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

Station:

KOAK

Date/Time:

18 SEP 2018

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 Tue 45 45 SE 6 3530 4590 0 Blue 0
6 AM Tue 44 44 SE 6 3530 4590 0 Blue 0
7 AM Tue 44 44 SE 6 3530 4590 0 Blue 0
8 AM Tue 46 46 SE 3 3530 4590 0 Blue 0
9 AM Tue 51 52 SE 3 3530 4590 0 Blue 0
10 AM Tue 58 60 SE 3 3711 4590 0 Blue 0
11 AM Tue 64 67 N 5 6478 5047 457 Blue 5
12 Noon Tue 68 72 N 5 7775 7140 2550 Blue 10
1 PM Tue 71 75 N 5 8803 7752 3162 Blue 13
2 PM Tue 73 77 NW 7 9579 8351 3761 Blue 15
3 PM Tue 74 77 NW 7 9579 8351 3761 Blue 15
4 PM Tue 74 76 NW 7 9193 7953 3363 Blue 14
5 PM Tue 73 74 W 8 8406 7556 2966 Blue 12
6 PM Tue 70 70 W 8 7382 6453 1863 Blue 8
7 PM Tue 66 66 W 8 6138 4590 0 Blue 4
8 PM Tue 61 61 SW 3 3947 4590 0 Blue 0
9 PM Tue 58 58 SW 3 3530 4590 0 Blue 0
10 PM Tue 55 55 SW 3 3530 4590 0 Blue 0
11 PM Tue 53 53 SE 5 3530 4590 0 Blue 0
12 Midnight Wed 51 51 SE 5 3530 4590 0 Blue 0
1 AM Wed 49 49 SE 5 3530 4590 0 Blue 0
2 AM Wed 48 48 SE 5 3530 4590 0 Blue 0
3 AM Wed 47 47 SE 5 3530 4590 0 Blue 0
4 AM Wed 47 47 SE 5 3530 4590 0 Blue 0
5 AM Wed 46 46 E 6 3530 4590 0 Blue 0
6 AM Wed 45 45 E 6 3530 4590 0 Blue 0
7 AM Wed 45 45 E 6 3530 4590 0 Blue 0
8 AM Wed 47 47 SE 5 3530 4590 0 Blue 0
9 AM Wed 51 52 SE 5 3530 4590 0 Blue 0
10 AM Wed 57 59 SE 5 3530 4590 0 Blue 0
11 AM Wed 62 65 N 6 5788 4590 0 Blue 3
12 Noon Wed 66 70 N 6 7382 6453 1863 Blue 8
1 PM Wed 70 75 N 6 8803 7752 3162 Blue 13
2 PM Wed 72 76 N 6 9193 7953 3363 Blue 14
3 PM Wed 73 77 N 6 9579 8351 3761 Blue 15
4 PM Wed 74 76 N 6 9193 7953 3363 Blue 14
5 PM Wed 73 74 N 6 8406 7556 2966 Blue 12
6 PM Wed 70 70 N 6 7382 6453 1863 Blue 8
7 PM Wed 66 66 N 6 6138 4590 0 Blue 4
8 PM Wed 62 62 N 6 4185 4590 0 Blue 0
9 PM Wed 58 58 N 6 3530 4590 0 Blue 0
10 PM Wed 55 55 N 6 3530 4590 0 Blue 0
11 PM Wed 52 52 E 5 3530 4590 0 Blue 0
12 Midnight Thu 51 51 E 5 3530 4590 0 Blue 0
1 AM Thu 49 49 E 5 3530 4590 0 Blue 0
2 AM Thu 48 48 E 5 3530 4590 0 Blue 0
3 AM Thu 47 47 E 5 3530 4590 0 Blue 0
4 AM Thu 45 45 E 5 3530 4590 0 Blue 0
5 AM Thu 44 44 E 5 3530 4590 0 Blue 0
6 AM Thu 44 44 E 5 3530 4590 0 Blue 0
7 AM Thu 45 45 E 5 3530 4590 0 Blue 0
8 AM Thu 48 48 E 5 3530 4590 0 Blue 0
9 AM Thu 53 54 E 5 3530 4590 0 Blue 0
10 AM Thu 60 62 E 5 4185 4590 0 Blue 0
11 AM Thu 66 70 NE 6 7382 6453 1863 Blue 8
12 Noon Thu 70 75 NE 6 8803 7752 3162 Blue 13
1 PM Thu 74 79 NE 6 10308 9130 4540 Blue 17
2 PM Thu 76 81 NE 6 11904 9887 5297 Blue 19
3 PM Thu 78 82 NE 6 12168 10246 5656 Blue 20
4 PM Thu 79 81 NE 6 11904 9887 5297 Blue 19
5 PM Thu 78 79 NW 7 10308 9130 4540 Blue 17
6 PM Thu 75 75 NW 7 8803 7752 3162 Blue 13
7 PM Thu 70 70 NW 7 7382 6453 1863 Blue 8
8 PM Thu 65 65 NW 7 5788 4590 0 Blue 3
9 PM Thu 61 61 NW 7 3947 4590 0 Blue 0
10 PM Thu 58 58 NW 7 3530 4590 0 Blue 0
11 PM Thu 56 56 E 5 3530 4590 0 Blue 0
12 Midnight Fri 54 54 E 5 3530 4590 0 Blue 0
1 AM Fri 53 53 E 5 3530 4590 0 Blue 0
2 AM Fri 52 52 E 5 3530 4590 0 Blue 0
3 AM Fri 51 51 E 5 3530 4590 0 Blue 0
4 AM Fri 50 50 E 5 3530 4590 0 Blue 0
5 AM Fri 49 49 E 5 3530 4590 0 Blue 0
6 AM Fri 47 47 E 5 3530 4590 0 Blue 0
7 AM Fri 47 47 E 5 3530 4590 0 Blue 0
8 AM Fri 49 49 E 5 3530 4590 0 Blue 0
9 AM Fri 55 56 E 5 3530 4590 0 Blue 0
10 AM Fri 62 64 E 5 5070 4590 0 Blue 2
11 AM Fri 69 72 W 6 7775 7140 2550 Blue 10
12 Noon Fri 74 78 W 6 9958 8744 4154 Blue 16
1 PM Fri 77 82 W 6 12168 10246 5656 Blue 20
2 PM Fri 78 82 W 6 12168 10246 5656 Blue 20
3 PM Fri 80 84 W 6 12690 11835 7245 Blue 22
4 PM Fri 80 82 W 6 12168 10246 5656 Blue 20
5 PM Fri 78 79 W 12 10308 9130 4540 Blue 17
6 PM Fri 75 75 W 12 8803 7752 3162 Blue 13
7 PM Fri 69 69 W 12 7174 6116 1526 Blue 7
8 PM Fri 64 64 W 12 5070 4590 0 Blue 2
9 PM Fri 60 60 W 12 3711 4590 0 Blue 0
10 PM Fri 57 57 W 12 3530 4590 0 Blue 0
11 PM Fri 55 55 S 6 3530 4590 0 Blue 0
12 Midnight Sat 54 54 S 6 3530 4590 0 Blue 0
1 AM Sat 53 53 S 6 3530 4590 0 Blue 0
2 AM Sat 51 51 S 6 3530 4590 0 Blue 0
3 AM Sat 50 50 S 6 3530 4590 0 Blue 0
4 AM Sat 49 49 S 6 3530 4590 0 Blue 0
5 AM Sat 48 48 S 5 3530 4590 0 Blue 0
6 AM Sat 46 46 S 5 3530 4590 0 Blue 0
7 AM Sat 46 46 S 5 3530 4590 0 Blue 0
8 AM Sat 48 48 S 5 3530 4590 0 Blue 0
9 AM Sat 52 53 S 5 3530 4590 0 Blue 0
10 AM Sat 59 61 S 5 3947 4590 0 Blue 0
11 AM Sat 65 68 SW 9 6828 5751 1161 Blue 6
12 Noon Sat 70 74 SW 9 8406 7556 2966 Blue 12
1 PM Sat 73 77 SW 9 9579 8351 3761 Blue 15
2 PM Sat 75 79 SW 9 10308 9130 4540 Blue 17
3 PM Sat 76 79 SW 9 10308 9130 4540 Blue 17
4 PM Sat 76 78 SW 9 9958 8744 4154 Blue 16
5 PM Sat 74 75 W 10 8803 7752 3162 Blue 13
6 PM Sat 70 70 W 10 7382 6453 1863 Blue 8
7 PM Sat 66 66 W 10 6138 4590 0 Blue 4
8 PM Sat 61 61 W 10 3947 4590 0 Blue 0
9 PM Sat 58 58 W 10 3530 4590 0 Blue 0
10 PM Sat 56 56 W 10 3530 4590 0 Blue 0
11 PM Sat 54 54 S 6 3530 4590 0 Blue 0
12 Midnight Sun 53 53 S 6 3530 4590 0 Blue 0
1 AM Sun 51 51 S 6 3530 4590 0 Blue 0
2 AM Sun 50 50 S 6 3530 4590 0 Blue 0
3 AM Sun 49 49 S 6 3530 4590 0 Blue 0
4 AM Sun 49 49 S 6 3530 4590 0 Blue 0
5 AM Sun 48 48 S 5 3530 4590 0 Blue 0
6 AM Sun 46 46 S 5 3530 4590 0 Blue 0
7 AM Sun 46 46 S 5 3530 4590 0 Blue 0
8 AM Sun 48 48 S 5 3530 4590 0 Blue 0
9 AM Sun 52 52 S 5 3530 4590 0 Blue 0
10 AM Sun 58 59 S 5 3530 4590 0 Blue 0
11 AM Sun 64 67 NW 9 6478 5047 457 Blue 5
12 Noon Sun 68 72 NW 9 7775 7140 2550 Blue 10
1 PM Sun 71 75 NW 9 8803 7752 3162 Blue 13
2 PM Sun 72 76 NW 9 9193 7953 3363 Blue 14
3 PM Sun 74 77 NW 9 9579 8351 3761 Blue 15
4 PM Sun 74 76 NW 9 9193 7953 3363 Blue 14
5 PM Sun 73 74 W 8 8406 7556 2966 Blue 12
6 PM Sun 69 69 W 8 7174 6116 1526 Blue 7
7 PM Sun 65 65 W 8 5788 4590 0 Blue 3
8 PM Sun 60 60 W 8 3711 4590 0 Blue 0
9 PM Sun 57 57 W 8 3530 4590 0 Blue 0
10 PM Sun 54 54 W 8 3530 4590 0 Blue 0
11 PM Sun 52 52 E 5 3530 4590 0 Blue 0
12 Midnight Mon 50 50 E 5 3530 4590 0 Blue 0
1 AM Mon 49 49 E 5 3530 4590 0 Blue 0
2 AM Mon 48 48 E 5 3530 4590 0 Blue 0
3 AM Mon 47 47 E 5 3530 4590 0 Blue 0
4 AM Mon 46 46 E 5 3530 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