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

Station:

KOAK

Date/Time:

26 MAY 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 45 45 NW 14 4091 4000 0 White 4
6 AM Sun 44 44 NW 14 3869 4000 0 White 3
7 AM Sun 44 44 NW 14 3869 4000 0 White 3
8 AM Sun 45 45 NW 13 4091 4000 0 White 4
9 AM Sun 46 46 NW 13 4312 4000 0 White 5
10 AM Sun 48 49 NW 13 4967 4775 775 White 8
11 AM Sun 49 51 N 9 5400 5179 1179 White 10
12 Noon Sun 51 53 N 9 5832 5580 1580 White 12
1 PM Sun 52 54 N 9 6046 6046 2046 White 13
2 PM Sun 54 56 N 7 6473 6473 2473 White 15
3 PM Sun 56 58 N 7 6898 6898 2898 White 17
4 PM Sun 57 58 N 7 6898 6898 2898 White 17
5 PM Sun 57 57 NW 8 6686 6686 2686 White 16
6 PM Sun 56 56 NW 8 6473 6473 2473 White 15
7 PM Sun 54 54 NW 8 6046 6046 2046 White 13
8 PM Sun 52 52 N 5 5616 5380 1380 White 11
9 PM Sun 50 50 N 5 5184 4977 977 White 9
10 PM Sun 49 49 N 5 4967 4775 775 White 8
11 PM Sun 48 48 NW 7 4749 4564 564 White 7
12 Midnight Mon 48 48 NW 7 4749 4564 564 White 7
1 AM Mon 47 47 NW 7 4533 4212 212 White 6
2 AM Mon 47 47 N 8 4533 4212 212 White 6
3 AM Mon 47 47 N 8 4533 4212 212 White 6
4 AM Mon 47 47 N 8 4533 4212 212 White 6
5 AM Mon 47 47 NE 7 4533 4212 212 White 6
6 AM Mon 48 48 NE 7 4749 4564 564 White 7
7 AM Mon 48 48 NE 7 4749 4564 564 White 7
8 AM Mon 50 50 N 3 5184 4977 977 White 9
9 AM Mon 53 54 N 3 6046 6046 2046 White 13
10 AM Mon 56 58 N 3 6898 6898 2898 White 17
11 AM Mon 59 61 SE 8 7533 7533 3533 White 20
12 Noon Mon 62 65 SE 8 8370 8370 4370 White 24
1 PM Mon 63 66 SE 8 8577 8577 4577 White 25
2 PM Mon 64 67 S 10 8787 8787 4787 White 26
3 PM Mon 65 68 S 10 8999 8999 4999 White 27
4 PM Mon 65 67 S 10 8787 8787 4787 White 26
5 PM Mon 64 65 NW 10 8370 8370 4370 White 24
6 PM Mon 63 63 NW 10 7952 7952 3952 White 22
7 PM Mon 61 61 NW 10 7533 7533 3533 White 20
8 PM Mon 58 58 NW 10 6898 6898 2898 White 17
9 PM Mon 56 56 NW 10 6473 6473 2473 White 15
10 PM Mon 54 54 NW 10 6046 6046 2046 White 13
11 PM Mon 53 53 NW 7 5832 5580 1580 White 12
12 Midnight Tue 52 52 NW 7 5616 5380 1380 White 11
1 AM Tue 52 52 NW 7 5616 5380 1380 White 11
2 AM Tue 52 52 NW 7 5616 5380 1380 White 11
3 AM Tue 52 52 NW 7 5616 5380 1380 White 11
4 AM Tue 51 51 NW 7 5400 5179 1179 White 10
5 AM Tue 51 51 NE 8 5400 5179 1179 White 10
6 AM Tue 52 52 NE 8 5616 5380 1380 White 11
7 AM Tue 53 53 NE 8 5832 5580 1580 White 12
8 AM Tue 55 56 NE 8 6473 6473 2473 White 15
9 AM Tue 59 61 NE 8 7533 7533 3533 White 20
10 AM Tue 62 66 NE 8 8577 8577 4577 White 25
11 AM Tue 66 70 N 8 9421 9421 5421 White 29
12 Noon Tue 69 74 N 8 10242 10242 6242 White 33
1 PM Tue 71 77 N 8 10847 10847 6847 White 36
2 PM Tue 73 78 N 8 11047 11047 7047 White 37
3 PM Tue 74 79 N 8 11251 11251 7251 White 38
4 PM Tue 74 77 N 8 10847 10847 6847 White 36
5 PM Tue 73 75 NW 10 10444 10444 6444 White 34
6 PM Tue 71 72 NW 10 9837 9837 5837 White 31
7 PM Tue 68 68 NW 10 8999 8999 4999 White 27
8 PM Tue 65 65 NW 10 8370 8370 4370 White 24
9 PM Tue 63 63 NW 10 7952 7952 3952 White 22
10 PM Tue 61 61 NW 10 7533 7533 3533 White 20
11 PM Tue 59 59 NW 7 7110 7110 3110 White 18
12 Midnight Wed 58 58 NW 7 6898 6898 2898 White 17
1 AM Wed 57 57 NW 7 6686 6686 2686 White 16
2 AM Wed 57 57 NW 7 6686 6686 2686 White 16
3 AM Wed 56 56 NW 7 6473 6473 2473 White 15
4 AM Wed 55 55 NW 7 6259 6259 2259 White 14
5 AM Wed 55 55 N 6 6259 6259 2259 White 14
6 AM Wed 56 56 N 6 6473 6473 2473 White 15
7 AM Wed 57 57 N 6 6686 6686 2686 White 16
8 AM Wed 60 60 N 6 7323 7323 3323 White 19
9 AM Wed 63 64 N 6 8161 8161 4161 White 23
10 AM Wed 66 69 N 6 9210 9210 5210 White 28
11 AM Wed 70 73 W 5 10040 10040 6040 White 32
12 Noon Wed 72 76 W 5 10647 10647 6647 White 35
1 PM Wed 74 78 W 5 11047 11047 7047 White 37
2 PM Wed 75 79 W 5 11251 11251 7251 White 38
3 PM Wed 76 80 W 5 11452 11452 7452 White 39
4 PM Wed 76 79 W 5 11251 11251 7251 White 38
5 PM Wed 75 77 W 9 10847 10847 6847 White 36
6 PM Wed 72 73 W 9 10040 10040 6040 White 32
7 PM Wed 69 69 W 9 9210 9210 5210 White 28
8 PM Wed 66 66 W 9 8577 8577 4577 White 25
9 PM Wed 64 64 W 9 8161 8161 4161 White 23
10 PM Wed 61 61 W 9 7533 7533 3533 White 20
11 PM Wed 60 60 NW 7 7323 7323 3323 White 19
12 Midnight Thu 59 59 NW 7 7110 7110 3110 White 18
1 AM Thu 58 58 NW 7 6898 6898 2898 White 17
2 AM Thu 57 57 NW 7 6686 6686 2686 White 16
3 AM Thu 56 56 NW 7 6473 6473 2473 White 15
4 AM Thu 56 56 NW 7 6473 6473 2473 White 15
5 AM Thu 56 56 N 6 6473 6473 2473 White 15
6 AM Thu 57 57 N 6 6686 6686 2686 White 16
7 AM Thu 59 59 N 6 7110 7110 3110 White 18
8 AM Thu 61 62 N 6 7743 7743 3743 White 21
9 AM Thu 64 66 N 6 8577 8577 4577 White 25
10 AM Thu 67 70 N 6 9421 9421 5421 White 29
11 AM Thu 69 72 NW 6 9837 9837 5837 White 31
12 Noon Thu 72 76 NW 6 10647 10647 6647 White 35
1 PM Thu 73 77 NW 6 10847 10847 6847 White 36
2 PM Thu 74 78 NW 6 11047 11047 7047 White 37
3 PM Thu 75 79 NW 6 11251 11251 7251 White 38
4 PM Thu 75 78 NW 6 11047 11047 7047 White 37
5 PM Thu 74 76 W 9 10647 10647 6647 White 35
6 PM Thu 72 73 W 9 10040 10040 6040 White 32
7 PM Thu 70 70 W 9 9421 9421 5421 White 29
8 PM Thu 67 67 W 9 8787 8787 4787 White 26
9 PM Thu 65 65 W 9 8370 8370 4370 White 24
10 PM Thu 63 63 W 9 7952 7952 3952 White 22
11 PM Thu 61 61 NW 7 7533 7533 3533 White 20
12 Midnight Fri 60 60 NW 7 7323 7323 3323 White 19
1 AM Fri 59 59 NW 7 7110 7110 3110 White 18
2 AM Fri 59 59 NW 7 7110 7110 3110 White 18
3 AM Fri 58 58 NW 7 6898 6898 2898 White 17
4 AM Fri 57 57 NW 7 6686 6686 2686 White 16
5 AM Fri 57 57 N 6 6686 6686 2686 White 16
6 AM Fri 58 58 N 6 6898 6898 2898 White 17
7 AM Fri 60 60 N 6 7323 7323 3323 White 19
8 AM Fri 62 63 N 6 7952 7952 3952 White 22
9 AM Fri 65 67 N 6 8787 8787 4787 White 26
10 AM Fri 68 71 N 6 9633 9633 5633 White 30
11 AM Fri 71 75 NW 6 10444 10444 6444 White 34
12 Noon Fri 74 79 NW 6 11251 11251 7251 White 38
1 PM Fri 76 82 NW 6 11854 11854 7854 White 41
2 PM Fri 77 82 NW 6 11854 11854 7854 White 41
3 PM Fri 77 81 NW 6 11653 11653 7653 White 40
4 PM Fri 76 79 NW 6 11251 11251 7251 White 38
5 PM Fri 75 77 W 9 10847 10847 6847 White 36
6 PM Fri 73 74 W 9 10242 10242 6242 White 33
7 PM Fri 71 71 W 9 9633 9633 5633 White 30
8 PM Fri 69 69 W 9 9210 9210 5210 White 28
9 PM Fri 67 67 W 9 8787 8787 4787 White 26
10 PM Fri 65 65 W 9 8370 8370 4370 White 24
11 PM Fri 64 64 NW 7 8161 8161 4161 White 23
12 Midnight Sat 63 63 NW 7 7952 7952 3952 White 22
1 AM Sat 62 62 NW 7 7743 7743 3743 White 21
2 AM Sat 61 61 NW 7 7533 7533 3533 White 20
3 AM Sat 60 60 NW 7 7323 7323 3323 White 19
4 AM Sat 59 59 NW 7 7110 7110 3110 White 18

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