Area Forecast Discussion
Issued by NWS Northern Indiana
Issued by NWS Northern Indiana
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
581 FXUS63 KIWX 051025 AFDIWX Area Forecast Discussion National Weather Service Northern Indiana 625 AM EDT Wed Jun 5 2024 .KEY MESSAGES... - There is a marginal risk of severe thunderstorms this afternoon and evening, primarily along and east of I-69. - Warm and humid conditions today give way to cooler than-normal temperatures for much of the next seven days. && .DISCUSSION... Issued at 232 AM EDT Wed Jun 5 2024 A cold front approaching the Mississippi River this morning will bring a marginal risk of severe thunderstorms in the afternoon and evening along and east of I-69 (generally speaking). Damaging wind gusts are the primary concern, followed by heavy rainfall and hail. The timing of these storms remains about 2pm to 8pm EDT. Showers and thunderstorms are ongoing over northwest Indiana early this morning, associated with a MCV lifting in from Illinois, aided further by a strengthening 850-mb jet. Heavy rainfall and perhaps strong wind gusts near 40 mph are possible (as reported over northeast IL). Elsewhere in the forecast area will be untouched by the time the cold front arrives in the afternoon. Temperatures rising in the 80s with dew points near 70 degrees will permit impressive CAPE ahead of the cold front while shear and lapse rates are lacking (25 knots 0-6km and 6C/KM mid-level, respectively). Coverage of storms along the cold front varies among model guidance, likely due to the marginal environment, but guidance favors discrete cells in our area perhaps congealing into a line across central Ohio. Drying out for a time early in the night behind the cold front but a a few showers may arrive later on associated with a screaming, 85- knot jet at 500mb. Moisture transport from the Pacific is somewhat poor, navigating significantly poleward atop a towering ridge over the Four Corners before spilling over the Great Lakes. However, RH remains elevated in the column through Friday, warranting at least slight chance POPs at times as various embedded vorticity maximums rotated around the closed low aloft. Temperature-wise, Friday looks to be the coolest of the next seven with highs right near 70 following two distinct waves of CAA. This upper-level low lingers over the (eastern) Great Lakes into at least the start of next week, if not longer. This complicates the forecast as models do not handle cut-off lows very well. Overall, showers at times are probable paired with cooler-than-normal temperatures for June. && .AVIATION /12Z TAFS THROUGH 12Z THURSDAY/... Issued at 624 AM EDT Wed Jun 5 2024 A trailing pre-frontal outflow has settled into nw IN and central IL behind a well defined MCV tracking into western MI. Ongoing moisture advection, and the approach of another convectively aided wave over western IL, should bring a round of showers/storms mid morning through early afternoon at KSBN. Remnants of this activity and growing diurnal instability should also allow for scattered convection to eventually impact KFWA, best chances 18-21z. Flight conditions should hover between MVFR and VFR for the bulk of the morning and early afternoon before a cold front sweeps through late in the day with quiet/cooler wx to follow into tonight. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...None. OH...None. MI...None. MARINE...None. && $$ DISCUSSION...Brown AVIATION...Steinwedel