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    Day 2 Outlook >
Aug 22, 2017 1630 UTC Day 1 Convective Outlook
Click to see valid 1Z - 12Z Day 1 Convective Outlook
Updated: Tue Aug 22 15:57:16 UTC 2017 (Print Version | 20170822 1630Z Day 1 shapefile | 20170822 1630Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
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 Forecast Discussion
   SPC AC 221557

   Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   1057 AM CDT Tue Aug 22 2017

   Valid 221630Z - 231200Z

   ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS NY/PA...

   ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OH VALLEY TO
   WESTERN NEW ENGLAND...

   ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS SOUTHERN HIGH
   PLAINS TO NEW ENGLAND...

   ...SUMMARY...
   Scattered to numerous swaths of damaging winds are expected from the
   Ohio Valley to western New England through this evening. A couple
   tornadic storms are possible, mainly over parts of New York into
   Pennsylvania.

   ...OH Valley to western New England...
   Minimal change necessary this outlook with numerous storms expected
   to develop in the next few hours. A pronounced shortwave trough over
   the Upper Great Lakes will continue to amplify while approaching
   Quebec tonight. Associated surface cyclogenesis will drive a cold
   front southeast across the Lower Great Lakes and OH Valley. Primary
   focus for storm development will be along the remnant
   outflow/differential heating zone ahead of the front. Strong
   tropospheric winds will support effective shear of 30-40 kt
   southwest to 40-50 kt northeast. In spite of poor mid-level lapse
   rates, robust diabatic heating will contribute to MLCAPE of
   1500-2500 J/kg southwest to 1000-2000 J/kg northeast. An initially
   mixed mode should transition to line segments with swaths of
   damaging winds expected, especially with bowing segments. Stronger
   low-level shear and enlarged hodographs are expected across parts of
   NY into northern PA. Although storm mode may limit the sustenance of
   rotating updrafts, embedded QLCS mesovortices should support a
   threat for a couple tornadoes. 

   For additional short-term discussion, please see MCDs 1547 and 1548.

   ...Southern High Plains to Mid-South...
   Deep-layer flow and shear will be substantially weaker along a
   southward-sagging cold front and pre-frontal outflow near the I-40
   corridor. Loosely organized multicell clusters are expected
   mid-afternoon to mid-evening with isolated downbursts and marginally
   severe hail possible.

   ..Grams/Cohen.. 08/22/2017

   CLICK TO GET WUUS01 PTSDY1 PRODUCT

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

        
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Page last modified: August 22, 2017
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