate in strength over the next 24 hours, which is often the case with a storm of this magnitude. A Hurricane Watch is in effect for Bermuda and will likely be upgraded to a Hurricane Warning this afternoon. Bermuda still recovered from last weekends direct hit from Tropical Storm Fay. Swells will reach the island Thursday and the risk for rip currents increases at Southeast U.S. beaches. Tropical storm force winds reach Bermuda late Thursday and possible major hurricane force winds arrive early Friday. Gonzalo will dissipate near the Canadian Maritimes this weekend.

Floater IR Enhanced

As of the 11 AM advisory the center of Gonzalo will pass just west of Bermuda Friday morning. Any slight wobble will play a huge role in the extent of strong winds over Bermuda Friday. The field of hurricane force winds now extends out 35 miles for the center of Gonzalo. Tropical storm force winds extend up to 115 miles from its center. Bermuda also braces for significant storm surge and heavy rain.

Gonzalo 2

TD 6

Computer models stopped running data on Invest 91L Tuesday afternoon. The broad low combats hostile upper level winds and the odds of tropical depression development are low. It tracks northward in the open Atlantic in the coming days.

Invest 91L

Tropical Storm Ana has its eye set on Hawaii this weekend and a Hurricane Watch may be issued soon. As of 11 AM EDT the center is now 675 miles from Hilo on the Big Island. It nears hurricane strength with winds of 70 mph. A west movement become more northwest Thursday into Friday. Swells will reach the Big Island Thursday and hurricane force winds are possible Saturday morning. The G-IV aircraft will assess the environment between Hawaii and Ana. This will give us valuable information as Ana needs the island state in a few days. Increasing wind shear near a trough near Hawaii’s western islands will cause at least some weakening.


The GFS model paints 3-7+” over the Big Island through the weekend (the heaviest on the less populated western side closest to the center of Ana. Honolulu could see a few inches of rain too.

GFS-Precip Acc

It’s a week away but worth noting. The reliable ECMWF model spins up an area of low pressure in the west-central Gulf of Mexico early next work week. The graphic below is paused Wednesday at 5 PM. The 12Z GFS also hints at pressure lowering the western Gulf this weekend. This makes sense with climatology in mid October.  Stay tuned.

ECMWF MSLP and Precip Rate


Gonzalo Becomes 2nd Major Hurricane of 2014-Eyes Bermuda; Watching Ana in Central Pacific-Could Threaten Hawaii

Hurricane Gonzalo becomes the second major hurricane of the 2014 Atlantic hurricane season Tuesday. At 5 PM EDT max sustained winds top out at 115 mph, pressure is down to a low 970 mb and it accelerates northwestward at 15 mph away from Puerto Rico and the Virgin Islands. The eye of Gonzalo is much more distinct Tuesday afternoon and cloud tops continue to cool. Major Hurricane Gonzalo could become the strongest hurricane of 2014 in the Atlantic Basin. It could reach category 4 strength Wednesday afternoon. Gonzalo will pass well east of the Bahamas and Turks and Caicos (and the U.S. thanks to a strong cold front)  but is a significant threat to Bermuda on Friday. It could still maintain major hurricane strength during this time too.

The only silver lining for Bermuda is the span of hurricane force winds is quite small. As of 5 PM hurricane force winds extend up to 25 miles from the center but the tropical storm force winds extend out up to 115 miles. Any slight wobble west or east could keep the strongest winds (possible major hurricane force) away from the tiny island. Nonetheless squalls and a period of flooding rains is likely for Bermuda during a period of time late in the day Friday. This forecast is subject to change.

Floater IR Enhanced

TD 6

Elsewhere in the Atlantic a disorganized Invest 91L churns between the Lesser Antilles and Africa. It is no threat to land and the odds of tropical depression development are low as it drifts northward over the open Atlantic.

Invest 91L

All eyes are on a strengthening Tropical Storm Ana in the central Pacific. It could become a hurricane late work week over warm waters and moderate wind shear. Ana rides the perimeter of a ridge in the Pacific and will track very close the Big Island of Hawaii late in the day Saturday EDT. This could be the second time this area in Hawaii sees tropical storm force winds in Hawaii this year (very rare).

Tropical Track Pacific


Hurricane Gonzalo Continues to Strengthen

Hurricane Gonzalo continued to look more and more organized on Monday, with plenty of convection around a low level center of circulation. The cloud pattern is becoming more symmetric and inner-core features are becoming evident on the enhanced satellite. Even the radar loop from San Juan shows a eyewall feature.

Floater IR Enhanced 2


With warm waters and low wind shear ahead of it, Gonzalo is likely to continue strengthening. As of 11pm Monday night, maximum sustained winds were 85mph with a minimum central pressure of 984mb and the storm was moving to the NW at 12mph. Hurricane warnings were up for the British Virgin Islands, St. Martin, and Anguilla, with Tropical Storm Warnings active for Puerto Rico and the US Virgin Islands among others.


The storm is expected to begin to curve more to the north and eventually the north-northeast over the next few days. With those warm waters and low wind shear though, it is forecasted to become a major hurricane by Wednesday and will be on a path very close to Bermuda by the end of the week. Interests in that area should pay close attention to any changes in the storm’s intensity and track.


Gonzalo isn’t the only storm we’re concerned about. In the Central Pacific, Tropical Storm Ana has formed southeast of Hawaii. The forecast calls for Ana to become a hurricane in the coming days, and take a dangerously close track toward the Big Island, which was already hit by a tropical storm earlier in the season. We’ll have to continue to watch Ana closely in the coming days.




Fay Becomes Hurricane Before Weakening; Gonzalo Forms and Threatens Puerto Rico

Fay became the fifth hurricane of the 2014 Atlantic Hurricane Season on Sunday as it brushed by Bermuda. The storm was picking up speed as of Sunday night and weakened by 11pm to a tropical storm with winds of 65mph. It is moving to the ENE at 25 mph and will continue out into the open Atlantic before being absorbed by a frontal system by Monday afternoon.


Meanwhile, in the eastern Caribbean, Invest 90L has become the 7th named storm of the season, Tropical Storm Gonzalo. The storm exhibits some low-level circulation and thunderstorm activity around a primitive eye feature and continues to become more and more impressive looking Sunday night. The location of the storm as of Sunday night was less than 100 miles east of the Lesser Antilles and its movement was to the west at about 12 mph.

Enhanced Satellite

Gonzalo is expected to strengthen over the coming days due to favorable environmental conditions. Sea surface temperatures are generally in the mid 80s, which are 0.5°-1.5° above average for this time of the year. Meanwhile, wind shear is expected to remain fairly low in the vicinity of Gonzalo through the middle of the week.

SST Anomalies

GFS Wind Shear

With these environmental conditions in place, Gonzalo will likely become a hurricane in the coming days. However, the intensity beyond that is still up in the air, with some models intensifying the storm much more than others. The official NHC forecast calls for Gonzalo to become a strong category 2 hurricane by Wednesday or Thursday. As far as the track goes, most of the models are in fairly good agreement that Gonzalo will continue off to the west before a frontal system lifts it north and eventually northeast for the middle of the week (timing differences do exist). Along that path, Gonzalo will impact the northern Lesser Antilles, Virgin Islands, and Puerto Rico. Therefore, Tropical Storm Warnings are up in those areas, with a Hurricane Watch up for the US and British Virgin Islands and Puerto Rico. Interests in those areas should heed warning and pay close attention to any changing details in the forecast over the next 24 hours.

Gonzalo Track plus spaghetti


Busy in the Tropics Worldwide; Fay Eyes Bermuda

It’s a busy weekend in the tropics worldwide. In the Atlantic Basin the core of Fay warms and enough convection gathers near its center to gain full blown tropical storm status. As of 11 AM recon data shows the storm has strengthened and max sustained winds top out near 70 mph. Tropical Storm Fay moves north at 16 mph and tropical storm force winds will reach Bermuda late Saturday into early Sunday. A Tropical Storm Warning is in effect.

Floater IR Enhanced

The wind speed forecast per data from the National Hurricane Center shows winds of 58 mph+ are possible in Bermuda early Sunday morning. The core of the strongest winds will pass very close the island. Bermuda could see 2-4″ of rain from Tropical Storm Fay along with rough surf.

Wind Radii

Here’s the official track as of 11 AM EDT. The center of Fay is expected to pass just southeast of Bermuda Sunday morning. While some strengthening is expected over the next 24 hours Tropical Fay will be absorbed into a strong cold front late Sunday into Monday.


There are two other areas of interest in the Atlantic. Of least concern is an area of disturbed weather (now invest 91L) west of the Cape Verde Islands. While convection is quite deep and impressive Saturday morning the long term atmospheric conditions do not favor tropical depression development as it moves west-northwest. Due to hostile upper level winds the odds of tropical depression development only sit at 10% over the next five days per the NHC (as of Saturday morning).

Floater IR Enhanced

Invest 90L east of the Lesser Antilles bears watching into the upcoming work week. While water temperatures and upper level winds (low to moderate shear) favor development there is quite a bit of dry air in the vicinity as this feature tracks  west-northwest at 10 mph. The odds of tropical depression development are at a low 20% by Monday morning but at a high 60% by Thursday morning. Interest in the Lesser Antilles, Puerto Rico, Hispaniola, Turks and Caicos, and the Bahamas need to closely monitor this disturbance in the coming days. 06Z computer models are in decent agreement that Invest 90L heads for the northern Lesser Antilles Sunday night and will pass close to Puerto Rico late Monday into Tuesday. It may not fully organize into a tropical cyclone (possible Tropical Storm Gonzalo) until Thursday or Friday (not until the weekend according to the 0Z Euro). During this time a trough may keep the disturbance well east of the U.S. but close to the Bahamas or Turks and Caicos. The 06Z GFS keeps future Tropical Storm Gonzalo east of the Bahamas. Stay tuned.

Invest 90L Models

In the western Pacific Typhoon Vongfong continues to weaken. As of Saturday morning (11 AM) EDT max sustained winds drop to 85 mph 24 miles SE of the U.S. Kadena Air Force Base in Okinawa. The looping radar image below is courtesy of the Japan Meteorological Agency. It shows squalls over Okinawa as the center of Vongfong passes by. The once Super Typhoon will continue to weaken due to land interaction. It moves over the Japan Mainland late Sunday and Monday EDT. Severe flooding is possible.



Lastly Tropical Cyclone Hudhud eyes southeast India. The center will make landfall overnight Saturday into Sunday with possible major hurricane force winds. In fact, as of Saturday morning EDT winds could strengthen up to category four hurricane force just before landfall. Evacuations are underway in Visakhapatnam. Major hurricane force winds, flooding and storm surge will batter southeast India into early Sunday. Wave heights build up to 30 ft.




Subtropical Storm Fay Forms; Watching Invest 90L

Subtropical Storm Fay formed on Friday several hundred miles south of Bermuda. The storm is designated subtropical because it has some characteristics that are tropical in nature, and some that are not. However, it is expected to fully transition into a tropical storm by Saturday and continue on a northward track. Eventually it will curve to the northeast and become absorbed by a front early next week. However, it will make a close pass to the southeast of Bermuda this weekend and may dump significant rainfall over the area.


We’ll get back to talking about the Atlantic in just a moment but first let’s head toward the recently active western Pacific. Vongfong continues its trek toward Japan. The storm was still a Category 3 typhoon with winds of 115mph as of Friday evening. It will no doubt lash Japan with strong winds, heavy rain, and high storm surge this weekend.

Tropical Track Pacific 2

Back to the Atlantic, there are two other areas of interest across the ocean basin. One is an area of showers and storms several hundred miles west of the Cape Verde Islands that is associated with a tropical wave. Environmental conditions are not favorable for this disturbance to become a tropical depression and the NHC keeps its chances for development at 10% over the next few days. The second disturbance is just a few hundred miles east of the Lesser Antilles and has much more potential. This disturbance, designated Invest 90L, has been given a 20% chance by the NHC to develop by Sunday evening, and a 60% chance to develop by Wednesday night.

Floater IR Enhanced 2

While development of 90L will be slow (if it does indeed develop), environmental conditions are ripe. Water temperatures in the area are still quite warm (mid 80s) and wind shear is expected to be in the light-to-moderate range over the coming days.

Caribbean and Atlantic Water Temperatures

Several computer models develop 90L but not until the middle or even end of next week. The GFS and ECMWF (Euro) both develop the disturbance close to Puerto Rico (though with timing differences) and then curve it east of the Bahamas and eventually out to sea. However, seeing as that the storm’s potential development is still almost a week away, a lot can change. That includes where this storm would go, how intense it would get, and whether it would even form at all. Therefore, be sure to check back here all weekend and into next week for the latest details.

GFS MSL and Precip RateECMWF MSLP and Precip Rate

One of