Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC

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000 FXUS62 KRAH 230536 AFDRAH Area Forecast Discussion National Weather Service Raleigh NC 135 AM EDT Mon MAY 23 2016 .SYNOPSIS...
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An upper level low will move across the area today, before tracking along the East Coast and away from the region on Tuesday. A strong upper level ridge will then build over the Southeast through the remainder of the week.
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&& .NEAR TERM /through tonight/... As of 935 PM Sunday... Interesting weather this evening with batches of strong to severe storms, driven in part by vigorous dynamic forcing for ascent associated with strong mid level DPVA and focused upper divergence in the presence of good deep layer bulk shear (eff shear near 30 kts) and marginal instability. Several cells generated small hail, reasonable given the somewhat low freezing level around 8 kft, and we also received a few reports of low level rotation, also reasonable considering the 20 kts of 0-1 km shear and radar indications of weak rotation up through the mid levels. Mid level lapse rates remain elevated at 6.5 C/km, although the loss of heating has allowed the initially quite steep low level lapse rates (over 8.0 C/km) to begin a downturn. Nevertheless, the -10C to -30C CAPE remains around 200 J/kg with favorable bulk Richardson numbers of 20-35 and 400-500 J/kg of MLCAPE (although CINH is encroaching with nightfall), so the risk of a strong storm or two will linger for another few hours, until the strong dynamics push to our south and nocturnal cooling facilitates stabilization. Will however leave a mention of isolated showers on through the late night over the eastern CWA where PW will stay above normal and MLLRs elevated beneath the core of the mid level low. Lows in the lower to mid 50s under partly to mostly cloudy skies. -GIH && .SHORT TERM /Monday and Monday Night/... As of 325 PM Sunday... Upper level low begins to pull away from our region by Monday afternoon, and exits offshore Monday night. Perturbations rotating around this feature will trigger scattered showers...mainly across the ne half of central NC, with a few thunderstorms possible during peak heating. With loss of heating, shower coverage expected to diminish with bulk of showers dissipated prior to midnight. High temp Monday highly dependent upon cloud coverage. With peeks of sun this afternoon, temps responded by climbing quickly into the mid 70s. May see a similar scenario Monday though presence of 850mb thermal trough over the region may dampen recovery a tad. Currently forecast temps near 70 far northeast to the mid 70s southwest. If clouds and showers more extensive than current thinking, then max temps may end up being 3-4 degrees cooler across the ne piedmont/northern coastal plain. Subsidence behind the exiting low and advection of a drier air mass should cause clouds to diminish over central NC, departing last over the ne counties. Residual low level moisture may allow areas of fog to develop, though confidence not high enough to mention in the forecast at this time. Min temps comparable to tonight in the mid 50s. && .LONG TERM /Tuesday through Sunday/... As of 235 PM Sunday... Conditions are expected to dry out on Tuesday as the upper low pulls further away and shortwave ridging builds over the region. As the low pulls away, the building ridge will keep the main storm track to our north and west, resulting in mostly dry conditions through the majority of the long term period. There are indications that the ridge may weaken some towards the end of the forecast period, allowing an uptick in mostly diurnal type convection. However, given the model disagreement (the GFS, which is known the break ridges down too quickly, breaks down the ridge, while the ECMWF holds strong), will just show a little increase in cloud cover and will bring in a slight chance of precip at the very end of the forecast period. Otherwise, temps will gradually warm up to above normal, from mostly lower 80s on Tuesday to mid/upper 80s for the remainder of the period. && .AVIATION /06Z Monday through Friday/...
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As of 135 AM Monday... The main aviation concern today is an area of low clouds moving south out of VA early this morning, which will impact areas east of KRDU through at least mid-morning. MVFR ceilings are most likely at KRWI, with a period of IFR and scattered showers after 12z. Showers will be more isolated to the west, especially west of KRDU, where cloud bases are more likely to be in the 3000-4000ft range. An 8- 12kt northerly wind will prevail for much of the day, becoming light and variable tonight as low pressure moves off the NC coast and VFR conditions return areawide. Long term: VFR conditions will be predominate this week as high pressure builds over the region.
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&& .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...KS NEAR TERM...Hartfield SHORT TERM...WSS LONG TERM...KRD AVIATION...22

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