Severe Storm Outlook Narrative (AC)
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000 ACUS11 KWNS 262156 SWOMCD SPC MCD 262155 ILZ000-WIZ000-IAZ000-MOZ000-262300- Mesoscale Discussion 1423 NWS Storm Prediction Center Norman OK 0455 PM CDT Wed Jul 26 2017 Areas affected...Northern and central Illinois...far eastern Iowa Concerning...Severe potential...Watch unlikely Valid 262155Z - 262300Z Probability of Watch Issuance...20 percent SUMMARY...Storms have exhibited somewhat greater organization and intensity intensity over the past hour or so. A WW issuance is not currently anticipated, although damaging wind gusts may occur as this line propagates through the discussion area over the next few hours. DISCUSSION...A north-to-south broken line of storms has organized and increased in intensity over the past hour or so from near CID southward to near UIN, with more isolated convection occurring farther south into far northeastern Missouri. A 48-knot wind gust was reported near UIN with this activity in the past half hour. These storms are in a strongly unstable environment (around 3000 to 4000 J/kg MUCAPE within the pre-convective airmass - highest in central Illinois) and deep shear (around 30-40 knots) favoring at least modest storm organization. These storms are beginning to propagate eastward at around 20-25 knots (especially across far eastern Iowa) and an isolated damaging wind threat should exist given the magnitude of downstream instability. Recent high-resolution guidance suggests that storms may propagate southeastward into central Illinois in the evening, which seems reasonable given the orientation of the moist axis and location of maximum instability. Convective trends will be monitored, although a WW issuance is unlikely at this time. ..Cook.. 07/26/2017 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LOT...ILX...MKX...LSX...DVN...ARX... LAT...LON 42229123 42529067 42518942 42058838 41178793 40238802 39668846 39308959 39279071 39429113 40179116 40919128 41969128 42229123

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