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.
WPC Met Watch

Mesoscale Precipitation Discussion: #0915 (2018)
(Issued at 442 AM EDT Tue Oct 02 2018 )

MPD Selection

Graphic for MPD #0915

Mesoscale Precipitation Discussion 0915
NWS Weather Prediction Center College Park MD
442 AM EDT Tue Oct 02 2018

Areas affected...Southern and Central Arizona

Concerning...Heavy rainfall...Flash flooding possible

Valid 020841Z - 021441Z

Summary...Steady moderate to occasionally heavy rainfall from Rosa
pose a localized flash flood threat across the region through the
morning hours. Rainfall totals of 1 to locally 2 inches will be

Discussion...Recent 1 minute IR imagery from GOES-East mesoscale
sector over Arizona shows a slight uptick in convection and
cooling cloud tops. This is supported by KYUX and KIWA radar
returns where reflectivity has increased in the last 30 minutes
with 1-hr rates between 0.5-1.0".

The latest mesoanalysis shows SBCAPE of 1000-1500 J/kg still
pooled across portions of southern Arizona with little to no CIN
in place as well. This aligns with the PWAT axis of 2-2.3" which
is a very impressive 4-4.5 SD above normal. Fueled by steady
moisture transport in the low-mid levels ahead of Rosa along with
favorable upper level divergence will keep plenty of lift in the
area through the morning hours.

Hi-res models have struggled capturing a lot of the activity and
its northward movement over the past 3-6 hours, but still depict
clusters of heavier showers across southern into south central
Arizona through the morning. With limited (but still present
instability) convection will be more steady/moderate but some
localized intense rates will be possible.

Given what has already fallen across extreme southern Arizona, the
steady rain occurring and to come over areas with low FFG,
localized flash flooding will be possible.




LAT...LON   34791306 34481133 33151122 31301189 31491287
            31791351 32001412 32321454 33231451

Last Updated: 442 AM EDT Tue Oct 02 2018

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, 12-May-2022 19:44:52 GMT