Area Forecast Discussion
Issued by NWS Northern Indiana
Issued by NWS Northern Indiana
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923 FXUS63 KIWX 061451 AFDIWX Area Forecast Discussion National Weather Service Northern Indiana 1051 AM EDT Sun Oct 6 2024 .KEY MESSAGES... * Elevated fire risk for brush and field fires this afternoon due to dry, mild and windy conditions. Pockets of Red Flag conditions are possible late this afternoon. * Dry pattern continues into the upcoming work week. * Warm conditions continue today followed by cooler (near normal) temperatures for Monday to Wednesday. Temperatures warm again to above normal late work week into next weekend. && .DISCUSSION... Issued at 340 AM EDT Sun Oct 6 2024 For today...Strong upper level short wave will continue to track across northern Wisconsin into northern Lower Michigan this morning. Pre-frontal shower development has been a struggle as a warm 800-700 mb layer associated with an elevated mixed layer has limited extent of instability realized. Any potential isolated shower would be very high based in this setup, and high based nature would likely limit coverage/intensity of any development. May keep just some slight chance PoPs across southern Lower MI for a few hours early this morning. Sfc cold front at 07Z extends from far SE Wisconsin into west central Illinois. This front will be progressive through midday and likely to shift east of far NE Indiana/NW Ohio Counties after 17Z. Favored diurnal timing for convection developing along this front still appears to be well east of the local area into eastern Ohio and will continue with a dry forecast. Despite the early frontal passage today, deep post frontal mixing should delay temp drops a bit behind the front. Some lower 80s are possible briefly across far northeast Indiana/NW Ohio south of US-24 before stronger cold advection takes over later in the afternoon. Intrusion of stratospheric air into the mid troposphere on western flank of aforementioned Great Lakes upper trough and low/mid level subsidence should act to enhance the post-frontal dry air advection today leading to fire weather concerns. Still some question into extreme northeast Indiana and northwest Ohio on timing of the sharper dew point drops, and some limited moisture recovery of low level dew points could occur downwind of Lake Michigan. However, most of the area does appear to drop to afternoon min RH`s of 20-30 percent this afternoon leading to an elevated fire risk in terms of the potential of brush and field fires when combined with strong post-frontal wind gusts to around 30 mph. More details on the fire weather forecast for this afternoon can be found in the fire weather section below. For tonight,,,wind gusts subside this evening but continued cold advection overnight will allow some degree of low level mixing to continue. This should prevent temps from bottoming out more than the mid 40s. Some patchy stratocu is possible also, particularly across northern half of the area more entrenched in low level thermal trough. For Monday through Wednesday...subtle mid level height rises and core of low level thermal trough shifting into the eastern Great Lakes should provide near normal/slightly below normal temperatures. Despite cooler temperatures this period, airmass will remain quite dry with low afternoon min RH values. Winds during this period should be on the light side however due to expansive low level anticyclone from the Great Lakes to the Ohio Valley. This should limit extent of fire weather concerns for this period. For Friday into next weekend...medium range guidance continues to indicate this period characterized by better progression of central CONUS mid/upper ridging, This leads to continued high confidence in warming trend back to above normal levels. Depending on timing of this evolution, may need to further adjust temps up Friday/Saturday with a potential of some low-mid 80s high temperatures during this period. Of lower confidence is any additional precip chances next weekend. Some indication of an upper short wave dampening with ridge with potential fropa, but will continue to hold off on mentionable PoPs late this period due to a large deterministic/ensemble spread. && .AVIATION /12Z TAFS THROUGH 12Z MONDAY/... Issued at 624 AM EDT Sun Oct 6 2024 A low pressure system is expected to push a cold front through the area this morning, but the front is expected to be dry. The airmass behind the front is even drier still and this should allow for prevailing VFR conditions through the TAF period. With the strong gradient along the front and sunny skies allowing for mixing, expect gusty winds between 25 and 30 kts during the day today. Initially southerly and southwesterly winds become more northwesterly behind the front. && .FIRE WEATHER... Issued at 1028 AM EDT Sun Oct 6 2024 BLUF: Regardless of the issuance (or lack of) any Red Flag warnings this afternoon, burning activities should be postponed and harvest operations should use extreme caution. Lots of coordination has taken place over the past couple of hours regarding concerns for Red Flag Warning criteria being met. A very difficult call to hoist in portions of the area as concerns for 1) 3 hour duration not being met, 2) 10 hour fuels near or just above thresholds and 3) degree of mixing of dewpoints this afternoon. GRR and DTX have hoisted RFWs with GRR up against our area in swath of strongest low RH signals as well as based on land management officials. Cold front was located from west of Coldwater, MI to near out office and southeast to Monticello. 10 to 15 degree drop in dewpoints has been fairly consistent showing after fropa. The lower mid to upr 30 dewpoints are advancing into NW IL and across WI and should arrive by mid afternoon. HRRR continues show a narrow swath of increased mixing of dry air with dewpoints into the upper 20s. RAP appears to have joined in as well. Winds will increase this afternoon as noted back in WI/NW IL with sustained 10 to 15 mph winds with gusts to 25 mph in spots. Waiting to hear from land management officials across N Indiana, but all other offices are holding off on any headlines and continuing with SPS/social media messaging which has been done here for the past 24 to 36 hours. Will closely monitor conditions with a hoisting of a RFW in portions of the area still possible over the next couple of hours with alignment of best conditions in the 20-23Z time frame. A freshen up of social media posts will likely be done to realign the greatest concern area more SW to NE. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...None. OH...None. MI...None. MARINE...Small Craft Advisory until 5 PM EDT Monday for LMZ043-046. && $$ DISCUSSION...Marsili AVIATION...Roller FIRE WEATHER...Fisher