Friday, August 16, 2013

August 2013 - Wet & Seasonally Cool


Summer 2013
Longhorn Milkweed Beetles 
( Tetraopes tetrophthalmus )
Photograph by Harold L. Jerrell - © All Rights Reserved.

A wet & seasonally cool weather pattern dominated the first half of August 2013 as the glory of Mother Nature increased NOISE levels across the mountain landscape. 


August is the month of SOUND.

This reminds me of a column I wrote some years ago:
When night falls upon the ancient Cumberlands the hum of cicadas and the twittering of songbirds cease, as a multitude of new sounds emerge to fill their voids!

   If you have lately been outside near nightfall, or even listened closely from inside, you have likely heard a great chorus of sounds coming from seemingly every nook and cranny!

   While some of these sounds are from Black Field and Green Tree Crickets, most of the loud thrills are from a group of American Long-horned Grasshoppers commonly called Katydids.
   The variable and rather extreme weather patterns of spring-summer seem to have been favorable for the development of a large population of Eastern Katydids or, as my grandparents used to call them, Sawyers!

   While there are many different species of Katydids, the ones that tend to stimulate eardrums most often are the robust Coneheaded Katydids whose sounds can travel a third of a mile, if not more, under ideal conditions.  They are, without question, the overwhelming "noise" makers of the night ( no disrespect to my beloved Barred & Screech Owls ).

   Some Katydids live in trees, while others prefer grass and ground vegetation.  Although most are green and blend well with the summer foliage, some species have brown, pink, or even rarely orange colorations. 

   Most male Katydids make their long stretched out thrills, and pulsating sounds, by rubbing together ridges and rough places located near the base of their outer wings.

   Varying arrangements of these ridges and rough places yield different sounds, thereby distinguishing different species.
  Incredible, yes indeed!

   The first Sawyers actually began to fill the nights with sound during mid to late July, so according to mountain tradition the first frost can be expected in early September.

While that may be questionable, there is little doubt that August in the ancient Cumberlands is truly, from day to night, a month of sound!

Common Butterfly-weed
( Asclepias tuberosa var. tuberosa )
Photograph by Wayne Browning - © All Rights Reserved.


Climate Statistics
For August 1-15, 2013

( Lower Elevations of Russell Fork Basin )
Clintwood 1 W - Elevation 1560 feet
Average Daily MAX: 76.7 degrees
Average Daily MIN: 61.5 degrees
MEAN: 69.1 degrees
Highest Temperature: 82 degrees
Lowest Temperature: 49 degrees
August 1-15 Rainfall: 3.69"
2013 Precipitation: 36.36"

( Northern Base of High Knob Massif )
City of Norton - Elevation 2141 feet
Average Daily MAX: 76.0 degrees
Average Daily MIN: 58.2 degrees
MEAN: 67.1 degrees
Highest Temperature: 81 degrees
Lowest Temperature: 45 degrees
August 1-15 Rainfall: 3.15"
2013 Precipitation: 45.80"

( Along the Tennessee Valley Divide )
Nora 4 SSE - Elevation 2650 feet
Average Daily MAX: 75.1 degrees
Average Daily MIN: 61.1 degrees
MEAN: 68.1 degrees
Highest Temperature: 79 degrees
Lowest Temperature: 51 degrees
August 1-15 Rainfall: 3.40"
2013 Precipitation: 42.26"

The first half of August produced a general 3.00" 
to 5.00" of rainfall across the High Knob Massif and surrounding region, with heaviest amounts generally along and west of the Appalachians on westerly dominated air flow trajectories ( verses along and east of the mountain chain during 
July on prolonged easterly component air flow ).

Gary Hampton reported one of the heavier rainfall totals during the first half of August with 5.47" being measured by him and staff of the 
Big Stone Gap Water Plant.

August 2013 Rainfall Days
Big Stone Gap Water Plant
Observer: Gary Hampton & Staff
( South Fork Gorge of High Knob Massif )
Elevation 1965 feet

08-01-2013  0.44"

08-03-2013  0.06"

08-06-2013  0.01"

08-08-2013  0.69"
08-09-2013  0.57"
08-10-2013  1.41"
08-11-2013  0.52"
08-12-2013  0.88"
08-13-2013  0.75"
08-14-2013  0.14"

August 1-14 Total: 5.47"

Total Since June 1: 20.26"

2013 Total: 50.21"

12-Month Total: 70.30"
( August 15, 2012 - August 14, 2013 )

With a general 20.00" to 25.00" of summer rain in South Fork of the Powell River Basin to August 15, there had been plenty of rainfall to keep Big Cherry Lake overflowing its spillway all summer. 

Big Cherry Dam is 2.0 air miles ENE of the Big Stone Gap
Water Plant ( and is 1155 vertical feet higher in elevation ).

( Centered on Virginia )
Doppler Estimated Rainfall During August 1-17, 2013

A bias toward westerly air flow trajectories being generalized in the rainfall pattern given the chaotic nature of convection which continued to dominate the precipitation mode.

( Centered on Tennessee )
Doppler Estimated Rainfall During August 1-17, 2013

The general WNW air flow trajectory during 
August 1-15 is visible on this 850 MB Composite.

August 1-15, 2013
Composite Mean 850 MB Wind Vectors

This represented a radical shift from the 
mean flow that dominated the July 1-24 period.

July 1-24, 2013
Composite Mean 850 MB Wind Vectors

Looking at Summer 2013 up to now, the 850 MB vector wind anomaly verses that of observed climatology reveals one factor driving excessive wetness along and east of the Appalachians.

June 1 to August 15, 2013
Composite Mean 850 MB Wind Vector Anomaly

Mean air flow has been dominated by trajectories off the Atlantic Ocean into the region from the Blue Ridge to Tidewater instead of from the Gulf of Mexico.  In other words, mean westerly air flow components that generate some drying with descent leeward of the Appalachians have been much less common this summer.

( 1981 to 2010 Climate Period )
 850 MB Wind Vector Climatology


Summer Taste of Autumn

Several notable cold frontal passages since July 24 have generated numerous chilly nights, especially amid higher mountain valleys.

First Jewelweeds Beginning To Bloom
Orange Spotted Jewelweed ( Impatiens capensis )
Photograph by Wayne Browning - © All Rights Reserved.

A certain sign that autumn is not far away, along with Katydids, is marked by the blooming of Orange Spotted & Yellow ( Impatiens pallida ) Jewelweeds.

Jewelweeds, also called Touch-Me-Nots for their seed pods that literally explode when touched by anything upon ripening, are 
a favorite late summer and early autumn wildflower of 
Ruby-throated Hummingbirds ( Archilochus colubris ).


MINS By The Numbers
Chilly Mornings In The City of Norton
( and higher valleys at 2400-3500 feet ) 

July 26
50 degrees
( mid-upper 40s )

July 29
46 degrees
 ( low-middle 40s )

July 30
48 degrees
( mid-upper 40s )

August 5
53 degrees
( upper 40s-lower 50s )

August 15
45 degrees
*( 40 to 45 degrees )

August 16
52 degrees
( upper 40s-lower 50s )

Minimums dropped to around 40 degrees in coldest valleys from the High Knob Massif to Burkes Garden into morning hours of August 15, marking the coolest night of Summer 2013.

*This was not a record.  Record lows for August 15 reached 
30 degrees in Burkes Garden during 1924 ( data period 1896-Present ) and 41 degrees in Wise ( data period 1955-Present ).

Summer 2013
Granddaddy Longlegs ( Opilione ) & Company
Photograph by Harold L. Jerrell - © All Rights Reserved.

Although records were not set, an interesting aspect of the mid-August cool spell was the formation of cold air advection upslope clouds during overnight-morning hours of August 14.

NASA Visible Image At 7:45 AM on August 14, 2013

A thick bank of upslope clouds formed along windward sides 
of the High Knob Massif - Black Mountain and Tennessee Valley Divide corridor northeast to around Flattop in West Virginia, as well as along windward ( with respect to NNW-N air flow ) slopes of higher portions of Clinch Mountain, Whitetop-Mount Rogers, and the TN-NC border.  Also note river valley fog across much of West Virginia and frontal zone cloudiness lee of the Appalachians in North Carolina and southeastern Virginia.

NASA Visible Image At 7:45 AM on August 14, 2013

NASA Visible Image At 8:32 AM on August 14, 2013

This section is under construction.  Check back for updates.

Thursday, August 1, 2013

Recap Of July 2013 - Huge Rainfall Gradients


Water Elevation 2734 feet
Jefferson National Forest & VDGIF
Bark Camp Lake of High Knob Massif
Gorgeous Sunshine Follows A Chilly July Morning
Photograph by Roddy Addington - © All Rights Reserved.


The High Knob Landform was amid excessive rainfall during the summers of 2010, 2011, and 2012 ( High Knob Massif & Cumberland Gap NHP areas ).

( Excessive Rainfall of August 2010 )


July 2012 - Doppler Estimated Rainfall


While rainfall has been locally excessive during Summer 2013, clearly the corridor of widespread excessive rains became focused along the eastern slopes of the Appalachians and western Piedmont during July ( and southern Cumberland Plateau ).

July 2013 - Doppler Estimated Rainfall

Many places had rainfall totals that were 10.00" to 15.00"+ above established normals for July, with near record to all-time record amounts.

The only previous July with more rainfall 
in many upslope locations was July 1916.

July 2013 - Doppler Estimated Rainfall

Observe on these graphics how the heaviest rains have been focused along the Blue Ridge escarpment, which plunges off to
the western Piedmont, with more inland areas to the west of this escarpment along the eastern slopes of the Blue Ridge having much less rainfall ( which fits climatology ).



July 2013 Rainfall Totals
Southern Appalachians

North Carolina

( 1981-2010 Climate Period )
North Carolina Observed Climate Normals

Elevation 5280 feet
*Grandfather Mountain: 23.91"
+17.93" above the July Normal

Note that the 17.93" surplus during July 2013 was only 0.04"
below the average rainfall for the entire summer season that was recorded on average during the 1981-2010 observation period.

Landis Taylor also reported the following additional
July rainfall totals from Grandfather Mountain:

Grandfather Entrance Gate: 29.24"
( Courtesy of Entrance Gate Employees )

Grandfather Fudge Shop: 28.91"
( Courtesy of The Naturalist Staff )

*All-time Record For July shattering the old
record of 11.92" established during July 1989.

Elevation 3840 feet
Highlands: 23.50"
+17.16" above 1981-2010 July Normal

The wettest July on record in Highlands
was in 1916 with 35.49" of rainfall

Elevation 3080 feet
Lake Toxaway: 23.00" ( M )
42.19" of rainfall since June 1 ( M )

Elevation 6240 feet
Mount Mitchell: 22.15"
+16.53" above 1981-2010 July Normal

Elevation 3770 feet
Banner Elk: 20.29"
+15.16" above 1981-2010 July Normal

The wettest July on record in Banner Elk
was in 1916 with 28.06" of rainfall

Elevation 3360 feet
Boone 1 SE: 19.70"
+14.97" above 1981-2010 July Normal

Elevation 5053 feet
Beech Mountain: 18.69"
+13.26" above 1981-2010 July Normal

Elevation 2165 feet
Asheville: 13.69"
+10.36" above 1981-2010 July Normal
( Only 0.06" shy of all-time wettest month of any year )

RECORD EVENT REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC

...A NEW MONTHLY RAINFALL RECORD
FOR JULY SET AT ASHEVILLE NC...

RAINFALL FOR THE MONTH OF JULY WAS 13.69 INCHES AT THE ASHEVILLE AIRPORT. THIS SURPASSES THE PREVIOUS RECORD RAINFALL FOR THE MONTH OF JULY FOR THE ASHEVILLE AREA OF 11.71 INCHES SET IN 1905.  CLIMATOLOGICAL RECORDS FOR THE ASHEVILLE AREA DATE BACK TO 1869.



Tennessee

( 1981-2010 Climate Period )
Tennessee Observed Climate Normals

Elevation 6400 feet
Mount LeConte: 15.28"
+8.47" above 1981-2010 July Normal

Elevation 1500 feet
Tri-Cities: 7.11"
+2.42" above 1981-2010 July Normal



Virginia

( 1981-2010 Climate Period )
Virginia Observed Climate Normals

Elevation 2360 feet
Galax WTP: 15.28"
+11.04" above 1981-2010 July Normal for area

Elevation 2225 feet
Meadows Of Dan 5 SW: 14.91"
+9.56" above 1981-2010 July Normal

Elevation 1175 feet
Roanoke: 12.73"
+8.69" above 1981-2010 July Normal

Elevation 571 feet
Danville: 11.50"
+6.91" above 1981-2010 July Normal

Elevation 4000 feet
Grayson Highlands State Park: 11.22"
( Davis Vantage Pro2 Automated Weather Station )

Elevation 2926 feet
Konnarock: 7.99"
( USGS Automated Gauge )

Elevation 2132 feet
Blacksburg: 7.78"
+3.52" above 1981-2010 July Normal

Elevation 2172 feet
Marion: 6.95"
( TVA Rain Gauge )

Elevation 1733 feet
Saltville 1 N: 6.17"
+1.14" above 1981-2010 July Normal

Elevation 3068 feet
Burkes Garden: 6.03"
+1.55" above 1981-2010 July Normal


NATIONAL WEATHER SERVICE BLACKSBURG VA
925 AM EDT THU AUG 1 2013

...RAINFALL TOTALS AND RECORDS SET IN JULY 2013...

ROANOKE VIRGINIA RECEIVED 12.73 INCHES OF RAIN...WHICH MADE JULY 2013 THE WETTEST JULY EVER RECORDED. THE OLD JULY RAINFALL RECORD WAS 10.09 INCHES FROM 1989. IT WAS ALSO THE SECOND WETTEST MONTH OF ALL TIME IN RECORDED HISTORY. THE CURRENT ALL TIME WETTEST MONTH RECORD IS 16.71 INCHES FROM AUGUST 1940. RECORDS FOR ROANOKE DATE BACK TO 1912.

DANVILLE VIRGINIA RECEIVED 11.50 INCHES OF RAIN...WHICH MADE JULY 2013 THE WETTEST JULY EVER RECORDED. THE OLD JULY RAINFALL RECORD WAS 8.81 INCHES FROM 1965. IT WAS ALSO THE FOURTH WETTEST MONTH OF ALL TIME IN RECORDED HISTORY. THE CURRENT ALL TIME WETTEST MONTH RECORD IS 14.64 INCHES FROM SEPTEMBER 1996. RECORDS FOR DANVILLE DATE BACK TO 1948.

BLACKSBURG VIRGINIA RECEIVED 7.78 INCHES OF RAIN...WHICH MADE JULY 2013 THE THIRD WETTEST JULY EVER RECORDED. THE CURRENT JULY RAINFALL RECORD IS 9.35 INCHES FROM 1992. RECORDS FOR BLACKSBURG DATE BACK TO 1952.

BLUEFIELD WEST VIRGINIA RECEIVED JUST 4.12 INCHES OF RAIN...WHICH WAS WELL SHORT OF THE CURRENT JULY RAINFALL RECORD OF 10.24 INCHES FROM 1980. BLUEFIELD ACTUALLY FINISHED BARELY BELOW THE 1981-2010 NORMAL FOR RAINFALL IN JULY...WHICH IS 4.17 INCHES. RECORDS FOR BLUEFIELD DATE BACK TO 1959.

FINALLY...LYNCHBURG VIRGINIA RECEIVED ONLY 3.41 INCHES OF RAIN...WHICH WAS FAR BEHIND THE CURRENT JULY RAINFALL RECORD OF 10.30 INCHES FROM 1984. LYNCHBURG FINISHED BELOW THE 1981-2010 NORMAL FOR RAINFALL IN JULY...WHICH IS 4.36 INCHES. RECORDS FOR LYNCHBURG DATE BACK TO 1893.

July 2013
Doppler Estimated Departure From Normal

July 2013 rain totals were somewhat above and below longer-term averages along the western slopes of the Appalachians and western portion of the Great Valley, as generally suggested by Doppler estimated departures, with 5.00" to 9.00" being common in the High Knob Massif - Tennessee Valley Divide and Clinch River Valley.

Elevation 2650 feet
Nora 4 SSE: 8.44"
( Long Ridge of Sandy Ridge )

Elevation 2290 feet
Little Stone Mountain Gap: 7.97"
( 3.0 miles WSW Norton - VDOT Station )

Elevation 2267 feet
Coeburn Filter Plant: 7.83"
( 3.5 air miles NE of Downtown )

Fort Blackmore IFLOWS: 7.83"
( 2.8 air miles SE of High Knob Massif )

Fort Blackmore 4 SE: 7.28"
( CoCoRaHS Station )

Elevation 2342 feet
City of Norton WP: 6.51"
+1.02" above 1983-2012 July Average

Elevation 2360 feet
Appalachia Lake WP: 6.16"
+0.46" above 1985-2012 July Average

Elevation 1912 feet
Lebanon: 5.66"
+1.09" above estimated 1981-2010 July Normal

Elevation 1170 feet
Grundy: 5.38"
+0.18" above 1981-2010 July Normal

Elevation 1910 feet
Richlands: 5.32"
+1.00" above estimated 1981-2010 Normal

Elevation 1560 feet
Clintwood 1 W: 4.05"
-0.70" below 1981-2010 July Normal



July 2013 Rainfall
Central Appalachians

West Virginia

( 1981-2010 Climate Period )
West Virginia Observed Climate Normals

Elevation 824 feet
Huntington: 7.90"
+3.35" above 1981-2010 July Normal

Elevation 910 feet
Charleston: 7.37"
+2.43" above 1981-2010 July Normal

Elevation 4850 feet
Snowshoe Mountain: 6.31"
+1.35" above 1981-2010 July Normal

Elevation 3815 feet
Davis 3 SE: 5.03"
-0.53" below 1981-2010 July Normal
( Canaan Mountain )

Elevation 2514 feet
Beckley: 4.62"
-0.41" below 1981-2010 July Normal

Elevation 1979 feet
Elkins: 4.32"
-1.04" below 1981-2010 July Normal

Elevation 2300 feet
Lewisburg 3 N: 4.15"
+0.13" above 1981-2010 July Normal

Elevation 2870 feet
Bluefield: 4.12"
-0.36" below 1981-2010 July Normal

Elevation 534 feet
Martinsburg: 3.14"
-0.53" below 1981-2010 July Normal

It is interesting to note that for Summer 2013 so far, from June 1 to July 31, rainfall totals have regionally varied from 42.19"+ at Lake Toxaway, NC., to 7.14" in Martinsburg, WV.

July 10, 2013
Along The Tennessee Valley Divide
Sunshine Through Falling Rain & Black Clouds
Photograph by Wayne Riner - © All Rights Reserved.

Wayne Riner Photograph Thoughts...
"The sounds of distant thunder marked the start of the usual afternoon and evening thunderstorms.  Here, the sun is partly hidden by a thin veil of rain."


Climate Statistics
For July 2013

( Lower Elevations of Russell Fork Basin )
Clintwood 1 W - Elevation 1560 feet
Average Daily MAX: 80.3 degrees
Average Daily MIN: 60.5 degrees
July MEAN: 70.4 degrees
Highest Temperature: 87 degrees
Lowest Temperature: 51 degrees
July Rainfall: 4.05"
Rainfall Since June 1: 11.71"
2013 Precipitation: 32.67"

( Northern Base of High Knob Massif )
City of Norton - Elevation 2141 feet
Average Daily MAX: 78.9 degrees
Average Daily MIN: 57.5 degrees
July MEAN: 68.2 degrees
Highest Temperature: 86 degrees
Lowest Temperature: 47 degrees
July Rainfall: 6.51"
Rainfall Since June 1: 15.08"
2013 Precipitation: 42.65"

( Along the Tennessee Valley Divide )
Nora 4 SSE - Elevation 2650 feet
Average Daily MAX: 77.5 degrees
Average Daily MIN: 62.3 degrees
July MEAN: 69.9 degrees
Highest Temperature: 84 degrees
Lowest Temperature: 53 degrees
July Rainfall: 8.44"
Rainfall Since June 1: 15.27"
2013 Precipitation: 38.86"

July featured near to below average temperatures with average daily maximums that only reached around 70 degrees at highest elevations amid the High Knob Massif.  This coupled with average nightly mins in mid 50s to lower 60s ( coolest in high valleys ) generated July MEANS 
in the mid-upper 60s.

A notable feature has been the lack of high temperatures with only 7 days this year climbing above 80 degrees at the 2650 foot elevation of Nora 4 SSE on Long Ridge of Sandy Ridge 
( 84 degrees being the 2013 max to date ).

No days have reached 80 degrees at highest elevations in the High Knob Massif ( ** ).

**This refers to calibrated thermometers that are
never in direct sunlight ( i.e., official NWS readings ).

The compensating factor, of course, has been many high dewpoint days such that feels-like conditions have made many days feel hotter.



Consistent Wetness
City of Norton
( January 1-August 1 )

The past 3 years up to this point in time have generated consistent wetness in the High Knob Massif area, as nicely exemplified 
by the City of Norton.

*City of Norton WP
Total Precipitation
January 1-August 1

2011
42.99"

2012
42.37"

2013
42.98"

1983-2012 Average
36.63" ( M )

*Totals up to 9:00 AM on August 1
( includes all rain falling through July 31 at midnight ).

( M ) - Missing data during the 1983-1998 period in snowfall.

Yes it seems ironic, as 2013 grabs the headlines with excessive rains that have places like the 
Tri-Cities, Tn., Blacksburg, Danville, and Roanoke in Virginia already near their annual precipitation totals, and rarely only a little behind the City of Norton, that its just HO-HUM for Norton where 2013 marks the third year with the same surplus. 

The change across Virginia this year has been radical as generalized by a comparison of the USA Drought Monitor for the Commonwealth during the 2011-2013 period.

Virginia Drought Monitor On August 2, 2011

Virginia Drought Monitor On July 31, 2012

Virginia Drought Monitor On July 30, 2013

No drought anywhere across Virginia at the end of July 2013 verses 50-75%+ of the state with at least abnormal dryness during the previous two years.

While the Old Dominion of Virginia has been north of the truly extreme wetness of late spring-summer 2013, as already highlighted by North Carolina records, its been wet enough that wetter areas along the southern Blue Ridge ( e.g., Meadows of Dan, Galax, Mount Rogers & Whitetop Mountain ) are now running close to the wettest areas in the High Knob Landform ( e.g., Big Cherry Lake Basin & Cumberland Gap NHP area ) for the year to date.