Detailed Predictions for: Mt Vaca
Launch Altitude (f): 2821
LZ Altitude (f): 2000
Sounding

Station:

KOAK

Date/Time:

20 OCT 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 Sun 55 55 N 13 2441 2821 0 Blue 0
6 AM Sun 54 54 N 13 2441 2821 0 Blue 0
7 AM Sun 53 53 N 13 2441 2821 0 Blue 0
8 AM Sun 53 53 NW 9 2441 2821 0 Blue 0
9 AM Sun 56 56 NW 9 2441 2821 0 Blue 0
10 AM Sun 58 59 NW 9 3207 2821 0 Blue 2
11 AM Sun 59 61 NW 13 4558 2897 76 Blue 4
12 Noon Sun 61 64 NW 13 5531 4530 1709 Blue 7
1 PM Sun 63 66 NW 13 6144 5176 2355 Blue 9
2 PM Sun 64 67 NW 14 6446 5500 2679 Blue 10
3 PM Sun 66 68 NW 14 6768 5809 2988 Blue 11
4 PM Sun 66 67 NW 14 6446 5500 2679 Blue 10
5 PM Sun 65 65 W 13 5840 4893 2072 Blue 8
6 PM Sun 63 63 W 13 5203 3502 681 Blue 6
7 PM Sun 62 62 W 13 4918 3201 380 Blue 5
8 PM Sun 61 61 NW 9 4558 2897 76 Blue 4
9 PM Sun 60 60 NW 9 3590 2821 0 Blue 3
10 PM Sun 60 60 NW 9 3590 2821 0 Blue 3
11 PM Sun 60 60 NW 8 3590 2821 0 Blue 3
12 Midnight Mon 59 59 NW 8 3207 2821 0 Blue 2
1 AM Mon 59 59 NW 8 3207 2821 0 Blue 2
2 AM Mon 59 59 NW 12 3207 2821 0 Blue 2
3 AM Mon 58 58 NW 12 2900 2821 0 Blue 1
4 AM Mon 58 58 NW 12 2900 2821 0 Blue 1
5 AM Mon 57 57 NW 14 2441 2821 0 Blue 0
6 AM Mon 57 57 NW 14 2441 2821 0 Blue 0
7 AM Mon 56 56 NW 14 2441 2821 0 Blue 0
8 AM Mon 56 56 N 17 2441 2821 0 Blue 0
9 AM Mon 60 60 N 17 3590 2821 0 Blue 3
10 AM Mon 62 63 N 17 5203 3502 681 Blue 6
11 AM Mon 64 67 N 21 6446 5500 2679 Blue 10
12 Noon Mon 66 69 N 21 7170 6110 3289 Blue 12
1 PM Mon 69 73 N 21 7830 7310 4489 Blue 16
2 PM Mon 72 75 N 16 8158 7638 4817 Blue 18
3 PM Mon 73 76 N 16 8530 7801 4980 Blue 19
4 PM Mon 73 74 N 16 7994 7474 4653 Blue 17
5 PM Mon 72 72 N 15 7665 7146 4325 Blue 15
6 PM Mon 69 69 N 15 7170 6110 3289 Blue 12
7 PM Mon 68 68 N 15 6768 5809 2988 Blue 11
8 PM Mon 66 66 NW 10 6144 5176 2355 Blue 9
9 PM Mon 65 65 NW 10 5840 4893 2072 Blue 8
10 PM Mon 65 65 NW 10 5840 4893 2072 Blue 8
11 PM Mon 64 64 NW 14 5531 4530 1709 Blue 7
12 Midnight Tue 63 63 NW 14 5203 3502 681 Blue 6
1 AM Tue 62 62 NW 14 4918 3201 380 Blue 5
2 AM Tue 63 63 N 14 5203 3502 681 Blue 6
3 AM Tue 62 62 N 14 4918 3201 380 Blue 5
4 AM Tue 61 61 N 14 4558 2897 76 Blue 4
5 AM Tue 60 60 N 14 3590 2821 0 Blue 3
6 AM Tue 59 59 N 14 3207 2821 0 Blue 2
7 AM Tue 58 58 N 14 2900 2821 0 Blue 1
8 AM Tue 58 58 N 9 2900 2821 0 Blue 1
9 AM Tue 62 62 N 9 4918 3201 380 Blue 5
10 AM Tue 64 65 N 9 5840 4893 2072 Blue 8
11 AM Tue 66 69 N 13 7170 6110 3289 Blue 12
12 Noon Tue 68 71 N 13 7500 6705 3884 Blue 14
1 PM Tue 71 75 N 13 8158 7638 4817 Blue 18
2 PM Tue 73 76 N 13 8530 7801 4980 Blue 19
3 PM Tue 75 78 N 13 9269 8128 5307 Blue 21
4 PM Tue 75 76 N 13 8530 7801 4980 Blue 19
5 PM Tue 74 74 N 10 7994 7474 4653 Blue 17
6 PM Tue 71 71 N 10 7500 6705 3884 Blue 14
7 PM Tue 70 70 N 10 7336 6408 3587 Blue 13
8 PM Tue 69 69 W 7 7170 6110 3289 Blue 12
9 PM Tue 67 67 W 7 6446 5500 2679 Blue 10
10 PM Tue 67 67 W 7 6446 5500 2679 Blue 10
11 PM Tue 67 67 N 9 6446 5500 2679 Blue 10
12 Midnight Wed 66 66 N 9 6144 5176 2355 Blue 9
1 AM Wed 65 65 N 9 5840 4893 2072 Blue 8
2 AM Wed 65 65 N 16 5840 4893 2072 Blue 8
3 AM Wed 64 64 N 16 5531 4530 1709 Blue 7
4 AM Wed 64 64 N 16 5531 4530 1709 Blue 7
5 AM Wed 63 63 N 21 5203 3502 681 Blue 6
6 AM Wed 62 62 N 21 4918 3201 380 Blue 5
7 AM Wed 61 61 N 21 4558 2897 76 Blue 4
8 AM Wed 61 61 N 18 4558 2897 76 Blue 4
9 AM Wed 64 64 N 18 5531 4530 1709 Blue 7
10 AM Wed 66 67 N 18 6446 5500 2679 Blue 10
11 AM Wed 67 69 N 20 7170 6110 3289 Blue 12
12 Noon Wed 69 72 N 20 7665 7146 4325 Blue 15
1 PM Wed 71 75 N 20 8158 7638 4817 Blue 18
2 PM Wed 72 75 N 21 8158 7638 4817 Blue 18
3 PM Wed 74 77 N 21 8902 7965 5144 Blue 20
4 PM Wed 74 75 N 21 8158 7638 4817 Blue 18
5 PM Wed 73 73 N 16 7830 7310 4489 Blue 16
6 PM Wed 70 70 N 16 7336 6408 3587 Blue 13
7 PM Wed 69 69 N 16 7170 6110 3289 Blue 12
8 PM Wed 68 68 N 16 6768 5809 2988 Blue 11
9 PM Wed 67 67 N 16 6446 5500 2679 Blue 10
10 PM Wed 67 67 N 16 6446 5500 2679 Blue 10
11 PM Wed 66 66 N 20 6144 5176 2355 Blue 9
12 Midnight Thu 65 65 N 20 5840 4893 2072 Blue 8
1 AM Thu 64 64 N 20 5531 4530 1709 Blue 7
2 AM Thu 65 65 N 21 5840 4893 2072 Blue 8
3 AM Thu 64 64 N 21 5531 4530 1709 Blue 7
4 AM Thu 63 63 N 21 5203 3502 681 Blue 6
5 AM Thu 62 62 N 21 4918 3201 380 Blue 5
6 AM Thu 62 62 N 21 4918 3201 380 Blue 5
7 AM Thu 61 61 N 21 4558 2897 76 Blue 4
8 AM Thu 61 61 N 21 4558 2897 76 Blue 4
9 AM Thu 64 64 N 21 5531 4530 1709 Blue 7
10 AM Thu 65 66 N 21 6144 5176 2355 Blue 9
11 AM Thu 66 68 N 20 6768 5809 2988 Blue 11
12 Noon Thu 68 71 N 20 7500 6705 3884 Blue 14
1 PM Thu 70 73 N 20 7830 7310 4489 Blue 16
2 PM Thu 71 74 N 17 7994 7474 4653 Blue 17
3 PM Thu 72 74 N 17 7994 7474 4653 Blue 17
4 PM Thu 72 73 N 17 7830 7310 4489 Blue 16
5 PM Thu 72 72 NE 14 7665 7146 4325 Blue 15
6 PM Thu 68 68 NE 14 6768 5809 2988 Blue 11
7 PM Thu 67 67 NE 14 6446 5500 2679 Blue 10
8 PM Thu 65 65 N 9 5840 4893 2072 Blue 8
9 PM Thu 64 64 N 9 5531 4530 1709 Blue 7
10 PM Thu 64 64 N 9 5531 4530 1709 Blue 7
11 PM Thu 63 63 NW 8 5203 3502 681 Blue 6
12 Midnight Fri 62 62 NW 8 4918 3201 380 Blue 5
1 AM Fri 61 61 NW 8 4558 2897 76 Blue 4
2 AM Fri 62 62 N 8 4918 3201 380 Blue 5
3 AM Fri 61 61 N 8 4558 2897 76 Blue 4
4 AM Fri 60 60 N 8 3590 2821 0 Blue 3
5 AM Fri 59 59 N 9 3207 2821 0 Blue 2
6 AM Fri 58 58 N 9 2900 2821 0 Blue 1
7 AM Fri 57 57 N 9 2441 2821 0 Blue 0
8 AM Fri 57 57 N 8 2441 2821 0 Blue 0
9 AM Fri 61 61 N 8 4558 2897 76 Blue 4
10 AM Fri 63 64 N 8 5531 4530 1709 Blue 7
11 AM Fri 64 66 NE 8 6144 5176 2355 Blue 9
12 Noon Fri 66 69 NE 8 7170 6110 3289 Blue 12
1 PM Fri 69 73 NE 8 7830 7310 4489 Blue 16
2 PM Fri 71 74 E 8 7994 7474 4653 Blue 17
3 PM Fri 73 75 E 8 8158 7638 4817 Blue 18
4 PM Fri 73 74 E 8 7994 7474 4653 Blue 17
5 PM Fri 72 72 SW 9 7665 7146 4325 Blue 15
6 PM Fri 68 68 SW 9 6768 5809 2988 Blue 11
7 PM Fri 66 66 SW 9 6144 5176 2355 Blue 9
8 PM Fri 65 65 W 7 5840 4893 2072 Blue 8
9 PM Fri 64 64 W 7 5531 4530 1709 Blue 7
10 PM Fri 64 64 W 7 5531 4530 1709 Blue 7
11 PM Fri 63 63 W 8 5203 3502 681 Blue 6
12 Midnight Sat 62 62 W 8 4918 3201 380 Blue 5
1 AM Sat 61 61 W 8 4558 2897 76 Blue 4
2 AM Sat 61 61 W 9 4558 2897 76 Blue 4
3 AM Sat 60 60 W 9 3590 2821 0 Blue 3
4 AM Sat 59 59 W 9 3207 2821 0 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 [email protected]