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

Station:

KOAK

Date/Time:

23 SEP 2017

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 Sat 50 50 NE 8 2536 4000 0 Blue 0
6 AM Sat 49 49 NE 8 2536 4000 0 Blue 0
7 AM Sat 49 49 NE 8 2536 4000 0 Blue 0
8 AM Sat 51 51 NE 10 2536 4000 0 Blue 0
9 AM Sat 54 55 NE 10 3680 4000 0 Blue 1
10 AM Sat 60 62 NE 10 7693 5983 1983 Blue 8
11 AM Sat 65 68 NE 10 9457 9457 5457 White 14
12 Noon Sat 68 73 NE 10 10513 10513 6513 White 19
1 PM Sat 71 76 NE 10 11126 11126 7126 White 22
2 PM Sat 72 77 N 8 11329 11329 7329 White 23
3 PM Sat 73 77 N 8 11329 11329 7329 White 23
4 PM Sat 73 76 N 8 11126 11126 7126 White 22
5 PM Sat 71 72 NE 7 10308 10308 6308 White 18
6 PM Sat 68 68 NE 7 9457 9457 5457 White 14
7 PM Sat 64 64 NE 7 8618 6986 2986 White 10
8 PM Sat 61 61 N 5 7046 4505 505 Blue 7
9 PM Sat 59 59 N 5 6029 4000 0 Blue 5
10 PM Sat 58 58 N 5 4546 4000 0 Blue 4
11 PM Sat 57 57 NE 6 4262 4000 0 Blue 3
12 Midnight Sun 57 57 NE 6 4262 4000 0 Blue 3
1 AM Sun 56 56 NE 6 4009 4000 0 Blue 2
2 AM Sun 56 56 NE 7 4009 4000 0 Blue 2
3 AM Sun 55 55 NE 7 3680 4000 0 Blue 1
4 AM Sun 55 55 NE 7 3680 4000 0 Blue 1
5 AM Sun 55 55 NE 7 3680 4000 0 Blue 1
6 AM Sun 54 54 NE 7 2737 4000 0 Blue 0
7 AM Sun 54 54 NE 7 2737 4000 0 Blue 0
8 AM Sun 56 56 NE 8 4009 4000 0 Blue 2
9 AM Sun 60 61 NE 8 7046 4505 505 Blue 7
10 AM Sun 65 67 NE 8 9249 8837 4837 White 13
11 AM Sun 71 74 N 8 10719 10719 6719 White 20
12 Noon Sun 74 78 N 8 11531 11531 7531 White 24
1 PM Sun 77 82 N 8 12335 12335 8335 White 28
2 PM Sun 78 82 N 6 12335 12335 8335 White 28
3 PM Sun 79 82 N 6 12335 12335 8335 White 28
4 PM Sun 79 81 N 6 12134 12134 8134 White 27
5 PM Sun 77 78 NW 7 11531 11531 7531 White 24
6 PM Sun 74 74 NW 7 10719 10719 6719 White 20
7 PM Sun 70 70 NW 7 9887 9887 5887 White 16
8 PM Sun 66 66 NW 7 9040 8268 4268 White 12
9 PM Sun 64 64 NW 7 8618 6986 2986 White 10
10 PM Sun 63 63 NW 7 8407 6540 2540 White 9
11 PM Sun 63 63 NE 7 8407 6540 2540 White 9
12 Midnight Mon 62 62 NE 7 7693 5983 1983 Blue 8
1 AM Mon 61 61 NE 7 7046 4505 505 Blue 7
2 AM Mon 61 61 NE 7 7046 4505 505 Blue 7
3 AM Mon 60 60 NE 7 6624 4249 249 Blue 6
4 AM Mon 60 60 NE 7 6624 4249 249 Blue 6
5 AM Mon 59 59 NE 6 6029 4000 0 Blue 5
6 AM Mon 58 58 NE 6 4546 4000 0 Blue 4
7 AM Mon 58 58 NE 6 4546 4000 0 Blue 4
8 AM Mon 60 60 NE 6 6624 4249 249 Blue 6
9 AM Mon 64 65 NE 6 8829 7574 3574 White 11
10 AM Mon 70 72 NE 6 10308 10308 6308 White 18
11 AM Mon 75 78 NE 7 11531 11531 7531 White 24
12 Noon Mon 79 84 NE 7 12735 12735 8735 White 30
1 PM Mon 81 86 NE 7 13134 13134 9134 White 32
2 PM Mon 83 88 NE 7 13532 13532 9532 White 34
3 PM Mon 84 88 NE 7 13532 13532 9532 White 34
4 PM Mon 84 87 NE 7 13334 13334 9334 White 33
5 PM Mon 82 83 N 6 12535 12535 8535 White 29
6 PM Mon 79 79 N 6 11733 11733 7733 White 25
7 PM Mon 75 75 N 6 10923 10923 6923 White 21
8 PM Mon 72 72 N 6 10308 10308 6308 White 18
9 PM Mon 70 70 N 6 9887 9887 5887 White 16
10 PM Mon 69 69 N 6 9666 9666 5666 White 15
11 PM Mon 68 68 NE 7 9457 9457 5457 White 14
12 Midnight Tue 67 67 NE 7 9249 8837 4837 White 13
1 AM Tue 67 67 NE 7 9249 8837 4837 White 13
2 AM Tue 66 66 NE 7 9040 8268 4268 White 12
3 AM Tue 66 66 NE 7 9040 8268 4268 White 12
4 AM Tue 65 65 NE 7 8829 7574 3574 White 11
5 AM Tue 65 65 NE 7 8829 7574 3574 White 11
6 AM Tue 64 64 NE 7 8618 6986 2986 White 10
7 AM Tue 64 64 NE 7 8618 6986 2986 White 10
8 AM Tue 66 66 NE 7 9040 8268 4268 White 12
9 AM Tue 69 70 NE 7 9887 9887 5887 White 16
10 AM Tue 74 76 NE 7 11126 11126 7126 White 22
11 AM Tue 79 82 E 7 12335 12335 8335 White 28
12 Noon Tue 83 88 E 7 13532 13532 9532 White 34
1 PM Tue 85 90 E 7 13928 13928 9928 White 36
2 PM Tue 87 92 E 7 14321 14321 10321 White 38
3 PM Tue 88 92 E 7 14321 14321 10321 White 38
4 PM Tue 88 91 E 7 14125 14125 10125 White 37
5 PM Tue 86 87 SE 6 13334 13334 9334 White 33
6 PM Tue 83 83 SE 6 12535 12535 8535 White 29
7 PM Tue 78 78 SE 6 11531 11531 7531 White 24
8 PM Tue 74 74 SE 6 10719 10719 6719 White 20
9 PM Tue 72 72 SE 6 10308 10308 6308 White 18
10 PM Tue 71 71 SE 6 10103 10103 6103 White 17
11 PM Tue 70 70 NE 5 9887 9887 5887 White 16
12 Midnight Wed 69 69 NE 5 9666 9666 5666 White 15
1 AM Wed 68 68 NE 5 9457 9457 5457 White 14
2 AM Wed 67 67 NE 5 9249 8837 4837 White 13
3 AM Wed 66 66 NE 5 9040 8268 4268 White 12
4 AM Wed 66 66 NE 5 9040 8268 4268 White 12
5 AM Wed 65 65 NE 8 8829 7574 3574 White 11
6 AM Wed 64 64 NE 8 8618 6986 2986 White 10
7 AM Wed 64 64 NE 8 8618 6986 2986 White 10
8 AM Wed 65 65 NE 8 8829 7574 3574 White 11
9 AM Wed 69 70 NE 8 9887 9887 5887 White 16
10 AM Wed 73 75 NE 8 10923 10923 6923 White 21
11 AM Wed 78 81 E 5 12134 12134 8134 White 27
12 Noon Wed 82 86 E 5 13134 13134 9134 White 32
1 PM Wed 84 88 E 5 13532 13532 9532 White 34
2 PM Wed 85 89 E 5 13729 13729 9729 White 35
3 PM Wed 86 89 E 5 13729 13729 9729 White 35
4 PM Wed 86 88 E 5 13532 13532 9532 White 34
5 PM Wed 84 85 S 3 12935 12935 8935 White 31
6 PM Wed 80 80 S 3 11934 11934 7934 White 26
7 PM Wed 76 76 S 3 11126 11126 7126 White 22
8 PM Wed 72 72 S 3 10308 10308 6308 White 18
9 PM Wed 69 69 S 3 9666 9666 5666 White 15
10 PM Wed 68 68 S 3 9457 9457 5457 White 14
11 PM Wed 67 67 N 3 9249 8837 4837 White 13
12 Midnight Thu 67 67 N 3 9249 8837 4837 White 13
1 AM Thu 66 66 N 3 9040 8268 4268 White 12
2 AM Thu 65 65 N 3 8829 7574 3574 White 11
3 AM Thu 65 65 N 3 8829 7574 3574 White 11
4 AM Thu 65 65 N 3 8829 7574 3574 White 11
5 AM Thu 64 64 E 3 8618 6986 2986 White 10
6 AM Thu 64 64 E 3 8618 6986 2986 White 10
7 AM Thu 64 64 E 3 8618 6986 2986 White 10
8 AM Thu 66 66 E 3 9040 8268 4268 White 12
9 AM Thu 69 69 E 3 9666 9666 5666 White 15
10 AM Thu 74 75 E 3 10923 10923 6923 White 21
11 AM Thu 79 82 E 5 12335 12335 8335 White 28
12 Noon Thu 83 87 E 5 13334 13334 9334 White 33
1 PM Thu 85 89 E 5 13729 13729 9729 White 35
2 PM Thu 87 91 E 5 14125 14125 10125 White 37
3 PM Thu 87 90 E 5 13928 13928 9928 White 36
4 PM Thu 86 88 E 5 13532 13532 9532 White 34
5 PM Thu 84 85 SW 7 12935 12935 8935 White 31
6 PM Thu 81 81 SW 7 12134 12134 8134 White 27
7 PM Thu 77 77 SW 7 11329 11329 7329 White 23
8 PM Thu 73 73 SW 7 10513 10513 6513 White 19
9 PM Thu 71 71 SW 7 10103 10103 6103 White 17
10 PM Thu 70 70 SW 7 9887 9887 5887 White 16
11 PM Thu 69 69 N 5 9666 9666 5666 White 15
12 Midnight Fri 68 68 N 5 9457 9457 5457 White 14
1 AM Fri 67 67 N 5 9249 8837 4837 White 13
2 AM Fri 67 67 N 5 9249 8837 4837 White 13
3 AM Fri 67 67 N 5 9249 8837 4837 White 13
4 AM Fri 66 66 N 5 9040 8268 4268 White 12

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