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Category: Tropical

Kate Arrives ! !

| 7:31 am November 9, 2015

Kate has arrived. The National Hurricane Center (NHC) has issued an advisory at 7:20 am CST as Tropical Depression 12 strengthened enough to become a tropical storm. That advisory is shown below. As we note, the Hurricane Hunter aircraft data were instrumental in providing the information to forecasters. The depression strengthened pretty much as expected and the future track for Kate will take it through the Bahamas and recurving before reaching Florida. After that Kate becomes a nuisance mainly for shipping as the track is expected to take it north of Bermuda. Bet they have some pretty good swells/waves on the island, though.


WTNT62 KNHC 091319

820 AM EST MON NOV 09 2015


Air Force Reserve hurricane hunter aircraft data indicate that
Tropical Depression Twelve has strengthened to Tropical Storm Kate.
The maximum sustained winds are estimated to be 40 mph (65 km/h)
with higher gusts.

LOCATION...24.2N 74.9W

Forecaster Cangialosi/Stewart 


Could We Have Kate Tomorrow?

| 8:18 pm November 8, 2015

The National Hurricane Center (NHC) is watching an area of showers and thunderstorms associated with a small low pressure area located just east of the southern Bahama Islands. This area has shown some signs of becoming better organized since this morning, and forecasters have pegged the chance of formation through the next 48 hours at 80 percent. According to the Tropical Weather Outlook from NHC, it will not take much more organization for it to become a tropical depression or perhaps a tropical storm. Should it gain enough strength to become a storm, it would be given the name Kate.

No matter what happens to it, heavy rainfall and gusty wind can be expected over portions of the Bahamas. An Air Force Reserve Hurricane Hunter aircraft is scheduled to investigate the system on Monday morning. The various computer model guidance, second graphic below, shows the disturbance is likely to move northwestward for the next day or so before beginning to recurve away from the US coast and out into the Atlantic where it would be a problem for shipping interests as well as the folks in Bermuda.




* * * U P D A T E * * *
At 9:00 pm CST, the National Hurricane Center issued an advisory on Tropical Depression 12. Thunderstorm activity has increased over the eastern portion of the circulation which has been enough to classify the system as a depression. A Hurricane Hunter aircraft will investigate the storm Monday morning providing NHC with much better information on the cyclone’s intensity. Initial NHC forecasts indicate that the system is likely to become a tropical storm in the next 24 hours.

Another Tropical Cyclone Aiming for Yemen

| 4:48 pm November 8, 2015

Yemen is a popular spot for tropical cyclones this time of year – well, at least this year. The second tropical cyclone in about a week is taking aim at Yemen. After forming in the Arabian Sea, Cyclone Megh has been tracking on a westerly course. It passed over the Socotra Archipelago yesterday and was moving by the northeast tip of Somalia this afternoon. The latest satellite view along with the past and forecast tracks are in the graphic below. Megh was a category 2 storm, however, it is forecast to dissipate over the next couple of days becoming a depression before making landfall on the western end of Yemen. At least there is some consolation that Megh is not following along the exact path taken by Chapala last week. Megh is not making the kind of headlines Chapala did simply because it is not as strong as Chapala was. Megh will bring more rain to Yemen whose annual rainfall is less than 5 inches according to what I’ve read.



48-Hour Rainfall Ending Nov. 2

| 8:06 am November 3, 2015

The National Weather Service (NWS) office in Birmingham tweeted this graphic which quite nicely shows the rain that has fallen over Alabama during the last several days.


The graphic illustrates two important items. First, ALL of the state of Alabama has had rain – some more than others. Looks like the northwest corner was a little short changed in the amount of rain they recorded.

Second, this really illustrates how narrow the bands of highest rainfall can be. Note in the map that there is a band of 3 to 4 inch rain running from eastern Bibb County northeastward to the northeast corner of Calhoun County. That band does not appear to be more 5 to 6 miles wide. A second and heavier band of rain shows up in the Florida Panhandle and stretches across portions of Southeast Alabama. The band starts as fairly broad, but splits into two heavy bands with more than 4 inches across Southeast Alabama. Each of those prongs is very narrow, maybe 10 to 12 miles. I think this clearly illustrates how difficult it is to forecast the exact location of heavy rain – or heavy snow.

Special thanks to the folks at the NWS in Birmingham for creating and sharing the graphic.

And for those who may have been following the record setting typhoon on the other side of the world, Chapala came ashore overnight on the coast of Yemen. Chapala is forecast to diminish fairly rapidly over the next 12 to 18 hours, but it will bring record rain to the western half of Yemen.



Chapala Churning Closer to Land

| 8:17 am November 2, 2015

Typhoon Chapala remained a hurricane this morning and continued to churn across the Arabian Sea and the Gulf of Aden as it gets closer to landfall in Yemen.


This is the latest satellite view of Chapala. It was getting closer to Yemen after brushing just north of the island of Socotra in the Arabian Sea. The Joint Typhoon Warning Center (JTWC) placed Chapala’s wind at 105 knots this morning with gusts to 130 knots (120 mph with gusts to 150 mph). The forecasters there continued to predict a gradual weakening trend as Chapala makes its was toward landfall just to the west of Mukalla (or Al Mukalla on some maps) around midnight tonight. Once the eye has made landfall, the tropical cyclone should diminish in strength rapidly falling below tropical storm strength about 24 hours after landfall. Here’s the graphic from JTWC.


Here’s another view of Cyclone Chapala.



Tropical Troubles in Arabian Sea

| 10:15 am October 31, 2015

I know that it is one the other side of the world, but while the Atlantic and Eastern Pacific basins were quiet, Tropical Cyclone Chapala was taking advantage of the warmest waters ever recorded in the Arabian Sea for this time of year to rapidly intensify overnight. Chapala topped out for the time being as a high-end Category 4 storm with 155 mph wind early Friday morning, according to the Joint Typhoon Warning Center (JTWC). The India Meteorology Department (IMD), responsible for tropical cyclone warnings in the North Indian Ocean, placed Chapala’s intensity at 130 mph winds with a central pressure of 942 mb on Friday morning. This made Chapala the second strongest tropical cyclone on record in the Arabian Sea right behind Category 5 Cylcone Gonu of 2007, the only Category 5 storm ever recorded in the Arabian Sea. The North Indian Ocean as a whole has seen five Category 5 storms in recorded history ; four of them occurred in the Bay of Bengal, so Chapala becomes the sixth strongest tropical cyclone ever observed in the North Indian Ocean.

Chapala.A2015303.0910.1kmImage: Tropical Cyclone Chapala as seen by the MODIS instrument at 0910 UTC October 30, 2015. At the time, Chapala was at peak strength with 155 mph winds. Image credit: NASA.

According to NOAA’s Historical Hurricanes tool, there have only been six major Category 3 or stronger tropical cyclones recorded in the Arabian Sea. The period of record, though, is somewhat short as accurate satellite records only go back to 1990. The Arabian Sea doesn’t see many tropical cyclones since it is small; furthermore, the Southwest Monsoon keeps the tropical cyclone season short with a season that lasts from May to early June before the monsoon arrives. Another short season occurs from late October through November after the monsoon has departed. Strong Arabian Sea storms are rare due to high wind shear and a generous supply of dry air from the deserts of the Middle East.

Recent satellite images showed that Chapala degraded slightly in organization Friday, and JTWC reduced the storm’s estimated intensity to 140 mph winds as of 12Z Saturday. The storm was still in a low wind shear environment with warm ocean water near 30°C or 86°F so Chapala is likely to remain a strong hurricane with landfall on Monday morning in a sparsely populated area in Yemen just west of the border with Oman as it begins to weaken.

The latest forecasts take Chapala into the east coast of Yemen as a Category 1 hurricane and into Saudi Arabia as a weakening tropical storm. Apart from any wind damage, this course will bring huge downpours to eastern Yemen and western Oman where almost any amount of rainfall is an event worth noting. Local rainfall totals from Chapala could easily exceed 10 inches


This information was gained from a number of sources including the Joint Typhoon Warning Center, Weather Underground, and USA Today.