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
249 FXUS63 KDVN 121711 AFDDVN Area Forecast Discussion National Weather Service Quad Cities IA IL 1211 PM CDT Wed Jun 12 2024 .KEY MESSAGES... - Showers and storms chances increase by tonight and again on Thursday. Strong to severe storms possible especially Thursday. - Slight Risk (Level 2 of 5) for severe storms on Thursday south of I-80. - Unseasonably warm temperatures will advect into the area, especially today and on the upcoming weekend. Many will see temperatures approach or exceed 90. More humid conditions may result in excessive heat for some! && .SHORT TERM /THROUGH TONIGHT/... Issued at 313 AM CDT Wed Jun 12 2024 Today...South to southwesterly return flow to increase and continue to warm air advect(WAA) today, boosting thermal profiles to support high temps in the upper 80s to around 90 acrs much of the fcst area. Mixing and dry top soil to temporarily keep sfc DPTs from climbing much out of the lower 60s until later tonight. Thus heat index readings not much more than the ambient temp. Ridge-riding westerlies with embedded short wave aloft to make today`s unsettled convective region be the eastern Dakotas into MN, with some of this activity bleeding down acrs the MN/IA border region this afternoon. With fcst soundings suggesting the local area to be capped/EML affected, we may just get some elevated weakening debris into the northwest through 00z Thu. With convective temps by late afternoon being in the upper 80s to around 90, may still have to be on guard for an isolated blow up if the cap can`t quite hold in spots. Tonight...While the EML looks to maintain acrs the area, all convective support parameters continue off to the north and convective clusters to MCS`s should be ongoing acrs eastern MN and evolving acrs the north half of WI. MCS ensemble convective support parameters and steering lower level thermal ribbons may allow for a portion of the northern activity to propagate southward down acrs western IA and the MO RVR Valley in area of lesser EML impact. The WI activity should look to tail down toward southern LK MI and lower MI/northeast IL into Thu morning. Either some of this to make it acrs the local area mainly after midnight, or we could have elevated WAA-type sctrd showers/storms develop overhead aided by 30- 40 KT LLJ. Thus unless something changes drastically, it appears like a limited sever risk for the local area especially if the EML wins out. && .LONG TERM /THURSDAY THROUGH TUESDAY/... Issued at 313 AM CDT Wed Jun 12 2024 Thursday...If we have limited activity/staying elevated and decaying early out of Wed night, less convective debris and further north boundary placement may allow for a big CAPE build up with ambient temps in the upper 80s to low 90s, and conservative sfc DPTs in the upper 60s to around 70...SBCAPEs still 2000-4000+ J/kg by mid afternoon. Still some capping to overcome, but the higher sfc DPTs, forcing of the front squeezing southeastward, and digging short wave aloft could allow for strong developing convection overhead and along/north of the current day 2 Slight Risk. All severe parameters plus heavy rainfall could happen under this scenario, if the 1.8 to 2 inch PWATs pooling along the boundary verify for Thu. All in all, still much uncertainty for thermodynamic and kinematic set ups for a severe wx scenario to unfold, but Thu remains a day to watch indeed. Friday...Still looking like a decent summer day in the wake of what ever happens on Thursday, with backdoor high pressure and seasonable temps along with lowered humidity. Saturday through Tuesday...Thermal ridging trying to build from upstream and into the region could make Saturday a warming to above normal scenario. Sat night through the rest of the extended will be the continued battle of incoming thermal ridge and heat, with ridge- riding MCS storm track potential close by. Some 90s likely through this stretch, depending on storm debris or track lay out, but the blend again looks to gone overly aggressive with max temps and heat index readings into early next week. && .AVIATION /18Z TAFS THROUGH 18Z THURSDAY/... Issued at 1203 PM CDT Wed Jun 12 2024 VFR conditions will prevail through the TAF period, with some periods of MVFR vis possible late tonight. After 06z, a line of showers and storms are expected to pass through the area. These storms will mainly lead to brief downpours and frequent lightning, with lower vis resulting from stronger storms. Severe weather probability remains low, but small hail will be possible in stronger storms. Confidence on timing and spatial coverage remains low. Thus, we have opted to cover this with a PROB30 group for the time being. Storms should largely be out of the area shortly after 12z tomorrow. Winds will remain out of the southwest today and through the night, with some gusts upwards to 20 KTs possible at times. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...None. IL...None. MO...None. && $$ SHORT TERM...12 LONG TERM...12 AVIATION...Gunkel