Detailed Predictions for: Chalk Bluffs
Launch Lat, Long, Altitude (f): 37.416328, -118.442829, 4500
LZ Altitude (f): 4220
Sounding

Station:

KVBG

Date/Time:

N/A

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 Sat 81 81 NW 6 13 N/A N/A N/A N/A N/A
1 AM Sat 80 80 NW 6 11 N/A N/A N/A N/A N/A
2 AM Sat 77 77 WNW 5 11 N/A N/A N/A N/A N/A
3 AM Sat 74 74 NW 5 10 N/A N/A N/A N/A N/A
4 AM Sat 73 73 NW 5 10 N/A N/A N/A N/A N/A
5 AM Sat 72 72 NW 4 9 N/A N/A N/A N/A N/A
6 AM Sat 69 69 WNW 3 8 N/A N/A N/A N/A N/A
7 AM Sat 74 74 NW 3 8 N/A N/A N/A N/A N/A
8 AM Sat 80 80 NW 3 6 N/A N/A N/A N/A N/A
9 AM Sat 84 86 NW 3 8 N/A N/A N/A N/A N/A
10 AM Sat 91 95 SSE 5 10 N/A N/A N/A N/A N/A
11 AM Sat 96 102 SSE 6 13 N/A N/A N/A N/A N/A
12 Noon Sat 96 103 SSE 9 17 N/A N/A N/A N/A N/A
1 PM Sat 98 104 SSE 11 19 N/A N/A N/A N/A N/A
2 PM Sat 100 105 SSW 13 21 N/A N/A N/A N/A N/A
3 PM Sat 98 102 S 13 23 N/A N/A N/A N/A N/A
4 PM Sat 97 99 SW 13 23 N/A N/A N/A N/A N/A
5 PM Sat 95 96 SSE 13 21 N/A N/A N/A N/A N/A
6 PM Sat 91 91 SSW 12 21 N/A N/A N/A N/A N/A
7 PM Sat 89 89 NW 11 20 N/A N/A N/A N/A N/A
8 PM Sat 85 85 N 10 18 N/A N/A N/A N/A N/A
9 PM Sat 83 83 NNW 9 14 N/A N/A N/A N/A N/A
10 PM Sat 82 82 NW 6 13 N/A N/A N/A N/A N/A
11 PM Sat 80 80 WNW 5 11 N/A N/A N/A N/A N/A
12 Midnight Sun 77 77 WNW 5 10 N/A N/A N/A N/A N/A
1 AM Sun 75 75 WNW 5 10 N/A N/A N/A N/A N/A
2 AM Sun 73 73 NW 4 9 N/A N/A N/A N/A N/A
3 AM Sun 71 71 NW 4 9 N/A N/A N/A N/A N/A
4 AM Sun 69 69 WNW 4 8 N/A N/A N/A N/A N/A
5 AM Sun 67 67 NW 4 8 N/A N/A N/A N/A N/A
6 AM Sun 66 66 NW 3 6 N/A N/A N/A N/A N/A
7 AM Sun 70 70 NW 3 6 N/A N/A N/A N/A N/A
8 AM Sun 76 76 WNW 3 8 N/A N/A N/A N/A N/A
9 AM Sun 81 82 W 3 9 N/A N/A N/A N/A N/A
10 AM Sun 86 88 SSW 4 11 N/A N/A N/A N/A N/A
11 AM Sun 90 93 SSE 5 12 N/A N/A N/A N/A N/A
12 Noon Sun 93 96 S 6 14 N/A N/A N/A N/A N/A
1 PM Sun 94 97 S 8 16 N/A N/A N/A N/A N/A
2 PM Sun 94 97 SSW 9 17 N/A N/A N/A N/A N/A
3 PM Sun 94 97 SW 10 17 N/A N/A N/A N/A N/A
4 PM Sun 93 95 WSW 10 17 N/A N/A N/A N/A N/A
5 PM Sun 91 92 W 10 17 N/A N/A N/A N/A N/A
6 PM Sun 89 89 W 10 17 N/A N/A N/A N/A N/A
7 PM Sun 87 87 WNW 10 17 N/A N/A N/A N/A N/A
8 PM Sun 85 85 NW 9 17 N/A N/A N/A N/A N/A
9 PM Sun 83 83 NW 8 16 N/A N/A N/A N/A N/A
10 PM Sun 81 81 WNW 8 14 N/A N/A N/A N/A N/A
11 PM Sun 79 79 WNW 6 13 N/A N/A N/A N/A N/A
12 Midnight Mon 76 76 WNW 6 12 N/A N/A N/A N/A N/A
1 AM Mon 74 74 WNW 5 11 N/A N/A N/A N/A N/A
2 AM Mon 71 71 WNW 5 10 N/A N/A N/A N/A N/A
3 AM Mon 68 68 WNW 5 10 N/A N/A N/A N/A N/A
4 AM Mon 66 66 WNW 5 10 N/A N/A N/A N/A N/A
5 AM Mon 66 66 WNW 5 10 N/A N/A N/A N/A N/A
6 AM Mon 68 68 NW 4 9 N/A N/A N/A N/A N/A
7 AM Mon 72 72 NW 4 9 N/A N/A N/A N/A N/A
8 AM Mon 76 77 NW 3 8 N/A N/A N/A N/A N/A
9 AM Mon 80 83 NNW 2 8 N/A N/A N/A N/A N/A
10 AM Mon 84 88 N 2 8 N/A N/A N/A N/A N/A
11 AM Mon 88 94 N 2 9 N/A N/A N/A N/A N/A
12 Noon Mon 90 97 NNW 2 10 N/A N/A N/A N/A N/A
1 PM Mon 92 99 W 3 11 N/A N/A N/A N/A N/A
2 PM Mon 93 99 WSW 4 12 N/A N/A N/A N/A N/A
3 PM Mon 94 99 WSW 5 13 N/A N/A N/A N/A N/A
4 PM Mon 94 97 W 8 14 N/A N/A N/A N/A N/A
5 PM Mon 93 94 W 9 16 N/A N/A N/A N/A N/A
6 PM Mon 91 92 W 9 16 N/A N/A N/A N/A N/A
7 PM Mon 89 89 WNW 9 16 N/A N/A N/A N/A N/A
8 PM Mon 86 86 WNW 9 16 N/A N/A N/A N/A N/A
9 PM Mon 84 84 WNW 9 16 N/A N/A N/A N/A N/A
10 PM Mon 82 82 WNW 9 14 N/A N/A N/A N/A N/A
11 PM Mon 80 80 W 9 14 N/A N/A N/A N/A N/A
12 Midnight Tue 77 77 W 8 13 N/A N/A N/A N/A N/A
1 AM Tue 73 73 WNW 8 13 N/A N/A N/A N/A N/A
2 AM Tue 70 70 WNW 6 12 N/A N/A N/A N/A N/A
3 AM Tue 67 67 WNW 6 12 N/A N/A N/A N/A N/A
4 AM Tue 64 64 WNW 5 11 N/A N/A N/A N/A N/A
5 AM Tue 64 64 WNW 5 11 N/A N/A N/A N/A N/A
6 AM Tue 66 66 WNW 5 10 N/A N/A N/A N/A N/A
7 AM Tue 70 70 NW 4 9 N/A N/A N/A N/A N/A
8 AM Tue 75 76 NW 4 8 N/A N/A N/A N/A N/A
9 AM Tue 80 83 W 4 8 N/A N/A N/A N/A N/A
10 AM Tue 85 90 S 3 8 N/A N/A N/A N/A N/A
11 AM Tue 89 96 SE 3 9 N/A N/A N/A N/A N/A
12 Noon Tue 92 100 SE 3 10 N/A N/A N/A N/A N/A
1 PM Tue 95 103 SSE 4 12 N/A N/A N/A N/A N/A
2 PM Tue 96 103 SSE 5 13 N/A N/A N/A N/A N/A
3 PM Tue 97 103 SSE 6 14 N/A N/A N/A N/A N/A
4 PM Tue 98 102 SSE 8 16 N/A N/A N/A N/A N/A
5 PM Tue 97 99 SSE 9 16 N/A N/A N/A N/A N/A
6 PM Tue 96 97 S 9 16 N/A N/A N/A N/A N/A
7 PM Tue 93 93 S 9 16 N/A N/A N/A N/A N/A
8 PM Tue 90 90 SSW 9 16 N/A N/A N/A N/A N/A
9 PM Tue 87 87 SW 9 16 N/A N/A N/A N/A N/A
10 PM Tue 83 83 WSW 10 16 N/A N/A N/A N/A N/A
11 PM Tue 79 79 W 10 16 N/A N/A N/A N/A N/A
12 Midnight Wed 76 76 W 10 14 N/A N/A N/A N/A N/A
1 AM Wed 73 73 W 9 14 N/A N/A N/A N/A N/A
2 AM Wed 70 70 WNW 8 13 N/A N/A N/A N/A N/A
3 AM Wed 67 67 WNW 6 12 N/A N/A N/A N/A N/A
4 AM Wed 64 64 WNW 6 12 N/A N/A N/A N/A N/A
5 AM Wed 63 63 WNW 5 11 N/A N/A N/A N/A N/A
6 AM Wed 65 65 WNW 4 10 N/A N/A N/A N/A N/A
7 AM Wed 68 68 WNW 3 9 N/A N/A N/A N/A N/A
8 AM Wed 73 74 WNW 3 8 N/A N/A N/A N/A N/A
9 AM Wed 78 81 W 3 8 N/A N/A N/A N/A N/A
10 AM Wed 83 88 S 3 9 N/A N/A N/A N/A N/A
11 AM Wed 88 95 SE 4 10 N/A N/A N/A N/A N/A
12 Noon Wed 92 100 SE 5 12 N/A N/A N/A N/A N/A
1 PM Wed 94 102 SSE 5 13 N/A N/A N/A N/A N/A
2 PM Wed 96 103 SSE 6 16 N/A N/A N/A N/A N/A
3 PM Wed 98 104 SSE 8 17 N/A N/A N/A N/A N/A
4 PM Wed 98 102 SSE 9 18 N/A N/A N/A N/A N/A
5 PM Wed 98 100 SSE 10 18 N/A N/A N/A N/A N/A
6 PM Wed 97 98 SSE 10 18 N/A N/A N/A N/A N/A
7 PM Wed 94 94 S 10 18 N/A N/A N/A N/A N/A
8 PM Wed 91 91 S 9 17 N/A N/A N/A N/A N/A
9 PM Wed 88 88 S 9 16 N/A N/A N/A N/A N/A
10 PM Wed 84 84 WSW 8 16 N/A N/A N/A N/A N/A
11 PM Wed 80 80 W 8 14 N/A N/A N/A N/A N/A
12 Midnight Thu 76 76 W 8 13 N/A N/A N/A N/A N/A
1 AM Thu 72 72 W 6 13 N/A N/A N/A N/A N/A
2 AM Thu 69 69 WNW 6 12 N/A N/A N/A N/A N/A
3 AM Thu 66 66 WNW 6 11 N/A N/A N/A N/A N/A
4 AM Thu 63 63 WNW 5 11 N/A N/A N/A N/A N/A
5 AM Thu 63 63 WNW 5 10 N/A N/A N/A N/A N/A
6 AM Thu 65 65 WNW 4 9 N/A N/A N/A N/A N/A
7 AM Thu 69 69 W 3 8 N/A N/A N/A N/A N/A
8 AM Thu 74 75 W 3 6 N/A N/A N/A N/A N/A
9 AM Thu 79 82 WSW 3 8 N/A N/A N/A N/A N/A
10 AM Thu 84 89 S 3 9 N/A N/A N/A N/A N/A
11 AM Thu 89 95 SE 4 11 N/A N/A N/A N/A N/A
12 Noon Thu 93 100 SE 5 13 N/A N/A N/A N/A N/A
1 PM Thu 95 103 SSE 6 16 N/A N/A N/A N/A N/A
2 PM Thu 97 104 SSE 8 17 N/A N/A N/A N/A N/A
3 PM Thu 98 103 SSE 9 18 N/A N/A N/A N/A N/A
4 PM Thu 98 101 S 10 19 N/A N/A N/A N/A N/A
5 PM Thu 97 99 S 10 19 N/A N/A N/A N/A N/A
6 PM Thu 95 96 SSW 10 19 N/A N/A N/A N/A N/A
7 PM Thu 92 92 SW 10 18 N/A N/A N/A N/A N/A
8 PM Thu 89 89 SW 9 17 N/A N/A N/A N/A N/A
9 PM Thu 86 86 WSW 8 16 N/A N/A N/A N/A N/A
10 PM Thu 84 84 W 8 13 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 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]