Section 8

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BBCC Aviation Meteorology

SECTION 8 FORECAST CHARTS
SHORT RANGE SURFACE PROG
Shows:
Surface pressure systems, fronts, isobars and precip
Good out to 2 days
4 forecast periods 12,24,36,48 hours

SHORT RANGE SURFACE PROG
This chart uses all the same standard symbology as the SA
The exception is the green lines which encircle precip area

SHORT RANGE SURFACE PROG
Shading indicates precip covers half or more of the area (BKN)
No shading indicates 30 to 50% coverage (SCT)

SHORT RANGE SURFACE PROG
12 and 24 hr charts issued 4 times a day
36 and 48 hr charts issued 2 times a day
Good for seeing the progression over 48hrs

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
Turbulence yellow dashed line
1 witch hat mod turb
2 witch hats sev turb
3 witch hats extreme turb
Whoa nelly!
Tops and bases separated by a /
Absence of lower number indicates to surface

LOW LEVEL SIG WX PROG
Freezing level at surface blue zigzag
Freezing level aloft green dashed line
Spaced at 4,000 foot intervals
Usually everything north of the zigzag is below freezing
Lines are drawn for the highest freezing level if multiple layers exist
Multiple layers may be drawn see example at right

LOW LEVEL SIG WX PROG
Comes out 4 times a day
2 charts 12 and 24hrs
MID LEVEL SIG WX
Covers altitude from 10,000msl to FL450

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

MID LEVEL SIG WX
Tropopause heights indicate the level of the tropopause
Tropical storms and hurricanes are also on this puppy
Moderate or severe icing is enclosed by the red scalloped lines
Moderate or severe turbulence may also be indicated by yellow dashed line
Non cumulus cloud coverage indicated using standard oktas scale
Volcanic eruptions and my personal favorite radioactive materials release

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

HIGH LEVEL SIG WX
Smokes on a daily basis but last eruption was 8/9/07
Also known as the volcano of fire, De Fuego is about 10,000 feet high
Is one of the most active volcanoes in the Americas
Has erupted on a regular basis since 1524

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