AgWeatherNet October 2013 Weather Review for Washington

Pleasant October Weather Blown Away on the 28th

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

Overview
The old adage that all good things must come to an end apparently holds true for the weather as well. October temperatures at Prosser were cooler than average, which ended an impressive streak of above normal temperatures during 14 of the preceding 15 months. Despite the unsettled beginning and end, October was nonetheless pleasant thanks to a long period of dry and calm weather during the middle to latter part of the month. Although western areas were mired in fog and low clouds for much of that time, eastern Washington experienced mainly sunny and mild days. October mean high temperatures were spatially variably but generally near average, while low temperatures were notably below average.

The cool and wet start to last month included a high temperature of just 46 degrees at Crane on October 2nd, as well as 0.91 inches of rainfall at Tokeland. The morning of October 4th brought the first notable frost of the autumn to Washington, with low temperatures as cold as 26 degrees at Pullman. A storm passage on the 7th dropped 0.77 inches of rain at Snohomish, while sustained winds of up to 35 mph were recorded at St. John.

A strong high pressure ridge arrived for mid October, bringing sunny days and cool nights to areas east of the Cascades from the 13th to the 26th. For instance, the low at Fairfield (south of Spokane) on October 14th was only 24 degrees. Unfortunately, low level moisture and stable conditions contributed to a persistent layer of low clouds in western Washington during much of the storm-free period. Conditions finally became more unsettled on October 27th, as a weather system brought as much as 0.3 inches of rain to parts of Washington. A rare wind event from the northeast blew through Washington on October 28th, with daily average values as high as 30 mph at St. John, and all-time record sustained and wind gust values measured in parts of central Washington. As dry air poured into the region, the morning of the 29th featured very chilly temperatures. The low temperature at Pullman on the morning of the 30th was 17 degrees, which was their coldest temperature since late January! Overall, October was a fairly dry and cool month, especially at night.

October 2013 Average Temperatures (°F)
Location (Period of Record) Maximum Anomaly Minimum Anomaly Mean Anomaly Soil Temperature
8 inches
Prosser (WSU IAREC; 1989-2013)
62.9
-0.1
36.7
-2.3
48.7
-1.8
57.0
Moxee (1989-2013)
64.8
1.1
30.0
-3.0
45.9
-1.9
55.0
Mt Vernon (WSU NWREC; 1994-2013)
56.8
-1.4
41.9
-1.0
49.1
-1.3
52.8
Wenatchee (WSU TFREC; 1994-2013)
63.9
1.5
36.1
-2.0
48.3
-1.1
54.4
Tri-Cities (1995-2013)
63.6
-0.8
37.5
-3.3
49.3
-2.9
57.5
Walla Walla (1993-2013)
61.1
-1.4
39.4
-2.6
49.0
-2.7
55.5
Moses Lake (1989-2013)
62.4
0.2
34.7
-2.7
47.6
-1.7
56.0
Omak (Pogue Flat; 2005-2013)
60.3
NA
36.0
NA
47.1
NA
54.6
Royal City East (2008-2013)
62.7
NA
40.3
NA
50.0
NA
54.3
Pullman (2008-2013)
57.2
NA
29.6
NA
43.1
NA
47.0
Long Beach (WSU Long Beach; 2005-2013)
61.9
NA
40.2
NA
50.2
NA
53.5
Sequim (2008-2013)
56.2
NA
38.3
NA
47.7
NA
53.3
Seattle (2011-2013)
57.9
NA
44.0
NA
50.2
NA
56.2
Vancouver (WSU RE; 2008-2013)
63.0
NA
39.4
NA
49.9
NA
56.8
2013 Rainfall and Evapotranspiration (ET) (inches)
Location (Period of Record) Rainfall ET Net
Oct. 2013 Oct. (Rain -ET)
Prosser (WSU IAREC; 1989-2013)
0.13
4.79
3.20
-3.07
Moxee (1989-2013)
0.05
3.67
2.87
-2.82
Mt. Vernon (WSU NWREC; 1994-2013)
1.51
24.69
1.27
0.24
Wenatchee (WSU TFREC; 1994-2013)
0.06
6.91
1.82
-1.76
Tri-Cities (1995-2013)
0.13
3.38
2.71
-2.58
Walla Walla (1993-2013)
0.27
9.55
2.18
-1.91
Moses Lake (1989-2013)
0.09
5.03
3.05
-2.96
Omak (Pogue Flat; 2005-2013)
0.02
7.34
2.42
-2.40
Royal City East (2008-2013)
0.11
3.70
2.81
-2.70
Pullman (2008-2013)
0.06
10.19
3.03
-2.97
Long Beach (WSU Long Beach; 2005-2013)
1.52
41.27
1.35
0.17
Sequim (2008-2013)
0.83
9.92
1.46
-0.63
Seattle (2011-2013)
0.88
18.91
1.40
-0.52
Vancouver (WSU RE; 2008-2013)
1.19
23.21
1.97
-0.78
October 2013 Daily Rainfall Time Series Graph for Prosser October 2013 Daily Rainfall Time Series Graph for Long Beach

October Weather
Early October-Cool and Unsettled
October began with cool, unsettled, and locally breezy conditions. Lows on the 1st were as cool as 33 degrees at Broadview, and highs reached only 51 degrees at Green Bluff (near Spokane), while 0.74 inches of rain fell at Tumwater SW (near Olympia). The low temperature on the 2nd dropped to 30 degrees at Pullman, and marked the first frost morning of the fall for Washington, albeit at only two stations. Although a few stations surpassed 60 degrees in the afternoon, numerous locations in north central Washington failed to reach 50 degrees. Crane topped out at just 46 degrees on the 2nd, which was their coldest daily high since March 24th. Another weak storm brought more rain to western areas, as Tokeland received 0.91 inches. Lows on October 3rd were as cold as 30 degrees at Ritzville, as several stations recorded the autumn's first frost, although drier air and sunshine allowed for daytime highs as warm as 68 degrees.

High pressure and dry air allowed for very chilly lows on the morning of October 4th, as minimum temperatures dropped to 26 degrees at Pullman and 28 degrees at Broadview (Ellensburg). Still, daytime highs peaked in the mid to upper 60s in the lower Yakima Valley. October 4th and 5th were mostly sunny and warmer, with numerous 70s returning to the region. Lows moderated slightly on the 5th, but still bottomed out below 32 degrees in some areas. The morning of October 7th was much milder, as another storm passed through the state. Rain, clouds, and windy conditions occurred, although parts of central Washington topped out near 70 degrees again. 0.77 inches of rain fell at Snohomish in the Puget Sound Convergence Zone, while 15 minute sustained winds topped out at 35 mph at St. John. Showers and cool high temperatures were the rule for October 8th, as Pullman NE reached only 47 degrees, and parts of south central Washington received more than 0.25 inches of rain. Lows were as cold as 27 degrees at Pullman on October 9th, although warmer and drier conditions prevailed by afternoon. High temperatures in many areas reached the 60s, although Huntsville topped out at just 45 degrees. After a low of 31 degrees at Pullman on the 10th, highs topped out in the 50s in the east and west, and reached the 60s to around 70 degrees in central areas. Light rain occurred in parts of western Washington, though most areas were fairly dry. After a showery and cool October 12th, high pressure built into the region, and began an extended period of benign weather.

Mid October-Sunny and Calm
The weather was sunny and pleasant by day and chilly and calm by night during the middle of October. Pullman dropped to 22 degrees on the 15th. However, offshore flow and sunshine allowed Long Beach to climb to 68 degrees on October 14th, while Vancouver reached 70 degrees on the 15th. A weak system dropping in from the north brought a few clouds and just enough mixing to make for a milder morning on October 16th, as only a few sites reached sub-freezing temperatures. High temperatures were in the 60s in parts of western Washington, while Puget Sound areas that failed to break out of the low clouds remained mired in the 50s. Otherwise, temperatures ranged from the upper 50s in eastern areas to the 60s in central Washington.

On the 17th, the low temperature dropped to 27 degrees at Pullman, but later the high temperature reached 69 degrees at Wapato. Low clouds and fog kept much of western Washington cool in the day and mild at night through the 24th. However, sunshine and mixing sent Long Beach to 78 degrees on the 21st, while Peshastin (near Wenatchee) reached 74 degrees. Much of central Washington reached the 70s on the 20th and 21st, while overnight lows also moderated. High temperatures on the 22nd ranged from 75 degrees at Vancouver to 49 degrees at foggy Sequim.

Late October-Pleasant Weather Yields to Unsettled Conditions
Light rainfall of up to 0.32 inches impacted much of the state on October 27th, which caused cool day-time temperatures. Although highs surpassed 60 degrees in parts of western Washington, temperatures peaked in only the upper 40s to mid 50s in south central Washington. The long period of benign and pleasant weather was literally blown away on the 28th, as strong winds slammed the region. The cause of the gale was an unusual setup involving a potent storm dropping down from the north, which was followed by strong Canadian high pressure in its wake. It is very rare to have such strong winds from a northeasterly direction. Outlook recorded an all-time record 15 minute sustained wind of 37.3 mph, and Sunnyside reported a record wind gust of nearly 46 mph. Amazingly, St. John's daily average wind speed for October 28th was 30 mph. High temperatures east of the Cascades reached only the mid 40s to mid 50s, despite the sunshine, while Long Beach was the warm spot in the state at 63 degrees. As winds decreased overnight, temperatures dropped as low as 18.5 degrees at Pullman and Moxee on the morning of the 29th. Highs reached only 43 degrees at Anatone, although much of western Washington approached 60 degrees. October 30th was another chilly morning in the east, as Pullman was the cold spot at 17 degrees. Light rain arrived in western areas late on the 30th, and lingered into the morning of the 31st.

October 2013 Daily Temperatures
2013 Temperature Time Series Graph for Prosser 2013 Temperature Time Series Graph for Moxee
2013 Temperature Time Series Graph for Wenatchee 2013 Temperature Time Series Graph for Tri-Cities
2013 Temperature Time Series Graph for:Walla Walla October 2013 Temperature Time Series Graph for WSU
October 2013 Temperature Time Series Graph for WSUMoses Lake October 2013 Temperature Time Series Graph for WSU Omak
October 2013 Temperature Time Series Graph for WSU Long Beach October 2013 Temperature Time Series Graph for WSU Mt. Vernon

October-By The Numbers
The average October temperature at Prosser (WSU IAREC) was 48.7°F, which is 1.8 degrees (1.2 standard deviations) below average. The average high temperature was 62.9°F, which is 0.1 degrees below average. The average low temperature was 36.7°F, which is 2.3 degrees (1.2 standard deviations) below average, and the coolest since 2002. The maximum temperature recorded last month was 70.9°F on October 21st, while the coolest daily high was 51.8°F on October 27th. Low temperatures ranged from 43.7°F on October 11th to 26.2°F on October 30th. Daily average temperatures ranged from 55.2°F on the 7th to 41.3°F on the 30th. The monthly precipitation total was 0.13 inches. The average wind speed was 4.0 mph, and the average 8 inch soil temperature was 57.0°F. Wenatchee (WSU TFREC) recorded an average temperature of 48.3°F, which is 1.1 degrees below average, while Walla Walla's average monthly temperature of 49.0°F was 2.7 degrees below average. Pullman was one of the cooler spots in eastern Washington, with an average October temperature of 43.1°F. In western Washington, Mt. Vernon's average temperature was 49.1°F, which is 1.3 degrees below average.


Notable October Events
  • October 2nd: The high temperature at Crane was only 46 degrees.
  • October 4th: The low temperature at Pullman plunged to 26 degrees.
  • October 7th: The 15 minute sustained wind at St. John peaked at 35 mph.
  • October 28th: The daily average wind speed at St. John was an incredible 30 mph.
  • October 29th: The temperature at Moxee plummeted to 19 degrees.

October Temperature Extremes (°F)
  Observed in 2013 Record Monthly Extremes
Site (Period of Record) Warmest Date Coldest Date Warmest Date Coldest Date
Prosser (WSU IAREC; 1989-2013)
70.9
10/21/2013
26.2
10/30/2013
83.7
10/1/2010
11.4
10/31/2002
Moxee (1989-2013)
72.3
10/20/2013
18.5
10/29/2013
88.5
10/1/1992
1.8
10/31/2002
Mt. Vernon (WSU NWREC; 1994-2013)
75.1
10/6/2013
31.3
10/29/2013
76.4
10/4/2001
24.3
10/31/2002
Wenatchee (WSU TFREC; 1994-2013)
72.7
10/21/2013
26.5
10/30/2013
85.9
10/1/2010
12.6
10/31/2002
Tri-Cities (1995-2013)
71.0
10/7/2013
25.1
10/30/2013
85.4
10/21/2003
11.4
10/31/2002
Walla Walla (1992-2013)
70.6
10/5/2013
28.8
10/30/2013
89.1
10/1/1997
14.8
10/31/2002
Moses Lake (1989-2013)
72.3
10/23/2013
23.6
10/30/2013
84.4
10/1/2003
7.7
10/31/2002
Omak (Pogue Flat; 2005-2013)
69.7
10/20/2013
24.0
10/30/2013
83.6
10/1/2008
15.2
10/11/2009
Royal City East (2008-2013)
71.5
10/23/2013
27.0
10/30/2013
82.6
10/1/2010
23.0
10/11/2009
Pullman (2008-2013)
70.7
10/6/2013
17.1
10/30/2013
88.3
10/1/2008
3.8
10/11/2009
Long Beach (WSU Long Beach; 2005-2013)
78.0
10/21/2013
29.4
10/29/2013
79.6
10/7/2012
23.8
10/31/2006
Sequim (2008-2013)
62.1
10/6/2013
29.7
10/30/2013
70.6
10/1/2012
24.4
10/12/2009
Seattle (2011-2013)
73.8
10/6/2013
34.4
10/29/2013
NA
NA
NA
NA
Vancouver (WSU RE; 2008-2013)
74.5
10/22/2013
28.7
10/29/2013
81.1
10/1/2012
27.0
10/11/2009

Agriculture Report
As of October 21st, Lincoln County's winter wheat crop was doing well, while potato and corn harvest continued in Grant County. Apple harvest continued in the Yakima Valley, with Jonagold and Honeycrisp coming in from the Upper Valley, and Fuji and Red Delicious coming in from the Lower Valley. The hop harvest was mostly complete as of mid to late October. Otherwise, raspberry growers in Thurston County capitalized on the nice weather to prune, while new plantings were going in for blueberries. As of October 28th, Whitman County fall wheat plantings were emerged and looking healthy, while Adams and Lincoln County winter wheat planting was completed. Meanwhile, the central Washington apple harvest was wrapping up for the season. In western Washington, Christmas tree growers continued preparing for harvest, while pumpkin sales were reported to be brisk (National Agricultural Statistics Service).

April 1 to October 31 Accumulated Growing Degree Days
  Base Temperature (°F)
32 43 50
Location 2013 5 Year Avg Difference 2013 5 Year Avg Difference 2013 5 Year Avg Difference
Prosser (WSU IAREC)
6606
6268
338
4255
3930
325
2851
2554
297
Tri-Cities
7113
6862
251
4763
4516
247
3332
3097
235
Walla Walla
6795
6501
294
4448
4159
289
3046
2769
277
Wenatchee (WSU TFREC)
6907
6579
328
4558
4244
314
3147
2865
282
Moxee
6053
5687
366
3736
3386
350
2430
2108
322
Omak (Pogue Flat)
6468
6193
275
4127
3875
252
2786
2560
226
Moses Lake
6468
6273
195
4132
3944
188
2765
2585
180
Pullman
5107
4936
171
2874
2701
173
1721
1546
175
Royal City East
6672
6324
348
4322
3987
335
2915
2618
297
Mt. Vernon (WSU NWREC)
5486
5215
271
3134
2863
271
1745
1489
256
Long Beach (WSU Long Beach)
4979
4749
230
2626
2408
218
1241
1070
171
Sequim
4957
4637
320
2610
2320
290
1311
1076
235

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 Halloween, October 31st, 2002, the temperature at Moxee plunged to 1.8 degrees, which is one of the coldest temperatures ever recorded so early in the cold season in Washington.

Climate Outlook
According to the Climate Prediction Center (CPC), slightly below average temperatures are expected in the east during November, along with near average precipitation statewide. During the winter season, there are no clear signals to suggest large departures from normal conditions. ENSO Neutral conditions are likely to persist into the spring.

Washington State University