Detailed Predictions for: McGee Creek
Launch Altitude (f): 9082
LZ Altitude (f): 7122
Sounding

Station:

KVBG

Date/Time:

18 AUG 2018

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 Sat 49 49 N 3 5092 9082 0 Blue 0
6 AM Sat 51 51 N 3 5092 9082 0 Blue 0
7 AM Sat 54 54 N 3 5092 9082 0 Blue 0
8 AM Sat 59 60 N 3 11307 9082 0 Blue 2
9 AM Sat 63 65 N 3 13726 12554 3472 Blue 7
10 AM Sat 66 70 N 3 15686 14461 5379 Blue 12
11 AM Sat 69 74 E 3 16751 15979 6897 White 16
12 Noon Sat 71 77 E 3 17400 17058 7976 White 19
1 PM Sat 72 79 E 3 17827 17357 8275 White 21
2 PM Sat 73 80 E 2 18040 17506 8424 White 22
3 PM Sat 74 79 E 2 17827 17357 8275 White 21
4 PM Sat 74 78 E 2 17615 17208 8126 White 20
5 PM Sat 73 75 NW 3 16968 16345 7263 White 17
6 PM Sat 72 73 NW 3 16533 15607 6525 White 15
7 PM Sat 70 70 NW 3 15686 14461 5379 Blue 12
8 PM Sat 67 67 NW 5 14528 13260 4178 Blue 9
9 PM Sat 64 64 NW 5 13314 11923 2841 Blue 6
10 PM Sat 61 61 NW 5 11980 9980 898 Blue 3
11 PM Sat 59 59 N 2 10557 9082 0 Blue 1
12 Midnight Sun 57 57 N 2 8985 9082 0 Blue 0
1 AM Sun 55 55 N 2 5092 9082 0 Blue 0
2 AM Sun 54 54 N 2 5092 9082 0 Blue 0
3 AM Sun 52 52 N 2 5092 9082 0 Blue 0
4 AM Sun 51 51 N 2 5092 9082 0 Blue 0
5 AM Sun 51 51 S 2 5092 9082 0 Blue 0
6 AM Sun 53 53 S 2 5092 9082 0 Blue 0
7 AM Sun 56 56 S 2 7414 9082 0 Blue 0
8 AM Sun 61 62 S 2 12622 10527 1445 Blue 4
9 AM Sun 65 67 S 2 14528 13260 4178 Blue 9
10 AM Sun 68 72 S 2 16317 15231 6149 White 14
11 AM Sun 71 76 SE 6 17184 16707 7625 White 18
12 Noon Sun 73 79 SE 6 17827 17357 8275 White 21
1 PM Sun 74 80 SE 6 18040 17506 8424 White 22
2 PM Sun 74 80 S 8 18040 17506 8424 White 22
3 PM Sun 74 79 S 8 17827 17357 8275 White 21
4 PM Sun 74 77 S 8 17400 17058 7976 White 19
5 PM Sun 73 75 SW 9 16968 16345 7263 White 17
6 PM Sun 72 72 SW 9 16317 15231 6149 White 14
7 PM Sun 70 70 SW 9 15686 14461 5379 Blue 12
8 PM Sun 68 68 SW 9 14920 13667 4585 Blue 10
9 PM Sun 64 64 SW 9 13314 11923 2841 Blue 6
10 PM Sun 61 61 SW 9 11980 9980 898 Blue 3
11 PM Sun 58 58 SW 7 9994 9082 0 Blue 0
12 Midnight Mon 57 57 SW 7 8985 9082 0 Blue 0
1 AM Mon 56 56 SW 7 7414 9082 0 Blue 0
2 AM Mon 55 55 SW 7 5092 9082 0 Blue 0
3 AM Mon 53 53 SW 7 5092 9082 0 Blue 0
4 AM Mon 51 51 SW 7 5092 9082 0 Blue 0
5 AM Mon 51 51 SW 5 5092 9082 0 Blue 0
6 AM Mon 53 53 SW 5 5092 9082 0 Blue 0
7 AM Mon 57 57 SW 5 8985 9082 0 Blue 0
8 AM Mon 62 62 SW 5 12622 10527 1445 Blue 4
9 AM Mon 66 68 SW 5 14920 13667 4585 Blue 10
10 AM Mon 70 74 SW 5 16751 15979 6897 White 16
11 AM Mon 72 77 SW 12 17400 17058 7976 White 19
12 Noon Mon 74 80 SW 12 18040 17506 8424 White 22
1 PM Mon 74 80 SW 12 18040 17506 8424 White 22
2 PM Mon 74 80 SW 12 18040 17506 8424 White 22
3 PM Mon 74 79 SW 12 17827 17357 8275 White 21
4 PM Mon 73 77 SW 12 17400 17058 7976 White 19
5 PM Mon 72 74 SW 15 16751 15979 6897 White 16
6 PM Mon 70 71 SW 15 16062 14849 5767 Blue 13
7 PM Mon 68 68 SW 15 14920 13667 4585 Blue 10
8 PM Mon 65 65 SW 15 13726 12554 3472 Blue 7
9 PM Mon 62 62 SW 15 12622 10527 1445 Blue 4
10 PM Mon 59 59 SW 15 10557 9082 0 Blue 1
11 PM Mon 56 56 SW 6 7414 9082 0 Blue 0
12 Midnight Tue 54 54 SW 6 5092 9082 0 Blue 0
1 AM Tue 53 53 SW 6 5092 9082 0 Blue 0
2 AM Tue 52 52 SW 6 5092 9082 0 Blue 0
3 AM Tue 50 50 SW 6 5092 9082 0 Blue 0
4 AM Tue 49 49 SW 6 5092 9082 0 Blue 0
5 AM Tue 49 49 SW 5 5092 9082 0 Blue 0
6 AM Tue 51 51 SW 5 5092 9082 0 Blue 0
7 AM Tue 54 54 SW 5 5092 9082 0 Blue 0
8 AM Tue 58 58 SW 5 9994 9082 0 Blue 0
9 AM Tue 62 64 SW 5 13314 11923 2841 Blue 6
10 AM Tue 66 70 SW 5 15686 14461 5379 Blue 12
11 AM Tue 70 75 S 7 16968 16345 7263 White 17
12 Noon Tue 73 79 S 7 17827 17357 8275 White 21
1 PM Tue 76 83 S 7 18690 18007 8925 White 25
2 PM Tue 76 82 S 7 18474 17771 8689 White 24
3 PM Tue 74 79 S 7 17827 17357 8275 White 21
4 PM Tue 72 76 S 7 17184 16707 7625 White 18
5 PM Tue 69 71 S 10 16062 14849 5767 Blue 13
6 PM Tue 68 69 S 10 15306 14067 4985 Blue 11
7 PM Tue 66 66 S 10 14130 12982 3900 Blue 8
8 PM Tue 65 65 S 10 13726 12554 3472 Blue 7
9 PM Tue 62 62 S 10 12622 10527 1445 Blue 4
10 PM Tue 59 59 S 10 10557 9082 0 Blue 1
11 PM Tue 56 56 SW 5 7414 9082 0 Blue 0
12 Midnight Wed 54 54 SW 5 5092 9082 0 Blue 0
1 AM Wed 52 52 SW 5 5092 9082 0 Blue 0
2 AM Wed 51 51 SW 5 5092 9082 0 Blue 0
3 AM Wed 50 50 SW 5 5092 9082 0 Blue 0
4 AM Wed 49 49 SW 5 5092 9082 0 Blue 0
5 AM Wed 49 49 SW 3 5092 9082 0 Blue 0
6 AM Wed 51 51 SW 3 5092 9082 0 Blue 0
7 AM Wed 54 54 SW 3 5092 9082 0 Blue 0
8 AM Wed 58 58 SW 3 9994 9082 0 Blue 0
9 AM Wed 62 64 SW 3 13314 11923 2841 Blue 6
10 AM Wed 66 69 SW 3 15306 14067 4985 Blue 11
11 AM Wed 70 75 S 6 16968 16345 7263 White 17
12 Noon Wed 73 79 S 6 17827 17357 8275 White 21
1 PM Wed 75 81 S 6 18256 17650 8568 White 23
2 PM Wed 76 82 S 6 18474 17771 8689 White 24
3 PM Wed 75 80 S 6 18040 17506 8424 White 22
4 PM Wed 72 75 S 6 16968 16345 7263 White 17
5 PM Wed 70 72 SW 8 16317 15231 6149 White 14
6 PM Wed 68 68 SW 8 14920 13667 4585 Blue 10
7 PM Wed 67 67 SW 8 14528 13260 4178 Blue 9
8 PM Wed 65 65 SW 8 13726 12554 3472 Blue 7
9 PM Wed 62 62 SW 8 12622 10527 1445 Blue 4
10 PM Wed 59 59 SW 8 10557 9082 0 Blue 1
11 PM Wed 56 56 SW 5 7414 9082 0 Blue 0
12 Midnight Thu 54 54 SW 5 5092 9082 0 Blue 0
1 AM Thu 52 52 SW 5 5092 9082 0 Blue 0
2 AM Thu 50 50 SW 5 5092 9082 0 Blue 0
3 AM Thu 49 49 SW 5 5092 9082 0 Blue 0
4 AM Thu 48 48 SW 5 5092 9082 0 Blue 0
5 AM Thu 48 48 SW 3 5092 9082 0 Blue 0
6 AM Thu 50 50 SW 3 5092 9082 0 Blue 0
7 AM Thu 53 53 SW 3 5092 9082 0 Blue 0
8 AM Thu 57 57 SW 3 8985 9082 0 Blue 0
9 AM Thu 62 64 SW 3 13314 11923 2841 Blue 6
10 AM Thu 67 70 SW 3 15686 14461 5379 Blue 12
11 AM Thu 71 76 SW 6 17184 16707 7625 White 18
12 Noon Thu 74 80 SW 6 18040 17506 8424 White 22
1 PM Thu 76 82 SW 6 18474 17771 8689 White 24
2 PM Thu 76 82 SW 6 18474 17771 8689 White 24
3 PM Thu 75 80 SW 6 18040 17506 8424 White 22
4 PM Thu 73 76 SW 6 17184 16707 7625 White 18
5 PM Thu 71 73 SW 8 16533 15607 6525 White 15
6 PM Thu 69 69 SW 8 15306 14067 4985 Blue 11
7 PM Thu 67 67 SW 8 14528 13260 4178 Blue 9
8 PM Thu 65 65 SW 8 13726 12554 3472 Blue 7
9 PM Thu 62 62 SW 8 12622 10527 1445 Blue 4
10 PM Thu 59 59 SW 8 10557 9082 0 Blue 1
11 PM Thu 56 56 SW 3 7414 9082 0 Blue 0
12 Midnight Fri 54 54 SW 3 5092 9082 0 Blue 0
1 AM Fri 52 52 SW 3 5092 9082 0 Blue 0
2 AM Fri 50 50 SW 3 5092 9082 0 Blue 0
3 AM Fri 49 49 SW 3 5092 9082 0 Blue 0
4 AM Fri 48 48 SW 3 5092 9082 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