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:

21 SEP 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 Tue 52 52 SE 11 17 3963 4590 0 Blue 0
1 AM Tue 52 52 SE 11 17 3963 4590 0 Blue 0
2 AM Tue 51 51 E 10 16 3963 4590 0 Blue 0
3 AM Tue 50 50 E 10 16 3963 4590 0 Blue 0
4 AM Tue 49 49 E 10 16 3963 4590 0 Blue 0
5 AM Tue 49 49 E 2 2 3963 4590 0 Blue 0
6 AM Tue 48 48 E 2 2 3963 4590 0 Blue 0
7 AM Tue 47 47 E 2 2 3963 4590 0 Blue 0
8 AM Tue 50 50 S 5 9 3963 4590 0 Blue 0
9 AM Tue 59 60 S 5 9 3963 4590 0 Blue 0
10 AM Tue 64 66 S 5 9 3963 4590 0 Blue 0
11 AM Tue 68 72 SE 4 4 4738 4590 0 Blue 2
12 Noon Tue 73 78 SE 4 4 5909 5046 456 Blue 8
1 PM Tue 76 81 SE 4 4 7164 5878 1288 Blue 11
2 PM Tue 79 84 W 8 12 7861 7144 2554 Blue 14
3 PM Tue 80 84 W 8 12 7861 7144 2554 Blue 14
4 PM Tue 81 83 W 8 12 7610 6938 2348 Blue 13
5 PM Tue 81 82 WNW 10 16 7371 6420 1830 Blue 12
6 PM Tue 78 78 WNW 10 16 5909 5046 456 Blue 8
7 PM Tue 76 76 WNW 10 16 5109 4847 257 Blue 6
8 PM Tue 73 73 WNW 4 4 4850 4590 0 Blue 3
9 PM Tue 68 68 WNW 4 4 3963 4590 0 Blue 0
10 PM Tue 63 63 WNW 4 4 3963 4590 0 Blue 0
11 PM Tue 61 61 SE 5 9 3963 4590 0 Blue 0
12 Midnight Wed 60 60 SE 5 9 3963 4590 0 Blue 0
1 AM Wed 59 59 SE 5 9 3963 4590 0 Blue 0
2 AM Wed 58 58 SE 5 9 3963 4590 0 Blue 0
3 AM Wed 57 57 SE 5 9 3963 4590 0 Blue 0
4 AM Wed 56 56 SE 5 9 3963 4590 0 Blue 0
5 AM Wed 56 56 SE 3 3 3963 4590 0 Blue 0
6 AM Wed 54 54 SE 3 3 3963 4590 0 Blue 0
7 AM Wed 53 53 SE 3 3 3963 4590 0 Blue 0
8 AM Wed 56 56 SSE 2 2 3963 4590 0 Blue 0
9 AM Wed 61 62 SSE 2 2 3963 4590 0 Blue 0
10 AM Wed 66 68 SSE 2 2 3963 4590 0 Blue 0
11 AM Wed 69 71 WNW 6 10 4627 4590 0 Blue 1
12 Noon Wed 72 75 WNW 6 10 5048 4736 146 Blue 5
1 PM Wed 74 77 WNW 6 10 5341 4959 369 Blue 7
2 PM Wed 76 80 W 10 16 6957 5319 729 Blue 10
3 PM Wed 77 80 W 10 16 6957 5319 729 Blue 10
4 PM Wed 77 79 W 10 16 6460 5107 517 Blue 9
5 PM Wed 76 77 W 10 16 5341 4959 369 Blue 7
6 PM Wed 75 75 W 10 16 5048 4736 146 Blue 5
7 PM Wed 72 72 W 10 16 4738 4590 0 Blue 2
8 PM Wed 69 69 NW 2 2 4158 4590 0 Blue 0
9 PM Wed 65 65 NW 2 2 3963 4590 0 Blue 0
10 PM Wed 61 61 NW 2 2 3963 4590 0 Blue 0
11 PM Wed 57 57 SSE 5 9 3963 4590 0 Blue 0
12 Midnight Thu 55 55 SSE 5 9 3963 4590 0 Blue 0
1 AM Thu 54 54 SSE 5 9 3963 4590 0 Blue 0
2 AM Thu 53 53 SSE 4 4 3963 4590 0 Blue 0
3 AM Thu 52 52 SSE 4 4 3963 4590 0 Blue 0
4 AM Thu 51 51 SSE 4 4 3963 4590 0 Blue 0
5 AM Thu 50 50 SSE 2 2 3963 4590 0 Blue 0
6 AM Thu 49 49 SSE 2 2 3963 4590 0 Blue 0
7 AM Thu 48 48 SSE 2 2 3963 4590 0 Blue 0
8 AM Thu 49 49 E 6 10 3963 4590 0 Blue 0
9 AM Thu 53 54 E 6 10 3963 4590 0 Blue 0
10 AM Thu 58 60 E 6 10 3963 4590 0 Blue 0
11 AM Thu 63 66 NNE 8 12 3963 4590 0 Blue 0
12 Noon Thu 68 72 NNE 8 12 4738 4590 0 Blue 2
1 PM Thu 72 76 NNE 8 12 5109 4847 257 Blue 6
2 PM Thu 75 78 ENE 10 16 5909 5046 456 Blue 8
3 PM Thu 77 80 ENE 10 16 6957 5319 729 Blue 10
4 PM Thu 79 81 ENE 10 16 7164 5878 1288 Blue 11
5 PM Thu 79 80 NNE 6 10 6957 5319 729 Blue 10
6 PM Thu 78 78 NNE 6 10 5909 5046 456 Blue 8
7 PM Thu 76 76 NNE 6 10 5109 4847 257 Blue 6
8 PM Thu 73 73 E 5 9 4850 4590 0 Blue 3
9 PM Thu 69 69 E 5 9 4158 4590 0 Blue 0
10 PM Thu 65 65 E 5 9 3963 4590 0 Blue 0
11 PM Thu 61 61 E 5 9 3963 4590 0 Blue 0
12 Midnight Fri 59 59 E 5 9 3963 4590 0 Blue 0
1 AM Fri 58 58 E 5 9 3963 4590 0 Blue 0
2 AM Fri 57 57 ESE 5 9 3963 4590 0 Blue 0
3 AM Fri 57 57 ESE 5 9 3963 4590 0 Blue 0
4 AM Fri 56 56 ESE 5 9 3963 4590 0 Blue 0
5 AM Fri 55 55 ESE 5 9 3963 4590 0 Blue 0
6 AM Fri 53 53 ESE 5 9 3963 4590 0 Blue 0
7 AM Fri 53 53 ESE 5 9 3963 4590 0 Blue 0
8 AM Fri 55 55 ESE 4 4 3963 4590 0 Blue 0
9 AM Fri 59 60 ESE 4 4 3963 4590 0 Blue 0
10 AM Fri 65 67 ESE 4 4 3963 4590 0 Blue 0
11 AM Fri 71 74 ESE 5 9 4962 4625 35 Blue 4
12 Noon Fri 75 79 ESE 5 9 6460 5107 517 Blue 9
1 PM Fri 79 84 ESE 5 9 7861 7144 2554 Blue 14
2 PM Fri 82 87 WNW 6 10 8683 7832 3242 Blue 17
3 PM Fri 83 87 WNW 6 10 8683 7832 3242 Blue 17
4 PM Fri 84 86 WNW 6 10 8129 7583 2993 Blue 16
5 PM Fri 84 85 W 8 12 7986 7350 2760 Blue 15
6 PM Fri 82 82 W 8 12 7371 6420 1830 Blue 12
7 PM Fri 79 79 W 8 12 6460 5107 517 Blue 9
8 PM Fri 75 75 SSW 3 3 5048 4736 146 Blue 5
9 PM Fri 70 70 SSW 3 3 4515 4590 0 Blue 0
10 PM Fri 64 64 SSW 3 3 3963 4590 0 Blue 0
11 PM Fri 60 60 S 4 4 3963 4590 0 Blue 0
12 Midnight Sat 58 58 S 4 4 3963 4590 0 Blue 0
1 AM Sat 57 57 S 4 4 3963 4590 0 Blue 0
2 AM Sat 57 57 SSE 4 4 3963 4590 0 Blue 0
3 AM Sat 56 56 SSE 4 4 3963 4590 0 Blue 0
4 AM Sat 55 55 SSE 4 4 3963 4590 0 Blue 0
5 AM Sat 54 54 SE 4 6 3963 4590 0 Blue 0
6 AM Sat 52 52 SE 4 6 3963 4590 0 Blue 0
7 AM Sat 52 52 SE 4 6 3963 4590 0 Blue 0
8 AM Sat 54 54 SSE 2 3 3963 4590 0 Blue 0
9 AM Sat 58 59 SSE 2 3 3963 4590 0 Blue 0
10 AM Sat 64 66 SSE 2 3 3963 4590 0 Blue 0
11 AM Sat 70 73 W 5 9 4850 4590 0 Blue 3
12 Noon Sat 75 79 W 5 9 6460 5107 517 Blue 9
1 PM Sat 78 83 W 5 9 7610 6938 2348 Blue 13
2 PM Sat 80 84 W 6 10 7861 7144 2554 Blue 14
3 PM Sat 82 85 W 6 10 7986 7350 2760 Blue 15
4 PM Sat 82 84 W 6 10 7861 7144 2554 Blue 14
5 PM Sat 81 82 W 9 13 7371 6420 1830 Blue 12
6 PM Sat 80 80 W 9 13 6957 5319 729 Blue 10
7 PM Sat 77 77 W 9 13 5341 4959 369 Blue 7
8 PM Sat 73 73 SW 4 6 4850 4590 0 Blue 3
9 PM Sat 68 68 SW 4 6 3963 4590 0 Blue 0
10 PM Sat 63 63 SW 4 6 3963 4590 0 Blue 0
11 PM Sat 59 59 S 5 9 3963 4590 0 Blue 0
12 Midnight Sun 57 57 S 5 9 3963 4590 0 Blue 0
1 AM Sun 56 56 S 5 9 3963 4590 0 Blue 0
2 AM Sun 55 55 SSE 3 5 3963 4590 0 Blue 0
3 AM Sun 54 54 SSE 3 5 3963 4590 0 Blue 0
4 AM Sun 53 53 SSE 3 5 3963 4590 0 Blue 0
5 AM Sun 52 52 SSE 2 3 3963 4590 0 Blue 0
6 AM Sun 51 51 SSE 2 3 3963 4590 0 Blue 0
7 AM Sun 51 51 SSE 2 3 3963 4590 0 Blue 0
8 AM Sun 53 53 SSE 2 3 3963 4590 0 Blue 0
9 AM Sun 57 58 SSE 2 3 3963 4590 0 Blue 0
10 AM Sun 63 65 SSE 2 3 3963 4590 0 Blue 0
11 AM Sun 68 71 W 5 9 4627 4590 0 Blue 1
12 Noon Sun 72 75 W 5 9 5048 4736 146 Blue 5
1 PM Sun 75 79 W 5 9 6460 5107 517 Blue 9
2 PM Sun 77 81 W 6 10 7164 5878 1288 Blue 11
3 PM Sun 79 82 W 6 10 7371 6420 1830 Blue 12
4 PM Sun 79 81 W 6 10 7164 5878 1288 Blue 11
5 PM Sun 78 79 W 9 13 6460 5107 517 Blue 9
6 PM Sun 77 77 W 9 13 5341 4959 369 Blue 7
7 PM Sun 74 74 W 9 13 4962 4625 35 Blue 4
8 PM Sun 70 70 SW 4 6 4515 4590 0 Blue 0
9 PM Sun 66 66 SW 4 6 3963 4590 0 Blue 0
10 PM Sun 62 62 SW 4 6 3963 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 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]