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

Station:

KOAK

Date/Time:

N/A

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)
4 AM Thu 38 38 S 16 N/A N/A N/A N/A N/A
5 AM Thu 37 37 S 16 N/A N/A N/A N/A N/A
6 AM Thu 36 36 S 16 N/A N/A N/A N/A N/A
7 AM Thu 36 36 S 14 N/A N/A N/A N/A N/A
8 AM Thu 37 37 S 14 N/A N/A N/A N/A N/A
9 AM Thu 39 39 S 14 N/A N/A N/A N/A N/A
10 AM Thu 41 41 SW 13 N/A N/A N/A N/A N/A
11 AM Thu 42 42 SW 13 N/A N/A N/A N/A N/A
12 Noon Thu 42 42 SW 13 N/A N/A N/A N/A N/A
1 PM Thu 42 42 SW 15 N/A N/A N/A N/A N/A
2 PM Thu 41 41 SW 15 N/A N/A N/A N/A N/A
3 PM Thu 39 39 SW 15 N/A N/A N/A N/A N/A
4 PM Thu 38 38 SW 12 N/A N/A N/A N/A N/A
5 PM Thu 36 36 SW 12 N/A N/A N/A N/A N/A
6 PM Thu 35 35 SW 12 N/A N/A N/A N/A N/A
7 PM Thu 34 34 SW 7 N/A N/A N/A N/A N/A
8 PM Thu 34 34 SW 7 N/A N/A N/A N/A N/A
9 PM Thu 34 34 SW 7 N/A N/A N/A N/A N/A
10 PM Thu 34 34 S 7 N/A N/A N/A N/A N/A
11 PM Thu 34 34 S 7 N/A N/A N/A N/A N/A
12 Midnight Fri 34 34 S 7 N/A N/A N/A N/A N/A
1 AM Fri 34 34 S 8 N/A N/A N/A N/A N/A
2 AM Fri 33 33 S 8 N/A N/A N/A N/A N/A
3 AM Fri 32 32 S 8 N/A N/A N/A N/A N/A
4 AM Fri 32 32 S 8 N/A N/A N/A N/A N/A
5 AM Fri 32 32 S 8 N/A N/A N/A N/A N/A
6 AM Fri 33 33 S 8 N/A N/A N/A N/A N/A
7 AM Fri 34 34 S 6 N/A N/A N/A N/A N/A
8 AM Fri 35 35 S 6 N/A N/A N/A N/A N/A
9 AM Fri 37 37 S 6 N/A N/A N/A N/A N/A
10 AM Fri 39 39 S 5 N/A N/A N/A N/A N/A
11 AM Fri 40 40 S 5 N/A N/A N/A N/A N/A
12 Noon Fri 42 42 S 5 N/A N/A N/A N/A N/A
1 PM Fri 42 42 S 5 N/A N/A N/A N/A N/A
2 PM Fri 42 42 S 5 N/A N/A N/A N/A N/A
3 PM Fri 41 41 S 5 N/A N/A N/A N/A N/A
4 PM Fri 40 40 SW 6 N/A N/A N/A N/A N/A
5 PM Fri 41 41 SW 6 N/A N/A N/A N/A N/A
6 PM Fri 41 41 SW 6 N/A N/A N/A N/A N/A
7 PM Fri 42 42 SW 6 N/A N/A N/A N/A N/A
8 PM Fri 42 42 SW 6 N/A N/A N/A N/A N/A
9 PM Fri 42 42 SW 6 N/A N/A N/A N/A N/A
10 PM Fri 42 42 SW 7 N/A N/A N/A N/A N/A
11 PM Fri 36 36 SW 7 N/A N/A N/A N/A N/A
12 Midnight Sat 36 36 SW 7 N/A N/A N/A N/A N/A
1 AM Sat 36 36 SW 7 N/A N/A N/A N/A N/A
2 AM Sat 36 36 SW 7 N/A N/A N/A N/A N/A
3 AM Sat 36 36 SW 7 N/A N/A N/A N/A N/A
4 AM Sat 36 36 SW 6 N/A N/A N/A N/A N/A
5 AM Sat 36 36 SW 6 N/A N/A N/A N/A N/A
6 AM Sat 36 36 SW 6 N/A N/A N/A N/A N/A
7 AM Sat 36 36 SW 6 N/A N/A N/A N/A N/A
8 AM Sat 36 36 SW 6 N/A N/A N/A N/A N/A
9 AM Sat 37 37 SW 6 N/A N/A N/A N/A N/A
10 AM Sat 39 39 SW 8 N/A N/A N/A N/A N/A
11 AM Sat 42 42 SW 8 N/A N/A N/A N/A N/A
12 Noon Sat 45 45 SW 8 N/A N/A N/A N/A N/A
1 PM Sat 47 47 SW 8 N/A N/A N/A N/A N/A
2 PM Sat 48 48 SW 8 N/A N/A N/A N/A N/A
3 PM Sat 48 48 SW 8 N/A N/A N/A N/A N/A
4 PM Sat 47 47 S 7 N/A N/A N/A N/A N/A
5 PM Sat 45 45 S 7 N/A N/A N/A N/A N/A
6 PM Sat 44 44 S 7 N/A N/A N/A N/A N/A
7 PM Sat 43 43 S 7 N/A N/A N/A N/A N/A
8 PM Sat 43 43 S 7 N/A N/A N/A N/A N/A
9 PM Sat 43 43 S 7 N/A N/A N/A N/A N/A
10 PM Sat 43 43 SW 8 N/A N/A N/A N/A N/A
11 PM Sat 41 41 SW 8 N/A N/A N/A N/A N/A
12 Midnight Sun 40 40 SW 8 N/A N/A N/A N/A N/A
1 AM Sun 39 39 SW 8 N/A N/A N/A N/A N/A
2 AM Sun 40 40 SW 8 N/A N/A N/A N/A N/A
3 AM Sun 42 42 SW 8 N/A N/A N/A N/A N/A
4 AM Sun 43 43 SW 12 N/A N/A N/A N/A N/A
5 AM Sun 42 42 SW 12 N/A N/A N/A N/A N/A
6 AM Sun 40 40 SW 12 N/A N/A N/A N/A N/A
7 AM Sun 39 39 SW 12 N/A N/A N/A N/A N/A
8 AM Sun 39 39 SW 12 N/A N/A N/A N/A N/A
9 AM Sun 40 40 SW 12 N/A N/A N/A N/A N/A
10 AM Sun 42 42 S 10 N/A N/A N/A N/A N/A
11 AM Sun 43 43 S 10 N/A N/A N/A N/A N/A
12 Noon Sun 45 45 S 10 N/A N/A N/A N/A N/A
1 PM Sun 45 45 S 10 N/A N/A N/A N/A N/A
2 PM Sun 45 45 S 10 N/A N/A N/A N/A N/A
3 PM Sun 44 44 S 10 N/A N/A N/A N/A N/A
4 PM Sun 42 42 W 13 N/A N/A N/A N/A N/A
5 PM Sun 40 40 W 13 N/A N/A N/A N/A N/A
6 PM Sun 37 37 W 13 N/A N/A N/A N/A N/A
7 PM Sun 35 35 W 13 N/A N/A N/A N/A N/A
8 PM Sun 33 33 W 13 N/A N/A N/A N/A N/A
9 PM Sun 32 32 W 13 N/A N/A N/A N/A N/A
10 PM Sun 31 31 W 6 N/A N/A N/A N/A N/A
11 PM Sun 30 30 W 6 N/A N/A N/A N/A N/A
12 Midnight Mon 29 29 W 6 N/A N/A N/A N/A N/A
1 AM Mon 28 28 W 6 N/A N/A N/A N/A N/A
2 AM Mon 28 28 W 6 N/A N/A N/A N/A N/A
3 AM Mon 27 27 W 6 N/A N/A N/A N/A N/A
4 AM Mon 27 27 NW 5 N/A N/A N/A N/A N/A
5 AM Mon 26 26 NW 5 N/A N/A N/A N/A N/A
6 AM Mon 25 25 NW 5 N/A N/A N/A N/A N/A
7 AM Mon 25 25 NW 5 N/A N/A N/A N/A N/A
8 AM Mon 27 27 NW 5 N/A N/A N/A N/A N/A
9 AM Mon 30 30 NW 5 N/A N/A N/A N/A N/A
10 AM Mon 33 33 NE 7 N/A N/A N/A N/A N/A
11 AM Mon 35 36 NE 7 N/A N/A N/A N/A N/A
12 Noon Mon 37 38 NE 7 N/A N/A N/A N/A N/A
1 PM Mon 39 40 NE 7 N/A N/A N/A N/A N/A
2 PM Mon 40 41 NE 7 N/A N/A N/A N/A N/A
3 PM Mon 41 41 NE 7 N/A N/A N/A N/A N/A
4 PM Mon 40 40 NE 6 N/A N/A N/A N/A N/A
5 PM Mon 38 38 NE 6 N/A N/A N/A N/A N/A
6 PM Mon 34 34 NE 6 N/A N/A N/A N/A N/A
7 PM Mon 31 31 NE 6 N/A N/A N/A N/A N/A
8 PM Mon 29 29 NE 6 N/A N/A N/A N/A N/A
9 PM Mon 28 28 NE 6 N/A N/A N/A N/A N/A
10 PM Mon 27 27 E 6 N/A N/A N/A N/A N/A
11 PM Mon 27 27 E 6 N/A N/A N/A N/A N/A
12 Midnight Tue 27 27 E 6 N/A N/A N/A N/A N/A
1 AM Tue 26 26 E 6 N/A N/A N/A N/A N/A
2 AM Tue 26 26 E 6 N/A N/A N/A N/A N/A
3 AM Tue 26 26 E 6 N/A N/A N/A N/A N/A
4 AM Tue 25 25 E 6 N/A N/A N/A N/A N/A
5 AM Tue 24 24 E 6 N/A N/A N/A N/A N/A
6 AM Tue 23 23 E 6 N/A N/A N/A N/A N/A
7 AM Tue 24 24 E 6 N/A N/A N/A N/A N/A
8 AM Tue 26 26 E 6 N/A N/A N/A N/A N/A
9 AM Tue 30 30 E 6 N/A N/A N/A N/A N/A
10 AM Tue 34 34 E 7 N/A N/A N/A N/A N/A
11 AM Tue 37 38 E 7 N/A N/A N/A N/A N/A
12 Noon Tue 40 41 E 7 N/A N/A N/A N/A N/A
1 PM Tue 43 44 E 7 N/A N/A N/A N/A N/A
2 PM Tue 44 45 E 7 N/A N/A N/A N/A N/A
3 PM Tue 45 45 E 7 N/A N/A N/A N/A N/A
4 PM Tue 44 44 E 6 N/A N/A N/A N/A N/A
5 PM Tue 41 41 E 6 N/A N/A N/A N/A N/A
6 PM Tue 38 38 E 6 N/A N/A N/A N/A N/A
7 PM Tue 35 35 E 6 N/A N/A N/A N/A N/A
8 PM Tue 33 33 E 6 N/A N/A N/A N/A N/A
9 PM Tue 33 33 E 6 N/A N/A N/A N/A N/A
10 PM Tue 33 33 E 6 N/A N/A N/A N/A N/A
11 PM Tue 32 32 E 6 N/A N/A N/A N/A N/A
12 Midnight Wed 31 31 E 6 N/A N/A N/A N/A N/A
1 AM Wed 31 31 E 6 N/A N/A N/A N/A N/A
2 AM Wed 30 30 E 6 N/A N/A N/A N/A N/A
3 AM Wed 30 30 E 6 N/A N/A N/A N/A N/A

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