Detailed Predictions for: Marina Beach
Launch Lat, Long, Altitude (f): 36.600, -121.89, 60
LZ Altitude (f): 0
Sounding

Station:

KOAK

Date/Time:

21 SEP 2021

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 Tue 63 43 E 6 8 0 60 0 Blue 0
1 AM Tue 65 45 E 6 8 0 60 0 Blue 0
2 AM Tue 68 48 E 8 9 0 60 0 Blue 0
3 AM Tue 69 49 ESE 4 6 0 60 0 Blue 0
4 AM Tue 69 49 SSW 2 2 0 60 0 Blue 0
5 AM Tue 70 50 WSW 6 9 0 60 0 Blue 0
6 AM Tue 70 50 SW 9 11 0 60 0 Blue 0
7 AM Tue 70 50 SW 8 9 0 60 0 Blue 0
8 AM Tue 69 49 S 2 3 0 60 0 Blue 0
9 AM Tue 71 52 S 0 0 0 60 0 Blue 0
10 AM Tue 75 57 NNE 2 2 0 60 0 Blue 0
11 AM Tue 76 59 N 3 4 0 60 0 Blue 0
12 Noon Tue 78 63 W 3 4 0 60 0 Blue 0
1 PM Tue 78 63 WSW 9 12 0 60 0 Blue 0
2 PM Tue 78 63 WSW 12 14 0 60 0 Blue 0
3 PM Tue 77 61 WSW 13 17 0 60 0 Blue 0
4 PM Tue 76 58 WSW 13 17 0 60 0 Blue 0
5 PM Tue 74 55 WSW 12 16 0 60 0 Blue 0
6 PM Tue 73 53 WSW 9 11 0 60 0 Blue 0
7 PM Tue 71 51 W 5 6 0 60 0 Blue 0
8 PM Tue 62 42 WSW 4 5 0 60 0 Blue 0
9 PM Tue 66 46 SW 3 4 0 60 0 Blue 0
10 PM Tue 66 46 SW 3 4 0 60 0 Blue 0
11 PM Tue 64 44 SW 4 4 0 60 0 Blue 0
12 Midnight Wed 64 44 SW 5 6 0 60 0 Blue 0
1 AM Wed 63 43 SW 5 6 0 60 0 Blue 0
2 AM Wed 62 42 SW 5 6 0 60 0 Blue 0
3 AM Wed 62 42 WSW 4 5 0 60 0 Blue 0
4 AM Wed 62 42 WSW 4 4 0 60 0 Blue 0
5 AM Wed 61 41 WSW 4 5 0 60 0 Blue 0
6 AM Wed 60 40 WSW 4 4 0 60 0 Blue 0
7 AM Wed 59 39 WSW 3 4 0 60 0 Blue 0
8 AM Wed 59 39 WSW 1 1 0 60 0 Blue 0
9 AM Wed 59 39 WNW 2 3 0 60 0 Blue 0
10 AM Wed 61 41 WNW 3 4 0 60 0 Blue 0
11 AM Wed 62 43 W 6 8 0 60 0 Blue 0
12 Noon Wed 63 45 W 6 8 0 60 0 Blue 0
1 PM Wed 64 46 W 6 8 0 60 0 Blue 0
2 PM Wed 64 48 W 8 10 0 60 0 Blue 0
3 PM Wed 64 47 W 8 10 0 60 0 Blue 0
4 PM Wed 63 45 W 8 10 0 60 0 Blue 0
5 PM Wed 63 44 W 6 9 0 60 0 Blue 0
6 PM Wed 62 42 W 6 9 0 60 0 Blue 0
7 PM Wed 62 42 W 6 9 0 60 0 Blue 0
8 PM Wed 61 41 WNW 3 4 0 60 0 Blue 0
9 PM Wed 60 40 WNW 3 4 0 60 0 Blue 0
10 PM Wed 58 38 WNW 3 4 0 60 0 Blue 0
11 PM Wed 57 37 NW 3 4 0 60 0 Blue 0
12 Midnight Thu 57 37 NW 3 4 0 60 0 Blue 0
1 AM Thu 57 37 NW 3 4 0 60 0 Blue 0
2 AM Thu 57 37 NNW 3 4 0 60 0 Blue 0
3 AM Thu 57 37 NNW 3 4 0 60 0 Blue 0
4 AM Thu 56 36 NNW 3 4 0 60 0 Blue 0
5 AM Thu 56 36 N 2 3 0 60 0 Blue 0
6 AM Thu 56 36 N 2 3 0 60 0 Blue 0
7 AM Thu 56 36 N 2 3 0 60 0 Blue 0
8 AM Thu 56 36 NNW 4 5 0 60 0 Blue 0
9 AM Thu 57 37 NNW 4 5 0 60 0 Blue 0
10 AM Thu 58 39 NNW 4 5 0 60 0 Blue 0
11 AM Thu 60 42 NW 6 8 0 60 0 Blue 0
12 Noon Thu 62 44 NW 6 8 0 60 0 Blue 0
1 PM Thu 63 45 NW 6 8 0 60 0 Blue 0
2 PM Thu 64 48 W 6 9 0 60 0 Blue 0
3 PM Thu 64 47 W 6 9 0 60 0 Blue 0
4 PM Thu 64 46 W 6 9 0 60 0 Blue 0
5 PM Thu 64 45 W 5 6 0 60 0 Blue 0
6 PM Thu 63 43 W 5 6 0 60 0 Blue 0
7 PM Thu 62 42 W 5 6 0 60 0 Blue 0
8 PM Thu 61 41 W 4 4 0 60 0 Blue 0
9 PM Thu 60 40 W 4 4 0 60 0 Blue 0
10 PM Thu 60 40 W 4 4 0 60 0 Blue 0
11 PM Thu 59 39 W 3 4 0 60 0 Blue 0
12 Midnight Fri 59 39 W 3 4 0 60 0 Blue 0
1 AM Fri 59 39 W 3 4 0 60 0 Blue 0
2 AM Fri 59 39 W 4 4 0 60 0 Blue 0
3 AM Fri 59 39 W 4 4 0 60 0 Blue 0
4 AM Fri 58 38 W 4 4 0 60 0 Blue 0
5 AM Fri 58 38 W 2 3 0 60 0 Blue 0
6 AM Fri 58 38 W 2 3 0 60 0 Blue 0
7 AM Fri 58 38 W 2 3 0 60 0 Blue 0
8 AM Fri 58 38 S 2 3 0 60 0 Blue 0
9 AM Fri 60 40 S 2 3 0 60 0 Blue 0
10 AM Fri 61 42 S 2 3 0 60 0 Blue 0
11 AM Fri 62 44 WSW 4 5 0 60 0 Blue 0
12 Noon Fri 63 45 WSW 4 5 0 60 0 Blue 0
1 PM Fri 64 47 WSW 4 5 0 60 0 Blue 0
2 PM Fri 64 48 WSW 8 10 0 60 0 Blue 0
3 PM Fri 64 48 WSW 8 10 0 60 0 Blue 0
4 PM Fri 64 46 WSW 8 10 0 60 0 Blue 0
5 PM Fri 63 44 W 8 10 0 60 0 Blue 0
6 PM Fri 63 43 W 8 10 0 60 0 Blue 0
7 PM Fri 62 42 W 8 10 0 60 0 Blue 0
8 PM Fri 62 42 W 3 4 0 60 0 Blue 0
9 PM Fri 60 40 W 3 4 0 60 0 Blue 0
10 PM Fri 60 40 W 3 4 0 60 0 Blue 0
11 PM Fri 59 39 E 3 4 0 60 0 Blue 0
12 Midnight Sat 58 38 E 3 4 0 60 0 Blue 0
1 AM Sat 58 38 E 3 4 0 60 0 Blue 0
2 AM Sat 58 38 S 2 2 0 60 0 Blue 0
3 AM Sat 58 38 S 2 2 0 60 0 Blue 0
4 AM Sat 58 38 S 2 2 0 60 0 Blue 0
5 AM Sat 58 38 S 2 2 0 60 0 Blue 0
6 AM Sat 57 37 S 2 2 0 60 0 Blue 0
7 AM Sat 57 37 S 2 2 0 60 0 Blue 0
8 AM Sat 57 37 S 3 4 0 60 0 Blue 0
9 AM Sat 58 38 S 3 4 0 60 0 Blue 0
10 AM Sat 59 40 S 3 4 0 60 0 Blue 0
11 AM Sat 60 42 WSW 5 6 0 60 0 Blue 0
12 Noon Sat 61 43 WSW 5 6 0 60 0 Blue 0
1 PM Sat 62 45 WSW 5 6 0 60 0 Blue 0
2 PM Sat 63 47 W 10 12 0 60 0 Blue 0
3 PM Sat 63 46 W 10 12 0 60 0 Blue 0
4 PM Sat 63 45 W 10 12 0 60 0 Blue 0
5 PM Sat 62 43 W 10 13 0 60 0 Blue 0
6 PM Sat 62 42 W 10 13 0 60 0 Blue 0
7 PM Sat 61 41 W 10 13 0 60 0 Blue 0
8 PM Sat 60 40 W 6 8 0 60 0 Blue 0
9 PM Sat 60 40 W 6 8 0 60 0 Blue 0
10 PM Sat 59 39 W 6 8 0 60 0 Blue 0
11 PM Sat 58 38 WNW 4 5 0 60 0 Blue 0
12 Midnight Sun 58 38 WNW 4 5 0 60 0 Blue 0
1 AM Sun 58 38 WNW 4 5 0 60 0 Blue 0
2 AM Sun 58 38 WNW 4 5 0 60 0 Blue 0
3 AM Sun 57 37 WNW 4 5 0 60 0 Blue 0
4 AM Sun 58 38 WNW 4 5 0 60 0 Blue 0
5 AM Sun 57 37 NW 4 5 0 60 0 Blue 0
6 AM Sun 57 37 NW 4 5 0 60 0 Blue 0
7 AM Sun 57 37 NW 4 5 0 60 0 Blue 0
8 AM Sun 56 36 NW 4 5 0 60 0 Blue 0
9 AM Sun 57 37 NW 4 5 0 60 0 Blue 0
10 AM Sun 57 38 NW 4 5 0 60 0 Blue 0
11 AM Sun 58 39 WNW 6 9 0 60 0 Blue 0
12 Noon Sun 59 41 WNW 6 9 0 60 0 Blue 0
1 PM Sun 60 42 WNW 6 9 0 60 0 Blue 0
2 PM Sun 60 44 W 11 13 0 60 0 Blue 0
3 PM Sun 60 43 W 11 13 0 60 0 Blue 0
4 PM Sun 60 42 W 11 13 0 60 0 Blue 0
5 PM Sun 60 41 W 10 13 0 60 0 Blue 0
6 PM Sun 59 39 W 10 13 0 60 0 Blue 0
7 PM Sun 59 39 W 10 13 0 60 0 Blue 0
8 PM Sun 59 39 WNW 6 9 0 60 0 Blue 0
9 PM Sun 58 38 WNW 6 9 0 60 0 Blue 0
10 PM Sun 58 38 WNW 6 9 0 60 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]