AgWeatherNet Spring 2014 Weather Review for Washington

Warmest Spring Season Since 1994 Concludes with Hottest May Since 1997

Nic Loyd, Meteorologist, 509-786-9357
Gerrit Hoogenboom, Director, 509-786-9371

Overview
Twenty years have passed since Prosser last experienced a spring as warm as 2014. This year also marks the continuation of an exceptional reversal of recent fortunes. During the early part of the present decade, cool spring weather was rather commonplace in Washington. Just 3 years ago, Washington observed near-record cold temperatures to start the growing season. In 2014, however, the mean May high temperature was more than 8 degrees warmer than in 2011, while the mean spring high temperature eclipsed its 2011 counterpart by a margin of greater than 6 degrees. Overall, May and the spring of 2014 were warmer than 2011 by 7.1 and 5.2 degrees, respectively. Despite their modest appearance, these numbers are significant changes for one and three-month average values.

Interestingly, the spring season began on a cold note. Green Bluff (near Spokane) recorded a high temperature of only 19 degrees on March 1st. However, arctic air rapidly retreated from eastern Washington, and warm conditions dominated for the remainder of the spring. The period from March 2nd to 8th was unusually wet, and Montesano recorded nearly 8 inches of rain during the week-long deluge. April was a generally unremarkable time, except for the coastal heat wave at month's end. The high temperature at Long Beach soared from 58 degrees on the 28th to 88 degrees on the 30th. The abnormally early hot spell culminated with Long Beach recording their warmest April temperature on record, while simultaneously surpassing their hottest temperature of 2013.

Overall, the month of May can be characterized with the following simple formula: Heat wave. Cool down. Repeat. Seattle soared to 89 degrees on the 1st, but reached only 69 degrees on the very next day. Another heat wave later in the month sent temperatures soaring above 90 degrees in northwestern Oregon on May 14th. Other notable May events include 1.7 inches of rainfall at Stevenson on the 9th, and a 30-degrees low temperature at Ritzville on the morning of May 27th.

May 2014 Average Temperatures (°F)
Location (Period of Record) Maximum Anomaly Minimum Anomaly Mean Anomaly Soil Temperature
8 inches
Prosser (WSU IAREC; 1989-2014)
75.6
3.4
46.8
1.4
62.2
2.5
61.7
Moxee (1989-2014)
74.8
2.9
41.4
0.9
60.0
2.1
54.5
Mt Vernon (WSU NWREC; 1994-2014)
65.9
3.2
49.1
3.1
57.1
3.0
60.8
Wenatchee (WSU TFREC; 1994-2014)
76.0
4.6
49.6
3.0
63.4
3.7
67.4
Tri-Cities (1995-2014)
78.9
4.3
49.2
1.7
64.9
3.2
71.1
Walla Walla (1993-2014)
73.8
4.1
48.6
1.0
61.1
2.3
65.6
Moses Lake (1989-2014)
75.3
4.1
46.8
1.8
61.7
2.9
66.1
Omak (Pogue Flat; 2005-2014)
73.9
NA
46.4
NA
60.4
NA
61.3
Royal City East (2008-2014)
73.9
NA
47.7
NA
61.0
NA
64.7
Pullman (2008-2014)
66.2
NA
40.1
NA
54.3
NA
59.1
Long Beach (WSU Long Beach; 2005-2014)
62.5
NA
47.7
NA
55.5
NA
58.8
Sequim (2008-2014)
64.8
NA
47.2
NA
55.8
NA
58.1
Seattle (2011-2014)
68.8
NA
50.5
NA
59.1
NA
61.4
Vancouver (WSU RE; 2008-2014)
69.8
NA
48.1
NA
58.9
NA
60.0
2014 Rainfall and Evapotranspiration (ET) (inches)
Location (Period of Record) Rainfall ET Net
May 2014 May (Rain - ET)
Prosser (WSU IAREC; 1989-2014)
0.46
3.01
7.92
-7.46
Moxee (1989-2014)
0.19
2.38
7.80
-7.61
Mt. Vernon (WSU NWREC; 1994-2014)
3.68
19.98
4.17
-0.49
Wenatchee (WSU TFREC; 1994-2014)
0.21
3.55
7.67
-7.46
Tri-Cities (1995-2014)
0.16
2.33
8.89
-8.73
Walla Walla (1993-2014)
0.72
7.74
6.37
-5.65
Moses Lake (1989-2014)
0.30
2.41
7.78
-7.48
Omak (Pogue Flat; 2005-2014)
0.32
3.60
6.69
-6.37
Royal City East (2008-2014)
0.40
2.35
7.46
-7.06
Pullman (2008-2014)
0.77
8.57
6.77
-6.00
Long Beach (WSU Long Beach; 2005-2014)
5.73
35.61
3.75
1.98
Sequim (2008-2014)
0.73
8.08
4.44
-3.71
Seattle (2011-2014)
2.24
22.91
4.55
-2.31
Vancouver (WSU RE; 2008-2014)
2.14
19.51
4.42
-2.28
May 2014 Daily Rainfall Time Series Graph for Prosser May 2014 Daily Rainfall Time Series Graph for Long Beach

May Weather
Early May-From Hot to Cool
May began with very hot temperatures and mostly sunny skies. A strong ridge of high pressure along with dry offshore flow initially made western Washington the hottest part of the state. However, an approaching upper low and a return to onshore flow allowed for a rapid high temperature drop in western areas on May 2nd. Areas such as Seattle reached 89 degrees on the 1st, but only 69 degrees on the 2nd, and 61 degrees on May 3rd.

Lows on the 2nd were as warm as 64 degrees, but mainly in the 40s and 50s. Meanwhile, highs reached the 80s to low 90s in much of central Washington. Simultaneously, western areas experienced notable cooling, with Long Beach peaking at just 57 degrees. On May 3rd, highs reached the mid 60s to low 70s in central areas, and mainly the upper 50s to mid 60s elsewhere. Lows were mostly in the mid 40s to mid 50s. 1.5 inches of rain fell at Tokeland, with some wet weather in most western areas.

Highs on the 4th were in the mid 50s to low 70s, with lows in the upper 30s to low 50s. Rain fell over nearly the entire state on the 8th, with 1.33 inches recorded at Long Beach. Highs ranged from the mid to upper 50s in southwestern Washington to the 60s and 70s east of the mountains. Lows were in the mid 30s to low 50s. It was windy in the east on May 9th, with isolated significant rain totals and cool temperatures. Highs only reached into the 50s and 60s, with lows in the upper 30s to low 50s. 1.7 and 1.3 inches fell at Stevenson and Stanwood, respectively.

Mid May-Another Heat Wave
Highs on the 10th ranged from the mid 60s to low 70s in central areas to the mid to upper 50s in eastern areas. Lows were in the 30s and 40s, with 0.2 inches of rainfall at the coast. Highs on May 14th reached the low 90s in northwest Oregon, and 89 degrees at Long Beach. Central areas climbed into the 80s, with 70s in eastern border areas. Lows varied from the upper 30s to around 60 degrees. On May 15th, parts of central Washington again topped 90 degrees, although the coast was already experiencing notable cooling.

Highs on the 18th reached the upper 50s to mid 70s, with lows in the mid 30s to mid 50s. 0.82 inches of rain fell at Long Beach, as breezy winds persisted in many areas. High temperatures peaked in the 60s and 70s on May 19th, with lows in the upper 30s to mid 50s. Conditions were mostly dry with isolated showers.

Late May-Changeable Weather Continues
The 20th was a calmer and warmer day. Highs ranged from the upper 70s to low 80s in central areas to the 60s at the coast. Lows were in the 40s to mid 50s. Temperatures peaked on the 22nd, before slightly more unsettled conditions arrived for the Memorial Day Holiday Weekend. After a very mild morning on the 23rd, a weak front brought rain to western areas, along with breezy and ultimately cooler conditions to the state. Western areas reached the 60s to low 70s, while central areas topped out in the mid 70s to mid 80s. Lows ranged from the mid 40s to low 60s. 1.2 inches of rain fell in western Whatcom County, although amounts were lighter over the remainder of western Washington.

Low temperatures on May 27th were as cold as 30 degrees at Ritzville, but predominantly in the upper 30s to 40s. High temperatures reached the 60s and 70s. Light rain fell around Long Beach and Pullman on the unstable spring day. Highs on the 28th ranged from 52 degrees at Garfield East to 74 degrees at Orondo. Lows varied from 36 degrees at Harrington South to 55 degrees at Wallula. 0.58 inches of rain fell at Long Beach, and winds gusted to 37 mph at Alderdale. Overall, there were widely scattered showers and even some thunderstorms across the state. Highs on May 31st reached the mid 60s to 80s, with lows in the 40s to low 60s.

May 2014 Daily Temperatures
2014 temperature Time Series Graph for Prosser 2014 temperature Time Series Graph for Moxee
2014 temperature Time Series Graph for Wenatchee 2014 temperature Time Series Graph for Tri-Cities
2014 temperature Time Series Graph for:Walla Walla May 2014 Temperature Time Series Graph for WSU
May 2014 Temperature Time Series Graph for WSUMoses Lake May 2014 Temperature Time Series Graph for WSU Omak
May 2014 Temperature Time Series Graph for WSU Long Beach May 2014 Temperature Time Series Graph for WSU Mt. Vernon

May-By The Numbers
The average May temperature at Prosser (WSU IAREC) was 62.2°F, which is 2.5 degrees (1 standard deviation) above average. The average high temperature was 75.6°F, which is 3.4 degrees (1.1 standard deviations) above average. The average low temperature was 46.8°F, which is 1.4 degrees above average. The maximum temperature recorded last month was 87.5°F on May 22nd, while the coolest daily high was 63.6°F on May 9th. Low temperatures ranged from 57.8°F on May 16th to 38.4°F on May 6th. Daily average temperatures ranged from 71.5°F on the 16th to 53.8°F on the 10th. The monthly precipitation total was 0.46 inches. The average wind speed was 5.0 mph, and the average 8 inch soil temperature was 61.7°F. Wenatchee (WSU TFREC) recorded an average temperature of 63.4°F, which is 3.7 degrees above average, while Walla Walla's average monthly temperature of 61.1°F was 2.3 degrees above average. Pullman was one of the cooler spots in the state, with an average May temperature of 54.3°F. In western Washington, Mt. Vernon's average temperature was 57.1°F, which is 3.0 degrees above average.


Notable May Events
  • May 1st: The temperature at Seattle soared to 89 degrees.
  • May 9th: 1.7 inches of rain fell at Stevenson.
  • May 12th: The temperature at LaCrosse fell to 30 degrees.
  • May 14th: The temperature at Long Beach rose to 89 degrees.
  • May 17th: The temperature at Ritzville fell to 30 degrees.

May Temperature Extremes (°F)
  Observed in 2014 Record Monthly Extremes
Site (Period of Record) Warmest Date Coldest Date Warmest Date Coldest Date
Prosser (WSU IAREC; 1989-2014)
87.5
5/22/2014
38.4
5/6/2014
98.4
5/12/1993
29.8
5/7/2002
Moxee (1989-2014)
87.3
5/15/2014
32.0
5/12/2014
98.0
5/23/2001
19.9
5/8/1996
Mt. Vernon (WSU NWREC; 1994-2014)
79.0
5/1/2014
41.8
5/30/2014
86.2
5/17/2008
32.6
5/7/2002
Wenatchee (WSU TFREC; 1994-2014)
88.1
5/15/2014
37.9
5/12/2014
97.7
5/17/2006
30.7
5/2/1997
Tri-Cities (1995-2014)
90.5
5/15/2014
39.6
5/12/2014
100.9
5/23/2001
29.8
5/1/2013
Walla Walla (1992-2014)
86.5
5/15/2014
38.0
5/12/2014
94.5
5/23/2001
32.7
5/2/2006
Moses Lake (1989-2014)
85.7
5/22/2014
36.0
5/12/2014
97.5
5/18/2006
27.8
5/8/2002
Omak (Pogue Flat; 2005-2014)
85.8
5/14/2014
35.2
5/7/2014
94.8
5/17/2006
29.1
5/4/2010
Royal City East (2008-2014)
84.5
5/22/2014
38.7
5/10/2014
93.3
5/17/2008
31.7
5/5/2010
Pullman (2008-2014)
80.7
5/15/2014
30.2
5/12/2014
85.2
5/17/2008
25.2
5/11/2012
Long Beach (WSU Long Beach; 2005-2014)
89.1
5/14/2014
37.9
5/7/2014
95.3
5/16/2008
31.1
5/1/2013
Sequim (2008-2014)
77.5
5/14/2014
35.9
5/7/2014
77.8
5/5/2013
26.5
5/1/2013
Seattle (2011-2014)
87.2
5/1/2014
43.1
5/11/2014
NA
NA
NA
NA
Vancouver (WSU RE; 2008-2014)
90.0
5/14/2014
37.0
5/7/2014
90.0
5/14/2014
31.7
5/10/2012

Spring Weather
March and April Review
Despite a cold beginning, much of March was mild and somewhat active. Green Bluff's high temperature on the 1st was a mere 19 degrees, but Vancouver reached 62 degrees on March 3rd. From March 2nd to 8th, Montesano received nearly 8 inches of rain. An unfortunate consequence of the wet weather in the west was the March 22nd Oso landslide, which caused significant loss of life. Despite the preponderance of dry days in central parts of the state, Long Beach recorded only 5 dry days during the month. Overall, monthly temperatures were around 1 to 2 degrees above average.

April was another mild but generally unremarkable month. The main highlight was the end of the month heat wave, which was noteworthy not only in terms of the absolute temperatures, but also for its unusually early and sudden arrival. Western areas recorded the greatest positive temperature anomalies for that time of the year. Long Beach soared from 58 degrees on the 28th to 88 degrees on May 30th. By contrast, the warmest temperature recorded during the summer of 2013 was just 75 degrees. Overall, Prosser's mean monthly temperature was nearly 2 degrees above average, which made April 2014 the warmest since 2000.

Winter 2013 Daily Rainfall Time Series Graph for Prosser Winter 2013 Daily Rainfall Time Series Graph for Long Beach

Spring-By The Numbers
The average spring temperature at Prosser (WSU IAREC) was 54.1°F, which is 1.8 degrees (1.1 standard deviations) above average. The average high temperature was 66.2°F, which is 2.1 degrees (1.1 standard deviations) above average, while the average low temperature was 41.0°F, which is 1.5 degrees (1.1 standard deviations) above average. Daily high temperatures ranged from 87.5°F on May 22nd to 26.3°F on March 2nd. Low temperatures varied from 57.8°F on May 16th to 23.8°F on March 2nd. Daily average temperatures ranged from 71.5°F on May 16th to 25.0°F on March 2nd. 1.96 inches of rain fell during the spring season. The average wind speed was 5.8 mph, while the average 8 inch soil temperature was 53.5°F. Other locations also experienced above normal spring temperatures. Wenatchee (WSU TFREC) had an average seasonal temperature of 53.3°F, which is 1.8 degrees above average.

Spring 2014 Average Temperatures (°F)
Location (Period of Record) Maximum Anomaly Minimum Anomaly Mean Anomaly Soil Temperature
8 inches
Prosser (WSU IAREC; 1989-2014)
66.2
2.1
41.0
1.5
54.1
1.8
53.5
Moxee (1989-2014)
65.4
1.9
35.4
1.2
51.6
1.6
49.7
Mt. Vernon (WSU NWREC; 1994-2014)
59.3
2.1
44.5
2.7
51.5
2.2
54.1
Wenatchee (WSU TFREC; 1994-2014)
65.4
2.4
40.7
1.2
53.3
1.8
55.7
Tri-Cities (1995-2014)
68.8
2.5
42.1
1.0
55.8
1.8
59.0
Walla Walla (1993-2014)
64.4
2.4
42.9
0.9
53.4
1.4
55.0
Moses Lake (1989-2014)
65.2
2.3
40.0
1.6
52.8
1.9
55.0
Omak (Pogue Flat; 2005-2014)
63.0
NA
38.3
NA
50.9
NA
50.3
Royal City East (2008-2014)
64.4
NA
41.7
NA
53.1
NA
54.2
Pullman (2008-2014)
57.1
NA
36.4
NA
47.0
NA
49.0
Long Beach (WSU Long Beach; 2005-2014)
57.7
NA
43.7
NA
51.0
NA
53.4
Sequim (2008-2014)
58.8
NA
40.9
NA
50.0
NA
51.6
Seattle (2011-2014)
61.7
NA
45.2
NA
52.9
NA
55.5
Vancouver (WSU RE; 2008-2014)
63.0
NA
42.9
NA
52.9
NA
53.6
Spring 2014 Rainfall and Evapotranspiration (ET) (inches)
Location (Period of Record) Rainfall ET Net
(Rain - ET)
Prosser (WSU IAREC; 1989-2014)
1.96
18.50
-16.54
Moxee (1989-2014)
1.37
17.58
-16.21
Mt. Vernon (WSU NWREC; 1994-2014)
11.39
9.08
2.31
Wenatchee (WSU TFREC; 1994-2014)
1.35
16.17
-14.82
Tri-Cities (1995-2014)
1.20
20.00
-18.80
Walla Walla (1993-2014)
5.48
14.01
-8.53
Moses Lake (1989-2014)
1.53
17.83
-16.30
Omak (Pogue Flat; 2005-2014)
1.95
15.04
-13.09
Royal City East (2008-2014)
1.54
17.94
-16.40
Pullman (2008-2014)
4.70
15.40
-10.70
Long Beach (WSU Long Beach; 2005-2014)
23.90
8.09
15.81
Sequim (2008-2014)
3.36
10.03
-6.67
Seattle (2011-2014)
13.54
9.88
3.66
Vancouver (WSU RE; 2008-2014)
11.56
11.77
-0.21
Notable Spring Events
  • March 1st: The high temperature at Green Bluff was 19 degrees.
  • March 5th: 2.19 inches of rain fell at Stevenson.
  • March 15th: The temperature at Mabton East reached 72 degrees.
  • April 14th: The temperature at Broadview plunged to 22 degrees.
  • April 30th: The temperature at Long Beach soared to 88 degrees.
  • May 9th: 1.7 inches of rain fell at Stevenson.

Spring Temperature Extremes (°F)
  Observed in 2014 Record Seasonal Extremes
Site (Period of Record) Warmest Date Coldest Date Warmest Date Coldest Date
Prosser (WSU IAREC; 1989-2014)
87.5
5/22/2014
23.8
3/2/2014
98.4
5/12/1993
11.5
3/2/1993
Moxee (1989-2014)
87.3
5/15/2014
17.0
3/3/2014
98.0
5/23/2001
9.7
3/1/1993
Mt. Vernon (WSU NWREC; 1994-2014)
79.0
5/1/2014
30.5
3/22/2014
86.2
5/17/2008
20.3
3/1/2007
Wenatchee (WSU TFREC; 1994-2014)
88.1
5/15/2014
20.0
3/3/2014
97.7
5/17/2006
15.6
3/2/1995
Tri-Cities (1995-2014)
90.5
5/15/2014
22.8
3/3/2014
100.9
5/23/2001
16.9
3/12/2009
Walla Walla (1992-2014)
86.5
5/15/2014
24.0
3/2/2014
94.5
5/23/2001
6.3
3/1/1993
Moses Lake (1989-2014)
85.7
5/22/2014
19.3
3/3/2014
97.5
5/18/2006
10.6
3/1/1993
Omak (Pogue Flat; 2005-2014)
85.8
5/14/2014
18.7
3/1/2014
94.8
5/17/2006
11.2
3/10/2009
Royal City East (2008-2014)
84.5
5/22/2014
17.9
3/3/2014
93.3
5/17/2008
16.3
3/10/2009
Pullman (2008-2014)
80.7
5/15/2014
19.2
3/1/2014
85.2
5/17/2008
-6.2
3/11/2009
Long Beach (WSU Long Beach; 2005-2014)
89.1
5/14/2014
28.7
3/22/2014
95.3
5/16/2008
25.4
3/11/2009
Sequim (2008-2014)
77.5
5/14/2014
25.7
3/22/2014
77.8
5/5/2013
19.5
3/12/2009
Seattle (2011-2014)
87.2
5/1/2014
31.6
3/22/2014
NA
NA
NA
NA
Vancouver (WSU RE; 2008-2014)
90.0
5/14/2014
26.5
3/22/2014
86.0
5/13/2012
21.0
3/12/2009
Weather Summary By Month
  • March: Mild, and wet in the west.
  • April: Warm and uneventful.
  • May: Warm and variable.

Agriculture Report
During early May, asparagus harvest was in full swing, and most spring wheat and barley had been planted. As of May 12th, winter wheat crop damage became apparent, while vegetable crops in the Palouse region showed the effects of reduced moisture and cold winter weather. By May 19th, wheat was showing signs of heat stress in response to the warm and dry weather. Meanwhile, the planting of beans and sweet corn continued. Most crops were showing signs of drought stress by the end of May, and the planting of field corn began. In western Washington, tree fruit blooming was complete as of late May (National Agricultural Statistics Service).

April 1 to May 31 Accumulated Growing Degree Days
  Base Temperature (°F)
32 43 50
Location 2014 5 Year Avg Difference 2014 5 Year Avg Difference 2014 5 Year Avg Difference
Prosser (WSU IAREC)
1540
1358
182
869
690
179
447
327
120
Tri-Cities
1680
1490
190
1009
820
189
582
432
150
Walla Walla
1513
1366
147
842
699
143
424
330
94
Wenatchee (WSU TFREC)
1574
1403
171
903
736
167
484
367
117
Moxee
1351
1188
163
680
539
141
296
230
66
Omak (Pogue Flat)
1423
1281
142
752
622
130
357
288
69
Moses Lake
1515
1343
172
844
680
164
427
322
105
Pullman
1068
970
98
406
358
48
125
126
-1
Royal City East
1529
1352
177
858
685
173
434
327
107
Mt. Vernon (WSU NWREC)
1358
1169
189
687
503
184
276
160
116
Long Beach (WSU Long Beach)
1239
1056
183
568
391
177
203
83
120
Sequim
1236
1021
215
565
366
199
206
89
117

GDD are calculated by subtracting a base temperature from the average daily temperature (°F). If the resulting value is less than 0, then it is set to 0. Thus GDD are always 0 or greater.

GDD = (Tmax+Tmin)/2 - Tbase


This Month in History
On May 10, 2013, the temperature at Hundred Circles soared to 97 degrees.

Climate Outlook
According to the Climate Prediction Center (CPC), warmer than average temperatures are expected in Washington during June and into the early autumn, and then slight odds for above average temperatures continue well into 2015. Generally, no clear signal exists for precipitation. El Niño is currently developing, and is likely to persist into 2015.

El Niño winters tend to be significantly warmer and somewhat drier than normal in Washington. However, this is especially true for areas from the Cascades and westward. In eastern areas, odds for warmer than normal temperatures are fairly strong, while odds are only slightly tilted toward drier than normal conditions.

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