NWS Raleigh, NC Reference Information - Understanding the Preliminary Climate Data (WS Form F-6)

NWS Raleigh, NC
Reference Information

Understanding the Preliminary Climate Data (WS Form F-6)

The preliminary climate data pages for Raleigh-Durham and Greensboro consist of 3 parts. The first part is the site information including the station location, the month and year of the report, and finally the latitude and longitude of the station. The second part of the report is the daily information which consists of 18 columns of data, with one row of data for each day of the month. The day runs from 0000 to 2359 LST (0100 to 0059 during daylight time). The third part of the report (noted as page 2) is the monthly section which consists of various averages and totals for the month.

* An excerpt from the second part of a WS Form F6 for January 2002 at Raleigh-Durham is shown below. An explanation of each column of data can be found below the example.

-1- Day	-2- Max	-3- Min	-4- Avg	-5- Dep.	-6a- HDD	-6b- CDD	-7- Water	-8- Snow	-9- Depth	-10- Avg.	-11- Speed	-12- Dir	-13- Mins.	-14- %PSBL	-15- SR-SS	-16- Weather	-17- Speed	-18- Dir

3	29	26	28	-12	37	0	0.59	6.5	6	7.7	16	10	M	M	10	14	23	10
4	39	13	26	-14	39	0	0.00	0.0	9	2.6	10	31	M	M	1		15	310
5	44	18	31	-9	34	0	0.00	0.0	5	4.6	15	250	M	M	2		14	190
6	38	25	32	-8	33	0	0.69	0.0	5	4.61	15	250	M	M	8	126	22	240
7	43	29	36	-4	29	0	T	0.0	1	7.2	18	300	M	M	6	1	25	310

1 The date of the month.

2 The highest temperature for the day.

3 The lowest temperature for the day.

4 The average temperature for the day, computed by finding the average of the values in columns 2 and 3, then rounding up (if necessary).

5 Departure from normal. The difference between column 4 and the 30 year normal temperature for this date.

6a Heating degree days. Computed by subtracting the average temperature from 65. If less than 0, HDD=0.

6b Cooling degree days. Computed by subtracting 65 from the average temperature. If less than 0, CDD=0.

7 Total precipitation for the day to the nearest hundredth of an inch. This includes all forms of precipitation, both liquid and water equivalent of any snow or ice that occurred (T = Trace).

8 Total snowfall for the day to the nearest tenth of an inch.

9 Snow depth to the nearest inch at 7am EST.

10 Average wind speed for the day in mph.

11 The highest wind speed in mph averaged over a 2 minute period.

12 The direction (in compass degrees divided by 10) from which the wind speed in column 11 came from. ( N=36 S=18 W=27 E=09, etc.)

13 The number of minutes of sunshine received at the station.

14 The percentage of possible sunshine. Computed by dividing the minutes of sunshine in column 13 by the total possible minutes.

15 The average sky cover between sunrise and sunset in tenths.

16 A coded number representing certain types of weather observed during the day.
1 = Fog
2 = Fog reducing visibilityto 1/4 mile or less
3 = Thunder
4 = Ice pellets
5 = Hail
6 = Glaze or rime
7 = Blowing dust or sand: visibility 1/2 mile or less
8 = Smoke or haze
9 = Blowing snow
X = Tornado

17 Peak wind speed for the day in mph. The highest wind speed observed at the station.

18 The compass direction from which the peak wind speed came.

* An excerpt from the third part of a WS Form F6 for January 2002 at Raleigh-Durham is shown below. An explanation of each column of data can be found below the example.


[TEMPERATURE DATA]      [PRECIPITATION DATA]        SYMBOLS USED IN COLUMN 16     

AVERAGE MONTHLY: 42.7   TOTAL FOR MONTH:   5.97    1 = FOG                      
DPTR FM NORMAL:   3.0   DPTR FM NORMAL:    1.95    2 = FOG REDUCING VISIBILITY  
HIGHEST:    80 ON 30    GRTST 24HR  2.05 ON 19-20      TO 1/4 MILE OR LESS      
LOWEST:     13 ON  4                               3 = THUNDER                  
                        SNOW, ICE PELLETS, HAIL    4 = ICE PELLETS              
                        TOTAL MONTH:  10.8 INCHES  5 = HAIL                     
                        GRTST 24HR   6.5 ON  3- 3  6 = GLAZE OR RIME            
                        GRTST DEPTH:   9 ON  4     7 = BLOWING DUST OR SAND:    
                                                       VSBY 1/2 MILE OR LESS    
                                                   8 = SMOKE OR HAZE            
NO. OF DAYS WITH      WEATHER - DAYS WITH          9 = BLOWING SNOW             
                                                   X = TORNADO                  
MAX 32 OR BELOW:   2    0.01 INCH OR MORE:  11                                  
MAX 90 OR ABOVE:   0    0.10 INCH OR MORE:   9                                  
MIN 32 OR BELOW:  22    0.50 INCH OR MORE:   4                                  
MIN  0 OR BELOW:   0    1.00 INCH OR MORE:   2                                  

HDD (BASE 65)                                                                 
TOTAL THIS MO.   687    CLEAR  (SCALE 0-3)  10                                  
DPTR FM NORMAL  -122    PTCLDY (SCALE 4-7)  15                                  
SEASONAL TOTAL  1767    CLOUDY (SCALE 8-10)  6                                  
DPTR FM NORMAL  -348                                                            

CDD (BASE 65)                                                                 
TOTAL THIS MO.     4                                                            
DPTR FM NORMAL     4    PRESSURE DATA                                         
SEASONAL TOTAL     4    HIGHEST SLP 30.45 ON 22                                 
DPTR FM NORMAL     4    LOWEST  SLP 29.50 ON  6                                 

REMARKS

TEMPERATURE DATA	Cumulative temperature information for the month including averages, departure from normal, and the highest/lowest temperatures observed and on what day they occurred.
NO. OF DAYS WITH	Number of days during the month that meet the criteria shown.
HDD (BASE 65)	Heating degree day information based on an average temperature of 65 degrees.
CDD (BASE 65)	Cooling degree day information based on an average temperature of 65 degrees.
REMARKS	Additive remarks made by observer.
PRECIPITATION DATA	Cumulative precipitation (for both rain and frozen precipitation) information, for the month including total for the month, departure from normal, greatest 24 hour amount and greatest snow depth at 7am EST.
WEATHER - DAYS WITH	Number of days during the month that meet the criteria shown.
PRESSURE DATA	Magnitude of highest and lowest sea level pressure and the day in which it occurred.
SYMBOLS USED IN COLUMN 16	A coded number representing certain types of weather observed during the day. 1 = Fog 2 = Fog reducing visibility to 1/4 mile or less 3 = Thunder 4 = Ice pellets 5 = Hail 6 = Glaze or rime 7 = Blowing dust or sand: visibility 1/2 mile or less 8 = Smoke or haze 9 = Blowing snow X = Tornado

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Raleigh Forecast Office
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Raleigh, North Carolina 27606
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1	The date of the month.
2	The highest temperature for the day.
3	The lowest temperature for the day.
4	The average temperature for the day, computed by finding the average of the values in columns 2 and 3, then rounding up (if necessary).
5	Departure from normal. The difference between column 4 and the 30 year normal temperature for this date.
6a	Heating degree days. Computed by subtracting the average temperature from 65. If less than 0, HDD=0.
6b	Cooling degree days. Computed by subtracting 65 from the average temperature. If less than 0, CDD=0.
7	Total precipitation for the day to the nearest hundredth of an inch. This includes all forms of precipitation, both liquid and water equivalent of any snow or ice that occurred (T = Trace).
8	Total snowfall for the day to the nearest tenth of an inch.
9	Snow depth to the nearest inch at 7am EST.
10	Average wind speed for the day in mph.
11	The highest wind speed in mph averaged over a 2 minute period.
12	The direction (in compass degrees divided by 10) from which the wind speed in column 11 came from. ( N=36 S=18 W=27 E=09, etc.)
13	The number of minutes of sunshine received at the station.
14	The percentage of possible sunshine. Computed by dividing the minutes of sunshine in column 13 by the total possible minutes.
15	The average sky cover between sunrise and sunset in tenths.
16	A coded number representing certain types of weather observed during the day. 1 = Fog 2 = Fog reducing visibilityto 1/4 mile or less 3 = Thunder 4 = Ice pellets 5 = Hail 6 = Glaze or rime 7 = Blowing dust or sand: visibility 1/2 mile or less 8 = Smoke or haze 9 = Blowing snow X = Tornado
17	Peak wind speed for the day in mph. The highest wind speed observed at the station.
18	The compass direction from which the peak wind speed came.


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