259 FXUS62 KRAH 101816 AFDRAH Area Forecast Discussion National Weather Service Raleigh NC 215 PM EDT Wed Oct 10 2018 .SYNOPSIS... Hurricane Michael will move quickly northeast over the Southeast states late today through tonight, before passing over the Carolinas as a tropical storm late tonight through Thursday. The storm will then track off the Mid Atlantic coast late Thursday night. High pressure will build in from the northwest on Friday. && .NEAR TERM /THROUGH TONIGHT/... As of 1040 AM Wednesday... Small adjustments made to pops and temps today. High rain chances will continue as the broad area of strong water vapor transport pivots northward through the area. Most areas will see rainfall of one half to one inch, with spotty 1-2" totals, and minor street flooding is certainly possible. The source region for this moisture stream indicates very efficient rainfall production, with an LCL-to- 0C depth of 4.3 km on the 12z CHS sounding. The heaviest precip looks to be across our southern half and western half. This rain will unfortunately set the table for Michael by elevating water levels and soaking soils, potentially contributing to weakened tree root structures, making them vulnerable to falling when Michael's wind field arrives. Expect highs today from the mid 70s to low 80s NE. -GIH Earlier discussion from 355 AM: Today... Enhanced southerly mid level flow in between the mid level high off the southeast U.S. coast and Hurricane Michael, which is expected to make landfall today across the FL Panhandle, will help to pull higher moisture content air northward and into central NC today. PW's are expected to surge into the 2-2.5 inch range, with an associated band of tropical showers and isolated storms moving northward across the area today. Given the individual cells within the band of showers/storms should have a decent motion today think the flooding threat should remain rather isolated (minor flooding/maybe isolated flash flooding) despite the high PW's. High temps today are expected to range from the mid 70s northwest to the mid 80s in our far east. Tonight: A general lull is expected in the activity late this evening into early Thursday morning. However, lingering showers will remain possible as Hurricane Michael approaches from the south- southwest tonight. However, the bulk of the rain associated Hurricane Michael is generally expected to be after daybreak on Thursday, along with any possible tornado threat across southeast/eastern NC. Low temps should be very warm for mid October, in the lower to mid 70s. && .SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/... As of 405 AM Wednesday... ...The most significant impacts associated with Michael are expected across central NC late Thursday morning into Thursday evening... After a lull in showers before daybreak, the rain shield associated with tropical cyclone Michael will quickly spread northeast into central NC after daybreak on Thursday and then spread across the area during the morning and afternoon. Given the upper air pattern with the approaching mid/upper level trough over the Mississippi Valley and the commencement of extratropical transition, the precipitation distribution will follow a left of track pattern, favoring the heaviest rain across the northern Piedmont. WPC guidance indicates an axis of heavy rain on the order of 3 to 6 inches is expected across much of central NC with the heaviest rain expected from Albemarle to Siler City to Durham to Henderson where amounts of 5 to possibly 7 inches are expected. Rainfall amounts will be a little less closer to the storm center across the southern Sandhills and southern Coastal Plain. Given the forecast amounts and short duration, no need to make any adjustments to the current flash flood watch thats in effect across the entire area from 6 am Thursday through 5 am Friday. The widespread heavy rain should be over by the pre dawn hours on Friday. Based on the latest official NHC track, sustained speeds are likely to be in the 15 to 30 mph range with gusts of 30 to 40 mph are expected across the Southern Piedmont, southern Sandhills and southern Coastal Plain. Lighter winds are expected to the west and north with sustained winds of 10-20 mph with gusts of 20 to 30 mph. These winds will likely result in some downed trees and power lines, mainly to the southeast of Laurinburg, Lillington, and Wilson. A tropical storm watch remains in effect for a portion of the southern Sandhills and southern Coastal Plain. With clouds, winds, and a tropical airmass, expected little diurnal change in temperatures from Wednesday night into late Thursday although some drier and cooler air is expected to arrive on the back side of Michael late Thursday night. -Blaes && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... As of 1235 PM Wednesday... Based on the official forecast track, TS Michael will be tracking quickly NE away from NC Fri morning. Models indicate dry air moving into the area, so expect plentiful sunshine, albeit with potential stray gusty winds in its wake. Michael will leave a broad trailing frontal zone off the SE coast, with a more substantial cold front sitting just to our NW, the coldest/densest air staying temporarily blocked by the mountains. So while a dip in temps is expected Fri, readings will be just slightly below normal initially. A shortwave trough moving through the N-central CONUS early Fri will progress eastward across the Northeast states late Fri into early Sat, allowing a cool surface high centered over the central CONUS to shift eastward and push the cold front SE/SSE into our area, initiating a further drop in thicknesses by Sat morning. We should see a few clouds to start the weekend, including potential terrain- enhanced mid clouds early Sat morning in the Piedmont. Thicknesses suggest highs about two categories below normal Sat. We'll start to see a more active pattern into early next week, with greater-than-usual day-to-day variability. The surface high will shift E off the Mid Atlantic and Northeast coast Sun, sending a coastal inverted trough northwestward into the Carolinas. This will cause a rebounding of thicknesses and increased cloud cover for the latter half of the weekend. With the increased moist upglide along the northward-shifting frontal zone, will bring in small chance pops (20-30%) Sun night into early Mon, with a rebound in temps Mon as brief warm air advection returns. Another broad but amplified shortwave trough swinging through the central CONUS early Mon will swing by to our N through early Tue, taking a cold front through the area, and expect good chances of showers and perhaps a storm late Mon through Mon night. The front will stall out just to our south for Tue/Wed, with cool high pressure building in from the W and NW. Expect quiet and dry weather to move in Tue, with increasing clouds Wed as the front begins to buckle back north into the area. -GIH && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... As of 215 PM Wednesday... Adverse aviation conditions will persist at INT/GSO (MVFR to IFR) as a band of showers moves through the area. VFR conditions should hold at RDU/RWI/FAY, although a brief period of MVFR conditions with rain is possible this afternoon. This rain will decrease in coverage and intensity as it tracks northward through this evening, and will be followed by a brief relative lull (low rain chances) from mid evening through much of the night. This will allow low clouds to develop areawide, with MVFR conditions expected (and likely IFR/LIFR at INT/GSO) after 03z. These poor conditions will hold through Thu, as Hurricane Michael tracks northeastward through our region as a tropical storm. While surface winds will have decreased somewhat, the winds just off the surface will remain very strong, resulting in considerable gustiness starting in the last few hours of the TAF valid period, along with a trend to very heavy rainfall. In short, starting tonight, conditions at all TAF sites will begin to deteriorate, with strong/shifting winds with height (and potential low level wind shear) making aircraft handling very difficult. Looking beyond 18z Thu, the low cigs/vsbys and strong/shifting winds will remain problematic through much of Thu night. Clearing skies and improving aviation conditions from W to E are expected Fri morning as Michael moves quickly NE away from the area, although winds may remain gusty for a longer time. VFR conditions are expected to dominate for much of the Fri through Mon period, with high pressure extending in from the NW, although sub-VFR stratus/fog is possible late Sat night into early Sun as a warm frontal zone briefly pushes northward into the region. A little rain is possible late Sun into Mon ahead of a cold front that will move in from the W late Mon. -GIH && .RAH WATCHES/WARNINGS/ADVISORIES... Tropical Storm Warning for NCZ028-042-043-073>078-083>086-088-089. Flash Flood Watch from Thursday morning through late Thursday night for NCZ007>011-021>028-038>043-073>078-083>086-088-089. && $$ SYNOPSIS...Hartfield NEAR TERM...Hartfield/BSD SHORT TERM...Blaes LONG TERM...Hartfield AVIATION...Hartfield