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

Station:

KFGZ

Date/Time:

25 SEP 2017

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)
6 AM Mon 36 36 N 7 0 6800 0 Blue 0
7 AM Mon 39 39 N 7 0 6800 0 Blue 0
8 AM Mon 43 44 N 7 0 6800 0 Blue 0
9 AM Mon 47 49 N 7 0 6800 0 Blue 0
10 AM Mon 52 56 N 6 0 6800 0 Blue 0
11 AM Mon 56 61 N 6 0 6800 0 Blue 0
12 Noon Mon 60 66 NE 6 15806 15587 8787 Blue 5
1 PM Mon 63 68 NE 6 16246 15703 8903 Blue 7
2 PM Mon 65 69 NE 6 16571 15766 8966 Blue 8
3 PM Mon 66 69 NE 6 16571 15766 8966 Blue 8
4 PM Mon 68 69 N 6 16571 15766 8966 Blue 8
5 PM Mon 68 68 N 6 16246 15703 8903 Blue 7
6 PM Mon 66 66 N 7 15806 15587 8787 Blue 5
7 PM Mon 62 62 N 6 0 6800 0 Blue 0
8 PM Mon 57 57 N 6 0 6800 0 Blue 0
9 PM Mon 53 53 N 7 0 6800 0 Blue 0
10 PM Mon 50 50 N 8 0 6800 0 Blue 0
11 PM Mon 49 49 N 8 0 6800 0 Blue 0
12 Midnight Tue 48 48 N 9 0 6800 0 Blue 0
1 AM Tue 46 46 N 9 0 6800 0 Blue 0
2 AM Tue 45 45 N 8 0 6800 0 Blue 0
3 AM Tue 43 43 N 8 0 6800 0 Blue 0
4 AM Tue 42 42 N 8 0 6800 0 Blue 0
5 AM Tue 41 41 N 7 0 6800 0 Blue 0
6 AM Tue 41 41 N 7 0 6800 0 Blue 0
7 AM Tue 44 44 N 7 0 6800 0 Blue 0
8 AM Tue 48 48 N 7 0 6800 0 Blue 0
9 AM Tue 52 54 N 7 0 6800 0 Blue 0
10 AM Tue 57 61 N 6 0 6800 0 Blue 0
11 AM Tue 62 67 NE 6 15931 15645 8845 Blue 6
12 Noon Tue 65 70 NE 6 16892 15889 9089 Blue 9
1 PM Tue 68 73 NE 5 18510 16775 9975 Blue 12
2 PM Tue 69 73 NE 5 18510 16775 9975 Blue 12
3 PM Tue 70 73 NE 5 18510 16775 9975 Blue 12
4 PM Tue 71 72 NE 6 17708 16456 9656 Blue 11
5 PM Tue 72 72 NE 6 17708 16456 9656 Blue 11
6 PM Tue 71 71 NE 6 17210 16134 9334 Blue 10
7 PM Tue 67 67 N 6 15931 15645 8845 Blue 6
8 PM Tue 62 62 N 6 0 6800 0 Blue 0
9 PM Tue 58 58 N 6 0 6800 0 Blue 0
10 PM Tue 54 54 NW 7 0 6800 0 Blue 0
11 PM Tue 53 53 NW 7 0 6800 0 Blue 0
12 Midnight Wed 51 51 NW 7 0 6800 0 Blue 0
1 AM Wed 50 50 NW 7 0 6800 0 Blue 0
2 AM Wed 49 49 NW 7 0 6800 0 Blue 0
3 AM Wed 48 48 NW 7 0 6800 0 Blue 0
4 AM Wed 47 47 NW 7 0 6800 0 Blue 0
5 AM Wed 46 46 N 7 0 6800 0 Blue 0
6 AM Wed 46 46 N 8 0 6800 0 Blue 0
7 AM Wed 48 48 N 7 0 6800 0 Blue 0
8 AM Wed 52 52 N 7 0 6800 0 Blue 0
9 AM Wed 56 57 N 7 0 6800 0 Blue 0
10 AM Wed 60 61 NE 6 0 6800 0 Blue 0
11 AM Wed 64 66 E 6 15806 15587 8787 Blue 5
12 Noon Wed 67 69 E 6 16571 15766 8966 Blue 8
1 PM Wed 69 71 E 7 17210 16134 9334 Blue 10
2 PM Wed 70 72 E 8 17708 16456 9656 Blue 11
3 PM Wed 70 71 E 8 17210 16134 9334 Blue 10
4 PM Wed 69 69 E 8 16571 15766 8966 Blue 8
5 PM Wed 68 68 E 8 16246 15703 8903 Blue 7
6 PM Wed 65 65 SE 8 15722 14780 7980 Blue 4
7 PM Wed 62 62 SE 7 0 6800 0 Blue 0
8 PM Wed 59 59 E 6 0 6800 0 Blue 0
9 PM Wed 55 55 NE 6 0 6800 0 Blue 0
10 PM Wed 53 53 N 5 0 6800 0 Blue 0
11 PM Wed 51 51 N 5 0 6800 0 Blue 0
12 Midnight Thu 50 50 N 5 0 6800 0 Blue 0
1 AM Thu 49 49 N 5 0 6800 0 Blue 0
2 AM Thu 48 48 N 5 0 6800 0 Blue 0
3 AM Thu 47 47 N 5 0 6800 0 Blue 0
4 AM Thu 46 46 N 5 0 6800 0 Blue 0
5 AM Thu 45 45 N 5 0 6800 0 Blue 0
6 AM Thu 45 45 N 5 0 6800 0 Blue 0
7 AM Thu 47 47 N 5 0 6800 0 Blue 0
8 AM Thu 50 50 N 3 0 6800 0 Blue 0
9 AM Thu 54 56 N 3 0 6800 0 Blue 0
10 AM Thu 59 62 N 3 0 6800 0 Blue 0
11 AM Thu 63 67 N 3 15931 15645 8845 Blue 6
12 Noon Thu 66 70 N 5 16892 15889 9089 Blue 9
1 PM Thu 68 71 N 5 17210 16134 9334 Blue 10
2 PM Thu 69 72 N 6 17708 16456 9656 Blue 11
3 PM Thu 70 72 N 6 17708 16456 9656 Blue 11
4 PM Thu 70 71 N 7 17210 16134 9334 Blue 10
5 PM Thu 70 70 N 8 16892 15889 9089 Blue 9
6 PM Thu 68 68 N 8 16246 15703 8903 Blue 7
7 PM Thu 65 65 N 8 15722 14780 7980 Blue 4
8 PM Thu 61 61 N 8 0 6800 0 Blue 0
9 PM Thu 58 58 N 8 0 6800 0 Blue 0
10 PM Thu 56 56 N 8 0 6800 0 Blue 0
11 PM Thu 55 55 N 8 0 6800 0 Blue 0
12 Midnight Fri 54 54 N 8 0 6800 0 Blue 0
1 AM Fri 53 53 N 8 0 6800 0 Blue 0
2 AM Fri 51 51 N 7 0 6800 0 Blue 0
3 AM Fri 50 50 N 7 0 6800 0 Blue 0
4 AM Fri 48 48 N 7 0 6800 0 Blue 0
5 AM Fri 47 47 NW 7 0 6800 0 Blue 0
6 AM Fri 47 47 NW 6 0 6800 0 Blue 0
7 AM Fri 49 49 NW 6 0 6800 0 Blue 0
8 AM Fri 52 52 N 5 0 6800 0 Blue 0
9 AM Fri 56 58 N 5 0 6800 0 Blue 0
10 AM Fri 60 63 NE 5 0 6800 0 Blue 0
11 AM Fri 65 69 NE 5 16571 15766 8966 Blue 8
12 Noon Fri 68 72 NE 5 17708 16456 9656 Blue 11
1 PM Fri 70 74 NE 5 19024 17090 10290 Blue 13
2 PM Fri 72 76 E 6 19606 18063 11263 Blue 15
3 PM Fri 72 74 E 6 19024 17090 10290 Blue 13
4 PM Fri 73 74 E 6 19024 17090 10290 Blue 13
5 PM Fri 73 73 E 6 18510 16775 9975 Blue 12
6 PM Fri 71 71 E 6 17210 16134 9334 Blue 10
7 PM Fri 67 67 E 6 15931 15645 8845 Blue 6
8 PM Fri 62 62 E 6 0 6800 0 Blue 0
9 PM Fri 58 58 NE 5 0 6800 0 Blue 0
10 PM Fri 55 55 NE 5 0 6800 0 Blue 0
11 PM Fri 54 54 N 5 0 6800 0 Blue 0
12 Midnight Sat 54 54 N 6 0 6800 0 Blue 0
1 AM Sat 53 53 N 6 0 6800 0 Blue 0
2 AM Sat 52 52 NW 5 0 6800 0 Blue 0
3 AM Sat 51 51 NW 5 0 6800 0 Blue 0
4 AM Sat 50 50 NW 5 0 6800 0 Blue 0
5 AM Sat 49 49 W 5 0 6800 0 Blue 0
6 AM Sat 49 49 W 3 0 6800 0 Blue 0
7 AM Sat 51 51 W 3 0 6800 0 Blue 0
8 AM Sat 55 55 NW 2 0 6800 0 Blue 0
9 AM Sat 60 61 NE 2 0 6800 0 Blue 0
10 AM Sat 64 67 E 2 15931 15645 8845 Blue 6
11 AM Sat 69 73 E 3 18510 16775 9975 Blue 12
12 Noon Sat 72 76 E 3 19606 18063 11263 Blue 15
1 PM Sat 74 78 E 3 20556 19183 12383 Blue 17
2 PM Sat 75 79 E 3 21104 19470 12670 White 18
3 PM Sat 76 78 NE 3 20556 19183 12383 Blue 17
4 PM Sat 76 77 NW 5 19932 18893 12093 Blue 16
5 PM Sat 76 76 NW 6 19606 18063 11263 Blue 15
6 PM Sat 74 74 NW 7 19024 17090 10290 Blue 13
7 PM Sat 70 70 NW 7 16892 15889 9089 Blue 9
8 PM Sat 65 65 NW 7 15722 14780 7980 Blue 4
9 PM Sat 61 61 W 7 0 6800 0 Blue 0
10 PM Sat 59 59 W 8 0 6800 0 Blue 0
11 PM Sat 58 58 W 8 0 6800 0 Blue 0
12 Midnight Sun 57 57 W 8 0 6800 0 Blue 0
1 AM Sun 56 56 W 8 0 6800 0 Blue 0
2 AM Sun 54 54 W 8 0 6800 0 Blue 0
3 AM Sun 53 53 W 7 0 6800 0 Blue 0
4 AM Sun 51 51 W 7 0 6800 0 Blue 0
5 AM Sun 50 50 W 6 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