Detailed Predictions for: McGee Creek
Launch Altitude (f): 9082
LZ Altitude (f): 7122
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 28 28 N 6 8973 9082 0 Blue 0
6 AM Mon 28 28 N 6 8973 9082 0 Blue 0
7 AM Mon 29 29 N 6 8973 9082 0 Blue 0
8 AM Mon 32 32 N 6 8973 9082 0 Blue 0
9 AM Mon 36 37 N 6 8973 9082 0 Blue 0
10 AM Mon 41 43 N 6 8973 9082 0 Blue 0
11 AM Mon 45 49 N 7 9904 9082 0 Blue 1
12 Noon Mon 48 53 N 7 11160 10212 1130 Blue 5
1 PM Mon 50 55 N 7 11773 10833 1751 Blue 7
2 PM Mon 51 55 NE 7 11773 10833 1751 Blue 7
3 PM Mon 53 56 NE 7 12075 11140 2058 Blue 8
4 PM Mon 54 56 NE 7 12075 11140 2058 Blue 8
5 PM Mon 53 54 N 10 11467 10524 1442 Blue 6
6 PM Mon 50 50 N 10 10223 9294 212 Blue 2
7 PM Mon 46 46 N 10 9009 9082 0 Blue 0
8 PM Mon 42 42 N 9 8973 9082 0 Blue 0
9 PM Mon 39 39 N 9 8973 9082 0 Blue 0
10 PM Mon 37 37 N 9 8973 9082 0 Blue 0
11 PM Mon 36 36 N 6 8973 9082 0 Blue 0
12 Midnight Tue 33 33 N 6 8973 9082 0 Blue 0
1 AM Tue 31 31 N 6 8973 9082 0 Blue 0
2 AM Tue 30 30 N 7 8973 9082 0 Blue 0
3 AM Tue 29 29 N 7 8973 9082 0 Blue 0
4 AM Tue 29 29 N 7 8973 9082 0 Blue 0
5 AM Tue 30 30 N 7 8973 9082 0 Blue 0
6 AM Tue 30 30 N 7 8973 9082 0 Blue 0
7 AM Tue 31 31 N 7 8973 9082 0 Blue 0
8 AM Tue 33 33 N 6 8973 9082 0 Blue 0
9 AM Tue 37 38 N 6 8973 9082 0 Blue 0
10 AM Tue 42 44 N 6 8973 9082 0 Blue 0
11 AM Tue 47 51 N 8 10538 9578 496 Blue 3
12 Noon Tue 50 55 N 8 11773 10833 1751 Blue 7
1 PM Tue 53 58 N 8 12674 11747 2665 Blue 10
2 PM Tue 55 60 NE 9 13835 12345 3263 Blue 12
3 PM Tue 56 59 NE 9 12971 12047 2965 Blue 11
4 PM Tue 57 59 NE 9 12971 12047 2965 Blue 11
5 PM Tue 56 57 NE 9 12376 11445 2363 Blue 9
6 PM Tue 53 53 NE 9 11160 10212 1130 Blue 5
7 PM Tue 48 48 NE 9 9583 9082 0 Blue 0
8 PM Tue 45 45 NE 9 8973 9082 0 Blue 0
9 PM Tue 42 42 NE 9 8973 9082 0 Blue 0
10 PM Tue 41 41 NE 9 8973 9082 0 Blue 0
11 PM Tue 40 40 NE 5 8973 9082 0 Blue 0
12 Midnight Wed 38 38 NE 5 8973 9082 0 Blue 0
1 AM Wed 36 36 NE 5 8973 9082 0 Blue 0
2 AM Wed 34 34 NE 5 8973 9082 0 Blue 0
3 AM Wed 33 33 NE 5 8973 9082 0 Blue 0
4 AM Wed 33 33 NE 5 8973 9082 0 Blue 0
5 AM Wed 33 33 NE 3 8973 9082 0 Blue 0
6 AM Wed 34 34 NE 3 8973 9082 0 Blue 0
7 AM Wed 35 35 NE 3 8973 9082 0 Blue 0
8 AM Wed 37 37 NE 3 8973 9082 0 Blue 0
9 AM Wed 42 43 NE 3 8973 9082 0 Blue 0
10 AM Wed 47 49 NE 3 9904 9082 0 Blue 1
11 AM Wed 52 56 NE 6 12075 11140 2058 Blue 8
12 Noon Wed 55 60 NE 6 13835 12345 3263 Blue 12
1 PM Wed 56 61 NE 6 14890 12641 3559 Blue 13
2 PM Wed 57 61 NE 6 14890 12641 3559 Blue 13
3 PM Wed 58 61 NE 6 14890 12641 3559 Blue 13
4 PM Wed 59 61 NE 6 14890 12641 3559 Blue 13
5 PM Wed 58 59 E 7 12971 12047 2965 Blue 11
6 PM Wed 56 56 E 7 12075 11140 2058 Blue 8
7 PM Wed 52 52 E 7 10850 9896 814 Blue 4
8 PM Wed 48 48 E 7 9583 9082 0 Blue 0
9 PM Wed 46 46 E 7 9009 9082 0 Blue 0
10 PM Wed 44 44 E 7 8973 9082 0 Blue 0
11 PM Wed 43 43 SE 3 8973 9082 0 Blue 0
12 Midnight Thu 41 41 SE 3 8973 9082 0 Blue 0
1 AM Thu 39 39 SE 3 8973 9082 0 Blue 0
2 AM Thu 37 37 SE 3 8973 9082 0 Blue 0
3 AM Thu 36 36 SE 3 8973 9082 0 Blue 0
4 AM Thu 35 35 SE 3 8973 9082 0 Blue 0
5 AM Thu 35 35 E 3 8973 9082 0 Blue 0
6 AM Thu 36 36 E 3 8973 9082 0 Blue 0
7 AM Thu 38 38 E 3 8973 9082 0 Blue 0
8 AM Thu 41 41 E 3 8973 9082 0 Blue 0
9 AM Thu 45 46 E 3 9009 9082 0 Blue 0
10 AM Thu 49 51 E 3 10538 9578 496 Blue 3
11 AM Thu 53 57 SE 5 12376 11445 2363 Blue 9
12 Noon Thu 57 62 SE 5 15786 12935 3853 Blue 14
1 PM Thu 59 64 SE 5 16697 14686 5604 Blue 16
2 PM Thu 60 65 SE 5 17137 15685 6603 Blue 17
3 PM Thu 61 64 SE 5 16697 14686 5604 Blue 16
4 PM Thu 60 62 SE 5 15786 12935 3853 Blue 14
5 PM Thu 58 59 N 5 12971 12047 2965 Blue 11
6 PM Thu 55 55 N 5 11773 10833 1751 Blue 7
7 PM Thu 51 51 N 5 10538 9578 496 Blue 3
8 PM Thu 48 48 N 5 9583 9082 0 Blue 0
9 PM Thu 46 46 N 5 9009 9082 0 Blue 0
10 PM Thu 44 44 N 5 8973 9082 0 Blue 0
11 PM Thu 43 43 SE 5 8973 9082 0 Blue 0
12 Midnight Fri 41 41 SE 5 8973 9082 0 Blue 0
1 AM Fri 39 39 SE 5 8973 9082 0 Blue 0
2 AM Fri 37 37 SE 5 8973 9082 0 Blue 0
3 AM Fri 36 36 SE 5 8973 9082 0 Blue 0
4 AM Fri 36 36 SE 5 8973 9082 0 Blue 0
5 AM Fri 37 37 S 3 8973 9082 0 Blue 0
6 AM Fri 38 38 S 3 8973 9082 0 Blue 0
7 AM Fri 39 39 S 3 8973 9082 0 Blue 0
8 AM Fri 42 42 S 3 8973 9082 0 Blue 0
9 AM Fri 46 47 S 3 9296 9082 0 Blue 0
10 AM Fri 50 52 S 3 10850 9896 814 Blue 4
11 AM Fri 55 58 S 3 12674 11747 2665 Blue 10
12 Noon Fri 58 62 S 3 15786 12935 3853 Blue 14
1 PM Fri 61 65 S 3 17137 15685 6603 Blue 17
2 PM Fri 62 66 S 3 17569 16141 7059 Blue 18
3 PM Fri 63 66 S 3 17569 16141 7059 Blue 18
4 PM Fri 63 65 S 3 17137 15685 6603 Blue 17
5 PM Fri 61 61 W 5 14890 12641 3559 Blue 13
6 PM Fri 58 58 W 5 12674 11747 2665 Blue 10
7 PM Fri 54 54 W 5 11467 10524 1442 Blue 6
8 PM Fri 50 50 W 5 10223 9294 212 Blue 2
9 PM Fri 48 48 W 5 9583 9082 0 Blue 0
10 PM Fri 47 47 W 5 9296 9082 0 Blue 0
11 PM Fri 45 45 S 3 8973 9082 0 Blue 0
12 Midnight Sat 43 43 S 3 8973 9082 0 Blue 0
1 AM Sat 41 41 S 3 8973 9082 0 Blue 0
2 AM Sat 39 39 S 3 8973 9082 0 Blue 0
3 AM Sat 37 37 S 3 8973 9082 0 Blue 0
4 AM Sat 37 37 S 3 8973 9082 0 Blue 0
5 AM Sat 37 37 SW 3 8973 9082 0 Blue 0
6 AM Sat 39 39 SW 3 8973 9082 0 Blue 0
7 AM Sat 41 41 SW 3 8973 9082 0 Blue 0
8 AM Sat 44 44 SW 3 8973 9082 0 Blue 0
9 AM Sat 48 49 SW 3 9904 9082 0 Blue 1
10 AM Sat 53 55 SW 3 11773 10833 1751 Blue 7
11 AM Sat 57 60 SE 5 13835 12345 3263 Blue 12
12 Noon Sat 60 64 SE 5 16697 14686 5604 Blue 16
1 PM Sat 62 66 SE 5 17569 16141 7059 Blue 18
2 PM Sat 63 67 SE 5 17992 16587 7505 Blue 19
3 PM Sat 64 67 SE 5 17992 16587 7505 Blue 19
4 PM Sat 64 66 SE 5 17569 16141 7059 Blue 18
5 PM Sat 62 63 NW 7 16246 13673 4591 Blue 15
6 PM Sat 58 58 NW 7 12674 11747 2665 Blue 10
7 PM Sat 54 54 NW 7 11467 10524 1442 Blue 6
8 PM Sat 50 50 NW 7 10223 9294 212 Blue 2
9 PM Sat 48 48 NW 7 9583 9082 0 Blue 0
10 PM Sat 47 47 NW 7 9296 9082 0 Blue 0
11 PM Sat 46 46 N 5 9009 9082 0 Blue 0
12 Midnight Sun 44 44 N 5 8973 9082 0 Blue 0
1 AM Sun 41 41 N 5 8973 9082 0 Blue 0
2 AM Sun 39 39 N 5 8973 9082 0 Blue 0
3 AM Sun 38 38 N 5 8973 9082 0 Blue 0
4 AM Sun 38 38 N 5 8973 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