


Prognostic Meteorological Discussion
Issued by NWS
Issued by NWS
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139 FXUS02 KWBC 090628 PMDEPD Extended Forecast Discussion NWS Weather Prediction Center College Park MD 228 AM EDT Wed Jul 9 2025 Valid 12Z Sat Jul 12 2025 - 12Z Wed Jul 16 2025 *** Heavy rain with potential for flash flooding for Southern/Central Plains. *** ...Pattern Overview... An upper low with several waves of embedded shortwave energy will propagate across south-central Canada and the northern/central tier of the U.S. over the next week. A pair of surface cold fronts will move through the Plains and Midwest respectively, acting as a focus for storms. A retrograding subtropical ridge will keep things warmer than average across the southern tier. ...Guidance/Predictability Assessment The latest guidance remains in good agreement with the broad upper level ridging across the southern tier of the country with differences around timing and placement of shortwaves spinning through the base of the parent low to the north. It was previously noted that The 06z ECMWF AIFS was more extreme than the rest of the guidance when it comes to Max/Min Ts, while the 00z CMC has a much higher magnitude qpf footprint than the GFS/EC/UK suite over the Plains and Upper Midwest throughout the period. This trend persisted with the latest model run. WPC utilized a starting point of the EC/CMC/GFS/UKMET before including GEFS mean, NAEFS mean and ECMWF ensemble mean by mid period and increasing the weighting through the later periods. ...Weather/Hazards Highlights... Scattered convection anticipated to fire ahead of, and along progressive cold fronts, stalled boundaries and round the upper high in the Southern Rockies. The exact location of anticipated higher QPF amounts remain a bit uncertain given persistent model differences, nevertheless, there is potential for isolated instances of excessive rainfall and localized flash flooding. For Day 4, there is a Slight Risk for excessive rain for portions of Kansas and Oklahoma where a MCS will likely setup and an enveloping broad Marginal Risk enveloping from the Southern Plains east to Pennsylvania and north to the Minnesota arrowhead. Another Day 4 Marginal Risk area is in effect for eastern New Mexico into the Texas Panhandle. The potential for heavy rainfall near the front boundary over the central U.S. will persist therefore a Marginal Risk was raised for Day 5 for portions of the Southern Plains, Midwest into the Ohio Valley. Convection along the eastern coast of Florida may lead to isolated flash flooding/ponding in urban areas so a small Marginal Risk area was raised for Day 5 as well. Although there is fair amount of spread in QPF placement, a couple model solutions are hinting at a concentration of QPF near parts of eastern New Mexico/West Texas and for southern parts of the Hill Country. Confidence is low at this time but worth noting that this area will continue to be monitored given the extreme sensitivity with ongoing flooding. Numerous locations will have daily reading above 100, with several nearing the 110s in the lower elevations. Conditions will mainly be dry across the West/Southwest, except for perhaps far southeastern Arizona into New Mexico where some monsoonal moisture may be present. Campbell 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 (QPF), excessive rainfall outlook (ERO), winter weather outlook (WWO) probabilities, heat indices, and Key Messages can be accessed from: 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 $$