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

Station:

KVBG

Date/Time:

20 AUG 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 Tue 65 65 E 5 4179 4600 0 Blue 0
6 AM Tue 65 65 E 5 4179 4600 0 Blue 0
7 AM Tue 65 65 E 5 4179 4600 0 Blue 0
8 AM Tue 68 68 SW 3 4455 4600 0 Blue 0
9 AM Tue 68 70 SW 2 4638 4600 0 Blue 0
10 AM Tue 71 75 SW 3 5665 4821 221 Blue 2
11 AM Tue 73 79 SW 6 7117 6016 1416 Blue 6
12 Noon Tue 75 82 W 6 8165 7087 2487 Blue 9
1 PM Tue 76 84 W 7 8846 7782 3182 Blue 11
2 PM Tue 77 84 W 7 8846 7782 3182 Blue 11
3 PM Tue 78 84 W 6 8846 7782 3182 Blue 11
4 PM Tue 78 82 W 7 8165 7087 2487 Blue 9
5 PM Tue 78 80 W 6 7470 6377 1777 Blue 7
6 PM Tue 77 78 W 6 6760 5651 1051 Blue 5
7 PM Tue 74 74 NW 6 5292 4729 129 Blue 1
8 PM Tue 71 71 NW 6 4730 4600 0 Blue 0
9 PM Tue 69 69 N 6 4546 4600 0 Blue 0
10 PM Tue 67 67 NE 6 4363 4600 0 Blue 0
11 PM Tue 68 68 NE 5 4455 4600 0 Blue 0
12 Midnight Wed 68 68 N 6 4455 4600 0 Blue 0
1 AM Wed 67 67 E 5 4363 4600 0 Blue 0
2 AM Wed 66 66 NE 5 4271 4600 0 Blue 0
3 AM Wed 66 66 E 6 4271 4600 0 Blue 0
4 AM Wed 66 66 E 6 4271 4600 0 Blue 0
5 AM Wed 66 66 E 6 4271 4600 0 Blue 0
6 AM Wed 65 65 E 6 4179 4600 0 Blue 0
7 AM Wed 65 65 E 6 4179 4600 0 Blue 0
8 AM Wed 68 68 N 3 4455 4600 0 Blue 0
9 AM Wed 68 70 SW 3 4638 4600 0 Blue 0
10 AM Wed 71 75 SW 3 5665 4821 221 Blue 2
11 AM Wed 74 80 W 5 7470 6377 1777 Blue 7
12 Noon Wed 76 83 W 5 8507 7436 2836 Blue 10
1 PM Wed 77 84 W 5 8846 7782 3182 Blue 11
2 PM Wed 78 85 W 7 9181 8124 3524 Blue 12
3 PM Wed 79 85 W 7 9181 8124 3524 Blue 12
4 PM Wed 79 83 W 7 8507 7436 2836 Blue 10
5 PM Wed 79 81 W 6 7819 6734 2134 Blue 8
6 PM Wed 77 78 W 6 6760 5651 1051 Blue 5
7 PM Wed 75 75 W 6 5665 4821 221 Blue 2
8 PM Wed 73 73 W 5 4914 4638 38 Blue 0
9 PM Wed 71 71 W 5 4730 4600 0 Blue 0
10 PM Wed 70 70 W 5 4638 4600 0 Blue 0
11 PM Wed 69 69 NE 5 4546 4600 0 Blue 0
12 Midnight Thu 68 68 NE 5 4455 4600 0 Blue 0
1 AM Thu 68 68 NE 5 4455 4600 0 Blue 0
2 AM Thu 68 68 NE 6 4455 4600 0 Blue 0
3 AM Thu 68 68 NE 6 4455 4600 0 Blue 0
4 AM Thu 68 68 NE 6 4455 4600 0 Blue 0
5 AM Thu 68 68 E 6 4455 4600 0 Blue 0
6 AM Thu 68 68 E 6 4455 4600 0 Blue 0
7 AM Thu 69 69 E 6 4546 4600 0 Blue 0
8 AM Thu 70 70 E 3 4638 4600 0 Blue 0
9 AM Thu 71 73 E 3 4914 4638 38 Blue 0
10 AM Thu 73 77 E 3 6399 5281 681 Blue 4
11 AM Thu 75 80 SW 6 7470 6377 1777 Blue 7
12 Noon Thu 77 83 SW 6 8507 7436 2836 Blue 10
1 PM Thu 78 84 SW 6 8846 7782 3182 Blue 11
2 PM Thu 79 84 SW 6 8846 7782 3182 Blue 11
3 PM Thu 80 84 SW 6 8846 7782 3182 Blue 11
4 PM Thu 80 83 SW 6 8507 7436 2836 Blue 10
5 PM Thu 80 82 W 6 8165 7087 2487 Blue 9
6 PM Thu 79 79 W 6 7117 6016 1416 Blue 6
7 PM Thu 77 77 W 6 6399 5281 681 Blue 4
8 PM Thu 75 75 W 3 5665 4821 221 Blue 2
9 PM Thu 74 74 W 3 5292 4729 129 Blue 1
10 PM Thu 73 73 W 3 4914 4638 38 Blue 0
11 PM Thu 72 72 NE 5 4822 4600 0 Blue 0
12 Midnight Fri 71 71 NE 5 4730 4600 0 Blue 0
1 AM Fri 70 70 NE 5 4638 4600 0 Blue 0
2 AM Fri 70 70 NE 5 4638 4600 0 Blue 0
3 AM Fri 70 70 NE 5 4638 4600 0 Blue 0
4 AM Fri 70 70 NE 5 4638 4600 0 Blue 0
5 AM Fri 71 71 E 6 4730 4600 0 Blue 0
6 AM Fri 71 71 E 6 4730 4600 0 Blue 0
7 AM Fri 72 72 E 6 4822 4600 0 Blue 0
8 AM Fri 73 73 E 5 4914 4638 38 Blue 0
9 AM Fri 75 77 E 5 6399 5281 681 Blue 4
10 AM Fri 77 81 E 5 7819 6734 2134 Blue 8
11 AM Fri 79 85 SW 6 9181 8124 3524 Blue 12
12 Noon Fri 80 87 SW 6 9843 8799 4199 Blue 14
1 PM Fri 81 88 SW 6 10169 9131 4531 Blue 15
2 PM Fri 82 89 SW 7 10876 9460 4860 Blue 16
3 PM Fri 83 89 SW 7 10876 9460 4860 Blue 16
4 PM Fri 83 87 SW 7 9843 8799 4199 Blue 14
5 PM Fri 83 85 W 6 9181 8124 3524 Blue 12
6 PM Fri 81 82 W 6 8165 7087 2487 Blue 9
7 PM Fri 79 79 W 6 7117 6016 1416 Blue 6
8 PM Fri 77 77 W 3 6399 5281 681 Blue 4
9 PM Fri 75 75 W 3 5665 4821 221 Blue 2
10 PM Fri 74 74 W 3 5292 4729 129 Blue 1
11 PM Fri 73 73 NE 5 4914 4638 38 Blue 0
12 Midnight Sat 72 72 NE 5 4822 4600 0 Blue 0
1 AM Sat 72 72 NE 5 4822 4600 0 Blue 0
2 AM Sat 72 72 NE 5 4822 4600 0 Blue 0
3 AM Sat 71 71 NE 5 4730 4600 0 Blue 0
4 AM Sat 71 71 NE 5 4730 4600 0 Blue 0
5 AM Sat 71 71 E 6 4730 4600 0 Blue 0
6 AM Sat 72 72 E 6 4822 4600 0 Blue 0
7 AM Sat 73 73 E 6 4914 4638 38 Blue 0
8 AM Sat 74 74 E 3 5292 4729 129 Blue 1
9 AM Sat 76 77 E 3 6399 5281 681 Blue 4
10 AM Sat 78 81 E 3 7819 6734 2134 Blue 8
11 AM Sat 80 85 SW 5 9181 8124 3524 Blue 12
12 Noon Sat 82 89 SW 5 10876 9460 4860 Blue 16
1 PM Sat 83 90 SW 5 11929 9786 5186 Blue 17
2 PM Sat 84 91 W 6 12856 10110 5510 Blue 18
3 PM Sat 85 91 W 6 12856 10110 5510 Blue 18
4 PM Sat 85 89 W 6 10876 9460 4860 Blue 16
5 PM Sat 84 86 W 6 9513 8463 3863 Blue 13
6 PM Sat 82 83 W 6 8507 7436 2836 Blue 10
7 PM Sat 80 80 W 6 7470 6377 1777 Blue 7
8 PM Sat 78 78 W 3 6760 5651 1051 Blue 5
9 PM Sat 76 76 W 3 6035 4913 313 Blue 3
10 PM Sat 75 75 W 3 5665 4821 221 Blue 2
11 PM Sat 74 74 E 5 5292 4729 129 Blue 1
12 Midnight Sun 73 73 E 5 4914 4638 38 Blue 0
1 AM Sun 73 73 E 5 4914 4638 38 Blue 0
2 AM Sun 73 73 E 6 4914 4638 38 Blue 0
3 AM Sun 72 72 E 6 4822 4600 0 Blue 0
4 AM Sun 72 72 E 6 4822 4600 0 Blue 0
5 AM Sun 72 72 E 6 4822 4600 0 Blue 0
6 AM Sun 73 73 E 6 4914 4638 38 Blue 0
7 AM Sun 74 74 E 6 5292 4729 129 Blue 1
8 AM Sun 75 75 S 5 5665 4821 221 Blue 2
9 AM Sun 77 79 S 5 7117 6016 1416 Blue 6
10 AM Sun 78 82 S 5 8165 7087 2487 Blue 9
11 AM Sun 80 86 W 5 9513 8463 3863 Blue 13
12 Noon Sun 81 88 W 5 10169 9131 4531 Blue 15
1 PM Sun 82 89 W 5 10876 9460 4860 Blue 16
2 PM Sun 83 90 W 6 11929 9786 5186 Blue 17
3 PM Sun 84 90 W 6 11929 9786 5186 Blue 17
4 PM Sun 84 88 W 6 10169 9131 4531 Blue 15
5 PM Sun 84 86 W 6 9513 8463 3863 Blue 13
6 PM Sun 83 84 W 6 8846 7782 3182 Blue 11
7 PM Sun 81 81 W 6 7819 6734 2134 Blue 8
8 PM Sun 79 79 W 5 7117 6016 1416 Blue 6
9 PM Sun 77 77 W 5 6399 5281 681 Blue 4
10 PM Sun 76 76 W 5 6035 4913 313 Blue 3
11 PM Sun 75 75 NE 5 5665 4821 221 Blue 2
12 Midnight Mon 74 74 NE 5 5292 4729 129 Blue 1
1 AM Mon 73 73 NE 5 4914 4638 38 Blue 0
2 AM Mon 73 73 E 6 4914 4638 38 Blue 0
3 AM Mon 73 73 E 6 4914 4638 38 Blue 0
4 AM Mon 73 73 E 6 4914 4638 38 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