864 FXUS62 KRAH 060837 AFDRAH AREA FORECAST DISCUSSION National Weather Service Raleigh NC 337 AM EST Mon Dec 6 2021 .SYNOPSIS... Temperatures will rebound Monday with strong winds in advance of a cold front that will bring isolated showers Monday evening and much colder air for Monday night and Tuesday. Rain is expected with low pressure on Wednesday. && .NEAR TERM /TONIGHT/... As of 930 PM Sunday... As a weak low pressure system off the coast of the Outer Banks will continue to produce offshore showers and storms overnight, Central NC will remain cloudy and dry through tonight's period. Temperatures overnight will be steady, remaining near 50 degrees, with cooler spots dipping down just below 50. Winds overnight will be mostly light from the south/southwest and increasing late morning. Previous discussion as of 245 PM Sunday... High pressure has moved offshore New England, with a ridge extending southwest into the Carolinas. In addition, a wave of low pressure is attempting to develop along a coastal front off North Carolina. Cloud cover took longer to develop than expected, which allowed highs to rise a few degrees above expected values, although cloud cover will now prevail for the rest of the day. The ridge across NC is already dissipating fairly quickly with the parent high moving away. Radar echoes to the east are extremely isolated across inland North Carolina, with greater coverage along the Outer Banks. While some models do show isolated showers across our eastern counties, most notably the NAM, the NAM's depiction of early afternoon showers is a bit farther west than what has developed on the radar, so I am forecasting that this bias will continue into the evening hours and will go with a dry forecast, although inland counties east of the Raleigh forecast area may have isolated showers. The cloud cover will result in a non-diurnal temperature curve tonight. Temperatures will likely drop through midnight, then remain steady or slightly increase through the rest of the overnight hours. Lows will be in the upper 40s and lower 50s. && .SHORT TERM /TUESDAY AND TUESDAY NIGHT/... As of 337 AM Monday... Tuesday will start off dry in the wake of the cold frontal passage. Weak surface high pressure will move in from the Ohio Valley throughout the day but with east/northeasterly surface winds increasing through the afternoon hours, clouds will likely thicken up as the day progresses. Meanwhile, a shortwave trough embedded within southwesterly flow will approach the area by late afternoon/early evening. Broad forcing for ascent ahead of this wave coupled with modest moisture transport should be enough to spread some light rain into the area after midnight Tuesday. Much of the precip will likely go into saturating the column as surface dewpoints will be in the teens/lower 20s to start the day. Thus, precip amounts Tuesday night/early Wednesday do not look to be more than a few hundredths of an inch. Given cool northeasterly flow throughout the day, Tuesday's highs will range from the upper 40s in the Triad to the mid 50s in the southern Coastal Plain. Lows Tuesday night will bottom out in the mid to upper 30s. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... As of 337 AM Monday... Wednesday's upper level shortwave trough is still expected to move through the area, but there is an increasing consensus among the models that the surface wave will take a more easterly track through the area per the EC solution. The GFS and its family of ensemble members have trended downward with QPF over the last 24 hours suggesting they are coming around to the EC/ECENS solution. That being said, it still appears there is a decent shot of rainfall across the area, with amounts ranging from a tenth to a quarter of an inch across the Triad, to a little more than half an inch to the east. Rain will overspread the area during the early morning hours on Wednesday. With surface temps in the mid/upper 30s and dewpoints in the 20s at precip onset, wet bulb temps should be near or slightly above freezing per various BUFKIT soundings across central NC and as such. mixed precip doesn't appear to be a concern. Given cloud cover and rainfall, temps will struggle throughout the day, likely only making it into the low/mid 40s. Overall there were no significant changes made to the previous forecast, other than nudging QPF downward a bit. Dry weather is expected on Thursday as a weak surface ridge builds into the area. Meanwhile to the west, southwesterly flow aloft will take a series of weak troughs west of the mountains and through the Ohio Valley Thursday into Friday. Ensembles suggest very low end probabilities of precip across the western Piedmont with dry weather elsewhere. As the longwave trough shifts east this weekend, precip chances should increase as the attendant surface cold front moves through the Mid Atlantic Saturday night into Sunday. Temps Thursday will remain on the cool side, with some moderation expected Friday and especially ahead of the cold front on Saturday. Above normal temperatures are likely to linger into Sunday as well. && .AVIATION /06Z MONDAY THROUGH FRIDAY/... As of 130 AM Monday... 24-hour TAF period: Observations show MVFR ceilings across the Triad (including INT/GSO), with mainly VFR elsewhere. Models have come into a bit better agreement that IFR ceilings will develop across much of central NC over the next several hours, though NAM soundings continue to show this much more than the GFS. Some LIFR ceilings can't even be ruled out around sunrise at the eastern TAF sites (RDU/FAY/RWI). Furthermore, with mostly clear skies and calm winds, there is potential for some patchy fog at the eastern TAF sites, with the highest confidence of this occurring at FAY. In fact, sites just to the south of FAY are reporting visibilities of 1/4 mile to 0. Any sub-VFR ceilings and visibilities will mix out by late morning in the east, and while current thinking is they should also mix out at INT/GSO, confidence there is lower. Southwest winds will gust to 20-30 mph from late morning into the afternoon. A cold front will then move across central NC from NW to SE from about 00z to 06z, accompanied by a band of MVFR ceilings and possibly a few isolated light showers. Behind the front, winds will shift to NW with VFR conditions returning. Looking beyond 06Z Tuesday: VFR conditions will return for Tuesday before restrictions and rain overspread the area Tuesday night into Wednesday. VFR and dry weather will prevail on Thursday, before a chance of light rain and sub-VFR conditions returns on Friday. && .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Green NEAR TERM...CA/Green SHORT TERM...Leins LONG TERM...Leins AVIATION...Danco