Frequently asked questions about DIFAX maps

What are the descriptions of the available DIFAX maps and charts?
What is Greenwich Mean (z) Time?
How do I print DIFAX maps?

Answers

What are the descriptions of the available DIFAX maps and charts?
(Click on map name below and you will go to description)

Radar/Weather Depictions
U.S. Radar Composite
U.S. Weather Depictions

Significant Weather Depictions
Significant Weather Forecasts (PROGS)
Significant Weather Forecasts, Flight Level 250 to 600

Upper Air Maps and Charts
Constant Pressure Analyses
Winds Aloft
RAFS/NGM Forecast
AVN/MRF (Spectral) Forecasts
LFM Forecasts
Wind and Temperature Progs

Surface/Low Level Weather Maps and Charts
Current Surface Weather Analyses
Forecast Weather
Thickness

Miscellaneous Maps and Charts
Temperature-Related Charts-U.S.
Sunshine/Air Stagnation
Precipitation and Snow
Crop Moisture-U.S.
Extended-Long Range Forecasts
Ocean and Marine

Radar/Weather Depictions

  • U.S. Radar Composite
    Chart depicts shaded areas of precipitation over the continental U.S. Precipitation cells and expected movement is shown. Weather Watch areas. Administrative messages from National Meteorlogical Center.
    Coverage Area: Continental U.S.
  • U.S. Weather Depiction
    Useful for flight planning. Shows sky cover, surface fronts, ceilings, visibility. Indicates IFR, MVFR and VFR areas.
    Update time(s): 0209z, 0517z, 0815z, 1123z, 1405z,1720z, 2017z, 2316z
    Coverage Area: Continental U.S. and Southern Canada

Significant Weather Depictions

Significant Weather Forecasts (progs)

  • 12 & 24-hour forecasts
    Weather systems, clouds, precipitation, turbulence, flight rules. Four panel chart. Upper two panels show 12 & 24-Hour prognosis of IFR and severe weather. Also shows freezing levels, ceilings, visibility, and any turbulence. Lower two panels depict 12 & 24-Hour areas of high and low pressure, frontal systems, and shaded areas of expected precipitation.
    Update time(s):0007z, 0551z, 1006z, 1739z
    Coverage Area: Continental U.S., Southern Canada
  • 36 & 48-hour forecasts
    Weather systems, clouds, precipitation.Two panel chart shows high and low pressure centers, frontal systems, areas of expected precipitation and cloud cover over the U.S. and southern Canada. Both panels include a prognostic discussion of chart prepared by the National Meteorological Center.
    Update time(s): 0720z, 1914z
    Coverage Area: Continental U.S., Southern Canada
  • Severe weather outlook
    Likelihood of severe thunderstorms over the next 48 hours. Two panel chart depicts areas of potentially severe thunderstorms over the Continental U.S. in the next 48-hours.
    Update time(s): 1030z
    Coverage Area: Continental U.S.

  • Thunderstorm & severe thunderstorm probabilities
    Likelihood of severe thunderstorms over the next 48 hours. Two panel chart depicts areas of potentially severe thunderstorms over the Continental U.S. in the next 48-hours.
    Update time(s): 1303z
    Coverage Area: Continental U.S.

  • Snow cover & 6-hour snowfall (available 9/17-4/15)
    Chart depicts total snow depth in inches and the 6 hour snowfall
    Update time(s): 1303z
    Coverage Area: Continental U.S.
  • Thunderstorm & severe thunderstorm probabilities (MOS)
    Chart depicts 24-hour probabilities of thunderstorms and severe thundertorms over the continental U.S. Also shows chart valid times.
    Update time(s): 0418z
    Coverage Area: Continental U.S.
  • Forecast surface wind, cloud cover, and flight rules (MOS)
    Four panel chart shows forecast 12-hr, 18-hr, 24-hr and 30-hr surface winds, cloud cover and visibility.
    Update time(s):0415z, 1553z
    Coverage Area: Continental U.S.

Significant Weather Forecasts

  • Clouds, weather systems, precipitation, turbulence
    Chart shows Flight Level 25,000-60,000 ft. cloud cover; wind speed and direction; frontal systems; and any significant weather; including turbulence, hail and icing. Altitude is shown in hundreds of feet.
    Update time(s): 0114z, 0857z, 1315z, 2028z
    Coverage Area: North & Central America and Surrounding Areas
  • Clouds, weather systems, precipitation, turbulence
    Chart shows Flight Level 25,000-60,000 ft. cloud cover; wind speed and direction; frontal systems; and any significant weather; including turbulence, hail and icing. Altitude is shown in hundreds of feet.
    Update time(s): 0154z, 0851z, 1328z, 1955z
    Coverage Area: Eastern Asia and the Pacific
  • Clouds, weather systems, precipitation, turbulence
    Chart shows Flight Level 25,000-60,000 ft. cloud cover; wind speed and direction; frontal systems; and any significant weather; including turbulence, hail and icing. Altitude is shown in hundreds of feet.
    Update time(s): 0854z, 1333z, 2044z
    Coverage Area: Europe, Africa, Atlantic
  • Clouds, weather systems, precipitation, turbulence
    Chart shows Flight Level 25,000-60,000 ft. cloud cover; wind speed and direction; frontal systems; and any significant weather; including turbulence, hail and icing. Altitude is shown in hundreds of feet.
    Update time(s): 0119z, 0712z, 1520z, 1917z
    Coverage Area: North America, Europe, Africa, Atlantic
  • Forecast clouds, weather systems, precipitation, turbulence
    Chart shows Flight Level 25,000-60,000 ft. cloud cover; wind speed and direction; frontal systems; and any significant weather; including turbulence, hail and icing. Altitude is shown in hundreds of feet.
    Update time(s): 0119z, 1320z, 6z, 18z
    Coverage Area: North America, Europe, Africa, Atlantic
  • Clouds, weather systems, turbulence
    Chart shows Flight Level 25,000-60,000 ft. cloud cover; wind speed and direction; frontal systems; and any significant weather; including turbulence, hail and icing. Altitude is shown in hundreds of feet.
    Update time(s):0141z, 1352z, 1939z
    Coverage Area: Alaska and the Pacific
  • Significant Weather Forecast Flight Level 0 to 400 millibar
    Hand analyzed chart shows Flight Level surface-40,000 ft. cloud cover; wind speed and direction; frontal systems; and any significant weather; including turbulence, hail and icing. Altitude is shown in hundreds of feet.
    Update time(s): 0203z, 1423z
    Coverage Area: North Atlantic & Europe

Upper Air Maps and Charts

Constant Pressure Analyses

  • 850 millibar analysis heights and temperatures with winds
    Chart shows centers of high and low heights, wind speed and direction, temperatures for specific locations, 850 mb heights and tendencies.
    Update time(s): 0243z, 1433z
    Coverage Area: North America
  • 700 millibar analysis heights and temperatures with winds
    Chart shows centers of high and low heights, wind speed and direction, temperatures for specific locations, 700 mb heights and tendencies.
    Update time(s): 0248z, 1436z
    Coverage Area: North America
  • 500 millibar analysis heights and temperatures with winds
    Chart shows centers of high and low heights, wind speed and direction, temperatures for specific locations, 500 mb heights and tendencies.
    Update time(s): 0251z, 1439z
    Coverage Area: North America
  • 500 millibar analysis
    Chart shows the height of the 500 mb surface and temperatures at 500 mb over the Northern Hemisphere.
    Update time(s): 0603z, 1840z
    Coverage Area: Northern Hemisphere
  • 500 millibar analysis height changes for North America
    Chart shows forecast 500 mb height changes.
    Update time(s): 0225z, 1420z
    Coverage Area: North America
  • 300 millibar height analysis
    Chart shows the height of the 300 mb surface and isotachs of wind speed at 300mb. Shaded areas indicate wind speeds above 70 knots.
    Update time(s): 1847z
    Coverage Area: Northern Hemisphere
  • 300 millibar analysis heights and temperatures with winds
    Chart shows temperature, wind speed and direction, centers of high and low heights, 300mb heights and tendencies. Shaded areas indicate wind speeds above 70 knots.
    Update time(s): 0311z, 1443z
    Coverage Area: Continental U.S. and Canada
  • 250 millibar analysis heights and temperatures with winds
    Chart shows temperature, wind speed and direction, centers of high and low heights, 250mb heights and tendencies. Shaded areas indicate wind speeds above 70 knots.
    Update time(s): 0235z, 1453z
    Coverage Area: Continental U.S. and Canada
  • 250 millibar analysis heights, winds, and PIREPS for the Pacific
    Chart shows 250 mb that includes wind and temperature data from Aircraft, satellite and radiosonde. Also PIREPS reports listing any turbulence, icing, cloud cover, etc., over 55N-20S, 40W-110W area.
    Update time(s): 0617z, 1852z
    Coverage Area: Pacific Ocean
  • 250 millibar analysis heights, winds, and PIREPS for the Americas
    Chart shows 250 mb heights, wind speed and direction, centers of high and low pressure, and PIREPS reports listing any turbulence, icing, cloud cover, etc., over an area from 50N-20S, 40W-110W area.
    Update time(s): 0621z, 2052z
    Coverage Area: U.S. & Central America
  • 200 millibar analysis heights, winds, and Pibals for U.S./Canada
    Chart shows 200 mb heights, wind speed and direction, temperatures, and height changes over the past 12 hours. The shaded areas indicate winds over 70 knots.
    Update time(s): 0353z, 1447z
    Coverage Area: Continental U.S. & Canada
  • 200 millibar analysis heights, winds, and Pibals for Americas/Atlantic
    Chart shows 200 mb streamlines and isotachs over 50N-20S, 10E-120W area.
    Update time(s): 1034z, 1633z
    Coverage Area: 50N-20S, 10E-120W

Winds Aloft

  • Trajectory Forecasts (prog)
    Four panel chart shows 24 hr. forecast surface dew point trajectories, 850 mb temperature trajectories, 700 mb dew point trajectories and 12 hr. 700 mb net vertical displacement/K index.
    Update time(s): 0420z
    Coverage Area: Continental U.S.
  • Observed winds aloft
    Four panel chart shows observed winds aloft for second standard level above surface at 10,000ft, 14,000ft, 24,000ft and 34,000ft. Upper levels also show temperature observations.
    Update time(s): 0222z, 1414z
    Coverage Area: Continental U.S.
  • Forecast winds aloft
    Eight panel chart shows LFM 12-hour forecast winds aloft. Also shows temperatures at 6,000ft, 9,000ft, 12,000ft, 18,000ft, 24,000 ft, 30,000ft, 34,000ft, and 39,000ft.
    Update time(s): 0336z, 1541z
    Coverage Area: Continental U.S.
  • Low level circulation and mixing ratio U.S. and Central America
    Chart shows lower mean circulation in the 1000-600 mb layer with mean mixing ratio.
    Update time(s): 0348z, 2233z
    Coverage Area: U. S. and Central America

RAFS/NGM Forecast

  • 850 millibar heights and temperatures
    Four panel chart shows 12-hr, 24-hr, 36-hr and 48-hr forecast 850 mb heights, centers of high and low heights and temperatures over North America.
    Update time(s): 0608z, 1818z
    Coverage Area: North America
  • 12-hour forecast
    Boundary layer winds and relative humidity. Chart shows forecast wind speed and direction and relative humidity values over the Continental U.S.
    Update time(s): 0547z, 1812z
    Coverage Area: Continental U.S.
  • 24-hour forecast
    Boundary layer winds and relative humidity. Same as Chart above, except forecast period.
    Update time(s): 0614z, 1824z
    Coverage Area: Continental U.S.
  • 36-hour forecast
    Boundary layer winds and relative humidity. Same as Chart above, except forecast period.
    Update time(s): 0627z, 1834z
    Coverage Area: Continental U.S.
  • 48-hour forecast
    Boundary layer winds and relative humidity. Same as Chart above, except forecast period.
    Update time(s): 0630z, 1837z
    Coverage Area: Continental U.S.
  • 0 to 36 -hour Lifted Index
    4-Layer Lifted Index. Four panel chart shows current and NGM forecast 12-hr, 24-hr and 36-hr maximum/minimum lifted indexes.
    Update time(s): 0526Z, 1733Z
    Coverage Area: North America
  • Initial 500 millibar heights/vorticity, 700 millibar heights/mean humidity, pressure/thickness, 850 millibar heights/temperature
    Four panel chart. First panel shows forecast 500mb heights/vorticity locations. Second panel shows forecast 1000-500mb thicknesses and surface pressure patterns. Third panel shows 700mb heights and relative humidity. Fourth panel shows 850 mb initial conditions.
    Update time(s): 0443z, 1647z
    Coverage Area: North America
  • 12-hour 500 millibar heights/vorticity, 700 millibar heights/mean humidity, pressure/thickness, precipitation/vertical velocity
    NGM (Nested Grid Model) Forecast Model. The top left panel show the heights and vorticity at 500 mb. The top right panel shows the MSL pressure and 1000-500 mb thickness. The lower left panel shows the 700 mb height and relative humidity. The lower right panel shows the total precipitation and 700 mb vertical velocity.
    Update time(s): 0450z, 1700z
    Coverage Area: North America
  • 24-hour 500 millibar heights/vorticity, 700 millibar heights/mean humidity, pressure/thickness, precipitation/vertical velocity
    NGM (Nested Grid Model) Forecast Model. The top left panel show the heights and vorticity at 500 mb. The top right panel shows the MSL pressure and 1000-500 mb thickness. The lower left panel shows the 700 mb height and relative humidity. The lower right panel shows the total precipitation and 700 mb vertical velocity.
    Update time(s): 0503z, 1706z
    Coverage Area: North America
  • 36-hour 500 millibar heights/vorticity, 700 millibar heights/mean humidity, pressure/thickness, precipitation/vertical velocity
    NGM (Nested Grid Model) Forecast Model. The top left panel show the heights and vorticity at 500 mb. The top right panel shows the MSL pressure and 1000-500 mb thickness. The lower left panel shows the 700 mb height and relative humidity. The lower right panel shows the total precipitation and 700 mb vertical velocity.
    Update time(s): 0510z, 1713z
    Coverage Area: North America
  • 48-hour 500 millibar heights/vorticity, 700 millibar heights/mean humidity, pressure/thickness, precipitation/vertical velocity
    NGM (Nested Grid Model) Forecast Model. The top left panel show the heights and vorticity at 500 mb. The top right panel shows the MSL pressure and 1000-500 mb thickness. The lower left panel shows the 700 mb height and relative humidity. The lower right panel shows the total precipitation and 700 mb vertical velocity.
    Update time(s): 0520z, 1723z
    Coverage Area: North America

AVN/MRF (Spectral) Forecasts

  • Initial to 36-hour 500 millibar heights/vorticity
    Chart shows AVN model forecast 500mb heights and vorticity over North America.
    Update time(s): 0633z, 2022z
    Coverage Area: North America
  • 36-hour 500 millibar heights/wind speeds
    Chart shows MRF forecast of 500mb heights and isotachs over North America and surroundiing areas.
    Update time(s): 0746z, 2152z
    Coverage Area: North America
  • 48-hour 500 millibar heights/vorticity
    Chart shows MRF forecast 500mb heights and vorticity over North America.
    Update time(s): 0750z, 2033z
    Coverage Area: North America

  • 72-hour 500 millibar heights
    Chart shows forecast MRF 500mb heights over North America and polar regions.
    Update time(s): 0951z, 2206z
    Coverage Area: North America
  • 84-hour 500 millibar heights
    Chart shows MRF forecast 500mb heights over Northern Hemisphere.
    Update time(s): 1053z
    Coverage Area: Northern Hemisphere
  • 60-hour 500 millibar heights/vorticity, 700 millibar heights/mean humidity, pressure/thickness, 850 millibar heights/temperature
    Four panel chart.First panel shows forecast 500mb heights and vorticity. Second panel shows forecast MSL pressure and 1,000-500mb thickness. Third panel shows forecast 700mb heights and relative humidity, and fourth panel shows forecast 850mb heights and temperatures.
    Update time(s): 0944z, 2346z
    Coverage Area: North America
  • 24-hour thickness, 700 millibar heights/wind speeds
    2 panel chart with 24 hour MRF forecast 850 mb heights/850-500 thickness; 700 mb heights/wind speeds
    Update time(s): 0014z
    Coverage Area: North America
  • 36-hour 300 millibar heights/wind speeds
    Chart shows MRF forecast of 300mb heights and isotachs over North America and surrounding areas.
    Update time(s): 010z, 0925z
    Coverage Area: North America
  • 12 to 48-hour humidity, vertical velocity
    Four panel chart shows 12, 24, 36 & 48 hour MRF forecasts of relative humidity and vertical velocities over North America.
    Update time(s): 0810z, 2209z
    Coverage Area: North America

LFM Forecasts

  • Initial to 36-hour 500 millibar heights/vorticity
    Four panel chart showing progression of heights/vorticity at 500 mb, beginning with actual observed heights through the next 36 hours over North America.
    Update time(s):0329z
    Coverage Area: North America

Wind and Temperature Progs

  • Flight Level 340
    Chart shows 24-hour forecast temperatures, wind speed and direction at 34,000 feet over entire geographic region.
    Update time(s): 0036z,0836z, 1211z, 1925z
    Coverage Area: North America, Europe & Atlantic Areas
  • Flight Level 340
    Chart shows 24-hour forecast temperatures, wind speed and direction at 34,000 feet over entire geographic region.
    Update time(s): 0046z, 0649z, 1236z, 1903z
    Coverage Area: Northern North America, Pacific & Asia
  • Flight Level 340 Chart shows 24-hour forecast temperatures, wind speed and direction at 34,000 feet over entire geographic region.
    Update time(s): 0041z, 0703z, 1220z, 1909z
    Coverage Area: Australia and the Pacific
  • Flight Level 340
    Chart shows 24-hour forecast temperatures, wind speed and direction at 34,000 feet over entire geographic region.
    Update time(s): 0825z, 1225z, 1931z, 2303z
    Coverage Area: U.S., South & Central America
  • Flight Level 450
    Chart shows 24-hour forecast temperatures, wind speed and direction at 45,000 feet over entire geographic region.
    Update time(s): 0052z, 0644z, 1250z, 2108z
    Coverage Area: Australia and the Pacific
  • Flight Level 450
    Chart shows 24-hour forecast temperatures, wind speed and direction at 45,000 feet over entire geographic region. Update time(s): 0143z, 0841z, 1150, 2009z
    Coverage Area: U.S., South & Central America
  • Flight Level 450
    Chart shows 24-hour forecast temperatures, wind speed and direction at 45,000 feet over entire geographic region.
    Update time(s): 0639z, 1137z, 2103z, 2239z
    Coverage Area: Asia, Europe, Oceans, and Northern North America
  • Flight Level 240
    Chart shows 24-hour forecast temperatures, wind speed and direction at 24,000 feet over entire geographic region.
    Update time(s): 0805z, 1142z, 2039z, 2251z
    Coverage Area: North America, Europe & Atlantic

Surface/Low Level Weather Maps and Charts

Current Surface Weather Analyses

  • U.S. Surface Analysis
    Chart shows surface high and low pressure centers and frontal systems. Each reporting station shows wind direction and speed, cloud cover, visibility, temperature, dew point, precipitation type and amounts, and barometric pressure.
    Update time(s): 0437z, 1041z, 1640z, 2239z
    Coverage Area: Continental U.S.
  • North America and nearby areas
    Chart shows surface high and low pressure centers and frontal systems. Each reporting station shows wind direction and speed, cloud cover, visibility, temperature, dew point, precipitation type and amounts, and barometric pressure.
    Update time(s): 0132z, 0738z, 1336z, 1943z
    Coverage Area: North America & Surrounding Areas
  • Atlantic Tropical Analysis
    Chart shows surface high and low pressure centers and frontal systems. Each reporting station shows wind direction and speed, cloud cover, visibility, temperature, dew point, precipitation type and amounts, and barometric pressure.
    Update time(s): 1015z
    Coverage Area: Atlantic Basin
  • Tropical Eastern Hemisphere
    Chart shows high and low pressure centers and stream lines; satellite winds are shown from low cloud motions. Each reporting station shows wind direction and speed, cloud cover, temperature, dew point, precipitation amounts, and barometric pressure, pressure tendencies and changes in pressure.
    Update time(s): 0104z, 0934z
    Coverage Area: Tropical Eastern Hemisphere
  • Tropical Western Hemisphere
    Chart shows high and low pressure centers and stream lines; satellite winds are shown from low cloud motions. Each reporting station shows wind direction and speed, cloud cover, temperature, dew point, precipitation amounts, and barometric pressure, pressure tendencies and changes in pressure.
    Update time(s): 0538z, 2135z
    Coverage Area: Tropical Western Hemisphere
  • Pacific Ocean and nearby areas
    Chart shows high and low pressure centers and frontal systems. Each reporting station shows wind direction and speed, cloud cover, visibility, temperature, dew point, precipitation type and amounts, and barometric pressure.
    Update time(s): 0301z, 0909z, 1510z, 2125z
    Coverage Area: Pacific Ocean & Surrounding Areas
  • Atlantic Ocean and nearby areas
    Chart shows high and low pressure centers and frontal systems. Each reporting station shows wind direction and speed, cloud cover, visibility, temperature, dew point, precipitation type and amounts, and barometric pressure.
    Update time(s): 0315z, 0917z, 1520z, 2144z
    Coverage Area: Atlantic Ocean & Surrounding Areas

Forecast Weather

  • 24-hour MRF Surface/Thickness prog
    Chart shows forecast high and low pressure centers, and 1000-500mb thickness over North America.
    Update time(s): 0732z, 2118z
    Coverage Area: North America
  • 36-hour MRF Surface/Thickness prog
    Chart shows forecast high and low pressure centers, and 1000-500mb thickness over North America.
    Update time(s): 0735z, 2056z
    Coverage Area: North America
  • 48-hour MRF Surface/Thickness prog
    Chart shows forecast high and low pressure centers, and 1000-500mb thickness over North America.
    Update time(s): 0753z, 2115z
    Coverage Area: North America
  • Surface prog for Days 3, 4, 5, & 108-hour 1000/500 millibar thickness/surface prog
    Four panel chart:Charts show forecast high and low pressure centers, surface frontal systems and isobars for Days 3, 4 and 5. Last panel depicts forecast 500 mb heights and departures from normal readings.
    Update time(s): 2003z
    Coverage Area: North America & Polar Regions

Thickness

  • 1000-500 millibar Thickness Analysis
    Chart shows high and low pressure centers, and surface frontal systems. Also shows 1000-500 mb thickness in decameters over North America.
    Update time(s): 0535z, 1729z
    Coverage Area: North America
  • 12-hour 1000-500 millibar Thickness/Surface prog
    Chart shows forecast high and low pressure centers, and frontal systems. Also shows 1000-500 mb thickness in decameters over North America.
    Update time(s): 0657z, 1844z
    Coverage Area: North America
  • 24/36-hour 1000-500 millibar Thickness/Surface prog
    Chart shows forecast high and low pressure centers, frontal systems. Also shows 1000-500 mb thickness in decameters over the northern Pacific.
    Update time(s): 0728z, 2121z
    Coverage Area: Northern Pacific Areas
  • 48-hour 1000-500 millibar Thickness/Surface prog
    Chart shows forecast high and low pressure centers, frontal systems. Also shows 1000-500 mb thickness in decameters.
    Update time(s): 1003z, 2236z
    Coverage Area: U.S., Atlantic, Europe
  • 72 to 120 hour 1000/500 millibar thickness/surface prog
    Four panel chart shows forecast high and low pressure centers, frontal systems. Also shows 1000-500 mb thickness in decameters.
    Update time(s): 1205z
    Coverage Area: North America

Miscellaneous Maps and Charts

Temperature-Related Charts-U.S.

  • Observed Minimum Temperatures
    Chart shows observed minimum temperatures for 12 hours ending at 12z.
    Update time(s): 1306z
    Coverage Area: Continental U.S. & Southern Canada
  • Observed Maximum Temperatures
    Chart shows observed maximum temperatures for 12 hours ending at 0z.
    Update time(s): 0206z
    Coverage Area: Continental U.S. & Southern Canada
  • Maximum/Minimum Temperatures prog
    Four panel chart shows 24 hour and 48 hour forecast minimum temperatures. Also shows 36 hour and 60 hour forecast maximum temperatures.
    Update time(s): 0403z
    Coverage Area: Continental U.S.

Sunshine/Air Stagnation

  • Sunshine/Solar Energy prog
    Four panel chart: Upper two panels show 24-hour and 48-hour forecast sunshine; hours are plotted, percentages expressed with contours. Lower two panels show 24-hour and 48-hour forecast; solar energy plotted at 10 x Kwh/m2; Kmh/m2 expressed with contours.
    Update time(s): 0411z
    Coverage Area: Continental U.S.
  • Sunshine prog
    Two panel chart showing 36-hour and 60-hour forecast sunshine. Hours are plotted, percentages expressed with contours.
    Update time(s): 1547z
    Coverage Area: Continental U.S.

Precipitation and Snow

  • Snow Cover Analysis (Available winter season)
    Update time(s): 1217z
    Coverage Area:
  • Observed 24-hour precipitation
    Observed 24-hour precipitation ending at 12z. Precipitation shown to the nearest 0.01 inches. T equals trace.
    Update time(s): 1309z
    Coverage Area: Continental U.S.
  • 18, 30, 42, & 54-hour precipitation prog
    Four panel chart shows probability and type of precipitation at the midpoints of those time Update time(s): 0407z, 1549z
    Coverage Area: Continental U.S.
  • Quantitative precipitation/excess rain/heavy snow prog 24-hour
    Four panel chart. Chart 1 shows prognosis of quantitative precip from 06z-12z. Chart 2 shows prognosis from 12z-18z. Chart 3 & 4 show forecast excessive rain and heavy snow over the continental U.S.
    Update time(s): 1203z
    Coverage Area: Continental U.S.
  • Quantitative precipitation/excess rain/heavy snow prog 48-hour
    Same as Chart above, except for forecast period.
    Update time(s): 1451z
    Coverage Area: Continental U.S.
  • Heavy rain/snow prog
    Heavy Rain / Snow Prognosis. Four panel chart showing forecasted precipitation amounts for selected time periods. Bottom panel depicts areas which have the potential for heavy rain or snow to occur over the period indicated.
    Update time(s): 0233z, 0726z, 1203z, 1344z, 1451z, 1941z
    Coverage Area: Continental U.S.
  • Quantitative precipitation/excess rain/heavy snow prog 6-hour
    Same as 2 charts above, except for forecast period.
    Update time(s): 0233z
    Coverage Area: Continental U.S.
  • Quantitative precipitation/excess rain/heavy snow prog 12-hour
    Quantitative Precipitation/Excessive Rain/Heavy Snow prog (beginning 00z). Same as chart above, except for forecast period.
    Update time(s): 0726z
    Coverage Area: Continental U.S.

Crop Moisture-U.S.

  • Crop Moisure Index (available Tues.)
    Chart depicts week-to-week abnormal dryness/wetness affecting agriculture during the warm season.
    Update time(s): 2322z Tuesdays
    Coverage Area: Continental U.S.
  • Crop Moisure Index by Division (available Tues.) Chart depicts abnormal dryness/wetness affecting agriculture by state agricultural divisions.
    Update time(s): 2324z Tuesdays
    Coverage Area: Continental U.S.

Extended-Long Range Forecasts

  • 3-5 Day Forecast Daily temperature/precipitation anomalies
    Top charts show 24 hour predicted precipitation anomalies. The lower charts show predicted departure of temperatures from the normal for the period.
    Update time(s): 2046z
    Coverage Area: Continental U.S.
  • 5 Day Forecast Mean temperature/precipitation anomalies
    Top chart show the forecast 5 day mean minimum temperature anomaly. The center chart show the forecast 5 day mean maximum temperature anomaly. The bottom chart shows the forecast 5 day total precipitation.
    Update time(s): 2113z
    Coverage Area: Continental U.S.
  • 30 day and 90 day outlooks (issued the middle of each month)
    These are the standard monthly 30 and 90 day weather outlooks issued by the NWS. They are issued once a month -- generally within a few days of the 15th. The 0.5 indicates they have a half month lead time before the forecast begins. The information is presented as percentages above 33% chance of the event taking place -- above, near or below normal -- with insufficient data, use climatology across the remainder of the nation.
    Update time(s): 2256z 15th of each month
    Coverage Area: Continental U.S.
  • Seasonal Outlooks 1.5 and 2.5 month lead time
    These are seasonal (30 and 90 day) weather outlooks issued by the NWS that are issued in advance. The table below indicates the amount of lead time for the 30 and 90 day outlooks. The number at the beginning of the description indicates the lead time before the forecast begins (1.5 would be 1.5 months, 12.5 would be a year and half a month). The information is presented as percentages above 33% chance of the event taking place -- above, near or below normal -- with insufficient data, use climatology across the remainder of the nation.
    Update time(s): 2353z Tuesday, Thursday & Sunday
    Coverage Area: Continental U.S.
  • Seasonal Outlooks 3.5 and 4.5 month lead time
    Same as above, except for lead time.
  • Seasonal Outlooks 5.5 and 6.5 month lead time
    Same as above, except for lead time.
  • Seasonal Outlooks 7.5 and 8.5 month lead time
    Same as above, except for lead time.
  • Seasonal Outlooks 9.5 and 10.5 month lead time
    Same as above, except for lead time.
  • Seasonal Outlooks 11.5 and 12.5 month lead time
    Same as above, except for lead time.

Ocean and Marine

  • 12 & 24-hour Wave direction/Period prog
    Two panel chart depicts wave directions and primary wave periods plotted in seconds for both 12-hr and 24-hr forecast periods.
    Update time(s): 1109z, Forecast Period: 12 & 24 hour
    Coverage Area: Atlantic and Pacific Oceans
  • 12 & 24-hour Wind/Wave height prog
    The height of the waves in the eastern and central Pacific and Gulf of Mexico along with the period of time between waves or the frequency of waves.
    Update time(s): 1115z, Forecast Period: 48 & 72 hour
    Coverage Area: Atlantic and Pacific Oceans
  • 48 & 72-hour Wave direction/Period prog
    Two panel chart depicts wind direction and significant wave heights plotted in feet for both 48-hr and 72-hr forecast periods.
    Update time(s): 1104z, Forecast Period: 12 & 24 hour
    Coverage Area: Atlantic and Pacific Oceans

  • 48 & 72-hour Wind/Wave height prog
    Two panel chart depicts wind direction and significant wave heights, plotted in feet for 48-hr and 72-hr forecast periods.
    Update time(s):1106z, Forecast Periods: 48 & 72 hour
    Coverage Area: Atlantic and Pacific Oceans
  • Gulf of Mexico 12 & 48-hour Wave Height/Direction prog
    Five panel chart depicts wave heights and wind directions for 12-hr and 48-hr forecast periods.
    Update time(s):0423z, 1605z, Forecast period: 12 & 48 hour
    Coverage Area: Gulf of Mexico
  • Atoll Wind Analysis
    Chart depicts a streamline analysis of surface winds in the Tropical Atlantic.
    Update time(s): 0342z, 1504z
    Coverage Area: Tropical Atlantic Ocean
  • 5 Day Mean 500 millibar Heights, 6-10 Day Temperature Anomalies, 6-10 day Total Precipitation
    Update time(s): 2100z Monday, Wednesday & Friday
    Coverage Area: North America, specifically United States



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