2015 Hurricane Season Outlook

[Paul Robison]

September 24th is usually the time the window shuts down for cane season.
Dr. Neil taught us that....I'm sticking a fork in it.....adios.

For Texas the realistic end of hurricane season is near. Right, TP11?

[Katdaddy]

The chance of a tropical cyclone along the Upper TX Coast after Sept 20th is rare as the pattern begins to transition to Fall.

[Paul Robison]

The chance of a tropical cyclone along the Upper TX Coast after Sept 20th is rare as the pattern begins to transition to Fall.

Then a visit from whatever forms in the Southern/Central or Western GOMEX is unlikely?

[Texaspirate11]

September 24th is usually the time the window shuts down for cane season.
Dr. Neil taught us that....I'm sticking a fork in it.....adios.

For Texas the realistic end of hurricane season is near. Right, TP11?

Yes Paul.

[Paul Robison]

[srainhoutx]

For those that follow our member Josh Morgerman in his adventures intercepting Tropical Cyclones, it looks like Typhoon Dujuan is his next intercept in Taiwan. Josh should be landing shortly and his intercept can be followed on the iCyclone Facebook Page...https://www.facebook.com/iCyclone

[srainhoutx]

Evening briefing from Jeff regarding TD 11 along the East Coast:
Tropical Depression # 11 formed late yesterday evening over the central Atlantic Ocean about 465 miles SW of the island of Bermuda.



I have not spent much time on Atlantic tropical cyclones this season due to the overall lack of organization of such systems and their general lack of threat to populated areas…however TD 11 may become a different story.



Discussion:

TD is poorly organized this evening with much of the convection removed to the south and southeast side of the center of circulation due to NW wind shear. The system is drifting westward at around 5mph with 35mph winds.



Track:

A highly complex pattern will be developing over the eastern US into the western Atlantic Ocean over the next 5 days as the current energy along the TX coast ejects ENE into the SE US allowing the tropical low over the eastern Gulf of Mexico to swing up the US east coast. High latitude blocking high pressure becomes established over SE Canada and NE by this weekend. TD 11 will drift westward and then make a hard turn to the right (north) as the system begins to feel the effects of the SE US trough by mid week. The ECMWF brings 11 northward and then has a hard left turn into the US coast indicating the system is captured by the SE US trough…similar to Sandy (2012). The GFS and HWRF models so somewhat of a leftward bend to the track by the end of the week, but not as dramatic as the ECMWF. The GFS ensembles have a general threat area from the mid-Atlantic up the east coast toward Long Island. The GFDL model is similar to the GFS and HWRF, but is much slower in its track. Nearly all guidance shows a significant increase in forward speed to the system from Friday into Saturday with the official NHC forecast points moving from well SE of NC to off the NJ coast in 24 hours. If you are going to get a hurricane hit north of Hatteras this time of year this is one way for it to happen with a fast forward speed system moving nearly up the entire length of the warm Gulf stream and a trough back to its WSW/SW. Pattern appears similar to Sandy (2012), but not as amplified. Still have much of the week to watch, but should models start to converge on the leftward turn into the east coast and continue the significant forward motion increase by late week the threat is certainly going to be increasing.



Intensity:

11 lacks overall organization and must continue to fight 20-30kts of wind shear. Over the next 48 hours the wind shear is forecast to relax and the system will likely develop into a tropical storm. Intensity guidance has significantly increased today in association with a somewhat more favorable pattern over the western Atlantic by the middle of the week…most notably the HWRF and ECWMF models. For now will downplay the extreme intensities being offered in those solutions for a more tamed very large tropical storm moving offshore of NC Friday and then racing N to NNW toward NJ/NY this weekend. Should models continue to trend stronger, then a much more serious impact would be possible along much of the east coast north of the outer banks.



It should be clearly noted that once 11 begins to make its northward turn on Thursday afternoon it will undergo a dramatic increase in forward speed and the potential preparation window will rapidly close

[srainhoutx]

We will keep a close eye on newly formed Hurricane Joaquin about 245 ENE of the Central Bahamas slowly moving SW around 6 miles per hour. There is some potential that it could bring significant impacts along the East Coast of the United States as well as the Bahamas during the week form torrential flooding rains, very high tides and winds. If Hurricane Joaquin does turn back toward the major cities along the 1-95 Corridor from North Carolina to New England, it will likely be the Major Weather Headline into the weekend,

TROPICAL STORM JOAQUIN DISCUSSION NUMBER 10
NWS NATIONAL HURRICANE CENTER MIAMI FL AL112015
500 AM EDT WED SEP 30 2015

The coldest convective cloud tops are located to the east of the
estimated center position, but there have been hints of an eye in
infrared imagery overnight. Based on a blend of the latest Dvorak
estimates from TAFB and SAB, the initial intensity remains 60 kt. An
Air Force Reserve Hurricane Hunter aircraft is on its way to
investigate Joaquin this morning. Conditions are expected to be
conducive for intensification during the next few days, with Joaquin
moving over very warm waters with shear steadily decreasing. The
hurricane intensity guidance and the latest runs of the GFS, UKMET,
and ECMWF all show Joaquin intensifying, and in fact, the global
models show the central pressure in the 950s or lower. The NHC
forecast is near the latest intensity model consensus, and has
Joaquin peaking in 72 hours. After that time, the cyclone will be
moving into a higher shear environment and over cooler waters, which
should result in slow weakening.

Joaquin continues to move west-southwestward under the influence of
a short-wave ridge to its north, and the initial motion estimate is
245/05. This motion should continue for the next 24 hours, and
Joaquin is expected to then turn slowly westward as the ridge
weakens on Thursday. The UKMET and ECMWF continue to show Joaquin
moving farther southwestward into the central Bahamas than the rest
of the guidance. The new NHC track in the short range is a little
south of the previous one, but north of the UKMET/ECMWF solution.
Given this new forecast, the government of the Bahamas has issued a
Hurricane Warning for the central Bahamas and a Hurricane Watch for
part of the northwestern Bahamas.

After 36 hours, Joaquin is forecast to turn northwestward and then
northward as it interacts with a deep-layer trough that cuts off
over the southeastern United States in about 3 days. Much of the
deterministic guidance shows Joaquin turning northwestward
toward the mid-Atlantic coast by days 4 and 5. However, the ECMWF
continues to show an offshore solution with a track west of Bermuda,
but has shifted to the left this cycle by about 150 miles at day 5.
While the overall synoptic pattern is similar between the models,
the eventual track of Joaquin appears sensitive to just how far
southwest it moves in the first 36 to 48 hours and how this affect
the eventual interaction with the upper-level low. The GFS, HWRF,
and GFDL show a sharp turn back to toward the coast in 4 days, while
the ECMWF is slower to bring Joaquin northward and ejects the
cyclone toward the northeast. The UKMET is between those two
scenarios with a broader turn back toward the coast by day 5. There
is still ensemble support for a wide range of solutions, so
confidence in any deterministic model solution remains quite low.
The NHC track has been nudged a little to the left this cycle to
reflect the westward shift in the guidance, but lies on the eastern
side of the guidance envelope given the ECMWF solution.

Confidence in the details of the track forecast late in the period
remains very low, since the environmental steering currents are
complex and not being handled in a consistent manner by the models.
Given that a wide range of outcomes is possible, it is too soon to
say what impacts, if any, Joaquin will have on the United States.

FORECAST POSITIONS AND MAX WINDS

INIT 30/0900Z 25.4N 72.5W 60 KT 70 MPH
12H 30/1800Z 25.1N 73.0W 70 KT 80 MPH
24H 01/0600Z 24.7N 73.8W 75 KT 85 MPH
36H 01/1800Z 24.7N 74.5W 80 KT 90 MPH
48H 02/0600Z 25.2N 74.7W 90 KT 105 MPH
72H 03/0600Z 28.3N 73.5W 95 KT 110 MPH
96H 04/0600Z 33.0N 73.0W 85 KT 100 MPH
120H 05/0600Z 37.0N 73.5W 80 KT 90 MPH

$$
Forecaster Brennan

[srainhoutx]

Morning briefing from Jeff regarding Hurricane Joaquin:

Joaquin upgraded to a hurricane…rapid intensification ongoing.

Hurricane Warnings are issued for the central Bahamas and a Hurricane Watch for the northern Bahamas.

Interests along the US east coast should closely monitor the progress of this hurricane.

Discussion:
Bottom is dropping out of Joaquin this morning as the first plane in the system since last evening found a central pressure of 972mb down from 990mb yesterday evening. The center dropsonde splashed with 11kts of wind so it did not hit the exact center and the pressure is likely slightly lower than the 972mb message sent from the aircraft. Max flight level wind was 69kts and the flight meteorologist reported any open eyewall on the northern side of the center which matches well with the latest satellite images. The aircraft also sampled the environment just west of the hurricane and found average RH of 50% or less indicating dry air is getting entrained into the western portion of the circulation and clearly seen on satellite images with an erosion of the western portion of the CDO. Center fixes indicate the hurricane continues to move SW trapped on the SE side of the mid level ridge over Cuba and the western Bahamas.

Track:
Near term concern is how close does Joaquin come to the central Bahamas…it now appears that the system will likely impact these islands with hurricane conditions and possibly major hurricane conditions…hence the issuance of the hurricane warning. Joaquin will continue to be under the influence of the mid to upper level ridge just to its west for the next 24-36 hours bringing the hurricane very close if not into the Bahamas.

The longer term track remain highly uncertain with the very big question remaining does Joaquin strike the US east coast. Overnight model guidance has come into loosely better agreement that the SE US trough will potentially capture Joaquin and bring a hurricane northward and then turn the system NW into the US mid-Atl coast. The ECMWF still maintains an escape of Joaquin toward the NE and misses the east coast, but this model has shifted roughly 150 miles westward overnight and the GFS which was siding with the ECMWF yesterday now brings Joaquin to the US coast as a significant hurricane. Pattern setup is similar to Sandy (2012) only displaced southward with respect to the expected leftward turn currently toward the DELMARVA instead of the New Jersey coast (2012).

It should be noted that the official forecast track is now near the eastern edge of the guidance cluster at days 3-5. Some significant shifts of the track are likely over the next 24 -48 hours.

Intensity:
Joaquin is over very warm water and under light wind shear conditions and has been intensifying at a fairly rapid rate since yesterday afternoon (994mb to 972mb in less than 24 hrs). As noted by the aircraft observations there is some dry air nearby and it is getting into the inner core circulation, but this seems to only be disrupting the near term intensification which has continued even with this obstacle. Most model guidance now brings Joaquin to category 2 and some to category 3 intensity over the Bahamas and then northward toward the US east coast. The official forecast brings the hurricane to a 110mph category 2 in 72 hours, but Joaquin may achieve this much faster given its current intensification. Model guidance does show some weakening as the hurricane begins to eject northward away from the Bahamas, but it is uncertain if and how much the hurricane will weaken as its interaction with the trough over the SE US coast will play a big role.

It should be noted that several of the global models are showing sub 950mb pressures with Joaquin and a massive 1043mb blocking high over the SE Canadian and NW Atlantic waters late this weekend. This would produce a very large and widespread pressure gradient of strong winds along much of the US east coast even well away from the hurricane.

NHC Forecast Track and Error Cone:

09302015 8 AM EDT Joaquin 114425W5_NL_sm.gif