Detailed Predictions for: Mt Vaca
Launch Lat, Long, Altitude (f): 38.400316, -122.106135, 2821
LZ Altitude (f): 2000
Sounding

Station:

 KOAK

Date/Time:

 11 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 Mon 48 48 N 5 8 2507 2821 0 Blue 0
1 AM Mon 45 45 NNW 5 8 2507 2821 0 Blue 0
2 AM Mon 45 45 N 5 8 2507 2821 0 Blue 0
3 AM Mon 44 44 N 5 9 2507 2821 0 Blue 0
4 AM Mon 44 44 N 6 10 2507 2821 0 Blue 0
5 AM Mon 45 45 N 6 10 2507 2821 0 Blue 0
6 AM Mon 45 45 N 6 10 2507 2821 0 Blue 0
7 AM Mon 44 44 N 8 11 2507 2821 0 Blue 0
8 AM Mon 44 44 NNW 6 10 2507 2821 0 Blue 0
9 AM Mon 45 45 NNW 6 10 2507 2821 0 Blue 0
10 AM Mon 47 48 NNW 6 10 2507 2821 0 Blue 0
11 AM Mon 48 49 NNW 6 10 2543 2821 0 Blue 0
12 Noon Mon 50 51 NNW 6 10 2927 2821 0 Blue 2
1 PM Mon 51 52 NNW 6 10 2983 2821 0 Blue 3
2 PM Mon 50 51 NW 5 10 2927 2821 0 Blue 2
3 PM Mon 50 50 NW 5 9 2746 2821 0 Blue 1
4 PM Mon 49 49 WNW 5 8 2543 2821 0 Blue 0
5 PM Mon 47 47 WNW 5 6 2507 2821 0 Blue 0
6 PM Mon 47 47 NW 5 8 2507 2821 0 Blue 0
7 PM Mon 48 48 NNW 5 8 2507 2821 0 Blue 0
8 PM Mon 48 48 NNW 5 9 2507 2821 0 Blue 0
9 PM Mon 48 48 NNW 6 10 2507 2821 0 Blue 0
10 PM Mon 49 49 NNW 6 10 2543 2821 0 Blue 0
11 PM Mon 49 49 NNW 9 11 2543 2821 0 Blue 0
12 Midnight Tue 49 49 NNW 9 11 2543 2821 0 Blue 0
1 AM Tue 48 48 N 9 12 2507 2821 0 Blue 0
2 AM Tue 48 48 N 9 13 2507 2821 0 Blue 0
3 AM Tue 48 48 N 11 13 2507 2821 0 Blue 0
4 AM Tue 48 48 N 11 16 2507 2821 0 Blue 0
5 AM Tue 47 47 N 12 17 2507 2821 0 Blue 0
6 AM Tue 47 47 N 12 18 2507 2821 0 Blue 0
7 AM Tue 46 46 N 12 18 2507 2821 0 Blue 0
8 AM Tue 46 46 N 12 18 2507 2821 0 Blue 0
9 AM Tue 46 46 N 12 18 2507 2821 0 Blue 0
10 AM Tue 48 49 N 11 16 2543 2821 0 Blue 0
11 AM Tue 49 50 N 11 16 2746 2821 0 Blue 1
12 Noon Tue 50 52 N 11 16 2983 2821 0 Blue 3
1 PM Tue 52 54 N 10 14 3208 2926 105 Blue 5
2 PM Tue 52 53 N 10 14 3087 2821 0 Blue 4
3 PM Tue 51 51 N 10 14 2927 2821 0 Blue 2
4 PM Tue 50 50 N 8 11 2746 2821 0 Blue 1
5 PM Tue 50 50 N 8 11 2746 2821 0 Blue 1
6 PM Tue 49 49 N 8 11 2543 2821 0 Blue 0
7 PM Tue 49 49 NNW 10 13 2543 2821 0 Blue 0
8 PM Tue 49 49 NNW 10 13 2543 2821 0 Blue 0
9 PM Tue 50 50 NNW 10 13 2746 2821 0 Blue 1
10 PM Tue 50 50 NNW 12 18 2746 2821 0 Blue 1
11 PM Tue 50 50 NNW 12 18 2746 2821 0 Blue 1
12 Midnight Wed 49 49 NNW 12 18 2543 2821 0 Blue 0
1 AM Wed 48 48 N 11 18 2507 2821 0 Blue 0
2 AM Wed 47 47 N 11 18 2507 2821 0 Blue 0
3 AM Wed 46 46 N 11 18 2507 2821 0 Blue 0
4 AM Wed 45 45 N 11 17 2507 2821 0 Blue 0
5 AM Wed 44 44 N 11 17 2507 2821 0 Blue 0
6 AM Wed 44 44 N 11 17 2507 2821 0 Blue 0
7 AM Wed 43 43 N 9 13 2507 2821 0 Blue 0
8 AM Wed 43 43 N 9 13 2507 2821 0 Blue 0
9 AM Wed 43 43 N 9 13 2507 2821 0 Blue 0
10 AM Wed 44 45 NNE 9 13 2507 2821 0 Blue 0
11 AM Wed 45 46 NNE 9 13 2507 2821 0 Blue 0
12 Noon Wed 46 47 NNE 9 13 2507 2821 0 Blue 0
1 PM Wed 47 48 NE 8 12 2507 2821 0 Blue 0
2 PM Wed 47 48 NE 8 12 2507 2821 0 Blue 0
3 PM Wed 47 47 NE 8 12 2507 2821 0 Blue 0
4 PM Wed 46 46 ENE 5 10 2507 2821 0 Blue 0
5 PM Wed 46 46 ENE 5 10 2507 2821 0 Blue 0
6 PM Wed 45 45 ENE 5 10 2507 2821 0 Blue 0
7 PM Wed 45 45 NNE 6 9 2507 2821 0 Blue 0
8 PM Wed 45 45 NNE 6 9 2507 2821 0 Blue 0
9 PM Wed 45 45 NNE 6 9 2507 2821 0 Blue 0
10 PM Wed 46 46 N 6 10 2507 2821 0 Blue 0
11 PM Wed 46 46 N 6 10 2507 2821 0 Blue 0
12 Midnight Thu 46 46 N 6 10 2507 2821 0 Blue 0
1 AM Thu 45 45 N 8 11 2507 2821 0 Blue 0
2 AM Thu 45 45 N 8 11 2507 2821 0 Blue 0
3 AM Thu 45 45 N 8 11 2507 2821 0 Blue 0
4 AM Thu 45 45 N 8 11 2507 2821 0 Blue 0
5 AM Thu 45 45 N 8 11 2507 2821 0 Blue 0
6 AM Thu 44 44 N 8 11 2507 2821 0 Blue 0
7 AM Thu 44 44 NNE 8 11 2507 2821 0 Blue 0
8 AM Thu 44 44 NNE 8 11 2507 2821 0 Blue 0
9 AM Thu 44 44 NNE 8 11 2507 2821 0 Blue 0
10 AM Thu 44 44 NE 8 11 2507 2821 0 Blue 0
11 AM Thu 44 45 NE 8 11 2507 2821 0 Blue 0
12 Noon Thu 45 46 NE 8 11 2507 2821 0 Blue 0
1 PM Thu 45 46 ENE 8 12 2507 2821 0 Blue 0
2 PM Thu 45 45 ENE 8 12 2507 2821 0 Blue 0
3 PM Thu 45 45 ENE 8 12 2507 2821 0 Blue 0
4 PM Thu 44 44 ENE 8 11 2507 2821 0 Blue 0
5 PM Thu 44 44 ENE 8 11 2507 2821 0 Blue 0
6 PM Thu 44 44 ENE 8 11 2507 2821 0 Blue 0
7 PM Thu 45 45 NNE 6 11 2507 2821 0 Blue 0
8 PM Thu 45 45 NNE 6 11 2507 2821 0 Blue 0
9 PM Thu 46 46 NNE 6 11 2507 2821 0 Blue 0
10 PM Thu 46 46 N 6 11 2507 2821 0 Blue 0
11 PM Thu 47 47 N 6 11 2507 2821 0 Blue 0
12 Midnight Fri 46 46 N 6 11 2507 2821 0 Blue 0
1 AM Fri 46 46 N 8 11 2507 2821 0 Blue 0
2 AM Fri 47 47 N 8 11 2507 2821 0 Blue 0
3 AM Fri 47 47 N 8 11 2507 2821 0 Blue 0
4 AM Fri 47 47 N 8 12 2507 2821 0 Blue 0
5 AM Fri 46 46 N 8 12 2507 2821 0 Blue 0
6 AM Fri 45 45 N 8 12 2507 2821 0 Blue 0
7 AM Fri 44 44 NNE 8 12 2507 2821 0 Blue 0
8 AM Fri 44 44 NNE 8 12 2507 2821 0 Blue 0
9 AM Fri 44 44 NNE 8 12 2507 2821 0 Blue 0
10 AM Fri 44 44 NNE 8 12 2507 2821 0 Blue 0
11 AM Fri 45 46 NNE 8 12 2507 2821 0 Blue 0
12 Noon Fri 45 46 NNE 8 12 2507 2821 0 Blue 0
1 PM Fri 46 47 NE 9 12 2507 2821 0 Blue 0
2 PM Fri 46 46 NE 9 12 2507 2821 0 Blue 0
3 PM Fri 45 45 NE 9 12 2507 2821 0 Blue 0
4 PM Fri 45 45 NE 6 11 2507 2821 0 Blue 0
5 PM Fri 44 44 NE 6 11 2507 2821 0 Blue 0
6 PM Fri 44 44 NE 6 11 2507 2821 0 Blue 0
7 PM Fri 45 45 N 6 11 2507 2821 0 Blue 0
8 PM Fri 45 45 N 6 11 2507 2821 0 Blue 0
9 PM Fri 46 46 N 6 11 2507 2821 0 Blue 0
10 PM Fri 46 46 N 8 12 2507 2821 0 Blue 0
11 PM Fri 46 46 N 8 12 2507 2821 0 Blue 0
12 Midnight Sat 46 46 N 8 12 2507 2821 0 Blue 0
1 AM Sat 46 46 N 9 12 2507 2821 0 Blue 0
2 AM Sat 46 46 N 9 12 2507 2821 0 Blue 0
3 AM Sat 46 46 N 9 12 2507 2821 0 Blue 0
4 AM Sat 46 46 NNE 8 12 2507 2821 0 Blue 0
5 AM Sat 46 46 NNE 8 12 2507 2821 0 Blue 0
6 AM Sat 45 45 NNE 8 12 2507 2821 0 Blue 0
7 AM Sat 44 44 NNE 9 13 2507 2821 0 Blue 0
8 AM Sat 44 44 NNE 9 13 2507 2821 0 Blue 0
9 AM Sat 44 44 NNE 9 13 2507 2821 0 Blue 0
10 AM Sat 45 46 NE 8 12 2507 2821 0 Blue 0
11 AM Sat 46 47 NE 8 12 2507 2821 0 Blue 0
12 Noon Sat 47 48 NE 8 12 2507 2821 0 Blue 0
1 PM Sat 47 48 NE 9 13 2507 2821 0 Blue 0
2 PM Sat 47 48 NE 9 13 2507 2821 0 Blue 0
3 PM Sat 47 47 NE 9 13 2507 2821 0 Blue 0
4 PM Sat 46 46 NE 8 11 2507 2821 0 Blue 0
5 PM Sat 46 46 NE 8 11 2507 2821 0 Blue 0
6 PM Sat 46 46 NE 8 11 2507 2821 0 Blue 0
7 PM Sat 46 46 NNE 6 11 2507 2821 0 Blue 0
8 PM Sat 47 47 NNE 6 11 2507 2821 0 Blue 0
9 PM Sat 47 47 NNE 6 11 2507 2821 0 Blue 0
10 PM Sat 48 48 N 8 11 2507 2821 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]