1 Monthly Long Range Weather Commentary Issued: May 15, 2014 Steven A. Root, CCM, President/CEO APRIL 2014 REVIEW Climate Highlights The Month in Review The average temperature for the contiguous U.S. during April was 51.7 F, which was 0.7 F ABOVE NORMAL. This was the 46th warmest April in the 120-year period of record. Much of the contiguous U.S. had April temperatures NEAR NORMAL. ABOVE NORMAL temperatures were scattered along the West Coast and in the Southwest, the Southern Plains, and across parts of the Ohio Valley and the Southeast. BELOW NORMAL temperatures were observed across parts of the Upper Midwest and Northern Plains. No state had April temperatures among their 10 warmest or coolest. Alaska had the 12th warmest April of its 96-year period of record, with a temperature 3.8 F ABOVE NORMAL. This was the warmest April for Alaska since Much of the warmth was situated in western Alaska, where Nome had its fourth warmest April since local records began in The April precipitation total in Alaska was 23.3 percent BELOW NORMAL, the 23rd driest April on record. Anchorage had its fifth driest April with only nine percent of normal monthly precipitation.
2 The April contiguous U.S. precipitation total of 2.83 inches was 0.31 inch ABOVE NORMAL and the 30th wettest April on record. ABOVE NORMAL precipitation in the Upper Midwest resulted in WI having its third wettest April and MN it s eighth wettest. Heavy precipitation across the Southeast, particularly near the end of the month, caused Alabama to have its fifth wettest April, GA it s seventh wettest, and FL it s ninth wettest. On April 29th and 30th, torrential rain fell across the Southeast, Mid-Atlantic and Northeast causing significant flash flooding. The Gulf Coast of AL and the FL panhandle bore the brunt of the heavy rains. At the Pensacola Regional Airport, in Florida, the two-day precipitation total was inches, with inches of the total falling on the 29th, breaking both one-day and two-day precipitation records; local records date back to On the 29th, Mobile, Alabama received inches of rain, the third greatest calendar day rainfall total for the city since local records began in According to the 2014 National Climate Assessment released on May 6th, the amount of heavy precipitation falling in single events has increased by 27 percent across the Southeast since This event is consistent with projections of increases in the frequency and intensity of extreme precipitation events across the U.S. as the world warms. BELOW NORMAL precipitation was observed across parts of the West, the central Rockies, and the Central and Southern Plains. OK had its 12th driest April on record, with 50 percent of average precipitation. Parts of Texas were also particularly dry, where San Angelo observed just 30 percent of normal monthly precipitation. According to the April 29th U.S. Drought Monitor report, 38.4 percent of the contiguous U.S. was in drought, nearly the same as the beginning of April, with both improvement and degradation of drought conditions on regional scales. Beneficial rain improved drought conditions across the Upper Midwest and Southeast during the month, while drought conditions worsened in parts of the West and across portions of the Central and Southern Plains. Drought conditions improved in Hawaii during April due in part to heavy rainfall at the end of March and the beginning of April. Only 0.7 percent of the state was experiencing drought conditions on April 29th, down from 14.4 percent at the beginning of the month. This was the smallest drought footprint for Hawaii since April 2008, and the first time since June 2008 that no part of the state was experiencing severe drought. Most of the drought improvement occurred across the Big Island, with central Molokai still experiencing moderate drought conditions. A severe weather outbreak on April spawned at least 38 tornadoes from NE to NC, according to preliminary estimates from NOAA's Storm Prediction Center. At least 32 fatalities were blamed on the tornadoes, with AR and MS being the hardest hit. An EF-4 tornado in Pulaski and White counties in AR resulted in 15 fatalities, while an EF-4 in Winston County, MS resulted in nine fatalities. Based on NOAA's Residential Energy Demand Temperature Index (REDTI), the contiguous U.S. temperature-related energy demand during April was 28 percent below average and the 37th lowest in the period of record. During April, there were about 75 percent more cold daily temperature records (1,419 cold maximum temperature records, 1,380 cold minimum temperature records; 2,799 total) than warm daily temperature records (544 warm maximum temperature records, 1,039 warm minimum temperature records; 1,583 total). Climate Highlights Year to Date (Jan Apr) For the first four months of 2014, the contiguous U.S. temperature was 38.7 F, 0.4 F BELOW NORMAL, and was the 46th coldest January-April on record. This was the coldest four-month start to a year since Below-average temperatures were widespread across the eastern U.S. where 13 states had January-April temperatures among their 10 coldest on record. The coldest departures from average occurred across the Midwest. No state had its coldest January-April on record.
3 Warm conditions were observed across a large portion of the West. AZ and CA were both record warm, with fourmonth temperatures 4.5 F and 5.2 F ABOVE NORMAL, respectively. NV, OR and UT each had one of their five warmest January-April periods on record. The year-to-date precipitation total for the contiguous U.S. was 8.79 inches, 0.68 inch ABOVE NORMAL, and the 33rd driest January-April on record. BELOW NORMAL four-month precipitation totals were widespread across the Southwest and the Central and Southern Plains. AZ, KS, NM, OK, and TX each had January-April precipitation totals that ranked among their 10 driest on record. OK had its second driest January-April on record, with less than half of average precipitation; 1936 was the driest. The dry conditions across OK decimated much of the winter wheat crop in the state, with estimates of the lowest harvested yield since In west TX, precipitation deficits that date back to 2010 have been unprecedented in the observational record, with nearly every major reservoir in the region at less than 40 percent of capacity. The U.S. Climate Extremes Index (USCEI) for the year-to-date was the 14th highest on record for the period at 145 percent of average. Elements that contributed to the above-average USCEI included the spatial extent of cold maximum and minimum temperatures, warm maximum temperatures and the spatial extent of drought. 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. Based on REDTI, the contiguous U.S. temperature-related energy demand during January-April was 27 percent above average and the 29th highest in the period of record.
7 Climate Highlights Soil Moisture Conditions
12 Climate Highlights Severe Weather Analytics All Event Distribution April Tornado Event Distribution April
13 Wind Event Distribution - April Hail Event Distribution - April
21 LONG RANGE TREND MAPPING Rendered MAY 12, 2014 The current pattern reviewed was APR 9 TH MAY 8 TH resulting in these two observations: looking back at the past 30, 60, 90 and 120-days, we have:
22 REVIEW of S ROOT s APRIL s ANALOG SELECTION: 50, 72, 77, 87, 92, and 1998 Only 1992 was on-trend, especially across the western USA, the rest fell dramatically off-trend
23 REVIEW of 2 nd MODEL ANALOGS: 51, 86, 94, 96, 02, and 2009 I like how 1994, 1996 and 2009 had the general idea of the current pattern S ROOT NEW ANALOGS for CONSIDERATION
24 I really liked 1954, 1962, 1989, 1992, 2000, and 2002 (above) for a couple of reasons; Strong, positive (warmer than normal) DFN s across the western USA; Significant roll-back of the cold into SE Canada; In order to gain additional insight on how the current DROUGHT may aid in analog selection I reviewed the SOIL MOISTURE DFN s for the AW and my new analogs:
25 It appears that the analog years of 1951, 1954, 1996, 2000, 2002, and 2009 have the best/cloeset-tocurrent SOIL MOISTURE mappings S ROOT REVIEW OF ALL TREND YEARS (above) 1 st PASS and MAPPED to 30-DAY T & P DFN:
28 S ROOT REVIEW OF ALL TREND YEARS (above) 2 nd PASS, ATTEMPTING TO MAINTAIN HEAT OUT WEST TREND MAPPING TREND MAPPING TEMP PRECIP TEMP PRECIP 1951 FAIR GOOD 1992 GOOD POOR 1954 GOOD GOOD 1994 GOOD POOR 1962 GOOD FAIR 1996 GOOD GOOD 1966 FAIR GOOD 2000 GOOD GOOD 1986 POOR POOR 2002 FAIR GOOD 1989 GOOD FAIR 2004 GOOD POOR 1990 GOOD POOR 2009 GOOD GOOD S ROOT ANALOG SELECTIONS ALL POSSIBLE + CALIBRATIONS Applying various combinations, and 1954, 1996, 2000, 2002, 2004, and 2009 as the anchor or base years, and applying a double weight on 2000 due strong TEMP and SOIL MOISTURE comparisons, I receive this calibration for MAY 2014:
29 I like what I see, so I have elected these calibrations as final; JUNE 2014 JULY 2014 AUGUST 2014 SEPT 2014 OCT 2014 NOV 2014 So, these inputs were installed by S ROOT on May 11, 2014: %; %, %, %, %, % ECMWF ENSEMBLE MEANS MODEL OUTPUTS - TEMPERATURES: JUNE, JULY, AUGUST JULY, AUGUST, SEPTEMBER
30 AUGUST, SEPTEMBER, OCTOBER SEPTEMBER, OCTOBER, NOVEMBER ECMWF MEAN MODEL OUTPUTS - PRECIPITATION: JUNE, JULY, AUGUST JULY, AUGUST, SEPTEMBER AUGUST, SEPTEMBER, OCTOBER SEPTEMBER, OCTOBER, NOVEMBER
31 CPC SEASONAL TEMP OUTLOOKS
32 CPC SEASONAL PRECIP OUTLOOKS Here is the NOAA CFS v2 Seasonal TEMP Outlook:
34 Here is the NOAA CFS v2 Seasonal PRECIP Outlook: