Archive for the ‘Tropical Weather Alert’ Category

IRMA POSTING – PLUS

– click mouse twice for full enlargement of this image –

 

 

FIRST ENTRY IN MORE THAN A YEAR – 9-6-2017

I apologize to those few of you who have been consulting this weblog. My last posting was August 31, 2016. I’m still going strong and my interest has not waned. I’m still in the learning mode and intend to stay there. But it’s been a long time since I retired from teaching full-time college geosciences in 2003 and a lot has changed. I continued adjunct teaching after I retired but then moved away from South Florida in 2005. From 2006 into 2013 I taught 14 short-term courses at the College of Central Florida. Interest in this weblog seems to have diminished since I stopped formal teaching. However, when I checked this site this morning I saw that it has gotten tons of hits over the last few days, probably due to hurricane Irma. Prior to this current event almost all geoscience questions and observations that have come my way have been from a few family members, a few neighbors, and one buddy at church. It is very rare for me to hear from former students.

In-so-far as weather reporting is concerned, the information available to the public has blossomed since I retired and, for the most part, its quality has improved to the point that there is little if anything I can add (beyond basics). Many of my notions concerning tropical weather events fall into the category of hunches or intuition. I don’t believe that my 37 years of teaching meteorology full-time gives me license to clutter minds with my ideas unless I’m honest about them. Instead, in the comments below about Irma, I will share the four tropical weather resources I consult most often.

I am planning a change of theme and/or purpose for this site soon – more in the realm of discovery, opinions, observations, analyses, experiences, and perhaps some attempts at humor. The “About” page for this site was updated earlier today and if you wish to contact me, you will find my address there.

 

 

MY INPUT ON OUR CURRENT TROPICAL WEATHER

WHICH IS BEING DOMINATED BY HURRICANE IRMA.

My four primary resources are:

  1. Dr. Jeff Masters’ weblog (blog) at WeatherUnderground.com. It can be found here: https://wwwwunderground.com/cat6

  2. The Weather Channel on television and on-line – including apps. There are things about the Weather Channel presentations I don’t like. Nevertheless I appreciate the convenience and their efforts.

  3. The National Hurricane Center. I go to this site to get a grip on what is going on in their world. I consider that they might tend to err on the side of caution, subconsciously at the very least. What an awesome responsibility they have. Http://www.nhc.noaa.gov/

  4. The ECMWF Model – commonly referred to as the European Model.

I rely upon it heavily because of it’s premier reputation due to its accuracy over the last few years. It has done well for the “Irma type” storms. To be sure, I don’t ignore the other models. The following paragraph is for those who have been trying to understand that model.

You are likely to have heard many references to the European Model. I admit it is confusing. For example, here is a quote from Dr. Jeff Masters. “The European Center does not permit public display of tropical storm positions from their hurricane tracking module of their model, so we are unable to put ECMWF forecasts on our computer model forecast page that plots positions from other major models.” Thus, even though on television or on-line you may see comparisons of the European Model to the myriad other models, you might have noticed that it’s not included in the spaghetti charts that show models from multiple sources. What you will see is either the European “operational” model track or the European Ensemble (a spaghetti graphic). For that spaghetti ensemble the operational model is re-run at a lower resolution (called the control run) and this is then repeated 50 times, each with slightly different starting conditions.

I get my favorite animated European model track from Penn State’s Department of Meteorology at http://mp1.met.psu.edu/~fxg1/ECMWF0.5_0z/ecmwfloop.html

Please note that this link is time-sensitive.

Of the four charts, I focus upon the one on the upper right as I scroll through f24 through f240 ( which means “24 hours into the future” through “240 hours into the future”).

You might fry your brain with the time signatures on the bottom – depending upon your comfort level with time at the prime meridian (Universal, Greenwich, Zulu) and your knowledge of Victor time.

 

THE CORIOLIS EFFECT

I’ve been thinking all day long about the Coriolis Effect as it relates to Irma. If you are my former student you might recall that the steering currents at high altitude are, in part, a function of the Coriolis Effect (the Penn State chart on the upper left) and I’ll bet you remember that the counterclockwise circulation of Irma is due to the Coriolis Effect. If you’re still sharp on the subject you might also remember that the outflow at the top of the storm is likely to be clockwise for the same reason – the Coriolis Effect. I know that sounds like a contradiction to those of you who are unfamiliar with this subject. If you are interested in the Coriolis Effect go here:

https://cloudman23.wordpress.com/2008/10/02/the-coriolis-effect-in-the-real-world-a-tutorial-part-1/

and here:

https://cloudman23.wordpress.com/2008/10/07/the-coriolis-effect-in-the-real-world-a-tutorial-part-2-cyclones-anticyclones/

 

MY NOTIONS TODAY ABOUT IRMA

Here is my zinger that comes from the “gut level” and is therefore probably not deserving of any classification other than “pure speculation.” (That’s the honesty I referred to in the second paragraph of this blog).

I am expecting (or is it hoping and praying for?) slightly more turning to the right than the experts are indicating. The itty-bitty turn last night was encouraging to me. I keep telling myself that the hurricane is a separate entity of its own and that the Coriolis Effect is influencing it’s path independent of the steering currents and the rotational motion. That path is the consequence of what is referred to as translational motion. Furthermore, the further north the storm gets, the stronger the Coriolis Effect will be. The Coriolis Effect is zero at the equator and increases to 100% at the poles. Maybe I’m just overly excited about last night’s noticeable veering of Irma’s path. Perhaps this is merely a good example of wishful thinking. We’ll see.

 

FOR CITRUS COUNTY, FLORIDA

Finally, for those of you who live in my county of Florida, Citrus, you might be interested in this August 2014 posting about hurricanes.

https://cloudman23.wordpress.com/2014/08/22/citrus-county-florida-and-hurricanes/

 

 

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Invest 99L Has Become Tropical Depression AL09

REMINDER:  THIS IS A TIME-SENSITIVE REPORT

As of late this afternoon, 8-29-2016, Invest 99L has strengthened to a tropical depression.  For up-to-date information on the system, I recommend Dr. Jeff Masters’ weblog (blog).  See link below:

https://www.wunderground.com/

Go to the top of the page and click on News & Blogs.

As of the time of this writing, Dr. Masters expresses reasonable confidence that the system will track in such a way that a landfall will occur somewhere in the Florida coast north of Tampa.  I urge all interested persons to pay close attention to Dr. Masters’ postings, the Weather Channel tropical reports, and your local news.

Here is the most recent version from my favorite spaghetti chart source, the National Center for Atmospheric Research in Boulder, Colorado (CLICK ON IMAGE TO ENLARGE):

2016-8-29 Model tracks

 

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%.

Sandy Alert – There Is No Shame In Evacuating!

What concerns me most is the number of people who will not address and act upon hurricane Sandy’s threat maturely. As a man who grew up in an environment where “being a man” meant being able to handle, support, protect, and defend – I can identify with the need to have it “together” in these types of situations. It was hard for me on the morning of 8-23-1992 to “order” my wife, two children, father-in-law, and mother-in-law into my van so that we could evacuate our two homes (separated by less than a mile) in Homestead, Florida to escape approaching hurricane Andrew. But, when we returned 3 days later we were thanking the Great Guy In the Sky that we were not there when the storm hit. It would have been a most traumatic experience and could have been deadly. Our house was a total loss and my in-laws’ house was severely damaged but not beyond repair. There are people today of all ages still suffering post traumatic stress syndrome over that hurricane of 20 years ago. Admittedly, the aftermath and rebuilding processes were extraordinarily difficult but we were together and healthy and I had very good insurance and did not lose my job. Thousands of people lost both their dwellings and their jobs! We had much for which to be grateful.

But, sometimes, in an attempt to handle, support, protect, and defend – people (men in particular, I think) tend to make macho decisions that they later regret – if they live to experience regret. One example is: Failing to evacuate dangerous areas that are subject to flooding, landslides, storm surges, etc. Believe me – there is no disgrace in fleeing in such circumstance. Sure, one wants to stay and protect his/her home and the “things” within it but such a mindset can backfire resulting in fatal consequences. Take my word for it, “things” can be replaced in time but once you lose your life of worse, that of a loved one – there is no going back or rebirth back into this dimension.

 Hurricane Sandy is a storm that has it all. Oh sure, it’s not a category 5 storm as was Andrew but it is a huge storm taking up an area more than the size of Texas one and one-half times! And – it has a strong pressure gradient. It has a very long fetch (distance of water over which the wind blows) which increases significantly the potential height of the storm surge.

 Just because the winds are within the category 1 range, remember that slight increases can cause exponential increases in the potential force. In fact, doubling the wind velocity quadruples the air’s potential force upon a surface that it strikes at right angles.  Early on in my teaching career it because quite apparent to me that most people assume that doubling the velocity simply doubles the force.  But that is far from true.  For example, an 80 mile per hour wind has FOUR TIMES the potential force of a 40 mile per hour wind. So DON’T think to yourself, “I know I can deal with a 40 mile per hour wind; in fact I and my dwelling can deal with one that is 80 miles per hour because that is just two times that of a “40.” YOU WOULD BE VERY, VERY WRONG! If you are interested in more on this subject, including an equation – go here:

https://cloudman23.wordpress.com/tag/wind-velocity-relative-to-force/

 A great deal of precipitation over land is expected with Sandy – so much that many of the drainage systems, both natural and man-made, will not be able to handle it. Trees will be less stable because of saturation of the soil and rock into which their roots are anchored. Combined with the wind force, many will come down. Unhealthy trees will snap. Mother Nature WILL do a great amount of pruning. Electricity will be cut off due to line damage from falling debris and flooding. Water pressure may drop or reduce to zero. Even modern gravity-feed systems require boosting due to the effects of friction and that usually requires electricity. If you have an electric pump with a well and no emergency generator, you could be out of luck. If your toilet is relatively modern you will still need about 1.6 gallons per flush. “If it’s yellow, let it mellow; if it’s brown, flush it down” might become your rule of thumb even if you have a lot of water stored (as in a tub that doesn’t slowly leak at the drain).

 Since much moisture will be drawn in by the storm from off the Atlantic and much cold air will be drawn down from the north, there is a very strong chance for SNOW with this storm.

 The bottom line, in my opinion is – If you are in the path of Sandy and:

  1. in a storm surge zone – evacuate.
  2. in a wooded area with big trees so close to your home that upon falling they are likely to do structural damage – evacuate.
  3. upon a hillside or mountainside where your area or an area above or below you has been stripped of most vegetation – evacuate.  Slides are a real danger in these cases.
  4. in a region that can easily flood  – evacuate.
  5. in a neighborhood where there is a lot of loose matter that could easily become damaging airborne projectiles – evacuate.
  6. in a mobile home or R.V. – evacuate.
  7. in a dwelling where, when you look out a front window you are looking down a street that is at right angles to your street – evacuate. The Venturi Effect can channel much higher winds and debris right into your dwelling!
  8. in any kind of a topographic restriction such as a narrow valley between two hills or mountains – evacuate for the same reason as in item 7.
  9. NOT prepared for many days without water service and/or electricity – evacuate.
  1. in an evacuation zone – evacuate!
  2. one who feels as though fleeing is a cowardly act – engage in a very quick but thorough attitude adjustment and ERR ON THE SIDE OF CAUTION.

BUT DON’T EVACUATE IF THE STORM IS UPON YOU UNLESS YOU FEEL THAT THE MOVE IS ACTUALLY SAFER THAN STAYING.

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.

TROPICAL STORM LEE 5 DAY PRECIPITATION FORECAST – VALID 8am EDT SUNDAY

Thanks to the National Weather Service Hydrometeorological Prediction Center for this graphic. 

What you see is a 5 day forecast for the total rainfall in inches between 8 AM Eastern Daylight Time Sunday and 8 AM EDT on Friday .  The feared 15″ of rain in the New Orleans area predicted 36 hours earlier seems highly unlikely.  For ease in reading, left click the image two times independently for full enlargement.

Lee Expected To Dump Lots Of Rain In the Next 5 Days!

Thanks to the National Weather Service Hydrometeorological Prediction Center for this graphic. 

What you see is a prediction for the total rainfall in inches between 8 AM Eastern Daylight Time Saturday and 8 AM EDT on Thursday (in other words – a 5 day total forecast).  Already, since this was released, the feared 15″ of rain in the New Orleans area seems highly unlikely due to dry air from Texas being drawn into the system.  For ease in reading, left click the image two times independently for full enlargement.

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.

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.”