Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC

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000 FXUS62 KRAH 161556 AFDRAH Area Forecast Discussion National Weather Service Raleigh NC 1156 AM EDT SUN OCT 16 2016 .SYNOPSIS...
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Surface high pressure offshore the DELMARVA coast will weaken and shift southward offshore the Carolina coast tonight and Monday as progressive shortwave energy erodes an upper level ridge along the eastern seaboard.
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As of 1100 AM Sunday... A potent (~150 knot) jet moving ashore the northern CA coast this morning will progress rapidly east through the Intermountain West this today, the central/northern Rockies tonight, emerging over the high plains of the Upper Midwest Monday morning (spanning ~15 degrees latitude from 35-50 degrees N). Progressive shortwave energy ejecting ENE across the Great Lakes into New England late tonight and early Monday will significantly erode /de-amplify/ a pronounced upper level ridge currently in place along/offshore the Mid- Atlantic/New England coast while providing sufficient force to nudge a slow moving /nearly cut-off/ upper level low from GA offshore the Southeast Coast by 12Z Monday. As a result, ~1030 mb surface high pressure centered offshore New England yesterday evening will weaken to ~1025 mb as it shifts southward offshore the DELMARVA coast this aft/eve, down to ~1020 mb offshore the Carolina coast tonight. In terms of sensible weather, expect conditions similar to yesterday albeit several degrees warmer in the mid 70s this afternoon and mid 50s tonight. -Vincent
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&& .SHORT TERM /MONDAY AND MONDAY NIGHT/... As of 335 AM Sunday... Surface high pressure begins to slip eastward on Monday and thus a return flow scenario that will begin to raise temperatures in the area back into the low 80s for highs which is about five degrees above normal at KFAY but 8 and 10 degrees above normal for KRDU and KGSO respectively. Another day of lots of sunshine is expected with no precipitation. Lows Monday night in the upper 50s. && .LONG TERM /Tuesday through Saturday/... As of 250 AM Sunday... Tue/Wed: Narrow Bermuda high pressure at the surface extending westward through the Carolinas will be capped by a mid level anticyclone, resulting in deep (850-300 mb) warming and subsidence. Apart from patchy early-morning fog, skies should be generally sunny, with well above normal temps -- highs in the lower 80s and lows around 60 -- as thicknesses are expected to be around 25-30 m above climo. Thu-Sat: The mid level ridge gives way to a narrow amplifying trough over the eastern third of the CONUS late in the week. Previous model runs had brought about some concern regarding the fate of broad weak low pressure spanning eastern Cuba, the Bahamas, and northeastward toward Bermuda, with some models developing what appears to be a tropical low east of the Bahamas and taking it northward near eastern NC within the strengthening SSW steering flow east of the encroaching trough. But the latest model runs keep such a low far enough offshore to be of little to no consequence for flood-ravaged eastern NC. We should still see increasing chances for showers however starting Thu night, and likely peaking Fri as the cold front sweeps eastward through the area, followed by dwindling pops Fri night. It doesn`t appear that there will be much opportunity for deep moisture return, which would hold down precip amounts for the event. Expect warm temps again Thu, with highs near 80 with increased cloud cover. High marginal of error for temps Fri with the front moving through, and for now will have highs around 70 in the Triad ranging to the mid-upper 70s in the SE, all with good chances for showers. Uncertainty grows heading into Fri night/Sat, as the operational GFS and ECMWF swing an amplified but open mid level trough to our east Fri night along with the surface front, bringing in cooler temps starting Fri night, although some model suites including earlier GEFS ensemble means were much slower with a closed low in the trough base. Will go with the more progressive solution of more recent runs, with lows Fri night in the low-mid 50s. Expect a return of some sunshine Sat with slightly below normal highs in the 60s to around 70. -GIH && .AVIATION /12Z SUNDAY THROUGH THURSDAY/... As of 730 AM Sunday... 24 Hour TAF period: Some patchy dense fog across the northeast has developed over the last hour or two but this is expected to be localized and fairly short lived. MVFR ceilings will continue to prevail in the Triad for the next couple of hours before all sites are expected to return to VFR. Another round of sub VFR ceilings and visibilities are possible near the end of the TAF period early Monday morning. Long term: Mostly VFR conditions expected for much of the work week aside from some early morning fog or stratus before some unsettled weather moves in towards the end of the week into next weekend. && .HYDROLOGY... As of 250 AM Sunday... Major river flooding continues on the lower reaches of the Neuse and Tar rivers, although levels are expected to fall to moderate flooding today. Minor flooding is expected for several days on the Roanoke River at Roanoke Rapids and Scotland Neck, due to upstream lake releases. For details, see && .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Vincent NEAR TERM...Vincent SHORT TERM...Ellis LONG TERM...Hartfield AVIATION...Ellis HYDROLOGY...RAH is the U.S. government's official web portal to all federal, state and local government web resources and services.