Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 10/09/17

Area Forecast Discussion
National Weather Service Albany NY
1031 PM EDT Sun Oct 8 2017 .SYNOPSIS... A widespread rainfall will overspread the area overnight with the rain continuing through Monday as the remnants of Nate move across the region. The rain will come down heavy at times Monday, mainly in the morning for areas north and west of the Capital District. The rain is expected to taper off in the evening with a fair and warm day Tuesday as higher pressure builds in. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... As of 1031 PM EDT...Remnant low from TC Nate is located over eastern Kentucky and continues to move north-northeast along a stalled frontal zone. This front extends northeast from the Ohio Valley across our area, with a noticeable change in dewpoints on either side of the boundary. Areas within the mid-Hudson Valley continue to see dewpoints near 70, while further north, dewpoints are in the mid 50s to low 60s. This front will initially remain stationary across our area late this evening, but will start to shift northwestward as a warm front overnight, as the remnant low continues to track along it and towards the upper Ohio River Valley and eastern Great Lakes. Although no precip is occurring yet across the area, mid and high level clouds continues to thicken thanks to the persistent south-southwest flow at all levels. Based off the latest 3km HRRR guidance, rainfall (currently located over central and western PA) will make it into our far southwestern areas by around Midnight and expand north- northeastward, reaching the Adirondacks, Lake George area and southern Vermont by 3 to 4 AM. Rainfall should pick up in intensity towards daybreak, especially for areas west of the Capital Region. Overnight lows will remain mild and muggy (especially for areas south of the frontal boundary). Lows range from the mid 50s over the Adirondacks to the upper 60s across the mid-Hudson Valley and NW CT. && .SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/... The track of the remnants of Nate have shifted a bit farther to the north and west and so has the highest expected QPF amounts. Still looking at a widespread rainfall across the area with the heavier rain north and west of the Capital District. Total QPF amounts of 1 to 2 inches with locally higher amount of 3 inches possible. Remnants move across quickly and with dry antecedent conditions flooding is not expected on rivers and streams. However, some ponding of water on roadways should occur with some flooding of poor drainage and low lying areas possible. Despite the rain and clouds tempertures will still run 5 to 10 degrees above normal Monday with highs in mid 60s to mid 70s as the warm front is expected to lift to the north of the forecast area. Rain is expected to quickly taper off during the evening hours with fair weather for Tuesday as the remnants quickly move off to the east and higher pressure builds in. Conditions warm with highs in the upper 60s to upper 70s but more comfortable with dew points in the 50s. A dampening short wave encountering the ridging across the region will be on the approach Wednesday resulting in an increase clouds. Temperatures will be more seasonable but still above normal by 5 to 10 degrees. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... This will be a mixed scenario of sun and clouds, and showers and dryness. The period kicks off with near normal temperatures and rain showers as a trof will lie across the Lower Great Lakes and northern New York. But high pressure will build quickly down the appalachian chain, and dryness will ensue for Thursday. Another weak trof will develop up the mid-Atlantic coast...bringing a somewhat lesser risk for showers for Friday. Dryness will return just in time for the weekend, along with a decent amount of sunshine. As daytime temperatures become increasingly warmer, highs for Saturday and Sunday will be markedly above normal, with highs Sunday ranging from around 60 degrees in the Greens of Vermont, to the lower to mid 70s down the Hudson Valley. Wednesday night will be coolest, with lows mostly in the 40s. Friday night will be mildest, with low temperatures ranging from the upper 40s in the higher elevations, to the lower and mid 50s in the bigger valleys and far southern zones. && .AVIATION /03Z MONDAY THROUGH FRIDAY/... Flying conditions are currently VFR for all sites, but rain is rapidly approaching the mid-Atlantic and Ohio Valley regions thanks to the remnants of TC Nate interacting with a frontal zone. Rain will arrive after midnight and initially lower vsby/cigs to MVFR levels for a few hours as it moves in from south to north. By 06z-10z, IFR conditions will begin from south to north and continue through the mid morning hours for both vsbys/cigs thanks to tropical downpours. Behind this heavier batch, precip will be more showery for the remainder of the day on Monday, with generally MVFR conditions, for both vsbys/cigs. There could be a brief improvement back to VFR around KALB by the late afternoon hours, although this is still unclear if it will occur or not. Light to calm winds overnight will become southerly for the morning hours on Monday around 5-10 kts. Winds look to become southwest by late in the day Monday at around 10 kts. Outlook... Monday Night: Moderate Operational Impact. Chance of SHRA. Tuesday: No Operational Impact. NO SIG WX. Tuesday Night: No Operational Impact. NO SIG WX. Wednesday: Low Operational Impact. Slight Chance of SHRA. Wednesday Night: Moderate Operational Impact. Chance of SHRA. Thursday: No Operational Impact. NO SIG WX. Thursday Night: No Operational Impact. NO SIG WX. Friday: Moderate Operational Impact. Chance of SHRA. && .FIRE WEATHER... A widespread rainfall will overspread the area overnight with the rain continuing through Monday as the remnants of Nate move across the region. The rain will come down heavy at times Monday, mainly in the morning for areas north and west of the Capital District. The rain is expected to taper off in the evening with a fair and warm day Tuesday as higher pressure builds in. && .HYDROLOGY... A widespread rainfall is on tap for late tonight and Monday as the remnant Nate approaches and move across the region. Rainfall of about an inch up to 2 inches is expected at this time with locally up to 3 inches possible. The rain is expected to come down heavy at times mainly in the morning for areas north and west of the Capital District. Due to antecedent dry conditions and the progressive nature of the system, flooding is not anticipated on rivers and streams. However, some ponding of water on roadways should occur with some flooding of poor drainage and low lying areas possible. This will be the first widespread rainfall since early September when moisture from Tropical Cyclone Jose impacted the region. 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. && .CLIMATE... The record high minimum temperature (warmest low) for October 8th for Albany is 62 degrees set in 1913. The morning low was only 69 degrees, however we have to see how much the temperature drops this evening. We should break this. Records highs were set today at Albany and Glens Falls. Albany NY: 80 degrees today; old record 79 degrees 2011 Glens Falls NY:80 degrees today; old record 77 degrees 1993 Poughkeepsie NY fell well short with a high of 80 degrees. The record is 89 degrees set in 2007. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. MA...None. VT...None. && $$ SYNOPSIS...IAA NEAR TERM...Frugis SHORT TERM...IAA LONG TERM...ELH AVIATION...Frugis FIRE WEATHER...IAA HYDROLOGY...IAA CLIMATE...WFO ALY
Area Forecast Discussion
National Weather Service La Crosse WI
945 PM CDT Sun Oct 8 2017 .SHORT TERM...(This evening through Monday) Issued at 222 PM CDT Sun Oct 8 2017 At 1 PM, a weak surface low was located over south-central Minnesota. The 08.12z models are in good agreement that this low will move northeast this afternoon and evening. By 1 AM Monday, it will be located near Green Bay. As this occurs, a Canadian cold front will move southeast across the region. The HRRR continues to try and generate a line of showers along this front. However, it is also showing dew points in the lower 60s and this seems unrealistic considering the soundings are very dry. As a result, only expecting some clouds with this front. Besides clouds, there will be gusty south and southwest winds. The winds will gust into the 20 to 30 knot range. On Monday, a longwave trough will advance eastward toward the Upper Mississippi River Valley from the Northern and Central Plains. As it approaches, mid and high clouds will move into the region during the afternoon. High temperatures will range from the upper 50s to mid 60s. .LONG TERM...(Monday night through Sunday) Issued at 222 PM CDT Sun Oct 8 2017 Main forecast concerns in the long term are on chances for showers Monday night through Wednesday morning. Areas of frost are possible north Monday night into Tuesday morning. Shower and possibly thunderstorm chances then return going into next weekend. A weak shortwave moves in Monday night into early into early Tuesday morning with showers possible mainly south of Interstate 90. Cool high pressure quickly builds in early Tuesday morning and we may see areas of frost across portions of northeast Minnesota through north central Wisconsin. Low pressure will track east across southern Iowa through northern Illinois and eventually into Indiana by late Wednesday morning. This feature is expected to bring showers to the forecast area. There is some question as to how far north these showers will get with high pressure/drier air moving in from the north. At this time it appears that areas along and south of Interstate 90 will have the highest chances for seeing rain showers. The Canadian/GFS/ECMWF are all in line with this idea. However the NAM is indicating a further south solution. Will have to keep a close eye on the possibility of the low tracking further south like the NAM solution. Treated the NAM as an outlier at this point and leaned toward a model consensus blend for rain chances. A weak shortwave looks to move across the Upper Mississippi River Valley Wednesday night into Thursday morning and may bring some light showers to the region. Confidence is low that this system will produce any measurable rainfall. Southwest flow aloft then sets up over the region for late week as a trough deepens over the western CONUS. A baroclinic zone sets up from central Nebraska northeast through central Wisconsin Friday through Saturday as the western conus trough pushes east towards the Great Lakes. Low pressure looks to develop over southeast Nebraska early on Saturday, then tracks northeast towards northeast Wisconsin through the day on Saturday into Saturday night. If the GFS and ECMWF solutions hold, widespread rain looks like a good possibility Friday night through Saturday night and possibly into Sunday, depending on how quickly the low departs. && .AVIATION...(For the 06Z TAFS through 06Z Monday night) Issued at 945 PM CDT Sun Oct 8 2017 Cigs/WX/Vsby: generally skc vfr conditions into Mon afternoon, with increasing high/mid level clouds by late monday afternoon/evening associated with an upper level shortwave trough. Should hold vfr through Monday night. Some hints in a few models that a few showers could develop on the leading edge of the shortwave/associated thin band of low/mid level frontogenetic lift. Doesn`t look like more then sprinkles/light showers for Mon evening - with better rain chances to the southwest. Not enough confidence in development/coverage to add to forecast. Impact would be minimal. Winds: will hold from the north/northwest through Monday night. Expect some gustiness for the afternoon. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. IA...None. && $$ SHORT TERM...Boyne LONG TERM...Wetenkamp AVIATION...Rieck
Area Forecast Discussion
National Weather Service Binghamton NY
935 PM EDT Sun Oct 8 2017 .SYNOPSIS... The remains of tropical system Nate, will bring rain to the region, later tonight and Monday. The weather dries out by Tuesday, as high pressure noses into the area. Temperatures will stay well above normal, for the middle of October. && .NEAR TERM /THROUGH MONDAY NIGHT/... 900 pm update...Rain associated with the remnants of Nate interacting with a frontal boundary draped from southeast NY to northeast PA to southwest PA was slowly moving north toward central NY and northeast PA. The rapid refresh HRRR has backed off on the onset timing of the showers which matches slower radar trends. So we have backed off on the onset timing in the grids by 1-3 hours. A look at the bigger picture shows that the only lightning so far detected was well south of PA. But SPC mesoanalysis page does have some surface based CAPE into eastern PA and NJ where dewpoints were close to 70F. So we will have isolated thunderstorms in our northeast PA zones overnight as the rain spreads north mainly between 03z and 06z as moisture advection rapidly spreads northward into a favorable dynamical set-up. Models have a jet entrance region lifting ahead of the surface low associated with Nate into Quebec by 12z. The right entrance region will be overhead tonight and lead to low-level frontogenetic forcing in the presence of strong moisture advection north of the surface boundary. Hence hi resolution models all spread showers north quickly. So other than backing off on initial onset timing of precipitation, forecast remains essentially unchanged. Chances for heavy rain seems to be lessening overnight as the main frontogentic forcing will quickly move north of our CWA by late tonight. There is concern that heavy bands of rain on the east side of Nate will affect the region Monday as the southerly inflow region of Nate reaches into eastern PA/central NY Monday. There will be a strong low-level jet of around 50 knots across eastern PA into NY state by Monday afternoon. The 0-1 km shear was around 45-50 knots and with deep tropical moisture, low LCL heights, any convective rainbands will not only be prolific rain producers but also could lead to isolated severe weather. We could potentially see an isolated tornado or two given the incredible low-level wind shear if any convective lines remain intact this far north. This will bear watching for Monday afternoon. 230 pm update... Model trends, which started with last night`s runs, of shifting the main axis of heavy rainfall from Nate farther north and west, have continued today. In fact, there is now tight model clustering of bringing the remnants of Nate across western/northern NY Monday, with a SW-NE oriented frontogenesis forced band of heavy rainfall now mainly north and west of our forecast area. Although this is certainly a good trend for our local area, the aforementioned heavier rain band could still perhaps brush the western Finger Lakes and some of our far northern areas early Monday. A trailing N-S oriented band of steadier and perhaps locally heavy rain should push eastward across southern NY and PA during the morning and midday hours Monday. Similar rain bands have been seen east and southeast of Nate today, across GA, eastern TN, and the western Carolinas. As a result of what was just mentioned, we still have to be vigilant for localized training of heavy rainfall, as copious amounts of moisture will be available. Hopefully, fairly rapid system movement and dry antecedent conditions will help us out, but we`ll certainly monitor things closely through Monday. Often, in the eastern/southern quadrants of a transitioning tropical cyclone, one has to watch out for low-topped thunderstorms. Although this has been observed today within some of the rain bands east and southeast of Nate, the progged environment Monday over CNY/NEPA should be characterized by very weak instability and lack of dry air at any level. At this point, we`ll keep just a mention of isolated thunder. As alluded to earlier, the overall system is moving quickly, thus we expect most of the rain to be out of our forecast area by later Monday afternoon, followed by dry weather Monday night. Temperatures will stay mild, only falling into the 60s to near 70 tonight, then reaching up into the 70s Monday. && .SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/... As the tropical moisture associated with the remnants of Nate move northeast of our region, the weather will rapidly improve over NY and PA on Tuesday. mainly a steady rain A building ridge with very mild 925mb temperatures will push highs well into 70s by Tuesday afternoon. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... Weak waves moving northeastward through the prevailing flow will keep the weather unsettled over NY and PA through the end of the work week. A chance for showers exists each day, with the best chance coming on Wednesday when a diffuse low pressure system slides out of the Ohio Valley toward Lake Erie. If the long term models are correct, next Saturday will be a beautiful mid-October day with plenty of sunshine and temperatures in the lower-70s. && .AVIATION /01Z MONDAY THROUGH FRIDAY/... Tropical moisture associated with Nate`s remnants will move into our terminals overnight. Rain will reduce visibilities to between 3/4 and 4SM through Monday morning, with ceilings falling to 300-900 feet at most locations. IFR to fuel alternate required ceilings will likely persist through most of the day with periods of heavy rain in the morning tapering to light rain after 16-18Z. The light rain should end after 21Z but with low cigs persisting. Light winds overnight will increase out of the south at 10 to 15 knots on Monday, with gusts of 20 to 25 knots in the late morning and afternoon. Outlook... Monday night and Tuesday... Most of the rain will be over but areas of MVFR cigs may persist. Wednesday through Friday...Primarily VFR but brief restrictions possible in scattered showers. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...None. NY...None. && $$ SYNOPSIS...DJN/MLJ NEAR TERM...DJN/MLJ SHORT TERM...DJP LONG TERM...DJP AVIATION...BJT/DJP
Area Forecast Discussion
National Weather Service Duluth MN
702 PM CDT Sun Oct 8 2017 .UPDATE... Issued at 653 PM CDT Sun Oct 8 2017 Updated aviation section below for 00Z TAF TAF issuance. && .SHORT TERM...(This evening through Monday) Issued at 303 PM CDT Sun Oct 8 2017 A cold front will continue shifting east through northwest Wisconsin this afternoon and evening. There are low chances of showers ahead of the front late this afternoon and evening, per the GFS, NAM, SREF, and earlier runs of the HRRR and RAP. The latest HRRR and RAP are trending drier though. Otherwise, surface high pressure centered will be building out of the Rocky Mountains into the Plains overnight and Monday. This evening looks clear with light wind flow, letting temperatures drop quickly in this dry airmass. However, models are indicating mid/high clouds will spread into the Northland later tonight, giving a little late night insulation. The clearest conditions for the overall night appear to be in north-central Minnesota, where temperatures should drop into the lower 30s. A Frost Advisory has been issued for this area. Patchy frost is in the forecast for other parts of northern Minnesota. We might need to expand the Advisory depending on the cloud development later this evening. If it looks clearer, then we would likely forecast colder temperatures and expand the Advisory. Cool air will pour into the Northland Monday. The cold air advection will mean good low-level mixing, breezy conditions, and cumulus development. Increased the cloud cover in the forecast, leaning on the regional Canadian. Highs should range from the upper 40s to low 50s across northeast Minnesota to the middle 50s in northwest Wisconsin. .LONG TERM...(Monday night through Sunday) Issued at 303 PM CDT Sun Oct 8 2017 The extended forecast period continues to feature a mainly dry pattern for the upcoming week, with a few cold nights possible, especially Monday night and Tuesday night. Monday night and Tuesday morning looks to be very chilly over the Northland, with sfc high pressure building into the region, along with mid- to upper-level ridging progged to develop over the Intermountain West states. Skies look to be mostly clear for this time frame, especially over the western counties, so the potential for a hard freeze in some spots will be possible. Lows Monday night are progged in the middle to upper 20s over north-central Minnesota, with lower 30s south. Due to the potential for widespread freezing temperatures, we have issued a Freeze Watch for all of northeast Minnesota and northwest Wisconsin, effective Monday evening into Tuesday morning. Another chilly night is expected for Tuesday night as well. However, the sfc high pressure should shift to the east, bringing a light southerly return flow. Temperatures are still expected to drop to the freezing mark in some spots, but not as cold or as widespread as Monday night. Lows Tuesday night should range from near 30 over the International Border/Iron Range regions into the middle 30s over the south. No appreciable chances of precipitation expected through the work week, except for some small chances of showers Wednesday morning and Thursday morning, mainly over our eastern counties due to weak 850- 700 mb layer warm air and moisture advection. Due to a lack of deeper moisture, precipitation chances will remain limited. Given the WAA over the region, Thursday should have the warmest temperatures of the upcoming work week, with highs in the lower to middle 60s over the Northland. The best chances of precipitation won`t arrive until Saturday, when a more potent shortwave trough rides the northern fringe of high pressure situated over the southeastern United States. Deeper lift and moisture will be present with the shortwave. At this point, the highest chances of precipitation will be Saturday afternoon. The shortwave energy will linger through the day Sunday, keeping chances of precipitation over the region. && .AVIATION...(For the 00Z TAFS through 00Z Monday evening) Issued at 653 PM CDT Sun Oct 8 2017 VFR conditions expected through the TAF period. Mid and high clouds moving into the area from the west is expected to continue to spread in and expand through 09z, but then thin and shift south through 18z as cumulus develop. Light west-northwest winds to increase after 15z and may increase to around 10kts in the 18z-23z time range. && .PRELIMINARY POINT TEMPS/POPS... DLH 39 52 31 52 / 0 0 0 0 INL 33 48 26 52 / 0 0 0 0 BRD 39 50 30 52 / 0 0 0 0 HYR 40 56 31 54 / 0 10 0 0 ASX 41 57 33 55 / 0 0 0 0 && .DLH WATCHES/WARNINGS/ADVISORIES... WI...Freeze Watch from Monday evening through Tuesday morning for WIZ001>004-006>009. MN...Freeze Watch from Monday evening through Tuesday morning for MNZ010>012-018>021-025-026-033>038. Frost Advisory from 3 AM to 9 AM CDT Monday for MNZ010-011-018. LS...None. && $$ UPDATE...LE SHORT TERM...Grochocinski LONG TERM...JTS AVIATION...LE
Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
1148 PM EDT Sun Oct 8 2017 .AVIATION... Canopy of opaque altocumulus from tropical remnants is in place over all of southeastern Michigan with MVFR stratus stratocumulus lifting northward across the Ohio border. Despite high ceilings yet north of the Detroit area, high based shower activity in most northern band has been sufficient enough to wet the ground. Plan view progs from the NAM suggest that near surface moisture will be slow to move in initially, so continue to keep the TAFS skewed toward the RAP which prefers stratus over fog. Extremely low midlevel static stability or even convective instability will exist just above the front at 4.0 to 5.0 kft agl late tonight. Thinking it will take rainfall and a wet surface to provide near surface moisture for a light ground fog after 07Z at the Detroit terminals. Did continue with a radiational fog at MBS late for daybreak given light winds and light northeast flow contribution off of Saginaw Bay. //DTW THRESHOLD PROBABILITIES... * High for cig at or below 5000 FEET tonight. * low for CIGS/VSBY to fall below 200ft and/or 1/2SM. && .PREV DISCUSSION... Issued at 309 PM EDT Sun Oct 8 2017 DISCUSSION... Sunny and warm conditions will again change rapidly this evening with increasing clouds from the south from the remnants of Nate. Impressive strong and deep deformation and Fgen across the Ohio River valley will lift north as Nate moves into the Upper Ohio River Valley tonight. These forcing features weaken as they move northward into the southern Lakes region by 03z-06z. There is also some upper divergence from the right entrance region of a jet streak that situates itself over the Great Lakes. Plenty of moisture moving north as well with Nate. All of this leads to more confidence in the models that indicate rain for the southeast half of the forecast area. Interesting to note that the GFS and NAM have switched with the GFS now the wetter solution, but given the consistency of the ECMWF and Canadian, will lean toward those depictions of POPs. Gradient of POPs will be over the forecast area with categorical for Monroe county, likely for much of metro Detroit and just chance north of that up to a Port Sanilac to Howell line. Other issue overnight is the chances of fog. Given a couple bouts of up to half inch of rain in the last few days, dew points in the 50s, light easterly component from the warmer Great Lakes and the longer nights of October, think areas of fog will develop where there will be a decent amount of clear skies overnight. Will go with areas of fog mainly north and west of that Port Sanilac to Howell line and just patchy fog south of there. Nate pulls away early Monday, leaving a few hours of morning clouds for the southeast half of the forecast area and chance POPs for just the far southeast corner. By noon all of southeast Lower MI will have sunny skies which allow temperatures to warm well above average in the mid and upper 70s again. A weak cold front drops down from the northwest later Monday night and into Tuesday. Forcing is very weak and moisture quality is lacking. Expect more clouds and cooler temps with a more pronounced northerly flow on Tuesday, but will leave out any chance of a shower to develop around the front. The next upper low moves toward the southern Great Lakes late Tuesday night and Wednesday. Trend is for a slightly slower and more southern track, but still expect widespread rain for the bulk of the forecast area. An advancing upper-level ridge and surface high pressure will move into the Midwest and eastern U.S. late Wednesday and will remain in place through the remainder of the week, providing minimal opportunities for rain showers or thunderstorms. As the ridge continues to advance east, wind direction will shift from the northeast to the southwest, allowing daytime high temperatures to return back into the upper 60s to lower 70s by the afternoon. For reference, normal daytime high temperatures reside in the lower 60s across SE Michigan for mid-October. A surface low is then expected to develop across the Plains later this week and push into Wisconsin to northern lower Michigan Saturday into Sunday, which will allow a strong surge of warm air to push across the state, as noted in the 850mb thermal layer, where temperatures averaging 7 - 9 degrees C by late Thursday peak between 16 - 18 C late Saturday. This will allow temperatures to peak in the mid-70s for a daytime high but will also bring the chance for showers and thunderstorms, mainly across the Tri-Cities to Thumb region as a baroclinic zones lines up across Central Michigan. Better rain and thunderstorm chances move in for all of SE Michigan through Sunday as the low moves through Ontario, allowing a cold front to swing through state throughout the day. MARINE... Quieter conditions across the eastern lakes through Monday as high pressure builds across the region. Winds continue to decrease today as do wave heights, resulting in minimal marine concerns. The remnants of Hurricane Nate will lift north today with the northern edge of the precipitation shield clipping the Eastern Lakes, with light showers possibly spreading from Lake Erie up into Southern Lake Huron tonight for a few hours. Winds will be light as they back from south to north through the overnight hours. A cold front will drop through the region late Monday which will bring about northwest flow and winds gusting to around 25 knots. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. Lake Huron...NONE. Lake St Clair...NONE. Michigan waters of Lake Erie...NONE. && $$ AVIATION.....CB DISCUSSION...RBP/AM MARINE.......DRK You can obtain your latest National Weather Service forecasts online at
Area Forecast Discussion
National Weather Service Green Bay WI
607 PM CDT Sun Oct 8 2017 Updated aviation portion for 00Z TAF issuance .SHORT TERM...Tonight and Monday Issued at 257 PM CDT Sun Oct 8 2017 The latest RAP analysis and satellite/radar imagery show a cold front moving into northwest Wisconsin early this afternoon. A very dry airmass ahead of the front based on 12z MSP and INL soundings have limited any shower activity to far northern Minnesota so far today. However, most of the hi-res model guidance show a narrow line of showers developing during the 22-00z time period over north-central WI and the western Upper Peninsula. Because of this strong general consensus, will keep these showers in the forecast despite precip pulling out of the arrowhead of Minnesota early this afternoon. Besides light precip chances, cloud trends are also one of the main forecast concerns. Tonight...The moisture starved cold front will sag southeast across the area from early evening through early overnight. Hi-res models continue to indicate that the saturated layer along the front will be the most robust over north-central WI this evening, and looks deep enough for light showers or sprinkles. The moisture dries up as it moves into eastern WI, though could see some broken clouds arrive late. With northerly winds picking up behind the front, conditions do not look to support fog, despite some hints from the sref and statistical guidance. Lows ranging from the low 40s in the north to mid 50s near the Lake. Monday...If clouds materialize as guidance indicates, sct to broken clouds could linger over eastern WI through early to mid afternoon. Otherwise, skies should range from mostly sunny to partly sunny. Temps will be cooler than todays readings, and range from near 60 in the north to the mid 60s south. .LONG TERM...Monday Night Through Sunday Issued at 257 PM CDT Sun Oct 8 2017 The main forecast concerns will be frost potential across northern WI Monday night and Tuesday night, then precipitation chances for the middle of the week and especially next weekend. High pressure will build into the northern Great Lakes Monday night, and linger over the region through Tuesday night. There is some potential for a frost/freeze event over northern WI both nights. There are concerns about whether or not clouds will decrease early enough on Monday night, and increase earlier than thought on Tuesday night, to allow for widespread frost events. However, confidence is high enough to lower temperatures a few more degrees in the typical cold spots and keep frost in the forecast/grids. Overall, these should be low impact events, as there have already been a number of frost (and localized freeze) events in northern WI, and the growing season is basically over there. An upper level trof and associated surface low will impact the region Tuesday night into Wednesday. The ECMWF continues to be more aggressive than other models, but no longer brings rain as far north as it was showing in earlier runs. Current indications are that northern WI will remain dry, with light to moderate rain developing farther south. Have bumped pops to likely in our southern tier of counties Tuesday night. Expect a quiet period of weather for the end of the work week, with above normal temperatures. Some light showers will develop late Friday and Friday night as a cold front moves through the region. A fairly potent frontal system is expected Saturday into Saturday night, as a surface wave lifts northeast along the lingering frontal boundary. Dynamics look fairly impressive with this system, with an 850 mb warm front and associated strong low-level jet lifting into the region, and the RRQ of a 150 knot jet providing upper support. Weak elevated instability will be in place Saturday and Saturday night, so kept a mention of thunder in the forecast for those periods. In addition, PWATs increase to 1.5 to 1.8 inches over the southeast half of the forecast area, so there is potential for heavy rainfall, especially Saturday afternoon and evening. && .AVIATION...for 00Z TAF Issuance Issued at 606 PM CDT Sun Oct 8 2017 A cold front will slide over the state tonight. Mainly VFR mid levels were associated with the cold front passage early this evening. Patchy MVFR clouds may develop Monday behind the front and in the cooler air mass cooler air working into the region. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM.....MPC LONG TERM......Kieckbusch AVIATION.......TDH
Area Forecast Discussion...UPDATED
National Weather Service North Platte NE
628 PM CDT Sun Oct 8 2017 .SYNOPSIS... Issued at 357 PM CDT Sun Oct 8 2017 H5 analysis this morning had a fairly low amplitude pattern across the CONUS. Two main features of note are a shortwave trough over the mid atlantic and a deepening trough of low pressure over the intermountain west. A third shortwave was noted over northern Manitoba. With respect to the western CONUS shortwave: Ht falls in association with this feature were running from 100 to 150 meters across southern Idaho, western Wyoming and northern Utah this morning. Further deepening of this feature is expected over the next 12 to 24 hours, as it is being fed by a 50 to 70 KT jet streak which is currently oriented from western British Columbia into western Oregon. Mid level cloud cover and precipitation in advance of the western CONUS feature was noted from swrn Wyoming into far western South Dakota this afternoon. This area of cloudiness was drifting slowly south and was approaching the northern Nebraska Panhandle as of mid afternoon. At the surface: Low pressure was located over southern Minnesota with a cold front extending ssw into sern Nebraska and swrn Kansas. North of this feature, winds were from the north or northeast and were gusting into the 20 to 25 MPH range across portions of central and southwestern Nebraska. Temperatures as of 3 PM CDT were in the mid 50s in the northwest, to the mid 60s south of Interstate 80. && .SHORT TERM...(This evening through Monday) Issued at 357 PM CDT Sun Oct 8 2017 Main forecast challenge through Monday afternoon deals with a potent mid level shortwave crossing the Rockies/Northern Plains and low that closes off over Kansas. Specifically, p-type will be tricky due to temps. Clouds will continue to thicken from northwest to southeast across the area as easterly H7-8 flow contributes to upslope flow ahead of the shortwave. Model consensus has slowed the start of the precip slightly, which agrees with current satellite and sfc ob trends. The best moisture aloft remains over central WY/far western SD per WV and IR imagery, and sfc dew point depressions around 25F remain at KAIA and KGRN as of 20z. Slowly work PoP in to cover areas west of Hwy 83 by 03z and Hwy 183 by 06z. Kept all precip as -RA through 05z, then begin to add RASN across the far NW. Initially used sfc temps of <37F to determine RASN and <34F for SN, then tweaked using forecast soundings. The NAM is the coolest model, suggesting a subfreezing layer as low as H85 and sfc wet bulb around 2C at KAIA, KCDR, and Merriman. RAP and GFS showing slightly warmer temp profiles, which will make a large difference in this scenario due to being near freezing. Brought RASN line east to Hwy 61 and north of Hwy 92, and all SN primarily invof the Pine Ridge. Went conservative on the snow amounts due to the amount of rain mixing in and warm sfc temps (4" soil readings in the 50s). Stayed near guidance for overnight lows with increasing cloud cover and precip, but trended toward the cooler solutions for Monday highs. The main concern of expanded area of RASN or SN is reliant on the magnitude of dynamic cooling. RAP and NAM agree with a couple deformation bands developing across the forecast area - one NW/panhandle and one central Sandhills to SW Neb. Cross section analysis suggests some slantwise instability, which could lead to enhanced precip rates and increased cooling in the temp profile. Can`t rule out mixed precip as far east as KOGA to KVTN with the deformation band setting up in the pre-dawn hours. Even if a complete switch to snow occurs, little accumulation is expected. Stronger lift occurs H5-7, but the DGZ lies primarily H4-6. Regardless, SLRs are low, i.e. <10. .LONG TERM...(Monday night through Sunday) Issued at 357 PM CDT Sun Oct 8 2017 Monday night through Wednesday: The main forecast challenge deals with precipitation chances in the east with the exiting h5 trough Monday night, along with low temperatures Tuesday morning and the threat for widespread freezing conditions. For Monday Night with respect to the timing of the exiting h5 system and precipitation chances: The latest NAM12 soln has slowed somewhat, allowing deformation precipitation to back into sern portions of the forecast area Monday evening. The GFS is more progressive and leads to a dry fcst for the sern CWA Monday evening. With the NAM12 and the gfs to a lesser degree, indicating some lingering cloud cover in the sern forecast are late Monday night, will hold onto a freeze watch for Frontier, Custer, Garfield and Wheeler counties. Elsewhere, feel we will be clear enough overnight to reach the mid to upper 20s and will upgrade the freeze and hard freeze watches to warnings. Utilized a blend of the MET and MAV guidance temps for lows Monday night, which was below the superblend. On Tuesday, we should see clear skies across most of the forecast area but highs will remain cool with readings in the 50s. Warmer air will push into the region for Wednesday, thanks to the development of a low amplitude ridge across the high plains downstream of a deepening trough across the Pacific Northwest. Highs Wednesday will reach the mid to upper 60s. Wednesday night through Sunday: Dry conditions will continue through Friday with highs Thursday in the 70s. An upper level wave will cross southern Canada Thursday Night, forcing a cold front into western and north central Nebraska. ATTM, forcing for post frontal pcpn will remain north of the forecast area, so a dry forecast continues. Highs Friday will be upper 50s to lower 60s. A second upper level trough of low pressure will deepen across the intermountain west Saturday, inducing surface cyclogenesis across eastern Colorado. This will lift the front north as a warm front Friday night into Saturday with an increasing threat for showers, mainly in the eastern forecast area Saturday. A better chance for showers will arrive Saturday night into Sunday as the trough of low pressure aloft traverses the Central Plains. && .AVIATION...(For the 00Z TAFS through 00Z Monday evening) Issued at 628 PM CDT Sun Oct 8 2017 Indications from the SREF suggest IFR/LIFR in SN/RA and low cigs/vsby will generally remain along and west of highway 61 tonight and Monday. MVFR/VFR will occur east of highway 61. VFR will become widspread along and north of I-80 by 00z Monday evening. && .LBF WATCHES/WARNINGS/ADVISORIES... Hard Freeze Warning from midnight CDT /11 PM MDT/ Monday night to 10 AM CDT /9 AM MDT/ Tuesday for NEZ004>006-008-009-022>027- 035>037-056>059-069-094. Freeze Warning from midnight Monday night to 10 AM CDT Tuesday for NEZ007-010-070. Freeze Watch from late Monday night through Tuesday morning for NEZ028-029-038-071. && $$ SYNOPSIS...Buttler SHORT TERM...Snively LONG TERM...Buttler AVIATION...CDC
Area Forecast Discussion
National Weather Service Marquette MI
738 PM EDT Sun Oct 8 2017 .SHORT TERM...(This evening through Monday) Issued at 402 PM EDT SUN OCT 8 2017 WV imagery and RAP analysis indicated a mid/upper level trough over the ern CONUS and a trough from nrn Manitoba into the Rockies resulting in sw flow through the plains and nrn Great Lakes. At the surface, a cold front extended from just west of James Bay through wrn Lake Superior. Clouds and light pcpn with fgen behind the front were lifting ne of the MN arrowhead. Tonight, increasing 850-700 mb fgen forcing along and in the wake of the front and associated upper level with the right entrance region of 140 knot 250-300 mb jet max over nrn Ontario will support an increase in clouds and potential for isold/sct -shra over mainly the northwest half of cwa this evening. With dry low levels and little moisture inflow, mainly sprinkles or only a few hundredths of an inch are expected. Expect decreasing clouds behind the front later tonight as min temps drop as low as upper 30s interior west and into upper 40s/lower 50s east half of the cwa. Monday, high pressure building into the area with anticyclonic nrly flow will bring mostly sunny skies and high temps into the upper 50s west and lower 60s southeast. .LONG TERM...(Monday night through Sunday) Issued at 328 PM EDT SUN OCT 8 2017 Overall, we`re looking at quiet weather and seasonable temperatures through the first half of the week. Above normal temperatures will return towards the end of the week ahead of an approaching cold front. Confidence is increasing that we will see another system track across the region bringing dreary and breezy conditions next weekend. Heavy rain look possible with this system; however, the exact location within the region that will see this heavy rain is hard to pinpoint at this time. A potent shortwave will track across the Middle Mississippi Valley and eventually across the Lower Great Lakes region as it weakens Tuesday night into Wednesday. The majority of the precipitation associated with this system is expected to remain south of Upper Michigan, but cannot rule out a few showers making into the far south central. Otherwise, dry weather and seasonable temperatures are expected to prevail as surface ridging tracks across the Upper Great Lakes Monday night through Wednesday. Thursday and Friday, surface ridging will slide east of the area in response to return flow developing across the Plains as shortwave energy embedded within longwave troughing across the western CONUS ejects out across the northern Plains. We will see temperatures warm 5 to 10 degrees above normal in response to this return flow. Precipitation wise, the main forcing is expected to remain north of the area; however, a weak cold front will push east across the area, which may bring a few scattered showers. The best chance for these scattered showers will be Friday and Friday night once stronger warm air advection arrives, along with enhanced jet dynamics. Saturday morning there could be a few lingering showers, mainly across the east; however, much of the area is expected to remain dry during the first half of the day on Saturday as the above mentioned cold front stalls out just south of Upper Michigan. Saturday afternoon/evening through Sunday this baroclinic zone will become reinforced and lift back north as the main longwave trough out west lifts across the central Plains, and eventually up across the Upper Great Lakes. This will result in the return of cooler, rainy and windy conditions. As mentioned above, it is difficult to pinpoint this far out what locations across the region will see the heaviest rainfall; however, based on current model guidance the heaviest rain looks like it may set up across southern portions of Upper Michigan or just south of of the area into Wisconsin and lower Michigan. && .AVIATION...(For the 00Z TAFS through 00Z Monday evening) Issued at 737 PM EDT SUN OCT 8 2017 VFR conditions will continue through the forecast period. && .MARINE...(For the 4 PM Lake Superior forecast issuance) Issued at 402 PM EDT SUN OCT 8 2017 Winds should be mostly less than 20kt tonight through Friday as high pressure generally dominates through the period. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... None. Lake Superior... None. Lake Michigan... None. && $$ SHORT TERM...JLB LONG TERM...Ritzman AVIATION...07 MARINE...JLB
Area Forecast Discussion
National Weather Service Mount Holly NJ
1151 PM EDT Sun Oct 8 2017 .SYNOPSIS... A cold front will become stationary just north of our region, then move slowly north overnight. Meanwhile, the remnants of Nate will traverse the Appalachians, moving just west of our area on Monday. Another cold front frontal passage is expected Tuesday night. A sprawling area of Canadian high pressure will settle across our region Wednesday through early next weekend. An additional cold front may approach our area by late next weekend. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... Showers will develop and become more widespread as we head into the early morning hours across eastern Pennsylvania and northern New Jersey with the remnants of Nate moving north. Both the HRRR and RAP models ramp this activity upward for a few hours followed by another lull toward sunrise. POP grids were adjusted to take into account convection trends and the new mesoscale model data. Lows will bottom out in the upper 60s to lower 70s. The exception will be the higher terrain where mid 60s are expected. && .SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/... Overall rainfall totals have come down a bit across the coastal plain. General totals are now expected to be in the 0.50 to 3.00 inch range across the CWA with the highest values across the western zones. We can`t rule out some higher isolated amounts as some convection is possible in the late morning through mid-afternoon period as the last remaining piece of Nate moves through. SPC isn`t all that excited about severe convection tomorrow as instability is almost non-exist. But it`s hard to ignore that amount of shear that will be crossing over the region. As for precipitation, there will be a break for many of us in the morning hours after daybreak. More showers (and maybe thunder) can be expected in the later morning hours into the mid-afternoon hours, from west to east. Models have sped up Nate. Any precipitation looks like it will be done by the evening hours. Winds in general will be in the 15 to 25 mph range. However, gusts up to 45 mph are possible in and near stronger convection as winds aloft are mixed down. Temperatures are expected to remain above normal, and top out about 10 degrees above normal once again. && .LONG TERM /MONDAY NIGHT THROUGH SUNDAY/... The mid level progs continue to feature a period of southwest to west flow aloft through the duration of the forecast period. Within this flow, brief shortwave ridging is expected in the wake of Post Tropical Cyclone Nate on Tuesday. The next shortwave impulse will traverse invof the NY/PA border Wednesday into Thursday. A higher amplitude shortwave will approach our region late next weekend. During the interim, there are several smaller perturbations in the somewhat zonal flow traversing our region. The main forecast challenges continue to be Tuesday`s high temps, as well as temporal and spatial uncertainty in precip Wednesday through Friday. Tuesday...The trend is for the cold front to time through our region earlier, therefore, PoPs have been updated accordingly. We maintain a slight chance across southeast NJ and southern Delmarva during the day. Elsewhere...dry. Skies will become mostly sunny north of the aforementioned area. While a drier airmass will gradually filter south across the area, it will remain warm for October, with model soundings indicating 850 hPa temps of around 17C east of the I-95 corridor. Model guidance has also been biased cold, up to 5 degrees recently with maximum temperatures. The 12Z/08 MAV and EC 2-meter temperatures are warmer compared to the MET, yet still seem too conservative. With this forecast, we have bumped high temps up on Tuesday where we expect full sun, and played it more conservative under the cloud cover. Record highs may be in jeopardy at ACY and GED, but overcast skies may hold temperatures below these levels (see the climate section). Also, given clearing skies and the recent rainfall, winds may decouple enough for some patchy fog Tuesday morning, mainly in the more prone locations northwest of I-95. Wednesday through Friday...We have the most confidence in precip during the Wed-Thu time frame as a shortwave to the north skirts by, so the forecast reflects continued chance PoPs. This timing is about 12-18 hours later compared to yesterday`s forecast package. Going into Thu night and Friday, less confidence. Despite a strong ridge at the surface, deterministic models continue to generate light precip, while the ensembles remain drier. This forecast continues to favor the drier solution, with slight chance PoPs across the area. This period will feature high temperatures at or below normal, while considerable cloud cover will keep low temps generally above normal. Saturday and Sunday...Increasing southwest flow leads to the return of above normal temperatures. There is uncertainty regarding how far east the Great Lakes cold front advances on Sunday. For now, we kept the forecast dry for both days. && .AVIATION /04Z MONDAY THROUGH FRIDAY/... The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY and surrounding areas. Tonight...VFR conditions will carry through a good portion of the evening hours. Ceilings everywhere are expected to drop into the MVFR range, and most likely through it, by daybreak. Precipitation should spread in across most/all the terminals after midnight. Monday...Terminals will start the day off with MVFR/IFR. The precipitation is expected to take a break in the morning hours for most of the terminals before spreading back into the picture late morning and afternoon. A low level jet will be developing. Directional shear won`t be present, but a fair amount of speed shear will. Outlook... Mon night...MVFR due to low ceilings possible at ACY and MIV. In addition, cannot rule out brief MVFR in fog at ABE and RDG. VFR otherwise. Tue through Wed...Predominantly VFR. Wed night through Fri...MVFR possible in low clouds all terminals, mainly Wed night and Thu night, with a return to VFR during the day time. && .MARINE... Tonight...winds and seas are expected to remain below SCA conditions. Monday...SCA conditions are expected to develop once again around daybreak and continue throughout the day. If convection develops in the afternoon, gale force gusts will be possible and will be covered short-fused SMWs. Outlook... Northwest winds will likely remain at SCA levels into early Monday night, with seas subsiding below SCA levels Tuesday morning. Thus, the SCA may be needed into Tue morning. Easterly winds may reach SCA levels again Wed afternoon, and this could linger into Thursday afternoon. While winds may subside by this point, the continued east flow (long fetch) may result in elevated seas into Friday. && .TIDES/COASTAL FLOODING... A few sites in southern New Jersey and Delaware could approach minor flooding thresholds with the high tide cycle again Monday morning (between 10:30 AM EDT and Noontime on the oceanfront). However, all guidance continues to indicate that we shouldn`t see widespread minor tidal flooding. Thus, we are not planning on issuing a coastal flood advisory at this time. Along the eastern short of MD, despite the southerly flow, we expect to remain below minor flooding thresholds for Monday evening`s high tide. && .CLIMATE... There is the potential for daily record high temps on Tuesday, October 10th. For your convenience, records are listed below. At this time, only ACY, GED, ILG, and PHL are forecast to be within 5 degrees of their respective daily record high temp. Site Record Year ____ ______ ____ ACY 85 1939 PHL 90 1939 ILG 89 1939 ABE 89 1949 TTN 89 1939 GED 86 1958 RDG 89 1949 MPO 86 1949 && .PHI WATCHES/WARNINGS/ADVISORIES... PA...None. NJ...None. DE...None. MD...None. MARINE...Small Craft Advisory from 7 AM Monday to 8 AM EDT Tuesday for ANZ450>455-470>473-475. && $$ Synopsis...Franck Near Term...Gaines/Kruzdlo/Miketta Short Term...Kruzdlo Long Term...Franck Aviation...Franck/Kruzdlo/Miketta Marine...Franck/Kruzdlo/Miketta Tides/Coastal Flooding... Climate...
Area Forecast Discussion
National Weather Service Blacksburg VA
1048 PM EDT Sun Oct 8 2017 .SYNOPSIS... Tropical Depression Nate will progress into the Ohio Valley overnight. The remnants of Nate will continue heading northeast through West Virginia and Pennsylvania early Monday with a cold front following in its wake across our region Monday afternoon. This front will briefly stall to our south, but then progress north again as a warm front starting Tuesday. && .NEAR TERM /THROUGH MONDAY/... As of 1040 PM EDT Sunday... Area of moderate to heavy rainfall continues to spread northeast across NW NC into SW Va late this evening. Have had reports of 2-4 inches of rain per automated gages, as well as reports via social media of flooding in the Boone area. Streams and creeks are reacting to this tropical rainfall, despite how dry we have been. Will continue with the flash flood watch overnight, but think we can cancel it before dawn as back edge of heavier rain shield is already moving toward northeast TN, while TD Nate weakens over the Cumberland Plateau. Synoptic models appear too slow with shield of rain and low, while the HRRR looks to start weakening the showers over the mountains by 10z/6am, as does the RAP13. With the next update will likely see lower pops past 8am Monday in the west. Previous early evening discussion... Rain becoming more widespread over the NC mountains/foothills northwest into SW VA early this evening. Had one tornadic cell cross from Caldwell into Wilkes County, but so far no confirmed tornadoes in Wilkes, but some damage reported. As far as Nate and the rain goes, appears models on track to give the southwest CWA about 2-3 inches of rain through dawn with locally higher amounts, with lighter amounts further east. Current flash flood watch and wind advisory cover the scenario well and no changes planned. Will be monitoring streams and rainfall rates for any possible flood/flash flood advisories or warnings. Severe threat is starting to diminish but some showers could bring down stronger winds this evening over NW NC. Previous discussion from mid afternoon... Have expanded the Flash flood Watch into Tazewell county. RFC forecast for the North Fork of the Holston River had the site going to action stage tomorrow evening. Expecting enough rainfall tonight that smaller streams have an enhanced threat of flooding across the watch area. Have expanded the Wind Advisory for tonight. Through 03Z/11PM surface through 850mb winds are out of the southeast and downsloping will enhance winds in areas like Tazewell and Mercer counties. For much of the period from 22Z/6PM through 12Z/8AM 3KM NAM was showing the potential for strong winds at higher elevations in southwest Virginia and northwest North Carolina, especially along the southern Blue Ridge. 850MB winds may be as high as 65 knots. So Advisory now covers into Mercer County WV and along the Blue Ridge through Floyd and Patrick Counties. Radar showed a well defined band of showers and thunderstorms associated with Tropical Depression Nate from eastern Tennessee into northern Florida. Models show good consensus bringing the leading edge of this band into Watauga County around 22Z/6PM and progressing the tropical precipitation southwest to northeast across the region by 15Z/10AM Monday. Much of any heavier precipitation will fall in the 00Z/8PM to 12Z/8AM time frame. By Monday morning winds turn to the west and the remnants of Nate will be well to the north. West winds will favor diminishing precipitation and cloud east of the Blue Ridge Monday afternoon. Guidance was forecasting steady or rising temperatures overnight. Challenging to agree with rising nightime temperatures in October but agree there will be no change in air mass. Will use a non-diurnal trend for hourly temperatures tonight. && .SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/... As of 230 PM EDT Sunday... Remnants of Nate will move off the New England shore Monday night. In the wake of Nate, a baroclinic zone will lay over the Carolinas Monday night, then lifts north over the area on Tuesday. Models are displaying a weak surface ridge developing over southern Virginia Tuesday night. Even though this surface ridge looks like a weak insitu wedge with easterly flow and diabatic cooling, it does not have a true parent center. Regardless of this feature`s classification, weak isentropic lift over a high PWAT/theta-E environment will bring either light rain, drizzle, low clouds and/or fog to the area, especially along and east of the Blue Ridge. Damp and dreary conditions remain over the area into late Wednesday morning. By Wednesday afternoon, pressure falls over the Ohio Valley may help this surface feature dissipate over the area to see some sun. Rain chances decrease, but fog and/or low stratus cloud deck likely to return Wednesday night. Temperatures will be cooler than what we have been seeing, but still running warmer than normal. Highs each afternoon will primarily be in the 70s. Overnight lows will be generally in the 60s. && .LONG TERM /THURSDAY THROUGH SUNDAY/... As of 230 PM EDT Sunday... The upper level ridge that has been along the southeast coast over the weekend will retrograde westward along the Gulf States during the work week. The center of this ridge may actual move over eastern Texas by Friday. This ridge will expand from the Gulf states and cover the Tennessee Valley and the southern Appalachains Mountains by next weekend. To start the period, Thursday afternoon temperatures will be close to seasonal with most locations in the low 70s. Afternoon temperatures will warm a few degrees each day. By Sunday, temperatures will range from the upper 70s to lower 80s. There will be chances for showers each afternoon, but areal coverage and duration will be limited to cover with a PoP less than 20 percent. && .AVIATION /03Z MONDAY THROUGH FRIDAY/... As of 720 PM EDT Sunday... Not a good night to fly with rain expected to overspread much of the area with strong winds associated with TD Nate. Cigs will drop to MVFR to IFR as will vsbys with moderate to heavy showers. Non-convective LLWS possible but with rain showers, wind shear will already be there through overnight. Should start to see some diminishing rainfall intensity Monday morning, with models starting to improve conditions in the afternoon back to MVFR to VFR with rainfall ending. Extended Aviation Discussion... A weak front will stall across VA/NC on Tuesday. This boundary will bring the chance for sub VFR ceilings and showers for a line south of KBLF, KROA and KLYH Tuesday and Tuesday night. A wave tracking along this boundary will likely bring rain to the region for Wednesday. High pressure and drier weather return on Thursday and Friday. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...Wind Advisory until noon EDT Monday for VAZ007-009-010-012- 015>017-032. Flash Flood Watch until 8 AM EDT Monday for VAZ007-009-015. NC...Wind Advisory until noon EDT Monday for NCZ001>003-018-019. Flash Flood Watch until 8 AM EDT Monday for NCZ001-002-018. WV...Wind Advisory until noon EDT Monday for WVZ042. && $$ SYNOPSIS...AMS/WP NEAR TERM...AMS/WP SHORT TERM...RCS LONG TERM...RCS AVIATION...AMS/DS/WP
Area Forecast Discussion
National Weather Service Seattle WA
836 PM PDT Sun Oct 8 2017 .SYNOPSIS...An upper ridge will move over the area tonight and Monday for dry weather and mostly clear skies. A series of upper troughs will bring cool weather, some showers, and occasional sun breaks Tuesday through Saturday. && .SHORT TERM...An upper ridge will cross the area tonight and Monday for dry weather. Areas of fog are likely later tonight and Monday morning with mostly clear skies, light winds, and lingering low level moisture from recent rains. It will be a bit chilly tonight with lows dipping into the upper 30s in the colder spots. Northerly flow aloft will back to westerly Monday ahead of a weak approaching frontal system. High clouds will probably increase ahead of this front during the day. The front and an upper trough will push into the area Tuesday for a chance of showers. A Puget Sound Convergence Zone is likely behind the front Tuesday night. The upper trough will remain over the area Wednesday for a continued shower threat. The mountains could pick up a few inches of snow Tuesday night and Wednesday as snow levels around 5500 feet Tuesday lower to 3000 to 3500 feet by Wednesday morning. There will be a corresponding cooling of daytime highs over the next few days going from lower 60s Monday to lower to mid 50s by Wednesday. Schneider .LONG TERM...Previous discussion...Although the trough axis pushes eastward of the area come Thursday...W WA will find itself still in a troughy pattern. GFS solutions have shown some variance here in the past 24 earlier solutions shifted any associated precip more to the south of the area...whereas current solution plows the moisture...and thus precip...directly into the area. The is becoming a theme in this discussion...maintains a wetter solution. While this may be an indication of the GFS adopting or at least transitioning toward a solution more akin to the ECMWF...the fact that this breaks from previous solutions cannot be overlooked and as such...have continued the forecast trend of finding a middle ground between the drier past GFS solution and the consistent wet ECMWF. Should the next GFS run continue this wet trend...however...would not be surprise to see POPs for this period trend upward. This trough and its associated moisture looks to linger on into Friday before a very weak ridge provides a breather late Friday night and into Saturday morning. From looks like another trough is on the way to allow for a wet weekend. SMR && .AVIATION...A transient upper ridge axis will pass across Western Washington early Monday morning, then an upper trough will start to move southeast down the B.C. coast on Monday night. Moderate northerly flow aloft tonight will become westerly on Monday afternoon, then southwesterly on Monday night. The air mass will be dry and stable, though high clouds AOA 150 will thicken quite a bit on Monday. Otherwise, expecting fog-prone locations such as river valleys to get socked in late tonight, followed by rapid late morning burnoff. KSEA...Other than some cirrus, clear night ahead. Expecting fog to form in the valleys to the east-southeast of the airport late tonight and Monday morning. Should mostly avoid the airfield. The latest LAMP guidance and HRRR models show no fog at KSEA in the morning. Still, there is the possibility of light east wind slopping a little fog up the hill and over the airfield for a short time (1 hr or less) as the fog starts to break up 1-2 hours after sunrise, or around 8-9 am. Latest TAF amendment trended more optimistic with prevailing conditions in the morning while narrowing the TEMPO group for cig/vsby restrictions into a smaller time window in that post-sunrise period. Haner && .MARINE...West-northwest swell over the coastal waters is in the process of subsiding. Buoy 87 now shows swell under 10 feet, so will end the SCA at the West Entrance. Elsewhere, swell will subside below 10 feet later tonight. Meanwhile, light northerly flow will develop tonight due to rising pressure over British Columbia with lower pressure over Oregon. Expect the flow to become nearly flat on Monday. A cold front will arrive from the northwest early Tuesday morning, with onshore flow following the front during the day. The flow will become more northerly on Wednesday. Haner && .SEW WATCHES/WARNINGS/ADVISORIES... WA...None. PZ...Small Craft Advisory for hazardous seas until 3 AM PDT Monday for Coastal Waters From Cape Flattery To James Island 10 To 60 Nm-Coastal Waters From James Island To Point Grenville 10 To 60 Nm-Coastal Waters From Point Grenville To Cape Shoalwater 10 To 60 Nm. Small Craft Advisory for rough bar until 11 PM PDT this evening for Grays Harbor Bar. Small Craft Advisory for hazardous seas until 11 PM PDT this evening for Coastal Waters From Cape Flattery To James Island Out 10 Nm-Coastal Waters From James Island To Point Grenville Out 10 Nm-Coastal Waters From Point Grenville To Cape Shoalwater Out 10 Nm. && $$ You can see an illustrated version of this discussion at
Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
530 PM MDT Sun Oct 8 2017 .DISCUSSION...(This Evening Through Sunday) Issued at 238 PM MDT Sun Oct 8 2017 The latest water vapor images and RAP analysis had a positively tilted upper trough over the northwestern CONUS with at least a 110 kt jet from KSLC to KINL. Banded rain/snow extended from southwestern WY into north-central SD, with some snow accumulating over the highest Black Hills. This was being forced by the jet along with midlevel frontogenesis. For tonight the best Q-G forcing will shift to the south of the CWA as does the frontogenesis and isentropic lift. This will allow for the band of precip to gradually move across southwestern SD. The latest radar trends show a contraction of the band with convective type elements along the southern edge of the band; thus, may see some locally heavier rain/snow amounts than what has been suggested by the models. The upper low will move to our south on Monday with drier air filtering into the area, and precip coming to an end over southern SD during the morning. Clear skies, light winds, and 850-mb temps of 0-3C will then set the stage for frost over south-central SD late Monday night and Tuesday morning. Otherwise, dry and warmer weather is expected later Tuesday into Friday as a flat ridge dominates much of the central/eastern CONUS. Another trough will move over the area next weekend, bringing another round of rain/snow. && .AVIATION...(For the 00Z TAFS Through 00Z Monday Evening) Issued At 528 PM MDT Sun Oct 8 2017 Bands of -RASN over northeast WY/southern SD with MVFR conditions will slip slowly southward this evening, leaving the area by morning. Local IFR conditions expected near the higher terrain of the Black Hills. Conditions will gradually improve everywhere overnight from north to south. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...Freeze Watch from late Monday night through Tuesday morning for SDZ049. WY...None. && $$ DISCUSSION...Bunkers AVIATION...Helgeson