514 FXUS62 KRAH 131036 AFDRAH AREA FORECAST DISCUSSION National Weather Service Raleigh NC 636 AM EDT Mon Sep 13 2021 .SYNOPSIS... High pressure centered just off the North Carolina coast will drift slowly eastward and further offshore through early this week, while continuing to extend westward into the Carolinas. && .NEAR TERM /TODAY AND TONIGHT/... As of 215 AM Monday... The center of the surface high will remain well offshore, with the high ridging westward into the Southeast US. A trough sitting over central NC will linger into the morning, with relatively low pressure over the area expected through tonight. A 595 dam H5 high pressure aloft, centered over the southern Appalachians, will weaken slightly as it drifts eastward to over the Carolinas today and offshore tonight. The weather should remain dry with generally south- southwesterly flow under the persistent high. Expect continued moderation in temperatures, with highs in the low to mid 90s and lows in the mid 60s. && .SHORT TERM /TUESDAY AND TUESDAY NIGHT/... As of 225 AM Monday... A surface low over the western Great Lakes will lift east-northeast into eastern Canada through Tuesday night while the attendant cold front extends west-southwest through the Great Lakes and Midwest. Meanwhile, Tropical Cyclone Nicholas is expected to be inland over TX Tuesday morning and should very slowly migrate east-northeastward into LA through Tuesday night. A second tropical low could move northward from the Caribbean over the western Atlantic Tuesday night into Wednesday. The result for central NC will be an increase in southerly/southwesterly flow and warm, moist advection into the area Tuesday night. With all three aforementioned systems still well away from the region, do not expect any significant weather impacts for central NC through Tuesday night. However, increasing cloudiness, especially from the southeast, is expected by early Wednesday morning. An isolated shower also cannot be completely ruled out, but should be limited to location along the coast until after daybreak Wednesday. Temperatures should be comparable to Monday, with highs in the low 90s and lows in the mid 60s. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... As of 355 AM Monday... There has been little change in forecast rationale and the associated sensible weather during the medium range. A mid level ridge now over the lwr OH Valley and cntl Appalachians, one which set or tied daily record 500 mb heights at GSO and RNK last evening, will have drifted ewd to near Bermuda by Wed-Wed night. A nrn stream, positive tilt trough will lift newd across the Great Lakes and Northeast during the same time, while the srn portion of that trough will be left behind within a broad weakness/trough in the heights aloft that will initially span most of the lwr MS Valley, sern US, and adjacent swrn Atlantic, the latter that will include a TUTT/low now moving wwd near the nrn coast of Hispaniola. The ridge is then forecast to retrograde across the swrn Atlantic to near FL through early next week. The consensus of model guidance continues to indicate that low pressure expected to form off the Southeast coast, related to the TUTT, will likely remain offshore while tracking nwd across the wrn Atlantic mid-late week, though an increasingly ely component to the low level flow will cause low level moisture/humidity to increase across cntl NC during that time. And given that a front related to the aforementioned nrn stream trough will likely stall on the west slopes of the cntl Appalachians, a warm-hot and humid airmass will likely remain in place, with associated conditional instability that will favor a late summertime pattern of diurnally-driven showers/storms across cntl NC throughout the forecast period. && .AVIATION /12Z MONDAY THROUGH SATURDAY/... As of 635 AM Monday... 24 hour TAF period: High confidence VFR conditions will prevail through the TAF period. Some scattered clouds in the 3-6 kft range will develop overnight area-wide. Looking ahead: VFR conditions are expected through Tuesday. The next chance for adverse aviation conditions will be Wednesday night or Thursday, though chances for afternoon convection and morning fog/stratus will increase Tuesday night through Saturday. && .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...KC/Hartfield NEAR TERM...KC SHORT TERM...KC LONG TERM...MWS AVIATION...KC