705 FXUS63 KEAX 091742 AFDEAX AREA FORECAST DISCUSSION National Weather Service Kansas City/Pleasant Hill MO 1242 PM CDT Tue Oct 9 2018 .Mesoscale Discussion... Issued at 1242 PM CDT TUE OCT 9 2018 Patches of clearing have allowed shallow convection to quickly develop in the form of a dense cumulus field across east central KS and central MO early this afternoon. SBCAPE is beginning to increase in these areas to around 500-1000 J/kg, and will continue to gradually increase in these pockets of sunshine early this afternoon. A line of thunderstorms currently lifting northeast will enter the southwestern portion of the forecast area by 130-200 PM, and may intensify as instability ahead of it builds. This line of storms has a history of producing quickly developing circulations and several tornadoes across Oklahoma; and while 0-1 and 0-3 km SRH decreases from west to east, 0-1 km shear in the 30-35 kt range and 50 kts of effective shear in our area will be more than sufficient for rotating updrafts and strong low-level circulations. We may also see some isolated development ahead of the line where cumulus is bubbling in central MO, which could quickly become strong and will need to be monitored for severe potential as well. These storms will continue to push northeast throughout the afternoon and evening, spreading the severe weather potential through the length of the forecast area. && .Discussion... Issued at 454 AM CDT TUE OCT 9 2018 Message of the day: Flooding concerns continue this morning through Wednesday morning, mainly along a line from Adair County, MO to Linn County, MO. Additionally, severe weather is possible this afternoon and evening with a few tornadoes, damaging winds around 60 mph, hail up to 1 inch possible. Moderate to heavy rain has been moving north along the MO/KS border overnight, dropping an additional one to two inches of rain and continuing flooding concerns. Therefore, the areal flood warnings remain in effect through at least the afternoon. These showers and storms will continue this morning, slowly lifting to the northwest, as the upper level trough, that has been parked over the western U.S., finally begins moving into the central U.S. This should provide a break from the rain for at least those along and east of I-35, but unfortunately the rain showers are likely to continue on and off all day across far northwest MO and northeast KS. This afternoon a surface low will strengthen over south-central KS and move northeast in conjunction with the shortwave trough. Additionally, the LLJ will ramp up over our area, with an upper level jet max. This will produce an environment with deep layer shear between 35 kts and 45 kts, SB and MU CAPE between 1500 J/kg and 2500 J/kg, and dew points in the upper 60s. Therefore, severe weather is very possible this afternoon into the early evening hours. A few isolated tornadoes are the primary concern due to the surface low enhancing the low-level backing of the winds. 0-1 km shear is between 25-35 kts, with SRH around 200 m2/s2 and LCLs 100 m or less. Additionally, damaging winds around 60 mph are possible with mean layer winds supportive of bowing segments. Finally, hail around a quarter of an inch is possible as well due to steep lapse rates and sufficient instability and shear. The severe threat should diminish once the sun goes down. There is a little caveat to today's severe weather threat which is the environment being able to realize the CAPE. Broken to overcast clouds should stick around most of the day over most of the area, making it a little more difficult for us to warm up. However, given we are deep in the warm sector of this system, and the time of year, we don't need much CAPE for severe storms to develop. Flooding is also going to be a concern this afternoon, especially for those who see the stronger storms. This is because PWAT values continue to average around 1.75", which is much higher than normal. Tonight, the overall pattern will begin to change, as the upper level low and cold front finally start push east. As the system does move, it will move the showers and storms with it. And while storms will be more progressive overnight tonight then we have seen the last few days, they will still be efficient rain producers, so the flooding threat will continue. The system and its rain will move out west to east early Wednesday morning, leaving the MO/KS border dry by late Wednesday morning, and central MO by late Wednesday afternoon. This morning through Wednesday afternoon, an additional 2- 4 inches of rain is expected in far northwest MO and northeast KS with 1-3 inches of rain in the KC Metro up to Kirksville, and then around 1 inch of rain for central MO. Therefore, the Flood Watch has been expanded south to Linn County, KS and east to Adair County, MO and remains in effect until 7 AM Wednesday morning. When all is said and done, we could see a widespread 10-12 inches with locally higher amounts. Wednesday, high pressure will settling into the area, giving us dry conditions and very fall like temperatures with highs in the 50s and lows dipping down into the upper 30s. We will remain cool for the forecast period, but rain chances return this weekend as the remnants of Sergio move into the central U.S. The good news is this system will move through quickly, making way for a more prolonged period of dry weather. && .Aviation...(For the 18Z TAFS through 18Z Wednesday Afternoon) Issued at 1242 PM CDT TUE OCT 9 2018 IFR stratus associated with the rain showers pushing north across all TAF sites this morning should depart over the next hour, leaving developing cumulus based around 3 kft as the primary ceiling. Isolated storms may develop over the next 1-2 hours, then the main line of storms will push through around 20z-22z at all TAF sites. Reduced visibility, variable wind, and lowered ceilings are all possible in the most intense storms. Showers with embedded thunderstorms will trail behind, gradually tapering off late this evening. After storms depart, lower ceilings will wrap in behind and gradually transition all TAF sites to IFR. && .EAX WATCHES/WARNINGS/ADVISORIES... KS...Flood Watch through Wednesday morning for KSZ025-057-060-102>105. MO...Flood Watch through Wednesday morning for MOZ001>008-011>017- 020>024-028>030-037-043. && $$ Mesoscale...Laflin Discussion...Grana Aviation...Laflin