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

Station:

KVBG

Date/Time:

25 SEP 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)
5 AM Mon 52 52 E 6 2497 4600 0 Blue 0
6 AM Mon 52 52 E 6 2497 4600 0 Blue 0
7 AM Mon 53 53 E 6 2497 4600 0 Blue 0
8 AM Mon 55 55 E 5 2497 4600 0 Blue 0
9 AM Mon 59 60 E 5 5626 4600 0 Blue 1
10 AM Mon 62 65 E 5 8173 7077 2477 Blue 6
11 AM Mon 66 70 W 6 8755 8390 3790 Blue 11
12 Noon Mon 69 74 W 6 9542 8854 4254 Blue 15
1 PM Mon 70 75 W 6 9838 8970 4370 Blue 16
2 PM Mon 71 76 W 7 10137 9233 4633 Blue 17
3 PM Mon 72 76 W 7 10137 9233 4633 Blue 17
4 PM Mon 72 74 W 7 9542 8854 4254 Blue 15
5 PM Mon 70 71 W 7 8871 8506 3906 Blue 12
6 PM Mon 67 67 W 7 8406 8042 3442 Blue 8
7 PM Mon 64 64 W 7 8056 6359 1759 Blue 5
8 PM Mon 61 61 NE 5 6407 4600 0 Blue 2
9 PM Mon 59 59 NE 5 4864 4600 0 Blue 0
10 PM Mon 59 59 NE 5 4864 4600 0 Blue 0
11 PM Mon 59 59 E 8 4864 4600 0 Blue 0
12 Midnight Tue 58 58 E 8 4159 4600 0 Blue 0
1 AM Tue 57 57 E 8 3375 4600 0 Blue 0
2 AM Tue 56 56 E 8 2534 4600 0 Blue 0
3 AM Tue 56 56 E 8 2534 4600 0 Blue 0
4 AM Tue 55 55 E 8 2497 4600 0 Blue 0
5 AM Tue 55 55 NE 10 2497 4600 0 Blue 0
6 AM Tue 55 55 NE 10 2497 4600 0 Blue 0
7 AM Tue 56 56 NE 10 2534 4600 0 Blue 0
8 AM Tue 59 59 NE 8 4864 4600 0 Blue 0
9 AM Tue 63 64 NE 8 8056 6359 1759 Blue 5
10 AM Tue 68 71 NE 8 8871 8506 3906 Blue 12
11 AM Tue 72 76 SW 5 10137 9233 4633 Blue 17
12 Noon Tue 74 79 SW 5 11013 10081 5481 Blue 20
1 PM Tue 75 81 SW 5 11587 10663 6063 Blue 22
2 PM Tue 76 81 W 6 11587 10663 6063 Blue 22
3 PM Tue 76 80 W 6 11301 10374 5774 Blue 21
4 PM Tue 76 78 W 6 10723 9786 5186 Blue 19
5 PM Tue 74 75 S 5 9838 8970 4370 Blue 16
6 PM Tue 71 71 S 5 8871 8506 3906 Blue 12
7 PM Tue 67 67 S 5 8406 8042 3442 Blue 8
8 PM Tue 64 64 S 5 8056 6359 1759 Blue 5
9 PM Tue 62 62 S 5 7139 4861 261 Blue 3
10 PM Tue 62 62 S 5 7139 4861 261 Blue 3
11 PM Tue 61 61 E 9 6407 4600 0 Blue 2
12 Midnight Wed 61 61 E 9 6407 4600 0 Blue 2
1 AM Wed 60 60 E 9 5626 4600 0 Blue 1
2 AM Wed 59 59 E 9 4864 4600 0 Blue 0
3 AM Wed 58 58 E 9 4159 4600 0 Blue 0
4 AM Wed 58 58 E 9 4159 4600 0 Blue 0
5 AM Wed 57 57 NE 7 3375 4600 0 Blue 0
6 AM Wed 57 57 NE 7 3375 4600 0 Blue 0
7 AM Wed 57 57 NE 7 3375 4600 0 Blue 0
8 AM Wed 60 60 NE 7 5626 4600 0 Blue 1
9 AM Wed 64 65 NE 7 8173 7077 2477 Blue 6
10 AM Wed 69 72 NE 7 9007 8622 4022 Blue 13
11 AM Wed 73 77 SW 5 10431 9497 4897 Blue 18
12 Noon Wed 76 81 SW 5 11587 10663 6063 Blue 22
1 PM Wed 77 82 SW 5 11871 10951 6351 Blue 23
2 PM Wed 78 83 SW 5 12153 11237 6637 Blue 24
3 PM Wed 78 82 SW 5 11871 10951 6351 Blue 23
4 PM Wed 78 80 SW 5 11301 10374 5774 Blue 21
5 PM Wed 76 77 NW 5 10431 9497 4897 Blue 18
6 PM Wed 73 73 NW 5 9275 8738 4138 Blue 14
7 PM Wed 70 70 NW 5 8755 8390 3790 Blue 11
8 PM Wed 66 66 NW 5 8289 7758 3158 Blue 7
9 PM Wed 64 64 NW 5 8056 6359 1759 Blue 5
10 PM Wed 63 63 NW 5 7831 5595 995 Blue 4
11 PM Wed 63 63 E 5 7831 5595 995 Blue 4
12 Midnight Thu 62 62 E 5 7139 4861 261 Blue 3
1 AM Thu 61 61 E 5 6407 4600 0 Blue 2
2 AM Thu 61 61 E 5 6407 4600 0 Blue 2
3 AM Thu 60 60 E 5 5626 4600 0 Blue 1
4 AM Thu 59 59 E 5 4864 4600 0 Blue 0
5 AM Thu 58 58 NE 7 4159 4600 0 Blue 0
6 AM Thu 58 58 NE 7 4159 4600 0 Blue 0
7 AM Thu 59 59 NE 7 4864 4600 0 Blue 0
8 AM Thu 61 61 NE 7 6407 4600 0 Blue 2
9 AM Thu 65 66 NE 7 8289 7758 3158 Blue 7
10 AM Thu 70 73 NE 7 9275 8738 4138 Blue 14
11 AM Thu 74 78 SW 5 10723 9786 5186 Blue 19
12 Noon Thu 77 82 SW 5 11871 10951 6351 Blue 23
1 PM Thu 78 84 SW 5 12433 11520 6920 Blue 25
2 PM Thu 79 84 SW 5 12433 11520 6920 Blue 25
3 PM Thu 79 83 SW 5 12153 11237 6637 Blue 24
4 PM Thu 79 81 SW 5 11587 10663 6063 Blue 22
5 PM Thu 77 78 W 5 10723 9786 5186 Blue 19
6 PM Thu 74 74 W 5 9542 8854 4254 Blue 15
7 PM Thu 71 71 W 5 8871 8506 3906 Blue 12
8 PM Thu 67 67 W 5 8406 8042 3442 Blue 8
9 PM Thu 65 65 W 5 8173 7077 2477 Blue 6
10 PM Thu 64 64 W 5 8056 6359 1759 Blue 5
11 PM Thu 64 64 NE 5 8056 6359 1759 Blue 5
12 Midnight Fri 63 63 NE 5 7831 5595 995 Blue 4
1 AM Fri 62 62 NE 5 7139 4861 261 Blue 3
2 AM Fri 62 62 NE 5 7139 4861 261 Blue 3
3 AM Fri 61 61 NE 5 6407 4600 0 Blue 2
4 AM Fri 61 61 NE 5 6407 4600 0 Blue 2
5 AM Fri 60 60 NE 5 5626 4600 0 Blue 1
6 AM Fri 59 59 NE 5 4864 4600 0 Blue 0
7 AM Fri 59 59 NE 5 4864 4600 0 Blue 0
8 AM Fri 60 60 NE 5 5626 4600 0 Blue 1
9 AM Fri 64 65 NE 5 8173 7077 2477 Blue 6
10 AM Fri 69 72 NE 5 9007 8622 4022 Blue 13
11 AM Fri 74 78 SW 5 10723 9786 5186 Blue 19
12 Noon Fri 77 82 SW 5 11871 10951 6351 Blue 23
1 PM Fri 78 83 SW 5 12153 11237 6637 Blue 24
2 PM Fri 79 84 SW 5 12433 11520 6920 Blue 25
3 PM Fri 79 83 SW 5 12153 11237 6637 Blue 24
4 PM Fri 79 81 SW 5 11587 10663 6063 Blue 22
5 PM Fri 77 78 W 6 10723 9786 5186 Blue 19
6 PM Fri 75 75 W 6 9838 8970 4370 Blue 16
7 PM Fri 71 71 W 6 8871 8506 3906 Blue 12
8 PM Fri 67 67 W 6 8406 8042 3442 Blue 8
9 PM Fri 65 65 W 6 8173 7077 2477 Blue 6
10 PM Fri 64 64 W 6 8056 6359 1759 Blue 5
11 PM Fri 63 63 NE 3 7831 5595 995 Blue 4
12 Midnight Sat 62 62 NE 3 7139 4861 261 Blue 3
1 AM Sat 61 61 NE 3 6407 4600 0 Blue 2
2 AM Sat 61 61 NE 3 6407 4600 0 Blue 2
3 AM Sat 60 60 NE 3 5626 4600 0 Blue 1
4 AM Sat 60 60 NE 3 5626 4600 0 Blue 1
5 AM Sat 60 60 NE 5 5626 4600 0 Blue 1
6 AM Sat 59 59 NE 5 4864 4600 0 Blue 0
7 AM Sat 59 59 NE 5 4864 4600 0 Blue 0
8 AM Sat 61 61 NE 5 6407 4600 0 Blue 2
9 AM Sat 65 66 NE 5 8289 7758 3158 Blue 7
10 AM Sat 70 72 NE 5 9007 8622 4022 Blue 13
11 AM Sat 74 77 SW 5 10431 9497 4897 Blue 18
12 Noon Sat 77 81 SW 5 11587 10663 6063 Blue 22
1 PM Sat 78 83 SW 5 12153 11237 6637 Blue 24
2 PM Sat 79 83 SW 5 12153 11237 6637 Blue 24
3 PM Sat 80 83 SW 5 12153 11237 6637 Blue 24
4 PM Sat 80 82 SW 5 11871 10951 6351 Blue 23
5 PM Sat 79 80 W 6 11301 10374 5774 Blue 21
6 PM Sat 76 76 W 6 10137 9233 4633 Blue 17
7 PM Sat 72 72 W 6 9007 8622 4022 Blue 13
8 PM Sat 68 68 W 6 8522 8158 3558 Blue 9
9 PM Sat 67 67 W 6 8406 8042 3442 Blue 8
10 PM Sat 66 66 W 6 8289 7758 3158 Blue 7
11 PM Sat 66 66 E 3 8289 7758 3158 Blue 7
12 Midnight Sun 65 65 E 3 8173 7077 2477 Blue 6
1 AM Sun 65 65 E 3 8173 7077 2477 Blue 6
2 AM Sun 64 64 E 3 8056 6359 1759 Blue 5
3 AM Sun 63 63 E 3 7831 5595 995 Blue 4
4 AM Sun 62 62 E 3 7139 4861 261 Blue 3

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