Detailed Predictions for: Boomer Ridge
Launch Altitude (f): 5833
LZ Altitude (f): 4093
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 51 51 S 8 4885 5833 0 Blue 0
6 AM Mon 51 51 S 8 4885 5833 0 Blue 0
7 AM Mon 53 53 S 8 4885 5833 0 Blue 0
8 AM Mon 55 55 N 20 4885 5833 0 Blue 0
9 AM Mon 58 59 N 20 7275 5833 0 Blue 0
10 AM Mon 61 64 N 20 8433 8069 2236 Blue 4
11 AM Mon 64 68 NE 20 8902 8536 2703 Blue 8
12 Noon Mon 66 71 NE 20 9624 8887 3054 Blue 11
1 PM Mon 68 74 NE 20 10522 9578 3745 Blue 14
2 PM Mon 69 74 NE 12 10522 9578 3745 Blue 14
3 PM Mon 69 73 NE 12 10226 9311 3478 Blue 13
4 PM Mon 69 71 NE 12 9624 8887 3054 Blue 11
5 PM Mon 68 69 NE 12 9079 8653 2820 Blue 9
6 PM Mon 66 66 NE 12 8667 8303 2470 Blue 6
7 PM Mon 64 64 NE 12 8433 8069 2236 Blue 4
8 PM Mon 62 62 SE 9 8198 7223 1390 Blue 2
9 PM Mon 60 60 SE 9 7963 5833 0 Blue 0
10 PM Mon 60 60 SE 9 7963 5833 0 Blue 0
11 PM Mon 59 59 S 15 7275 5833 0 Blue 0
12 Midnight Tue 59 59 S 15 7275 5833 0 Blue 0
1 AM Tue 58 58 S 15 6541 5833 0 Blue 0
2 AM Tue 58 58 NE 13 6541 5833 0 Blue 0
3 AM Tue 57 57 NE 13 5760 5833 0 Blue 0
4 AM Tue 56 56 NE 13 4919 5833 0 Blue 0
5 AM Tue 56 56 NE 12 4919 5833 0 Blue 0
6 AM Tue 56 56 NE 12 4919 5833 0 Blue 0
7 AM Tue 57 57 NE 12 5760 5833 0 Blue 0
8 AM Tue 59 59 N 20 7275 5833 0 Blue 0
9 AM Tue 62 63 N 20 8315 7904 2071 Blue 3
10 AM Tue 65 68 N 20 8902 8536 2703 Blue 8
11 AM Tue 68 72 NE 21 9926 9043 3210 Blue 12
12 Noon Tue 70 76 NE 21 11108 10176 4343 Blue 16
1 PM Tue 71 77 NE 21 11398 10469 4636 Blue 16
2 PM Tue 72 77 NE 18 11398 10469 4636 Blue 16
3 PM Tue 72 76 NE 18 11108 10176 4343 Blue 16
4 PM Tue 72 74 NE 18 10522 9578 3745 Blue 14
5 PM Tue 70 71 N 12 9624 8887 3054 Blue 11
6 PM Tue 68 68 N 12 8902 8536 2703 Blue 8
7 PM Tue 66 66 N 12 8667 8303 2470 Blue 6
8 PM Tue 64 64 N 12 8433 8069 2236 Blue 4
9 PM Tue 63 63 N 12 8315 7904 2071 Blue 3
10 PM Tue 62 62 N 12 8198 7223 1390 Blue 2
11 PM Tue 62 62 N 15 8198 7223 1390 Blue 2
12 Midnight Wed 61 61 N 15 8081 6504 671 Blue 1
1 AM Wed 61 61 N 15 8081 6504 671 Blue 1
2 AM Wed 60 60 N 15 7963 5833 0 Blue 0
3 AM Wed 59 59 N 15 7275 5833 0 Blue 0
4 AM Wed 59 59 N 15 7275 5833 0 Blue 0
5 AM Wed 58 58 N 13 6541 5833 0 Blue 0
6 AM Wed 58 58 N 13 6541 5833 0 Blue 0
7 AM Wed 59 59 N 13 7275 5833 0 Blue 0
8 AM Wed 61 61 N 13 8081 6504 671 Blue 1
9 AM Wed 64 65 N 13 8550 8186 2353 Blue 5
10 AM Wed 67 70 N 13 9349 8770 2937 Blue 10
11 AM Wed 70 74 NE 12 10522 9578 3745 Blue 14
12 Noon Wed 71 76 NE 12 11108 10176 4343 Blue 16
1 PM Wed 73 79 NE 12 11971 11050 5217 Blue 18
2 PM Wed 73 78 NE 12 11686 10761 4928 Blue 17
3 PM Wed 74 78 NE 12 11686 10761 4928 Blue 17
4 PM Wed 74 76 NE 12 11108 10176 4343 Blue 16
5 PM Wed 73 74 E 8 10522 9578 3745 Blue 14
6 PM Wed 71 71 E 8 9624 8887 3054 Blue 11
7 PM Wed 69 69 E 8 9079 8653 2820 Blue 9
8 PM Wed 66 66 E 8 8667 8303 2470 Blue 6
9 PM Wed 65 65 E 8 8550 8186 2353 Blue 5
10 PM Wed 64 64 E 8 8433 8069 2236 Blue 4
11 PM Wed 63 63 S 6 8315 7904 2071 Blue 3
12 Midnight Thu 62 62 S 6 8198 7223 1390 Blue 2
1 AM Thu 61 61 S 6 8081 6504 671 Blue 1
2 AM Thu 61 61 S 6 8081 6504 671 Blue 1
3 AM Thu 60 60 S 6 7963 5833 0 Blue 0
4 AM Thu 59 59 S 6 7275 5833 0 Blue 0
5 AM Thu 59 59 N 8 7275 5833 0 Blue 0
6 AM Thu 59 59 N 8 7275 5833 0 Blue 0
7 AM Thu 60 60 N 8 7963 5833 0 Blue 0
8 AM Thu 61 61 N 8 8081 6504 671 Blue 1
9 AM Thu 64 65 N 8 8550 8186 2353 Blue 5
10 AM Thu 67 70 N 8 9349 8770 2937 Blue 10
11 AM Thu 70 74 E 6 10522 9578 3745 Blue 14
12 Noon Thu 72 77 E 6 11398 10469 4636 Blue 16
1 PM Thu 73 79 E 6 11971 11050 5217 Blue 18
2 PM Thu 74 79 E 6 11971 11050 5217 Blue 18
3 PM Thu 75 79 E 6 11971 11050 5217 Blue 18
4 PM Thu 75 77 E 6 11398 10469 4636 Blue 16
5 PM Thu 74 75 SE 7 10816 9878 4045 Blue 15
6 PM Thu 72 72 SE 7 9926 9043 3210 Blue 12
7 PM Thu 69 69 SE 7 9079 8653 2820 Blue 9
8 PM Thu 67 67 SE 7 8784 8419 2586 Blue 7
9 PM Thu 65 65 SE 7 8550 8186 2353 Blue 5
10 PM Thu 64 64 SE 7 8433 8069 2236 Blue 4
11 PM Thu 64 64 NW 6 8433 8069 2236 Blue 4
12 Midnight Fri 63 63 NW 6 8315 7904 2071 Blue 3
1 AM Fri 62 62 NW 6 8198 7223 1390 Blue 2
2 AM Fri 61 61 NW 6 8081 6504 671 Blue 1
3 AM Fri 61 61 NW 6 8081 6504 671 Blue 1
4 AM Fri 60 60 NW 6 7963 5833 0 Blue 0
5 AM Fri 60 60 N 7 7963 5833 0 Blue 0
6 AM Fri 60 60 N 7 7963 5833 0 Blue 0
7 AM Fri 61 61 N 7 8081 6504 671 Blue 1
8 AM Fri 62 62 N 7 8198 7223 1390 Blue 2
9 AM Fri 65 66 N 7 8667 8303 2470 Blue 6
10 AM Fri 68 71 N 7 9624 8887 3054 Blue 11
11 AM Fri 71 75 E 6 10816 9878 4045 Blue 15
12 Noon Fri 74 79 E 6 11971 11050 5217 Blue 18
1 PM Fri 75 81 E 6 12537 11623 5790 Blue 20
2 PM Fri 76 81 E 6 12537 11623 5790 Blue 20
3 PM Fri 77 81 E 6 12537 11623 5790 Blue 20
4 PM Fri 77 79 E 6 11971 11050 5217 Blue 18
5 PM Fri 76 77 S 6 11398 10469 4636 Blue 16
6 PM Fri 73 73 S 6 10226 9311 3478 Blue 13
7 PM Fri 70 70 S 6 9349 8770 2937 Blue 10
8 PM Fri 68 68 S 6 8902 8536 2703 Blue 8
9 PM Fri 66 66 S 6 8667 8303 2470 Blue 6
10 PM Fri 65 65 S 6 8550 8186 2353 Blue 5
11 PM Fri 64 64 NW 7 8433 8069 2236 Blue 4
12 Midnight Sat 64 64 NW 7 8433 8069 2236 Blue 4
1 AM Sat 63 63 NW 7 8315 7904 2071 Blue 3
2 AM Sat 63 63 NW 7 8315 7904 2071 Blue 3
3 AM Sat 62 62 NW 7 8198 7223 1390 Blue 2
4 AM Sat 61 61 NW 7 8081 6504 671 Blue 1
5 AM Sat 61 61 NW 7 8081 6504 671 Blue 1
6 AM Sat 61 61 NW 7 8081 6504 671 Blue 1
7 AM Sat 62 62 NW 7 8198 7223 1390 Blue 2
8 AM Sat 63 63 NW 7 8315 7904 2071 Blue 3
9 AM Sat 66 67 NW 7 8784 8419 2586 Blue 7
10 AM Sat 70 73 NW 7 10226 9311 3478 Blue 13
11 AM Sat 73 77 E 6 11398 10469 4636 Blue 16
12 Noon Sat 75 80 E 6 12255 11338 5505 Blue 19
1 PM Sat 77 83 E 6 13165 12188 6355 Blue 22
2 PM Sat 77 82 E 6 12817 11906 6073 Blue 21
3 PM Sat 78 82 E 6 12817 11906 6073 Blue 21
4 PM Sat 78 80 E 6 12255 11338 5505 Blue 19
5 PM Sat 77 78 S 7 11686 10761 4928 Blue 17
6 PM Sat 74 74 S 7 10522 9578 3745 Blue 14
7 PM Sat 71 71 S 7 9624 8887 3054 Blue 11
8 PM Sat 69 69 S 7 9079 8653 2820 Blue 9
9 PM Sat 68 68 S 7 8902 8536 2703 Blue 8
10 PM Sat 67 67 S 7 8784 8419 2586 Blue 7
11 PM Sat 67 67 NW 6 8784 8419 2586 Blue 7
12 Midnight Sun 66 66 NW 6 8667 8303 2470 Blue 6
1 AM Sun 65 65 NW 6 8550 8186 2353 Blue 5
2 AM Sun 64 64 NW 6 8433 8069 2236 Blue 4
3 AM Sun 63 63 NW 6 8315 7904 2071 Blue 3
4 AM Sun 62 62 NW 6 8198 7223 1390 Blue 2

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