Detailed Predictions for: Merriam Crater
Launch Altitude (f): 6800
LZ Altitude (f): 6000
Sounding

Station:

KFGZ

Date/Time:

14 DEC 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 Fri 18 18 W 2 6122 6800 0 White 0
6 AM Fri 17 17 SW 2 6122 6800 0 White 0
7 AM Fri 17 17 S 2 6122 6800 0 White 0
8 AM Fri 20 20 S 3 6122 6800 0 White 0
9 AM Fri 25 25 S 5 6122 6800 0 White 0
10 AM Fri 32 33 SE 6 6122 6800 0 White 0
11 AM Fri 39 40 SE 7 6122 6800 0 White 0
12 Noon Fri 42 43 SE 7 6122 6800 0 White 0
1 PM Fri 44 45 SE 7 6122 6800 0 White 0
2 PM Fri 44 45 SE 7 6122 6800 0 White 0
3 PM Fri 43 43 SE 6 6122 6800 0 White 0
4 PM Fri 42 42 SE 5 6122 6800 0 White 0
5 PM Fri 40 40 E 3 6122 6800 0 White 0
6 PM Fri 38 38 SE 3 6122 6800 0 White 0
7 PM Fri 35 35 S 5 6122 6800 0 White 0
8 PM Fri 33 33 S 5 6122 6800 0 White 0
9 PM Fri 32 32 S 5 6122 6800 0 White 0
10 PM Fri 31 31 SW 3 6122 6800 0 White 0
11 PM Fri 30 30 SW 3 6122 6800 0 White 0
12 Midnight Sat 29 29 SW 3 6122 6800 0 White 0
1 AM Sat 28 28 SW 2 6122 6800 0 White 0
2 AM Sat 28 28 SW 2 6122 6800 0 White 0
3 AM Sat 28 28 SW 2 6122 6800 0 White 0
4 AM Sat 29 29 W 2 6122 6800 0 White 0
5 AM Sat 29 29 NW 2 6122 6800 0 White 0
6 AM Sat 27 27 W 2 6122 6800 0 White 0
7 AM Sat 25 25 S 2 6122 6800 0 White 0
8 AM Sat 26 26 SE 3 6122 6800 0 White 0
9 AM Sat 31 31 SE 3 6122 6800 0 White 0
10 AM Sat 38 38 E 3 6122 6800 0 White 0
11 AM Sat 44 45 E 3 6122 6800 0 White 0
12 Noon Sat 48 49 E 3 6122 6800 0 White 0
1 PM Sat 50 51 E 5 6122 6800 0 White 0
2 PM Sat 50 51 E 5 6122 6800 0 White 0
3 PM Sat 50 50 E 5 6122 6800 0 White 0
4 PM Sat 49 49 E 3 6122 6800 0 White 0
5 PM Sat 46 46 E 3 6122 6800 0 White 0
6 PM Sat 42 42 SE 3 6122 6800 0 White 0
7 PM Sat 38 38 S 3 6122 6800 0 White 0
8 PM Sat 34 34 S 3 6122 6800 0 White 0
9 PM Sat 32 32 S 3 6122 6800 0 White 0
10 PM Sat 31 31 SW 3 6122 6800 0 White 0
11 PM Sat 30 30 SW 3 6122 6800 0 White 0
12 Midnight Sun 29 29 W 3 6122 6800 0 White 0
1 AM Sun 27 27 NW 2 6122 6800 0 White 0
2 AM Sun 26 26 N 2 6122 6800 0 White 0
3 AM Sun 26 26 N 2 6122 6800 0 White 0
4 AM Sun 26 26 N 2 6122 6800 0 White 0
5 AM Sun 25 25 N 2 6122 6800 0 White 0
6 AM Sun 24 24 N 2 6122 6800 0 White 0
7 AM Sun 24 24 NE 2 6122 6800 0 White 0
8 AM Sun 26 26 E 2 6122 6800 0 White 0
9 AM Sun 32 32 E 2 6122 6800 0 White 0
10 AM Sun 39 40 E 3 6122 6800 0 White 0
11 AM Sun 45 46 E 3 6122 6800 0 White 0
12 Noon Sun 49 51 E 3 6122 6800 0 White 0
1 PM Sun 51 53 E 5 6122 6800 0 White 0
2 PM Sun 51 52 E 5 6122 6800 0 White 0
3 PM Sun 51 51 E 5 6122 6800 0 White 0
4 PM Sun 50 50 E 3 6122 6800 0 White 0
5 PM Sun 47 47 E 3 6122 6800 0 White 0
6 PM Sun 43 43 E 3 6122 6800 0 White 0
7 PM Sun 39 39 S 3 6122 6800 0 White 0
8 PM Sun 36 36 S 3 6122 6800 0 White 0
9 PM Sun 34 34 S 3 6122 6800 0 White 0
10 PM Sun 33 33 SW 2 6122 6800 0 White 0
11 PM Sun 33 33 SW 2 6122 6800 0 White 0
12 Midnight Mon 32 32 SW 2 6122 6800 0 White 0
1 AM Mon 31 31 S 2 6122 6800 0 White 0
2 AM Mon 30 30 S 2 6122 6800 0 White 0
3 AM Mon 30 30 SW 2 6122 6800 0 White 0
4 AM Mon 30 30 SW 2 6122 6800 0 White 0
5 AM Mon 29 29 SW 2 6122 6800 0 White 0
6 AM Mon 28 28 SW 2 6122 6800 0 White 0
7 AM Mon 28 28 SW 2 6122 6800 0 White 0
8 AM Mon 30 30 S 2 6122 6800 0 White 0
9 AM Mon 34 34 S 3 6122 6800 0 White 0
10 AM Mon 40 40 S 3 6122 6800 0 White 0
11 AM Mon 45 46 S 5 6122 6800 0 White 0
12 Noon Mon 48 49 S 5 6122 6800 0 White 0
1 PM Mon 49 50 SW 6 6122 6800 0 White 0
2 PM Mon 49 49 SW 6 6122 6800 0 White 0
3 PM Mon 48 48 SW 6 6122 6800 0 White 0
4 PM Mon 47 47 W 7 6122 6800 0 White 0
5 PM Mon 45 45 W 7 6122 6800 0 White 0
6 PM Mon 43 43 W 7 6122 6800 0 White 0
7 PM Mon 41 41 W 7 6122 6800 0 White 0
8 PM Mon 39 39 W 7 6122 6800 0 White 0
9 PM Mon 38 38 W 7 6122 6800 0 White 0
10 PM Mon 37 37 W 6 6122 6800 0 White 0
11 PM Mon 37 37 W 6 6122 6800 0 White 0
12 Midnight Tue 35 35 W 6 6122 6800 0 White 0
1 AM Tue 34 34 W 5 6122 6800 0 White 0
2 AM Tue 33 33 NW 5 6122 6800 0 White 0
3 AM Tue 33 33 NW 5 6122 6800 0 White 0
4 AM Tue 33 33 NW 6 6122 6800 0 White 0
5 AM Tue 32 32 NW 6 6122 6800 0 White 0
6 AM Tue 30 30 NW 5 6122 6800 0 White 0
7 AM Tue 28 28 NW 6 6122 6800 0 White 0
8 AM Tue 28 28 N 6 6122 6800 0 White 0
9 AM Tue 32 32 N 6 6122 6800 0 White 0
10 AM Tue 37 37 N 7 6122 6800 0 White 0
11 AM Tue 41 42 N 7 6122 6800 0 White 0
12 Noon Tue 45 46 N 7 6122 6800 0 White 0
1 PM Tue 46 47 N 7 6122 6800 0 White 0
2 PM Tue 47 48 N 7 6122 6800 0 White 0
3 PM Tue 47 47 N 7 6122 6800 0 White 0
4 PM Tue 46 46 N 7 6122 6800 0 White 0
5 PM Tue 45 45 N 7 6122 6800 0 White 0
6 PM Tue 42 42 N 7 6122 6800 0 White 0
7 PM Tue 38 38 N 7 6122 6800 0 White 0
8 PM Tue 36 36 N 7 6122 6800 0 White 0
9 PM Tue 34 34 N 7 6122 6800 0 White 0
10 PM Tue 34 34 N 7 6122 6800 0 White 0
11 PM Tue 33 33 N 7 6122 6800 0 White 0
12 Midnight Wed 33 33 N 7 6122 6800 0 White 0
1 AM Wed 32 32 N 7 6122 6800 0 White 0
2 AM Wed 31 31 NW 6 6122 6800 0 White 0
3 AM Wed 30 30 NW 6 6122 6800 0 White 0
4 AM Wed 30 30 NW 6 6122 6800 0 White 0
5 AM Wed 29 29 NW 6 6122 6800 0 White 0
6 AM Wed 27 27 NW 6 6122 6800 0 White 0
7 AM Wed 27 27 N 7 6122 6800 0 White 0
8 AM Wed 29 29 N 7 6122 6800 0 White 0
9 AM Wed 33 33 N 7 6122 6800 0 White 0
10 AM Wed 38 39 N 8 6122 6800 0 White 0
11 AM Wed 44 46 NE 8 6122 6800 0 White 0
12 Noon Wed 47 49 NE 8 6122 6800 0 White 0
1 PM Wed 49 51 N 8 6122 6800 0 White 0
2 PM Wed 50 52 N 8 6122 6800 0 White 0
3 PM Wed 50 51 N 8 6122 6800 0 White 0
4 PM Wed 50 50 N 7 6122 6800 0 White 0
5 PM Wed 48 48 N 7 6122 6800 0 White 0
6 PM Wed 45 45 N 7 6122 6800 0 White 0
7 PM Wed 41 41 N 6 6122 6800 0 White 0
8 PM Wed 38 38 N 6 6122 6800 0 White 0
9 PM Wed 36 36 N 6 6122 6800 0 White 0
10 PM Wed 35 35 NW 5 6122 6800 0 White 0
11 PM Wed 34 34 NW 5 6122 6800 0 White 0
12 Midnight Thu 33 33 NW 5 6122 6800 0 White 0
1 AM Thu 32 32 W 3 6122 6800 0 White 0
2 AM Thu 31 31 W 3 6122 6800 0 White 0
3 AM Thu 31 31 SW 2 6122 6800 0 White 0
4 AM Thu 31 31 S 2 6122 6800 0 White 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