4 Days and Counting - Fireworks Ahead!

We started with 6 days to go and  now it is four and the past two days have provided a great deal of information. 

First no model can predict precise location and timing this far out. (This far out is how meteorologists describe an event far in the future in forecast-time). Second the models continue to indicate rain in the forecast and so I am fairly confident that we will see rain SOMETIME Sunday.  But As far as a washout for the Cincinnati Bell/WEBN Fireworks vs. a dry evening I still have to be iffy.

We are looking for trends in successive model runs and there are some useful indications. The video fills you in.

5 Days and Counting - Fireworks Ahead!

In yesterday's post I made the case for forecasts being MUCH better now than 10, 15 or 20 years ago. It is all because of numerical forecast models which have become very sophisticated and much better in the last decade.

However models are still subject to errors.  Some models over forecast rainfall and some over forecast just the thunderstorm part of the total rainfall. Systematic errors like these are easy to deal with because after studying the results of a mode for years we expect this kind of error.

Models can have big errors due to bad data which are very hard to deal with because until the next run we are generally not aware of the problem.

So we look for odd behavior and flip-flops, we look for trends and we compare models and as we get closer and closer to an event we get more and more specific.

The video shows what the weather looks like 5 Days out from the Cincinnati Bell/WEBN Fireworks.

6 Days and Counting - Fireworks Ahead!

In the good ol' days when forecasting beyond the day after tomorrow was often more a guess than an art - and definitely not a science - there were no expectations that we could give you even the slightest idea what the weather would be like 10 days down the road.

But as my hair greyed and forecasting models matured what was a miracle when I was a young whipper-snapper is now in many circumstances not all that hard, within limits of course.

Beware the pretentious braggadocio of the boastful meteorologist claiming 92% accuracy and a special method to forecast what no others can.  There is no such person who is that reliable.

If the truth be told some weather situations are more easily forecast than others, some weather systems behave and others frustratingly defy  our futile attempts to pinpoint their effects.

The models put us in the ball park but 10 days from now a time shift of 48 hours is not out of the ordinary. So anyone too confident that it will rain Sunday morning and be clear Sunday evening is not being honest.

So in the video below is my best educated guess of the forecast for the Cincinnati Bell/WEBN fireworks six days out.

Traffic Jam

Whenever a tropical cyclone gets into the mix meteorologists expect weather systems to slow to a halt until the hurricane or tropical story is out of the way.

We like to call it a traffic jam and it is an observation we use to adjust the forecast. Usually that means little change in the weather until the hurricane passes by.

For this particular forecast the pleasant air stays put over us and it is reinforced by the sinking air around the margin of the hurricane and we get a great weekend of weather.

The video has more.

High Octane Hurricane Fuel

Hurricanes are gargantuan heat engines that release the energy of water vapor molecules and along the way generate destructive winds, torrential rains, mountainous waves and the deadly storm surge.

The energy of a water vapor molecule came ultimately from the sun. While a molecule is in the surface layer of the ocean it is free to move about in an incessant dance with its neighbors but it can not escape their attractive forces. Once a water molecule intercepts enough solar energy, it is moving fast enough to break free of those bonds and rocket into the atmosphere independent at last. The molecule has evaporated.

The process does not change a water molecule in any way, it merely energizes it. A vaporous water molecule is identical to a liquid or solid water molecule in all but one aspect.  The vapor molecule is moving faster than the liquid or solid molecules, in other words it has more energy and it can give that energy back to the environment when it slows and is recaptured by a group of liquid water molecules in a drop or at a water surface.

So when molecules evaporate from warm tropical waters they await a storm to provide lift and enable the return of their kinetic energy to environment and drive a storm like a tropical cyclone.

The video below has more on warm water and Irene.

More On Hurricane Irene

There is more to hurricanes than spaghetti plots, probability cones and damaging winds.  Eventhough you may not think we are getting the effects of Irene it is more correct to say we are not getting the BAD effects, what we will experience are the GOOD effects.

By the way the image above is from FOX19's Interactive Hurricane Tracker. You can find it on FOX19.com @  http://www.fox19.com/category/213714/hurricane-center

The video below explains the two factors that may make the effects of Irene pleasant here in the FOX19 viewing area.

Humidity is on the Way Back!

Today was a nearly perfect August day with sunshine, a nice breeze, low humidity and warm temperatures. The humidity is on the way back and the video below explains what meteorologists look for  to tells us the stickies aill soon return.

Will We Get Storms with the Front Thursday?

It is summer and often an approaching cold front means big thunderstorms. Before that can happen conditions have to be just right.

On Thursday we will NOT see big storms because of the lack of low level moisture. Upper level moisture is also lacking but the key this time is what is going on at the surface.

Take a look at the video below for an explanation.

Rain This Weekend - Say It Ain't So!

When looking several days ahead we have to look far to the west.  What is going on right now in the Gulf of Alaska and in the pacific Northwest will affect our weekend.

In the video below look at the storm curling its way eastward  across southern British Columbia, Washington and Oregon.  The storm in the Gulf of Alaska will catch the Pacific Northwest storm and dig southeast ward bringing rain for Saturday and early Sunday.

Watch the jet stream animation. As the storm digs the winds ahead of it become more and more southerly bringing moisture from the Gulf of Mexico.

Cool Nights Ahead!

Just like a water flowing down hill because it is pulled that way by gravity cool air is more dense than surrounding warmer air and it is pulled more by gravity than the warm, so ..... cool air will sink to the surface, flow down slope along the surface, pool in low spots and at times fill valleys.

Any experienced mountaineer or backpacker knows that most nights are warmer a ways up the slopes than at the bottom of the valley because of cold air drainage.

So at night cool air sinks and because the ground cools faster than the air the air is cooled even more by contact with the ground. This explains frost when your home thermometer, mounted at eye-level reads 35° - the cold air is hugging the ground.

Watch this video for more.

Why Only A Small Risk of Severe Storms This Evening?

To the casual observer it seems simple ... with plenty of sun today and a great deal of moisture why did we not get bigger and more widespread thunderstorms?

The answer is always something was missing. It may be missing because bigger thunderstorms sucked up the moist air or because the energy just did not get there. It could also be that meteorologists over or under estimated a parameter.

In this case it was because a front was in the area dividing the soupy, moisture laden air to the south of the front from less humid air where we are.  With some sun the conditions then were marginal for severe weather and as the sun set the storms diminished.

A Fly In The Ointment, The Bible and A Streak Buster!

First, just what is a fly in the ointment?

For more than 500 years English speaking cultures have been using this phrase to describe a spoiler that was not at first apparent.  In weather forecasting we know a great deal about flies in the ointment (or atmosphere).

The saying most likely originated in the king James Bible,

"Dead flies cause the ointment of the apothecary to send forth a stinking savour: so doth a little folly him that is in reputation for wisdom and honour." Ecclesiastes 10:1

The earliest known use of our more modern version dates from 1707 in  A Practical Treatise Concerning Humility, by John Norris. He wrote,

   
          "Tis that dead fly in the ointment of the Apothecary".

The fly in this case was a big complex of thunderstorms, many more than any model had forecast. Though they were marginally severe and did cause some damage the cloud cover left behind in their wake kept our high temperature down to 89° and thus the streak ended.

WILL THE STREAK SURVIVE?

It is official - the high temperature today was 94°, the 17th consecutive day that the high temperature equalled or exceeded 90° and that ties the record streak set using official data in 1901 or set earlier than that using Smithsonian Institution Observer data in 1868.

Before the formation of the U.S. Weather Bureau (now the National Weather Service) the U.S. Army Signal Corps was the official U.S. Government weather organization. It became apparent after the Civil Warm,  in the late 1860s, that there needed to be a bureau or service with only one mission - weather observation, forecasting and warning.

Years earlier, in 1846  the Smithsonian Institution was founded and its first secretary was Joseph Henry. At the time there was no central agency to provide timely weather data.

Henry's interest in meteorology dated to his days as a professor at the Albany Academy in Albany, New York, where he compiled reports of statewide meteorological observations for the University of the State of New York. When he joined the Smithsonian he called for "a system of extended meteorological observations for solving the problem of American storms." By 1859 the project had more than 600 volunteer observers, including people in Canada, Mexico, Latin America, and the Caribbean. The project cost 30% of the Smithsonian's research and publication budget in 1860.

Joseph Henry then went on to apply the new "lightning fast technology" of the telegraph to weather reporting and forecasting and inspired the first organized forecasting efforts in the U.S. by Cleveland Abbe from the observatory on Mt. Ida, named for washer woman Ida Martin who lived in the hollow of a Sycamore tree on the hill above Cincinnati. After former President John Quincy Adams dedicated the Astronomical Observatory there the hill was renamed Mt. Adams.

So looking back through the data from 1859 to the present there have been 25 such streaks where the high temperature was above 90 for 10 or more consecutive days.  This feat on average occurs about once every 6 years.  To help give you a better prespective I have compiled the list of years that this happen and the length of the streak into a bar graph.  The thing that stands out is the cluster in the center of the graph during the 1930s to the mid 1950s.  During this time America was experiencing the Dust Bowl and the Mid-Century Drought but outside of those years the streaks are really scattered.  So, this extreme heat that the tri-state has experience from the mid of July into August is a really historical occurrence.