- August 1, 2016 -- Changes introduced to
WPC's excessive rainfall outlook, including the addition of a Marginal risk
area and shading to the web graphics.
- April 5, 2016 -- WPC introduces a new experimental homepage.
- December 1, 2015 -- WPC introduces an experimental Day 4-7 Winter Weather Outlook.
- September 1, 2015 -- Changed our short range forecasts (Days ½-2½) to
only display National Digital Forecast Database (NDFD) products for the weather portion of the forecast charts.
- May 11, 2015 -- Introduced
winter weather verification for the day 1-3 probability forecasts.
- April 16, 2015 -- Changed the interface for displaying our high resolution surface analysis.
Now you can easily pan and zoom around the image and more quickly navigate through the archive of these graphics. This analysis can be
accessed through our main surface analysis page or the
surface analysis archive.
- March 26, 2014 -- Updated our surface analysis archive page, providing a
calendar to choose the date and allowing easier access to archived charts before or after the requested date and time.
- February 14, 2014 -- Introduced an
object-oriented verification method for our 24-hour QPFs.
- January 7, 2014 -- WPC creates a single location to access archived products.
- October 28, 2013 -- WPC increases the resolution of our QPF products to 5 kilometers.
The most prominent impact on the graphics will be increased forecast detail over mountainous terrain.
- September 4, 2013 -- WPC starts tweeting! Follow us @NWSWPC.
- July 23, 2013 -- Added archives of the daily National High and Low Temperature
and WPC's Mesoscale Precipitation Discussions (MPDs). The high and low temperature archive begins on
November 22, 2011, while MPDs are available back to April 10, 2013.
- May 28, 2013 -- WPC adds to its short range forecast page
an option to view the National Digital Forecast Database (NDFD) weather type
in conjunction with the WPC forecast of fronts, isobars, and high/low pressure centers.
- April 9, 2013 -- WPC assumes responsibility for the
Mesoscale Precipitation Discussions (MPDs) for heavy rainfall.
- March 5, 2013 -- The Hydrometeorological Prediction Center (HPC) is renamed to the Weather Prediction Center (WPC).
- December 18, 2012 -- Began creating experimental Day 6-7 and
7-Day Total QPFs.
- December 13, 2012 -- Added experimental snow and freezing rain percentile accumulation
guidance to our winter weather product suite.
- December 12, 2012 -- Implemented several changes to our CONUS Day 3-7 forecast products. They include adding a night
shift suite of guidance
(view details) and
consolidating our Sea Level Pressure and Fronts charts to a single page.
- October 22, 2012 -- Added KML files containing raster images of HPC's surface analyses and Day 3-7 PMSL forecasts
- August 23, 2012 -- Custom QPF graphics are now available for
tropical cyclones forecast to affect the Continental U.S.
- April 3, 2012 -- Added KML files containing raster images of HPC's Alaska products,
including 3-hour analyses for the past 24 hours, the latest Day 4-8 PMSL forecasts, and latest Day 4-8 500mb forecasts.
- March 13, 2012 -- Updated the color version of our short range forecasts.
- December 5, 2011 -- HPC adds a page displaying the
high and low temperature extremes
for the contiguous United States. The product is updated four times daily.
- October 31, 2011 -- Added 48-hour periods to our probabilistic
winter weather guidance pages.
- October 12, 2011 -- HPC has added the Daily Weather Map (DWM) display to the surface analysis page. They are available every 3 hours in a
black and white pdf or as a color gif image.
- August 19, 2011 -- Added 24-hour periods
to our Probabilistic QPF product suite.
- August 17, 2011 -- Added a link to HPC's QPF archive.
Products are available from April 1, 2010 to the present.
- June 16, 2011 -- Updated the format of most of our discussions.
Users can now view at least 10 previous issuances.
- June 6, 2011 -- Began producing a National Forecast for Day 2.
This forecast will be available Monday through Friday by 1000 UTC, and on an as-needed during weekends.
- June 2, 2011 -- HPC enters the world of social media, launching its
- April 25, 2011 -- HPC begins compiling detailed reviews
of selected significant weather events for which
or tropical advisories are written.
- April 12, 2011 -- Added to our short range forecast pages a link to the
latest coded forecast bulletin, along with steps to
decode this product.
- April 7, 2011 -- Added KML versions of HPC's multi-day QPFs to the GIS product suite.
- November 23, 2010 -- HPC begins providing experimental 24-hour probabilistic snow and
freezing rain accumulation forecasts for Days 1-3.
- September 15, 2010 -- Began creating winter weather
products in KML format.
- August 5, 2010 -- Created a separate web page for Today's National Forecast,
which includes an experimental version of the chart in Spanish.
- June 22, 2010 -- Three changes are made to the site.
- May 17, 2010 -- Added a CONUS viewing option to our final
Day 3-7 sea level pressures/fronts graphics.
- April 19, 2010 -- HPC adds 6-hour Probabilistic QPFs
to its product suite. The new products include probability of precipitation forecasts of at least a specified
amount and forecasts of precipitation amount by percentile.
- December 14, 2009 -- Added to HPC's winter weather product suite are
3-hour probability of freezing rain forecasts for Days 1-3 across the continental U.S.
- May 18, 2009 -- HPC begins producing QPF products and the Significant River Flood Outlook in
- January 12, 2009 -- The Selected Cities Forecast
is no longer produced by HPC. This product is now being derived directly from the National Weather Service's
National Digital Forecast Database (NDFD) and is available at
Please update your bookmarks accordingly.
- January 5, 2009 -- Two changes were made to the medium range forecast pages.
- October 6, 2008 -- Beginning today, the National Forecast Chart
will be issued twice daily. The initial product will be sent by 0900 UTC, with an update of this forecast by 2100 UTC.
- October 1, 2008 -- Introduced an experimental graphic that displays
24-hour observed precipitation over the continental U.S.
Please view its Product Description Document for additional information.
- March 17, 2008 -- Added 6-hour and 60-hour forecasts to our Short Range Forecast
product suite and made significant changes to the display of the forecasts on our web site. For more details on the web changes,
please view information about using the new web pages. Also added short range HPC 500-mb pattern graphics to the Model diagnostics page.
- January 29, 2008 -- Modified the area of our day 3-7 500mb height forecasts
to include the entire CONUS, and added 500mb height forecasts
to our Alaskan product suite.
- December 3, 2007 -- We have added to our product suite
Day 4-8 Forecasts for Alaska. At this time, only fronts and mean sea level pressure
graphics, along with a written discussion, are being created. More products will be added over the next
couple of months. In addition, this function is currently experimental, therefore content may not update regularly.
- November 30, 2007 -- Recently added Model Trend Graphics for the GFS and NAM to
HPC's Model Diagnostics Page.
- June 14, 2007 -- Recently added Heat Index forecasts to
HPC's Product Suite in GIS format.
- June 5, 2007 -- Experimental Day 2 and Day 3 Excessive Rainfall
forecasts are added to our product suite.
- December 7, 2006 -- We have introduced a higher resolution version of the
Surface Analysis coded bulletin.
- September 5, 2006 -- Modified the look of the
Significant River Flood Outlook product. Categories are now color-coded and all significant water bodies
are shown in light blue.
- August 9, 2006 -- A subset of the HPC product suite is now being provided in a GIS (Geographic Information System).
This includes all QPF products, the Excessive Rainfall forecast, and the Significant River Flood Outlook.
See how to access these products in GIS format.
- June 29, 2006 -- In response to calibration studies conducted at HPC, the probability categories for the
Excessive Rainfall Forecast have been
modified. View additional information regarding
- May 8, 2006 -- We've added a Surface Analysis Archive
page where you can view individual maps dating back to March 30, 2006 or loop up to one week's worth of recent analyses.
- March 22, 2006 -- As of March 20, 2006, the page where you can download a week's worth of
Daily Weather Maps will contain downloadable daily files
for the current week. These files will usually be available around 1:00 p.m. EST each day.
- March 20, 2006 -- Moved several items from the Experimental Products
page to operational pages. These include the HPC QPF files in GRIB Format
, Day 4-7 Gridded Forecasts, and
Day 3-7 500mb Height Forecasts for the Western U.S.
- February 13, 2006 -- Modified the background of the combination
CONUS (Continental United States) analysis/Radar image.
- November 28, 2005 -- Experimental SREF derived
Winter Weather Impact Graphics.
- August 26, 2005 -- Short range forecasts and selected surface analyses are now available in
- August 4, 2005 -- Created a new page which provides the capability to
convert and calculate numerous
- March 14, 2005 -- Added a page containing an archive of our
Winter Storm Summaries.
- March 8, 2005 -- Added to the Surface Analysis
page a combination
CONUS (Continental United States) analysis/Radar image.
- October 5, 2004 -- Changes are
made to the Excessive Rainfall products.
- September 15, 2004 -- Significant changes
are made to the Winter Weather product suite.
The Excessive Rainfall web page is also modified.
- August 31, 2004 -- The Day 4-5 and
5-day QPFs are now being produced twice per day.
- July 13, 2004 -- Added a link to
HPC's Day 4-7 Gridded Forecasts to the Experimental Products page.
- March 8, 2004 -- Upgraded the Daily Forecast Archive page
to more easily navigate through the forecast days.
- February 24, 2004 -- Added to the Surface Observations page
the ability to view wind chill temperatures and heat indices.
- January 26, 2004 -- Two changes were made to the site.
- January 22, 2004 -- Added a link on the HPC home page that allows users to
view Daily Forecasts for the past several years.
- December 17, 2003 --
12-hour probability of precipitation forecasts are now available for days 3-7.
- December 8, 2003 -- Added a link displaying
Medium-Range Sea-level Pressure verification to the
HPC Verification page.
- November 5, 2003 -- Created the ability to view our QPFs in
12-hour increments for days 1-3, including the capability to
loop the images.
- August 25, 2003 -- Enhanced the
HPC 3-7 Day Temperature and PoP Forecast Text File to include both maximum and mininum temperatures AND departures from normal.
Plus, have added 12-hour PoP forecasts and departures from normal.
- July 10, 2003 -- Added a link to
Day 3-7 500mb height forecasts for the Western U.S. to the
Experimental Products page.
- June 3, 2003 -- The domain of the
North American Surface Analysis is modified.
View information regarding
- May 8, 2003 -- Modified the appearance of the
National Precipitation Verification Units' (NPVU) pages.
- May 7, 2003 -- Added a photo gallery
of the current meteorologists visiting the
- April 11, 2003 -- Added a page detailing the
proposed changes to the North American Surface Analysis.
- March 5, 2003 -- Upgraded the preliminary and
final day 3-7 graphics to allow for easier navigation among the
- February 27, 2003 -- Added a 5-panel display of the preliminary
and final day 3-7 forecasts over the continental U.S.
- February 25, 2003 -- Upgraded the
hourly surface data page to allow for easier navigation among observation times.
- February 10, 2003 -- Added buoy and ship observations to the high resolution
hourly surface data plots.
- January 29, 2003 -- Two changes were made to the site.
- Modified the Daily Weather Map page to ease navigation to online maps
and provide a link to download the weekly printed versions.
- Added the capability to loop Surface Analyses for the previous 24 hours.
- January 3, 2003 -- Added a link for the Prelimary Extended
Forecast Discussion, usually available by 1430 UTC. This discussion highlights medium-range model differences and
provides initial model preferences and/or changes to MOS for the three collaborative clusters of the National Digital
Forecast Database (NDFD).
- December 31, 2002 -- Provided new information regarding the distribution of the
Daily Weather Map.
- December 9, 2002 -- Implemented a new version of the
Model Diagnostics page. The major changes include:
- December 8, 2002 -- Added a table of black and white images to the Surface Analysis page.
- November 18, 2002 -- Added a loop of sea level pressures
and fronts for days 0-7. This product incorporates the current surface analysis (day 0) and the short and medium range forecasts (days 1-7).
This loop can be accessed from the Surface Analysis,
Days 1-2, and
Medium range (Days 3-7) pages.
- October 31, 2002 -- Added a loop of 24-hour QPF
for Days 1-3 and modified the 6-hourly loop to include Day 3.
- October 28, 2002 -- Black and white graphics added to the Surface Analysis
- October 22, 2002 -- Added color-filled graphics for days 3-7 minimum and maximum temperatures
and probability of precipitation forecasts.
Click here to view a sample.
- October 21, 2002 -- Numerous changes made to the web site. They include: