Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC

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975 FXUS62 KRAH 200523 AFDRAH Area Forecast Discussion National Weather Service Raleigh NC 1225 AM EST Mon Feb 20 2017 .SYNOPSIS...
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High pressure will build into the region tonight, then move offshore on Tuesday. A low pressure system will cross to our south on Wednesday.
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&& .NEAR TERM /THROUGH TONIGHT/... As of 1059 PM Sunday... Clear skies at sunset noted from the Mississippi Valley eastward to well off in the western Atlantic. The light NW flow over central NC continued to diminish. Nearly calm conditions are expected the rest of the overnight. Temperatures late evening were around 50 NW ranging to 60 SE. Clear skies expected overnight with lows very mild, mostly in the lower to mid 40s, except for some upper 30s in the normally colder locations of the northern Piedmont. && .SHORT TERM /MONDAY THROUGH MONDAY NIGHT/... As of 150 PM Sunday... The center of a high pressure ridge will drift across southern Quebec during this time frame while nosing southward through central NC. Dry and deeply stable air will persist through Monday, yielding mostly sunny skies, with just a few high clouds within fast northwesterly upper flow. Thicknesses will start out a bit lower than in the last couple of mornings, particularly over the NE sections of the forecast area, beneath the heart of the ridge axis. But values will still be well above normal, supporting highs from the upper 60s NE to the mid 70s in the far southern CWA. As the ridge axis shifts to our east Mon night, resulting in a southeasterly and southerly low level flow into central NC, low level moisture will steadily advect into the area, with increasing moist upglide focused around 290K across the western CWA overnight. Will have increasing clouds Mon night, especially in the west, with the relatively cooler ridge lingering in the NE CWA. Expect lows from the upper 30s NE ranging to the mid to perhaps upper 40s in the western CWA. -GIH && .LONG TERM /TUESDAY THROUGH SUNDAY/... As of 254 PM Sunday... Tuesday will begin with the upper level ridge axis right overhead and a surface low pressure system over New England. Clouds will increase throughout the day ahead of a frontal system over the Mississippi Valley. Highs in the mid to upper 60s. As the surface high moves offshore and the front gets closer, warm air advection will begin and temperatures on Wednesday will soar into the mid 70s. As the front moves through there will be some chance for rain showers but not a soaker of a day by any means. Despite the front moving through it eventually washes out and the high pressure that was over new England dips southward off of the Carolina Coast and thus no real change in airmass occurs as return flow keeps warm air moving into central NC. This will keep temperatures in the mid to upper 70s for Thursday as frontogenesis begins to occur across the Appalachians as a low pressure system develops over the plains and pushes eastward. This will give slight chances for rain across the north on Thursday but again with meager moisture content as a warm front organizes and pulls away to the north as the parent low moves front the Plains northeastward towards the Great Lakes. The timing of the evolution of this system is in a big of question with the GFS showing a quicker progression of the advancing cold front and the ECMWF still a little slower but faster than yesterday. As a result the best chance for some significant rainfall and perhaps a thunderstorm or two will begin on Friday and progress through Saturday but clearing out for Sunday. Highs in the 70s through Saturday before easing back into the mid 60s for Sunday. && .AVIATION /06Z MONDAY THROUGH FRIDAY/...
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As of 1225 AM Monday... There is a high likelihood of VFR conditions across central NC through 06Z Tuesday. An area of high pressure at the surface will build in from the north today. This system will maintain mostly clear skies and light surface winds through tonight. With high pressure to our north-northeast later tonight, a low level ely flow will develop. This flow will transport moisture off the Atlantic, and into the Piedmont. As the moisture meets the upslope region of the foothills and the higher terrain of western NC, areas of stratus will develop. This stratus layer may spread into the western Piedmont after 06Z Tuesday, increasing the risk for sub VFR ceilings. The risk for sub VFR ceilings appear higher late Tues day night into Wednesday morning. There will be a chance for sub VFR ceilings Wednesday through Friday across central NC as a moderately moist air mass and an unsettled weather pattern is expected.
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&& .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...WSS NEAR TERM...Badgett SHORT TERM...Hartfield LONG TERM...Ellis AVIATION...WSS is the U.S. government's official web portal to all federal, state and local government web resources and services.