Area Forecast Discussion
Issued by NWS Springfield, MO
Issued by NWS Springfield, MO
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813 FXUS63 KSGF 061813 AFDSGF Area Forecast Discussion National Weather Service Springfield MO 113 PM CDT Mon May 6 2024 .KEY MESSAGES... - Severe thunderstorms are likely tonight with the highest risk areas along and west of Highway 65. Primary hazard is damaging wind gusts of 70 to 80 mph. Additional hazards include frequent lightning, a few short- lived tornadoes and half dollar sized hail. Severe storms will move into the area after 9pm and continue overnight. - Localized flooding is also a concern tonight across southeast Kansas and western Missouri where localized pockets of 1-2 inches of rain will occur. - Additional strong to severe thunderstorms on Wednesday. Exact hazards remains in question, but very large hail, damaging, and a conditional tornado threat are all in play. SPC has a hatched Enhanced Risk (3/5) for most of the area. && .SHORT TERM /THROUGH TUESDAY NIGHT/... Issued at 100 PM CDT Mon May 6 2024 Current Conditions and Synoptic Pattern: Water vapor and upper air analysis shows a strong upper level shortwave trough across Wyoming and Colorado with a 120kt upper level jet across Arizona and New Mexico. Surface low pressure continues to deepen across South Dakota with a secondary low across Kansas. A warm front was in the process of lifting north through the area at this time. A dry line was located across western Kansas and western Oklahoma with storms already initiating across northern Kansas. 12z KSGF sounding showed a stable airmass in place (north of the warm front) however soundings south of the warm front measured a moist and unstable airmass. Visible satellite showed breaks in the clouds across the area which should allow the warm front to continue lifting north. A few showers were occuring however many areas were dry with temps in the upper 60s to lower 70s. Dewpoints were also creeping up into the lower 60s. This Afternoon through early evening (1pm-8pm): The warm front will continue lifting north through the area and temps will continue warming up into the 70s which will increase instability. While a few showers and even a thunderstorm may develop, upper level forcing will still be to the west therefore many areas will remain dry. All eyes will be on developing supercells in a High Risk severe environment across southern Kansas and northern Oklahoma. These storms will begin to evolve into a line with time. Tonight (After 9pm): High res ensembles continue to be in good agreement that a line of severe storms will approach far southeast Kansas in that 9-10pm timeframe. RAP forecast soundings across southeast Kansas and western Missouri indicate around 1500j/kg of ML CAPE (potentially up to 2000j/kg) with 40kts of 0-6km shear (this will increase further with time). The 120kt 300mb jet will be nosing into the area tonight. Also of note is that 1.4-1.5in PW values which indicates a very moist airmass. All this leads to high confidence that storms will remain severe as they approach the area. Given the expected linear mode and high instability/shear combo, damaging winds of 60-80mph will be the most likely risk as highlighted in the SPC Moderate/Enhanced risk areas. That being said, any bowing segments to the east- northeast or northeast could cause brief tornadoes. We believe that the threat for supercells and significant tornadoes will remain just west of the area however if storms were slower to morph into a line then this expectation would change. Southeast Kansas will need to closely monitor storm mode tonight. The hail threat looks lower with this system given the linear mode however hail up to the size of half dollars will be possible. As the line moves further east (between I-49 and Highway 65), the damaging wind threat (60-80mph winds) and brief tornado threat will continue. Latest RAP sounding for Springfield between 11pm-1am still shows 1000-1500j/kg of ML CAPE with 40kts of shear. PW values are also in the 1.4-1.5in range which supports heavy rainfall rates. While it does look like storms will gradually weaken as they move east of Highway 65, the instability/shear combo will remain high enough to keep the damaging wind/brief tornado threat going however perhaps not as high a threat as areas further west. In general, the line of storms will likely be clearing the area by 5-7am. Overall a busy overnight period is expected with the increasing potential for widespread damaging winds. We will continue to heavily message safety information for this night time severe event. Contemplated a Flood Watch for areas west of Springfield tonight however given the progressive nature of this line, flooding will remain localized and brief. 12z HREF does show a few pockets of 1-2 inches of rainfall across far southeast Kansas therefore we will be monitoring this risk. Tuesday: The airmass will likely be worked over from overnight storms and combined with mid level height rises we should see low precip chances (less than 20 percent). Winds will turn southwesterly during the day with skies clearing and temps reaching the upper 70s. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... Issued at 100 PM CDT Mon May 6 2024 Wednesday: Another shortwave trough will move through the southern Plains with a surface front moving through the area during the afternoon or early evening. Strong instability will be available with the NBM mean showing between 2000-2500j/kg of surface based CAPE along and southeast of the I-44 corridor. This instability and unidirectional shear could produce supercell thunderstorms and the area is in a Enhanced Risk on Wednesday. There still remains uncertainty with frontal timing and since we are not in the window of time yet for the high res guidance it is urged to stay up on the forecast for Wednesday. Thursday into the Weekend: The overall trend during this time period is drier conditions and cooler temps. This is likely due to a pattern shift with northwest flow aloft causing north surface winds. Friday looks to be the coolest day with highs in the 60s in many locations. && .AVIATION /18Z TAFS THROUGH 18Z TUESDAY/... Issued at 100 PM CDT Mon May 6 2024 MVFR ceilings will continue at SGF and BBG for a few more hours this afternoon however a return to VFR ceilings should occur with time. While a few rain showers will be possible this afternoon, the more hazardous time period will be after 9pm as a line of thunderstorms moves in from the west. These storms will bring the potential for damaging winds and frequent lightning along with a reduction in flight categories. Outside of thunderstorms, southerly winds will continue with gusts of 25-30kts outside of the storms. A brief period of low level wind shear will likely occur before the storms arrive overnight. Winds will turn more southwesterly on Tuesday with drier conditions and VFR ceilings. && .SGF WATCHES/WARNINGS/ADVISORIES... KS...None. MO...None. && $$ SHORT TERM...Burchfield LONG TERM...Burchfield AVIATION...Burchfield