Detailed Predictions for: Hat Creek Rim
Launch Altitude (f): 4590
LZ Altitude (f): 3575
Sounding

Station:

KOAK

Date/Time:

23 SEP 2017

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 Sat 40 40 E 5 3802 4590 0 Blue 0
6 AM Sat 39 39 E 5 3802 4590 0 Blue 0
7 AM Sat 39 39 E 5 3802 4590 0 Blue 0
8 AM Sat 40 40 E 5 3802 4590 0 Blue 0
9 AM Sat 44 45 E 5 3802 4590 0 Blue 0
10 AM Sat 48 50 E 5 4461 4590 0 Blue 1
11 AM Sat 53 56 NE 9 8140 6951 2361 White 7
12 Noon Sat 56 60 NE 9 9001 9001 4411 White 11
1 PM Sat 59 64 NE 9 9859 9859 5269 White 15
2 PM Sat 60 64 NE 8 9859 9859 5269 White 15
3 PM Sat 62 65 NE 8 10082 10082 5492 White 16
4 PM Sat 63 65 NE 8 10082 10082 5492 White 16
5 PM Sat 63 64 NE 8 9859 9859 5269 White 15
6 PM Sat 60 60 NE 8 9001 9001 4411 White 11
7 PM Sat 57 57 NE 8 8356 7534 2944 White 8
8 PM Sat 53 53 NE 6 6992 4590 0 Blue 4
9 PM Sat 50 50 NE 6 4461 4590 0 Blue 1
10 PM Sat 48 48 NE 6 3945 4590 0 Blue 0
11 PM Sat 46 46 E 5 3802 4590 0 Blue 0
12 Midnight Sun 45 45 E 5 3802 4590 0 Blue 0
1 AM Sun 44 44 E 5 3802 4590 0 Blue 0
2 AM Sun 44 44 E 5 3802 4590 0 Blue 0
3 AM Sun 43 43 E 5 3802 4590 0 Blue 0
4 AM Sun 43 43 E 5 3802 4590 0 Blue 0
5 AM Sun 42 42 E 6 3802 4590 0 Blue 0
6 AM Sun 41 41 E 6 3802 4590 0 Blue 0
7 AM Sun 41 41 E 6 3802 4590 0 Blue 0
8 AM Sun 42 42 E 6 3802 4590 0 Blue 0
9 AM Sun 46 47 E 6 3802 4590 0 Blue 0
10 AM Sun 51 53 E 6 6992 4590 0 Blue 4
11 AM Sun 57 60 NE 8 9001 9001 4411 White 11
12 Noon Sun 60 64 NE 8 9859 9859 5269 White 15
1 PM Sun 63 68 NE 8 10708 10708 6118 White 19
2 PM Sun 65 69 NE 8 10916 10916 6326 White 20
3 PM Sun 67 70 NE 8 11124 11124 6534 White 21
4 PM Sun 68 70 NE 8 11124 11124 6534 White 21
5 PM Sun 67 68 N 6 10708 10708 6118 White 19
6 PM Sun 65 65 N 6 10082 10082 5492 White 16
7 PM Sun 61 61 N 6 9213 9213 4623 White 12
8 PM Sun 58 58 N 6 8572 8251 3661 White 9
9 PM Sun 55 55 N 6 7924 6446 1856 White 6
10 PM Sun 53 53 N 6 6992 4590 0 Blue 4
11 PM Sun 51 51 E 7 5952 4590 0 Blue 2
12 Midnight Mon 50 50 E 7 4461 4590 0 Blue 1
1 AM Mon 48 48 E 7 3945 4590 0 Blue 0
2 AM Mon 48 48 E 7 3945 4590 0 Blue 0
3 AM Mon 47 47 E 7 3802 4590 0 Blue 0
4 AM Mon 47 47 E 7 3802 4590 0 Blue 0
5 AM Mon 47 47 NE 6 3802 4590 0 Blue 0
6 AM Mon 46 46 NE 6 3802 4590 0 Blue 0
7 AM Mon 46 46 NE 6 3802 4590 0 Blue 0
8 AM Mon 48 48 NE 6 3945 4590 0 Blue 0
9 AM Mon 52 53 NE 6 6992 4590 0 Blue 4
10 AM Mon 57 59 NE 6 8786 8786 4196 White 10
11 AM Mon 62 65 NE 8 10082 10082 5492 White 16
12 Noon Mon 66 70 NE 8 11124 11124 6534 White 21
1 PM Mon 69 73 NE 8 11740 11740 7150 White 24
2 PM Mon 71 75 NE 8 12149 12149 7559 White 26
3 PM Mon 72 75 NE 8 12149 12149 7559 White 26
4 PM Mon 73 75 NE 8 12149 12149 7559 White 26
5 PM Mon 72 73 NE 10 11740 11740 7150 White 24
6 PM Mon 69 69 NE 10 10916 10916 6326 White 20
7 PM Mon 65 65 NE 10 10082 10082 5492 White 16
8 PM Mon 61 61 NE 10 9213 9213 4623 White 12
9 PM Mon 58 58 NE 10 8572 8251 3661 White 9
10 PM Mon 56 56 NE 10 8140 6951 2361 White 7
11 PM Mon 54 54 E 6 7707 5926 1336 White 5
12 Midnight Tue 53 53 E 6 6992 4590 0 Blue 4
1 AM Tue 53 53 E 6 6992 4590 0 Blue 4
2 AM Tue 52 52 E 6 6516 4590 0 Blue 3
3 AM Tue 51 51 E 6 5952 4590 0 Blue 2
4 AM Tue 51 51 E 6 5952 4590 0 Blue 2
5 AM Tue 50 50 NE 7 4461 4590 0 Blue 1
6 AM Tue 49 49 NE 7 4197 4590 0 Blue 0
7 AM Tue 49 49 NE 7 4197 4590 0 Blue 0
8 AM Tue 51 51 NE 7 5952 4590 0 Blue 2
9 AM Tue 55 56 NE 7 8140 6951 2361 White 7
10 AM Tue 60 62 NE 7 9426 9426 4836 White 13
11 AM Tue 66 69 N 9 10916 10916 6326 White 20
12 Noon Tue 70 74 N 9 11945 11945 7355 White 25
1 PM Tue 73 78 N 9 12760 12760 8170 White 29
2 PM Tue 76 81 N 9 13369 13369 8779 White 32
3 PM Tue 77 81 N 9 13369 13369 8779 White 32
4 PM Tue 78 80 N 9 13166 13166 8576 White 31
5 PM Tue 77 78 N 8 12760 12760 8170 White 29
6 PM Tue 74 74 N 8 11945 11945 7355 White 25
7 PM Tue 69 69 N 8 10916 10916 6326 White 20
8 PM Tue 65 65 N 8 10082 10082 5492 White 16
9 PM Tue 63 63 N 8 9637 9637 5047 White 14
10 PM Tue 61 61 N 8 9213 9213 4623 White 12
11 PM Tue 60 60 E 5 9001 9001 4411 White 11
12 Midnight Wed 59 59 E 5 8786 8786 4196 White 10
1 AM Wed 57 57 E 5 8356 7534 2944 White 8
2 AM Wed 56 56 E 5 8140 6951 2361 White 7
3 AM Wed 55 55 E 5 7924 6446 1856 White 6
4 AM Wed 54 54 E 5 7707 5926 1336 White 5
5 AM Wed 53 53 E 7 6992 4590 0 Blue 4
6 AM Wed 52 52 E 7 6516 4590 0 Blue 3
7 AM Wed 52 52 E 7 6516 4590 0 Blue 3
8 AM Wed 54 54 E 7 7707 5926 1336 White 5
9 AM Wed 59 60 E 7 9001 9001 4411 White 11
10 AM Wed 65 67 E 7 10500 10500 5910 White 18
11 AM Wed 71 74 E 6 11945 11945 7355 White 25
12 Noon Wed 76 80 E 6 13166 13166 8576 White 31
1 PM Wed 79 83 E 6 13771 13771 9181 White 34
2 PM Wed 81 85 E 6 14173 14173 9583 White 36
3 PM Wed 82 85 E 6 14173 14173 9583 White 36
4 PM Wed 82 84 E 6 13972 13972 9382 White 35
5 PM Wed 80 81 E 6 13369 13369 8779 White 32
6 PM Wed 76 76 E 6 12353 12353 7763 White 27
7 PM Wed 71 71 E 6 11330 11330 6740 White 22
8 PM Wed 66 66 E 6 10292 10292 5702 White 17
9 PM Wed 63 63 E 6 9637 9637 5047 White 14
10 PM Wed 61 61 E 6 9213 9213 4623 White 12
11 PM Wed 59 59 SE 5 8786 8786 4196 White 10
12 Midnight Thu 58 58 SE 5 8572 8251 3661 White 9
1 AM Thu 56 56 SE 5 8140 6951 2361 White 7
2 AM Thu 55 55 SE 5 7924 6446 1856 White 6
3 AM Thu 54 54 SE 5 7707 5926 1336 White 5
4 AM Thu 53 53 SE 5 6992 4590 0 Blue 4
5 AM Thu 52 52 E 6 6516 4590 0 Blue 3
6 AM Thu 51 51 E 6 5952 4590 0 Blue 2
7 AM Thu 51 51 E 6 5952 4590 0 Blue 2
8 AM Thu 53 53 E 6 6992 4590 0 Blue 4
9 AM Thu 58 59 E 6 8786 8786 4196 White 10
10 AM Thu 65 67 E 6 10500 10500 5910 White 18
11 AM Thu 71 74 E 5 11945 11945 7355 White 25
12 Noon Thu 76 80 E 5 13166 13166 8576 White 31
1 PM Thu 80 85 E 5 14173 14173 9583 White 36
2 PM Thu 82 86 E 5 14372 14372 9782 White 37
3 PM Thu 83 86 E 5 14372 14372 9782 White 37
4 PM Thu 83 85 E 5 14173 14173 9583 White 36
5 PM Thu 81 82 W 5 13571 13571 8981 White 33
6 PM Thu 77 77 W 5 12557 12557 7967 White 28
7 PM Thu 73 73 W 5 11740 11740 7150 White 24
8 PM Thu 69 69 W 5 10916 10916 6326 White 20
9 PM Thu 65 65 W 5 10082 10082 5492 White 16
10 PM Thu 61 61 W 5 9213 9213 4623 White 12
11 PM Thu 59 59 S 5 8786 8786 4196 White 10
12 Midnight Fri 58 58 S 5 8572 8251 3661 White 9
1 AM Fri 57 57 S 5 8356 7534 2944 White 8
2 AM Fri 56 56 S 5 8140 6951 2361 White 7
3 AM Fri 56 56 S 5 8140 6951 2361 White 7
4 AM Fri 55 55 S 5 7924 6446 1856 White 6

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