Area Forecast Discussion
Issued by NWS Springfield, MO
Issued by NWS Springfield, MO
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343 FXUS63 KSGF 240540 AFDSGF Area Forecast Discussion National Weather Service Springfield MO 1240 AM CDT Tue Sep 24 2024 .KEY MESSAGES... - Marginal (1 of 5) Risk for severe thunderstorms this afternoon and evening across the eastern Ozarks. Potential hazards will be damaging wind gusts up to 60 mph, large hail up to the size of quarters. There is a very low chance of a tornado east of a Gainesville to Salem line. - Rainfall is likely this afternoon through this evening (60-90% chance). Most locations will see an additional 0.10 to 0.50 inch of rainfall through tonight, with localized amounts of 1 to 2 inches east of Springfield. - Much cooler temperatures will occur this week with highs in the 70s. - Rainfall chances (50-80%) continue to increase for late in the week as confidence increases on track of the next system. There is the potential for widespread and prolonged rainfall with this system by Friday and Saturday. && .SHORT TERM /THROUGH WEDNESDAY/... Issued at 218 PM CDT Mon Sep 23 2024 Current Conditions and Synoptic Pattern: Water vapor and upper air analysis continues to show a slow moving shortwave across Iowa into Kansas. Surface low pressure was located near West Plains with a trailing front. An area of showers has developed across southwest Missouri behind the main front in an area of increased lift as the upper level jet noses into the area. Clouds have kept temps down into the 60s to lower 70s with the exception of south central Missouri where temps have increased into the upper 70s. This is also where a pocket of 1000j/kg of ML CAPE exists. We are currently in a lull of bulk shear however a mid level speed max was moving up the Red River and will likely increase bulk shear to 40kts by later this afternoon. This afternoon and evening: Lift will continue to increase and expect a gradual uptick in showers and thunderstorms, especially along and east of Highway 65 this afternoon, lasting through late evening. Areas along and east of a Branson to Salem line are in a marginal severe risk as this area is overlapped with ML CAPE around 1000j/kg and increasing shear. A few multicells and perhaps even some low topped supercells look to form late this afternoon and evening. Latest RAP sounding for Oregon county around 4-6pm shows the potential for around 1500j/kg of ML CAPE< 35-40kts effective shear which would be enough for a few severe storms with large hail up to the size of quarters (if the supercell threat was higher then the expected hail size would need to be increased) and damaging winds up to 60 mph. There is a low tornado risk briefly as the low passes with southeast winds however this window looks brief with surface winds quickly becoming southwesterly. Hodographs mainly look long and straight which could promote a few splitting cells. The window for severe storms is mainly from 3pm-9pm. PW values of 1.5-1.6in will continue to promote heavy rainfall rates. Latest HREF data suggests pockets around 0.5inch with localized areas seeing 1-2 inches east of Highway 65. This could produce a localized flash flood threat this evening. Most of the heavier rainfall will have ended by 9pm however scattered showers will likely continue across the eastern Ozarks through the overnight hours as the shortwave trough moves through. Locations further west will likely have low clouds and patchy fog. Low temperatures will likely reach the upper 50s west of Springfield. Tuesday: Additional shortwave energy looks to drop down into the area during the day which will promote clouds and cool temps with northerly winds. Seeing a signal in short term guidance that drizzle or light rain showers will occur across areas northeast of Springfield during the day. If confidence increases in this scenario then precip chances will need to be increased (even though amounts would be very light). High temps in the 70s are likely with the coolest readings (perhaps upper 60s), across the northeast CWA. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... Issued at 218 PM CDT Mon Sep 23 2024 An unsettled stretch is shaping up during the late week into the weekend as an upper low drops south into Missouri and potentially interacts with the developing Potential Tropical Cyclone Nine. Guidance has come into decent agreement that the upper low will move south over Missouri on Wednesday. There is a 10-20% chance of rain east of Springfield during the afternoon however not expecting widespread rain. The track of the tropical system will be key from Thursday into the weekend as ensembles still continue to struggle with its exact track through the southeast US. Ensemble clusters all support rain across the area Thursday and Friday, especially given the lift from the upper low and increasing moisture. It should be noted that the multi modal mean in the ensemble clusters shows the potential for over 2 inches of rainfall. ECMWF extreme forecast index/shift of tails also shows the potential for an anomalous rainfall event across the eastern half of the area. Lastly, the latest NBM is showing greater than a 60 percent chance of at least 3 inches of rainfall Thursday through Saturday. With all this said, confidence is increasing that a period of prolonged excessive rainfall is increasing somewhere across the region, with increasing signals for the eastern half of the area being in this zone. This will all be dependent on the track of the tropical system and its interaction with the upper low therefore stay up on the forecast through the week. Temperatures will likely remain below average through the week and into next week with precip and north winds. && .AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/... Issued at 1240 AM CDT Tue Sep 24 2024 Medium-high confidence that low ceilings will persist through 16Z or so, creating LIFR conditions at SGF and MVFR conditions at JLN and BBG with periods of IFR conditions through at least 10Z. Additionally, fog is expected to develop at JLN, bringing visibilities down to 1 mile between 10-14Z with periods below 1/2 mile. Furthermore, periods of light drizzle may occur at all TAF sites (but especially SGF) through 18Z. Lastly, a band of light rain showers could move through all TAF sites between the 19-02Z timeframe (15-30% chance). Otherwise, winds will be at 5-10 kts out of the WNW through the period, decreasing to 2-5 kts after 00Z. Low clouds will dissipate by 16-18Z, leaving scattered mid- and high-level clouds for the rest of the period. && .SGF WATCHES/WARNINGS/ADVISORIES... KS...Dense Fog Advisory from 4 AM to 10 AM CDT this morning for KSZ073-097-101. MO...Dense Fog Advisory from 4 AM to 10 AM CDT this morning for MOZ066-077-088-093-101. && $$ SHORT TERM...Burchfield LONG TERM...Burchfield AVIATION...Price