Detailed Predictions for: Dunlap
Launch Altitude (f): 4460
LZ Altitude (f): 1950
Sounding

Station:

KOAK

Date/Time:

17 SEP 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 Tue 55 50 E 3 1729 4460 0 Blue 0
6 AM Tue 54 49 E 3 1729 4460 0 Blue 0
7 AM Tue 54 49 E 3 1729 4460 0 Blue 0
8 AM Tue 56 51 SE 2 1729 4460 0 Blue 0
9 AM Tue 62 58 SW 3 2427 4460 0 Blue 0
10 AM Tue 66 63 SW 3 4576 4460 0 Blue 5
11 AM Tue 68 67 SW 6 5831 4745 285 Blue 9
12 Noon Tue 70 70 SW 6 6662 5812 1352 Blue 12
1 PM Tue 72 73 SW 6 7374 6603 2143 Blue 15
2 PM Tue 72 73 SW 6 7374 6603 2143 Blue 15
3 PM Tue 74 73 W 6 7374 6603 2143 Blue 15
4 PM Tue 74 72 W 6 7261 6174 1714 Blue 14
5 PM Tue 74 70 W 6 6662 5812 1352 Blue 12
6 PM Tue 72 67 W 6 5831 4745 285 Blue 9
7 PM Tue 70 65 NW 5 4942 4460 0 Blue 7
8 PM Tue 66 61 N 5 3614 4460 0 Blue 3
9 PM Tue 61 56 NE 5 1729 4460 0 Blue 0
10 PM Tue 59 54 NE 3 1729 4460 0 Blue 0
11 PM Tue 58 53 E 3 1729 4460 0 Blue 0
12 Midnight Wed 57 52 E 3 1729 4460 0 Blue 0
1 AM Wed 57 52 E 3 1729 4460 0 Blue 0
2 AM Wed 56 51 E 3 1729 4460 0 Blue 0
3 AM Wed 56 51 E 3 1729 4460 0 Blue 0
4 AM Wed 56 51 E 5 1729 4460 0 Blue 0
5 AM Wed 57 52 E 3 1729 4460 0 Blue 0
6 AM Wed 55 50 E 3 1729 4460 0 Blue 0
7 AM Wed 55 50 E 5 1729 4460 0 Blue 0
8 AM Wed 58 53 E 2 1729 4460 0 Blue 0
9 AM Wed 64 60 SW 2 3233 4460 0 Blue 2
10 AM Wed 69 67 SW 3 5831 4745 285 Blue 9
11 AM Wed 71 71 W 6 7088 5987 1527 Blue 13
12 Noon Wed 72 73 W 6 7374 6603 2143 Blue 15
1 PM Wed 73 74 W 6 7549 7024 2564 Blue 16
2 PM Wed 74 75 W 6 7754 7243 2783 Blue 17
3 PM Wed 75 74 W 6 7549 7024 2564 Blue 16
4 PM Wed 75 73 W 6 7374 6603 2143 Blue 15
5 PM Wed 74 70 W 7 6662 5812 1352 Blue 12
6 PM Wed 72 67 W 7 5831 4745 285 Blue 9
7 PM Wed 69 64 W 7 4759 4460 0 Blue 6
8 PM Wed 66 61 NW 5 3614 4460 0 Blue 3
9 PM Wed 63 58 NW 5 2427 4460 0 Blue 0
10 PM Wed 60 55 NW 5 1729 4460 0 Blue 0
11 PM Wed 58 53 S 5 1729 4460 0 Blue 0
12 Midnight Thu 57 52 S 5 1729 4460 0 Blue 0
1 AM Thu 57 52 S 5 1729 4460 0 Blue 0
2 AM Thu 57 52 SW 5 1729 4460 0 Blue 0
3 AM Thu 57 52 SW 5 1729 4460 0 Blue 0
4 AM Thu 56 51 SW 5 1729 4460 0 Blue 0
5 AM Thu 56 51 SW 3 1729 4460 0 Blue 0
6 AM Thu 56 51 SW 3 1729 4460 0 Blue 0
7 AM Thu 56 51 SW 3 1729 4460 0 Blue 0
8 AM Thu 56 51 W 3 1729 4460 0 Blue 0
9 AM Thu 59 55 W 3 1729 4460 0 Blue 0
10 AM Thu 63 61 W 3 3614 4460 0 Blue 3
11 AM Thu 67 65 W 6 4942 4460 0 Blue 7
12 Noon Thu 69 68 W 6 6008 4927 467 Blue 10
1 PM Thu 70 69 W 6 6228 5106 646 Blue 11
2 PM Thu 70 69 W 7 6228 5106 646 Blue 11
3 PM Thu 71 69 W 7 6228 5106 646 Blue 11
4 PM Thu 71 68 W 7 6008 4927 467 Blue 10
5 PM Thu 70 66 W 7 5467 4563 103 Blue 8
6 PM Thu 68 63 W 7 4576 4460 0 Blue 5
7 PM Thu 65 60 W 7 3233 4460 0 Blue 2
8 PM Thu 62 57 N 6 1966 4460 0 Blue 0
9 PM Thu 59 54 N 6 1729 4460 0 Blue 0
10 PM Thu 57 52 N 6 1729 4460 0 Blue 0
11 PM Thu 55 50 NE 6 1729 4460 0 Blue 0
12 Midnight Fri 54 49 NE 6 1729 4460 0 Blue 0
1 AM Fri 55 50 NE 6 1729 4460 0 Blue 0
2 AM Fri 55 50 NE 5 1729 4460 0 Blue 0
3 AM Fri 55 50 NE 5 1729 4460 0 Blue 0
4 AM Fri 56 51 NE 5 1729 4460 0 Blue 0
5 AM Fri 56 51 NE 6 1729 4460 0 Blue 0
6 AM Fri 56 51 NE 6 1729 4460 0 Blue 0
7 AM Fri 56 51 NE 6 1729 4460 0 Blue 0
8 AM Fri 58 53 E 3 1729 4460 0 Blue 0
9 AM Fri 62 58 E 3 2427 4460 0 Blue 0
10 AM Fri 66 64 E 3 4759 4460 0 Blue 6
11 AM Fri 70 69 SW 6 6228 5106 646 Blue 11
12 Noon Fri 72 72 SW 6 7261 6174 1714 Blue 14
1 PM Fri 73 74 SW 6 7549 7024 2564 Blue 16
2 PM Fri 74 74 W 6 7549 7024 2564 Blue 16
3 PM Fri 75 74 W 6 7549 7024 2564 Blue 16
4 PM Fri 76 74 W 6 7549 7024 2564 Blue 16
5 PM Fri 76 72 W 6 7261 6174 1714 Blue 14
6 PM Fri 74 69 W 6 6228 5106 646 Blue 11
7 PM Fri 70 65 W 6 4942 4460 0 Blue 7
8 PM Fri 67 62 NE 5 4393 4460 0 Blue 4
9 PM Fri 64 59 NE 5 2846 4460 0 Blue 1
10 PM Fri 62 57 NE 5 1966 4460 0 Blue 0
11 PM Fri 60 55 NE 5 1729 4460 0 Blue 0
12 Midnight Sat 59 54 NE 5 1729 4460 0 Blue 0
1 AM Sat 59 54 NE 5 1729 4460 0 Blue 0
2 AM Sat 59 54 NE 5 1729 4460 0 Blue 0
3 AM Sat 59 54 NE 5 1729 4460 0 Blue 0
4 AM Sat 59 54 NE 5 1729 4460 0 Blue 0
5 AM Sat 59 54 NE 6 1729 4460 0 Blue 0
6 AM Sat 59 54 NE 6 1729 4460 0 Blue 0
7 AM Sat 60 55 NE 6 1729 4460 0 Blue 0
8 AM Sat 62 57 E 3 1966 4460 0 Blue 0
9 AM Sat 66 62 E 3 4393 4460 0 Blue 4
10 AM Sat 72 70 E 3 6662 5812 1352 Blue 12
11 AM Sat 76 76 SW 5 7958 7356 2896 Blue 18
12 Noon Sat 78 79 SW 5 8685 7921 3461 Blue 21
1 PM Sat 79 80 SW 5 8984 8123 3663 Blue 22
2 PM Sat 80 81 W 6 9282 8325 3865 Blue 23
3 PM Sat 81 80 W 6 8984 8123 3663 Blue 22
4 PM Sat 82 80 W 6 8984 8123 3663 Blue 22
5 PM Sat 81 77 W 6 8161 7515 3055 Blue 19
6 PM Sat 78 73 W 6 7374 6603 2143 Blue 15
7 PM Sat 75 70 W 6 6662 5812 1352 Blue 12
8 PM Sat 71 66 NE 5 5467 4563 103 Blue 8
9 PM Sat 68 63 NE 5 4576 4460 0 Blue 5
10 PM Sat 65 60 NE 5 3233 4460 0 Blue 2
11 PM Sat 63 58 E 5 2427 4460 0 Blue 0
12 Midnight Sun 62 57 E 5 1966 4460 0 Blue 0
1 AM Sun 63 58 E 5 2427 4460 0 Blue 0
2 AM Sun 63 58 NE 6 2427 4460 0 Blue 0
3 AM Sun 63 58 NE 6 2427 4460 0 Blue 0
4 AM Sun 62 57 NE 6 1966 4460 0 Blue 0
5 AM Sun 62 57 E 6 1966 4460 0 Blue 0
6 AM Sun 62 57 E 6 1966 4460 0 Blue 0
7 AM Sun 63 58 E 6 2427 4460 0 Blue 0
8 AM Sun 65 60 E 5 3233 4460 0 Blue 2
9 AM Sun 69 65 E 5 4942 4460 0 Blue 7
10 AM Sun 75 73 E 5 7374 6603 2143 Blue 15
11 AM Sun 79 78 SW 6 8383 7718 3258 Blue 20
12 Noon Sun 81 81 SW 6 9282 8325 3865 Blue 23
1 PM Sun 83 84 SW 6 10552 9214 4754 Blue 26
2 PM Sun 83 83 W 7 9948 8920 4460 Blue 25
3 PM Sun 84 83 W 7 9948 8920 4460 Blue 25
4 PM Sun 84 82 W 7 9576 8623 4163 Blue 24
5 PM Sun 83 79 W 7 8685 7921 3461 Blue 21
6 PM Sun 80 75 W 7 7754 7243 2783 Blue 17
7 PM Sun 76 71 W 7 7088 5987 1527 Blue 13
8 PM Sun 72 67 W 6 5831 4745 285 Blue 9
9 PM Sun 69 64 W 6 4759 4460 0 Blue 6
10 PM Sun 67 62 W 6 4393 4460 0 Blue 4
11 PM Sun 65 60 NE 5 3233 4460 0 Blue 2
12 Midnight Mon 64 59 NE 5 2846 4460 0 Blue 1
1 AM Mon 64 59 NE 5 2846 4460 0 Blue 1
2 AM Mon 64 59 NE 5 2846 4460 0 Blue 1
3 AM Mon 64 59 NE 5 2846 4460 0 Blue 1
4 AM Mon 63 58 NE 5 2427 4460 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