Monthly Long Range Weather Commentary Issued: July 18, 2014 Steven A. Root, CCM, President/CEO sroot@weatherbank.com JUNE 2014 REVIEW Climate Highlights The Month in Review The average temperature for the contiguous U.S. during June was 69.6 F, 1.1 ABOVE NORMAL, ranking as the 33rd warmest June in the 120-year period of record. The average maximum (daytime) June temperature for the contiguous U.S. was 81.8 F, 0.4 F ABOVE NORMAL, while the average minimum (nighttime) June temperature was 57.4 F, 1.7 F ABOVE NORMAL, tying as the 10th warmest June minimum temperature. ABOVE NORMAL June temperatures were observed along the East Coast and into the Midwest. The Southwest was also warmer than average, where AZ and CA both had their 11th warmest June on record. No state had a top 10 warm June. Near-average June temperatures were observed from the central Gulf Coast, through the Central Plains, and into the Northwest. BELOW NORMAL temperatures were observed in the Northern Rockies and parts of the Northern Plains. No state had a top 10 cool June.
Interestingly, in much of the Lower Mississippi Valley and mid-south, afternoon temperatures were below normal, while nighttime temperatures were much above normal. This likely reflects a relatively wet and cloudy summer month acting to moderate both afternoon and overnight temperatures. The June national precipitation total was 3.62 inches, 0.69 inch ABOVE NORMAL, marking the sixth wettest June on record, and the wettest since 1989. A significant portion of the contiguous U.S. parts of the Northeast, Southeast, Midwest, and the Great Plains had ABOVE NORMAL precipitation during June. Eight states had one of their 10 wettest Junes on record, with MN being record wet for the month. The 7.75 inches of precipitation averaged across Minnesota was 3.64 inches ABOVE NORMAL, marking the wettest month of any month for the state, surpassing July 1897 and June 1914 when 7.32 inches of precipitation was observed. In Canton, South Dakota, 19.65 inches of precipitation fell during June, setting a new record among all months for any location in the state, according to the South Dakota State Climatologist. BELOW NORMAL June precipitation was observed in the Southwest, across parts of the coastal Southeast, and southern New England. AZ tied its third driest June on record, with 0.01 inch of precipitation, 0.28 inch BELOW NORMAL; only June 1916 and 1951 were drier. AK was much wetter than average during June with a statewide precipitation total 53% above the 1971-2000 average, the second wettest June for the state. The wettest June occurred in 1980 when the monthly precipitation was 74 percent above average. Juneau and Fairbanks each had their wettest June on record, while Anchorage had its second wettest. According to the July 1 U.S. Drought Monitor report, 34.0 percent of the contiguous U.S. was in drought, down about 3.3 percent compared to the beginning of June. Beneficial rain improved drought conditions by one to three categories across parts of the Midwest and the Central and Southern Plains. NE, which had its fourth wettest June, saw dramatic drought improvement. Warm and dry conditions in parts of the West led to scattered locations experiencing worsening drought conditions. In CA, the percent area of the state experiencing exceptional drought, the worst category, expanded to 36.5 percent, up over 11 percent since early June. In the East, abnormally dry conditions expanded in the Tennessee River Valley and southern New England. Based on NOAA's Residential Energy Demand Temperature Index (REDTI), the contiguous U.S. temperature-related energy demand during June was 33 percent above average and the 25th highest in the 1895-2014 period of record. There were more record cool high temperature records (676) than record warm high temperature records (391), but warm nighttime temperatures dominated with more record warm low temperatures (1257) than record cold low temperatures (344). When aggregated together, there were more than one and a half times as many record warm daily highs and lows (1648) as record cold daily highs and lows (1020). Climate Highlights Year to Date (Jan June) The contiguous U.S. average temperature for the first half of 2014 was 47.6 F, 0.1 F ABOVE NORMAL. This ranked near the middle value in the 120-year period of record, and marked the coldest first half of any year since 1993. The average maximum (daytime) year-to-date temperature for the contiguous U.S. was 59.8 F, 0.4 F ABOVE NORMAL, while the average minimum (nighttime) January-June temperature was 35.4 F, 0.3 F BELOW NORMAL.
During the January-June period, above-average temperatures dominated from the Rockies, westward. AZ, NV, OR, and UT each had one of their 10 warmest starts to the year, while CA was record warm. The CA statewide average temperature was 58.0 F, 4.8 F ABOVE NORMAL, surpassing the previous record warm January-June that occurred in 1934 by 1.1 F. For CA, all six months so far in 2014 have been above-average, with five falling in the "much above average" or top ten percent. BELOW NORMAL temperatures were widespread east of the Rockies. Two regions, the western Great Lakes and the southern Mississippi River Valley, had much-below-average temperatures during the six-month period. AR, IL, IN, LA, MI, MS, and WI each had a top 10 cold January-June. No state had six-month temperatures that were record cold. The national precipitation total for the January-June period was 15.29 inches, 0.02 inch BELOW NORMAL. ABOVE NORMAL precipitation was observed across the Northern tier and parts of the Southeast. MN had its second wettest six-month period, with 17.49 inches of precipitation, 5.46 inches ABOVE NORMAL, behind only 1896. WI had its sixth wettest start to the year. BELOW NORMAL precipitation stretched from the Southwest into the Southern Plains. AZ had its third driest six-month period, with 1.42 inches of precipitation, 3.19 inches BELOW NORMAL. The city of Wichita Falls, Texas, experienced its driest 45 consecutive months ending in June 2014. The U.S. Climate Extremes Index (USCEI) for January-June was above average. On the national-scale, the spatial extent of one-day precipitation extremes ranked as the third highest value on record at 80 percent above average. On the regional scale, the West had its highest value on record, driven largely by warm daytime and nighttime temperatures and the spatial extent of drought. The Upper Midwest had its second highest value on record, driven largely by cold daytime and nighttime temperatures, high one-day precipitation totals, and high number of days with precipitation. The USCEI is an index that tracks extremes (falling in the upper or lower 10 percent of the record) in temperature, precipitation, drought, and land-falling tropical cyclones across the contiguous United States. Based on REDTI, the contiguous U.S. temperature-related energy demand during January-June was 25 percent above average and the 24th highest in the 1895-2014 period of record.
Climate Highlights Soil Moisture Conditions
Climate Highlights Severe Weather Analytics All Event Distribution June
Tornado Event Distribution June Wind Event Distribution - June
Hail Event Distribution - June
LONG RANGE TREND MAPPING Rendered JULY 1, 2014 Trend Adjustments Made by S.A. Root --- JULY 1, 2014 The current pattern reviewed was MAY 15 TH JUN 29 TH resulting in these two observations: looking back at the past 30, 60, 90 and 120-days, we have:
REVIEW of S ROOT s JUNE 01 ANALOG SELECTION: 54, 58, 69, 92, 04, and 2009
These previous trend selections were carrying too much cold across central and eastern Canada, and I consider all of these significant off-trend 1954 and 2009 may potentially, still be used. REVIEW of AW s updated ANALOGS: 51, 86, 94, 02, 06 and 2009 these selections were better; 1986 and 2006 are still good candidates, and well in-trend as is 1994. S ROOT NEW ANALOGS for CONSIDERATION
I think 2012 and 2013 are strong candidates, because of the warmth across Canada and 2001 has warmth out west, a good input. As a further test, and to gain insight, the AVERAGE DFN from NORMAL DAILY TEMPS for all 59 regional hub cities were gathered, then averaged across May 15 th June 29 th for every year, 1950 through 2013 correlation coefficients were calculated comparing each year to 2014; typically during fall, winter and spring, I see CC values from 65% to 90%, and thus gain good insight; during summer, this is usually not the case, and this effort was no different the highest CC values ranged from 25% to 40%, and thus were of little support. In order to gain additional insight on how the current DROUGHT may aid in analog selection I reviewed the SOIL MOISTURE DFN s for all analogs under review:
It appears that the analog years of 1951, 1954, 1986, 2001, 2006 and 2013 have the best/cloeset-tocurrent SOIL MOISTURE and temperature mappings S ROOT REVIEW OF ALL TREND YEARS (above) 1 st PASS and MAPPED to 30-DAY T & SOIL MOISTURE DFN:
S ROOT ANALOG SELECTIONS ALL POSSIBLE + CALIBRATIONS It appears that the analog years of 1951, 1954, 1986, 2001, 2006 and 2013 have the best/cloeset-tocurrent SOIL MOISTURE and TEMP mappings so I render these projectsion based upon: 1951, 1954, 1986, 2001, 2006 and 2013 all equally weighted (16.67%) Here are the TEMP trend mappings (analog forecasts):
JULY 2014 AUGUST 2014 SEP 2014 OCT 2014 NOV 2014 DEC 2014 So, these inputs were installed by S ROOT on July 3, 2014: 1951, 1954, 1986, 2001, 2006 and 2013 all @ 16.67%
ECMWF ENSEMBLE MEANS MODEL OUTPUTS TEMPERATURES and PRECIPITATION:
CPC SEASONAL TEMP OUTLOOKS
CPC SEASONAL PRECIP OUTLOOKS
Here is the NOAA CFS v2 Seasonal TEMP Outlook:
Here is the NOAA CFS v2 Seasonal PRECIP Outlook:
WeatherBank s 2014 Summer Forecast Monthly CDDs for SUMMER 2014 (out of 64 past summer s from 1950-2013, GCS = Gas Consuming States): Forecast Made June 6, 2014: o Summer 2014 Full USA: 54,019 CDDs; 22 nd Warmest; o Summer 2014 GCS: 25,530 CDDs; 16 th Warmest; Forecast Made July 21, 2014: o Summer 2014 Full USA: 54,019 CDDs; 22 nd Warmest; o Summer 2014 GCS: 24,555 CDDs; 28 th Warmest; Summer 2013: Summer 2012: Summer 2011: Summer 2010: Summer 2009: Summer 2008: Summer 2007: 5-Year Summer Average: 10-Year Summer Average: HOTTEST SUMMER since 1950: COLDEST SUMMER since 1950: 58,245 CDDs; #8 Hottest 62,987 CDDs; #1 Hottest 60,402 CDDs; #2 Hottest 58,908 CDDs; #5 Hottest 50,054 CDDs; #41 Hottest 53,932 CDDs; #231 Hottest 58,404 CDDs; #7 Hottest 58,119 CDDs 56,801 CDDs 2012, 62,987 CDDs 1965, 43,3329 CDDs Background Methodology for the WeatherBank LROM Using observed calendar day MAX and MIN temperatures at major cities across North America, WeatherBank generates daily Heating Degree Days (HDDs) and Daily Cooling Degree Days (CDDs). By comparing observations of HDDs in winter and CDDs during summer, one may obtain a real-time description of how warm or cold the current season is. Basically, the hotter a location is in summer, or colder in winter, the more degree days that location earns. By adding all degree days from all locations, one can obtain a relative description of the current season. By comparing the current season to the degree days totals for past seasons, one obtains a ranking of the current season. WeatherBank's Long Range Outlook Model (LROM) fundamentally assumes that future weather patterns will be similar to a highly correlating, past weather pattern that was determine by trend composite. All similar weather trends of the past are compared to the current weather trend, then analyzed using a variety of tests. Global inputs such as MEI, average upper level flow patterns, etc., are also used. Correlation coefficients for each input years are generated, and used to define the relative strength of each year and how that trend could be used in the forecast process. Since mid- August 2007, strong correlations have remained between the equally weighted (same calendar 13-week period called current, to the same 13-week period of all past years; no lag applied) time-periods of the past.