Detailed Predictions for: Elk Mountain
Launch Altitude (f): 4000
LZ Altitude (f): 1600
Sounding

Station:

KOAK

Date/Time:

22 MAY 2018

Temp/Wind data from:

NOAA Digital Forecast

Site Forecasts
Time
(Local)
High
Temp

Puddle
Temp

Wind
(mph)
Thermal
Ceiling

(ft)
Soaring
Ceiling

(ft)
Above
Launch

(ft)
Thermal
Type
Thermal
Index

(F)
5 AM Tue 57 57 E 5 3401 4000 0 Blue 4
6 AM Tue 57 57 E 5 3401 4000 0 Blue 4
7 AM Tue 58 58 E 5 3514 4000 0 Blue 5
8 AM Tue 60 61 E 7 3851 4000 0 Blue 8
9 AM Tue 63 65 E 7 4302 4000 0 Blue 12
10 AM Tue 66 69 E 7 4752 4408 408 Blue 16
11 AM Tue 69 73 E 5 5480 4856 856 Blue 20
12 Noon Tue 71 75 E 5 7767 5077 1077 Blue 22
1 PM Tue 72 77 E 5 9104 6455 2455 Blue 24
2 PM Tue 73 77 SE 7 9104 6455 2455 Blue 24
3 PM Tue 73 77 SE 7 9104 6455 2455 Blue 24
4 PM Tue 73 76 SE 7 8180 5443 1443 Blue 23
5 PM Tue 71 73 NW 7 5480 4856 856 Blue 20
6 PM Tue 69 70 NW 7 4864 4520 520 Blue 17
7 PM Tue 67 67 NW 7 4527 4184 184 Blue 14
8 PM Tue 64 64 N 3 4189 4000 0 Blue 11
9 PM Tue 62 62 N 3 3964 4000 0 Blue 9
10 PM Tue 61 61 N 3 3851 4000 0 Blue 8
11 PM Tue 60 60 S 2 3739 4000 0 Blue 7
12 Midnight Wed 59 59 S 2 3626 4000 0 Blue 6
1 AM Wed 58 58 S 2 3514 4000 0 Blue 5
2 AM Wed 57 57 SW 2 3401 4000 0 Blue 4
3 AM Wed 57 57 SW 2 3401 4000 0 Blue 4
4 AM Wed 56 56 SW 2 3289 4000 0 Blue 3
5 AM Wed 56 56 SE 2 3289 4000 0 Blue 3
6 AM Wed 56 56 SE 2 3289 4000 0 Blue 3
7 AM Wed 57 57 SE 2 3401 4000 0 Blue 4
8 AM Wed 59 59 E 2 3626 4000 0 Blue 6
9 AM Wed 61 62 E 2 3964 4000 0 Blue 9
10 AM Wed 63 66 E 2 4414 4071 71 Blue 13
11 AM Wed 65 69 SE 5 4752 4408 408 Blue 16
12 Noon Wed 68 73 SE 5 5480 4856 856 Blue 20
1 PM Wed 69 74 SE 5 6602 4967 967 Blue 21
2 PM Wed 71 76 SE 8 8180 5443 1443 Blue 23
3 PM Wed 71 75 SE 8 7767 5077 1077 Blue 22
4 PM Wed 71 74 SE 8 6602 4967 967 Blue 21
5 PM Wed 69 71 S 6 4975 4632 632 Blue 18
6 PM Wed 67 68 S 6 4640 4296 296 Blue 15
7 PM Wed 64 64 S 6 4189 4000 0 Blue 11
8 PM Wed 61 61 S 6 3851 4000 0 Blue 8
9 PM Wed 59 59 S 6 3626 4000 0 Blue 6
10 PM Wed 57 57 S 6 3401 4000 0 Blue 4
11 PM Wed 56 56 SW 3 3289 4000 0 Blue 3
12 Midnight Thu 56 56 SW 3 3289 4000 0 Blue 3
1 AM Thu 56 56 SW 3 3289 4000 0 Blue 3
2 AM Thu 56 56 SW 3 3289 4000 0 Blue 3
3 AM Thu 55 55 SW 3 3178 4000 0 Blue 2
4 AM Thu 54 54 SW 3 3068 4000 0 Blue 1
5 AM Thu 54 54 SE 2 3068 4000 0 Blue 1
6 AM Thu 55 55 SE 2 3178 4000 0 Blue 2
7 AM Thu 56 56 SE 2 3289 4000 0 Blue 3
8 AM Thu 59 59 SE 2 3626 4000 0 Blue 6
9 AM Thu 62 63 SE 2 4076 4000 0 Blue 10
10 AM Thu 64 66 SE 2 4414 4071 71 Blue 13
11 AM Thu 67 70 SE 8 4864 4520 520 Blue 17
12 Noon Thu 69 72 SE 8 5086 4745 745 Blue 19
1 PM Thu 71 74 SE 8 6602 4967 967 Blue 21
2 PM Thu 72 75 SE 8 7767 5077 1077 Blue 22
3 PM Thu 72 75 SE 8 7767 5077 1077 Blue 22
4 PM Thu 71 73 SE 8 5480 4856 856 Blue 20
5 PM Thu 69 70 SW 8 4864 4520 520 Blue 17
6 PM Thu 65 65 SW 8 4302 4000 0 Blue 12
7 PM Thu 61 61 SW 8 3851 4000 0 Blue 8
8 PM Thu 57 57 SW 8 3401 4000 0 Blue 4
9 PM Thu 54 54 SW 8 3068 4000 0 Blue 1
10 PM Thu 52 52 SW 8 2928 4000 0 Blue 0
11 PM Thu 51 51 SW 3 2887 4000 0 Blue 0
12 Midnight Fri 51 51 SW 3 2887 4000 0 Blue 0
1 AM Fri 51 51 SW 3 2887 4000 0 Blue 0
2 AM Fri 51 51 SW 3 2887 4000 0 Blue 0
3 AM Fri 51 51 SW 3 2887 4000 0 Blue 0
4 AM Fri 50 50 SW 3 2846 4000 0 Blue 0
5 AM Fri 49 49 SW 2 2805 4000 0 Blue 0
6 AM Fri 49 49 SW 2 2805 4000 0 Blue 0
7 AM Fri 49 49 SW 2 2805 4000 0 Blue 0
8 AM Fri 51 51 SW 2 2887 4000 0 Blue 0
9 AM Fri 53 53 SW 2 2969 4000 0 Blue 0
10 AM Fri 57 58 SW 2 3514 4000 0 Blue 5
11 AM Fri 59 61 S 6 3851 4000 0 Blue 8
12 Noon Fri 61 63 S 6 4076 4000 0 Blue 10
1 PM Fri 62 64 S 6 4189 4000 0 Blue 11
2 PM Fri 62 64 S 6 4189 4000 0 Blue 11
3 PM Fri 63 65 S 6 4302 4000 0 Blue 12
4 PM Fri 63 64 S 6 4189 4000 0 Blue 11
5 PM Fri 62 63 W 6 4076 4000 0 Blue 10
6 PM Fri 60 60 W 6 3739 4000 0 Blue 7
7 PM Fri 57 57 W 6 3401 4000 0 Blue 4
8 PM Fri 55 55 W 6 3178 4000 0 Blue 2
9 PM Fri 53 53 W 6 2969 4000 0 Blue 0
10 PM Fri 51 51 W 6 2887 4000 0 Blue 0
11 PM Fri 50 50 NW 6 2846 4000 0 Blue 0
12 Midnight Sat 50 50 NW 6 2846 4000 0 Blue 0
1 AM Sat 49 49 NW 6 2805 4000 0 Blue 0
2 AM Sat 49 49 NW 6 2805 4000 0 Blue 0
3 AM Sat 48 48 NW 6 2764 4000 0 Blue 0
4 AM Sat 47 47 NW 6 2723 4000 0 Blue 0
5 AM Sat 47 47 NW 5 2723 4000 0 Blue 0
6 AM Sat 48 48 NW 5 2764 4000 0 Blue 0
7 AM Sat 50 50 NW 5 2846 4000 0 Blue 0
8 AM Sat 52 52 NW 5 2928 4000 0 Blue 0
9 AM Sat 55 57 NW 5 3401 4000 0 Blue 4
10 AM Sat 59 62 NW 5 3964 4000 0 Blue 9
11 AM Sat 62 66 W 6 4414 4071 71 Blue 13
12 Noon Sat 64 69 W 6 4752 4408 408 Blue 16
1 PM Sat 66 71 W 6 4975 4632 632 Blue 18
2 PM Sat 67 72 W 6 5086 4745 745 Blue 19
3 PM Sat 68 72 W 6 5086 4745 745 Blue 19
4 PM Sat 68 71 W 6 4975 4632 632 Blue 18
5 PM Sat 67 69 W 10 4752 4408 408 Blue 16
6 PM Sat 65 66 W 10 4414 4071 71 Blue 13
7 PM Sat 62 62 W 10 3964 4000 0 Blue 9
8 PM Sat 59 59 W 10 3626 4000 0 Blue 6
9 PM Sat 56 56 W 10 3289 4000 0 Blue 3
10 PM Sat 55 55 W 10 3178 4000 0 Blue 2
11 PM Sat 54 54 NW 7 3068 4000 0 Blue 1
12 Midnight Sun 53 53 NW 7 2969 4000 0 Blue 0
1 AM Sun 53 53 NW 7 2969 4000 0 Blue 0
2 AM Sun 52 52 NW 7 2928 4000 0 Blue 0
3 AM Sun 51 51 NW 7 2887 4000 0 Blue 0
4 AM Sun 51 51 NW 7 2887 4000 0 Blue 0
5 AM Sun 51 51 N 7 2887 4000 0 Blue 0
6 AM Sun 52 52 N 7 2928 4000 0 Blue 0
7 AM Sun 54 54 N 7 3068 4000 0 Blue 1
8 AM Sun 57 58 N 7 3514 4000 0 Blue 5
9 AM Sun 60 62 N 7 3964 4000 0 Blue 9
10 AM Sun 65 68 N 7 4640 4296 296 Blue 15
11 AM Sun 69 74 W 3 6602 4967 967 Blue 21
12 Noon Sun 72 78 W 3 9945 7595 3595 Blue 25
1 PM Sun 74 80 W 3 10869 8921 4921 White 27
2 PM Sun 75 81 W 3 11076 9754 5754 White 28
3 PM Sun 76 81 W 3 11076 9754 5754 White 28
4 PM Sun 76 79 W 3 10661 8107 4107 White 26
5 PM Sun 75 77 W 6 9104 6455 2455 Blue 24
6 PM Sun 73 74 W 6 6602 4967 967 Blue 21
7 PM Sun 70 70 W 6 4864 4520 520 Blue 17
8 PM Sun 66 66 W 6 4414 4071 71 Blue 13
9 PM Sun 64 64 W 6 4189 4000 0 Blue 11
10 PM Sun 62 62 W 6 3964 4000 0 Blue 9
11 PM Sun 61 61 N 6 3851 4000 0 Blue 8
12 Midnight Mon 60 60 N 6 3739 4000 0 Blue 7
1 AM Mon 59 59 N 6 3626 4000 0 Blue 6
2 AM Mon 58 58 N 6 3514 4000 0 Blue 5
3 AM Mon 57 57 N 6 3401 4000 0 Blue 4
4 AM Mon 56 56 N 6 3289 4000 0 Blue 3

DISCLAIMER: These estimates are intended to assist in daily site selection only.  No warranty is made concerning the accuracy of these estimates.  These estimates cannot be used to determine if conditions are safe for flying.  Conditions should be evaluated at the launch site by experienced pilots before launching.

Sounding: This is the site at which the weather balloon was released.  If the flying site predicted is far from the sounding site, the estimate is not valid.  Also, the sounding is done at 12Z (4AM PST).  If a front comes through, the sounding is no longer valid. The sounding becomes less valid later in the day.

Thermal Ceiling: the lower of the height at which the thermal stops rising and the cloud level.  We can't fly into the clouds, so it doesn't matter how much higher the thermal goes.  Remember that we can't get to the top of the thermal because of our sink rate.  Our upper limit will be lower than the reported ceiling.

Soaring Ceiling: We will stop going up when the thermal is rising just fast enough to offset our sink.  It is estimated that this happens when the temperature difference between the thermal and the surrounding air is about 2 degrees F. This number is an estimate of the maximum altitude we might reach if we start at launch height, and should be more reflective of our chances of soaring than the thermal top. Please let me know how this compares with actually flying, and I will adjust it as necessary.

Above Launch: The difference between how high we might get and how high we start. This estimate does not account for ridge lift.

High Temp: This estimate is taken from the National Weather Service website.  Puddle temperatures can exceed this temperature. 

Puddle Temp: This estimate is based on the High Temp and the National Weather Service estimate of cloudiness, and the angle of the sun.  When the sun is directly overhead on a sunny day, the puddle temp is esimated to be 25 degrees warmer than the high ambient temperature. This estimate now includes a rigorous calculation of the Sun Angle, and accounts for the seasonal differences in zenith and daylight hours.

Wind: This estimate is taken from the National Weather Service website.

Thermal Type: Blue (no cloud formation) or White (Cloud formation)

Thermal Index: This is the maximum difference in temperature between the rising packet of air (the thermal) and the surrounding air.  The difference in temperature is responsible for the buoyancy of the thermal, and larger temperature differences mean faster rising thermals.  A value of about 10 F or greater often means that the conditions are soarable.  Values above 20 could indicate rowdy thermals.

Validity of estimate: Many factors (including strong wind, fronts, cloud shadows, incorrectly predicted temperatures, etc) can affect the validity of the estimates. 

Author: Tad Hurst

Supported By: Alan Crouse ac_soaring@yahoo.com