Area Forecast Discussion
Issued by NWS Quad Cities, IA IL
Issued by NWS Quad Cities, IA IL
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618 FXUS63 KDVN 031751 AFDDVN Area Forecast Discussion National Weather Service Quad Cities IA IL 1251 PM CDT Wed Jul 3 2024 ...18z Aviation Update... .KEY MESSAGES... - Showers and storms are possible on Independence Day as a warm front lifts north through the area followed by a cold front. There is a Marginal Risk for severe weather for the western third of the CWA. - Active pattern remains through the long term, with near daily chances for precipitation somewhere in our forecast area. Saturday may be the best chance at a dry day, with slight- chance PoPs daily from there. - Moderate to Major River Flooding continues, with further changes to river forecasts expected as we transition from predicted rainfall to observed rainfall over the next 36 hrs. && .SHORT TERM /THROUGH THURSDAY/... Issued at 249 AM CDT Wed Jul 3 2024 As the cold front that brought the severe weather yesterday slowly moves out, we may continue to see remnant showers and storms, especially in our southeast this morning. Much of this activity should be out of the area by 7am-10am. Weak high pressure will move through the area today, which should allow for a brief break in the weather. Much of the day should remain dry, as dry advection works into the area behind yesterdays system. A weak upper wave will pass through the area today, but we are not expecting much precipitation from this, due to lacking moisture. The best chance will be late tonight, where we introduce slight-chance PoPs to the area, mainly focusing in the south. This is the area in which the best forcing and moisture will be found, but confidence remains low on overall coverage of shower activity. Plus, much of this will be seen well after dark, so you may not even notice it rained. Any area that receives rain tonight will be overall low on the accumulation-side. Rather, enough to wet the pavement for most, with maybe upwards to a quarter of an inch for some. If we manage to get some embedded thunderstorms, we may see some higher amounts up to a half inch. Although, confidence in that is quite low. Thus, enjoy this brief period of calm weather, as an active pattern continues throughout the midwest. Temperatures today will be in the mid-80s, thanks to some sun, cooling off into the 60s once again tonight. There will be a nice mix of clouds/sun through the day today, with more cloud cover moving in this evening and tonight. && .LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/... Issued at 249 AM CDT Wed Jul 3 2024 July 4th...Unfortunately, it looks like we will have the potential to see more showers and storms on Thursday, July 4th. Wave digs south towards the area through the day, with a weak leading wave passing through during the morning. The wave moving through that morning is the remnant wave from the prior night, which may bring light precipitation to the area. This will fade out through the day, leaving the focus on the deeper wave pushing towards us. Moisture return is relatively weak through much of the day, limiting the coverage until later in the day, when the deeper wave brings a bit more moisture into the area. Temperatures will be in the mid 80s through the day, with surface dew points increasing into the mid- upper 60s, yields upwards to 1000-2000 J/Kg CAPE. This will couple with 40-50+ KTs of shear, resulting in the potential for some strong to severe storms. Cold front is expected to come through that evening, which will be the focus for the strong storms. Thus, we should get through much of the day without much of a severe chance. Currently, the SPC highlights our area in a Marginal Risk (level 1/5) for severe weather. The overall confidence in the severe threat is low, as it will be conditional on how much instability we build through the day. So, the more sun that we get, the more instability we can build. Although, if we are left with clouds and showers/storms through much of the day, that will limit destabilization, along with the severe threat. Will watch this closely, but be prepared for the potential of a damp cookout! Friday...Longer range projections suggest upper low complex to meander eastward acrs WI, with cool pool aloft effects making for isolated to wdly sctrd instability showers possible acrs the area, especially north of I-80. Ambient cumulus, a few showers and the cool pool itself may keep temps in the 70s to around 80, so a below normal day for July. Saturday and Sunday...Medium range ensemble patterns hint at rather broad upper troffiness establishing or more accurately getting re- established acrs much of the upper midwest by another digging northern stream upper wave into the upper MS RVR Valley. Hopefully most of Saturday will be dry ahead of this incoming process with moderating temps back into the 80s. There may be a few showers and storms in the north Sat night, but as the upper trof axis slides overhead, Sunday afternoon and evening may be a better chance for isolated to sctrd showers and storms to occur. Seasonable temps in the low to mid 80s Sunday. Early next week...Upper jet and synoptic scale feature progs suggest the longer wave upper trof to linger and even deepen acrs much of the mid to upper MS RVR Valley this period. This would allow for wdly sctrd shower and storm development in the afternoon heating under this feature. The unorganized buoyancy pop up type precip warrants only low CHC POPs at this juncture in time. Near seasonable to somewhat below normal temps this period. && .AVIATION /18Z TAFS THROUGH 18Z THURSDAY/... Issued at 1248 PM CDT Wed Jul 3 2024 Generally a VFR TAF cycle, unless a light and variable sfc wind regime can allow for some MVFR fog getting into the VCNTY of a few sites. Also, there may be a low chance for some high based showers skirting acrs the BRL site out of northern MO tomorrow morning. Other than that, again expect just high clouds in varying degrees of opaqueness through the period with west winds this afternoon going light and variable tonight. Some southerly sfc wind pick up to 5-10 KTs by late Thu morning. && .HYDROLOGY... Issued at 1211 PM CDT Wed Jul 3 2024 The forecasts along the Mississippi River havn`t changed much from the previous ones, with many forecast points cresting into the weekend. Locations from Dubuque to Keokuk are still expected to crest over their respective Major Flood Stage levels. At Gregory Landing, a crest in the Moderate category is forecast. The crest is forecast near Dubuque and Bellevue on July 4th and 5th, with sites from Fulton to Keokuk seeing a crest between July 6th and 8th. On the Maquoketa at Manchester, the heavy rains and training thunderstorms to produce them did not materialize and shifted to the south of that basin. Thus it is no longer expected to reach the minor flood stage and the warning has been cancelled. Also with the rainfall amounts not being quite as high or widespread as earlier anticipated in some of the more northern basins, several tributary forecasts have been toned down some. Ongoing river flood watches and warnings on the Cedar, Iowa, Wapsi, Skunk, and Maquoketa Rivers have been adjusted accordingly to the rainfall reports from this morning. But with a few other areas indeed receiving torrential rainfall a bit further south, the river flood watches for the North Skunk River near Sigourney and English River at Kalona have been upgraded to river flood warnings. Current projections for additional rainfall over the next few days through the end of the week look more spotty with widespread heavy rain not likely. This should help maintain the current forecasts from deviating too much from the most recent forecasts. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...None. IL...None. MO...None. && $$ SHORT TERM...Gunkel LONG TERM...Gunkel/12 AVIATION...12 HYDROLOGY...12