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

Station:

KOAK

Date/Time:

25 AUG 2019

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 Sun 71 71 N 2 2635 4000 0 Blue 0
6 AM Sun 72 72 N 2 2635 4000 0 Blue 0
7 AM Sun 70 70 N 2 2635 4000 0 Blue 0
8 AM Sun 74 74 W 3 2635 4000 0 Blue 0
9 AM Sun 79 80 W 3 3729 4000 0 Blue 3
10 AM Sun 83 86 W 3 6194 4557 557 Blue 9
11 AM Sun 85 90 SW 5 7353 6585 2585 Blue 13
12 Noon Sun 87 93 SW 5 8528 7337 3337 Blue 16
1 PM Sun 89 96 SW 5 9177 8490 4490 Blue 19
2 PM Sun 91 98 SW 10 9681 8891 4891 Blue 21
3 PM Sun 92 98 SW 10 9681 8891 4891 Blue 21
4 PM Sun 91 95 SW 10 8931 7553 3553 Blue 18
5 PM Sun 90 92 W 10 7570 7151 3151 Blue 15
6 PM Sun 85 86 W 10 6194 4557 557 Blue 9
7 PM Sun 80 80 W 10 3729 4000 0 Blue 3
8 PM Sun 72 72 W 9 2635 4000 0 Blue 0
9 PM Sun 71 71 W 9 2635 4000 0 Blue 0
10 PM Sun 72 72 W 9 2635 4000 0 Blue 0
11 PM Sun 72 72 N 5 2635 4000 0 Blue 0
12 Midnight Mon 71 71 N 5 2635 4000 0 Blue 0
1 AM Mon 71 71 N 5 2635 4000 0 Blue 0
2 AM Mon 71 71 NE 3 2635 4000 0 Blue 0
3 AM Mon 72 72 NE 3 2635 4000 0 Blue 0
4 AM Mon 71 71 NE 3 2635 4000 0 Blue 0
5 AM Mon 71 71 NE 5 2635 4000 0 Blue 0
6 AM Mon 70 70 NE 5 2635 4000 0 Blue 0
7 AM Mon 70 70 NE 5 2635 4000 0 Blue 0
8 AM Mon 74 74 NE 3 2635 4000 0 Blue 0
9 AM Mon 82 83 NE 3 4608 4000 0 Blue 6
10 AM Mon 85 88 NE 3 6924 5697 1697 Blue 11
11 AM Mon 88 93 S 6 8528 7337 3337 Blue 16
12 Noon Mon 90 96 S 6 9177 8490 4490 Blue 19
1 PM Mon 93 100 S 6 10629 9376 5376 Blue 23
2 PM Mon 95 102 S 7 10911 9873 5873 Blue 25
3 PM Mon 96 102 S 7 10911 9873 5873 Blue 25
4 PM Mon 96 100 S 7 10629 9376 5376 Blue 23
5 PM Mon 92 94 SW 12 8730 7445 3445 Blue 17
6 PM Mon 86 87 SW 12 6639 5239 1239 Blue 10
7 PM Mon 79 79 SW 12 3225 4000 0 Blue 2
8 PM Mon 74 74 SW 12 2635 4000 0 Blue 0
9 PM Mon 72 72 SW 12 2635 4000 0 Blue 0
10 PM Mon 73 73 SW 12 2635 4000 0 Blue 0
11 PM Mon 74 74 N 5 2635 4000 0 Blue 0
12 Midnight Tue 74 74 N 5 2635 4000 0 Blue 0
1 AM Tue 73 73 N 5 2635 4000 0 Blue 0
2 AM Tue 73 73 N 5 2635 4000 0 Blue 0
3 AM Tue 72 72 N 5 2635 4000 0 Blue 0
4 AM Tue 73 73 N 5 2635 4000 0 Blue 0
5 AM Tue 73 73 NE 5 2635 4000 0 Blue 0
6 AM Tue 73 73 NE 5 2635 4000 0 Blue 0
7 AM Tue 74 74 NE 5 2635 4000 0 Blue 0
8 AM Tue 76 76 NE 5 2635 4000 0 Blue 0
9 AM Tue 80 81 NE 5 4018 4000 0 Blue 4
10 AM Tue 85 88 NE 5 6924 5697 1697 Blue 11
11 AM Tue 89 94 S 7 8730 7445 3445 Blue 17
12 Noon Tue 92 98 S 7 9681 8891 4891 Blue 21
1 PM Tue 94 101 S 7 10770 9625 5625 Blue 24
2 PM Tue 95 102 S 7 10911 9873 5873 Blue 25
3 PM Tue 96 102 S 7 10911 9873 5873 Blue 25
4 PM Tue 96 100 S 7 10629 9376 5376 Blue 23
5 PM Tue 93 95 SW 9 8931 7553 3553 Blue 18
6 PM Tue 86 87 SW 9 6639 5239 1239 Blue 10
7 PM Tue 79 79 SW 9 3225 4000 0 Blue 2
8 PM Tue 74 74 SW 9 2635 4000 0 Blue 0
9 PM Tue 72 72 SW 9 2635 4000 0 Blue 0
10 PM Tue 73 73 SW 9 2635 4000 0 Blue 0
11 PM Tue 75 75 W 3 2635 4000 0 Blue 0
12 Midnight Wed 75 75 W 3 2635 4000 0 Blue 0
1 AM Wed 73 73 W 3 2635 4000 0 Blue 0
2 AM Wed 72 72 W 3 2635 4000 0 Blue 0
3 AM Wed 72 72 W 3 2635 4000 0 Blue 0
4 AM Wed 72 72 W 3 2635 4000 0 Blue 0
5 AM Wed 72 72 NE 5 2635 4000 0 Blue 0
6 AM Wed 72 72 NE 5 2635 4000 0 Blue 0
7 AM Wed 73 73 NE 5 2635 4000 0 Blue 0
8 AM Wed 75 75 NE 5 2635 4000 0 Blue 0
9 AM Wed 79 80 NE 5 3729 4000 0 Blue 3
10 AM Wed 83 85 NE 5 5740 4286 286 Blue 8
11 AM Wed 87 91 SW 9 7461 6888 2888 Blue 14
12 Noon Wed 90 95 SW 9 8931 7553 3553 Blue 18
1 PM Wed 92 98 SW 9 9681 8891 4891 Blue 21
2 PM Wed 92 97 SW 9 9430 8691 4691 Blue 20
3 PM Wed 93 98 SW 9 9681 8891 4891 Blue 21
4 PM Wed 92 95 SW 9 8931 7553 3553 Blue 18
5 PM Wed 89 91 W 10 7461 6888 2888 Blue 14
6 PM Wed 83 84 W 10 5277 4006 6 Blue 7
7 PM Wed 76 76 W 10 2635 4000 0 Blue 0
8 PM Wed 71 71 W 10 2635 4000 0 Blue 0
9 PM Wed 70 70 W 10 2635 4000 0 Blue 0
10 PM Wed 71 71 W 10 2635 4000 0 Blue 0
11 PM Wed 73 73 W 6 2635 4000 0 Blue 0
12 Midnight Thu 73 73 W 6 2635 4000 0 Blue 0
1 AM Thu 73 73 W 6 2635 4000 0 Blue 0
2 AM Thu 72 72 W 6 2635 4000 0 Blue 0
3 AM Thu 72 72 W 6 2635 4000 0 Blue 0
4 AM Thu 72 72 W 6 2635 4000 0 Blue 0
5 AM Thu 72 72 W 5 2635 4000 0 Blue 0
6 AM Thu 72 72 W 5 2635 4000 0 Blue 0
7 AM Thu 72 72 W 5 2635 4000 0 Blue 0
8 AM Thu 73 73 W 5 2635 4000 0 Blue 0
9 AM Thu 76 77 W 5 2794 4000 0 Blue 0
10 AM Thu 80 83 W 5 4608 4000 0 Blue 6
11 AM Thu 84 89 SW 9 7188 6145 2145 Blue 12
12 Noon Thu 86 92 SW 9 7570 7151 3151 Blue 15
1 PM Thu 87 94 SW 9 8730 7445 3445 Blue 17
2 PM Thu 88 95 SW 9 8931 7553 3553 Blue 18
3 PM Thu 89 95 SW 9 8931 7553 3553 Blue 18
4 PM Thu 89 93 SW 9 8528 7337 3337 Blue 16
5 PM Thu 86 88 W 10 6924 5697 1697 Blue 11
6 PM Thu 81 82 W 10 4295 4000 0 Blue 5
7 PM Thu 74 74 W 10 2635 4000 0 Blue 0
8 PM Thu 69 69 W 10 2635 4000 0 Blue 0
9 PM Thu 68 68 W 10 2635 4000 0 Blue 0
10 PM Thu 69 69 W 10 2635 4000 0 Blue 0
11 PM Thu 71 71 NW 6 2635 4000 0 Blue 0
12 Midnight Fri 71 71 NW 6 2635 4000 0 Blue 0
1 AM Fri 70 70 NW 6 2635 4000 0 Blue 0
2 AM Fri 69 69 NW 6 2635 4000 0 Blue 0
3 AM Fri 69 69 NW 6 2635 4000 0 Blue 0
4 AM Fri 69 69 NW 6 2635 4000 0 Blue 0
5 AM Fri 69 69 NW 6 2635 4000 0 Blue 0
6 AM Fri 69 69 NW 6 2635 4000 0 Blue 0
7 AM Fri 69 69 NW 6 2635 4000 0 Blue 0
8 AM Fri 71 71 NW 6 2635 4000 0 Blue 0
9 AM Fri 74 75 NW 6 2635 4000 0 Blue 0
10 AM Fri 78 81 NW 6 4018 4000 0 Blue 4
11 AM Fri 82 87 SW 8 6639 5239 1239 Blue 10
12 Noon Fri 85 91 SW 8 7461 6888 2888 Blue 14
1 PM Fri 87 94 SW 8 8730 7445 3445 Blue 17
2 PM Fri 88 95 SW 8 8931 7553 3553 Blue 18
3 PM Fri 89 95 SW 8 8931 7553 3553 Blue 18
4 PM Fri 89 93 SW 8 8528 7337 3337 Blue 16
5 PM Fri 86 88 W 10 6924 5697 1697 Blue 11
6 PM Fri 80 81 W 10 4018 4000 0 Blue 4
7 PM Fri 73 73 W 10 2635 4000 0 Blue 0
8 PM Fri 68 68 W 10 2635 4000 0 Blue 0
9 PM Fri 67 67 W 10 2635 4000 0 Blue 0
10 PM Fri 68 68 W 10 2635 4000 0 Blue 0
11 PM Fri 69 69 NW 7 2635 4000 0 Blue 0
12 Midnight Sat 70 70 NW 7 2635 4000 0 Blue 0
1 AM Sat 69 69 NW 7 2635 4000 0 Blue 0
2 AM Sat 68 68 NW 7 2635 4000 0 Blue 0
3 AM Sat 69 69 NW 7 2635 4000 0 Blue 0
4 AM Sat 69 69 NW 7 2635 4000 0 Blue 0

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