Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC

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000 FXUS62 KRAH 241902 AFDRAH Area Forecast Discussion National Weather Service Raleigh NC 300 pM EDT Tue May 24 2016 .SYNOPSIS...High pressure near the surface and aloft will build into central NC through midweek. && .NEAR TERM /through tonight/... As of 300 pm Tuesday... High pressure expanding at the surface and aloft will maintain clear skies and light wind regime. In the relatively dry air mass, temps will cool appreciably this evening...cooling into the 60s by 10 pm. Overnight temps in the 55-60 degree range. && .SHORT TERM /Wednesday through Thursday Night/... As of 300 PM Tuesday... Wednesday...while the low level air mass will be slightly unstable, primarily over the coastal plain, a subsidence cap attributed to the ridge aloft will likely inhibit convective development during the heat of the day. If there was a mentionable threat for an isolated thunderstorm, guidance would suggest the I-95 corridor has the favored region. May see a slightly better chance for afternoon-early evening convection on Thursday as upper heights falter a bit in response to a minor s/w crossing the OH valley into the Mid-Atlantic. This weakening of the cap along with another day of string heating resulting in a slight to moderately unstable low level air mass should support a few thunderstorms. The threat for late day convection appears highest in the Piedmont in vicinity of a lee side trough. Above normal temperatures expected both Wednesday and Thursday with max temps in the mid-upper 80s common. Potential for a few spots to hit 90 as the 850mb/700mb anti-cyclones are in a favorable position/strength for hot conditions. Mild conditions expected Wednesday night with min temps in the lower 60s. A bit warmer Thursday night with min temps in the mid 60s. && .LONG TERM /THURSDAY THROUGH MONDAY/... As of 355 AM Tuesday... The pattern aloft this period will be characterized by a western CONUS trough and an a ridge from near Bermuda to Ontario/Quebec. At the base of/beneath the eastern ridge, southern stream energy -- the lead of which is now crossing the lower-middle MS Valley-- will help re-develop a mid to upper-level low INVOF the Bahamas during the next couple of days. A shear axis, or weakness between sub- tropical ridge centers near Bermuda, and across much of the Gulf of Mexico and north-central Mexico, will extend north from the low over the Bahamas, into the southeastern U.S. The trend in model guidance in the past 24 hours has been toward a more pronounced surface reflection in association with the Bahamas low, which subsequently would get steered --at the base of the sub- tropical ridge near Bermuda-- toward the southeast U.S. coast this weekend. Thu-Fri: Subsidence in association with the sub-tropical ridge near Bermuda, along with the absence of lifting mechanisms and incomplete modification of the initially cool and dry continental air mass over the eastern U.S., will help suppress deep convection over central NC late this week. Sat-Mon: There remains a high degree of uncertainty in the details, but the overwhelming trend toward a more substantial influence from the aforementioned low pressure near the southeast U.S coast suggests we are likely to see an increase in clouds and precipitation chances as the weekend wears on, some of which may linger into early next week, as whatever becomes of the aforementioned low pressure may get trapped beneath the higher latitude ridging to the north. Thicknesses support temps slightly above normal, though tempered by the increase in clouds. && .AVIATION /18Z Tuesday through Sunday/... As of 1250 PM Tuesday... An area of high pressure at the surface and aloft will result in mostly clear skies and generally (less than 10kts) light winds through Wednesday night. The VFR conditions are expected to continue Thursday and Friday though there will be a threat for isolated-scattered convection each afternoon. The threat for adverse aviation weather conditions will increase Saturday through Monday as an area of low pressure is expected to develop then move slowly along the coast. && .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...WSS NEAR TERM...WSS SHORT TERM...WSS LONG TERM...26 AVIATION...WSS is the U.S. government's official web portal to all federal, state and local government web resources and services.