700 FXUS02 KWBC 110714 PMDEPD Extended Forecast Discussion NWS Weather Prediction Center College Park MD 314 AM EDT Sun Oct 11 2026 Valid 12Z Wed Oct 14 2026 - 12Z Sun Oct 18 2026 ...Heavy Rainfall threat for the south-central U.S. Wednesday and Thursday... ...Record heat for the Southern Plains, Mid-South, and Southeast through Thursday... ...Overview... An upper low lingering over the Intermountain West through mid week will allow for moisture from ex- Simon to stream northward as the period begins, with an expanding area of rain over the Central U.S.. Despite model guidance waffling, it appears most likely that energy from this trough will combine with strong northern stream energy to establish deep troughing into the central and eastern U.S. Friday-Saturday. Before then, strong upper ridging over the south- central to southeastern U.S. early in the period should allow for much above normal to record- setting warm temperatures into at least midweek, slowly moderating with time. ...Guidance/Predictability Assessment... Model guidance begins in fairly good agreement with an upper low over the central Great Basin on Wednesday, with upper ridging in place over the Southeast, and a few weak shortwaves sliding through the northern tier. After Thursday especially, spread and forecast uncertainty quickly increases as guidance continues to struggle with how much northern stream energy from western Canada will dive southeast into the north-central U.S. and if it will combine with the preexisting trough over the West. Including the 00z guidance tonight, there may finally be a trend towards more phasing with the two systems, leading to a bit slower and more amplified trough into the East late period. The ECMWF and UKMET are now looking more like outliers wanting to hold the upper low back over the West, weakening and eventually getting picked up by the next deep trough towards the West next weekend. Given the uncertainty, the WPC forecast tonight leaned closest to those more phased models including the GFS, CMC, and EC- AIFS, with more ensemble mean inclusion late in the period. Despite some better consensus, this remains a low confidence forecast. ...Weather/Hazards Highlights... The low aloft over the West will continue to bring snow to portions of the Northern/Central Rockies Wednesday and perhaps into Thursday. Ahead of this upper low, a Plains lee low pressure system and moisture from what is leftover from Simon will stream northward and aid in producing a widespread area of rain in the central U.S. Wednesday and Thursday. Thunderstorms and heavy rain/flooding potential are likely in the Southern/Central Plains to Lower/Middle Mississippi Valley ahead of a cold front with WPC Slight Risk areas in place on the Wednesday and Thursday Excessive Rainfall Outlooks. Farther north, there is some uncertainty with how progressive the trough and surface lows could be, but the current forecast is for rain to shift across the north- central U.S. Wednesday-Thursday and toward the Northeast Friday. Gusty winds may accompany the surface low through the north-central U.S. and Great Lakes. Showers and storms will accompany the front as it pushes through Florida late week as well. Ahead of the front, temperatures in the southern Plains to the Southeast will be well above normal and likely set new daily high temperature records (upper 80s to the mid 90s). Low temperatures may only fall into the 70s for several nights, with the combination yielding widespread Moderate HeatRisk and perhaps reaching Major over south Texas. The warmer temperatures in the 90s will gradually cool back into the 80s as fronts approach. Meanwhile, the upper trough in the West will bring broadly below average temperatures from the Southwest into the Intermountain West, along with frost/freeze threats. Gradual warming is likely in the West after that as upper ridging comes in. Moderately below normal temperatures will progress across the Central into Eastern U.S. during the latter half of the week. Santorelli/Tate Additional 3-7 Day Hazard information can be found on the WPC medium range hazards outlook chart at: https://www.wpc.ncep.noaa.gov/threats/threats.php WPC medium range 500mb heights, surface systems, weather grids, quantitative precipitation forecast, excessive rainfall outlook, winter weather outlook probabilities, heat indices and Key Messages are at: https://www.wpc.ncep.noaa.gov/medr/5dayfcst500_wbg.gif https://www.wpc.ncep.noaa.gov/medr/5dayfcst_wbg_conus.gif https://www.wpc.ncep.noaa.gov/5km_grids/5km_gridsbody.html https://www.wpc.ncep.noaa.gov/qpf/day4-7.shtml https://www.wpc.ncep.noaa.gov/#page=ero https://www.wpc.ncep.noaa.gov/wwd/pwpf_d47/pwpf_medr.php?day=4 https://www.wpc.ncep.noaa.gov/heat_index.shtml https://www.wpc.ncep.noaa.gov/#page=ovw $$