Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 01/09/22

Area Forecast Discussion
National Weather Service Binghamton NY
917 PM EST Sat Jan 8 2022 .SYNOPSIS... A storm system brings a wintry mix late tonight into Sunday. Most areas will see a mix of freezing rain and sleet, with some snow mixed in early. Precipitation will change to scattered rain and snow showers in afternoon. Significant lake effect snow will set up mainly north of the Thruway Sunday night into Monday, followed by a blast of Arctic air for the whole region. && .NEAR TERM /THROUGH SUNDAY NIGHT/... 915 PM Update... Winter Weather Advisory start time for Central Southern Tier- Finger Lakes-Syracuse areas has been moved up to 3 AM. Initial radar echoes will be virga or perhaps sleet with dry low level air that has to be overcome, but then possible freezing rain sooner than had previously been forecast. This faster apparent evolution is not too surprising considering the abrupt warm air advection/strong southwest flow aloft; it is typical for the models to have to play catch up for this type of situation. Also, remainder of Winter Weather Advisory for Northeast PA and in NY from Tioga-Cortland-Madison east, now has end time out to 4 PM Sunday since higher terrain will still be vulnerable to freezing rain into the afternoon, albeit light. With Arctic air visiting today, just prior to the event, ground temperatures are quite cold. Even as air temperatures creep above freezing midday-early afternoon, there may be lingering additional light ice accretion on untreated ground-based surfaces. As expected, the initially clear sky and very low dewpoints are promoting good radiational cooling this early evening; temperatures are in teens-mid 20s. However, there will be a limit to that with increasing south-southwesterly flow already getting underway just above the surface, and inbound clouds now over western PA- NY which are quickly spreading east. Temperatures will mostly creep up overnight. Previous discussion... Steep isentropic lift and slow top-down moistening of the column will result in a lot of virga to start off, which consequently will help keep the boundary layer cool via evaporational cooling. Precip will first reach the ground closer to 09-10Z, becoming more widespread towards dawn as upper level lift increases in response to strong divergence in aloft. Model QPF is still generally focused across the Upper Susquehanna headwaters, Catskills, and Poconos, as well as along and north of the Thruway in an area of steeper isentropic lift, and also at the nose of the strongest low level winds aloft. Lighter precip is likely across the Finger Lakes due to downsloping off the Allegheny Plateau. Still seeing large differences in QPF maximums, with the 12Z GFS and NAM showing the widest differences near and north of the Thruway (0.50-0.60 storm total QPF on the GFS, over 1 inch on the NAM). NAM appears to be too quick in developing accumulating precip with the dry airmass, and overall too wet later in the day. Basically went with a mix of WPC Guidance with WRF ARW and 12Z HRRR which are which provide some orographic details. Forecast soundings look to waver between sleet and freezing rain for much of the area as the strength of the warm nose varies (and may weaken with evaporative cooling), and the depth of the near-surface freezing layer may be significant at first, but slowly erode. Expect sleet will eat into the freezing rain totals significantly in places, but it`s going to be highly variable across the area. NBM ensemble p-type methods were trying to put too many eggs solidly in the sleet basket over freezing rain, resulting in extremely low ice accumulation. Instead we took a more balanced approach, applying 50-70 percent of mixed QPF to freezing rain accumulation. Result is broadly similar to WPC guidance, but with localized amounts a little higher, especially over the Susquehanna headwaters and Thruway corridor. Max amounts look to be just under 0.25 inches. A little concerned that some pockets of heavier amounts could develop, particularly in the area north of I-88 and up into the Mohawk Valley (but east of SYR). Heading into Sunday morning, downsloping will warm up the Finger Lakes region first, perhaps even before dawn, after which mixing will help finally bring some of the warmer air aloft down to the surface. Syracuse should go over to rain a couple hours after sunrise, and then it will be slow slog for the rest of the area. By afternoon, however, winds aloft will veer more towards the west, with the warm nose shifting east, and profiles generally trending towards a rain and snow (depending on surface temps). Precip coverage will also diminish greatly after 18Z, even a little ahead of the cold front associated with this system. It should be noted that very cold temperatures this morning and expected rapid cooling early this evening will keep ground temperatures cold, and may even allow for ice accretion for a few hours after ambient (2 meter) temperatures tick above the freezing mark. So the risk of black ice on untreated surfaces will linger even if ice starts melting from tree branches and utility lines. Much colder air will filter into the area Sunday night, and as winds turn westerly, lake effect snow will take aim on Oneida County, possibly grazing northern Onondaga and Madison Counties. Localized heavy snowfall looks likely given very strong CAA, a rapidly falling DGZ, multi-lake connection, and closer to dawn, higher mid level RH values. The focus for the band, and heaviest amounts, look to remain just north of the Thruway, but it`ll be close. For now, we went with a Winter Storm Watch for Lake Effect Snow for Oneida County which stretches on into Monday. && .SHORT TERM /MONDAY THROUGH TUESDAY/... Monday starts off cold and breezy behind the cold front, with persistent west/northwest flow leading to an extended window of lake effect Monday through Tuesday. 850mb temperatures starting at -16 to -18C will fall to below -20C by Monday evening as another shortwave rippling through brings a reinforcing shot of cold air advection. Lapse rates will be steep through a saturated DGZ, and shear increases to around 20 to 30kts which should be sufficient to maintain a single band of snow. With a saturated snow growth zone, a warm lake and much colder air advecting into the region ratios should get to around 20:1 for this event. The band first sets up north of the Thruway during the daytime Monday, with the heaviest snow possibly in excess of 6inches expected across Oneida county. Winds shifting to more northwesterly for a time Monday night will allow snow showers to drop into the Finger Lakes, Southern Tier, and portions of the Southern/Western Catskills. We may even be able to see some enhancement from the Finger Lakes across the Southern Tier. With ratios up around 20:1, a fluffy inch or so is not out of the question. Any snow showers across NE PA would be more isolated with more opportunities for some peaks of sun as well. Tuesday, lingering lake effect snow showers gradually become more isolated to areas immediately downstream of Lake Ontario, and eventually taper off during the afternoon as winds turn lighter and soundings start to dry out. Still will not rule out some additional light accumulations below an inch. The other story for the beginning of the work week will be temperatures. Monday, we should see highs only in the teens and lower 20s, but with a bitter airmass, temperatures will plummet into the single digits above and below zero overnight. Northern Oneida county may even see lows in the teens below zero. This will yield bitter wind chills into early Tuesday that will certainly meed advisory criteria. Highs will only reach into the single digits and possibly the teens Tuesday afternoon. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... Little change to the long term. High pressure will be building into the area by Tuesday evening, and though this should start to bring in a moderating airmass into the middle of the week, Tuesday night will still be very bitter with lows generally in the single digits and wind chills below 0F. The remainder of the period will be milder, with highs generally ranging in the 30s and lows in the 20s. Wednesday will be dry with high pressure in control, but another trough digging in will bring in another round of snow showers Thursday before a ridge builds back in Friday. Yet another system digging into the Great Lakes may bring our next round of snow showers Friday night into the weekend. && .AVIATION /02Z SUNDAY THROUGH THURSDAY/... Though we start off at VFR at 00Z, a storm system is about to bring a complicated wintry mix and restrictions to all terminals late tonight through Sunday morning. Ahead of the system, flow off the surface will increase rapidly this evening, causing southwesterly low level wind shear of 35-45 knots for all terminals which will linger for a good chunk of Sunday. See TAFs for specifics on precipitation type and timing, but all terminals should see at least some freezing rain and sleet before temperatures warm up for plain light rain or mist. Ceilings will also drop into fuel alternate required to IFR levels as the wintry mix develops; then it will persist even as the precipitation wanes. Outlook... Sunday night through Monday...Ceilings improve for most terminals Sunday night with even VFR for several into Monday, but KSYR and especially KRME will be vulnerable to significant lake effect snow and at times blowing snow with associated restrictions. Monday night through Tuesday...Occasional restrictions at NY terminals due to lake effect snow showers, especially KSYR- KITH-KBGM. Gusty NW winds and bitter cold Tuesday morning may impact ground operations as temperatures dip into the single digits, with lows well below zero at KRME. Tuesday night through Wednesday night...Mainly VFR. Thursday...Disturbance with chance of snow showers and associated restrictions. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...Winter Weather Advisory from 5 AM to 4 PM EST Sunday for PAZ038>040-043-044-047-048-072. NY...Winter Weather Advisory from 5 AM to 4 PM EST Sunday for NYZ009-036-037-044>046-055>057-062. Winter Storm Watch from Sunday afternoon through late Monday night for NYZ009-037. Winter Weather Advisory from 3 AM to 2 PM EST Sunday for NYZ015>018-022>025. && $$ SYNOPSIS...MDP/MPH NEAR TERM...MDP/MPH SHORT TERM...HLC LONG TERM...HLC AVIATION...MDP
Area Forecast Discussion
National Weather Service Grand Rapids MI
1018 PM EST Sat Jan 8 2022 LATEST UPDATE... Update .UPDATE... Issued at 1017 PM EST Sat Jan 8 2022 There are no changes planned to the Winter Weather Advisory at this time. Everything looks to be coming together as expected with freezing drizzle or light freezing rain now being reported at several locations. Cloud bases have lowered below 1000 ft and 2-4 mile visibilities are common. HRRR Bufkit profiles continue to show good omega/lift in the low cloud deck and an unsaturated DGZ above that, so a fairly classic looking freezing drizzle set up. QPF/glaze amounts still expected to remain mostly below a tenth of an inch although HRRR updates continue to suggest locally higher amounts just inland from MKG/BIV due to enhanced sfc convergence. At this point travel does not look to be greatly impacted, with the MDOT MiDrive map indicating relatively free-flowing travel speeds on the major interstates and highways. That could change though with several hours still to go and temperatures near to below freezing. While many places near the lakeshore and south of I-96 will see temps poke above freezing for a time tonight, roads/sfc temps should remain colder with glazing of surfaces still possible. Arrival of deeper moisture after 06Z could provide seeder- feeder/ice nucleation activation leading to some light snow mixing in with the drizzle before ending, especially south and east of GRR. We allowed the Gale Warning in the northern marine zones to expire and transition to a Small Craft Advisory like the rest of the zones. && .DISCUSSION...(This evening through next Saturday) Issued at 332 PM EST Sat Jan 8 2022 - Freezing light rain/drizzle tonight Tonight we will see a period of light freezing rain/drizzle later this evening into the early morning hours of Sunday. This event is one of those jet entrance region lift events. There is even 50 knots perpendicular to the isentropic surfaces this evening. However near 700 mb, the pressure deficit is near 70 mb. That means the air being lifted at mid levels is very, very, very dry. However there is enough moisture between the surface and 5000 ft and there is lift there to due to the warm advection going on. This means we are not cold enough in the clouds to create snow, so we get drizzle. The problem there is the air is below freezing all the way to the surface. This will mean freezing drizzle instead of snow. Curiously we do get lake shore convergence even so. That will enhance the drizzle west of US-131 overnight. That would mean ice accumulations near a tenth of an inch are possible north of Holland and west of Grand Rapids overnight. The timing of this is for the drizzle to develop after 9 pm and continue past midnight before ending with the passage of the first cold front. Currently surface temperatures are below freezing to well south of I-80 and surface dew points are near 10 above. The dew points will come up but not get above freezing. Drizzle falling into air below 28 degrees is very efficient and creating ice so this will likely create travel issues later tonight into Sunday morning, even after the drizzle has ended since there is not a real warm up to melt the drizzle. - Mostly cloudy breezy and colder during the day Sunday The cold front comes through around sunrise but the really cold air comes in after dark. The first cold front does have cold air with it so temperatures will fall all day. The air coming in is so cold even if the sun were to be out (which it will not be all that much) the temperatures would fall. In fact temperatures will likely fall into the teens by late Sunday afternoon. Normally we`d get lake effect snow showers with an event like this but the polar jet axis does not come through here till late in the day on Sunday. It will take that to get the lake effect snow showers up and going once again. - Arctic cold front brings snow shower and colder Monday The passage of the polar jet axis puts us in deep cold air and typically that means lake effect snow showers when 850 temperatures get much below -12c. As we have been saying, this is the coldest air of the season to date. 850 temps fall below -20c on Monday over just about the entire state of Michigan. This will likely be the first day this winter with day time highs below 20 degrees across most if not all of the area. In this situation we have a large surface high moving into the area. The models are not doing much at all with lake effect snow showers due to the anticyclonic winds around the surface high. However, it has been my experience that with air this cold and with us being on the cyclonic side of the polar jet we will get a surface trough over Lake Michigan. That will be just enough to kick of snow showers anyway. Due to the lack of Moisture at mid levels and the DGZ nearly on the ground, we will not create large fluffy snowflakes. That will limit accumulations but it will be breezy and small flakes can really lower the visibility so there may be travel issues later Sunday into Monday even so. - Warmer than normal and dry midweek, the much cold and it stays The polar jet comes back through Monday night. That will end the snow showers and bring milder air back into the area. The really cold air will not come back until next weekend. We have a system passing north of us mid-week but that will not impact our weather much. It is later Friday we get another digging northern stream jet that will push a strong cold front through the area. This time though it seems once we get into the cold air, it will stay longer and not just last 2 day. In fact the ensembles and operational runs of the GFS, ECMWF and Canadian models all show highs below freezing from Jan 15th through the 24th (and beyond). So, winter is HERE! && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) Issued at 702 PM EST Sat Jan 8 2022 Some fairly big impacts to aviation are expected tonight due to icing and IFR or lower cigs. Light freezing rain/drizzle will become widespread over the next few hours with moderate icing expected between the sfc and 6000 ft. The current MVFR cigs will lower into IFR or LIFR category before midnight at most locations. Improving conditions will arrive from the northwest toward 12Z Sunday, with any freezing drizzle ending and cigs improving quickly to MVFR. A few flurries are possible Sunday but no appreciable reductions to visibilities are anticipated at this time. Gusty southerly winds to 25 kts tonight will shift to the west/northwest for Sunday and remain gusty. && .MARINE... Issued at 332 PM EST Sat Jan 8 2022 We have a gale warning in effect over our northern part of the near shore and small craft over the rest of the near shore. At this point I see no real reason to change that though we are not really getting any reports of gales yet, it still could happen so it`s best to leave it as is. Once the first cold front comes through we get all that cold air moving in. So, guess what, we will need a small craft advisory into Tuesday but we did not change the lenght of the small craft advisory just yet, once the gales are done, then we will likely do that. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...Winter Weather Advisory until 4 AM EST Sunday for MIZ037>039- 043>045-050-051-056>059-064>067-071>074. LM...Gale Warning until 10 PM EST this evening for LMZ848-849. Small Craft Advisory until 7 AM EST Monday for LMZ844>847. && $$ UPDATE...Meade DISCUSSION...WDM AVIATION...Meade MARINE...WDM
Area Forecast Discussion
National Weather Service Houston/Galveston TX
554 PM CST Sat Jan 8 2022 .AVIATION [00Z TAF Issuance]... With the bulk of the stronger cells moving out to the east and the sunsetting, it looks like things are on a downward trend as far as convective activity goes. However, in the wake of these storms and its associated coastal low, deep/strong onshore winds will persist across the region with MVFR/IFR ceilings prevailing tonight. Light showers/areas of drizzle/patchy fog are expected as well given the continuing WAA/fetch from the Gulf. For now, going to maintain the current timing of this next cold front: reaching our northern ter- minals around noon...central mid afternoon and the coast late aft- ernoon. 41 && .PREV DISCUSSION... /ISSUED 230 PM CST Sat Jan 8 2022/ SHORT TERM [Today through Sunday Night]... Currently, a warm front is draped across the I-10 corridor with widespread showers across the eastern portion of our CWA. Activity has been further northeast than previously anticipated, but storms will continue to increase in strength and coverage this afternoon and early evening as the warm front pushes further north. Satellite imagery shows breaks in cloud cover west of I-45 which should help destabilize the atmosphere further for that area. SPC mesoanalysis also hints at this with higher CAPE values west of I-45 and less CIN. Scattered showers are currently growing across that area, but as previously mentioned, we expect this area to have storms grow in strength and coverage over the next few hours. Across our CWA, these storms will be capable of producing strong to severe wind and small hail. Our HGX radar VWP shows a significant decrease in low level directional shear which indicates a drop in low level helicity across the area, but some short term soundings such as the RAP and NAM still show decent values of effective SRH near 150-200 m2/s2 across our CWA, so we still can`t rule out some rotating updrafts and possibly some brief and weak tornadoes. With strong buoyancy of 1500-2000 J/kg, 90th percentile PWs, skinny cape, and organized updrafts, some of these cells will also be capable of producing some localized heavy rainfall amounts with rainfall rates near 2 inches per hour with the strongest storms. Otherwise, 1 to 2 inches are expected across the area over the weekend with isolated higher amounts possible. Overnight, the warm front will still linger across our CWA and we`ll still see some scattered to widespread showers, but the threat for severe weather and heavy rainfall will begin to diminish. Overnight lows will stay warm and humid in the upper 60s. Fortunately, a cold front is expected to arrive tomorrow and reach the Brazos Valley by early afternoon and reach the coast by the late evening. This should sweep out any lingering precip as the coast pushes offshore. Temps and humidity will quickly decrease behind the frontal passage. Northern counties will be noticeably colder and reach the mid 60s tomorrow, but elsewhere will have plenty of opportunity to heat up ahead of the frontal passage and reach the mid 70s. Overnight lows will dip into the lower 40s for our northern counties and upper 40s everywhere else as CAA behind the front ushers in colder and drier air. Lenninger LONG TERM [Monday through Saturday]... A drier and cooler air mass will settle across Southeast TX on Monday with surface high pressure building across Central TX. High temperatures in the mid 50s to low 60s expected. It will remain breezy with northerly winds ranging between 10 and 15 mph during the day and relax Monday night as the high pressure moves closer to the local area. CAA will allow for low temperatures to dip into the low to upper 30s for areas north of I-10, the mid 30s to low 40s for areas souther of I-10, and the low to mid 40s along the immediate coasts and Barrier Islands. Light variable winds expected Tuesday as the high pressure shifts eastward. Highs will be in the upper 50s to low 60s and lows in the upper 30s to mid 40s early Wednesday morning. By midweek, SE Texas will be wedged between a mid-upper level low moving eastward over the northern portions of Baja California and an upper level trough moving into the Great Lakes region. The upper low is expected weaken as it slowly moves into the Four Corners region on Thursday and begins to merge with a trough located over the northern Great Plains as it moves into Northern TX/Oklahoma/Kansas region on Friday. Low pressure along the surface and associated cold front will move into the Northern TX and Oklahoma by early Friday and could cross Southeast TX sometime late Friday into Saturday morning. We can expect rain chances to increase by Thursday night or early Friday as low level moisture and instability increases ahead of the front, possibly some streamer showers. The higher PoPs however, remain just ahead and along the front (Friday into Saturday morning). 24 MARINE... Moderate to strong south to southeast winds and elevated seas will persist across the bays and Gulf waters through tonight. Chance of showers and thunderstorms expected through Sunday as a warm front continues to move further inland today followed by a cold front moving into the coastal waters Sunday afternoon. Strong northeast winds will develop in the wake of the front Sunday night into Monday and will likely require Caution Flags and Advisories for the bays and Gulf waters. Winds relax Tuesday and turn northeast to east as high pressure moves close to the region. Light east to southeast winds expected Wednesday with onshore flow persisting through Friday. Chance of rain will return on Friday ahead of the next cold front which is expected to move into the coastal waters sometime late Friday into early Saturday. 24 && .PRELIMINARY POINT TEMPS/POPS... College Station (CLL) 60 66 43 58 35 / 50 0 0 0 0 Houston (IAH) 67 74 47 59 39 / 70 60 10 10 0 Galveston (GLS) 68 73 51 61 49 / 80 60 10 10 0 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...High Rip Current Risk until midnight CST tonight for the following zones: Bolivar Peninsula...Brazoria Islands... Galveston Island...Matagorda Islands. GM...Small Craft Advisory until midnight CST tonight for the following zones: Waters from Freeport to Matagorda Ship Channel TX from 20 to 60 NM...Waters from High Island to Freeport TX from 20 to 60 NM. && $$
Area Forecast Discussion
National Weather Service Wilmington NC
1029 PM EST Sat Jan 8 2022 .SYNOPSIS... High pressure to slide offshore from the Mid-Atlantic Coast tonight while a weak coastal trof persists just off the NC and SC Coasts. A strong cold front accompanied with showers, will approach from the NW Sun, sweeping off the Carolina Coasts and offshore late Sun night. Cold high pressure will follow through the upcoming mid-week period. && .UPDATE... Some tweaking to sky conditions, based on latest sat imagery and HRRR model trends and a quick 1st look at 00z model runs. Temps also tweaked base don extent of the blanket of clouds. Held onto the NE-E winds longer across the FA and within the nearshore waters based on slower demise of the inverted sfc trof ie. coastal trof. 733PM EDT Update... Moisture in the low levels has been creeping northward from southern SC from this aftn and early this evening...and has now encompassed atleast 2/3rds of the FA with the exception of the immediate coast and a portion of Southeast NC. Sky conditions have been updated to account for this northward push of stratocu cloudiness. Stratocu offshore from the coast will eventually get drawn onshore overnight into Sun as a weak coastal trof drifts to the immediate coast. This blanket of clouds will limit the drop of temps this evening except across Southeast NC. Temps will either straight line as the cloud deck pushes overhead or actually climb a few degrees overnight as sfc dewpoints also moderate. Tweaked seas a foot hier this evening but kept the trend decreasing after midnight as wind produced seas subside-some. && .NEAR TERM /THROUGH SUNDAY/... Latest sfc analysis shows 1037 mb high pressure centered over the DELMARVA. The high slides offshore tonight but continues ridging down into the local area, leading to light NE flow and mostly clear skies until some increasing clouds late. Low temps range from near 30 inland to the upr 30s along the coast. Continued dry then for daytime Sunday ahead of the next cold front. Main story will be a brief return to above normal temps...highs 65-70 with increasing low-level WAA. Expect the rain to hold off until the evening/nighttime as mid levels will remain rather dry and shortwave energy will be positioned still well off to the west. && .SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/... Alberta Clipper system drags a cold front across the area quickly Sunday night. Forecast rainfall amounts are still consistent, coming in around half an inch, with locally higher amounts possible. Still think it`s possible that these amounts could decrease in future forecasts, as the surface front moves through well before the jet dynamics sweep through. The front will be offshore by sunrise Monday morning, bringing very cold air behind it. Rain quickly tapers off in a west to east fashion, with chances along the coast dying off by late Monday morning. High temperatures for the day (around 50) will be recorded not long after the clock strikes midnight and the day changes from Sunday into Monday. From there, temperatures will drop throughout the day, with the mid 40s likely by Monday afternoon. Strong high pressure originating from the upper Midwest quickly slides down into the Ohio River Valley by Monday night. This sets up a decent night for radiational cooling, and temperatures dive down into the mid 20s. && .LONG TERM /TUESDAY THROUGH SATURDAY/... Tuesday is the coldest day of the period, as high pressure shifts to just north of the area. Expect highs in the lower 40s and lows in the teens to lower 20s with clear skies. High pressure tries to shift offshore by Wednesday, but won`t get very far. As a result, very little southerly flow is introduced. Wednesday`s highs are only a few degrees warmer than the previous day, with lows near freezing. Temperatures slowly continue to modify through the rest of the period, with highs in the upper 50s possible by Saturday. Meanwhile, an upper low near the Baja California region introduces some split flow for our neck of the woods towards the end of the work week, setting up for a potentially challenging forecast. For now, forecast remains dry. By the weekend, another clipper system may emerge and drag another cold front across the area, so I`ve kept a chance of rain for next Saturday. && .AVIATION /04Z SUNDAY THROUGH THURSDAY/... VFR to dominate this issuance period. Ceilings will become BKN/OVC 3500-4500 ft this evening thru the overnight as a stratocu deck drifts/develops across the area. During Sun this stratocu deck will become SCT with a BKN 8k-12k ft altocu deck dominating much of the day. A coastal trof will just off the coast will drift onshore and dissipate with initially NE-E 4 kt or less flow becomes a synoptic driven SE-SSW flow around the departing offshore Mid-Atlantic high. The sfc pg will tighten Sun aftn/evening with winds increasing to around 10 kt with around g15 kt. Extended Outlook...VFR early Sun evening deteriorate to MVFR and possibly periodic IFR from pcpn and ceilings associated with a CFP Sun night or early Mon. VFR and dry conditions to follow Mon through mid week with dry and cold high pressure dominating. && .MARINE... Through Sunday: After some gusts up to 15-20 kt early this evening, expect mainly ~10 kt winds for tonight out of the east as sfc high pressure is positioned off to the NE. A cold front then approaches from the west on Sunday, with SSW flow slowly increasing through the day, up to 15-20 kt by late aftn. Seas 2-4 ft through this timeframe, which includes a weak 8-9 second swell component. Sunday Night Through Thursday: Strong cold front moves through the area Sunday night, where SSW flow will quickly transition to NW flow by Monday morning. Seas increase, but remain below Small Craft Advisory thresholds. However, there is increasing confidence that winds will increase after frontal passage, pushing to SCA territory. An advisory is possible late Sunday night into early Monday afternoon. High pressure starts to settle in, with decent northerly flow at 15-20kts and seas at 2-4ft through Tuesday. Wednesday, winds decrease to around 10kts, and back slightly to the NNE, with seas at 1-3ft. Winds continue to back to the NW by Thursday, increasing to 10-15kts, with seas consistently hanging at 1-3ft. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...None. NC...None. MARINE...None. && $$ SYNOPSIS...DCH UPDATE...DCH NEAR TERM...MAS SHORT TERM...IGB LONG TERM...IGB AVIATION...DCH MARINE...MAS/IGB
East Central Florida Forecast Discussion
National Weather Service Melbourne FL
747 PM EST Sat Jan 8 2022 .DISCUSSION... Currently-Tonight...Strong high pressure emerging offshore the Mid- Atlc seaboard will produce defined onshore flow conditions locally into early next week. Marine based CU were producing some weak radar returns, however the overall airmass wl not support much beyond a transitory sprinkle into the overnight period. Silent PoPs wl be maintained. Winds have diminished west of the Indian River and interior with a scattering of clouds expected to remain overnight. Lows in the upper 50s across the north to the upper 60s/lower 70s for the Treasure Coast. from prev disc... Sunday...The surface high over the western Atlc basin will retreat further seaward driven east by the next approaching cold front. The ridge axis will dig deep towards the FL peninsula, with easterly winds veering southeast by mid morning. This southeasterly component may drag additional moisture from the Caribbean towards south FL late in the afternoon. PoPs will return to the forecast but only spread across the south from Stuart towards the upper Kissimmee River basin and remain at a mere 15-20%. Winds will subside becoming 5-10 mph, with afternoon highs returning once again to the 80s. Monday-Tuesday...Things will finally get a little more "exciting" around the Space Coast to kick off the workweek as a strong cold front approaches the region. High pressure will remain to the east- northeast of Florida as it weakens and slides farther away the northeastern seaboard - allowing a shortwave to deepen as it moves across the upper-Midwest on Monday. Reflected at the surface, a cold front will slowly dig east-southeast and sweep across central Florida with the tail end likely clearing the Treasure Coast by late Monday into early Tuesday. Ahead of the boundary, isolated-to-scattered showers and lighting storms will potentially develop near the Treasure Coast and move across the Gulf Stream with lingering moisture from a "washed out" boundary coupled with weak onshore flow (mainly south of Melbourne) leading to sea breeze driven precipitation to develop and drift towards the coast during the morning hours before flow backs offshore. A better chance for showers and storms are expected to spread east-southeastward as the previously mentioned cold front moves across central Florida through the afternoon and evening. While guidance is in decent agreement with the timing and coverage of precipitation, they somewhat disagree on how much instability we will see. The GFS indicates weak instability, however, that tends to be a trend with the model recently, so I would think the RAP, NAM, and HRRR are closer to reality with moderate instability more plausible, especially given the synoptic setup. With that said, some storms may become strong with moderate instability expected, moderate helicity values, conditionally unstable mid-level lapse rates, as well as relatively cold air aloft. We`ll need to watch for flooding, especially towards the Treasure Coast where signals point to the potential for training storms/precipitation. Any strong storms that develop will have the potential to produce gusty winds, heavy rainfall, flooding, and brief spinups (mainly near the coast). Dry conditions will follow behind the front Tuesday night as it moves out to sea - leaving the chance for showers and lightning storms off the coast and over the local waters through the day on Tuesday. High temperatures will reach the mid 70s to low 80s on Monday before FROPA occurs and drops highs into more seasonable levels with afternoon temperatures in the mid 60s to mid 70s. Low temperatures will be in the upper 50s to mid 60s before dropping further Monday night. Temperatures will drop down into the upper 40s to mid 50s inland and the mid 50s to mid 60s near the coast. && .AVIATION... VFR. A steady-state sct CU field wl continue with sct coverage. Onshore winds of around 6 to 12 knots tonight, veering southeast Sunday as the surface high drifts seaward. Rain chances remain minimal, with no impacts to terminals expected. && .MARINE... Tonight-Sunday...Seas of 3-5 feet tonight. The Small Craft Advisory will expire at 10 PM, reverting to caution statements. Sunday, winds will veer southeasterly and diminish below 15 knots with seas 4-5 ft. Monday-Wednesday...Conditions over the waters will improve temporarily Monday morning before a cold front enters the Atlantic waters on Tuesday. West winds around 10-15kts will increase to 20- 25kts and veer to the north-northeast by Monday evening. Swell heights will build from 3-6ft north to south on Monday to 6-8 ft with up to 11 feet over the offshore (20-60nm) waters. SCA will likely be needed by Monday night. && .PRELIMINARY POINT TEMPS/POPS... DAB 63 80 61 77 / 0 10 20 50 MCO 63 83 64 80 / 0 10 20 50 MLB 66 80 64 80 / 0 10 30 60 VRB 66 82 63 82 / 0 10 30 60 LEE 61 83 63 79 / 0 10 20 40 SFB 63 82 63 80 / 0 10 20 50 ORL 64 83 65 80 / 0 10 20 50 FPR 66 79 62 80 / 10 20 30 60 && .MLB WATCHES/WARNINGS/ADVISORIES... FL...None. AM...Small Craft Advisory until 10 PM EST for Sebastian Inlet to Jupiter Inlet 0-20 nm-Sebastian Inlet to Jupiter Inlet 20-60 nm-Volusia-Brevard County Line to Sebastian Inlet 20- 60 nm. && $$ JP/AC
Area Forecast Discussion
National Weather Service Blacksburg VA
953 PM EST Sat Jan 8 2022 .SYNOPSIS... A front moves across Sunday into Sunday night with mainly rain, with a brief period of freezing rain over Southeast West Virginia into the Alleghanys Sunday morning. High pressure builds in Monday, with mainly dry weather expected into midweek. && .NEAR TERM /THROUGH SUNDAY/... As of 953 PM EST Saturday... Winter Weather Advisory remains in effect for portions of southeast WV into the Alleghanys of Virginia Sunday morning for freezing rain. High pressure along the coast continues to move east tonight as cold front approaches from the west. Rain along the frontal boundary is pushing into the Ohio valley this evening. This evening 00z RNK sounding showed a warm nose around plus 6. As stated earlier expect a few pockets of freezing rain before the intensity of the rain warms the surface/low levels to above freezing Sunday morning. Looking at the latest HREF data, appears that forecast capture the areas with the best potential for freezing rain. The Highresw-ARW and HRRR still support the precip arrival time after 12z in the west tonight. As the precipitation get closer may need to expand the weather advisory or issue sps for additional pockets of freezing rain depending on conditions. It still looks like a small window for freezing rain with amounts light and less than a tenth of an inch. Will review the 00z run of models before making any additional changes. Previous discussion: As of 633 PM EST Saturday... Winter Weather Advisory remains in effect for portions of southeast WV into the Alleghanys of Virginia Sunday morning. Made some minor adjustments in temperatures for this evening into tonight utilizing the latest surface obs, their trends and blended in the NBM. Made some minor adjustments in cloud cover for tonight. The Highresw-ARW and HRRR still support the precip arrival time after 12z. More changes later tonight. Previous discussion: As of 125 PM EST Saturday... Expect A Little Ice Across The Alleghanys and Southeast WV Sunday Morning... The deep freeze will rise to near or just below normal temperatures by Sunday afternoon, thanks to increasing heights, and southwest flow ahead of a cold front. Prior to it, cold high pressure centered along the mid-Atlantic coast is going to shift east through tomorrow, while a warm front/isentropic lift enhance across the TN Valley into the central Appalachians late tonight, with clouds increasing this evening, and lowering overnight. Not a classic or hardly an in-situ wedge set up, but with it being very cold the last couple of nights, and temps expected to drop into the upper teens/lower 20s late this evening then steady or rise overnight, we may be seeing an issue with precip coming in around 12z/7am in the WV mountains. Models have slowed down timing of precip til mainly after 12z, and most agree that a strong low level 8h jet will send a warm nose of of +7 to +10C over the area when the precip arrives. This leads to somewhat of a conundrum, as think the sub-freezing surfaces and temps for a couple hours will harness freezing on contact of rainfall, before the intensity of of the rain warms the surface/low levels to above freezing by late Sunday morning. Although there does not look like a large window for ice and amounts will be under a tenth of an inch, it only takes a trace of ice on roads/sidewalks to cause problems. Will be putting up a winter weather advisory for portions of southeast WV into the Alleghanys of Virginia starting around 5am, lasting til 11am, though bulk of accretion will likely be a 2 hour window from 11/13z/-13/15z. Otherwise, should see convergence of moisture along/ahead of the cold front to bring a period of rain to most of the forecast area by late Sunday afternoon. The rainfall totals overall should be higher in the WV/far SW VA/NC mountains, where up to an inch is likely, with around a half inch for most of the area. Forecast confidence is high for all but ice amounts this forecast period. && .SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/... As of 100 PM EST Sunday... A cold front will move across the area Sunday evening with rain ending by early evening across the mountains and around midnight over the piedmont. Behind the front, a 45 kts cross-barrier jet and a tight pressure gradient will bring windy and gusty conditions to the area Sunday night into Monday. Winds relax late in the afternoon as high pressure builds in. An upper level trough will pivot over the region Monday night. The GFS brings upslope snow showers Monday afternoon into Tuesday morning. The ECM only brings an increase in clouds. Since substantial dry air follows the front, leaning towards the ECM. More dry weather follows this trough with high pressure building over the region Tuesday. Temperatures will remain cooler than normal. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... As of 115 PM EST Sunday... An upper level trough will dive out of the Great Lakes and into the mid-Atlantic states Thursday. Models differ with the GFS being wet and the ECM only increases clouds. Leaning towards the ECM with lingering dry air in the region and the Gulf being closed. We will carry low PoPs just in case moisture from the Great Lake survives the trip. There is another potential weather maker for next weekend. Models are in better agreement with a frontal passage Saturday. Temperatures becoming warmer than normal Thursday continuing into the weekend. && .AVIATION /03Z SUNDAY THROUGH THURSDAY/... As of 658 PM EST Saturday... Pilots should watch for icing and low level wind shear late tonight into Sunday. VFR conditions will continue this evening into tonight. High pressure will slowly slide east tonight as a cold front approaches from the west. In general, clouds will increase tonight. Rain associated with frontal boundary will push into the western taf sites of BLF and LWB by 14-16z. At the start, temperatures will be cold enough to have freezing rain at LWB for a couple hours. Early Sunday morning, moisture increases enough to bring all sites to ceilings to at or below 3000ft, though confidence is higher in the mountains as precip moves in. Vsbys also could be MVFR at BLF/LWB by 18z. In addition, a low level inversion sets up tonight, while a very strong low level jet from the southwest moves overhead, which looks to bring the potential for low level wind shear to all taf sites in the 09-19z time frame. Rain will be moderate, possibly heavy in the mountains Sunday afternoon. MVFR and IFR conditions will be common in areas of rain. Average confidence in ceilings,visibilities and winds during the taf period. .Extended Aviation Discussion... Rain moves out by Sunday evening, and until then, expect sub- VFR weather. As the front exits on Sunday night, any lingering moisture near BLF and LWB may turn back to snow before fading by Monday as drier air returns. Brisk northwest winds are anticipated for Monday, but high pressure should build overhead by Tuesday to provide VFR conditions at all TAF sites through Wednesday. Dry weather expected Thursday into Friday. Moistures return to the west late Friday night into Saturday with a front. && .EQUIPMENT... The tipping bucket at the Bluefield ASOS is inoperable. Return to service is expected sometime Monday. Until then precipitation will not be reported from KBLF. In addition, there is a comms outage at Bluefield preventing the observation from being transmitted at times. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...Winter Weather Advisory from 4 AM to 11 AM EST Sunday for VAZ018>020-024. NC...None. WV...Winter Weather Advisory from 4 AM to 11 AM EST Sunday for WVZ042>044-507-508. && $$ SYNOPSIS...WP NEAR TERM...KK/WP SHORT TERM...RCS LONG TERM...RCS AVIATION...KK/WP EQUIPMENT...SH