Area Forecast Discussion
Issued by NWS Quad Cities, IA IL

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731 FXUS63 KDVN 110819 AFDDVN Area Forecast Discussion National Weather Service Quad Cities IA IL 319 AM CDT Tue Jun 11 2024 .KEY MESSAGES...
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- Warmer today with a MRGL Risk (Level 1 of 5) for severe storms in the northwest this evening. - Turning hot and more humid by mid week. - Another MRGL Risk across the northwest for late Wednesday - SLGT Risk (Level 2 of 5) for severe storms on Thursday.
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&& .SHORT TERM /TODAY THROUGH TONIGHT/...
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Issued at 317 AM CDT Tue Jun 11 2024 Today...short wave upper trof currently seen on water vapor(WV) imagery arching from western MN into southwest NE, will continue to try and shunt an associated elongated band of mainly light showers and sprinkles acrs the area from late morning and through the afternoon. As this activity encounters dry air and weak lapse rates in place, expect a lot of it to initially decay upon arrival or be in partial virga form. Then there may be some patchy rejuvenation here and there in afternoon pre-frontal heating but most of this may still look to be light and high based/elevated making for mainly sprinkles or light showers. Attention will then turn to the main incoming front itself, where it may interact with 600-1000 J/kg SBCAPEs or 500 J/kg elevated MUCAPEs if it stays elevated for potential isolated thunderstorm development this evening mainly in the northwestern third of the DVN CWA. Lapse rates are marginal(below 6 C/km), but storm layer shear may range from 35-45 KTs. Thus a low chance for a stronger storm for hail and winds in the local area this evening, but feel the Marginal Risk may not be really warranted. Low POPs for low coverage on the evening convective activity. Despite high clouds filtering the insolation at times, return flow and associated WAA will help temps warm into the upper 70s to low 80s in most areas except the northeast. Tonight...after the evening isolated shower/storm chances, the rest of the night light sfc flow and a bit higher sfc DPTS may allow for some patchy fog inn spots. But lingering cirrus and short night`s make for low confidence in this and won`t mention yet. Milder night with lows in the upper 50s to low 60s in most areas.
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&& .LONG TERM /WEDNESDAY THROUGH MONDAY/...
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Issued at 317 AM CDT Tue Jun 11 2024 Wednesday...More robust southwesterly return flow and mixing winds will warm things up with the CWA reaching the mid 80s to near 90. Higher sfc DPTs seem to lag or get mixed out in the upper 50s to low 60s, so no extreme humidity or heat index`s. More enhance westerly mid to upper jet regime nosing acrs the northern plain and NW MN with another short wave interacting with 30-40 KT southwesterly LLJ fed higher THTA-E should spawn storm clusters or initial MCS development Wed afternoon and evening acrs the south half of MN into the MO RVR Valley. Low to mid level vector propagation paths and currently progged LLVL thermal gradient may allow for some of this activity to bleed down into portions of the local area Wed night. But stronger storm support/maintenance parameters remain just off to the west Wed night and the more robust convection may occur acrs western into central IA with us getting secondary activity. Right now Wed night PWATs(precipital water) project to be 1.5 to 1.8 inches, so heavy rain may possible if we can get in on some convection that maintains, as well as marginally severe wind gusts. Thursday...A day of still somewhat of uncertainty regarding strong convection potential, as much will depend on what occurs and lingers out of Wed night. A further southward shunted boundary or storm outflow, as well as lingering debris will affect local airmass recharge potential and where late afternoon and evening storms may re-fire. That axis looks to be shifting southward day by day, with latest ensemble blend MCS generation tools/parameters now hi-lighting areas from northeast KS, acrs the northern half of MO and acrs central IL by early Thu evening. Only the southern DVN CWA may now be impacted by strong convection if the current trends are correct. Convective debris, rain-cooled outflow and other things will make high temp fcst for Thu very challenging, and worried the blend will be too warm in spots. Friday through Monday...Incoming LLVL ridging under temporary northwesterly steering flow will make for some nice summer days Friday into portions of Saturday, but Sat could be warming to above normal. Sat night through the rest of the extended will be the battle of incoming thermal ridge and heat, with ridge-riding MCS storm track potential close by. Some 90s likely by Sunday and Monday depending on storm debris or track lay out, but the blend again looks to gone overly aggressive with the heat these days and have loaded mid 90s.
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&& .AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/... Issued at 1248 AM CDT Tue Jun 11 2024 Largely a VFR TAF cycle through Tuesday. Light and variable winds overnight into early Tuesday, before they veer to the south and southwest and increase to 10-15 KTs by mid morning. A band of high based light showers and sprinkles will move in from the west and overtake most of the TAF sites on Tue, but expect them to maintain at VFR CIGs and VSBYs. Behind that swath, a low chance for an isolated shower or thunder storm to develop in the VCNTY of CID and DBQ Tue evening after 00z. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...None. IL...None. MO...None. && $$ SHORT TERM...12 LONG TERM...12 AVIATION...12