Archive for the ‘Cone of Uncertainty’ Category

Hurricane Irma Entry – 9-7-2017

NOAA 9-7-17 8P ET

The image above is from the NOAA National Hurricane Center.  It is the 8 PM EDT Intermediate Advisory for hurricane Irma. 

Here is a link to that site:  http://www.nhc.noaa.gov/

I have no particular “feel” for the path that this storm is going to take.  It appears that my “zinger” notion yesterday for a right turn greater than the experts were anticipating might have been about as meaningful as a small rat’s flatulence in a Fujita-5 tornado.  But, I’m still clinging to hope.

The mass migration from South Florida is effecting us here in Citrus County.  Log-jammed I-75 is about 17 miles due east of my home.  Today I took my father-in-law to our “late breakfast” in Inverness where we get together weekly with some other buddies. The drive home northward on U.S. 41 involved extreme congestion.  What was happening is this:  Some northbound traffic on I-75 was exiting at eastbound U.S. 44 and driving on in to Inverness before heading back north on 41 – many probably guided by the GPS features in their vehicles. Sadly, even before that started happening, our gas stations were on empty. 

I understand from television news that lodging in Florida is getting extremely difficult to find.  Even in Atlanta, I-75 has been experiencing overload.  This is one reason why we are not migrating.  I fear we would end up in a traffic jam of monumental proportions.

So, I’m hoping that the morning brings favorable news.  My wish is that this storm goes out into the open Atlantic leaving us all in peace. But, that is most certainly NOT in the forecast.  As each hour passes, such a lucky turn seems more and more like an irrational fantasy.  My heart goes out to all of those who are traveling tonight – not knowing what they will be returning to once this is all over.  Actually, my heart goes out to everyone threatened by this storm.  I remember clearly what it was like returning to our totaled home in Homestead, Florida after Andrew plowed through on August 24, 1992.  That event changed our lives forever.  Driving in we hardly recognized the scene.  Even the street signs were down!  Because of debris we were unable to get down our street in my van.  Paradoxically, only one pane of glass on our house was damaged and that was a mere crack.  It was something that could have been easily taped to prevent air from getting through until I got around to replacing it.  You see, we had storm shutters on every window.  The trouble is, the roof failed!  So much for preparedness.  LOL  I admit that I have higher hopes this time; every window of this Citrus County home is protected also and it was surely built to a higher standard.   We’ll see.

I won’t go into specifics but, as has happened so many times in the past, I was surprised today by a few of the misconceptions about hurricanes that I heard expressed while I was out and about.  For those of you who are interested in common misconceptions about hurricanes, here is a link: 

https://cloudman23.wordpress.com/2008/09/23/952/

 

 

 

 

 

 

 

 

 

 

 

 

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Tropical Storm Hermine – Tallahassee Alert –

 

THIS IS A VERY “TIME-SENSITIVE” REPORT

After viewing the graphic below my concerns for the residents of Tallahassee have increased; of course it goes without saying that my concerns are for everyone who might have to deal with this storm – no matter where they might be located.  Mainly, there are three factors involved in my concern for the 7th most highly populated city in Florida and its capital city.  One is that there is a strong chance that Hermine will become a hurricane before reaching the Florida coast.

Another:  The minimum distance from Gulf of Mexico waters to Tallahassee is about 25 miles.  One might consider 25 miles to be an adequate “buffer” to provide friction and thus slow down the winds approaching the city.  I think that assumption would be a mistake.  Furthermore, when surface or near-surface winds leave the water for land the slight slowing that might occur would tend to cause more air to rise.  A similar rising is what causes lake effect snows in certain Great Lakes coastal or near-coastal downwind locations.  In the case of humid winds from Hermine possibly decelerating due to friction over the land when approaching Tallahassee, the net effect could very well be more vertical cloud development (due to a greater amount of rising air) than would have occurred otherwise.  This phenomenon can intensify thunderstorms, the gusts that spill out from them, and the chaos that can generate tornadoes.  The increase in rainfall amounts can be dramatic.  So – be careful what you wish for.  Flooding is typically a bigger issue than the wind velocities in these cases.

Here is the third cause for my concern:  The graphic below from the National Weather Service showing the “cone of uncertainty” (8 PM EST, 8-31-2016) causes me to consider that Tallahassee might very well be under the right-hand leading quadrant of the storm when it makes landfall.  The right-hand leading quadrants of tropical cyclonic systems are usually the quadrants with the highest wind velocities, greatest probability for tornadoes, heaviest rains, and in coastal areas the greatest storm surge height.  The fact that currently the whole storm is beginning to move faster can increase the danger of the right-hand leading quadrant.

I urge residents of the Tallahassee area to be alert during the approach, passage, and departure of what is now Tropical Storm Hermine.  Do not take it lightly just because it is on the low side of the tropical storm wind velocity range at this time (evening of 8-31-2016).  

CLICK ON THE IMAGE BELOW TO ENLARGE. 

2016-8-31 8pm EST

CLICK ON THE IMAGE ABOVE TO ENLARGE. 

Karen Is A Gulf Coast Concern

Karen– Click on image to enlarge –

The graphic above is the Friday, October 4, 2013 10 a.m CDT (advisory #6) from the National Hurricane Center.

 Those who follow this web-log know that my primary source of information regarding tropical weather is Dr. Jeff Masters of Weather Underground. His blog can be found by clicking on the “community” tab once you open the following page: http://www.wunderground.com/

 It would be a waste of my time and yours for me to try to explain it any better. Here is his verbatim forecast report posted at 1:44 PM GMT on October 04, 2013

Forecast for Karen

Wind shear for the next three days is expected to stay high, around 20 – 30 knots, according to the 8 am EDT SHIPS model forecast. The atmosphere is quite dry over the Western Gulf of Mexico, and this dry air combined with high wind shear will retard development, making only slow intensification possible until landfall. A trough of low pressure and an associated cold front will be moving through Louisiana on Saturday, and the associated upper-level westerly winds will bring higher wind shear near 30 knots and turn Karen more to the northeast as it approaches the coast on Saturday. The higher shear, combined with ocean temperatures that will drop to 28°C, may be able to induce weakening, and NHC has sharply reduced its odds of Karen achieving hurricane strength. The 5 am EDT Friday wind probability forecast from NHC put Karen’s best chance of becoming a hurricane as a 23% chance on Sunday at 2 am EDT. This is down from the 41% odds given in Thursday afternoon’s forecast. Most of the models show Karen intensifying by 5 – 10 mb on Saturday afternoon and evening as the storm nears the coast, as the storm interacts with the trough of low pressure turning it to the northeast. This predicted intensification may be because of stronger upper-level outflow developing (due to diverging winds aloft sucking up more air from the surface.) We don’t have much skill making hurricane intensity forecasts, so I wouldn’t be surprised to see Karen do the opposite of what the models predict, and decay to a weak tropical storm just before landfall, due to strong wind shear. In any case, residents of New Orleans should feel confident that their levee system will easily withstand any storm surge Karen may generate, as rapid intensification of Karen to a Category 3 or stronger hurricane has a only a minuscule probability of occurring (1% chance in the latest NHC forecast.)

Since Karen is expected to make a sharp course change to the northeast near the time it approaches the south coast of Louisiana, the models show a wide range of possible landfall locations. The European and UKMET models are the farthest west, with a landfall occurring west of New Orleans. The GFS model is at the opposite extreme, showing a landfall about 400 miles to the east, near Apalachicola, Florida. NHC is splitting the difference between these extremes, which is a reasonable compromise. Most of Karen’s heavy thunderstorms will be displaced to the east by high wind shear when the storm makes landfall, and there will likely be relatively low rainfall totals of 1 – 3″ to the immediate west of where the center. Much higher rainfall totals of 4 – 8″ can be expected to the east. NHC’s 5 am EDT Friday wind probability forecast shows the highest odds of tropical storm-force winds to be at the tip of the Mississippi River at Buras, Louisiana: 66%. New Orleans, Gulfport, Mobile, and Pensacola have odds ranging from 47% – 51%.

ISAAC SHOULD NOT BE IGNORED

This is the 4 pm EDT advisory for August 30, 2012.

Two left clicks on the image will enlarge it fully.

By the time you see this posting, the forecast graphic for what remains of Isaac (above) will probably be obsolete. Here is where to go to get a comparable update (however, the advisory above might be the last):

 http://www.nhc.noaa.gov/index.shtml

 In spite of modern technology the tasks of the National Hurricane Center’s forecasters are not easy and I guarantee they burned the midnight oil as this event unfolded. They have so many variables and unknowns to deal with.  I think they do a wonderful job.

Where I live, in west-central Florida about 18 miles inland from where the tiny Crystal River flows into the Gulf of Mexico, there are long-term concerns about our fresh water supply. So I had hoped that Isaac would provide just the right amount of water WITHOUT damaging and costly winds and flooding. Like most humans, I want all of the good but none of the bad that can come from Nature’s wonders.  At this time, Thursday evening, 8-30-2012, we are still getting some rain directly related to Isaac even though its center is about to move into Arkansas.  Hopefully the system will provide needed rain to drought stricken areas in it’s predicted path.  My retired-farmer uncle in Indiana indicates that it’s probably too late for the field corn but could be helpful to the soybeans.  As I write, flooding and potential flooding in certain areas of Louisiana are creating real headaches there.  There are some places claiming to have more water than with Katrina, albeit for different sets of circumstances.

There is so much information available today and I understand the great value of our acquired knowledge about tropical weather since I first began studying it formally (over 50 years ago) but sometimes, I confess, I think fondly of the days when we had little notion of what was going on until much later in a tropical cyclone’s life cycle. Now, it seems that the media devotes an inordinate amount of time telling us about the negatives and potential negatives that are going on all over the world and I can no longer bask in my ignorance as I used to because I haven’t the will-power or inclination to ignore the resources that are available. But, I concede, there are limits to the notion that ignorance is bliss.

I wish you peace, good health, and happiness.

OFFICIAL IRENE FORECAST – CONE OF UNCERTAINTY – FRIDAY 8 PM EDT

TWO LEFT CLICKS FOR TOTAL ENLARGEMENT

This is self-explanatory.  If you are anywhere within the cone of uncertainty please do not be careless in your thinking.  Stay alert, keep a clear head, and do not allow that epidemic disease, terminal uniqueness, to cause you to think that “it” always happens to the other guy (or gal).  Do not take any unnecessary chances.  Be patient, use common sense, and remember that this too shall pass.

My thoughts are with you.

For previous reports go to the blog tab near the upper left of the page and then scroll down.

Forecast for Irene by the European Model – posted 8-24-2011

This posting is time-sensitive and is now out of date.  For step by step instructions on access to an animated loop of the most current ECMWF (“European”) model go to the following link:  https://cloudman23.wordpress.com/2011/08/25/ecmwf-model-run-the-european-model/

Hurricane Irene is now a category 3 storm.

IF YOU ARE WITHIN THE PUBLISHED CONE OF UNCERTAINTY IT WOULD BE FOOLISH TO IGNORE THIS STORM EVEN THOUGH YOU MIGHT NOT BE CLOSE TO WHERE IT IS CURRENTLY PREDICTED TO GO.  That is not just my opinion but also the opinion of National Weather Service forecasters.

TO FIND THE MOST RECENT CONE OF UNCERTAINTY DEPICTION, GO TO THE RIGHT-HAND MARGIN OF THIS PAGE AND UNDER “TROPICAL WEATHER” CLICK ON “NATIONAL HURRICANE CENTER HOME.

The graphic that follows is a 72 hour (3 day) forecast position that originated at 0000 Greenwich Time on the 24th (which is 2000 hours on the 23rd EDT time – or 8 pm).   The path that this European Model predicts correspond closely with today’s official forecast track of the National Weather Service.

On this graphic, and most on this site, two independent left clicks will enlarge to the fullest.  The poorness of the resolution is due to considerable enlargement from the original.

2 LEFT CLICKS FOR FULL ENLARGEMENT

Early U.S. Landfall forecast for Irene by the European Model – 8-23-2011

 

 

 

 

This posting is time-sensitive and is now out of date.  For step by step instructions on access to an animated loop of the most current ECMWF (“European”) model go to the following link:  https://cloudman23.wordpress.com/2011/08/25/ecmwf-model-run-the-european-model/

 

 

Mind you, I am not formally trained in forecasting.  I am conveying to you what I am deriving from others and when I include my personal opinion I try to make that clear.  Also, very small changes in course can make a huge change in the location of a storm’s landfall, particularly when it is so far out as is Irene this moment.  For example, I am in West-Central Florida, 17 miles inland from the Gulf of Mexico but none-the-less, you can bet your sweet bippie that I’m on the alert.  SO IF YOU ARE WITHIN THE PUBLISHED CONE OF UNCERTAINTY IT WOULD BE FOOLISH TO IGNORE THIS STORM EVEN THOUGH YOU MIGHT NOT BE CLOSE TO WHERE IT IS CURRENTLY PREDICTED TO GO.  That is not just my opinion but also the opinion of National Weather Service forecasters.

TO FIND THE MOST RECENT CONE OF UNCERTAINTY DEPICTION, GO TO THE RIGHT-HAND MARGIN OF THIS PAGE AND UNDER “TROPICAL WEATHER” CLICK ON “NATIONAL HURRICANE CENTER HOME.

Over the last two years the European Model has done the best at predicting the paths of tropical systems under these particular circumstances.  The graphic that follows is a 5 day forecast position that originated at 0000 Greenwich Time on the 23rd (which is 2000 hours on the 22nd EDT time – or 8 pm).  A lot can happen in 5 days so take this for what it’s worth.  This does correspond closely with determinations made by the National Weather Service today.

I will check the next run (they occur at 0000 and 1200 or twice a day – Greenwich Time) and if there is a significant change I will post it.

On this graphic, and most on this site, two independent left clicks will enlarge to the fullest.

Irene Is Now a Hurricane – 8-22-2011

PLEASE NOTE – THIS IS A TIME-SENSITIVE POSTING

Below is the 11 am (Eastern Daylight Time) cone of uncertainty for hurricane Irene from the National Hurricane Center.  Remember, only minor shifts toward the west or east can change the complexion of things drastically.  Such changes are common – in fact, some meteorologists refer to resultant realignments of the spreading cone as “windshield wipering.”  Left click the image twice for full enlargement.

LEFT CLICK TWICE FOR FULL ENLARGEMENT

HAITI IS NOT LIKELY TO ESCAPE TOMAS

Two independent left clicks will enlarge to the fullest.

Though Tomas has weakened to a tropical depression, indications are that intensification to at least a category 1 hurricane will occur in the predicted journey northward.  But, even as a lesser storm (tropical depression or tropical storm) the system can cause severe problems with fatalities.  Just last month 23 people died in Haiti from the results of regular seasonal rainfall events, according to Dr. Jeff Masters’ blog this morning!  The pitiful deforestation of that country allows for rapidly flooding streams and mass wasting events (e.g. mud slides) which can be deadly.

Certain deadly diseases can be spread by contaminated water which is a likely outcome of the flooding that Tomas will trigger.  Cholera is probably the greatest current concern.

I am alarmed by the projected probability path of the storm (see this morning’s cone of uncertainty above) because, if it turns out this way, Haiti will be under the influence of the right hand leading quadrant of Tomas.  That quadrant is typically the one possessing the strongest winds, most prominent storm surges, and greatest probability for imbedded mesoscale tornadic systems.

Of course, Haiti is not the only place that should be concerned.  For example, the Dominican Republic, Jamaica, and the Bahamas need to be “ready.”