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

Station:

 KOAK

Date/Time:

 10 MAR 2010

Temp/Wind data from:

NOAA Digital Forecast

Time
(Local)		 High
Temp
Puddle
Temp
Wind
 (mph)		 Thermal
Ceiling
(ft)		 Soaring
Ceiling
(ft)		 Above
Launch
(ft)		 Thermal
Type		 Thermal
Index
(F)
7 AM Wed 36 36 E 6 1919 4460 0 Blue 0
8 AM Wed 38 38 E 6 2734 4460 0 Blue 0
9 AM Wed 42 42 E 6 5822 4460 0 Blue 4
10 AM Wed 44 45 W 2 6594 5768 1308 White 7
11 AM Wed 45 46 W 2 6805 6242 1782 White 8
12 Noon Wed 46 48 W 2 7227 6958 2498 White 10
1 PM Wed 46 47 SW 7 7016 6449 1989 White 9
2 PM Wed 46 47 SW 7 7016 6449 1989 White 9
3 PM Wed 47 47 SW 7 7016 6449 1989 White 9
4 PM Wed 46 46 W 6 6805 6242 1782 White 8
5 PM Wed 44 44 W 6 6382 5307 847 White 6
6 PM Wed 43 43 W 6 6170 4875 415 White 5
7 PM Wed 41 41 SW 1 5345 4460 0 Blue 3
8 PM Wed 40 40 SW 1 5025 4460 0 Blue 2
9 PM Wed 39 39 SW 1 3227 4460 0 Blue 1
10 PM Wed 38 38 N 4 2734 4460 0 Blue 0
11 PM Wed 38 38 N 4 2734 4460 0 Blue 0
12 Midnight Thu 38 38 N 4 2734 4460 0 Blue 0
1 AM Thu 37 37 E 6 2147 4460 0 Blue 0
2 AM Thu 37 37 E 6 2147 4460 0 Blue 0
3 AM Thu 36 36 E 6 1919 4460 0 Blue 0
4 AM Thu 36 36 E 6 1919 4460 0 Blue 0
5 AM Thu 36 36 E 6 1919 4460 0 Blue 0
6 AM Thu 35 35 E 6 1919 4460 0 Blue 0
7 AM Thu 35 35 E 7 1919 4460 0 Blue 0
8 AM Thu 38 38 E 7 2734 4460 0 Blue 0
9 AM Thu 47 48 E 7 7227 6958 2498 White 10
10 AM Thu 50 53 SW 5 8271 8135 3675 White 15
11 AM Thu 52 56 SW 5 8894 8629 4169 White 18
12 Noon Thu 53 58 SW 5 9307 8958 4498 White 20
1 PM Thu 54 58 SW 4 9307 8958 4498 White 20
2 PM Thu 55 58 SW 4 9307 8958 4498 White 20
3 PM Thu 56 58 SW 4 9307 8958 4498 White 20
4 PM Thu 54 55 W 11 8686 8465 4005 White 17
5 PM Thu 53 53 W 11 8271 8135 3675 White 15
6 PM Thu 51 51 W 11 7854 7790 3330 White 13
7 PM Thu 48 48 W 11 7227 6958 2498 White 10
8 PM Thu 47 47 W 11 7016 6449 1989 White 9
9 PM Thu 46 46 W 11 6805 6242 1782 White 8
10 PM Thu 44 44 E 5 6382 5307 847 White 6
11 PM Thu 44 44 E 5 6382 5307 847 White 6
12 Midnight Fri 44 44 E 5 6382 5307 847 White 6
1 AM Fri 43 43 E 5 6170 4875 415 White 5
2 AM Fri 43 43 E 5 6170 4875 415 White 5
3 AM Fri 42 42 E 5 5822 4460 0 Blue 4
4 AM Fri 42 42 E 6 5822 4460 0 Blue 4
5 AM Fri 41 41 E 6 5345 4460 0 Blue 3
6 AM Fri 40 40 E 6 5025 4460 0 Blue 2
7 AM Fri 40 40 E 6 5025 4460 0 Blue 2
8 AM Fri 43 43 E 6 6170 4875 415 White 5
9 AM Fri 50 51 E 6 7854 7790 3330 White 13
10 AM Fri 52 53 SW 4 8271 8135 3675 White 15
11 AM Fri 54 55 SW 4 8686 8465 4005 White 17
12 Noon Fri 56 57 SW 4 9101 8793 4333 White 19
1 PM Fri 56 57 SW 4 9101 8793 4333 White 19
2 PM Fri 57 58 SW 4 9307 8958 4498 White 20
3 PM Fri 58 58 SW 4 9307 8958 4498 White 20
4 PM Fri 56 56 SW 4 8894 8629 4169 White 18
5 PM Fri 55 55 SW 4 8686 8465 4005 White 17
6 PM Fri 53 53 SW 4 8271 8135 3675 White 15
7 PM Fri 50 50 SW 4 7646 7617 3157 White 12
8 PM Fri 49 49 SW 4 7436 7436 2976 White 11
9 PM Fri 48 48 SW 4 7227 6958 2498 White 10
10 PM Fri 46 46 E 8 6805 6242 1782 White 8
11 PM Fri 46 46 E 8 6805 6242 1782 White 8
12 Midnight Sat 46 46 E 8 6805 6242 1782 White 8
1 AM Sat 45 45 E 8 6594 5768 1308 White 7
2 AM Sat 45 45 E 8 6594 5768 1308 White 7
3 AM Sat 44 44 E 8 6382 5307 847 White 6
4 AM Sat 44 44 E 8 6382 5307 847 White 6
5 AM Sat 43 43 E 8 6170 4875 415 White 5
6 AM Sat 42 42 E 8 5822 4460 0 Blue 4
7 AM Sat 42 42 E 8 5822 4460 0 Blue 4
8 AM Sat 44 44 E 8 6382 5307 847 White 6
9 AM Sat 50 50 E 8 7646 7617 3157 White 12
10 AM Sat 52 53 SW 5 8271 8135 3675 White 15
11 AM Sat 53 54 SW 5 8479 8300 3840 White 16
12 Noon Sat 54 55 SW 5 8686 8465 4005 White 17
1 PM Sat 55 56 SW 5 8894 8629 4169 White 18
2 PM Sat 55 56 SW 5 8894 8629 4169 White 18
3 PM Sat 56 56 SW 5 8894 8629 4169 White 18
4 PM Sat 54 54 W 5 8479 8300 3840 White 16
5 PM Sat 53 53 W 5 8271 8135 3675 White 15
6 PM Sat 51 51 W 5 7854 7790 3330 White 13
7 PM Sat 48 48 W 5 7227 6958 2498 White 10
8 PM Sat 47 47 W 5 7016 6449 1989 White 9
9 PM Sat 46 46 W 5 6805 6242 1782 White 8
10 PM Sat 44 44 E 6 6382 5307 847 White 6
11 PM Sat 44 44 E 6 6382 5307 847 White 6
12 Midnight Sun 44 44 E 6 6382 5307 847 White 6
1 AM Sun 43 43 E 6 6170 4875 415 White 5
2 AM Sun 43 43 E 6 6170 4875 415 White 5
3 AM Sun 42 42 E 6 5822 4460 0 Blue 4
4 AM Sun 42 42 E 5 5822 4460 0 Blue 4
5 AM Sun 41 41 E 5 5345 4460 0 Blue 3
6 AM Sun 40 40 E 5 5025 4460 0 Blue 2
7 AM Sun 40 40 E 5 5025 4460 0 Blue 2
8 AM Sun 43 44 E 5 6382 5307 847 White 6
9 AM Sun 50 52 E 5 8063 7963 3503 White 14
10 AM Sun 52 56 SW 5 8894 8629 4169 White 18
11 AM Sun 54 59 SW 5 9514 9121 4661 White 21
12 Noon Sun 56 61 SW 5 9726 9448 4988 Blue 23
1 PM Sun 56 61 SW 5 9726 9448 4988 Blue 23
2 PM Sun 57 61 SW 5 9726 9448 4988 Blue 23
3 PM Sun 58 60 SW 5 9667 9285 4825 Blue 22
4 PM Sun 56 57 W 4 9101 8793 4333 White 19
5 PM Sun 55 55 W 4 8686 8465 4005 White 17
6 PM Sun 53 53 W 4 8271 8135 3675 White 15
7 PM Sun 51 51 W 4 7854 7790 3330 White 13
8 PM Sun 50 50 W 4 7646 7617 3157 White 12
9 PM Sun 49 49 W 4 7436 7436 2976 White 11
10 PM Sun 48 48 E 3 7227 6958 2498 White 10
11 PM Sun 48 48 E 3 7227 6958 2498 White 10
12 Midnight Mon 47 47 E 3 7016 6449 1989 White 9
1 AM Mon 47 47 E 3 7016 6449 1989 White 9
2 AM Mon 46 46 E 3 6805 6242 1782 White 8
3 AM Mon 46 46 E 3 6805 6242 1782 White 8
4 AM Mon 45 45 E 5 6594 5768 1308 White 7
5 AM Mon 45 45 E 5 6594 5768 1308 White 7
6 AM Mon 44 44 E 5 6382 5307 847 White 6
7 AM Mon 44 44 E 5 6382 5307 847 White 6
8 AM Mon 46 47 E 5 7016 6449 1989 White 9
9 AM Mon 53 55 E 5 8686 8465 4005 White 17
10 AM Mon 55 59 SW 5 9514 9121 4661 White 21
11 AM Mon 57 62 SW 5 9785 9594 5134 Blue 24
12 Noon Mon 58 63 SW 5 9838 9652 5192 Blue 25
1 PM Mon 59 64 SW 5 9892 9711 5251 Blue 26
2 PM Mon 59 63 SW 5 9838 9652 5192 Blue 25
3 PM Mon 60 62 SW 5 9785 9594 5134 Blue 24
4 PM Mon 58 59 SW 10 9514 9121 4661 White 21
5 PM Mon 56 56 SW 10 8894 8629 4169 White 18
6 PM Mon 54 54 SW 10 8479 8300 3840 White 16
7 PM Mon 52 52 SW 10 8063 7963 3503 White 14
8 PM Mon 50 50 SW 10 7646 7617 3157 White 12
9 PM Mon 49 49 SW 10 7436 7436 2976 White 11
10 PM Mon 48 48 SW 13 7227 6958 2498 White 10
11 PM Mon 47 47 SW 13 7016 6449 1989 White 9
12 Midnight Tue 47 47 SW 13 7016 6449 1989 White 9
1 AM Tue 46 46 SW 13 6805 6242 1782 White 8
2 AM Tue 46 46 SW 13 6805 6242 1782 White 8
3 AM Tue 45 45 SW 13 6594 5768 1308 White 7
4 AM Tue 45 45 SW 15 6594 5768 1308 White 7
5 AM Tue 44 44 SW 15 6382 5307 847 White 6
6 AM Tue 43 43 SW 15 6170 4875 415 White 5

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