Area Forecast Discussion
Issued by NWS Quad Cities, IA IL
Issued by NWS Quad Cities, IA IL
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189 FXUS63 KDVN 151730 AFDDVN Area Forecast Discussion National Weather Service Quad Cities IA IL 1230 PM CDT Sun Sep 15 2024 .KEY MESSAGES... - Mainly dry with a continuation of late summer warmth (highs 5-10+ degrees above normal) for much of the week ahead. - Low chance (15-25%) for showers/storms again later today into early evening. - Low confidence with rain prospects and timing heading into next weekend. && .SHORT TERM /THROUGH TONIGHT/... Issued at 245 AM CDT Sun Sep 15 2024 The weather pattern remains stagnant due to an upper level Rex Block to our east, formed by eastern Great Lakes to Mid- Atlantic ridging and weakening remnants of TC Francine over portions of the Mid-South. Meanwhile, south to southwest flow prevails aloft across the region with upper troughing along the West Coast. A moisture axis (PWATs around 1.5+ inches) lingers across the region on the western periphery of the Great Lakes ridge, and may once again foster isolated/widely scattered convection later today into early evening with aid of convective temps (mid 80s) being breached and weak mid level vorticity advection. These low rain chances (15-25%) would appear to favor near and especially west of the Mississippi River within a mid level theta-e gradient. Severe weather is not expected, but there could be some gusty winds. With more solar insolation today and little change thermally I would anticipate similar highs to those of Saturday or even a bit warmer in some areas, with more widespread mid/upper 80s and even a couple sites possibly touching 90 degrees yet again. Any convection should gradually diminish with sunset, leaving behind mainly clear to partly cloudy skies. Slightly drier air advection on light easterly winds and good radiational cooling should get lows down into the range of 60-65 with a few upper 50s possible. && .LONG TERM /MONDAY THROUGH SATURDAY/... Issued at 245 AM CDT Sun Sep 15 2024 Not seeing a whole lot of change in the pattern throughout the week ahead, as we continue to see a blocky pattern to our east with a Rex Block lingering early in the week that will keep ridging influence over the region. That said, isolated diurnally driven convection can`t be totally ruled out, particularly again on Monday PM west of the Mississippi River within the residual mid level theta-e gradient. Beyond, another warm core low (potential tropical cyclone formation) is expected to develop off the Mid-Atlantic coast. This will reinforce the Rex Block and keep the pattern stagnant, with mainly dry and summer warmth conditions heading into late week. There is some potential for the Rex Block to break down by next weekend, which would allow for rain chances to return as a western trough makes inroads. However, confidence is low on just when rain chances may make a return due to 1) blocky nature of the pattern and uncertainties on when it will break down and 2) indications of a more meridional jet configuration ahead of an ejecting waves from the western trough, which would tend to favor more widespread precipitation staying well to our west and decaying/weakening further eastward toward our area being under the influence of more subsidence. && .AVIATION /18Z TAFS THROUGH 18Z MONDAY/... Issued at 1227 PM CDT Sun Sep 15 2024 Diurnal convection is again expected through 01z/16 across mainly eastern and southeast Iowa. No SHRA/TSRA were included in the 18z TAFs as the probability of a TAF site being impacted is 5 percent at best. Another round of even more isolated SHRA/TSRA is expected after 18z/16 in southeast Iowa. Otherwise VFR conditions will continue. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...None. IL...None. MO...None. && $$ SHORT TERM...McClure LONG TERM...McClure AVIATION...08