ALERT NEWSLETTER – January 2021

Hi Everyone & Happy New Year.

I hope that Santa treated you well and that Father Time will be kind to you also.

What does 2021 hold in store for us? Hopefully peace, prosperity, good health and good DX!

I am glad to say that ALERT is alive and well.

While we cannot respond personally to K4NWS for callouts due to COVID restrictions, we are uniquely suited to provide offsite coverage. I would expect this to continue and to grow.

We have perfected distance meetings, or shall we say that I finally figured out how to make the blessed thing work, after a few misfires and mishaps.

New Years is the time of resolutions and the tweaking of lifestyles. I’ve always made a point of making resolutions I know will fall flat, like gain 300 pounds, take up cliff diving and never taking my meds (I won’t say what they are for) again. That way when I break all the resolutions it is a positive rather than a negative situation.

But, I will say I “hope” to be more active on the air, more active in ALERT, to go hiking and camping and as always keep embracing positivity, which I usually drift towards anyway, and keep leaving negativity in the dust.

So as we enter 2021 I wish you and yours the best.

Happy New Year!

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A Layman’s Guide To The New NWS Radar Site

In mid-December the NWS radar site changed to a new format. This new format has met with mixed reviews, as the older version was fairly simple to navigate and the new one definitely isn’t.

To be fair though, the older site was fairly limited feature wise. It did feature composite reflectivity, base reflectivity, storm relative velocity, base velocity, 1 hour rainfall total, storm total rainfall and long range base reflectivity, all of which could be looped.

You could also choose regional radar and from those sites a full nationwide mosaic.

The newer version, is slower, much slower, very much slower, excruciatingly slower, did I mention it’s slow? It also has many more advanced features available; however, a user guide is not one of them.

But, never fear, Mark is here to reveal some of the closely guarded secrets of “radar.gov”.

The easiest way to access the new radar site, until you bookmark it, is go to your local NWS page which for the Birmingham area is NWS Birmingham, Alabama (weather.gov). Scrolling down the page you will come to a radar display appropriately named “local radar”. Clicking this display will take you to the radar image of the radar site serving the area covered by that NWS office, in this case Shelby County.

To the upper left of the display is a menu. If you click the icon which is three horizontal lines you can change the background. Standard is the default, but, you can change it to topographic, satellite, ocean or dark canvas. At the bottom of this menu is an icon called “advanced” which deals with event logging. I just use the default basic option.

Below the three horizontal lines you will find three dots. By clicking these three dots you can adjust the type of warnings displayed, either storm based or all hazard, the display transparency and whether the radar site icon is on or off.

The most interesting option here is that you have the option of using the NWS WSR-88D radar system or the FAA’s Terminal Doppler Weather Radar system.

The Terminal Doppler Weather Radar (TDWR) is a Doppler weather radar system of 45 radar sites covering airports in major metropolitan areas across the United Stated and Puerto Rico. It is used
primarily for the detection of hazardous wind shear conditions, precipitation, and winds aloft.

The closest TDWR sites to Birmingham are Atlanta, Nashville, Memphis and New Orleans. If you choose the TDWR system and click on these sites, by going to the option “BNET (Net)” you can see the height of the thunderstorm tops, or Echo Tops, Long Range Base Reflectivity, Short Range Base Reflectivity, Vertical Integrated Liquid and Composite Reflectivity.

Though Birmingham is out of range in the Short Range Reflectivity mode, if you choose Long Range Reflectivity on the Atlanta, Nashville and Memphis sites the coverage will reach the Birmingham area, though due to the curvature of the Earth it will be limited to the upper levels of the storms displayed.

Of particular interest to me are the sites at Houston, New Orleans, Orlando and Miami, as they can provide additional radar coverage of tropical systems in addition the standard NWS WSR-88D sites that form the coastal radar picket.

Going back to our three dots and choosing WSE-88D, the map will have light blue dots which are the individual NWS radar sites. By clicking the dot to go to that site a disturbing thing happens – namely nothing. The dot just disappears and you sit waiting some seconds, sometimes more than a few, until anything happens. You sit there thinking you have killed the display, but, then suddenly voila! You have radar!

Looking at the menu you will see “BTRF-RAW”. By clicking this you can access advanced radar tools.

These are:

Super Resolution Base Reflectivity – Base Reflectivity is a display of echo intensity or reflectivity at a given radar beam angle. Base reflectivity images in Precipitation Mode are available at four radar “tilt” angles, 0.5°, 1.45°, 2.40° and 3.35° above the horizon. These angles are slightly higher when the radar is operated in Clear Air Mode. In Severe Mode there are up to 14 angles.

Super Resolution Base Reflectivity is an improvement as it shows reflectivity at a much higher resolution than the older site, giving you the ability to see storms at greater detail. You can zoom the map, but, to a limited degree. If one could zoom just one step closer you would have street level mapping, albeit with a very pixelated display

Super Resolution Base Velocity – this mode provides a picture of the wind field of the storm which is useful in determining areas of strong wind from downbursts, derechos or detecting the speed of cold fronts.

One caution in reading this is that it only depicts surface winds in areas close to the radar sight. So if you are 50 miles from the site, a display of high winds does not necessarily mean those elevated winds are actually reaching ground level.

This display provides the highest-resolution velocity available from NEXRAD radars to a distance of 230 kilometers or 143 miles from the radar site.

Dual-Pol Precipitation Type – the radar “best guesses” what type of precipitation it is seeing.

There are twelve possible types:

BI – Biological, such as bug, birds and bats.
GC – Ground Clutter, such as hills, tree and buildings.
IC – Freezing rain
DS – Dry snow –snow with low water content, such as the West and Midwest receive.
WS – Wet snow – snow high water content, as seen with Lake Effect or Gulf enhanced snow.
RA – Rain
HR – Heavy Rain
BD – Big Drops
GR – Graupel, aka “soft hail”
HA – Hail
UK – Unknown – “officially” the radar can’t make up its mind as to what it is seeing. But….my cousin Donnie Ray told me that his uncle Wilbur told him that he saw an expert on the internet revealing the truth about the radar picking up those shape shifting lizard people from Neptune that have been spraying us with chemtrails. Since its online, we know it must be true. But…..shhhh….it’s a secret.
RF – Range Folding – WSR-88D radars can clearly see out to 143 miles. If the radar pulse goes beyond this distance and bounces back off a target, it can return after another pulse has already been sent out causing the radar to see two images at the same time, one of which is correct and one, which is being detected at the wrong time, and therefore interpreted at the wrong distance.

Which one is real?

In my mental imagery I think of the old days of analog TV when because of signals being received at slightly differing times, one directly from the transmitter and the other being reflected off of some object, you would see two images at once. The true image and the “ghost image”. If they are of equal strength and you are trying to associate them with a location, which one would you use?

Crude example perhaps, but you get the idea.

Dual-Pol Differential Reflectivity – a simple explanation I can’t offer, but, let’s just say it compares whether targets are larger in a horizontal or vertical aspect. It is used to help identify hail shafts, detect updrafts, determine rain drop size, and identify the gathering of dry snow within a storm.

High Resolution Echo Tops – this displays an estimate of the highest altitude where the echo signal strength exceeds a specified threshold. The threshold adopted by the NWS and most providers of radar imagery on the Internet is 18.5 dBZ.

“Echo tops” should not be confused with the actual height of the storm. The detectable threshold may be at 50,000 feet, but the actual top at 55,000 feet, remembering that clouds are not solid. The rest of the cloud is still there, just less dense, and therefore not displayed. Not unlike setting a radios squelch to mute a distant signal. The signal is still there, but, you can’t hear it because it is too weak to break the squelch.

One Hour Precipitation Accumulation – this displays accumulated rainfall observed in the last hour.

Storm Relative Motion – this is a measure of the winds in the storm as compared to, for lack of a better word, “background winds” or base velocity. Let’s say that the winds in a storm or system are consistently from the Southwest at 30 MPH. The radar looks for distortions in this wind field. If it starts showing winds moving towards the radar at 70 MPH and right beside this the winds are going away from the radar at 40 MPH (which is the speed you would get after a 70 MPH wind overcomes a 40 MPH headwind from the opposite direction) then it is a good indication that you have a rotation within this wind field.

Storm Total Precipitation – this is the estimated total precipitation accumulation which has occurred since the storm began. It is continuously updated and is used to locate flood potential over urban or rural areas, estimate total basin runoff, and provide rainfall data 24 hours a day.

Base Velocity – this is a measure of the wind direction either toward the radar, which is considered a negative value and displayed in green or away from the radar, which is considered a positive value and displayed in red. This product is used to estimate wind speed and direction, locate boundaries, locate severe weather signatures, and identify suspected areas of turbulence.

Composite Reflectivity – this is a display of the maximum echo intensity detected at any of the radars different angles at a given time. When compared with Base Reflectivity, the Composite Reflectivity can reveal important storm structure features and intensity trends of storms.

One caution when using this product is that, as compared to Base Reflectivity, which normally scans at the lowest radar angle, the Composite Reflectivity, since it includes scan information from all radar elevation angles, may appear to indicate more widespread rain than is actually reaching the ground.

This could indicate one of two things:

It could be detecting Virga: the precipitation, rain or snow, is probably not reaching the ground but evaporating as it falls from very high in the atmosphere. This is a regular situation in winter as snowflakes can easily sublimate in dry air near the ground.

It could be due to strong updrafts: air rising in a thunderstorm updraft will saturate at a higher level than the rest of the cloud forming an overhang region. In case of a very strong updraft, a Bounded Weak Echo Region (BWER) will form and lead to the possibility of severe weather.

High Resolution Vertical Integrated Liquid – this is an estimate of the concentration of liquid water vertically in a cloud. This is used to locate most significant storms, and to identify areas of heavy rainfall. The higher the indicated concentration, the heavier the precipitation potential. If it is nearly off the scale, it is probably a hail shaft.

You will not find Correlation Coefficient, which detects solid objects aloft, which some of our broadcaster friends call “Debris Tracker” nor can you adjust the radar tilt, as you can on some sites.

But, regardless, that a lot of tools at your fingertips to choose from.

 

Here are a few radar hints for you.

1. During severe weather the NWS radar site can become intermittent due to so many viewing the site at one time. I use a different source, College of Dupage COD NEXRAD: BMX as my primary site. It’s from the same source, but, doesn’t get overwhelmed like the NWS site. Plus it does offer the Correlation Coefficient mode, the ability to look at different radar angles and has more flexibility as to looping.

2. All local broadcast stations, one exception, uses the NWS radar information for their broadcasts. They may tinker with it by inserting imitation radar sweep lines, why I’m not sure, call products clever names, or use catchphrases such as “switching our quad Doppler 48 storm vison radar to deep scan mode”, but, when all is said and done, the NWS is the source of their radar data.

3. There is one exception to the above. If the NWS weather site becomes disabled, there is another local weather radar source independent of the NWS. WVTM Channel 13 operates their own radar. In 2017, WVTM constructed a new dual pole Doppler radar in western Tuscaloosa County in Vance, known as “WVTM 13 Live Doppler Radar”. This replaced a one megawatt radar installation they operated on Bald Rock in St. Clair County.

This can be viewed at Central Alabama Interactive Weather Radar – WVTM 13

There is an old saying that the best radar site is the closest radar site. So remember WVTM.

Otherwise switch to another NWS radar site, though it will not be a near ground level image.

4. There will be times you will see inbound intense storms over western Alabama. As time progresses and they near Birmingham they may seem to weaken substantially, pass over and then reintensify over eastern Alabama.

Two things may have happened:

A. The storms, due to the wacky world of inflows and outflows may have actually momentarily weakened and then restrengthened after leaving Birmingham.

Also I’ve seen lines of doom divide once they hit the Warrior River like Moses at the Red Sea and pass North and South of Birmingham,

B. The radar beam is seeing the mid-levels of the distant storm, which is experiencing heavy rain, but, much of this has dissipated by the time it reaches the lower levels, and so when the radar is able to see these lower levels, there is nothing much there. There may still be intense activity 10,000 feet overhead, but, it won’t be detectable until the storm is once again at a distance where the radar beam is once again hitting those mid-levels. It looks like a reintesification, but, it really isn’t.

5. NEXRAD can occasionally show some interesting non-weather returns, such as “bird rings” where hundreds of birds suddenly take off at once in every direction. This usually occurs along rivers at dawn. Smoke from forest fires. UHF band openings, either due to a cold front causing a temperature inversion, or a daily temperature inversion at dawn, cause by the Sun heating the upper atmosphere and the lower levels still being cold, can cause ground clutter to blossom in every direction.

For more information on the new NWS radar site check out the following link:
New Radar Webpage (RIDGE2) Frequently Asked Questions (weather.gov)

The WSR-88D is considered by many to be the most powerful radar in the world, transmitting at 750,000 watts. This power enables the signal to travel long distances, and detect many kinds of weather phenomena. It also allows energy to continue past an initial shower or thunderstorm near the radar, thus seeing additional storms farther away.

Many other radar systems do not have this kind of power, nor can they look at more than one “slice” of the atmosphere. During severe weather, the NWS WSR-88D is looking at 14 different elevations every 5 minutes, generating a radar image of each elevation. That’s about 3 elevations per minute, or one radar image every 20 seconds.

Before this system was established there was only one radar site in Alabama and it was at Centerville. This was the old WSR-57, which had a CRT like a sonar screen in old submarine movies. Someone had to watch the screen constantly when storms were possible to make sure nothing important was missed and the storms were tracked using grease pencils, and the forecasters had to manually turn a crank to adjust the radar’s scan elevation. Any archiving of the imagery was done by taking a picture of the screen using a Polaroid camera.

Back then, in the Stone Age, there were only 66 radar sites nationwide. By the mid 70’s Mobile, Montgomery and Huntsville were added as three of the 62 WSR-74C radar sites. These were designed to help fill in the gaps in WSR-57 coverage.

Today we are blessed with a transcontinental network of WSRD88’s. Every weather office has a NEXRAD radar unit – 159 of them. Though experiments continue with at the National Severe Storm Laboratory with Phase Array Doppler Radar, (See:

NSSL EXPERIMENTAL PHASE ARRAY DOPPLER RADAR – Oklahoma Coverage Only

http://wdssii.nssl.noaa.gov/web/wdss2/products/radar/nwrt_ref_loop.shtml Reflectivity
http://wdssii.nssl.noaa.gov/web/wdss2/products/radar/nwrt_vel_loop.shtml Velocity
http://wdssii.nssl.noaa.gov/web/wdss2/products/radar/nwrt_et_loop.shtml Echo Tops
http://wdssii.nssl.noaa.gov/web/wdss2/products/radar/nwrt_azshr_loop.shtml AzShear)

The WSR-8-D system is the most sensitive, most detailed radar network on the planet.

No other nation has this resource that we have. Australia has a good radar picket of their coast, but nothing inland over the deserts. Even our deserts are radar covered. Britain has decent radar system now, but, it only updates every 15 minutes & Europe has radar, but Birmingham’s WVTM radar is a better radar system than they have.

Think of Birmingham for a moment. At any given time we are being painted by radar from Shelby County, Columbus AFB, Montgomery, Hytop/Huntsville & Atlanta/Peach Tree City. Not to mention the TDWR sites & WVTM.

So, next time you are looking at these radar image, just remember how unique it is and realize how totally rotten we are spoiled

 

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Mark’s Almanac

January is named for the Roman god Janus, the god of gates and doors, and so openings and beginnings.

January receives more sunlight than December, but the equilibrium between incoming solar heat and the heat radiated into space by the northern snowfields does not peak until late January and early February, six weeks after winter solstice. So the weather continues to cool, with January 8 – 20 being the coldest part of the year.

Typically in January there is a 53% chance of up to one inch of snow and a 25% chance of over one inch of snow.

With the exception of the southern tip of Nova Scotia, all of Canada and roughly one half of the Continental US, or “CONUS”, are now covered with snow. Canada’s Hudson’s Bay is frozen, as is the ocean water between Baffin Island and Greenland.

http://www.natice.noaa.gov/pub/ims/ims_gif/DATA/cursnow_usa.gif
Barometric pressure is highest in January.

Though the Atlantic Hurricane Season officially ended November 30, every now and then Mother Nature will give us a surprise as there have been 5 tropical storms and 3 Category 1 hurricanes from 1851 to 2019. This includes an unnamed hurricane in 1938 in the Eastern Atlantic & Hurricane Alex which in 2016 effected Bermuda and the Azores.

Birmingham January climatology per Intellicast is monthly rainfall 5.45” inches and snowfall 0.7”. Average high temperature is 53 degrees and the average low 32 degrees. Record high of 81 degrees occurred in 1941 and a record low of -6 degrees in 1985.

Barometric pressure is highest in January.

Days grow longer as the Sun’s angle above the noonday horizon steadily increases from 33.5 degrees at the beginning of the month to 39.2 degrees at the month’s end. Daylight increases from 9 hours 59 minutes on January 1 to 10 hours 33 minutes on January 31.

Sunrise and sunset times for Birmingham are:

January 1 Sunrise 6:52 AM Sunset 4:50 PM
January 15 Sunrise 6:51 AM Sunset 5:02 PM
January 31 Sunrise 6:44 AM Sunset 5:17 PM

Looking skyward, at the beginning of the month, the Sun, magnitude -26.8 is in Sagittarius. The Sun is the beginning stages of Solar Cycle 25, and there should be an increase in solar activity and good HF radio propagation.

At the beginning of the month Mercury, magnitude –1.0, in Sagittarius, is hidden in the glare of the Sun.

He then emerges in the evening sky passing by Saturn on the 9th and Jupiter on the 11th.

Mercury reaches his highest point in the evening sky, or “Greatest Eastern Elongation” of 18.6 degrees from the Sun on January 23. This is the best time to view Mercury since it will be at its highest point above the horizon in the evening sky. Look for the planet low in the western sky just after sunset.

He will be at “Dichotomy” or at half lit phase on January 25.

He will reach his closest distance to the Sun or Perihelion on January 28.

Venus, magnitude –3.9, in Ophiuchus, near the head of Scorpius, is very low in the Southeast during dawn.

Earth, magnitude -4.0, as viewed from the Sun, is in the Constellation Gemini.

Earth will reach her closest distance to the Sun on Jan 2, when the planet will be 0.98324 Astronomical Units or 91,399,000 miles from the Sun.

Mars, magnitude –0.3, in Pisces, shines very high in the South in early evening. The bright yellow-orange globe is fading and shrinking into the distance. Telescopes will reveal it is gibbous, being
89% sunlit from Earth’s point of view..

Dwarf Planet Ceres, magnitude 9.3, is in Aquarius.

Jupiter, magnitude –2.0, in Capricorn, is low in the southwest during and after twilight; he will soon disappear below the horizon and pass behind the Sun on January 28.

Saturn, magnitudes +1.4, in Capricorn, still shines with Jupiter, though their separation is increasing, in the southwest during and after twilight, and like Jupiter will soon disappear from the night sky. Saturn will pass behind the Sun on January 23.

Uranus, magnitude 5.7, in Aries, is high in the south in early evening.

Neptune, magnitude 7.9, in Aquarius, is lower in the southwest just after dark.

Dwarf Planet Pluto, with his five moons shines at a dim 14.4 in Sagittarius.

Dwarf Planet 136108 Haumea, its ring and moons Hiʻiaka and Namaka, shines at a faint magnitude of 17.4 in Bootes.

Dwarf Planet 136472 Makemake with his moon faintly shines at magnitude 17.3 in Coma Berenices.

Dwarf Planet 136199 Eris and her moon Dysnomia is barely visible in the most powerful telescopes at magnitude 18.8 in Cetus the Sea Monster

4323 planets beyond our solar system have now been confirmed as of December 17, per NASA’s Exoplanet Archive http://exoplanetarchive.ipac.caltech.edu/

The Quadrantids Meteor Shower will occur Saturday & Sunday, January 2 & 3. This is an above average shower producing between 40 to 100 meteors per hour radiating from the constellation Bootes, in the area near the end of the handle of the Big Dipper and the head of Draco the Dragon.

The shower runs annually from January 1-5. It peaks this year on the night of the 2nd and morning of the 3rd. The waning gibbous moon will block out most of the faintest meteors this year. But if you are patient, you should still be able to catch a few good ones. Best viewing will be from a dark location after midnight. Meteors will radiate from the constellation Bootes, but can appear anywhere in the sky.

This shower favors the Northern Hemisphere because its radiant point, or the point where the meteors appear to originated in the sky, is so far north on the sky’s dome.

This shower is believed to be produced by dust grains from burnt out comet 2003 EH1, which may also be the remainder of comet c/1490 Y1, which was lost to history after a prominent meteor shower was observed in 1490, possibly due to the breakup of the comet.

Last Quarter Moon, or when the moon has only the Eastern side illuminated, will occur January 6.

The Moon will be at Perigee or its closest approach to Earth on January 9, when she will be 228,285 miles from Earth.

New Moon occurs January 12 at 11:02 PM CST on January 12 or 5:02 UTC January 13 when the Moon will on the same side of the Earth as the Sun and will not be visible in the night sky. This is the best time of the month to observe faint objects such as galaxies and star clusters because there is no moonlight to interfere.

First Quarter Moon, or when the moon has only the Western side illuminated, will occur January 20.

The Moon will be at Apogee or its farthest distance from Earth on January 21, when she will be 251258 miles from Earth.

Full Moon will occur Thursday, January 28, at 1:18 PM CST or 19:18 PM UTC. The Moon will be located on the opposite side of the Earth as the Sun and its face will be will be fully illuminated.

January’s Full Moon is “Wolf Moon” in Native American folklore. This was also called “Wulf-Monath” or “Wolf Month” by the Saxons, because at this full Moon, packs of wolves howled in hunger outside of the villages.

It has also been called “Old Moon” and “Moon After Yule”.

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This month’s meeting will be on January 12 at 7PM.

The meeting will be done remotely as was last month’s meeting. Details and instructions will be issued as the time nears.

I hope to see you there!

Mark Wells
WD4NYL & WRJE893
Editor
ALERT Newsletter
wd4nyl@bellsouth.net

Mark’s Weatherlynx
Weather Resource Database
https://weatherlynx.webs.com/