Area Forecast Discussion
Issued by NWS Springfield, MO
Issued by NWS Springfield, MO
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976 FXUS63 KSGF 081734 AFDSGF Area Forecast Discussion National Weather Service Springfield MO 1134 AM CST Fri Nov 8 2024 .KEY MESSAGES... - High probability (80-95%) for widespread rain with another system moving through tonight and Saturday. Rainfall amounts from 0.25" to 0.75". Localized amounts around 1.50" to 2.00" along and west of the I-49 corridor. - Additional potential (20-40%) for showers and thunderstorms next Tuesday night and Wednesday. && .SHORT TERM /THROUGH SUNDAY/... Issued at 330 AM CST Fri Nov 8 2024 It is quite easy to pick out the mid- and upper-level low across the Four Corners region in current water vapor imagery. East of the low across the southern Plains states, a broad area of divergence and diffluence aloft paired with a deepening surface low pressure system is producing widespread areas of rain and thunderstorms. These are situated north of the developing warm front draped across central to east TX. Radar imagery does show some weak echoes clipping our Kansas counties, but given a large portion of the atmosphere is dry according to our 00Z observed sounding, these returns are not expected to hit the ground yet. High clouds from this system are also spreading over our forecast area, which will keep low surface temperatures in the 40s (warmer along the southern border). This cloud cover will persist through Saturday, keeping high temperatures a little cool in the upper 50s and lower 60s today and Saturday, and low temperatures a little warmer in the middle 40s to lower 50s tonight and Saturday night. 80-95% chance for widespread rain tonight and Saturday: The cut-off low will slowly progress eastward this morning as the jet and positive vorticity advection maxima revolve from the south to the east side. Once the jet and PVA maxima become established on the ENE side of the cut-off low, the wave will accelerate northeastward through the Central Plains late tonight through Saturday. A quickly occluding surface cyclone will follow suit, with an occluded front traversing our area late tonight into Saturday, bringing 80-95% chances for rain across our whole area. 20-40% chances of showers will first begin along the I-49 corridor after 2 PM today. These will linger through the afternoon and early evening as the system slowly progresses east, as previously mentioned. Once the system accelerates, chances will increase to 70-90% for the I-49 corridor around 8-10 PM this evening. These high chances will then spread eastward over the course of the night and Saturday morning. The latest CAMs suggest that rain will initially start out as a widespread shield across our western forecast area before progressively becoming more scattered as the rain spreads eastward and the occluding surface low retrogrades northwestward, and thins out the moisture supply. Rain chances are expected to exit much of the area by Saturday night, with 20-50% chances lingering in the eastern Ozarks through Sunday morning. Clearing skies behind the system will allow highs in the middle 60s Sunday and lows in the lower 40s Sunday night. Rainfall amounts from 0.25-0.75", localized amounts of 1.50-2": The evolution to more scattered showers and thunderstorms as the rain spreads eastward late tonight and Saturday morning will keep totals a bit lower than previously forecast east of I-49. HREF LPMMs depict widespread areas of 0.25-0.75" east of I-49, which is noticeably lower than the NBM mean at 0.75-1.00". The lower values make more sense, however, due to CAMs depicting more scattered coverage over this area. The exception to the lower totals is along and west of the I-49 corridor. Here, the initial slow progression of the cut-off low will bring multiple rounds of more widespread rain, allowing totals to reach the 1.00 inch mark with localized amounts up to 1.50-2.00", especially in our southeast Kansas counties. Despite the widespread lower totals, HREF depicts a tongue of 100-200 J/kg MUCAPE, which is just enough for isolated embedded thunderstorms. Additionally, PWATs are forecast to reach the 1.25-1.50" mark thanks to 99th percentile moisture all the way through 500 mb. These combined factors will allow for areas to receive locally higher amounts where thunderstorms track. Nevertheless, no severe or flooding threat is expected thanks to the accelerating system and lower forecasted rainfall amounts. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... Issued at 330 AM CST Fri Nov 8 2024 After the short-term system exits the area, there will be a brief period of warm air advection beneath amplified ridging ahead of the next system moving through the west CONUS. This will allow highs Monday and Tuesday to warm into the middle 60s to lower 70s. Lows during this period will be in the lower to middle 40s Monday night, and upper 40s Tuesday night. 20-40% chance for rain next Tuesday night and Wednesday: The next system then arrives Tuesday night and Wednesday. Model disagreement in trough timing, position, and intensity is still high as shown by ensemble cluster analysis. This is still leading to broad areas of 20-40% chances of showers and thunderstorms. Despite the uncertainty in the trough, the high amplitude of the wave will bring through a cold front that should force some form of showers and thunderstorms across the region. Subsequent forecasts will hone in on better details. After the cold front moves through, temperatures will cool. The degree of cooling is still uncertain, largely because of the aforementioned uncertainties with the trough. NBM spreads are still high, but the current forecast calls for highs in the upper 50s to lower 60s with lows in the upper 30s to lower 40s Wednesday through Thursday. In the extended range, confidence is increasing that above normal temperatures and precipitation will continue through mid-November, per the CPC 8-14 day outlook. This is largely due to ensembles developing yet another deep trough across the west CONUS that will translate eastward into the central CONUS during the 8-16 day period. && .AVIATION /18Z TAFS THROUGH 18Z SATURDAY/... Issued at 1123 AM CST Fri Nov 8 2024 A storm system in the plains will make its way to the east and into the Ozarks region by this evening. This will bring lowering ceilings, showers and gusty surface winds. Initially VFR conditions will deteriorate into this evening to MVFR tonight and eventually IFR by Saturday morning as ceilings progressively lower over the next 24 hours and rain spreads across the region. As the system approaches, surface winds will also become gusty mainly from the south to southeast. && .SGF WATCHES/WARNINGS/ADVISORIES... KS...None. MO...None. && $$ SHORT TERM...Price LONG TERM...Price AVIATION...Hatch