Detailed Predictions for: Big Sur
Launch Altitude (f): 3200
LZ Altitude (f): 60
Sounding

Station:

KOAK

Date/Time:

19 NOV 2017

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)
4 AM Sun 45 35 N 3 2720 3200 0 Blue 0
5 AM Sun 45 35 N 3 2720 3200 0 Blue 0
6 AM Sun 47 37 N 3 2720 3200 0 Blue 0
7 AM Sun 43 33 W 3 2720 3200 0 Blue 0
8 AM Sun 49 39 W 3 2720 3200 0 Blue 0
9 AM Sun 54 45 W 3 2720 3200 0 Blue 0
10 AM Sun 58 49 W 3 3858 3200 0 Blue 1
11 AM Sun 62 54 W 3 4162 3977 777 Blue 6
12 Noon Sun 61 53 W 3 4101 3916 716 Blue 5
1 PM Sun 62 54 W 5 4162 3977 777 Blue 6
2 PM Sun 62 53 W 5 4101 3916 716 Blue 5
3 PM Sun 61 51 W 5 3979 3200 0 Blue 3
4 PM Sun 61 51 W 3 3979 3200 0 Blue 3
5 PM Sun 57 47 W 3 2720 3200 0 Blue 0
6 PM Sun 54 44 W 3 2720 3200 0 Blue 0
7 PM Sun 54 44 NW 6 2720 3200 0 Blue 0
8 PM Sun 54 44 NW 6 2720 3200 0 Blue 0
9 PM Sun 54 44 NW 6 2720 3200 0 Blue 0
10 PM Sun 54 44 NW 3 2720 3200 0 Blue 0
11 PM Sun 53 43 NW 3 2720 3200 0 Blue 0
12 Midnight Mon 54 44 NW 3 2720 3200 0 Blue 0
1 AM Mon 53 43 N 3 2720 3200 0 Blue 0
2 AM Mon 52 42 N 3 2720 3200 0 Blue 0
3 AM Mon 52 42 N 3 2720 3200 0 Blue 0
4 AM Mon 52 42 NW 3 2720 3200 0 Blue 0
5 AM Mon 53 43 NW 3 2720 3200 0 Blue 0
6 AM Mon 52 42 NW 3 2720 3200 0 Blue 0
7 AM Mon 52 42 NW 3 2720 3200 0 Blue 0
8 AM Mon 56 46 NW 3 2720 3200 0 Blue 0
9 AM Mon 60 50 NW 3 3919 3200 0 Blue 2
10 AM Mon 64 55 S 2 4224 4038 838 Blue 7
11 AM Mon 67 58 S 2 4409 4221 1021 Blue 10
12 Noon Mon 66 57 S 2 4347 4160 960 Blue 9
1 PM Mon 67 58 SW 2 4409 4221 1021 Blue 10
2 PM Mon 67 58 SW 2 4409 4221 1021 Blue 10
3 PM Mon 66 56 SW 2 4285 4099 899 Blue 8
4 PM Mon 66 56 E 8 4285 4099 899 Blue 8
5 PM Mon 62 52 E 8 4040 3856 656 Blue 4
6 PM Mon 59 49 E 8 3858 3200 0 Blue 1
7 PM Mon 59 49 E 8 3858 3200 0 Blue 1
8 PM Mon 59 49 E 8 3858 3200 0 Blue 1
9 PM Mon 60 50 E 8 3919 3200 0 Blue 2
10 PM Mon 59 49 E 8 3858 3200 0 Blue 1
11 PM Mon 58 48 E 8 2720 3200 0 Blue 0
12 Midnight Tue 59 49 E 8 3858 3200 0 Blue 1
1 AM Tue 58 48 E 8 2720 3200 0 Blue 0
2 AM Tue 58 48 E 8 2720 3200 0 Blue 0
3 AM Tue 58 48 E 8 2720 3200 0 Blue 0
4 AM Tue 58 48 E 6 2720 3200 0 Blue 0
5 AM Tue 58 48 E 6 2720 3200 0 Blue 0
6 AM Tue 57 47 E 6 2720 3200 0 Blue 0
7 AM Tue 57 47 E 6 2720 3200 0 Blue 0
8 AM Tue 62 52 E 6 4040 3856 656 Blue 4
9 AM Tue 66 56 E 6 4285 4099 899 Blue 8
10 AM Tue 70 61 E 6 4629 4405 1205 Blue 12
11 AM Tue 73 64 E 6 5178 4624 1424 Blue 15
12 Noon Tue 73 64 E 6 5178 4624 1424 Blue 15
1 PM Tue 74 65 E 6 5299 4702 1502 Blue 16
2 PM Tue 74 65 E 6 5299 4702 1502 Blue 16
3 PM Tue 72 62 E 6 4707 4468 1268 Blue 13
4 PM Tue 72 62 E 12 4707 4468 1268 Blue 13
5 PM Tue 66 56 E 12 4285 4099 899 Blue 8
6 PM Tue 63 53 E 12 4101 3916 716 Blue 5
7 PM Tue 63 53 E 12 4101 3916 716 Blue 5
8 PM Tue 63 53 E 12 4101 3916 716 Blue 5
9 PM Tue 64 54 E 12 4162 3977 777 Blue 6
10 PM Tue 63 53 E 7 4101 3916 716 Blue 5
11 PM Tue 62 52 E 7 4040 3856 656 Blue 4
12 Midnight Wed 62 52 E 7 4040 3856 656 Blue 4
1 AM Wed 62 52 E 7 4040 3856 656 Blue 4
2 AM Wed 61 51 E 7 3979 3200 0 Blue 3
3 AM Wed 61 51 E 7 3979 3200 0 Blue 3
4 AM Wed 61 51 E 7 3979 3200 0 Blue 3
5 AM Wed 61 51 E 7 3979 3200 0 Blue 3
6 AM Wed 61 51 E 7 3979 3200 0 Blue 3
7 AM Wed 60 50 E 7 3919 3200 0 Blue 2
8 AM Wed 64 54 E 7 4162 3977 777 Blue 6
9 AM Wed 68 59 E 7 4473 4282 1082 Blue 11
10 AM Wed 71 62 E 2 4707 4468 1268 Blue 13
11 AM Wed 74 66 E 2 5419 5001 1801 Blue 17
12 Noon Wed 74 66 E 2 5419 5001 1801 Blue 17
1 PM Wed 74 66 E 2 5419 5001 1801 Blue 17
2 PM Wed 74 65 E 2 5299 4702 1502 Blue 16
3 PM Wed 73 63 E 2 5018 4546 1346 Blue 14
4 PM Wed 73 63 SW 0 5018 4546 1346 Blue 14
5 PM Wed 68 58 SW 0 4409 4221 1021 Blue 10
6 PM Wed 64 54 SW 0 4162 3977 777 Blue 6
7 PM Wed 64 54 SW 0 4162 3977 777 Blue 6
8 PM Wed 64 54 SW 0 4162 3977 777 Blue 6
9 PM Wed 65 55 SW 0 4224 4038 838 Blue 7
10 PM Wed 65 55 N 6 4224 4038 838 Blue 7
11 PM Wed 64 54 N 6 4162 3977 777 Blue 6
12 Midnight Thu 64 54 N 6 4162 3977 777 Blue 6
1 AM Thu 63 53 N 6 4101 3916 716 Blue 5
2 AM Thu 62 52 N 6 4040 3856 656 Blue 4
3 AM Thu 62 52 N 6 4040 3856 656 Blue 4
4 AM Thu 63 53 W 0 4101 3916 716 Blue 5
5 AM Thu 63 53 W 0 4101 3916 716 Blue 5
6 AM Thu 62 52 W 0 4040 3856 656 Blue 4
7 AM Thu 62 52 W 0 4040 3856 656 Blue 4
8 AM Thu 65 55 W 0 4224 4038 838 Blue 7
9 AM Thu 69 59 W 0 4473 4282 1082 Blue 11
10 AM Thu 71 62 W 3 4707 4468 1268 Blue 13
11 AM Thu 74 66 W 3 5419 5001 1801 Blue 17
12 Noon Thu 73 65 W 3 5299 4702 1502 Blue 16
1 PM Thu 74 66 W 3 5419 5001 1801 Blue 17
2 PM Thu 74 65 W 3 5299 4702 1502 Blue 16
3 PM Thu 72 62 W 3 4707 4468 1268 Blue 13
4 PM Thu 72 62 N 9 4707 4468 1268 Blue 13
5 PM Thu 66 56 N 9 4285 4099 899 Blue 8
6 PM Thu 62 52 N 9 4040 3856 656 Blue 4
7 PM Thu 62 52 N 9 4040 3856 656 Blue 4
8 PM Thu 62 52 N 9 4040 3856 656 Blue 4
9 PM Thu 63 53 N 9 4101 3916 716 Blue 5
10 PM Thu 62 52 NE 3 4040 3856 656 Blue 4
11 PM Thu 61 51 NE 3 3979 3200 0 Blue 3
12 Midnight Fri 61 51 NE 3 3979 3200 0 Blue 3
1 AM Fri 60 50 NE 3 3919 3200 0 Blue 2
2 AM Fri 60 50 NE 3 3919 3200 0 Blue 2
3 AM Fri 60 50 NE 3 3919 3200 0 Blue 2
4 AM Fri 60 50 N 2 3919 3200 0 Blue 2
5 AM Fri 60 50 N 2 3919 3200 0 Blue 2
6 AM Fri 59 49 N 2 3858 3200 0 Blue 1
7 AM Fri 59 49 N 2 3858 3200 0 Blue 1
8 AM Fri 62 52 N 2 4040 3856 656 Blue 4
9 AM Fri 65 55 N 2 4224 4038 838 Blue 7
10 AM Fri 67 58 N 1 4409 4221 1021 Blue 10
11 AM Fri 69 60 N 1 4551 4344 1144 Blue 12
12 Noon Fri 69 61 N 1 4629 4405 1205 Blue 12
1 PM Fri 69 60 N 1 4551 4344 1144 Blue 12
2 PM Fri 69 60 N 1 4551 4344 1144 Blue 12
3 PM Fri 68 58 N 1 4409 4221 1021 Blue 10
4 PM Fri 68 58 NW 7 4409 4221 1021 Blue 10
5 PM Fri 62 52 NW 7 4040 3856 656 Blue 4
6 PM Fri 59 49 NW 7 3858 3200 0 Blue 1
7 PM Fri 59 49 NW 7 3858 3200 0 Blue 1
8 PM Fri 59 49 NW 7 3858 3200 0 Blue 1
9 PM Fri 60 50 NW 7 3919 3200 0 Blue 2
10 PM Fri 60 50 E 5 3919 3200 0 Blue 2
11 PM Fri 58 48 E 5 2720 3200 0 Blue 0
12 Midnight Sat 59 49 E 5 3858 3200 0 Blue 1
1 AM Sat 58 48 E 5 2720 3200 0 Blue 0
2 AM Sat 57 47 E 5 2720 3200 0 Blue 0
3 AM Sat 57 47 E 5 2720 3200 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 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