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

Station:

KFGZ

Date/Time:

17 NOV 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)
5 AM Fri 50 50 SW 21 0 6800 0 Blue 0
6 AM Fri 49 49 SW 21 0 6800 0 Blue 0
7 AM Fri 49 49 SW 22 0 6800 0 Blue 0
8 AM Fri 50 50 SW 23 0 6800 0 Blue 0
9 AM Fri 53 53 SW 24 0 6800 0 Blue 0
10 AM Fri 58 59 SW 25 10012 9060 2260 Blue 5
11 AM Fri 61 62 SW 26 10706 9977 3177 Blue 8
12 Noon Fri 63 65 SW 28 12161 10665 3865 White 11
1 PM Fri 64 66 SW 28 12376 11461 4661 White 12
2 PM Fri 64 65 SW 28 12161 10665 3865 White 11
3 PM Fri 63 64 SW 28 11948 10439 3639 White 10
4 PM Fri 61 61 W 26 10469 9704 2904 Blue 7
5 PM Fri 60 60 W 25 10255 9429 2629 Blue 6
6 PM Fri 58 58 W 24 9737 7374 574 Blue 4
7 PM Fri 56 56 W 22 9180 7149 349 Blue 2
8 PM Fri 55 55 W 20 7382 7149 349 Blue 1
9 PM Fri 54 54 W 16 7197 7149 349 Blue 0
10 PM Fri 53 53 NW 15 0 6800 0 Blue 0
11 PM Fri 51 51 NW 14 0 6800 0 Blue 0
12 Midnight Sat 49 49 N 14 0 6800 0 Blue 0
1 AM Sat 46 46 N 14 0 6800 0 Blue 0
2 AM Sat 44 44 N 14 0 6800 0 Blue 0
3 AM Sat 42 42 N 13 0 6800 0 Blue 0
4 AM Sat 41 41 N 10 0 6800 0 Blue 0
5 AM Sat 38 38 N 9 0 6800 0 Blue 0
6 AM Sat 36 36 N 8 0 6800 0 Blue 0
7 AM Sat 34 34 N 7 0 6800 0 Blue 0
8 AM Sat 34 34 N 6 0 6800 0 Blue 0
9 AM Sat 37 37 N 6 0 6800 0 Blue 0
10 AM Sat 42 44 NE 6 0 6800 0 Blue 0
11 AM Sat 47 49 NE 6 0 6800 0 Blue 0
12 Noon Sat 50 53 NE 6 0 6800 0 Blue 0
1 PM Sat 52 55 NE 6 7382 7149 349 Blue 1
2 PM Sat 53 55 NE 6 7382 7149 349 Blue 1
3 PM Sat 53 54 NE 5 7197 7149 349 Blue 0
4 PM Sat 53 53 NE 5 0 6800 0 Blue 0
5 PM Sat 51 51 NE 5 0 6800 0 Blue 0
6 PM Sat 47 47 NE 2 0 6800 0 Blue 0
7 PM Sat 42 42 N 2 0 6800 0 Blue 0
8 PM Sat 38 38 NW 2 0 6800 0 Blue 0
9 PM Sat 35 35 NW 2 0 6800 0 Blue 0
10 PM Sat 33 33 NW 2 0 6800 0 Blue 0
11 PM Sat 33 33 NW 3 0 6800 0 Blue 0
12 Midnight Sun 32 32 NW 2 0 6800 0 Blue 0
1 AM Sun 30 30 S 2 0 6800 0 Blue 0
2 AM Sun 30 30 S 2 0 6800 0 Blue 0
3 AM Sun 29 29 S 2 0 6800 0 Blue 0
4 AM Sun 28 28 SE 2 0 6800 0 Blue 0
5 AM Sun 28 28 SE 2 0 6800 0 Blue 0
6 AM Sun 27 27 SE 2 0 6800 0 Blue 0
7 AM Sun 28 28 SE 2 0 6800 0 Blue 0
8 AM Sun 31 31 SE 2 0 6800 0 Blue 0
9 AM Sun 37 37 SE 2 0 6800 0 Blue 0
10 AM Sun 44 45 E 3 0 6800 0 Blue 0
11 AM Sun 50 52 E 5 0 6800 0 Blue 0
12 Noon Sun 54 57 E 5 9459 7191 391 Blue 3
1 PM Sun 56 59 E 5 10012 9060 2260 Blue 5
2 PM Sun 57 59 E 5 10012 9060 2260 Blue 5
3 PM Sun 58 59 NE 5 10012 9060 2260 Blue 5
4 PM Sun 58 58 NE 3 9737 7374 574 Blue 4
5 PM Sun 55 55 N 3 7382 7149 349 Blue 1
6 PM Sun 51 51 NE 3 0 6800 0 Blue 0
7 PM Sun 46 46 SW 2 0 6800 0 Blue 0
8 PM Sun 41 41 SW 2 0 6800 0 Blue 0
9 PM Sun 38 38 SW 2 0 6800 0 Blue 0
10 PM Sun 37 37 SW 3 0 6800 0 Blue 0
11 PM Sun 36 36 SW 3 0 6800 0 Blue 0
12 Midnight Mon 35 35 SW 3 0 6800 0 Blue 0
1 AM Mon 34 34 SW 5 0 6800 0 Blue 0
2 AM Mon 33 33 SW 5 0 6800 0 Blue 0
3 AM Mon 32 32 SW 5 0 6800 0 Blue 0
4 AM Mon 31 31 SW 3 0 6800 0 Blue 0
5 AM Mon 31 31 SW 3 0 6800 0 Blue 0
6 AM Mon 31 31 S 3 0 6800 0 Blue 0
7 AM Mon 32 32 S 3 0 6800 0 Blue 0
8 AM Mon 36 36 S 2 0 6800 0 Blue 0
9 AM Mon 42 42 S 3 0 6800 0 Blue 0
10 AM Mon 50 51 S 3 0 6800 0 Blue 0
11 AM Mon 56 57 S 3 9459 7191 391 Blue 3
12 Noon Mon 60 61 E 3 10469 9704 2904 Blue 7
1 PM Mon 61 62 E 6 10706 9977 3177 Blue 8
2 PM Mon 62 63 SE 6 11731 10226 3426 White 9
3 PM Mon 63 63 SE 7 11731 10226 3426 White 9
4 PM Mon 62 62 SE 7 10706 9977 3177 Blue 8
5 PM Mon 60 60 S 8 10255 9429 2629 Blue 6
6 PM Mon 56 56 SE 7 9180 7149 349 Blue 2
7 PM Mon 50 50 NW 7 0 6800 0 Blue 0
8 PM Mon 45 45 W 7 0 6800 0 Blue 0
9 PM Mon 43 43 W 7 0 6800 0 Blue 0
10 PM Mon 42 42 W 7 0 6800 0 Blue 0
11 PM Mon 41 41 W 6 0 6800 0 Blue 0
12 Midnight Tue 41 41 W 6 0 6800 0 Blue 0
1 AM Tue 40 40 W 6 0 6800 0 Blue 0
2 AM Tue 39 39 W 6 0 6800 0 Blue 0
3 AM Tue 38 38 W 5 0 6800 0 Blue 0
4 AM Tue 37 37 W 5 0 6800 0 Blue 0
5 AM Tue 37 37 W 5 0 6800 0 Blue 0
6 AM Tue 36 36 W 3 0 6800 0 Blue 0
7 AM Tue 36 36 SW 3 0 6800 0 Blue 0
8 AM Tue 39 39 SW 3 0 6800 0 Blue 0
9 AM Tue 44 44 SW 3 0 6800 0 Blue 0
10 AM Tue 50 51 S 3 0 6800 0 Blue 0
11 AM Tue 56 58 E 5 9737 7374 574 Blue 4
12 Noon Tue 59 61 NE 5 10469 9704 2904 Blue 7
1 PM Tue 61 63 NE 6 11731 10226 3426 White 9
2 PM Tue 62 64 NE 6 11948 10439 3639 White 10
3 PM Tue 63 64 NE 5 11948 10439 3639 White 10
4 PM Tue 63 63 NE 5 11731 10226 3426 White 9
5 PM Tue 60 60 NE 6 10255 9429 2629 Blue 6
6 PM Tue 55 55 NE 6 7382 7149 349 Blue 1
7 PM Tue 50 50 N 5 0 6800 0 Blue 0
8 PM Tue 45 45 N 5 0 6800 0 Blue 0
9 PM Tue 43 43 N 5 0 6800 0 Blue 0
10 PM Tue 43 43 N 6 0 6800 0 Blue 0
11 PM Tue 43 43 NW 6 0 6800 0 Blue 0
12 Midnight Wed 42 42 NW 5 0 6800 0 Blue 0
1 AM Wed 41 41 NW 5 0 6800 0 Blue 0
2 AM Wed 40 40 NW 5 0 6800 0 Blue 0
3 AM Wed 39 39 NW 5 0 6800 0 Blue 0
4 AM Wed 39 39 NW 3 0 6800 0 Blue 0
5 AM Wed 38 38 NW 5 0 6800 0 Blue 0
6 AM Wed 38 38 N 3 0 6800 0 Blue 0
7 AM Wed 38 38 NE 3 0 6800 0 Blue 0
8 AM Wed 40 40 E 3 0 6800 0 Blue 0
9 AM Wed 46 46 E 3 0 6800 0 Blue 0
10 AM Wed 52 53 NE 5 0 6800 0 Blue 0
11 AM Wed 58 60 NE 6 10255 9429 2629 Blue 6
12 Noon Wed 62 65 NE 6 12161 10665 3865 White 11
1 PM Wed 64 66 NE 6 12376 11461 4661 White 12
2 PM Wed 65 67 NE 6 12589 12142 5342 White 13
3 PM Wed 66 67 NE 7 12589 12142 5342 White 13
4 PM Wed 65 65 N 6 12161 10665 3865 White 11
5 PM Wed 62 62 N 6 10706 9977 3177 Blue 8
6 PM Wed 58 58 N 6 9737 7374 574 Blue 4
7 PM Wed 53 53 N 5 0 6800 0 Blue 0
8 PM Wed 48 48 NW 6 0 6800 0 Blue 0
9 PM Wed 46 46 NW 6 0 6800 0 Blue 0
10 PM Wed 45 45 NW 6 0 6800 0 Blue 0
11 PM Wed 45 45 NW 6 0 6800 0 Blue 0
12 Midnight Thu 44 44 NW 6 0 6800 0 Blue 0
1 AM Thu 43 43 NW 6 0 6800 0 Blue 0
2 AM Thu 42 42 NW 5 0 6800 0 Blue 0
3 AM Thu 41 41 NW 5 0 6800 0 Blue 0
4 AM Thu 40 40 N 5 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