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 Mon 67 67 NW 5 10 N/A N/A N/A N/A N/A
1 AM Mon 65 65 NW 5 10 N/A N/A N/A N/A N/A
2 AM Mon 63 63 NW 5 10 N/A N/A N/A N/A N/A
3 AM Mon 62 62 NW 5 9 N/A N/A N/A N/A N/A
4 AM Mon 60 60 NW 5 9 N/A N/A N/A N/A N/A
5 AM Mon 58 58 NW 5 9 N/A N/A N/A N/A N/A
6 AM Mon 57 57 NW 4 8 N/A N/A N/A N/A N/A
7 AM Mon 56 56 NW 4 6 N/A N/A N/A N/A N/A
8 AM Mon 61 61 NW 3 8 N/A N/A N/A N/A N/A
9 AM Mon 67 67 NNW 2 5 N/A N/A N/A N/A N/A
10 AM Mon 75 76 NW 1 4 N/A N/A N/A N/A N/A
11 AM Mon 79 81 E 2 5 N/A N/A N/A N/A N/A
12 Noon Mon 81 83 SE 2 8 N/A N/A N/A N/A N/A
1 PM Mon 83 85 SSE 4 11 N/A N/A N/A N/A N/A
2 PM Mon 85 86 SSE 5 12 N/A N/A N/A N/A N/A
3 PM Mon 85 85 SSE 5 13 N/A N/A N/A N/A N/A
4 PM Mon 86 86 SSE 5 13 N/A N/A N/A N/A N/A
5 PM Mon 84 84 S 6 13 N/A N/A N/A N/A N/A
6 PM Mon 81 81 S 5 13 N/A N/A N/A N/A N/A
7 PM Mon 78 78 N 5 12 N/A N/A N/A N/A N/A
8 PM Mon 73 73 NW 5 11 N/A N/A N/A N/A N/A
9 PM Mon 71 71 NNW 5 10 N/A N/A N/A N/A N/A
10 PM Mon 69 69 WNW 4 10 N/A N/A N/A N/A N/A
11 PM Mon 67 67 WNW 4 10 N/A N/A N/A N/A N/A
12 Midnight Tue 64 64 WNW 4 9 N/A N/A N/A N/A N/A
1 AM Tue 63 63 NW 4 9 N/A N/A N/A N/A N/A
2 AM Tue 61 61 WNW 4 9 N/A N/A N/A N/A N/A
3 AM Tue 60 60 NW 4 8 N/A N/A N/A N/A N/A
4 AM Tue 58 58 NW 4 8 N/A N/A N/A N/A N/A
5 AM Tue 56 56 NW 5 8 N/A N/A N/A N/A N/A
6 AM Tue 55 55 WNW 4 8 N/A N/A N/A N/A N/A
7 AM Tue 54 54 WNW 3 8 N/A N/A N/A N/A N/A
8 AM Tue 59 59 WNW 3 6 N/A N/A N/A N/A N/A
9 AM Tue 65 66 NNW 2 5 N/A N/A N/A N/A N/A
10 AM Tue 72 74 NE 2 5 N/A N/A N/A N/A N/A
11 AM Tue 78 81 ENE 2 5 N/A N/A N/A N/A N/A
12 Noon Tue 81 85 E 3 8 N/A N/A N/A N/A N/A
1 PM Tue 83 87 SE 4 10 N/A N/A N/A N/A N/A
2 PM Tue 84 87 SSE 5 12 N/A N/A N/A N/A N/A
3 PM Tue 85 87 S 5 12 N/A N/A N/A N/A N/A
4 PM Tue 86 87 S 5 12 N/A N/A N/A N/A N/A
5 PM Tue 85 85 S 5 11 N/A N/A N/A N/A N/A
6 PM Tue 82 82 S 5 11 N/A N/A N/A N/A N/A
7 PM Tue 79 79 SW 5 11 N/A N/A N/A N/A N/A
8 PM Tue 75 75 SW 5 11 N/A N/A N/A N/A N/A
9 PM Tue 72 72 WSW 5 11 N/A N/A N/A N/A N/A
10 PM Tue 69 69 WSW 5 11 N/A N/A N/A N/A N/A
11 PM Tue 66 66 W 5 11 N/A N/A N/A N/A N/A
12 Midnight Wed 63 63 W 5 10 N/A N/A N/A N/A N/A
1 AM Wed 60 60 W 5 10 N/A N/A N/A N/A N/A
2 AM Wed 58 58 W 5 9 N/A N/A N/A N/A N/A
3 AM Wed 56 56 W 5 9 N/A N/A N/A N/A N/A
4 AM Wed 54 54 W 5 9 N/A N/A N/A N/A N/A
5 AM Wed 53 53 W 5 9 N/A N/A N/A N/A N/A
6 AM Wed 53 53 W 4 8 N/A N/A N/A N/A N/A
7 AM Wed 55 55 W 4 8 N/A N/A N/A N/A N/A
8 AM Wed 58 58 W 3 6 N/A N/A N/A N/A N/A
9 AM Wed 64 65 WSW 3 6 N/A N/A N/A N/A N/A
10 AM Wed 71 73 S 3 6 N/A N/A N/A N/A N/A
11 AM Wed 77 80 SSE 3 8 N/A N/A N/A N/A N/A
12 Noon Wed 81 85 SSE 4 10 N/A N/A N/A N/A N/A
1 PM Wed 83 88 SSE 6 12 N/A N/A N/A N/A N/A
2 PM Wed 85 89 SSE 8 14 N/A N/A N/A N/A N/A
3 PM Wed 87 90 SSE 9 16 N/A N/A N/A N/A N/A
4 PM Wed 87 88 SSE 9 16 N/A N/A N/A N/A N/A
5 PM Wed 86 86 SSE 9 16 N/A N/A N/A N/A N/A
6 PM Wed 83 83 S 8 14 N/A N/A N/A N/A N/A
7 PM Wed 79 79 SSW 8 13 N/A N/A N/A N/A N/A
8 PM Wed 74 74 SSW 6 12 N/A N/A N/A N/A N/A
9 PM Wed 70 70 SW 6 12 N/A N/A N/A N/A N/A
10 PM Wed 67 67 WSW 6 12 N/A N/A N/A N/A N/A
11 PM Wed 64 64 W 6 12 N/A N/A N/A N/A N/A
12 Midnight Thu 61 61 W 6 12 N/A N/A N/A N/A N/A
1 AM Thu 59 59 W 5 11 N/A N/A N/A N/A N/A
2 AM Thu 57 57 W 5 11 N/A N/A N/A N/A N/A
3 AM Thu 55 55 W 5 11 N/A N/A N/A N/A N/A
4 AM Thu 54 54 W 5 10 N/A N/A N/A N/A N/A
5 AM Thu 53 53 W 5 10 N/A N/A N/A N/A N/A
6 AM Thu 53 53 W 5 9 N/A N/A N/A N/A N/A
7 AM Thu 54 54 W 5 9 N/A N/A N/A N/A N/A
8 AM Thu 57 57 WSW 5 8 N/A N/A N/A N/A N/A
9 AM Thu 63 63 SW 4 6 N/A N/A N/A N/A N/A
10 AM Thu 70 71 S 3 6 N/A N/A N/A N/A N/A
11 AM Thu 76 78 S 2 6 N/A N/A N/A N/A N/A
12 Noon Thu 80 82 S 3 9 N/A N/A N/A N/A N/A
1 PM Thu 82 84 SSE 4 11 N/A N/A N/A N/A N/A
2 PM Thu 83 84 SSE 5 13 N/A N/A N/A N/A N/A
3 PM Thu 84 85 S 5 13 N/A N/A N/A N/A N/A
4 PM Thu 85 85 S 5 13 N/A N/A N/A N/A N/A
5 PM Thu 84 84 S 5 12 N/A N/A N/A N/A N/A
6 PM Thu 81 81 S 6 12 N/A N/A N/A N/A N/A
7 PM Thu 77 77 SSW 6 13 N/A N/A N/A N/A N/A
8 PM Thu 73 73 SW 8 13 N/A N/A N/A N/A N/A
9 PM Thu 70 70 SW 9 13 N/A N/A N/A N/A N/A
10 PM Thu 67 67 WSW 9 14 N/A N/A N/A N/A N/A
11 PM Thu 64 64 W 9 14 N/A N/A N/A N/A N/A
12 Midnight Fri 61 61 W 9 14 N/A N/A N/A N/A N/A
1 AM Fri 58 58 W 8 13 N/A N/A N/A N/A N/A
2 AM Fri 56 56 W 6 12 N/A N/A N/A N/A N/A
3 AM Fri 54 54 W 6 11 N/A N/A N/A N/A N/A
4 AM Fri 52 52 W 5 11 N/A N/A N/A N/A N/A
5 AM Fri 51 51 W 5 10 N/A N/A N/A N/A N/A
6 AM Fri 51 51 W 5 10 N/A N/A N/A N/A N/A
7 AM Fri 53 53 WSW 5 9 N/A N/A N/A N/A N/A
8 AM Fri 56 56 WSW 5 9 N/A N/A N/A N/A N/A
9 AM Fri 62 62 SW 4 8 N/A N/A N/A N/A N/A
10 AM Fri 68 69 S 3 8 N/A N/A N/A N/A N/A
11 AM Fri 74 76 SSE 3 8 N/A N/A N/A N/A N/A
12 Noon Fri 78 81 SSE 4 10 N/A N/A N/A N/A N/A
1 PM Fri 80 83 SSE 5 13 N/A N/A N/A N/A N/A
2 PM Fri 82 84 SSE 6 16 N/A N/A N/A N/A N/A
3 PM Fri 84 86 S 8 17 N/A N/A N/A N/A N/A
4 PM Fri 84 85 S 9 17 N/A N/A N/A N/A N/A
5 PM Fri 83 83 S 9 17 N/A N/A N/A N/A N/A
6 PM Fri 80 80 S 9 17 N/A N/A N/A N/A N/A
7 PM Fri 76 76 SSW 9 16 N/A N/A N/A N/A N/A
8 PM Fri 72 72 SSW 9 14 N/A N/A N/A N/A N/A
9 PM Fri 68 68 SW 9 14 N/A N/A N/A N/A N/A
10 PM Fri 65 65 WSW 8 13 N/A N/A N/A N/A N/A
11 PM Fri 62 62 WSW 8 13 N/A N/A N/A N/A N/A
12 Midnight Sat 59 59 WSW 8 13 N/A N/A N/A N/A N/A
1 AM Sat 56 56 W 6 12 N/A N/A N/A N/A N/A
2 AM Sat 54 54 W 6 12 N/A N/A N/A N/A N/A
3 AM Sat 52 52 W 6 12 N/A N/A N/A N/A N/A
4 AM Sat 50 50 W 6 11 N/A N/A N/A N/A N/A
5 AM Sat 49 49 W 6 11 N/A N/A N/A N/A N/A
6 AM Sat 49 49 W 6 10 N/A N/A N/A N/A N/A
7 AM Sat 51 51 W 5 10 N/A N/A N/A N/A N/A
8 AM Sat 54 54 W 5 9 N/A N/A N/A N/A N/A
9 AM Sat 60 60 WSW 4 8 N/A N/A N/A N/A N/A
10 AM Sat 66 67 S 3 6 N/A N/A N/A N/A N/A
11 AM Sat 72 74 SSE 3 6 N/A N/A N/A N/A N/A
12 Noon Sat 75 78 SSE 3 8 N/A N/A N/A N/A N/A
1 PM Sat 78 81 SSE 4 10 N/A N/A N/A N/A N/A
2 PM Sat 79 82 SSE 4 11 N/A N/A N/A N/A N/A
3 PM Sat 81 83 SSE 4 11 N/A N/A N/A N/A N/A
4 PM Sat 82 83 S 5 11 N/A N/A N/A N/A N/A
5 PM Sat 81 81 S 5 11 N/A N/A N/A N/A N/A
6 PM Sat 78 78 SSW 5 11 N/A N/A N/A N/A N/A
7 PM Sat 74 74 W 5 11 N/A N/A N/A N/A N/A
8 PM Sat 69 69 W 5 11 N/A N/A N/A N/A N/A
9 PM Sat 66 66 WNW 5 11 N/A N/A N/A N/A N/A
10 PM Sat 63 63 WNW 5 12 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]