Detailed Predictions for: Dunlap
Launch Altitude (f): 4600
LZ Altitude (f): 2200
Sounding

Station:

 KVBG

Date/Time:

 3 SEP 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)
5 AM Fri 66 66 N 5 3340 4600 0 Blue 0
6 AM Fri 65 65 N 5 3340 4600 0 Blue 0
7 AM Fri 64 64 N 5 3340 4600 0 Blue 0
8 AM Fri 66 66 NE 3 3340 4600 0 Blue 0
9 AM Fri 70 72 NE 3 3340 4600 0 Blue 0
10 AM Fri 76 79 NE 3 4668 4600 0 Blue 0
11 AM Fri 81 86 SW 7 10313 8338 3738 Blue 6
12 Noon Fri 84 91 SW 7 12118 11097 6497 Blue 11
1 PM Fri 85 92 SW 7 12430 11415 6815 Blue 12
2 PM Fri 85 92 W 8 12430 11415 6815 Blue 12
3 PM Fri 86 91 W 8 12118 11097 6497 Blue 11
4 PM Fri 86 90 W 8 11804 10776 6176 Blue 10
5 PM Fri 86 88 W 6 11166 9639 5039 Blue 8
6 PM Fri 83 83 W 6 8441 5545 945 Blue 3
7 PM Fri 79 79 W 6 4668 4600 0 Blue 0
8 PM Fri 76 76 N 3 3340 4600 0 Blue 0
9 PM Fri 75 75 N 3 3340 4600 0 Blue 0
10 PM Fri 74 74 N 3 3340 4600 0 Blue 0
11 PM Fri 73 73 NE 8 3340 4600 0 Blue 0
12 Midnight Sat 73 73 NE 8 3340 4600 0 Blue 0
1 AM Sat 72 72 NE 8 3340 4600 0 Blue 0
2 AM Sat 72 72 N 8 3340 4600 0 Blue 0
3 AM Sat 71 71 N 8 3340 4600 0 Blue 0
4 AM Sat 71 71 N 8 3340 4600 0 Blue 0
5 AM Sat 71 71 N 6 3340 4600 0 Blue 0
6 AM Sat 70 70 N 6 3340 4600 0 Blue 0
7 AM Sat 69 69 N 6 3340 4600 0 Blue 0
8 AM Sat 70 70 NE 6 3340 4600 0 Blue 0
9 AM Sat 74 76 NE 6 3340 4600 0 Blue 0
10 AM Sat 79 82 NE 6 7581 4663 63 Blue 2
11 AM Sat 83 88 SW 7 11166 9639 5039 Blue 8
12 Noon Sat 85 92 SW 7 12430 11415 6815 Blue 12
1 PM Sat 86 93 SW 7 12739 11729 7129 Blue 13
2 PM Sat 86 93 W 8 12739 11729 7129 Blue 13
3 PM Sat 87 92 W 8 12430 11415 6815 Blue 12
4 PM Sat 87 91 W 8 12118 11097 6497 Blue 11
5 PM Sat 86 88 W 7 11166 9639 5039 Blue 8
6 PM Sat 83 83 W 7 8441 5545 945 Blue 3
7 PM Sat 79 79 W 7 4668 4600 0 Blue 0
8 PM Sat 75 75 N 7 3340 4600 0 Blue 0
9 PM Sat 73 73 N 7 3340 4600 0 Blue 0
10 PM Sat 71 71 N 7 3340 4600 0 Blue 0
11 PM Sat 70 70 NE 7 3340 4600 0 Blue 0
12 Midnight Sun 69 69 NE 7 3340 4600 0 Blue 0
1 AM Sun 69 69 NE 7 3340 4600 0 Blue 0
2 AM Sun 68 68 N 7 3340 4600 0 Blue 0
3 AM Sun 67 67 N 7 3340 4600 0 Blue 0
4 AM Sun 66 66 N 7 3340 4600 0 Blue 0
5 AM Sun 65 65 NE 7 3340 4600 0 Blue 0
6 AM Sun 63 63 NE 7 3340 4600 0 Blue 0
7 AM Sun 62 62 NE 7 3340 4600 0 Blue 0
8 AM Sun 62 62 NE 7 3340 4600 0 Blue 0
9 AM Sun 66 68 NE 7 3340 4600 0 Blue 0
10 AM Sun 71 74 NE 7 3340 4600 0 Blue 0
11 AM Sun 76 81 SW 8 6640 4600 0 Blue 1
12 Noon Sun 78 85 SW 8 9736 7494 2894 Blue 5
1 PM Sun 80 87 SW 8 10842 9048 4448 Blue 7
2 PM Sun 80 87 SW 8 10842 9048 4448 Blue 7
3 PM Sun 81 86 SW 8 10313 8338 3738 Blue 6
4 PM Sun 81 85 SW 8 9736 7494 2894 Blue 5
5 PM Sun 79 81 W 9 6640 4600 0 Blue 1
6 PM Sun 76 76 W 9 3340 4600 0 Blue 0
7 PM Sun 72 72 W 9 3340 4600 0 Blue 0
8 PM Sun 67 67 W 9 3340 4600 0 Blue 0
9 PM Sun 65 65 W 9 3340 4600 0 Blue 0
10 PM Sun 63 63 W 9 3340 4600 0 Blue 0
11 PM Sun 62 62 NE 6 3340 4600 0 Blue 0
12 Midnight Mon 61 61 NE 6 3340 4600 0 Blue 0
1 AM Mon 61 61 NE 6 3340 4600 0 Blue 0
2 AM Mon 60 60 NE 6 3340 4600 0 Blue 0
3 AM Mon 60 60 NE 6 3340 4600 0 Blue 0
4 AM Mon 59 59 NE 6 3340 4600 0 Blue 0
5 AM Mon 58 58 E 6 3340 4600 0 Blue 0
6 AM Mon 56 56 E 6 3340 4600 0 Blue 0
7 AM Mon 54 54 E 6 3340 4600 0 Blue 0
8 AM Mon 54 54 E 6 3340 4600 0 Blue 0
9 AM Mon 59 61 E 6 3340 4600 0 Blue 0
10 AM Mon 66 69 E 6 3340 4600 0 Blue 0
11 AM Mon 72 77 SW 7 3340 4600 0 Blue 0
12 Noon Mon 75 82 SW 7 7581 4663 63 Blue 2
1 PM Mon 76 83 SW 7 8441 5545 945 Blue 3
2 PM Mon 76 83 SW 7 8441 5545 945 Blue 3
3 PM Mon 77 82 SW 7 7581 4663 63 Blue 2
4 PM Mon 76 80 SW 7 5586 4600 0 Blue 1
5 PM Mon 75 77 W 6 3340 4600 0 Blue 0
6 PM Mon 72 72 W 6 3340 4600 0 Blue 0
7 PM Mon 69 69 W 6 3340 4600 0 Blue 0
8 PM Mon 65 65 W 6 3340 4600 0 Blue 0
9 PM Mon 63 63 W 6 3340 4600 0 Blue 0
10 PM Mon 61 61 W 6 3340 4600 0 Blue 0
11 PM Mon 59 59 SE 6 3340 4600 0 Blue 0
12 Midnight Tue 59 59 SE 6 3340 4600 0 Blue 0
1 AM Tue 59 59 SE 6 3340 4600 0 Blue 0
2 AM Tue 59 59 SE 6 3340 4600 0 Blue 0
3 AM Tue 59 59 SE 6 3340 4600 0 Blue 0
4 AM Tue 58 58 SE 6 3340 4600 0 Blue 0
5 AM Tue 57 57 E 6 3340 4600 0 Blue 0
6 AM Tue 56 56 E 6 3340 4600 0 Blue 0
7 AM Tue 54 54 E 6 3340 4600 0 Blue 0
8 AM Tue 55 55 E 6 3340 4600 0 Blue 0
9 AM Tue 59 61 E 6 3340 4600 0 Blue 0
10 AM Tue 65 68 E 6 3340 4600 0 Blue 0
11 AM Tue 70 75 SW 9 3340 4600 0 Blue 0
12 Noon Tue 73 80 SW 9 5586 4600 0 Blue 1
1 PM Tue 74 81 SW 9 6640 4600 0 Blue 1
2 PM Tue 75 82 SW 9 7581 4663 63 Blue 2
3 PM Tue 75 80 SW 9 5586 4600 0 Blue 1
4 PM Tue 75 79 SW 9 4668 4600 0 Blue 0
5 PM Tue 73 75 SW 9 3340 4600 0 Blue 0
6 PM Tue 71 71 SW 9 3340 4600 0 Blue 0
7 PM Tue 67 67 SW 9 3340 4600 0 Blue 0
8 PM Tue 64 64 SW 9 3340 4600 0 Blue 0
9 PM Tue 61 61 SW 9 3340 4600 0 Blue 0
10 PM Tue 59 59 SW 9 3340 4600 0 Blue 0
11 PM Tue 58 58 SE 6 3340 4600 0 Blue 0
12 Midnight Wed 57 57 SE 6 3340 4600 0 Blue 0
1 AM Wed 57 57 SE 6 3340 4600 0 Blue 0
2 AM Wed 58 58 SE 6 3340 4600 0 Blue 0
3 AM Wed 59 59 SE 6 3340 4600 0 Blue 0
4 AM Wed 59 59 SE 6 3340 4600 0 Blue 0
5 AM Wed 59 59 SE 5 3340 4600 0 Blue 0
6 AM Wed 55 55 SE 5 3340 4600 0 Blue 0
7 AM Wed 52 52 SE 5 3340 4600 0 Blue 0
8 AM Wed 51 51 SE 5 3340 4600 0 Blue 0
9 AM Wed 55 57 SE 5 3340 4600 0 Blue 0
10 AM Wed 60 63 SE 5 3340 4600 0 Blue 0
11 AM Wed 66 71 SW 8 3340 4600 0 Blue 0
12 Noon Wed 68 75 SW 8 3340 4600 0 Blue 0
1 PM Wed 69 76 SW 8 3340 4600 0 Blue 0
2 PM Wed 68 75 SW 8 3340 4600 0 Blue 0
3 PM Wed 69 74 SW 8 3340 4600 0 Blue 0
4 PM Wed 68 72 SW 8 3340 4600 0 Blue 0
5 PM Wed 68 70 W 8 3340 4600 0 Blue 0
6 PM Wed 66 66 W 8 3340 4600 0 Blue 0
7 PM Wed 65 65 W 8 3340 4600 0 Blue 0
8 PM Wed 63 63 W 8 3340 4600 0 Blue 0
9 PM Wed 61 61 W 8 3340 4600 0 Blue 0
10 PM Wed 59 59 W 8 3340 4600 0 Blue 0
11 PM Wed 57 57 NE 3 3340 4600 0 Blue 0
12 Midnight Thu 57 57 NE 3 3340 4600 0 Blue 0
1 AM Thu 57 57 NE 3 3340 4600 0 Blue 0
2 AM Thu 57 57 NE 3 3340 4600 0 Blue 0
3 AM Thu 56 56 NE 3 3340 4600 0 Blue 0
4 AM Thu 54 54 NE 3 3340 4600 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