


Area Forecast Discussion
Issued by NWS Indianapolis, IN
Issued by NWS Indianapolis, IN
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
077 FXUS63 KIND 111806 AFDIND Area Forecast Discussion National Weather Service Indianapolis IN 206 PM EDT Mon Aug 11 2025 .KEY MESSAGES... - Isolated storms ending early evening. Locally heavy rain is possible - Isolated/scattered storms Tuesday and Wednesday - Muggy conditions to persist; Potential for heat index values to near or exceed 100 this weekend && .SHORT TERM (This evening through Tuesday)... Issued at 206 PM EDT Mon Aug 11 2025 Rest of This Afternoon... Some convection has developed along an area of convergence in west central Indiana (which could be an old boundary). Meanwhile additional convection is developing farther north, where deeper moisture exists. Weak winds through the atmosphere will bring slow storm motions and the potential for locally heavy rain. The lack of shear will keep the threat for severe convection low, but collapsing storms could bring some gusty winds. Will continue to monitor coverage of storms and expand the low PoPs as needed. Otherwise, very warm and humid conditions will persist. Tonight... Convection should be gone or nearly so by the start of the tonight period due to loss of heating, so will only have some slight chance PoPs early in the period. These will be across the northwest forecast area where the deeper moisture will continue. Some patchy ground fog will be possible again overnight as skies become clear to mostly clear. Lows will be around 70. Tuesday... An upper trough will approach the area on Tuesday, bringing an increase in forcing to the northwestern half of the forecast area. Meanwhile, a surge of moisture and weak forcing will rotate into the area around an upper high. These will allow scattered convection to develop, especially during the afternoon. Will have chance PoPs most areas. Lack of shear will once again mean that locally heavy rain will be the main threat. Even with the scattered convection developing, high temperatures should still reach around 90 degrees. && .LONG TERM (Tuesday night through Monday)... Issued at 206 PM EDT Mon Aug 11 2025 The long term will start off near seasonal with the passage of an elongated mid level trough and subsequent weak surface boundary. This should lead to extensive cloud cover with scattered showers and thunderstorms Tuesday night into Wednesday morning. Additional showers and storms are possible Wednesday, but they should be centralized along the boundary of which should be generally located south of the I-70 corridor. For a brief period behind the boundary, dew points should drop into the mid 60s with temperatures around 85-87. However, conditions shift back towards oppressive, with the return of moderate WAA within SW flow. By Friday, temperatures should exceed 90 once again with dew points back in the low 70s. Sunday could be our warmest day of the long term as the thermal ridge axis nears and dew points remain elevated. This combination will likely lead to HI values near to possible above 100, and will be monitored throughout the week for possible heat related headlines. Week 2 onwards becomes a bit murky, mostly due to the entrance of a deep warm core low from the Atlantic. This will likely bottle up the overall pattern, keeping central Indiana under above seasonal temperatures. That said, confidence in and specifics regarding rainfall are very low as of this issuance, with at minimum slight chances existing from Monday through the middle of next week. && .AVIATION (18Z TAF Issuance)... Issued at 102 PM EDT Mon Aug 11 2025 Impacts: - Patchy fog cannot be ruled out again tonight, especially at KBMG - Low chances for convection, mainly at KLAF Discussion: An isolated shower or storm is possible this afternoon, mainly near KLAF. However, odds are too low to mention in the TAF. Additional isolated to scattered convection will develop on Tuesday, but again odds are too low to include, especially that far out in the forecast. Scattered to perhaps broken VFR cumulus will continue into early evening before dissipating. More scattered to broken cumulus will develop again on Tuesday. Some mid cloud will also be around at times, especially near KLAF. Some patchy ground fog may develop overnight. && .IND WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...50 LONG TERM...Updike AVIATION...50