Detailed Predictions for: Weaver Bally
Launch Altitude (f): 6900
LZ Altitude (f): 1480
Sounding

Station:

KOAK

Date/Time:

27 MAY 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 Sun 48 48 NE 3 4934 6900 0 Blue 0
6 AM Sun 48 48 NE 3 4934 6900 0 Blue 0
7 AM Sun 50 50 NE 3 4934 6900 0 Blue 0
8 AM Sun 52 53 N 3 6550 6900 0 Blue 0
9 AM Sun 54 57 N 3 7755 7514 614 Blue 4
10 AM Sun 56 60 N 3 7990 7749 849 Blue 7
11 AM Sun 59 65 NW 1 9405 8394 1494 Blue 12
12 Noon Sun 62 70 NW 1 11120 10294 3394 Blue 17
1 PM Sun 66 74 NW 1 12567 11379 4479 Blue 21
2 PM Sun 69 77 W 3 13089 12525 5625 Blue 24
3 PM Sun 71 78 W 3 13594 12699 5799 Blue 25
4 PM Sun 73 78 W 3 13594 12699 5799 Blue 25
5 PM Sun 74 77 NW 5 13089 12525 5625 Blue 24
6 PM Sun 73 74 NW 5 12567 11379 4479 Blue 21
7 PM Sun 71 71 NW 5 11460 10529 3629 Blue 18
8 PM Sun 69 69 N 7 10805 9776 2876 Blue 16
9 PM Sun 65 65 N 7 9405 8394 1494 Blue 12
10 PM Sun 62 62 N 7 8427 7905 1005 Blue 9
11 PM Sun 59 59 N 6 7912 7671 771 Blue 6
12 Midnight Mon 56 56 N 6 7677 6900 0 Blue 3
1 AM Mon 55 55 N 6 7598 6900 0 Blue 2
2 AM Mon 54 54 NE 6 7520 6900 0 Blue 1
3 AM Mon 53 53 NE 6 6550 6900 0 Blue 0
4 AM Mon 53 53 NE 6 6550 6900 0 Blue 0
5 AM Mon 53 53 NE 5 6550 6900 0 Blue 0
6 AM Mon 54 54 NE 5 7520 6900 0 Blue 1
7 AM Mon 55 55 NE 5 7598 6900 0 Blue 2
8 AM Mon 57 58 N 3 7833 7592 692 Blue 5
9 AM Mon 58 61 N 3 8095 7827 927 Blue 8
10 AM Mon 61 66 N 3 9858 8720 1820 Blue 13
11 AM Mon 63 69 NW 1 10805 9776 2876 Blue 16
12 Noon Mon 66 73 NW 1 12281 11059 4159 Blue 20
1 PM Mon 70 78 NW 1 13594 12699 5799 Blue 25
2 PM Mon 73 81 NW 3 15049 13428 6528 Blue 28
3 PM Mon 75 81 NW 3 15049 13428 6528 Blue 28
4 PM Mon 77 82 NW 3 15243 14020 7120 Blue 29
5 PM Mon 77 80 NW 5 14763 13044 6144 Blue 27
6 PM Mon 76 77 NW 5 13089 12525 5625 Blue 24
7 PM Mon 74 74 NW 5 12567 11379 4479 Blue 21
8 PM Mon 71 71 NW 5 11460 10529 3629 Blue 18
9 PM Mon 68 68 NW 5 10569 9363 2463 Blue 15
10 PM Mon 64 64 NW 5 9082 8065 1165 Blue 11
11 PM Mon 61 61 N 3 8095 7827 927 Blue 8
12 Midnight Tue 59 59 N 3 7912 7671 771 Blue 6
1 AM Tue 58 58 N 3 7833 7592 692 Blue 5
2 AM Tue 57 57 N 3 7755 7514 614 Blue 4
3 AM Tue 56 56 N 3 7677 6900 0 Blue 3
4 AM Tue 56 56 N 3 7677 6900 0 Blue 3
5 AM Tue 56 56 N 2 7677 6900 0 Blue 3
6 AM Tue 57 57 N 2 7755 7514 614 Blue 4
7 AM Tue 58 58 N 2 7833 7592 692 Blue 5
8 AM Tue 59 60 N 2 7990 7749 849 Blue 7
9 AM Tue 60 62 N 2 8427 7905 1005 Blue 9
10 AM Tue 62 66 N 2 9858 8720 1820 Blue 13
11 AM Tue 65 70 W 3 11120 10294 3394 Blue 17
12 Noon Tue 68 73 W 3 12281 11059 4159 Blue 20
1 PM Tue 71 77 W 3 13089 12525 5625 Blue 24
2 PM Tue 73 79 W 3 14191 12871 5971 Blue 26
3 PM Tue 75 80 W 3 14763 13044 6144 Blue 27
4 PM Tue 76 79 W 3 14191 12871 5971 Blue 26
5 PM Tue 75 77 W 10 13089 12525 5625 Blue 24
6 PM Tue 74 75 W 10 12741 11864 4964 Blue 22
7 PM Tue 71 71 W 10 11460 10529 3629 Blue 18
8 PM Tue 67 67 W 10 10333 9043 2143 Blue 14
9 PM Tue 63 63 W 10 8756 7984 1084 Blue 10
10 PM Tue 59 59 W 10 7912 7671 771 Blue 6
11 PM Tue 56 56 NW 8 7677 6900 0 Blue 3
12 Midnight Wed 53 53 NW 8 6550 6900 0 Blue 0
1 AM Wed 51 51 NW 8 5116 6900 0 Blue 0
2 AM Wed 50 50 NW 8 4934 6900 0 Blue 0
3 AM Wed 49 49 NW 8 4934 6900 0 Blue 0
4 AM Wed 49 49 NW 8 4934 6900 0 Blue 0
5 AM Wed 49 49 NW 7 4934 6900 0 Blue 0
6 AM Wed 50 50 NW 7 4934 6900 0 Blue 0
7 AM Wed 51 51 NW 7 5116 6900 0 Blue 0
8 AM Wed 52 53 NW 7 6550 6900 0 Blue 0
9 AM Wed 53 55 NW 7 7598 6900 0 Blue 2
10 AM Wed 55 58 NW 7 7833 7592 692 Blue 5
11 AM Wed 57 61 N 5 8095 7827 927 Blue 8
12 Noon Wed 59 64 N 5 9082 8065 1165 Blue 11
1 PM Wed 60 66 N 5 9858 8720 1820 Blue 13
2 PM Wed 62 67 N 5 10333 9043 2143 Blue 14
3 PM Wed 63 67 N 5 10333 9043 2143 Blue 14
4 PM Wed 64 67 N 5 10333 9043 2143 Blue 14
5 PM Wed 64 66 W 6 9858 8720 1820 Blue 13
6 PM Wed 63 64 W 6 9082 8065 1165 Blue 11
7 PM Wed 62 62 W 6 8427 7905 1005 Blue 9
8 PM Wed 61 61 W 6 8095 7827 927 Blue 8
9 PM Wed 59 59 W 6 7912 7671 771 Blue 6
10 PM Wed 58 58 W 6 7833 7592 692 Blue 5
11 PM Wed 56 56 NW 5 7677 6900 0 Blue 3
12 Midnight Thu 55 55 NW 5 7598 6900 0 Blue 2
1 AM Thu 54 54 NW 5 7520 6900 0 Blue 1
2 AM Thu 53 53 NW 5 6550 6900 0 Blue 0
3 AM Thu 52 52 NW 5 5736 6900 0 Blue 0
4 AM Thu 51 51 NW 5 5116 6900 0 Blue 0
5 AM Thu 50 50 N 2 4934 6900 0 Blue 0
6 AM Thu 49 49 N 2 4934 6900 0 Blue 0
7 AM Thu 48 48 N 2 4934 6900 0 Blue 0
8 AM Thu 47 47 N 2 4934 6900 0 Blue 0
9 AM Thu 46 46 N 2 4934 6900 0 Blue 0
10 AM Thu 46 47 N 2 4934 6900 0 Blue 0
11 AM Thu 47 50 S 1 4934 6900 0 Blue 0
12 Noon Thu 48 51 S 1 5116 6900 0 Blue 0
1 PM Thu 50 54 S 1 7520 6900 0 Blue 1
2 PM Thu 52 56 S 1 7677 6900 0 Blue 3
3 PM Thu 54 57 S 1 7755 7514 614 Blue 4
4 PM Thu 56 58 S 1 7833 7592 692 Blue 5
5 PM Thu 57 58 W 7 7833 7592 692 Blue 5
6 PM Thu 57 57 W 7 7755 7514 614 Blue 4
7 PM Thu 56 56 W 7 7677 6900 0 Blue 3
8 PM Thu 54 54 W 7 7520 6900 0 Blue 1
9 PM Thu 51 51 W 7 5116 6900 0 Blue 0
10 PM Thu 49 49 W 7 4934 6900 0 Blue 0
11 PM Thu 47 47 W 6 4934 6900 0 Blue 0
12 Midnight Fri 46 46 W 6 4934 6900 0 Blue 0
1 AM Fri 45 45 W 6 4934 6900 0 Blue 0
2 AM Fri 45 45 W 6 4934 6900 0 Blue 0
3 AM Fri 45 45 W 6 4934 6900 0 Blue 0
4 AM Fri 46 46 W 6 4934 6900 0 Blue 0
5 AM Fri 46 46 NW 6 4934 6900 0 Blue 0
6 AM Fri 47 47 NW 6 4934 6900 0 Blue 0
7 AM Fri 47 47 NW 6 4934 6900 0 Blue 0
8 AM Fri 48 49 NW 6 4934 6900 0 Blue 0
9 AM Fri 49 51 NW 6 5116 6900 0 Blue 0
10 AM Fri 50 53 NW 6 6550 6900 0 Blue 0
11 AM Fri 52 57 W 5 7755 7514 614 Blue 4
12 Noon Fri 54 60 W 5 7990 7749 849 Blue 7
1 PM Fri 56 63 W 5 8756 7984 1084 Blue 10
2 PM Fri 59 65 W 5 9405 8394 1494 Blue 12
3 PM Fri 60 65 W 5 9405 8394 1494 Blue 12
4 PM Fri 62 66 W 5 9858 8720 1820 Blue 13
5 PM Fri 62 64 W 6 9082 8065 1165 Blue 11
6 PM Fri 61 62 W 6 8427 7905 1005 Blue 9
7 PM Fri 59 59 W 6 7912 7671 771 Blue 6
8 PM Fri 57 57 W 6 7755 7514 614 Blue 4
9 PM Fri 54 54 W 6 7520 6900 0 Blue 1
10 PM Fri 52 52 W 6 5736 6900 0 Blue 0
11 PM Fri 50 50 NW 5 4934 6900 0 Blue 0
12 Midnight Sat 48 48 NW 5 4934 6900 0 Blue 0
1 AM Sat 47 47 NW 5 4934 6900 0 Blue 0
2 AM Sat 47 47 NW 5 4934 6900 0 Blue 0
3 AM Sat 47 47 NW 5 4934 6900 0 Blue 0
4 AM Sat 48 48 NW 5 4934 6900 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