Detailed Predictions for: Marina Beach
Launch Altitude (f): 60
LZ Altitude (f): 0
Sounding

Station:

KOAK

Date/Time:

25 APR 2019

Temp/Wind data from:

NOAA Digital Forecast

Site Forecasts
Time
(Local)
High
Temp

Puddle
Temp

Wind
(mph)
Thermal
Ceiling

(ft)
Soaring
Ceiling

(ft)
Above
Launch

(ft)
Thermal
Type
Thermal
Index

(F)
5 AM Thu 53 33 W 3 384 384 324 Blue 0
6 AM Thu 52 32 W 3 384 384 324 Blue 0
7 AM Thu 52 32 W 3 384 384 324 Blue 0
8 AM Thu 55 35 W 5 384 384 324 Blue 0
9 AM Thu 59 39 W 5 384 384 324 Blue 0
10 AM Thu 62 43 W 5 384 384 324 Blue 0
11 AM Thu 64 47 W 9 384 384 324 Blue 0
12 Noon Thu 65 48 W 9 384 384 324 Blue 0
1 PM Thu 66 50 W 9 384 384 324 Blue 0
2 PM Thu 65 48 W 10 384 384 324 Blue 0
3 PM Thu 64 47 W 10 384 384 324 Blue 0
4 PM Thu 65 47 W 10 384 384 324 Blue 0
5 PM Thu 64 46 W 9 384 384 324 Blue 0
6 PM Thu 62 42 W 9 384 384 324 Blue 0
7 PM Thu 60 40 W 9 384 384 324 Blue 0
8 PM Thu 56 36 W 5 384 384 324 Blue 0
9 PM Thu 55 35 W 5 384 384 324 Blue 0
10 PM Thu 54 34 W 5 384 384 324 Blue 0
11 PM Thu 54 34 W 3 384 384 324 Blue 0
12 Midnight Fri 53 33 W 3 384 384 324 Blue 0
1 AM Fri 52 32 W 3 384 384 324 Blue 0
2 AM Fri 52 32 W 3 384 384 324 Blue 0
3 AM Fri 51 31 W 3 384 384 324 Blue 0
4 AM Fri 51 31 W 3 384 384 324 Blue 0
5 AM Fri 51 31 W 2 384 384 324 Blue 0
6 AM Fri 50 30 W 2 384 384 324 Blue 0
7 AM Fri 51 31 W 2 384 384 324 Blue 0
8 AM Fri 55 35 W 5 384 384 324 Blue 0
9 AM Fri 58 38 W 5 384 384 324 Blue 0
10 AM Fri 61 42 W 5 384 384 324 Blue 0
11 AM Fri 64 48 W 8 384 384 324 Blue 0
12 Noon Fri 65 50 W 8 384 384 324 Blue 0
1 PM Fri 65 50 W 8 384 384 324 Blue 0
2 PM Fri 65 50 W 10 384 384 324 Blue 0
3 PM Fri 64 48 W 10 384 384 324 Blue 0
4 PM Fri 64 47 W 10 384 384 324 Blue 0
5 PM Fri 64 46 W 8 384 384 324 Blue 0
6 PM Fri 62 42 W 8 384 384 324 Blue 0
7 PM Fri 60 40 W 8 384 384 324 Blue 0
8 PM Fri 57 37 W 2 384 384 324 Blue 0
9 PM Fri 55 35 W 2 384 384 324 Blue 0
10 PM Fri 55 35 W 2 384 384 324 Blue 0
11 PM Fri 54 34 NW 3 384 384 324 Blue 0
12 Midnight Sat 54 34 NW 3 384 384 324 Blue 0
1 AM Sat 52 32 NW 3 384 384 324 Blue 0
2 AM Sat 52 32 NW 5 384 384 324 Blue 0
3 AM Sat 52 32 NW 5 384 384 324 Blue 0
4 AM Sat 52 32 NW 5 384 384 324 Blue 0
5 AM Sat 52 32 W 3 384 384 324 Blue 0
6 AM Sat 51 31 W 3 384 384 324 Blue 0
7 AM Sat 52 32 W 3 384 384 324 Blue 0
8 AM Sat 55 35 SW 5 384 384 324 Blue 0
9 AM Sat 59 40 SW 5 384 384 324 Blue 0
10 AM Sat 62 44 SW 5 384 384 324 Blue 0
11 AM Sat 64 48 W 7 384 384 324 Blue 0
12 Noon Sat 65 50 W 7 384 384 324 Blue 0
1 PM Sat 66 52 W 7 384 384 324 Blue 0
2 PM Sat 65 50 W 9 384 384 324 Blue 0
3 PM Sat 64 48 W 9 384 384 324 Blue 0
4 PM Sat 65 48 W 9 384 384 324 Blue 0
5 PM Sat 64 46 W 9 384 384 324 Blue 0
6 PM Sat 62 42 W 9 384 384 324 Blue 0
7 PM Sat 60 40 W 9 384 384 324 Blue 0
8 PM Sat 57 37 W 7 384 384 324 Blue 0
9 PM Sat 56 36 W 7 384 384 324 Blue 0
10 PM Sat 55 35 W 7 384 384 324 Blue 0
11 PM Sat 54 34 SW 5 384 384 324 Blue 0
12 Midnight Sun 54 34 SW 5 384 384 324 Blue 0
1 AM Sun 53 33 SW 5 384 384 324 Blue 0
2 AM Sun 52 32 W 6 384 384 324 Blue 0
3 AM Sun 52 32 W 6 384 384 324 Blue 0
4 AM Sun 52 32 W 6 384 384 324 Blue 0
5 AM Sun 52 32 SW 5 384 384 324 Blue 0
6 AM Sun 51 31 SW 5 384 384 324 Blue 0
7 AM Sun 52 32 SW 5 384 384 324 Blue 0
8 AM Sun 54 34 SW 5 384 384 324 Blue 0
9 AM Sun 57 38 SW 5 384 384 324 Blue 0
10 AM Sun 60 42 SW 5 384 384 324 Blue 0
11 AM Sun 62 45 SW 8 384 384 324 Blue 0
12 Noon Sun 62 46 SW 8 384 384 324 Blue 0
1 PM Sun 63 47 SW 8 384 384 324 Blue 0
2 PM Sun 63 47 SW 8 384 384 324 Blue 0
3 PM Sun 62 45 SW 8 384 384 324 Blue 0
4 PM Sun 62 44 SW 8 384 384 324 Blue 0
5 PM Sun 61 42 W 7 384 384 324 Blue 0
6 PM Sun 60 40 W 7 384 384 324 Blue 0
7 PM Sun 59 39 W 7 384 384 324 Blue 0
8 PM Sun 56 36 W 7 384 384 324 Blue 0
9 PM Sun 55 35 W 7 384 384 324 Blue 0
10 PM Sun 54 34 W 7 384 384 324 Blue 0
11 PM Sun 54 34 S 2 384 384 324 Blue 0
12 Midnight Mon 53 33 S 2 384 384 324 Blue 0
1 AM Mon 52 32 S 2 384 384 324 Blue 0
2 AM Mon 52 32 S 2 384 384 324 Blue 0
3 AM Mon 52 32 S 2 384 384 324 Blue 0
4 AM Mon 52 32 S 2 384 384 324 Blue 0
5 AM Mon 52 32 SW 3 384 384 324 Blue 0
6 AM Mon 51 31 SW 3 384 384 324 Blue 0
7 AM Mon 52 32 SW 3 384 384 324 Blue 0
8 AM Mon 54 34 SW 3 384 384 324 Blue 0
9 AM Mon 56 37 SW 3 384 384 324 Blue 0
10 AM Mon 58 40 SW 3 384 384 324 Blue 0
11 AM Mon 60 45 SW 9 384 384 324 Blue 0
12 Noon Mon 61 48 SW 9 384 384 324 Blue 0
1 PM Mon 61 48 SW 9 384 384 324 Blue 0
2 PM Mon 61 48 SW 9 384 384 324 Blue 0
3 PM Mon 60 45 SW 9 384 384 324 Blue 0
4 PM Mon 60 44 SW 9 384 384 324 Blue 0
5 PM Mon 60 42 SW 8 384 384 324 Blue 0
6 PM Mon 59 39 SW 8 384 384 324 Blue 0
7 PM Mon 57 37 SW 8 384 384 324 Blue 0
8 PM Mon 55 35 SW 8 384 384 324 Blue 0
9 PM Mon 54 34 SW 8 384 384 324 Blue 0
10 PM Mon 54 34 SW 8 384 384 324 Blue 0
11 PM Mon 53 33 SW 3 384 384 324 Blue 0
12 Midnight Tue 53 33 SW 3 384 384 324 Blue 0
1 AM Tue 52 32 SW 3 384 384 324 Blue 0
2 AM Tue 52 32 SW 3 384 384 324 Blue 0
3 AM Tue 51 31 SW 3 384 384 324 Blue 0
4 AM Tue 52 32 SW 3 384 384 324 Blue 0
5 AM Tue 51 31 W 5 384 384 324 Blue 0
6 AM Tue 51 31 W 5 384 384 324 Blue 0
7 AM Tue 51 31 W 5 384 384 324 Blue 0
8 AM Tue 54 34 W 5 384 384 324 Blue 0
9 AM Tue 56 38 W 5 384 384 324 Blue 0
10 AM Tue 58 42 W 5 384 384 324 Blue 0
11 AM Tue 60 45 W 13 384 384 324 Blue 0
12 Noon Tue 61 47 W 13 384 384 324 Blue 0
1 PM Tue 61 48 W 13 384 384 324 Blue 0
2 PM Tue 61 47 W 13 384 384 324 Blue 0
3 PM Tue 60 45 W 13 384 384 324 Blue 0
4 PM Tue 60 44 W 13 384 384 324 Blue 0
5 PM Tue 60 42 W 13 384 384 324 Blue 0
6 PM Tue 58 38 W 13 384 384 324 Blue 0
7 PM Tue 57 37 W 13 384 384 324 Blue 0
8 PM Tue 54 34 W 13 384 384 324 Blue 0
9 PM Tue 53 33 W 13 384 384 324 Blue 0
10 PM Tue 53 33 W 13 384 384 324 Blue 0
11 PM Tue 52 32 NW 7 384 384 324 Blue 0
12 Midnight Wed 52 32 NW 7 384 384 324 Blue 0
1 AM Wed 51 31 NW 7 384 384 324 Blue 0
2 AM Wed 51 31 NW 7 384 384 324 Blue 0
3 AM Wed 50 30 NW 7 384 384 324 Blue 0
4 AM Wed 50 30 NW 7 384 384 324 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 website.  Puddle temperatures can exceed this temperature. 

Puddle Temp: This estimate is based on the High Temp and the National Weather Service 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 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 ac_soaring@yahoo.com