How is PlaneWX different from my EFB or aviationweather.gov?

Your EFB is excellent for charts, filing, and day-of flying. Aviationweather.gov and Flight Service (including 1800WXBRIEF) give you official weather products. PlaneWX sits beside those tools. It does not replace them. What PlaneWX adds is decision support days out: a WX Score matched to your aircraft and personal minimums, a dynamic FRAT on the FAA PAVE framework, and mentors who see the same briefing you see. You can also share a flight plan into PlaneWX from a supported EFB. You stay PIC. Charts, filing, and official sources stay where they belong.

Is the briefing accurate?

Your briefing uses the same official observations and forecasts every pilot relies on: METARs, TAFs, PIREPs, SIGMETs and model guidance. It can only be as accurate as those forecasts, and every forecast carries some uncertainty. Every weather briefing, from any provider, also has the same built-in limit. It describes one departure time, one route, one altitude and one arrival time. Real flights change. You leave late, get rerouted, or get assigned a different altitude, and each change puts you in weather the briefing didn't look at. That's why PlaneWX can keep updating your briefing for monitored flights as the forecast changes, and why your decision-making continues in the air.

How can I make my briefing more accurate?

Enter the flight the way you'll really fly it: a realistic departure time, the route you expect to file or be cleared, your planned altitude, and the right aircraft profile. If any of those change, update the trip and brief again. Check again close to departure, when the forecasts are freshest.

Yes, in specific places. Weather reports, forecasts, model data and NOTAMs are fetched and decoded by code. AI reads forecaster discussions and writes the plain-language briefing, the hazard summary and most section ratings. It also proposes a starting WX Score and some deductions, such as for convection. Ceiling and visibility are always scored by code. Within 12 hours of departure, your personal minimums and aircraft limits are checked by rule-based code, not the AI. Further out, AI also helps weigh icing and turbulence against your limits. You always make the final call.

What is the WX Score?

The WX Score is a 0-100% metric calculated against YOUR personal minimums and your specific aircraft, not generic VFR/IFR categories. It tells you, in a single number, how well conditions are expected to match your standards. Every deduction is transparent and explained.

What is the PAVE framework?

PAVE is the FAA risk framework: Pilot, Aircraft, enVironment, and External pressures. It is the structure behind a serious preflight risk assessment, not a weather product by itself. We walk through it in plain language in our PAVE risk assessment guide. PlaneWX FRAT uses that same framework as a living sit-down assessment near departure. See how PlaneWX FRAT works, including how the briefing and airport context feed the enVironment side.

How far in advance can PlaneWX forecast weather?

PlaneWX provides weather intelligence from 14 days out through departure. Confidence improves as your flight approaches. We are transparent about uncertainty at every time horizon.

What is the mentor system?

PlaneWX connects you with experienced pilots who can review your full briefing (WX Score, aircraft profile, personal minimums) and offer a second set of eyes grounded in shared data, not guesswork. Mentor sits alongside the risk-management loop when you want it.

Is there a free plan?

Yes. Free forever includes full-quality briefings. We limit how much you can use PlaneWX, not how good the analysis is. Details on plans and what each tier includes are in PlaneWX Plans help.

What's the difference between Casual, Pro, and Pro Plus?

Casual is for pilots who fly a few times a month and want auto-monitoring. Pro raises limits and automation. Pro Plus adds Ground Protection, Auto-Brief, Pre-Flight Text, briefed fuel stops, and Labs. Compare current limits and features in Plans help, or start from the pricing section on this page. Personal minimums still drive the WX Score on every plan. If you are setting those for the first time, see personal minimums for weather planning.

What happens after the 14-day free trial?

You keep access on Free, or choose Casual, Pro, or Pro Plus. No card is required to start the trial. Plan details stay in Plans help.

Weather Radar for Pilots: NEXRAD, TDWR, Reflectivity, and Datalink Delay

PlaneWX · Updated September 29, 2026

Weather radar shows precipitation, measured as reflectivity in dBZ. Most images pilots see come from NEXRAD, the network of 160 WSR-88D radars [1, paras. 24.6.1 and 24.6.1.1.1]. A datalinked radar mosaic in the cockpit always shows older weather than its time stamp suggests, in extreme cases by 15 to 20 minutes [3]. Assume at least 7 to 8 minutes, and use it to avoid storms by a wide margin, never to pick a path between them [4, para. 8.2.1].

Key takeaways

The age on a cockpit radar image is the age of the mosaic, not of the weather. The weather is always older [3].
Radar sees precipitation, not clouds, fog, or turbulence. A clear screen doesn't mean clear weather [2, paras. 7-1-11 and 7-1-12].
Datalink radar supports strategic decisions, 20 minutes or more ahead, not tactical ones [2, para. 7-1-9].

Key facts

NEXRAD is a network of 160 WSR-88D radars run by the NWS, FAA, and DOD [1, para. 24.6.1.1.1].
Each volume scan takes 4 to 11 minutes, and radars are not synchronized [1, para. 24.6.1.1].
Reflectivity is in dBZ; about 15 dBZ means light precipitation [1, para. 24.6.1.4].
ATC calls precipitation LIGHT below 26 dBZ, MODERATE 26 to 40, HEAVY over 40 to 50, EXTREME over 50 [2, para. 7-1-12].
Avionics NEXRAD mosaics use composite reflectivity [1, para. 24.6.1.5.2].
Radar does not detect clouds, fog, or turbulence [2, paras. 7-1-11 and 7-1-12].
The mosaic age stamp is not the age of the weather [3].
Assume datalink radar is at least 7 to 8 minutes older than its time stamp [4, para. 8.2.1].
It may be 15 to 20 minutes older in extreme cases [3][2, para. 7-1-27].
Datalink radar is for strategic avoidance, not threading storms [2, paras. 7-1-9 and 7-1-27].

Hover, focus, or tap any dotted term for a definition and its official source.

Radar is the best tool for finding precipitation, and the easiest to overtrust. This page explains how NEXRAD and the FAA's terminal radar work, how to read reflectivity and the common radar products, where radar misses weather, and the single most important limit for pilots: datalink delay. The sources are the FAA Aviation Weather Handbook, the AIM, NTSB Safety Alert SA-017, and FAA Advisory Circular 00-63B on flight deck weather displays [1][2][3][4].

What is NEXRAD?

NEXRAD is the WSR-88D Doppler radar. "The WSR-88D radar network consists of 160 radars operated by the NWS, FAA, and DOD." [1, para. 24.6.1.1.1] Its 10-cm wavelength matters: "The WSR-88D’s 10-cm wavelength is not significantly attenuated by precipitation." [1, para. 15.2.5.1] Heavy rain close to the radar doesn't hide storms behind it the way it does on a typical airborne radar.

How often NEXRAD updates

"Each radar observation, called a volume scan, consists of 5 to 14 separate elevation 'tilts,' and takes between 4 and 11 minutes to generate, depending on the radar’s mode of operation." "Radar observation times are not standard nor are they synchronized with other radars." "The valid time of the observation is the time assigned to the product, which is the end of the last radar scan." [1, para. 24.6.1.1]

Two main modes set the pace. In Clear Air Mode, used when there is no rain in range, the radar is at its most sensitive and images update about every 10 minutes. In Precipitation Mode, faster rotation updates images about every four to six minutes [1, paras. 24.6.1.3.1 and 24.6.1.3.2]. So even a single-site image is minutes old before anyone sends it anywhere.

What do the radar colors mean?

The colors show reflectivity, the power returned by targets, measured in dBZ. "For example, in Precipitation Mode, when the decibel value reaches 15, light precipitation is present." Higher values mean higher rainfall rates [1, para. 24.6.1.4]. Below that, "Values below 15 dBZ are typically associated with clouds." They can also be dust, insects, or pollen. And "The scale cannot reliably be used to determine the intensity of snowfall." [1, para. 24.6.1.4]

Check the legend every time: "The color scale and decibel scale can vary depending on the service provider and website." [1, para. 24.6.1.4]

How ATC describes precipitation

Controllers with intensity-capable weather processors use four terms [2, para. 7-1-12]:

ATC term	Reflectivity (dBZ)	Notes
LIGHT	Less than 26	Not displayed on en route WARP
MODERATE	26 to 40	ARSR backup: 30 to 40
HEAVY	Over 40 to 50	ARSR backup: HEAVY TO EXTREME, over 40
EXTREME	Over 50

The en route Weather and Radar Processor (WARP) doesn't display light precipitation. When WARP is unavailable, the backup Air Route Surveillance Radar shows only two levels. Without intensity data, the controller says "INTENSITY UNKNOWN" [2, para. 7-1-12]. ATC can't see clouds either: "ATC systems cannot detect the presence or absence of clouds." [2, para. 7-1-12]

Source conflict, noted: the Handbook's Table 24-8 labels HEAVY as over 40 to 50 dBZ and EXTREME as 50+ dBZ, which overlap at exactly 50; the AIM defines EXTREME as over 50 dBZ [1, para. 24.6.1.4][2, para. 7-1-12]. This page follows the AIM, which governs what controllers say.

Convective or stratiform?

Convective echoes form lines or cells with strong reflectivity gradients, usually moderate to extreme, and "Echo patterns change rapidly when animating the image." Stratiform echoes are widespread, with weak gradients, and "Precipitation intensities are generally light or moderate (39 dBZ or less)." [1, paras. 15.2.15.1.2 and 15.2.15.1.3] Animate the loop to tell them apart.

What are composite reflectivity, base reflectivity, and echo tops?

The NWS makes many radar products. These are the ones pilots meet most [1, para. 24.6.1.5]:

Product	What it shows	Watch for
Composite reflectivity	The strongest return anywhere in the column above each point [1, para. 24.6.1.5.2]	"NEXRAD radar displays on airplane avionics use the Composite Reflectivity data for their radar mosaics."
Base reflectivity	The lowest scan only, 0.5° above the horizon, out to 124 or 248 NM [1, para. 24.6.1.5.3]	"Precipitation at any location may be heavier than depicted on the Base Reflectivity image because it is occurring above the lowest elevation angle."
Echo tops	Height of the 18 dBZ echo above sea level [1, para. 24.6.1.5.4]	"Cloud tops will be higher than the top of the precipitation."
Radar mosaic	Many radar sites stitched into one regional or national image [1, para. 24.6.1.5.1]	The time stamp is the mosaic's age, not the weather's [3]

Base reflectivity arrives a few minutes sooner than composite, but composite can show heavier precipitation aloft that the lowest scan misses [1, paras. 24.6.1.5.2 and 24.6.1.5.3].

Where does radar miss weather?

Overshooting. The beam rises with distance. "For example, at a distance of 124 NM from the radar, the lowest radar beam is at an altitude of approximately 18,000 ft; at 248 NM the beam height is approximately 54,000 ft." Low-topped precipitation far from a radar may not appear on a single-site image [1, para. 15.2.8].
Mountain sites. The radar near Cedar City, Utah, sits on a 10,000 ft mountain. "This means that the coverage begins at 10,000 ft AGL in that area." [1, para. 24.6.1.2] The FAA adds that "Also, NWS NEXRAD coverage has gaps, especially in the western states." [4, para. 8.2.4]
Directly overhead. Precipitation above the highest scan near a radar can be missed even in mosaics. "This region above the radar is known as the 'cone of silence'" [1, para. 15.2.8].
Blockage and false echoes. Terrain can block the beam, and images can be contaminated by ground clutter, ghosts, angels, and anomalous propagation [1, paras. 15.2.9 and 24.6.1.6].
Clouds and fog. "A clear radar display (no echoes) does not mean that there is no significant weather within the coverage of the radar site. Clouds and fog are not detected by the radar." [2, para. 7-1-11]
Turbulence. "ATC radar is not able to detect turbulence." Within 20 miles of thunderstorms, turbulence can be much worse than the precipitation suggests [2, para. 7-1-12]. See the turbulence guide.

What is TDWR?

The TDWR is "a Doppler weather radar system operated by the FAA, which is used primarily for the detection of hazardous wind shear conditions, precipitation, and winds aloft on and near major airports situated in climates with great exposure to thunderstorms" [1, para. 24.6.2]. It has long- and short-range scans and two modes. "Update times vary from around five minutes in monitor mode to one minute in hazardous weather mode." Select TDWR products appear on NWS radar websites [1, para. 24.6.2].

Why is cockpit radar older than it looks?

This is the core safety point. NTSB Safety Alert SA-017 explains the mechanism. A mosaic combines many radar sites, and "When a mosaic image is updated, it may not contain new information from each ground site." "The age indicator associated with the mosaic image on the cockpit display does not show the age of the actual weather conditions as detected by the NEXRAD network." "Instead, the age indicator displays the age of the mosaic image created by the service provider." [3]

The NTSB's conclusion, in its own capitals: "Weather conditions depicted on the mosaic image will ALWAYS be older than the age indicated on the display." It adds that "in extreme latency and mosaic-creation scenarios, the actual age of the oldest NEXRAD data in the mosaic can EXCEED the age indication in the cockpit by 15 to 20 minutes." "Actual maximum age differences can vary between service type (FIS-B versus satellite) and provider." [3]

Two accidents

The alert cites two fatal accidents. In 2010, a helicopter pilot's display showed one NEXRAD image as about 1 minute old when the weather in it was about 5 minutes old; the image put severe weather about 7 miles from the landing site as it was actually crossing it. In 2011, a Piper PA-32 pilot diverting around weather likely received images labeled 1 minute old that were really about 6, 7, and almost 8 minutes old; the display would have shown the airplane clear of the rain it had flown into [3]. "Even small time differences between the age indicator and actual conditions can be important for safety of flight, especially when considering fast-moving weather hazards, quickly developing weather scenarios, and/or fast-moving aircraft." [3]

How much delay to assume

The figures differ because they measure different things:

Source	Delay figure	What it describes
NTSB SA-017	Can exceed the display age by 15 to 20 minutes	Oldest NEXRAD data in a cockpit mosaic, in extreme cases [3]
AC 00-63B	At least 7 to 8 minutes older than the time stamp	What pilots must assume for any datalink weather [4, para. 8.2.1]
AIM and Handbook	May be 15 to 20 minutes older than displayed	Datalinked NEXRAD mosaic imagery [2, para. 7-1-27][1, para. 24.6.1.6]
Handbook	5 to 15 minutes or more	NEXRAD in weather apps and uplink services [1, para. 3.2.2]
AIM	Up to 6 minutes old	Precipitation on an ARTCC controller's WARP display [2, para. 7-1-12]

The FAA's working rule: "pilots must assume that data link weather information will always be a minimum of 7 to 8 minutes older than shown on the time stamp." "Thus, pilots should only use data link weather radar images for broad strategic avoidance of adverse weather." [4, para. 8.2.1] And the NTSB's: "Understand that the common perception of a '5-minute latency' with radar data is not always correct." [3]

Strategic, not tactical

The AIM draws the line in minutes. "FIS aviation weather products (for example, graphical ground-based radar precipitation depictions) are not appropriate for tactical (typical timeframe of less than 3 minutes) avoidance of severe weather such as negotiating a path through a weather hazard area." "FIS supports strategic (typical timeframe of 20 minutes or more) weather decision-making such as route selection to avoid a weather hazard area in its entirety." [2, para. 7-1-9] In its thunderstorm guidance: "Don't use data-linked weather next generation weather radar (NEXRAD) mosaic imagery as the sole means for negotiating a path through a thunderstorm area (tactical maneuvering)." [2, para. 7-1-27]

FIS-B radar products and update rates

Over ADS-B, FIS-B broadcasts two radar products, built from the most recent mosaic of NEXRAD composite reflectivity: a CONUS image and a more detailed Regional image [4, app. A]. The AIM lists them as MRMS NEXRAD (CONUS), updated every 2 minutes and transmitted every 15 minutes, and MRMS NEXRAD (Regional), updated every 2 minutes and transmitted every 2.5 minutes [2, para. 7-1-9]. None of the FAA documents used here describes how the MRMS system itself works, so this page gives no other numbers for it. Coverage matters too: "ground-based systems that require a line of sight may have relatively limited coverage below 5,000 feet above ground level (AGL)." [4, para. 8.2.4]

Source conflict, noted: AC 00-63B (June 2024) lists the FIS-B CONUS NEXRAD update interval as 15 minutes and the Regional as 5 minutes. The current AIM (Change 3, July 2026) lists 2 minutes for both [4, app. A][2, para. 7-1-9]. This page uses the newer AIM. Either way, the update interval is not the age of the weather.

How is onboard radar different?

Onboard radar has minimal latency, which is why the Handbook contrasts it with NEXRAD: "Onboard aircraft radar has minimal latency, while NEXRAD data has a latency of 5 to 15 minutes or more with weather apps and data uplink services." "This is why NEXRAD data is used for broad strategic avoidance of thunderstorms and never used to navigate through thunderstorms." [1, para. 3.2.2] Onboard radar has its own limits. Typical 3-cm airborne radars suffer heavy attenuation in precipitation. "As a result, aircraft weather radar typically only shows the leading edge of extreme intensity echoes." [1, para. 15.2.5.1] "However, most airborne radars only compensate for range attenuation out to a distance of 50 to 75 NM." [1, para. 15.2.5.2] The Handbook's summary: "Airborne weather avoidance radar is, as the name implies, for avoiding severe weather", not for penetrating it [1, para. 22.8.1].

Where is the official radar guidance?

Official radar guidance

Start here: FAA Aviation Weather Handbook, Section 24.6, Radar Observations (PDF pages 321 to 329), and Chapter 15, Weather Radar [1, paras. 15.2 and 24.6].
NTSB Safety Alert SA-017, In-Cockpit NEXRAD Mosaic Imagery [3].
AC 00-63B, Use of Flight Deck Displays of Digital Weather and Aeronautical Information, especially paragraph 8.2 [4].
AIM 7-1-12, ATC Inflight Weather Avoidance Assistance, and 7-1-27, Thunderstorm Flying [2].

Links checked September 29, 2026: all returned HTTP 200.

Where does radar mislead pilots?

Trusting the time stamp. It is the mosaic's age. The weather is older [3].
Threading gaps. Gaps between cells on a delayed image may already be closed [2, para. 7-1-27].
Reading light echoes as safe. "Never regard any thunderstorm lightly, even when radar observers report the echoes are of light intensity." [1, para. 22.8.2]
Reading blank as clear. Clouds, fog, turbulence, and some low-topped precipitation don't show [2, para. 7-1-11][1, para. 15.2.8].

How do you use radar in a go/no-go decision?

The decision is yours as pilot in command. A few habits:

Decide early, with margin. Use radar for route selection well ahead. The AIM says to avoid by at least 20 miles any thunderstorm identified as severe or giving an intense radar echo [2, para. 7-1-27].
Add the delay. Picture the storms where they will be, not where the image shows them [3].
Use more than one source. "FIS should not serve as the sole source of aviation weather and other operational information." [2, para. 7-1-9] Ask ATC or Flight Service, and listen for PIREPs.
Get the briefing anyway. "Having in-cockpit weather capabilities does not circumvent the need for a complete weather briefing before takeoff." [3] Record the plan in a FRAT [5, ch. 3].

Where does radar fit in a disciplined decision?

PlaneWX is decision support for general aviation pilots, built around one idea: "Fly like it's your job." Treat the weather decision the way a professional crew would, with the same process every time. That process is a loop: Brief, then FRAT, then Fly or Stay, then Debrief, with a Mentor if you want one. Radar feeds the Brief. Here's how PlaneWX handles it, as described in the help center [6]:

Brief: radar along the route. "PlaneWX samples NOAA’s Multi-Radar/Multi-Sensor (MRMS) mosaic along a corridor around your route" when part of your flight falls within roughly the next 2 hours, and shows it beside the model thunderstorm risk (Live Radar Corridor).
Brief: freshness first. "Radar is an observation of now, but you reach most of your route later." "Reflectivity older than 20 minutes is not a nowcast, and nothing is reduced." (Live Radar Corridor)
Brief: radar can only soften. A quiet radar corridor can reduce the model thunderstorm deduction; it can't add one or undo a Convective SIGMET, a TAF or METAR thunderstorm report, or a personal-minimum hard limit. "Radar only ever moves that one deduction, and only downward." (Live Radar Corridor)
Brief: the models. Convective scoring combines model instability indices, TAFs, and METAR thunderstorm reports into the WX Score (Convective Scoring).
FRAT. The flight risk assessment opens within 4 hours of departure, and your own ratings drive it (FRAT).
Fly or Stay. "PlaneWX never recommends GO or NO-GO. You make the call as PIC." (The Risk Loop)
Debrief. Compare what radar showed with what you met. Self Debrief is a PlaneWX Labs feature for Pro Plus (The Risk Loop).

The help center is plain about the limits: "PlaneWX is not a substitute for a complete, independent pre-flight weather briefing. Pull one from a source you already trust before you fly." (The Risk Loop)

See radar along your next route in a PlaneWX briefing, or read how the live radar corridor works. Related: convective scoring and the PlaneWX announcement of the live radar convective score.

Frequently asked questions

What is NEXRAD?

The WSR-88D Doppler weather radar network: 160 radars operated by the NWS, FAA, and Department of Defense [1, paras. 24.6.1 and 24.6.1.1.1]. Its data feeds the radar images in apps and avionics.

How old is the radar picture in my cockpit?

Older than it says. The age indicator shows the age of the mosaic, not of the weather [3]. The FAA says to assume at least 7 to 8 minutes older than the time stamp [4, para. 8.2.1], and the AIM says it may be 15 to 20 minutes older [2, para. 7-1-27].

Can I use datalink radar to pick a way through thunderstorms?

No. The AIM says not to use datalinked NEXRAD mosaic imagery as the sole means of negotiating a path through a thunderstorm area, and to use it for route selection to avoid thunderstorms entirely [2, para. 7-1-27].

What does dBZ mean?

It is the unit of radar reflectivity, the power returned by a target. Higher values generally mean heavier precipitation. About 15 dBZ marks light precipitation [1, para. 24.6.1.4].

What is the difference between composite and base reflectivity?

Base reflectivity is the lowest scan only. Composite reflectivity is the strongest return in the whole column, and it is what avionics NEXRAD mosaics use [1, paras. 24.6.1.5.2 and 24.6.1.5.3].

Does a clear radar mean clear weather?

No. "A clear radar display (no echoes) does not mean that there is no significant weather within the coverage of the radar site. Clouds and fog are not detected by the radar." [2, para. 7-1-11]

What is TDWR?

Terminal Doppler Weather Radar, an FAA radar near major airports built mainly to detect hazardous wind shear. It updates about every 5 minutes in monitor mode and every minute in hazardous weather mode [1, para. 24.6.2].

Can radar show turbulence?

Not directly. "ATC radar is not able to detect turbulence." Turbulence generally increases with precipitation intensity, and it can be severe within 20 miles of thunderstorms [2, para. 7-1-12].

How does PlaneWX use radar?

The help center says PlaneWX samples NOAA's MRMS radar mosaic along your route for near-term flights, and radar can only reduce a model thunderstorm deduction, never add one or override a hard limit. PlaneWX never recommends GO or NO-GO; you make the call as PIC [6].

Glossary

Every term below links to the FAA, NWS, or NOAA document that defines it. The same definitions appear when you hover, focus, or tap a dotted term on this page.

Base reflectivity: Radar returns from the lowest scan only, 0.5° above the horizon. It arrives sooner than composite but can miss heavier precipitation higher up. Source: FAA Aviation Weather Handbook, 24.6.1.5.3
Composite reflectivity: The strongest radar return found anywhere in the vertical column above each point. Avionics NEXRAD mosaics use it. Source: FAA Aviation Weather Handbook, 24.6.1.5.2
dBZ (Decibels of reflectivity): The unit radar uses for reflectivity, the power returned from a target. Higher values generally mean heavier precipitation. Source: FAA Aviation Weather Handbook, 24.6.1.4
Echo tops: An estimate of the top of the precipitation, from the height of the 18 dBZ radar echo above sea level. Cloud tops are higher. Source: FAA Aviation Weather Handbook, 24.6.1.5.4
FIS-B (Flight Information Service-Broadcast): The free FAA broadcast of weather and aeronautical information to ADS-B In receivers over the 978 MHz UAT link. Source: FAA Aviation Weather Handbook, 3.3.4.1
FRAT (Flight Risk Assessment Tool): A form or checklist for recording flight hazards and the risk they add up to before you fly. Source: FAA Risk Management Handbook, Chapter 3, Using a Flight Risk Assessment Tool (FRAT)
NEXRAD (Next Generation Weather Radar, the WSR-88D): The network of 160 NWS, FAA, and military Doppler weather radars whose data feeds the radar images pilots see. Source: FAA Aviation Weather Handbook, 24.6.1
Radar mosaic: Many single-site radar images stitched into one regional or national picture. Its time stamp is the mosaic’s age, not the weather’s. Source: FAA Aviation Weather Handbook, 24.6.1.5.1
TDWR (Terminal Doppler Weather Radar): An FAA Doppler radar near major airports, built mainly to detect hazardous wind shear, that updates as often as once a minute in hazardous weather mode. Source: FAA Aviation Weather Handbook, 24.6.2

This page explains published FAA and NTSB guidance. Always get a current briefing before you fly.

References

FAA-H-8083-28B, "Aviation Weather Handbook." Federal Aviation Administration, Flight Standards Service. April 2, 2026. Paragraphs cited: 3.2.2, 15.2, 15.2.5.1, 15.2.5.2, 15.2.8, 15.2.9, 15.2.15.1.2, 15.2.15.1.3, 22.8.1, 22.8.2, 24.6.1, 24.6.1.1, 24.6.1.1.1, 24.6.1.2, 24.6.1.3.1, 24.6.1.3.2, 24.6.1.4 (Table 24-8), 24.6.1.5 to 24.6.1.6, 24.6.2. https://www.faa.gov/regulationspolicies/handbooksmanuals/aviation/faa-h-8083-28b-aviation-weather-handbook. PDF: https://www.faa.gov/sites/faa.gov/files/FAA-H-8083-28B.pdf
"7-1-9. Flight Information Services (FIS)," "7-1-11. Weather Radar Services," "7-1-12. ATC Inflight Weather Avoidance Assistance," and "7-1-27. Thunderstorm Flying." Aeronautical Information Manual (AIM), Chapter 7, Section 1. Federal Aviation Administration. Effective July 9, 2026 (Change 3). https://www.faa.gov/air_traffic/publications/atpubs/aim_html/chap7_section_1.html
NTSB Safety Alert SA-017, "In-Cockpit NEXRAD Mosaic Imagery: Actual Age of NEXRAD Data Can Differ Significantly From Age Indicated on Display." National Transportation Safety Board. June 2012, revised December 2015. https://www.ntsb.gov/Advocacy/safety-alerts/Documents/SA-017.pdf
AC 00-63B, "Use of Flight Deck Displays of Digital Weather and Aeronautical Information." Federal Aviation Administration. June 3, 2024. Paragraphs cited: 8.2.1, 8.2.4, Appendix A. https://www.faa.gov/documentLibrary/media/Advisory_Circular/AC_00-63B.pdf
FAA-H-8083-2A, "Risk Management Handbook." Federal Aviation Administration. 2022. Chapter 3, "Using a Flight Risk Assessment Tool (FRAT)." https://www.faa.gov/regulationspolicies/handbooksmanuals/risk-management-handbook-faa-h-8083-2a
PlaneWX Help Center: "Live Radar Corridor," "Convective Scoring," "FRAT," "The Risk Loop." PlaneWX. Accessed September 29, 2026. Live Radar Corridor · Convective Scoring · FRAT · The Risk Loop