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Climate Indices Related to the Central and Southern Appalachian Mountains: A Correlational Study

Climate Indices Related to the Central and Southern Appalachian Mountains: A Correlational Study. April 23, 2010 Gary Votaw (SOO, JKL). Indices that correlate to snowfall in the southern Appalachians. PDO INDEX

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Climate Indices Related to the Central and Southern Appalachian Mountains: A Correlational Study

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  1. Climate Indices Related to the Central and Southern Appalachian Mountains: A Correlational Study April 23, 2010 Gary Votaw (SOO, JKL)

  2. Indices that correlate to snowfallin the southern Appalachians PDO INDEX Updated standardized values for the PDO index, derived as the leading PC (principal component) of monthly SST anomalies in the North Pacific Ocean, poleward of 20N. The monthly mean global average SST anomalies are removed to separate this pattern of variability from any "global warming" signal that may be present in the data. http://jisao.washington.edu/pdo/PDO.latest AO/AAO The loading pattern of AO (AAO) is defined as the first leading mode from the Emperical Orthogonal Function (EOF) analysis of monthly mean height anomalies at 1000-hPa (NH) or 700-hPa (SH). Note that year-round monthly mean anomaly data has been used to obtain the loading patterns. http://www.esrl.noaa.gov/psd/data/climateindices/list/#AO To identify the leading teleconnection patterns in the atmospheric circulation, the EOF was applied to the monthly mean 1000-hPa (700-hPa) height anomalies poleward of 20° latitude for the Northern (Southern) Hemisphere. http://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/history/method.shtml

  3. Indices that correlate to snowfallin the southern Appalachians NAO Strong positive phases of the NAO tend to be associated with above-average temperatures in the eastern United States and across northern Europe and below-average temperatures in Greenland and oftentimes across southern Europe and the Middle East. They are also associated with above-average precipitation over northern Europe and Scandinavia in winter, and below-average precipitation over southern and central Europe. Opposite patterns of temperature and precipitation anomalies are typically observed during strong negative phases of the NAO. During particularly prolonged periods dominated by one particular phase of the NAO, anomalous height and temperature patterns are also often seen extending well into central Russia and north-central Siberia.  http://www.cpc.ncep.noaa.gov/data/teledoc/nao.shtml At low levels, a positive NAO brings enhanced southerlies across the midwestern and eastern United States as a result of a strengthened Azores high, while in the mid- to upper troposphere, positive height anomalies in the east contribute to mostly zonal flow. Variations in the NAO index reflect changes in the meridional pressure gradient across the North Atlantic and changes in the strength and location of the upper-level jet stream(Notaro, Wang & Gong, 2006). These indices combine to suggest that if the NH subtropical jet stream is strong, NAO is in a positive mode (cold for eastern CONUS), and the PDO is positive (warm Pacific water west of CONUS) then a high seasonal snowfall may be forecast.

  4. “Namias (1960) demonstrated that heavy snow years over the eastern United States are associated with an enhanced eastern U.S. trough, with the large-scale situation similar to what is now termed the Pacific–North American (PNA) teleconnection pattern” (Serreze et al. (1998). Serreze et al. also found that a “positive PNA pattern, with an enhanced midtropospheric trough in the eastern United States supported greater snowfall in the Midwest, mid-Atlantic, and Southeast “(Notaro, Wang & Gong, 2006). In that study correlations with the PNA index, which were significant at p < 0.01 for 15 states, reached r ≥ 0.6 for the more southern states of West Virginia, Virginia, Kentucky, Ohio, and Delaware. Correlations between the NAO index and state-average temperatures were significant (p < 0.05) for all 16 states, with the highest correlations, r ≥ 0.5, in the lower Northeast states of Rhode Island, Massachusetts, and Connecticut (Notaro, Wang & Gong, 2006). On PNA and NAO

  5. Serreze et al. (1998) studied principal components representing PNA, TNH, and EP (EPO). With PNA as the principal component (below), the best correlation with snowfall was found across Tennessee & North Carolina. A negative PNA implies a high snowfall anomaly for the circled locations. TNH and EP did not correlate well with eastern locations. Serreze et al. (1998) Nov. – Dec.

  6. PNA Jan. – Feb. Serreze et al. (1998) PNA Mar. – Apr.

  7. Climate Indices: Monthly Atmospheric and Ocean Time Serieshttp://www.esrl.noaa.gov/psd/data/climateindices/list(best correlators in red) SOI Pacific Warm Pool Atlantic Tripole SST EOF PNA Tropical Pacific SST AMO NAO EOFAMM Jones NAO TNA ACE EPO (EP/NP)TSA Solar Cycle TNH WHWP Central India Monsoon ONI WP Precipitation NTA QBO Sahel Precipitation CARPDOBrazil Rainfall MEI PMM SW USA Monsoon BESTNPGlobal Mean Temperature NINO 3 NOI ESPI NINO 1+2AOGlobally Integrated NINO 3+4AAOAngular Momentum NINO 4 TNI(GIAM)

  8. Stations Included in Analysis Jackson, MS Mt. LeConte, TN Monticello 3NE, KY Mobile, AL Mt. Mitchell, NC Jackson, KY Montgomery, AL Grandfather Mt., NC Lexington, KY Birmingham, AL Asheville, NC Bluefield, WV Tallahassee, FL Charlotte, NC Beckley, WV Columbus, GA Raleigh-Durham, NC Princeton, WV Atlanta, GA Wilmington, NC Charleston, WV Augusta, GA Nashville, TN Elkins, WV Savannah, GA Knoxville McGhee-Tyson, TN Bayard, WV Charleston, SC Tri-Cities, TN Washington DC Columbia, SC Wise, VA (National Arpt) Greensboro, SC Roanoke, VA Frostburg, MD Chattanooga, TN Louisa, VA Columbus, OH Swannanoa 2SSE, NC Trout Dale 3SSE, VA Pittsburgh, PA Blowing Rock, NC Burkes Garden, VA State College, PA Sparta 2SE, NC Millgap 2NNW, VA Williamsport, PA Jefferson 2E, NC Norfolk, VA Philadelphia, PA

  9. Stations in Mississippi, Alabama, Georgia,South Carolina, plus Chattanooga, TN AAO PDO AO NP NAO GIAM EPO AMO Jackson, MS -0.19 0.17 -0.29 0.04 -0.20 0.09 -0.09 0.18 Mobile, AL -0.47 0.08 0.40 0.10 0.09 0.31 -0.06 -0.27 Montgomery, AL -0.49 0.27 0.45 0.04 0.01 0.15 -0.05 -0.27 Birmingham, AL -0.54 0.20 0.31 0.16 0.03 0.24 -0.24 -0.08 Tallahassee, FL -0.04 -0.10 0.14 0.16 0.13 0.06 -0.20 -0.22 Columbus, GA -0.38 0.06 0.07 0.15 0.03 0.39 -0.03 -0.23 Atlanta, GA -0.52 0.21 -0.11 0.23 0.04 0.61 0.06 -0.17 Augusta, GA 0.12 -0.01 0.00 0.27 -0.06 0.02 -0.09 -0.18 Savannah, GA -0.02 0.03 0.21 0.08 0.10 -0.02 -0.22 -0.39 Chattanooga, TN -0.62 0.15 0.10 0.37 -0.25 0.24 -0.15 -0.03 Greensboro, SC (GSP) -0.46 -0.08 -0.20 0.23 -0.18 0.48 0.20 -0.14 Columbia, SC -0.01 0.07 -0.03 0.34 -0.13 0.05 0.04 -0.12 Charleston, SC 0.00 -0.01 0.03 0.14 0.07 0.05 -0.08 -0.29

  10. AAO PDO AO NP NAO GIAM EPO AMOBlowing Rock, NC -0.64 0.11 0.11 0.15 -0.27 0.41 -0.10 -0.17 Sparta 2SE, NC -0.42 0.10 -0.19 0.22 -0.36 0.25 -0.02 -0.04 Jefferson 2E, NC -0.24 -0.07 -0.26 0.13 -0.29 0.65 0.00 0.01 Mt. Mitchell, NC -0.33 0.40 -0.45 0.00 -0.13 0.26 0.25 -0.09 Grandfather Mtn. -0.20 0.30 -0.42 -0.15 0.02 0.19 0.19 0.08 Asheville, NC -0.51 -0.08 -0.30 0.22 -0.30 0.35 0.04 -0.05 Charlotte, NC -0.24 -0.01 -0.320.38 -0.25 0.28 0.10 -0.06 Raleigh-Durham, NC 0.04 0.00 -0.11 0.38-0.26 -0.01 0.09 -0.04 Wilmington, NC -0.13 -0.17 0.16 0.24 0.10 0.18 -0.16 -0.22 Greensboro, NC -0.46 -0.08 -0.20 0.23 -0.18 0.48 0.20 -0.14 Swannanoa 2 SSE, NC -0.440.54 -0.36 -0.03 -0.14 0.11 0.12 -0.03 Wilmington, NC -0.13 -0.17 0.16 0.24 0.10 0.18 -0.16 -0.22 Norfolk, VA 0.01 0.08 -0.23 0.33 0.25 -0.17 0.05 -0.03 Roanoke, VA -0.36 0.23 -0.25 0.29 -0.40 0.13 -0.15 -0.03 Trout Dale, VA -0.35 -0.15 0.01 0.01 -0.29 0.64 -0.22 -0.08 Louisa, VA -0.34 0.21 -0.20 0.27-0.27 0.07 0.03 -0.01 Washington, DC -0.37 0.24 -0.32 -0.02 -0.25 0.30 0.19 -0.01 Philadelphia, PA -0.360.27 -0.21 0.00 -0.09 0.06 0.23 -0.07 Stations east of the Appalachian crest & north of Chattanooga, TN

  11. Stations west of the Appalachian crest & north of Chattanooga, TN AAO PDO AO NP NAO GIAM EPO AMO Nashville, TN -0.18 0.11 -0.50 0.09 -0.45 -0.16 0.02 0.29 Knoxville, TN -0.56 0.15 -0.41 0.11 -0.45 0.10 -0.03 0.04 Tri-Cities, TN -0.44 0.21 -0.30 0.19 -0.47 0.12 -0.11 0.00 Mt. LeConte TN -0.30 0.44 -0.30 -0.02 0.10 0.02 0.18 -0.02 Wise, VA -0.17 0.43-0.39 -0.02 -0.07 0.06 0.12 0.01 Burkes Garden, VA -0.31 0.43 -0.33 0.00 -0.20 0.08 0.16 -0.01 Millgap 2NNW, VA -0.330.53 -0.25 0.04 -0.04 0.13 0.24 0.04 Frostburg, MD -0.44 0.32 -0.10 0.06 -0.07 0.02 0.38 -0.32 Columbus, OH -0.08 0.30 -0.27 -0.01 -0.18 -0.31 0.34 0.14 Pittsburgh, PA -0.24 0.27 -0.09 0.06 -0.19 -0.03 0.20 0.21 Burkes Garden, VA -0.31 0.43 -0.33 0.00 -0.20 0.08 0.16 -0.01 Millgap 2 NNW, VA -0.33 0.53 -0.25 0.04 -0.04 0.13 0.24 0.04 Monticello 3NE, KY 0.03 -0.10 -0.07 -0.10 -0.15 0.03 0.11 -0.11 Jackson, KY 0.29 0.03 -0.29 -0.25 -0.10 0.04 0.21 0.00 Lexington, KY 0.33 0.23 -0.43 0.03 -0.33 0.02 0.13 0.16 Bluefield, WV -0.07 0.25 -0.24 0.08 -0.26 0.07 0.03 0.33 Beckley, WV -0.420.49 -0.40 0.07 -0.21 0.15 0.11 -0.11 Princeton, WV -0.26 0.01 -0.13 0.18 -0.14 0.16 0.04 -0.34 Charleston, WV -0.09 0.41-0.49 0.15 -0.27 -0.06 0.16 -0.11 Elkins, WV -0.340.49 -0.21 0.22 0.04 -0.07 0.07 -0.24 Bayard, WV -0.270.45 -0.20 0.01 -0.20 -0.09 0.13 0.02 State College, PA -0.23 0.26 -0.08 0.10 -0.04 -0.02 0.34 0.01 Williamsport, PA -0.20 0.23 -0.27 0.03 -0.16 -0.08 0.28 0.07

  12. Most Dominant Indices AAO–PDO-AO–NP–GIAM–NAO–EPO-AMO

  13. References Annual climate indices obtained at: http://www.esrl.noaa.gov/psd/data/climateindices/list Notaro, Wang & Gong (2006). Model and Observational Analysis of the Northeast U.S. Regional Climate and Its Relationship to the PNA and NAO Patterns during Early Winter. Monthly Weather Review, 134, 3479-3505. Serreze, Clark, McGinnis & Robinson (1998). Characteristics of Snowfall over the Eastern Half of the United States and Relationships with Principal Modes of Low-Frequency Atmospheric Variability. Journal of Climate, 11, 234-250.

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