Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 04/02/19

National Weather Service Jackson KY
1103 PM EDT Mon Apr 1 2019 .UPDATE... Issued at 1102 PM EDT MON APR 1 2019 Have made a couple of updates over the last few hours, loading in the latest observations to make sure the near term forecast for temps is on track with the current conditions. Currently we are still mostly clear outside, with clouds developing well to our SW across western TN. It is not apparent by the satellite that the progression of these clouds will allow them to work all the way into the CWA during the overnight as is currently forecast, unless new clouds develop on the front edge. If clouds do not fill in as forecast, this may have some impact on the overnight lows. As of now the forecast temps are still in good shape, but will need to continue to monitor as we head through the overnight in case temps need to be lowered. All updates have been published and sent to NDFD/web. A new forecast package was sent out to change to overnight wording. A new NPW and SPS was also sent out to remove evening start time wording. UPDATE Issued at 743 PM EDT MON APR 1 2019 Forecast is in good shape so far this evening, with high wispy clouds and otherwise calm conditions. Loaded in the latest observations for temps, dew points, and winds to make sure the near term forecast was on track with the current conditions. Will continue to monitor temperatures closely as we lose sunlight in case any adjustments to the lows and overnight diurnal curve are needed. This could also have some impact on the extent of the below freezing temps and frost potential. As of now, updates were not significant enough to warrant any updates to the ongoing forecast package. && .SHORT TERM...(This evening through Tuesday night) Issued at 335 PM EDT MON APR 1 2019 19z sfc analysis shows high pressure passing through the Ohio Valley. This has kept skies mostly sunny for much of the day across eastern Kentucky, though a developing wave of low pressure to the south is pushing some high clouds into the area from the southwest. Despite the sunshine, temperatures have been slow to rise - from chilly morning lows - so that at 3 pm they range from the low 40s northwest to the upper 40s in the southeast. Dewpoints, meanwhile, are mainly in the teens across the area with generally northeast winds of 5 to 10 mph. The models continue to struggle a bit aloft with the southern stream wave due to pass by to the south of Kentucky late tonight. The NAM is a tad shallower with this than the GFS and ECMWF. Either way the core of this wave`s energy will stay south of eastern Kentucky minimizing its impact for the JKL CWA. The pattern will then flatten out in the wake of this wave with northwest flow and slightly depressed 5h heights over Kentucky into Wednesday morning. With the model uncertainty for tonight`s wave have favored a blended solution along with a lean toward the HRRR for near term specifics. Sensible weather will feature another cool night, but not nearly as cold as last night. Still a big question as to how quickly the clouds from the south move in and thicken this evening. This will affect the temperature drop off following sunset in our western and southern locations. Further east the thinner clouds should do little to limit the temperature drop resulting in several hours of sub freezing temperatures likely in the deeper valleys. Accordingly, have issued another freeze warning for our northeast counties (in conjunction with RLX). The questions as to the ability for frost to form with the increasing clouds limited the mention of frost to just areas in the freeze warning and the remainder of the CWA. Therefore an SPS was issued for the rest of the JKL CWA where the growing season has begun with a potential for frost highlighted as well as temperatures in the valleys getting close to freezing in the predawn hours. With the southern system nearing towards dawn do expect readings to rebound slightly by 12z for much of the area. Would not be surprised to see a few sprinkles strafe the southeast border from this system but for now have kept it dry. A warmer day is expected for Tuesday with highs near 60 for most of eastern Kentucky under partly cloudy skies. Some frost will be possible again in the valleys on Tuesday night as the skies clear out allowing readings to drop into the low to mid 30s in the valleys to around 40 on the ridges. The CONSShort and ShortBlend guidance were used to initiate the grids with some significant ridge to valley temperature adjustments tonight and Tuesday night. As for PoPs, did keep them in the single digits or less for the area as that southern wave passes late tonight - slightly lower than CONSShort. .LONG TERM...(Wednesday through Monday) Issued at 300 PM EDT MON APR 1 2019 The long term portion of the forecast will feature a rather progressive pattern across the United States, with a couple of short wave troughs affecting eastern KY during the period. It will also be a warm period with above normal temperatures throughout this portion of the forecast. At the start of the period surface high pressure will be over the southern Appalachians, with a mid level southern stream short wave trough over the southern Rockies. Out ahead of the mid/upper wave surface low pressure will be developing in the southern high plains. Dry warm weather will be on tap for Wednesday, with moisture return likely to be slow to develop across the area. As the high shifts southeast Wednesday night, and the short wave trough advances into the southern plains we will see a gradual increase in moisture across the area. A cold front will drop south into the southern Great Lakes and stall over northern parts of the OH valley by Thursday morning, with the southern plains mid/upper level wave and associated surface low moving east. There is good agreement that the short wave trough and associated surface low will weaken as they move east. This southern stream system will still bring a chance of showers to the area Thursday night and Friday. However the system will be weakening, there will be very limited instability, and convection over the southern MS valley and southeast U.S. will likely prevent deep moisture flow into our area. Rain may also be more focused along the stalled front to our north. As a result rain amounts in our area should be relatively light, with amounts generally less than 0.40 inch. Thunder chances will also be limited with the Thursday-Friday system. Will scale back thunder chances to just Thursday night for the southwest part of the forecast area. With this first trough passing east by the end of the work week, the surface front to our north should drop south into our area temporarily to start the weekend before quickly retreating north in advance of the next short wave trough. On Saturday we`ll turn our attention to the next short wave trough in the southern stream emerging from the southern Rockies. This system looks to take a more northwesterly track over the weekend into early next week, with surface low pressure tracking from the southern plains into the Great Lakes by early next week. Out ahead of this, instability should increase in our area Saturday and Sunday, with warming surface temperatures and dewpoints increasing this weekend. As a result shower chances will continue, and will introduce thunder chances for Sunday afternoon. By the end of the period a cold front should be moving through the area, with a potential cool down by the middle of next week. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) ISSUED AT 747 PM EDT MON APR 1 2019 High pressure will dominate the weather through the period, with VFR skies expected. However, a weak wave will track east out of the Central Plains tonight bringing increased mid to high level clouds for east KY later tonight and persisting through much of the day Tuesday. Expect the nearby high pressure area to keep winds light and generally out of the north and east overnight, switching to the southwest generally under 10 kts during the day tomorrow as the center of high pressure shifts farther east of the region. && .JKL WATCHES/WARNINGS/ADVISORIES... Freeze Warning until 9 AM EDT Tuesday for KYZ060-104-106>115- 118>120. && $$ UPDATE...JMW SHORT TERM...GREIF LONG TERM...SBH AVIATION...JMW
Area Forecast Discussion
National Weather Service Raleigh NC
942 PM EDT Mon Apr 1 2019 .SYNOPSIS... Chilly high pressure will move off the Mid Atlantic and Northeast coast tonight. Low pressure will develop off the Georgia coast and track northeastward along the Carolina coast through Tuesday. High pressure will build into the area from the southwest Tuesday night through Wednesday. && .NEAR TERM /THROUGH TONIGHT/... As of 945 PM Monday... Evening update: Very little change in the forecast this evening as numbers are on track based on observations. Modified the onset of precipitation slightly earlier across the south due to actual rainfall currently near Charleston, which the high resolution models don`t have reaching until a couple of hours from now. Otherwise the previous thinking remains the same and that discussion follows. - Ellis Confidence has grown in the precip pattern and coastal surface low track and evolution, but considerable uncertainty persists regarding precip type. The mid level shortwave trough over OK/TX early this afternoon will track E into the Southeast states tonight, with falling heights late downstream over NC. We`re already seeing falling surface pressures off the GA coast along the old frontal zone associated with precip forced in part by passage of an upper divergence max over N FL and off the Southeast coast, a product of a WSW upper jet from E NC offshore. The approach of the mid level wave will further lower surface pressures late, with fairly rapid cyclogenesis anticipated late tonight just off Hilton Head SC. The strengthening flow between this low and the surface high shifting E off the Northeast coast will draw increasing moisture and deepening moist upglide into SE and extreme S sections of the forecast area late, although the initially dry subcloud layer (current dewpoints in the teens to lower 20s) will greatly reduce amounts, particularly at the onset. Regarding precip type, given the initial dry air evident both in the low levels and in the 700-600 mb depth, the strengthening dynamic lift will foster wet bulbing of the profile, although it remains to be seen if this will be enough to totally overcome the dry near-surface air, especially well inland beneath the lingering narrow surface ridge. If so, wet bulbs both at the surface and just aloft support a potential for a little rain/wet snow mix in the far SW Piedmont late tonight. But the latest RAP guidance shows the surface wet bulb rising just above freezing as the profile zippers down, along with a warm nose aloft near 5C, both of which would not be conducive for much wintry precip. Plus, latest 4" soil temps are no cooler than 45-50F across our area, and today`s insolation with a warm early-April sun will likely make the skin temps too warm for any accumulation. Will include a small chance of rain/snow mix in the far SW Piedmont late tonight, with a chance of just rain across the rest of the S, following consensus of model timing. Skies will trend mostly cloudy to cloudy SSE to NNW through tonight, with lows in the lower to mid 30s. No freeze products tonight, as any 32F readings in the far N will likely last only briefly. -GIH && .SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/... As of 325 PM Monday... The models are not in perfect agreement on the precip pattern and amounts with the low moving up the Carolina coast and related mid and upper level forcing for ascent, but they`re in a lot better agreement than yesterday`s runs. Will have categorical pops over roughly the SE half, tapering to mid range chance pops in the NW Piedmont. Forecast soundings in this area indicate a possible light rain/snow mix at onset over the Triad region/Yadkin Valley for a few hours in the morning. As noted above, the skin and soil temps should greatly limit the accumulation potential, but the warm nose aloft may be a bit less prominent and cooler that far NW, bolstering the wintry weather concern. Will continue to refrain from mentioning any accumulation at this time, but will closely monitor trends of observations and high res guidance, along with surface wet bulb trends as we head into Tue, as the circulation around the low keeps drawing the cooler/drier air into NW sections. The mid level shortwave trough will take on a negative tilt and will likely deepen further as it swings NE through the Carolinas, prompting further strengthening of the surface low and a westward expansion of moisture advection N and NW of the low. Expect categorical pops E, within increasing and gusty surface winds due to the tightening MSLP gradient, tapering to chance far W, lasting well into the afternoon. Modified surface high pressure will build in from the SW late in the day and through Tue night as the surface low heads offshore with increasing low level NW flow over central NC, so expect a W to E end to precip and a clearing trend Tue evening and night. After highs Tue in the mid 40s to lower 50s (near to within a couple degrees of record low maxes for the date), expect lows Tue night in the lower to mid 30s, which may prompt another freeze product for a portion of the forecast area. -GIH && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... As of 335 PM Monday... The long term will be characterized by above normal temperatures and a chance of precipitation Friday into Saturday. The latest runs of the GEFS, GEPS, and EPS are in high agreement showing above normal height anomalies (approaching 15 dam) starting Thursday and continuing through the remainder of the extended. These type of height anomalies will easily support temperatures 10 to 15 degrees above normal for this time of year. Wednesday morning surface high pressure will be centered near Charleston, SC and slowly drift east offshore. Dry weather will be in store for the area Wednesday into Thursday as the upper level disturbance continues to rotate northeast and the corresponding surface high moves offshore. During the day Thursday 500 mb heights begin to surge with 850 mb temperatures rising to around 6 degrees C. This will easily allow highs to rise into the 70s. Thursday night into Friday morning a weak upper level disturbance will approach the area from the west. The ECMWF and GFS continue to advertise slight differences with the wave. The GFS has a stronger wave across the Great Lakes with very weak PVA washing over central North Carolina. The ECMWF on the other hand as a weaker wave across the Great Lakes, but a slightly stronger wave over central North Carolina (the PV is more compacted). The ECMWF solution generates a surface low off the North Carolina coast while the GFS only shows a very weak surface reflection. Not surprisingly, the ECMWF has higher QPF totals Friday into Saturday than the GFS. The CMC resembles more of the ECMWF solution. Either way, the chance for precipitation looks likely Friday into Saturday. Forecast soundings are also looking much more promising at this time for the chance of thunder. For now have left the mention out. The slightly stronger amplification of the CMC and ECMWF solutions brings a cold front temporarily into the northern zones Friday morning. If this trend ends up continuing temperatures will have to be lowered Friday/ Saturday. On the back side of the wave weak subsidence will take hold with the surface front washing out. The ECMWF and GFS show weak showers still possible on the back side though thanks to the stalled boundary. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/... As of 840 PM Monday... 24 Hour TAF Period: VFR conditions are expected to continue this evening into the early morning hours of Tuesday. However, a developing area of low pressure off the coast of GA/FL and S SC later tonight will track NE along the Carolina coast Tue, spreading precipitation to its N and W starting around daybreak in southern portions of central NC, while the low level flow from the ENE ahead of this low draws increasing low level moisture into the area. The rain will spread north/northeastward Tuesday morning into the afternoon, before shifting to the east/northeast of the area by late afternoon/evening. Snow may mix with the rain at KGSO/KINT during the morning as well. Otherwise, expect increasing cloud cover this evening into early Tuesday morning. Winds will also increase as the surface low approaches and strengthens on Tuesday, with gust of up to 20 to 25 kts possible for the eastern TAF sites (KFAY/KRWI/RDU). Outlook: Any sub-VFR conditions will end W to E between 21z and 03z as the coastal low tracks NE and away from NC, leaving VFR conditions as high pressure builds in from the SW. VFR conditions will hold through Thu. Our next storm system moving in from the W will bring a chance of showers and sub-VFR conditions Thu night and Fri, perhaps lasting into early Sat morning. && .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Hartfield NEAR TERM...Ellis/Hartfield SHORT TERM...Hartfield LONG TERM...Haines AVIATION...BSD/Hartfield
Area Forecast Discussion
National Weather Service Reno NV
749 PM PDT Mon Apr 1 2019 .UPDATE... Increasing upper level divergence due to a jet nudging into northern California/Nevada is helping to bring widespread rain and high elevation snow to the region. This is producing higher liquid totals than previously anticipated, therefore have adjusted the forecast to better line up with latest radar trends and HRRR guidance. Anticipate precipitation chances through the night, becoming more showery by morning. Snow levels will be above 7500 feet much of the night, but could briefly fall in heavier precipitation bands. By daybreak, snow could be sticking down to around 6500-7000 feet, with minor accumulations impacting travel along Sierra passes. -Dawn && .PREVIOUS DISCUSSION... /Issued 210 PM PDT Mon Apr 1 2019/ SYNOPSIS... Occasional showers and gusty winds are forecast through this week as weak to moderate spring storms impact the region. The wettest periods look to be tonight through Tuesday, and again Friday night. Temperatures will be generally near early April averages, with some warming possible later this weekend into early next week. SHORT TERM... No major changes were made to the short term forecast, although we increased precip chances and amounts tonight-Tuesday for much of west central NV, generally near and east of US-95. Daytime temperatures near early April averages are projected for the next few days. An early spring storm system moving inland near the CA-Oregon border will bring increased moisture to much of eastern CA-western NV tonight and Tuesday. While for the Sierra the precip amounts don`t look too spectacular, for west central NV there is some good agreement among much of the guidance for a couple waves of moisture bringing periods of steady light-moderate rain this evening through Tuesday morning. Then by Tuesday afternoon, increasing instability associated with the negatively tilted trough could lead to a few thunderstorms producing brief heavy rainfall or snow pellets. While isolated lightning strikes are possible across any portion of eastern CA-western NV, the best chances for thunder favor west central NV including Lovelock, Fallon and Hawthorne. Precip totals look to range from 0.10-0.25" for the urban corridor of western NV southward along US-395 to Mono County, but heavier amounts between 0.25-0.50" (locally up to 0.75") are likely from US-95 eastward, and also for the Sierra northward into western Lassen County. Snow impacts will be limited to higher elevations as snow levels generally settle between 7000-7500 feet later tonight into Tuesday. Impacts would mainly be wet roadways and perhaps some light slushy accumulations on higher passes. A few inches of snow are expected for the higher elevations of the Sierra and Carson Range, with isolated amounts around 8" near the crest. Periods of breezy winds are expected with gusts 30-35 mph Tuesday afternoon and evening. The widespread cloud cover should limit wind duration, and although some moderate chop is likely on the main lakes, overall conditions look to be just below lake wind advisory criteria. For Wednesday, dry weather prevails as a shortwave ridge moves across CA-NV, with the only possible exception being a few very light showers brushing across northeast CA. The next weather system for Thursday-Thursday night looks weaker compared to the system for tonight-Tuesday, with light rain and high elevation snow showers mainly for northeast CA and near the Sierra. Precip amounts look to be 0.10" or less, except for up to 0.25" possible for parts of northeast CA. For western NV, only trace amounts to a couple hundredths of an inch are expected. Snow levels will generally range from 6500-7000 feet, but accumulations will be sparse due to most of the shower activity occurring in the afternoon. MJD LONG TERM...Friday through Monday... The story for the extended remains largely the same: decent spring storm for Friday afternoon into Saturday morning with typical impacts including gusty winds, high elevation snow, and valley rain showers. Plan for impacts to the Sierra passes if you have travel plans! The rest of the week into next week still holds a bit of a question mark, but a warm up could be on tap with the potential for increased snowmelt. Friday-Saturday Storm: Friday morning will still feature a bit of a break in the precipitation, but gusty winds will impact the foothills and mountain areas ahead of the next storm. The main portion of the storm will push into the Sierra and western Nevada late Friday afternoon through early Saturday morning. Gusty winds will increase in the upper terrain and foothills early afternoon, and will mix down to the lower valleys later in the day. Gusty winds between 35 to 45 mph will be possible, but the latest GFS soundings for Friday afternoon do show the potential for some downslope enhancement. With the strong jet pushing into northern CA/NV, there may be aviation impacts including wind shear, mountain waves, and turbulence. Timing of the heaviest precipitation will likely occur in the northern Sierra Friday evening and overnight. Snow levels start above 6500-7000 feet, then fall to 6000-6500 feet by late Saturday morning. Latest simulations continue to show the snow levels dropping after the bulk of the precipitation has pushed through, which should limit snow accumulations to higher terrain of the northern Sierra and northeast California. Liquid totals range from 0.50" to up to 2" along the crest with the lower values across the southern Sierra. A third of an inch will be possible in far western Nevada and the lower valleys of northeast California; with lesser amounts forecast in the Basin and Range. Beyond Saturday the simulations aren`t in outstanding agreement, but the weather pattern still looks unsettled. The GFS is still attempting to build a shortwave ridge across the region, but the ECMWF keeps precipitation chances across the northern portion of the area through at least Sunday. -Edan AVIATION... A series of disturbances are on track to affect area terminals today through Thursday, with the possibility of another system affecting the forecast area Friday through this upcoming weekend. Rain and high mountain snow are likely tonight and Tuesday across much of eastern CA-western NV. Expect conditions to deteriorate through this evening, with MVFR conditions expected at Sierra terminals becoming MVFR/IFR early Tuesday morning as ceilings and visibility begin to lower. Conditions at western Nevada terminals will mainly remain VFR through this evening, becoming MVFR at times late tonight-Tuesday morning, with periods of moderate rainfall mainly for parts of west central NV. Snow levels will likely remain above 6500-7000 feet, therefore no accumulating snow is expected at either KTVL or KTRK. However, light snow may accumulate at KMMH by early Tuesday morning. For Tuesday, breezy surface winds can be expected with gusts of 30-35 mph possible east of the Sierra. An area of instability may develop east of the Sierra, where isolated thunderstorms could develop. Brief heavy rains and a few lightning strikes may occur with these cells. A break will occur Wednesday before the next system affects our region Thursday through Friday. Increased winds along with possible low level wind shear and turbulence are likely Friday. -Johnston && .REV Watches/Warnings/Advisories... NV...None. CA...None. && $$ For more information from the National Weather Service visit...
Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
808 PM MDT Mon Apr 1 2019 .UPDATE... Issued at 806 PM MDT Mon Apr 1 2019 Short wave and associated showers over northeast MT have some chance of crossing our northwest SD zones after midnight, so have added pops for that area. Rest of forecast largely unchanged. && .DISCUSSION...(This Evening Through Monday) Issued at 235 PM MDT Mon Apr 1 2019 The latest water vapor images and RAP analysis indicated an upper trough over the CWA in northwest flow, while one short-wave trough was over the eastern CWA and another short-wave trough was moving southeast across central MT. The lead trough was producing mostly snow that has brought a few to several inches across a narrow swath from roughly K2WX to KPHP. This wave should exit to the east this evening with snow/rain coming to an end. Otherwise, steep (7-7.5 C/km) midlevel lapse rates and the upstream wave will allow for scattered snow/rain to move across most of the rest of the CWA through early evening, with perhaps isolated thunder over northeastern WY. This too should come to an end by 06z. On Tuesday the flow aloft will be northwesterly and confluent while an upper trough moves over the western CONUS. The net result should be dry weather, but with some increasing clouds over the southwest ahead of the next trough in the weak warm advection regime. Tuesday night and Wednesday an upper low will move across AZ/UT and then across the TX/OK panhandles to eastern OK by 12z Thursday. The overall forcing for ascent looks weak over the CWA as upper divergence, Q-vector convergence, and isentropic lift will be minimal. Some frontogenesis is progged over the far southern CWA, but midlevel lapse rates only look to be 5-5.5 C/km (much less than today). Flow aloft also will remain confluent Tuesday night, with westerly flow on Wednesday. The net result will be modest lift with relatively minor snow/rain accumulations--highest near the Nebraska border. Ridging will ensue Thursday as an upper trough moves from MT to ND during the day. Low-level temperatures should really shoot up Thursday afternoon with above-average temperatures through the weekend. A broad upper trough will reach MT/WY on Saturday, passing through the CWA overnight. This may bring scattered showers and a few thunderstorms to the area. && .AVIATION...(For the 00Z TAFS Through 00Z Tuesday Evening) Issued At 518 PM MDT Mon Apr 1 2019 Isolated convective rain showers across portions of SW SD will wane after 00-03Z tonight. These showers and low clouds will produce transient MVFR conditions, mainly across SW SD and central SD. Otherwise, VFR conditions will prevail through the forecast period. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...None. WY...None. && $$ Update...Johnson DISCUSSION...Bunkers AVIATION...Eagan