Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 02/07/20

National Weather Service Albany NY
951 PM EST Thu Feb 6 2020 .SYNOPSIS... Intermittent periods of rain and freezing rain will occur overnight, turning to snow from west to east Friday morning into the afternoon. The snow is expected to be heavy at times, especially along and north of I-90. It will become windy and much colder Friday night into Saturday. Mainly dry weather is expected for the weekend. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... Winter Storm Warning for portions of the southern Adirondacks and western Mohawk Valley through Friday night... Winter Weather Advisory for areas mainly along and north of I-88/I-90 through Friday... Winter Weather Advisory for eastern Albany and Rensselaer Counties until Midnight... As of 945 pm EST...A full-latitude mid and upper level trough centered over the MS River Valley will become negatively tilted overnight with a strong sfc cyclone going through rapid cyclogenesis moving northeast from the Southeast towards the Piedmont Region overnight night. Strong water vapor transport continues out of the Gulf. An inverted sfc trough coupled with weak impulses in the southwest flow aloft bring intermittent periods of rain and freezing rain. We have caught another lull in the wake of one impulse in the last hour. However, we believe another one will cause the pcpn to increase once again between midnight and 3 am. We lowered the PoPs briefly, but then start to increase them after midnight based on the 3-km HRRR and upstream radar returns. The temps are slowly creeping up in the Capital Region. KALB finally hit 33F but the dewpt is 29F. The NYS mesonet shows most temps in the 30-32F range in eastern Albany and Rensselaer Counties, so we will keep the advisory going until midnight for any patchy freezing drizzle or light freezing rain around. Further north, shallow cold air remains in place with north/northeast winds. Temps remain in the upper 20s to lower 30s. A gradual upward trend is done tonight, though locaitons in the Mohawk Valley north into the southern Adirondacks may never get above freezing. We also added patchy fog to much of the forecast area due to the adbundant low-level moisture and some melting of the snow/sleet/ice. Additional ice accretion of a light glaze in the Capital District up to a quarter to third of an inch over the southern Adirondacks/Lake George Region. Temps will be steady in the upper 20s to mid 30s. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY/... Winter Storm Warning for portions of the southern Adirondacks and western Mohawk Valley through Friday night... Winter Weather Advisory for areas mainly along and north of I-88/I-90 through Friday... On Friday, a shortwave rounding the base of the trough will become negatively tilted as it progresses northward from the southern Appalachians to southern New England. Models have been consistent in depicting the potential for rapid cyclogenesis attendant to this wave as it moves into the lee of the Appalachians. For instance, several solutions show the central pressure falling 20 mb in 12 hours, from ~990 to ~970 mb 06-18Z Friday. The track of the storm has come into better agreement, from south-central PA to near KPOU to the Maine coast 12Z Fri to 00Z Sat. Impressive dynamics attendant to the wave and surface low will work into the area, resulting in a band of heavy precipitation in the deformation zone which looks to set up from the Catskills, Capital District, and southern Vermont and points west. Strong frontogenesis in the 850 to 700 mb layer will be occurring here, and could lead to a band of intense snowfall. Temperatures will be rapidly crashing throughout the troposphere as the low pulls away. One question for snowfall accumulations is how much of the heavy QPF occurs as rain before turning to snow, and how quickly can it accumulate on the relatively warm ground. HREF probabilities for greater than an inch per hour are mainly confined north and west of the Capital District, which is where the highest probability of accumulating snow will occur. A Winter Storm Warning was issued for the zones with the highest combination of snow and ice, as there will likely be some freezing rain ongoing over portions of the southern Adirondacks/western Mohawk Valley after sunrise before turning to snow. In the Winter Weather Advisory area, periods of moderate to heavy snow are still possible in the afternoon, and even briefly for areas outside of the advisory area. The rain/snow transition zone is expected to be located in the Glens Falls to Schoharie vicinity by around noon, and from southern Vermont to the eastern Catskills by around 3 pm. There could be a brief period of sleet/freezing rain with temps near the surface possibly falling faster than aloft. As the wave pulls away, strong westerly winds will develop in the afternoon and evening, enhanced by the strong cold advection. This could result in borderline wind advisory criteria, although mixing depths will likely be hampered by cloud cover. Still, pressure rises of up to 10 mb in 3 hours are modeled. The gusty winds will exacerbate issues where there is snow and ice on the trees, and could result in some power outages. The snow will be tapering off from west to east roughly 4-7 pm, except lingering over the western Adirondacks and southern Vermont due to orographic lift. A much colder airmass will be filtering in Friday night, with minimum wind chills ranging from the negative to positive teens. On Saturday, it will be mainly dry as high pressure briefly builds in. A weak wave interacting with some lake-induced instability may result in a few snow showers over the western Mohawk Valley; otherwise, dry weather is expected. The pressure gradient will relax, but it will still be a bit breezy with high temps around 5-10F below normal. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... An active weather pattern looks to continue during the long range period as a series of systems affect the region every two or so days. High pressure will remain overhead for Saturday night which will result in a mainly clear sky and bitterly cold night. Lows are expected to range from -10 F across the northern Adirondacks to the mid-teens across the mid-Hudson Valley. As the surface high pushes off the coast on Sunday, an upper-level shortwave and warm air advection will bring the return of clouds and perhaps a few flurries. Little if any accumulation is expected with this activity. The southwesterly warm air advection flow will continue Sunday night ahead of the next system set to arrive on Monday. This will result in a milder night Sunday night and a milder day on Monday. Precipitation is expected to begin as snow late Sunday night before changing to rain in most locations on Monday. Precipitation may remain all snow across the Adirondacks. This system and associated cold front will push through the area Monday evening and stall somewhere across the mid-Atlantic on Tuesday. The next upper-level trough reaches the Great Lakes late Tuesday into Wednesday as a surface low attempts to form along the stalled front to our south. These two features may collide across our region late Tuesday into Wednesday with another round of rain/snow. Yet another system may arrive on Thursday; however, there are widely variable model solutions on this. Went with a blended approach for this update which led to chance PoPs for more rain/snow. && .AVIATION /03Z FRIDAY THROUGH TUESDAY/... An inverted trough and a low pressure system will continue to bring mixed precipitation to eastern NY and western New England tonight through tomorrow. Widespread IFR and low MVFR conditions continue to impact KGFL/KALB/KPSF/KPOU tonight. Light freezing rain and drizzle continue to impact KALB/KGFL/KPSF this evening with IFR and periodic LIFR conditions, especially in terms of cigs and sometimes vsbys. KPOU is above freezing and has had some IFR/MVFR conditions with rain. Expect widespread IFR/low MVFR cigs/vsbys overnight with some lapses to LIFR. The ptype should transition to plain rain at KALB/KPSF between 04Z-08Z/FRI. KGFL will likely have -FZRA/-FZDZ until possibly 12Z-14Z, where a brief period of rain occurs, but then a deepening sfc low will pass north of KPOU drawing in colder air transitioning all the rain to sleet/fzra and then snow at KALB between 17Z-20Z/FRI. Expect conditions to remain IFR into the afternoon. Widespread IFR/low MVFR will persist the duration of the TAF cycle. KPOU will continue to have rain with IFR conditions rising to MVFR briefly in the afternoon, before a rain/snow mix could move in between 22Z/FRI to 00Z/SAT and a PROB30 group was used to for now. Winds will be light from the north/northeast to east at 4-6 kts tonight, and the shift to the northeast to southeast at less than 10 kts toward daybreak. The winds will increase quickly from the west/northwest at 10-16 kts shortly before or just noontime, and further strengthen from the west/northwest at 15-22 kts with some gusts 30-35 kts at KALB/KPSF/KPOU between 19Z/FRI and 00Z/SAT. Outlook... Friday Night: Low Operational Impact. Breezy. NO SIG WX. Saturday: No Operational Impact. NO SIG WX. Saturday Night: Low Operational Impact. NO SIG WX. Sunday: Low Operational Impact. Slight Chance of SHSN. Sunday Night: Moderate Operational Impact. Likely SHSN. Monday: High Operational Impact. Likely SHRA...SHSN. Monday Night: Low Operational Impact. Slight Chance of SHRA. Tuesday: Moderate Operational Impact. Chance of SHRA...SHSN. && .HYDROLOGY... Precipitation will increase in coverage tonight, becoming moderate to heavy Friday morning into the afternoon. Rain and freezing rain will turn to snow from west to east. Total QPF of 0.50 to 1.25 inches is expected through Friday evening, lowest south and highest north. The heaviest precipitation is expected where temperatures are not likely to be much above freezing, so hydro issues are not anticipated. Mainly drier and much colder weather is expected over the weekend, allowing for rivers and streams to recede and potential build ice. 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...Wind Advisory from 1 PM to 10 PM EST Friday for CTZ001-013. NY...Winter Weather Advisory until 7 PM EST Friday for NYZ039>041- 043-047>051-082>084. Winter Storm Warning until 10 PM EST Friday for NYZ032-033-038- 042. Winter Weather Advisory until midnight EST tonight for NYZ052>054. MA...Winter Weather Advisory until 7 PM EST Friday for MAZ001-025. VT...Winter Weather Advisory until 7 PM EST Friday for VTZ013>015. && $$ SYNOPSIS...Thompson/Wasula NEAR TERM...Thompson/Wasula SHORT TERM...Thompson LONG TERM...Rathbun AVIATION...Wasula HYDROLOGY...Thompson
Area Forecast Discussion
National Weather Service Binghamton NY
1006 PM EST Thu Feb 6 2020 .SYNOPSIS... A rapidly developing low pressure system will bring a wintry mix changing to snow tonight through Friday. Several inches of snow is expected in Central New York through Friday. Steadier snow tapers off Friday afternoon, before lake effect snow showers kick in southeast of Lake Ontario late Friday. && .NEAR TERM /THROUGH FRIDAY/... With the 18Z model guidance and some of the 00z model guidance such as the NAM and HRRR some trends are becoming more apparent. The 18Z RGEM/00z NAM appear a bit overdone with snow banding having almost 1 inch of QPF centered from Tioga to Chenango county late tomorrow morning in a six hour period. However, the possibility of an intense snow band leading to dangerous travel is increasing from the mid-morning to early afternoon hours. The latest Snow Banding tool from FSU indicates frontogenesis supportive of snowfall rates of 2 to even perhaps 4 inches per hour under the band for a few hours. The location of this snow band is still somewhat uncertain as any deviation in the expected low track could lead to altered snowfall totals with the next update. Some modeling is also keying on two different bands a weaker one from Ithaca to Syracuse around mid-morning then another one from across NE PA into the Catskills. This possibility appears less likely at this time, particularly with the less than reliable track record of the GFS. Model consensus is shifting to the band having more of an impact further southeast into the Souther Tier and perhaps Bradford PA than the previous update. As a result, portions of the southern Finger Lakes and Southern Tier have been upgraded to a winter storm warning. Based on the trends so far tonight the warning may need to be expanded into Otsego and Broome counties as well. 515 PM Update: Temperatures continue to run at or just below freezing at many locations across the western portions of the area. Some light freezing rain/freezing drizzle as been reported at several locations across these areas. Therefore, made adjustments to hourly temperatures for this evening and increased coverage of freezing rain/freezing drizzle somewhat. Also issued an SPS to address potentially slippery conditions on untreated surfaces this evening in these same areas. Otherwise, the forecast remains on track and the previous discussion remains valid. Previous Discussion: Temperatures continue to be the main forecast challenge this afternoon, as cold air at the surface continues to be locked in across a good portion of the area, especially in Central New York. As a result, some light freezing rain and freezing drizzle has lingered a bit longer than expected across portions of the Finger Lakes and northward towards the Syracuse area and towards the Tug Hill. At this point, expecting temperatures to remain fairly steady across these areas the remainder of this afternoon and into this evening, allowing for an additional glaze of ice accumulation. Further south and east, temperatures are above freezing and therefore any light precipitation the remainder of this afternoon and this evening will likely be in the form of rain. Conditions really begin to go downhill tonight as a strong and rapidly deepening low pressure system moves up the Appalachians and to the Hudson Valley by midday Friday. 12Z model consensus has indicated that this storm will be deeper/stronger than previous model runs, potentially near 970mb as it will be situated over the Hudson Valley midday Friday. Frontogenesis axis at the mid levels appears to set up right over the Finger Lakes through NY Thruway, with dynamic cooling changing rain/freezing rain to heavy snow late tonight-early Friday. The axis may pivot into the Twin Tiers for a time early- to-mid Friday before precipitation begins to take on a more showery nature, and lake-enhanced for that matter southeast of Lake Ontario late Friday into Friday night. The exact positioning of this band is what remains somewhat uncertain, as a small shift west or east from the current forecast can have a significant impact on overall snowfall totals. Opted to upgrade the Winter Storm Watch to a Winter Storm Warning for Seneca, Cayuga, Tompkins, Cortland, Onondaga, Madison, and Oneida counties, as this is where the greatest confidence is for higher snowfall totals, mainly 6 to 9 inches with locally higher amounts possible. Further south and east, Winter Weather Advisories will be in effect for generally 4 to 7 inches of snow. Potential expansion of the Winter Storm Warning will be re-evaluated in future forecast updates as updated high-res model guidance continues to come in. No headlines have been issued for Sullivan, Pike, Southern Wayne, Lackawanna, and Luzerne counties as any snowfall accumulations will likely be minimal in these locations (generally 1 to 3 inches, with some areas seeing less than an inch). It is important to note that this will be a high impact system for Central New York, as most of the snow will fall within a 6-8 hour period Friday morning with snowfall rates of 1 to 2 inches per hour in the heaviest snow bands. This will be a rather large concern for the morning commute. Heavy snow combined with gusty winds may also cause scattered power outages. Snow tapers off Friday afternoon, but transitions to lake effect snow showers southeast of Lake Ontario. && .SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY NIGHT/... Lake effect snow showers will set up Friday night and should persist into early Saturday afternoon. However, high pressure/ridging pushes in from the west and moves over Central NY by Saturday evening and this will bring an end to any lingering lake effect snow showers. Skies clear out Saturday night and with a fresh snow pack temperatures should drop below zero across Northern Oneida County and to near zero to single digit readings across Central NY and into the Catskills. && .LONG TERM /SUNDAY THROUGH THURSDAY/... After a quiet and seasonable Sunday, a lake cutter approaches the area. Surface low track is from lake Huron then up the St Lawrence valley on Monday. This will bring snow to the area initially, followed by mixed precipitation Monday as warmer air is dragged into the area. Best chance of a full change over will be over NEPA while the Tug Hill may remain as all snow. Tuesday features another low, this time zipping up the east coast. Mild air left in place may result in rain of mixed precip at the start, turning to snow as colder air moves in behind the low as it moves into New England. Brief lake effect snow showers are likely Wednesday before high pressure builds in late in the day. && .AVIATION /03Z FRIDAY THROUGH TUESDAY/... IFR conditions are forecast for much of the next 24 hours. Light fog and patchy drizzle or freezing drizzle will keep clouds between 500 and 1500 feet this evening with visibilities between 2SM and 5SM. A mix of freezing rain, sleet, and rain will slide across the terminals overnight. Ceilings will drop to between 200 and 1000 feet. As colder air moves into the region early Friday, snow will develop and become heavy at times. Widespread LIFR conditions are likely. Outlook... Friday night...Lake enhanced snow showers and occasional restrictions for KSYR-KRME; possibly at times KITH-KBGM. Saturday through Monday... Occasional snow showers with restrictions, mixed with rain on Monday. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...Winter Weather Advisory from 1 AM to 5 PM EST Friday for PAZ038>040-043. NY...Winter Weather Advisory from 1 AM to 5 PM EST Friday for NYZ046-056-057. Winter Storm Warning until 4 PM EST Friday for NYZ023-024-055. Winter Storm Warning until midnight EST Friday night for NYZ009-016>018-025-036-037-044-045. Winter Weather Advisory until 1 PM EST Friday for NYZ015-022. && $$ SYNOPSIS...BJG NEAR TERM...BJG/MWG SHORT TERM...MPK LONG TERM...DGM AVIATION...DJP
Area Forecast Discussion
National Weather Service Bismarck ND
934 PM CST Thu Feb 6 2020 .UPDATE... Issued at 934 PM CST Thu Feb 6 2020 Latest fog/stratus imagery loop show clearing continuing to push from northeast to southwest, with the leading edge now nearing locations along and east of the Missouri River. The NAM and RAP13 925mb-850mb are the closest models to reality when initializing with the current satellite and surface observations. Over the next few hours, have essentially cleared out the sky and lowered temperatures significantly along and east of a line from near Crosby to New Town, and from Hazen to Linton. Although there is another batch of stratus just east of Jamestown that will roll into the James River Valley 04z-09z then clearing. With this update, also have opted to issue a wind chill advisory for Rolette County until 15z Friday as they are and will continue to meet wind chill advisory until shortly after daybreak Friday. This also blends in well with the wind chill advisory already in place across northeast North Dakota. UPDATE Issued at 521 PM CST Thu Feb 6 2020 Latest surface map shows the surface-850mb cold front/isotherm packing/baroclinicity residing over southwest North Dakota. Reflectivities have been increasing over the past hour per Bowman radar. SPC mesoanalysis indicates an area of low level/925mb frontogenetical forcing with additional forcing from a mid level/700mb over eastern Montana sliding atop the low level front. Expect forcing at its peak now, then on the decrease shortly after 00z Friday as the mid level shortwave shifts into northwestern South Dakota by 03z Friday. Current forecast has the southwest PoPs handled well and no changes needed. Clearing continues to slowly nudge back to the southwest from the Turtle Mountains. Feel the HRRR has the best initialization on this and would anticipate some clearing to push into the James River Valley, but fall short of reaching Bismarck at this time. Low level winds back from north-northeast to the northwest 12z-15z Friday, and in doing so, will counteract any clearing trying to progress in from the Turtle Mountains. Otherwise, with a clear sky in the Turtle Mountains, wind chills will be monitored closely tonight. As of now, wind chills at Rolla are at 16 below zero. && .SHORT TERM...(This evening through Friday) Issued at 308 PM CST Thu Feb 6 2020 The short term forecast is highlighted by light snow accumulations in western North Dakota, and very cold morning temperatures in the north central. The base of a longwave trough was located over the south central CONUS, with ridging over the Pacific and northwest flow aloft over the Northern Plains. At the surface, a slow-moving cold front was draped from Beach to Linton. A weak area of low-level frontogenesis and warm air advection behind the frontal boundary is continuing to produce light snow across much of central North Dakota this afternoon. Although snow is expected to taper off this evening across central North Dakota, a weak upper-level impulse has already started producing snow in western Montana and far southwestern North Dakota. This is likely to continue tonight, with an additional 1 to 2 inches of snow for the western part of the state. Locally higher amounts are possible in the far southwest with a potential for banded snow, due to a band of low-level frontogenesis collocated with strong lapse rates. Clouds are expected to clear in north central North Dakota tonight as surface high pressure moves in. Radiational cooling coupled with cold air advection behind the front will drop overnight low temperatures much lower than they have been lately. Forecast lows are currently in the -10 to -15 range for Bottineau, Rollette, and Pierce Counties, with lows near zero and colder along and north/east of the Missouri River. Light snow could linger in the western half of the state through much of Friday, although no accumulation is expected. As the high pressure slides through eastern North Dakota, expect highs temperatures ranging from the single digits in the east to the lower 30s in the west. .LONG TERM...(Friday night through Thursday) Issued at 308 PM CST Thu Feb 6 2020 The extended forecast is highlighted by more snow in southwest North Dakota Saturday night, with more precipitation possible midweek and colder temperatures on the horizon. Quiet weather on Saturday ahead of a shortwave moving through the broad northwest flow that will bring more snow to the region. A surface low is projected to slide to our south with a baroclinic zone setting up on the northern side of the low. This, along with large- scale ascent aloft, may produce an area of higher snow accumulations. Model guidance is quite variable in QPF and thus snow amounts with this system, which will be dependent on where exactly this baroclinic zone ends up. GEFS/WPC plumes have a wide range of solutions but for our forecast area, the highest snow amounts are expected in far southwestern North Dakota, with amounts decreasing to the north and east. For QPF amounts with this update, opted to blend the previous shift`s amounts with the latest WPC guidance. Due to it being a banded snow event with amounts quickly decreasing through the forecast area, it`s not surprising to have fluctuations in how much and where the snow is expected, but we wanted to keep some continuity to the forecasted snow totals. Snow should end quickly on Sunday before a few days of quiet weather and high temperatures in the 20s and 30s with northwest flow aloft. The potential exists for more precipitation mid-week, but model guidance has been too inconsistent to have much confidence in anything specific. However, there is agreement in both model guidance and CIPS analogs that temperatures will drop well below average by the end of next week. && .AVIATION...(For the 00Z TAFS through 00Z Friday evening) Issued at 934 PM CST Thu Feb 6 2020 MVFR to low VFR cigs can be expected this taf period at KXWA and KDIK. Clearing continues to push from KMOT and on into KBIS by 06z. Expect KJMS to clear after 09z Friday. Flurries and/or a period of light snow also can be expected KDIK through Friday afternoon. && .BIS WATCHES/WARNINGS/ADVISORIES... Wind Chill Advisory until 9 AM CST Friday for NDZ005. && $$ UPDATE...KS SHORT TERM...MJ LONG TERM...MJ AVIATION...KS
Area Forecast Discussion
National Weather Service Boston/Norton MA
1032 PM EST Thu Feb 6 2020 .SYNOPSIS... Low pressure in the Mississippi Valley will intensify into a strong storm as it tracks across New England Friday. This will bring a period of rain tonight into Friday, changing to snow across interior Massachusetts before ending late Friday or Friday evening. The storm will also result in strong to damaging wind gusts Friday afternoon and evening as the storm exits. Expect dry and cold conditions to prevail Saturday as high pressure builds across. Quick moving weather systems may bring periods of light rain and/or snow at times from Sunday through Thursday. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... Tweaked the forecast this evening, mainly temperatures and timing of precipitation. For temperatures, preferred the ideas presented by the 06/18Z 3-km NAM and the latest few runs of the HRRR, which held temperatures closer to freezing across the northern tier of MA through much of tonight. Thus, a slightly higher risk for additional freezing rain/drizzle later tonight. Since this is where the present Winter Weather Advisory exists, will let that continue as is. Latest NationalBlend and HRRR guidance also picked up on current relatively dryness across much of southern New England. While not a widespread rainfall, trace precipitation reports indicated plenty of lingering drizzle. Expecting measurable rainfall chances to increase once more after midnight. Previous Discussion... Next area of steady rain lifting north from the Mid Atlc region. Potent mid level shortwave rounding the base of a deep and amplified trough with right entrance region of upper jet will result in deepening low pres as it moves into PA late tonight. Strong low level jet develops ahead of this system. While the axis remains offshore, enough convergence combined with deep and anomalous PWAT plume, 3-4SD above normal, will bring widespread rainfall to SNE tonight. A period of heavy rain is possible along the south coast and Cape/Islands closest to the low level jet. There is some instability noted above the frontal inversion over the southern waters late tonight and toward daybreak so can`t rule out a t-storm over Nantucket and adjacent waters. Potential for 1-2 inches rainfall Cape/Islands tonight with amounts dropping off to the north, decreasing to around 0.25" in northern MA. Temps are mostly above freezing, but still near and a bit below 32F over the higher elevations in interior MA. Most of the hi- res guidance keeps temps in the elevated terrain near freezing through the night as light north persists so pockets of freezing rain possible. As a result will extend the winter weather advisory through tonight for higher terrain in MA. Additional ice accretion will be less than one tenth of an inch. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/... Highlights... * Period of strong to damaging wind gusts mid/late afternoon, strongest near the south coast * Rain changing to a period of snow mid/late afternoon in western and interior northern MA before ending Rather potent storm will be tracking across interior SNE, deepening below 970 mb as it moves across the region and to the NE. The main concern with such an anomalous and rapidly deepening low pres is strong to damaging winds as it lifts to the north. 60 to 75 kt low level jet with strong cold advection behind the storm and isallobaric contribution from a very impressive pressure fall rise couplet gives high confidence in damaging west wind gusts from about mid afternoon into Friday evening as the storm lifts to the north. Expect the strongest gusts, 60+ mph near the south coast and Cape/Islands. This is where temps should briefly spike well into the 50s which will enhance boundary layer mixing. We issued a high wind warning for this area, with a wind advisory for 50-55 mph gusts for much of the rest of central/eastern MA and Rhode Island. The advisory may eventually need to be expanded across rest of SNE. While the strongest winds are expected mid/late afternoon, may see an initial surge of strong SW gusts along the south coast early afternoon. Mid level low will be tracking well to the north across northern NY and northern VT. This will result in dry slot moving up across New Eng during the morning which will bring a temporary lull in the rainfall. Then what`s left of the comma head will bring another shot of precip, especially to central and western MA during the afternoon. Ptype starting as rain but as colder air deepens, expect a change to snow for interior northern and western MA toward mid afternoon. A coating to 2 inches possible before the snow ends in the early evening. By the time the colder air arrives in the coastal plain, it will likely have dried out so not expecting any snow here. Temps tricky as warm front will be lifting north across SNE with temps warming well into the 50s to the south of the boundary and remaining in the 30s/low 40s to the north. Best chance of seeing 50s will be across RI and SE MA for a brief time in the afternoon. && .LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/... Highlights... * Dry and cold Saturday * Light snow/rain showers possible sunday * Next widespread rain/high elevation snow system comes Sunday night/Monday * Periodically unsettled weather and mild temperatures continue through next week. Details... Friday night... The main takeaways for Friday night will be drying out, dropping temps, and decreasing wind. By the overnight hours the last vestiges of snow will be lingering over the Berkshires, with dry weather elsewhere as the low moves past Nova Scotia, taking the moisture with it. Behind it and behind the cold front CAA will be in full force bringing 850 mb temps from ~0C Friday afternoon down to -15 C by Saturday morning. Given this pattern we can expect a drop in low temperatures of about 10 to 15 F from Friday morning to Saturday the teens and low 20s. This puts us right around normal for this time of year...something we haven`t been able to say much in the past month. Winds will be diminishing after peaking in the late afternoon/evening along the southeast coast as the low quickly exits and the pressure gradient on the backside begins to relax. We`re looking at wind gusts 40-45 kts before midnight, coming down to around 30 mph for the early morning hours of Saturday. Highest gusts will continue to be over southeast MA but it will be windy everywhere as CAA promotes good mixing of 40-50 kt 850 mb jet. Saturday and Sunday... Saturday will be both the coldest and driest day of the extended forecast as high pressure moves overhead. W and NW winds continue to bring in colder air before we`ll rebound to end the weekend. Highs on Saturday will likely be subfreezing for many, especially along and north of the MA Pike, with highs in the low to mid 30s along the immediate south coast. A nice break from the clouds is on tap as well, given the drier air moving in through the entire column, though winds will still be a bit breezy, moreso along the coast. Saturday night with calm winds and clear skies we`ll see good radiational cooling; lows dipping into the single digits in northern and western MA and teens elsewhere. Sunday we`re tracking a very weak mid level shortwave as well as a sfc disturbance to our south that may work with some marginal moisture (PWATs approaching 0.40") to bring light snow/rain showers to the region. Odds are that the majority of locations will miss the chance of showers being the orographically favored western MA/CT. Clouds do increase through the day, though, as mid and low level moisture increases. High temps rebound as flow turns out of the south ahead of the next system...reaching low to upper 30s. Sunday night and Monday... A more organized (though still weak) system impacts southern New England Sunday night and Monday as a trough and ~1010 mb surface low move out of the Great Lakes into Canada. A warm front moves north Sunday night bringing warm and moist flow into Monday which will take temps back well above normal, in the mid to upper 40s Monday. Rain and high elevation snow begin early Monday morning as a robust LLJ moves in and precip lasts at least through the day on Monday bringing up to a quarter inch or locally more. Tuesday through Thursday... This is where confidence drops appreciably as long range guidance introduces very large discrepancies with the synoptic pattern, especially toward mid week. The overall pattern continues to be very zonal and progressive, which most likely keeps things unsettled with quick hitters periodically through the week. Next chance comes as soon as Tuesday, but timing these systems will be better done in the coming days. Temperatures remain mild as the zonal flow precludes any real intrusions of arctic air. && .AVIATION /03Z FRIDAY THROUGH TUESDAY/... Forecaster Confidence Levels... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Through tonight...High confidence overall, but lower confidence in exact details. Widespread IFR with areas of LIFR continue through tonight. Patchy drizzle this evening with steady rainfall returning after midnight. The rain may be locally heavy along the south coast. The risk for pockets of freezing rain/drizzle will continue tonight over the higher elevations. Friday...Moderate confidence. IFR/LIFR in the morning with areas of rain and fog, improving to MVFR/VFR in the afternoon as winds shift to west. Rain with pockets of freezing rain in the Berkshires may change to a period of snow across western MA during the afternoon before ending. The main issue for Friday afternoon will be very strong west wind gusts developing behind departing strong low pres. Wind gusts 40-50 kt will develop after 20z, especially south of the Pike. Gusts may exceed 50 kt late Fri over Cape/Islands. KBOS Terminal...High confidence overall. Lower confidence in exact timing and details. KBDL Terminal...High confidence overall. Lower confidence in exact timing and details. Outlook /Friday Night through Tuesday/... Friday Night: Mainly VFR, with local MVFR possible. Strong winds with gusts up to 50 kt. Saturday through Saturday Night: VFR. Breezy. Sunday: Mainly VFR, with areas MVFR possible. Slight chance SN. Sunday Night: Mainly MVFR, with local IFR possible. Breezy. Chance SN, chance RA. Monday: Mainly MVFR, with local IFR possible. Breezy. Chance RA. Monday Night: Mainly MVFR, with areas VFR possible. Chance SN, slight chance RA. Tuesday: Mainly MVFR, with local IFR possible. Chance RA. && .MARINE... Short Term /through Friday/...High confidence. Continued Storm Warnings for all south coastal waters with gales elsewhere. Expecting a surge to 45-55 kt westerly wind gusts Fri afternoon and early evening as the strong low pres moves by. Seas building to 15-20 ft over southern waters. Outlook /Friday Night through Tuesday/... Friday Night: Moderate risk for gale force winds with gusts up to 45 kt. Rough seas up to 18 ft. Saturday: Moderate risk for Small Craft Advisory winds with gusts up to 30 kt. Rough seas up to 14 ft. Saturday Night: Winds less than 25 kt. Areas of rough seas. Sunday: Winds less than 25 kt. Areas of seas approaching 5 ft. Sunday Night: Winds less than 25 kt. Seas up to 5 ft. Slight chance of rain. Monday: Low risk for Small Craft Advisory winds with gusts up to 25 kt. Areas of rough seas. Chance of rain. Monday Night: Winds less than 25 kt. Areas of rough seas. Chance of rain. Tuesday: Winds less than 25 kt. Seas up to 5 ft. Chance of rain. && .EQUIPMENT... KBOX WSR-88D had a transmitter failure early Thursday morning. It will remain offline until further notice. It is currently expected to be fixed by Friday afternoon or evening. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...Wind Advisory from 2 PM to 10 PM EST Friday for CTZ002>004. MA...High Wind Warning from 2 PM to 10 PM EST Friday for MAZ022>024. Wind Advisory from 2 PM to 10 PM EST Friday for MAZ005>007- 011>019. High Wind Warning from 2 PM to 7 PM EST Friday for MAZ020-021. Winter Weather Advisory until 7 AM EST Friday for MAZ002>004- 008-009-026. RI...High Wind Warning from 2 PM to 10 PM EST Friday for RIZ008. Wind Advisory from 2 PM to 10 PM EST Friday for RIZ001>005. High Wind Warning from 2 PM to 7 PM EST Friday for RIZ006-007. MARINE...Storm Warning from 1 PM to 10 PM EST Friday for ANZ232-254>256. Storm Warning from 1 PM to 7 PM EST Friday for ANZ231-233>237. Gale Warning from 1 PM to 11 PM EST Friday for ANZ230. Gale Warning from 1 PM Friday to 4 AM EST Saturday for ANZ250- 251. && $$ SYNOPSIS...KJC/BW NEAR TERM...Belk/KJC/BW SHORT TERM...KJC LONG TERM...BW AVIATION...Belk/KJC/BW MARINE...KJC/BW EQUIPMENT...Staff
Area Forecast Discussion
National Weather Service Goodland KS
548 PM MST Thu Feb 6 2020 .UPDATE... Issued at 545 PM MST Thu Feb 6 2020 Simulated reflectivity forecasts via the most recent runs of the HRRR suggest that light snow will largely be confined to eastern Colorado (Kit Carson/Cheyenne counties) and will end later this evening (by midnight). Given that snow is light/intermittent, for example -- Burlington reported snow for only 10 minutes (5:00-5:10 pm MST) with visibilities no lower than 2-3 miles -- and that temperatures are in the lower 30s, expect little in the way of accumulation. A dusting to half inch will be possible in western portions of Kit Carson and Cheyenne counties -- where light snow will be relatively more persistent. && .SHORT TERM...(This evening through Friday night) Issued at 219 PM MST Thu Feb 6 2020 Today, 500 mb RAP analysis and water vapor imagery showed a large upper trough exiting the region to the east across the center of the CONUS. As northwest flow increased over the western half of the country, a series of weak shortwave troughs pushed through the flow across the Rockies. As a result, some thick mid level clouds developed and filtered into the area through the day. At 2 PM MT, temperatures were in the upper 30s through mid 40s with northwest winds at 10 to 20 mph (gusting to around 30 mph). The main forecast concern during this short term period is the potential for some light snow this evening through Friday for locations west of the Colorado border. Narrow bands of snowfall are expected to develop along the Rockies and adjacent Plains in Colorado starting this evening and continuing into Friday. The tri-state region is on the eastern edge of the system making it very difficult to determine how far east will be impacted. At this time, it appears that up to one inch of snowfall is possible for the the western portions of our Colorado counties. However, if the storm shifts its track, that will change snow amounts so please stay tuned for updated information. Chances for light snow linger into Friday with strong northwest flow continuing aloft. Any snow in the area should dissipate Friday afternoon and evening, yielding dry conditions overnight. Low temperatures tonight will be warmer than previous nights, as our cold air mass continues to shift east, mixing keeps winds up slightly, and cloud cover remains in place. Am expecting lows in the upper teens to low 20s. Highs on Friday will be slightly cooler behind a weak cold front, ranging in the mid 30s to low 40s. And finally, low temperatures on Friday night should be in the mid teens to low 20s. .LONG TERM...(Saturday through Thursday) Issued at 317 PM MST Thu Feb 6 2020 Long range models show a ridge moving across the central Plains through Saturday.A trough moves southeast from the Pacific Northwest into the central Plains Saturday night. A low cuts off over the western U.S. from the main trough by Sunday night. This is when models start going their own way on the upper level pattern. Most models show the main trough continuing eastward as the cutoff low shifts southward over the Baja of California. The GFS is the outlier so while it could be correct, it is not as likely. Continuing the split flow, a ridge follows behind the trough into the central Plains Tuesday as the cutoff low remains to the southwest. Another trough digs south over the Intermountain West towards the cutoff low. The cutoff low rejoins the main flow over the southwestern U.S. Wednesday becoming a shortwave along the front edge of the trough. The shortwave crosses the central Plains into the Midwest Wednesday night into Thursday. The trough deepens over the northern Plains Thursday with the Tri-State area remaining under west-southwest upper level flow just ahead of the trough axis. A cold front moves south through the Tri-State area by Sunday. High pressure then moves over the area through Tuesday. As a surface low shifts southeast from northwest Canada into the northern Plains by Wednesday, a surface low develops along the Front Range of the Rockies in eastern Colorado. As both surface lows move south and east across the central U.S. through Wednesday night, a strong cold front is expected to trail behind the lows and pass through the Tri-State area Wednesday. Once again, high pressure begins pushing back into the central U.S. behind the system of lows. The first cold front this weekend will lower temperatures slightly but be dry. The second cold front looks to be more significant with a much more noticeable change in temperatures as well as being accompanied by rain and snow. For Saturday through Wednesday, highs will range from the mid-30s to lower 50s and lows will drop into mid-teens to lower 30s. Wednesday night and Thursday will be much colder with lows Wednesday night in the teens and highs Thursday in the upper 20s to mid-30s. There are some slight chance PoPs after midnight Monday night until Tuesday afternoon but confidence is very low in any precip at that time. The better chances for rain and snow will be Tuesday night continuing through Thursday. There is still a lot of uncertainty in how the upper level pattern will progress next week therefore reflecting the same uncertainty on the precipitation chances. It looks like a breezy extended forecast period with a hectic surface pattern. Much of the extended forecast period could see gusts up to 35 mph particularly when associated with passing cold fronts. This next week upper level pattern will need to be monitored closely particularly for snow and wind potential. && .AVIATION...(For the 00Z TAFS through 00Z Friday evening) Issued at 342 PM MST Thu Feb 6 2020 Increased cloud cover is expected this evening and overnight as light snow develops in eastern Colorado. Biggest concern during this TAF period will be how low ceilings get as well as how far east snowfall pushes into the region. At this time, low end VFR conditions are forecast for this evening. However, it is possible that ceilings could dip into the MVFR category. Additionally, it appears that any precipitation should remain west of KGLD, but this will need to be monitored. Northwest winds are forecast through the period, generally around 10 knots. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ UPDATE...VINCENT SHORT TERM...JBH LONG TERM...NEWMAN AVIATION...JBH
Area Forecast Discussion
National Weather Service Wichita KS
600 PM CST Thu Feb 6 2020 .SYNOPSIS... Issued at 323 PM CST Thu Feb 6 2020 Near normal temperatures will continue through Friday, followed by above normal temperatures and breezy conditions on Saturday. Late in the weekend, a cold front will cross the region, sending temperatures back down closer to, or below, normal. The chance of precipitation looks very low through Saturday. On Sunday, a band of showers may develop across southeast Kansas ahead of the advancing cold front. Behind that front, precipitation may tend to be focused south of Kansas, but at least a low chance may develop by mid- week. && .SHORT TERM...(This evening through Saturday night) Issued at 323 PM CST Thu Feb 6 2020 Early this afternoon, a weak area of low pressure was centered over eastern SD, with a cold front trailing back to the W/NW into the NRN Rockies. South of the low, a light, westerly downslope flow has allowed temps to reach the low to mid 40s across central Kansas. Lingering snowcover and less of a downslope component to the wind is keeping eastern Kansas cooler (only in the mid to upper 30s). The SFC low will gradually shift E/SE through Friday, allowing a weak cold front to push SE across central/eastern KS. We`re not expecting a significant airmass change behind the front, with thickness values very similar to what we are seeing today. 850mb temps will be colder than today, but the NW component of the SFC-low level flow may offset the cooler temps aloft somewhat. Weak high pressure then settles in Friday night. Mid-level clouds may attempt to stream into the area during that time, preventing a more ideal radiational cooling setup. However, I did go ahead an nudge lows down some, especially SE KS where winds will likely remain lighter the longest. Return flow very quickly ramps up on Saturday within a transient, zonal flow regime. While the SFC winds may tend to back a bit as cyclogenesis occurs over the Central High Plains, the westerly low- level flow combined with increasing southerly SFC flow should support above normal temperatures Saturday afternoon. The more backed/southerly component of the SFC winds may lend itself to a less-than-perfect downslope setup, but confidence is still high regarding warmer temps. For those reasons, I went above blended guidance for highs Saturday. Warmer SFC temps (assuming that verifies) should also support steeper low-level lapse rates and better mixing, leading to stronger winds than blended guidance suggests. Martin .LONG TERM...(Sunday through Thursday) Issued at 323 PM CST Thu Feb 6 2020 The focus during this period continues to be the evolution of a broad, amplified, and positively-tilted upper level trough developing over the WRN US. Within that trough, embedded shortwaves will also be an important consideration. Initially, the SFC low developing over the High Plains on Saturday will translate east, allowing a cold front to push across the Central Plains Sunday afternoon/evening. Ahead of this front, we may briefly be able to tap into some Gulf moisture returning north ahead of the developing upper level trough. As the previous shift mentioned, the best chance of this still appears to be focused over SE KS where PWats may approach 1" briefly. It is in that area where a narrow band of showers should be able to develop ahead of the front. In the wake of that front, a more broad area of SFC high pressure will spread south across the Plains, and more or less remain in place through mid-week. From mid-week on, model guidance (deterministic and ensemble) begins to show more variation. The main culprit appears to be what happens with a deeper, closed low that is forecast to dig south along the US West Coast early next week. The trend has been deeper and further south with the low as it digs into the SW US, potentially reaching as far south as NRN Mexico. This trend would likely favor a drier solution, with precip being focused south of Kansas. That said, we don`t want to jump too quick on a completely dry solution as there remains some uncertainty in how that WRN US closed low evolves. Should it not dig as far south, the precip potential could end up higher in our neck of the woods. Even with the further south solution, there could still be some precip potential with other waves embedded within the trough. We`ll continue with some low pops next week, but keep in mind the latest trend has been towards less precip potential. Temperatures also fall in the less-certain camp due to differences with the timing and amplitude of various embedded waves. In general, it appears each wave may have a brief warmup followed by a quick surge of colder air. The net effect is probably near average temps. Martin && .AVIATION...(For the 00Z TAFS through 00Z Friday evening) Issued at 600 PM CST Thu Feb 6 2020 At issuance, a weak pre-cold frontal sfc trof was entering Eastern Nebraska, Central & South-Central KS while the cold front extended from Central Nebraska, thru NW KS to extreme SE CO. Winds across C & most of SC KS have shifted to the NW but speeds were only ~10kts with no gusts. The trof & front will continue their E/SE treks across the rest of KS tonight with Altocu from 10,000-13,000ft dropping to ~50,000ft (Stratocu) late this eve & overnight. Cigs may become a problem across C KS 09-12Z as short-term soundings, more specifically the HRRR & RAP, depict a potential for IFR & perhaps even LIFR cigs spreading into the KRSL, KGBD & KSLN terminals during this period. This period will be monitored closely as evening progresses. && .FIRE WEATHER... Issued at 323 PM CST Thu Feb 6 2020 Overall, fire weather concerns should remain on the lower side through the weekend. However, it is worth noting there will be a period of breezy conditions on Saturday, which may slightly elevate fire concerns during the afternoon. && .PRELIMINARY POINT TEMPS/POPS... Wichita-KICT 26 45 25 53 / 0 0 0 0 Hutchinson 27 44 23 52 / 0 0 0 0 Newton 26 42 24 51 / 0 0 0 0 ElDorado 25 43 24 51 / 0 0 0 0 Winfield-KWLD 25 47 26 53 / 0 0 0 0 Russell 25 43 21 51 / 10 0 0 0 Great Bend 26 44 22 53 / 10 0 0 0 Salina 26 42 22 52 / 10 10 0 0 McPherson 26 42 22 51 / 0 10 0 0 Coffeyville 22 46 24 51 / 0 0 0 0 Chanute 23 44 23 48 / 0 0 0 0 Iola 23 43 23 48 / 0 0 0 0 Parsons-KPPF 22 45 23 49 / 0 0 0 0 && .ICT WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...RM SHORT TERM...RM LONG TERM...RM AVIATION...EPS FIRE WEATHER...RM
National Weather Service Jackson KY
907 PM EST Thu Feb 6 2020 .UPDATE... Issued at 905 PM EST THU FEB 6 2020 The last few HRRR runs and RAP runs continue to predict a band of heavier QPF between 6Z and 12Z a few miles either side of a line from near the I 75 corridor northeast to near Hazard and Jackson and then into Martin and Johnson Counties. With this agreement and a slightly quicker changeover it appears that snowfall could reach the 2 to 3 inch range, especially on the ridgetops from near Williamsburg and London northeast to near Jackson, West Liberty, and Paintsville. QPF, snowfall, T, and min T were updated accordingly for the overnight hours. This scenario will continue to be monitored for any needed further adjustments. UPDATE Issued at 730 PM EST THU FEB 6 2020 Drizzle or light rain is occurring across the region at this time as a shortwave trough approaches from the southwest. Precipitation should increase in coverage and probably intensity as well as midnight approaches. Temperatures aloft will also begin to cool and additional cooling is expected overnight which should lead to rain changing to snow. Warm and wet ground will limit any accumulations at least initially with elevated and grassy surfaces and ridgetops being most favored for accumulations. Some minor adjustments were made at this point based on hourly observations to temperatures and dewpoints. Trends for the wintry weather threat and HRRR trends for later tonight will continue to be monitored for any adjustments to qpf and snowfall. High water and some flooding will continue overnight on portions of the KY, Cumberland, and Big Sandy basins. && .SHORT TERM...(This evening through Friday night) Issued at 451 PM EST THU FEB 6 2020 An area of low pressure is progressing east this afternoon based on the afternoon surface analysis. An upper level trough axis is set up across the ARKLATEX region. We remain more or less in a dry slot ahead of the previously mentioned upper level trough axis. This feature will eject northeastward tonight and become negatively tilted. This along with frontogenetical forcing at around 700mb will lead to a swath of precipitation across eastern Kentucky. This moisture will arrive as west and northwest winds advect cold air into the region through the night. This will allow this to change from rain to snow through the night as this colder air arrives. There are some caveats to this...first one is it has been relatively warm heading into the event that would lessen any initial accumulations, and the second is where the higher precipitation amounts setup is in question. This is mainly agreement among the models on where the deformation zone sets up. However, despite the caveats we issued a Winter Weather Advisory for all of eastern Kentucky given this will be falling during commute time and could at least affect elevated road surfaces. This west to northwest flow on Friday will give portions of the Ohio Valley some weak connection to lake Michigan into the day tomorrow especially in the far southeast. This will keep chances of rain and snow and eventually flurries as we move through the day. Eventually moisture will dry up some as weak nosing of high pressure progresses north. The next wave will arrive after this period so keep it mostly dry on Friday night. .LONG TERM...(Saturday through Thursday) Issued at 505 PM EST THU FEB 6 2020 The long-term period starts 12Z Saturday with a broad low- amplitude 500 mb trough across much of the CONUS with its mean axis near the Mississippi River Valley. Meanwhile, a persistent subtropical ridge will be parked across eastern Pacific. Closer to the CWA, a robust shortwave trough and vort max, embedded in the fast cyclonic flow rounding the base of the trough, will be crossing the Lower Ohio Valley. The trough axis and attendant vort max pass across eastern Kentucky during the day Saturday, then dampen and exit to the east Saturday night. At the same time, a positively tilted trough will dig across the Pacific Northwest, resulting in a fast, zonal flow across much of the US for Sunday. Multiple shortwaves will continue to carve out the deep upper-level trough across the Western CONUS Monday through Thursday, while a compensating subtropical ridge builds northward from the Caribbean into Western Atlantic. At the surface, Saturdays shortwave trough will be accompanied by a weak surface low traversing the Ohio Valley. This will bring renewed chances of light precipitation, starting off as snow during the morning hours, changing to mainly rain in the valleys by afternoon; but, likely remaining more of a mix over the higher elevations. Some models are hinting at some weak instability late afternoon and early evening with a pseudo-cold frontal passage, which could result in briefly heavier precipitation rates. At this time, confidence in this materializing is low, so little to no accumulation is expected. This weak system quickly exits Saturday evening as the zonal flow takes over aloft. Surface high pressure builds across the Southern Appalachians Sunday morning, bringing dry conditions and sunshine, which should boost afternoon temperatures into the upper 40s to mid 50s. While we enjoy a brief respite from the gray skies, a weak clipper low will race from the High Plains of Montana early Sunday to the St. Lawrence Valley by 12Z Monday. The next chance of precipitation arrives Monday as this system drags a trailing cold front across eastern Kentucky. The front becomes nearly stationary to our south and east Monday night through Tuesday night while multiple disturbances ride along the front. Models diverge as to where the front stalls, which will have significant bearing on the sensible weather in Eastern Kentucky during this time frame. At this point, the GFS keeps the front farther to the south keeping our area colder, with most precipitation, aside from a little snow early Wednesday, falling to our southeast. Meanwhile, the Euro brings periods of heavier rainfall into eastern Kentucky ending as a little snow Wednesday morning. The Euro, then brings in surface high pressure for Wednesday with modest height rises while the GFS keeps the area under a more cyclonic pattern. Ahead of the cold front on Monday, temperatures will warm well into the 50s. Thereafter, temperatures will strongly depend on the location of the front. && .AVIATION...(For the 00Z TAFS through 00Z Friday evening) ISSUED AT 730 PM EST THU FEB 6 2020 Mostly IFR with some spotty MVFR was observed at issuance time. CIGs will generally remain in the IFR range through 12Z as low stratus persists as a shortwave trough approaches. This should lead to an increase in coverage of precipitation with a change over to snow from around 4Z to 12Z. This snow or a rain and snow mix should lead to IFR or lower vis at times as well. Improvements into the MVFR range are generally expected 11Z to 18Z as the shortwave departs. Overall the winds will remain northwest and west near 10 KT. && .JKL WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory until 1 PM EST Friday for KYZ044-050>052- 058>060-068-069-079-080-083>088-104-106>120. && $$ UPDATE...JP SHORT TERM...DJ LONG TERM...GEERTSON AVIATION...JP
Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
610 PM CST Thu Feb 6 2020 .SHORT TERM... 207 PM CST Through Friday night... Lingering deformation with transient f-gen bands continues to peel slowly off to the east and lingers mainly over northwest IN early this afternoon. This synoptic system snow will end late this afternoon and likely an inch or less of additional snow before ending. Attention will then turn toward lake effect snow (LES) potential. Have already seeing some lake effect/lake enhanced snows into northeast IL. Will probably see some waning in the intensity of the snow this afternoon as depth of saturation decreases with departing synoptic forcing and otherwise marginal lake effect parameters. Forecast soundings this evening suggest inversion heights will rise with the approach of the upper trough. Air mass is not particularly cold, so instability isn`t terribly impressive. However, ambient low level lapse rates are progged to already be pretty steep which when combined with some modest lake induced instability and a developing land breeze convergence axis, the set-up looks modestly decent for LES. LES can be very difficult to predict, particularly in these somewhat borderline cases. Most likely scenario looks to be light to occasionally moderate lake effect snow showers, potentially with some fairly deep inland penetration given the steep low level lapse rates. Residence time of the beefier LES and will probably be short enough to keeps mainly less than 2" most areas. Have seen LES over perform in otherwise marginal looking set-ups before, so wouldn`t completely rule out higher totals, but not seeing anything that would lead me to believe that will be the case this go around. LES should shift into northwest IN late tonight/early Friday, then east out of Porter County Friday afternoon. - Izzi && .LONG TERM... 226 PM CST Friday Night through Thursday... An unsettled pattern with frequent disturbances and associated precipitation chances will be the rule for the next week. In summary of forecast expectations, first light snow is likely for at least a portion of the area Friday evening into the night with minor accumulation of one inch or less expected. On Sunday, the likelihood of precipitation has increased and mainly looks to be snow north. Depending on the specific track of this system, which is still of lower confidence, some of that snow could be moderate in intensity. A couple inches north are certainly in the realm of possibilities with this. Temperatures have fluctuations but nothing major either way through Tuesday, typical of a progressive pattern and mainly low amplitude features. A low amplitude short wave across the Dakotas this afternoon will gradually work its way southeast in the next 36 hours, rounding a broader long wave trough over central/eastern Canada and United States. This looks to hold its own at least through Friday evening before de-amplifying/weakening. While upper forcing is limited with this detached wave from the stronger upper flow, the lift and saturation are collocated with the dendritic-growth zone in forecast guidance. Commonly in these situations, it does not take much to rattle out light snow. So have increased PoPs for this low QPF event, and this increase was especially in the western and southern forecast area. Flurries may linger into Saturday. The next system arrives on Sunday with stronger jet support but is more progressive. This is a Pacific/Clipper hybrid system and brings precipitable waters up to one half inch with it. The warm sector of this system is quickly impinging into the area on Sunday, but depending how early precipitation starts (especially in the northern CWA) it may prevent a changeover to rain and a wet snow would be more favored. This system has an orientation and path that would favor a swath of decent accumulating snow immediately north of the surface low given the forecast parameters presently in the GFS and ECMWF, but right now on both of these this is projected across central/southern Wisconsin. The Canadian model is more focused over the area though and that will be something to watch. For now have raised PoPs consistent with guidance and their ensembles, and do have some minor accum noted in the northern half of the CWA. The northwest flow continues for the first part of next week. The split flow pattern has waves forecast midweek that have shown phasing in the EC guidance but a more mixed signal in others. Conceptually there are several ingredients in place for a broader-reaching synoptic system and one with a lot of moisture and baroclinicity to work with in the middle of the country. A great deal of uncertainty but a fair signal for six or so days out. MTF && .AVIATION... For the 00Z TAFs... Aviation forecast concerns: -Lake effect snow showers impacting ORD/MDW/GYY this tonight (into Friday for GYY). Brief IFR visibilities in heavier snow showers. Low pressure continues to track northeast across the upper Ohio Valley and Appalachians early this evening, pulling away from the local area. Light snow on the trailing edge of this system is transitioning to lake effect snow showers, due to northeasterly low level flow off the lake and colder air aloft. The main low- level convergent axis was focused along the west shore of the lake as of late afternoon, from off MKE into the Chicago terminals. High-res model guidance is not doing a particularly good job of indicating the westward extent of this activity at this time, though the general trends in guidance would support a gradual southward shift of the band through the evening hours. RAP model forecasts of the low-level convergence fields indicate the focus would setup mainly just east/southeast of ORD (into MDW) by mid- evening. Surface observations beneath the stronger radar returns have generally indicated IFR visibilities (around 1 1/2SM) and MVFR ceilings. Given the bands expected southward movement, ORD would likely have the shortest period of potential impact early this evening, with the threat lingering longer at MDW, and persisting into Friday morning at GYY. Outside of the lake effect snow bands and associated MVFR clouds, quiet VFR conditions are expected. Winds will shift from north or north-northeast this evening, to northwest and eventually west during the day Friday as the low pressure system to our east continues to move away, and weak high pressure moves in. A clipper-like system will approach the area later Friday and Friday night, with development of a gradually lowering VFR cloud layer during the day. The greatest potential for precipitation with this approaching system looks to go mainly south of the terminals Friday night, though there is the potential for some low-impact light snow across the terminals. Have indicated a PROB30 at ORD and MDW later in the evening for that potential. Ratzer && .LOT WATCHES/WARNINGS/ADVISORIES... IL...None. IN...None. LM...Small Craft Advisory...IL nearshore waters until noon Friday. Small Craft Advisory...IN nearshore waters until 3 PM Friday. && $$ Visit us at Follow us on Facebook, Twitter, and YouTube at:
Area Forecast Discussion
National Weather Service Newport/Morehead City NC
843 PM EST Thu Feb 6 2020 .SYNOPSIS... A strong cold front will cross through tonight and move offshore by Friday morning. High pressure will have a brief stint Friday before a weak shortwave passes through late Saturday. High pressure will rebuild into the area for early next week before more unsettled weather possible by Tuesday. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... As of 815 PM Thu...Tornado Watch remains in effect for all of MHX CWA through 1 AM. Latest radar imagery shows strong bowing storms lifting ENE through Eastern NC. Instability has lessened with loss of diurnal heating with MUCAPE around 500 J/Kg ahead of this line however shear remains very strong around 60-70 kt. Will continue to watch this convection for tornado and damaging wind threat through early this evening as it moves into a more favorable environment. Generally seeing stratiform rain behind the heavier line, but HRRR shows another enhanced line as the LLJ increases to aoa 70 kt ahead of approaching cold front as the sfc low deepens as it moves newrd through the interior Carolinas. Have seen 1-2" of rainfall and locally up to 3" where cells have been training this evening. Still think any flash flooding would be localized, and be mainly associated with the main QLCS moving through. Gusty gradient winds will continue, peaking tonight along the coast, with gusts reaching 45 to 50 mph for the coastal areas, namely downeast Carteret through the OBX, where Wind Advisory continues. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/... As of 250 PM Thu...Cold front will push offshore Friday morning, and bulk of precip assoc with front should be offshore by daybreak with just low chc of lingering shra mainly cst and north through late morning. Main story Fri will be gusty winds due to tight pres grdnt and deep mixing. Expect WSW winds to gust 40 to 45 mph inland and 45 to 55 mph coast. Issued Wind Advisory for all counties beginning Fri morning. High temps will be mild still, mostly in the low 60s. && .LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/... As of 230 AM Thu...Quiet weather expected thru early next week. Unsettled weather will develop Tue as another front impacts the region. Saturday through Monday...Cooler and drier high pressure returns for Sat with highs around 50. Temps then begin to moderate Sun as SW winds return with highs around 60. Very warm again by Monday with some inland sites reaching 70...60s for the coast. This period will be mainly dry with just slight chc of a shra Sat night as weak short wave passes to the N. Tuesday and Wed...Rain chc increase Tue as next cold front approaches and crosses Tue night...for now will keep pops in chc range given uncertainty on timing. Looks like front will push thru Wed with just very slight chc of shra. Cont mild with highs Tue ahead of the front 65 to 70 inland...highs Wed in the 60s. && .AVIATION /02Z FRIDAY THROUGH TUESDAY/... Short Term /through Friday/... As of 730 PM Thu...Line of strong storms moving across rtes this evening with stratiform precip continuing behind the line. Sub-VFR conditions expected much of the overnight, generally MVFR, but dropping to LIFR in heavier showers. A period of LLWS is likely tonight as well. The widespread precipitation is forecast to end by 10Z Fri with VFR conditions following through Fri. Gusty SSW winds with gusts to 40 kt will occur through early Fri afternoon. Long Term /Fri night through Tuesday/... As of 100 PM Thu...VFR conditions are expected through Tue with only slight chc of a shra Sat night, otherwise dry. && .MARINE... Short Term /through Friday/... As of 830 PM Thu...Dangerous marine conditions will continue across the waters through Friday. Latest obs show SSW winds 20-30 kt gusting to 35-45 kt across the outer waters with seas 4-6 ft north of Oregon Inlet and 7-12 ft south. Strong winds will continue through Friday along with dangerous seas. Gale Warnings continue for the waters with SSW winds 25-35 kt gusting 40-45 kt tonight, becoming more W/WSW Friday. Seas will build to 10-20 ft, highest across the outer waters. Winds may briefly diminish early Friday morning, but increase again dramatically again Friday behind the front. Low water expected across the Neuse, Pamlico, Pungo Rivers tonight into Friday. Long Term /Fri night through Tuesday/... As of 230 AM Wed...Winds become NW and diminish to 10 to 20 kts later Fri night. On Sat winds become light as high pres builds across. Seas will subside to 6 to 9 feet late Fri night and drop to 3 to 5 ft later Sat. Light winds cont Sun with seas dropping to 2 to 3 ft. SW winds return Mon as high pres moves offshore with speeds increasing to 10 to 20 kts late and seas building to 3 to 5 ft. && .HYDROLOGY... As of 3 PM Thu...The combination of already high river levels, and heavy rains across most of the state, will lead to the possibility of minor river flooding on the main stem rivers (Tar, Neuse, NE Cape Fear basins) by this weekend. && .TIDES/COASTAL FLOODING... As of 3 PM Thu...Coastal Flood Advisory conts for soundside Outer Banks with minor inundation 1-2 ft agl. Strong southwest winds will peak tonight. This may bring minor coastal flooding across soundside locations of the northern Outer Banks and Hatteras Island. Then gusty west to southwest winds will continue through Friday night keeping water levels elevated along soundside Hatteras Island. High Surf Advisory conts for oceanside areas south of Rodanthe, with potential for minor beach erosion and localized ocean overwash. Low water levels are likely to occur on the Neuse River starting tonight and a Low Water Advisory has been issued as water levels up to 2 ft below normal expected thru Fri evening. Low water advisory continues into Fri evening for Neuse, Tar, Pamlico and Pungo Rivers. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...High Surf Advisory until 1 AM EST Saturday for NCZ195-196-199- 204-205. Wind Advisory from 8 AM to 7 PM EST Friday for NCZ029-044>047- 079>081-090>092-094-193>195-198-199. Wind Advisory until 7 PM EST Friday for NCZ196-203>205. Coastal Flood Advisory until 1 AM EST Saturday for NCZ203-205. MARINE...Low Water Advisory from 10 AM Friday to 1 AM EST Saturday for AMZ136. Gale Warning until 5 PM EST Friday for AMZ136-137. Low Water Advisory until 1 AM EST Saturday for AMZ137. Gale Warning until 7 PM EST Friday for AMZ131-135-150-230-231. Gale Warning until 11 PM EST Friday for AMZ152-154-156-158. && $$ SYNOPSIS...MHX NEAR TERM...CQD/SK SHORT TERM...CQD LONG TERM...RF AVIATION...JME/SK/TL MARINE...RF/CQD/SK HYDROLOGY...MHX TIDES/COASTAL FLOODING...MHX
National Weather Service Morristown TN
904 PM EST Thu Feb 6 2020 .DISCUSSION... Updated to extend Winter Weather Advisory into the northern Plateau and Lee County Virginia. Also, up winds for Friday to near wind advisory levels. Satellite shows another short-wave rotating across the lower Mississippi valley into the Gulf coast states. A 135-140kt 300mb jet associated with the trough will rotate across the Gulf coast states toward the southern Appalachians overnight placing the area under the favored left exit region of the jet. Mosiac radar already shows an increasing coverage and intensity of precipitation developing. Decent dynamics will occur between 04-13Z time-frame spreading widespread precipitation across the region. Enough dynamic cooling and closer proxmity to colder airmass west and northwest of area will allow the northern Plateau to change quickly over the snow. This is being advertised by the SPC HRRR Browser. Expect several hour period of light to moderate snow there between 06-12Z with accumulations of 1 to 3 inches possible over mainly grassy and elevated surfaces. However, secondary roadways and higher elevations of intersate 75 on Jellico mountain may experience travel concerns. As dynamics lifts northeast Friday morning cold air aloft will steepen the lapse rates with models showing 40-80 J/Kg of CAPE. This will be enough to keep scattered showers in the forecast. Also, orogaphic lift will increase as surface low lifts northeast and high pressure builds into the region tightening the pressure gradients. Windy conditions will develop Friday with westerly winds of 15 to 30 mph. Made some minor changes to hourly temperature forecast especially across the northern Plateau. && .AVIATION... 00Z TAF DISCUSSION. Another system will move across the area overnight through Friday morning producing another round of precipitation, mainly rain but may mix with snow or sleet at TRI (possibly TYS) tomorrow. Flight conditions will remain MVFR/IFR through most of the forecast but a period of LIFR due to ceilings expected between 06-14Z. Winds will increase to the west Friday morning as the associated surface trough moves through the region tightening the pressure gradients. Gusts over 25kts are possible. && .PRELIMINARY POINT TEMPS/POPS... Chattanooga Airport, TN 35 42 32 50 31 / 60 30 20 20 10 Knoxville McGhee Tyson Airport, TN 35 39 31 46 29 / 100 50 10 40 20 Oak Ridge, TN 34 39 30 46 28 / 90 50 10 40 10 Tri Cities Airport, TN 34 38 27 42 28 / 100 70 30 40 30 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...Winter Weather Advisory from 1 AM to 4 PM EST Friday for Blount Smoky Mountains-Cocke Smoky Mountains-Johnson-Sevier Smoky Mountains-Southeast Carter-Southeast Greene-Southeast Monroe-Unicoi. Winter Weather Advisory from 1 AM EST /midnight CST/ to 1 PM EST /noon CST/ Friday for Bledsoe-Campbell-Claiborne-Morgan- Scott. VA...Winter Weather Advisory from 1 AM to 4 PM EST Friday for Russell- Wise. Winter Weather Advisory from 1 AM to 1 PM EST Friday for Lee. && $$
Area Forecast Discussion
National Weather Service Pueblo CO
641 PM MST Thu Feb 6 2020 .UPDATE... Issued at 638 PM MST Thu Feb 6 2020 upper dynamics and a little low level upslope, have caused a band of heavier snow to develop over western El Paso County. Forecast models have a poor handle on this situation and it is difficult to know how long this band of snow may remain over the area. Have added a winter weather advisory for southern El Paso County (there is already one out for northern El Paso County), for the snow and the potential for icy/snowpacked roads in El Paso County. && .SHORT TERM...(This evening through Friday) Issued at 334 PM MST Thu Feb 6 2020 Main forecast concerns are with heavy snow and strong winds across the central mountains continuing tonight into Friday, as well as the higher likelihood of light to moderate with occasional bursts of heavy snow across the lower elevations, especially along and just east of the I-25 corridor. Have seen snow really blossom across the central mountains over the last several hours, as stronger mid/upper level northwest flow with embedded shortwave energy has moved overhead. This will not only continue but also likely further intensify tonight, as even stronger flow and impulses of energy moves overhead. Latest RAP analysis indicating steepening lapse rates across the region with short term guidance showing this trend continue into tonight, which will further support increasing snow intensity. With high snowfall rates and with increasing gusts up to 65 mph tonight, current winter storm warning is on track for the Mosquito and Sawatch Mountains as well as Lake county. No real change expected for these areas going into Friday as the pattern will remain the same, and support additional heavy snow with strong wind gusts. Snow should begin to see a diminishing trend late in the day on Friday as this system begins to slowly pull away. However, do think snow will likely continue across the central mountains into Friday night. Concerns for snow across the lower elevation remains at this time, especially for northern El Paso county where a Winter Weather Advisory had been issued tonight into Friday. Latest radar imagery depicting some light returns across the plains this afternoon, but with little to no snow likely falling at his time. Flow and forcing are increasing this afternoon, however, some drier air in the lower levels will need to be eroded first. The previously mentioned strengthening mid/upper level flow with embedded energy will help support additional snow development this evening into later tonight and Friday for parts of the plains. As flow aloft further increases this evening and as additional upstream energy moves overhead, will see already noted lee troughing across the eastern half of Colorado dive south across the state. This trough axis is anticipated to push across the Palmer Divide this evening, with this low level convergence and then northerly flow assisting in snow development this evening into the overnight hours. The support/forcing along with the previously noted mid level lapse rates and now steep low level lapse rates, will support light to moderate snow, with occasional brief bursts of heavy snow. Highest confidence for this occurrence is across the northern half of El Paso county, where the current Advisory is in effect. Have not made any changes to the forecast snowfall, with 2 to 5 inches still expected across this location. Also, no changes to this start time with snow beginning by early to mid evening. Those traveling in this location can expect rapidly deteriorating conditions through mid evening, with the brief bursts of heavier snow supporting high hourly snowfall rates possibly up to 1-2 inches at times. This will significantly reduce visibility and quickly create snow covered roads, with hazardous driving conditions likely this evening. Snow will likely continue across this location on Friday and have maintained higher pops during the day. Somewhat lower confidence with additional snowfall on Friday, however, do think the hazardous conditions will remain and impact the Friday morning commute. Have been closely monitoring additional snow expected for areas along and just east of the I-25 corridor tonight. Guidance indicating the southward moving trough axis will support snow over additional parts of southeast Colorado. However, guidance also continues to vary greatly as to the placement of this snow as well as the amount of snowfall. Even at this time, short term guidance and even 18z guidance coming in at this time is varying. This has been frustrating as guidance has been hinting that the moderate to heavy snow which will be observed to the north could extend southward. Additional forcing owing to strengthening FGEN has been something worth watching, as well as the possibility for both upright and slantwise instability. This would support more banded snowfall, with moderate to occasionally heavy snow. However, once again guidance has not been consistent with this idea or placement of any bands of snow tonight. It`s possible that bands of snow could setup along a line from Colorado Springs to Pueblo, or to the east maybe more towards the La Junta area. With this lower confidence, have not issued any additional Advisories this afternoon, but did try to raise pops and snowfall amounts as well as issued a Special Weather Statement to highlight this possible snow and impacts. If this band sets up, wherever it does I do think that a quick 1-2 inches or possibly more under heavier snow will be possible. This would support reduced vis, snow covered roads and hazardous driving conditions. Please continue to monitor the forecast for any updates this evening, and those traveling along and just east of I-25 from Colorado Springs southward should be prepared for possible hazardous driving conditions. .LONG TERM...(Friday night through Thursday) Issued at 334 PM MST Thu Feb 6 2020 Friday night-Saturday...Strong north to northwest flow aloft across the region is progged to moderate Friday night and then become more westerly through the day Saturday, as an embedded jet streak, translating east across the Rockies, continues out into the Upper Midwest and High Plains, as more eastern Pacific energy, moving onshore across the Pacific Northwest Friday night, digs across the Intermountain West. With that said, will continue to see orographic snowfall across the central mountains Friday evening, with snow tapering off into early Saturday morning. Looking at an additional 1 to 4 inches across the central mountains through Saturday morning, greatest accumulations north of Cottonwood Pass. Further east, best potential for banded snow remains generally north and east of southeast Colorado, though kept scattered pops intact across the Palmer Dvd through the evening, with all pops tapering off through the overnight hours. Pops slowly increase again into Saturday after noon across the central mountains, with moisture increasing once again within the westerly flow aloft. Near seasonal lows expected across the region overnight Friday, with the developing westerly flow expected to help boost temperatures into the mid 40s to mid 50s across the lower elevations on Saturday, with highs mainly in the 30s and 40s across the higher terrain. Saturday night-Monday night...Latest model runs and ensemble data are in fairly good agreement of a split flow pattern developing across the region, as a portion of the Intermountain West system continues across the Northern Tier and Upper Midwest through the day Monday, while secondary energy digs across the southern Great Basin and into the Desert Southwest by Monday night. This pattern supports good chances of precipitation for areas over and near the higher terrain, especially along the ContDvd where more winter weather highlights may be needed in the near future. Pattern also supports below seasonal temperatures, especially across the Plains behind a passing cold front late Saturday night and early Sunday morning. Tuesday-Thursday...Lower confidence forecast remains in the offing as more, hard to time energy, digs across the Rockies within a continued northwest flow pattern. Models are also struggling on where or if the southern stream energy across the Desert Southwest merges with more northern stream energy digging across the Rockies. With that said, stayed with the blended model solution, which starts to ramp up pops again from west to east Wednesday and Thursday, along with temperatures at to slightly below seasonal levels. && .AVIATION...(For the 00Z TAFS through 00Z Friday evening) Issued at 334 PM MST Thu Feb 6 2020 No real big changes to the TAFs at this time, with the main concerns/challenges still snow and low ceilings later this evening through Friday morning mainly for COS and PUB. Latest radar imagery is showing some returns, however, snow is not likely occurring at this time. Still expect snow to develop by early to mid evening for both locations, with COS likely starting slightly sooner than PUB. A period of light snow, possibly moderate to briefly heavy, is then expected for a time during the overnight hours. Have maintained similar vis and not really trended the TAFs toward the heavier snow with this forecast as confidence is still low on this occurrence. Will continue to monitor trends though, and update as needed. Under this snow, VFR ceilings will fall to MVFR, possibly low end MVFR, tonight. These lower ceilings will likely remain Friday morning as well as some snow, but do expect an upward trend through midday along with diminishing snow. && .PUB WATCHES/WARNINGS/ADVISORIES... Winter Storm Warning until midnight MST Friday night for COZ058- 060. Winter Weather Advisory until 8 PM MST Friday for COZ084. Winter Weather Advisory until 3 AM MST Friday for COZ085. Winter Storm Warning until 5 PM MST Friday for COZ059. && $$ UPDATE...28 SHORT TERM...RODRIGUEZ LONG TERM...MW AVIATION...RODRIGUEZ