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Instrument

METAR
KMWH 170052Z 30006KT 10SM OVC005 M03/M11 A3060 RMK AO2 SLP383 T10281111 RAE42SNB42
Winds are true on these puppies
Clouds are in AGL
To find the thickness of a cloud layer
Add field elevation to the base of the layer
Subtract from reported top
Example for tops reported at 6500:
500+1189=1689
6500-1689=4811 thick

TERMINAL AERODROME FORECAST
Issued 4 times a day:
0000z
0600z
1200z
1800z
Good for 24 hours
Some are good for 30 hours
Covers an area out to 5SM
May be AMD or COR

TAF
1. Type
2. Location
3. Date / time
4. Valid period
5. Forecast
6. Probability forecast
7. Temporary conditions
8. Forecast change groups

TAF
VRB is issued when winds are 3kts or less
WS005/27050kt indicates low level wind shear at 500 feet out of 270 true at 50kts
KGEG 162326Z 1700/1724 07003KT P6SM SKC
FM171000 VRB03KT 2SM BR SKC
FM171400 06005KT P6SM SKC

AREA FORECAST
Known as FA
Covers a large geographical area
Useful for forecast enroute wx and for airports that do not issue a TAF
Issued 3 times a day from 6 areas
We get both the SFO and SLC
12 hour forecast with a 6 hour outlook, good for a total of 18 hours.
All heights given are MSL unless denoted as AGL or CIG

AREA FORECAST
Headers:
Synopsis
General picture of wx covering 18hrs
VFR clouds and weather
12 hrs
Sky condition in msl unless noted
Surface vis when between 3-5 miles over 3,000 sq. miles
If no vis then implied to be greater than 5
Weather precip, fog, haze dust
Included when it lowers vis below 5 mi
Wind 20kts or greater gusts 25 or greater on surface
Categorical outlook
Good for 6hrs
IFR, MVFR, VFR
WND is noted if 20kts or greater gusts 25kts or greater on surface

PIREPS
The only means of getting:
1. Cloud tops
2. Icing
Reported as Trace, Light, Moderate, Extreme
3. Turbulence
Reported as Light, Moderate, Severe, Extreme
4. Layers
5. In-flight vis
They are available on the ADDS site

PIREP
PIREPS
All altitudes are MSL unless otherwise noted
Distance for visibility is in statute miles
Distance for everything else is in nautical miles
Time is in Zulu

PIREP
MWH UA /OV MWH070015 /TM 1448 /FL370 /TP B757 /SK OVC040-TOP080 /WX FV50SM /TA M58 /WV 32052KT /TB SMOOTH WITH OCSNL MOD CHOP /IC LGT RIME /RM MOUNTAIN WAVE +/- 20K…LAST 30 MILES

WIND AND TEMP ALOFT
Based on the North American Mesoscale (NAM) model
Remember there are 12 models
Altitudes in msl:
3000
6000
9000
12000
18000
24000
30000
39000
Temps above 24,000 feet are negative
They come out 4 times a day every 6 hours
Good for the time on the chart

WIND AND TEMP ALOFT
Winds not issued for stations within 1,500
GEG’s elevation is 2,376
Since it is 624 feet from the 3,000 foot level no forecast is issued
Temps not issued for stations within 2,500 feet
YKM’s elevation is 1,099
Since it is 1,901 feet from the 3,000 foot level no temp is issued

******** FD Winds Aloft Forecast ******** DATA BASED ON 140000Z
VALID 141200Z FOR USE 0900-1800Z. TEMPS NEG ABV 24000
FT 3000 6000 9000 12000 18000 24000 30000 34000 39000
GEG 3332-06 3130-13 3046-19 3079-26 8129-31 827141 826952 813157
YKM 3112 3131-03 3142-07 3151-12 3191-18 8108-25 812740 823751 823363
LWS 2922 2932-04 3138-12 2952-17 3094-24 8027-31 826941 827452 813858
bla

WIND AND TEMP ALOFT
Winds are true and in knots
9900 codes calm winds
100 to 199 kts is coded by subtracting 100 from the speed and adding 50 to the direction
To decode subtract 50 and add a 100

AIRMET Airmen’s Meteorological Advisory
3 different types of AIRMETS:
Sierra for IFR and mountain obscuration
Tango for moderate turbulence
Zulu for moderate icing

AIRMET
Issued for:
Ceilings less than 1000 & 3 miles vis
Mountain obscurations
Moderate turbulence
Surface winds 30kts or greater
Moderate icing
Non convective low-level wind shear below 2,000 feet AGL
Good for 6 hours
Found in the Area Forecast

Severe Weather Watch Bulletins
Unscheduled issuance
Deal with severe thunderstorms and tornadoes

SIGMET Significant Meteorological Advisory
Sigmets are issued with a unique ID.
Continental US are N thru Y except for S and T
S and T are used for Airmets
Each wx event is assigned a number indicating continuation
Example: November 1, November 2, November 3

SIGMET
All heights are MSL
Lat and Long in whole degrees and minutes
Some messages may be abbreviated and or contractions may be used (see appendix A)

SIGMET
Things that make up a SIGMET:
Severe or greater turbulence (SEV TURB)
Severe Icing (SEV ICE)
Widespread Dust storm (WDSPR DS)
Affecting 3,000 square miles
Widespread Sand storm (WDSPR SS)
Affecting 3,000 square miles
Volcanic Ash (VA)

SIGMET
Good for up to 4 hours
Issued whenever currently needed
Issued whenever conditions are forecasted in the next 4 hours

CONVECTIVE OUTLOOKS
Known as AC
Covers severe and non-severe convective activity
Tornadoes, winds 50kts or greater, hail 1 inch or greater
3 levels of threat:
Slight risk (SLGT)
Moderate risk (MDT)
High risk (HIGH)

CONVECTIVE OUTLOOKS
Issued for a 24 hr period
Beginning at 1200z
These are very general in nature
The day 1 and day 2 AC depict general T-storm
The day 1, day 2 and day 3 use descriptive text to indicate the convective activity

CONVECTIVE OUTLOOKS
The area affected is read to the right of the arrow

SURFACE ANALYSIS CHART
Every 3 hours
Shows past wx history
Station data comes from surface observations
Commonly referred to as the weather map

SURFACE ANALYSIS CHART
Shows pressure systems and fronts
Troughs and ridges
Drylines, outflow boundaries (gust front), sea-breeze fronts, convergence lines, squall lines
Isobar lines of equal pressure are plotted usually spaced at intervals of 4 millibars

WEATHER DEPICTION CHART
Beginning at 0100z
every 3 hours
information for this chart taken from METAR
computer generated
] to the right of the station circle means automated

WEATHER DEPICTION CHART
Shows:
1. Total sky cover
2. Cloud height or ceiling
3. Wx and obstructions to vision
4. Visibility

WEATHER DEPICTION CHART

RADAR SUMMARY CHART
Computer generated graphic representation of radar echoes
Info comes from NWS radar network
Shows
Precip types
Cell movement
Max echo tops
Lines of echoes
Some remarks
Prepared hourly

RADAR SUMMARY CHART
There are 6 precip intensity levels coded into 3 contour intervals
Correlated for liquid precip only

RADAR SUMMARY CHART
Contour levels

CONSTANT PRESSURE ANALYSIS CHART
Covers a surface of equal pressure
Gives a 3 dimensional view of upper air wx
Twice daily
Valid at 12Z and 00Z
Mainly good for winds aloft at a certain pressure level

LOW LEVEL SIG WX PROG (SIGWX)
Used for wx briefings
Covers CONUS 24,000 and below
Depicts wx categories
Less than 1,000 and 3 encircled by solid red line (IFR)
1,000-3,000 ceiling 3-5 vis blue scalloped line (MVFR)
Everything else (VFR)
LOW LEVEL SIG WX PROG

MID LEVEL SIG WX
Coverage of CBs are indicated by a box appended to area enclosed by a red scalloped line
xxx means bases are below the lower limit of the chart

MID LEVEL SIG WX
Fronts have an arrow showing speed of movement
Jet streams are green
Standard wind pennants indicate core speed
Altitude separated by a / indicate top and bottom of 80kt jet field
Double hash marks indicate change in speed in 20kt intervals

HIGH LEVEL SIG WX
Covers altitudes from FL250 to FL630
U2 and SR71 pilots use these
Pretty much the same symbology is used here with a few additions
Oh look there’s a volcano in Guatemala

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