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Map 2. Wind/Visibility/Cloudiness Graphs: Precipitation Types

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Map 2. Wind/Visibility/Cloudiness Graphs: Precipitation Types I I.30 Map 2. Wind/visibility/cloudiness BLACK LINE - Percent frequency of optimum conditions: Low cloud ceiling (LCC) 25000 feet, (or no LCC), visibility 25 nautical miles and wind 11-21 knots. BLUE LINE - Percent frequency of poor conditions. Any one of the following constitutes poor conditions: LCC <300 feet, visibility <l nautical mile or wind <6 or 234 knots. Albers Equal-Area Conic Projection Graphs: Precipitation types Percent frequency of precipitation by type and intensity (S - slight, M - moderate and H- heavy). 25 _------ Number of observations. Bars show percent frequency of observations Z reporting Precipitation of various types and 0 2o intensities. t- Q -------- 0 indicates no observations in the category F l5 _-----__ >k indicates <.05% but >O. n -_-- - - - (4% of all observations recorded moderate 0 10 to heavy precipitation.) W a a 5 ix 0 s M-H 5 M-H s U-H s M-H 5 M-H PlLL DRIZZLE RAIN SNOW SHOWERS ALL PCPN Present weather elements that can be reported in an observation are thunderstorms, lightning, waterspouts, squalls, fog, haze, smoke, dust, and all forms of precipitation. Most present weather codes (ww = 00-99, see table) apply to phenomena occur- ring at the time of observation, but a few refer to phenomena occurring in the past hour. The highest applicable numerical ww code figure is recorded (except that code 17 has preference over 20 to 49, inclusive). Precipitation includes all forms of water par- ticles, whether liquid or solid, that fall to the earth’s surface -rain, drizzle, snow, snow pellets, snow grains, ice crystals, ice pellets, and hail. Each form is classified by its character (continuous, intermittent, showery, or combination), intensity (slight, moderate, or heavy), and type (liquid, freezing, or frozen). In this study, frozen precipitation is defined as any precipitation that reaches the ground in frozen form; it does not include liquid that freezes upon impact with the ground or exposed objects. Refer to the text in Set 1 for additional information on precipitation. 2 Legend Legend 2 II-31 PRESENT WEATHER (WMO Code, 1982) The present weather (ww) code is arranged in priority order. Reading down the list, select the first applicable (most severe) weather condition that you observe and enter the code number for ww. 50.99 PRECIPITATION AT SHIP AT TIME OF Intermittent Continuous 32 Duststorm or sandstorm, increasing 35 OBSERVATION 74 Heavy snow in flakes 75 31 Duststorm or sandstorm, unchanging 34 72 Moderate snow in flakes 73 30 Duststorm or sandstorm, decreasing 33 70 Slight snow in flakes 71 95-99 THUNDERSTORM AT TIME OF OBSERVATION 20-29 PHENOMENA IN PAST HOUR BUT NOT AT 99 Heavy thunderstorm with hail* 60-69 RAIN (NOT FALLING AS SHOWERS) TIME OF OBSERVATION 98 Thunderstorm with duststorm or sandstorm Slight Moderate br Heavy 97 Heavy thunderstorm with rain and/or snow, 68 Rain or drizzle with snow 69 29 Thunderstorm, with or without precipitation but no hail* 66 Freezing rain 67 28 Fog (in past hour but not at time of obs.) 96 Slight or moderate thunderstorm with hail* 27 Shower(s) of hail’, or of hail*, and rain mixed 95 Slight or moderate thunderstorm with rain OI Intermittent Continuous 26 Shower(s) of snow, or of rain and snow mrxed snow. but no hail’ 64 Heavy rain 65 25 Shower(s) of rain 62 Moderate rain 63 24 Freezing drizzle or freezino rain \ ‘Includes hail, ice pellets, or snow pellets 60 Slight rain 61 23 Rain and snow mixed, or ice pellets Not falhng 22 Snow as showers 91.94 THUNDERSTORM DURING THE PAST HOUR BUT 50.59 DRIZZLE 21 Rain (not freezing) NOT AT THE TIME OF OBSERVATION 20 Drizzle (not freezing) or snow grains I Slight Moderate or heavy Note: Use code 29 if there is no precipitation at time of 58 Drizzle and rain mixed 59 *Includes hail, ice pellets or snow pellets observation. 56 Freezing drizzle 57 18-19 SQUALLS, FUNNEL CLOUDS 94 Moderate or heavy snow, or rain Intermittent Continuous and snow mixed, or hail’ 54 Heavy drizzle 55 19 Funnel cloud(s) seen in past hour or at time of obs. 93 Slight snow, or rain and snow Thunderstorm 52 Moderate drizzle 53 18 Squalls (no precip.) in past hour or at time of obs. mixed, or hail’ ’ in past 50 Slight drizzle 51 92 Moderate or heavy rain hour 13-16 PHENOMENA WITHIN SIGHT BUT NOT AT SHIP 91 Slight rain 16 Precip. within 3 naut. mi.-reaching surface ‘Includes hail, ice pellets, or snow pellets 00.49 NO PRECIPITATION AT SHIP AT TIME OF 15 Precip. beyond 3 naut. mi.-reaching surface OBSERVATION 14 Precipitation in sight, not reaching surface 85-90 SOLID PRECIPITATION IN SHOWERS 13 Lightning visible, no thunder heard Fog not Slight Moderate or Heavy 17 Thunder at time of observation, no precipitation lo-12 MIST AND SHALLOW FOG 12 deeper 89 Shower or hail’, no thunder 90 at ship Shallow fog-more or less continuous 87 Shower of snow pellets or ice pelletst 88 11 Shallow fog in patches 1 than 10 m feet) 85 Shower of snow 86 40-49 FOG AT TIME OF OBSERVATION 10 Mist (Visibility % nautical mile or more) (33 tWith or without rain, or rain and snow mrxed (Visibility in fog is less than % nautical mile) 04.09 HAZE, DUST, SAND, OR SMOKE *Include hail, ice pellets, or snow pellets Sky Sky 09 Duststorm or sandstorm within sight 80.84 RAIN SHOWERS visible invisible 08 Dust whirls in past hour (NOT FOR MARINE USE) 48 Fog, depositing rime 49 07 Blowing spray at ship 84 Shower of rain and snow mixed, moderate or heavy 46 Fog, has begun or thickened in past hour 47 06 Widespread dust suspended in the air 83 Shower of rain and snow mixed, slight 44 Fog, no change in past hour 45 05 Dry haze 82 Violent rain shower 42 Fog, has become thinner in past hour 43 04 Visibility reduced by smoke 81 Moderate or heavy rain shower 41 Fog in patches 80 Slight rain shower 40 Fog at a distance but not at ship in past hour 00.03 CHANGE OF SKY DURING PAST HOUR 70-79 SOLID PRECIPITATION NOT FALLING AS SHOWERS 30-39 (Not likely to be used in ship reports) Code figs. 79 Ice pellets Slight or 03 Clouds generally forming or developing 78 Isolated star-like snow crystals(with or without fog) moderate Heavy 02 State of the sky on the whole unchanged 77 Snow grains (with or without fog) 38 Blowing snow, high (above eye level) 39 01 Clouds dissolving or becoming less developed 76 Diamond dust (with or without fog) 36 Drifting snow, low (below eye level) 37 00 Cloud development not observable 2 Legend Legend 2 henuey 11, *-II I Y-” L *-II I Y-” I *-)I I -0 I I 0 I I $9 24 --OLD -ot u . ..- O,Q ._.... a ;o La m m m m .. -0zn ._.__ -0zn ,..... -ozn . ..- o,n - - . u -0 . u . -0 - - - - -0E-i -0s -I -0E-l ,............ ” - 51 + 9 9 9 9 -I -I -I . -I - - I.... - o -0*; o*; ........ O*o z z z . z LZZ61 BSEZZ F OS601 F E:lIZ -05 -- -- UAUlOllS ?@PV Inod -as !~~l‘V!N I, ~- 0 0 *= m-m n . 3 t .‘9 -t 3 -01 lJ -...cs Q ____ a n al m I m I- m- _.. ,....... -020 . -..Coin . I............. LoLn_. - - . -0 u -0 - I - I -0E-l c SL -I I... ..Lc,_~ -I 9 9 9 . + I -I I I -I Coz, 1’ -o*; - I- I 2 z PS6Z1 i II ‘I,ZOiSi I Los SZ UeP!OH lJod UOWlBS 6U!)( UJBlllJOMON ado3 1 .O I -0 -0 I 0 *- *-* 0 *- 0 *= 0 0 0-o x 3 . 24 . ,\9 ___ ......... s -0 ...... ........... ....... ... s -0 ___._, .. -PI -0 ._____ __.......... -5 u a a a a m m m m .......... ........ .... 01 n ... ... ....... ...... ..... 0~ n ,...__ ___......... _.... -Ozn ._,... __.... -0, n - - - Q u . -0 u - - ........ ........... SL -I .... ............... ... Sl -I . ..-OE-l ..____ __.......... _..... -s, -I 9 9 9 9 -I -I -I ’ -1 op oz; oz; 0 .. -or; z It- -.... .......” -... .“’ z z O-P@LI I LSLSL 8i78OZ t- SZ ~OZUDWO~ edB3 @WON ,,. *-II I Y-” I *-I s q -” s Y-” s 0 0 w .‘4 G-3 OL u 01 Q 01 Q a xl a m m m m m -0zn 0zn 0zn 0zn - - . -0 -II -0 -cl - -()E -I OE -I 0C-I Of4 9 9 9 9 . + -I -I -I -0%. 0 0*; 0*; 0*; . z 2 2 z 099v SE85 04 O!UOP!AOJd cum c#m,loln Marine Area 0 Marina Area C Marine Area D 50 25 4769 3670 7436 z 2 . 2 340 020- 020 - i - - - 1 I- . F a u a a I I- 30- - 30- + IS- k ‘5 - - a * 1 a - - w20- J20- u '0 w J w IT I [1: a lo- 1 lo- a 5 x M K * 0 mm 0 Marine Area F *5- z 6786 0 -?O- t- Q I- ‘5- I .-. I “.. t I.. , I.. I I...,& I.‘,,,, ..I. I.0. I.* .,., .,I ..,CI. ------- - -15- 2 Wind=Visibility-Cloudiness Januar; 9. PRECIPITATION u 0 z 0 :: g :- I m % PRECIPITATION % PRECIPITATION N 0 w ; ; 0 :- 5 :r w T’* W “0 : : ;’ x % PRECIPITATION II-35 Marine Area A Marine Area B Marine Area C Marine Area D 1 50 I 5OB 25 1564 5885 7540 Z Z /?“‘I I Z 340 040 - - 020- I I- i.
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