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

Station:

KOAK

Date/Time:

18 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 Sat 41 36 E 3 679 4460 0 Blue 0
5 AM Sat 40 35 E 3 679 4460 0 Blue 0
6 AM Sat 40 35 E 3 679 4460 0 Blue 0
7 AM Sat 42 37 E 2 679 4460 0 Blue 0
8 AM Sat 46 41 E 2 679 4460 0 Blue 0
9 AM Sat 52 47 E 2 679 4460 0 Blue 0
10 AM Sat 58 54 W 3 4957 4460 0 Blue 6
11 AM Sat 62 59 W 3 6567 5481 1021 Blue 11
12 Noon Sat 64 61 W 3 7240 6087 1627 Blue 13
1 PM Sat 65 61 W 3 7240 6087 1627 Blue 13
2 PM Sat 64 60 W 3 6985 5755 1295 Blue 12
3 PM Sat 63 58 W 3 6140 5205 745 Blue 10
4 PM Sat 60 55 SE 2 5231 4460 0 Blue 7
5 PM Sat 57 52 SE 2 4336 4460 0 Blue 4
6 PM Sat 54 49 SE 2 4123 4460 0 Blue 1
7 PM Sat 51 46 NE 5 679 4460 0 Blue 0
8 PM Sat 49 44 NE 5 679 4460 0 Blue 0
9 PM Sat 48 43 NE 5 679 4460 0 Blue 0
10 PM Sat 47 42 E 5 679 4460 0 Blue 0
11 PM Sat 46 41 E 5 679 4460 0 Blue 0
12 Midnight Sun 45 40 E 5 679 4460 0 Blue 0
1 AM Sun 45 40 NE 5 679 4460 0 Blue 0
2 AM Sun 44 39 NE 5 679 4460 0 Blue 0
3 AM Sun 44 39 NE 5 679 4460 0 Blue 0
4 AM Sun 43 38 NE 2 679 4460 0 Blue 0
5 AM Sun 42 37 NE 2 679 4460 0 Blue 0
6 AM Sun 42 37 NE 2 679 4460 0 Blue 0
7 AM Sun 43 38 NE 2 679 4460 0 Blue 0
8 AM Sun 48 43 NE 2 679 4460 0 Blue 0
9 AM Sun 53 49 NE 2 4123 4460 0 Blue 1
10 AM Sun 58 54 W 2 4957 4460 0 Blue 6
11 AM Sun 62 58 W 2 6140 5205 745 Blue 10
12 Noon Sun 64 60 W 2 6985 5755 1295 Blue 12
1 PM Sun 64 60 W 2 6985 5755 1295 Blue 12
2 PM Sun 63 59 W 2 6567 5481 1021 Blue 11
3 PM Sun 62 57 W 2 5786 4799 339 Blue 9
4 PM Sun 59 54 S 1 4957 4460 0 Blue 6
5 PM Sun 56 51 S 1 4271 4460 0 Blue 3
6 PM Sun 53 48 S 1 3065 4460 0 Blue 0
7 PM Sun 50 45 S 1 679 4460 0 Blue 0
8 PM Sun 48 43 S 1 679 4460 0 Blue 0
9 PM Sun 47 42 S 1 679 4460 0 Blue 0
10 PM Sun 46 41 NE 3 679 4460 0 Blue 0
11 PM Sun 46 41 NE 3 679 4460 0 Blue 0
12 Midnight Mon 45 40 NE 3 679 4460 0 Blue 0
1 AM Mon 45 40 NE 3 679 4460 0 Blue 0
2 AM Mon 45 40 NE 3 679 4460 0 Blue 0
3 AM Mon 44 39 NE 3 679 4460 0 Blue 0
4 AM Mon 44 39 E 2 679 4460 0 Blue 0
5 AM Mon 43 38 E 2 679 4460 0 Blue 0
6 AM Mon 43 38 E 2 679 4460 0 Blue 0
7 AM Mon 45 40 E 2 679 4460 0 Blue 0
8 AM Mon 49 44 E 2 679 4460 0 Blue 0
9 AM Mon 55 50 E 2 4207 4460 0 Blue 2
10 AM Mon 60 55 W 2 5231 4460 0 Blue 7
11 AM Mon 63 58 W 2 6140 5205 745 Blue 10
12 Noon Mon 65 60 W 2 6985 5755 1295 Blue 12
1 PM Mon 66 61 W 2 7240 6087 1627 Blue 13
2 PM Mon 66 61 W 2 7240 6087 1627 Blue 13
3 PM Mon 65 60 W 2 6985 5755 1295 Blue 12
4 PM Mon 63 58 N 2 6140 5205 745 Blue 10
5 PM Mon 60 55 N 2 5231 4460 0 Blue 7
6 PM Mon 56 51 N 2 4271 4460 0 Blue 3
7 PM Mon 53 48 N 2 3065 4460 0 Blue 0
8 PM Mon 51 46 N 2 679 4460 0 Blue 0
9 PM Mon 50 45 N 2 679 4460 0 Blue 0
10 PM Mon 50 45 NE 2 679 4460 0 Blue 0
11 PM Mon 50 45 NE 2 679 4460 0 Blue 0
12 Midnight Tue 51 46 NE 2 679 4460 0 Blue 0
1 AM Tue 50 45 NE 2 679 4460 0 Blue 0
2 AM Tue 48 43 NE 2 679 4460 0 Blue 0
3 AM Tue 47 42 NE 2 679 4460 0 Blue 0
4 AM Tue 46 41 E 2 679 4460 0 Blue 0
5 AM Tue 47 42 E 2 679 4460 0 Blue 0
6 AM Tue 50 45 E 2 679 4460 0 Blue 0
7 AM Tue 53 48 E 2 3065 4460 0 Blue 0
8 AM Tue 58 53 E 2 4439 4460 0 Blue 5
9 AM Tue 62 57 E 2 5786 4799 339 Blue 9
10 AM Tue 66 62 S 2 7363 6508 2048 Blue 14
11 AM Tue 68 64 S 2 7610 7220 2760 Blue 16
12 Noon Tue 70 66 S 2 7738 7465 3005 Blue 18
1 PM Tue 71 67 S 2 7792 7588 3128 Blue 19
2 PM Tue 71 67 S 2 7792 7588 3128 Blue 19
3 PM Tue 70 65 S 2 7685 7343 2883 Blue 17
4 PM Tue 69 64 NE 1 7610 7220 2760 Blue 16
5 PM Tue 67 62 NE 1 7363 6508 2048 Blue 14
6 PM Tue 65 60 NE 1 6985 5755 1295 Blue 12
7 PM Tue 62 57 NE 1 5786 4799 339 Blue 9
8 PM Tue 59 54 NE 1 4957 4460 0 Blue 6
9 PM Tue 57 52 NE 1 4336 4460 0 Blue 4
10 PM Tue 54 49 E 3 4123 4460 0 Blue 1
11 PM Tue 51 46 E 3 679 4460 0 Blue 0
12 Midnight Wed 49 44 E 3 679 4460 0 Blue 0
1 AM Wed 48 43 E 3 679 4460 0 Blue 0
2 AM Wed 47 42 E 3 679 4460 0 Blue 0
3 AM Wed 47 42 E 3 679 4460 0 Blue 0
4 AM Wed 49 44 E 3 679 4460 0 Blue 0
5 AM Wed 51 46 E 3 679 4460 0 Blue 0
6 AM Wed 55 50 E 3 4207 4460 0 Blue 2
7 AM Wed 59 54 E 3 4957 4460 0 Blue 6
8 AM Wed 63 58 E 3 6140 5205 745 Blue 10
9 AM Wed 67 62 E 3 7363 6508 2048 Blue 14
10 AM Wed 70 66 SW 2 7738 7465 3005 Blue 18
11 AM Wed 73 70 SW 2 7902 7782 3322 Blue 22
12 Noon Wed 74 71 SW 2 7927 7836 3376 Blue 23
1 PM Wed 75 71 SW 2 7927 7836 3376 Blue 23
2 PM Wed 75 71 SW 2 7927 7836 3376 Blue 23
3 PM Wed 74 69 SW 2 7876 7729 3269 Blue 21
4 PM Wed 72 67 N 2 7792 7588 3128 Blue 19
5 PM Wed 70 65 N 2 7685 7343 2883 Blue 17
6 PM Wed 67 62 N 2 7363 6508 2048 Blue 14
7 PM Wed 64 59 N 2 6567 5481 1021 Blue 11
8 PM Wed 61 56 N 2 5509 4460 0 Blue 8
9 PM Wed 57 52 N 2 4336 4460 0 Blue 4
10 PM Wed 54 49 E 3 4123 4460 0 Blue 1
11 PM Wed 52 47 E 3 679 4460 0 Blue 0
12 Midnight Thu 50 45 E 3 679 4460 0 Blue 0
1 AM Thu 49 44 E 3 679 4460 0 Blue 0
2 AM Thu 48 43 E 3 679 4460 0 Blue 0
3 AM Thu 48 43 E 3 679 4460 0 Blue 0
4 AM Thu 50 45 E 2 679 4460 0 Blue 0
5 AM Thu 53 48 E 2 3065 4460 0 Blue 0
6 AM Thu 56 51 E 2 4271 4460 0 Blue 3
7 AM Thu 60 55 E 2 5231 4460 0 Blue 7
8 AM Thu 64 59 E 2 6567 5481 1021 Blue 11
9 AM Thu 68 63 E 2 7486 6922 2462 Blue 15
10 AM Thu 71 67 SW 3 7792 7588 3128 Blue 19
11 AM Thu 73 70 SW 3 7902 7782 3322 Blue 22
12 Noon Thu 74 71 SW 3 7927 7836 3376 Blue 23
1 PM Thu 75 71 SW 3 7927 7836 3376 Blue 23
2 PM Thu 75 71 SW 3 7927 7836 3376 Blue 23
3 PM Thu 74 69 SW 3 7876 7729 3269 Blue 21
4 PM Thu 72 67 E 2 7792 7588 3128 Blue 19
5 PM Thu 69 64 E 2 7610 7220 2760 Blue 16
6 PM Thu 66 61 E 2 7240 6087 1627 Blue 13
7 PM Thu 62 57 E 2 5786 4799 339 Blue 9
8 PM Thu 59 54 E 2 4957 4460 0 Blue 6
9 PM Thu 56 51 E 2 4271 4460 0 Blue 3
10 PM Thu 53 48 E 3 3065 4460 0 Blue 0
11 PM Thu 50 45 E 3 679 4460 0 Blue 0
12 Midnight Fri 49 44 E 3 679 4460 0 Blue 0
1 AM Fri 47 42 E 3 679 4460 0 Blue 0
2 AM Fri 47 42 E 3 679 4460 0 Blue 0
3 AM Fri 47 42 E 3 679 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