Skip Navigation Links weather.gov 
NOAA logo-Select to go to the NOAA homepage NOAA's National Weather Service   Select to go to the NWS homepage
Storm Prediction Center
navigation bar left  
  navigation bar end cap


 
USA.gov is the U.S. Government's official Web portal to all Federal, state and local government Web resources and services.

    Day 2 Outlook >
Aug 20, 2018 1630 UTC Day 1 Convective Outlook
Updated: Mon Aug 20 16:30:25 UTC 2018 (Print Version | 20180820 1630Z Day 1 shapefile | 20180820 1630Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Tornado Wind Hail
 Population  Cities/Towns  CWAs  Interstates  Counties  ARTCC  FEMA Regions

 Forecast Discussion
   SPC AC 201630

   Day 1 Convective Outlook CORR 1
   NWS Storm Prediction Center Norman OK
   1130 AM CDT Mon Aug 20 2018

   Valid 201630Z - 211200Z

   ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER PARTS OF
   SOUTHERN ILLINOIS...SOUTHEAST MISSOURI...NORTHEAST
   ARKANSAS...WESTERN KENTUCKY...WESTERN TENNESSEE...AND NORTHWEST
   MISSISSIPPI......

   CORRECTED FOR NDFD THUNDER GRID ERROR

   ...SUMMARY...
   Scattered severe storms are likely across the Mid-South from
   mid-afternoon to early evening. Damaging winds should be the primary
   hazard, but a couple tornadoes and large hail are possible.

   ...Mid MS Valley...
   Only minor changes have been made to the ongoing forecast.  An
   unseasonably strong upper low is present today over MO, with a band
   of moderately strong mid-level winds rotating cyclonically around
   the base of the low into parts of MO/AR/IL/KY/TN.  It appears that
   initial convection will develop soon over south-central MO and
   north-central AR, and track eastward across the ENH risk area
   through the afternoon.  Forecast soundings show favorable winds
   aloft and sufficient CAPE for a risk of bowing line segment capable
   of damaging wind gusts.  Initial activity could also pose a threat
   of hail and perhaps a tornado or two.  Have expanded the risk areas
   a little farther north into central/southern IL where
   clearing/destabilization appears likely.  Further details will be
   available in an MCD that will be issued soon.

   ...Northern IL and vicinity...
   Easterly surface winds over northern IL, will result in marginally
   favorable hodographs for a few rotating storms later this afternoon
   along and north of the warm front lifting across the region. 
   Widespread clouds will limit heating/destabilization, but morning
   model guidance suggests the potential for a few isolated storms
   capable of brief spin ups or damaging wind gusts.

   ...NC...
   Scattered thunderstorms are expected once again today over parts of
   NC, where ample low level moisture remains.  Winds in the lower
   troposphere are weak, but the strongest cells will be capable of
   locally gusty/damaging winds.

   ...Northern Great Basin...
   A strong shortwave trough is moving across eastern OR and will
   affect parts of ID/MT/UT/WY later today.  Low level moisture is
   limited, but forecast soundings suggest steep low-level lapse rates
   and increasing risk of a few damaging wind gusts as the mid-level
   wind max overspreads the region.  Small hail will also be possible
   in the higher elevations.

   ..Hart.. 08/20/2018

   CLICK TO GET WUUS01 PTSDY1 PRODUCT

   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 2000Z

        
Top/Latest Day 2 Outlook/Today's Outlooks/Forecast Products/Home
Weather Topics:
Watches, Mesoscale Discussions, Outlooks, Fire Weather, All Products, Contact Us

NOAA / National Weather Service
National Centers for Environmental Prediction
Storm Prediction Center
120 David L. Boren Blvd.
Norman, OK 73072 U.S.A.
spc.feedback@noaa.gov
Page last modified: August 20, 2018
Disclaimer
Information Quality
Help
Glossary
Privacy Policy
Freedom of Information Act (FOIA)
About Us
Career Opportunities