Detailed Predictions for: Hat Creek Rim
Launch Lat, Long, Altitude (f): 40.843037, -121.427406, 4590
LZ Altitude (f): 3575
Sounding

Station:

KOAK

Date/Time:

23 JUN 2021

Temp/Wind data from:

NOAA Digital Forecast

Site Forecasts
Time
(Local)
High
Temp

Puddle
Temp

Wind
(mph)
Wind
Gust
Thermal
Ceiling

(ft)
Soaring
Ceiling

(ft)
Above
Launch

(ft)
Thermal
Type
Thermal
Index

(F)
12 Midnight Wed 63 63 E 4 5 4082 4590 0 Blue 0
1 AM Wed 62 62 E 4 5 4030 4590 0 Blue 0
2 AM Wed 61 61 E 5 9 3978 4590 0 Blue 0
3 AM Wed 59 59 E 5 9 3976 4590 0 Blue 0
4 AM Wed 58 58 E 5 9 3976 4590 0 Blue 0
5 AM Wed 57 57 SE 4 6 3976 4590 0 Blue 0
6 AM Wed 55 55 SE 4 6 3976 4590 0 Blue 0
7 AM Wed 61 61 SE 4 6 3978 4590 0 Blue 0
8 AM Wed 65 66 WNW 4 6 4238 4590 0 Blue 2
9 AM Wed 69 72 WNW 4 6 5839 4894 304 Blue 8
10 AM Wed 73 78 WNW 4 6 12384 7195 2605 Blue 14
11 AM Wed 76 82 W 9 13 13393 12608 8018 Blue 18
12 Noon Wed 79 86 W 9 13 15276 13632 9042 White 22
1 PM Wed 80 88 W 9 13 15679 14239 9649 White 24
2 PM Wed 80 87 W 12 19 15478 13945 9355 White 23
3 PM Wed 81 87 W 12 19 15478 13945 9355 White 23
4 PM Wed 81 85 W 12 19 15074 13285 8695 White 21
5 PM Wed 80 82 W 12 19 13393 12608 8018 Blue 18
6 PM Wed 81 82 W 12 19 13393 12608 8018 Blue 18
7 PM Wed 80 80 W 12 19 12900 10630 6040 Blue 16
8 PM Wed 79 79 W 8 12 12695 7771 3181 Blue 15
9 PM Wed 74 74 W 8 12 6515 5221 631 Blue 10
10 PM Wed 70 70 W 8 12 5006 4590 0 Blue 6
11 PM Wed 66 66 ESE 5 9 4238 4590 0 Blue 2
12 Midnight Thu 65 65 ESE 5 9 4183 4590 0 Blue 1
1 AM Thu 62 62 ESE 5 9 4030 4590 0 Blue 0
2 AM Thu 61 61 ESE 5 9 3978 4590 0 Blue 0
3 AM Thu 60 60 ESE 5 9 3976 4590 0 Blue 0
4 AM Thu 58 58 ESE 5 9 3976 4590 0 Blue 0
5 AM Thu 57 57 SSE 3 5 3976 4590 0 Blue 0
6 AM Thu 57 57 SSE 3 5 3976 4590 0 Blue 0
7 AM Thu 61 61 SSE 3 5 3978 4590 0 Blue 0
8 AM Thu 67 68 NNE 3 5 4514 4590 0 Blue 4
9 AM Thu 70 73 NNE 3 5 6204 5003 413 Blue 9
10 AM Thu 73 77 NNE 3 5 11124 6491 1901 Blue 13
11 AM Thu 75 79 NNW 5 9 12695 7771 3181 Blue 15
12 Noon Thu 80 84 NNW 5 9 14017 13021 8431 Blue 20
1 PM Thu 83 88 NNW 5 9 15679 14239 9649 White 24
2 PM Thu 84 88 NW 10 16 15679 14239 9649 White 24
3 PM Thu 83 87 NW 10 16 15478 13945 9355 White 23
4 PM Thu 81 84 NW 10 16 14017 13021 8431 Blue 20
5 PM Thu 79 80 NE 12 19 12900 10630 6040 Blue 16
6 PM Thu 79 79 NE 12 19 12695 7771 3181 Blue 15
7 PM Thu 79 79 NE 12 19 12695 7771 3181 Blue 15
8 PM Thu 78 78 W 6 10 12384 7195 2605 Blue 14
9 PM Thu 74 74 W 6 10 6515 5221 631 Blue 10
10 PM Thu 70 70 W 6 10 5006 4590 0 Blue 6
11 PM Thu 65 65 WSW 5 9 4183 4590 0 Blue 1
12 Midnight Fri 63 63 WSW 5 9 4082 4590 0 Blue 0
1 AM Fri 62 62 WSW 5 9 4030 4590 0 Blue 0
2 AM Fri 61 61 S 4 6 3978 4590 0 Blue 0
3 AM Fri 59 59 S 4 6 3976 4590 0 Blue 0
4 AM Fri 57 57 S 4 6 3976 4590 0 Blue 0
5 AM Fri 57 57 ESE 4 6 3976 4590 0 Blue 0
6 AM Fri 59 59 ESE 4 6 3976 4590 0 Blue 0
7 AM Fri 62 62 ESE 4 6 4030 4590 0 Blue 0
8 AM Fri 66 67 ENE 3 5 4422 4590 0 Blue 3
9 AM Fri 69 72 ENE 3 5 5839 4894 304 Blue 8
10 AM Fri 73 78 ENE 3 5 12384 7195 2605 Blue 14
11 AM Fri 76 82 NNE 6 10 13393 12608 8018 Blue 18
12 Noon Fri 79 86 NNE 6 10 15276 13632 9042 White 22
1 PM Fri 82 89 NNE 6 10 15880 15880 11290 White 25
2 PM Fri 85 92 NNW 9 13 16480 16480 11890 White 28
3 PM Fri 86 92 NNW 9 13 16480 16480 11890 White 28
4 PM Fri 87 92 NNW 9 13 16480 16480 11890 White 28
5 PM Fri 88 91 NW 10 16 16281 16281 11691 White 27
6 PM Fri 88 89 NW 10 16 15880 15880 11290 White 25
7 PM Fri 87 87 NW 10 16 15478 13945 9355 White 23
8 PM Fri 85 85 W 8 12 15074 13285 8695 White 21
9 PM Fri 80 80 W 8 12 12900 10630 6040 Blue 16
10 PM Fri 75 75 W 8 12 7258 5815 1225 Blue 11
11 PM Fri 71 71 SW 5 9 5230 4590 0 Blue 7
12 Midnight Sat 68 68 SW 5 9 4514 4590 0 Blue 4
1 AM Sat 66 66 SW 5 9 4238 4590 0 Blue 2
2 AM Sat 64 64 SSE 4 6 4134 4590 0 Blue 0
3 AM Sat 62 62 SSE 4 6 4030 4590 0 Blue 0
4 AM Sat 61 61 SSE 4 6 3978 4590 0 Blue 0
5 AM Sat 61 61 ESE 4 6 3978 4590 0 Blue 0
6 AM Sat 63 63 ESE 4 6 4082 4590 0 Blue 0
7 AM Sat 66 66 ESE 4 6 4238 4590 0 Blue 2
8 AM Sat 71 72 ENE 3 5 5839 4894 304 Blue 8
9 AM Sat 75 78 ENE 3 5 12384 7195 2605 Blue 14
10 AM Sat 80 85 ENE 3 5 15074 13285 8695 White 21
11 AM Sat 84 90 NNE 5 9 16081 16081 11491 White 26
12 Noon Sat 87 95 NNE 5 9 17077 17077 12487 White 31
1 PM Sat 89 97 NNE 5 9 17467 17467 12877 White 33
2 PM Sat 90 97 NNW 6 10 17467 17467 12877 White 33
3 PM Sat 91 97 NNW 6 10 17467 17467 12877 White 33
4 PM Sat 92 97 NNW 6 10 17467 17467 12877 White 33
5 PM Sat 92 95 NW 11 17 17077 17077 12487 White 31
6 PM Sat 93 94 NW 11 17 16879 16879 12289 White 30
7 PM Sat 93 93 NW 11 17 16681 16681 12091 White 29
8 PM Sat 90 90 WNW 6 10 16081 16081 11491 White 26
9 PM Sat 85 85 WNW 6 10 15074 13285 8695 White 21
10 PM Sat 79 79 WNW 6 10 12695 7771 3181 Blue 15
11 PM Sat 74 74 SSE 5 9 6515 5221 631 Blue 10
12 Midnight Sun 71 71 SSE 5 9 5230 4590 0 Blue 7
1 AM Sun 70 70 SSE 5 9 5006 4590 0 Blue 6
2 AM Sun 68 68 SE 4 6 4514 4590 0 Blue 4
3 AM Sun 66 66 SE 4 6 4238 4590 0 Blue 2
4 AM Sun 64 64 SE 4 6 4134 4590 0 Blue 0
5 AM Sun 64 64 E 4 6 4134 4590 0 Blue 0
6 AM Sun 66 66 E 4 6 4238 4590 0 Blue 2
7 AM Sun 70 70 E 4 6 5006 4590 0 Blue 6
8 AM Sun 75 76 E 2 3 7838 6184 1594 Blue 12
9 AM Sun 81 84 E 2 3 14017 13021 8431 Blue 20
10 AM Sun 86 91 E 2 3 16281 16281 11691 White 27
11 AM Sun 90 97 E 8 12 17467 17467 12877 White 33
12 Noon Sun 93 101 E 8 12 18246 18246 13656 White 37
1 PM Sun 95 103 E 8 12 18654 18654 14064 White 39
2 PM Sun 97 105 SE 5 9 19051 19051 14461 White 41
3 PM Sun 98 105 SE 5 9 19051 19051 14461 White 41
4 PM Sun 98 103 SE 5 9 18654 18654 14064 White 39
5 PM Sun 98 101 S 9 13 18246 18246 13656 White 37
6 PM Sun 98 99 S 9 13 17856 17856 13266 White 35
7 PM Sun 96 96 S 9 13 17271 17271 12681 White 32
8 PM Sun 93 93 SW 5 9 16681 16681 12091 White 29
9 PM Sun 88 88 SW 5 9 15679 14239 9649 White 24
10 PM Sun 83 83 SW 5 9 13799 12850 8260 Blue 19
11 PM Sun 77 77 S 5 9 11124 6491 1901 Blue 13
12 Midnight Mon 74 74 S 5 9 6515 5221 631 Blue 10
1 AM Mon 72 72 S 5 9 5839 4894 304 Blue 8
2 AM Mon 71 71 SSE 3 5 5230 4590 0 Blue 7
3 AM Mon 68 68 SSE 3 5 4514 4590 0 Blue 4
4 AM Mon 67 67 SSE 3 5 4422 4590 0 Blue 3
5 AM Mon 66 66 ESE 3 5 4238 4590 0 Blue 2
6 AM Mon 68 68 ESE 3 5 4514 4590 0 Blue 4
7 AM Mon 71 71 ESE 3 5 5230 4590 0 Blue 7
8 AM Mon 75 76 E 2 3 7838 6184 1594 Blue 12
9 AM Mon 79 82 E 2 3 13393 12608 8018 Blue 18
10 AM Mon 84 89 E 2 3 15880 15880 11290 White 25
11 AM Mon 88 95 SSW 6 10 17077 17077 12487 White 31
12 Noon Mon 92 100 SSW 6 10 18050 18050 13460 White 36
1 PM Mon 95 103 SSW 6 10 18654 18654 14064 White 39
2 PM Mon 97 105 W 9 13 19051 19051 14461 White 41
3 PM Mon 97 104 W 9 13 18856 18856 14266 White 40
4 PM Mon 96 101 W 9 13 18246 18246 13656 White 37
5 PM Mon 95 98 WSW 12 19 17662 17662 13072 White 34
6 PM Mon 95 97 WSW 12 19 17467 17467 12877 White 33
7 PM Mon 93 93 WSW 12 19 16681 16681 12091 White 29
8 PM Mon 90 90 WSW 5 9 16081 16081 11491 White 26
9 PM Mon 85 85 WSW 5 9 15074 13285 8695 White 21
10 PM Mon 80 80 WSW 5 9 12900 10630 6040 Blue 16

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 or WeatherAPI.com website.  Puddle temperatures can exceed this temperature. 

Puddle Temp: This estimate is based on the High Temp and the National Weather Service or WeatherAPI.com 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 or WeatherAPI.com website.

Wind Gust: This estimate is taken from the National Weather Service or WeatherAPI.com 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 [email protected]