Area Forecast Discussion
Issued by NWS Quad Cities, IA IL
Issued by NWS Quad Cities, IA IL
Versions:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
882 FXUS63 KDVN 290537 AFDDVN Area Forecast Discussion National Weather Service Quad Cities IA IL 1237 AM CDT Mon Apr 29 2024 .KEY MESSAGES... - Isolated shower chances continue into tonight. There could be a few storms, but the potential continues to decrease due to limited instability. - Active forecast remains through the long term, with near daily chances for precipitation after Monday. - Temperatures will remain above normal through midweek, trending towards normal for the end of the week. && .SHORT TERM /THROUGH TUESDAY/... Issued at 140 PM CDT Sun Apr 28 2024 Early afternoon surface analysis showed an area of low pressure centered across the Iowa/Missouri border, with a near stationary front extending out to its east along the Hwy 20 corridor. A cold front extended south of the low, and stretched from southeast Nebraska into central Oklahoma. This surface low was ahead of a robust upper level low over the Nebraska Panhandle, with a trough extending to its south. Across our area, widespread rain showers have waned early this afternoon as the LLJ to our south has weakened. Partly to mostly cloudy skies remain in place with temperatures in the 60s to low 70s. Through this evening, the surface low will lift to the northeast, bringing the cold front across the region. This cold front and a jet streak associated with the upper level low will act as the forcing mechanisms for renewed shower and storm development across much of the region. There is some potential for storms to be strong, but the overall threat for severe weather has trended lower thanks to the morning rain showers and persistent clouds over the area. That being said, our area does remain in Level 1 (marginal) risk of severe thunderstorms, mainly due to the strong jet dynamics with this system. If we do see severe storms, the primary threats will be severe winds and hail, with tornadoes being the secondary threat. An additional quarter to three quarters of an inch of rain is expected from showers and storms, with the later favored mainly along and east of the Mississippi River. This rain will have potential to prolong or worsen ongoing tributary river flooding. Please see the hydro discussion below for additional details. Leftover showers and storms will exit the area Monday morning, with more clouds than sun expected for the remainder of the day. Some breaks of sun may be seen along and south of Interstate 80 during the late morning and afternoon. Temperatures will be cooler with lower humidities, with highs in the 60s. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... Issued at 140 PM CDT Sun Apr 28 2024 Another period of active weather is expected across the Midwest as a deep trough setting up across the Rockies ejects several shortwaves over the area. Tuesday looks to start dry with increasing shower and storm chances by the late afternoon and evening as a weak cold front and vort max approach from the west. Guidance is in good agreement of this being a quick mover, with all precip out of the area by early Wednesday morning. At this time, severe storms are favored to remain west of the area. Late in the week, the aforementioned deep trough will progress out of the Rockies into the Plains and Midwest, bringing yet another round of showers and storms to the area. As the previous discussion eluded to, this will be the one to watch as it will be accompanied by abundant Gulf moisture and forcing. Details on the severe threat aren`t clear at this time, but there is potential for this system to produce heavy rain. Please continue to monitor the latest forecast information over the coming days. && .AVIATION /06Z TAFS THROUGH 06Z TUESDAY/... Issued at 1237 AM CDT Mon Apr 29 2024 VFR to MVFR conditions are being seen throughout, but will continue to trend all VFR by 12z. Spotty showers are being seen, but we are not expecting much of an impact from these. BRL will be the terminal that sees more of an impact, as they are along an area of stratiform rain, with lower cigs. Winds will remain out of the south tonight, shifting southwesterly and gusting upwards to 25 KTs by 18z. Cloud cover will start to decrease through the day as well. && .HYDROLOGY... Issued at 1124 AM CDT Sun Apr 28 2024 Several tributary rivers are now over flood stage in our southern portions of the CWA due to last night`s 1-2 inch rainfall on top of moist soil conditions and already elevated river stages. Other rivers will see significant in-bank rises to action stage, to the north of this rainfall swath. The rates of rainfall last night were initially very heavy, but the QPF was split from this heavy first 1" to a more conservative 0.20/ hr rate that fell the rest of the night. Thus, the rises may be more steady, rather than sharply felt this morning following the first few hours of rapid rises observed early today. La Moine River near Colmar... This river is above flood stage, and rising steadily today. Forecast rises to the upper end of moderate flooding is forecast by the RFC...and that could have a chance on exceeding the Major flood threshold of 24 feet Wednesday. This forecast is the one to watch most closely over the next 24 hours. Fox River near Wayland... The Fox saw the heaviest QPF upstream, but already seems be slowing it`s rise, near 16ft. A forecast of moderate flooding is in place cresting near 19ft late tonight/early Monday. The Pecatonica at Freeport and Rock River from Moline through Joslin... Rise to action stage are forecast by the end of the work week. Skunk River at Augusta... Another site that saw very heavy qpf fall in this basin, over 2 inches in some cases. The stage is rising rapidly this morning, a bit faster than modeled. Though it will be watched carefully, it appears likely to top out shy of flood stage Wednesday. This is the 2nd most needed to be watched carefully through tomorrow, and could potentially lead to a minor flood warning. Heavy rains remain possible later this week again as forecast by WPC. The timing of this rain would fall just past the crest on most active tributary rivers, and near the crest or just prior on the Rock River. Keep a general awareness of rivers in the week ahead, as this wet pattern continues to evolve. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...None. IL...None. MO...None. && $$ SHORT TERM...Speck LONG TERM...Speck AVIATION...Gunkel HYDROLOGY...Ervin