Area Forecast Discussion
Issued by NWS Northern Indiana
Issued by NWS Northern Indiana
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472 FXUS63 KIWX 040558 AFDIWX Area Forecast Discussion National Weather Service Northern Indiana 158 AM EDT Thu Jul 4 2024 .KEY MESSAGES... - Chances for showers and thunderstorms remain in the forecast Thursday into Friday, best chances (40-60%) late Thursday night into Friday. Warm and humid with highs in the mid 80s. - Dry conditions and near normal temperatures for the weekend. Near normal temperatures look to stick around for much of next week (highs mid 80s, lows mid 60s) with sporadic, low chances for rain/storms. The best chances for rain/storms will be on Tuesday. && .DISCUSSION... Issued at 224 PM EDT Wed Jul 3 2024 Warm and humid conditions have returned as a warm front lifted north through the area overnight. A weak cold front is currently entering our area, with showers/storms possibly developing out ahead of it this afternoon and early evening. There is a Marginal Risk for severe weather (level 1 of 5) along and south of US 24. A few storms could be strong to severe, with damaging wind gusts and heavy rain as the primary threats. Storm coverage should be isolated to scattered at best. I would not be surprised if SPC chooses to pull the Marginal Risk entirely from our area as there is very low confidence in storms reaching severe criteria. Model guidance continues to trend with less instability (500-1000 MLCAPE) this afternoon, and low/mid level lapse rates are sub- par amidst only 20 to 30 knots of 0-6 km shear to work with. If the RAP is correct, there also could be an EML to work with this afternoon that caps any storm development. There are additional chances for rain/storms for the Fourth of July and again Friday. As a surface low lifts northeast across Missouri Thursday evening, the attendant warm front will lift north through our area. This could result in some rain/storm chances for Thursday evening, although I`ve kept the highest chances (30-40%) confined to along and south of US 30 for now. These PoPs will likely need adjusting in subsequent forecast updates as we get more certainty as to how far north the warm front gets. Should the boundary stall across our area, this would lead to lingering showers/clouds overnight Thursday into Friday morning. Friday`s rain/storm chances are conditional to what happens Thursday; should any clearing occur Friday morning, there would be chances for rain/storms to redevelop again late morning through the afternoon on Friday along a cold front. I would not be surprised if SPC adds us into a Marginal Risk on Friday given the favorable parameters for severe weather, especially on the NAM and NAMNST. Soundings midday Friday from the NAMNST depict an unstable environment with 2000+ J/kg MLCAPE, 40 kts of shear, and moderately steep low and mid level lapse rates. For the weekend, dry conditions, comfortable humidity, and cooler temperatures return! Saturday will be the cooler day of the weekend with highs in the mid 70s. Next week, the latest CPC outlook has near normal temperatures favored (which would mean highs in the low 80s, lows in the mid 60s), which is somewhat unusual for mid July. There has been a pretty consistent signal in model guidance the past few days that next week will be near normal for temperatures with sporadic, low chances for rain/storms. There are no consistent signals for high heat to return until possibly 10 to 14 days from now. && .AVIATION /06Z TAFS THROUGH 06Z FRIDAY/... Issued at 150 AM EDT Thu Jul 4 2024 VFR Conditions are expected at the TAF sites for a majority of the period, with the exception of brief dips to MVFR this morning with any BR that develops. Calm winds, low level moisture, and a mix of clearing/clouds led to areas of BR and patchy FG. Most of the visibilities at the moment are in the 2-6SM range where BR has developed, with isolated spots less than 2 miles. Most of the guidance keeps both KFWA/KSBN VFR, but there are a few suggesting around 4-5SM for KFWA later this morning. Held of for KSBN at the moment given no drops in visibility yet and the guidance all showing VFR/P6SM tonight-but wouldn`t be surprised if I had to add in later. Have a tempo in at KFWA from 10-13z. Otherwise, variable winds will shift south-southwest and increase slightly through the afternoon. There are chances for showers at both terminals in the afternoon, but the better confidence is at KFWA so have a prob30 in there from 19-23z, then becoming a prevailing group after 00z. KSBN is dry for now. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...None. OH...None. MI...None. MARINE...None. && $$ DISCUSSION...Johnson AVIATION...MCD