549 FXUS63 KSGF 091741 AFDSGF Area Forecast Discussion National Weather Service Springfield MO 1241 PM CDT Tue Oct 9 2018 ...Update to Aviation for 18Z TAFS... .MESOSCALE DISCUSSION... Issued at 1050 AM CDT Tue Oct 9 2018 A line of storms is currently spreading northeast across northeastern Oklahoma this morning. These storms have developed in an area of MLCAPE vales of 1000 to 1500 J/kg. Deep layer shear is greater than 40kt and 0-3km bulk shear vectors are in the 30 to 40kt range. This environment will continue to spread northeast into the area ahead of the line of storms. There are a few showers develop across the area out ahead, but do not think coverage will be enough to effect the environment. Therefore, think the line of storms will continue to track northeast and into southeastern Kansas and the far western Ozarks this afternoon then across the rest of the area this evening. The primary risk will be damaging wind gust in excess of 60mph. Given the 0-3km bulk shear vectors there will be the potential for mesovorts and a few spin up tornadoes within any surges in the line to the northeast. This is what has occurred with the line as it has tracked across Oklahoma and should continue into our area. The line should push out of the area late this evening. The actual cold front will spread west to east across the area late this evening into the overnight hours. Storms will be possible along the front and there could be a few strong storms overnight as well. && .SYNOPSIS... Issued at 242 AM CDT Tue Oct 9 2018 Deep trough remains over the Rockies with pesky ridge axis still off the east coast. This has brought significant amounts of rainfall just to the west of the area the past few days along with some flooding. Frontal boundary was located from the northwest corner of MO into the TX panhandle early this morning. Temperatures were very mild with readings in the low to mid 70s and dew points in the mid to upper 60s. Moist axis was ahead of the front to just west of the CWA where 1.7 to 1.9 in. PWAT values are occurring. With the upper trough expected to be on the move later today/tonight along with the surface front, our focus will be on convection increasing across the area, the chance of severe storms and flooding from today into Wednesday morning. && .SHORT TERM...(Today and tonight) Issued at 242 AM CDT Tue Oct 9 2018 For today...Should continue to see convection expand eastward during the day today as the upper level trough and energy out ahead of the main trough moves through the area. Instability does not look overly impressive, but do have 0-6km shear of 30-40 kts during the day, so would not be surprised to see a few stronger storms develop within the broad area of scattered convection developing ahead of the front. PWAT values over 1.7 in. will support the heavy rain potential and some localized flooding. The front will start making its way into the area tonight. Squall line or line segments will be possible this evening and tonight as the front moves into the area and is supportive of the various CAMS solutions...although the CAMS output have varying timing with these features. Damaging wind risk will be the main severe weather risk. With southwest to northeast oriented 0-3km shear vectors of 30 to 40 kts, any line segments lifting northeast would have the potential of producing some spin up tornadoes as well. There will be a heavy rain risk with the squall line as well, however it should be fairly progressive through the area which would limit the flash flood risk to more localized areas. For this reason, am not planning on a flash flood watch at this time. .LONG TERM...(Wednesday through Monday) Issued at 242 AM CDT Tue Oct 9 2018 Most of the convection will move out of the area by Wednesday morning, however the back edge of the precipitation may take until mid morning to push out. Behind the front, a MUCH drier and cooler air mass will move into the area. Highs on Wednesday from the low 60s in the west to the mid 70s east with lows in the 40s Wednesday night. Highs on Thursday will only be in the upper 50s to mid 60s with lows Thursday night dipping into the upper 30s in some locations. Models are coming into better agreement with decent precipitation chances late in the weekend (Sat night into Sunday) as an area of low pressure tracks across the area. With the cooler temperatures, we are not expecting lightning with this activity, but decent rainfall totals from 0.75 to 1.40 inches of rain possible. Behind this system, even cooler temperatures are expected with some mid 30s possible by Monday morning. && .AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon) Issued at 1240 PM CDT Tue Oct 9 2018 A few showers have developed across portions of the area early this afternoon, ahead of an approaching storm system. MVFR conditions will be possible within this activity. A line of storms in northeast Oklahoma and southeastern Kansas will spread into the area this afternoon into this evening. Strong to severe winds will be possible with these storms, along with IFR conditions. A cold front will move through the area late this evening into the overnight hours. Additional showers and maybe a few storms will be possible along the front. Winds will become more west to northwesterly behind the front with MVFR ceilings possible. && .SGF WATCHES/WARNINGS/ADVISORIES... MO...NONE. KS...NONE. && $$ MESOSCALE...Wise SYNOPSIS...Lindenberg SHORT TERM...Lindenberg LONG TERM...Lindenberg AVIATION...Wise