237 FXUS63 KDVN 100508 AFDDVNArea Forecast Discussion National Weather Service Quad Cities IA IL 1208 AM CDT Fri Oct 10 2025
.KEY MESSAGES...
- Isolated/scattered showers (30-50%) and isolated storms will be possible late tonight. Light rainfall will be common (less than a tenth of an inch for most locations). Another chance of rain is possible Sunday night.
- Temperatures gradually warm up through Monday.
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.SHORT TERM /THROUGH SATURDAY/... Issued at 159 PM CDT Thu Oct 9 2025
Dry conditions will prevail for the remainder of the afternoon and evening hours today, thanks to abundant dry air over the region. The area of high pressure that has brought lots of sunshine over the last few days will continue to move off to the east, and a weak front will cross the area late tonight. Southerly return flow around the high has brought temperatures into the mid to upper 60s today, which is actually closer to average for this time of the year.
We continue to track a weak front progged to sweep through the area after midnight tonight through Friday morning. The main question continues to be how much rainfall will result from this front as there is plenty of dry air in place (seen in the 09.12z HREF ensemble soundings). The column appears to saturate via top-down saturation processes, but even if we get sufficient depth to the moisture, we quickly dry out aloft, so thinking rainfall will remain limited. Most locations will probably see at least measurable rain, so we have boosted PoPs slightly to the 30 to 50% range, which falls more in line with the HREF 1-hr probabilities of 0.01" or more of rainfall. The HREF ensemble probability matched-mean (PMM) QPF fields suggest less than a tenth of an inch for most of the region. However, higher amounts remain possible, especially for areas south of Highway 34 where Pwats (1 to 1.2 inches) and instability (nearly 500 J/kg of MUCAPE) appear to be their highest. Any locations that see thunderstorms will see the most rainfall with this front (up to around a quarter inch of rain possible per the HREF PMM QPF).
Chances of rain will continue into the late morning/early afternoon hours Friday across the southeastern CWA before tapering off, leading to a pleasant afternoon. High temperatures look to warm into the lower to middle 70s, warmest where skies clear out and daytime heating increases over the northwestern CWA.
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.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... Issued at 159 PM CDT Thu Oct 9 2025
Friday night through Sunday: the aforementioned front that will move through late tonight and Friday will be well out of the area by Friday night, leading to a period of dry and quiet conditions as high pressure develops in its wake. Friday night should be another cool night, but frost potential appears unlikely given less than 10% chance of overnight lows below 40 degrees F per the latest LREF. Still, Friday night lows should dip to the lower to middle 40s for most. Temperatures will remain seasonal on Saturday, with mostly sunny skies, as highs warm to the upper 60s to near 70. Temperatures look to warm up slightly for Sunday as winds turn more southeasterly, warming to the lower to middle 70s. Sunday will be a day to keep an eye on for some elevated fire danger potential as the southeast winds look to strengthen as surface pressure gradient tightens. NBM maximum wind gust potential on Sunday appears to be around 25 to 35 mph, so we`ll need to keep an eye on this.
Sunday night through Wednesday: a more active pattern looks to develop as a longwave upper trough builds over the Pacific Northwest. Ahead of the trough, the remnant moisture of what is presently Tropical Storm Priscilla will be lapped up and advect northeastward over the Corn Belt. This moisture should result in another round of showers and an isolated storm (20-40% chance) possible Sunday night into Monday. Pwats should be a bit higher with the tropical moisture as the ECMWF ensemble climatological percentiles reach over 90%, but still dry air in place could help to limit amounts. Another chance of rain is possible for Wednesday.
Monday looks to be the warmest day of this stretch, with highs in the middle 70s to near 80.
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.AVIATION /06Z TAFS THROUGH 06Z SATURDAY/... Issued at 1204 AM CDT Fri Oct 10 2025
Southerly flow will continue overnight with a band of showers and a few brief thunderstorms moving through between midnight and 9 AM Saturday. All of these will be brief, and any rainfall may be moderate to heavy, but only last a couple minutes, thus with a scattered nature, I`ve kept the Prob30 group going in all sites through the 13-14Z time frame as this band of shower/storms moves from northwest to southeast. Following this band of activity, a cold front will arrive with no further rainfall later this afternoon, shifting winds to northwest for late afternoon through Saturday night.
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.DVN WATCHES/WARNINGS/ADVISORIES... IA...None. IL...None. MO...None.
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SHORT TERM...Schultz LONG TERM...Schultz AVIATION...Ervin
NWS DVN Office Area Forecast Discussion