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

Station:

 KVBG

Date/Time UTC:

 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 Wed 80 80 NNW 6 12 N/A N/A N/A N/A N/A
1 AM Wed 77 77 NW 5 10 N/A N/A N/A N/A N/A
2 AM Wed 74 74 NW 5 9 N/A N/A N/A N/A N/A
3 AM Wed 70 70 NW 4 9 N/A N/A N/A N/A N/A
4 AM Wed 68 68 NW 4 8 N/A N/A N/A N/A N/A
5 AM Wed 67 67 NW 4 8 N/A N/A N/A N/A N/A
6 AM Wed 63 63 NW 4 6 N/A N/A N/A N/A N/A
7 AM Wed 70 70 NW 3 6 N/A N/A N/A N/A N/A
8 AM Wed 76 77 N 2 5 N/A N/A N/A N/A N/A
9 AM Wed 81 84 N 1 4 N/A N/A N/A N/A N/A
10 AM Wed 90 95 NNW 2 5 N/A N/A N/A N/A N/A
11 AM Wed 93 100 WNW 3 6 N/A N/A N/A N/A N/A
12 Noon Wed 95 103 S 3 8 N/A N/A N/A N/A N/A
1 PM Wed 97 106 S 4 8 N/A N/A N/A N/A N/A
2 PM Wed 99 107 SE 5 9 N/A N/A N/A N/A N/A
3 PM Wed 99 105 ESE 5 11 N/A N/A N/A N/A N/A
4 PM Wed 99 103 ESE 5 12 N/A N/A N/A N/A N/A
5 PM Wed 101 102 NE 5 12 N/A N/A N/A N/A N/A
6 PM Wed 99 99 N 5 12 N/A N/A N/A N/A N/A
7 PM Wed 98 98 NNW 6 14 N/A N/A N/A N/A N/A
8 PM Wed 95 95 N 8 16 N/A N/A N/A N/A N/A
9 PM Wed 90 90 NNW 6 13 N/A N/A N/A N/A N/A
10 PM Wed 87 87 NNW 6 12 N/A N/A N/A N/A N/A
11 PM Wed 83 83 NNW 8 12 N/A N/A N/A N/A N/A
12 Midnight Thu 80 80 NW 8 12 N/A N/A N/A N/A N/A
1 AM Thu 77 77 WNW 6 11 N/A N/A N/A N/A N/A
2 AM Thu 75 75 WNW 6 10 N/A N/A N/A N/A N/A
3 AM Thu 71 71 WNW 5 10 N/A N/A N/A N/A N/A
4 AM Thu 70 70 NW 4 9 N/A N/A N/A N/A N/A
5 AM Thu 68 68 NW 4 8 N/A N/A N/A N/A N/A
6 AM Thu 65 65 NW 3 6 N/A N/A N/A N/A N/A
7 AM Thu 70 70 NW 3 5 N/A N/A N/A N/A N/A
8 AM Thu 77 78 N 2 4 N/A N/A N/A N/A N/A
9 AM Thu 81 84 N 2 5 N/A N/A N/A N/A N/A
10 AM Thu 89 94 NNE 2 6 N/A N/A N/A N/A N/A
11 AM Thu 92 99 E 3 8 N/A N/A N/A N/A N/A
12 Noon Thu 94 102 SE 5 11 N/A N/A N/A N/A N/A
1 PM Thu 96 104 SSE 9 14 N/A N/A N/A N/A N/A
2 PM Thu 97 104 SSE 12 18 N/A N/A N/A N/A N/A
3 PM Thu 97 101 S 14 20 N/A N/A N/A N/A N/A
4 PM Thu 98 102 SSE 14 21 N/A N/A N/A N/A N/A
5 PM Thu 99 101 SSW 13 23 N/A N/A N/A N/A N/A
6 PM Thu 97 98 WNW 13 21 N/A N/A N/A N/A N/A
7 PM Thu 95 95 NW 11 18 N/A N/A N/A N/A N/A
8 PM Thu 92 92 NW 8 14 N/A N/A N/A N/A N/A
9 PM Thu 89 89 NW 6 12 N/A N/A N/A N/A N/A
10 PM Thu 85 85 WNW 5 11 N/A N/A N/A N/A N/A
11 PM Thu 81 81 W 5 10 N/A N/A N/A N/A N/A
12 Midnight Fri 77 77 W 4 9 N/A N/A N/A N/A N/A
1 AM Fri 73 73 W 4 8 N/A N/A N/A N/A N/A
2 AM Fri 70 70 W 3 6 N/A N/A N/A N/A N/A
3 AM Fri 66 66 W 3 5 N/A N/A N/A N/A N/A
4 AM Fri 64 64 WSW 2 5 N/A N/A N/A N/A N/A
5 AM Fri 63 63 WSW 2 5 N/A N/A N/A N/A N/A
6 AM Fri 65 65 SW 2 5 N/A N/A N/A N/A N/A
7 AM Fri 68 68 S 2 5 N/A N/A N/A N/A N/A
8 AM Fri 73 74 SSE 2 5 N/A N/A N/A N/A N/A
9 AM Fri 78 81 SSE 2 6 N/A N/A N/A N/A N/A
10 AM Fri 84 89 SSE 3 8 N/A N/A N/A N/A N/A
11 AM Fri 88 95 SSE 4 10 N/A N/A N/A N/A N/A
12 Noon Fri 91 99 SSE 6 13 N/A N/A N/A N/A N/A
1 PM Fri 92 100 S 8 18 N/A N/A N/A N/A N/A
2 PM Fri 93 101 S 10 20 N/A N/A N/A N/A N/A
3 PM Fri 94 100 S 11 20 N/A N/A N/A N/A N/A
4 PM Fri 94 98 SSW 11 19 N/A N/A N/A N/A N/A
5 PM Fri 93 95 SW 11 18 N/A N/A N/A N/A N/A
6 PM Fri 90 91 WSW 10 17 N/A N/A N/A N/A N/A
7 PM Fri 87 87 W 10 17 N/A N/A N/A N/A N/A
8 PM Fri 83 83 WNW 9 16 N/A N/A N/A N/A N/A
9 PM Fri 80 80 WNW 9 16 N/A N/A N/A N/A N/A
10 PM Fri 76 76 WNW 10 17 N/A N/A N/A N/A N/A
11 PM Fri 73 73 WNW 10 16 N/A N/A N/A N/A N/A
12 Midnight Sat 69 69 WNW 8 13 N/A N/A N/A N/A N/A
1 AM Sat 65 65 WNW 5 10 N/A N/A N/A N/A N/A
2 AM Sat 62 62 WNW 3 6 N/A N/A N/A N/A N/A
3 AM Sat 58 58 WNW 3 5 N/A N/A N/A N/A N/A
4 AM Sat 56 56 WNW 3 5 N/A N/A N/A N/A N/A
5 AM Sat 55 55 WNW 3 5 N/A N/A N/A N/A N/A
6 AM Sat 57 57 NW 2 4 N/A N/A N/A N/A N/A
7 AM Sat 60 60 NW 1 3 N/A N/A N/A N/A N/A
8 AM Sat 65 66 NNW 1 3 N/A N/A N/A N/A N/A
9 AM Sat 70 73 N 1 4 N/A N/A N/A N/A N/A
10 AM Sat 76 81 E 2 6 N/A N/A N/A N/A N/A
11 AM Sat 81 88 ESE 3 9 N/A N/A N/A N/A N/A
12 Noon Sat 85 93 SE 4 11 N/A N/A N/A N/A N/A
1 PM Sat 87 96 SSE 5 14 N/A N/A N/A N/A N/A
2 PM Sat 89 97 S 6 16 N/A N/A N/A N/A N/A
3 PM Sat 91 98 SSW 6 16 N/A N/A N/A N/A N/A
4 PM Sat 92 97 SW 6 14 N/A N/A N/A N/A N/A
5 PM Sat 91 94 WSW 6 13 N/A N/A N/A N/A N/A
6 PM Sat 89 90 WSW 6 13 N/A N/A N/A N/A N/A
7 PM Sat 87 87 WSW 6 13 N/A N/A N/A N/A N/A
8 PM Sat 84 84 SW 6 13 N/A N/A N/A N/A N/A
9 PM Sat 81 81 WSW 6 13 N/A N/A N/A N/A N/A
10 PM Sat 77 77 W 6 13 N/A N/A N/A N/A N/A
11 PM Sat 74 74 WNW 6 13 N/A N/A N/A N/A N/A
12 Midnight Sun 70 70 WNW 5 12 N/A N/A N/A N/A N/A
1 AM Sun 67 67 WNW 4 10 N/A N/A N/A N/A N/A
2 AM Sun 64 64 NW 3 8 N/A N/A N/A N/A N/A
3 AM Sun 61 61 NW 2 6 N/A N/A N/A N/A N/A
4 AM Sun 60 60 NW 2 5 N/A N/A N/A N/A N/A
5 AM Sun 60 60 NW 2 5 N/A N/A N/A N/A N/A
6 AM Sun 62 62 NW 2 4 N/A N/A N/A N/A N/A
7 AM Sun 66 66 NNW 2 4 N/A N/A N/A N/A N/A
8 AM Sun 71 72 N 2 4 N/A N/A N/A N/A N/A
9 AM Sun 75 78 NNE 2 5 N/A N/A N/A N/A N/A
10 AM Sun 79 84 E 3 8 N/A N/A N/A N/A N/A
11 AM Sun 83 90 ESE 4 10 N/A N/A N/A N/A N/A
12 Noon Sun 86 95 ESE 5 12 N/A N/A N/A N/A N/A
1 PM Sun 88 97 SE 8 13 N/A N/A N/A N/A N/A
2 PM Sun 90 98 SSE 9 14 N/A N/A N/A N/A N/A
3 PM Sun 92 99 SSE 9 14 N/A N/A N/A N/A N/A
4 PM Sun 93 98 SSE 9 14 N/A N/A N/A N/A N/A
5 PM Sun 93 96 SSE 8 14 N/A N/A N/A N/A N/A
6 PM Sun 92 93 SSE 8 14 N/A N/A N/A N/A N/A
7 PM Sun 90 90 SSE 6 13 N/A N/A N/A N/A N/A
8 PM Sun 87 87 SSE 5 12 N/A N/A N/A N/A N/A
9 PM Sun 84 84 S 4 10 N/A N/A N/A N/A N/A
10 PM Sun 81 81 SW 2 6 N/A N/A N/A N/A N/A
11 PM Sun 77 77 WSW 1 4 N/A N/A N/A N/A N/A
12 Midnight Mon 73 73 W 1 4 N/A N/A N/A N/A N/A
1 AM Mon 69 69 WNW 1 4 N/A N/A N/A N/A N/A
2 AM Mon 66 66 NW 2 5 N/A N/A N/A N/A N/A
3 AM Mon 63 63 WNW 2 5 N/A N/A N/A N/A N/A
4 AM Mon 62 62 WNW 2 5 N/A N/A N/A N/A N/A
5 AM Mon 62 62 WNW 2 5 N/A N/A N/A N/A N/A
6 AM Mon 65 65 NW 2 5 N/A N/A N/A N/A N/A
7 AM Mon 69 69 N 2 5 N/A N/A N/A N/A N/A
8 AM Mon 74 75 N 2 5 N/A N/A N/A N/A N/A
9 AM Mon 78 81 NE 3 6 N/A N/A N/A N/A N/A
10 AM Mon 82 87 ESE 4 9 N/A N/A N/A N/A N/A
11 AM Mon 86 93 SE 5 11 N/A N/A N/A N/A N/A
12 Noon Mon 89 98 SE 6 12 N/A N/A N/A N/A N/A
1 PM Mon 91 100 SE 8 13 N/A N/A N/A N/A N/A
2 PM Mon 93 101 SE 8 13 N/A N/A N/A N/A N/A
3 PM Mon 94 101 SE 8 13 N/A N/A N/A N/A N/A
4 PM Mon 95 100 SE 8 13 N/A N/A N/A N/A N/A
5 PM Mon 95 98 SE 8 12 N/A N/A N/A N/A N/A
6 PM Mon 94 95 SSE 6 12 N/A N/A N/A N/A N/A
7 PM Mon 93 93 SSE 5 11 N/A N/A N/A N/A N/A
8 PM Mon 90 90 SSE 4 10 N/A N/A N/A N/A N/A
9 PM Mon 87 87 SSE 3 9 N/A N/A N/A N/A N/A
10 PM Mon 83 83 S 3 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 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]