Aviation Weather Services: The Complete Pilot's Reference

By Renzo, CPL · Updated March 2026

Every flight begins and ends with weather. Knowing how to find, decode, and interpret the full suite of aviation weather products is what separates a prepared pilot from one who gets surprised. This guide covers every weather service available to pilots — from raw METAR and TAF reports to PIREPs, SIGMETs, AIRMETs, prog charts, radar, satellite, winds aloft, briefing types, 1800wxbrief, ForeFlight, and ADS-B weather in the cockpit.

Last updated: March 2026 · Sources: FAA Aviation Weather Services (AC 00-45H), AIM Chapter 7, NWS, AWC

~900

ASOS/AWOS Stations in US

24-30hr

TAF Forecast Period

122.0

Flight Watch (EFAS) MHz

978 MHz

FIS-B ADS-B Frequency

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1. Aviation Weather Products Overview

Aviation weather products fall into two categories: observations (what the weather is right now) and forecasts (what the weather is expected to be). Understanding which products are observations versus forecasts is critical — they have different levels of reliability and different uses in your decision-making.

Observations (Current)

METAR/SPECI — Surface observations at airports
PIREPs (UA/UUA) — Pilot reports from aircraft in flight
RADAR — Precipitation location and intensity
Satellite Imagery — Cloud cover and movement
ATIS/AWOS/ASOS — Automated surface observations
Radiosonde (RAOB) — Upper air temperature, humidity, wind

Forecasts (Predicted)

TAF — Terminal aerodrome forecast (24-30 hours)
Area Forecast / GFA — Regional forecast (graphical)
Winds Aloft (FB) — Wind and temperature at altitude
Prog Charts — Surface and significant weather forecasts
SIGMETs/AIRMETs — Hazardous weather advisories
Convective Outlook — Thunderstorm probability

Key principle: Observations tell you what IS happening. Forecasts tell you what MIGHT happen. Always cross-reference multiple sources. When observations and forecasts disagree, the observations win — but be prepared for conditions to change as the forecast suggests.

2. METAR Decoding — Full Format with Examples

A METAR (Meteorological Aerodrome Report) is the standard format for surface weather observations at airports worldwide. METARs are issued hourly, with SPECI (special) reports issued whenever conditions change significantly. Every pilot must be able to decode a METAR quickly and accurately.

Example METAR:

SPECI KORD 121956Z 18025G38KT 1/2SM +TSRA FG BKN008 OVC025CB 24/23 A2968 RMK AO2 PK WND 19042/1952 TWR VIS 1 PRESRR SLP045 FRQ LTGICCCCG TS OHD MOV E T02440233

Element-by-Element Breakdown

METAR / SPECI — Report type: routine hourly (METAR) or special unscheduled (SPECI) observation triggered by significant changes

KJFK — Station identifier. ICAO four-letter code (K prefix = contiguous US, C = Canada, EG = UK, etc.)

121856Z — Date/time in UTC (Zulu). 12th day of the month at 1856Z. All aviation weather uses UTC exclusively

31015G25KT — Wind: from 310 degrees true at 15 knots, gusting 25 knots. VRB = variable direction, 00000KT = calm

1/2SM — Prevailing visibility in statute miles. P6SM = greater than 6 miles. Can be fractional (1/4SM, 1 1/2SM)

R04R/2400FT — Runway Visual Range for runway 04R: 2,400 feet. Reported when visibility is 1 mile or less

+TSRA — Weather phenomena. Intensity (+ heavy, - light, no prefix moderate), descriptor (TS thunderstorm), type (RA rain)

BKN025CB — Cloud cover: Broken (5-7 oktas) at 2,500 ft AGL, cumulonimbus. SKC/CLR, FEW, SCT, BKN, OVC

18/12 — Temperature/dew point in Celsius. M prefix = negative (M02 = -2C). Spread < 3C warns of fog/low clouds

A2992 — Altimeter setting: 29.92 inHg. International reports use Q1013 (QNH in hPa/mb)

RMK AO2 SLP132 — Remarks: AO2 = automated with precipitation sensor, SLP132 = sea-level pressure 1013.2 hPa

Cloud Cover Abbreviations

Abbreviation	Meaning	Oktas	Ceiling?
SKC / CLR	Sky clear	0	No
FEW	Few clouds	1-2	No
SCT	Scattered	3-4	No
BKN	Broken	5-7	Yes
OVC	Overcast	8	Yes
VV	Vertical visibility (obscured sky)	8	Yes

Ceiling definition: The ceiling is the height of the lowest layer reported as BKN (broken), OVC (overcast), or VV (vertical visibility / obscured). FEW and SCT layers are NOT ceilings. This matters for determining flight categories and whether VFR or IFR rules apply.

Practice decoding with our density altitude calculator — temperature and altimeter from METARs feed directly into density altitude calculations.

3. Weather Phenomena Codes

Weather phenomena in METARs and TAFs use standardized abbreviations with intensity prefixes: + (heavy), no prefix (moderate), - (light), and VC (in the vicinity, 5-10 sm from the station). Descriptors include TS (thunderstorm), SH (shower), FZ (freezing), BL (blowing), DR (drifting), MI (shallow), PR (partial), and BC (patches).

Code	Meaning
RA	Rain
SN	Snow
FG	Fog (visibility < 5/8 sm)
BR	Mist (visibility 5/8 to 6 sm)
HZ	Haze
TS	Thunderstorm
FZRA	Freezing rain
FZDZ	Freezing drizzle
SQ	Squall
FC	Funnel cloud/tornado
GR	Hail (> 1/4 inch)
GS	Small hail / snow pellets
PL	Ice pellets (sleet)
DZ	Drizzle
FU	Smoke
VA	Volcanic ash
SA	Sand
DU	Widespread dust
SS	Sandstorm
DS	Dust storm
VCSH	Showers in the vicinity
VCTS	Thunderstorm in the vicinity

+TSRA — Heavy thunderstorm with rain. The + applies to the precipitation (RA), not the thunderstorm.

FZRA — Freezing rain. One of the most dangerous conditions for aircraft. Immediate action required.

VCSH — Showers in the vicinity (5-10 sm away). Monitor for movement toward the airport.

4. TAF Decoding & Change Groups

Terminal Aerodrome Forecasts (TAFs) predict weather conditions at airports for the next 24 to 30 hours. TAFs are issued four times daily (00Z, 06Z, 12Z, 18Z) and use the same weather codes as METARs plus change indicators that describe how conditions will evolve. TAFs are the single most important forecast product for flight planning.

Example TAF:

TAF KJFK 121730Z 1218/1324 31012KT P6SM FEW040 BKN250
  FM122200 28015G25KT 4SM -RA BKN020
  TEMPO 1222/1302 2SM +RA OVC010
  FM130600 33008KT P6SM SCT030 BKN100
  BECMG 1312/1314 SKC
  PROB30 TEMPO 1316/1320 3SM TSRA BKN030CB

Decoding the Header

TAF — Report type. "TAF AMD" = amended, "TAF COR" = corrected.

KJFK — Station identifier (same ICAO code as METARs).

121730Z — Issue date/time: 12th day at 1730 UTC.

1218/1324 — Valid period: from 12th at 1800Z to 13th at 2400Z (30 hours).

Change Indicators

FM (From)

Complete change to new conditions at specified time. All previous conditions replaced. Example: FM122200 = from 12th at 2200Z

Example: FM122200 28015G25KT 4SM -RA BKN020

TEMPO (Temporary)

Fluctuations expected for less than half the time period. Conditions alternate between prevailing and TEMPO forecast

Example: TEMPO 1222/1302 2SM RA OVC015

BECMG (Becoming)

Gradual, permanent transition during the specified window. Once complete, new conditions persist

Example: BECMG 1312/1314 33010KT P6SM SKC

PROB30/PROB40

30% or 40% probability of specified conditions. Only used with TEMPO. PROB values below 30% or above 50% are not used

Example: PROB40 TEMPO 0200/0600 1SM FG

NSW

No significant weather. Used in BECMG or TEMPO groups to indicate weather phenomena ending

Example: BECMG 1806/1808 NSW

AMD / COR

AMD = amended forecast replacing previous. COR = corrected forecast fixing errors in previously issued TAF

Example: TAF AMD KJFK 121800Z...

TAF reading tip: Think of a TAF as a timeline. Start with the baseline conditions, then overlay each change group in chronological order. FM replaces everything. TEMPO and PROB are temporary fluctuations on top of the prevailing conditions. BECMG is a gradual transition to new prevailing conditions.

5. PIREPs — Pilot Reports (UA vs UUA)

Pilot Reports (PIREPs) are weather observations made by pilots in flight. They are the only source of direct observation of conditions between surface weather stations and at altitude. PIREPs report turbulence, icing, cloud tops/bases, visibility, and wind at the pilot's actual location. They are invaluable because no instrument or model can replace what a pilot actually experiences.

UA — Routine PIREP

Reports routine or moderate conditions: light-to-moderate turbulence, light-to-moderate icing, cloud layers, visibility, and winds at altitude. Filed voluntarily but always encouraged.

UUA — Urgent PIREP

Reports severe or extreme conditions: severe or extreme turbulence, severe icing, tornadoes or funnel clouds, hail, volcanic ash, low-level wind shear (LLWS). ATC is required to solicit UUAs.

Example PIREP:

UA /OV KJFK090020 /TM 1830 /FL085 /TP B738 /SK BKN045-TOP065 /WX FV03SM HZ /TA M02 /WV 27045KT /TB MOD 050-080 /IC LGT RIME 060-085 /RM LLWS -15KT SFC-030

PIREP Field Codes

Field	Meaning	Example
/OV	Location (over)	OV JFK090020 = on 090 radial, 20 NM from JFK
/TM	Time (UTC)	TM 1830 = 1830Z
/FL	Flight level or altitude	FL085 = 8,500 ft MSL; DURGD = during descent
/TP	Aircraft type	TP BE36 = Beechcraft Bonanza
/SK	Sky conditions	SK BKN045-TOP065 = broken layer 4,500-6,500 ft
/WX	Weather / flight visibility	WX FV03SM HZ = 3 miles in haze
/TA	Temperature (Celsius)	TA M05 = -5 degrees Celsius
/WV	Wind velocity	WV 270045KT = 270 degrees at 45 knots
/TB	Turbulence	TB MOD 050-080 = moderate between 5,000-8,000 ft
/IC	Icing	IC LGT-MOD RIME 060-085 = light-mod rime 6,000-8,500
/RM	Remarks (free text)	RM LLWS -15KT SFC-030 = low-level wind shear

Turbulence & Icing Intensity Scale

Turbulence (TB)

LGT (Light) — Slight erratic changes in altitude/attitude
MOD (Moderate) — Changes in altitude/attitude but aircraft remains in positive control
SEV (Severe) — Large abrupt changes; aircraft may momentarily be out of control
EXTRM (Extreme) — Aircraft practically impossible to control; structural damage possible

Icing (IC)

Trace — Barely perceptible; deicing/anti-icing not required
LGT (Light) — Rate allows safe flight; occasional deicing may be needed
MOD (Moderate) — Rate may create a hazard; deicing/diversion necessary
SEV (Severe) — Rate exceeds deice capability; immediate exit required

Filing PIREPs matters: ATC and Flight Service rely on PIREPs to verify or correct forecasts. The absence of PIREPs does NOT mean the absence of hazards — it means no one reported. Always file PIREPs, especially when you encounter conditions different from the forecast. Call ATC or Flight Watch (122.0).

6. SIGMETs vs AIRMETs

SIGMETs (Significant Meteorological Information) and AIRMETs (Airmen's Meteorological Information) are in-flight weather advisories issued by the Aviation Weather Center (AWC). Understanding the difference between them is essential for every pilot and is a common exam topic.

Feature	SIGMET	AIRMET
Severity	Severe or extreme conditions	Moderate conditions (hazardous to light aircraft)
Turbulence	Severe turbulence	Moderate turbulence (AIRMET Tango)
Icing	Severe icing	Moderate icing (AIRMET Zulu)
Visibility	N/A	IFR: ceilings < 1,000 ft, vis < 3 sm (AIRMET Sierra)
Mountain obscuration	N/A	Mountains obscured (AIRMET Sierra)
Sustained surface winds	N/A	Sustained winds > 30 kt (AIRMET Tango)
Volcanic ash	Yes (separate SIGMET series)	N/A
Dust/sandstorm	Visibility < 3 nm	N/A
Duration	Up to 4 hours	Up to 6 hours
Applies to	All aircraft	Primarily GA and light aircraft

AIRMET Types (The Three Letters)

Sierra (S)

IFR conditions: ceilings below 1,000 ft, visibility below 3 sm, and/or mountain obscuration. Affects VFR pilots most.

Tango (T)

Turbulence: moderate turbulence, sustained surface winds 30+ knots, and/or low-level wind shear (non-convective).

Zulu (Z)

Icing: moderate icing and freezing level information. Critical for aircraft without known-ice certification.

Memory aid: Sierra = See (IFR/visibility), Tango = Turbulence, Zulu = freeZing (icing). AIRMETs are issued every 6 hours and are routinely included in weather briefings.

7. Convective SIGMETs

Convective SIGMETs are the highest-level thunderstorm advisory. They are issued for the contiguous United States and cover the most dangerous convective hazards. A Convective SIGMET implies severe or greater turbulence, severe icing, and low-level wind shear — all hazards that can be catastrophic.

Convective SIGMET Criteria

Tornadoes — reported or indicated by radar
Lines of thunderstorms — at least 60 nm long with cells within 30 nm of the line
Embedded thunderstorms — thunderstorms hidden within cloud layers or precipitation
Area of heavy precipitation — ≥ 40% coverage over 3,000+ square miles
Surface hail — ≥ 3/4 inch diameter
Surface wind gusts — ≥ 50 knots from thunderstorms

Example Convective SIGMET:

CONVECTIVE SIGMET 22C
VALID UNTIL 2055Z
KS OK TX
FROM 30NW ICT-30S MKC-50SW SGF-40SW TUL-30NW ICT
AREA EMBD TS MOV FROM 24035KT. TOPS ABV FL450.
WIND GUSTS TO 60KTS RPRTD. TORNADOES...HAIL TO 2 IN...WIND GUSTS TO 65KTS POSS.

2 hrs

Valid duration

Hourly

Issue frequency (H+55)

3 regions

East (E), Central (C), West (W)

Absolute rule: Never fly through or under a Convective SIGMET area. There is no safe altitude to fly through a thunderstorm. Detour, delay, or divert. The FAA recommends at least 20 nm lateral clearance from severe thunderstorms.

8. Area Forecasts & Graphical Forecasts for Aviation (GFA)

The traditional text-based Area Forecast (FA) has been replaced by the Graphical Forecasts for Aviation (GFA) tool on the Aviation Weather Center website (aviationweather.gov). The GFA provides a visual, interactive display of forecast weather conditions across the US.

GFA Layers Available

Surface

Fronts, pressure systems, surface winds, precipitation type and intensity

Clouds

Cloud coverage, bases, tops, and layers at multiple altitudes. Essential for VFR planning

Precipitation / Weather

Type (rain, snow, freezing rain), intensity, and areal coverage

Ceiling & Visibility

Flight categories (VFR/MVFR/IFR/LIFR) color-coded across the map

Turbulence

Forecast turbulence intensity at multiple flight levels (surface through FL450)

Icing

Forecast icing severity, type, and freezing level at multiple altitudes

The GFA allows you to step through time (every 3 hours, out to 18 hours) and toggle between observed conditions and forecast conditions. This is one of the most powerful free tools available to pilots — use it for every cross-country.

9. Prognostic Charts (Prog Charts)

Prognostic charts are forecast maps that depict expected weather conditions at specific future times. They provide the big-picture view that individual METARs and TAFs cannot. Two types are most relevant to pilots:

Surface Prog Chart

Shows forecast positions of fronts (cold, warm, stationary, occluded), pressure systems (high/low centers with central pressure), precipitation areas, and surface pressure isobars. Issued for 12, 24, 36, and 48 hours in advance. Critical for understanding how weather systems are moving and when fronts will affect your route.

Cold front: blue triangles pointing direction of movement
Warm front: red semicircles pointing direction of movement
Stationary front: alternating blue/red symbols
Occluded front: purple alternating triangles/semicircles

Significant Weather Prog Chart

The Low-Level Significant Weather (SIGWX) chart covers surface to FL240 (24,000 ft) and shows forecast areas of IFR and MVFR conditions, turbulence, freezing levels, and significant weather. The High-Level SIGWX chart covers FL250-FL630 and is primarily for jet/airline operations, showing jet streams, tropopause height, CAT areas, and volcanic ash.

Scalloped lines: areas of IFR or MVFR (check legend)
Dashed lines: freezing level contours
Moderate turbulence: dashed hatching

10. Winds & Temperatures Aloft (FB)

The Winds and Temperatures Aloft Forecast (FB) provides forecast wind direction, wind speed, and temperature at specific altitudes above selected stations. FB data is critical for flight planning — choosing your cruising altitude, calculating fuel burn, estimating ground speed, and determining wind correction angles. Use our wind correction calculator to apply winds aloft to your flight planning.

Example Winds Aloft (FD):

STN	3000	6000	9000	12000	18000	24000
FT	---	2714	2725+07	2741+02	2756-07	2770-15

How to Decode FB Reports

2714 — Wind from 270 degrees at 14 knots. First 2 digits = direction (in tens of degrees), next 2 = speed (knots). No temperature at 3,000/6,000 ft level.

2725+07 — Wind from 270 degrees at 25 knots, temperature +7C. The +/- sign indicates above/below zero Celsius. Above 24,000 ft, all temperatures are assumed negative.

9900 — Light and variable winds (less than 5 knots). The "99" code specifically indicates light and variable.

7545 — High-speed encoding: subtract 50 from direction (75-50=25, so 250 degrees) and add 100 to speed (45+100=145 knots). Used when wind speed exceeds 99 knots.

--- — Data not available. Winds are not forecast for the 3,000-ft level when the station elevation is within 1,500 ft of that level.

FB forecasts are issued twice daily for periods of 6, 12, and 24 hours in advance. Use them with our true airspeed calculator and fuel burn calculator for accurate flight planning.

11. Flight Categories — VFR, MVFR, IFR, LIFR

Flight categories classify weather conditions based on ceiling and visibility. These categories are color-coded on weather maps and are the first thing to check when evaluating whether a flight is feasible.

Category	Ceiling	Visibility	Color	Action
VFR	> 3,000 ft AGL	> 5 sm	Green	Go — standard VFR operations
MVFR	1,000 – 3,000 ft AGL	3 – 5 sm	Blue	Caution — marginal, monitor closely
IFR	500 – 999 ft AGL	1 – 2 sm	Red	IFR flight plan required. Not suitable for VFR pilots
LIFR	< 500 ft AGL	< 1 sm	Magenta	Low IFR — instrument approach required, circling may not be possible

Critical distinction: Flight categories are determined by the LOWEST of either ceiling OR visibility. If the ceiling is 4,000 ft (VFR) but visibility is 2 sm (IFR), the station is categorized as IFR. Always check both values.

12. Radar Interpretation for Pilots

Weather radar (NEXRAD in the US) detects precipitation intensity and movement. Understanding how to read radar imagery is critical for avoiding thunderstorms, heavy precipitation, and associated turbulence. Radar shows where precipitation IS, not where clouds are — clear air turbulence (CAT) will not appear on radar.

Radar Reflectivity Scale (dBZ)

5-20 dBZ (Light) — Light precipitation. Generally safe for VFR and IFR flight.

20-30 dBZ (Light-Moderate) — Light to moderate rain. Possible reduced visibility.

30-40 dBZ (Moderate) — Moderate rain. Turbulence likely. Use caution.

40-50 dBZ (Heavy) — Heavy rain, possible hail. Avoid this area.

50-60 dBZ (Intense) — Severe thunderstorm. Hail, severe turbulence, wind shear. AVOID.

60+ dBZ (Extreme) — Extreme precipitation. Tornado possible. Large hail. NEVER penetrate.

Radar Products for Pilots

Composite Reflectivity

Maximum reflectivity at any altitude in the column. The most common view — shows worst-case precipitation intensity.

Base Reflectivity

Reflectivity at the lowest radar scan angle (~0.5 degrees). Shows precipitation closest to the surface.

Echo Tops

Highest altitude where radar detects precipitation. Higher tops = stronger storms. Tops above FL350 indicate severe convection.

Vertically Integrated Liquid (VIL)

Total water content in a vertical column. Higher VIL = more intense storm. VIL > 50 kg/m2 suggests severe weather.

Datalink radar is NOT real-time. NEXRAD images on your iPad, EFB, or ADS-B receiver are 5-15+ minutes old. A thunderstorm can move 5-10 miles and grow from 30 dBZ to 55 dBZ in that time. Use datalink radar for strategic routing, NOT for tactical thunderstorm penetration or threading between cells.

13. Satellite Imagery Types

Satellite imagery provides the broadest view of weather patterns and is especially valuable for identifying cloud systems, moisture patterns, and developing convection. Three types of satellite imagery are used in aviation:

Visible (VIS)

Shows sunlight reflected by clouds and the earth's surface. Only available during daylight hours. Thicker clouds appear brighter. Best for identifying cloud type, coverage, and texture. Fog and low stratus are easily visible.

Limitation: not available at night

Infrared (IR)

Measures thermal radiation emitted by clouds and the surface. Available 24 hours. Colder objects (higher cloud tops) appear brighter/white. Essential for identifying thunderstorm intensity — the brightest, coldest tops indicate the strongest updrafts.

24-hour availability, shows cloud-top temperature

Water Vapor (WV)

Shows moisture content in the middle and upper troposphere (roughly 10,000-30,000 ft). Reveals moisture patterns even where no clouds exist. Shows jet stream position, areas of rising/sinking air, and potential convection zones.

24-hour, reveals invisible moisture patterns

Satellite loops (animated sequences) are far more useful than single images. They reveal cloud movement, development, and dissipation trends. Check satellite loops on aviationweather.gov or in your EFB app as part of every pre-flight briefing.

14. Weather Briefing Types

FAR 91.103 requires pilots to become familiar with all available information concerning a flight. A weather briefing from Flight Service satisfies this requirement and provides information tailored to your specific route and time. There are three types of briefings:

Standard Briefing

When: Initial briefing for any flight. Requested when you have not previously received any weather information

Includes: Adverse conditions, VFR flight not recommended (if applicable), synopsis, current conditions, en route forecast, destination forecast, winds aloft, NOTAMs, ATC delays

Tip: Always start here for flights more than 2 hours away. Say: 'I'd like a standard briefing from [departure] to [destination], departing at [time]'

Abbreviated Briefing

When: Update a previous standard briefing or supplement information from other sources (ForeFlight, etc.)

Includes: Only the specific information you request, plus any adverse conditions or significant changes since your last briefing

Tip: Tell the briefer what information you already have. Say: 'Abbreviated briefing, I have current METARs and TAFs, need PIREPs and NOTAMs for...'

Outlook Briefing

When: Flight planned 6+ hours in the future. Used for initial planning before a go/no-go decision

Includes: General weather trends, forecast conditions for your proposed departure time, potential hazards

Tip: Follow up with a standard briefing closer to departure. Say: 'Outlook briefing for a flight tomorrow morning from [departure] to [destination]'

Standard Briefing Format (In Order)

1
Adverse Conditions — Any weather or conditions that may affect flight safety: SIGMETs, AIRMETs, CWAs, PIREPs of severe conditions
2
VFR Flight Not Recommended — If conditions make VFR flight questionable (advisory only, not regulatory)
3
Synopsis — Big picture: fronts, pressure systems, and how they will affect your route over the next 12-18 hours
4
Current Conditions — Latest METARs, SPECIs, radar, satellite, and PIREPs along your route
5
En Route Forecast — Forecast conditions along your route including clouds, visibility, weather, winds
6
Destination Forecast — TAF and expected conditions at your destination for your ETA window
7
Winds Aloft — FB data for selected altitudes along your route
8
NOTAMs — Notices including TFRs, runway closures, navaid outages, and FDC NOTAMs
9
ATC Delays — Any known flow control programs, ground stops, or expected delays

15. 1800wxbrief & Leidos Flight Service

1-800-WX-BRIEF (1-800-992-7433) connects you to Leidos Flight Service, the contractor that operates the FAA's Flight Service Stations (FSS). Leidos replaced Lockheed Martin in 2018. The telephone number has not changed, and the same services are available online at 1800wxbrief.com.

By Phone

Weather briefings — standard, abbreviated, outlook
File flight plans — VFR, IFR, DVFR
Open/close VFR flight plans
Activate/cancel IFR flight plans (in non-radar areas)
File PIREPs
NOTAM information
En Route Flight Advisory Service (EFAS / Flight Watch on 122.0 MHz)

Have ready: pilot certificate number, aircraft N-number, departure/destination, proposed route, altitude, departure time, aircraft type.

Online (1800wxbrief.com)

Graphical briefings — visual weather along your route
Electronic flight plan filing
NOTAM search and management
TFR map — graphical display of all active TFRs
Decoded weather products
Briefing records — downloadable for your records
ICAO flight plan filing

Create a free account. Briefings obtained online count as "having received a briefing" for FAR 91.103 compliance.

When to call vs. use the website: Call when weather is marginal or complex — a human briefer can highlight subtle hazards, suggest alternate routes, and answer your specific questions. Use the website for routine VFR flights in good weather or to supplement information from your EFB app.

16. ForeFlight & EFB Weather Tools

Electronic Flight Bag (EFB) apps like ForeFlight, Garmin Pilot, and FlyQ have transformed how pilots access weather. ForeFlight is the most popular in the US and connects to Leidos Flight Service for official briefings.

ForeFlight Weather Features

Graphical Briefing

Route-specific weather summary with METARs, TAFs, SIGMETs, AIRMETs, PIREPs, NOTAMs, and winds aloft displayed graphically along your route.

Radar Overlay

NEXRAD radar, satellite imagery, lightning, and turbulence overlaid on the map. Color-coded by intensity with time slider for history and forecast.

Profile View

Vertical cross-section of weather along your route showing cloud layers, icing, turbulence at altitude. Invaluable for altitude selection.

Aeronautical Decision Support

Color-coded flight categories on airports (green/blue/red/magenta), wind barbs, ceiling/visibility text on the map.

Imagery

Surface analysis, prog charts, satellite, radar, SPC convective outlook — all accessible in-app without switching to external websites.

File & Brief

File VFR/IFR flight plans and receive official Leidos briefings directly in the app. Briefing is stored for regulatory compliance.

Other Popular EFB Apps

Garmin Pilot — Integrates with Garmin avionics and ADS-B receivers. Full weather briefing capability via Leidos. Strong situational awareness tools.
FlyQ EFB — Popular for its simplicity and one-time purchase model. Includes weather overlays, flight planning, and approach plates.
Fltplan.com / FltPlan Go — Free flight planning with weather briefings. Popular with professional pilots. Now part of Garmin ecosystem.
aviationweather.gov — Free. The Aviation Weather Center's official site. GFA tool, TAFs, METARs, prog charts, SIGMETs — every product available.

17. ADS-B Weather (FIS-B) in the Cockpit

ADS-B In receivers on 978 MHz (UAT) can pick up FIS-B (Flight Information Service — Broadcast) data transmitted by ground stations. This gives you free, subscription-free weather in the cockpit — a game-changer for GA pilots.

FIS-B Weather Products

Product	Update Rate	Coverage
NEXRAD (Regional)	~2.5 min	Within ~250 NM
NEXRAD (National)	~15 min	CONUS-wide
METARs / SPECIs	~5 min	All reporting stations
TAFs	~5 min	All TAF stations
PIREPs	~10 min	All current PIREPs
SIGMETs / AIRMETs	~5 min	CONUS
Convective SIGMETs	~5 min	CONUS
Winds & Temps Aloft	~10 min	All FB stations
NOTAMs (D and FDC)	~10 min	Within ~100 NM
ATIS	~5 min	Within ~100 NM

FIS-B Limitations

Latency: NEXRAD images are 5-15+ minutes old by the time they display. Never use for thunderstorm penetration.

Coverage gaps: FIS-B requires line-of-sight to a ground station. At low altitudes or in remote areas, coverage may be spotty.

Not a substitute: FIS-B supplements but does NOT replace a pre-flight weather briefing. You must still comply with FAR 91.103.

978 MHz only: ADS-B on 1090ES (used above 18,000 ft / Class A) does NOT receive FIS-B. You need a 978 MHz UAT receiver.

18. NOTAMs & TFRs

Notices to Air Missions (NOTAMs) communicate temporary changes, hazards, or conditions that affect flight. Missing a critical NOTAM — especially a TFR — can have severe consequences including certificate action and interception by military aircraft.

NOTAM Categories

D-NOTAMs

Airport and facility-specific: runway closures, taxiway restrictions, lighting outages, navaid shutdowns, obstacle construction, crane activity, wildlife hazards.

FDC NOTAMs

Regulatory and procedural: TFRs, instrument approach procedure amendments, chart corrections, airspace changes. FDC NOTAMs can modify published procedures — always check before flying an approach.

TFRs (Temporary Flight Restrictions)

Restricted airspace for: presidential/VIP movements, sporting events, disaster/hazard areas (wildfires, chemical spills), space launches, national security. TFR violations can result in certificate suspension, fines, and/or military intercept.

Military NOTAMs

Military airspace activation, special use airspace (MOAs, restricted areas, warning areas), military exercises, drone operations in military airspace.

Center Area NOTAMs

ARTCC-specific information: navigation, communication, and airspace changes within a specific Center's area of responsibility.

TFR protocol: Always check TFRs before every flight at tfr.faa.gov or in your EFB app. TFRs can be issued on short notice (presidential movements may have only 30 minutes warning). Set up TFR alerts in ForeFlight or your EFB. Ignorance is never a defense for TFR violation.

19. Weather Decision-Making Framework

Having access to weather products is only valuable if you know how to use them in a structured decision-making process. The following framework ensures you check the right products at the right time, whether flying VFR or IFR.

1. Big Picture (24-48 hrs out)

Check prog charts, convective outlooks, and area forecasts for general trends

Sources: AWC prog charts, GFA, SPC convective outlook

2. Route Planning (6-12 hrs)

Get an outlook briefing. Review TAFs, SIGMETs/AIRMETs, winds aloft for route selection

Sources: 1800wxbrief, ForeFlight, TAFs, winds aloft

3. Go/No-Go (2-4 hrs)

Standard briefing. Check METARs, PIREPs, radar/satellite, NOTAMs. Apply personal minimums

Sources: Standard briefing, METARs, PIREPs, radar

4. Pre-Departure (30-60 min)

Final METAR/TAF check, abbreviated briefing for changes, ATIS at departure airport

Sources: ATIS, abbreviated briefing, latest METARs

5. In-Flight

Monitor HIWAS, EFAS (Flight Watch 122.0), ADS-B weather, ATC PIREPs. Continuous evaluation

Sources: FIS-B, Flight Watch, ATC, onboard weather

6. Destination (30 min out)

Get destination ATIS/AWOS. Verify conditions meet approach minimums. Have alternates ready

Sources: ATIS/AWOS, METAR, alternate planning

VFR vs IFR: Different Weather Concerns

VFR Pilot Priorities

Ceilings and visibility along entire route
Terrain clearance vs cloud bases
Trends: improving or deteriorating?
Fog/low stratus risk (temp/dewpoint spread)
Convective activity and movement
Mountain obscuration (AIRMET Sierra)
Wind and turbulence at planned altitude
Escape routes and divert options

IFR Pilot Priorities

Destination weather vs approach minimums
Alternate weather requirements (1-2-3 rule)
Icing levels vs MEA/planned altitude
Turbulence (AIRMET Tango, PIREPs)
Convective activity (avoid, not penetrate)
Winds aloft for fuel planning
NOTAMs: navaid outages, approach availability
Missed approach procedure weather viability

The PAVE checklist: Before every flight, evaluate: Pilot (am I fit, current, rested?), Aircraft (is it capable for these conditions?), enVironment (weather, terrain, airspace, NOTAMs), External pressures (schedule, passengers, "must-get-there" thinking). A weak link in any element warrants a cancel or delay. Use our crosswind calculator and density altitude calculator as part of your go/no-go process.

Frequently Asked Questions

What is 1800wxbrief and how do I use it?

1800wxbrief (1-800-WX-BRIEF) is the FAA's official Flight Service telephone number, now operated by Leidos Flight Service. You can call to request standard, abbreviated, or outlook weather briefings, file flight plans, open/close VFR flight plans, and get NOTAMs. The same services are available online at 1800wxbrief.com, where you can access graphical weather, file flight plans electronically, and review briefing documents. You must provide your pilot certificate number and aircraft N-number when calling.

What is the difference between a SIGMET and an AIRMET?

SIGMETs warn of severe weather hazardous to ALL aircraft: severe turbulence, severe icing, volcanic ash, dust/sandstorms reducing visibility below 3 nm, and thunderstorms (Convective SIGMETs). They last up to 4 hours. AIRMETs warn of moderate-level hazards primarily affecting light aircraft and less experienced pilots: moderate turbulence (Tango), moderate icing and freezing levels (Zulu), and IFR conditions/mountain obscuration (Sierra). AIRMETs last up to 6 hours.

How do I decode a METAR report?

Read a METAR left to right: report type (METAR/SPECI), station ID (KJFK), date/time in UTC (121856Z), wind direction/speed/gusts (31015G25KT), visibility in statute miles (10SM), runway visual range if applicable, weather phenomena (+TSRA = heavy thunderstorm with rain), cloud layers (BKN025 = broken at 2,500 ft AGL), temperature/dewpoint in Celsius (18/12), altimeter setting (A2992 = 29.92 inHg), and remarks. The lowest BKN or OVC layer is the ceiling.

What is a Convective SIGMET and when is it issued?

Convective SIGMETs are issued for the most dangerous thunderstorm-related hazards in the contiguous US: tornadoes, lines of thunderstorms (squall lines), embedded thunderstorms, thunderstorm areas with heavy precipitation covering 40%+ of an area at least 3,000 square miles, hail at the surface 3/4 inch or greater, and wind gusts to 50 knots or more. They are issued hourly and valid for 2 hours. Convective SIGMETs imply severe or greater turbulence, severe icing, and low-level wind shear.

What is a PIREP and why is it important?

A Pilot Report (PIREP) is a weather observation made by a pilot in flight. PIREPs are the ONLY direct observation of conditions between weather stations and at altitude. They report turbulence intensity, icing type and severity, cloud tops and bases, visibility, and wind. Routine PIREPs (UA) report normal or moderate conditions. Urgent PIREPs (UUA) report severe or extreme turbulence, severe icing, tornadoes, funnel clouds, hail, volcanic ash, or low-level wind shear. Filing PIREPs is both helpful and encouraged — it directly helps other pilots make better decisions.

How do I read a TAF forecast?

A TAF starts with the station ID, issue time, and valid period (e.g., 1218/1324 = valid from 12th at 18Z to 13th at 24Z). The initial line shows baseline forecast conditions. Change groups modify the forecast: FM (from) = complete change at that time, TEMPO = temporary fluctuation for less than half the period, BECMG = gradual permanent change over the specified window, PROB30/40 = probability percentage used only with TEMPO. TAFs cover 24-30 hours and are issued 4 times daily.

What weather information does ADS-B provide in the cockpit?

ADS-B In receivers pick up FIS-B (Flight Information Service - Broadcast) data on 978 MHz, which includes: NEXRAD radar imagery (composite and regional), METARs and SPECIs, TAFs, PIREPs, SIGMETs and AIRMETs, Convective SIGMETs, winds and temperatures aloft, NOTAMs, and ATIS. Important limitations: NEXRAD imagery is 5-15 minutes old (never use for thunderstorm penetration), and coverage depends on proximity to ground-based transmitters. FIS-B supplements but does not replace a proper pre-flight briefing.

What is the difference between ForeFlight weather and an official briefing?

ForeFlight, Garmin Pilot, and similar EFB apps are approved sources for pre-flight weather when they connect to Leidos Flight Service (QICP-qualified). ForeFlight's briefing feature generates a legal weather briefing that satisfies FAR 91.103. The graphical interface makes it easier to visualize weather along your route. However, the telephone briefing from 1800wxbrief lets you discuss weather with a human specialist who can highlight nuances. Many experienced pilots use EFB apps for primary weather review and call Flight Service when conditions are marginal or complex.

How do I read winds aloft forecasts (FB)?

Winds aloft (FB — Winds and Temperatures Aloft Forecast) are reported as a 4-digit or 6-digit code: the first 2 digits are wind direction in tens of degrees, the next 2 are wind speed in knots, and the last 2 (if present) are temperature in Celsius. Example: 2714 = 270 degrees at 14 knots; 2725+07 = 270 degrees at 25 knots, temperature +7C. If the wind speed is 100-199 knots, 50 is added to the direction and 100 subtracted from speed (e.g., 7545 = 250 degrees at 145 knots). Winds at 3,000 ft are not forecast if the station elevation is within 1,500 ft. Temps are not forecast for the 3,000 ft level or if within 2,500 ft of station elevation.

What are the types of satellite imagery used in aviation?

Three types of satellite imagery are used: Visible imagery shows clouds by reflected sunlight (only available during daylight, best for identifying cloud type and coverage), Infrared (IR) imagery measures thermal radiation and shows cloud-top temperatures (available 24 hours, colder/higher tops appear brighter — critical for thunderstorm identification), and Water Vapor imagery shows moisture content in the mid and upper troposphere (reveals moisture patterns, jet stream location, and areas of potential convection even where clouds have not yet formed). Pilots should use all three together for a complete picture.

What does 'VFR flight not recommended' mean in a briefing?

When a Flight Service briefer says 'VFR flight not recommended' (VNR), it means current or forecast conditions along all or part of your route make safe VFR flight questionable. This is advisory — it does not prohibit VFR flight. However, it should be taken very seriously. Conditions typically include MVFR or IFR ceilings, reduced visibility, mountain obscuration, or convective activity. As PIC, the final go/no-go decision is yours, but the briefer's recommendation carries significant weight. Many accident chains begin with a pilot ignoring VNR.

How current are NEXRAD radar images on my iPad or in the cockpit?

NEXRAD radar images in the cockpit via ADS-B (FIS-B) are 5-15+ minutes old by the time they reach your display. This delay includes radar scan time, data processing, satellite uplink, and your receiver refresh rate. On ground-based apps (ForeFlight, etc.), data is typically 5-6 minutes old. This latency means NEXRAD should NEVER be used for real-time thunderstorm avoidance or penetration. A cell can grow or move several miles in 10 minutes. Use onboard weather radar (if equipped) or ATC guidance for tactical avoidance. Datalink weather is for strategic planning only.

What NOTAMs should I check before every flight?

Check these NOTAM categories: D-NOTAMs (airport/facility specific — runway closures, navaid outages, lighting), FDC NOTAMs (regulatory — TFRs, approach procedure changes, chart corrections), TFRs (Temporary Flight Restrictions — presidential movements, sporting events, wildfires, disaster areas, space launches), Center Area NOTAMs (ARTCC-specific), and Military NOTAMs. Pay special attention to TFRs, which can carry severe penalties for violation. Always check NOTAMs for your departure, destination, alternate, and any navaids along your route. FDC NOTAMs can modify published instrument approach procedures.

Related Resources

Aviation Weather Theory

Fronts, thunderstorms, icing, turbulence

Density Altitude Calculator

Calculate DA from METAR data

Crosswind Calculator

Headwind and crosswind components

Wind Correction Calculator

Apply winds aloft to your heading

Pressure Altitude Calculator

Convert altimeter to pressure altitude

True Airspeed Calculator

TAS from CAS and altitude

Flight Planning Guide

Complete cross-country planning

Airspace Guide

All airspace classes explained

Free Practice Test

Test your weather knowledge

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