Storm Summary of 2010-2011 Winter Season (November - March) - 77 Storms

Surface Observations from Portland International Airport Weather Station, Oregon (45°35'N , 122°36'W / Elevation: 5.8 m)

Blue highlighted rows: Snow, freezing rain, or mixed cases

Grey highlighted rows: Virga or mix of virga and rain, no snow

* = general trend 6 hours before storm
Tall (> 4.0 km AGL)   Continuity for Storm Maturity
Borderline ( 2.5-4.0 km AGL)   Scattered: Several Breaks
Shallow (< 2.5 km AGL)  
Storm Types

Storm Continuity


Trends
Wind Direction
Temperature
RH
Pressure
Year
Month
Day
Type
AGL
Continuity
Start Time (UTC)
Duration (hrs)
Avg. Temp. (°C)
Avg.
At Storm Maturity
Wind Speed (m/s)
Precip. (in)
before*
during
before*
during
before*
during
2010
11
22
Rain to Mixed
Shallow to Tall to Borderline
Continuous
14:07
14.7
3.5
SW
SW
12.6
0.15
down - up
up - down
up - down
down - up
increasing
decreasing
2010
11
26
Virga to Rain
Tall to Shallow to Borderline
Scattered
09:09
23.0
2.5
SE
E
13.8
0.20
decreasing
increasing
decreasing
increasing
decreasing
decreasing
2010
11
27
Rain
Borderline to Tall to Shallow
Scattered
08:11
12.4
3.9
SE
E
6.6
0.08
up - down
increasing
down - up
decreasing
decreasing
down - up
2010
11
28
Virga to Rain
Tall to Shallow
Continuous
06:08
2.5
3.9
S
S
2.5
0.01
decreasing
flat
up - down
flat
increasing
increasing
2010
11
29
Virga to Rain
Tall to Shallow
Continuous
20:46
10.3
4.3
SE
SE
15.0
0.14
increasing
decreasing
decreasing
increasing
up - down
decreasing
2010
11
30
Virga to Rain
Tall to Shallow to Borderline
Continuous
07:06
17.4
3.0
SE
E
17.1
0.66
decreasing
increasing
up - down
increasing
decreasing
decreasing
2010
12
01
Rain
Tall to Shallow
Scattered
00:32
10.2
5.6
E
E
10.1
0.06
increasing
up - down
down - up
down - up
decreasing
increasing
2010
12
06
Virga to Rain
Borderline to Tall to Shallow
Continuous
12:24
3.7
4.1
SE
E
15.3
0.09
decreasing
down - up
increasing
up - down
down - up
increasing
2010
12
07
Virga to Rain to Virga
Borderline to Tall to Shallow
Scattered
08:21
12.5
5.9
SE
SE
14.8
0.02
down - up
down - up
decreasing
up - down
up - down
decreasing
2010
12
07
Virga to Rain to Virga
Tall to Borderline
Scattered
20:51
21.6
5.1
SE
SE
15.7
0.59
up - down
down - up
decreasing
increasing
decreasing
down - up
2010
12
08
Rain to Virga
Shallow to Tall
Scattered
18:27
17.8
7.2
SE
E
11.5
0.67
increasing
increasing
down - up
down - up
increasing
up - down
2010
12
09
Rain to Virga to Rain
Borderline to Tall to Shallow
Scattered
12:13
16.8
9.7
S
S
7.2
1.36
increasing
up - down
down - up
down - up
flat
down - up
2010
12
10
Rain to Virga to Rain
Shallow to Tall to Shallow
Scattered
05:03
13.8
7.3
S
S
8.7
0.24
decreasing
decreasing
decreasing
down - up
down - up
increasing
2010
12
11
Virga to Rain
Tall to Shallow
Continuous
10:18
16.5
5.4
E
E
11.5
1.36
decreasing
increasing
up - down
down - up
increasing
decreasing
2010
12
12
Rain
Tall to Shallow to Borderline
Scattered
16:54
17.5
13.4
S
SW
8.9
0.13
up - down
decreasing
decreasing
increasing
decreasing
up - down
2010
12
13
Rain to Virga
Borderline to Shallow to Borderline
Scattered
19:09
5.2
14.1
SE
S
7.4
none
increasing
decreasing
down - up
increasing
decreasing
decreasing
2010
12
14
Rain
Borderline to Tall to Borderline
Scattered
00:18
13.7
10.3
S
SW
11.7
0.20
decreasing
decreasing
increasing
decreasing
decreasing
decreasing
2010
12
14
Rain
Tall to Shallow
Scattered
13:58
22.3
6.6
S
S
11.3
0.46
decreasing
decreasing
down - up
down - up
down - up
increasing
2010
12
15
Rain
Shallow to Tall to Shallow
Scattered
12:16
20.2
6.2
S
S
9.6
0.09
up - down
up - down
up - down
down - up
increasing
increasing
2010
12
18
Virga to Rain
Tall to Shallow
Scattered
08:24
13.2
4.0
E
E
22.6
0.19
down - up
down - up
decreasing
increasing
decreasing
increasing
2010
12
19
Virga to Rain
Tall to Shallow
Scattered
03:23
9.3
2.9
SE
E
14.7
0.04
decreasing
decreasing
up - down
up - down
up - down
up - down
2010
12
19
Rain
Tall to Shallow to Tall
Scattered
23:46
22.7
2.5
SE
E
16.5
0.51
up - down
down - up
down - up
increasing
decreasing
increasing
2010
12
21
Rain
Shallow to Tall to Shallow
Scattered
03:10
8.2
3.4
SE
SE
12.3
0.03
up - down
flat
decreasing
up - down
increasing
increasing
2010
12
21
Virga to Rain to Virga
Tall to Borderline
Scattered
17:38
8.6
5.4
E
SE
19.4
0.01
increasing
increasing
decreasing
decreasing
down - up
decreasing
2010
12
22
Rain to Virga to Rain
Borderline to Tall to Shallow
Scattered
08:08
14.1
4.7
SE
E
13.3
0.02
decreasing
down - up
down - up
increasing
increasing
increasing
2010
12
23
Virga to Rain
Borderline to Tall to Borderline
Scattered
19:03
6.0
6.1
SE
SE
17.3
trace
increasing
decreasing
decreasing
down - up
increasing
decreasing
2010
12
24
Rain
Tall
Scattered
13:59
23.0
5.7
SE
Unknown
13.0
0.04
up - down
up - down
decreasing
increasing
decreasing
decreasing
2010
12
26
Rain
Tall to Shallow
Scattered
14:17
22.7
5.3
S
S
14.0
0.26
down - up
up - down
decreasing
down - up
decreasing
increasing
2010
12
27
Rain
Tall to Shallow to Tall
Scattered
18:14
22.8
8.1
S
S
11.9
1.07
increasing
increasing
up - down
increasing
increasing
decreasing
2010
12
28
Rain
Tall to Borderline
Scattered
17:04
23.5
5.1
W
NW
9.3
0.94
flat
decreasing
increasing
down - up
decreasing
down - up
2010
12
31
Mixed
Tall
Scattered
08:07
4.8
-2.6
NE
NE
1.5
none
down - up
decreasing
flat
decreasing
increasing
up - down
2011
01
05
Mixed to Rain
Tall to Shallow
Continuous
10:48
20.7
2.6
E
E
4.6
0.37
down - up
increasing
increasing
increasing
up - down
increasing
2011
01
06
Rain
Shallow to Tall to Shallow
Continuous
13:53
10.2
6.0
E
E
3.0
trace
down - up
up - down
up - down
down - up
decreasing
decreasing
2011
01
07
Virga to Rain
Borderline to Tall to Shallow
Scattered
17:29
8.2
7.5
S
S
8.8
0.08
increasing
up - down
decreasing
down - up
decreasing
down - up
2011
01
08
Mixed to Rain
Shallow to Borderline to Shallow
Scattered
13:36
3.9
0.9
SE
E
4.4
trace
down - up
increasing
up - down
decreasing
up - down
flat
2011
01
09
Rain
Shallow to Tall to Shallow
Scattered
07:00
9.5
2.5
S
S
3.1
0.04
decreasing
decreasing
increasing
down - up
decreasing
increasing
2011
01
10
Virga to Rain to Virga
Borderline to Tall to Shallow
Continuous
12:53
4.6
2.2
SE
E
11.1
none
flat
down - up
up - down
decreasing
increasing
increasing
2011
01
11
Virga to Mixed
Tall to Borderline
Scattered
14:54
13.3
0.9
E
E
20.7
0.01
flat
up - down
decreasing
increasing
decreasing
decreasing
2011
01
12
Mixed to Rain
Shallow to Tall
Continuous
04:12
20.8
4.4
SE
S
14.0
0.74
decreasing
increasing
increasing
up - down
decreasing
increasing
2011
01
13
Rain
Tall to Shallow to Tall
Scattered
01:01
11.9
9.6
SE
E
10.0
0.57
increasing
down - up
decreasing
up - down
increasing
decreasing
2011
01
13
Rain
Borderline to Tall to Borderline
Scattered
18:46
8.6
13.3
S
S
11.9
0.02
increasing
decreasing
decreasing
increasing
down - up
increasing
2011
01
14
Virga to Rain
Tall to Borderline
Scattered
11:19
10.6
12.8
S
S
11.4
trace
flat
increasing
decreasing
decreasing
increasing
down - up
2011
01
15
Virga to Rain
Tall to Borderline to Tall
Continuous
11:29
22.0
11.8
SE
S
10.2
0.87
decreasing
down - up
increasing
up - down
decreasing
decreasing
2011
01
16
Rain
Tall to Shallow
Scattered
09:28
21.2
13.7
S
S
10.9
0.55
down - up
decreasing
decreasing
decreasing
decreasing
increasing
2011
01
17
Rain
Shallow
Continuous
06:40
13.6
11.8
SW
SW
14.8
trace
decreasing
down - up
decreasing
decreasing
increasing
increasing
2011
01
18
Virga to Rain
Tall to Shallow to Tall
Continuous
12:40
15.1
6.4
N
N
1.1
0.62
decreasing
up - down
increasing
up - down
decreasing
decreasing
2011
01
20
Rain
Shallow to Tall to Shallow
Scattered
19:23
12.4
4.1
E
E
2.6
trace
increasing
increasing
decreasing
down - up
up - down
decreasing
2011
01
21
Rain
Tall to Shallow to Tall
Continuous
07:44
14.6
5.6
SE
E
3.4
0.79
increasing
increasing
flat
increasing
decreasing
decreasing
2011
01
24
Virga to Rain
Borderline to Tall to Shallow
Scattered
17:40
3.8
6.9
SE
E
3.5
trace
up - down
increasing
flat
decreasing
decreasing
up - down
2011
01
29
Rain
Shallow to Tall to Shallow
Scattered
00:03
17.2
10.2
S
S
10.0
none
increasing
decreasing
decreasing
increasing
decreasing
up - down
2011
02
04
Rain
Borderline to Tall to Shallow
Continuous
19:42
4.8
9.6
NE
NW
2.2
trace
increasing
up - down
decreasing
increasing
decreasing
decreasing
2011
02
05
Rain
Shallow to Borderline to Shallow
Continuous
23:05
1.6
8.9
E
E
6.0
trace
up - down
decreasing
down - up
increasing
decreasing
flat
2011
02
06
Rain
Shallow to Tall to Shallow
Scattered
21:37
20.6
9.4
SW
SW
8.4
0.19
increasing
decreasing
decreasing
up - down
decreasing
down - up
2011
02
07
Rain
Shallow
Scattered
18:13
11.2
7.8
W
W
11.7
0.02
increasing
decreasing
decreasing
down - up
increasing
decreasing
2011
02
11
Virga
Tall
Continuous
21:07
2.1
9.3
E
E
4.3
none
increasing
decreasing
decreasing
increasing
decreasing
decreasing
2011
02
12
Rain to Virga
Shallow to Tall
Continuous
23:37
6.5
10.6
SW
S
16.0
0.48
increasing
decreasing
decreasing
increasing
decreasing
increasing
2011
02
13
Rain to Virga
Shallow to Tall
Continuous
21:36
6.5
8.5
S
E
4.6
0.11
increasing
decreasing
decreasing
increasing
decreasing
decreasing
2011
02
14
Virga to Rain
Tall to Borderline to Tall
Scattered
11:37
23.9
7.5
SE
S
11.1
0.36
up - down
up - down
down - up
down - up
decreasing
up - down
2011
02
15
Rain
Tall to Borderline
Scattered
11:32
18.7
5.7
SE
S
10.9
0.55
decreasing
up - down
increasing
down - up
up - down
decreasing
2011
02
16
Mixed to Rain
Borderline to Tall
Scattered
13:53
10.1
3.6
S
SW
8.7
0.20
decreasing
up - down
up - down
down - up
decreasing
increasing
2011
02
17
Rain
Shallow
Scattered
05:26
8.5
3.1
SE
S
6.9
trace
decreasing
up - down
increasing
decreasing
increasing
increasing
2011
02
18
Mixed to Rain
Tall to Borderline to Tall
Continuous
07:41
19.6
3.6
SE
SE
8.1
0.11
decreasing
up - down
increasing
down - up
increasing
increasing
2011
02
24
Mixed to Rain to Mixed
Shallow to Tall to Shallow
Scattered
15:16
13.5
1.1
SE
E
7.7
0.03
up - down
up - down
increasing
decreasing
up - down
increasing
2011
03
08
Rain to Virga to Rain
Borderline to Tall to Shallow
Scattered
02:50
13.5
5.7
SE
S
10.3
0.14
up - down
decreasing
down - up
increasing
decreasing
down - up
2011
03
09
Virga to Rain
Tall to Shallow
Scattered
04:21
18.8
10.2
SE
S
12.8
0.12
up - down
increasing
down - up
decreasing
increasing
decreasing
2011
03
09
Rain to Virga to Rain
Shallow to Tall
Scattered
23:08
22.2
9.7
SE
S
12.9
1.11
down - up
decreasing
increasing
decreasing
increasing
decreasing
2011
03
10
Rain to Virga to Rain
Shallow to Borderline
Scattered
21:21
21.0
6.9
S
SW
10.4
0.05
increasing
down - up
decreasing
increasing
down - up
increasing
2011
03
12
Rain
Borderline to Tall to Shallow
Continuous
13:25
17.5
7.9
SE
S
10.1
0.21
decreasing
up - down
up - down
increasing
decreasing
increasing
2011
03
13
Virga to Rain
Tall to Borderline to Tall
Scattered
06:57
22.9
8.2
SE
SW
16.4
0.54
decreasing
increasing
increasing
up - down
increasing
down - up
2011
03
14
Rain
Shallow to Tall to Shallow
Scattered
05:49
14.5
8.9
S
S
14.1
0.07
decreasing
increasing
up - down
decreasing
increasing
increasing
2011
03
14
Rain to Virga
Shallow to Tall to Shallow
Scattered
20:21
17.8
9.8
SE
S
12.2
0.25
increasing
decreasing
decreasing
increasing
up - down
decreasing
2011
03
15
Virga to Rain to Virga
Tall
Scattered
14:07
17.5
8.5
S
W
11.8
0.59
up - down
up - down
increasing
decreasing
decreasing
down - up
2011
03
16
Rain to Virga to Rain
Tall to Shallow
Scattered
07:37
14.3
6.0
S
S
7.9
0.12
decreasing
decreasing
up - down
increasing
increasing
increasing
2011
03
16
Rain
Tall to Shallow to Tall
Scattered
21:57
12.6
5.5
S
S
8.6
0.29
decreasing
up - down
down - up
down - up
increasing
increasing
2011
03
17
Rain
Borderline
Scattered
10:33
20.1
6.4
E
E
8.1
0.10
up - down
up - down
up - down
down - up
increasing
decreasing
2011
03
18
Rain to Virga to Rain
Borderline to Tall
Scattered
06:36
22.0
6.7
E
E
11.0
0.21
down - up
decreasing
up - down
down - up
decreasing
decreasing
2011
03
19
Rain to Virga to Rain
Borderline to Tall to Borderline
Scattered
18:34
4.5
9.5
E
E
10.0
0.01
increasing
increasing
decreasing
decreasing
increasing
decreasing

Version 3, 5 August 2013

web page credits: Micheal Tai Bryant, Spencer Rhodes, Sandra Yuter

Department of Marine, Earth, and Atmospheric Sciences, North Carolina State University

This material is based upon work supported by the National Science Foundation under Grant No. ATM-0544766 and ATM-0908420
Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s)
and do not necessarily reflect the view of the National Science Foundation (NSF).

contacts:
Dr. Sandra Yuter seyuter@ncsu.edu