228 FXUS62 KRAH 112343 AFDRAH Area Forecast Discussion National Weather Service Raleigh NC 743 PM EDT Wed Jun 11 2025 .SYNOPSIS... A weak front extending from southeastern Virginia across the North Carolina Piedmont into upstate SC will linger across the area through Thursday before washing out on Friday. A Bermuda high pressure system will build west into the region through early next week, bringing warm and humid conditions. && .NEAR TERM /THROUGH TONIGHT/... As of 255 PM Wednesday... * Showers and storms developing across eastern NC, with a Marginal Risk (Level 1 of 5) of severe weather in place from SPC Early afternoon visible satellite imagery and surface obs continue to depict a stationary boundary across the western Piedmont of NC, stretching from roughly Roxboro to Wadesboro. While the cu field has filled in across much of central NC, dewpoints west of the boundary have mixed out into the lower 60s while remaining elevated in the upper 60s to lower 70s to the east. Meanwhile, convection has blossomed across eastern NC with the first hints of a sea breeze/outflow moving inland. Additional isolated showers and storms have started developing across the northern Coastal Plain as well. MLCAPEs around 1500 J/KG are commonplace east of the stalled boundary, as are PW`s around 1.5 to 1.75". Conditions are far less favorable for convection to the west given dry air at the surface and aloft, resulting in a cap of more than 200 J/KG. The previous forecast thinking remains largely on track, with the best chances of showers and thunderstorms along and east of US-1 through sunset. 12Z HREF depicts the best chances for storm development across the Coastal Plain, although if outflow boundaries collide we could see additional development as far west as Raleigh. Some isolated 30-40kt wind gusts can`t be ruled out with the strongest storms, nor can some brief periods of heavy rain although widespread severe weather and flooding are not anticipated today. CAMs typically struggle within weakly forced environments so it`s hard to pin down exactly how far west to draw in precip chances, but US-1 seems like a relatively reasonable western edge based on obs and 12Z hi res model data. PoPs will linger into the early evening hours before conditions dry out tonight with the loss of daytime heating and BL instability. As for temps, the boundary will begin to slowly slosh back to the north late tonight, yielding relatively uniform temperatures across the area in the upper 60s to mid 70s. && .SHORT TERM /THURSDAY AND THURSDAY NIGHT/... As of 255 PM Wednesday... * Scattered storms are possible, mainly across southern areas during the late afternoon or evening, with weakening convection lifting northeast across the area overnight. The weak surface boundary extending northeast to southwest across the Carolina Piedmont will wash out on Thursday. As the boundary dissipates, a south to southwesterly low level flow will develop across the area. Afternoon and evening instability will be maximized across the south and decrease with northern extent. A disturbance in the southwesterly flow aloft may trigger scattered convection across southwestern NC an western SC during the afternoon that may spread slowly northeast and favor subsequent convection to the northeast during the afternoon into the evening across the Southern Piedmont and Sandhills. Some convection allowing models suggest some lingering light showers may spread northeast overnight. Highs on Thursday should range in the upper 80s to around 90 with max heat index values in the lower to mid 90s. It will be muggy on Thursday night with lows in the upper 60s and lower 70s. -Blaes && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... As of 225 PM Tuesday... * Chances of mainly afternoon and evening showers and storms increase later in the week into early next week. * Humidity values increase with surface dew points reaching the lower 70s at times producing max heat index values in the 90s and moderate heat risk across southern and eastern areas over the weekend into early next week. A Bermuda high pressure system will extend into the southeastern U.S. over the weekend into early next week resulting in a general southwesterly low-level flow. There are indications of some weak surface troughing may develop in the lee of the mountains across VA into northern NC late in the weekend into early next week. Further aloft, ridging across the Southeast and FL combined with forms and episodes of troughing across the Midwest and Great Lakes will result in deep feed of warm moist air into the region. PW values will increase to 1.75 to 2.25 inches late Friday into Sunday which is about 150-175% of normal before values decrease early next week. While the main westerlies will be well removed to our north, there will be episodes of some weak disturbances dropping into the region from the northwest over the weekend into early next week. The result will be an active pattern featuring largely diurnally driven showers and thunderstorms across central NC. It`s worth noting that the pattern supports limited predictability on the details of the timing of storms for each day outside of diurnal heating. The best storm chances should occur during the Friday through Monday period with PoPs of 50-70%. Rather weak low and mid level flow will limit the threat of organized and severe weather but the deep moisture and potential for multiple days with storms may result in an isolated flooding threat. Highs will average 1 to 5 degrees above average and range in the mid 80s to around 90. There are signs of some slightly cooler highs on Tuesday across the north. With a southwesterly flow it will be humid with dew points mainly ranging in the upper 60s to lower 70s. This will keep overnight lows elevated, generally 5 to 10 degrees above average with lows mainly in the lower 70s with a few upper 60s in the Triad and near the VA border and mid 70s across southeastern areas. The combination of the heat and humidity will result in max heat index values in the 90s and a moderate heat risk across southern and eastern areas over the weekend into early next week. The widespread cloudiness and risk of storms should keep highs down enough to avoid widespread 90s and major heat risk values. -Blaes && .AVIATION /00Z THURSDAY THROUGH MONDAY/... As of 740 PM Wednesday... Convection continues in the vicinity of the eastern terminals (FAY/RWI) with an outflow boundary pushing towards RDU where additional showers and isolated thunder is possible. Showers and storms should slowly fade after 8 to 10 PM. A brief period of VFR is expected, but fog/stratus should fill back in across the area from RDU, to RWI and FAY into early Thurs morning. Timing and cig category remains low at this time, but moderate to heavy precip around RWI and FAY increase confidence in some restrictions into Thurs morning. A brief period of MVFR cigs are possible as patchy fog/stratus lifts through Thurs morning returning to VFR by the afternoon. Scattered showers/storms will again be possible Thurs afternoon, best chances at FAY. Outlook: Daily shower/thunderstorm chances, along with early morning sub-VFR fog, are expected through the weekend into early next week. Best chances for showers/storms appears to be Fri into the weekend with less coverage into early next week. && .EQUIPMENT... ...Computer System Upgrade at NWS Raleigh from June 16th through 18th... The National Weather Service Raleigh Weather Forecast Office in Raleigh will be conducting a required, scheduled update to our Advanced Weather Interactive Processing System (AWIPS) computer system. NWS offices use AWIPS to display and integrate weather and water information, and to send life-saving information, such as weather and water warnings, to the public. AWIPS is updated periodically, but this update is comprehensive and requires that the system be taken completely offline for approximately three days, from the morning of Monday, June 16th through the afternoon hours of Wednesday, June 18th. During that time, NWS Raleigh forecasters will produce and disseminate products for the area using the AWIPS system at one of our backup offices at NWS Blacksburg, VA. No impacts to our core services of forecast products and weather watches, warnings and advisories are expected during this period. A few of our services will be impacted as they originate only from AWIPS facilities at NWS Raleigh, namely: * NOAA Weather Radio broadcast: The following NOAA Weather Radio transmitters, programmed by NWS Raleigh, will be off the air during most of the AWIPS update: Buck Mountain (WWF 60 - 162.500 mhz) Chapel Hill (WXL 58 - 162.550 mhz) Ellerbe(WNG 597 - 162.400 Mhz) Garner(WNG 706 - 162.450 mhz) Henderson (WNG 586 - 162.500 mhz) Tarboro (WXL 59 - 162.475 mhz) Winston-Salem (WXL 42 - 162.400 mhz) * Climate: Data will be updated in a limited fashion from Monday afternoon, June 16th through Wednesday, June 18th. Climate graphs for the Raleigh Forecast Area at https://www.weather.gov/rah/climatePlots will not be updated. * Graphical Hazardous Weather Outlook images normally at www.weather.gov/erh/ghwo?wfo=rah will not be updated. * The Weather Story available at https://www.weather.gov/rah/weatherstory will not be updated. * Water level forecast services will be degraded due to a less frequent update cycle. Forecasts will remain at https://water.noaa.gov/wfo/rah through this period. * NWS Raleigh will remain operational and staffed while AWIPS is offline, taking public and partner phone calls, communicating via social media, and performing other functions that can be completed without AWIPS. We apologize for any inconvenience. Please direct any questions to Jonathan Blaes at jonathan.blaes@noaa.gov && .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Blaes NEAR TERM...DL SHORT TERM...Blaes LONG TERM...Blaes AVIATION...Swiggett/DL EQUIPMENT...RAH