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

Station:

KOAK

Date/Time:

27 MAY 2018

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 Sun 51 46 E 3 1906 4460 0 Blue 0
6 AM Sun 52 47 E 3 1906 4460 0 Blue 0
7 AM Sun 57 52 E 3 1906 4460 0 Blue 0
8 AM Sun 61 57 SW 6 1954 4460 0 Blue 0
9 AM Sun 65 63 SW 6 3865 4460 0 Blue 3
10 AM Sun 67 67 SW 6 5097 4460 0 Blue 7
11 AM Sun 70 70 SW 7 7440 5046 586 White 10
12 Noon Sun 73 74 SW 7 7805 7565 3105 Blue 14
1 PM Sun 76 78 SW 7 8261 7867 3407 Blue 18
2 PM Sun 79 80 SW 8 8890 8019 3559 Blue 20
3 PM Sun 80 80 SW 8 8890 8019 3559 Blue 20
4 PM Sun 81 79 SW 8 8577 7943 3483 Blue 19
5 PM Sun 80 77 W 7 8033 7792 3332 Blue 17
6 PM Sun 76 71 W 7 7578 5624 1164 Blue 11
7 PM Sun 72 67 W 7 5097 4460 0 Blue 7
8 PM Sun 68 63 N 2 3865 4460 0 Blue 3
9 PM Sun 65 60 N 2 2514 4460 0 Blue 0
10 PM Sun 64 59 N 2 2328 4460 0 Blue 0
11 PM Sun 63 58 E 3 2141 4460 0 Blue 0
12 Midnight Mon 63 58 E 3 2141 4460 0 Blue 0
1 AM Mon 63 58 E 3 2141 4460 0 Blue 0
2 AM Mon 60 55 E 3 1906 4460 0 Blue 0
3 AM Mon 57 52 E 3 1906 4460 0 Blue 0
4 AM Mon 53 48 E 3 1906 4460 0 Blue 0
5 AM Mon 53 48 E 5 1906 4460 0 Blue 0
6 AM Mon 57 52 E 5 1906 4460 0 Blue 0
7 AM Mon 64 59 E 5 2328 4460 0 Blue 0
8 AM Mon 71 67 SW 2 5097 4460 0 Blue 7
9 AM Mon 76 74 SW 2 7805 7565 3105 Blue 14
10 AM Mon 79 79 SW 2 8577 7943 3483 Blue 19
11 AM Mon 82 84 W 7 10385 9131 4671 Blue 23
12 Noon Mon 84 87 W 7 11047 10325 5865 White 26
1 PM Mon 86 89 W 7 11459 10774 6314 White 28
2 PM Mon 88 90 W 7 11665 11061 6601 White 29
3 PM Mon 90 91 W 7 11870 11367 6907 White 30
4 PM Mon 90 89 W 7 11459 10774 6314 White 28
5 PM Mon 88 85 NW 5 10612 9436 4976 Blue 24
6 PM Mon 84 80 NW 5 8890 8019 3559 Blue 20
7 PM Mon 78 73 NW 5 7729 7355 2895 Blue 13
8 PM Mon 73 68 NW 5 5684 4519 59 Blue 8
9 PM Mon 71 66 NW 5 4761 4460 0 Blue 6
10 PM Mon 71 66 NW 5 4761 4460 0 Blue 6
11 PM Mon 70 65 E 5 4535 4460 0 Blue 5
12 Midnight Tue 69 64 E 5 4308 4460 0 Blue 4
1 AM Tue 67 62 E 5 3339 4460 0 Blue 2
2 AM Tue 64 59 E 5 2328 4460 0 Blue 0
3 AM Tue 61 56 E 5 1906 4460 0 Blue 0
4 AM Tue 58 53 E 5 1906 4460 0 Blue 0
5 AM Tue 59 54 E 5 1906 4460 0 Blue 0
6 AM Tue 63 58 E 5 2141 4460 0 Blue 0
7 AM Tue 71 66 E 5 4761 4460 0 Blue 6
8 AM Tue 77 73 E 5 7729 7355 2895 Blue 13
9 AM Tue 82 80 E 5 8890 8019 3559 Blue 20
10 AM Tue 85 85 E 5 10612 9436 4976 Blue 24
11 AM Tue 87 88 W 5 11254 10550 6090 White 27
12 Noon Tue 89 91 W 5 11870 11367 6907 White 30
1 PM Tue 91 94 W 5 12481 12479 8019 White 33
2 PM Tue 92 94 W 5 12481 12479 8019 White 33
3 PM Tue 94 95 W 5 12684 12660 8200 White 34
4 PM Tue 94 93 W 5 12278 12158 7698 White 32
5 PM Tue 92 89 W 5 11459 10774 6314 White 28
6 PM Tue 88 84 W 5 10385 9131 4671 Blue 23
7 PM Tue 82 77 W 5 8033 7792 3332 Blue 17
8 PM Tue 77 72 W 5 7654 6187 1727 Blue 12
9 PM Tue 74 69 W 5 6349 4744 284 Blue 9
10 PM Tue 73 68 W 5 5684 4519 59 Blue 8
11 PM Tue 71 66 NE 5 4761 4460 0 Blue 6
12 Midnight Wed 70 65 NE 5 4535 4460 0 Blue 5
1 AM Wed 68 63 NE 5 3865 4460 0 Blue 3
2 AM Wed 65 60 NE 5 2514 4460 0 Blue 0
3 AM Wed 62 57 NE 5 1954 4460 0 Blue 0
4 AM Wed 59 54 NE 5 1906 4460 0 Blue 0
5 AM Wed 58 53 E 2 1906 4460 0 Blue 0
6 AM Wed 59 54 E 2 1906 4460 0 Blue 0
7 AM Wed 62 57 E 2 1954 4460 0 Blue 0
8 AM Wed 66 62 E 2 3339 4460 0 Blue 2
9 AM Wed 72 70 E 2 7440 5046 586 White 10
10 AM Wed 77 77 E 2 8033 7792 3332 Blue 17
11 AM Wed 81 82 SW 8 9508 8513 4053 Blue 22
12 Noon Wed 84 86 SW 8 10839 9877 5417 Blue 25
1 PM Wed 86 88 SW 8 11254 10550 6090 White 27
2 PM Wed 87 89 SW 8 11459 10774 6314 White 28
3 PM Wed 87 87 SW 8 11047 10325 5865 White 26
4 PM Wed 85 84 SW 8 10385 9131 4671 Blue 23
5 PM Wed 83 80 S 5 8890 8019 3559 Blue 20
6 PM Wed 79 75 S 5 7881 7641 3181 Blue 15
7 PM Wed 75 70 S 5 7440 5046 586 White 10
8 PM Wed 71 66 S 5 4761 4460 0 Blue 6
9 PM Wed 66 61 S 5 2798 4460 0 Blue 1
10 PM Wed 62 57 S 5 1954 4460 0 Blue 0
11 PM Wed 58 53 S 5 1906 4460 0 Blue 0
12 Midnight Thu 55 50 S 5 1906 4460 0 Blue 0
1 AM Thu 53 48 S 5 1906 4460 0 Blue 0
2 AM Thu 51 46 S 5 1906 4460 0 Blue 0
3 AM Thu 51 46 S 5 1906 4460 0 Blue 0
4 AM Thu 51 46 S 5 1906 4460 0 Blue 0
5 AM Thu 53 48 S 3 1906 4460 0 Blue 0
6 AM Thu 55 50 S 3 1906 4460 0 Blue 0
7 AM Thu 58 53 S 3 1906 4460 0 Blue 0
8 AM Thu 61 57 S 3 1954 4460 0 Blue 0
9 AM Thu 64 62 S 3 3339 4460 0 Blue 2
10 AM Thu 68 68 S 3 5684 4519 59 Blue 8
11 AM Thu 71 73 SW 9 7729 7355 2895 Blue 13
12 Noon Thu 73 76 SW 9 7957 7716 3256 Blue 16
1 PM Thu 75 79 SW 9 8577 7943 3483 Blue 19
2 PM Thu 76 79 SW 9 8577 7943 3483 Blue 19
3 PM Thu 76 78 SW 9 8261 7867 3407 Blue 18
4 PM Thu 75 75 SW 9 7881 7641 3181 Blue 15
5 PM Thu 74 72 W 7 7654 6187 1727 Blue 12
6 PM Thu 71 67 W 7 5097 4460 0 Blue 7
7 PM Thu 68 63 W 7 3865 4460 0 Blue 3
8 PM Thu 65 60 W 7 2514 4460 0 Blue 0
9 PM Thu 61 56 W 7 1906 4460 0 Blue 0
10 PM Thu 58 53 W 7 1906 4460 0 Blue 0
11 PM Thu 54 49 W 7 1906 4460 0 Blue 0
12 Midnight Fri 52 47 W 7 1906 4460 0 Blue 0
1 AM Fri 50 45 W 7 1906 4460 0 Blue 0
2 AM Fri 48 43 W 7 1906 4460 0 Blue 0
3 AM Fri 48 43 W 7 1906 4460 0 Blue 0
4 AM Fri 49 44 W 7 1906 4460 0 Blue 0
5 AM Fri 50 45 NW 5 1906 4460 0 Blue 0
6 AM Fri 53 48 NW 5 1906 4460 0 Blue 0
7 AM Fri 56 51 NW 5 1906 4460 0 Blue 0
8 AM Fri 60 56 NW 5 1906 4460 0 Blue 0
9 AM Fri 65 63 NW 5 3865 4460 0 Blue 3
10 AM Fri 69 69 NW 5 6349 4744 284 Blue 9
11 AM Fri 72 74 W 6 7805 7565 3105 Blue 14
12 Noon Fri 75 78 W 6 8261 7867 3407 Blue 18
1 PM Fri 77 81 W 6 9200 8200 3740 Blue 21
2 PM Fri 79 82 W 6 9508 8513 4053 Blue 22
3 PM Fri 79 81 W 6 9200 8200 3740 Blue 21
4 PM Fri 79 79 W 6 8577 7943 3483 Blue 19
5 PM Fri 77 75 W 7 7881 7641 3181 Blue 15
6 PM Fri 75 71 W 7 7578 5624 1164 Blue 11
7 PM Fri 72 67 W 7 5097 4460 0 Blue 7
8 PM Fri 69 64 W 7 4308 4460 0 Blue 4
9 PM Fri 65 60 W 7 2514 4460 0 Blue 0
10 PM Fri 62 57 W 7 1954 4460 0 Blue 0
11 PM Fri 59 54 NE 5 1906 4460 0 Blue 0
12 Midnight Sat 56 51 NE 5 1906 4460 0 Blue 0
1 AM Sat 54 49 NE 5 1906 4460 0 Blue 0
2 AM Sat 53 48 NE 5 1906 4460 0 Blue 0
3 AM Sat 53 48 NE 5 1906 4460 0 Blue 0
4 AM Sat 54 49 NE 5 1906 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