Weather

"Talking the Tropics With Mike": Officially "Matthew" - Sept. 28th

Sept. 28, 2016 — 97L strengthens into "Matthew" over the Eastern Caribbean..... anyone with travel plans to the Caribbean should stay up to date on the latest developments & forecasts..... heads-up Puerto Rico, Haiti, Dominican Republic, Cuba, Jamaica, Aruba & the coastal U.S.

You will hear & see lots of "hubbub" regarding the wave (97L)/"Matthew" approaching the Caribbean this week.... stay HERE for the "real deal" - just the facts. :) ... models have been, are & will bounce around a lot.  We'll have a tropical cyclone in the Caribbean the next few days then "Matthew" slows down & reaches a crossroads -- to continue west, turn more northwest.... OR take a sharp turn to the north.  We MIGHT be able to take a hint from what's going on over the W. Pacific as typhoon "Megi" went west/northwest through Taiwan Mon. night/early Tue.  This (teleconnection) could imply a stronger ridge will develop over the W. Atlantic during the next week.  If so, "Matthew" may be destined for a more westward track than currently indicated by some forecast models.  Also -- as I've mentioned several times in this blog -- several forecast models have had a tendency to recurve systems too soon this season & so reality is farther west.

WE'RE JUST A FEW WEEKS PAST THE PEAK MONTH OF THE HURRICANE SEASON...  You should always be prepared & aware.  First Alert Hurricane Center ** here **.  Reminder that flood insurance policies take 30 days to take effect..... & will not be written when/if a named storm is nearby.

The band of clouds nearing the U.S. east coast on the satellite imagery below is being driven by a cold front & strong upper level trough of low pressure (see 2nd image below) that will spawn a strong low & heavy rain set-up for the Mid Atlantic.  This upper trough will close off & settle over the Eastern U.S. by the weekend & could be reinforced by a 2nd upper level trough early next week.  This upper level pattern will be the key for the tropical disturbance that will soon be over the Carribean.  A clear alleyway of lower pressure exists right now over the W. Atlantic which is what the GFS model seems to follow which is initially reinforced by a weaker yet very important upper level trough into the Southeast U.S. by early next week which in turn -- according to the GFS model -- keeps "Matthew" to the east of Fl. though with a recent trend more west later in the period (middle of next week).  The European model is much slower & -- very importantly -- farther to the west & south implying the first upper trough over the Eastern U.S. misses "Matthew" followed by little in the way of a secondary upper level trough.  Both models are just about in lockstep until the weekend which looks to be the so-called crossroads for movement of "Matthew" which is speeding west only to slow a great deal over the weekend allowing for the northward turn.  Most of the other global forecast models are somewhere inbetween the GFS & European models.  Also throwing a wrench in things: a possible move more southwest for a while over the Caribbean which could introduce the landmass of S. America & -- in addition -- would result in more distance between the tropical cyclone & the upper level trough to the north.

Upper level forecast for late Fri. shows the trough over the Eastern U.S. followed by a strong trough moving into the Western U.S. which may also play a role in the eventual movement of "Matthew":

The strong wave -- 97L -- that moved off Africa late last week is at a more southern latitude has become "Matthew".  Most of the long range global forecast models are in good agreement into the Central Caribbean until the pivotal slowing then northward turn over the weekend.  Despite the current fast movement, the wave will slow considerably by the weekend at which point we see some kind of turn more northward.  As mentioned above... the key to this wave's track in the long run will likely be a strong mid-latitude trough of low pressure that is forecast to develop over the Lower 48 of the U.S.  This feature may very well draw northward whatever is in the Caribbean.  But if the upper trough is not deep enough (far enough south), "Matthew" could be missed initially which would mean movement farther to the west & -- for a while -- even a little southwest.  Caribbean tropical cyclones do have a tendency to thrive in late Sept. - Oct. which adds even more confidence to the forecast of a possible hurricane over &/or near the Caribbean within the next 3-6 days or so.

Zoomed in image of "Matthew" shows heavy rain & wind already lashing the Windward Islands with decent upper level outflow evident to the north & northeast:

Forecast models have certainly trended east recently (after the turn north) but model flip-flops will remain possible & adjustments are almost a certainty......

Image below shows the oceanic heat content.  Yellow, orange & red indicates higher heat content which can give tropical cyclones added "energy".  Pretty impressive over the Caribbean, SW Atlantic & Western Gulf.....

0

Water vapor imagery below shows plenty of moisture pooling over the SW Atlantic/Caribbean & Gulf of Mexico....

1

The wind shear (red lines represent strongest shear) analysis shows strong shear in the vicinity of "Matthew" but the shear is relaxing to the north & west.....

A disturbance is near the coast of Mexico but proximity to land should limit development.  Gulf of Mexico:

East Atlantic where tropical waves continue to march westward.  We're nearing what is typically the end of the "Cape Verde season":

Lots of warm water to help "feed" tropical cyclones.  Water temps. of 28 degrees Celsius equates to 82 degrees Fahrenheit.  Tropical cyclones generally need at least 80 degree water to thrive.

Sea surface temps. vs. average:

Meanwhile.... Hurricane "Joaquin" was born this week a year ago on Sept. 27th, 2015.  The infamous storm will be remembered for the sinking of the El Faro (it was later determined that the ship's captain was using old forecast info. [at least 24 hours old] for "Joaquin" which likely proved to be fatal since "Joaquin" was so rapidly intensifying while also shifting south & west) & the tropical cyclone's forecasting headaches.  The tropical depression on the 27th became a tropical storm on the 28th... the El Faro left port in Jacksonville on the 29th... "Joaquin" became a hurricane on the 30th going through a rapid intensification cycle whereby it became a Cat. 3+ later in the day in less than 24 hours... the El Faro was sunk near the Bahamas on Oct. 1 when "Joaquin" was a Cat. 4... peak intensity -- close to Cat. 5 -- was on Oct. 2 as "Joaquin" moved northeast away from the battered Bahamas.

Below I've reprinted my "Buresh Blog" & Tracking the Tropics With Mike" info. on "Joaquin" from the first week of Oct., 2015:

A quick review: "Joaquin" went hurricane early Wednesday undergoing a rapid intensification cycle that saw the storm go from a tropical storm to Cat. 3 in a little more than 24 hours then to a Cat. 4 early Thu. afternoon.   The hurricane briefly dropped to a Cat. 3 Friday afternoon - early Sat. before going through yet another "growth spurt" Saturday taking the violent hurricane to near Cat. 5 status as hurricane hunter aircraft found winds near 155 mph & falling pressure.  That peak intensity did not last long & there has been a steady weakening since due to cooler water temps. & increasing shear.  The tropical cyclone passed Bermuda to the west as Cat. 2 dropping to Cat. 1 in the process.  Dry air is being drawn into the storm by the strong circulation with much of the more intense convection over the northern & northeast part of the circulation, but the hurricane has remained remarkably well intact north & northeast of Bermuda.  

The sometimes more reliable European model in the past was an outlier to the west -- far to the west -- on "Joaquin".  So the European model wins this forecast battle, hands down.  The European model was one of the first models to take an intense hurricane initially southwest & deep into the Bahamas -- where it went.  Most of the hurricane forecast models -- HWRF & GFDL -- hooked the hurricane rather abruptly west/northwest into the U.S.  The problem is these models have bordered on being horrible the past few years.... & certainly this season.  In fact, the NAM (North American Model) -- which is a mesoscale (small) scale model not necessarily intended for tropical cyclones but has been tweaked on & off the last few years to try to do better on "in-close" tropical cyclones -- was shutting down last week during its forecast cycle unable to finish the job.  One of theories put forth by modelers is that the NAM was not handling the environment well (namely anomalously warm water) near "Joaquin".  Will be an interesting offseason for tropical cyclone numerical modelers - time to get busy!

"Thanks" to national & even some local media outlets, it has to be pointed out that THERE HAVE NOT BEEN & WILL NOT BE DIRECT U.S. IMPACTS FROM "JOAQUIN".  But there will still be some very rough & dangerous weather for areas from Eastern Ga. through the Carolina's to near Chesapeake Bay where there has been flooding, gusty winds, very rough seas & surf & a high rip current risk.  But these weather elements were a combination of a stalled front & the strong upper level disturbance vs. a any kind of hurricane input.  It's true there have been some added surface winds courtesy the pressure gradient between hurricane "Joaquin" & high pressure to the north, but the tropical cyclone's circulation was way, way, way, way to the east.

It's likely that "Joaquin" will remembered for several outstanding "traits", & I would think the name will probably be retired late winter/early spring (the annual list of names returns every 6 years). For blow by blow details with regards to forecasting "Joaquin" last week, you can check "Talking the Tropics With Mike".

(1) the forecast model mayhem

(2) the first Oct. Cat. 4 hurricane to directly hit the Bahamas since 1866

(3) the sinking of the large cargo ship - El Faro.  There have been a lot of questions regarding why El Faro ventured into an intensifying hurricane.  It's possible there was not much the captain could do because of mechanical failure, but it will be up to a future investigation to determine if mechanical difficulty was indeed the beginning of the end for the ship.  Initial forecasts certainly were of little value BUT rapidly changed & were updated such that the crew would have had more than enough time to steer clear of the mighty storm.  Below you'll find a series of track/intensity forecasts + satellite images:

The forecast below was from early Tue. - about when El Faro left port from Jacksonville.  Looking at this forecast, the captain would have little to be concerned about if simply taken for face value.

But the forecast changed drastically in just 12 hours.  Below is the forecast from Tue. evening -- a hurricane dipping more southwest toward the Bahamas.  Crooked Island (where El Faro disappeared) is in the "cone of uncertainty" as is most of the Bahamas.

The early Wed. forecast takes "Joaquin" to Cat. 2.... BUT still not far enough southwest.  In fact, there's been a slight adjustment to the east.

Late Wednesday (a forecast a bit farther southwest)......

Late Wed. evening.... taking the storm to Cat. 3 + closer to the Bahamas......

The forecast models were in disarray - this is from Wed. evening.... through Mon. evening.  We know now that this simply wasn't even close (I believe the models were greatly confused by an incoming area of strong upper level low pressure & therefore the models developed too much low pressure near the east coast which the models mistook for "Joaquin".  In the end, the 2 systems stayed apart -- by a long ways.  Only the European global forecast model picked up on this possibility Wed./Thu. of last week, & it wasn't until Thu./Fri. that most of the rest of the models started to catch on.

IR satellite imagery below at 7:15am, Thu. Oct. 1 - the approximate time of the last transmission from El Faro.  Strong high end Cat. 3 "Joaquin's" eye was just north of Crooked Island which means the ship would have been very near the violent eyewall where winds were 120+ mph & seas were reported to be 40+ feet!

The IR image below is 24 hours later -- early Fri. (7:15am EDT) -- when search & rescue was underway for the El Faro.  The eye of now Cat. 4 "Joaquin" is only about 40-50 miles northwest of Crooked Island & the search area was besieged by the more violent southeast quadrant of the powerful hurricane.

Thursday evening (Oct. 1) storm analysis -- immediate northwest of Crooked Island......