Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 10/14/22


Area Forecast Discussion
National Weather Service Charleston SC
958 PM EDT Thu Oct 13 2022 .SYNOPSIS... High pressure will extend across the region through the weekend. A strong cold front will push offshore Monday with cold high pressure prevailing for much of next week. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... The 00Z sounding from KCHS reveals a dry atmosphere, especially in the layer between 800 and 350 mb, where much of the RH is less than 10%. PWat is just 1 inch, or around 70% of normal. Surface analysis late Thursday is showing a cold front still upstream from the local counties, mainly delineated by dew points down in the 50s in its wake. Our region still has dew points in the 60s, with the accompanied dew point depressions mainly less than about 3 or 4F. Using a blend of the HRRR and NAM yields a frontal passage between about 12 AM and 3 AM from west to east. Other than few to scattered cirrus clouds skies will be mostly clear, and cold advection will allow for min temps to get down to mainly the lower and middle 50s. However, some upper 40s can occur near and west of US-301, while places at and near the coast will be in the upper 50s. Prior to the cold front moving through, there will be a little ground fog. But this will be short lived and there are no significant visibility concerns. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/... Longwave troughing will dominate the Eastern U.S. through the period yielding mean temperatures a bit cooler than average. Surface high pressure will extend across much of the Southeast Friday through the weekend. Clear skies and light/calm winds within a decoupled boundary layer will produce strong radiational cooling regimes both Friday and Saturday nights away from warmer bodies of water. Highs will warm into the mid-upper 70s Friday with upper 70s/lower 80s Saturday. Highs will peak Sunday in the lower- mid 80s Sunday just ahead of a cold front. Lows Saturday morning will drop into the mid-upper 40s well inland to the lower 60s at the beaches and Downtown Charleston with upper 40s/lower 50s well inland to the mid 60s at the beaches and Downtown Charleston for Sunday morning. Rain-free weather will prevail. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... Quiet weather with below normal temperatures will prevail for much of the extended period. A strong cold front will push through the area Monday as the longwave trough over the Eastern CONUS deepens. Moisture will increase ahead of the front with a ribbon of PWATs potentially surging to near 1.50" by Monday afternoon. Despite this increase in moisture, model RH/omega cross sections only show weak deep-layered UVVs in place with the front, likely associated with the left exit region of a subtropical jet streak. Slight chance pops will be maintained based on this and the various model blends. This is slightly above the 13/13z NBM which keeps pops below 20%. After a warm start Monday, temperatures will run well below normal for much of next week with a cP airmass dominating in the wake of the strong cold front. Some areas inland could see lows dropping into the upper 30s both Tuesday and Wednesday nights. && .AVIATION /02Z FRIDAY THROUGH TUESDAY/... VFR. Extended Aviation Outlook: Prevailing VFR. && .MARINE... Broad cyclonic flow around low pressure off the Delmarva will give way to a cold front that moves into the waters during the post midnight hours, then clears the entire marine area before 6 AM. SW and W winds at no more than 10 or 12 kt ahead of the front will clock around to the NW and NW in its wake. Modest cold advection behind the front will result in winds climbing to 15 or 20 kt. Seas will be held down by the offshore trajectories, and generally just 2 or 3 feet. Friday through Tuesday: There are no major concerns through the period. A strong cold front will push offshore Monday. There will be an increase on both winds and seas with the front, but current data support conditions below Small Craft Advisory thresholds. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. MARINE...None. && $$ NEAR TERM... SHORT TERM... LONG TERM... AVIATION... MARINE...
Area Forecast Discussion
National Weather Service Des Moines IA
618 PM CDT Thu Oct 13 2022 ...Updated for the 00z Aviation Discussion... .DISCUSSION.../Tonight through Thursday/ Issued at 343 PM CDT Thu Oct 13 2022 Key Messages: -- Very high fire danger into early evening, elevated concern Friday -- Strong winds lessening into this evening, not as windy Friday -- Less wind, dry and cool weather this weekend into next week Details: GOES-East upper level water vapor imagery shows the broad cyclonic flow from the Manitoba province to over the western Great Lakes with several embedded shortwaves noted. Clouds have been rotating over the northeastern third or so of the state with all of Iowa experiencing strong, gusty winds from the northwest since mid- morning. The airmass is rather parched with the surrounding 12z RAOBs showing precipitable water values around or under a quarter of an inch. Boundary layer mixing up to 2.5 to 3 km has resulted in entrainment of the dry airmass with very low dewpoints and relative humidities in the upper teens and 20s this afternoon. This has yielded very high grassland fire danger over portions of our area. There was at least one field fire today near Lynnville in far southeast Jasper County as detected from the GOES-East fire temperature, which was also seen on radar and confirmed listening to Poweshiek County dispatch. More recently, an unknown type of fire was near Bussey. These fire weather conditions will lessen into this evening as the nocturnal inversion sets up and deeper mixing ceases along with relative humidity recovery. Into Friday, a potent shortwave trough in the vicinity of the western shore of Hudson Bay as of this afternoon will pivot counter- clockwise around the mean low into our area by later Friday afternoon. Forecast BUFKIT soundings and model cross sections show a fair amount of dry air below 800mb. However, as clouds move in Friday morning into the afternoon and precipitation falls and evaporates in this dry layer, it will aid to moisten the lower atmosphere. NAM and GFS soundings would support a few hours at most of light, spotty showers with the RAP staying on the drier side. The most likely location based on saturation and omega along with QPF placement in the models would be over southern Iowa at this point. While Friday will not be as windy as today, it will still be a blustery day with wind gusts generally not exceeding 40 mph. Relative humidity also will not be as low and therefore do not see anything worse than elevated fire weather concerns at this time. Through the weekend into next week, the sprawling mid-level closed low will drift east or southeastward before lifting northeastward toward the northeastern Canadian provinces late next week. For Iowa, this will mean cyclonic flow with shortwave ripples percolating through this flow into early next week before the flow becomes more northerly as the low`s influence diminishing toward mid to late week. The forecast will favor dry conditions with only a few ensemble members hinting at sporadic, light QPF and near to generally below normal temperatures during this period. The coolest days will be Monday and Tuesday with highs struggling to reach 50 degrees as a zone of high pressure moves over the region. Monday night into Tuesday morning will also likely have a widespread freeze with temperatures below 30 degrees. However, no further frost/freeze headlines will occur this fall with the criteria for these headlines already met earlier this month. && .AVIATION.../For the 00Z TAFS through 00Z Friday evening/ Issued at 618 PM CDT Thu Oct 13 2022 VFR conditions will prevail through the period with gusty northwest winds from this afternoon diminishing in the next hour or so after sunset. Winds will increase again on Friday afternoon at all sites, though lower than today with gusts of 25-35 kts expected. Patchy sprinkles are possible on Friday as well, though with little anticipated impact. && .DMX WATCHES/WARNINGS/ADVISORIES... Red Flag Warning until 7 PM CDT this evening for IAZ004-015-023- 024-033>036-044>049-057>062-070>075-081>086-092>097. && $$ DISCUSSION...Ansorge AVIATION...Hagenhoff
Area Forecast Discussion
National Weather Service Gray ME
1129 PM EDT Thu Oct 13 2022 .SYNOPSIS... A strong cold front will slowly cross through the area tonight and tomorrow, bringing a period of heavy rainfall and strong winds through Friday. A few thunderstorms are possible as well tonight and Friday. The precipitation gradually pulls east Friday night into Saturday morning. Skies clear up briefly Saturday before unsettled conditions return next week. && .NEAR TERM /TONIGHT/... 1130 PM Update... Only minor changes to the forecast at this point through the overnight period to pull in line with observations. The forecast remains well on track otherwise. Looking to regional radar and satellite... the atmospheric river is evident out ahead of a cold front with convection firing east of a coastal circulation off DELMARVA. This circulation is of particular interest... with hires guidance hinting that the mesoscale LLJ associated with this could pack a powerful punch as it tracks up the coast Friday. I do think convective feedback is leading so some exaggeration in these solutions, especially given the statistical suite in general doesn`t support 50+ kt gusts depicted here, but have nudged the wind forecast up a tad owing to the presence of the low itself. Closer to home... rainfall totals so far are generally 0.25-0.75 with small pockets of higher and lower amounts. Latest HREF data has highest rainfall rates mainly over the CT River Valley in the coming hours, although a ribbon of higher rates is tracking up through eastern Mass/RI ... flung north from the DELMARVA circulation. I expect these higher rates to fill in over the forecast area through the morning hours as the cold front pushes into New England with maximum convergence into the mountains as moist southeasterly flow increases. 645 PM Update... Have performed the usual round of tweaks to T/Td to account for observed trends and blend in more raw model guidance for overnight trends. Also reran through PoP to better capture radar trends, boosting it up in many places... and reduced sustained winds a bit per observations. Previously... A strong cold front continues to slowly move east through NY state and down through the Carolinas this afternoon with pre- frontal showers developing across much of southern New England and over NH and western ME. Satellite imagery and surface observations indicate that an area of low pressure is beginning to form along this front near Cape Hatteras, and this low is expected to move northeastward through tonight before moving overhead of our area by early tomorrow afternoon. Scattered showers will continue through early this evening before becoming more of a steady moderate to heavy rainfall between 8pm-12am from west to east. Latest CAMs and global guidance continues to indicate that the combination of strong theta-e advection and PWATS of around +2 standard deviations will allow for a fairly widespread heavy rainfall event across the CWA with 1-3" expected for most locations but locally higher amounts of 3-5" across south facing mountains. Due to this and in collaboration with neighboring offices, the Flood Watch was expanded to include southern NH except for Rockingham county where amounts are expected to be lower. For more on flooding concerns please see the hydrology section below. The other forecast concern continues to be for the potential of strong southeasterly winds late tonight through the first half of Friday. The HRRR and NamNest indicates the potential for up to 80kts of wind at 925mb, which translates to surface wind gusts up to 45-50mph. The strongest winds look to occur just before the frontal passage as the aforementioned coastal low moves through. As a result, went ahead and issued a Wind Advisory for the southern 2 forecast zone tiers that will run from 3am to 3pm Friday. Some power outages are possible since most trees still have a lot of leaves on them. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/... Moderate to heavy rain will continue through at least the first half of Friday as the front and weak coastal low slowly moves across the region. Given that soils will be primed by Friday morning, any additional heavy rainfall will likely cause flooding issues, especially across the higher terrain. There could also be flooding in urban areas as fallen leaves clog storm drains. Later in the afternoon and early evening drier air aloft will begin to work in from west to east, which will help to lighten up the rainfall across much of western NH. Strong southeast winds will continue through Friday morning with the peak winds likely occuring between roughly 8am to 12pm. Later on in the day the core of the LLJ will move east of our area, thus allowing for winds to slowly subside. Saturday night will feature mainly cloudy skies with rain ending from west to east, although a few lingering showers may persist through daybreak on Saturday across eastern locations. Further to the west, clearing skies will allow lows to fall back into the 40s. && .LONG TERM /SATURDAY THROUGH THURSDAY/... Overview: Troffing prevails thru the extended with temps becoming colder as the trof axis approaches. Impacts: Another slow moving storm system is possible midweek...but at this time looks to be more progressive than tonight/Fri and so QPF lower. Forecast Details: With very active short term the extended forecast is mostly a blend of the multi-model consensus. Cyclonic flow prevails after the passage of the front but the amplified nature of the pattern means more southerly flow than westerly or northwesterly. For at least the weekend that should keep things mostly dry. Gradually as the trof axis/upper low approaches clouds and chance for showers will increase. Early in the week it looks like a trailing S/WV trof will pass thru the flow and bring a more widespread threat of rain. Based on ensemble and extreme forecast index products there is at least a subset of members that elongate the moisture transport and produce another atmospheric river type event. Given that I felt comfortable with the high PoP that the NBM has in the midweek time period. && .AVIATION /03Z FRIDAY THROUGH TUESDAY/... Short Term...A slow moving cold front will cross through the area tonight through Friday, bringing widespread RA with pockets of +RA and isolated -TSRA. Low ceilings and reduced visibilities will lead to IFR/LIFR restrictions tonight through much of Friday, and some patchy BR is also possible. In addition, LLWS of WS020/17045 kts is likely across most terminals tonight through about 16Z Friday. SE winds will gust up to 35-45kts late tonight through early Friday afternoon, highest across coastal TAF sites. Conditions will gradually improve from west to east on Friday night, but FG may develop resulting in continued restrictions. Long Term...Generally VFR conditions expected this weekend outside of some lingering upslope clouds around HIE that produce local MVFR conditions. The next chance for widespread flight category restrictions will be early next week with another slow moving storm system. && .MARINE... Short Term...A slow moving cold front will cross tonight through Friday, bringing strong gale to near storm force winds and seas of 6-11 ft. Winds and seas will gradually begin to diminish late Friday but SCA level seas will likely linger through Saturday. Heavy rain is also expected tonight through Friday along with some fog. Long Term...Winds and seas will gradually subside following the passage of the cold front. Seas may linger above 5 ft outside of the bays thru the weekend. && .HYDROLOGY... Soaking rain event on track for the region over the next 24 hours. Antecedent conditions with below normal soil moisture support ample in-channel storage and infiltration capacity, which will delay the runoff response until Friday. The rainfall tonight will be sufficient to saturate the ground if exceeding 1 to 2 inches. Any convection or training heavy showers thereafter could trigger flash flooding, particularly along steep slopes and urban areas. Although widespread flooding is not expected, locally high rainfall amounts of 3-5" in areas of steep terrain are likely to produce flooding. Outside of the mountains between 1-3" of rainfall is expected, with locally higher amounts possible. Riverine responses will be high flows and bankfull levels for some headwaters and small streams/creeks, with isolated risk for minor flooding. A significant concern will be the clogging of culverts and other drains by leaf and other debris, which will worsen as winds strip leaves throughout the event. Clogged drainage can lead to water running over roads or even washouts, which is unpredictable and require a lot less runoff to cause damages. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...Flood Watch through Saturday morning for MEZ007>009-012>014- 018>028-033. Wind Advisory from 3 AM to 3 PM EDT Friday for MEZ018>028. NH...Flood Watch through Saturday morning for NHZ002>012-015. Wind Advisory from 3 AM to 3 PM EDT Friday for NHZ010-013-014. MARINE...Gale Warning until 2 PM EDT Friday for ANZ150>154. && $$ UPDATE...Casey SHORT TERM...Tubbs LONG TERM...Legro HYDROLOGY...Tubbs
Area Forecast Discussion
National Weather Service Melbourne FL
834 PM EDT Thu Oct 13 2022 ...New UPDATE, MARINE, AVIATION... .UPDATE... Issued at 826 PM EDT Thu Oct 13 2022 Marginally unstable conds linger at the present hour, however shower cvrg remains sparse ahead of the apchg sfc front. Recent hourly HRRR runs have continued to back off on potential for any development of pcpn ahd of the frontal psg tonight and thus short term PoPs have been reduced from the earlier pkg. Considerable clouds wl linger into the overnight with eventual wind shift early Fri leading to a drying trend as anticipated. && .PREV DISCUSSION... Tonight...Drier air associated with an approaching cold front will continue to work southward tonight and help to lower rain chances from north to south. Activity will largely wind down after 9 PM, though lingering rain along the Treasure Coast is possible through the early morning hours on Friday. As winds start to swing around from the north overnight and sky conditions begin to clear, temperatures will respond by falling into the low 70s and upper 60s. Friday-Sunday (previous)...A large mid-upper level trough over the western Great Lakes will drift slowly east through this weekend. As this occurs, progressive/zonal flow aloft will veer slightly from WSW to WNW. This will push the cool front from its initial position near Lake Okeechobee early Fri morning across SOFL and into the Straits on Sat. The boundary will become stationary/diffuse as it gets bridged by onshore NE-E flow associated with the post-frontal high pressure ridge centered from southern GA to the Carolinas. The drier ECM/CMC model runs from the past few days have trended a little toward the GFS, showing a slightly slower, less "clean" FROPA. This keeps the threat for showers in play from Osceola and Brevard Cos southward Fri, along with a slight chance for TS along the Treasure Coast. Lingering shallow moisture may keep a small shower threat for the Lake O/Treasure Coast region Sat, before drier air finally spreads across the southernmost CWA by Sun. Max temps generally in the L-M80s through the period, except for M-U80s across the interior south. L-M60s inland, and U60s closer to the coast. && .MARINE... Issued at 250 PM EDT Thu Oct 13 2022 Tonight...Generally favorable boating conditions outside of isolated rain and lightning storms, which are mainly expected from Sebastian Inlet southward. A stronger storm or two may produce wind gusts in excess of 35 kts over inland lakes and the Intracoastal/Atlantic waters. A cold front bringing drier air will swing winds around to the west tonight, becoming NNW overnight. Seas 2-3 ft with occasional seas around 4 ft offshore and north of the Cape. Friday-Monday (modified previous)...Surface cold front will continue moving southward through the local waters south of Sebastian Inlet by Fri afternoon. Model guidance has trended ever- so-slightly weaker (closer to 15kt) with post-frontal winds, and veers flow more quickly to onshore/NE-E. This limits the magnitude/temporal extent of winds opposing the Gulf Stream, and thus it looks less likely for seas there to have time to reach 6ft, lessening the confidence that an SCEC will be needed for this event. Still, conditions will remain choppy with 4-5ft seas over the offshore waters Fri- Sat, before winds/seas subside 10-15kt/3-4ft Sun and AOB 10kt/2-3ft Mon. && .AVIATION... (00Z TAFS) Issued at 826 PM EDT Thu Oct 13 2022 VCSH lingering at coastal terminals through about 03z then becoming mostly dry overnight. Scattered showers Friday afternoon from MLB south. VCSH around 18z along the Treasure Coast and 20z at MLB. Light and variable winds overnight becoming northeasterly Friday. && .PRELIMINARY POINT TEMPS/POPS... DAB 69 83 69 83 / 30 10 0 10 MCO 70 86 70 86 / 20 20 0 10 MLB 70 84 71 84 / 30 30 10 20 VRB 69 85 71 86 / 30 40 20 20 LEE 68 84 67 85 / 20 10 0 10 SFB 69 85 69 84 / 20 20 0 10 ORL 71 85 71 86 / 20 20 0 10 FPR 68 84 70 84 / 30 40 20 20 && .MLB WATCHES/WARNINGS/ADVISORIES... FL...None. AM...None. && $$ JP/RH/ZL
Area Forecast Discussion
National Weather Service Morristown TN
1019 PM EDT Thu Oct 13 2022 ...New UPDATE... .UPDATE... Issued at 1010 PM EDT Thu Oct 13 2022 No major changes to the immediate forecast. Blended observations to the hourlies. Clear skies everywhere except scattered to broken clouds in the far NE corner of TN and SW VA. Expect dry and clear conditions to continue as surface high pressure builds over the area. && .SHORT TERM... (This evening through Friday) Issued at 315 PM EDT Thu Oct 13 2022 Key Messages: 1. Dry tonight and Friday with temperatures near to below normal. 2. Gusty southwest winds, and relative humidity will promote elevated fire weather conditions Friday. Discussion: RAP upper analysis and GOES-16 imagery depict a deep upper level low essentially situated from just south of Hudson Bay, extending into the western Great Lakes. The local area remains on the southern periphery of this low with WSW upper flow. Much drier air continues to move into the area this afternoon with increasing surface pressure. CAA this morning helped to keep low level stratus in place, but subsidence and drier air moving in has won out, and skies have began to clear out. Tonight and Friday, the upper levels remain unchanged with a deep upper low to the north keeping the local area within westerly flow aloft. At the surface, generally high pressure will be located across the southeast. Trended a bit lower than NBM guidance on overnight lows. With how dry this airmass is, believe that if winds relax as expected, temperatures should drop off fairly quickly. As a result, have low temperatures in the upper 30`s to mid 40`s. Dry weather will prevail through the short term period. Guidance continues to favor strong mixing on Friday, with mixing heights rising to near 5-7kft. The result will be low RH, and gusty southwesterly winds on Friday. Followed the NBM 10th percentile for dewpoints, which will bring RH values into the 20-30% range. Additionally, momentum transfer could bring wind gusts between 10-20 kts to the surface tomorrow afternoon. However, there has been a trend for lower wind gusts for Friday in the models. The combination of low relative humidity, gusty southwest winds, and dry conditions (especially with the gusty winds already drying out what little rain we saw overnight) will result in elevated fire weather conditions on Friday. Otherwise, high temperatures should be similar to today with highs in the 60`s to lower 70`s. Locations across the southern valley could see highs approach the mid 70`s given southwest flow. && .LONG TERM... (Friday night through next Thursday) Issued at 315 PM EDT Thu Oct 13 2022 .LONG TERM...(Friday Night through Thursday)... Key Messages: 1. Dry, breezy and unseasonably warm conditions Saturday. 2. Scattered showers and possibly a thunderstorm for Sunday afternoon and evening. Rainfall amounts will be limited. 3. Well below normal temperatures early/mid next week will bring first widespread frost and freeze conditions. Highs will be 15 degrees or more below normal for Tuesday and Wednesday. 4. Moderation of temperatures and dry RH values for Thursday. Discussion: For Saturday, a short-wave upper trough moves across the northern Great Lakes with the associated weak frontal boundary stretching from the mid-Atlantic states into the lower Ohio and Tennessee valleys. Boundary layer southwesterly jet of 20-25kts within a well mixed environment. Trended toward slightly drier and stronger southwesterly winds. Airmass is too dry for shower development along this frontal boundary. For Sunday and Sunday night, the frontal boundary stalls across the Tennessee valley. Models show a short-wave rotating around the upper low over the northern Great Lakes. This wave is associated with jet streak of 120kts+ which will strengthening the frontal-genetic forcing along this boundary. ECMWF showed cyclogenesis over Kentucky. Latest deterministic run of the GFS shows elevated instability with CAPES of around 500. Will continue with a chance of thunderstorms as well for Sunday afternoon and evening. GEFS and NBM probabilities keep show QPF amounts less than 0.25 inch with this system which seem reasonable given the limited Gulf moisture return. Some orographic showers expected across the far east Tennessee and southwest Virginia mountains through Monday morning. For Monday through Wednesday, deep upper trough across the Great Lakes, and Ohio and Tennessee valleys will bring unseasonably cold temperatures into the southern Appalachians. The 850mb temperatures drop to -5 to -8 degrees. The Ensemble Situational Awareness Table and ECMWF Extreme Forecast Index table show strong signals and anomaly cold air mass. Temperatures will be some 15 degrees or more below normal. Widespread freeze and frost conditions are expected across much of the area, especially for Tuesday night/Wednesday morning. For late Wednesday and Thursday, upper trough lifts northwest with widespread warm air advection for the latter half of the week. Moderation of temperatures are expected along with dry relative humidity. && .AVIATION... (00Z TAFS) Issued at 723 PM EDT Thu Oct 13 2022 The most notable key item for this TAF package is gusty SW winds. Winds from this afternoon for the most part at all sites, have stopped reporting gusts. Winds will continue to come down overnight and be variable at times. SW winds will then increase during the day Friday again with gusts between 15-20KT. Skies are also clearing and will about to clear at TRI soon. Skies will remain clear for much of Friday with maybe a FEW250 layer. Otherwise, VFR conditions expected with no VIS or CIG restrictions overnight. && .PRELIMINARY POINT TEMPS/POPS... Chattanooga Airport, TN 45 74 51 81 / 0 0 0 0 Knoxville McGhee Tyson Airport, TN 45 71 51 78 / 0 0 0 0 Oak Ridge, TN 42 71 48 78 / 0 0 0 0 Tri Cities Airport, TN 40 66 43 76 / 0 0 0 0 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$ SHORT TERM...Diegan LONG TERM....DH AVIATION...KS
Area Forecast Discussion
National Weather Service Raleigh NC
915 PM EDT Thu Oct 13 2022 .SYNOPSIS... A cold front will pass through central NC tonight. Dry conditions then return Friday and Saturday as high pressure settles into the southeast. Another cold front approaches the area late Sunday. && .NEAR TERM /THROUGH TONIGHT/... As of 915 PM Thursday... The latest surface analysis shows that the cold front has just passed Mt Airy and Statesville, and is approaching INT and CLT. Low level moisture remains abundant ahead of the front, including surface dewpoints still in the mid to upper 60s over much of central NC, and this high RH combined with calm to nearly calm air has contributed to pockets of fog over the forecast area. 00z soundings at GSO and RNK show sufficiently steep low level lapse rates and low dewpoint depressions below 700 mb for a lingering threat of showers just ahead of the front as it progresses eastward through the rest of the night. These same soundings, as well as RAP forecast soundings, do show a couple hundred J/kg ahead of the front, although little to none of this CAPE gets anywhere close to the mixed phase depth aloft, with dry/stable air above 700 mb, resulting in a very low risk of thunder. Any rainfall will be brief and fairly light, given the fairly shallow moist depth. In addition to the isolated to scattered showers crossing the area over the next several hours, along with a brief period of overcast clouds, a groundward surge in stronger WNW winds just aloft will culminate in a couple hours of gusty winds with fropa, and these winds are already evident just to our W in the higher terrain. Have held onto this scenario from the earlier forecast with an upward bump to gusts, which could reach 20-25 kts. Have made just minor tweaks to lows, with a terrain-induced delay in noteworthy CAA, and expect mostly upper 40s NW (with a few mid 40s) ranging to 50-56 along and east of Hwy 1. -GIH Earlier discussion from 300 PM: Latest surface analysis this afternoon shows that the cold front has reached the high terrain of the NC mountains. Ahead of the front, isolated showers have developed primarily along and east of US-1 coincident with where dew points and instability is highest. Given that the main axis of anomalous PWAT has shifted offshore, available moisture and instability (~250 J/kg) will be limited during the arrival of the cold front. As such, still expecting just widely scattered showers ahead of and during the passage of the front. Considerably drier air will usher in quickly behind the front (PWAT has already dropped to < 1 inch across the high terrain), spreading from west to east through the overnight period. A brief burst of gusty northwesterly winds is likely immediately behind the front as it pass through our area. Otherwise, skies will clear overnight, with temperatures dipping into the mid to upper 40s (NW) to lower 50s (SE). && .SHORT TERM /FRIDAY AND FRIDAY NIGHT/... As of 300 PM Thursday... Dry and cooler conditions are expected Friday as high pressure settles in across the southeast. In absence of strong CAA, developing southerly flow Friday afternoon will help to moderate temperatures with highs in the upper 60s across the north to mid 70s across the far south. Calm winds and clear skies Friday night will allow temperatures to radiationally cool into the mid 40s area wide. && .LONG TERM /SATURDAY THROUGH THURSDAY/... As of 250 PM Thursday... In the upper-levels, a trough will swing across the Midwest on Saturday, with southwest to zonal flow lingering across central NC. Another deeper trough will traverse east across the Mid-Mississippi River Valley Sunday, moving across central NC late Sunday into Monday. The trough will tap into some moisture across the Deep South, and increase precipitable water values across the region ahead of the trough on Sunday. A deep low will then dive south out of Canada, with a trough digging south from the low across central NC on Wednesday. NW flow aloft will then set up for Thursday as the trough ejects NE. At the surface, high pressure will linger across the Carolinas for the weekend, then a cold front will push southeast across the region on Monday. Cold high pressure will then dive south out of Canada Monday into the Mississippi River Valley through mid- next week. Dry weather and slightly above normal temperatures will develop this weekend under high pressure. Most areas will continue highs in the 70s, with some areas near the SC border rising to the low 80s. Conditions will then deteriorate Sunday as an upper trough and cold front approach the region. Some ensemble members develop rain starting Sunday afternoon across western central NC, with the majority of areas observing rain Sunday night into Monday. Colder and very dry air will filter in behind the cold front as Canadian high pressure builds in to our west, also keeping our weather dry through the middle of the week. Dewpoint temps will lower into the 20s and 30s by Tuesday, and with thicknesses lowering to near 1310- 1315m, lows in the 30s are expected across most areas by Wednesday and Thursday mornings. Frost will likely be an issue by Wednesday morning, and could affect sensitive plants left outdoors. && .AVIATION /00Z FRIDAY THROUGH TUESDAY/... As of 800 PM Thursday... 24-hour TAF period: The cold front is starting to make its way into the far NW Piedmont (including INT) this evening. It will continue to push SE and clear central NC by around 06z. The environment has been too dry and stable for much shower activity with the front let alone storms, so expecting a largely dry frontal passage. The main impact to aviation will be potential for a burst of gusty northwesterly surface winds that may occur for a few hours behind the cold front tonight. Winds will then diminish before shifting to the SW tomorrow afternoon, remaining light. Broken cloud ceilings are expected along and for several hours behind the frontal passage, but they should remain VFR. Skies will clear from west to east overnight, remaining clear through the day tomorrow. Looking beyond 00Z Saturday: Another cold front will approach the area on Sunday which may induce sub-VFR conditions and showers Sunday night into Monday. Dry and VFR conditions will return on Tuesday. && .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Luchetti NEAR TERM...Hartfield/Luchetti SHORT TERM...Luchetti LONG TERM...JJT AVIATION...Danco/Luchetti