Saturday, May 3, 2014

April 2014 Stats - Atypically Dry Spring


May 5, 2014
Queen Of The Deep Woods
Yellow Lady's Slipper ( Cypripedium parviflorum )
Photograph by Wayne Riner - © All Rights Reserved.

Wayne Riner Photograph Thoughts...
"Hidden in the deep woods, two yellow slippers 
face west to enjoy the setting sun."

The High Knob Landform

A rather strange 2014 pattern has generated an atypically dry spring along the Appalachians in contrast to above average rainfall both northwest and southeast of the main mountain chain.

April 30, 2014
Along The Tennessee Valley Divide
Rue Anemone ( Thalictrum thalictroides )
Photograph by Wayne Riner - © All Rights Reserved.

Rue Anemone is a delicate looking but hardy little ephemeral wildflower decorating mountain woodlands along with a
vast array of other beauties upon the forest floor.


Climate Statistics
For April 2014

( Lower Elevations of Russell Fork Basin )
Clintwood 1 W - Elevation 1560 feet
Average Daily MAX: 70.4 degrees
Average Daily MIN: 36.5 degrees
MEAN: 53.4 degrees
Highest Temperature: 86 degrees
Lowest Temperature: 23 degrees
Total Precipitation: 2.68"
Total Snowfall: 0.4"
March-April Precip: 6.58"
2014 Precipitation: 12.72"
( -2.49" below 1981-2010 )

( Northern Base of High Knob Massif )
City of Norton - Elevation 2141 feet
Average Daily MAX: 66.3 degrees
Average Daily MIN: 35.6 degrees
MEAN: 51.0 degrees
Highest Temperature: 81 degrees
Lowest Temperature: 19 degrees
Total Precipitation: 2.89"
Total Snowfall: 1.2"
March-April Precip: 7.02"
2014 Precipitation: 15.57"
( -4.59" below 1983-2013 )

( Along the Tennessee Valley Divide )
Nora 4 SSE - Elevation 2650 feet
Average Daily MAX: 65.9 degrees
Average Daily MIN: 44.7 degrees
MEAN: 55.3 degrees
Highest Temperature: 78 degrees
Lowest Temperature: 21 degrees
Total Precipitation: 2.13"
Total Snowfall: 1.6"
March-April Precip: 5.61"
2014 Precipitation: 11.75"

While April temperatures were above average nights were locally chilly, especially amid mountain valleys where lower-middle 30s were common.

The coldest night of April 16 featured widespread 10s
from the City of Norton across the High Knob Massif.

Across The USA In April 2014
850 MB Air Temp Composite Anomalies

Anomalously weak SE air flow during April was a factor in below average precipitation along most of the Appalachians, especially the western side of the mountain chain where stronger SSW flow is climatologically favored.

April 2014
850 MB Vector Wind Composite Anomaly

 ( Mean During 1981-2010 Period )
850 MB Vector Wind Climatology


( Updated April 30, 2014 )
Monthly Precipitation Totals
Big Cherry Dam of High Knob Massif
Observer: Gary Hampton & Staff of Big Stone Gap WP
Elevation 3120 feet

2013
November: 5.04"

December: 8.38"

2014
January: 4.68"

February: 6.16"

March: 5.35"

April: 3.54"

2014 Total: 19.73" ( M )*
 ( January 1 to April 30, 2014 )

-4.77" below the January-April average
observed during the 2008-2013 period

Orographic Forcing Season
November-April: 33.15"
( -4.04" below 2008-2013 period )

Mean Per Month: 5.52"
( November 2013 - April 2014 )

16 Month Total: 94.11" ( M )**
 ( Since January 1, 2013 )

Mean Per Month: 5.88"
( January 2013 - April 2014 )

  *The NWS rain gauge busted due to extreme coldness in January with the late January-February total being partially based upon an automated IFLOWS rain gauge at the Dam ( with missing data ).

  **Actual total is estimated to be around 99.00" with missing moisture in snow too deep for the rain gauge to physically contain and between hand-measurements at the Dam throughout the year ( averaging 1 measurement per week ).

May 5, 2014
Wild Geranium ( Geranium maculatum )
Photograph by Wayne Riner - © All Rights Reserved.


On The Cusp Of Drought
Abnormal Dryness Along Mountains

USA Drought Monitor

Upper Tennessee River Basin
Abnormal Dryness - Far Southwestern Virginia

The long-term forecast suggests a transition 
into +ENSO ( commonly called El Nino ) 
during coming weeks and months.

El Nino WATCH Declared
NOAA-CPC ENSO Advisory - 8 May 2014

There have been 11 years since 1950 featuring a transition from neutral or weak La Nina conditions into El Nino amid the critical equatorial Pacific Ocean sector watched for main ENSO forcing.

+ENSO or El Nino In RED
-ENSO or La Nina In BLUE
Neutral Seasons In WHITE
ONI Index - CPC Climate Monitoring

The 11 years of interest
include the following:

1951
1957
1963
1965
1972
1982
1986
1997
2002
2006
2009

While recent great drought years such as 1988, 1999, and 2007 featured the opposite signal, with a transition from El Nino into
La Nina during or before the year of drought, it is worth looking
back at these 11 years to check for any obvious trends.

Northern Hemisphere
Sea Level Composite Anomalies
Neutral-La Nina To El Nino Years

There is correlation seen, when comparing this composite of 11 years featuring a shift from neutral or La Nina into El Nino amid the equatorial Pacific Ocean, with the pattern observed since October.

Northern Hemisphere
Sea Level Composite Anomalies
October 1, 2013 to May 15, 2014

This indicates that a look back at these 11 years, using local data points, can be useful.

Tri-Cities ( TRI )
Annual Precipitation Totals

1951: 48.29"
1957: 51.18"
1963: 38.58"
1965: 37.26"
1972: 51.17"
1982: 51.78"
1986: 33.49"
1997: 41.49"
2002: 40.25"
2006: 40.64"
2009: 48.66"

Period MEAN: 43.89"
( +2.88" above 41.01" average )

While this period of 11 different years featuring a transition from neutral-weak La Nina conditions into El Nino amid the equatorial Pacific Ocean sector was collectively wetter than average at TRI, 
it displayed marked diversity from -7.82" below average to +10.77" above average.

Burkes Garden
Annual Precipitation Totals

1951: 43.45"
1957: 54.12"
1963: 34.46"
1965: 39.02"
1972: 63.02"
1982: 49.55"
1986: 44.57"
1997: 33.20"
2002: 49.53"
2006: 48.33"
2009: 54.68"

Period MEAN: 46.72"
( +1.45" above 45.27" average )

While these years were again somewhat wetter than average as a whole, large diversity prevailed from -12.07" below average to +17.75" above average in Burkes Garden.

Most interesting, it should be noted that the 63.02" observed
in 1972 is the all-time wettest year on record during the entire
1896-2013 data period in Burkes Garden.

Clintwood
Annual Precipitation Totals

1965: 36.95"
1972: 50.08"
1982: 51.81"
1986: 43.51"
1997: 38.82"
2002: 47.80"
2006: 44.23"
2009: 55.69"

Period MEAN: 46.11"
( -0.01" below 46.12" average )

With only 8 of the 11 years having available data 
in Clintwood the composite average was nearly identical to that of the past 50 years; however, variations from -9.17" below to +9.57" above average were observed.

City of Norton
Annual Precipitation Totals

1986: 49.10"
1997: 52.54"
2002: 60.02"
2006: 57.21"
2009: 69.15"

Period MEAN: 57.60"
**( -0.44" below 1983-2013 period )

Only 5 of these 11 years have available data for the City of Norton, but variations from -9.37" below to +10.68" above the 1999-2013 period ( featuring no missing data ) were observed.

**Missing data during the 1983-1998 period in snowfall.
Annual mean of 58.47", with no missing NWS data,
is more representative during the 1999-2013 period.

The bottom line from the above four points, there is a tendency for average to slightly above average precipitation in the composite of all years featuring a neutral-La Nina to El Nino transition; however, the signal from ENSO alone is weak with variations from drought to wetness having been observed.

Many factors working together forced the variations observed during these 11 years, not just the change in ENSO phases.


Dry Start To 2014
Sets Climatological Benchmark

With 50 years of data records in Clintwood the 12.72" measured during January-April marks the 10th driest start to any year on record during 
1964-2013.  This means that Mother Nature has a steep hill to climb in order to prevent 2014 from having below average precipitation for the year 
( 50-year annual average of 46.12" in Clintwood ).

Clintwood NWS Cooperative Station
Driest Starts / Departure For Year

Rank Of Year
January-April Total ( Departure For Year )

1.  1988
9.08" ( -11.76" )

2.  1983
10.11" ( -10.20" )

3.  1968
10.41" ( -10.47" )

*4.  1986
10.47" ( -2.61" )

5.  1985
10.50" (-10.43" )

6.  1992
11.53" ( -4.67" )

7.  1976
11.82" ( -2.87" )

8.  1969
12.06" ( -8.45" )

9.  2001
 12.14" ( +0.84" )

10.  2014
12.72" 
( Yet to Be Determined )

11.  1981
12.73" ( -8.52" ) 

Average Departure For Year With As Dry As,
Or Drier, Start To Year Than January-April 2014
-6.91"

*The only year to be one of the 11 years featured previously with a transition from neutral or La Nina into El Nino conditions amid the equatorial Pacific Ocean sector ( when not including 2014 ).

Out of 11 past years with a January-April as dry 
as or drier than this year, 9 out of 10 featured significantly below average precipitation for the entire year in Clintwood ( 2014 to be determined ).

In fact, the average annual departure was 
-6.91" below the 50-year average of 46.12" . 

These statistics set a steep hill or formidable climatological benchmark for Mother Nature to climb in order for 2014 to NOT end up with below average precipitation in Clintwood. 

With the above noted, of course, its understood that any given system could work to turn this trend around with heavy rainfall, even flooding, but these statistics remain impressive against a 50-year data period and can not be ignored.

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