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
45
46
426 FXUS63 KDVN 100823 AFDDVN Area Forecast Discussion National Weather Service Quad Cities IA IL 323 AM CDT Fri May 10 2024 .KEY MESSAGES... - Gusty winds are possible in scattered showers and isolated thunderstorms late this evening and tonight (Friday night). - Warm weather is expected on Sunday with highs near 80 F! - The wet pattern will continue with occasional chances for showers and storms from Sunday into Tuesday AM. There may be a break in the rain later Tuesday through Wednesday before the next system arrives late next week. && .SHORT TERM /THROUGH TONIGHT/... Issued at 300 AM CDT Fri May 10 2024 Early This Morning: GOES nighttime microphysics imagery showed an area of low clouds covering most of eastern Iowa and northwest Illinois, coincident with a sharp SW to NE oriented 500mb trough axis across the local area. Radar trends continue to show isolated (less than 20% coverage) shower activity in the outlook area, slowly drifting from north to south. Much of the area will stay dry into early this morning, but a few locations could receive a brief period of light to moderate rain. Light winds and low dewpoint depressions may result in areas of shallow fog where skies clear out. Mid Morning through Afternoon: A shortwave trough extending from the western Great Lakes into Illinois and Iowa will shift into the Ohio Valley by early to mid morning, taking any lingering isolated showers with it. Seasonable temps are expected today with afternoon highs near 70F. This Evening and Tonight: Another shortwave trough and associated cold front will drop in from the NW, kicking off scattered showers and possibly a few thunderstorms mainly between 7 PM - midnight. A few of the showers/storms could produce gusty winds over 40 mph. The late timing of the front should limit the wind gust potential and models are showing minimal MLCAPE (few hundred J/kg) across the outlook area by tonight. Skies will quickly clear from NW to SE between about 10 PM - 1 AM, giving us a chance to see the Northern Lights (Aurora)! && .LONG TERM /SATURDAY THROUGH THURSDAY/... Issued at 300 AM CDT Fri May 10 2024 Saturday: A nice day is expected with breezy NW winds and highs near 70 F. Sunday: Low pressure passing across Minnesota and Wisconsin will pull warm and more moist air northward into the local area with forecast highs in the upper 70s to lower 80s. However, surface dewpoints holding in the 50s will limit instability to near 1000 J/kg (MLCAPE) or less during the afternoon/evening, and deep layer shear looks low too. For these reason, do not anticipate severe weather but scattered showers and storms could develop during peak heating and last into Sunday night. Monday: A cut-off upper low is forecast to track from the Four Corners region through the Lower to Mid Mississippi Valley early in the week. Model consensus keeps the local area on the cool northern side of this system, which would limit the severe potential and could lead to colder highs than currently forecast. The latest NBM has max temps close to 70 F and the highest rain chances south of I-80 (60-80%). Tuesday On: There is uncertainty on how fast the rain moves out with most of the models lingering it across the south through Tuesday morning. Generally, we`ll be looking at a more tranquil pattern later Tuesday into Wednesday as a backdoor cold front advects in a cooler and drier air mass from the NE. NBM highs may be too warm for Wednesday, and latest trends in the deterministic models is to delay the next round of showers and storms until Wednesday night into Thursday. && .AVIATION /06Z TAFS THROUGH 06Z SATURDAY/... Issued at 1258 AM CDT Fri May 10 2024 Scattered slow moving showers are expected overnight, mainly at DBQ and BRL, as an upper low drifts across the area. This will lead to periods of MVFR ceilings into Friday morning. A return to VFR is expected mid to late Friday AM with winds increasing out of the west. A cold front may bring another round of scattered showers and storms late Friday evening/Friday night; held off on mentioning in the TAFs due to low confidence on coverage. && .HYDROLOGY... Issued at 846 PM CDT Thu May 9 2024 Changes... The flood watch for the Wapsipinicon River near De Witt has been changed to a flood warning. Discussion:Active period again with periodic rounds of showers and thunderstorms as another deep trough comes out of the Rockies and into the middle of the country. However, way too early to determine severe threats or rainfall amounts. Highs will be well into the 70s to around 80. The Cedar, Iowa and Wapsipinicon Rivers continue to rise as a result of the rainfall over the past 30 hours. The forecast for De Witt has not changed much over the past 24 hours, thus confidence has increased that it will reach flood stage within the next 24 hours. The overall situation with the Cedar and Iowa Rivers is more uncertain. While there is a better accounting of the overall runoff compared to 24 hours ago, the forecast for Marengo on the Iowa river is just barely above flood stage. Since the flood crest will gradually attenuate due to gravity as it moves downstream, there is a 30 to 40 percent chance that the crest at Marengo may occur just below flood stage. On the Cedar River near Conesville the flood crest will also attenuate as it moves downstream. However, the crest is further above flood stage which means there is a 50 percent chance of reaching flood stage. Rainfall over the next 72 hours and where it occurs will be the deciding factor as to whether or not the Cedar and Iowa Rivers will reach flood stage near Conesville and at Marengo respectively. If the rainfall is lighter than expected then river forecasts may be lowered. However, if rainfall is heavier than expected then river forecasts may be raised. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...None. IL...None. MO...None. && $$ SHORT TERM...Uttech LONG TERM...Uttech AVIATION...Uttech HYDROLOGY...8