Change Logs by Product

Note: While we are transitioning our web pages, products marked with an (*) link to product pages on the old system. Products on those pages are up-to-date, but links on those pages may go to old information or may be broken. Thank you for your patience!

For more information on changes to MOS and GMOS, please see the MOS Technical Notices page.

General History of Gridded MOS Products

DATE	GRID	DETAILS	SOFTWARE VERSION
March 13, 2012	2.5km CONUS	Traditional 6- and 12-hr Probability of Precipitation (PoP) and 6- and 12-hr Quantitative Precipitation Forecast (QPF) have been replaced with an experimental High Resolution MOS POP/QPF.	version 9
February 27, 2012	2.5km CONUS	Initial implementation of 2.5 km GFS-based Gridded MOS for CONUS Elements: max/min temperature, 2m temperature, 2m dewpoint, relative humidity, wind speed and direction, wind gust, opaque sky cover, 6- and 12-h probability of precipitation, 6- and 12-hr quantitative precipitation forecast (QPF), 24-hr snowfall amount, and 3-, 6-, and 12-hr probability of thunderstorms.	version 9
November 9, 2010	2.5km Hawaii	Initial implementation of GFS-based Gridded MOS for Hawaii Elements: max/min temperature, 2m temperature, 2m dewpoint, relative humidity, wind speed and direction, and 6- and 12-h probability of precipitation	version 9
March 30, 2010	3km Alaska	Added two (2) extra projections for 24-hr Snowfall Amount out to 156-h for both 0000 and 1200 UTC cycles.	version 9
March 30, 2010	5km CONUS	Added extended-range 24-hr Snowfall Amount out to 156-h for 1200 UTC cycle. Added two (2) extra projections for 24-hr Snowfall Amount out to 156-h for 0000 UTC cycle. Modified output mask for all elements except 24-hr Snowfall Amount.	version 5
January 12, 2010	3km Alaska	Implemented a new version (9) of the analysis code for Alaska. Added 6- and 12-hr Quantitative Precipitation Forecast (QPF) and 24-hr Snowfall Amount guidance.	version 9
December 16, 2008	3km Alaska	Implemented new version (8) of analysis code for Alaska and modified some analysis parameters in temp, dew, max/min analysis. Added 6- and 12-hr POP, wind speed, direction and gusts, and sky cover guidance. Expanded coverage of grid on the Eastern edge.	version 8
December 16, 2008	5km CONUS	Removed unrepresentative stations from dewpoint analysis per WFO request.	version 5
August 12, 2008	5km CONUS	Turned off cycle averaging of station data in wind grids.	version 5
June 10, 2008	3km Alaska	Implement new GFS-based gridded MOS for Alaska. Initial elements available are temperature, dewpoint temperature, maximum/minimum temperature, relative humidity, and 3-, 6-, and 12-hr probability of thunderstorms.	version 6a
December 18, 2007	5km CONUS	Implement new land/water mask. Modify precipitation amount analysis scheme. Removal of stations at users' request.	version 5
June 5, 2007	5km CONUS	New version of analysis code with many modifications to analysis settings including using cycle averaging for all elements. Added new elements opaque sky cover, 24-hr snowfall amount, wind gusts, and 6- and 12-h precipitation amounts.	version 5
December 19, 2006	5km CONUS	Corrected lapse rate computational algorithm. Removed bad stations at request of users. Modified Boston in land/water mask.	version 4
October 10, 2006	5km CONUS	Corrected wind post-processing problem that was setting some north winds to calm. Made slight modifications to analysis settings for temp, winds and POPs (modified R, less elevation correction).	version 4
August 15, 2006	5km CONUS	Official implementation of GFS-based gridded MOS for CONUS. GRIB2 files provided on SBN/NOAAPORT and in NDGD operational area. Elements include max/min temperature, 2m temperature, 2m dewpoint, relative humidity, wind speed and direction, 3-, 6-, and 12-h probability of thunderstorms, and 6- and 12-h probability of precipitation. Cycle averaging used for dewpoint, temperature, max and min for the first time.	version 4
End of experimental phase
July 5, 2006	5km CONUS	Expanded coverage of experimental guidance to full CONUS	version 3
March 2005 -June 2006	5km Western Tile	Initial development and testing was done for a 5km Western Tile subset of CONUS grid (image). We initially worked on temperature, dewpoint, max and min, with wind speed and direction, POP, and probability of thunderstorms added over time. During this period we provided sample GRIB2 files both manually and eventually in the experimental area of the NDGD. These GRIB2 files had the full 5km CONUS grid, but we only provided forecast values for the Western Tile.	version 3 - 2/2006 version 2 - 9/2005 version 1 - 3/2005

Experimental GFS GMOS Precipitation Type Changes

CONUS 2.5km

DATE	CYCLE	CHANGES
March 27, 2013	1200 UTC	Added case study page - Early Spring snow event
March 8, 2013	1200 UTC	Added case study page - "Snowquester" storm
November 6, 2012	1200 UTC	Added case study page - Superstorm Sandy
December 17, 2011	1200 UTC	Climatological relative frequencies available for viewing
December 16, 2011	1200 UTC	Added improved legend to best category maps
December 10, 2011	1200 UTC	Menu added to select cycle
November 23, 2011	0000 UTC	GRIB2 data available for download
October 5, 2011	1200 UTC	Added unconditional probability grids
September 21, 2011	1200 UTC	Experimental 2.5 km GMOS precipitation type site established

Alaska 3km

DATE	CYCLE	CHANGES
December 16, 2011	1200 UTC	Added improved legend to best category maps
December 10, 2011	1200 UTC	Menu added to select cycle
November 29, 2011	0000 UTC	GRIB2 data available for download
November 29, 2011	0000 UTC	Experimental Alaska GMOS precipitation type site established

Experimental NAM MOS Precipitation Type Changes

2.5km CONUS

DATE	CYCLE	CHANGES
March 27, 2013	1200 UTC	Added case study page - Early Spring snow event
March 8, 2013	1200 UTC	Added case study page - "Snowquester" storm
November 6, 2012	1200 UTC	Added case study page - Superstorm Sandy
October 26, 2012	1200 UTC	Experimental 2.5 km NAM MOS precipitation type site established

Alaska

DATE	CYCLE	CHANGES
December 16, 2011	1200 UTC	Added improved legend to best category maps
December 10, 2011	1200 UTC	Menu added to select cycle
November 29, 2011	0000 UTC	GRIB2 data available for download
November 29, 2011	0000 UTC	Experimental Alaska GMOS precipitation type site established

Hi-Res Gridded MOS QPF Changes

DATE	CYCLE	CHANGES
November 18, 2009	1200 UTC	The website was updated to include additional links. The new links include Publications, Recent Changes, Join the Mailing List, FAQ, and Contact Us.
November 10, 2009	1200 UTC<	A link to comparative categorical 6-h QPF verification scores was added. The QPF products included in the scoring are from the (experimental) HRMOS QPF model together with other operational model and manually QPF products in categorical form. The scores are for the 2008-09 cool season and the 2009 warm season. Corresponding scores for the 2007-08 cool season are available at https://sats.nws.noaa.gov/~qpf/* for NWS users.
October 13, 2009	1200 UTC	Created public site at http://www.nws.noaa.gov/mdl/hrqpf/*. A private website created in November 2008, which is available to selected NWS members, is being retained because it contains information not available at this public site.
October 1, 2009	0000 UTC	Switched to an upgraded cool season system. Upgrades include new regression equations and probability thresholds, extension of the forecast projections up to 192 hours, and additional QPF predictands [i.e., a 12-h valid period for both the probability of ≥ 0.01" (POP) and the continuous precipitation product].

Experimental MOS Weather Grid Changes

2014

DATE	CYCLE	CHANGES
December 12, 2014	1200 UTC	Added weather grid verification preprint from 39th National Weather Association Annual Meeting to the Publications page.
April 8, 2014	1200 UTC	GMOS Weather, precipitation type probability, PPI, and PoPO added to the experimental GMOS guidance over the CONUS and Alaska. See Technical Implementation Notice 13-49.

2013

DATE	CYCLE	CHANGES
November 5, 2013	1200 UTC	Updated Alaska weather example* page with a case of more active weather. Added link to survey for comments on GFS GMOS Precipitation Type and Predominant weather to several pages.
November 4, 2013	1200 UTC	Added PPI GRIB2 files to GRIB2 download area on the GMOS weather grid homepage. Added links in sidebar and on *FAQ page to the CONUS unconditional severe thunderstorm probabilities.**
July 25, 2013	0000 UTC	Began populating webpages with data and images created on the Weather and Climate Operational Supercomputer System (WCOSS).

2012

DATE	CYCLE	CHANGES
November 16, 2012	1200 UTC	Added MOS weather grid preprint from 37th National Weather Association Annual Meeting to the Publications page.
September 10, 2012	1200 UTC	Added comparisons of freezing, frozen, liquid, and thunder components of the GMOS and NDFD weather grids to the Alaska GMOS/NDFD Comparison page*.
August 31, 2012	1200 UTC	Split GRIB2 files into short-range and extended range. These are available in the GRIB2 download area on the weather grid homepage.
August 13, 2012	1200 UTC	Improvements to unconditional probability of severe thunderstorms have been made to improve coverage over the Great Lakes.
July 13, 2012	1200 UTC	Removed links to December 2010 2.5 km CONUS (Winter Example) sample case. Updated links to 2.5 km CONUS Weather Example* (formerly Severe Example) page. Added graphics to display GMOS-NDFD comparisons of freezing, frozen, liquid, and thunderstorm categories to the 2.5 km CONUS Weather Example* page.
July 13, 2012	1200 UTC	Updated the Frequently Asked Questions Page to include links to images of GMOS elements.
June 22, 2012	1200 UTC	Updated the Frequently Asked Questions Page to include availability information of GMOS elements.
June 20, 2012	1200 UTC	Conditional precipitation type equations updated to produce missing forecasts in summer (2.5 km CONUS: June 1-August 31, Alaska: June 16-August 31).
June 14, 2012	0000 UTC	Added Alaska GMOS Weather Evalutation Page*, which updates daily at 00Z and shows the GMOS forecasts and observations for the previous day.
June 10, 2012	0000 UTC	Added links to download GRIB2 files for Alaska to https://sats.nws.noaa.gov/~wxgrid/index.php*.
May 10, 2012	1200 UTC	Alaska Weather Example* page established.
May 2, 2012	1200 UTC	Improved probability of 2.5 km CONUS thunderstorm guidance so that Thunder Potential Index and Severe Potential Index now have the same extent as other elements.
May 2, 2012	1200 UTC	Alaska GMOS Weather page* and GMOS/NDFD Alaska Comparison page* established.
February 29, 2012	1200 UTC	The GMOS/NDFD Comparison page* now compares 00Z GMOS to 00Z NDFD and 12Z GMOS to 12Z NDFD.
January 12, 2012	1200 UTC	Added comparisons of freezing, frozen, liquid, thunder, and severe components of the weather grid to the GMOS/NDFD Comparison page*.

2011

DATE	CYCLE	CHANGES
December 30, 2011	1200 UTC	Removed reliance on precipitation type best category thresholds from precipitation phase assignment.
December 16, 2011	1200 UTC	Adjusted smoother settings for precipitation potential, thunder potential, and severe potential to smooth less.
December 14, 2011	0000 UTC	Started using HRMOS PoP/QPF* as an input for the weather grid. A before/after comparison of the 00z forecast for December 14 is available here*.
October 2011	-----	Added 2.5 km CONUS GMOS Weather Evalutation Page*, which updates daily at 00Z and shows the GMOS forecasts and observations for the previous day.
September 26, 2011	1200 UTC	Adjusted method for assigning order of weather type subkeys.
September 23, 2011	0000 UTC	Added Precipitation Potential Index (PPI) comparison to GMOS/NDFD Comparison page*.
September 19, 2011	1200 UTC	Improved method for determining precipitation type potential indices.
August 26, 2011	1200 UTC	Severe Weather Example* page established. Added graphics to display precipitation intensity to https://sats.nws.noaa.gov/~wxgrid/gmos_wx.php*.
August 25, 2011	1200 UTC	Replaced display of freezing, frozen, and liquid categories with freezing, frozen, and liquid potential indices.
August 15, 2011	1200 UTC	Added GMOS-NDFD comparison to Winter Weather Example* page.
August 5, 2011	1200 UTC	Winter Weather Example* page established.
July 18, 2011	1200 UTC	Added graphics to display precipitation potential index; freezing, frozen, and liquid categories; and thunder and severe potential on https://sats.nws.noaa.gov/~wxgrid/gmos_wx.php*. Updated Frequently Asked Questions.
July 11, 2011	1200 UTC	Adjusted scheme for displaying severe weather. Isolated severe will not display on images.
June 15, 2011	1200 UTC	Smoothing routine introduced to underlying precipitation, thunder, and severe probabilities.
June 9, 2011	1200 UTC	GMOS/NDFD comparison page established.
June 7, 2011	1200 UTC	Sample points no longer display two of the same weather type (e.g. T+/T is now T+/RW).
June 2011	-----	GMOS Weather site established at https://sats.nws.noaa.gov/~wxgrid

GMOS Change Log - MDL