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:

14 APR 2024

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 Sun 34 34 WSW 6 10 4275 4590 0 White 0
1 AM Sun 33 33 SW 8 11 3570 4590 0 Blue 0
2 AM Sun 33 33 SW 8 12 3570 4590 0 Blue 0
3 AM Sun 33 33 SSW 6 10 3570 4590 0 Blue 0
4 AM Sun 33 33 S 6 10 3570 4590 0 Blue 0
5 AM Sun 33 33 SSE 5 9 3570 4590 0 Blue 0
6 AM Sun 33 33 S 5 8 3570 4590 0 Blue 0
7 AM Sun 33 33 NNE 5 9 3570 4590 0 Blue 0
8 AM Sun 33 33 ENE 5 10 3570 4590 0 Blue 0
9 AM Sun 33 33 ESE 5 9 3570 4590 0 Blue 0
10 AM Sun 32 32 NNE 6 10 2732 4590 0 Blue 0
11 AM Sun 32 32 NE 8 11 2732 4590 0 Blue 0
12 Noon Sun 35 35 ENE 8 11 4503 4590 0 White 1
1 PM Sun 35 35 NNW 8 12 4503 4590 0 White 1
2 PM Sun 35 35 NNE 6 11 4503 4590 0 White 1
3 PM Sun 36 36 N 8 11 4735 4590 0 White 2
4 PM Sun 36 36 SSW 8 11 4735 4590 0 White 2
5 PM Sun 38 38 S 6 10 5177 4620 30 White 4
6 PM Sun 37 37 SSE 5 8 4957 4590 0 White 3
7 PM Sun 37 37 S 4 5 4957 4590 0 White 3
8 PM Sun 37 37 SSE 4 5 4957 4590 0 White 3
9 PM Sun 36 36 SSE 3 5 4735 4590 0 White 2
10 PM Sun 36 36 SE 3 4 4735 4590 0 White 2
11 PM Sun 36 36 SSE 2 4 4735 4590 0 White 2
12 Midnight Mon 36 36 SSE 2 3 4735 4590 0 White 2
1 AM Mon 36 36 SE 2 2 4735 4590 0 White 2
2 AM Mon 36 36 SSE 1 2 4735 4590 0 White 2
3 AM Mon 35 35 SSE 2 2 4503 4590 0 White 1
4 AM Mon 35 35 S 1 2 4503 4590 0 White 1
5 AM Mon 35 35 SSE 1 2 4503 4590 0 White 1
6 AM Mon 35 35 SSE 1 2 4503 4590 0 White 1
7 AM Mon 35 35 SSE 1 2 4503 4590 0 White 1
8 AM Mon 36 36 SE 2 2 4735 4590 0 White 2
9 AM Mon 37 37 SE 2 2 4957 4590 0 White 3
10 AM Mon 41 42 SE 2 2 6056 6056 1466 White 8
11 AM Mon 43 45 N 4 6 6705 6705 2115 White 11
12 Noon Mon 45 48 N 4 6 7350 7350 2760 White 14
1 PM Mon 48 51 N 4 6 7990 7990 3400 White 17
2 PM Mon 50 54 NNW 6 10 8626 8626 4036 White 20
3 PM Mon 51 54 NNW 6 10 8626 8626 4036 White 20
4 PM Mon 52 54 NNW 6 10 8626 8626 4036 White 20
5 PM Mon 52 53 NW 6 10 8416 8416 3826 White 19
6 PM Mon 52 52 NW 6 10 8202 8202 3612 White 18
7 PM Mon 51 51 NW 6 10 7990 7990 3400 White 17
8 PM Mon 49 49 W 4 6 7565 7565 2975 White 15
9 PM Mon 46 46 W 4 6 6921 6921 2331 White 12
10 PM Mon 44 44 W 4 6 6490 6490 1900 White 10
11 PM Mon 41 41 SSE 4 5 5837 5837 1247 White 7
12 Midnight Tue 39 39 SSE 4 5 5397 5022 432 White 5
1 AM Tue 37 37 SSE 4 5 4957 4590 0 White 3
2 AM Tue 36 36 ESE 3 3 4735 4590 0 White 2
3 AM Tue 34 34 ESE 3 3 4275 4590 0 White 0
4 AM Tue 33 33 ESE 3 3 3570 4590 0 Blue 0
5 AM Tue 33 33 ESE 3 3 3570 4590 0 Blue 0
6 AM Tue 33 33 ESE 3 3 3570 4590 0 Blue 0
7 AM Tue 34 34 ESE 3 3 4275 4590 0 White 0
8 AM Tue 37 37 E 2 2 4957 4590 0 White 3
9 AM Tue 40 41 E 2 2 5837 5837 1247 White 7
10 AM Tue 45 47 E 2 2 7135 7135 2545 White 13
11 AM Tue 49 53 NNE 4 5 8416 8416 3826 White 19
12 Noon Tue 52 56 NNE 4 5 9045 9045 4455 White 22
1 PM Tue 55 60 NNE 4 5 9898 9898 5308 White 26
2 PM Tue 57 61 NW 6 10 10104 10104 5514 White 27
3 PM Tue 59 62 NW 6 10 10310 10310 5720 White 28
4 PM Tue 59 61 NW 6 10 10104 10104 5514 White 27
5 PM Tue 59 60 WNW 11 18 9898 9898 5308 White 26
6 PM Tue 57 57 WNW 11 18 9255 9255 4665 White 23
7 PM Tue 55 55 WNW 11 18 8836 8836 4246 White 21
8 PM Tue 52 52 W 8 11 8202 8202 3612 White 18
9 PM Tue 50 50 W 8 11 7779 7779 3189 White 16
10 PM Tue 47 47 W 8 11 7135 7135 2545 White 13
11 PM Tue 45 45 ESE 5 6 6705 6705 2115 White 11
12 Midnight Wed 43 43 ESE 5 6 6273 6273 1683 White 9
1 AM Wed 41 41 ESE 5 6 5837 5837 1247 White 7
2 AM Wed 39 39 E 4 6 5397 5022 432 White 5
3 AM Wed 38 38 E 4 6 5177 4620 30 White 4
4 AM Wed 37 37 E 4 6 4957 4590 0 White 3
5 AM Wed 37 37 E 4 5 4957 4590 0 White 3
6 AM Wed 37 37 E 4 5 4957 4590 0 White 3
7 AM Wed 38 38 E 4 5 5177 4620 30 White 4
8 AM Wed 41 41 ENE 5 9 5837 5837 1247 White 7
9 AM Wed 44 45 ENE 5 9 6705 6705 2115 White 11
10 AM Wed 48 50 ENE 5 9 7779 7779 3189 White 16
11 AM Wed 52 56 NE 8 11 9045 9045 4455 White 22
12 Noon Wed 55 60 NE 8 11 9898 9898 5308 White 26
1 PM Wed 58 63 NE 8 11 10514 10514 5924 White 29
2 PM Wed 61 65 N 10 14 10922 10922 6332 White 31
3 PM Wed 62 65 N 10 14 10922 10922 6332 White 31
4 PM Wed 63 65 N 10 14 10922 10922 6332 White 31
5 PM Wed 62 63 N 10 14 10514 10514 5924 White 29
6 PM Wed 60 60 N 10 14 9898 9898 5308 White 26
7 PM Wed 57 57 N 10 14 9255 9255 4665 White 23
8 PM Wed 54 54 NE 6 11 8626 8626 4036 White 20
9 PM Wed 51 51 NE 6 11 7990 7990 3400 White 17
10 PM Wed 48 48 NE 6 11 7350 7350 2760 White 14
11 PM Wed 46 46 ESE 5 9 6921 6921 2331 White 12
12 Midnight Thu 44 44 ESE 5 9 6490 6490 1900 White 10
1 AM Thu 42 42 ESE 5 9 6056 6056 1466 White 8
2 AM Thu 41 41 ESE 5 9 5837 5837 1247 White 7
3 AM Thu 40 40 ESE 5 9 5617 5470 880 White 6
4 AM Thu 39 39 ESE 5 9 5397 5022 432 White 5
5 AM Thu 39 39 ESE 5 8 5397 5022 432 White 5
6 AM Thu 39 39 ESE 5 8 5397 5022 432 White 5
7 AM Thu 40 40 ESE 5 8 5617 5470 880 White 6
8 AM Thu 43 43 E 5 9 6273 6273 1683 White 9
9 AM Thu 47 48 E 5 9 7350 7350 2760 White 14
10 AM Thu 52 54 E 5 9 8626 8626 4036 White 20
11 AM Thu 57 61 NE 6 10 10104 10104 5514 White 27
12 Noon Thu 61 66 NE 6 10 11126 11126 6536 White 32
1 PM Thu 64 69 NE 6 10 11731 11731 7141 White 35
2 PM Thu 65 69 NW 9 13 11731 11731 7141 White 35
3 PM Thu 67 70 NW 9 13 11933 11933 7343 White 36
4 PM Thu 67 69 NW 9 13 11731 11731 7141 White 35
5 PM Thu 66 67 W 10 14 11327 11327 6737 White 33
6 PM Thu 64 64 W 10 14 10718 10718 6128 White 30
7 PM Thu 61 61 W 10 14 10104 10104 5514 White 27
8 PM Thu 58 58 SW 6 10 9463 9463 4873 White 24
9 PM Thu 55 55 SW 6 10 8836 8836 4246 White 21
10 PM Thu 52 52 SW 6 10 8202 8202 3612 White 18
11 PM Thu 50 50 S 5 8 7779 7779 3189 White 16
12 Midnight Fri 48 48 S 5 8 7350 7350 2760 White 14
1 AM Fri 47 47 S 5 8 7135 7135 2545 White 13
2 AM Fri 46 46 S 5 8 6921 6921 2331 White 12
3 AM Fri 44 44 S 5 8 6490 6490 1900 White 10
4 AM Fri 43 43 S 5 8 6273 6273 1683 White 9
5 AM Fri 43 43 SSE 4 6 6273 6273 1683 White 9
6 AM Fri 43 43 SSE 4 6 6273 6273 1683 White 9
7 AM Fri 44 44 SSE 4 6 6490 6490 1900 White 10
8 AM Fri 47 47 ESE 5 6 7135 7135 2545 White 13
9 AM Fri 51 52 ESE 5 6 8202 8202 3612 White 18
10 AM Fri 56 59 ESE 5 6 9669 9669 5079 White 25
11 AM Fri 60 64 NW 6 10 10718 10718 6128 White 30
12 Noon Fri 63 68 NW 6 10 11529 11529 6939 White 34
1 PM Fri 65 70 NW 6 10 11933 11933 7343 White 36
2 PM Fri 66 71 WNW 10 16 12133 12133 7543 White 37
3 PM Fri 67 71 WNW 10 16 12133 12133 7543 White 37
4 PM Fri 67 69 WNW 10 16 11731 11731 7141 White 35
5 PM Fri 67 68 W 11 17 11529 11529 6939 White 34
6 PM Fri 65 65 W 11 17 10922 10922 6332 White 31
7 PM Fri 62 62 W 11 17 10310 10310 5720 White 28
8 PM Fri 59 59 WSW 8 11 9669 9669 5079 White 25
9 PM Fri 56 56 WSW 8 11 9045 9045 4455 White 22
10 PM Fri 53 53 WSW 8 11 8416 8416 3826 White 19

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]