Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 01/03/17

Area Forecast Discussion
National Weather Service Wakefield VA
940 PM EST Mon Jan 2 2017 .SYNOPSIS... A stationary front will remain over the Carolina coastal plain overnight, before slowly tracking back north as a warm front Tuesday as low pressure passes through the region. A cold front crosses the region later Wednesday, with weak high pressure building into the area Wednesday night into early Thursday. && .NEAR TERM /THROUGH TUESDAY/... Evening update...Convective complex continues to rumble across the deep south this evening. Next batch of rainfall extends from the mid-south (S KY/Central TN back toward South Central GA, just ahead of SFC warm front. Coastal trough remains aligned sw-ne along the Carolina coast, with 1020mb low pressure associated with the RRQ of a 110kt jet aloft has now pushed off the Delmarva coast. Most of the area remains within the CAD wedge airmass this evening, with the exception of ne NC adjacent to the Albemarle Sound and Atlantic Coast. Accordingly, expect little change (light rain/drizzle) into the early overnight hours. By late tonight, the time-lagged HRRR and RAP are in good agreement in bringing next slug of moisture up the I-85 corridor into the Piedmont after 07-09z/2-4am EST. Pops increase to high end likely then back into categorical range (AOA 80%) during and after this time late tonight into Tuesday morning. Will also include areas of fog all zones overnight with increasing Dewpoints/lowering Cond. Pressure Deficits overnight. Some locally dense fog is possible along the eastern half of the area, but will hold off on any statements or headlines for now. Temperatures will fall little overnight with lows ranging from the low/mid 40s over the Piedmont to the upper 40s/low 50s se. Next slug of moisture, associated with next trough pushes from the Tennessee Valley tonight to the Mid-Atlantic Tuesday morning. Categorical PoPs continue across the entire area Tuesday morning through midday. At this time, additional QPF is expected to average 0.5-0.75" for most of the area. A slight chc/chc of thunder has been maintained for far se VA/ne NC where some instability is present for late Tuesday morning into the aftn. A dry slot pushes into the region during the aftn, so PoPs taper to chc from sw-ne. The latest data continues to show that it will be difficult for the wedge airmass to fully erode, so highs should only be around 50 far nw, to the low/mid 50s for central portions, and low/mid 60s far se. && .SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/... A drier airmass pushes into the area Tuesday night, with a cold front approaching from the nw later Wednesday aftn. Lows Tuesday night range from the low 40s nw, to low 50s se. There will be a lack of CAA, so some low-level moisture may linger, which could result in patchy stratus or fog. The airmass Wednesday will be mild and somewhat more mixed with the approach of a cold front. Therefore, forecast highs range from the mid/upper 50s nw to the low 60s se. The cold front will cross the region late Wednesday aftn into the evening. Colder and drier air will gradually filter in from the nw, with lows dropping into the upper 20s nw to mid 30s se. Weak high pressure is progged to be over the area early Thursday, with weak low pressure approaching from the west by aftn. Variably cloudy to eventually mostly cloudy conditions are expected, with a slight chc of light rain or light snow across nw portions by aftn. Forecast highs range from the upper 30s nw to the mid 40s se. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... Confidence is still not high regarding the extended period forecast, but there have been incremental steps toward a workable forecast. The issues now reside in developing a southern system low over the Southern Plains or along the Southeast coast Friday night. The ECMWF/CMC remain in good agreement (with good run to run continuity) with developing the low along the Southeast coast, while the UKMET and several members of the GEFS begin to trend toward the ECMWF/CMC. However, the deterministic GFS continues to be a troubling outlier, lifting the Southern Plains low into the region Saturday night resulting in a major winter storm over the region. Based on it being a significant outlier and the inconsistent run to run continuity, have opted to trend the extended period forecast significantly toward the ECMWF/CMC. With that said, there is increasing confidence of some light wintry precipitable Thursday night as height falls arrive along a weak boundary and developing low pressure along the coast. Moisture will be limited, so any precipitation that does fall will be light with little QPF expected. Expect a lull in POP`s Friday as the front remains along the coast and another area of low pressure develops along the Southeast coast ahead of more substantial height falls from the approaching upper level trough. Highs Friday in the upper 30`s to mid 40`s. Precipitation chances ramp back up Friday night as the low lifts along the coast. Have increased POPs to 30-40% across the southeast half of the forecast area. Trough axis digs into the eastern CONUS Saturday as the front pushes farther offshore. Large scale confluence behind the trough axis will allow strong Canadian high pressure to plunge southward into the Midwest, nudging eastward into the Mid-Atlantic region. The result will likely be drying conditions Saturday. Highs in the mid to upper 30`s. Expect dry conditions Saturday night, but will keep mention of slight chance POPs to account for the uncertainty. Thereafter, all guidance in good agreement with building cold Canadian high pressure into the region Sunday. The result will be a cold/dry day with highs in the low to mid 30`s. Teens to low 20`s forecast Sunday night. High pressure prevails Monday with highs in the 30`s. && .AVIATION /03Z TUESDAY THROUGH SATURDAY/... Mainly IFR/LIFR conditions anticipated through the 18Z TAF period, as a pair of shortwave trofs move through the region. First system will exit the region over the next few hours, temporarily ending the steady rain, but maintaining low ceilings, and some fog/drizzle. KECG is closer to the warmer air with the initial shortwave, and have allowed their conditions to be mainly VFR/MVFR, through 23Z. Ceilings and visibilities may actually drop further after 05Z tonight (to 100-200 ft/1 mile or less), as next area of rain/showers moves in, and stronger surge of warmer air comes northward. Expect conditions to improve just after the 18z as drier air moves into the region from the southwest. OUTLOOK...Building High pressure and fair weather return for Wednesday (though some lows clouds and fog may still linger Wed morning). Overrunning moisture will bring an increase in cloud cover Thursday. Spotty light rain or snow is possible late Thursday through early Friday, followed by dry weather Friday night/early Saturday. && .MARINE... Latest surface analysis centers ~1019mb low pressure just offshore of the Mid-Atlantic coast with high pressure over the Northeast. The result is a north to northeast wind at 10-20 knots. Few gusts to around 25 knots still observed in the northern coastal waters. Seas range from 3-4 feet in the south to 4-6 feet in the north. SCA headlines remain in effect north of Parramore Island. The low lifts northeast of the region tonight as flow becomes north to northeast at or below 15 knots. Onshore flow will keep seas 4-5 feet in the northern waters tonight. Fog will also be a concern where the winds are light with visibilities dropping below 1 mile in the Bay, lower James River, and coastal waters, where a dense fog advisory is in effect through late morning Tuesday. This may possibly need to be extended through Tuesday afternoon. Another area of low pressure approaches the region Tuesday as high pressure builds into southeast Canada. Flow becomes southerly late tomorrow at 5-15 knots. Expect 5 feet seas to persist through the day Tuesday in the northern coastal waters, with 4-5 feet possible from Cape Charles Light to Parramore Island. Will keep headlines north of Parramore and extend through Tuesday night as guidance is in good agreement. The low pushes offshore Tuesday night as the trailing front pushes across the waters Wednesday. Flow becomes westerly Wednesday and the northwesterly Wednesday afternoon behind the front. Seas subside to 3-4 feet. Waves 1-2 feet. Expect a northwest surge Wednesday night as low level cold air advection increases, with winds increasing to 15-25 knots. Seas 3-4 feet and waves 2-3 feet. Thereafter, high pressure slowly builds into the region through the end of the work week as the frontal boundary stalls along the Southeast coast. Extended winds and waves have been trended away from the GFS/WaveWatch, due to inconsistencies in the guidance compared to the preferred ECMWF. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...None. NC...None. VA...None. MARINE...Dense Fog Advisory until 10 AM EST Tuesday for ANZ630>632-634- 638-650-652-654-656-658. Small Craft Advisory until 6 AM EST Wednesday for ANZ650-652. && $$ SYNOPSIS...AJZ NEAR TERM...AJZ/MAM SHORT TERM...AJZ/LKB LONG TERM...SAM AVIATION...LKB/WRS MARINE...JDM/MAS/SAM/WRS
Area Forecast Discussion
National Weather Service Bismarck ND
955 PM CST Mon Jan 2 2017 .UPDATE... Issued at 950 PM CST Mon Jan 2 2017 Little change with this update other than to convert Burke and Mountrail counties to a Wind Chill Advisory. Elsewhere, maintained the Winter Storm Warning as gradient winds continue to slowly increase with 0.5 km winds of 25-35 kts expected to continue through the night. Thus, expect significant drifting snow to impact travel sufficiently to continue the Winter Storm Warning, especially with light snow continuing to fall. UPDATE Issued at 650 PM CST Mon Jan 2 2017 Based on webcam trends through 0030 UTC, have converted most of western North Dakota over to a Wind Chill Advisory. The Winter Storm Warning remains in effect for central North Dakota. However, portions of this will likely be converted to a Wind Chill Advisory later this evening. UPDATE Issued at 455 PM CST Mon Jan 2 2017 Quick update to begin the process of replacing Winter Storm Warning and Winter Weather Advisory headlines with a Wind Chill Advisory as visibility improves and snowfall decreases. This has first been completed for Bowman and Slope counties based on webcam trends through 2245 UTC. && .SHORT TERM...(This evening through Tuesday) Issued at 404 PM CST Mon Jan 2 2017 A winter storm continues to impact North Dakota and much of the Northern Plains. Snow is expected to taper off through early Tuesday morning. Significant snowfall accumulations between 8 and 14 inches are forecast for most of western and central North Dakota. Thus far, totals between 6 and 10 inches have been reported in west/central areas. Higher snowfall amounts of up to 14 inches are possible in portions of Kidder, Stutsman, Wells, and Foster counties. Responsible for the snowfall, a mid/upper level low has progressed northeastward and strengthened through the day. Snowfall has intensified with rates around 1 inch per hour or greater. Forecast soundings indicate plenty of atmospheric moisture and lift in the dendritic growth zone, which would support intense snowfall rates. Snowfall intensity should begin to taper off in western and central areas by late afternoon with light snow expected to linger through early Tuesday morning. The 18Z HRRR along with the current suite of short term high resolution models are indicating snowfall ending around 03Z Tuesday. Though, we will currently maintain tapering off snowfall in the forecast through 12Z Tuesday. Wind gusts around 35 mph will accompany this system. Blowing and drifting snow have created dangerous travel conditions. Visibilities as low as a quarter of a mile have been reported, along with significant drifts causing difficult travel. After the storm, frigid conditions with dangerously cold wind chill values are expected through much of Tuesday. Wind chill values near 30 below zero are forecast. .LONG TERM...(Tuesday night through Monday) Issued at 404 PM CST Mon Jan 2 2017 Arctic air will impact the Northern Plains through much of the long term period. Below average temperatures and extreme wind chill values are expected. Wind chill values between 25 and 35 below zero are forecast with periodic wind chill values near 40 below zero overnight Tuesday/Wednesday. Otherwise, look for a fairly dry period with only slight chances for snow returning to the forecast towards the end of the term. && .AVIATION...(For the 06Z TAFS through 06Z Tuesday night) Issued at 950 PM CST Mon Jan 2 2017 Widespread IFR conditions associated with a winter storm will gradually improve to MVFR across the region tonight through Tuesday morning from west to east as a winter storm departs the region. Then very cold air with follow Tuesday. && .BIS WATCHES/WARNINGS/ADVISORIES... Winter Storm Warning until 6 AM CST /5 AM MST/ Tuesday for NDZ003>005-011>013-019>023-025-034>037-042-045>048-050-051. Wind Chill Advisory until midnight CST /11 PM MST/ Tuesday night for NDZ001-002-009-010-017-018-031>033-040-041-043-044. && $$ UPDATE...AYD SHORT TERM...AC LONG TERM...AC AVIATION...AYD
Area Forecast Discussion
National Weather Service Denver/Boulder CO
850 PM MST Mon Jan 2 2017 .UPDATE... Issued at 830 PM MST Mon Jan 2 2017 Latest observations and radar only showing some very light snow over Western Larimer and Jackson counties but no snow further south over the Interstate 70 cooridor through Summit county. The jet core across Central Wyoming will continue to put far Northern Colorado under favored ascent region of jet through the night along with some banded snowfall possible. Given upstream observations over Southwest Wyoming and Northern Utah expect a bit better enhancement of snowfall over zone 31 through the night and sections North of Rocky Mountain National Park. Forecast amounts tonight look a bit over done and will lower a tad, especially in zone 33 and 34. Will go 4-8 inches in zone 31 and lower amounts further South. As for lower elevations, stratus deck has developed over much of the urban corridor but much of the far plains only have mid and high level clouds for now. Could be a few flurries that try and drift off the hills tonight and especially far northern areas bordering Wyoming which is closer to the jet dynamics. && .SHORT TERM...(This evening through Tuesday) Issued at 201 PM MST Mon Jan 2 2017 The jetstream will remain over Colorado with a strong west/southwesterly flow aloft over the state. No changes regarding the current highlights for the northern mountains tonight through Tuesday. The HRRR runs continue to show potential for locally heavy bands of snowfall overnight. This enhancement is evident on the composite radar mosaic this aftn, most areas focus on zone 31 and maybe 33. The first disturbance will gradually lift northward tonight. The best window for snowfall will be tonight into Tuesday morning with some decrease in moisture Tuesday afternoon. The arctic front pushed through Denver this aftn, much faster than any of the mdls suggested. Forecast soundings tonight show shallow post frontal moisture around but limited moisture in the mid and upper levels. As a result, slgt chc pops for snow in most areas tonight and Tuesday morning. Could see better coverage north along the Cheyenne Ridge in better proximity to the jet aloft. Fcst temperatures for Denver around 25 degrees colder than today. .LONG TERM...(Tuesday night through Monday) Issued at 201 PM MST Mon Jan 2 2017 Strong NW flow will continue through Thursday over the state bringing a moist flow over the mountains for an extended period of time. This flow combined with decent lapse rates over the higher terrain will bring snow showers to the mountains through Friday. Winds over the higher terrain will gust up to 35 mph over the higher passes WEdnesday that could cause some blowing snow. For the plains moisture will extend into the northern portions of the state and with favorable SE winds over the Cheyenne ridge some light snow will be possible over the CO/WY border and south into northern Weld and Logan counties Wednesday. Conditions should remain dry over Denver on Wednesday with highs in the lower 20s behind the arctic push earlier in the week. Another push will drop south over the NE plains by Wednesday evening increasing moisture and turning winds to the NE. This will help to bring snow into Denver with deepening moisture profiles and favorable upslope. The upper level jet will return on Wednesday night into Thursday with the left exit region over the plains. Model cross sections show areas that could be favorable for CSI late Wednesday. This set-up could result in higher snowfall amounts under localized bands on the plains. As of right now looking at snowfall totals from Late Wednesday into Thursday evening being from 2 to 5 inches on the plains with aforementioned higher amounts possible under any developed bands. Temperatures will continue to be below normal with highs Thursday and Friday in the teens and 20s with single digits overnight. Thursday and Friday the models start to differ on the placement of the next upper level feature. The EC has the open wave dropping out of the Pacific NW faster then the GFS which keeps it a tighter low and doesn`t move it into the state until Friday night. Both show some surge of moisture moving through Thursday night into Friday so kept a chance in the mountains and a slight chance on the plains. Temperatures will slowly bounce back on Saturday to freezing with normal expected by the Sunday when ridging and high pressure takes over. && .AVIATION...(For the 06Z TAFS through 06Z Tuesday night) Issued at 830 PM MST Mon Jan 2 2017 Stratus now solid over BJC/DEN, but still hasn`t made it into APA. Given the thickenss of the high level cloudiness it is hard to tell where the southern/eastern extent of the stratus is but still think it will work into APA between 04-06z. Stratus may lift a bit over night as low level flow turns a bit more southeast. Could be some flurries but don`t expect accumulation due to shallow depth of moisture. && .BOU WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory until 6 PM MST Tuesday for COZ031-033. && $$ UPDATE...Entrekin SHORT TERM...Cooper LONG TERM...Bowen AVIATION...Entrekin
Area Forecast Discussion...Updated
National Weather Service Billings MT
848 PM MST Mon Jan 2 2017 .UPDATE... Weak shortwave moving through the area has generated a little light snow. Accumulation has been limited, generally less than a half inch. Shortwave will progress east and weaken overnight and all models trend the precipitation downward. The HRRR has been of little use with this event and have relied on the GFS which has seemed to handle it rather well. Trimmed back pops over the west as definitely see the back edge of the light snow on radar. Maintained low PoPs through the night as another weaker wave was moving through eastern Idaho and will swing across the forecast area overnight, though models do not generate much QPF with it all. Some light snow just now being generated at Livingston with this energy, hence the reason to keep some PoPs in place. This wave was weaker though, and am not anticipating as much coverage on the light snow as with the current wave this evening. Will not issue any wind chill highlights at this time. Winds were below 10 mph in most locations. As surface high pressure settles over the area, this should keep winds below criteria. Overnight lows will be very cold and certainly wind chills will be low, but do not think widespread 10 mph winds will be present (as is the criteria for a wind chill highlight) through the night. Temperatures have dropped off quickly at Miles City and adjusted the low there down a few degrees. Lows tonight will be tricky and based solely on when, and to what degree, the clouds will break up. Models project that happening after the secondary wave later tonight and this should allow forecast lows to be touched. Will let the temperatures forecast ride, with the exception of some downward tweaks here and there to better match current conditions. TWH && .SHORT TERM...valid for Tue and Wed... Arctic high pressure will remain over the area at the surface through the short term with very cold temperatures. Aloft will continue to see Pacific impulses work over the top of the cold air for periods of light snow. A disturbance moving slowly over the area tonight will bump up northeast winds a bit tonight, enhancing upslope winds and light snowfall as it does so. Already seeing snow increase over western foothills and should see this activity spread east as far as Rosebud county by midnight. Snow accumulations with this activity will be generally an inch or less with snowflake size being hurt by temperatures pushing colder than favored dendritic growth zones. Despite winds increasing just a bit tonight don`t think sustained winds will be sustained over 10 mph across a broad enough area to justify wind chill highlites tonight, though some areas may reach criteria for a few hours. Overnight lows will be in the teens below zero. Any breaks in the clouds will produce some -20 type readings in lower valley locations. Tuesday...Any accumulating snow will likely end early in the morning across the area. Very light snow or flurries will probably continue at times through Tuesday night. Temperatures will hover around zero in the afternoon as core of the 1044mb surface high settles over the area. After another bitter cold night expect some sunshine of Wednesday afternoon. Expect westerly winds to increase in the afternoon as surface high begins to shift southeast. This will trend temperatures warmer than Tuesday but will bring threat of dangerous wind chill values more prominently into the forecast. Doesn`t look like winds will support blowing snow to any extent but drifting may be a problem. Chambers .LONG TERM...valid for Thu...Fri...Sat...Sun...Mon... Upper pattern keeps northerly flow over the area Thursday holding cold surface air in place. By Friday flow begins to back to the northwest which will bring some downslope influence to begin a warming trend for the weekend as ridging builds into the area. As Arctic air retreats will turn focus to strong winds developing west of Billings possibly resulting in Blowing Snow/Ground Blizzard issues Saturday and Sunday. Looks like another chunk of Arctic air may drop back into the area Sunday night lingering through Monday which would end strong wind/blowing snow threat but bring in a chance for widespread light snowfall. Chambers && .AVIATION... IFR to occasional LIFR conditions continue across central routes...including KBIL and KSHR...with low CIGS and VIS in snow. Clearing has occurred in LVM...but another wave of snow is expected tonight...bringing a return of IFR to LIFR conditions across western routes. LIFR conditions also prevail over eastern routes...including KBHK...with low CIGS and VIS in fog. Otherwise...occasional MVFR conditions can be expected with scattered areas of light snow across eastern routes. Conditions will begin to improve by sunrise Tuesday. AAG && .PRELIMINARY POINT TEMP/POPS... Tue Wed Thu Fri Sat Sun Mon ----------------------------------------------------------- BIL 914/902 916/007 904/012 001/011 002/020 011/031 016/026 61/I 22/S 00/U 12/S 11/B 11/B 23/S LVM 916/004 913/007 910/011 000/015 004/026 018/038 023/032 41/B 22/S 01/U 12/S 11/Q 22/S 23/S HDN 914/901 919/008 913/011 901/011 903/016 004/029 013/025 62/S 22/S 11/B 12/S 11/B 11/B 23/S MLS 918/903 916/003 908/012 902/009 905/017 004/022 008/019 41/I 22/S 11/B 22/S 11/B 11/B 23/S 4BQ 914/001 917/004 910/013 901/010 905/019 007/028 011/026 41/E 22/S 21/B 12/S 11/B 01/B 13/S BHK 916/903 916/000 910/009 904/005 907/012 002/023 006/016 31/I 22/S 21/B 22/S 11/B 11/B 23/S SHR 912/002 916/006 909/015 903/014 001/020 007/034 016/031 62/S 22/S 10/U 12/S 11/B 11/B 12/S && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...None. WY...None. && $$
Area Forecast Discussion
National Weather Service Cheyenne WY
856 PM MST Mon Jan 2 2017 .UPDATE... Issued at 851 PM MST Mon Jan 2 2017 Watching IR satellite imagery, cloud tops cooling in a band that is moving from northern Colorado into southern Albany County at this time. Talking with Albany Dispatch, they have already received 4 inches of snow in the city of Laramie and with this band moving directly over southern Albany County, decided to upgrade the advisory to a warning for zones 115 and 116. Moderate to heavy snow with 6 hour QPFs on the order of .20 to .30 inches are expected through roughly 15Z, so they should get another 3-4 inches before all is said and done. Updates have been sent. && .SHORT TERM...(This evening through Tuesday) Issued at 232 PM MST Mon Jan 2 2017 Initial band of snow that moved across parts of the CWA this morning has pretty much lifted northeast leaving just some snow showers over mainly western and northern parts of the CWA this afternoon. Overall pattern will change little overnight through Tuesday with a moist westerly flow across the CWA overrunning a cold surface air mass. This will keep snow going over the higher mtns through the day Tuesday with periods of heavier snow thus the winter storm warning there looks in good shape with an additional 6 to 10 inches of snow tonight through Tuesday. Another ripple of energy looks to pass across southern parts of the CWA later tonight into Tuesday and should enhance snowfall for a time over adjacent lower elevations around the mtns to the South Laramie Range so have opted to post a winter weather advsy for late this evening through Tuesday morning as 3 to 6 inches look a decent bet in those areas...highest over the S. Laramie Range. Some snow should also trickle east over the Cheyenne Ridge area into the far southern Panhandle but amounts lighter there. Otherwise colder air will filter into the CWA tonight as an arctic high settles down the high plains with cold temperatures continuing Tuesday...likely remaining in the single digits over lower elevations east of the mtns through the day. .LONG TERM...(Tuesday night through Monday) Issued at 232 PM MST Mon Jan 2 2017 Rather complex pattern expected through the course of this week with the Arctic frontal boundary stalled to our southwest while a series of upper shortwaves move across the region in the west to northwesterly flow aloft. We have high confidence that temperatures will remain some 15 to 20 degrees below normal for this time of year through at least Friday. Of lower confidence is the timing of the shortwaves moving across and timing of snowfall, especially towards late in the week. We have a little more confidence with the GFS and ECMWF trending closer in their solutions bringing a shortave across Wednesday into Wednesday we have a bit higher PoPs for snowfall along the Colorado border westward into the mountains where greater forcing will be at play. This week should see some significant snowfall totals in the mountains given the setup with the frontal boundary stalled to the southwest and a moist westerly and active upper flow going. Given the large spreads of solutions in the various model guidance for Friday, we kept PoPs somewhat low for Friday with not much expected by Saturday, but that may trend up as model solutions start to converge on a solution by mid week. By the weekend the frontal boundary should start to retreat northward and that will bring PoPs up again Sunday going into Monday for portions of Carbon and Albany counties. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 419 PM MST Mon Jan 2 2017 Hampered some with loss of HRRR guidance, but do think lowering ceilings will be the theme tonight as upsloping low level winds are occurring. Looking at snow moving out of north central Colorado this evening that will aid in lowering conditions as well. GFS and NAM soundings also showing strong surface inversion with low cloudiness in the inversion, so there is some confidence in IFR/LIFR becoming widespread as the evening progresses. && .FIRE WEATHER... Issued at 232 PM MST Mon Jan 2 2017 Fire weather concerns nil for at least the next few days with conditions remaining non-critical due to cold temperatures and snow cover. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...Winter Storm Warning until 5 PM MST Tuesday for WYZ112-114. Winter Weather Advisory from midnight tonight to noon MST Tuesday for WYZ110-111-113. Winter Storm Warning from midnight tonight to noon MST Tuesday for WYZ115-116. NE...None. && $$ UPDATE...GCC SHORT TERM...RE LONG TERM...JG AVIATION...GCC FIRE WEATHER...RE
Area Forecast Discussion...Updated for Aviation
National Weather Service Peachtree City GA
710 PM EST Mon Jan 2 2017 .PREV DISCUSSION... /issued 1042 AM EST Mon Jan 2 2017/ UPDATE... Currently getting a break from the rain across much of the area but areas of drizzle and patchy dense fog remain in its wake. Does not appear widespread enough as of now for a dense fog advisory but will be covering with a special weather statement through this afternoon. Main change in the grids has been to back off considerably on the anticipated pops through late afternoon. Latest HRRR keeps activity in check until 21Z at which time widespread activity moves back into the western portions of the forecast area. Still looking for some type of line of storms to move through the area around 03Z or so with isolated severe potential at this point. Best instability is not in phase with the best shear but enough overlap that we will still be concerned with damaging winds and even an isolated tornado through the overnight hours. Latest HRRR shows an additional 2 to 3 inches possible across the southern tier. Will likely expand the Flood Watch eastward with next update. Deese && PREV DISCUSSION... /Issued 430 AM EST Mon Jan 2 2017/ SHORT TERM /Today through Tuesday/... Active pattern setting up for all of the area through early Tuesday. 06z surface analysis shows the warm front extending form Carrollton to FFC to Eatonton and finally beginning to make northward progression. The northward advance thanks in part to a potent shortwave located over central Texas that is moving through the generally southwest mid level flow. South of the front dewpoints have surged into the 60s and even touch the upper 60s across SW GA. Strong area of moisture convergence extending from SE AL northeastward across CSG and MCN this evening which combined with PW 1.7 inches is increasing the flood potential...see hydrology section for discussion on the threat and the new flood watch. SEVERE... the main focus for the short term will be the severe risk across a good portion of the state later in the day monday through early tue am. The strong shortwave over central TX attm swings east and takes on a slight negative tilt by 00z. Short term hi res solutions prog the current activity to wane by late morning followed by a resurge during the afternoon into the evening. the rain shield surge will be important as to potentially hamper and significant destabilization...however...models do generally agree on decent sfc based cape and mu cape values of 700-1200 j/kg after 18z through around 03z ahead of the rain shield. Do think the values drop in the models after that time as a result of the feedback from the rain shield...but am not completely sold on values going as low as 100 late in the evening. particularly after the event last week which maintained 500 j/kg well into the overnight with not nearly as impressive as a system. While shear is impressive with deep layer values ranging from 35 kts to 50kts late in the does not look as impressive as the previous system. 0-1 km helicity values are sufficient in the 100-200 m2/s2 range throughout the event. All of this points to the potential for severe storms including damaging winds and tornadoes...particularly in the afternoon and late into the evening Monday. SPC has placed most of the region in either a marginal or slight risk with the highest tornado probs running generally west of I75. If any tornadoes occur...they would be embedded with a cluster of storms or within a line making them likely rain wrapped. 30 LONG TERM /Tuesday Night through Sunday/... Models start off in good agreement at the beginning of the extended but differ quite a bit around day 5. The extended period starts off dry as main frontal system exits the area Tuesday afternoon and a drier airmass moves in from the northern gulf. After the cold front moves east of the state...this is where the GFS and ECMWF start to change course. The ECMWF sets up broad zonal upper level flow keeping moisture streaming across the region through day 7. The ECMWF also shows another frontal system pushing through the region Friday with cooler temps and possible rain and light snow amounts across north GA. The ECMWF then builds in a very Strong high pressure ridge beginning sat morning keeping things dry through the weekend. As for the GFS...once the front exits the area Tues it brings in a high pressure ridge and dries things out for a bit. There is a secondary wave that develops over the central plains and sweeps across N GA Thu but another high pressure ridge sets up Friday and keeps things dry through Sat morning before another frontal boundary move into the region for the weekend. With these to very different solutions to work with have decided to keep in a slight chance of pops in the extended for now and keeping in the chance for some mixed precip for the end of the week and weekend. Will have to keep modifying the forecast over the next few days and watch to see which models begins to get a better handle on the situation. 01 HYDROLOGY... Main rain axis across central GA shows up nicely on moisture convergence progs. Do expect this area to wane as a weak impulse in the flow is generally responsible for the enhancements in the past several hours. Short term models diffuse this area later in the morning as another area develops further West in AL and MS. Rainfall has been efficient which would be expected given the 1.7 PW values and we have been approaching some 1" per hour rates in some of the stronger storms. Given the potential for 2-4" more rain and the 1-2" that has already fallen across SW GA...have opted to add a Flood Watch through Tuesday AM. Will need to monitor areas further north for possible expansion. 30 && .AVIATION... 00Z UPDATE... Large area of rain with embedded thunderstorms slowly moving east through Tuesday morning. Ceilings and visibilities mostly ifr...but varying from lifr to mvfr. Expect ifr through the night should prevail with some improvement after 16z Tuesday. Winds east to southeast but variable and gusty in thunderstorms. Winds becoming southwest around 08z and west to northwest by afternoon. //ATL CONFIDENCE...00Z UPDATE... Medium on LIFR duration. High on remaining elements. 41 && .PRELIMINARY POINT TEMPS/POPS... Athens 60 55 67 49 / 80 100 60 5 Atlanta 65 59 67 50 / 90 100 50 5 Blairsville 57 53 62 45 / 60 100 70 20 Cartersville 62 56 66 48 / 90 100 50 10 Columbus 70 62 69 52 / 90 100 50 5 Gainesville 57 55 66 50 / 80 100 60 5 Macon 70 61 71 52 / 90 100 60 5 Rome 63 57 66 48 / 90 100 50 10 Peachtree City 67 59 68 49 / 90 100 50 5 Vidalia 74 63 75 55 / 60 100 70 5 && .FFC WATCHES/WARNINGS/ADVISORIES... Flood Watch through Tuesday morning for the following zones: Baldwin...Bibb...Bleckley...Chattahoochee...Crawford...Crisp... Dodge...Dooly...Emanuel...Glascock...Hancock...Harris... Houston...Jefferson...Johnson...Jones...Lamar...Laurens... Macon...Marion...Meriwether...Monroe...Montgomery...Muscogee... Peach...Pike...Pulaski...Schley...Stewart...Sumter...Talbot... Taylor...Telfair...Toombs...Treutlen...Troup...Twiggs...Upson... Warren...Washington...Webster...Wheeler...Wilcox...Wilkinson. && $$ SHORT TERM...41 LONG TERM....20 AVIATION...41
Area Forecast Discussion...UPDATED
National Weather Service Fort Worth TX
948 PM CST Mon Jan 2 2017 .UPDATE... A couple updates to the inherited forecast on this much more tranquil weather evening across the state. Regional surface analysis places a southward-surging cold front from the Oklahoma Panhandle, to Enid, and near Ponca City this hour. Aloft, a 100+ kt extension of the subtropical jet is guiding an abundance of high-level cloud cover across the region, and as such, have bumped cloud cover wording up into the mostly cloudy category for most of the area. As a result, also nudged low temperatures up a hair in most locales as it looks like this cirrus shield will act to mute radiational cooling overnight. Finally, based on upstream observations, made a few adjustments to the timing of the aforementioned cold front based largely on the evening runs of the NAM and HRRR which are tracking this feature well. We`ll show the initial wind shift moving into our far northwestern counties around 6-7 AM, and then through our far southeastern counties during the early afternoon. After coordinating with surrounding offices, opted to introduce patchy drizzle/fog wording to roughly the northern two rows of counties coincident with the frontal passage Tuesday morning. The combination of an already cool boundary layer, some moisture advection out of southeastern Oklahoma, and a hint of lift below 850 mb should allow for the development of patchy fog/drizzle. Any impacts should not last long as drier air starts filtering in. Finally, could also see some very localized fog tonight near Palestine where dewpoint depressions are just about nil, but its highly localized nature and increasing high cloud cover precludes patchy fog wording at this time. Updated products have been transmitted. Carlaw && .AVIATION... /ISSUED 543 PM CST Mon Jan 2 2017/ /00Z TAFs/ Concerns...Cold front arrives Tuesday with breezy north-northwest winds and MVFR cigs. Metroplex airports: VFR conditions are expected through late Tuesday morning. Light southwest winds will become westerly overnight, and then shift to the northwest Tuesday morning as a cold front approaches. Wind speeds will pick up to 12-16 kts around midday with some gusts near 20 kts. BKN high clouds are expected through the night, and then MVFR cigs with bases between 1200-2500 feet are expected behind the front. With this TAF issuance, will spread MVFR cigs across all the Metroplex airports but will monitor trends in the event the low cigs shift more to the east. Waco airport: VFR conditions will prevail through the period with high clouds expected through tonight. Light southwest winds will become westerly Tuesday morning, and then northwesterly as the front arrives around midday. Winds behind the front will be 10-15 kts. Some MVFR cigs may approach the airport near the end of this valid TAF period but there is low confidence in the speed and track of the low cigs at this time. JLDunn && .SYNOPSIS... After an active night of weather to start off 2017, a majority of the forecast period looks to be mostly dry. Today was likely the last day of well above normal temperatures for most areas (there are a few exceptions) at least over the next 5 days. Right now, the chances for any sort of precipitation look to be on the low side, but there are a couple of days we will need to monitor closely. && .SHORT TERM (Tonight through Thursday)... Early afternoon surface analysis showed that west to northwest winds continued to overspread much of North and Central TX. Looking at the temperatures across the area, one would think that it was early spring as opposed to the dead of winter this afternoon. IF you`re a big fan of the cold, you`re in luck as a stout cold front continues to slide southward through portions of southwest and central KS and is expected to move through the area on Tuesday. For tonight---some mid/high level clouds will slide southward into the area from the northwest. This afternoon`s west winds have likely instigated some good drying and temperatures after sunset should plummet quickly with partly clear skies, decreasing winds and low dew points. Unlike the past several nights, the low levels look too dry to support any type of fog development, but we will keep an eye on this low potential. For Tuesday and Tuesday Night---the front will slide southward through the northern two-thirds of North and Central TX as the parent upper low continues to rocket eastward towards the OH River Valley/Great Lakes region. While the air in the wake of the front won`t be the coldest the region has experienced over the winter 2016-2017 season, it will still feel quite cold compared to the past week or so. Temperatures will likely fall through the day for most locations, with some areas down across southern/southeastern zones remaining warm through the entire day as southwesterly flow at the surface continues. Overall lift looks to be quite meager with the passage of this front, but there should be enough remnant low level moisture for some stratocumulus. Breezy north winds will likely result in wind chill values in the teens and twenties along the Red River to thirties elsewhere come Tuesday night into Wednesday morning. Overnight low temperatures into Wednesday morning are expected to fall into the 20s and upper 30s across the region. For Wednesday and Thursday---Cooler conditions can be expected on Wednesday as north winds continue to advect colder air southward into North and Central TX. Fortunately, north winds should diminish so apparent temperatures should not be quite as low as Tuesday night. With the north winds and dry airmass, however, actual air temperatures will fall into the low to mid 20s across northwest zones to low to mid 30s elsewhere. Things potentially get interesting on Thursday as another surge of colder air slides southward. While most models have little to no QPF or PoP, most models do hint at what appears to be modest 850mb frontogenesis. I do question the amount of available low level moisture for precip given Tuesday`s FROPA, but the tight packing of the isotherms coupled with some modest shear along the deformation zone does suggest that there may be the potential for some very light precipitation, mainly along I-20 and points northward. There may not be a ton of assistance for lift on the synoptic scale, so this lowers the confidence as to whether or not precipitation will even occur. With the zonal upper air pattern, however, I cannot completely rule out a weak perturbation rippling through the mid-level flow aloft late Thursday into Friday. For now, I`ll increase low and mid level clouds and introduce a mention of snow flurries along the Red River. There will also be a slight chance for rain down across far southeastern zones where models do indicate enough moisture ahead of the cold front for some very light rain showers. Otherwise, Thursday looks to be quite cold for most areas though far southern/southeastern zones may experience slightly milder conditions ahead of the shallow cold airmass. && .LONG TERM (Friday through Monday)... Friday and Saturday---Model differences continue into the day on Friday lowering confidence in the extended portion of the forecast. The GFS quickly modifies the low level airmass as it advertises a very stout surface cyclone across southwest KS. In this solution, the resultant wind field draws a large quantity of moisture over and eventually through the colder airmass resulting in likely cloudy, foggy and warmer conditions on Friday. The GFS has exhibited a little bit of run-to-run consistency in this solution, but given that it stands alone compared to the ECMWF and Canadian, I`m a little hard-pressed to side with it just yet given that it may be difficult to overcome the cold/dense airmass at the surface. The ECMWF and Canadian appear to offer more plausible solutions and sweep the front clear through much of the region with high pressure building in. The resultant forecast for Friday and Saturday features cool conditions with a slow warming trend into the heart of the weekend. Chances will remain near zero during the weekend with perhaps the next best chance coming early next week. The increase in rain chances would also mean slightly higher temperatures as low level warm air advection occurs. 24-Bain && .PRELIMINARY POINT TEMPS/POPS... Dallas-Ft. Worth 49 59 34 46 30 / 0 5 5 5 5 Waco 46 68 36 49 30 / 0 5 5 5 5 Paris 47 59 33 45 28 / 0 5 5 5 5 Denton 44 56 28 45 24 / 0 5 5 5 5 McKinney 45 58 32 44 27 / 0 5 5 5 5 Dallas 50 60 34 46 31 / 0 5 5 5 5 Terrell 47 62 35 47 32 / 0 5 5 5 5 Corsicana 49 67 37 48 33 / 0 5 5 5 5 Temple 46 74 36 50 33 / 0 5 5 5 5 Mineral Wells 43 57 28 46 25 / 0 5 5 5 5 && .FWD WATCHES/WARNINGS/ADVISORIES... None. && $$ 82/90
Area Forecast Discussion...UPDATED
National Weather Service Green Bay WI
827 PM CST Mon Jan 2 2017 New Information added to update section .UPDATE... Issued at 827 PM CST Mon Jan 2 2017 Waushara county air temp and wautoma hovering near freezing with mixed pcpn. Added this county to the advisory. UPDATE Issued at 522 PM CST Mon Jan 2 2017 More organized banded mixed precipitation gradually expanding across central Wisconsin late afternoon before the rest of the area by early evening. Quick glance at ongoing raob shows no warm layer aloft, with the exception at the surface, so pcpn will likely start out as a rain/snow mix this evening for the non advisory area, especially with any higher radar return regions. Will watch temp trends across the southeast area of the advisory area for a possible earlier cancellation, otherwise no changes at this time. Dense fog developed over parts of far southwest Wisconsin prior to the mixed precipitation earlier today, but then diminished a tad with the pcpn. Could see a period of dense fog over parts of central and east central Wisconsin toward early morning as east winds subside. && .SHORT TERM...Tonight and Tuesday Issued at 231 PM CST Mon Jan 2 2017 The latest rap analysis and satellite/radar imagery show a cold front positioned from central Minnesota to southern Lake Superior early this afternoon. A series of weak shortwave impulses are lifting northeast over the central Plains and northern Mississippi Valleys, with light precip being reported on surface obs from northern Iowa to central WI. Closer to home, 12z soundings and rap analysis show a significant dry wedge centered around 850-800mb over eastern WI, that has prevented the many returns on area radars from reaching the ground. With southerly flow in this layer advecting in higher dewpoints, should see this dry wedge erode by mid to late afternoon over central WI and the southern Fox Valley, which then should mark the arrival of the better precip. With wet bulbs still below freezing, could see a dusting of snow over central WI by the start of the evening. Precip and precip type trends are the main forecast concerns in the short term. Tonight...Broad southerly flow aloft will continue until late tonight ahead of weak shortwave impulses lifting northeast across the region. With dry air expected to erode, light precip will spread from southwest to northeast across the region during the evening. Models are more ambitious in the 12z cycle in regards to the degree of saturation above -10C, which is often used as a bench mark for ice crystals being introduced in the cloud. As a result, potential for freezing rain looks rather limited this evening, but does increase from southwest to northeast after about 08z tonight when dry slotting arrives. Until this occurs, looking at an inch or two of snow over central and north-central WI. Then a minor glaze could occur on top of the snow late tonight. Though snow/ice totals do not look quite as significant as before, the combo of snow/ice could still create hazardous conditions on roadways, so no changes to the current headlines. Over the Fox Valley and Lakeshore, temperatures should remain relatively steady around 34-36 degrees, which will likely lead to a rain/snow mix for the evening, changing to all rain/drizzle overnight. Tuesday...A strong shortwave will be pushing an arctic front across the region from late morning through the afternoon. Will see gusty west winds develop as cold advection ramps up behind the front. May also see a few snow showers move into north-central WI late in the day. Prior to this though, drizzle/freezing drizzle may continue through 15z before the column rapidly dries out. Therefore, the end time of the advisory remains on track. Sky conditions remain problematic, however, and think there is potential for some clearing to move into central and northeast WI for a period during the afternoon. Temps will peak around late morning or midday, before falling during the afternoon. .LONG TERM...Tuesday Night Through Monday Issued at 231 PM CST Mon Jan 2 2017 Much colder air will arrive Tuesday night, with H8 temperatures dropping to near -20 C in northern WI overnight. Northwest flow off Lake Superior and synoptic enhancement from a sharp upper trof will generate numerous snow showers over far north central WI, and bring up to 2 inches of accumulation to northern Vilas county. The rest of the region should see flurries late Tuesday night into Wednesday morning. The cold air will remain over the region until the first half of the weekend, with a reinforcing shot arriving in the wake of another arctic frontal passage on Friday. Precipitation chances will be minimal, except in Vilas county, where scattered snow showers or flurries will occur from time to time. The main story during this period is below normal temperatures, with the potential for wind chill advisories over north central and central WI, where wind chills of -20 to -25 F are possible Wed ngt, Thu ngt and Fri ngt. There is some concern that abundant cloud cover may limit the temperature fall Weds ngt and Thu ngt, so have edged min temps up a degree or two. Arctic high pressure is expected to slide east of the region Sunday night into Monday, with increasing south winds leading to significant warm air advection. Aside from moderating temps, there is a small chance of precipitation. Confidence in the details is low at this time. && .AVIATION...for 00Z TAF Issuance Issued at 451 PM CST Mon Jan 2 2017 Cigs will lower to IFR levels over most locations this evening as mixed precipitation spreads over the area. After a brief mix at the onset, mostly rain is expected at MTW/OSH/ATW/GRB and SUE. Freezing or frozen precipitation to the north and west of the Fox cities toward Central and North Central Wisconsin. The precipitation will diminish to freezing drizzle and flurries toward early Tuesday morning. Gusty west surface winds and rising ceilings expected after late Tuesday morning and especially Tuesday afternoon with the start of colder air pouring into the region. && .GRB WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory until 8 AM CST Tuesday for WIZ005- 010>013-018>021-030-031-035>037-045-073-074. && $$ UPDATE.........TDH SHORT TERM.....MPC LONG TERM......Kieckbusch AVIATION.......TDH
National Weather Service Jackson KY
1053 PM EST Mon Jan 2 2017 .UPDATE... Issued at 1050 PM EST MON JAN 2 2017 Showers are moving north across parts of the Cumberland Plateau and into parts of the TN Valley with a few stray showers exiting the northeast part of the CWA. As the upper level low/trough over the TN Valley moves northeast into KY overnight, an area of showers should move across much of the western, central and northwestern parts of the CWA. However, convection over the Southeastern Conus, especially the deeper convection over GA and FL appears to be disrupting moisture transport into the area. Thus, parts of the region nearer to the VA border may essentially be split and receive very light rain amounts or even not receive measurable precipitation at all tonight. For now held onto the previous QPF and Pops, but confidence in this is lowest nearest to the VA border. UPDATE Issued at 745 PM EST MON JAN 2 2017 Hourly grids have been freshened up based on radar and short term model trends as well as recent observations. Showers continue to move north across parts of TN and northern GA and are nearing the I 24 corridor. This is generally in line with the most recent couple of HRRR runs as far as timing. Thus, as it stands now it looks like showers will encroach on the Lake Cumberland area in about 10 to 11 PM EST and the I 75 corridor around 11 PM EST to midnight and overspread the rest of the area by about 2 AM EST. && .SHORT TERM...(This evening through Tuesday night) Issued at 310 PM EST MON JAN 2 2017 19z sfc analysis shows a developing warm front over eastern Kentucky linked back to low pressure in the deep south. Showers and a few thunderstorms have broken out ahead of this to the south of the area. Locally, low clouds cover much of eastern Kentucky with some breaks occurring in the far east. This has helped temperatures to climb into the low and mid 60s there while mid to upper 50s hold on north of Interstate 64 where the fog is just now clearing up. Dewpoints remain quite moist in the low to mid 50s north to the upper 50s and low 60s south. Winds have switched to the southeast for most of the area but are still rather light. The models are in good agreement aloft through the short term portion of the forecast. They all depict a fairly strong southern stream wave rolling into and through the Tennessee Valley this evening and overnight. Though it is weakening as it passes, the core of this feature will pass fairly close to the southern parts of the forecast area keeping its dynamics in play through the night. The pattern then flattens a bit as trailing energy passes through East Kentucky and a northern stream trough to the northwest starts to influence the region on Tuesday. This mid level low to the north is exhibiting a fair amount of spread in the models by mid week with the GFS quicker and a smidge stronger than the ECMWF as it passes through the Great Lakes. By Wednesday morning, the northern stream trough will be dominant through the Ohio Valley with falling heights for Kentucky and much of the southeast. Given the good agreement aloft early and some differences late will favor a general model blend, but confidence wanes after midday Tuesday on specifics. Have also leaned toward the HRRR and NAM12 for details through Tuesday morning. Sensible weather will feature a mild and quiet start to the night across eastern Kentucky, but showers will push into the CWA from the southwest for late evening with a few embedded thunderstorms possible. As the sfc low works its way northeast along the Ohio River tonight, widespread showers and a few thunderstorms will overspread eastern Kentucky. Do expect the strongest storms to stay to the south of the area given the limited instability this far north. Will continue a small chance for thunder into the start of the day Tuesday as the low starts to pull away. The track of this sfc low will keep conditions quite mild through the day with spotty showers continuing across the area into Tuesday night. CAA in the wake of the low will then bring in cooler air toward dawn, Wednesday, but not enough to worry about any mixed wx. Once again started with the CONSShort and ShortBlend for most of the wx elements with only minor adjustments in the near term for current conditions and then to fine tune lows tonight and Tuesday night. Also held off the PoPs initially this evening before going 100 percent for a significant amount of the time over much of the CWA into Tuesday morning - higher than the blend. .LONG TERM...(Wednesday through Monday) Issued at 300 PM EST MON JAN 2 2017 The extended period looks to be active, with one weather system and its associated rain showers exiting the area on Wednesday. The weather should be quiet for awhile, from Wednesday afternoon through early Thursday morning. The models are trying to bring a weather system across the Ohio and Tennessee valley regions Thursday and Thursday night, but the different models are still having a difficult time converging on a common solution, so the forecast from Thursday onward is still going to be low confidence. At this time, have chosen to go with low precipitation chances across eastern Kentucky Thursday through Friday, with another dry period forecast from Friday afternoon through early Saturday morning. The real uncertainty is expected for the weekend. The GFS model currently has a potent winter storm with significant precipitation moving across the Tennessee and lower Ohio Valley regions over the weekend. The ECMWF model, however, is building a ridge across the region, with dry weather on tap for the weekend. That being said, decided to split the difference between the two models with slight chance pops across the board. Some very light snow accumulations are possible on Thursday and again Saturday through Sunday, should the forecast verify. For now, will be going with lower PoPs, QPF, and snowfall amounts than what the model blend gave, accounting for uncertainty. Temperatures through out the period are still looking to be well below normal, especially from Thursday onward, when we are still expecting daily highs in the 20s and 30s each day. Nightly lows are still looking like they will be bottoming out in the teens and 20s across the area. The warmest day in the period will be Wednesday, when highs are forecast to max out in the 40s for most locations. The area along and north of I-64 may see highs only in the upper 30s. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) ISSUED AT 735 PM EST MON JAN 2 2017 A mix of MVFR and VFR cigs were occurring across the area this evening. An area of low pressure will track into Central KY by late tonight with a rather potent mid level shortwave also doing the same. Showers should overspread the region between 3Z and 7Z, with ceilings dropping back into the MVFR range as the atmosphere saturates. Later tonight, between 8Z and 14Z as the low tracks across the area and stratus builds down, further deterioration to IFR is anticipated as fog will also be possible. A few thunderstorms are also possible during that period. IFR should linger in most locations through the end of the period, though some locations may improve to MVFR. Winds will remain light through the period - away from any limited thunderstorm activity. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JP SHORT TERM...GREIF LONG TERM...AR AVIATION...JP
Area Forecast Discussion
National Weather Service Melbourne FL
932 PM EST Mon Jan 2 2017 .UPDATE... Tonight...Mid level shortwave trough over the lower Mississippi Valley is lifting out and the models show pre frontal convective complex slowly weakening and staying well north of the local area. A vort lobe is shown crossing the area but stability over land will preclude any additional development, except over the Gulf Stream like both the GFS and HRRR models suggest. The other forecast problem is stratus/fog chances. The current Canaveral profilers are showing low level winds around 25 knots. This would favor stratus over fog, so our current forecast which just has patchy fog looks sufficient. Higher dew points tonight and stronger low level winds will moderate low temps with current forecast in the mid-upper 60s looking good. && .AVIATION... MOS continues to show low stratus and fog especially KISM-KMCO-KTIX northward. Think that with boundary layer flow forecast around 15 knots, we will mainly have IFR ceilings. Inherited TAFs introduced LIFR ceilings at some sites and decided not to change, but kept the emphasis more on low ceilings rather than visibility. The breezy low level winds will break up the stratus shortly after sunrise but there could be lingering MVFR ceilings until around 15z. && .MARINE... Tonight-Tue...GFS shows the pressure gradient tightening ahead of the frontal boundary with MOS indicating southerly winds 15-20 knots. Canaveral profiler confirms that winds in the low levels will support gusty conditions over the warmer Gulf Stream. Current exercise caution statement for the offshore waters looks good. && .CLIMATE... Daytona Beach and Vero Beach should tie or exceed record high temperatures on Tuesday. Record Highs for Jan 3rd Daytona Beach 83 in 1947 Orlando 86 in 1967 Melbourne 86 in 1967 Vero Beach 83 in 2006 && .MLB WATCHES/WARNINGS/ADVISORIES... FL...None. AM...None. && $$ Lascody/Ulrich
Area Forecast Discussion
National Weather Service Marquette MI
612 PM EST Mon Jan 2 2017 .SHORT TERM...(This evening through Tuesday) Issued at 348 PM EST MON JAN 2 2017 WV imagery and RAP analysis indicated a mid/upper level trough from east of Hudson Bay to the Pacific northwest resulting in sw flow from the cntrl plains through the western Great Lakes. A vigorous shortwave trough was located over the wrn Dakotas. Another was lifting through se IA while the main srn branch shrtwv was moving into the lower MS valley. At the surface, an inverted trough extended into Mn from low pres over cntrl KS. Radars indicated extensive returns over WI/MN into Upper Michigan supported by WAA/285k-295k but with only patchy light snow observed. Tonight, expect light snow to gradually spread to the northeast across the cwa as the nrn plains shrtwv approaches and the WAA pattern strengthens. However, with only weak to moderate isentropic lift and a persistent 925-750 mb dry layer, the pcpn will be slow to accumulate. Some light rain will also be possible over the southeast near Lake Michigan. Only around an inch of accumulations is expected. Tuesday, models suggest that as the deeper moisture departs the probability of ice present will drop off enough while some light pcpn persists for the potential of some freezing drizzle. Once the sfc trough moves through and drier low level air moves in with the wrly flow, any lingering pcpn will end. Although snow accumulations will be light with the fzdz possibility and SPS was issued to highlight potential hazard with slipper roads. By late in the afternoon, lake enhanced snow will increase over the far west with low level conv along the sfc trough and 850 mb temps dropping to around -9C. .LONG TERM...(Tuesday night through Monday) Issued at 407 PM EST MON JAN 2 2017 Long duration lake effect snow event expected for northwest to west-northwest wind favored snowbelts, Tuesday night through Friday. This will likely require a long duration headline. At this point, have gone with a SPS to highlight the areas of concern due to initial weak system sliding through the area during the short-term. Broad upper level troughing will be in place across the Upper Great Lakes region through much of the extended forecast with several shortwaves rotating through the area. 850mb temperatures will steadily cool from -15C to -18C Tuesday night to the -20C to -25C range Wednesday through Friday. This will allow for more than enough instability to create lake effect snow downwind of Lake Superior. Tuesday night through much of Wednesday, northwest wind favored snowbelts would be the most likely places to see lake effect snow as low pressure slowly lift north and east of the U.P. High pressure at the surface will slide into the Central Plains Wednesday night and into the Mid Mississippi Valley by Friday. At the same time, the aforementioned low pressure will continue the trek across into northern Quebec. The movement and positions of these systems will allow winds to become more westerly to west-northwesterly through this time period, effectively shifting the heaviest lake effect snow over the Keweenaw Peninsula and the far eastern U.P. for the last half of the work week. This looks to be a fairly long duration lake effect snow event with heavy snowfall totals expected across the Keweenaw Peninsula through Friday. Many locations in the Keweenaw will see snow totals in excess of a foot through the day Saturday. One thing that may end up pulling totals back to some extent will be the very shallow DGZ, which crashes down to the lowest couple thousand feet late Tuesday night through the end of the work week as the much colder air slides in aloft. Lake effect snow will definitely be ongoing across the Keweenaw Peninsula, but the snow ratios may be a little lower because of the shallow DGZ. Gusty winds over the eastern Lake will lead to waves building to 9 to 12 feet along the Lake Superior shoreline east of Marquette. This may lead to some minor beach erosion at times Tuesday night into Wednesday morning. Models continue to differ on the timing of the southerly wind shift, which will push the lake effect over Lake Superior; however, the GFS/EC both have the southerly winds in place by late Sunday afternoon into Sunday evening. Due to the continued lower confidence in the timing of this wind shift, will continue to stick with a consensus of the models for the Sunday into Monday time period. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 612 PM EST MON JAN 2 2017 Conditions will continue to deteriorate as light snow moves into the area overnight and conditions will drop to IFR/LIFR at all sites. Conditions will improve slowly as the snow moves out Tue afternoon. && .MARINE...(For the 4 PM Lake Superior forecast issuance) Issued at 348 PM EST MON JAN 2 2017 East to northeast winds of 15 to 25 knots will give way to w winds to 30 knots Tuesday as low pressure moves through Lake Superior. Northwest winds 20 to 30 knots Tuesday night into Wednesday could reach gales to 35 knots at times over the east half of Lake Superior Tuesday night into Wednesday morning as the deepening low exits east of the lake. Northwest to west winds to around 30 knots will then linger from Wednesday afternoon into Wednesday night before diminishing to 15 to 25 knots Thursday into Friday. There is a potential for heavy freezing spray Wednesday into Friday as Arctic air moves over the area. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... None. Lake Superior... None. Lake Michigan... None. && $$ SHORT TERM...JLB LONG TERM...KEC AVIATION...07 MARINE...JLB
Area Forecast Discussion
National Weather Service New York NY
959 PM EST Mon Jan 2 2017 .SYNOPSIS... Strong high pressure over New England will slowly retreats northeast tonight. Low pressure develops off the mid atlantic coast Tuesday then passes over the region Tuesday night. The low will then move into the Canadian Maritimes on Wednesday. High pressure will then build in through Thursday night, followed by low pressure passing to the south Friday into Friday night, and another high building to the west next weekend. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... Continuing to see just light echoes on regional radar mosaic, KOKX and terminal doppler radars. Most locations reporting light rain or drizzle with the exception of the northern zones where some drier air continues to battle with low level moisture. This is due to the some lingering cold air damming from the high located over Maine. Have changed the forecast wording to chance of light rain or drizzle for the rest of the night. HRRR and latest high res NAM agree that any precip overnight will be spotty and light. Temperatures across inland sections have been running a few degrees warmer than most high res model guidance as well as statistical guidance. Will have to watch temperature trends through the night. With lingering cold air damming across inland locations, temperatures may fall close to freezing. Any precipitation would then be in the form of light freezing rain. Have already issued an SPS possibly icy conditions for Putnam, northern Fairfield, northern New Haven, and northern Middlesex counties where precipitation has been spotty the last few hours with temperatures close to freezing. Temperatures elsewhere across the interior have remained above freezing with not much change so far. The SPS may need to be extended or expanded overnight if temperatures fall overnight. However, latest high res model trends actually show temperatures holding steady or even rising a few degrees. Low temps elsewhere tonight should be in the mid/upper 30s most elsewhere, and near 40 in NYC and across Long Island where maritime influence will be greatest via easterly flow between the retreating sfc high and the sfc low off the Mid Atlantic coast. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/... With the approach of the shortwave trough, one weak sfc low should dissipate to the south on Tue, while primary low pressure passes west of the Appalachians late Tue into Tue night, and a secondary low develops over the Mid Atlantic region late day Tue, and passes over Long Island Tue evening. Best chances for a steady light to moderate rain will be Tue afternoon/evening ahead of the secondary low. and easterly winds between this low and the retreating high to the north could become brisk along the coast, especially out east. Highs on Tue should range from the upper 30s well inland, to the lower/mid 40s elsewhere. Temps tue night should only drop a few degrees due to cloud cover and lighter winds, remaining above freezing throughout. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... As the secondary low moves away toward the Canadian Maritimes, drying conditions expected for most of Wed. A few showers may be possible well inland. High pressure builds in Wednesday night and Thursday with with dry conditions continuing. Confidence starts to decrease Friday through the weekend with models diverging on solutions. The high moves east and low pressure over the Gulf states moves off the Southeast coast and moves towards the Northeast. The question is how far north the precip reaches. For now, most of the precipitation stays south of the region. However, will continue to mention at least some slight chance pops in the forecast mainly across the far southeast portions of the CWA. High pressure to the north should keep enough cold air in place to keep any precipitation all snow. && .AVIATION /03Z TUESDAY THROUGH SATURDAY/... High pressure over Maine and the Canadian maritimes tracks slowly east overnight into Tuesday as one wave of low pressure off the DELMARVA coast tracks south of Long Island. Another wave of low pressure approaches during Tuesday and tracks over the terminals late in the day and into Tuesday evening. Ceilings will be mainly IFR to LIFR through Tuesday, with brief periods of MVFR possible. MVFR visibilities become IFR after 04Z and will be variable in drizzle and fog into Tuesday morning. ENE winds around 10 KTs become more easterly Tuesday and increase with gusts to around 20 KTs developing during the morning. .OUTLOOK FOR 00Z WEDNESDAY THROUGH SATURDAY... .Tuesday night...IFR early, improving to MVFR as rain tapers off. .Wednesday-Thursday...VFR. .Thursday night-Saturday...Possible MVFR or lower in snow showers. && .MARINE... Winds have increased on LI sound, especially on the western sound noting Execution Rocks has gusted close to 25 kt. Have therefore gone ahead and started the SCA here to match with the eastern Sound with both zones now in effect continuing through Tuesday evening. Winds will gradually increase on the Harbor and south shore Bays by day break Tuesday morning. SCA conditions continue on the ocean. There is still potential for gales on Tue, especially out east; in collaboration with adjacent WFOs maintained the SCA that was already in effect, but if this signal continues with the next forecast cycle a gale warning could be issued. Wave forecast during this time is close to or no more than a foot higher than a 12Z WaveWatch/NWPS blend, with max ocean seas 10-11 ft, and possibly reaching 5 ft east of Orient. SCA conditions should continue on the ocean Tue night, mainly for hazardous seas remaining above 5 ft. Decent mixing should produce some SCA gusts Wednesday evening and overnight. Then winds fall below SCA levels for the remainder of the week and first half of the weekend. Seas however will remain at or above 5 ft on the ocean through early Thursday. There is a chance that seas east of Moriches remains up a bit longer. Seas then fall below SCA levels Thursday night through Saturday night. Winds and seas both build back to SCA levels on Sunday as low pressure moves near the area waters. && .HYDROLOGY... Around an inch of rain is possible Tuesday and Tuesday night. Otherwise, no other significant widespread precipitation is expected. && .TIDES/COASTAL FLOODING... Continued onshore flow should bring water levels close to minor flood thresholds on Tuesday along the shorelines of Staten Island and Brooklyn, and south shore back bays of Brooklyn, Queens, Nassau, and western Suffolk. No special products have been issued to address this yet. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...Small Craft Advisory from 6 AM to 6 PM EST Tuesday for ANZ338- 345. Small Craft Advisory until 6 PM EST Tuesday for ANZ330-335-340. Small Craft Advisory until 6 AM EST Wednesday for ANZ350-353- 355. && $$ SYNOPSIS...BC/Goodman NEAR TERM...Goodman/DS SHORT TERM...Goodman LONG TERM...BC AVIATION...MET MARINE...BC/Goodman/DS HYDROLOGY...BC/Goodman TIDES/COASTAL FLOODING...
Area Forecast Discussion
National Weather Service Charleston WV
1005 PM EST Mon Jan 2 2017 .SYNOPSIS... A cold front crosses late Tuesday. Cold air arrives Wednesday and remains into the weekend. && .NEAR TERM /THROUGH TUESDAY/... As of 10 PM Monday... Slowed the onset of pops by a few hours based on radar trends. As of 125 PM Monday... Low stratus and fog is hanging tough across southeast OH this afternoon and also along the eastern slopes of the mountains. As the low level flow backs around to the southeast and strengthens...I expect gradual improving conditions in southeast OH later this afternoon. Elsewhere, clouds bases will lift too with the downsloping low level wind component into this evening. There may even be some peaks of sun or filtered sun before sunset, primarily along the I 79 corridor and parts of southwest Virginia. For tonight...we await the arrival of the next system and slug of moisture. The models are in good agreement taking the upper level short wave and associated surface meso vortex from the lower MS Valley this afternoon into the TN Valley this evening. Have timed the arrival of showers based on the lasted HRRR and 4KM NAM. There is enough elevated instability that a clap of thunder or two cannot be ruled out, particularly across NE KY and along the OH River late tonight. Otherwise, the area will get a good soaking rain overnight with QPF amounts ranging from half and inch to an inch. Temperatures overnight will remain very mild despite the rains. This system will move into the upper OH Valley Tuesday morning, helping to drag a cold front through Tuesday evening. As such, showers and perhaps some drizzle will linger for much of the day. It will remain warm, however. && .SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY NIGHT/... As of 320 PM Monday... Winter finally arrives by Wednesday as an arctic front crosses the area Tuesday night into early Wednesday. Models in fairly good agreement on a band of relatively light rain showers proceeding the front Tuesday night into early Wednesday. Rain showers taper off fairly quickly behind the front, possibly ending as a little snow especially in the mountains. Temperatures will be falling through the 30s during Wednesday, and well down in the 20s Wednesday night. && .LONG TERM /THURSDAY THROUGH MONDAY/... As of 325 PM Monday... Another arctic front will move across the area Thursday with a band of light snow expected. An upper disturbance following the front will bring some more light snow Thursday night, but with minor accumulation. The big question is for the weekend with a storm system that tracks south of our area. Model consensus has the track far enough south so that most of the snow with this system will be to our south. So have coded up lower pops for snow across the southeast half of the area for this weekend. Otherwise, arctic air with well below normal temperatures will be in control this period. && .AVIATION /03Z TUESDAY THROUGH SATURDAY/... As of 650 PM Monday... Widespread IFR/LIFR has formed along the higher terrain, including at site KBKW in southeasterly upslope flow. Expect this to linger much of the night, although could see periods of brief improvement to MVFR mainly after 09Z as rain moves into the region. Otherwise, still expecting areas of MVFR across parts of southeast Ohio and northeast KY for much of the evening, with mainly VFR across WV lowlands including at sites KCRW and KCKB. Rain will quickly overspread the region after 09Z, with widespread MVFR and local IFR conditions developing. Bulk of rain will move out of the area after 15-18Z, however, the potential for widespread IFR and local LIFR cigs exists at all TAF sites for much of the remainder of the TAF period. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z WEDNESDAY... FORECAST CONFIDENCE: Medium. ALTERNATE SCENARIOS: Timing of any improvement in flight conditions across the higher terrain including at KBKW may vary from forecast. Conditions on Tuesday may deteriorate quicker to IFR/LIFR quicker than currently forecast. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. DATE TUE 01/03/17 UTC 1HRLY 03 04 05 06 07 08 09 10 11 12 13 14 EST 1HRLY 22 23 00 01 02 03 04 05 06 07 08 09 CRW CONSISTENCY H H H H H M M H M H M L HTS CONSISTENCY H H H H H H H H M M L L BKW CONSISTENCY M M M M L M H M M M H L EKN CONSISTENCY H M H H M M M M M M M L PKB CONSISTENCY H H H H H H H H M M L L CKB CONSISTENCY H H H L H H H H H M H L AFTER 00Z WEDNESDAY... IFR may linger in the mountains into Wednesday. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...None. OH...None. KY...None. VA...None. && $$ SYNOPSIS...JMV/30 NEAR TERM...SL/30 SHORT TERM...JMV LONG TERM...JMV AVIATION...SL