Monthly Long Range Weather Commentary Issued: APRIL 1, 2015 Steven A. Root, CCM, President/CEO sroot@weatherbank.com FEBRUARY 2015 Climate Highlights The Month in Review The February contiguous U.S. temperature was 33.1 F, 0.7 F below the 20th century average, ranking near the median value in the 121-year period of record. The average February maximum (daytime) temperature for the contiguous U.S. was 44.6 F, 0.2 F below average, while the average minimum (nighttime) temperature was 21.7 F, 1.2 F below average. The western U.S. was warmer than average, where eight states had a top 10 warm February. Arizona, California, Utah, and Washington each had their warmest February on record. Locations from the Mississippi River to the East Coast were colder than average, where 23 states had a top ten coldest February. Nine states had their second coldest February, while no state was record cold. However, several cities in the Northeast had their coldest month of any month on record including Buffalo, New York where the monthly average temperature was 10.9 F, dipping below the 11.6 F observed in February 1934. Several additional cities, including Chicago, Illinois and Cleveland, Ohio observed their coldest February on record. During February, there were 5,448 warm daily temperature records (2,866 daily warm maximum temperature records and 2,582 daily warm minimum temperature records) broken or tied while there were 8,281 cold daily temperature
records (4,778 daily cold maximum temperature records and 3,503 daily cold minimum temperature records) broken or tied. The February Lower 48 precipitation total was 1.70 inches, 0.43 inch below average, and marked the 20th driest February on record and the driest since 2009. Most locations across the contiguous U.S. had near to below-average monthly precipitation, with the exception of Colorado which was wetter than average. No state had February precipitation totals that ranked among the 10 wettest or driest on record. At the local scale, several cities across the Intermountain West observed high precipitation totals. In Colorado, Boulder experienced its wettest and snowiest February in a 123-year period of record. Boulder received 3.69 inches of precipitation, 450 percent of normal, and 54.8 inches of snow, 22.7 inches greater than the previous record set in 2012. In Wyoming, Riverton, observed its wettest February on record with a total 1.28 inches of precipitation, 388 percent of normal. This February was also the second snowiest at Riverton with 17.8 inches of snowfall. According to analysis of NOAA data by the Rutgers Global Snow Lab, the February contiguous U.S. snow cover extent was 1.3 million square miles, 91,000 square miles above the 1981-2010 average. This marked the 20th largest February snow cover extent in the 49-year period of record. Below-average snow cover and snowpack was observed across much of the West, while above-average snow cover was observed in the East. The Northeast was particularly snowy, where Boston, Massachusetts had its snowiest month of any month since records began there in 1872 with 64.8 inches of snow, besting the previous record of 43.3 inches set in January 2005. According to the March 3rd U.S. Drought Monitor report, 31.9 percent of the contiguous U.S. was in drought, up from 28.4 percent at the beginning of February. Drought conditions worsened across parts of the Central Rockies, Southern Plains, and central Gulf Coast. Drought conditions improved in parts of the West, Southern Rockies, Midwest, and Ohio Valley. Abnormally dry conditions developed across central parts of Alaska. Based on NOAA's Residential Energy Demand Temperature Index (REDTI), the contiguous U.S. temperature-related energy demand during February was 65 percent above average and the 10th highest in the 1895-2015 period of record. The record and near-record cold in the densely populated Northeast and Midwest contributed to the high REDTI for February.
Climate Highlights Winter to Date December 2014 February 2015 The winter contiguous U.S. temperature was 34.3 F, 2.1 F above the 20th century average, the 19th warmest winter on record. The first half of the winter season was very warm, with the December-January 2-month temperature being the fifth highest on record. The frigid February in the eastern U.S. lowered the overall winter temperature for the contiguous United States. The average winter maximum temperature (daytime) was 44.4 F, 1.7 F above the 20th century average, the 20th warmest on record. The average winter minimum temperature (nighttime) was 24.3 F, 2.5 F above the 20th century average, the 15th warmest on record. Arizona, California, Nevada, Utah, and Washington each had their warmest winter on record. In California, the winter temperature bested the previous seasonal record that occurred just last year by 1.5 F. An additional five states, including Alaska, from the Rockies to West Coast, had one of their 10 warmest winters on record. Below-average winter temperatures, driven in large part by a frigid February, were observed from the Mississippi River to the East Coast. Due to a mild first half of winter, no state had winter temperatures that ranked among their 10 coldest on record. The winter contiguous U.S. precipitation total was 6.12 inches, 0.67 inch below average, and the 27th driest on record. Below-average winter precipitation was observed across parts of the Great Basin, Upper Midwest, Mid-South, Great Lakes, and Mid-Atlantic. Above-average precipitation was observed in the Southern Rockies. No state had winter precipitation totals that ranked among their 10 driest or wettest on record. For the winter season (December 2014-February 2015), the contiguous U.S. snow cover extent was 62,000 square miles below the 1981-2010 average. This was the 23rd largest (27th smallest) winter snow cover extent for the contiguous U.S. and the smallest since the winter of 2011/12.
The U.S. Climate Extremes Index (USCEI) for winter was 15 percent above average, ranking as the 30th largest winter USCEI on record. On the national scale, the components that examine extremes in warm daily maximum and minimum temperatures and 1-day precipitation totals were much above average. Regionally, the CEI was record high for the West climate region due to extremes in warm maximum and minimum temperatures, the spatial extent of drought, and 1-day precipitation totals. The Northwest climate region had its fourth most extreme winter due to warm maximum and minimum temperatures and 1-day precipitation totals. The USCEI is an index that tracks extremes (falling in the upper or lower 10 percent of the record) in temperature, precipitation, and drought across the contiguous U.S. The REDTI for the winter season was 8 percent below average and the 51st lowest in the 120-year period of record. Climate Highlights Soil Moisture Conditions
Climate Highlights Severe Weather Analytics All Event Distribution February Tornado Event Distribution February
Wind Event Distribution February Hail Event Distribution - January
LONG RANGE TREND MAPPING Rendered MARCH 24, 2015 The current pattern reviewed was FEB 1 st MAR 12 th resulting in these two observations: Looking back at the past 30, 60, 90 and 120-days, we have:
REVIEW of S ROOT s LATE JAN. 2015 ANALOG SELECTION: 1958, 1963, 1967, 1970, 1980 and 1995: I was very pleased with the outcome of this prior selection; especially 1963 and 1995 and while as an aggregated SUM, the eastern USA did quite well, as did the west (albeit not quite warm enough). REVIEW of SOURCE-2 (PP) ANALOGS as of 03/15: 1963, 1970, 1977, 1980, 2003 and 2005:
Many of these analogs had great promise S ROOT NEW ANALOGS for CONSIDERATION, USING 02/01/15 03/12/15:
Next, I sought insight into the current weather pattern which was gained by using Balance of the Month (MAR 2015; as of 03/22/15, part observed, part forecasted), and comparing current pattern to the same period of these trend years:
Lastly, testing various ideas, such as using all of these years into an Equally Weighted of All Years and multiple combinations of weighted years, I found this set best:
While no combination could adequately WARM the northern Rockies, I default to this final analog mapping: 1972 X 5.. 2003.. 2005 X 4.. 2007.. 2014 X 3.. 2000 36% 7% 29% 7% 21% 0% Applying these years as inputs resulted in this new trend, which I installed into the system today (02/08/15); as a means to check run to run consistency, that is, this new trend to that currently in the systems, here are both (new trend on the left, current trend in the system on the right):
S ROOT REVIEW OF FINAL ANALOG MAPPING (next six months): TEMPERATURES ---------- CALIBRATION MONTH: MARCH 2015 ---------- PRECIPITATION
TEMPERATURES ---------- APRIL 2015 ---------- PRECIPITATION TEMPERATURES ---------- MAY 2015 ---------- PRECIPITATION
TEMPERATURES ---------- JUNE 2015 ---------- PRECIPITATION TEMPERATURES ---------- JULY 2015 ---------- PRECIPITATION
TEMPERATURES ---------- AUGUST 2015 ---------- PRECIPITATION TEMPERATURES ---------- SEPTEMBER 2015 ---------- PRECIPITATION
EUROPEAN MODEL OUTPUTS: APR, MAY, JUN MAY, JUN, JUL JUN, JUL, AUG
JUL, AUG, SEP NOAA CFS V2 MODEL OUTPUTS - TEMPERATURE and PRECIPITATION:
NOAA OFFICIAL SEASONAL FORECASTS - TEMPERATURE and PRECIPITATION:
Long Range Forecast 2014-2015 Winter Forecast Monthly HDDs for WINTER 2014-2015 (out of 65 past winters from 1950, GCS = Gas Consuming States): Forecast Made September 22, 2014: o Winter 2014-2015 Full USA: 260,404 HDDs; 24 th Coldest; o Winter 2014-2015 GCS: 75,368 HDDs; 31 st Coldest; Forecast Made October 23, 2014: o Winter 2014-2015 Full USA: 244,870 HDDs; 52 nd Coldest; o Winter 2014-2015 GCS: 70,973 HDDs; 52 nd Coldest; Forecast Made November 27, 2014: o Winter 2014-2015 Full USA: 252,342 HDDs; 42 nd Coldest; o Winter 2014-2015 GCS: 75,251 HDDs; 32 nd Coldest; Forecast Made December 26, 2014: o Winter 2014-2015 Full USA: 249,582 HDDs; 43 rd Coldest; o Winter 2014-2015 GCS: 73,446 HDDs; 40th Coldest; Forecast Made January 16, 2015: o Winter 2014-2015 Full USA: 248,633 HDDs; 44 th Coldest; o Winter 2014-2015 GCS: 74,819 HDDs; 35 th Coldest; Forecast Made February 15, 2015: o Winter 2014-2015 Full USA: 245,913 HDDs; 50 th Coldest; o Winter 2014-2015 GCS: 75,192 HDDs; 32 nd Coldest; Forecast Made March 22, 2015: o Winter 2014-2015 Full USA: 243,626 HDDs; 53 rd Coldest; o Winter 2014-2015 GCS: 76,714 HDDs; 27 th Coldest; Winter 2013-2014: Winter 2012-2013: Winter 2011-2012: Winter 2010-2011: Winter 2009-2010: Winter 2008-2009: Past 5-Winter Average: Past 10-Winter Average: 270,535 HDDs; 6 th Coldest; 246,823 HDDs; 45 th Coldest; 246,823 HDDs; 45 th Coldest; 246,823 HDDs; 45 th Coldest; 246,823 HDDs; 45 th Coldest; 246,823 HDDs; 45 th Coldest; 245,633 HDDs 245,374 HDDs COLDEST WINTER since 1950-51: 1978-1979; 281,794 HDDs WARMEST WINTER since 1950-51: 2011-2012; 217,316 HDDs