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Scales & Tables




PAGE NAVIGATION:

Use the drop-down menu below to view a weather table or scale. Want to request a new table or new data? Click here.






WATCH VS. WARNING:

EMERGENCY
Significant and life-threatening weather is about to occur in a densely populated area. Seek sturdy shelter with extreme haste, as dangerous weather has been observed or confirmed on the ground. Weather emergencies are rare, but must be taken with the utmost seriousness when issued.
WARNING
Significant or severe weather is about to occur. Seek shelter immediately. If a warning is issued, then be aware that dangerous weather conditions have been observed or confirmed on the ground and are likely heading to your location.
WATCH
Weather watches are meant to make the public more aware of the chance for significant weather. This means that conditions are favorable for the specified weather to occur. Weather watches are issued when high confidence exists in significant weather developing soon.
ADVISORY
Do NOT underestimate or ignore a weather advisory. Advisories alert the public to potential significant weather that may stay below warning criteria, but will still pose a threat to life and property. Remain vigilant for potential changes to the weather advisory.






TEMPERATURE CONVERSION TABLE:

Fahrenheit
[°F]

Celsius
[°C]

Kelvin
[°K]
-40
-40
233.1
-35
-37.2
235.9
-30
-34.4
238.7
-25
-31.7
241.5
-22
-30
243.2
-20
-28.9
244.3
-15
-26.1
247.0
-10
-23.2
249.8
-5
-20.6
252.6
-4
-20
253.2
0
-17.8
255.4
5
-15
258.2
10
-12.2
260.9
14
-10
263.2
15
-9.4
263.7
20
-6.7
266.5
25
-3.9
269.3
30
-1.1
272.0
32
0
273.1
35
1.7
247.8
40
4.4
277.6
45
7.2
280.4
50
10
283.2
55
12.8
285.9
60
15.6
288.7
65
18.3
291.5
68
20
293.2
70
21.1
294.3
75
23.9
297.0
80
26.7
299.8
85
29.4
302.6
86
30
303.2
90
32.2
305.4
95
35
308.2
100
37.8
310.9
104
40
313.2
105
40.6
313.7
110
43.3
316.5
~9,941
5505
5778
~53,540
~28,000+
~30,000
WIND CONVERSION TABLE:
Miles Per Hour
[mph]
Knots
[kn]
Meters Per Second
[m/s]
1.15
1
0.51
5.8
5
2.57
11.5
10
5.14
17.3
15
7.72
23.0
20
10.29
28.8
25
12.86
34.6
30
15.43
40.3
35
18.01
46.1
40
20.58
51.8
45
23.15
57.6
50
25.72
63.4
55
28.29
69.1
60
30.87
74.9
65
33.44
80.6
70
36.01
86.4
75
38.58
92.2
80
41.16
97.9
85
43.73
97.9
90
46.3
103.7
95
48.87
109.4
100
51.44
115.2
105
54.02
121
110
56.59
132.5
115
59.16
138.2
120
61.73
144.0
125
64.31
149.8
130
66.88
155.5
135
69.45
161.3
140
72.02
167.0
145
74.59
172.8
150
77.17
178.4
155
79.74
184.1
160
82.31
189.9
165
84.88
195.6
170
87.46
201.4
175
90.03
207.1
180
92.6
212.9
185
95.17
218.6
190
97.74
224.4
195
100.32
230.2
200
102.89
TIME CONVERSION TABLE:
UTC/Zulu
[Universal]
EDT
[Daylight Saving]
EST
[Standard]
0000
8:00 PM
7:00 PM
0100
9:00 PM
8:00 PM
0200
10:00 PM
9:00 PM
0300
11:00 PM
10:00 PM
0400
12:00 AM
11:00 PM
0500
1:00 AM
12:00 AM
0600
2:00 AM
1:00 AM
0700
3:00 AM
2:00 AM
0800
4:00 AM
3:00 AM
0900
5:00 AM
4:00 AM
1000
6:00 AM
5:00 AM
1100
7:00 AM
6:00 AM
1200
8:00 AM
7:00 AM
1300
9:00 AM
8:00 AM
1400
10:00 AM
9:00 AM
1500
11:00 AM
10:00 AM
1600
12:00 PM
11:00 AM
1700
1:00 PM
12:00 PM
1800
2:00 PM
1:00 PM
1900
3:00 PM
2:00 PM
2000
4:00 PM
3:00 PM
2100
5:00 PM
4:00 PM
2200
6:00 PM
5:00 PM
2300
7:00 PM
6:00 PM



What is UTC/Z Time?
United States Time Zones





THE BEAUFORT SCALE:
Force
Wind
[Knots]
Wind
[mph]
WMO Classification
Effect on Land
Effect on Water
0
< 1
< 1
Calm
Smoke rises vertically
Sea surface smooth and mirror-like
1
1-3
1-3
Light Air
Smoke drift indicates wind direction;
wind vanes still
Scaly ripples; No foam crests
2
4-6
4-7
Light Breeze
Wind felt on face; Leaves rustle;
Weather vanes being to move
Small wavelets; Crests glassy;
No breaking
3
7-10
8-12
Gentle Breeze
Leaves and small twigs constantly moving;
Light flags extended
Large wavelets; crests begin to break;
Scattered whitecaps
4
11-16
13-18
Moderate Breeze
Dust, leaves, and loose paper lifted;
Small tree branches move
Small waves 1-4 ft. becoming longer;
Numerous whitecaps
5
17-21
19-24
Fresh Breeze
Small trees in leaf begin to sway
Moderate waves 4-8 ft taking longer form;
Many whitecaps; Some spray
6
22-27
25-31
Strong Breeze
Larger tree branches moving;
Whistling in wires
Larger waves 8-13 ft;
Whitecaps common; More spray
7
28-33
32-38
Near Gale
Whole trees moving;
Resistance felt walking against wind
Sea heaps up, waves 13-19 ft;
White foam streaks off breakers
8
34-40
39-46
Gale
Twigs breaking off trees;
Generally impedes forward progress
Moderately high (18-25 ft) waves of greater length;
Edges of crests begin to break into spindrift;
Foam blown in streaks
9
41-47
47-54
Strong Gale
Slight structural damage occurs;
Slate (shingles) blow off roofs
High waves (23-32 ft), sea begins to roll;
Dense streaks of foam;
Spray may reduce visibility
10
48-55
55-63
Storm
Seldom experienced on land;
Trees broken or uprooted, "considerable structural damage"
Very high waves (29-41 ft) with overhanging crests;
Sea white with densely blown foam;
Heavy rolling, lowered visibility
11
56-63
64-72
Violent Storm
Very rarely experienced;
Accompanied by widespread damage.
Exceptionally high (37-52 ft) waves;
Foam patches cover sea, visibility more reduced
12
64+
73+
Hurricane
Devastation
Air filled with foam, waves over 45 ft;
Sea completely white with driving spray;
Visibility greatly reduced




THE ENHANCED FUJITA-PEARSON SCALE:
EF Rating
Wind Speed [mph]
Damage Indicators
EF0
65-85
Light Damage; peels surface off of some roofs; shallow-rooted trees pushed over
EF1
86-110
Moderate Damage; roofs severely stripped; windows or other glass broken; mobile homes overturned or badly damaged
EF2
111-135
Considerable Damage; roofs torn off well-constructed houses; foundations of frame homes shifted; light-object missiles generated; cars lifted off ground
EF3
136-165
Severe Damage; heavy cars lifted off the ground and thrown; trains overturned; entire stories of well-constructed buildings destroyed; severe damage to large buildings
EF4
166-200
Devastating Damage; whole frame houses and well-constructed buildings completely leveled; cars thrown long distances, and small missiles generated
EF5
200+
Incredible Damage; incredible phenomena will occur; car-sized missiles fly through the air in excess of 100 meters, high-rise buildings have significant damage; large buildings obliterated
THE RICHTER MAGNITUDE SCALE:

Magnitude


Damage

Frequency/
Description
< 2.0
Mirco
~8,000 per day/Not perceivable
2.0-2.9
Minor
~1,000 per day/Generally not perceivable, but recorded
3.0-3.9
Minor
~49,000 per year/Often felt, but cause no damage
4.0-4.9
Light
~6,200 per year/Noticeable shaking of indoor items; significant damage unlikely
5.0-5.9
Moderate
~800 per year/Can cause major damage to poorly constructed buildings over small regions; Slight damage possible to well-designed buildings
6.0-6.9
Strong
~120 per year/Can be destructive in areas up to about 100 miles across in populated areas
7.0-7.9
Major
~18 per year/Can cause serious damage over large areas
8.0-8.9
Massive
~1 per year/Can cause severe damage in areas hundreds of miles across
9.0-9.9
Catastro-phic
~1 per year/Devastating and catastrophic damage in areas several thousand miles across
10.0+
Incredible
(Unknown)
Never recorded/Widespread damage across very large areas (Unknown)
THE SAFFIR-SIMPSON SCALE:
Category
Wind Speed
[mph]
Storm Surge
[ft]
Mean Minimum
Surface Pressure [mb]
Tropical Depression
< 39
Minimal
N/A
Tropical Storm
39-74
< 4
> 990
1
74-95
4-5
> 980
2
96-110
6-8
965-979
3
111-130
9-12
945-964
4
131-155
13-18
920-944
5
> 155
> 18
< 920







SPATIAL SCALES OF WEATHER:
Name
Spatial Scale
[km]
Examples
Synoptic Scale
1000-2500
Mid-latitude Cyclones; Tropical Cyclones; Fronts; Jet Streams
Mesoscale
10-1000
Squall Lines; Gap Winds; Land-Sea Breeze Circulations; Large Convective Complexes
Storm Scale
2-10
Individual Thunderstorm Cells
Microscale
< 2
Tornado; Dust Devil; Downburst; Features too small to be depicted on a weather map






AIR QUALITY INDEX:

The Air Quality Index (AQI) is an index for reporting daily air quality. This scale describes how clean or polluted your region's air is, and outlines any health effects that may occur due to exposure to poor air quality.

Color Code
& Range
Category & Description
Precautions
& Tips
Code Green
0-50
Good - Air quality is good
None
Code Yellow
51-100
Moderate - Air quality becomes a concern for people with extra sensitivity to air pollution
People who are extra sensitive to air pollution should reschedule outdoor activities to when air quality improves
Code Orange
101-150
Unhealthy for Sensitive Groups - Air quality is unhealthy for many people, especially those with lung disease, asthma, older adults, and children
Sensitive groups should cut back or reschedule strenuous outdoor activities
Code Red
151-200
Unhealthy - Air quality is unhealthy for everyone, especially those with heart or lung disease
Everyone should avoid strenuous outdoor activities
Code Purple
201-300
Very Unhealthy - Air quality is unhealthy for everyone, especially those with heart or lung disease
Everyone should avoid any physical outdoor activities
Code Maroon
301-500
Hazardous - Air quality is hazardous for everyone
Everyone should avoid any outdoor activities at all costs



BORTLE SCALE OF NIGHT-SKY DARKNESS:

The Bortle Scale is a nine-level numeric scale that quantifies the astronomical observability of celestial objects and the visible interference cause by light pollution. The lower the number, the darker the night sky.

Bortle Class
Color Key/Magnitude
Sky Description
1
Black / 7.6-8.0
Excellent, naturally dark skies
2
Gray / 7.1-7.5
Typical, truly dark skies - the Milky Way is clearly visible
3
Blue / 6.6-7.0
Rural sky - Weak glow at the horizon above distant towns
4
Green / 6.1-6.5
Rural/Suburban transition - Negative effect on stargazing
5
Yellow / 5.6-6.0
Suburban sky - Strong negative effect on stargazing
6
Orange / 5.1-5.5
Bright Suburban sky - Milky Way is invisible
7
Red / 4.6-5.0
Suburban/Urban transition - Less than 100 stars visible to the naked eye
8
White / 4.1-4.5
City sky - Less than 20 stars visible to the naked eye
9
White / 4.0 at best
Inner City sky - Entire night sky has a bright glow, only the brightest constellations are discernable

UV INDEX:

The UV Index [UVI] is a next day forecast of the amount of skin-damaging ultraviolet radiation expected to reach the earth's surface at the time when the sun is highest in the sky (solar noon).

UV Index Values
Description
Protection Level
1,2
Low - You can safely stay outside without the risk of sunburn
No skin protection required
3,4,5,6,7
Medium - Seek shade during midday hours (1:00-4:00 PM) - Sunscreen and hat recommended
Skin protection required if prolonged exposure outdoors
8,9,10,11+
High to Extreme - Avoid being outdoors during midday hours (1:00-4:00 PM) - Sunscreen required, hat strongly recommended
Extra skin protection required




APPLEMAN CHART [CONTRAILS]:

The Appleman Chart was created by H. Appleman in 1953 as a way to predict when a jet airplane would or would not produce a contrail. The current version of this chart is used today to determine the formation of contrails using upper air data.




LEARN MORE:

Learn more about the Appleman Chart
Learn more about the Bortle Scale












SOLAR FLARE/CORONAL MASS EJECTION [CME] INTENSITY CLASSIFICATIONS:

Classification
Peak Flux [W/m^2]
Percentage of Annual
Flares (2013 Data)
Earth Impacts:
X
I >= 10^-4
0.34%
The most intense solar flares; ten times as intense as M-class flares; capable of causing planet-wide radio blackouts and radiation storms.
M
10^-5 < I < 10^-4
2.66%
Ten times as intense as C-class flares; medium-sized flares capable of causing brief radio blackouts or interference. Occasionally causes subsequent geomagnetic storms.
C
10^-6 < I < 10^-5
59.23%
The most frequent flare classification - ten times as intense as B-class flares; these flares are relatively small with few noticeable consequences on Earth.
B
I < 10^-6
37.77%
These and A-class flares are generally regarded as near-background levels.








SPERRY-PLITZ ICE ACCUMULATION INDEX [SPIA]:

The SPIA Index predicts the total impact an impending ice storm may have on a particular location. It is a tool that can be used for risk management for significant winter weather events. Learn all about the SPIA Index here.

Ice Damage Index
Average NWS Ice Amount [inches]
Wind [mph]
Damage & Impact Descriptions
0
< 0.25
< 15
"Minimal risk of damage to exposed utility systems; no alerts or advisories needed for crew; few outages"
1
0.10-0.25
0.25-0.50
15-25
> 15
"Some isolated or localized utility interruptions are possible, typically lasting only a few hours. Roads and bridges may become slick and hazardous."
2
0.10-0.25
0.25-0.50
0.50-0.75
25-35
15-25
> 15
"Scattered utility interruptions expected, typically lasting 12 to 24 hours. Roads and travel conditions may be extremely hazardous due to ice accumulation."
3
0.10-0.25
0.25-0.50
0.50-0.75
0.75-1.00
>= 35
25-35
15-25
> 15
"Numerous utility interruptions with some damage to main feeder lines and equipment expected. Tree limb damage is excessive. Outages lasting 1-5 days."
4
0.25-0.50
0.50-0.75
0.75-1.00
1.00-1.50
>= 35
25-35
15-25
> 15
"Prolonged and widespread utility interruptions with extensive damage to main distribution feeder lines and some high voltage transmission lines/structures. Outages lasting 5-10 days.
5
0.50-0.75
0.75-1.00
1.00-1.50
> 1.50
>= 35
>= 25
>= 15
Any
"Catastrophic damage to entire exposed utility systems, including both distribution and transmission networks. Outages could last several weeks in some areas. Shelters needed."







TORINO SCALE OF ASSESSING ASTEROID/COMET IMPACTS:

The Torino Scale is a scale developed in the 21st Century that is geared toward assessing the dangers from celestial bodies and their potential impact hazards here on earth. View another version of the Torino Scale here, or visit the CNEOS (Center for Near Earth Object Studies) Website.

Hazard Level
& Color Zone
Category Number
Description
No Hazard (White Zone)
0
"The likelihood of a collision is zero, or is so low as to be effectively zero. Also applies to small objects such as meteors and bodies that burn up in the atmosphere as well as infrequent meteorite falls that rarely cause damage."
Normal (Green Zone)
1
"A routine discovery in which a pass near the Earth is predicted that poses no unusual level of danger. Current calculations show the chance of collision is extremely unlikely with no cause for public attention or public concern. New telescopic observations very likely will lead to re-assignment to Level 0."
Meriting Attention by Astronomers (Yellow Zone)
2
"A discovery, which may become routine with expanded searches, of an object making a somewhat close but not highly unusual pass near the Earth. While meriting attention by astronomers, there is no cause for public attention or public concern as an actual collision is very unlikely. New telescopic observations very likely will lead to re-assignment to Level 0."
Meriting Attention by Astronomers (Yellow Zone)
3
"A close encounter, meriting attention by astronomers. Current calculations give a 1% or greater chance of collision capable of localized destruction. Most likely, new telescopic observations will lead to re-assignment to Level 0. Attention by public and by public officials is merited if the encounter is less than a decade away."
Meriting Attention by Astronomers (Yellow Zone)
4
"A close encounter, meriting attention by astronomers. Current calculations give a 1% or greater chance of collision capable of regional devastation. Most likely, new telescopic observations will lead to re-assignment to Level 0. Attention by public and by public officials is merited if the encounter is less than a decade away."
Threatening (Orange Zone)
5
"A close encounter posing a serious, but still uncertain threat of regional devastation. Critical attention by astronomers is needed to determine conclusively whether or not a collision will occur. If the encounter is less than a decade away, governmental contingency planning may be warranted."
Threatening (Orange Zone)
6
"A close encounter by a large object posing a serious but still uncertain threat of a global catastrophe. Critical attention by astronomers is needed to determine conclusively whether or not a collision will occur. If the encounter is less than three decades away, governmental contingency planning may be warranted."
Threatening (Orange Zone)
7
"A very close encounter by a large object, which if occurring this century, poses an unprecedented but still uncertain threat of a global catastrophe. For such a threat in this century, international contingency planning is warranted, especially to determine urgently and conclusively whether or not a collision will occur."
Certain Collisions (Red Zone)
8
"A collision is certain, capable of causing localized destruction for an impact over land or possibly a tsunami if close offshore. Such events occur on average between once per 50 years and once per several 1000 years."
Certain Collisions (Red Zone)
9
"A collision is certain, capable of causing unprecedented regional devastation for a land impact or the threat of a major tsunami for an ocean impact. Such events occur on average between once per 10,000 years and once per 100,000 years."
Certain Collisions (Red Zone)
10
"A collision is certain, capable of causing global climatic catastrophe that may threaten the future of civilization as we know it, whether impacting land or ocean. Such events occur on average once per 100,000 years, or less often."







UNITED STATES AIRPORT CODES:

KABR
Aberdeen, SD
KGFK
Grand Forks, NC
KLGA
New York City, NY
KABQ
Albuquerque, NM
KGRR
Grand Rapids, MI
KPHF
Newport News, VA
KAMA
Amarillo, TX
KGTF
Great Falls, MT
KOKC
Oklahoma City, OK
PANC
Anchorage, AK
KGRB
Green Bay, WI
KOMA
Omaha, NE
KAVL
Asheville, NC
KGSO
Greensboro, NC
KPIA
Peoria, IL
KATL
Atlanta, GA
KPGV
Greenville, NC
KPHL
Philadelphia, PA
KACY
Atlantic City, NJ
KGSP
Greenville, SC
KPHX
Phoenix, AZ
KBWI
Baltimore, MD
KBDL
Hartford, CT
KPIT
Pittsburgh, PA
KBGR
Bangor, ME
KHKY
Hickory, NC
KPWM
Portland, ME
KBIL
Billings, MT
PHNL
Honolulu, HI
KPDX
Portland, OR
KBHM
Birmingham, AL
KHSV
Huntsville, AL
KRDU
Raleigh, NC
KBIS
Bismarck, ND
KIDA
Idaho Falls, ID
KRAP
Rapid City, SD
KBOI
Boise, ID
KIND
Indianapolis, IN
KRNO
Reno, NV
KBOS
Boston, MA
KINL
International Falls, MN
KRIC
Richmond, VA
KBTV
Burlington, VT
KJAN
Jackson, MS
KIXA
Roanoke Rapids, NC
KCPR
Casper, WY
KJAX
Jacksonville, FL
KROC
Rochester, NY
KCHS
Charleston, SC
KOAJ
Jacksonville, NC
KRCZ
Rockingham-Hamlet, NC
KCRW
Charleston, WV
KMCI
Kansas City, MO
KRWI
Rocky Mount, NC
KCLT
Charlotte, NC
KEYW
Key West, FL
KSLC
Salt Lake City, UT
KCYS
Cheyenne, WY
KISO
Kinston, NC
KSAY
San Antonio, TX
KORD
Chicago, IL
KTYS
Knoxville, TN
KSFO
San Francisco, CA
KCLE
Cleveland, OH
KLAS
Las Vegas, NV
KSAV
Savannah, GA
KCOD
Cody, WY
KLWS
Lewiston, ID
KBFF
Scottsbluff, NE
KCOS
Colorado Springs, CO
KLEX
Lexington, KY
KSEA
Seattle, WA
KLCK
Columbus, OH
KLIT
Little Rock, AR
KSHV
Shreveport, LA
KCVG
Covington, KY
KLAX
Los Angeles, CA
KFSD
Sioux Falls, SD
KDFW
Dallas-Fort Worth, TX
KMEM
Memphis, TN
KSBN
South Bend, IN
KDEN
Denver, CO
KMIA
Miami, FL
KSGF
Springfield, MO
KDSM
Des Moines, IA
KMKE
Milwaukee, WI
KSTL
St. Louis, MO
KDTW
Detroit, MI
KMSP
Minneapolis, MN
KUNV
State College, PA
KDLH
Duluth, MN
KMOB
Mobile, AL
KTLH
Tallahassee, FL
KEGC
Elizabeth City, NC
KMGM
Montgomery, AL
KTVC
Traverse City, MI
KERI
Erie, PA
KACK
Nantucket, MA
KALO
Waterloo, IA
KFAY
Fayetteville, NC
KBNA
Nashville, TN
KART
Watertown, NY
KFLG
Flagstaff, AZ
KEWN
New Bern, NC
KICT
Wichita, KS
KFWA
Fort Wayne, IN
KHVN
New Haven, CT
KILM
Wilmington, NC
KGCK
Garden City, KS
KMSY
New Orleans, LA
KINT
Winston-Salem, NC







SNOWFALL/MELTWATER TABLE:

This snowfall meltwater table displays how much snow would theoretically would fall to the ground if 1) all precipitation fell as snow and 2) how much QPF (Quantitative Precipitation Forecast) denoted as "Meltwater Equivalent [inches]" in this chart, is available. What you can take from this table is that the more moisture and QPF you have available, the more snow will fall, and that snow production rate increases rapidly with lowering air temperatures. Learn more here!

New Snowfall [inches]
Meltwater Equivalent [inches]
Temperature [°F]
34 to 28
27 to 20
19 to 15
14 to 10
9 to 0
-1 to -20
-21 to -40
TRACE
TRACE
0.1
0.2
0.3
0.4
0.5
1.0
.01
0.1
0.2
0.2
0.3
0.4
0.5
1.0
.02
0.2
0.3
0.4
0.6
0.8
1.0
2.0
.03
0.3
0.5
0.6
0.9
1.2
1.5
3.0
.04
0.4
0.6
0.8
1.2
1.6
2.0
4.0
.05
0.5
0.8
1.0
1.5
2.0
2.5
5.0
.06
0.6
0.9
1.2
1.8
2.4
3.0
6.0
.07
0.7
1.1
1.4
2.1
2.8
3.5
7.0
.08
0.8
1.2
1.6
2.4
3.2
4.0
8.0
.09
0.9
1.4
1.8
2.7
3.6
4.5
9.0
.10
1.0
1.5
2.0
3.0
4.0
5.0
10.0
.11
1.1
1.7
2.2
3.3
4.4
5.5
11.0
.12
1.2
1.8
2.4
3.6
4.8
6.0
12.0
.13
1.3
2.0
2.6
3.9
5.2
6.5
13.0
.14
1.4
2.1
2.8
4.2
5.6
7.0
14.0
.15
1.5
2.3
3.0
4.5
6.0
7.5
15.0
.16
1.6
2.4
3.2
4.8
6.4
8.0
16.0
.17
1.7
2.6
3.4
5.1
6.8
8.5
17.0
.18
1.8
2.7
3.6
5.4
7.2
9.0
18.0
.19
1.9
2.9
3.8
5.7
7.6
9.5
19.0
.20
2.0
3.0
4.0
6.0
8.0
10.0
20.0
.21
2.1
3.1
4.2
6.3
8.4
10.5
21.0
.22
2.2
3.3
4.4
6.6
8.8
11.0
22.0
.23
2.3
3.4
4.6
6.9
9.2
11.5
23.0
.24
2.4
3.6
4.8
7.2
9.6
12.0
24.0
.25
2.5
3.8
5.0
7.5
10.0
12.5
25.0
.30
3.0
4.5
6.0
9.0
12.0
15.0
30.0
.35
3.5
5.3
7.0
10.5
14.0
17.5
35.0
.40
4.0
6.0
8.0
12.0
16.0
20.0
40.0
.45
4.5
6.8
9.0
13.5
18.0
22.5
45.0
.50
5.0
7.5
10.0
15.0
20.0
25.0
50.0
.60
6.0
9.0
12.0
18.0
24.0
30.0
60.0
.70
7.0
10.5
14.0
21.0
28.0
35.0
70.0
.80
8.0
12.0
16.0
24.0
32.0
40.0
80.0
.90
9.0
13.5
18.0
27.0
36.0
45.0
90.0
1.00
10.0
15.0
20.0
30.0
40.0
50.0
100.00
2.00
20.0
30.0
40.0
60.0
80.0
100.00
200.00
3.00
30.0
45.0
60.0
90.0
120.00
150.00
300.00








CLOUD TYPES:

Genus
Image
Altitude [feet]
Composition
Indication
Cirrus [Ci]
> 20,000 ft
Ice crystals
Fair weather; Uniform cirrus indicate an approaching warm front
Cirrocumulus [Cc]
> 20,000 ft
Primarily ice crystals
In winter, indicate fair, cold weather; At tropical latitudes, Cc may indicate an approaching tropical cyclone
Cirrostratus [Cs]
>= 20,000 ft
Ice crystals
Signals an approaching warm front if Cs thicken; Forms when layer of air lifted by convergence
Altostratus [As]
Between 6,500 and 20,000 ft
Water droplets
Signals incoming continuous rain or snow; Occasionally, rain may fall from As
Altocumulus [Ac]
Between 6,500 and 20,000 ft
Primarily of water droplets
Presence of Ac on a warm, humid summer morning suggest afternoon thunderstorms; Ac form in an unstable layer aloft
Stratocumulus [Sc]
Generally < 6,500 ft
Water droplets
Sc generally represent improving weather conditions; During winter, stable weather likely
Cumulonimbus [Cb]
Up to 50,000+ ft
Mixed phase
Convective/stormy weather in the vicinity; NOTE: Lightning can strike well outside of these clouds - Always remain aware of your weather surroundings
Cumulus [Cu]
< 6,500 ft
Water droplets
As long as no vertical development is taking place, Cu indicate fair weather
Nimbostratus [Ns]
< 6,500 ft
Primarily of water droplets; can contain ice crystals in sub-freezing air temperature
Ns are precipitation clouds; Ns are accompanied by light to moderate falling precipitation
Shelf/Arcus [-]
< 6,500 ft
Water development
Approaching thunderstorm; Form when cool, sinking air from a storm's downdraft spread out ahead of the storm
Wall Cloud [-]
< 4,000 ft
Water droplets
Severe weather is occurring nearby; These clouds mean trouble. Wall clouds often rotate and are usually the location where tornadoes form in a thunderstorm
Scud/Fractus [-]
< 4,000 ft
Water droplets
If you are seeing scud clouds, that means that a parent thunderstorm clouds is nearby, where rain, hail, gusty winds, and lightning is likely occurring; Rain will very likely start soon
Mammatus [CBMAM]
Between 30,000 and 50,000 ft
Water droplets; Often mixed phase with ice crystals as well
These clouds occur when moist air sinks into a layer of dry air, creating pouch-like clouds; These clouds signal a nearby, thunderstorm, usually an intense one, and typically appear after the passage of said storm
Contrails [-]
Between 25,000 and ~60,000 ft
Primarily water droplets; can also contain sulfurous compounds or jet fuel impurities
Contrails form when there is ample moisture in the high levels of the atmosphere and the air is very cold; Short lived contrails may indicate fair weather due to the relatively dry air, and conversely, long-lived contrails may suggest a changing weather pattern (see the Appleman Chart above)
Noctilucent [NLC]
Between 250,000 and 280,000 ft
Dust particles and water vapor
These polar mesospheric clouds form when temperatures in the mesosphere are below -200 degrees Fahrenheit, causing water droplets to freeze into ice clouds








NUMERICAL WEATHER PREDICTION MODELS:

Model Abbreviation
Model Name
Source Country
Forecast Output Time
Availibility
[UTC|EST]
GFS
Global Forecast System
USA
384 hours
[3 hour intervals through 240 hrs
12 hour intervals from 252 hr to 384hr]
4 times per day
[00, 06, 12, 18 UTC]
[7PM, 1AM, 7AM, 1PM EST]
NAM
North American Mesoscale Forecast System
USA
84 hours
[3 hour intervals]
4 times per day
[00, 06, 12, 18 UTC]
[7PM, 1AM, 7AM, 1PM EST]
RAP
Rapid Refresh
USA
18 hours
[1 hour intervals]
24 times per day [Hourly]
SREF
Short Range Ensemble Forecast
USA
87 hours
[3 hour intervals]
4 times per day*
[03, 09, 15, 21 UTC]
[10PM, 4AM, 10AM, 4PM EST]
HRRR
High Resolution Rapid Refresh
USA
15 hours
[1 hour intervals]
24 times per day [Hourly]
ECMWF
European Centre for Medium-Range Weather Forecasts
United Kingdom
168 hours
[24 hour intervals]
2 times per day
[00, 12]
[~2AM, ~2PM EST]
GEFS
Global Ensemble Forecast System
USA
384 hours
[6 hour intervals]
4 times per day
[00, 06, 12, 18 UTC]
[7PM, 1AM, 7AM, 1PM EST]
GDAS
Global Data Assimilation System
USA
9 hours
[3 hour intervals]
4 times per day
[00, 06, 12, 18 UTC]
[7PM, 1AM, 7AM, 1PM EST]
NAVGEM (Replaced NOGAPS)
Navy Global Environmental Model
USA
144 Hours
[3,6,12 hour intervals]
2 times per day
[10, 23 UTC]
[5AM, 6PM EST]
UKMET
United Kingdom Meteorological Office Unified Prediction Model
United Kingdom
144 hours
[6 hour intervals]
2 times per day
[00, 12 UTC]
[7PM, 7AM EST]
WRF
Weather Research & Forecasting Model
USA
72 hours
[3 hour intervals]
2 times per day
[00, 12 UTC]
[7PM, 7AM EST]
WRF-NMM
Nonhydrostatic Mesoscale Model of the Weather Research & Forecasting System
USA
36 hours
[1 hour intervals]
2 times per day
[00, 12 UTC]
[7PM, 7AM EST]
JMA (GSM)
Japan Meteorological Agency Global Spectral Model
Japan
84, 264 hours
[3,6,12 hour intervals |
264 hr once per day]
4 times per day
[00, 06, 12, 18 UTC]
[7PM, 1AM, 7AM, 1PM EST]
CMC (GDPS)
Canadian Meteorological Centre (Global Deterministic Prediction System)
Canada
144 hours
[12 hour intervals]
-
GEM
Global Environmental Multiscale Model
Canada
144 hours
[12 hour intervals]
4 times per day
[00, 06, 12, 18 UTC]
[7PM, 1AM, 7AM, 1PM EST]
CFS
Climate Forecast System v2
USA
798 hours
[6 hour intervals]
4 times per day
[00, 06, 12, 18 UTC]
[7PM, 1AM, 7AM, 1PM EST]








ANNUAL METEOR SHOWERS:

Meteor Shower Name:
Pronounciation:
Peak Nights:
Mean Meteor Velocity:
Best Viewed From:
Quadrantids
[kwa-DRAN-tids]
January 3-4
26 miles/sec [medium]
Northern Hemisphere
Lyrids
[LIE-rids]
April 22-23
30 miles/sec [medium]
Northern Hemisphere
Eta Aquariids
[EIGHT-a ACK-wah-rids]
May 6-7
42 miles/sec [swift]
Southern Hemisphere
Alpha Capricornids
[AL-fa CAP-rih-CORN-ids]
July 27-28
15 miles/sec [slow]
Everywhere
Delta Aquariids
[DEL-ta ACK-wah-rids]
July 28-29
26 miles/sec [medium]
Southern Hemisphere/Tropics
Perseids
[PURR-see-ids]
NOT "Per-sade"
August 12-13
37 miles/sec [swift]
Northern Hemisphere
Orionids
[o-RYAN-ids]
October 21-22
41 miles/sec [swift]
Everywhere
Southern Taurids
[southern TORR-ids]
October 23-24
17 miles/sec [slow]
Southern Hemisphere
Northern Taurids
[northern TORR-ids]
November 11-12
18 miles/sec [medium]
Northern Hemisphere
Leonids
[LEO-nids]
November 17-18
44 miles/sec [swift]
Everywhere
Geminids
[JIM-o-nids]
December 13-14
22 miles/sec [medium]
Northern Hemisphere
Ursids
[ER-sids]
December 21-22
20 miles/sec [medium]
Northern Hemisphere Only