1

Arizona Climate Summary March 2018

Summary of conditions for February 2018

February 2018 Temperature and Precipitation Summary February 1st – 11th: The warm, dry conditions of January continued into the first 11 days of February with clear skies and unseasonably warm temperatures. A very strong high pressure ridge sat off the coast of California blocking storm systems from moving down the California coast and into Arizona. Southwest deserts enjoyed daytime temperatures in the mid- to upper 80s, and nighttime temperatures in the mid to upper 50s. The higher elevations had daytime temperatures in the upper 40s and low 50s and nighttime temperatures in the upper teens, due to the clear skies. Up until the 12th, the state was on track to have another record breaking month for temperature, but the rest of the month had both cooler than normal and near normal temperatures that came with a series of winter storms. February 12th – 28th: By the 12th, the ridge moved to the west, allowing a deep low pressure trough to set up over the western U.S. The trough remained in place through the end of the month, and a series of storms moved through Arizona. Temperatures dropped back to near normal values for the rest of the month. The lower deserts ranged from the mid 60s to mid 70s in the daytime and 40s to 50s at night. Higher elevations ranged from the lower 20s to lower 40s in daytime and negative teens to mid positive teens at night. The first storm moved in on the 12th and lasted through the 15tth, bringing rain to northern and central Arizona, with snow at the higher elevations. Snow totals included 7.0” at Flagstaff Airport, 2.0” at Bellemont, and 14.0” at the north rim of the Grand Canyon. This cold storm was immediately followed by a warmer storm that moved across the whole state, with heavy rainfall in southern Arizona. Three and four day rain totals included 0.90” at Bisbee-Douglas, 1.74” at Davis-Monthan AFB, 2.76” at Elgin, 0.68” at Nogales, 0.27” at Deer Valley, 0.30” at Phoenix AP, 0.65” at Prescott, 1.20” at Safford, 0.32” at Scottsdale AP, 1.18” at Sonora Desert Museum, 1.55” at Tucson AP, 3.05” at Coronado National Monument, 1.01” at Douglas, 0.52” at Payson, 1.01” at Picacho Peak. This was followed on the 19th by another colder storm that brought more snow to the high country. Flagstaff and Bellemont each received 1.5” of snow, Grand Canyon north rim had 4.0”, Seligman had 0.5”, Show Low had 1.5”, and Williams had 2.0”. The 22nd was dry across the state, but the next cold system moved through on the 23rd and 24th. That storm dropped 1.0” of snow on Flagstaff and Seligman, 4.5” at Bellemont, 6.0” at Williams, 0.2” at Payson, and 0.3” at Show Low. The 25th through 27th were dry and clear, and the last big storm moved through on the 28th. This storm covered most of the state with snow at the higher elevations and rain elsewhere. Snow totals included 8.5” at Flagstaff, 7.3” at Bellemont, 1.5” at Payson, 0.5” at Springerville, and 6.0” at Williams. Rainfall totals included 0.28” at Pinnacle Peak, 0.11” at Picacho Peak, 0.11” at Apache Junction, 0.20” at Eloy, 0.11” at East Mesa, 0.23” at Coronado NM, 0.36” at Carefree, 0.20” at Tucson AP, 0.22” at Scottsdale AP, 0.08” at Safford, 0.12” at Prescott, 0.22” at Phoenix AP, 0.35” at Deer Valley, 0.18” at Nogales and 0.09” at Bisbee-Douglas AP. The snowstorms in February were the first significant snows of the winter across the state. In This Issue: Overview of February, graphs of the February daily maximum and minimum temperatures, precipitation, mean daily dew points for Flagstaff, Phoenix, and Tucson; February climate statistics, maps of mean monthly maximum and minimum temperatures, precipitation, dew points, wind speeds for February; short-term drought maps for the beginning and end of February 2018; Long-term Drought Map; and graphs of the mean February temperature and precipitation for the period of record for Tucson, Phoenix, and Flagstaff, graphs of the cumulative precipitation for the calendar year for Flagstaff, Phoenix, and Tucson. Climate calendars for Flagstaff, Phoenix, Tucson, Prescott, Winslow and Yuma, including daily and monthly normals and extremes, for each month of the year, are not yet updated through 2017. See p.21 of this report for calendar abbreviations. Data are preliminary and are from the National Weather Service Forecast Offices in Flagstaff, Phoenix and Tucson.

Dr. Nancy J. Selover, State Climatologist http://azclimate.asu.edu 480-965-0580 Edited by Nancy J. Selover © 2018 Arizona State Climate Office

2

**Note: The discrepancy between the Statewide Temperature and Precipitation values for Phoenix, Flagstaff and Tucson and the daily values in their graphs are due to the reporting times. Statewide Temperature and Precipitation

values are taken at 5pm, while official daily records at the airports are taken from Midnight to Midnight.

February 2018 Daily Temperature, Precipitation, & Dew Point for Flagstaff, Phoenix, and Tucson

3

4

FLAGSTAFF CLIMATE STATISTICS February 2018

This February had no significant ranking for temperature or precipitation. Avg Max Temp(F) 46.1 Normal 44.8 Avg Min Temp(F) 18.8 Normal 19.3 Avg Mean Temp(F) 32.4 Normal 32.1 Departure from Normal (F) +0.3 Highest Monthly Avg Temp (F) 39.7 in 2015 Lowest Monthly Avg Temp (F) 19.5 in 1939 Highest Temp this month (F): 64 on 1st Lowest Temp this month (F): -3 on 24th Record High (F): 71 on 2/26/1986 Record Low (F): -23 on 2/01/1985 Temperature or precipitation records this month: 1st HiMax 65 set, previous record 60 in 2003 12th Precip 0.83”set. previous record 0.70” in 1931 24th LoMin -4 tied, first set in 1909 Flagstaff Number of Days of: Minimum Temp 25oF or higher 10 Minimum Temp 10oF or lower 6 Maximum Temp 60oF or higher 6 Maximum Temp 40oF or lower 12

Heating Degree Days 904 Normal 923 Cooling Degree Days 0 Normal 0 Degree base 65oF Total February Precipitation 2.37” Normal February Precipitation 2.16” Departure from normal +0.21” Greatest 24-Hr Precipitation 0.83” on 12th Total Precipitation Year-to-Date 4.08” Departure from Normal -0.13” Total February Snowfall 23.0” Normal 20.9” Record February Snowfall 84.3” in 1901 Number of Days: Clear 20 Partly Cloudy 5 Cloudy 3 Greatest February Precipitation 10.05” in 1993 Least February Precipitation: Trace in 1967 Average Wind Speed 8.2 mph Highest Peak Gust 59 mph from 200o on 19th

PHOENIX CLIMATE STATISTICS February 2018

This February had no significant ranking for temperature or precipitation. Avg Max Temp(F) 71.1 Normal 70.7 Avg Min Temp(F) 48.4 Normal 48.7 Avg Mean Temp (F) 59.8 Normal 59.7 Departure from Normal (F) +0.1 Highest Monthly Avg Temp (F) 66.0 in 1991 Lowest Monthly Avg Temp (F) 48.5 in 1939 Highest Temp this month (F) 84 on 8th Lowest Temp this month (F): 39 on 25, 24, 21 Record High (F): 92 on 2/25/1921, 2/27/1986 Record Low (F): 24 on 2/7/1899, 2/8/1933

No temperature or precipitation records this month: Phoenix Number of Days of: Minimum Temp 45oF or lower 9 Minimum Temp 55oF or higher 2 Maximum Temp 65oF or lower 8 Maximum Temp 80oF or higher 7 Heating Degree Days 150 Normal 163 Cooling Degree Days 10 Normal 15 Degree base 65oF Total February Precipitation 0.52” Normal February Precipitation 0.92” Departure from normal -0.40” Greatest 24-Hr Precipitation 0.28” on 14th

5

Total Precipitation Year-to-Date 0.73” Departure from Normal -1.10” Greatest February Precipitation 4.64” in 1905 Least February Precipitation 0.00” in 2014, 2016 and 11 other years

Number of Days: Clear 12 Partly Cloudy 14 Cloudy 2 Average Wind Speed 5.6 mph Highest Peak Gust 40 mph from 270o on 19th

TUCSON CLIMATE STATISTICS

February 2018 This February was the 20th warmest on record and was the 10th wettest. Avg Max Temp(F) 70.1 Normal 68.5 Avg Min Temp(F) 44.8 Normal 42.2 Avg Mean Temp(F) 57.4 Normal 55.3 Departure from Normal (F) +2.1 Highest Monthly Avg Temp (F) 62.1 in 2015 Lowest Monthly Avg Temp (F) 45.3 in 1903 Highest Temp this month (F): 84 on 8th Lowest Temp this month (F): 33 on 25th Record High (F): 92 on 2/14/1957 Record Low (F): 17 on 2/07/1899 Temperature or precipitation records this month: 8th HiMax 84 set, previous record 81 in 2006 15th Precip 1.01” set, previous record 0.94” in 2008 Tucson Number of Days of: Minimum Temp 40oF or lower 7 Minimum Temp 50oF or higher 8 Maximum Temp 70oF or lower 15 Maximum Temp 80oF or higher 6

Heating Degree Days 203 Normal 273 Cooling Degree Days 0 Normal 0 Degree base 65oF Total February Precipitation 1.96” Normal February Precipitation 0.86” Departure from normal +1.10” Greatest 24-Hr Precipitation 1.01” on the 15th Total Precipitation Year-to-Date 1.98”

Departure from Normal +0.18” Greatest February Precipitation 4.15” in 1905 Least February Precipitation 0.00” in 2006, 1972, 1895, and 7 other years. Number of Days: Clear 19 Partly Cloudy 2 Cloudy 7 Average Wind Speed 6.5 mph Highest Peak Gust 44 mph from 220o on 19th Data are from the National Weather Service and the National Climatic Data Center and are preliminary.

6

Wind Speeds for February: Day Phoenix Flagstaff Tucson (mph) Avg Max Avg Max Avg Max 1 4.3 13 4.4 19 7 25 2 4.6 14 4.2 22 7 18 3 4.5 12 3.8 20 6.4 20 4 5.1 13 2.9 25 6 19 5 5 17 5.6 23 6.9 19 6 7.8 25 7 28 6.6 28 7 4 21 6 24 4.5 15 8 3.2 15 2.7 17 7.5 30 9 5.2 14 6.2 26 6.9 20 10 5.6 16 15.4 44 10.1 33 11 7.5 25 10.3 34 4.8 22 12 10 28 17.6 38 9.7 38 13 5.8 27 7.6 36 5.1 26 14 3.2 13 8.2 29 3.1 16 15 3.3 14 4.5 17 3.5 16 16 3.9 13 3.6 16 1.4 14 17 2.1 11 3.3 22 3.6 19 18 13.9 40 19.3 50 7 23 19 5.6 18 23.8 59 14.2 44 20 5.7 18 4.9 26 5.9 20 21 4.6 19 7.9 28 6.1 23 22 5.1 21 14 40 3.8 14 23 8.8 31 11.1 35 8.6 32 24 5.2 16 7.1 23 5.4 22 25 3.9 14 3.4 20 4.8 16 26 4 16 9.9 36 6.6 20 27 8.7 38 9.6 43 12.1 40 28 5.3 22 7.1 21 7.6 25

Dew Points for February: Daily Average Dew Point (oF): Day Phx Tuc Flg 1 24 11 16 2 24 17 19 3 27 19 16 4 30 20 14 5 31 22 16 6 22 22 13 7 21 13 11 8 19 9 11 9 21 10 14 10 20 19 5 11 36 29 26 12 39 35 27 13 45 35 31 14 50 47 32 15 52 54 26 16 50 53 24 17 47 51 29 18 46 47 26 19 22 36 9 20 17 32 5 21 15 22 3 22 23 24 15 23 23 22 9 24 20 21 8 25 17 18 7 26 19 16 7 27 33 28 19 28 46 30 22

7

The

8

February 2018 The minimum temperatures ranged from -17oF at Grand Canyon National Park to 45oF at Litchfield Park. The lowest maximum temperature of 40oF was

recorded at McNary and the highest was 89oF at Yuma. The highest rainfall totals were 4.46” at Coronado National Monument and 4.40” at Promontory, and the lowest was 0.00” at many stations. The lowest average dew point was 16oF at Winslow and the highest was 35oF at Paloma. The highest peak wind gust

was 38 mph at Fort Mohave. Average wind speeds ranged from 2 mph in the Phoenix area to 13 mph at Laughlin-Bullhead City and Show Low Airports.

9

T

February 2018 The highest average minimum temperature was 52oF at Yuma, and the lowest average minimum temperature was 12oF at Grand Canyon National Park. The

highest average maximum temperature was 77oF at Yuma and the lowest average maximum temperature was 39oF at Beaver Spring.

10

Short term drought maps for January 30th on left and February 27th on right. The relatively dry February led to an expansion of Severe Drought (D2) across

Coconino and Yavapai counties, and its introduction into Mohave County. Extreme Drought (D3) was also introduced into northern Apache County.

11

Long-term drought map for February for Arizona shows hydrologic drought, and is based on both precipitation and evaporation using the Standardized Precipitation Index (SPI) and Standardized Precipitation Evaporative Index (SPEI) over the past 24-, 36-, and 48-months.

12

13

February

February minimum temperatures in eastern Arizona ranged from 4oF cooler than average to 3oF warmer than average. The southeast was warmer than average as the coldest storms did not move into southeastern Arizona. Northwestern and northeastern Arizona were cooler than average, as was Yuma

County. Daytime temperatures were within 2oF of average across most of the state. Northeastern Arizona was 2-6oF warmer than average at night due to persistent cloud cover. Most of the state received less than 70% of average February precipitation while southeastern Arizona and southern Apache County

received over 150% of average.

14

15

Calendar Year 2018

Calendar year minimum temperatures across Arizona were generally within 2oF of average. Daytime temperatures were 2 to 6oF warmer than average across the state and 6-8oF warmer in the northeast corner. Most of the state has received less than 70% of average precipitation while southeastern Arizona and

central Apache County received over 110% of average, primarily in February.

16

17

s aham, Cochise, La Paz, OPima and

2018 Water Year Water Year 2018 minimum temperatures were 0 to 4oF warmer than normal across the southern half of the state and within 2oF of normal in northern Arizona. La Paz County appears to have been much warmer than normal, but the bullseye may be due to bad data or a station move. Daytime temperatures were 2 to

6oF warmer than normal in southern Arizona and 6-8oF warmer than normal across northern Arizona. The entire state, except the southeast corner, has received less than 50% of normal precipitation since October 1st.

18

February Mean Temperature Graphs – Flagstaff, Phoenix, and Tucson 1895-2018:

19

February Mean Precipitation Graphs – Flagstaff, Phoenix, and Tucson 1895-2018

20

2018 Cumulative Precipitation Graphs – Flagstaff, Phoenix and Tucson: Flagstaff is 0.13” below normal, Tucson is 0.18” above normal, and Phoenix is 1.10” below normal.

21

The downloadable normals and extremes calendars use the following abbreviations: NORM = 30 year (1971-2000) average value (degrees Fahrenheit (F)) OBS = The temperature observation for that day this year AVG = Average daily temperature HI MAX = Highest maximum temperature for that day (F) LO MAX = Lowest maximum temperature for that day (F) LO MIN = Lowest minimum temperature for that day (F) HI MIN = Highest minimum temperature for that day (F) Mx PCP = Maximum precipitation for that day (inches) Mx SNO = Maximum snowfall for that day (inches)