Area Forecast Discussion
Issued by NWS Quad Cities, IA IL
Issued by NWS Quad Cities, IA IL
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516 FXUS63 KDVN 022003 AFDDVN Area Forecast Discussion National Weather Service Quad Cities IA IL 303 PM CDT Thu May 2 2024 .KEY MESSAGES... - Upper level pattern remains active, with periodic chances for showers and storms through next week. - There is the risk for heavy rain and a Marginal Risk for Severe Weather today and into this evening. && .SHORT TERM /THROUGH FRIDAY/... Issued at 302 PM CDT Thu May 2 2024 Early afternoon surface analysis showed a weak area low pressure centered across west central Iowa, wit ha warm front nearly right along the Interstate 80 corridor and a cold front across southwest Iowa to eastern Kansas. Rain showers and storms from WAA processes have wained significantly in the last few hours, though some remained mainly in southeast Iowa nearer to some stronger forcing aloft. Elsewhere, skies featured a mix of clouds and sun to dense overcast with temperatures ranging from the low 60s (east central Iowa) to upper 70s (northwest Illinois). Look for the surface low, warm front and cold front to progress northeast across the region over the next 12-18 hours. A passing shortwave currently over southeast Kansas and southwest Missouri will interact with this system and increase lift across the region, leading to renewed shower and thunderstorm development this afternoon and evening. This is favored ahead of the front mainly along and east of the Mississippi River where temperatures are warmer and higher instability exists. Latest CAMs favor instability in this area climbing to around 1000-2000 J/kg thanks to steep low- level lapse rates, along with sufficient deep layer shear around 25- 35 kts for organization. Damaging winds and large hail would be the primary threats with storms, with a tornado threat possible if any storms can latch on to the warm front or remnant outflow boundaries. Latest In addition to the severe threat, PWATs across the region ahead of the cold front remain high around 1.25-1.50". This will ensure thunderstorms capable of producing torrential rains in a short amount of time, especially over areas that seeing training storms. The primary areas of concern are urban areas and locations in southeast Iowa (a Flood Watch is in effect here due to the heavy rains from this morning), west central Illinois and northeast Missouri thanks to their heavy rains from the past week. Elsewhere, soil conditions remain near normal to anomalously dry per CPC analysis, which favors the ground being able to soak up a majority of the rainfall. Once the cold front front passes through the area tonight, conditions will improve for the end of the work week with high pressure quickly passing across the area. Areas of mist/fog may be possible Friday morning mainly in east central Iowa where leftover moisture from this morning`s rains persist. Elsewhere, skies will be mostly sunny with continued above normal highs in the 70s expected. && .LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/... Issued at 302 PM CDT Thu May 2 2024 The weather will remain active going into early next week as a trough over the eastern Rockies and strong closed low just north of Montana sends several disturbances into the area. Each day through next Thursday will feature at least a slight chance of precipitation. The first definite chance of precip comes Saturday morning and afternoon as a complex of showers and storms moves across the area with a weak front and shortwave aloft. At this time the primary threat looks to be lightning and heavy rain with PWATs climbing back to around 1.50". Severe chances are low with increasing cloud cover hampering instability and unfavorable lapse rates. Conditions will dry out to close the weekend with precipitation chances returning for Tuesday with another round of AM showers and storms expected. There is quite a bit of uncertainty with this system as guidance varies on the frontal timing and availible moisture, so look for additional changes to this period in subsequent forecast packages. Temperatures look to remain above normal with highs in the 70s/near 80 and lows in the 50s/60s. As the previous AFD mentioned, outside of the rain chances it will be a nice week! && .AVIATION /18Z TAFS THROUGH 18Z FRIDAY/... Issued at 1233 PM CDT Thu May 2 2024 An active TAF period is in store for the area thanks to a nearby cold front and an approaching disturbance aloft. Rain showers currently in the KCID/KDBQ vicinities will give way to renewed shower and storm development areawide in the next 2-4 hours, with impacts expected mainly expected at KMLI/KBRL (TEMPO groups have been included in this forecast). Conditions will deteriorate to MVFR, with heavier showers and storms bringing brief drops to IFR. There is a low risk that these storms will be severe, with the primary risks being variable wind gusts around 40-45 kts and large hail. These storms will move east by 03.00z, with leftover MVFR rain showers and ceilings along the front persisting through the evening hours. Conditions will improve to VFR after 03.06z, with gusty winds decreasing and veering to the north. For Friday morning, latest CAMs are hinting at fog development at KCID/KDBQ thanks to leftover moisture from rains from this morning. However, this is low confidence, so have only introduced a brief drop to MVFR visibilities. Look for more detail in this from later shifts. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...Flood Watch until midnight CDT tonight for IAZ076-077-087-088- 098. IL...None. MO...None. && $$ SHORT TERM...Speck LONG TERM...Speck AVIATION...Speck