Detailed Predictions for: Merriam Crater
Launch Lat, Long, Altitude (f): 35.33876269790076, -111.2860844211301, 6800
LZ Altitude (f): 6000
Sounding

Station:

 KFGZ

Date/Time:

 25 APR 2024

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 Thu 57 57 S 7 14 14579 10140 3340 White 25
1 AM Thu 56 56 S 7 13 14368 9598 2798 White 24
2 AM Thu 55 55 S 7 15 10740 9040 2240 Blue 23
3 AM Thu 54 54 SSW 8 16 10200 8568 1768 Blue 22
4 AM Thu 52 52 SSW 9 18 9083 8289 1489 Blue 20
5 AM Thu 51 51 SSW 11 21 8578 8205 1405 Blue 19
6 AM Thu 37 37 SW 5 21 7439 7280 480 Blue 6
7 AM Thu 52 52 SSW 10 19 9083 8289 1489 Blue 20
8 AM Thu 54 55 S 11 15 10740 9040 2240 Blue 23
9 AM Thu 57 60 S 11 13 15212 15212 8412 White 28
10 AM Thu 59 64 SSW 16 18 16051 16051 9251 White 32
11 AM Thu 61 68 SSW 19 22 16882 16882 10082 White 36
12 Noon Thu 61 62 WSW 19 22 15633 15633 8833 White 30
1 PM Thu 60 61 W 19 22 15422 15422 8622 White 29
2 PM Thu 60 61 W 19 22 15422 15422 8622 White 29
3 PM Thu 61 62 W 23 26 15633 15633 8833 White 30
4 PM Thu 61 63 W 20 23 15842 15842 9042 White 31
5 PM Thu 60 61 WSW 24 27 15422 15422 8622 White 29
6 PM Thu 59 59 WSW 25 29 15001 15001 8201 White 27
7 PM Thu 59 59 WSW 24 27 15001 15001 8201 White 27
8 PM Thu 58 58 WSW 18 24 14790 10672 3872 White 26
9 PM Thu 57 57 WSW 19 25 14579 10140 3340 White 25
10 PM Thu 56 56 WSW 20 28 14368 9598 2798 White 24
11 PM Thu 55 55 WSW 18 25 10740 9040 2240 Blue 23
12 Midnight Fri 54 54 WSW 17 25 10200 8568 1768 Blue 22
1 AM Fri 53 53 SW 16 24 9649 8384 1584 Blue 21
2 AM Fri 52 52 SW 16 24 9083 8289 1489 Blue 20
3 AM Fri 51 51 SW 15 23 8578 8205 1405 Blue 19
4 AM Fri 50 50 SW 13 23 8394 8122 1322 Blue 18
5 AM Fri 50 50 WSW 14 22 8394 8122 1322 Blue 18
6 AM Fri 49 49 SW 13 22 8293 8038 1238 Blue 17
7 AM Fri 51 51 WSW 14 21 8578 8205 1405 Blue 19
8 AM Fri 53 55 WSW 16 19 10740 9040 2240 Blue 23
9 AM Fri 55 58 SW 21 24 14790 10672 3872 White 26
10 AM Fri 58 63 SW 22 25 15842 15842 9042 White 31
11 AM Fri 60 65 SW 23 27 16260 16260 9460 White 33
12 Noon Fri 61 68 SW 25 29 16882 16882 10082 White 36
1 PM Fri 62 69 SW 26 30 17083 17083 10283 White 37
2 PM Fri 63 69 SW 28 32 17083 17083 10283 White 37
3 PM Fri 62 66 SW 29 33 16468 16468 9668 White 34
4 PM Fri 61 64 SW 29 34 16051 16051 9251 White 32
5 PM Fri 60 61 SW 27 31 15422 15422 8622 White 29
6 PM Fri 58 58 SW 27 31 14790 10672 3872 White 26
7 PM Fri 55 55 SW 25 29 10740 9040 2240 Blue 23
8 PM Fri 52 52 SW 23 26 9083 8289 1489 Blue 20
9 PM Fri 49 49 WSW 18 23 8293 8038 1238 Blue 17
10 PM Fri 48 48 W 19 25 8209 7955 1155 Blue 16
11 PM Fri 48 48 SW 14 17 8209 7955 1155 Blue 16
12 Midnight Sat 48 48 SW 13 16 8209 7955 1155 Blue 16
1 AM Sat 48 48 SW 12 15 8209 7955 1155 Blue 16
2 AM Sat 47 47 SW 12 15 8125 7871 1071 Blue 15
3 AM Sat 46 46 SW 16 21 8042 7788 988 Blue 14
4 AM Sat 45 45 SW 19 25 7958 7705 905 Blue 13
5 AM Sat 44 44 SW 17 21 7874 7648 848 Blue 12
6 AM Sat 44 44 WSW 13 15 7874 7648 848 Blue 12
7 AM Sat 44 44 W 12 14 7874 7648 848 Blue 12
8 AM Sat 44 44 WSW 15 17 7874 7648 848 Blue 12
9 AM Sat 44 44 WSW 17 20 7874 7648 848 Blue 12
10 AM Sat 45 45 W 18 21 7958 7705 905 Blue 13
11 AM Sat 46 49 WSW 19 22 8293 8038 1238 Blue 17
12 Noon Sat 48 49 WSW 19 22 8293 8038 1238 Blue 17
1 PM Sat 50 51 WSW 16 19 8578 8205 1405 Blue 19
2 PM Sat 51 52 WSW 19 21 9083 8289 1489 Blue 20
3 PM Sat 51 52 W 20 24 9083 8289 1489 Blue 20
4 PM Sat 50 50 W 13 15 8394 8122 1322 Blue 18
5 PM Sat 52 52 WNW 5 6 9083 8289 1489 Blue 20
6 PM Sat 54 54 W 5 6 10200 8568 1768 Blue 22
7 PM Sat 55 55 WNW 9 11 10740 9040 2240 Blue 23
8 PM Sat 54 54 WNW 14 19 10200 8568 1768 Blue 22
9 PM Sat 52 52 W 11 18 9083 8289 1489 Blue 20
10 PM Sat 51 51 W 10 18 8578 8205 1405 Blue 19
11 PM Sat 49 49 WSW 10 20 8293 8038 1238 Blue 17

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 [email protected]