WEATHER CHARTS
SURFACE ANALYSIS
OBSERVED EVERY 3 HRS
CHART NAME
OBSERVED OR FORECAST ISSUED
WEATHER DEPICTION
OBSERVED EVERY 3 HRS
FROM 0100Z
RADAR SUMMARY
OBSERVED EVERY HOUR
FROM 0035Z
CONSTANT PRESSURE ANALYSIS
OBSERVED EVERY 12 HRS
COMPOSITE MOISTURE STABILITY
OBSERVED EVERY 12 HRS
WINDS AND TEMPS ALOFT
FORECAST EVERY 12 HRS
LLVL SIG WX HLVL SIG WX CONVECTIVE PROG PROG OUTLOOK
FORECAST EVERY 6 HRS FORECAST EVERY 6 HRS FORECAST SEE "NOTES"
PURPOSE (USE)
Primarily to locate SFC Primarily to fronts & pressure locate SFC IFR systems conditions
FRONTS - TIC]
-IFR (Shaded) -MVFR (Contoured with shading) -VFR (Everything else) -[Know definitions!] -Fronts/Trofs
Identify areas of precipitation & TSTMS. Check intensity coverage and movement
PRECIPITATION INTENSITIES:
Locate upper level pressure systems, winds, and fronts. Can check moisture and TURBC possibility.
CONTOURS:
900
4 panel chart used to locate areas of possible TSTM activity. To check for TSTM severity potential.
ISOPLETHS:
Wind direction & wind speed at planned flight level gives idea of avg enroute WCP. Temp. useful for effect on TAS & fuel flow.
30k
O
Locate IFR areas, precip. Areas, turbc area, fronts, pressure systems, inversions, and FRZLVLS. SFC-400mb ~(24000')
12 - hr SFC - 400mb
Locate: Jets, Areas which may CBs, CAT, expect general TROP LVLS, TSTMS and Hurricanes, SVR areas which may Squall LNS, expect SVR Sand/Duststorms TSTMS. , fronts. Includes: SVRTS ~FL250 RISK notations. ~FL600 (LEVELS)
100 80k FL35 CAT 100 80k
-4
Lines of an equal value. In this case "LI " LI > O LI < O PLOTS: 3
C
L
24 - hr SFC - 400mb
- 50 or 50 *
12 - hr SFC 24 - hr SFC
912
360 300
SVR SQUALLN
(To the right of line is general TSTM activity forecasted.
SEVERE TSTM areas are: Shaded
DEPICTS
PRESSURE - 1010
12
L
. 10
H.
1014 IFR
KNOW: LGT - MDT STG - V.S. int. - XTRM
> 80% COV.
WINDS PARALLEL and increase when? ISOTACHS:
_ 3 _ = DIRECTION
0
-V-V-V-V
Upper panels have a Legend: LI KI BAD DAY
O O 1 2 3 IFR MVFR TBC FRZLVL(s)
CBs:
10k
30k
-10 45
ISOL ( < 1/8 ) OCNL (1/8-4/8) ) FRQ (5/8-8/8) )
or with a RISK notation in the circle or near.
WHAT IS ALSO REQUIRED TO DETERMINE HOW?
SLD
MVFR
VFR
SLD
ISOTHERM -35
10 -2
GOOD DAY
AUTO 1/2
VIS. CIG / CLD base
WS 500 WS 500
WX / obs to vision
SVR TSTM* WATCH 500 / YT TORNADO WATCH 501 / YT 400 Precipitation tops 40000' MSL
ISOTACHS: Shading: 70 - 110K 150 - 190K etc. CLR within shading: 110 - 150K 190 - 230K etc. STATION MODELS: TT T-D HGT HC(LV,M)
Negative LIs = unstable Positive LIs = stable Positive (& high) KI = moist & unstable Low (or negative) KI = dry & stable L - severity potential K - TSTM probability
notes:
MDT
SVR TBC
T.S. HURRICANE
DAY 1 5 X DAILY DAY 2 2 X DAILY COVERS (2 DAYS)
S
NOTES
25
* *
145 13 .03
*
CALM
>5sm
don't expect these on SVR MDT NWS Charts. ICG (others - yes)
TROP LEVEL: 450 = 45000'
TROP HIGH: H 500 TROP LOW:
COLD WK MDT STG
100
22
R RW
S SW
T NA
NE OM
DECODE THE STATION MODEL. [ KNOW THE UNITS! ]
Frontal intensity given TEST will exclude ' human frontal analysis'.
15 cell movement LM=? 15K to NE
Shaded black when T-D spread is 5 degrees or less (moist).
-8 12
is possible!
MDT TBC within the lines from SFC - 10000'
300 L
VOLCANIC ERUPTION
AUTO
shading - Precip. Cov. > 50%.