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

Station:

KFGZ

Date/Time:

5 DEC 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 Thu 38 38 SW 9 0 6800 0 Blue 0
6 AM Thu 37 37 SW 9 0 6800 0 Blue 0
7 AM Thu 36 36 SW 6 0 6800 0 Blue 0
8 AM Thu 36 36 SW 6 0 6800 0 Blue 0
9 AM Thu 38 38 W 7 0 6800 0 Blue 0
10 AM Thu 40 41 W 7 7249 7149 349 White 1
11 AM Thu 42 43 W 7 7694 7245 445 White 3
12 Noon Thu 44 46 W 7 8359 8359 1559 White 6
1 PM Thu 45 47 W 8 8580 8580 1780 White 7
2 PM Thu 46 48 N 7 8800 8800 2000 White 8
3 PM Thu 45 46 N 6 8359 8359 1559 White 6
4 PM Thu 45 45 N 6 8137 8031 1231 White 5
5 PM Thu 43 43 NE 5 7694 7245 445 White 3
6 PM Thu 42 42 N 3 7472 7149 349 White 2
7 PM Thu 40 40 W 2 7026 7026 226 White 0
8 PM Thu 38 38 W 3 0 6800 0 Blue 0
9 PM Thu 36 36 SW 2 0 6800 0 Blue 0
10 PM Thu 34 34 SW 2 0 6800 0 Blue 0
11 PM Thu 34 34 SW 2 0 6800 0 Blue 0
12 Midnight Fri 34 34 SW 2 0 6800 0 Blue 0
1 AM Fri 33 33 SW 2 0 6800 0 Blue 0
2 AM Fri 33 33 S 1 0 6800 0 Blue 0
3 AM Fri 32 32 S 1 0 6800 0 Blue 0
4 AM Fri 31 31 S 2 0 6800 0 Blue 0
5 AM Fri 31 31 S 2 0 6800 0 Blue 0
6 AM Fri 31 31 S 2 0 6800 0 Blue 0
7 AM Fri 30 30 E 2 0 6800 0 Blue 0
8 AM Fri 32 32 SE 2 0 6800 0 Blue 0
9 AM Fri 36 36 SE 3 0 6800 0 Blue 0
10 AM Fri 38 38 E 5 0 6800 0 Blue 0
11 AM Fri 39 39 E 5 0 6800 0 Blue 0
12 Noon Fri 41 41 E 6 7249 7149 349 White 1
1 PM Fri 43 43 E 6 7694 7245 445 White 3
2 PM Fri 45 45 E 6 8137 8031 1231 White 5
3 PM Fri 46 46 E 5 8359 8359 1559 White 6
4 PM Fri 46 46 SE 5 8359 8359 1559 White 6
5 PM Fri 44 44 E 3 7915 7641 841 White 4
6 PM Fri 41 41 SE 3 7249 7149 349 White 1
7 PM Fri 38 38 SE 3 0 6800 0 Blue 0
8 PM Fri 35 35 S 3 0 6800 0 Blue 0
9 PM Fri 34 34 S 3 0 6800 0 Blue 0
10 PM Fri 34 34 SW 3 0 6800 0 Blue 0
11 PM Fri 34 34 SW 2 0 6800 0 Blue 0
12 Midnight Sat 34 34 SW 3 0 6800 0 Blue 0
1 AM Sat 34 34 SW 3 0 6800 0 Blue 0
2 AM Sat 33 33 W 2 0 6800 0 Blue 0
3 AM Sat 32 32 SW 2 0 6800 0 Blue 0
4 AM Sat 31 31 SW 2 0 6800 0 Blue 0
5 AM Sat 31 31 SW 2 0 6800 0 Blue 0
6 AM Sat 30 30 SW 2 0 6800 0 Blue 0
7 AM Sat 30 30 SW 3 0 6800 0 Blue 0
8 AM Sat 32 32 SW 2 0 6800 0 Blue 0
9 AM Sat 35 35 S 5 0 6800 0 Blue 0
10 AM Sat 40 40 S 5 7026 7026 226 White 0
11 AM Sat 44 45 S 6 8137 8031 1231 White 5
12 Noon Sat 47 48 S 6 8800 8800 2000 White 8
1 PM Sat 49 50 S 6 9240 9240 2440 White 10
2 PM Sat 50 50 SW 8 9240 9240 2440 White 10
3 PM Sat 50 50 SW 6 9240 9240 2440 White 10
4 PM Sat 49 49 SW 6 9021 9021 2221 White 9
5 PM Sat 47 47 SW 7 8580 8580 1780 White 7
6 PM Sat 44 44 SW 6 7915 7641 841 White 4
7 PM Sat 41 41 SW 7 7249 7149 349 White 1
8 PM Sat 39 39 SW 7 0 6800 0 Blue 0
9 PM Sat 39 39 SW 8 0 6800 0 Blue 0
10 PM Sat 40 40 SW 8 7026 7026 226 White 0
11 PM Sat 40 40 SW 7 7026 7026 226 White 0
12 Midnight Sun 40 40 SW 8 7026 7026 226 White 0
1 AM Sun 40 40 SW 7 7026 7026 226 White 0
2 AM Sun 39 39 SW 7 0 6800 0 Blue 0
3 AM Sun 39 39 SW 6 0 6800 0 Blue 0
4 AM Sun 38 38 SW 6 0 6800 0 Blue 0
5 AM Sun 38 38 SW 6 0 6800 0 Blue 0
6 AM Sun 37 37 SW 7 0 6800 0 Blue 0
7 AM Sun 37 37 SW 7 0 6800 0 Blue 0
8 AM Sun 38 38 SW 6 0 6800 0 Blue 0
9 AM Sun 40 40 SW 9 7026 7026 226 White 0
10 AM Sun 42 42 SW 10 7472 7149 349 White 2
11 AM Sun 45 45 SW 12 8137 8031 1231 White 5
12 Noon Sun 46 46 SW 13 8359 8359 1559 White 6
1 PM Sun 48 48 SW 13 8800 8800 2000 White 8
2 PM Sun 48 48 SW 15 8800 8800 2000 White 8
3 PM Sun 47 47 SW 14 8580 8580 1780 White 7
4 PM Sun 46 46 SW 14 8359 8359 1559 White 6
5 PM Sun 43 43 SW 14 7694 7245 445 White 3
6 PM Sun 41 41 SW 14 7249 7149 349 White 1
7 PM Sun 39 39 SW 13 0 6800 0 Blue 0
8 PM Sun 37 37 W 12 0 6800 0 Blue 0
9 PM Sun 36 36 W 12 0 6800 0 Blue 0
10 PM Sun 36 36 W 10 0 6800 0 Blue 0
11 PM Sun 36 36 W 9 0 6800 0 Blue 0
12 Midnight Mon 35 35 W 8 0 6800 0 Blue 0
1 AM Mon 35 35 W 7 0 6800 0 Blue 0
2 AM Mon 34 34 W 6 0 6800 0 Blue 0
3 AM Mon 33 33 W 6 0 6800 0 Blue 0
4 AM Mon 32 32 W 5 0 6800 0 Blue 0
5 AM Mon 31 31 W 5 0 6800 0 Blue 0
6 AM Mon 30 30 W 6 0 6800 0 Blue 0
7 AM Mon 30 30 NW 6 0 6800 0 Blue 0
8 AM Mon 31 31 NW 7 0 6800 0 Blue 0
9 AM Mon 34 34 NW 8 0 6800 0 Blue 0
10 AM Mon 37 38 N 9 0 6800 0 Blue 0
11 AM Mon 40 41 N 10 7249 7149 349 White 1
12 Noon Mon 43 44 N 10 7915 7641 841 White 4
1 PM Mon 44 45 N 10 8137 8031 1231 White 5
2 PM Mon 44 45 N 10 8137 8031 1231 White 5
3 PM Mon 44 44 N 9 7915 7641 841 White 4
4 PM Mon 43 43 N 9 7694 7245 445 White 3
5 PM Mon 41 41 N 8 7249 7149 349 White 1
6 PM Mon 37 37 N 8 0 6800 0 Blue 0
7 PM Mon 34 34 N 7 0 6800 0 Blue 0
8 PM Mon 31 31 N 7 0 6800 0 Blue 0
9 PM Mon 30 30 N 6 0 6800 0 Blue 0
10 PM Mon 30 30 N 5 0 6800 0 Blue 0
11 PM Mon 30 30 N 5 0 6800 0 Blue 0
12 Midnight Tue 30 30 N 3 0 6800 0 Blue 0
1 AM Tue 29 29 N 3 0 6800 0 Blue 0
2 AM Tue 28 28 N 3 0 6800 0 Blue 0
3 AM Tue 27 27 N 2 0 6800 0 Blue 0
4 AM Tue 26 26 N 2 0 6800 0 Blue 0
5 AM Tue 25 25 N 2 0 6800 0 Blue 0
6 AM Tue 25 25 N 2 0 6800 0 Blue 0
7 AM Tue 25 25 N 3 0 6800 0 Blue 0
8 AM Tue 27 27 NE 3 0 6800 0 Blue 0
9 AM Tue 30 30 NE 5 0 6800 0 Blue 0
10 AM Tue 34 35 E 6 0 6800 0 Blue 0
11 AM Tue 38 39 E 6 0 6800 0 Blue 0
12 Noon Tue 41 43 E 6 7694 7245 445 White 3
1 PM Tue 43 45 E 6 8137 8031 1231 White 5
2 PM Tue 44 45 E 6 8137 8031 1231 White 5
3 PM Tue 44 45 E 6 8137 8031 1231 White 5
4 PM Tue 43 43 E 5 7694 7245 445 White 3
5 PM Tue 40 40 E 5 7026 7026 226 White 0
6 PM Tue 37 37 E 5 0 6800 0 Blue 0
7 PM Tue 33 33 E 5 0 6800 0 Blue 0
8 PM Tue 30 30 SE 5 0 6800 0 Blue 0
9 PM Tue 29 29 S 3 0 6800 0 Blue 0
10 PM Tue 29 29 S 3 0 6800 0 Blue 0
11 PM Tue 29 29 S 3 0 6800 0 Blue 0
12 Midnight Wed 29 29 S 3 0 6800 0 Blue 0
1 AM Wed 28 28 S 2 0 6800 0 Blue 0
2 AM Wed 27 27 S 2 0 6800 0 Blue 0
3 AM Wed 26 26 S 1 0 6800 0 Blue 0
4 AM Wed 26 26 S 1 0 6800 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