BBS: TELESC.NET.BR Assunto: DAY1SVR: Day 1 Convective Outlook De: COD Weather Processor Data: Mon, 27 Apr 2026 06:01:37 +0000 ----------------------------------------------------------- ACUS01 KWNS 270601 SWODY1 SPC AC 270600 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CDT Mon Apr 27 2026 Valid 271200Z - 281200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS PORTIONS OF THE MID-MISSISSIPPI VALLEY INTO THE LOWER OHIO VALLEY AND PARTS OF THE MID-SOUTH... ...SUMMARY... Widespread strong to severe thunderstorm development appears probable across the middle Mississippi into lower Ohio Valleys this afternoon through this evening, accompanied by potential for a few strong tornadoes, damaging wind gusts and large hail. ...Synopsis... Water vapor imagery shows a prominent shortwave trough promoting elevated strong to severe convection across central and eastern Kansas. This activity is expected to move north and eastward through Iowa/Missouri/Wisconsin/northern Illinois into daybreak and perhaps part of the afternoon for some areas. The outflow from this convection should act to limit the northern extent of greater destabilization during the afternoon and thus the greatest severe threat. A surface low will track northeastward along the parent shortwave. Though this low has trended downward in intensity in recent model runs, strong low-level wind fields are expected within the warm sector throughout the day and into the evening. Areas of pre-frontal convergence and a cold front will be the focus for convective development along with more strongly forced convection tied to the shortwave trough. The front will be draped south and westward into the Ozarks and the southern Plains. ...Mid-Mississippi Valley/Lower Ohio Valley... As mentioned, surface based buoyancy will be limited by early day activity. The current expectation is for parts of central/eastern Missouri into central/southern Illinois and western Kentucky to see greater destabilization. There is activity ongoing within central Missouri early this morning that may have some impact, however. This is the source of greatest uncertainty for these regions. The kinematic environment will certainly be favorable for supercells. The moderate to strong 850 mb jet will also lead to potential for several tornadoes, some of which could be strong. Lapse rates at mid-levels will be rather steep. Large to very-large hail potential is evident given the long hodographs. Some upscale growth into one or more linear segments is expected to occur. This will increase the threat for damaging winds. An increase in tornado probabilities was considered. Given the questions regarding early day convection and where favorable convergence zones/outflow boundaries might be located reduces confidence. Convective trends into daybreak will need to be closely monitored. ...Mid-South... Models indicate potential for supercells along the cold front and even potentially ahead of it. Forcing for ascent will be weaker, but this may help to keep activity cellular longer. Some of this activity could develop after 00Z. Mid-level lapse rates are expected to be steep enough and mid-level flow strong enough to support large to potentially very large hail and damaging winds. The tornado threat will likely be lower given the time of day and tendency for storms to be at least slightly elevated. ...Upper Midwest... Observational and model trends suggest destabilization will be more limited on account of convection at daybreak and beyond. Even so, strong low-level and effective shear will still allow storms to be organized and capable of large hail, damaging winds and a couple tornadoes. There will be potential for both convection at daybreak and also during the afternoon. The greatest potential for afternoon supercells would be in parts of eastern Iowa along with the surface low and colder air aloft. ...Western/central Texas... As moisture returns westward during the evening, some model guidance suggest convection might try to develop along the retreating dryline. Buoyancy and shear would support a threat for large hail and perhaps severe winds. However, mid-level ascent will be very weak and models generally do not sustain these convective attempts. Severe probabilities may be needed if confidence in development increases. ..Wendt/Moore.. 04/27/2026 $$ = = = To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM. --- SBBSecho 3.28-Linux * Origin: Capitol City Online (1:2320/107) ----------------------------------------------------------- [Voltar]