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
625 FXUS63 KDVN 280549 AFDDVN Area Forecast Discussion National Weather Service Quad Cities IA IL 1249 AM CDT Sun Apr 28 2024 .KEY MESSAGES... - Active period continues into the overnight and also into Sunday. - Flash flooding remains a concern overnight into Sunday morning for areas that will have received repeated rounds of storms south of I-80, and this is where a Flood Watch continues. - Scattered severe weather remains possible, mainly well south of I-80 overnight, but also into Sunday although prior convection may have an impact on the magnitude/timing/location of severe weather Sunday PM. - Unsettled weather continues through next week, with periodic rain chances. && .SHORT TERM /THROUGH MONDAY/... Issued at 140 PM CDT Sat Apr 27 2024 Late morning surface analysis shows a surface low centered across eastern Minnesota and western Wisconsin, with a cold front draped to its south across east central Iowa and northwest Missouri. Off to our southwest, another surface low with a warm front and dry line was centered over the Oklahoma panhandle, with storms ongoing along this and ahead of a shortwave in the same location. This shortwave will progress northeast over the next few hours, and will be the driver of our weather over the next couple of hours. The overall forecast remains on track for the area, with shower and storm coverage expected to increase over the next few hours. The first round should be focused along the stalled cold front draped across east central Iowa as we destabilize and reach our convective temperature in the upper 70s. Latest CAMs focus the threat mainly along and northwest of the HWY 151 corridor. Ample 0-6km shear and steep mid-level lapse rates pushing CAPEs around 1000-2000 J/kg may lead to storms capable of large hail initially. The second round of storms will come this evening as the aforementioned shortwave rides the front and drives additional lift across the area. A renewed LLJ will also ensure ample lift and increased vertical shear. There remains some uncertainty as to where storms will initiate and track, which is likely tied to early PM convection and how much it stabilizes that warm sector air in eastern Iowa. Regardless, HREF ensembles continue to paint areas mainly south of Interstate 80 with high POPs. Severe storms will also be possible with mainly a large hail and damaging wind threat with near straight hodographs and cold pool dynamics in play. While low, can`t rule out a tornado threat in the QLCS and with any remnant boundaries from early PM storms. Look for this threat to wane by midnight, with concerns turning more towards a heavy rain/flash flood risk. Speaking of which, we will need to keep a close eye on flash flooding potential with these storms. LLJ will advect in a rather robust PWAT feed across the region with values approaching 1.75" by midnight. Where storms do train, latest CAMs show QPF by Sunday morning approaching 2-4 inches. This looks to be favored mainly in southeast Iowa, west central Illinois and northeast Missouri, where a Flood Watch is now in effect through Sunday morning. Heading into Sunday, scattered showers and storms will persist through the morning and early afternoon, with a renewed round of more widespread linear showers and storms expected by the evening ahead of another robust shortwave ejecting out of the Rockies. There is potential for this activity to become severe, with the Storm Predication Center advertising a Level 1 to 2 risk for the area. The primary threats with storms will be damaging winds and large hail, with a secondary tornado threat if low-level shear can materialize. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... Issued at 140 PM CDT Sat Apr 27 2024 Post cold front passage, we will be in for a dry start to the week with high pressure moving across the central Plains and mid-Mississippi River Valley. By mid to late week, a renewed round of showers and storms is expected for the area as a trough in the Rockies ejects several shortwaves across the Plains and Midwest. && .AVIATION /06Z TAFS THROUGH 06Z MONDAY/... Issued at 1243 AM CDT Sun Apr 28 2024 Showers and storms will continue through the night and Sunday, resulting in periods of MVFR to IFR conditions. Some locations are currently seeing VFR, but we will see these conditions frequently changing through the night. In heavier showers and storms, cigs may drop between 1000-3000 ft, with vis between 3-5 SM. Winds will remain light and out of the southeast tonight, increasing through the morning. After 12z, cigs are forecast to plummet to below 1000 ft at CID and DBQ. Currently, we are forecasting cigs between 700-900 ft, but some brief periods lower than that are possible. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...Flood Watch until 10 AM CDT this morning for IAZ087>089-098- 099. IL...Flood Watch until 10 AM CDT this morning for ILZ025-026-034- 035. MO...Flood Watch until 10 AM CDT this morning for MOZ009-010. && $$ SHORT TERM...Friedlein LONG TERM...Speck AVIATION...Gunkel