National Weather Service United States Department of Commerce

Soaring Forecast

 

 

 

It is emphasized...this soaring forecast information is valid only for the RAOB site area, and frequently will not apply to other areas of the state.

 


Soaring Forecast
National Weather Service Wichita, Kansas
2006 CST Tuesday, November 30, 2021

This forecast is for Wednesday December  1, 2021
:

If the trigger temperature of 69.1 F/20.6 C is reached...then
   Thermal Soaring Index....................... Poor
   Maximum rate of lift........................ 72 ft/min (0.4 m/s)
   Maximum height of thermals.................. 4407 ft MSL (2865 ft AGL)

Forecast maximum temperature................... 72.0 F/22.7 C
Time of trigger temperature.................... 1345 CST
Time of overdevelopment........................ None
Middle/high clouds during soaring window....... None
Surface winds during soaring window............ 20 mph or less
Height of the -3 thermal index................. 3041 ft MSL (1499 ft AGL)
Thermal soaring outlook for Thursday 12/02..... Poor

Wave Soaring Index............................. Not available

Remarks... 

Sunrise/Sunset.................... 07:29:08 / 17:12:33 CST
Total possible sunshine........... 9 hr 43 min 25 sec (583 min 25 sec)
Altitude of sun at 12:20:50 CST... 29.96 degrees

Upper air data from numerical model forecast valid on 11/30/2021 at 0500 CST

Freezing level.................. 10947 ft MSL (9405 ft AGL)
Convective condensation level... 16176 ft MSL (14634 ft AGL)
Lifted condensation level....... 11212 ft MSL (9670 ft AGL)
Lifted index.................... +8.7
K index......................... +10.8

Height  Temperature  Wind  Wind Spd  Lapse Rate  ConvectionT  Thermal  Lift Rate
ft MSL  deg C deg F   Dir   kt  m/s  C/km F/kft  deg C deg F   Index    fpm  m/s
--------------------------------------------------------------------------------
 18000  -11.7  10.9   350  136   70   8.4   4.6   39.2 102.5    10.8      M    M
 17000   -9.9  14.2   355  139   71   4.0   2.2   37.8 100.1    10.3      M    M
 16000   -8.8  16.2   355  141   72   4.3   2.4   35.8  96.4     9.7      M    M
 15000   -7.4  18.7   355  143   73   6.6   3.6   34.0  93.3     9.0      M    M
 14000   -5.5  22.1   355  139   72   7.0   3.8   33.0  91.4     8.2      M    M
 13000   -3.4  25.9   355  130   67   6.4   3.5   32.1  89.8     7.6      M    M
 12000   -1.8  28.8   350  112   58   5.6   3.1   30.8  87.4     7.0      M    M
 11000   -0.3  31.5   350  108   55   6.0   3.3   29.3  84.7     6.7      M    M
 10000    1.8  35.2   355  109   56   7.2   3.9   28.3  83.0     6.5      M    M
  9500    3.0  37.4   350  105   54   7.4   4.1   27.9  82.3     6.2      M    M
  9000    4.6  40.3   350   97   50   6.6   3.6   27.3  81.2     5.7      M    M
  8500    5.7  42.3   350   90   47   6.3   3.5   26.8  80.3     5.3      M    M
  8000    6.4  43.5   355   89   46   4.6   2.5   26.1  79.0     4.9      M    M
  7500    7.0  44.6   355   88   45   5.1   2.8   25.3  77.5     4.4      M    M
  7000    7.8  46.0   355   95   49   5.5   3.0   24.6  76.3     3.9      M    M
  6500    8.6  47.5   355  102   53   5.3   2.9   23.9  75.1     3.4      M    M
  6000    9.4  48.9   355  107   55   5.3   2.9   23.2  73.8     2.7      M    M
  5500   10.1  50.2   355  109   56   5.5   3.0   22.6  72.6     1.9      M    M
  5000   10.9  51.6   355  108   56   5.1   2.8   21.9  71.4     1.1      M    M
  4500   11.7  53.1   355  107   55   5.4   2.9   21.2  70.1     0.2      M    M
  4000   12.4  54.3   355  104   54   3.6   2.0   20.4  68.7    -0.8     47  0.2
  3750   12.6  54.7   355  104   53   3.3   1.8   19.9  67.8    -1.2     32  0.2
  3500   12.8  55.0   355  102   53   2.9   1.6   19.4  66.9    -1.8     18  0.1
  3250   13.0  55.4   355  101   52   0.3   0.2   18.8  65.8    -2.4      6  0.0
  3000   12.9  55.2   355   99   51  -1.2  -0.7   18.0  64.4    -3.1      M    M
  2750   12.7  54.9   355   96   49  -2.7  -1.5   17.1  62.8    -3.8      M    M
  2500   12.3  54.1   355   91   47 -10.1  -5.5   16.1  60.7    -5.0      M    M
  2250   11.3  52.3   355   82   42 -13.5  -7.4   14.2  57.6    -7.1     29  0.1
  2000   10.3  50.5   355   74   38 -13.9  -7.6   12.5  54.5    -9.1     61  0.3
  1750    8.7  47.7   355   48   25 -35.7 -19.6   10.1  50.3   -11.7    110  0.6

 * * * * * * Numerical weather prediction model forecast data valid * * * * * * 

           11/30/2021 at 0800 CST          |       11/30/2021 at 1100 CST        
                                           |
CAPE...     0.0    LI...      +12.5        | CAPE...     0.0    LI...      +12.7
CINH...     0.0    K Index...  -8.4        | CINH...    -0.1    K Index...  -5.5
                                           |
Height Temperature  Wnd WndSpd  Lapse Rate | Temperature  Wnd WndSpd  Lapse Rate
ft MSL deg C deg F  Dir kt m/s  C/km F/kft | deg C deg F  Dir kt m/s  C/km F/kft
--------------------------------------------------------------------------------
 18000  -9.9  14.2  355 184 95   8.3   4.6 |  -9.3  15.3  355 189 97   8.7   4.8
 17000  -8.0  17.6  355 184 95   5.8   3.2 |  -6.8  19.8  355 191 98   8.0   4.4
 16000  -6.4  20.5  355 190 98   5.2   2.8 |  -4.6  23.7  355 194 100   6.6   3.6
 15000  -4.8  23.4  355 198 102   4.7   2.6 |  -2.8  27.0  355 199 102   5.5   3.0
 14000  -3.4  25.9  355 207 106   4.6   2.5 |  -1.2  29.8  355 203 105   3.8   2.1
 13000  -2.0  28.4  360 208 107   4.6   2.5 |  -0.1  31.8  360 208 107   3.7   2.0
 12000  -0.7  30.7  360 206 106   5.3   2.9 |   1.0  33.8  360 214 110   4.2   2.3
 11000   1.0  33.8  360 195 100   5.4   3.0 |   2.6  36.7  360 212 109   4.0   2.2
 10000   2.7  36.9  355 180 93   4.1   2.3 |   3.7  38.7  360 205 106   3.2   1.8
  9500   3.3  37.9  355 176 91   4.2   2.3 |   4.2  39.6  360 202 104   3.1   1.7
  9000   3.9  39.0  355 180 93   4.1   2.3 |   4.5  40.1  360 200 103   2.0   1.1
  8500   4.5  40.1  355 187 96   4.4   2.4 |   4.8  40.6  360 200 103   2.3   1.3
  8000   5.2  41.4  360 196 101   4.8   2.7 |   5.1  41.2  360 202 104   2.6   1.4
  7500   6.0  42.8  360 206 106   5.0   2.8 |   5.5  41.9  360 204 105   4.4   2.4
  7000   6.7  44.1  360 214 110   5.1   2.8 |   6.3  43.3  360 208 107   5.1   2.8
  6500   7.5  45.5  360 223 115   5.7   3.1 |   7.2  45.0  360 212 109   6.5   3.6
  6000   8.4  47.1  360 232 119   5.2   2.8 |   8.2  46.8  360 216 111   5.9   3.2
  5500   9.1  48.4  360 201 104   6.6   3.6 |   9.0  48.2  360 221 114   6.2   3.4
  5000  10.2  50.4  360 120 62   7.0   3.8 |  10.0  50.0  360 228 117   5.7   3.1
  4500  11.2  52.2  360 123 63   6.8   3.7 |  10.8  51.4  360 230 119   5.8   3.2
  4000  12.2  54.0  360  71 37   6.6   3.6 |  11.6  52.9  360 231 119   6.0   3.3
  3750  12.7  54.9  010   9  5   5.5   3.0 |  12.0  53.6  360 230 118   3.8   2.1
  3500  13.0  55.4  010   9  4   3.8   2.1 |  12.2  54.0  360 228 117   2.9   1.6
  3250  13.2  55.8  015   9  5   2.8   1.5 |  12.5  54.5  360 223 115   4.7   2.6
  3000  13.4  56.1  015   9  5   3.3   1.8 |  12.8  55.0  360 217 112   4.1   2.2
  2750  13.5  56.3  020   9  5  -3.4  -1.8 |  13.1  55.6  360 212 109   5.0   2.8
  2500  12.7  54.9  360  54 28 -13.6  -7.4 |  13.6  56.5  360 208 107   7.3   4.0
  2250  11.6  52.9  360 132 68 -15.5  -8.5 |  14.1  57.4  360 203 105   6.9   3.8
  2000  10.4  50.7  360 209 108 -14.3  -7.8 |  14.6  58.3  360 198 102   9.5   5.2
  1750   9.3  48.7  360 205 106 -15.6  -8.6 |  15.6  60.1  360 196 101  17.5   9.6

           11/30/2021 at 1400 CST          |       11/30/2021 at 1700 CST        
                                           |
CAPE...     0.0    LI...      +10.2        | CAPE...     0.0    LI...       +8.8
CINH...    -0.0    K Index...  +2.4        | CINH...     0.0    K Index...  +7.2
                                           |
Height Temperature  Wnd WndSpd  Lapse Rate | Temperature  Wnd WndSpd  Lapse Rate
ft MSL deg C deg F  Dir kt m/s  C/km F/kft | deg C deg F  Dir kt m/s  C/km F/kft
--------------------------------------------------------------------------------
 18000  -9.3  15.3  355 149 77   7.8   4.3 |  -9.3  15.3  350 101 52   7.1   3.9
 17000  -7.0  19.4  355 161 83   7.9   4.3 |  -7.2  19.0  350 104 54   7.3   4.0
 16000  -4.8  23.4  355 169 87   7.1   3.9 |  -5.0  23.0  350 107 55   7.1   3.9
 15000  -2.8  27.0  355 176 90   6.1   3.4 |  -3.0  26.6  355 108 55   6.7   3.7
 14000  -1.1  30.0  355 182 94   4.9   2.7 |  -1.0  30.2  355 108 55   6.0   3.3
 13000   0.4  32.7  355 190 98   4.4   2.4 |   0.7  33.3  355 111 57   6.0   3.3
 12000   1.6  34.9  360 199 102   4.4   2.4 |   2.8  37.0  355 119 61   4.8   2.6
 11000   2.9  37.2  360 200 103   4.8   2.6 |   4.3  39.7  355 124 64   5.5   3.0
 10000   4.7  40.5  360 197 101   4.8   2.6 |   5.9  42.6  355 127 66   4.9   2.7
  9500   5.4  41.7  360 195 100   4.7   2.6 |   6.6  43.9  355 128 66   4.9   2.7
  9000   6.1  43.0  360 194 100   4.3   2.4 |   7.3  45.1  355 126 65   4.5   2.5
  8500   6.7  44.1  360 193 99   4.0   2.2 |   8.0  46.4  355 124 64   4.8   2.6
  8000   7.2  45.0  360 194 100   3.5   1.9 |   8.7  47.7  355 119 61   5.1   2.8
  7500   7.7  45.9  360 196 101   3.6   2.0 |   9.5  49.1  355 115 59   5.4   2.9
  7000   8.3  46.9  360 197 102   3.6   2.0 |  10.3  50.5  355 108 56   5.5   3.0
  6500   8.9  48.0  360 194 100   5.0   2.7 |  11.0  51.8  355  99 51   5.0   2.7
  6000   9.7  49.5  360 185 95   5.1   2.8 |  11.8  53.2  355  88 45   6.4   3.5
  5500  10.5  50.9  360 166 86   5.6   3.1 |  12.7  54.9  355  75 39   4.3   2.3
  5000  11.4  52.5  355 133 68   4.5   2.5 |  13.4  56.1  350  56 29   4.7   2.6
  4500  11.8  53.2  355 100 51   1.5   0.8 |  13.9  57.0  345  34 18   2.3   1.3
  4000  12.3  54.1  355  55 28   6.4   3.5 |  14.1  57.4  295  10  5  -0.6  -0.3
  3750  12.8  55.0  350  34 18   5.2   2.8 |  14.1  57.4  230  12  6   1.6   0.9
  3500  13.1  55.6  350  24 12   6.5   3.6 |  14.3  57.7  200  25 13   4.6   2.5
  3250  13.7  56.7  345  19 10   9.5   5.2 |  14.7  58.5  195  37 19   5.7   3.1
  3000  14.4  57.9  345  16  8   9.5   5.2 |  15.1  59.2  190  48 25   6.8   3.7
  2750  15.1  59.2  340  12  6   9.5   5.2 |  15.6  60.1  185  61 31   6.7   3.7
  2500  15.9  60.6  335  10  5  10.1   5.6 |  16.0  60.8  185  71 37   3.6   2.0
  2250  16.6  61.9  330   8  4  10.3   5.6 |  16.2  61.2  185  77 40   4.3   2.3
  2000  17.4  63.3  325   7  4  10.5   5.7 |  16.4  61.5  185  82 42  -2.0  -1.1
  1750  18.2  64.8  310   5  3  12.1   6.6 |  15.4  59.7  185  87 45 -27.3 -15.0
________________________________________________________________________________

This product is issued twice per day, once by approximately 0630 CST/0730 CDT 
(1330 UTC) and again by approximately 1830 CST/1930 CDT (0130 UTC).  It is not 
continuously monitored nor updated after its initial issuance. 

The information contained herein is based on rawinsonde observation and/or
numerical weather prediction model data taken at the Wichita Gliderport at 

                   North Latitude: 37 deg 45 min 48.420 sec
                   West Longitude: 97 deg 10 min 41.220 sec
                   Elevation: 1380 feet (420 meters)

and may not be representative of other locations around the Wichita area.  Note
that some elevations in numerical weather prediction models differ from actual
station elevations, which can lead to data which appear to be below ground.
Erroneous data such as these should not be used.

The content and format of this report as well as the issuance times are subject
to change without prior notice.  Comments and suggestions are welcome and should
be directed to one of the addresses or phone numbers shown at the bottom of this
page.  To expedite a response to comments, be sure to mention your interest in 
the soaring forecast.

DEFINITIONS:

CAPE (Convective Available Potential Energy) - An integrated measure of the
     energy available for convective development, also known as the positive 
     area on a thermodynamic diagram.  Units are Joules per kilogram.  Larger
     values are indicative of greater instability and the possibility of 
     stronger convective activity, including thunderstorms.  Values around or
     greater than 1000 suggest the possibility of severe weather should
     convective activity develop.

CIN (Convective Inhibition) - An integrated measure of the amount of energy
     needed to initiate convective activity, also known as the negative area on
     a thermodynamic diagram.  Units are Joules per kilogram.  The more negative
     this number, the more energy is required to initiate convection.  This
     inhibitive energy can be overcome through surface heating, cooling aloft,
     lifting mechanisms (orographic, frontal, gravity waves, etc.)

Convective Condensation Level - The height to which an air parcel possessing the
     average saturation mixing ratio in the lowest 4000 feet of the airmass,
     if heated sufficiently from below, will rise dry adiabatically until it 
     just becomes saturated.  It estimates the base of cumulus clouds that are
     produced by surface heating only.

Convection Temperature (ConvectionT) - The surface temperature required to make
     the airmass dry adiabatic up to the given level.  It can be considered a
     "trigger temperature" for that level.

Freezing Level - The height where the temperature is zero degrees Celsius.

Height of Stable Layer - The height (between 12,000 and 18,000 feet above 
     mean sea level) where the smallest lapse rate exists.  The location and
     existence of this feature is important in the generation of mountain 
     waves.

K Index - A measure of stability which combines the temperature difference
     between approximately 5,000 and 18,000 feet above the surface, the amount
     of moisture at approximately 5,000 feet above the surface, and a measure
     of the dryness at approximately 10,000 feet above the surface.  Larger 
     positive numbers indicate more instability and a greater likelihood of 
     thunderstorm development.  One interpretation of K index values regarding
     soaring in the western United States is given in WMO Technical Note 158 
     and is reproduced in the following table:

          below -10    no or weak thermals
           -10 to 5    dry thermals or 1/8 cumulus with moderate thermals
            5 to 15    good soaring conditions
           15 to 20    good soaring conditions with occasional showers
           20 to 30    excellent soaring conditions, but increasing
                       probability of showers and thunderstorms
           above 30    more than 60 percent probability of thunderstorms

Lapse Rate - The change with height of the temperature. Negative values indicate
     inversions. 

Lifted Condensation Level - The height to which an air parcel possessing the 
     average dew point in the lowest 4000 feet of the airmass and the forecast
     maximum temperature must be lifted dry adiabatically to attain saturation.

Lifted Index (LI) - The difference between the environmental temperature at a
     level approximately 18,000 feet above the surface and the temperature of
     an air parcel lifted dry adiabatically from the surface to its lifted
     condensation level and then pseudoadiabatically thereafter to this same
     level.  The parcel's initial temperature is the forecast maximum 
     temperature and its dew point is the average dew point in the lowest 4000
     feet of the airmass.  Negative values are indicative of instability with
     positive values showing stable conditions.

Lift Rate - An experimental estimate of the strength of thermals.  It is
     computed the same way as the maximum rate of lift but uses the actual
     level rather than the maximum height of thermals in the calculation.
     Also, none of the empirical adjustments based on cloudiness and K-index
     are applied to these calculations.

Maximum Height of Thermals - The height where the dry adiabat through the
     forecast maximum temperature intersects the environmental temperature.

Maximum Rate of Lift - An estimate of the maximum strength of thermals.  It 
     is computed from an empirical formula which combines the expected maximum
     height of thermals with the difference in the environmental temperatures 
     between the maximum height of thermals and the temperature 4,000 feet 
     above the ground.  After this computation, further empirical adjustments
     are made based on the value of the K-index and the amount and opacity of
     middle and high level cloudiness expected between the time of trigger
     temperature and the time of overdevelopment.  

Middle/High Clouds - The amount and opacity of middle (altostratus, altocumulus)
     or high (cirrus, cirrostratus, cirrocumulus) clouds.  Broken means that
     between 60% and 90% of the sky is covered by the cloud, with overcast
     conditions occurring when more than 90% of the sky is covered by the cloud.
     Thin implies that the clouds are predominantly transparent, meaning that
     some sunlight is reaching the ground, in contrast to opaque which suggests
     that little sunlight is reaching the ground.
  
Potential Height of Wave - The minimum of the following two heights: 
     1. Level above the height of stable layer (or 14,000 feet if none exists)
        where the wind direction changes by 30 degrees or more
     2. Level above the height of stable layer (or 14,000 feet if none exists)
        where the wind speed no longer increases with height

PVA/NVA - Positive vorticity advection (PVA)/negative vorticity advection (NVA)
     on the 500 millibar isobaric surface (approximately 18,000 feet above mean
     sea level).  Weak PVA has been shown to assist in mountain wave soaring.

Soaring Window - The time between the time the trigger temperature is reached
                 and the time of overdevelopment.

Thermal Index - The difference between the environmental temperature and the
     temperature at a particular level determined by following the dry adiabat
     through the forecast maximum temperature up to that level.  Negative values
     are indicative of thermal lift.

Thermal Soaring Index - An adjective rating (for sailplanes) based on the 
     computed maximum rate of lift, and the wind speed and middle and high
     cloud cover expected during the soaring window (the time of the trigger
     temperature and the time of overdevelopment) according to the following:

                 Maximum rate of lift        Adjective Rating
                      >= 800 fpm                 Excellent
                 >= 400 and < 800 fpm              Good
                 >= 200 and < 400 fpm              Fair
                       < 200 fpm                   Poor  

Time of Overdevelopment - The time one or more of the following phenomena,
     which essentially shut off thermal lift, is expected to occur:
     1. formation of broken to overcast convective cloud cover
     2. formation of scattered to numerous downbursts
     3. initiation of widespread precipitation

Time of Trigger Temperature - The time the surface temperature is expected to
     reach the trigger temperature.

Trigger Temperature - The surface temperature required to make the first 4000
     feet of the atmosphere dry adiabatic.

Wave Soaring Index - An empirical, adjective rating (for sailplanes) which 
     attempts to combine a variety of phenomena important in mountain wave
     soaring into a single index number.  Objective points are assigned to
     these phenomena: wind speed and direction at 14,000 ft MSL, the static
     stability in the 12,000-18,000 ft MSL layer, the wind speed gradient above
     the stable layer, jet stream location and frontal and upper trough 
     movements.

051515