Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 01/29/22


AREA FORECAST DISCUSSION
National Weather Service Albany NY
958 PM EST Fri Jan 28 2022 .SYNOPSIS... As a cold front continues to settle southward across the area, some light snow showers and flurries will continue through the early evening hours. Tonight, a strong coastal storm will be forming off the mid Atlantic coast. This storm will spread some snow and gusty winds for areas from the Hudson Valley on eastward for late tonight into Saturday, along with very cold temperatures, as the storm lifts offshore eastern New England. Behind the departing storm, it will remain cold and blustery with dry weather into early next week. Temperatures will gradually moderate towards the middle of next week. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... Cold and dry air deepening over eastern NY, and with the storm developing off the Carolinas and mid Atlantic, the northern and western edge of the precipitation shield will be sharp. Any snow from the Capital Region west and north would occur around daybreak at the earliest. Satellite imagery is showing the expanding upper cloud shield with cooling cloud tops expanding into Long Island and eastern New England. So, some temperature adjustments in northern areas as the cold air advects in steadily. Otherwise, still consistent signal from upper air data, surface data and some of the newest 00Z model data to not make many if any changes to the snow forecasts. PREVIOUS DISCUSSION: Surface cold front continues to slowly settle southeast across the southern and eastern portions of the forecast area this afternoon. This front has been moving very slowly, thanks to a weak wave of low pressure that developed further south along the front across Pennsylvania. Upstream temps and dewpoints over western and central NY have fallen into the teens with a northerly wind, while temps continue to remain well into the 20s with a light south wind across eastern New York. Satellite imagery continues to show plenty of widespread cloud cover over the area, however, clearing can be seen over the Adirondacks and this clearing is starting to slowly spread southward in the wake of the boundary. Along and ahead of the boundary, there have been some scattered snow showers and flurries that have been lifting from southwest to northeast ahead of the front. MRMS continues to show some light snow showers over northern PA and the Southern Tier of NY that have been lifting across the area. Most of this activity has been occurring across the southern half of the area, such as over the Catskills, mid Hudson Valley, Capital Region and western New England. Low-levels are fairly dry and a lot of this precip is being lost as virga or just not heavy enough to accumulate. Still, some coating to half inch amounts are possible for areas that see a steadier snow shower, especially for the Catskills or Berkshires. The 3KM HRRR suggests the best chance for these snow showers will be through the late afternoon hours, as the front continues to push south and southeast, so the threat for snow showers should be ending fairly soon. As the front continues to settle southward, the dry northerly flow will continue to allow for clearing to build south towards the Mohawk Valley. While the lower clouds will continue to clear out for central/southern areas, mid/high level clouds will be expanding from the south as a storm system begins to rapidly develop off the coast of the mid-Atlantic States for overnight. The combination of shortwaves within both the northern and southern streams phasing over the eastern seaboard, along with favorable jet dynamics, will allow for a rapidly deepening surface low to form overnight off the coast of the mid-Atlantic States. While there continues to be some subtle differences in the model guidance, the same idea remains in place that the developing surface low will be just far enough south/east to avoid a major impact on the bulk of the forecast area (NW CT will be the one exception). As the low starts to develop, light precip will pushing northward along the eastern seaboard for tonight. This light snow will spread across southeastern areas for after the late evening hours, although it will be running into a lot of dry air. While it will likely be snowing for Dutchess/Litchfield County by midnight, it may take until daybreak for any light snow to reach as far north as the Capital Region/Southern VT. Initially, precip will be fairly light, so only expecting a coating to an inch or two by for NW CT or eastern Dutchess County, NY by sunrise. Northerly winds will be increasing during the overnight hours. All areas will be seeing sustained northerly winds of 10 to 15 with some gusts of 15 to 25 mph for southern areas by the late night hours. Overnight lows will be very cold across the entire area with temps falling into the single digits. Temps may fall a few degrees below zero over the Adirondacks. Wind Chill Values will be close to -20 F over the Adirondacks by late in the overnight and a Wind Chill Advisory is in effect for those areas. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/... The rapidly developing storm will be tracking northeast on Saturday, and will be passing east of Cape Cod before heading towards western Nova Scotia by Saturday evening. The powerful storm will deepen as low as 960-970 hpa during the day on Saturday. Strong frontogenesis will be ongoing over New England with a heavy mesoscale snow band likely to form. Based on latest guidance, this heaviest snowband should remain just east of the area, but the backside of the steady shield of snow should expand back far enough west to reach close to the Hudson Valley. Based on the latest guidance, the back edge of the snow shield may reach the Capital Region, where an inch or two of snow will occur. Meanwhile, a few inches is expected for the eastern Catskills and mid Hudson Valley, with 2 to 6 inches for the Taconics, Berkshires and southern VT. Steady and moderate snowfall is expected for most of the day in NW CT and snow rates may get close to 1" per hour there for a time on Sat morning. As a result, a total of 5 to 10 inches is expected for Litchfield County, with the highest amounts in eastern parts of the county, before snowfall taper off for Sat aftn/eve. In addition, the strong pressure gradient will allow for very strong winds through the day on Saturday. North to northwest winds will be 10 to 20 mph across the entire area, with some gusts of 20 to 40 mph, especially for eastern areas. These winds will leading to blowing/drifting, especially for western New England. In addition, with temps remaining in the single digits and teens, wind chill values will remain below zero for much of the area through the day. Behind the storm, any precip will be done with skies starting to clear out for Saturday night. However, gusty northwest winds will continue across the entire area, with some gusts over 25 mph through Saturday night. With temps falling as low as 10 below to 5 above, wind chill advisories will likely be needed for many high terrain areas. High pressure should allow for mostly dry weather for Sunday into Sunday night with a partly to mostly clear sky. Winds will decrease through the day on Sunday and be much lighter by Sunday night. Daytime temps will be in the teens and 20s for Sunday, with single digits at night. && .LONG TERM /MONDAY THROUGH FRIDAY/... The long-term forecast period will feature a large scale pattern change that will result in a mean ridge-trough-ridge sequence with ridging over the eastern Pacific, troughing over the central U.S., and ridging over the eastern U.S. extending into the western Pacific. Flat ridging and southwesterly winds aloft over the local forecast area will result in a warming trend over eastern New York and western New England through mid week. However, a couple of cold fronts associated with a couple of storm systems will result in a widespread wintry mix followed by a cool down Friday into next weekend. We start off the extended forecast period on Monday with a broad surface high pressure system centered over Quebec Canada that will be shifting east-northeastward and strengthening as it departs further away from the local area/region. There will be a weak shortwave embedded within this high. However, the influence of the aforementioned high will be greater than the shortwave and will result in dry and tranquil conditions for the area Monday into Tuesday. High temperatures are expected to be in the upper 20s to low 30s. Overnight lows will be in the single digits to lower teens. Tuesday into Wednesday, a storm system, the first of two, is progged to track from central Canada eastward into eastern Canada. Because this storm system and the forcing associated with it will be well to our north, much of the area during this time frame should remain dry, but with quite a bit of cloud cover. Some computer models do indicate the southern extent of the precipitation shield from this storm system getting into areas north of Albany (i.e. Herkimer, Hamilton, Warren, Saratoga, Washington counties). To take into account this possibility, have included just low chance PoPs (20- 30%) over these areas during this time period. High temperatures on Tuesday are expected to be in the low to id 30s along the river valleys. Overnight lows will be in the 20s most places (low 30s along the Hudson River Valley. On the heels of this first storm system, will be a second, more robust storm system brewing over the central U.S. will have the chance to bring widespread precipitation to the area Wednesday- Wednesday night into Friday. This storm system has the potential to come with quite a bit of moisture as potent energy from the northern stream wave will phase with energy that will be attached to rich Gulf moisture from the southern stream wave. To put into perspective of how much moisture will accompany this storm system, PWAT values from NAEFS are running 1-3 STDEVs above normal and the GFS has PWATs topping 1 inch over a good portion of our cwa. Given how dry it`s been across the area (i.e. precipitation values -1.71" below normal since Dec. 1 and -1.10" below normal since Jan. 1), any precipitation that we get will be much needed. With temperatures running above 32F over the valleys, p-types will be mostly in the form of rain during the day though we could see a transition over to a rain/snow mix during the nighttime hours (Wednesday and Thursday night). For the higher elevations, there`s greater confidence in a rain/snow mix to all snow given the temperature layout. High temperatures Wednesday and Thursday will be in the upper 30s to lower 40s and low to mid 40s along the river valleys, respectively. Once the cold fronts push through the area in the Thursday evening to noon Friday timeframe, colder and drier air will advect into the region. We could see a transition over to all snow for the entire area Thursday night into Friday amid the cold fropa. High temperatures on Friday are expected to climb only into the mid 20s to low 30s along the river valleys with teens over the higher elevations. && .AVIATION /03Z SATURDAY THROUGH WEDNESDAY/... Through 00z Sunday...Currently seeing a mix of MVFR and VFR conditions at this time. With the exception of GFL, expecting deteriorating condition`s overnight and through the day tomorrow as a strong cyclone moves up the east coast. GFL should improve from MVFR to VFR within the next few hours, with VFR conditions then continuing through the end of the TAF period. Expecting snow showers to begin at POU between 3-6z, PSF 4-7z, and ALB after 9z. Snow becomes steadier overnight and tomorrow, resulting in reductions in visibility to IFR at POU and PSF, and possible at ALB. Ceilings should remain MVFR at these TAF sites during the snow. Snow tapers off for ALB around mid- morning, but will continue into early afternoon at POU and into the evening at PSF with continued IFR visibilities. After snow ends, should see visibilities and ceilings improve to mainly VFR. When all is said and done, expecting 3-6 inches of snow at POU and PSF with around an inch or two at ALB. Winds now are currently light and mainly from the north/northeast. Winds increase out of the northeast overnight tonight to around 10 kt with gusts to around 20 kt after midnight. Tomorrow, winds continue to increase from the northeast during the morning at 10-15 kts with gusts of 20-25 kts at ALB and GFL with gusts of 25-30 kts at POU and PSF. Tomorrow afternoon, winds shift to the northwest and remain strong at around 15 kts with gusts around 30kts possible at PSF and POU (northwest winds of 10-15 kts with gusts of 25-30 kts at GFL and ALB tomorrow afternoon). Due to the gusty surface winds, did not mention wind shear in the TAFs, but will note here that winds at ALB and GFL around 2000 ft will increase to 35+kt at GFL and ALB, and 40+ kt at POU and PSF from the north/northeast overnight tonight through tomorrow morning. Tomorrow afternoon, winds at 2000 ft switch to the northwest with little change in windspeed. Outlook... Saturday Night: Low Operational Impact. Breezy. NO SIG WX. Sunday: No Operational Impact. NO SIG WX. Sunday Night: No Operational Impact. NO SIG WX. Monday: No Operational Impact. NO SIG WX. Monday Night: No Operational Impact. NO SIG WX. Tuesday: No Operational Impact. NO SIG WX. Tuesday Night: Low Operational Impact. Slight Chance of SHSN. Wednesday: Moderate Operational Impact. Chance of SHRA...SHSN. && .HYDROLOGY... Cold weather will remain in place through the weekend into early next week, although temps may start to moderate towards the middle of next week. With the cold temperatures in place, this should continue to keep plenty of ice in place on rivers and streams. A winter storm will impact southeastern areas for tonight into Saturday. Any precipitation with this system will be in the form of snow, which will have no immediate impact on rivers and streams. Behind this storm, dry weather is expected through the middle of next week, which will keep river levels fairly steady. For details on specific area rivers and lakes, including observed and forecast river stages and lake elevations, please visit the Advanced Hydrologic Prediction Service /AHPS/ graphs on our website. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...Winter Storm Warning until midnight EST Saturday night for CTZ001-013. NY...Winter Weather Advisory until midnight EST Saturday night for NYZ065-066. Wind Chill Advisory from 1 AM to 9 AM EST Saturday for NYZ032- 033-042. MA...Winter Weather Advisory until midnight EST Saturday night for MAZ001-025. VT...Winter Weather Advisory until midnight EST Saturday night for VTZ014-015. && $$ SYNOPSIS...Frugis NEAR TERM...Frugis/NAS SHORT TERM...Frugis/NAS LONG TERM...Evbuoma AVIATION...Main HYDROLOGY...Frugis
Area Forecast Discussion
National Weather Service Binghamton NY
1037 PM EST Fri Jan 28 2022 .SYNOPSIS... Falling temperatures behind the cold front this evening and tonight, leading to another period of dangerously low wind chills overnight tonight and again Saturday night. A warming trend will develop Sunday into the first half of the work week with quiet weather expected. && .NEAR TERM /THROUGH SATURDAY NIGHT/... 1020 PM Update... Looking at the latest satellite, radar and hi-res guidance trends have decided to go with a winter weather advisory for Pike County. Light snow has already overspread our far southeastern zones, and although there may be a brief 1-2 hour lull just before midnight, the steady light to occasionally moderate snow should pivot back in from the east-southeast during the predawn hours and continue across Sullivan-Pike county until midday. With around 12 hours of steady light snow expected, feel the current 2-4 inch range is certainly attainable, and the most likely forecast at this time. The NNW winds seem to be upsloping into the Pocono plateau and this could bump QPF/Snow amounts a little higher across Pike county compared to surrounding locations. Also factored in to the decision to issue the advisory are the falling temperatures (to around 10-15 degrees by daybreak) cold wind chills 0-10 below by morning and increasing NW winds (15-25 MPH, gusts to 30 mph late morning) which could cause areas of blowing snow. Otherwise, the latest 02z HRRR is holding course, bring the light snow shield as far west as Cooperstown--Binghamton-- Tunkhannock for a few hours Saturday morning. Snow amount will be light on the western edge of this storm, less than 1 inch. Also added in areas of blowing snow tomorrow afternoon, evening and night for areas that are forecast to receive more than 1 inch of new snow, combined with wind gusts over 30 mph. 830 PM Update... Coastal storm is now developing off the NC coast with a baroclinic leaf beginning to develop on the latest WV/IR satellite loops. Not much change in the late afternoon/evening guidance for this system in our area. Snow amounts were bumped up across Pike and Sullivan counties, now closer to what WPC has as well. These two zones should see a period of steady light to occasionally moderate snow rotate in from the SE after midnight, continuing through midday or early afternoon Saturday. Now forecasting 2-4 inches southeast of a Monticello--Honesdale-- Avoca line. This does put Pike County PA especially close to winter weather advisory criteria. Will evaluate the hi-res near term guidance and consider going with an advisory here if amounts still look to average over 3 inches. Other considerations were: strong gusty northwest winds Saturday afternoon and evening look to peak with gusts 35-45 mph across the higher elevations of CNY and NE PA...with perhaps the strongest winds being over the hills of NE PA. Will need to watch this closely for potential wind advisory criteria being met, as a 975mb low deepens southeast of New England and a 1024mb high noses into Ontario...quite the pressure gradient sets up. 850mb winds peak around 50-55kts over NE PA around 7PM Saturday, with boundary layer winds pushing 35 kts. Wind chill advisories looks good tonight into Saturday morning, with minimum values between 10 to 20 below in most of the advisory locations...some locally colder values possible across northern Oneida county. Overnight lows will be quite cold with single digits above zero for most...except some below zero values across the higher elevations of CNY and Oneida county. Staying very cold on Saturday and blustery. High temperatures hover in the single digits to mid-teens as strong cold air advection envelops the area and 850mb temps fall to around -18C. May very well need to extend the wind chill advisory in time and area into Saturday night as overnight lows dip back down between -5 and +5F and NW winds remain elevated...should see even colder wind chill values this period compared to tonight. Will hold off on any expansions for now and let the next shift take another looks at winds and temperatures, but confidence is increasing. 320 PM Update... Cold front has push through BGM and is working its way across NE PA this afternoon. Very cold air mass coming in behind the front, and it is squeezing out every little bit of moisture available to it. Expecting light snow to continue across the Southern Tier and into NE PA into late afternoon to early this evening. There is also likely going to be some lake effect flurries behind the front across the Finger Lakes region through midnight tonight, however very little accumulations is expected. The main concern will be the very cold airmass that will be in place over the region the next couple of days. Not only are the temperatures cold, but the increased pressure gradient from an intensifying coastal low will increase winds across the region tomorrow morning. Wind chill advisories remain posted for a large portion of the region for tonight through tomorrow morning. Another advisory will likely be needed at some point for tomorrow night into Sunday morning, as wind chills again dip below -20F in some areas. As for the coastal storm that everyone has been focusing on this past week, models continue to keep the track of the system too far east for major impacts to our region. However, our far eastern counties may get brushed by the western snow shield and possibly see 1-3 inches of snow across the Poconos/southern Catskills late tonight through Saturday morning, with the top end of this range likely into far southeastern Pike County PA and eastern Sullivan County NY. For now, it appears that snowfall amounts will remain winter weather advisory criteria, but if the track of the system ends up just 25-50 miles further west, then advisories would be needed for at least Pike County, PA and Sullivan County, NY. Saturday will remain very cold and blustery through the day, with temperatures topping from upper single digits to mid teens and winds gusting 20 to 30 mph. As temperatures fall later in the day Saturday and Saturday night, the winds will ease up a bit, but another wind chill advisory is likely going to be needed through Sunday morning as temperatures dip below zero overnight. && .SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/... 345 PM update... Lake effect snow will continue across the northern Finger Lakes and into the Mohawk Valley Sunday morning. An approaching shortwave trough from the west will change the winds from NNW to W by Sunday afternoon. This will push the lake effect snow into northern Onondaga and Oneida counties by Sunday afternoon, tapering off by very early Monday morning. Models are hinting at some low level convergence across eastern Lake Ontario which could help increase snow fall across northern Oneida county, but at this time, not enough evidence is present to bump snow totals up. Currently, 1-2 inches is expected across the northern Finger Lakes, with up to an inch across northern Onondaga and Oneida counties. The shortwave that moves into the area Sunday morning may bring some scattered snow showers to the western counties, but it looks like weak high pressure over the area will suppress most of the snow chances south of the lake effect area. A ridge will build into the area Sunday afternoon through Monday night, bringing quiet weather conditions and warmer temperatures. Highs on Sunday will be in the low 20s and the upper 20s by Monday with lows Monday night in the mid to upper teens. && .LONG TERM /TUESDAY THROUGH FRIDAY/... 345 PM update... High pressure will remain in place over the area Tuesday, bringing another quiet weather day and warmer temperatures. Highs in the mid 30s and lows in the lower 30s are expected. A low pressure system moving through Ontario Wednesday could bring some scattered rain and snow showers as isentropic lift associated with warm air advection over the area meets the energy being pushed through the area from the low. The next large weather system looks to impact the area on Thursday into Friday morning. Current model guidance has not come together in regards to location or timing and the storm will have different impacts on the CWA depending on the track it takes through the area. A western track would bring warm Gulf air into the region with highs on Thursday in the upper 40s and rain showers for most of the day. A track east of the area keeps the warm air mostly to the east and colder air and snow would impact the CWA. Because of the highly variable nature of this system, the NBM was used for the forecast during this period. Once the storm moves out of the area Friday morning, another blast of arctic air will flow into the area, significantly dropping temperatures from where they were on Thursday. && .AVIATION /04Z SATURDAY THROUGH WEDNESDAY/... Occasional MVFR to Fuel Alternate restrictions are possible overnight following the passage of a cold front, along with some light snow showers. KAVP will be on the western fringe of the extent of snowfall from the coastal system, but right now, any IFR restrictions look to remain east of there. Conditions likely become VFR at all terminals by late morning/early afternoon Saturday. Winds will become gusty, especially during the day on Saturday with occasional gusts up to 20 to 25 kts possible. Outlook... Saturday Night...VFR. Sunday...VFR early, with a weakening system approaching Sunday night bringing possible restrictions from light snow showers. Monday and Tuesday...VFR conditions under high pressure. Wednesday...Restrictions possible as low pressure approaches the region, especially late Wednesday. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...Wind Chill Advisory until 11 AM EST Saturday for PAZ038-039- 043. Winter Weather Advisory until 1 PM EST Saturday for PAZ048. NY...Wind Chill Advisory until 11 AM EST Saturday for NYZ009- 015>018-022>025-036-037-044-045-055-056. && $$ SYNOPSIS...MPK NEAR TERM...MPK/MJM SHORT TERM...JTC LONG TERM...JTC AVIATION...BJG
.Afternoon Area Forecast Discussion...

SHORT TERM /Tonight through Saturday Night/... Low pressure is currently situated off the east central coast of Florida. This low center will begin to deepen overnight and rapidly move up the eastern seaboard. This weather system will bring several types of hazards to the CWA along with some small chances of accumulating snow at the highest elevations. Accumulating snow: Orographically induced snow showers are possible across the higher elevations of north Georgia overnight. Any accumulations will be light, under an inch and mainly confined to elevations above 2000 feet. The moisture remains very shallow across north Georgia, but with strong mid level energy/lift moving across overnight, a few flurries are possible mainly north of the I-20 corridor. (By definition, flurries do not accumulate.) Wind Advisory: Sustained winds on the back side of the low pressure center will continue to increase overnight along with the gust potential. Have blended some of the MAV guidance in with the higher res guidance, as it tends to do better in these situations. The HRRR also has some 30-35mph gusts across the CWA and it performed very well in the last high wind event. Sustained speeds between 15 and 20 mph will be likely. Slightly higher sustained speeds are possible in the mountains. In addition, gusts to around 35mph or slightly higher are possible across northeast GA. Elsewhere, frequent gusts to 30-35mph will be likely. Soils remain very wet across the area, so downed trees and limbs will be likely with these kind of wind speeds. Even though outside of northeast GA is a bit more marginal meeting Wind Advisory criteria due to speeds, will go ahead and expand the Advisory for the entire CWA. Wind Chill Advisory: Will go ahead and expand the Wind Chill Advisory a little further westward this afternoon. Cold temperatures combined with the windy conditions will create Wind Chills in the single digits for much of north and northwest GA. Red Flag Warning: MinRH values will dip down into the teens tomorrow afternoon. With frequent gusts to over 20mph and low fuel moistures, we will be meeting criteria for Red Flag Warning. This is has been coordinated with Fire Officials. NListemaa LONG TERM /Sunday through Friday/... The long term period kicks off with dry conditions courtesy of northwesterly flow aloft and high pressure at the surface across the Southeast for Sunday, Monday, and Tuesday. Portions of eastern-central Georgia could have minimum relative humidity values just below 25% for several hours and wind gusts between 15-20 mph on Sunday afternoon, which could warrant a Fire Danger Statement. Wednesday and Thursday will bring a transition to a WAA/moisture advection regime with southerly-component winds at the low- and mid-levels. Meanwhile, an upper-level trough will swing across the Four Corners and southern Great Plains with a cold front in tow. Have chance to likely PoPs on Wednesday and likely PoPs on Thursday. Still leaving thunder out of the grids as progged instability remains slim to none. In addition, the best forcing for ascent looks to remain well to our north, so for now there is no signal for widespread severe weather. PWATs will be well-above- normal (surging to 1.25" to 1.50" on Wednesday and Thursday) so periods of heavy rain could be a potential hazard. The QPF for the period of 00z Wednesday to 18z Friday is 1.00" to 1.75" for much of the CWA, with 2.00" to 3.00" roughly along and north of a line from Rome to Canton to Gainesville. The GFS and ECMWF depict the FROPA occurring Thursday night into Friday morning. For Monday through Thursday, high temps will run as much as ~10 degrees above average and lows as much as ~20 degrees above average, courtesy of the WAA/moisture advection regime. Martin AVIATION... 18Z Update... Cigs still showing up as mid level this afternoon and have delayed the onset of the bkn/ovc MVFR. Some light -sn (flurries) are possible early this evening. Winds will also begin to pick up and become very gusty late this afternoon and linger into tomorrow. Winds will remain on the west side. Rapid clearing after 12Z. //ATL Confidence...18Z Update... Med confidence flurries. High confidence remaining elements. NListemaa AVIATION... 00Z Update... SCT/BKN cloud decks currently over the area with CIGs generally between 3-6kft, through 05Z with models pushing an MVFR CIGs in Atlanta area through 10Z. Winds will be blustery out of the northwest between 10-20 kts with gusts up to 27-33 kts at times through 22Z tomorrow. Some occasional light snow flurries are also possible between 02-07Z for the ATL area, but no accumulations are expected. Rapid clearing after 12Z. //ATL Confidence...00Z Update... Medium to high on MVFR CIGs and snow flurries tonight. High on all other elements. Thiem && .PRELIMINARY POINT TEMPS/POPS... Athens 25 40 22 53 / 20 0 0 0 Atlanta 23 36 25 53 / 10 0 0 0 Blairsville 13 29 17 47 / 30 0 0 0 Cartersville 20 37 20 53 / 10 0 0 0 Columbus 25 43 22 59 / 5 0 0 0 Gainesville 22 36 22 50 / 30 0 0 0 Macon 27 43 20 58 / 5 0 0 0 Rome 18 38 19 55 / 20 0 0 0 Peachtree City 23 39 20 55 / 10 0 0 0 Vidalia 29 44 23 57 / 5 0 0 0 && .FFC WATCHES/WARNINGS/ADVISORIES... Red Flag Warning from noon to 7 PM EST Saturday for the following zones: Baldwin...Banks...Barrow...Bartow...Bibb... Bleckley...Butts...Carroll...Catoosa...Chattahoochee... Chattooga...Cherokee...Clarke...Clayton...Cobb...Coweta... Crawford...Crisp...Dade...Dawson...DeKalb...Dodge...Dooly... Douglas...Emanuel...Fannin...Fayette...Floyd...Forsyth... Gilmer...Glascock...Gordon...Greene...Gwinnett...Hall... Hancock...Haralson...Harris...Heard...Henry...Houston... Jackson...Jasper...Jefferson...Johnson...Jones...Lamar... Laurens...Lumpkin...Macon...Madison...Marion...Meriwether... Monroe...Montgomery...Morgan...Murray...Muscogee...Newton... North Fulton...Oconee...Oglethorpe...Paulding...Peach... Pickens...Pike...Polk...Pulaski...Putnam...Rockdale...Schley... South Fulton...Spalding...Stewart...Sumter...Talbot... Taliaferro...Taylor...Telfair...Toombs...Towns...Treutlen... Troup...Twiggs...Union...Upson...Walker...Walton...Warren... Washington...Webster...Wheeler...White...Whitfield...Wilcox... Wilkes...Wilkinson. Wind Advisory until 10 AM EST Saturday for the following zones: Baldwin...Banks...Barrow...Bartow...Bibb...Bleckley...Butts... Carroll...Chattahoochee...Cherokee...Clarke...Clayton...Cobb... Coweta...Crawford...Crisp...Dawson...DeKalb...Dodge...Dooly... Douglas...Emanuel...Fannin...Fayette...Forsyth...Gilmer... Glascock...Greene...Gwinnett...Hall...Hancock...Haralson... Harris...Heard...Henry...Houston...Jackson...Jasper... Jefferson...Johnson...Jones...Lamar...Laurens...Lumpkin... Macon...Madison...Marion...Meriwether...Monroe...Montgomery... Morgan...Muscogee...Newton...North Fulton...Oconee... Oglethorpe...Paulding...Peach...Pickens...Pike...Polk... Pulaski...Putnam...Rockdale...Schley...South Fulton...Spalding... Stewart...Sumter...Talbot...Taliaferro...Taylor...Telfair... Toombs...Towns...Treutlen...Troup...Twiggs...Union...Upson... Walton...Warren...Washington...Webster...Wheeler...White... Wilcox...Wilkes...Wilkinson. Wind Chill Advisory from midnight tonight to 1 PM EST Saturday for the following zones: Bartow...Catoosa...Chattooga... Cherokee...Dade...Dawson...Fannin...Floyd...Gilmer...Gordon... Haralson...Lumpkin...Murray...Pickens...Polk...Towns...Union... Walker...White...Whitfield. Wind Advisory until 7 AM EST Saturday for the following zones: Catoosa...Chattooga...Dade...Floyd...Gordon...Murray...Walker... Whitfield. && $$ SHORT TERM...Thiem LONG TERM....Martin AVIATION...Thiem
Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
903 PM EST Fri Jan 28 2022 .SYNOPSIS... An upper low pressure system and associated cold front will cross the region tonight. Dry high pressure will build over the region from the west through the rest of the weekend. A weak clipper system will cross the southern Appalachians on Monday, but with limited moisture. A more potent storm system will arrive from the west mid to late week with more abundant moisture. && .NEAR TERM /THROUGH SATURDAY/... As of 850 pm EST Friday: Water vapor imagery shows the deep upper trough just west of the southern Appalachians and poised to move east across the region overnight. Coastal cyclogenesis is underway off the NC Outer Banks, but this moisture remains limited to coastal regions. The main forcing and moisture source for our area will be with the trough itself, and steepening lapse rates aloft should permit precipitation rates to increase along and near the I-77 corridor through late evening. Recent HRRR runs are indicating better reflectivity and snow rates within the Piedmont Winter Weather Advisory area through midnight. The main limiting factor thus far has been warm surface wet bulb temperatures, but these are now cooling quickly late this evening, so no adjustments are planned to the current Piedmont Winter Weather Advisory. An SPS has been posted for spotty light accums and freezing temperatures just west of the advisory. High elevation warning/lower valley advisory conditions remain on track across the mountains with deep northwest flow moisture wringing out accumulating snow there. A sharp gradient of accumulations will persist east of the Blue Ridge and the current hazard cutoff seems reasonable. 850 mb flow of 40 to 45 kt in the peak cold advection overnight through Saturday morning will bring advisory gusts to the mountains and the existing Wind Advisory has this covered. Wind Chill Advisories exist east of the Winter hazards but these may need to be expanded throughout the mountains as the winter storm hazards expire around daybreak. An SPS for black ice may be needed in areas outside of existing hazards for freezing conditions and wet roadways overnight as temperatures dip into the teens and 20s. Gusty winds and cold conditions will continue despite increasing sunshine in the wake of the trough passage Saturday afternoon, with highs generally in the 20s in the mountains and 30s east of the mountains. && .SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/... As of 1225 PM Friday: The rest of the weekend and into the first part of the next week looks fair and quiet, in spite of continued mean mid/upper troffing over the east and the passage of a few short waves. Weakening high pressure should settle down across the region Saturday night, giving us one of our coldest nights of the season, with temps dropping down into the teens across the mtns and out over the NC foothills/wrn Piedmont. The high moves offshore on Sunday, though, and temps start to rebound back toward normal. One short wave should pass overhead late Sunday and the next on Monday, but most will hardly notice. There could be an increase in clouds on the TN border Sunday night behind the first wave, and the second wave should bring some thicker high clouds overhead on Monday. Even with the higher clouds, temps will probably climb up to a category or so above normal for highs Monday afternoon. By Monday night, heights rise as the eastern trof pulls out, establishing a nearly zonal flow aloft. && .LONG TERM /TUESDAY THROUGH FRIDAY/... As of 214 PM Friday: Nearly zonal flow aloft on Tuesday will gradually come around to southwesterly by Wednesday as the next upper trof digs down over the high Plains and ridging builds off the Eastern Seaboard. Models suggest this will open up the Gulf of Mexico for moisture transport into our region, with increasing precip chances Tuesday night into Wednesday. The first issue is the onset of light precip early Wednesday morning relative to low temperatures. Operational runs keep us dry through daybreak Wednesday while blends incorporate enough alternate scenarios to introduce a small precip prob over the mtns. If precip begins that early, however, it will be in concert with strong warm advection, especially at the high elevations that will stick up into the developing southerly flow aloft, the implication being that wintry precip would be unlikely in that event. By Wednesday afternoon, the models agree with a setup that continues to favor strong temp/moisture advection from the south and is unfavorable for cold air damming. From Wednesday night, through Thursday, into Thursday night, the guidance shows some differences in the strength and timing of low pressure that develops out ahead of the mid/upper trof over the Plains, but not the track. Models have a sfc low moving up to the west of the Appalachians, which has good support in the ensembles. In this situation, we would remain un-wedged and warm-sectored, thus open to the possibilities of severe thunderstorms and excessive rainfall, and with above normal temps. For the time being, the GFS shows very modest sfc-based CAPE with little support for anything more than a hundred J/kg in the GEFS, but shear should be impressive on Thursday afternoon as a low level jet moves overhead. The 12Z ECMWF is similarly unimpressed thus far. This suggests that perhaps heavy rain might be the bigger concern, what with model precipitable water over 1.5 inches east of the mtns on Thursday, which is up in record territory. That we would lack the protection of cold air damming suggests that we keep an eye on this situation, but for now confidence is too low to mention in the HWO. Cold air should move in behind the trailing cold front Thursday night and into Friday. Model blends naturally smear out the departure of the precip and the arrival of the cold air, allowing for a non-specific changeover to snow at the high elevations early Friday. We retain some low precip chances across the region for Friday, but a large cool continental high could easily build in by daybreak and keep Friday dry everywhere. && .AVIATION /02Z SATURDAY THROUGH WEDNESDAY/... At KCLT and elsewhere: Steeper lapse rates moving over the deeper moisture in the NC foothills and Piedmont should lead to briefly heavier snow showers at KHKY and KCLT this evening before the activity moves east overnight. Precipitation appears done for the Upstate TAF sites, with mainly occasional vicinity snow showers reaching near KAVL through the night in moist northwest flow in the French Broad Valley. Anticipate occasional IFR to MVFR cigs under the snow area, but with mostly VFR conditions elsewhere. Gusty north to northwest winds will get stronger through the night, with G20+ kt outside of the mountains and G30+ kt at KAVL. Gusty winds will persist through Saturday, but with clouds scattering and clearing behind the departing wave of low pressure. Outlook: Drier high pressure will return through Sunday. Mainly dry VFR conditions will persist early next week, but with a moist system beginning to return from the west by Wednesday. Restrictions and brief mixed precipitation could be possible. && .FIRE WEATHER... In the wake of low pressure moving away, a very dry air mass will move into the region on Saturday. Even though temps will be cold, afternoon relative humidity is expected to drop down into the teens and lower 20s percent in the afternoon east of the mountains. Northwest winds will be breezy as well, with occasional gusts up to around 25 mph through much of the day. Light precipitation is expected to fall across much of the region tonight, but failing that, fuels could dry out even more during the afternoon. Some coordination with land management agencies might be needed to address the increasing fire danger for Saturday. && .GSP WATCHES/WARNINGS/ADVISORIES... GA...Wind Advisory until 4 PM EST Saturday for GAZ010-017. NC...Wind Advisory until 4 PM EST Saturday for NCZ033-048>053-058- 059-062>065-501-503-505-507-509-510. Winter Weather Advisory below 3500 feet until 7 AM EST Saturday for NCZ033-048>052-058. Winter Storm Warning above 3500 feet until 7 AM EST Saturday for NCZ033-048>052-058. Winter Weather Advisory until 7 AM EST Saturday for NCZ036-037- 053-056-057-059-069>072-082. Wind Chill Advisory above 3500 feet until noon EST Saturday for NCZ062>064-505. SC...Wind Advisory until 4 PM EST Saturday for SCZ001>003. Winter Weather Advisory until 7 AM EST Saturday for SCZ009-014. && $$ SYNOPSIS...PM NEAR TERM...HG SHORT TERM...PM LONG TERM...PM AVIATION...HG FIRE WEATHER...PM