Skip Navigation Links weather.gov 
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 X
WPC Home
Analyses and Forecasts
   National High & Low
   WPC Discussions
   Surface Analysis
   Days ½-2½ CONUS
   Days 3-7 CONUS
   Days 4-8 Alaska
   QPF
   PQPF
   Flood Outlook
   Winter Weather
   Storm Summaries
   Heat Index
   Tropical Products
   Daily Weather Map
   GIS Products
Current Watches/
Warnings

Satellite and Radar Imagery
  GOES-East Satellite
  GOES-West Satellite
  National Radar
Product Archive
WPC Verification
   QPF
   Medium Range
   Model Diagnostics
   Event Reviews
   Winter Weather
International Desks
Development and Training
   Development
WPC Overview
   About the WPC
   WPC History
   Other Sites
   FAQs
Meteorological Calculators
Contact Us
   About Our Site
 
USA.gov is the U.S. Government's official web portal to all federal, state, and local government web resources and services.
 
 
< Day 1 Outlook Valid Through 12Z Today Day 2 Outlook >
 
WPC Day 1 Excessive Rainfall Outlook
Risk of 1 to 6 hour rainfall exceeding flash flood guidance at a point
 
Updated: 0830 UTC Tue Jul 1, 2025
Valid: 12 UTC Jul 01, 2025 - 12 UTC Jul 02, 2025
 
Day 1 Excessive Rainfall Forecast
 
Forecast Discussion
Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
426 AM EDT Tue Jul 1 2025
Day 1
Valid 12Z Tue Jul 01 2025 - 12Z Wed Jul 02 2025

..THERE IS A MODERATE RISK OF EXCESSIVE RAINFALL OVER NORTHERN
PORTIONS OF THE MID-ATLANTIC REGION...

...Eastern Seaboard...

Per collaboration with WFOs CTP, PHI, and LWX, we have included a
Moderate Risk to the Day 1 ERO across parts of the northern Mid
Atlantic Region to include NoVa and the DC-Balt metro regions,
northern DE and into southeast PA.

Longwave upper trough over the Upper Great Lakes/Midwest early
this morning will pivot eastward Tue-Tue night, pushing east of the
Appalachians Wed morning. Embedded within the longwave trough is a
shortwave, currently along the IA/IL/MO tri- state area, which
will track across the OH Valley later this afternoon and across the
Mid Atlantic later this evening and overnight. This shortwave
should enhance the broad- scale across the Mid Atlantic region
(especially), while low-level frontogenesis also gets a boost south
of the 90-100kt upper jet streak in the lee of the large-scale
trough.

0-6km bulk shear values increasing to 25+ kts within the inherited
broad Slight Risk area (30-40+ knots over the northern Mid Atlantic
into the Northeast) will support the formation of
widespread/multi-cluster line segments ahead of the upper
trough/surface cold front during peak diurnal instability hours
this afternoon into the evening. MUCAPEs peak between 2000-3000
J/Kg, while TPWs remain around 2 standard deviations above normal
for early July (between 2.00-2.25" within the non-convective
environment across much of the Mid Atlantic into southern New
England). The concern over the Slight and especially Moderate Risk
areas will be with upwind propagation and cell training, as the
pre-frontal southwesterly low-level flow (20-25 kts at 850 mb
becomes nearly parallel and of similar magnitude as the mean
850-300 mb flow. 00Z HREF and RRFS probabilities of 24hr QPF
exceeding 3" climb above 60% within much of the Moderate Risk
area (highest with the RRFS), while probs exceeding 5" within the
24hr period reach 40-60% in spots per the RRFS (though 20-25% tops
per the HREF). Given the favorable thermodynamic profile (high
CAPE/PW environment) along with the broad-scale forcing, anticipate
areas of 2 to 3+ inch/hr rainfall rates this afternoon and evening.

The Moderate Risk area also encompasses areas recently hit by
heavier rainfall, evidenced by the lower FFGs (in some areas, 1 hr
FFGs 1.00" or less). This includes areas SE PA including the
Middletown/Lancaster/Lebanon/Redding areas that received 4-7" of
rain on Monday.

...West Texas into New Mexico...

Farther south/west along the stalled frontal boundary...convection
is expected to be develop within a region of decent CAPE and
precipitable water values in excess of 2 standard deviations above
climatology. This area will also benefit from weak upper level
vorticity/shear axis within the broad-scale ridge, with tropical
moisture feeding in per the low-mid layer southeasterly flow.
850-700 mb moisture transport is pretty solid across the outlook
areas, but especially within the Slight Risk region across parts of
West TX into southeast NM where the 850-700 mb moisture flux
standardized anomalies peak between 3-4 standard deviations above
normal per the 00Z SREF and GEFS. Given the relatively healthy
low-level flow compared to the overall weaker mean flow, areas of
heavy, possibly excessive rainfall are anticipated, especially
within the Slight Risk area, considering the uptick in upwind
propagation and thus chances for cell training.

...South Texas...

An influx of abnormally high TPW from the remnants of Tropical
Cyclone Barry (2.2 to 2.4", which is close to 3 standard
deviations above normal for early July) will combine with a
modestly unstable environment (MUCAPEs increasing to 1500-2500
J/Kg) in producing very heavy short-term rainfall rates later this
afternoon/evening and potentially later into the overnight period.
Both the HREF and RRFS ensembles show high probabilities (>50%) of
3+ inch rainfall, with 30-40% probs of exceeding 5 inches.
Therefore expect more than a localized risk of flash flooding
(i.e. Slight vs Marginal) across portions of South Texas from
Corpus Christi south through Brownsville and the RGV.

Hurley


Day 1 threat area: www.wpc.ncep.noaa.gov/qpf/94epoints.txt
 

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
Disclaimer
Credits
Glossary
Privacy Policy
About Us
Career Opportunities