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:

 6 DEC 2023

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 Wed 43 43 S 5 11 4341 4590 0 Blue 0
1 AM Wed 42 42 S 5 11 4341 4590 0 Blue 0
2 AM Wed 42 42 S 6 12 4341 4590 0 Blue 0
3 AM Wed 41 41 S 6 13 4341 4590 0 Blue 0
4 AM Wed 41 41 S 6 13 4341 4590 0 Blue 0
5 AM Wed 40 40 S 6 13 4341 4590 0 Blue 0
6 AM Wed 39 39 S 6 13 4341 4590 0 Blue 0
7 AM Wed 39 39 S 6 14 4341 4590 0 Blue 0
8 AM Wed 39 39 S 7 15 4341 4590 0 Blue 0
9 AM Wed 39 39 SSW 7 13 4341 4590 0 Blue 0
10 AM Wed 41 42 SSW 8 10 4341 4590 0 Blue 0
11 AM Wed 43 43 SW 12 14 4341 4590 0 Blue 0
12 Noon Wed 45 45 SW 14 16 4341 4590 0 Blue 0
1 PM Wed 46 46 SSW 15 18 4341 4590 0 Blue 0
2 PM Wed 42 42 SSW 16 19 4341 4590 0 Blue 0
3 PM Wed 38 38 SSW 15 18 4341 4590 0 Blue 0
4 PM Wed 37 37 S 11 12 4341 4590 0 Blue 0
5 PM Wed 39 39 SSW 8 9 4341 4590 0 Blue 0
6 PM Wed 37 37 WSW 9 11 4341 4590 0 Blue 0
7 PM Wed 37 37 SW 7 8 4341 4590 0 Blue 0
8 PM Wed 37 37 SW 8 10 4341 4590 0 Blue 0
9 PM Wed 37 37 SW 7 9 4341 4590 0 Blue 0
10 PM Wed 37 37 SW 6 7 4341 4590 0 Blue 0
11 PM Wed 37 37 SW 6 7 4341 4590 0 Blue 0
12 Midnight Thu 34 34 WSW 8 9 4341 4590 0 Blue 0
1 AM Thu 33 33 WSW 8 10 4341 4590 0 Blue 0
2 AM Thu 35 35 SW 6 8 4341 4590 0 Blue 0
3 AM Thu 31 31 SW 6 8 4341 4590 0 Blue 0
4 AM Thu 32 32 SW 7 10 4341 4590 0 Blue 0
5 AM Thu 35 35 SW 7 10 4341 4590 0 Blue 0
6 AM Thu 32 32 SW 6 7 4341 4590 0 Blue 0
7 AM Thu 31 31 SSW 6 8 4341 4590 0 Blue 0
8 AM Thu 28 28 SSW 6 7 4341 4590 0 Blue 0
9 AM Thu 31 31 SSW 6 8 4341 4590 0 Blue 0
10 AM Thu 32 32 SSW 8 9 4341 4590 0 Blue 0
11 AM Thu 31 31 SSW 9 11 4341 4590 0 Blue 0
12 Noon Thu 35 35 SSW 10 11 4341 4590 0 Blue 0
1 PM Thu 35 35 SSW 9 11 4341 4590 0 Blue 0
2 PM Thu 33 33 SW 11 12 4341 4590 0 Blue 0
3 PM Thu 33 33 SW 10 12 4341 4590 0 Blue 0
4 PM Thu 32 32 WSW 10 12 4341 4590 0 Blue 0
5 PM Thu 31 31 WSW 8 10 4341 4590 0 Blue 0
6 PM Thu 31 31 WSW 6 7 4341 4590 0 Blue 0
7 PM Thu 30 30 W 5 7 4341 4590 0 Blue 0
8 PM Thu 30 30 W 3 4 4341 4590 0 Blue 0
9 PM Thu 29 29 WNW 2 2 4341 4590 0 Blue 0
10 PM Thu 28 28 W 1 2 4341 4590 0 Blue 0
11 PM Thu 27 27 W 2 3 4341 4590 0 Blue 0
12 Midnight Fri 28 28 WNW 2 2 4341 4590 0 Blue 0
1 AM Fri 27 27 NW 1 1 4341 4590 0 Blue 0
2 AM Fri 26 26 ESE 0 1 4341 4590 0 Blue 0
3 AM Fri 20 20 SSE 2 4 4341 4590 0 Blue 0
4 AM Fri 17 17 SSE 3 7 4341 4590 0 Blue 0
5 AM Fri 24 24 SSE 3 6 4341 4590 0 Blue 0
6 AM Fri 16 16 SE 3 6 4341 4590 0 Blue 0
7 AM Fri 16 16 SE 3 7 4341 4590 0 Blue 0
8 AM Fri 22 22 ESE 4 8 4341 4590 0 Blue 0
9 AM Fri 18 18 ESE 4 8 4341 4590 0 Blue 0
10 AM Fri 26 27 E 3 4 4341 4590 0 Blue 0
11 AM Fri 29 30 ENE 4 5 4341 4590 0 Blue 0
12 Noon Fri 31 32 NE 5 5 4341 4590 0 Blue 0
1 PM Fri 32 33 NE 4 5 4341 4590 0 Blue 0
2 PM Fri 32 33 NE 4 5 4341 4590 0 Blue 0
3 PM Fri 33 33 NE 4 5 4341 4590 0 Blue 0
4 PM Fri 32 32 NE 3 4 4341 4590 0 Blue 0
5 PM Fri 29 29 NE 3 4 4341 4590 0 Blue 0
6 PM Fri 21 21 ESE 3 7 4341 4590 0 Blue 0
7 PM Fri 19 19 SE 3 8 4341 4590 0 Blue 0
8 PM Fri 22 22 SE 4 8 4341 4590 0 Blue 0
9 PM Fri 19 19 SE 4 9 4341 4590 0 Blue 0
10 PM Fri 19 19 SE 4 9 4341 4590 0 Blue 0
11 PM Fri 23 23 SE 4 10 4341 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]