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

Station:

KOAK

Date/Time:

26 MAY 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 Sun 49 44 SE 9 3499 4460 0 White 2
6 AM Sun 48 43 SE 10 3278 4460 0 White 1
7 AM Sun 48 43 SE 10 3278 4460 0 White 1
8 AM Sun 50 45 S 10 3721 4460 0 White 3
9 AM Sun 50 45 S 12 3721 4460 0 White 3
10 AM Sun 51 46 S 13 3941 4460 0 White 4
11 AM Sun 52 48 S 13 4381 4460 0 White 6
12 Noon Sun 52 47 S 12 4162 4460 0 White 5
1 PM Sun 52 47 SW 10 4162 4460 0 White 5
2 PM Sun 53 48 S 10 4381 4460 0 White 6
3 PM Sun 53 48 SW 7 4381 4460 0 White 6
4 PM Sun 53 48 SW 7 4381 4460 0 White 6
5 PM Sun 53 48 SW 6 4381 4460 0 White 6
6 PM Sun 52 47 SW 6 4162 4460 0 White 5
7 PM Sun 51 46 W 5 3941 4460 0 White 4
8 PM Sun 48 43 W 5 3278 4460 0 White 1
9 PM Sun 46 41 W 3 2346 4460 0 Blue 0
10 PM Sun 45 40 W 5 2346 4460 0 Blue 0
11 PM Sun 44 39 NW 5 2346 4460 0 Blue 0
12 Midnight Mon 44 39 W 5 2346 4460 0 Blue 0
1 AM Mon 43 38 W 2 2346 4460 0 Blue 0
2 AM Mon 43 38 NW 3 2346 4460 0 Blue 0
3 AM Mon 43 38 E 2 2346 4460 0 Blue 0
4 AM Mon 43 38 E 3 2346 4460 0 Blue 0
5 AM Mon 42 37 NE 3 2346 4460 0 Blue 0
6 AM Mon 42 37 N 3 2346 4460 0 Blue 0
7 AM Mon 43 38 NW 3 2346 4460 0 Blue 0
8 AM Mon 47 42 W 3 2346 4460 0 Blue 0
9 AM Mon 50 46 W 3 3941 4460 0 White 4
10 AM Mon 52 48 W 5 4381 4460 0 White 6
11 AM Mon 54 49 W 6 4601 4460 0 White 7
12 Noon Mon 57 52 W 6 5248 5075 615 White 10
1 PM Mon 57 54 W 6 5679 5476 1016 White 12
2 PM Mon 58 54 W 6 5679 5476 1016 White 12
3 PM Mon 59 56 W 6 6106 6106 1646 White 14
4 PM Mon 59 56 NW 5 6106 6106 1646 White 14
5 PM Mon 59 55 NW 5 5893 5675 1215 White 13
6 PM Mon 58 53 NW 5 5464 5275 815 White 11
7 PM Mon 56 51 NW 3 5033 4873 413 White 9
8 PM Mon 54 49 NW 3 4601 4460 0 White 7
9 PM Mon 52 47 NW 3 4162 4460 0 White 5
10 PM Mon 51 46 N 5 3941 4460 0 White 4
11 PM Mon 49 44 N 5 3499 4460 0 White 2
12 Midnight Tue 49 44 N 5 3499 4460 0 White 2
1 AM Tue 48 43 NE 3 3278 4460 0 White 1
2 AM Tue 48 43 NE 3 3278 4460 0 White 1
3 AM Tue 48 43 NE 3 3278 4460 0 White 1
4 AM Tue 48 43 NE 5 3278 4460 0 White 1
5 AM Tue 47 42 NE 5 2346 4460 0 Blue 0
6 AM Tue 47 42 NE 5 2346 4460 0 Blue 0
7 AM Tue 49 44 N 3 3499 4460 0 White 2
8 AM Tue 54 50 N 3 4817 4672 212 White 8
9 AM Tue 58 56 NW 5 6106 6106 1646 White 14
10 AM Tue 61 59 W 5 6742 6742 2282 White 17
11 AM Tue 63 62 W 6 7377 7377 2917 White 20
12 Noon Tue 66 66 W 6 8211 8211 3751 White 24
1 PM Tue 66 66 W 6 8211 8211 3751 White 24
2 PM Tue 68 67 W 6 8419 8419 3959 White 25
3 PM Tue 69 68 W 6 8626 8626 4166 White 26
4 PM Tue 69 67 W 6 8419 8419 3959 White 25
5 PM Tue 69 65 W 6 8004 8004 3544 White 23
6 PM Tue 68 63 W 5 7586 7586 3126 White 21
7 PM Tue 65 60 NW 3 6954 6954 2494 White 18
8 PM Tue 62 57 NW 3 6318 6318 1858 White 15
9 PM Tue 59 54 N 3 5679 5476 1016 White 12
10 PM Tue 58 53 NE 5 5464 5275 815 White 11
11 PM Tue 56 51 NE 6 5033 4873 413 White 9
12 Midnight Wed 55 50 NE 6 4817 4672 212 White 8
1 AM Wed 55 50 NE 6 4817 4672 212 White 8
2 AM Wed 54 49 NE 6 4601 4460 0 White 7
3 AM Wed 54 49 NE 6 4601 4460 0 White 7
4 AM Wed 54 49 NE 6 4601 4460 0 White 7
5 AM Wed 53 48 NE 6 4381 4460 0 White 6
6 AM Wed 53 48 E 6 4381 4460 0 White 6
7 AM Wed 55 50 E 5 4817 4672 212 White 8
8 AM Wed 60 55 E 5 5893 5675 1215 White 13
9 AM Wed 64 60 SE 5 6954 6954 2494 White 18
10 AM Wed 67 63 S 5 7586 7586 3126 White 21
11 AM Wed 69 67 SW 5 8419 8419 3959 White 25
12 Noon Wed 72 69 SW 5 8835 8835 4375 White 27
1 PM Wed 72 70 SW 5 9047 9047 4587 White 28
2 PM Wed 74 70 SW 5 9047 9047 4587 White 28
3 PM Wed 75 72 W 5 9466 9466 5006 White 30
4 PM Wed 75 72 W 3 9466 9466 5006 White 30
5 PM Wed 75 71 W 3 9257 9257 4797 White 29
6 PM Wed 74 69 W 3 8835 8835 4375 White 27
7 PM Wed 71 66 W 3 8211 8211 3751 White 24
8 PM Wed 67 62 W 3 7377 7377 2917 White 20
9 PM Wed 63 58 W 3 6530 6530 2070 White 16
10 PM Wed 62 57 W 3 6318 6318 1858 White 15
11 PM Wed 60 55 NE 6 5893 5675 1215 White 13
12 Midnight Thu 59 54 NE 6 5679 5476 1016 White 12
1 AM Thu 58 53 NE 6 5464 5275 815 White 11
2 AM Thu 58 53 NE 6 5464 5275 815 White 11
3 AM Thu 57 52 NE 6 5248 5075 615 White 10
4 AM Thu 57 52 NE 6 5248 5075 615 White 10
5 AM Thu 56 51 E 5 5033 4873 413 White 9
6 AM Thu 56 51 E 5 5033 4873 413 White 9
7 AM Thu 58 53 E 5 5464 5275 815 White 11
8 AM Thu 63 59 E 5 6742 6742 2282 White 17
9 AM Thu 66 63 E 5 7586 7586 3126 White 21
10 AM Thu 69 68 E 5 8626 8626 4166 White 26
11 AM Thu 71 70 W 5 9047 9047 4587 White 28
12 Noon Thu 74 73 W 5 9676 9676 5216 White 31
1 PM Thu 74 74 W 5 9878 9878 5418 White 32
2 PM Thu 76 75 W 5 10080 10080 5620 White 33
3 PM Thu 77 75 W 5 10080 10080 5620 White 33
4 PM Thu 77 74 W 5 9878 9878 5418 White 32
5 PM Thu 77 74 W 3 9878 9878 5418 White 32
6 PM Thu 75 70 W 3 9047 9047 4587 White 28
7 PM Thu 72 67 W 3 8419 8419 3959 White 25
8 PM Thu 68 63 W 3 7586 7586 3126 White 21
9 PM Thu 64 59 W 3 6742 6742 2282 White 17
10 PM Thu 63 58 W 3 6530 6530 2070 White 16
11 PM Thu 60 55 NE 5 5893 5675 1215 White 13
12 Midnight Fri 59 54 NE 5 5679 5476 1016 White 12
1 AM Fri 59 54 NE 5 5679 5476 1016 White 12
2 AM Fri 58 53 NE 5 5464 5275 815 White 11
3 AM Fri 57 52 NE 5 5248 5075 615 White 10
4 AM Fri 57 52 NE 5 5248 5075 615 White 10
5 AM Fri 56 51 E 2 5033 4873 413 White 9
6 AM Fri 56 51 E 2 5033 4873 413 White 9
7 AM Fri 58 53 E 2 5464 5275 815 White 11
8 AM Fri 63 59 E 2 6742 6742 2282 White 17
9 AM Fri 66 63 E 2 7586 7586 3126 White 21
10 AM Fri 69 67 E 2 8419 8419 3959 White 25
11 AM Fri 71 69 W 5 8835 8835 4375 White 27
12 Noon Fri 74 72 W 5 9466 9466 5006 White 30
1 PM Fri 74 72 W 5 9466 9466 5006 White 30
2 PM Fri 76 74 W 5 9878 9878 5418 White 32
3 PM Fri 77 74 W 5 9878 9878 5418 White 32
4 PM Fri 77 74 W 5 9878 9878 5418 White 32
5 PM Fri 77 73 NW 5 9676 9676 5216 White 31
6 PM Fri 76 71 NW 5 9257 9257 4797 White 29
7 PM Fri 73 68 NW 5 8626 8626 4166 White 26
8 PM Fri 69 64 NW 5 7795 7795 3335 White 22
9 PM Fri 65 60 NW 5 6954 6954 2494 White 18
10 PM Fri 64 59 NW 5 6742 6742 2282 White 17
11 PM Fri 62 57 NE 5 6318 6318 1858 White 15
12 Midnight Sat 61 56 NE 5 6106 6106 1646 White 14
1 AM Sat 60 55 NE 5 5893 5675 1215 White 13
2 AM Sat 60 55 NE 5 5893 5675 1215 White 13
3 AM Sat 59 54 NE 5 5679 5476 1016 White 12
4 AM Sat 59 54 NE 5 5679 5476 1016 White 12

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