Interesting Weather Information

Monday, March 2, 2015

Three Years Back - The Tornadoes of March 2, 2012

CLICK on any image for a larger view
The Crittenden-Piner-Morning View EF4 tornado just after touchdown before it struck Piner, KY.
Taken from south of Crittenden. .Photographer unknown.

Three times in my 36 year career I have looked at the camera and told my viewers to stop watching and take cover immediately.

The first was June 2, 1990 when Harrison, OH and many other communities were struck by a F3 tornado (the EF system began Feb. 1, 2007).

The second time was during the early morning hours of April 9, 1999 when a F4 tornado struck first near Rexville, IN and travelled through Sycamore Twp. and Blue Ash.

March 2, 2012 was the third. That's an average of once time every 12 years.

No matter how long a TV meteorlogist is on the air, no matter what we do someone will not get the life-saving information they need. On March 2, 2012, 9 individuals died.

We tracked the supercells from 10:20AM EST (15:20z) until nearly 7PM EST (00z March 3). That 's 8.5 hours as they travelled more that 500 miles. 

Satellite Views

The GOES East satellite loop showing the progression of the tornadic supercells.
POES (Polar-orbiting Operational Environmental Satellite) NOAA-15 HRPT image strip taken on 02Mar2012, from 2133 to 2141z (4:33 to 4:41 PM EST). Tornadic thunderstorms moving through the Cincinnati tristate area.

Enlargement of  the NOAA-15 image strip above. Cincinnati at the yellow circle.

The "V" shape indicates the storms were energized by a jet-streak which is a strong disturbance in the jet stream

Tornado Hook Echoes

Take a look at the 4 radar images below. They are from the EF4 and EF3 tornadoes that struck the  FOX19 NOW viewing area 2 March 2012. The first two images are fro just before the Crittenden-Piner-Fiskburg-Morning View tornado struck Piner, KY. The third is from the Peach Grove-Moscow-Hamersville tornado and the fourth is from the Holton, IN tornado.

Here is what TCVG,  the Terminal  Doppler Weather Radar near CVG in Kenton County, KY at 4:21:26:57 PM EST (21:26:57 UTC) Friday 2 March 2012.The well defined hook echo, just minutes before the tornado struck Piner, KY is attenuated by heavy rain at the radar site (blank circle north of the hook). A debris ball is visible near the end of the hook.  Just what is a debris ball? It is parts of houses, trees, peoples memories and prized possesions aducted and pirated away by the 160 mph winds of the EF4 Crittenden-Piner-Fiskburg-Morning View tornado.

Monday, February 9, 2015

Wave Clouds over Warsaw


What I like best about being a TV meteorologist is that you never know when out of the blue something really cool ends up in your in box and you get to talk or write about it.

This is another one of those moments.

This post is divided into two parts: A discussion of wave clouds and this particular occurrence for the general public which is followed by a more technical discussion of this situation for the meteorologist.

Wave Clouds Feb 24, 2014 photographed by Kathleen Niece in Warsaw, KY.

The photos below were taken a Kathleen Niece, a talented photographer and frequent contributor of great images for Picture the Weather on WXIX-TV, locally known as FOX19.

Wave clouds over Warsaw, KY Feb. 24, 2014 at 4:40 PM EST  (2140z). 
Photographer: Kathleen Niece.

Wave clouds over Warsaw, KY Feb. 24, 2014 at 4:40 PM EST  (2140z). 
Photographer: Kathleen Niece.

Wave clouds over Warsaw, KY Feb. 24, 2014 at 4:40 PM EST  (2140z). 
Photographer: Kathleen Niece.

These are called wave clouds and are caused by gravity waves. On any given day you can see them on satellite pictures around the world.

Satellite Views of This Wave Cloud Occurrence

GOES East  2145z (4:45 PM EST) visible image the highlighted circle is the area of interest. This is 5 minutes after Kathleen Niece photographed the wave clouds. The resolution along with jpg compression artifacts make this image useless as a source of information on the wave clouds.
The GOES (Geostationary Operational Environmental Satellite) image above is taken from approximately 22,236 miles above the equator.  The orbit of the satellite matches Earth's rotation so the satellite appears stationary. This is called a geosynchronous orbit.

The information here lacks enough resolution to see the wave clouds.

As luck would have it this time polar orbiting satellite NOAA 15 passed over the Cincinnati metro area and the area of the wave clouds at 22:30z (5:30 PM EST) about 50 minutes after Kathleen Niece's photographs.

Polar orbiting satellites orbit at an altitude between 515 and 540 miles (830 to 870 miles in a sun synchronous orbit over the poles. As they move north and south Earth rotates and the data looks like the strip below taken late afternoon (22:30:15 to 22:30:56 or 5:30:15 PM EST to 5:30:56 PM EST) on February 24, 2014. Larger images are stitched together from the strips.

The NOAA 15 images were processed with HRPT Reader by David J. Taylor of Edinburgh, Scotland. The software is available online at

NOAA 15 Polar-orbiting satellite image from 22:30z (5:30PM EST) February 24, 2014. Click image for a larger view.

Close up view of  the NOAA 15 false color image above. Warsaw, KY is on the Ohio River in the center of the circle. Note the stripes of cloud cover north of the circle.

A tighter view of the NOAA 15 image with the circle removed. This has been contrast enhanced and selectively smoothed in Photoshop. The dots are transmission noise and the wave clouds are clearly visible southwest of  "Cin" which is Cincinnati, Ohio, USA.

Same as above but a very tight enlargement.

Waves and Wave Clouds From Around the World

Wave clouds downwind of the Appalachian Mountains, NOAA.

Wave clouds downwind of the South Sandwich Islands, South Atlantic Ocean. Courtesy: NASA

Tropical Cyclone Mahasen moving north the in the Indian Ocean on 
May 13, 2013 as seen by the  the Suomi NPP satellite. Note the gravity 
waves with out clouds but visible because of air glow, moving outwards from 
the  center of the tropical cyclone. Courtesy: NASA

From the ground they look like Kathleen's photos above or the following:

Wave clouds in a dry atmosphere over southern Algeria. 
Photographer: Pir6mon from Wikipedia.

Waves in altostratus. Courtesy: NOAA Photo Library

Wave clouds over Burra, Australia. 
Photographer: David McIlroy from Wikipedia.

Noctilucent (night shining) wave clouds over Follestaddalen, Orsta, Norway,  
2:00 a.m. July 27, 2008. Noctilucent clouds form in very cold air at altitudes 
around 50 miles and are thought to be composed of ice coated meteoric dust. 
 Photographer: Geir T. Øye from Earth Science Picture of the Day.
Waves in cirrocumulus March 11, 2014, 3 PM EDT (19z), Cincinnati, OH, USA. 
Photographer: Steve Horstmeyer

Waves in altostratus, March 11, 2014 3 PM EDT (19z), Cincinnati, OH, USA. 
Photographer: Steve Horstmeyer

 The waves that generate wave clouds are called gravity waves and named for the force that tries to restore the displaced air to its original position.

In the concentric waves that radiate outward from the pebble tossed in the pond, gravity pulls the displaced water back towards the pre-disturbed position. But the water overshoots the original position and as the energy radiates outward as the wave oscillates above and below the middle or equilibrium position.

Waves on the surface of water are called surface gravity waves to distinguish them from internal gravity waves.  The waves that cause parallel lines of cloud rolls are within the atmosphere and the restoring force is gravity. Therefore they are called  internal gravity waves. Technically the waves on the surface of water could also be called internal if you consider the atmosphere and water making up a single  two-fluid system.

There are many other names that can be applied for specific circumstances, for example waves on the surface of the ocean are surface gravity waves but they are often called wind waves or just water waves.

Waves like this occur frequently in the atmosphere and they are not always visible especially in dry air.  In fact clear air turbulence, the bane of uneasy air travelers, often rattles aircraft with no visible warning.

I have borrowed the best diagram I have ever seen that illustrates wave clouds from this very nice website:

Here is that illustration:

This diagram specifically refers to wave clouds over open water but could apply to air flow downwind of a mountain range or any of the wave clouds pictured above.

As the air flows upwards into a crest of a wave it cools. When it cools so that the relative humidity has  reached 100% clouds form in the crest.

As the air sinks into the trough of the wave it is compressed and warms, the relative humidity drops and the clouds evaporate.  This continues through the entire wave system.

Meteorological Analysis: February 24, 2014

The following is a technical discussion aimed at meteorologists and students of meteorology that discusses the cause of the wave clouds photographed by Kathleen Niece from Warsaw, KY, USA (Latitude 38.78, Longitude -84.90) shown above.

Surface Map 20z 24Feb2014

Surface analysis Feb. 24, 2014 at 20z (3PM EST USA). The ridge of high pressure extending from the Gulf of Mexico into western Canada is an arctic air mass.  The dense cold air hugs the surface, the top boundary of the anticyclone is the altitude where the wave clouds occurred.

700 hPa Chart 00z 25Feb2014, Height (solid) and Wind Speed in knots (dashed).

At 700 hPa the axis of maximum wind speed is shown with the red arrows.

 700 hPa Wind Speed and 500 hPa Absolute Vorticity  00z 25Feb2014

850 hPa Streamlines 00z 25Feb2014

Confluence of the 700 hPa winds from eastern Iowa and Missouri over central and southern Illinois, western Kentucky and southern Indiana. The confluent pattern indicates a jet flowing across the top of the cold air mass. take a look at the sounding below.

Wilmington, Ohio (KILN) Sounding 00z 25Feb2014

Skew-T/log P Diagram 00z 25Feb2014 KILN, Wilmington, OH. Plotted with RAOB.

Skew-T/log P Diagram 00z 25Feb2014 KILN, Wilmington, OH, same as above, plotted with RAOB with inversion and frontal analysis.

Atmospheric cross section , 00z 25Feb2014 west to east  from Denver (KDNR)  to Pittsburgh ( KPIT)KILN. Plotted and analyzed with RAOB. Colored background = potential temperature (isentropes) showing surface arctic air mass in blue. Dashed line is the zone of vertical wind shear immediately above the arctic air.

Atmospheric cross section , 00z 25Feb2014 north to south from Alpena, MI (KAPX) to  Birmingham, AL (KBMX). Plotted and analyzed with RAOB. Colored background = potential temperature (isentropes) showing surface arctic air mass in blue. "X" indicates a center of maximum wind shear.

Atmospheric cross section , 00z 25Feb2014 north to south from International Falls, MN (KINL) to  Little Rock, AR (KLZK)  Plotted and analyzed with RAOB. Colored background = potential temperature (isentropes) showing surface arctic air mass in blue. "X" indicates a center of maximum wind shear.

Monday, October 6, 2014

What is Graupel?

Congratulations to Adams Co. Ohio.

Introduction to Graupel

The first reports of frozen precipitation into the FOX19 NOW weather office this year consisted of observations of graupel (grah - pull) in Adams County on Saturday October 4, 2014.

The term graupel does not mean much to you unless you are a meteorologist or  know the German language.  Even if you do know German the mental image it provokes will not tell you much about what graupel is and how it forms.

Graupel, in German means small hailstone or soft hail both of which will lead you to the wrong conclusions about just what graupel is.

In the United States graupel is used interchangeably with soft hail and snow pellets.  When you see and feel graupel it feels like little snow balls.  So I prefer to use snow pellets or graupel forgoing the term soft hail.

There are a couple of interesting science concepts that you may not be aware of  that explain the formation of graupel.

First a couple photos of graupel.

Via: NOAA, Courtesy: Jodi Paige, Lexington, SC, USA.

Courtesy: Ray Murphy, Montreal, Quebec, Canada.

How Graupel Forms

Copyright: Steven L. Horstmeyer. Permission is granted for use in any non-commercial project.
Copyright: Steven L. Horstmeyer. Permission is granted for use in any non-commercial project.

Copyright: Steven L. Horstmeyer. Permission is granted for use in any non-commercial project.

LT-SEM (Low Temperature Scanning Electron Microscope) supercooled water drops accreted on ice needles.
The resulting accumulation of ice is called rime. Courtesy: USDA Agricultural Research Center, Beltsville, MD.

LT-SEM (Low Temperature Scanning Electron Microscope) supercooled water drops accreted to the extent that the original particles's identity is obsecured. The result is a graupel particle. Courtesy: USDA Agricultural Research Center, Beltsville, MD.

Monday, July 28, 2014

Highland County - "Tail-End Charlie" Hook Echo July 27, 2014

Take a look at the following 4 images. What you see in the top image is a wide view of the KILN NEXRAD Radar at 8:43PM EDT 27July2014 (00:43 UTC 28JUL22014). All other images are at the same time.

At the very western edge of the system it narrows to almost a point, but at that western edge you see a hook.

The second image is the hook enlarged.

The third image is a 3D volume rendering using GR Level2 Analyst, in my opinion the finest radar software tool out there.

The fourth image is an annotated version of the third image.

What you see in the volume rendering is the rotating updraft above the hook.  There is no doubt in my mind - and this is being written before a damage survey by NWS meteorologists - that this was a small, probably EF0 tornado.

In addition it is what, in storm geek slang, we call a "Tail-End Charlie".

The term was first used in the UK during  WWII to refer to the last aircraft in a formation or to the tail gunner in an aircraft.

Rarely you will hear the term "Tail-End Charlie" refer to a cluster of thunderstorms behind a front.

The most likely meaning, if you overhear storm geeks like me chattering about storms, is the trailing edge of a line of thunderstorms.

The orientation can be north-to-south, east to west but is most frequently northeast to southwest. In this case it is east-northeast to west-southwest.

The shape fans out (gets wider) down wind because of the wind blowing out of the exit region of an upper level disturbance.

Because of the location at the trailing tip of the thunderstorm line, flow into the updraft is imparted with a large amount of rotation and I always closely watch the "Tail-End Charlie" for small, weak tornadoes.

KILN NEXRAD 8:43PM EDT 27JUL2014 (00:43 UTC 28JUL2014)

KILN NEXRAD 8:43PM EDT 27JUL2014 (00:43 UTC 28JUL2014)

Echo that became the hook
Time 00:28:58
Lat: 39.246487  Lon: -83.755119

Center of Hook (red spot in hook above)
Time: 00:43:14
Lat: 39.175713  Lon: -83.634094

Time Span: 14 min 16 sec (.2378 hours)
Distance: 13.06 km (7.052 nmiles) - this is NOT the distance the tornado was on the ground.
Storm Speed: 29.66 kts (54.92 km per hr)
Bearing: 127.067 deg.(from 307.067 deg.)

Friday, July 4, 2014

Global Cooling? Not A Chance! It Is Just The Opposite.

Global warming has not paused or slowed it continues in full force and is still accelerating.

That's right it's like the silent movie days. The piano player is playing frantically, the will be hero is racing to reach the locomotive engine, running atop the box cars, leaping from one to the next trying to reach the engine and ease the throttle back and apply the brakes before the entire train plunges in the abyss no longer spanned by the bridge.

In the rapid fire frenetic world of Global Warming Denialism  (GWD for short) you may have encountered so much disinformation that you want to shut down and walk away from the entire issue because you just do not know what to believe.

It crucial that you do not walk away and you understand the truth.

First two definitions. A Global Warming Skeptic is a person who does good science and is not convinced that Earth is warming and/or that humans are driving the heat energy accumulation in the natural systems that make up our planet.

A Global Warming Denier is a person who uses false logic, incomplete information, contorted physical principles, modified data and graphics and denies global warming in whole or in part. A denier may have monetary gain in mind when crafting her/his argument.

Skeptics are few in number. Deniers  are plentiful.

There are no (i.e. zero) arguments presented by deniers that can pass the litmus test as good science.

Deniers are inconvenient to scientists in that their often simple arguments have appeal and seem to make sense.

Here are a few examples:

Denier Statement: Lake Superior had record ice cover during the winter of 2013-2014. Earth must be cooling.

My Reply: It is "global" warming and not just about the Lake Superior region. There are fluctuations and temporary regional cooling events. The GLOBE is still accumulating heat and at an accelerating rate.

Denier Statement: Warming stopped in the late 1990s.

My Reply: Completely false. The rate of warming of surface temperatures has slowed but the average global temperature is still on the rise.

In Addition: There is more to our planet than surface temperatures. there is the middle and upper atmosphere, the cryosphere (ice) and the ocean where more than 90% of the thermal energy is accumulating.

Denier Statement: Ice in Antarctica is increasing.

My Reply: This statement is partially correct but incomplete and misleading in three important ways:

Deception #1: Sea ice around the Antarctic continent has been increasing since 1979. But sea ice melts every southern summer so ice is not accumulating.

Deception #2: It is plenty cold during Antarctic winters to support even more floating sea ice. Sea ice is NOT increasing because it is colder, which is what deniers want you to think. Sea ice is increasing because winds are stronger, pushing sea ice in specific directions and exposing more water to cold winter Antarctic winds. Sea ice insulates water below it and greatly slows or stops freezing at the bottom edge of the ice. When winds open up expanses of the Southern Ocean by moving existing ice more water is frozen.

Deception #3: Sea ice is only 1/3 of the antarctic ice story. The other two parts are the ice of the high ice plateau of East Antarctica and the ice of West Antarctica. The high ice plateau is either gaining ice slightly or in balance. There is no definite trend there. In West Antarctica the ice is melting at a catastrophic rate and ice losses there exceed any gains elsewhere in or around the continent.

The Real Story:

Globally 2014 has been a  warm year.

Here are graphs from NOAA. They depict:


for January through August 2014.

Please note the words "average" and especially  "global". An anomaly is the difference between a monthly average temperature and the long-term average. 

In this case the base is the 20th Century average.

January 2014
4th Warmest January on Record (Land + Ocean)
4th Warmest January on Record (Land only)
7th Warmest January on Record (Ocean only)

February 2014
21st Warmest February on Record - Tied with 2001 (Land + Ocean)
44th Warmest February on Record (Land only)
7th Warmest February on Record (Ocean only)

March 2014
4th Warmest March on Record (Land + Ocean)
5th Warmest March on Record (Land only)
7th Warmest March on Record (Ocean only)

April 2014
Tied with 2010 for Warmest April on Record  (Land + Ocean)
3rd Warmest April on Record (Land only)
6th Warmest April on Record (Ocean only)

May 2014
Warmest May on Record  (Land + Ocean)
4th Warmest May on Record (Land only)
2nd Warmest May on Record (Ocean only)

June 2014
Warmest June on Record  (Land + Ocean)
7th Warmest June on Record (Land only)
Warmest June on Record and Warmest Month on Record (Ocean only)

July 2014
4th Warmest July on Record  (Land + Ocean)
10th Warmest July on Record (Land only)
Warmest July on Record - tied with 2009  (Ocean only)

August 2014
Warmest August on Record  (Land + Ocean)
2nd Warmest August on Record (Land only)
Warmest August on Record, Warmest Month on Record - beats June 2014  (Ocean only)