980 FXUS63 KILX 212357 AFDILX Area Forecast Discussion National Weather Service Lincoln IL 657 PM CDT Sat Sep 21 2019 .SYNOPSIS... Issued at 254 PM CDT Sat Sep 21 2019 Bands of rainfall will continue to spread across the the western half of Illinois as the remnants from Imelda slide into the Midwest. This will continue into the overnight, then another frontal system will approach the region from the west on Sunday. This will bring additional rainfall to the area through the end of the weekend. && .SHORT TERM...(This evening through Sunday) ISSUED AT 254 PM CDT Sat Sep 21 2019 The biggest issue with today's forecast was model depiction of the showers and isolated storms, also total rainfall amounts were a big issue. Upon further analysis, rainfall totals have been lowered slightly due to the more northerly track of the remnants of Imelda. This will bring the heaviest rainfall amounts to the DVN CWA, leaving central Illinois with slightly lower totals. With the change, totals are expected to be more likely in the 2 to 3 inch range, with a few locations receiving just over 3 inches. Most of this is expected to impact locations along and west of the Illinois River Valley, therefore the FFA will remain in place beginning tonight and lasting through Sunday evening. Heavy rainfall during this period is expected, as remnants mix with another approaching cold front. This will bring excess precipitation to the region, mainly midday Sunday through Sunday evening. However, with the possibility of heightened rainfall tonight, it was decided to begin early to cover the overnight period where flooding is more hazardous. Models still remain uncertain about the exact development of shower and thunderstorm activity for Sunday. Some CAMs have scattered shower activity, while others indicate more widespread rainfall. The idea is that with High pressure off the se coast of the US, this will hold the movement of today's shower activity in the area. This High will also slow the progression of the frontal system on Sunday, leading to the chance for flash flooding. As Sunday passes, the frontal boundary will slide eastward, bringing rainfall to eastern and southeast Illinois. However, at this time, it forecasts are calling for substantially lower totals across this area, with 1 inch or less of total rainfall expected. .LONG TERM...(Sunday night through Saturday) ISSUED AT 254 PM CDT Sat Sep 21 2019 Once the frontal system pushes through the region late Sunday night, rainfall will slide out. This will allow High pressure to arrive Tuesday morning, bringing drier and more seasonable conditions to the area during the first half of the week. Another system will develop across the northern Plains mid-week, bringing the next chance for precipitation to central Illinois and surrounding areas. As of now, this system has about a 50% chance of bringing rainfall to the region. With the placement of the Low core this time in southern Canada and High pressure in sern US, abundant moisture will need to be lifted into the region to provide instability along the weak frontal boundary. After fropa Wednesday night, another High will slide into the area for the second half of this week, limiting chances of precipitation. && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) Issued at 656 PM CDT Sat Sep 21 2019 Scattered showers and a few storms will linger in the central portion of the forecast area for the first couple of hours of the 00z TAFs. Prevailing rain should only be needed for a couple of hours at PIA and BMI as a result. SPI, DEC and CMI should see a wave of rain move through, but not persistent. Beyond the evening, it still appears that our NW counties will be under the threat for the worst conditions and heaviest rainfall while a cold front slowly shifts east. However, on Sunday, the front is expected to become more progressive as it pushes east across the remainder of the central Illinois terminals. Winds should remain southerly until at least Sunday morning, with a shift toward the SW during the day on Sunday. Winds should become gusty again on Sunday, with 20-25kt possible at times before the cold FROPA. && .ILX WATCHES/WARNINGS/ADVISORIES... Flash Flood Watch through late Sunday night for ILZ027>031-036- 037-040-041-047>050. && $$ SYNOPSIS...Baker SHORT TERM...Baker LONG TERM...Baker AVIATION...Shimon