Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC
Issued by NWS Raleigh/Durham, NC
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947 FXUS62 KRAH 122333 AFDRAH Area Forecast Discussion National Weather Service Raleigh NC 730 PM EDT Fri Jul 12 2024 .SYNOPSIS... Areas of low pressure will ripple along a quasi-stationary front over the Piedmont through tonight. The front will weaken and dissipate over the region this weekend. && .NEAR TERM /THROUGH TONIGHT/... As of 730 PM Friday... Latest radar scans showing a few MCVs moving over the area. The main one could be seen across over the Northern Piedmont swirling over Vance, Warren and Franklin counties. The bulk of the rain is over the Coastal Plain and Northeastern Piedmont. While areas are expected to briefly dry out, another round of showers and storms are expected to develop later tonight. The heavy rain threat and flooding threats will continue into the overnight hours. Thus, the Flood Watch for most of NC will not be cancelled early. Latest model guidance is showing the best chance for redevelopment anywhere along and east of the US1 corridor. Lingering showers overnight should be pushing near the coast by sunrise as dry air moves into the region. Lows overnight will range from low to mid 70s. As of 218 PM Friday... * Flood Watch remains in effect for all but the far western Piedmont counties until midnight tonight * Potential exits for localized 4+ inches of rainfall over portions of the Piedmont and Coastal Plain Sfc analysis this afternoon shows the sfc boundary stretching from the southern Piedmont northeast through the northern Coastal Plain. This area continues to see the strongest convection and rain rates. A MCV was observed spinning over the Sandhills/central Piedmont when looping radar scans. This feature, along with the instability axis east of the boundary will continue to shift northeast over time through this evening. Latest high-res ensemble guidance (HREF/REFS/WoFS) all suggest the possibility of higher rainfall rates falling first over the southern/central Piedmont the next few hours, before pivoting up into the northern Coastal Plain later this evening. There is a signal for localized amounts as high as 5 inches in these areas. Given the high rain rates thus far, the continued highly anomalous moisture flux, and some reports of flooding, will continue the Flood Watch through midnight tonight. The bulk of the rain will pull north overnight tonight, but latest runs of the HRRR do maintain the potential for some linger showers/storms over our central/northern Piedmont. Overall though, most of the rain should be north of our area through sunrise tomorrow. Overnight lows will remain in the mid 70s with patchy fog possible. && .SHORT TERM /SATURDAY AND SATURDAY NIGHT/... As of 218 PM Friday... While the sfc/mid-level low will have pulled bulk of the precipitation north of our area by 12Z Saturday, anomalous moisture will linger especially along and east of US-1. As such, additional showers and a few storms will likely develop Saturday afternoon along the dissipating frontal boundary. Highest chances will focus further east. Flash flooding potential should be limited Saturday, but we are still outlooked in a Marginal ERO from WPC across eastern areas. FFG should be a bit lower given the heavy rain on Friday, and thus urban areas could be susceptible to flash flooding. Although, overall coverage should be more limited compared to Friday. Temperatures will rise back into the lower to mid 90s, peaking across the far southwestern Piedmont. Dew points will likely max in the 70s again Saturday afternoon (highest to the east). However, some fleeting wnwly flow aloft may introduce a bit of mixing (especially out west where it will be hottest). Thus, heat indices should stay below advisory criteria. Warm overnight lows in the lower to mid 70s is expected. && .LONG TERM /SUNDAY THROUGH FRIDAY... As of 252 PM Friday... ...Dangerous Heat Returns Sunday Through the Middle Part of Next Week... ...Pattern change with trough developing to our west (Ohio Valley into the TN Valley) late week into next weekend brings threat of a stalling front and heavy rain/cooling temperatures... The main weather story will be the return of dangerous heat beginning Sunday and peaking Monday and Tuesday. Heights continue to rise Monday and Tuesday. The low level flow is forecast to be more westerly. Heat Advisory criteria looks likely to be met in the southern and eastern areas where index values should reach and exceed 105 Sunday and Monday even with some mixing out of the dew points in the afternoon, then possibly Excessive Heat Warning criteria of 110 on Tuesday and Wednesday as the heat wave peaks. Actual highs should reach the mid 90s to lower 100s Monday, Tuesday, and possibly Wednesday. Lows in the mid 70s to lower 80s. Both could challenge daily records. There is only a small chance of PM storms Monday and Tuesday. The chance of mainly afternoon and evening thunderstorms returns Wednesday especially in the west. All areas have a good chance to likely Thursday and Friday as a cold front will approach from the NW. Highs will "cool" into the lower to mid 90s Thursday and 80s by Friday. A potential wet period with less heat late next week into the weekend. && .AVIATION /23Z FRIDAY THROUGH WEDNESDAY/... As of 705 PM Friday... TAF period: While most terminals are reporting VFR conditions around 00Z, widespread ceiling restrictions will develop overnight. While RWI has a narrow window for dropping to LIFR ceilings, there is high confidence in all other terminals dropping to 500 ft ceilings or lower. Coverage of showers and thunderstorms has dropped a little bit more quickly than anticipated, and a VCSH/VCTS mention should be enough at most sites. The low ceilings should begin to lift shortly after sunrise Saturday, and all sites should return to VFR conditions by Saturday afternoon. A chance of thunderstorms will return to RDU/FAY/RWI Saturday afternoon. Outlook: Morning low stratus and/or fog will be possible again Sun morning mainly at RWI and FAY, followed by primarily hotter and mainly dry, VFR conditions until the next front settles into the region late Wed through Thu. && .CLIMATE... Record High Temperatures: July 15: KGSO: 97/1974 KRDU: 99/1997 July 16: KGSO: 99/1915 KRDU: 101/1887 KFAY: 103/1937 Record High Minimum Temperatures: July 12: KGSO: 76/2011 KRDU: 78/2011 KFAY: 80/1935 July 13: KGSO: 75/2017 KRDU: 78/2017 KFAY: 78/2017 July 14: KGSO: 77/1981 KRDU: 77/2017 KFAY: 80/2017 July 15: KGSO: 74/2019 KRDU: 76/1992 KFAY: 78/2015 July 16: KGSO: 75/2010 KRDU: 77/2010 KFAY: 78/1992 && .RAH WATCHES/WARNINGS/ADVISORIES... Flood Watch from midnight EDT tonight through Friday evening for NCZ007>011-022>028-039>043-074>078-083>086-088-089. && $$ SYNOPSIS...MWS NEAR TERM...CA/Luchetti SHORT TERM...Luchetti LONG TERM...Badgett AVIATION...Green/MWS CLIMATE...RAH