Detailed Predictions for: Hat Creek Rim
Launch Altitude (f): 4590
LZ Altitude (f): 3575
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 62 62 S 6 3573 4590 0 Blue 0
6 AM Sun 66 66 S 6 3573 4590 0 Blue 0
7 AM Sun 62 62 S 6 3573 4590 0 Blue 0
8 AM Sun 69 69 S 2 3573 4590 0 Blue 0
9 AM Sun 73 75 S 2 4444 4590 0 Blue 1
10 AM Sun 74 77 S 2 5678 4590 0 Blue 3
11 AM Sun 76 81 W 5 7176 6115 1525 Blue 7
12 Noon Sun 80 86 W 5 8742 7448 2858 Blue 12
1 PM Sun 83 90 W 5 9716 8916 4326 Blue 16
2 PM Sun 86 93 W 14 10799 9671 5081 Blue 19
3 PM Sun 86 92 W 14 10656 9417 4827 Blue 18
4 PM Sun 87 91 W 14 9971 9161 4571 Blue 17
5 PM Sun 86 88 W 13 9203 8508 3918 Blue 14
6 PM Sun 84 85 W 13 8536 7338 2748 Blue 11
7 PM Sun 83 83 W 13 7460 6883 2293 Blue 9
8 PM Sun 78 78 W 8 6144 4590 0 Blue 4
9 PM Sun 75 75 W 8 4444 4590 0 Blue 1
10 PM Sun 74 74 W 8 4245 4590 0 Blue 0
11 PM Sun 72 72 S 5 3657 4590 0 Blue 0
12 Midnight Mon 70 70 S 5 3573 4590 0 Blue 0
1 AM Mon 68 68 S 5 3573 4590 0 Blue 0
2 AM Mon 66 66 E 5 3573 4590 0 Blue 0
3 AM Mon 64 64 E 5 3573 4590 0 Blue 0
4 AM Mon 63 63 E 5 3573 4590 0 Blue 0
5 AM Mon 62 62 SE 5 3573 4590 0 Blue 0
6 AM Mon 60 60 SE 5 3573 4590 0 Blue 0
7 AM Mon 61 61 SE 5 3573 4590 0 Blue 0
8 AM Mon 67 67 SE 2 3573 4590 0 Blue 0
9 AM Mon 72 74 SE 2 4245 4590 0 Blue 0
10 AM Mon 74 77 SE 2 5678 4590 0 Blue 3
11 AM Mon 78 83 N 3 7460 6883 2293 Blue 9
12 Noon Mon 81 87 N 3 8947 7558 2968 Blue 13
1 PM Mon 84 91 N 3 9971 9161 4571 Blue 17
2 PM Mon 88 95 NW 5 11086 10626 6036 Blue 21
3 PM Mon 90 96 NW 5 11230 10769 6179 Blue 22
4 PM Mon 90 94 NW 5 10943 9924 5334 Blue 20
5 PM Mon 89 91 W 8 9971 9161 4571 Blue 17
6 PM Mon 87 88 W 8 9203 8508 3918 Blue 14
7 PM Mon 84 84 W 8 7570 7150 2560 Blue 10
8 PM Mon 81 81 W 8 7176 6115 1525 Blue 7
9 PM Mon 78 78 W 8 6144 4590 0 Blue 4
10 PM Mon 76 76 W 8 5202 4590 0 Blue 2
11 PM Mon 73 73 SE 5 3952 4590 0 Blue 0
12 Midnight Tue 71 71 SE 5 3573 4590 0 Blue 0
1 AM Tue 69 69 SE 5 3573 4590 0 Blue 0
2 AM Tue 66 66 SE 5 3573 4590 0 Blue 0
3 AM Tue 64 64 SE 5 3573 4590 0 Blue 0
4 AM Tue 63 63 SE 5 3573 4590 0 Blue 0
5 AM Tue 62 62 E 5 3573 4590 0 Blue 0
6 AM Tue 63 63 E 5 3573 4590 0 Blue 0
7 AM Tue 65 65 E 5 3573 4590 0 Blue 0
8 AM Tue 68 68 E 5 3573 4590 0 Blue 0
9 AM Tue 72 73 E 5 3952 4590 0 Blue 0
10 AM Tue 75 78 E 5 6144 4590 0 Blue 4
11 AM Tue 79 83 SE 5 7460 6883 2293 Blue 9
12 Noon Tue 83 89 SE 5 9460 8712 4122 Blue 15
1 PM Tue 87 93 SE 5 10799 9671 5081 Blue 19
2 PM Tue 90 96 SE 5 11230 10769 6179 Blue 22
3 PM Tue 91 96 SE 5 11230 10769 6179 Blue 22
4 PM Tue 91 95 SE 5 11086 10626 6036 Blue 21
5 PM Tue 90 92 W 8 10656 9417 4827 Blue 18
6 PM Tue 87 88 W 8 9203 8508 3918 Blue 14
7 PM Tue 84 84 W 8 7570 7150 2560 Blue 10
8 PM Tue 81 81 W 8 7176 6115 1525 Blue 7
9 PM Tue 78 78 W 8 6144 4590 0 Blue 4
10 PM Tue 75 75 W 8 4444 4590 0 Blue 1
11 PM Tue 73 73 SW 5 3952 4590 0 Blue 0
12 Midnight Wed 71 71 SW 5 3573 4590 0 Blue 0
1 AM Wed 68 68 SW 5 3573 4590 0 Blue 0
2 AM Wed 66 66 SW 5 3573 4590 0 Blue 0
3 AM Wed 64 64 SW 5 3573 4590 0 Blue 0
4 AM Wed 63 63 SW 5 3573 4590 0 Blue 0
5 AM Wed 63 63 SE 5 3573 4590 0 Blue 0
6 AM Wed 64 64 SE 5 3573 4590 0 Blue 0
7 AM Wed 66 66 SE 5 3573 4590 0 Blue 0
8 AM Wed 69 69 SE 5 3573 4590 0 Blue 0
9 AM Wed 72 73 SE 5 3952 4590 0 Blue 0
10 AM Wed 76 79 SE 5 6601 5186 596 Blue 5
11 AM Wed 79 83 SW 7 7460 6883 2293 Blue 9
12 Noon Wed 83 88 SW 7 9203 8508 3918 Blue 14
1 PM Wed 87 93 SW 7 10799 9671 5081 Blue 19
2 PM Wed 89 95 SW 7 11086 10626 6036 Blue 21
3 PM Wed 90 95 SW 7 11086 10626 6036 Blue 21
4 PM Wed 89 92 SW 7 10656 9417 4827 Blue 18
5 PM Wed 88 90 SW 12 9716 8916 4326 Blue 16
6 PM Wed 86 86 SW 12 8742 7448 2858 Blue 12
7 PM Wed 84 84 SW 12 7570 7150 2560 Blue 10
8 PM Wed 81 81 SW 12 7176 6115 1525 Blue 7
9 PM Wed 79 79 SW 12 6601 5186 596 Blue 5
10 PM Wed 77 77 SW 12 5678 4590 0 Blue 3
11 PM Wed 74 74 S 6 4245 4590 0 Blue 0
12 Midnight Thu 72 72 S 6 3657 4590 0 Blue 0
1 AM Thu 70 70 S 6 3573 4590 0 Blue 0
2 AM Thu 68 68 S 6 3573 4590 0 Blue 0
3 AM Thu 65 65 S 6 3573 4590 0 Blue 0
4 AM Thu 64 64 S 6 3573 4590 0 Blue 0
5 AM Thu 63 63 S 5 3573 4590 0 Blue 0
6 AM Thu 64 64 S 5 3573 4590 0 Blue 0
7 AM Thu 66 66 S 5 3573 4590 0 Blue 0
8 AM Thu 69 69 S 5 3573 4590 0 Blue 0
9 AM Thu 71 72 S 5 3657 4590 0 Blue 0
10 AM Thu 74 77 S 5 5678 4590 0 Blue 3
11 AM Thu 77 82 SW 9 7350 6566 1976 Blue 8
12 Noon Thu 80 86 SW 9 8742 7448 2858 Blue 12
1 PM Thu 83 90 SW 9 9716 8916 4326 Blue 16
2 PM Thu 85 92 SW 9 10656 9417 4827 Blue 18
3 PM Thu 86 92 SW 9 10656 9417 4827 Blue 18
4 PM Thu 86 90 SW 9 9716 8916 4326 Blue 16
5 PM Thu 85 87 SW 10 8947 7558 2968 Blue 13
6 PM Thu 83 84 SW 10 7570 7150 2560 Blue 10
7 PM Thu 81 81 SW 10 7176 6115 1525 Blue 7
8 PM Thu 78 78 SW 10 6144 4590 0 Blue 4
9 PM Thu 76 76 SW 10 5202 4590 0 Blue 2
10 PM Thu 74 74 SW 10 4245 4590 0 Blue 0
11 PM Thu 71 71 S 7 3573 4590 0 Blue 0
12 Midnight Fri 69 69 S 7 3573 4590 0 Blue 0
1 AM Fri 67 67 S 7 3573 4590 0 Blue 0
2 AM Fri 65 65 S 7 3573 4590 0 Blue 0
3 AM Fri 62 62 S 7 3573 4590 0 Blue 0
4 AM Fri 60 60 S 7 3573 4590 0 Blue 0
5 AM Fri 60 60 S 5 3573 4590 0 Blue 0
6 AM Fri 61 61 S 5 3573 4590 0 Blue 0
7 AM Fri 64 64 S 5 3573 4590 0 Blue 0
8 AM Fri 67 67 S 5 3573 4590 0 Blue 0
9 AM Fri 70 71 S 5 3573 4590 0 Blue 0
10 AM Fri 72 75 S 5 4444 4590 0 Blue 1
11 AM Fri 75 80 W 8 6906 5655 1065 Blue 6
12 Noon Fri 79 85 W 8 8536 7338 2748 Blue 11
1 PM Fri 82 89 W 8 9460 8712 4122 Blue 15
2 PM Fri 85 92 W 8 10656 9417 4827 Blue 18
3 PM Fri 86 92 W 8 10656 9417 4827 Blue 18
4 PM Fri 86 90 W 8 9716 8916 4326 Blue 16
5 PM Fri 85 87 SW 9 8947 7558 2968 Blue 13
6 PM Fri 82 83 SW 9 7460 6883 2293 Blue 9
7 PM Fri 80 80 SW 9 6906 5655 1065 Blue 6
8 PM Fri 77 77 SW 9 5678 4590 0 Blue 3
9 PM Fri 74 74 SW 9 4245 4590 0 Blue 0
10 PM Fri 71 71 SW 9 3573 4590 0 Blue 0
11 PM Fri 68 68 S 7 3573 4590 0 Blue 0
12 Midnight Sat 66 66 S 7 3573 4590 0 Blue 0
1 AM Sat 64 64 S 7 3573 4590 0 Blue 0
2 AM Sat 61 61 S 7 3573 4590 0 Blue 0
3 AM Sat 59 59 S 7 3573 4590 0 Blue 0
4 AM Sat 58 58 S 7 3573 4590 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