Skip Navigation Links 
NOAA logo - Click to go to the NOAA homepage National Weather Service   NWS logo - Click to go to the NWS homepage
The Weather Prediction Center



Follow the Weather Prediction Center on Facebook Follow the Weather Prediction Center on Twitter
NCEP Quarterly Newsletter
WPC Home
Analyses and Forecasts
   National High & Low
   WPC Discussions
   Surface Analysis
   Days ½-2½ CONUS
   Days 3-7 CONUS
   Days 4-8 Alaska
   Flood Outlook
   Winter Weather
   Storm Summaries
   Heat Index
   Tropical Products
   Daily Weather Map
   GIS Products
Current Watches/

Satellite and Radar Imagery
  GOES-East Satellite
  GOES-West Satellite
  National Radar
Product Archive
WPC Verification
   Medium Range
   Model Diagnostics
   Event Reviews
   Winter Weather
International Desks
Development and Training
WPC Overview
   About the WPC
   WPC History
   Other Sites
Meteorological Calculators
Contact Us
   About Our Site is the U.S. Government's official web portal to all federal, state, and local government web resources and services.

About the Quantitative Precipitation Forecasts

About 24 Hour QPF      About 6 Hourly QPF

 24 Hour QPF Issuance Times

Product Time
94q (preliminary Day 1) 0615Z & 1815Z
94q (final Day 1) 1015Z & 2215Z
98q (preliminary Day 2) 0700Z & 1900Z
98q (final Day 2) 1015Z & 2215Z
99q 1015Z & 2215Z
95e (Day 1-5 total) 1730Z
QPFPFD (prelim. Day 1) 0700Z  & 1900Z
QPFPFD (prelim. Day 2) 0745Z & 1945Z
QPFPFD (with Days 1-3) 1100Z & 2300Z

About The 24 Hour QPF Products

Isohyets of expected areal average rainfall of .01 inch, .25 inch, .50 inch, 1 inch, 1.50 inch and greater (in inch increments) are drawn for the 24 hour forecast period ending at 1200Z on both days 1, 2, and 3. The daily QPF package begins on the midnight shift with the 0000Z model run.  A preliminary Day 1 forecast (94Q) is issued by 06Z and the Final Day 1 (94Q) is issued by 10Z and is valid at 1200Z the following morning. The Day 2 QPF (98Q) is issued by 1000Z. The Day 2 forecast (98Q) is updated on the day shift and is issued by 1800Z. 

An electronically generated bulletin, which describes the location of the forecast isohyets using latitude and longitude points, is transmitted at the end of the qpf discussion for the Day 1 through Day 3 finals. 

 0.25 350731 349761 349789 347803 340819 327837 310854 297864 284874
 0.50 404072 395071 390076 387081 389084 395085 402082 404076 404072

The first field is the value of the contour (in this case...0.25" or 0.50"). The following fields are the latitude/longitude pairs for the contour. The first three digits of the pair are the degrees of latitude (in tenths of degrees North latitude). The last three digits of the pair are the degrees of longitude (in tenths of degrees West longitude). If the fourth digit is less than 5, a leading "1" is added to indicate longitudes greater than or equal to 100° W. From the above message...the following table gives the decoded lat/long pairs 

Value: 0.25" Value: 0.50"
35.0N, 73.1W 40.4N, 107.2W
34.9N, 76.1W 39.5N, 107.1W
34.9N, 78.9W 39.0N, 107.6W
34.7N, 80.3W 38.7N, 108.1W
34.0N, 81.9W 38.9N, 108.4W
32.7N, 83.7W 39.5N, 108.5W
31.0N, 85.4W 40.2N, 108.2W
29.7N, 86.4W 40.4N, 107.6W
28.4N, 87.4W 40.4N, 107.2W

NOAA/ National Weather Service
National Centers for Environmental Prediction
Weather Prediction Center
5830 University Research Court
College Park, Maryland 20740
Weather Prediction Center Web Team
Privacy Policy
About Us
Career Opportunities
Page last modified: Thursday, 01-Mar-2007 18:43:03 UTC