FXUS63 KIWX 090336 AFDIWX Area Forecast Discussion National Weather Service Northern Indiana 1136 PM EDT Thu May 8 2025 .KEY MESSAGES... - Colder Friday morning with lows in the mid to upper 30s. Patchy to areas of frost will be possible especially for the areas in southern Michigan. Protect your frost sensitive plants. - Pleasant through the weekend with highs in the 60s on Friday and warming into the 70s to around 80 early next week. Temperatures a bit cooler near the lake. - Shower and thunderstorm chances will begin late Monday night and increase on Tuesday and Wednesday. && .UPDATE... Issued at 855 PM EDT Thu May 8 2025 Southern Great Lakes/Ohio Valley remain situated between mid level ridging across the Corn Belt/Upper Midwest and a negative upper height anomaly across southeast Ontario/western Quebec. This pattern has been conducive for ongoing low level cold/dry air advection across the region. A reinforcing shot of low level cold advection is anticipated later tonight as the southeast Canadian upper trough digs southward. Frost potential still appears to be in place, particularly north of US 6, but some questions still persist as to how well near sfc will remain mixed overnight. Ridge axis will remain situated west of the area, keeping a moderate northeasterly gradient in place. At this time still feel best chance of more widespread frost is across southern Lower Michigan, but patchy to areas of frost cannot be ruled out across portions of far northwest Ohio/northwest Indiana. Have expanded the patchy frost mention south of the frost advisory area, and have updated the HWO to include patchy frost potential for areas outside of the current advisory. Some consideration has been given to areal expansion of frost advisory, but confidence in coverage at this time remains on the low side. && .DISCUSSION... Issued at 320 PM EDT Thu May 8 2025 A slow moving cold post frontal trough has been gradually moving southward through the area and has increased the cloud cover across the area and increased chances of light rain/sprinkles as it does so. We will see drier air behind this boundary begin to push southward and with that a decrease in the clouds as we go into the evening tonight. Winds will also be on the decrease and with more optimal radiational cooling conditions will see lows drop into the mid to upper 30s tonight with the coldest temperatures on our northern side of the CWA especially for our southern MI counties. A frost advisory for those areas has been issued to address that concern. May want to be proactive and cover your frost sensitive plants just in case. This will lead up to one more cool day on Friday with highs in the 60s. Ridging over the central CONUS will continue to move eastward with the blocky omega pattern finally flattening out and losing its grip this weekend. This will allow for the mostly dry weather to continue through Mother's Day weekend along with a warming trend for temperatures. By Saturday and Sunday we will be in the mid to upper 70s for most locations. Of course a bit cooler near Lake Michigan will be the theme with the lake water temperatures still in the mid to upper 40s. Further warming early next week with with the ridge axis moving further eastward into the region with highs on Monday through Wednesday into the upper 70s and low 80s. Highs may be muted slightly on Tuesday and Wednesday with a low pressure disturbance from the Gulf moving northeastward into the Ohio River Valley which will increase clouds and chances for afternoon showers/thunderstorms. Ridging returns by Thursday and a return to dry conditions and slightly warmer weather with highs in the mid to upper 80s. && .AVIATION /00Z TAFS THROUGH 00Z SATURDAY/... Issued at 1134 PM EDT Thu May 8 2025 VFR through the period within a cool and very dry ridge. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...None. OH...None. MI...Frost Advisory until 10 AM EDT Friday for MIZ078>081-177-277. MARINE...Small Craft Advisory until 5 AM EDT Friday for LMZ043-046. && $$ UPDATE...Marsili DISCUSSION...Andersen AVIATION...T