


Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC
Issued by NWS Raleigh/Durham, NC
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-- Discussion containing changed information from previous version are highlighted. --298 FXUS62 KRAH 301837 AFDRAH Area Forecast Discussion National Weather Service Raleigh NC 237 PM EDT Mon Jun 30 2025 .SYNOPSIS... Sub-tropical high pressure centered south of Bermuda will extend westward across the South Atlantic states today, then gradually lose influence as a mid and upper-level trough and surface cold front settle into the Middle Atlantic and Carolinas Tuesday and Wednesday. && .NEAR TERM /THROUGH TONIGHT/... As of 1100 AM Monday... The previous forecast of persistence hot and humid, with isolated/ widely scattered afternoon-evening showers/storms (relative highest coverage over the Piedmont/wrn Sandhills) remains on track. A weakening mid/upr-level low over the Southeast in recent days had edged as far northeast as the nrn GA/SC border on Sunday, with associated cyclonic flow and influence extending across the wrn half of NC. However, water vapor satellite data indicate that feature has since drifted swwd to the s-cntl GA/AL border this morning, while continuing to weaken. Anticyclonic flow has consequently become established through the mid/upr-levels throughout cntl NC, which may further decrease convective coverage in cntl NC relative to Sunday. Nonetheless, the heat and humidity will contribute to another day of moderate destabilization and little to no CINH, so there will remain a 15-30 percent chance of convection, particularly where a surface trough will support weak convergence over the wrn/srn Piedmont and wrn Sandhills. .PREV DISCUSSION... /ISSUED 245 AM EDT Mon Jun 30 2025/ Yet another day of diurnally showers and thunderstorms is expected across the region. Similar to previous days, the greatest coverage is expected to be across the west compared to the east. However, high resolution models are indicating less coverage across the eastern half of the forecast area than previous days. Thunderstorms are likely to continue into the evening across the Triad, then fizzle out by midnight. Once again, highs should be in the low to mid 90s, with lows perhaps a degree or two warmer with slowly increasing high cloud cover in advance of the next system. && .SHORT TERM /TUESDAY/...-- Changed Discussion --As of 245 AM Monday... On Tuesday morning, a cold front will extend from Lake Ontario southwest into Kentucky and continuing into Texas. Over the last couple of days, models have slowed the arrival of the front into the region. While much of the region will still have showers and thunderstorms on Tuesday, the highest rainfall totals will likely be delayed to Tuesday night. Considering the delay in the arrival of precipitation, Tuesday`s high temperatures have come up a degree or two compared to the previous forecast, but will still range from the mid 80s to the low 90s. Much of the forecast area remains in a Marginal (level 1 of 5) risk for severe weather on Tuesday, which seems appropriate considering there would be modest instability, but minimal shear to organize storms. In addition, if things trend closer to the 00Z run of the HRRR, an even slower solution, more precipitation would occur overnight when instability would be further reduced. Will not wait for the new Day 2 WPC Excessive Rainfall Outlook to send out this discussion, but the Sunday afternoon ERO included much of the forecast area west of I-95 in a Marginal (level 1 of 4) risk for excessive rainfall.-- End Changed Discussion --&& .LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...-- Changed Discussion --As of 230 PM Monday... * Unseasonably warm weather continues into early next week, with the exception of Wednesday when widespread cloud cover and lingering rain chances will keep temperatures a few degrees below normal. A parent shortwave will be motoring through Ontario into the Newfoundland and Labrador province by Tues evening with the base of the trailing trough axis over the lower Ohio Valley expected to swing across the Carolinas through Wed afternoon. This feature, along with any embedded MCV`s from prior upstream convection, will act as the primary forcing mechanism for ongoing showers/storms over the Piedmont of NC early Tues evening. This activity is expected to continue, although gradually weakening and becoming more localized, as it slowly shifts eastward through the overnight and into Wed. Most locations along and west of I-95 should see at least trace amounts up to around 0.5". Narrow swaths of 1.5" to 2.5" will be possible and may result in localized areas of flash flooding mainly in urban corridors. Given the low predictability of these MCVs, as they depend entirely on the initiation and evolution of convection that has yet to develop, confidence on more precise locations of heavier rainfall remains low at this time. A narrow band of unseasonably high deep-layer moisture extending through the Mid-Atlantic into the Southeast, will slowly sag southeastward immediately ahead of the trailing trough axis and associated cold front reach the Carolina coast by late Wed afternoon. Cloud cover and precipitation chances through peak heating will likely keep temperatures up to 5 degrees below normal, marking the coolest day in the Triangle since early June. Drier air through a deep layer will overspread the region as surface high pressure settles overhead through the holiday weekend. One caveat is that aforementioned cold front is forecast across northern FL, and models have signaled a chance a low developing along the front. Models have been split on whether that low would develop over the northeast Gulf or off the Florida east coast. No local impacts are evident in current model guidance, but there could be some enhancement of POPs over the east by Sun into early next week.-- End Changed Discussion --&& .AVIATION /18Z MONDAY THROUGH SATURDAY/... As of 150 PM Monday... Widely scattered convection will continue to bubble in the vicinity of a surface trough over the Piedmont through early to mid-evening, then dissipate with loss of heating/instability. There is a signal in model guidance for the development of an area of IFR-MVFR ceilings over the Sandhills and srn Piedmont and adjacent areas Tue morning, centered closest to FAY and where a short period of flight restrictions are indicated in the 18Z TAFs. Some of this cloudiness may also glance Piedmont sites and require introduction in their forecasts with later issuances. Outlook: The chance of showers/storms will increase with the approach of a mid/upr-level trough and embedded disturbances Tue afternoon-night, particularly across the Piedmont. Chances for convection, and also morning stratus and fog, will linger at ern sites Wed-Thu, with the slow passage and dissipation of a weak front. && .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...MWS NEAR TERM...MWS/Green SHORT TERM...Green LONG TERM...Swiggett/BLS AVIATION...MWS