Astro's Blog

125th Anniversary of the 1889 Johnstown, PA Flood-A Brief Review

By: Astrometeor, 12:34 AM GMT on June 01, 2014

Today, May 31, marks the 125th anniversary of the dam break that led to a massive and devastating flood that killed 2,209 people, slaughtered entire families, and left Johnstown and several other communities swept clean.

Some facts of the flood.

A Brief History of the Event, along with more links to further your research: Johnstown Flood Museum

The U.S. Army Signal Corps recorded 6-10 inches of rainfall in various locations in the 24 hours leading up to the event on May 31. On the morning of May 31, Mr. Unger awoke to see water lapping over the the top of South Fork Dam, a dam located 14 miles upstream from Johnstown. During the day, dozens of men, led by a local engineer, tried in vain to relieve pressure from the dam, which was known in the area as weak and poorly built. A little after 3 o'clock, the workers watched in horror as the entire dam moved away from its moorings, and Lake Conemaugh behind the dam was let loose in a fierce torrent.


Figure 1. The John Schultz house at Johnstown, PA after the flood. Skewered by a huge tree uprooted by the flood, the house floated down from Union Street to the end of Main. Six people, including Schultz, were inside the house when the flood hit. All survived.


Figure 2. Main street after flood.


Figure 3. A modern view of the home of Elias Unger, who was president of South Fork Fishing and Hunting Club. The Club was the overseer of South Fork Dam.

Wikipedia Entry on the Great Johnstown Flood of 1889.

The Flood killed the greatest number of U.S. civilians at that time. This mark would later be eclipsed by the 1900 Galveston Hurricane and the 9/11 Terrorist Attacks.

Thanks for reading, and don't find yourself in Johnstown, PA during a rainstorm!

Feel free to comment below.

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Weather Severe Weather Flash Flood Johnstown, PA Flood of 1889 Aftermath of Storm Disaster Phenomenon

May 10, 1864-Nashville, TN (150 Year-Anniversary)

By: Astrometeor, 2:45 AM GMT on May 11, 2014

In the heart of the Civil War, an interesting and severe weather event struck Nashville, TN.

Transcribed from the NWS Middle TN Weather History of the Day:

The Nashville Dispatch reports on May 12 "The storm of wind and rain which visited our city on Tuesday [10th] evening, we learn, has been particularly destructive in the vicinity of Nashville for miles around. In the region of country skirting the Nolensville Pike, the storm which amounted to a perfect hurricane, in its course uprooted trees, tore down fences, and tumbled over houses to an alarming extent, carrying in its track devastation and ruin to many small farmers and their families, and in some cases loss of life as well as property.

Rev. John Rains, living about three miles from the city, near the Nolensville Pike, had his home utterly stripped and ruined - carriagehouse, stable, smoke-house, servants' house, and fencing were entirely destroyed, and his dwelling house is nearly so. Mr. Woodward, in the same vicinity, had his dwelling-house literally torn to pieces, and his wife seriously, if not fatally injured, besides three children badly hurt; the hand of the eldest was so badly crushed as to require amputation of the thumb.

Nast. F. Dortch, Mr. McConnico, Mr. Harper, Mr. Lucus, Dr. Whitsitt, and others in the same locality, suffered considerably. Mrs. Aaron V. Brown had a large lot of beautiful timber land destroyed. Mr. John Hooper sustained considerable damage, his barn and fencing being destroyed. In the vicinity of the Hermitage, we learn, a large amount of valuable timber, dwelling houses, etc. were destroyed. Tim. Dodson had his barn, cut house, and fences utterly wrecked. A brick house, on Mill Creek, the property of P. Vickers, is in ruins.

The storm traversed a large extent of country Wilson county, doing great damage to fences and out houses. Altogether, from what we hear, this is one of the most disastrous hurricanes that has visited Tennessee for many years."


Source

Article-Library (page 26)

Back then, all bad wind storms in this part of the country were labeled as hurricanes. There is discussion as to whether this was a derecho or a tornado, but regardless, the residents of Nashville that day were caught off-guard by the firepower of Mother Nature.

Hope everyone enjoyed that tidbit of weather history. Thanks for reading!

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Aftermath of Storm Disaster Severe Weather Weather Civil War

Nashville NWS Needs Your Help!

By: Astrometeor, 3:11 AM GMT on May 04, 2014

***Important Note***
The following has been transcribed from the Nashville NWS-WFO's page. Click here to be taken to source. The message is particularly aimed for anyone living in the southern Middle Tennessee region of the state.

Have you seen debris in your yard this week? It may be from the Lincoln County EF-3 Tornado!
We Need Your Help!
Did you see any debris in your yard this week?
It may have come from the Lincoln County Tornado!

On Monday April 28th, 2014, a severe weather outbreak across the lower Mississippi Valley and much of the southeast US resulted in multiple tornadoes spanning from the Louisiana/Mississippi border up into northern Alabama, Southern Middle Tennessee and northern Georgia. One such tornado occurred just south of the Nashville county warning area (in Huntsville's area) in Lincoln, County Tennessee which resulted in 2 fatalities.

Here is a map of the active weather period across the southeast US from April 27th - April 30th. The April 28th tornado outbreak is highlighted in red:

(fatalities are indicated by boxed numbers)



The Lincoln County EF-3 tornado was one that both the Huntsville and Nashville offices were watching very closely. While the Huntsville NWS office was busy tracking the tornado that was moving through Lincoln County, the Nashville office was preparing their warning and letting the emergency manager in Coffee County know that the city of Tullahoma was in the path of the tornado, should it continue to stay on the ground.

This is what the meteorologists at both offices were seeing in chronological order:



At 8:09 PM CDT, according to the NWS Huntsville damage survey (Found Here), the tornado touched down in extreme southern Lincoln county. Five minutes later at 8:14 PM, the radar first detected a Tornado Debris Signature (or TDS) on the KHTX radar in northern Alabama. You can see it on the right hand side of the picture as the little blue speck south of Fayetteville (see above).

The image on the left is traditional reflectivity, which tells the meteorologist about intensity of rainfall and/or hail within the storm. In classic supercells, the reflectivity structure looks much like a backwards comma. The comma head part of the storm is called the "hook echo" as indicated on the left hand side of the picture above. This is where the tornado would typically be found. With the recent upgrade to Dual-Polarization technology, the radar can see much more than before. On the right hand side, is the new Dual-Pol radar called Correlation Coefficient which can differentiate between rain, hail, or in this case, tornado debris. The lower the CC value, the more likely that it is NOT a meteorological target. In the above image, the very low CC values (indicated in blue colors among the purple), located within the hook echo, tells the meteorologist that this signature is most likely tornado debris and that a tornado is in fact on the ground at this time.



At 8:23 PM, or 14 minutes after the tornado touched down, the TDS signature (right) continues to be seen on the CC radar image. Also, the hook echo on the left shows dark red colors meaning that the objects within the hook echo are reflecting back to the radar very brightly. When the reflectivity values within the hook echo are in the reds or higher, it too indicates debris within the tornado. In fact, this signature is often called a "debris ball" since it looks like the comma head has a ball at the end of it. The CC signature is quite a bit larger than the previous scan, which means the tornado continues to intensify and becoming stronger as it moves northeast through Lincoln County.



At 8:33 PM, or 24 minutes after touchdown, the tornado begins to lift, ending its damage path in southern Moore County (again according to the NWS Huntsville damage survey). As can be seen in the reflectivity image on the left, the hook echo is not as defined as in the previous scan, indicating weakening in the circulation. The supercell is looking less like a comma and losing its overall structure. Good news for residents of Lynchburg and Tullahoma which were in the path of this storm! However, if you look at the CC image, the TDS looks even bigger and brighter than it had in the last two scans. Well, it can't be that the tornado is getting stronger and wider, because the survey concluded it had ended at this point. What could it be?

As it turns out, the debris associated with the tornado continued to be carried in the winds associated with the supercell. Although not shown here, the TDS was seen over 20,000 feet! At these heights, the wind field was over 50 knots from the southwest. So what happened here is the debris was lofted so high that it was beginning to get caught in the upper level winds and carried downstream into southern Middle Tennessee! So while on radar, it may seem like the tornado was getting bigger, it had actually dissipated and its debris was being carried by the winds to the northeast.



Now at 8:47 PM, it is becoming more clear what is happening. The supercell continues to deteriorate with the hook echo very small and moving north into southern Bedford County. The CC values on the right are not as deeply blue, although some pixels are still very blue but they are more spread out and broad than previously. The debris cloud is expanding to the northeast, which makes sense considering the winds at this height are strongly southwesterly. So while the debris cloud indicated on the CC radar image begins to expand into Coffee and Bedford counties, a phone call comes from the Coffee County EMA Allen Lendley...

"Hey there Nashville, this may sound strange but a volunteer fire fighter on the road outside of Manchester just reported that pieces of paper are falling from the sky. Do you know anything about what he is talking about?"
(*not a direct quote)

Why yes Allen, we might have an explanation for that!



Now here at 8:56 PM, 23 minutes after the tornado lifted and 47 minutes after it initially touched down in southern Lincoln County, the supercell has more or less fallen completely apart. The Nashville office has cancelled their tornado warning they issued for this storm due to it weakening and losing its velocity signature as well (not shown). However the debris cloud continues to spread out and drift to the northeast in the upper level winds. The cloud is beginning to enter southeast Warren County and approach the city of McMinnville. Preliminary reports from the McMinnville area have come in since Monday with reports of debris being found. This debris cloud would continue to drift northeast before dissappearing finally just before reaching Crossville!

The Nashville county warning area (all of Middle Tennessee excluding Franklin, Lincoln, and Moore counties) was lucky enough to avoid any tornado activity that evening. One tornado was confirmed earlier in the day in White County but for the most part, the Mid-State dodged quite a bullet on Monday night!

The NWS Nashville office has analyzed the debris signature on both KHTX and KOHX radars and have put together this subjectively analyzed map of where debris may have landed across southeastern Middle Tennessee. If you live in the area shaded yellow in the below image, you may have had some debris fall in your yard! In order for debris to be picked up and lofted this far, its most likely the debris you might find would be lightweight, like paper, envelopes, pictures, or insolation.



If you happen to discover something like this in your yard over the next week, PLEASE LET US KNOW! We are attempting to put together a map of debris fall based off your reports to correlate with the radar data so we can better understand how these TDS signatures can help us see what is happening in reality. Also, you might find something like someone's family photos that might want to be returned by the people who lost them. Hopefully we can return some of these lost items back to their owners!

If you find anything in your yard that you think is debris associated with the tornado, please submit a picture of the debris and either the GPS coordinates of where you found it, or the address information to our Facebook page, tweeting the information to our Twitter page(@NWSNashville) or emailing us at sr-ohx.spotters@noaa.gov.

We appreciate your help!

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NWS News Tornado Aftermath of Storm Severe Weather Weather

Review of April 2014 Weather for Middle TN

By: Astrometeor, 3:55 AM GMT on May 02, 2014

The Nashville National Weather Service has released its review of April 2014. My favorite part is this:

“...FIRST MONTH THIS YEAR WITH ABOVE NORMAL TEMPERATURES... “. Like, lmao. Finally, warmer weather. Next week is scheduled to have 80-85F degrees for highs, about time. Anyways, here's the report:

13th wettest April in Nashville
PUBLIC INFORMATION STATEMENT
NATIONAL WEATHER SERVICE NASHVILLE TN
416 AM CDT THU MAY 1 2014

...RAINFALL ADDS UP TO THE 13TH WETTEST APRIL ON RECORD IN NASHVILLE...
...FIRST MONTH THIS YEAR WITH ABOVE NORMAL TEMPERATURES...

APRIL WAS THE FIRST MONTH SINCE DECEMBER 2013 WITH ABOVE NORMAL
TEMPERATURES IN NASHVILLE. THE TEMPERATURE AVERAGED 61.1 DEGREES
DURING THE MONTH WHICH IS 2.1 DEGREES ABOVE NORMAL. THE AVERAGE
HIGH WAS 73.8 DEGREES AND THE AVERAGE LOW WAS 48.5 DEGREES. THE
WARMEST TEMPERATURE DURING THE MONTH WAS 83 DEGREES ON THE 26TH
AND COOLEST WAS 31 DEGREES ON THE 16TH...WHICH WAS ALSO THE LAST
FREEZE DATE FOR THIS SPRING. NO TEMPERATURE RECORDS WERE SET OR
TIED DURING THE MONTH OF APRIL.

APRIL WAS VERY WET...WITH RAINFALL TOTALING 7.29 INCHES WHICH IS
3.29 INCHES ABOVE NORMAL. THE GREATEST RAINFALL DURING A 24 HOUR
PERIOD WAS 3.19 INCHES ON THE 28TH. APRIL 2014 WAS THE 13TH
WETTEST ON RECORD IN NASHVILLE. THE WETTEST APRIL WAS BACK IN 1874
WHEN 11.84 INCHES OF RAIN FELL. IT'S INTERSTING TO NOTE THAT THREE
OF THE FIVE WETTEST APRILS ON RECORD OCCURRED IN THE LATTER PART
OF THE 1800S...AND THE OTHER TWO OCCURRED IN THE EARLY 1900S.

A DAILY RAINFALL RECORD WAS BROKEN ON THE 28TH WHEN 3.19 INCHES OF
RAIN FELL...SET PREVIOUSLY IN 1945.

SNOW FLURRIES ON THE 15TH.

THUNDERSTORMS OCCURRED ON 8 DAYS IN APRIL.

THE AVERAGE WIND SPEED WAS 8.0 MILES AN HOUR. THE FASTEST GUST WAS 37
MILES AN HOUR ON THE 3RD.

FOG OCCURRED ON 17 DAYS WITH NO DAYS WITH DENSE FOG.



...

...CLARKSVILLE WAS ABOVE NORMAL IN TEMPERATURE AND NEAR NORMAL IN
RAINFALL FOR APRIL...

THE TEMPERATURE FOR CLARKSVILLE AVERAGED 58.8 DEGREES IN APRIL. THIS
IS 1.2 DEGREES ABOVE NORMAL. THE AVERAGE HIGH WAS 71.4 DEGREES AND
THE AVERAGE LOW WAS 46.1 DEGREES. THE WARMEST TEMPERATURE WAS 82
DEGREES ON THE 26TH...AND THE COLDEST WAS 29 DEGREES ON THE 16TH
WHICH WAS ALSO THE LAST FREEZE DATE FOR THIS SPRING.

RAINFALL TOTALED 4.28 INCHES WHICH IS 0.19 INCH BELOW NORMAL. THE
GREATEST RAINFALL DURING A 24 HOUR PERIOD WAS 1.22 INCHES ON THE
14TH.

THUNDERSTORMS OCCURRED ON 9 DAYS IN APRIL.

THE AVERAGE WIND SPEED WAS 8.7 MILES AN HOUR. THE FASTEST GUST WAS
43 MILES AN HOUR ON THE 14TH.

FOG OCCURRED ON 13 DAYS WITH ONE DAY OF DENSE FOG.

...

...CROSSVILLE WAS ABOVE NORMAL IN RAINFALL AND TEMPERATURE FOR APRIL...

THE TEMPERATURE FOR CROSSVILLE AVERAGED 57.8 DEGREES IN APRIL.
THIS IS 2.0 DEGREES ABOVE NORMAL. THE AVERAGE HIGH WAS 69.0 DEGREES
AND THE AVERAGE LOW WAS 46.7 DEGREES. THE WARMEST TEMPERATURE WAS
79 DEGREES ON THE 26TH AND 27TH AND THE COLDEST WAS 27 DEGREES ON
THE 16TH...WHICH WAS ALSO THE LAST FREEZE DATE THIS SPRING.

RAINFALL TOTALED 6.00 INCHES WHICH IS 1.18 INCHES ABOVE NORMAL.
THE GREATEST RAINFALL DURING A 24 HOUR PERIOD WAS 1.25 INCHES ON
THE 29TH AND 30TH.

THUNDERSTORMS OCCURRED ON 7 DAYS IN APRIL.

THE AVERAGE WIND SPEED WAS 6.7 MILES AN HOUR. THE FASTEST GUST WAS
39 MILES AN HOUR ON THE 13TH.

FOG OCCURRED ON 18 DAYS WITH ONE DAY OF DENSE FOG.

...

THERE WERE THREE TORNADOES IN MIDDLE TENNESSEE DURING THE MONTH OF
APRIL. TWO WERE IN LINCOLN COUNTY WHERE TWO PEOPLE WERE KILLED AND
ONE TORNADO WAS IN WHITE COUNTY...ALL ON APRIL 28TH.

FLOODING RAINS FELL ON APRIL 28TH IN MIDDLE TENNESSEE. SOME OF THE
LARGER RAINFALL AMOUNTS WERE KINGSTON SPRINGS IN CHEATHAM COUNTY
WITH 5.39 INCHES...DICKSON WITH 4.80 INCHES AND CENTERVILLE WITH 4.39
INCHES OF RAIN.



$$
BOYD
01
Source

Thanks for reading everyone, and welcome to May! Countdown to graduation on May 24 is on. Tick...tick...tick...

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Weather April NWS News


The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.