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.
Day 2 Outlook >
WPC Day 1 Excessive Rainfall Outlook
Risk of 1 to 6 hour rainfall exceeding flash flood guidance at a point
Updated: 2349 UTC Sat Jul 20, 2024
Valid: 01 UTC Jul 21, 2024 - 12 UTC Jul 21, 2024
Day 1 Excessive Rainfall Forecast
Forecast Discussion
Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
746 PM EDT Sat Jul 20 2024
Day 1
Valid 01Z Sun Jul 21 2024 - 12Z Sun Jul 21 2024


...Eastern North Carolina...
A shortwave trough moving eastward from the central Appalachians
into the Mid-South is allowing for diffluence aloft near a front.
Earlier convection across VA has moved east out to sea, and a new
convection is attempting to form between central and northeast NC
at this time. The latest HREF shows the strongest linger signal
near the NC convection, so realigned the Slight southward. Hourly
rain totals as high as 3" and with local amounts to 5" are possible
here into the overnight hours, with the threat waning during the
early morning hours of Sunday.

...Southwest and Southern Rockies...
An upper level high combined with monsoon moisture have led to
thunderstorm activity this afternoon, with the most concentrated
activity across portions of NM and southeast AZ.  Local totals of
1-2" with some locally enhanced amounts remain in the forecast
overnight across southern NM and southeast AZ, with activity
generally on the wane near and after 9 pm MST as CIN sets in.
Activity across much of UT has waned, except near the southern
border with NV. Risk areas were realigned based on HREF and radar
reflectivity trends.  The combination of multi- day impact within
complex terrain and remnant burn scars exacerbating the flash flood
concerns was reason to maintain the southern portion of the
previously assigned Slight Risk, with convective and HREF trends
supporting removal of the northern portion of the risk areas.

...In and near Oklahoma...
The HREF guidance shows activity flaring through the overnight and
early morning hours on Sunday as an upper level disturbance moves
into the area and interacts with 1.5-1.75" precipitable water
values and MU CAPE of 2000+ J/kg, which would take a while to
erode. Effective bulk shear sits around 30 kts, which is sufficient
organize thunderstorms. Hourly rain totals to 2" with local amounts
to 4" look possible here where cells merge and train, and near any
random mesocyclones. The southeast half of OK has been quite dry
this past week, leaving their flash flood guidance values quite
high, though values are more modest across central OK. Left the
threat area as Marginal but Slight Risk impacts are possible if
heavy rainfall aligns with urban areas.


Day 1 threat area:

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