Hurricane Irma soon to head to Keys then Florida mainland

Sept. 9, 2017 — HURRICANE IRMA: Latest updates, shelter info, evacuation info
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There is a hurricane warning for most of Florida - including Jacksonville & all of Northeast Fl.... along with storm surge watches & warnings. Warnings will eventually.

Good deal of uncertainty continues regarding the final path of Irma in the longer range.... models seem to be "settling down" at this point - indicating a hit on Florida's west coast....

The "Buresh Bottom Line" is: stay tuned!... Always be prepared!..... City of Jacksonville Preparedness Guide... Georgia Hurricane Guide.

It's still a little too early to pinpoint exact & especially magnitude local (Jacksonville/NE Fl./SE Ga) impacts, but I am certain that there will be at least some impact Sunday through Mon. in the form of heavy rain, strong winds, storm surge, flooding & a few tornadoes.

IT IS STILL QUITE LIKELY THAT THERE WILL BE ADJUSTMENTS IN THE FORECAST TRACK FOR HOW CLOSE TO JACKSONVILLE THE EYE WILL BE EARLY MON.... WITH SOME EASTWARD ADJUSTMENT POSSIBLE. DON'T GET TOO CAUGHT UP IN JUST TRACKING THE EYE & ITS IMPACTS ON YOUR LITTLE NECK OF THE WOODS BECAUSE IRMA'S HIGH WINDS EXTEND NEARLY 200 MILES FROM THE EYE & WILL EXPAND EVEN MORE THROUGH MON.

NE FL./SE GA:

- winds will increase through Sunday & peak Sunday night-Mon. .... ranging from 40 - 70 mph sustained, higher gusts. Breezy onshore flow will precede the true Irma winds with gusts of 30-40 mph Sat. through Sun., especially with any rain bands. Irma's wind field will expand over the next couple days with strong winds far from the eye.

- storm surge flooding will begin by Sunday and continue into Monday. Surge values - not including wave action - appear destined to average 3-5 feet above ground level along the coast, 2 - 4 feet for the intracoastal & 2 - 4 feet along the St. Johns River, but will vary depending on topography & exact location/intensity of Irma.... & especially in relation to the approach angle to the coast vs. river with locally unique bends & topography along any waterways causing major fluctuations in actual level of water with wind direction & speed playing a major role in the levels as well.

- heavy rain from fringe Irma bands will affect the local area into Sunday but "prime time" will be Sunday - Monday. Rainfall will average 6 - 12 inches but could reach a 15" or more from I-95 to the beaches. In fact, as much as 5" of rain fell Fri. afternoon in parts of St. Johns Co.

- a few tornadoes & waterspouts will likely occur into Monday

- there is an extreme rip current risk - stay out of the ocean!

This does - at the very least - look like a pounding for area beaches. Areas hit hard by Matthew less than a year ago are potentially especially vulnerable. If you are told to evacuate, then evacuate is what you should do. If utilities are cut &/or compromised, you could have no modern conveniences for days. If flooding is considerable, you could become isolated & will have to deal with fire ants (see Texas during Harvey), snakes & other wildlife that might be seeking refuge.

It is important that you do not make decisions based on trying to compare Matthew to Irma as the comparison is not apples to apples, so to speak. Inland areas will suffer more damage then during Matthew because of the location of the eye of Irma. The tornado threat & winds will be higher than during Matthew while the storm surge will not be as severe with Irma.

Know your evacuation zone......

"Irma" remains a classic deep tropics long track (trans-Atlantic) hurricane. Changes in structure due to eyewall replacement cycles & especially interaction with the land mass of Cuba have occurred & will continue. Once the eye is back over the very warm water of the Fl. Straits & far SE Gulf, the hurricane will have a chance to reorganize & strengthen. The question at that point will be how quickly can Irma get its act back together again before moving over or alongside Fl. There will also be a good deal of shear once Irma is north of about Ft. Myer's latitude which will help with the weakening process. NOAA hurricane recon & research planes are flying through (avg. 1,000-10,000 feet) & around "Irma" almost 'round the clock giving us a better idea of the structure & intensity & - above all - hopefully add to some consistency & accuracy in model forecasts assuming better analysis/input for the models.

I cannot emphasize enough -- forecasting exactly where Irma is going to go in the long run is still difficult. But it's becoming more & more obvious that there will be direct impacts in one form another & to one degree or another for almost all of Fl. & northward to Georgia, parts of the Carolina's & even into Tennessee.  Stay cool, calm & collected... NOW is the time to prepare:

(1) peak of the hurricane season is upon us

(2) you'll be prepared for anything mother nature throws at us - hurricane, lightning, flooding, tornadoes, etc. Preparations do not need to take a long time nor do preparations need to be expensive. But preparing now will offer peace of mind for when & if a storm is headed your direction & will also give you a better chance to survive the storm then allow you thrive after the storm.

(3) know your evacuation zone

Forecast models are still jumping some but have seemed to generally stabilize recently. Virtually all of the normally decent modeling shows a hurricane moving some semblance of north anywhere from I-75 to the west coast of Fl. moving generally northward after the all important turn to the north out of Cuba & the Keys. It's important to not hang on each & every individual model run but rather look at the bigger picture in the coming days. The terrain of Cuba is eating away at the hurricane but the eye will miss the highest mountains & still is very close to the "bath water". The strong Bermuda High - which has been a strong mainstay for months - makes full storm recurvature more difficult - this is a sentence have had in this blog since early last week & obviously has been coming into play. The model's differences seem to be related to the upper level trough over the Eastern U.S. & just how strong the Bermuda high remains. The UKMET insists the Bermuda high will break down enough for more of northeast movement across Fl. & the far Southeast U.S. while other models - GFS & European - are more due north or even an eventual bend back to the northwest. Splitting the difference may end up being the best & most accurate forecast. We have to look for slowing of this large hurricane before it can make the northward turn - laws of physics generally won't allow for a dead turn north while steadily moving W/NW. And we are seeing a gradual slowing of the movement so the turn northwest then north should play out Sat. night into Sunday. Anyone that lives from Tampa to the SW coast of Fl. should be evacuating given the history of Irma & the possibility of a major hit from the south & southwest (possibly similar to Charley in 2004 but much wider storm).

There will be quite an increase in mid & upper level shear once Irma starts to gain latitude not to mention being over land so once over Fl., there should be fairly steady, rather fast weakening.

Topographical map of Cuba shows the highest mountains in the Central & far eastern parts of the country are not likely to come into play as much as the lower elevation northern coast.

A rather deep upper level trough over the Eastern U.S. today which lifts well to the north Sunday will play a pivotal role in the eventual movement of "Irma". The GFS model upper level (500 mb) chart below for Sun., 09/10 shows a wake zone of sorts left behind leading to a clear alleyway over the Southeast U.S. As the trough lifts out, a strong surface high will build into the Northeast U.S. which will block Irma from getting too far north while an upper level ridge builds underneath the departing trough. This puts the extreme Eastern Gulf, Fl./Ga. to Virginia on high alert!.... with a move that will be into Florida & quite possibly rather close to Jacksonville by Monday. And by no means is this set in stone!

I still believe an abrupt turn to the north will occur Sat. - Sat. night. The question becomes when & where. But it is clear - to me - the big eastern U.S. trough will be fast moving & transient & that "Irma" does not get sucked up into the trough & taken far to the east over the Atlantic. In other words, no escape route & the question is what part of the U.S. coast line is most at risk & then gets hit the hardest.

SUMMARY:

Global forecast models will continue to try to correct into Sun. A combination of plots from each model's run (ensemble) points to near Florida Sunday then into the Southeast U.S. Mon./Tue.

People have been asking about a "way out" - where Irma doesn't impact Florida at all or at least that Irma weakens ... or even the U.S. While that seems unlikely, the possibility of a landfall on Cuba has happened. Now the question is can Irma regain strength when it makes the turn north.... land interaction with Cuba will probably continue into Sat. night so further weakening is likely before any threat of reorganization &, therefore, strengthening.

Upper level (500 mb) chart forecast below from GFS for early Sunday (Irma forecast a little to far north but has the general idea):

Key West Doppler radar loop:

Casablanca, Cuba radar:

"Irma" model plots:

Fascinating imagery(!) from CIMMS, University of Wisconsin, Madison - Microwave radar-simulated imagery showing Irma wrapping up... click here for full definition.....

Wave forecast:.

NOAA WaveWatch III below predicated on GFS model - will change & update - hit refresh for latest + loop:

Hurricane "Jose" to the east/southeast of "Irma"....

Very warm ocean water ahead for Irma:

Even more telling - the oceanic heat content showing a wealth of deep warm water over the SW Atlantic/Caribbean & Gulf of Mexico:

And let's dust off our Pacific typhoon teleconnection for trying to forecast "Irma" - it's lined up pretty nicely but is to draw some parallels. The 500mb chart below from the GFS for the N. Pacific to the Northern U.S. shows trough, ridge, trough, ridge, trough - the last trough being over or near the Eastern U.S. (it's what's picking up the "Harvey" remnants). The W. Pacific trough is picking up typhoon "Sanvu" keeping the tropical cyclone very near or to the immediate east of Japan. This MIGHT be - & so far has been - an early clue that at least some semblance of troughing or alleyway will remain in place over or near the Eastern U.S. which COULD draw Irma northward near or over U.S. coast.

Satellite imagery below shows a band of clouds over the Eastern U.S./W. Atlantic - a weakening front that will be reinforced over the next couple days & is part of the weakness in the upper level flow that gradually pulls Irma northward....

Jose:

.... has become a hurricane & will languish in the "backwash" of Irma for many days but will impact the Northern Lesser Antilles over the weekend where warnings are in effect for some of the same islands hit by Irma! I'm still not certain this simply stays out to sea so bears watching in the long run - 10-14 days - for a possible loop then turn more to the west. At least a brush with the U.S. east coast is not out of the question as an upper level ridge rebuils underneath departing/decaying Irma & to the north of "Jose". At the very least it appears a loop will occur over the Central Atlantic about the middle of next week. "Jose" almost reached Cat. 5 intensity Fri. night!

"Katia":

The 11th named storm of the season developed over the far W. Gulf of Mexico & moved into Mexico Fri. night - a Cat. 1 landfall. No impacts for the U.S. & no additional widespread significant rain for Texas or Louisiana from Katia.

East Atlantic IR satellite shows another strong tropical wave which has a good chance to become a named storm(!):

Mid & upper level wind shear (enemy of tropical cyclones) analysis (CIMMS) - note how strong the shear is across the N. Gulf of Mexico, the north two-thirds of Fl. into the W. Atlantic which eventually will shred Irma:

The main development region (MDR) remains above avg. temps. - in fact - only 2005 & 2010 were warmer. The deep warm ocean water can "energize" tropical cyclones: