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Day 4-8 Severe Weather Outlook Issued on Apr 8, 2018
Updated: Sun Apr 8 08:56:03 UTC 2018
Day 4-8 Severe Weather Outlook Graphics Issued on Apr 8, 2018
Day 4 Severe Weather Outlook Graphics Issued on Apr 8, 2018
Day 4 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
No Risk Areas Forecast
Day 5 Severe Weather Outlook Graphics Issued on Apr 8, 2018
Day 5 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
No Risk Areas Forecast
Day 6 Severe Weather Outlook Graphics Issued on Apr 8, 2018
Day 6 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
15 % 116,285 6,381,058 Shreveport, LA...Little Rock, AR...Springfield, MO...Tyler, TX...Fort Smith, AR...
Day 7 Severe Weather Outlook Graphics Issued on Apr 8, 2018
Day 7 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
No Risk Areas Forecast
Day 8 Severe Weather Outlook Graphics Issued on Apr 8, 2018
Day 8 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
No Risk Areas Forecast
D4Wed, Apr 11, 2018 - Thu, Apr 12, 2018 D7Sat, Apr 14, 2018 - Sun, Apr 15, 2018
D5Thu, Apr 12, 2018 - Fri, Apr 13, 2018 D8Sun, Apr 15, 2018 - Mon, Apr 16, 2018
D6Fri, Apr 13, 2018 - Sat, Apr 14, 2018 (All days are valid from 12 UTC - 12 UTC the following day)
Note: A severe weather area depicted in the Day 4-8 period indicates 15%, 30% or higher probability for severe thunderstorms within 25 miles of any point.
PREDICTABILITY TOO LOW is used to indicate severe storms may be possible based on some model scenarios. However, the location or occurrence of severe storms are in doubt due to: 1) large differences in the deterministic model solutions, 2) large spread in the ensemble guidance, and/or 3) minimal run-to-run continuity.
POTENTIAL TOO LOW means the threat for a regional area of organized severe storms appears unlikely (i.e., less than 15%) for the forecast day.
 Forecast Discussion

   ZCZC SPCSWOD48 ALL
   ACUS48 KWNS 080854
   SPC AC 080854

   Day 4-8 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0354 AM CDT Sun Apr 08 2018

   Valid 111200Z - 161200Z

   ...DISCUSSION...
   The primary feature of interest during the extended period will be a
   deep/amplified mid-level trough that will reach the central US by
   D6/Fri. As it does so, strengthening west/southwesterly flow aloft
   will transport steep lapse rates over much of the southern/central
   Plains. Meanwhile, a robust low-level mass response will feature a
   narrow corridor of enhanced poleward theta-e transport, generally
   from eastern Texas to the lower Missouri Valley. As a dry line and
   cold front accelerate east across the region, low/mid-level ascent
   is forecast to strengthen sufficiently to overcome convective
   inhibition and promote thunderstorms from eastern Texas to parts of
   the Midwest through Friday night. 

   While medium-range guidance continues to exhibit run-to-run
   variability with regards to the amplitude/timing of the trough, most
   deterministic/ensemble guidance suggest strong/severe thunderstorms
   will be most likely from eastern Texas to the Ozarks and Mid-South
   Friday afternoon through the overnight. Within this corridor,
   vigorous low/mid-level wind fields should overlap adequate
   surface-based buoyancy, such that all severe hazards may be possible
   with maturing convection. Therefore, a 15-percent probability has
   been introduced with this forecast cycle. Further refinements of
   this area (with some potential for a northward expansion) will
   likely be needed in future updates.

   The trough will advance further east through D7/Sat-D8/Sun, with
   pockets of strong/severe convection potentially persisting across
   areas from the Ohio Valley south to the Gulf Coast. Despite this
   potential, uncertainties regarding availability of adequate
   instability, the eastward evolution of the trough, and subsequent
   timing/placement of stronger convection remain too high to introduce
   probabilities beyond D6/Fri.

   ..Picca.. 04/08/2018

   CLICK TO GET WUUS48 PTSD48 PRODUCT
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Page last modified: April 08, 2018
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