Area Forecast Discussion
Issued by NWS Quad Cities, IA IL
Issued by NWS Quad Cities, IA IL
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294 FXUS63 KDVN 161559 AFDDVN Area Forecast Discussion National Weather Service Quad Cities IA IL 1059 AM CDT Thu May 16 2024 .KEY MESSAGES... - Scattered showers and a few storms late tonight and Thursday. - Highs warming into the 80s for several days ahead. - Depending on where a developing storm track lays out, it could be a potentially wet pattern across the region next week with several rounds of heavy rain possible. && .SHORT TERM /THROUGH TONIGHT/... Issued at 250 PM CDT Wed May 15 2024 Weak area of high pressure was centered across eastern Missouri early this morning, with a cold front just off to our west across northwest Iowa and southeast Nebraska. This front was just ahead of a weak shortwave, which per water vapor imagery was over eastern South Dakota. Scattered showers and storms were noted ahead of the shortwave and front per KDMX/KMPX, but had showed a decreasing intensity trend as they were moving east into more stable air across our CWA. Heading through today, we will begin to see shower and storm coverage increase as the front and shortwave move across the area. Look for more scattered activity during the morning hours to become more pronounced mainly along and east of the Mississippi during the afternoon with increasing instability and moisture interacting with the wave. SBCAPE, depending on degree of warmth with clouds in place, should get up to around 1000-1500 J/kg by early afternoon with increasing deep layer shear around 30-35 kts. This is especially favored across northwest Illinois where there is some potential for storms to become strong. SPC maintains a Level 1 (marginal) risk for severe weather in this area, with the risk mainly focused across southwest Wisconsin nearer to better surface convergence. The primary threats would be large hail and damaging winds. Elsewhere, showers and storms could produce some heavy rain as PWATs ahead of the front climb to around 1.00-1.20". Tonight, another round of weak high pressure will bring quiet weather to the area. Weak CAA and low-level flow with keep temps from falling too much, with lows in the mid to upper 50s expected. && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... Issued at 250 PM CDT Wed May 15 2024 Friday through Saturday... A stretch of quiet weather is expected during this period as mid- level ridging builds over the Midwest and Great Lakes. Though some deterministic guidance paints a weak shortwave moving overhead Friday into Saturday, they have backed off on POPs with weaker overall forcing and moisture. Therefore, we should remain dry with warm temps. Look for highs each day in the 80s, with overnight lows in the 50s/60s. Saturday Night on... Ridging will shift southeast of the area and open the door for a shortwave train to set up across portions of the Midwest and upper Midwest. Guidance places us either pretty close to the track or within the track itself, which would increase potential for clusters of showers & storms/MCSs to impact the area at times beginning early next week. There remains quite a bit of uncertainty in storm tracks, severity and timing at this time, as models do not handle these features well several days out. Regardless, will run with the NBM which has all of eastern Iowa, northwest Illinois and northeast Missouri in at least a chance (20-50%) of precipitation Sunday on. Please continue to monitor the latest forecast information, especially over the weekend. && .AVIATION /12Z TAFS THROUGH 12Z FRIDAY/... Issued at 529 AM CDT Thu May 16 2024 A weak shortwave trough aloft and attendant surface front will be moving slowly through the area from west to east today, and will be accompanied by MVFR ceilings and chances (~30%) of rain showers & storms. The threat is greatest at KMLI/KDBQ/KBRL where PROB30s have been maintained. The primary threats with storms are lightning, hail, and wind gusts to around 40 MPH. As the front passes, winds will shift to the northwest, but will remain around or below 10 kts. These light winds may allow for formation of mist at the terminals early Friday morning, with confidence higher at KBRL which will be nearer to the passing front. && .HYDROLOGY... Issued at 1051 AM CDT Thu May 16 2024 Changes: None. Discussion... Most tributary rivers in eastern Iowa have crested and are slowly dropping. The exception is the lower Iowa River where the crest is currently working its way through Wapello and Oakville. On the Mississippi, Gladstone and Burlington will begin a broad crest just above flood stage that will continue through Friday. After a relatively dry weekend, the active weather pattern will return next week with the potential for several rounds of rain. While rainfall amounts continue to be somewhat uncertain, any heavy rainfall would prolong the high river levels on tributary rivers in eastern Iowa, northern Illinois and on the Mississippi River. The longer range outlook through the end of the month has a 40-42 percent probability of above normal rainfall. This outlook suggests the potential for additional improvement with the severe drought conditions across eastern Iowa. Unfortunately, this outlook would also suggest that river levels could remain higher than normal. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...None. IL...None. MO...None. && $$ SHORT TERM...Speck LONG TERM...Speck AVIATION...Speck HYDROLOGY...08