Detailed Predictions for: Weaver Bally
Launch Lat, Long, Altitude (f): 40.796231, -123.00509, 6900
LZ Altitude (f): 1480
Sounding

Station:

KMFR

Date/Time:

N/A

Temp/Wind data from:

NOAA Digital Forecast

Site Forecasts
Time
(Local)
High
Temp

Puddle
Temp

Wind
(mph)
Wind
Gust
Thermal
Ceiling

(ft)
Soaring
Ceiling

(ft)
Above
Launch

(ft)
Thermal
Type
Thermal
Index

(F)
12 Midnight Sat 37 37 WNW 4 6 N/A N/A N/A N/A N/A
1 AM Sat 34 34 WNW 4 5 N/A N/A N/A N/A N/A
2 AM Sat 30 30 WNW 4 5 N/A N/A N/A N/A N/A
3 AM Sat 30 30 WNW 4 5 N/A N/A N/A N/A N/A
4 AM Sat 30 30 WNW 4 5 N/A N/A N/A N/A N/A
5 AM Sat 29 29 WNW 4 5 N/A N/A N/A N/A N/A
6 AM Sat 29 29 WNW 4 5 N/A N/A N/A N/A N/A
7 AM Sat 29 29 WNW 4 5 N/A N/A N/A N/A N/A
8 AM Sat 28 28 WNW 3 5 N/A N/A N/A N/A N/A
9 AM Sat 33 34 W 3 4 N/A N/A N/A N/A N/A
10 AM Sat 38 40 W 3 4 N/A N/A N/A N/A N/A
11 AM Sat 43 46 W 3 3 N/A N/A N/A N/A N/A
12 Noon Sat 47 50 WNW 3 3 N/A N/A N/A N/A N/A
1 PM Sat 51 54 WNW 2 3 N/A N/A N/A N/A N/A
2 PM Sat 55 58 NW 2 3 N/A N/A N/A N/A N/A
3 PM Sat 54 56 NNW 3 4 N/A N/A N/A N/A N/A
4 PM Sat 54 55 NNW 4 4 N/A N/A N/A N/A N/A
5 PM Sat 53 53 N 5 5 N/A N/A N/A N/A N/A
6 PM Sat 51 51 NNW 4 6 N/A N/A N/A N/A N/A
7 PM Sat 49 49 NNW 4 7 N/A N/A N/A N/A N/A
8 PM Sat 47 47 NNW 4 8 N/A N/A N/A N/A N/A
9 PM Sat 45 45 NNW 3 8 N/A N/A N/A N/A N/A
10 PM Sat 43 43 NW 3 6 N/A N/A N/A N/A N/A
11 PM Sat 40 40 NW 2 6 N/A N/A N/A N/A N/A
12 Midnight Sun 36 36 NW 2 5 N/A N/A N/A N/A N/A
1 AM Sun 31 31 NW 2 5 N/A N/A N/A N/A N/A
2 AM Sun 27 27 NNW 2 5 N/A N/A N/A N/A N/A
3 AM Sun 27 27 NNW 2 5 N/A N/A N/A N/A N/A
4 AM Sun 27 27 NW 2 5 N/A N/A N/A N/A N/A
5 AM Sun 27 27 NW 2 5 N/A N/A N/A N/A N/A
6 AM Sun 28 28 NW 2 5 N/A N/A N/A N/A N/A
7 AM Sun 28 28 NNW 2 5 N/A N/A N/A N/A N/A
8 AM Sun 29 29 NNW 2 5 N/A N/A N/A N/A N/A
9 AM Sun 37 38 SW 2 4 N/A N/A N/A N/A N/A
10 AM Sun 45 47 SE 2 3 N/A N/A N/A N/A N/A
11 AM Sun 52 55 NE 1 2 N/A N/A N/A N/A N/A
12 Noon Sun 55 59 NE 2 2 N/A N/A N/A N/A N/A
1 PM Sun 58 61 ENE 2 2 N/A N/A N/A N/A N/A
2 PM Sun 61 64 E 2 3 N/A N/A N/A N/A N/A
3 PM Sun 61 63 E 3 3 N/A N/A N/A N/A N/A
4 PM Sun 60 61 E 3 3 N/A N/A N/A N/A N/A
5 PM Sun 59 59 E 3 3 N/A N/A N/A N/A N/A
6 PM Sun 57 57 E 2 3 N/A N/A N/A N/A N/A
7 PM Sun 54 54 ENE 1 2 N/A N/A N/A N/A N/A
8 PM Sun 52 52 ENE 1 2 N/A N/A N/A N/A N/A
9 PM Sun 49 49 ENE 1 2 N/A N/A N/A N/A N/A
10 PM Sun 47 47 ENE 1 3 N/A N/A N/A N/A N/A
11 PM Sun 45 45 ENE 1 3 N/A N/A N/A N/A N/A
12 Midnight Mon 40 40 ENE 2 4 N/A N/A N/A N/A N/A
1 AM Mon 35 35 ENE 2 4 N/A N/A N/A N/A N/A
2 AM Mon 31 31 ENE 2 4 N/A N/A N/A N/A N/A
3 AM Mon 30 30 ENE 2 4 N/A N/A N/A N/A N/A
4 AM Mon 29 29 ENE 2 4 N/A N/A N/A N/A N/A
5 AM Mon 29 29 ENE 2 4 N/A N/A N/A N/A N/A
6 AM Mon 28 28 ENE 2 4 N/A N/A N/A N/A N/A
7 AM Mon 28 28 ENE 2 4 N/A N/A N/A N/A N/A
8 AM Mon 28 28 ENE 2 4 N/A N/A N/A N/A N/A
9 AM Mon 35 36 E 2 4 N/A N/A N/A N/A N/A
10 AM Mon 42 44 E 3 4 N/A N/A N/A N/A N/A
11 AM Mon 49 51 E 4 5 N/A N/A N/A N/A N/A
12 Noon Mon 51 54 E 5 6 N/A N/A N/A N/A N/A
1 PM Mon 52 55 ESE 6 7 N/A N/A N/A N/A N/A
2 PM Mon 54 56 ESE 6 8 N/A N/A N/A N/A N/A
3 PM Mon 53 54 ESE 6 7 N/A N/A N/A N/A N/A
4 PM Mon 52 52 ESE 5 6 N/A N/A N/A N/A N/A
5 PM Mon 52 52 ESE 5 6 N/A N/A N/A N/A N/A
6 PM Mon 50 50 E 4 6 N/A N/A N/A N/A N/A
7 PM Mon 48 48 E 3 6 N/A N/A N/A N/A N/A
8 PM Mon 46 46 ENE 2 6 N/A N/A N/A N/A N/A
9 PM Mon 44 44 NE 2 5 N/A N/A N/A N/A N/A
10 PM Mon 42 42 NNE 2 4 N/A N/A N/A N/A N/A
11 PM Mon 39 39 NNE 2 4 N/A N/A N/A N/A N/A

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 or WeatherAPI.com website.  Puddle temperatures can exceed this temperature. 

Puddle Temp: This estimate is based on the High Temp and the National Weather Service or WeatherAPI.com 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 or WeatherAPI.com website.

Wind Gust: This estimate is taken from the National Weather Service or WeatherAPI.com 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