Area Forecast Discussion
Issued by NWS Central Illinois
Issued by NWS Central Illinois
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
47
48
49
50
876 FXUS63 KILX 310108 AFDILX Area Forecast Discussion...Updated National Weather Service Lincoln IL 808 PM CDT Thu May 30 2024 .KEY MESSAGES... - Showers and thunderstorms return to the forecast Friday night into Saturday (70-80 percent chance). Severe storms are not expected but there is around a 30 percent chance for some areas to see over an inch of rain. - Additional showers and storms are expected Monday through Wednesday of next week. && .UPDATE... Issued at 808 PM CDT Thu May 30 2024 Light but persistent easterly flow has brought quite the dewpoint gradient to central IL, ranging from the upper 30s at Bloomington and Danville to the lower 50s in west central IL. Convective debris high clouds well east of a north-south oriented thunderstorm complex stretched across western IA and eastern KS, will thicken somewhat overnight. This will keep lows a few degrees warmer than last night, mainly in the mid 50s. 25 && .DISCUSSION... Issued at 152 PM CDT Thu May 30 2024 This afternoon, high pressure is centered over the western Great Lakes with ridging extending across east central Illinois and to the lower Mississippi Valley. To our west, troughing stretches across much of the Great Plains. In the near term, fair weather will continue across central Illinois under the influence of the ridge. As the ridge shifts to our east Friday, S/SW flow will overspread central Illinois. A favorable fetch off of the Gulf of Mexico will advect higher dewpoints towards central Illinois. While this will be partially offset Friday by deep mixing into dry mid levels, dew points will eventually build back into the 60s over the weekend. Meanwhile, a shortwave trough is progged to push across central Illinois Friday night into Saturday. This will bring the next chance for showers and thunderstorms to the area. Given the unfavorable diurnal timing of the wave, instability will be weak (around 200-300 J/kg MUCAPE) and elevated, rooted generally between 700-900mb. Severe storms are not expected due to these conditions, but locally heavy rain appears possible. PWats are expected to increase to around 1.6 inches and the slow moving upper level disturbance and weak flow aloft in the vicinity of the wave will result in slower storm motions. HREF LPMM (which only covers through 12Z Saturday) shows a narrow swath of 1.5-2.0 inches of rain. NBM 90th percentile shows similar values across the area through Saturday evening. Behind the departing wave, ridging will briefly build back across central Illinois Sunday providing a break in the rain chances most of the day. Warm and humid conditions are expected instead with highs in the lower 80s and dew points in the lower to mid 60s. An initially zonal upper pattern early next week will gradually give wave to digging trough evolving into a closed upper low by midweek. There will be some chances for showers and storms Monday and Tuesday as low amplitude waves move through the zonal flow, but precip chances continue Wednesday as the closed upper low digs into the Upper Midwest. Forecast PoPs are a bit broad brushed Monday through Wednesday owing to timing differences in the models, and anticipate plenty of dry hours on those days despite the persistent chance PoPs. In addition, the midweek system could be accompanied by an increase in shear and instability so wouldn`t rule out some severe weather potential somewhere in the region, though at this distance plenty can change. Deubelbeiss && .AVIATION... (For the 00z TAFs through 00z Friday Evening) Issued at 608 PM CDT Thu May 30 2024 Another round of VFR TAFs with scattered cirrus tonight and scattered cu Friday late morning to afternoon. Light east winds tonight veer southeast by mid-morning and gust to around 20 kt. 25 && .ILX WATCHES/WARNINGS/ADVISORIES... None. && $$