Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC

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172 FXUS62 KRAH 240659 AFDRAH Area Forecast Discussion National Weather Service Raleigh NC 255 AM EDT Mon Jun 24 2024 .SYNOPSIS... A strong mid level trough and accompanying surface front will cross North Carolina today, then settle just to our southeast tonight. Weak high pressure will pass over the area late tonight through early Tuesday, then push quickly offshore late Tuesday, allowing hot and humid conditions to return for Wednesday. Another front will approach from the northwest early Thursday. && .NEAR TERM /TODAY THROUGH TONIGHT/... As of 220 AM Monday... Temps will remain above normal today, although humidity will be trending lower through the day. A potent mid level shortwave will move through the eastern Great Lakes, St Lawrence Valley, and Northeast toward NB/NS through the day. The corresponding surface front will approach the Appalachians this morning and likely jump into the prefrontal trough over the NC Piedmont by early afternoon, before pushing ESE and to our southeast by early evening. As other shifts have alluded to, this front will be more of a dewpoint front, with values dropping into the 60s, while the actual temperature change will be very modest, just a few degrees at most. It still appears that convection chances ahead of and along the front will be largely confined to this afternoon over our southeast half, particularly S and E of Raleigh, a scenario supported by recent HREF output and several recent RAP runs. The W Piedmont will see falling PWs and surface dewpoints by midday, limiting afternoon SBCAPE, with low level flow becoming northwesterly. But from the Triangle to the S and E, with decent heating and still-elevated prefrontal dewpoints allowing for moderate SBCAPE by early afternoon and greatly steepening 925-700 mb lapse rates to 8.5-9.5 C/km, we should see initially isolated convection grow upscale and become scattered to numerous as they push SE of Raleigh. With these steep lapse rate and improving deep layer bulk shear to 25-35 kt along the southern fringe of the mid level trough, a few intense downbursts are possible. By early to mid evening, most CAMs depict convection winding down and exiting as the front starts to settle to our SE and drier low level air spills in from the NW. A few clouds may linger overnight across the SE, but otherwise we should see a clearing trend from the NW with dry weather after midnight. Given the slightly lower temps (I hesitate to say "cooler") and lowering dewpoints with enough clouds to temper isolation a bit, we don`t have heat advisory concerns today, although of course caution should still be exercised given the prolonged period of above normal temps. Expect highs today in the lower to mid 90s, and lows in the mid 60s to lower 70s. -GIH && .SHORT TERM /TUESDAY AND TUESDAY NIGHT/... As of 230 AM Monday... Expect a mostly dry day with returning heat. The weak high pressure passing over the Mid Atlantic region early Tue will quickly weaken further and push offshore, placing our area back into a light southerly component flow with low level thicknesses rebounding back to around 10 m above normal. PWs will have dropped to around 1", with higher values lingering near our extreme SE sections, where an isolated afternoon storm can`t be ruled out, particularly along an inland-pushing sea breeze. Otherwise, skies should be fair with deep mixing and just some high-based flat afternoon cu beneath warm and stable mid levels. Highs will be mostly in the mid 90s. Expect lows Tue night in the upper 60s to lower 70s as higher dewpoints begin to advect back into the area. -GIH && .LONG TERM /WEDNESDAY THROUGH SUNDAY/...
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As of 255 AM Monday... A front will approach from the northwest on Wednesday, and the ensembles are slightly faster than the deterministic models with the arrival of precipitation chances - while the deterministic models keep conditions dry through the day, the SREF, GEFS, and EPS all bring some pops into the Triad by sunset. The chance for rain continues Wednesday night, with the ensembles again showing higher chances than the deterministic models. The actual front moves through sometime late Wednesday night into Thursday morning, and have added an area of likely pops southeast of Raleigh Thursday afternoon. Any showers/storms Friday should be less organized, with isolated coverage to the north and scattered coverage to the south. Coverage again remains isolated everywhere on Saturday. Both deterministic and ensemble models are coming into better agreement that another front will approach the region from the northwest, with perhaps better agreement for a chance of rain that day compared to Thursday. Will make some modest increases for the chances of rain on Sunday. As for temperatures, Wednesday appears likely to have the hottest temperatures of the next seven days, and is the most likely day for triple digits to make their return. Otherwise, temperatures should remain in the 90s for the majority of locations through the rest of the forecast period. Lows should generally be in the 70s. Heat index values are also the highest on Wednesday, with that day having the greatest coverage of 100-105, although every day in the forecast has some location reaching at least a 100 degree heat index.
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&& .AVIATION /06Z MONDAY THROUGH FRIDAY/... As of 1250 AM Monday... VFR conditions will be dominant across central NC for the next 24 hours, with a couple exceptions through early this evening. Isolated showers over the NE will likely hold N of RWI before exiting in the next hour or two. MVFR cigs are possible in the far E (RWI) for a couple of hours near daybreak. Attention then turns to an approaching front that will move into the area by midday, then move through the area and push to our SE by mid evening. This will prompt scattered to numerous storms this afternoon through early evening across the SE, with gusty/erratic winds in/near storms. The chance of storms is fairly high near FAY from mid afternoon through early evening, but lower near RDU/RWI where storms will be more isolated and occur earlier in the day, in the early to mid afternoon. Any storms will exit the SE by 02z, leaving VFR conditions through the end of the TAF valid period. Surface winds will be light from the SW and WSW through sunrise, then increase to around 10-15 kt with around 20 kt gusts (stronger near storms) as they shift around to be from the NW as the front passes through. Light winds from the N and NE are expected later tonight. Looking beyond 06z Tue, expect mostly dry and VFR conditions late tonight through Tue night. Isolated late day storms are possible late Wed, followed by a better chance of afternoon/evening showers and storms Thu. Otherwise, outside of any storms, the risk of widespread sub-VFR conditions is low through Fri. -GIH && .CLIMATE... Record High Temperatures: June 24: KRDU: 99/2010 KFAY: 102/1914 June 25: KRDU: 100/1952 KFAY: 102/1914 June 26: KRDU: 102/1952 KFAY: 101/1951 June 27: KFAY: 102/1998 Record High Minimum Temperatures: June 24: KGSO: 76/2015 KRDU: 76/1888 KFAY: 79/2010 June 25: KFAY: 75/1952 June 26: KGSO: 74/2010 KRDU: 76/1902 KFAY: 76/1997 June 27: KGSO: 76/1969 KRDU: 76/1952 KFAY: 77/1998 June 28: KGSO: 76/1969 KRDU: 76/1952 KFAY: 78/1914 && .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Hartfield NEAR TERM...Hartfield SHORT TERM...Hartfield LONG TERM...Green AVIATION...Hartfield CLIMATE...RAH