Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 08/17/18

Area Forecast Discussion
National Weather Service Albany NY
1054 PM EDT Thu Aug 16 2018 .SYNOPSIS... A warm front and a disturbance ahead of a cold front will bring showers and thunderstorms back into the region late tonight through tomorrow. In addition, rainfall could be locally heavy due to high moisture content in the atmosphere. The last in the series of the these fronts moves across Saturday as a cold front. This will end the showers and thunderstorms from north to south and leave behind a mainly drier and calmer weather pattern for the second half of the weekend. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... As of 1054 PM EDT...The latest observational and 3-km HRRR and Namnest trends continues to show a slower progression of the showers and isolated thunderstorms moving into the ALY forecast area ahead of the warm front to sfc low near the Upper MS River Valley and the Upper Midwest. The boundary will be a focus for increasing showers and isolated thunderstorms overnight. We decreased the timing to 2-5 am west of the Hudson River Valley, and then expanding eastward between 5-8 am. The latest 00Z NAM indicates elevated instability with Showalter values of 0 to -2C. The low-level jet increases from the south to southwest transporting some subtropical moisture into the region towards daybreak. The 00Z PWAT on the KALY sounding is 1.25" so it will take a little bit of time to moisten the low- levels with the dry air aloft due the low and mid level ridge hanging tough. We also may get some radiative mist/fog over the Lake George Region, CT River Valley into the Berkshires before the mid and high clouds increase. We added patchy fog to the forecast in these areas. It will be another mild night with lows in the 60s to around 70F across the region. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/... Slight Risk with both severe weather and excessive rainfall outlooks on Friday into Friday night... Complex pattern setting up for the region on Friday as much will depend on insolation and training echoes. As has been mentioned in several excellent discussions the past several shifts, large scale positive tilted trough axis along with the surface wave reflection will be approaching from the central Great Lakes and Ohio Valley. The warm front is expected to lift northward during the morning with elevated convection accompanying its passage. Thereafter, PWATs climb toward or above 2 inches as low level jet magnitudes and PWAT anomalies climb toward 2 standard deviations above normal. While heavy rainfall threat will remain, areas to the west and southwest of Albany will be the most susceptible for flooding concerns due to antecedent wet conditions the past several days. Otherwise, MBE speeds of 10kts or less could result in training echoes across the region. Hence the excessive rainfall outlook will be upgraded to slight risk for most of eastern NY. As for severe potential, SPC has upgraded most of our region into slight risk with the day 2 outlook. The main consideration here will be how much insolation we will receive after the warm front lifts north. Based on satellite imagery upstream, there is considerable cloud coverage at the present time as mid level lapse rates were near moist adiabatic. HREF and CAMS members vary significantly to where the best instability axis will occur and convective modes/trends. While lapse rates are not too ideal, given low LCL`s and increase instability with modest shear profiles, several multi- cells and some bows are possible. An isolated tornado risk may evolve for the Hudson River Valley locations where low level channeling and veering profiles in the lowest 1km could result in a couple supercell structures which again will be highly dependent on sunshine. Temperatures Friday should be able to tap out into the lower 80s for valley locations and well into the 70s elsewhere with dewpoints near 70F as well. The region remains well embedded in the warm and moist sector Friday night with additional convection and heavy rainfall. As overall instability does wane, shear remains in place as well as those high moisture content with PWATs near 2 inches. So additional heavy rainfall threat will continue as we remain warm and muggy once again. The cold front is expected to move from north to south through the day Saturday. There is excellent agreement between the global and hires models that this front should clear our southern zones close to 00Z Sunday. So we will have a graduated PoPs in the forecast with showers lingering along and south of I90 for most of the day. Dewpoints will drop back into the upper 50s across the Dacks and Lake George Region later in the day which will slowly advect southward heading into Saturday night. && .LONG TERM /SUNDAY THROUGH THURSDAY/... The weather will be dry at both the beginning and end of the period, with rain in between. High pressure will dominate the first 48 hours. This will give in to an area of low pressure which will track from lower Michigan to southern Quebec Tuesday and Tuesday night. Rainfall could be significant Tuesday night, but things zip through as the stagnant pattern of mid-summer finally begins to change. The cold front associated with this system is expected to slide east across our forecast area Tuesday night into early Wednesday. This will be replaced by a broadening dome of high pressure...centered over the Ohio Valley early Thursday, resulting in comfortable conditions with lowering humidities, increasing daytime sunshine, and temperatures that are near or slightly below normal with little day-to-day variation. High temperatures prior to the frontal passage will range from the upper 60s to upper 70s each day...and thereafter...from the mid 60s to lower 80s. Overnight lows initially will be in the mid 50s to lower 60s, with a brief pre-frontal boost of a few degrees Tuesday night, then back around the 50 to 60 degree range for Wednesday night. && .AVIATION /03Z FRIDAY THROUGH TUESDAY/... High pressure that briefly ridged in today will shift eastward, as the weak cold front lifts north as a warm front overnight into tomorrow. A prefrontal trough and a cold front will focus showers and thunderstorms tomorrow afternoon into the evening period. VFR conditions are expected prior to midnight with just scattered to broken cirrus. The mostly clear skies, and calm winds will allow for some radiational mist or fog to form. The favored climatological fog sites of KGFL/KPSF have the best chance of IFR vsbys between 04Z-09Z/FRI. Some MVFR mist is possible at KALB/KPOU, but then the mid and high clouds will increase. The isentropic lift with the warm front will focus some showers and elevated thunderstorms. PROB30 groups were used at KGFL/KALB between 09Z-13Z and 10Z-15Z. The threat expands eastward into KPSF/KPOU between 12Z-16Z. Conditions will lower to MVFR/IFR levels in the showers and thunderstorms. Another round of showers and thunderstorms, some of which could be strong to severe are possible between 18Z/FRI to 00Z/SAT. IFR/MVFR conditions are possible in the thunderstorms. Later TAF issuances will have to pinpoint the timing for the thunderstorms. PROB30 groups were used for now. Conditions in terms of cigs will likely be VFR/high MVFR ahead of the showers and thunderstorms. The winds will be light to calm tonight, and then increase from the south to southeast at 5-10 kts in the late morning into the afternoon. KALB due to funneling up the Hudson River Valley could be a little breezier with southerly winds of 10-12 kts with a few gusts approaching 20 kts in the afternoon. 0utlook... Friday Night: High Operational Impact. Likely SHRA...TSRA. Saturday: Moderate Operational Impact. Chance of SHRA. Saturday Night to Tuesday: No Operational Impact. NO SIG WX. && .FIRE WEATHER... Minimal to no fire weather related concerns as higher moisture content will advect into the region tonight with showers and thunderstorms increasing late tonight and through most of Friday. Rainfall could be locally heavy. This will keep relative humidity values elevated through at least Saturday. Conditions dry out Saturday night and into Sunday. && .HYDROLOGY... Slight Risk of Excessive Rainfall across most of eastern New York into Friday... Showers and thunderstorms will be on the increase overnight and into Friday. Combine that with higher moisture content will potentially result in heavy rainfall and training thunderstorms. Portions to the west and southwest of Albany have higher antecedent conditions with wet soils compared to the Adirondacks and portions of the southern Greens. However, convection with heavy rainfall can quickly change those drier areas as we will continue to monitor trends closely. Flash flood guidance across portions of the Mohawk Valley, Schoharie Valley and Catskills are generally between 1.5-2.5 inches within 1-3 hours respectfully. The values are a bit higher to the east of those areas. Per coordination , if confidence levels increase then Flash Flood Watches would be needed. Showers will linger into Saturday, before high pressure builds in with a dry stretch of weather expected for Sunday into early next week. For details on specific area rivers and lakes, including observed and forecast river stages and lake elevations, please visit the Advanced Hydrologic Prediction Service /AHPS/ graphs on our website. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. MA...None. VT...None. && $$ SYNOPSIS...BGM/Wasula NEAR TERM...Wasula SHORT TERM...BGM LONG TERM...ELH AVIATION...Wasula FIRE WEATHER...BGM/JPV HYDROLOGY...BGM/JPV
Area Forecast Discussion
National Weather Service Bismarck ND
909 PM CDT Thu Aug 16 2018 .UPDATE... Issued at 908 PM CDT Thu Aug 16 2018 No major changes required for this update. UPDATE Issued at 545 PM CDT Thu Aug 16 2018 Increased smoke coverage and duration with this update. A rather pronounced area of smoke is encompassing the northern half of North Dakota this evening as seen on satellite and web cameras. The mid/upper level flow pattern and latest run of the HRRR smoke model indicate smoke will likely remain through the day tomorrow and maybe even into the weekend. && .SHORT TERM...(This evening through Friday) Issued at 321 PM CDT Thu Aug 16 2018 The challenge with the short term is how far south the smoke will shift out of Canada. Current satellite observations show smoke entering northern North Dakota this afternoon. Current visibilities in southern Manitoba and Saskatchewan are ranging between 4 to 6 SM. HRRR Near-Surface smoke model guidance suggests this plume of smoke will continue to push south throughout the rest of the afternoon into tonight. The current forecast has northwestern and north central North Dakota with patchy smoke now through the overnight hours. Will need to continue to monitor to see how far south the smoke shifts throughout the afternoon and overnight. An upper level ridge builds over eastern Montana and western North Dakota Thursday night into Friday, bringing sunny skies and temperatures in the upper 80s to mid 90s on Friday. .LONG TERM...(Friday night through Thursday) Issued at 321 PM CDT Thu Aug 16 2018 Chances for showers and thunderstorms Saturday night and Sunday highlight the extended forecast. The upper level ridge remains in place Friday night into early Saturday, allowing temperatures to rise into the low 90s. A shortwave and attendant surface cold front break up this upper level ridge, passing through North Dakota Saturday night into Sunday. This will bring chances for widespread showers and thunderstorms to the area. A few strong to severe thunderstorms are possible, mainly in southern North Dakota given moderate MUCAPE (2000 J/Kg) and weak bulk shear (20 kts). Behind the cold front, a stable and cooler air mass moves in Sunday as showers and a few thunderstorms linger across the area. Highs are expected to only be in the 70s Sunday through Tuesday. A shortwave passes through the area on Monday, bringing a chance of showers to the far western part of North Dakota. Temperatures will rise back into the 80s and lower 90s by midweek. Another shortwave is possible Thursday that could bring thunderstorms to the northern part of the state. && .AVIATION...(For the 00Z TAFS through 00Z Friday evening) Issued at 545 PM CDT Thu Aug 16 2018 Aside from the smoke, VFR conditions are expected with light and variable winds becoming southerly near 10 kts by Friday afternoon. Visible satellite imagery shows smoke settling in across northern North Dakota. Surface visibilities have not been reduced much yet. However, widespread MVFR visibilities have been observed across much of central and southern Saskatchewan so far today. While this thicker smoke may be transported into North Dakota later today and tonight, confidence on MVFR visibility at KISN and KMOT is not high enough to include at this time. A period of MVFR visibility may need to be added in future TAF issuances. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...AJ SHORT TERM...BRM/Hollan LONG TERM...BRM/Hollan AVIATION...AJ
Area Forecast Discussion
National Weather Service State College PA
1102 PM EDT Thu Aug 16 2018 .SYNOPSIS... A weakening cold front will push through the area Friday. A secondary cold front will move across the state Saturday followed by slightly cooler air and more comfortable humidity for the second half of the upcoming weekend. && .NEAR TERM /UNTIL 7 AM FRIDAY MORNING/... Disorderly and barely noteable convection roaming around the region right now, as earlier storms have dissipated. A fight between NVA aloft and sfc convergence is occurring over NW PA, NE OH at this time. Result: Numerous showers but little organization. A cluster of showers in central WV is slated to arrive in the Scent mtns before sunrise, but time of day argues for the showers to remain garden variety and sct at worst. The QPF for the NW third of the area from almost all guidance seems overdone overnight. The newest NAM seems to have a decent trend, with mainly sct shra and only light qpf thru the night over the NW half of the area. The next influx of decent organization may come with the forcing over the OH/IN border. That should arrive just after sunrise in the west. Prev... Multiple clusters of storms rolling across the area. None seeming particularly dangerous but some are exhibiting a tendency to hold a good reflectivity core aloft for a short time. Rainfall is briefly heavy, but most top out in the 0.5-0.75" max per hour. Main changes with this update were to refine PoPs in the period. There should be a short lull behind this current shortwave trough/vort max over the west, then perhaps a resurgence of the storms -mainly in the NW- as the next upper forcing rolls in along with a bit of an increase in 8H wind. But, that forcing wanes by morning. Much of the night looks dry in the SErn few counties, but a stray shower cannot be ruled out. Prev... Satellite is showing a gradual increase in mid and high cloudiness out ahead of a shearing shortwave moving out of the OH Valley. The first small cells are starting to break out from just west of IPT back to Elk County. The latest HRRR shows the most organized showers and scattered thunderstorms spreading across the NW portion of the CWA after 22Z/6PM this evening. All Hi-Res CAMS and other regional scale models keep the SE third to half of our CWA dry through most or all of this afternoon and tonight. Ensembles confine the best surge in PWATs up into my NWRN zones this evening and overnight. This is also where they paint the highest probs of seeing a quarter inch of rain or more through Friday morning. This implies the showers over central and eastern areas will be more scattered in nature. The HRRR supports this, keeping the bulk of its rain along or north of I-80. Overnight lows will be well above normal ranging from the mid 60s over the north to lower 70s over the SE. && .SHORT TERM /7 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/... The axis of high PWAT air will slide across the NW portions of PA and the Laurel Highlands during the morning hours Friday. The close proximity of this feature and approach of one or more weak mid/upper short waves embedded in the SW flow aloft will maintain the chances for intermittent showers and scattered thunderstorms. For Friday afternoon, the weakening remnants of the surface cold front are made to hang up over central or eastern PA. Models are generous in creating a fair amount of CAPE in the humid airmass so expect an uptick in thunderstorm activity during the afternoon into the evening. SPC has the area under a Marginal Risk for severe storms which looks reasonable. Damaging wind gusts will be the main threat mainly along/east of the Susquehanna River. Saturated ground will make it easier for gusty storms to topple trees and cause power outages. In addition, with many areas experiencing record or near record summer rainfall totals, more heavy downpours will pose an isolated risk of localized flooding. && .LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/... Leftover convection should generally decrease in coverage and intensity Friday night. Models show the best chance for lingering showers/storms over the western Alleghenies. A trailing frontal wave of low pressure will likely bring another round of showers/storms across the southern 1/2 to 1/3 of central PA during the day on Saturday. Above-normal moisture (PW) pooling along the east-west boundary will support risk for heavy downpours/marginal risk of flash flooding. Latest model trends have remained supportive of an increase in precip probs into Saturday night with some north-to-south clearing expected by early Sunday. We are still favoring mainly dry weather Sunday into Monday. However, the 16/12Z ECMWF is less optimistic on Sunday over the southern tier of central PA. A spotty/isolated P.M. shower or t-storm is possible on Monday over the southern Alleghenies, as south/southeast flow brings increasing moisture back into the area. Models and ensemble continue to track a mature cyclone through the Great Lakes early next week. The well-defined trailing cold front will trigger T-storms as it crosses the Alleghenies Tuesday into Tuesday night. A severe storm and heavy rain/flash flooding risk may accompany the frontal passage before a push of drier air delivers a possible stretch of rain-free days later next week. PoPs were increased by 10% or so on Tuesday based on a multi-model/ensemble blend. && .AVIATION /03Z FRIDAY THROUGH TUESDAY/... Isolated showers about all that is left as of 11 PM. Main issue later will be some fog. Earlier discussion below. Storms fell apart just south of State College at 5 PM. However, typical of this summer, activity has picked up again after sunset, mainly in the State College area. TAFS updated for the activity. Main issue late will be some fog. For Friday, went with VCSH for now. Some improvement possible for the weekend, mainly across the north on Sunday. .Outlook... Fri...Cold front will bring more numerous showers/tstms areawide with local restrictions. Sat...Still a chance of showers and storms, mainly across the south early on. Sun-Mon...Mainly VFR. Tue...Restrictions developing with showers and thunderstorms. && .CTP WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Dangelo/La Corte NEAR TERM...Dangelo/La Corte SHORT TERM...La Corte LONG TERM...Steinbugl AVIATION...Martin
National Weather Service Jackson KY
1045 PM EDT Thu Aug 16 2018 .UPDATE... Issued at 1045 PM EDT THU AUG 16 2018 Did a quick update to the grids to handle the near term radar and sky cover trends as well as the latest CAMs guidance through the rest of the night. Will be on the lookout for heavy rain potential in the Bluegrass area later tonight where training could become a concern by dawn. Otherwise, have updated the grids through morning with the inclusion of T/Td obs and trends. These have been sent to the NDFD and web servers. An updated ZFP will hit the streets shortly as well. UPDATE Issued at 735 PM EDT THU AUG 16 2018 23z sfc analysis shows low pressure off to the northwest of the area with the local pressure field overwhelmed by the meso high associated with the early storms that progressed through the area over the past few hours. These have mostly dissipated to just light showers and sprinkles with the last cell near LOZ weakening rapidly. The latest HRRR and other CAMs indicate that the rest of the evening into the first part of the overnight will be rather quiet before another round of convection is expected to develop to the west or overhead towards dawn. Have depicted this in the grids going forward through dawn with this update. Did also add in some moderate fog in the river valleys after midnight as the clouds thin over the area and some radiational cooling will be possible. The cooling will be limited by the high dewpoint air in place with current obs in the upper 60s to lower 70s. Meanwhile, temperatures are in the low to mid 70s while winds, away from any convection, are generally light from the southwest. Have also updated the grids to add in the latest obs and trends for the T/Td ones. These grids have been sent to the NDFD and web servers. An update to the HWO and zones will be forthcoming once the last of the convection fades. && .SHORT TERM...(This evening through Friday night) Issued at 415 EDT THU AUG 16 2018 Current conditions across the area feature a swath of showers and embedded showers and thunderstorms crossing the I-75 corridor this hour along with a few discrete pop up cells ahead of the swath moving eastward as well. Relatively rain free area over the eastern portion of the area has resulted in some instability developing and this is seen on the current radar returns as some strong cells have developed and will be moving through the area into this evening. Model soundings suggest good instability lingering into the overnight hours as the cold front to the northwest slowly tracks into Kentucky. Due to this, will expect convection lasting across eastern Kentucky past 00z. Cams do suggest a brief break this evening into early tonight before convection reinvigorates later tonight into tomorrow as the front approaches the area. In fact, there may be some fog development in the valleys if there is any clearing behind the first swath of showers and thunderstorms. Heading into the day on Friday, PWATs will remain in the 1.75 to 2.00 inch range through the day. With the amount of moisture and skinny CAPE shown by the model soundings, the threat of flooding will continue through the day and into Friday night. From the activity today, guidance will take a hit, especially the basins in the south. Thus flooding concerns will something that needs to be monitored, especially cells that begin to train over the same area. Model soundings and CAMs suggests that precip chances will linger into the Friday night period as well. This is in agreement as well with operational models as the front will eventually stall over the eastern portion of the state leading into the Friday night hours. .LONG TERM...(Saturday through Thursday) Issued at 350 PM EDT THU AUG 16 2018 The majority of the long term will feature a continued dynamic pattern. A shortwave trough will make its way through the Ohio Valley this weekend. A brief period of drier conditions will occur early Monday due to a weak upper level ridge. Then, a deep upper level trough will progress over the Ohio Valley through Wednesday before moving to the northeast Thursday. At the surface, a slow moving front will bring daily chances of showers and thunderstorms through the weekend. A brief lull in precip will occur early Monday, then a warm front associated with a low pressure system located in the Central Plains will bring increased chances for showers and thunderstorms Monday afternoon and evening. As the low pressure system moves northeast over the Great Lakes Tuesday, a cold front will advance towards the Commonwealth. Shower and thunderstorm potential will increase with the passage of this cold front through mid week. Drier conditions will return to eastern Kentucky Thursday as a surface high pressure builds over the region. Overall, the models are in fairly good agreement and therefore, did not stray too far from the Blend beyond some minor adjustments. Through Tuesday, high temperatures will be in the low to mid 80s with low temps generally in the mid to upper 60s. Frontal passage on Wednesday will cool down temperatures to be around 60 degrees in the morning with highs only reaching the upper 70s. Highs will increase slightly to be in the low 80s to round out the long term period && .AVIATION...(For the 00Z TAFS through 00Z Friday evening) ISSUED AT 800 PM EDT THU AUG 16 2018 Current radar trends are showing the limited convection fading out and drifting east this evening. Expect a lull in activity through the first part of the night per the CAMs before addition showers and some thunderstorms develop over the area or just to the west in the pre-dawn hours. Valley fog can be expected late tonight but likely having limited impact on the TAF sites. The better potential for thunderstorms will come Friday morning and into the afternoon as the cold front moves closer towards the state. VCTS and a period of prevailing TSRA are mentioned for each TAF site with the exception of SJS since the better threat for any thunderstorm activity at this site may occur late in the period, if at all. Visibility will also lower to at least MVFR conditions in thunderstorms and CIGs may touch on MVFR, for a time. Winds will generally be out of the southwest at around 5 knots, but be higher in and near thunderstorms. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...GREIF SHORT TERM...SHALLENBERGER LONG TERM...CGAL AVIATION...GREIF
Area Forecast Discussion
National Weather Service Louisville KY
900 PM EDT Thu Aug 16 2018 .Forecast Update... Issued at 900 PM EDT Thu Aug 16 2018 Convection this evening has been rather weak, but seems to be best organized north of the river from northern Harrison into Jefferson counties in southern Indiana. Further south, convection has been rather sparse with a few pop up showers here and there. Activity has increased slightly over the last half hour or so. Latest HRRR runs continue to show convection redeveloping this evening, in areas mainly east of the I-65 corridor. Have gone ahead and bumped up PoPs a bit to bring them up faster in time than previously. In general, we believe that scattered convection will be most likely over our southern IN and east-central KY locations through the overnight. Severe weather doesn`t look likely given the weak-mid level lapse rates and being near the nocturnal instability minimum. However, the low-level jet and isentropic lift will help offset things to keep convection going. Further west, sharp upper trough axis will pivot in from the northwest. HRRR has a decent handle on the convection over northern MO and west-central IL. This activity is expected to continue to develop overnight and then spread southeastward into southern IN and central KY towards dawn Friday. This will likely result in another wet AM commute for many areas with heavy rain being possible. Organized severe weather doesn`t look likely with this activity. Heavy rainfall appears the be the main hazard which may result in a renewed flooding threat for our southern IN and far northern KY counties. Issued at 729 PM EDT Thu Aug 16 2018 Did a quick update to lower PoPs and sky cover across the region with the departure of earlier convection. Latest HRRR runs suggest that convection will refire over southern IN and north-central KY in the next few hours. GOES-16 visible imagery does show an agitated Cu field developing a few showers have sprouted across southern IN and in portions of northern KY (north of the Parkways). Mesoanalysis does show some increase in instability due to the late day heating. CAPE values are in the 1000-1300 J/Kg with very weak bulk shear values. Low level lapse rates are OK at 6-7 C/km though the mid- level lapse rates are much weaker. Current thinking is that we`ll see some weak convection continue to develop and utilize the available instability. Question is how strong/widespread could this activity become. Best chances look to be north of the Parkways in KY through the evening hours. A secondary round of convection looks to swing in here late tonight. Will get into the details of that in a later update. && .Short Term...(This evening through Friday) Issued at 305 PM EDT Thu Aug 16 2018 ...Round 1 of storms pushing east... ...Convective uncertainty late tonight into Friday.... Well...The widespread advertised rain event is pushing east of the I- 75 corridor except for southern extent of the convection along KY/TN border where some cloud top temps of -62C exist. The Lake Cumberland counties will have to be watched for any localized heavy rain issues. The sun is peeking out west of I-65 which will allow some afternoon mixing and get SW winds to gust to 15-20 mph through sunset. After a lull in precip over most of the region tonight, muggy conditions will continue with dewpoints hovering in the lower 70s. There could be spotty showers/storms but for now we appear to be in a lull... although the latest HRRR keeps sct convection with afternoon heating over IL/W KY and moves east. With no widespread additional convection expected in the near term, will let the Flash Flood Watch expire on schedule at 20 UTC (4 pm EDT). Next on the horizon, we await the vigorous next vort max. A fairly stout upper low will dive out of the SD/NE/IA border and be the trigger for more convection towards daybreak tonight from the Show Me State eastward. PWATs will remain high so we will need to watch radar and KY Mesonet precip trends late tonight and Friday. Around 12z the rain showers and storms will spread farther south and east into central and eastern Kentucky. SPC Day 2 seems reasonable with a marginal risk for isolated wind potential. Temperatures will stay mild overnight in the lower to mid 70s and may struggle again with rain and cloud cover. My plan is to lower highs to around 80 except down in southern KY where mid 80s looks good with mid and late day sun. .Long Term...(Friday night through Thursday) Issued at 305 PM EDT Thu Aug 16 2018 ...Very transitory with some active weather expected during the extended forecast period... Friday night and Saturday... Shortwave trough aloft will progress slowly across the Ohio Valley during the period. At the same time, a weak surface boundary will sag southeast across our forecast area and either go stationary or wash out. On Friday night, models suggest up to 30 kts low-level flow from the SW, which could contribute to additional showers and storms. Location and coverage will be dictated by how convection plays out during the day Friday. In any event, additional heavy rain potential exists Friday night, mainly over central KY. On Saturday, deeper moisture and forcing should slide east with the upper trough, but residual moisture, instability, and weak surface boundary(ies) will remain resulting in isolated to scattered convection, especially in the afternoon and along and south of the Ohio River. Widespread heavy rain is not expected Saturday, but individual cells could still be efficient rain producers. Expect high temperatures in the lower and mid 80s. Sunday... Sunday remains the day with the best chance to dry out between the exiting system and the next system approaching from the west. Nevertheless, isolated afternoon convective cells are still possible in parts of central KY where some instability will remain, but even there many areas should remain dry. Highs Sunday afternoon should reach the mid and upper 80s. Monday through Thursday... The next weather system will quickly dig across the central U.S. and MS River Valley during the period. This anomalous, stout trough aloft will result in unusually deep/strong surface low development for mid-late August. The low will develop over the central U.S. and then race NE into the Great Lakes states Monday night and Tuesday. The 12 UTC GFS/ECMWF/GEM actually are in pretty good agreement with this, albeit some timing differences and the GFS is weaker in its surface low strength than the other models. Regardless, initial warm advection ahead of this system should produce at least a round of showers and scattered storms Monday afternoon and/or night across our area with additional convection along the trailing cold front Monday night or Tuesday. With moderate instability forecast along with some deep-layered shear and favorable mid-upper jet pattern, some strong and potentially a few severe storms are possible, probably in the form of a convective line or line segments over the mid MS and/or OH River Valleys during this period. Models then show a secondary trough digging southeast late Tuesday and Wednesday on the heals of the first trough Monday and Tuesday. This system could keep a chance of showers in the forecast for Tuesday night and Wednesday. Dry weather should finally arrive again by Thursday. These systems also will usher in cooler weather and much lower humidity with highs Wednesday in the upper 70s and lower 80s, and generally lower 80s Thursday. && .Aviation...(00Z TAF Issuance) Issued at 722 PM EDT Thu Aug 16 2018 Convection has largely moved out of the area, with the exception of a few storms up along the I-71 corridor between KSDF and KCVG. Latest CAMs suggest more convection developing in the KEVV-KOWB-KSDF corridor this evening. GOES-16 visible imagery does show some agitated Cu field across southern IN and northern KY with a few cells trying to develop. For now, plan on keeping some VCSH early at KSDF and KHNB. Will have to watch to see if the HRRR is right in developing more convection in this area tonight. Otherwise, after sunset, we should see a stratus deck develop and lower at all the sites. Didn`t take things down as low as the previous forecast based on the latest data. However, next round of convection is expected to develop out across MO/IL and slide into the region after 17/10Z. This activity may affect KHNB by 17/09Z and then KSDF/KBWG in the 17/11-12Z time frame and then KLEX by mid- late morning. && .LMK WATCHES/WARNINGS/ADVISORIES... IN...None. KY...None. && $$ Update.......MJ Short Term...JDG Long Term....TWF Aviation.....MJ
Area Forecast Discussion
National Weather Service Lubbock TX
614 PM CDT Thu Aug 16 2018 .AVIATION... VFR expected through the forecast period as thunderstorm activity to the west of all three terminals diminishes near sunset tonight. && .PREV DISCUSSION... /issued 307 PM CDT Thu Aug 16 2018/ DISCUSSION... A center of high pressure has continued to expand across the most of Texas this afternoon as shown RAP analysis. The decaying MCS from overnight that gave some of our northern counties some decent rain has floated into north-central OK, where it`s beginning to find some rejuvenation. Storms have begun across the mountains of NM and should slowly drift towards TX late this evening. As for these affecting our forecast area overnight, our neighbors to the north in the Amarillo area look to most likely be the benefactors, though a bit of the complex may hold on to impact some of our northern counties. Friday will be warmer as the high expands across the region one more time. One caveat, should our northwestern counties get rainfall again tonight, the forecasted highs in this package may need to be pulled down a degree or two thanks to the moist ground from last nights` copious rain. Now, back to the high. All models, save the ECMWF, have the high expanding back across our region along with a high at H700. Yet, several CAMs want to convect Friday afternoon in our forecast area. It`s a hard sell. Decided to pull PoPs down significantly from the Blend output until the evening/overnight hours as the high retreats and convection from NM can drift into the region. With the retrograding high, weak NW flow may develop on Saturday allowing for another shot at rain. By Sunday, a front pushes through, and models are beginning to show the best rain chances from it may be across the eastern two-thirds of the forecast area, with deeper rain developing south of us. By next week, models begin to part ways a bit too much to put much value in high PoP forecasts. An example, the GFS pulls a front through on Tuesday afternoon with no rain but with a glancing blow of NW flow storms that night. On the other hand, the Euro brings the front in the next day with quite a bit of rain. It seemed a bit aggressive at this time to keep with the high PoPs of the Blend next week with too much uncertainty, so this package includes lowered and smoothed PoPs through the end of the forecast period. && .LUB WATCHES/WARNINGS/ADVISORIES... None. && $$ 55/99/99
Area Forecast Discussion
National Weather Service Midland/Odessa TX
606 PM CDT Thu Aug 16 2018 .DISCUSSION... See 00z aviation discussion below. && .AVIATION... VFR conditions are expected outside of thunderstorms. Thunderstorms will continue to impact the area for the next few hours and should primarily affect FST and PEQ. Will amend as needed if storms move close to the other terminals. Mainly light southerly winds are expected outside of areas of thunderstorms. && .PREV DISCUSSION... /issued 226 PM CDT Thu Aug 16 2018/ DISCUSSION...As of 2:00 PM CDT Thursday...The old saying "Fool me once shame on you fool me twice shame on me" applies to this meteorologist. Yesterdays convection spread further than any of the short-tern CAM models indicated...basically Mother Nature couldn`t care a less what the models showed. Well...I`m not going to fall for that nonsense a second day in a row! Currently KMAF radar is indc an earlier beginning of convection in the Davis/Guadalupe/Sacramento Mtns and adjacent Plains. An MCS that rolled thru the northern Panhandle has dropped an outflow boundary into the north-central CWA. Since the flow is weak there is no doubt other outflow boundaries lurking in the area that are too small to be discerned by the 3km CAM models such as the HRRR and the NAM Nest. Therefore...have kept pops more extensive than the models...similar to what last nights forecaster had (to give him credit). Even with the ridge strengthening overhead a combination of intense heating...ample moisture...and remnant outflow boundaries will lead to more extensive pops beyond what the CAM models show. Storms will form in the aftn over the Sangre De Cristo Mtns of north-central New Mexico and develop into an MCS as they roll east overnight into the Panhandle. This will continue each day into the CWA thru Saturday. Temps will remain hot hot and hot with mid/upper 90s across most of the area...with temps just lightly kissing the century mark in the Trans Pecos and along the Rio Grande Valley. On Sunday a strong shortwave will drop southeast thru the northern and central Plains as the center of the ridge becomes centered over the AZ/NM border. As the shortwave passes east a cold front (in name only) will drop south over the area bringing a chance of showers/thunderstorms Sunday aftn/night. It looks like the front will wash out as it stalls across the CWA. Whereas Sunday will again Monday could "cool" into the lower to mid 90s! Celebration time! It looks like the remainder of next week will feature the ridge nearly stationary over the AZ/NM border with impulses dropping south into the CWA around the ridge. This pattern would favor overnight convection/MCS with each impulse combined with the nocturnal LLJ. As of now...which is of course subject to change...the best chances for nocturnal convection will be Tuesday night/Wednesday morning and Thursday night/Friday morning. Temps will remain hot (what else is new) but near normal with highs mainly in the lower 90s. Fall can`t come soon enough!! Strobin && .PRELIMINARY POINT TEMPS/POPS... Big Spring 75 97 75 99 / 10 10 0 0 Carlsbad 71 96 71 97 / 20 20 20 30 Dryden 73 97 73 99 / 10 0 0 0 Fort Stockton 72 96 71 98 / 20 10 0 20 Guadalupe Pass 70 89 68 91 / 20 30 30 40 Hobbs 70 93 69 94 / 10 10 20 20 Marfa 61 88 62 88 / 30 30 10 40 Midland Intl Airport 75 97 75 98 / 10 10 0 0 Odessa 75 97 74 98 / 10 10 0 0 Wink 75 99 74 100 / 20 20 10 20 && .MAF WATCHES/WARNINGS/ADVISORIES... NM...None. TX...None. && $$ 99/99/
Area Forecast Discussion
National Weather Service Newport/Morehead City NC
1012 PM EDT Thu Aug 16 2018 .SYNOPSIS... High pressure will extend over the area from well offshore through the weekend with a weak trough over the central part of the state. A cold front will move slowly through the area next Wednesday into Thursday. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... As of 1005 PM Thursday...Adjusted forecast to add slight chance POPs west of Hwy 17 through 2 AM with isolated activity continuing to SW, NW and NE. Latest HRRR indicates this activity persisting next few hours, then isolated threat along coast overnight. Rest of forecast on track with muggy low temps in mid to upper 70s. /Previous discussion/ As of 230 PM Thursday...High pressure centered offshore will continue to ridge into the area tonight. Isolated to scattered showers have developed across the region this afternoon, most concentrated along the sea breeze along the Crystal Coast and far NE sections. Expect activity to diminish with loss of heating this evening but high-res models showing a weakness in the ridge with a few showers continuing near the coast so kept 20% PoPs in this area most of the overnight. Could see some patchy light fog in sheltered locations inland late but guidance keeps light winds and couple degree dewpoint depression so not anticipating any widespread fog. Lows tonight will generally be in the mid 70s. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/... As of 330 AM Thu...High pressure continues to ridge into the area from offshore while a robust upper trough pushes east across the Mid-west states. A moist and unstable airmass persists across eastern NC with weak shortwave energy moving through SW flow aloft bringing scattered showers and thunderstorms across the region through the afternoon. Not anticipating storms to reach severe limits with very little shear present. Highs expected in the lower 90s inland to mid/upper 80s along the coast. && .LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/... As of 315 AM Thursday...A mean upper trough is forecast over the Eastern US through the period while low level southerly flow continues to circulate a very moist airmass across our region with PW values AOA 2". The favorable combination of forcing aloft and moisture/instability in the low levels will result in unsettled conditions late this week through the middle of the upcoming week with precipitation chances at or above normal and temperatures at or slightly below normal. Saturday through Wednesday...Shower and thunderstorm chances increase above climatological norms through most of the period as conditions become favorable for scattered to numerous showers and thunderstorms. Temps are expected to be near normal with highs inland around 90 Sat, then cooling slightly to the mid to upper 80s Sunday through mid next week. && .AVIATION /02Z FRIDAY THROUGH TUESDAY/... Short Term /through 00Z Saturday/... As of 800 PM Thursday...VFR expected to prevail through most of period. Lingering isolated evening tstms will avoid TAF sites and any overnight activity will be along coast. Cannot rule out local sub-VFR stratus at KOAJ and KISO that has occurred past several mornings but not seeing enough forecast support other than peristence, thus not enough confidence to include in this TAF issuance. A bit more tstm coverage expected Friday afternoon and included VCTS all sites. Long Term /Friday night through Monday/... As of 315 AM Thursday...Scattered to numerous showers and thunderstorms will produce sub VFR conditions at times through the period. In addition conditions will be favorable for periods of low clouds and fog early each morning. && .MARINE... Short Term /Through Friday/... As of 1010 PM changes with update. /Previous discussion/ As of 3 PM Thursday...High pressure remains centered offshore with a thermal trough inland and a mid-level system approaching from the NW. Gradients between these systems gradually tighten through the period bringing increasing winds and seas. Across the water north of Oregon Inlet and Albemarle Sound and rivers, expect SW winds around 5-10 kt increase to 10-15 kt tonight into Friday, then to 15-20 kt by late Friday afternoon. South of Oregon Inlet and Pamlico Sound will see SW winds around 15 kt tonight into Friday, perhaps a bit stronger at times, increase to around 20 kt by late Friday. Seas expected around 1-2 ft northern waters and 2-3 ft southern and central waters through the period building to 2-3 ft north and 2-4 ft south tonight and Friday. Long Term /Friday night through Monday/... As of 315 AM Thursday...Little change to the surface pattern of a trough of low pressure inland and high pressure offshore into early next week producing S-SW flow 10-20 kt through Sat night. Could see conditions approaching Advisory levels over the southern and central waters Fri night into Sat night as the S-SW flow increases to 20 kt with higher gusts. Seas of 2 to 4 ft late Fri will build to at least 3 to 5 ft Fri night through Sat night with the Wave Watch wave model indicating 6 ft seas possible over the outer southern and central waters. The flow is forecast to become westerly and diminish to 10-15 kt Sunday with seas subsiding to 2 to 4 ft. Monday the flow will briefly become easterly 10 kt or less over the Sounds and northern and central waters, while becoming SW 10 kt or less over the southern waters. Seas are forecast 2-4 ft. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...None. MARINE...None. && $$ SYNOPSIS...SK NEAR TERM...JBM/SK SHORT TERM...SK LONG TERM...JME AVIATION...JME/JBM MARINE...JME/JBM/SK
Area Forecast Discussion
National Weather Service Marquette MI
631 PM EDT Thu Aug 16 2018 .SHORT TERM...(This evening through Friday) Issued at 421 PM EDT THU AUG 16 2018 Updated for note on wildfire smoke that will move across the area on Fri. Water vapor imagery and RAP analysis show zonal flow across much of Canada. In the weaker flow to the s, a well-defined shortwave is over nw IA/ne NE/se SD/sw MN. With daytime heating, sct shra/tsra associated with the wave have been increasing across IA/southern MN into sw WI. It appears a subtle wave ahead of the main feature has also been aiding some shra/tsra development farther ne in WI. Closer to home, quite a bit of cloud cover has helped slow build up of instability. That said, latest SPC mesoanalysis shows mlcapes have increased to 1000+j/kg from northern WI toward Marquette. Aforementioned well-defined shortwave is fcst to shift ese and weaken tonight/Fri. While it won`t have any direct impact on the weather here, avbl instability and subtle wave in WI should support development of a few shra/possibly a tstm across the border into portions of central Upper MI over the next several hrs. Vis satellite imagery indicates CU are becoming more well-developed in the area bounded roughly by Ironwood/Marquette/Iron Mtn, which supports the idea that some shra may develop late aftn/early evening. Very weak mean wind under 10kt will lead to little movement of any shra that develop. Shra should end by midnight, though some models hint that pcpn could linger overnight. Light/calm wind, decrease in clouds overnight, and temps falling into 50s will likely lead to some radiation fog development over the interior w half. Fri looks like a quiet day. However, under a slightly more wnw mid- level flow, models do show a weak shortwave approaching in the aftn. There is some TCU developing ahead of the feature in southern Manitoba/adjacent northern Ontario, so not out of the question that there could be isold aftn shra. On the other hand, prevailing gradient northerly flow will essentially eliminate lake breeze convergence as a low-level forcing mechanism unless lake breeze off Lake MI can develop. So for now, left any mention of pcpn out of fcst. Expect highs ranging from around 70F along Lake Superior to well into the 80s inland. On another note, satellite imagery, especially MODIS/AQUA imagery, shows a very thick layer of wildfire smoke extending from ND ne into northern Ontario. Unfortunately, this band of smoke will likely move across the area on Fri. The smoke will be much thicker than anything experienced this summer. .LONG TERM...(Friday night through Thursday) Issued at 340 PM EDT THU AUG 16 2018 Rather quiet start to the extended forecast, with a weak mid-lvl trough axis departing the Great Lakes region late Sat. Closer to the surface an elongated surface ridge will continue to provide dry condtiions to the area through Sat, but heading into the second half of the weekend with the surface ridge departing to the east. Some of the guidance is starting to slow the departing surface ridge until later Sun, which could further delay clouds returning and precip chances until Mon. A frontal boundary continues to be progged by guidance for approaching from the west/northwest early Mon, with a shortwave developing across the Central Plains early in the week. This shortwave is being progged to lift northeast towards Lower Michigan Tue/Wed with a wide precip shield accompanying this low pressure system. This should increase chances for showers/thunderstorms Tue/Wed of next week. Temperatures will steadily warm and become more humid over the second half of the weekend, with highs in the upper 70s to middle 80s. Mild overnight temps are also expected as cloud cover is not going to dissipate, keeping lows in the 60s for the bulk of the extended. With the system arriving Tue/Wed, this should provide cooler temps with rainfall with highs back into the upper 60s to lower 70s for many areas then warming yet again later in the week. && .AVIATION...(For the 00Z TAFS through 00Z Friday evening) Issued at 630 PM EDT THU AUG 16 2018 VFR conditions are likely to prevail at KIWD/KCMX/KSAW thru this fcst period. Could be some fog for brief times at IWD overnight and at SAW late tonight. && .MARINE...(For the 4 PM Lake Superior forecast issuance) Issued at 421 PM EDT THU AUG 16 2018 Winds across Lake Superior will be under 15kt thru Sun. However, high pres building over northern Ontario on Fri may lead to ne wind gusts of 15-20kt over western Lake Superior. A vigorous low pres system for Aug is expected to track ne into the Great Lakes region late Mon/Tue. This system will bring northerly winds of at least 15- 25kt with gusts to 30kt. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... None. Lake Superior... None. Lake Michigan... None. && $$ SHORT TERM...Rolfson LONG TERM...Beachler AVIATION...07 MARINE...Rolfson
Area Forecast Discussion
National Weather Service New York NY
1036 PM EDT Thu Aug 16 2018 .SYNOPSIS... High pressure will remain off the southeastern coast as a warm front moves into upstate New York and into central New England overnight. Meanwhile, low pressure across the eastern Great Lakes will bring a cold front toward the region Friday and Friday night. The cold front will be moving into the region Saturday, and then southeast of Long Island, but with some weak lows forming along it Saturday night. The low pressure along the front and front itself will linger offshore for Sunday into Sunday night. High pressure from the Canadian Maritimes will build in Monday into Tuesday next week. A frontal system approaches the region for the middle of next week and exiting the area next Thursday. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... Updated winds, gusts, temperatures, dew points, and sky grids for current conditions and overnight trends. Both the temperatures and dew points were in generally on track, with some area slightly warmer than forecast. With increased cloud cover and the warm and humid airmass in place, temperatures, especially along the coast, are not expected to reach the previously forecast lows and raised overnight lows a couple of degrees. High pressure centered off the southeastern coast remains in place overnight. Meanwhile,a nearly stationary frontal boundary across northern Connecticut into upstate New York will move north as a warm front, maintaining a warm and humid airmass across the region. A mid and upper level ridge will slide slowly to the east as a shortwave rides along the frontal boundary through upstate New York. The area will remain dry, however, some showers and thunderstorms may develop toward morning into the mid Hudson Valley region. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/... With the 00Z NAM showing a slower trend in the shortwave riding along the warm frontal boundary lifting into upstate NY delayed the onset of precipitation and cut back on the areal extent of the precipitation probabilities through Friday morning. Looking to be closer to 15Z to 16Z before any precipitation arrives. Even the latest HRRR is keeping the precipitation north of Orange and Putnam counties. The mid and upper level ridge move into the western Atlantic Friday as a shortwave trough, amplifying slightly, moves into the Great Lakes by 00Z Saturday. The mid and upper flow will be nearly parallel to a cold front which will move little during the day. Daytime heating should be sufficient to produce instability, especially inland, and a pre-frontal trough will provide focus for the development of thunderstorms. Some of the storms may become strong with gusty winds and potentially damaging winds across portions of the lower Hudson Valley and into southwestern Connecticut. Added some enhanced wording of gusty winds in these areas for the afternoon and into early Friday evening. Also highlighted this in the Hazardous Weather Outlook, HWOOKX. Clouds increase Friday morning with showers and thunderstorms becoming more likely Friday afternoon and evening mainly across the interior, as a cold front nears the area. Localized flooding will also be a threat with any strong thunderstorms. Temperatures Friday will be in the mid to upper 80s to near 90. The combination of warm temperatures and a southerly flow will allow dew points to climb into the 70s. This will result in heat indices in the lower to mid 90s, with some upper 90s in northeastern New Jersey, across the advisory area. Most areas did not reach the minimum of 95 heat indices Thursday afternoon. However, will continue the heat advisory for Friday until 22Z. There is a moderate risk for the development of rip currents at the Atlantic ocean beaches Friday. && .LONG TERM /SATURDAY THROUGH THURSDAY/... The region remains on the backside of an upper level trough with mid to upper level WSW flow. The cold front will move into the region and with daytime heating Saturday as highs reach well into the 80s, would expect scattered showers and thunderstorms to develop. The showers and thunderstorms will still be capable or producing heavy rain with PWATS being near 2 inches, characterizing a very humid airmass. The showers and thunderstorms could very well linger into the evening Saturday along the coast as there are some small areas of low pressure forecast to develop along the front, which will decelerate its forward movement to the southeast. Mid and upper level flow remain out of the SW too, so the steering flow would halt the progress of the front as well. The front eventually is expected to move far enough offshore Sunday and with a pressure gradient between the low southeast and an approaching high to the Canadian Maritimes, more of a NE flow is expected to develop. The high pressure area eventually settles into the Canadian Maritimes, prolonging the NE flow to close out the weekend and into early next week. This will promote a relatively cooler and a little less humid airmass with highs in the upper 70s to near 80 and lows in the low to upper 60s. However, clouds could linger much of the time along the coast, especially Eastern Long Island. There is a lingering chance of showers Sunday for the whole region and a slight chance of them Sunday night along the coast. Thunderstorms are not expected Sunday and Sunday night with more stable air in the region. The airmass starts to warm again with decreasing NE flow and more sun Monday and Tuesday. Shower and thunderstorm chances return towards midweek period with the next frontal system approaching. Airmass will continue to warm with highs more in the low to mid 80s forecast for Wednesday. && .AVIATION /03Z FRIDAY THROUGH TUESDAY/... A cold front will slowly approach from the west through Friday. Winds diminish tonight, then strengthen from the S-SW on Fri. Cut back on speeds compared to the previous forecast except right along the coast, and it now appears that the sea breeze should make it to KEWR/KTEB after 18Z. Could see a few showers and maybe a stray tstm near KEWR/KTEB between 18Z-21Z, with the main push of activity with the approaching front arriving late day or early evening. .OUTLOOK FOR 00Z SATURDAY THROUGH TUESDAY... .Fri night...MVFR or lower conditions likely in showers/tstms, especially before 04Z Sat. .Sat...MVFR or lower conds at times in any showers/tstms. W flow becoming NE Sat eve. .Sun...Chance of MVFR cigs in the morning. .Mon...VFR. .Tue...Chance of MVFR cigs. && .MARINE... Winds and seas forecast remain as forecast with no changes at this time. Ocean seas remain below SCA conditions through Friday then slowly build to SCA levels by Friday night ahead of a frontal boundary. A brief period of sub-SCA conditions for all waters Saturday through much of Saturday night will be followed by increased NE flow increasing the easterly fetch and swell behind the cold front with increasing chances for SCA conditions on the ocean starting late Saturday night. The forecast has this increase in NE flow leading to more swell and increasing ocean seas up to 5 ft and forecast wind gusts on the ocean increasing up to 25 kt late Saturday night through Sunday. The SCA ocean seas will remain probable Sunday night and into Monday and Monday night for eastern ocean waters while winds are expected to remain below SCA. All waters are forecast to remain below SCA late Monday night through Tuesday night. && .HYDROLOGY... Heavy tstms late Friday through Friday night could result in minor urban flooding. Thunderstorms Saturday could still produce some locally torrential downpours with a marginal threat for flooding, mainly minor. Otherwise, no significant widespread rainfall is expected. && .EQUIPMENT... NYC NOAA Weather Radio Station KWO-35 (162.55 MHz) remains off the air for an extended period of time. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...Heat Advisory until 6 PM EDT Friday for NYZ071>075-176>179. NJ...Heat Advisory until 6 PM EDT Friday for NJZ006-104-106>108. MARINE...None. && $$ SYNOPSIS...Fig/JM NEAR TERM...Fig/19 SHORT TERM...Fig/19 LONG TERM...JM AVIATION...Goodman MARINE...Fig/JM/19 HYDROLOGY...Fig/JM EQUIPMENT...
Area Forecast Discussion
National Weather Service Paducah KY
611 PM CDT Thu Aug 16 2018 .SHORT TERM...(Tonight through Saturday night) Issued at 253 PM CDT Thu Aug 16 2018 Weak isolated convection on radar this afternoon driven by only weak mid level support and instability. Not expecting much change through the afternoon. The instability isn`t too shabby, so a flare up storm possible, but isolated. Locally heavy rain, perhaps. Not much change this evening. Overnight, as a mid level s/wv trof approaches, forcing and instability should result in an uptick in convection, especially after midnight through sunrise. How coverage will play out is still uncertain, as the CAM`s models continue to be of little help, typical in this kind of regime. Energy associated with the trof will be slow to shift east Friday. A weak front will move into the area late Friday and Friday night. Good chance PoPs for convection as a result, with strong storms and locally heavy rainfall possible. PoPs will taper off from NW to SE late Friday night through Saturday. Expect some diurnal enhancement during the day Saturday with heating given the close proximity of the upper system, especially west KY. We should dry out Saturday night. For the short term, basically used a blend of the EC/GFS and NAM, smoothing out the details, accounting for uncertainty. Temps were derived from the NBM and previous forecast numbers. .LONG TERM...(Sunday through Thursday) Issued at 253 PM CDT Thu Aug 16 2018 Sunday continues to look mainly dry as an upper level ridge builds in over the area. Meanwhile our next weather maker will be slowly moving east across the country`s mid section. Although there continues to be some timing differences, there is enough consensus now to believe parts of southeast Missouri will see at least a chance for rain as early as Sunday evening as the system nears. Showers and storms will surge eastward overnight on Sunday and into Monday morning as this warm front continues pushing northward. How far east and north the precipitation reaches before 12Z Monday is still questionable but it looks like most of southwest Indiana and even the Pennyrile region of west Kentucky will be dry prior to 7am Monday with the latest GFS/GFS ensembles actually providing the slower solutions. Nonetheless, will indicate a tight POP gradient with likely POPs far west to slight chance or no POP east. During the day on Monday, we will see periods of showers and storms as the upper system moves into the area and more than one upper level shortwave may swing through. The rain should taper off from west to east Monday night. PWs will surge back to 2+ inches with this system so heavy rainfall is possible with the individual cells. We could see a brief respite from the rain on Tuesday but another quick moving upper trough will arrive from the northwest and impact the area Tuesday night into Wednesday, bringing another small chance for rain. Models are actually in pretty good agreement on the timing of this as well. In addition, the cold front will actually pass through the area Tuesday/Tuesday evening. In the wake of the front, much drier and cooler air will infiltrate the area as high pressure slowly builds in. Highs will be in the lower 80s Tuesday through Thursday with lows in the lower 60s, possibly even upper 50s in some locations. Dry weather will continue through at least the end of the week. && .AVIATION... Issued at 610 PM CDT Thu Aug 16 2018 For the most part, convective activity should remain out of the WFO PAH TAF locations for the 00z Friday issuance. However, given the proximity of towering cumulus and isolated showers near KOWB, left an evening mention of vicinity thunderstorms for this particular location. Prefer the NAMNest ensemble and 13km RAP guidance for initialization of the TAF`s. They both keep the best chances for convection and MVFR ceilings until after the 07z-09z time frame, in line with the expected arrival of overnight convection from Missouri and Illinois. Also prefer the lower VFR/upper MVFR ceilings during the morning, then the development of afternoon convection. Favored mention of vicinity convection over explicit convection, given the very poor timing and placement of the showers and thunderstorms by the high resolution/medium range guidance this afternoon. && .PAH WATCHES/WARNINGS/ADVISORIES... IL...None. MO...None. IN...None. KY...None. && $$ AVIATION...Smith
Area Forecast Discussion
National Weather Service Portland OR
305 PM PDT Thu Aug 16 2018 .SYNOPSIS...Some isolated thunderstorms are possible over the Oregon Cascades and Coast Range this afternoon and evening as an upper level trough approaches the region. The trough will increase the onshore winds and push marine clouds inland Friday morning for cooler afternoon temperatures inland. Haze and air quality will gradually improve over the next 12 to 24 hours with some blue skies possible Friday afternoon. High pressure returns this weekend for less morning clouds inland and warmer afternoon temperatures. Low clouds will likely linger along the coast. && .SHORT TERM...Tonight through Sunday....A weak upper level trough is approaching the region this afternoon and will transit the area tonight and Friday. There has been some light showers and even some isolated thunderstorms over the elevated terrain today. The threat for thunderstorms over the Cascades and Coast Range will continue through the evening hours. The onshore winds are a bit stronger today, which is helping improve air quality over the region. Most of the air quality sensors have improved into the moderate category with a few remaining in the unhealthy category. There are even a couple sensors in the good range this afternoon. The marine layer will deepen tonight into Friday morning as the weak upper trough moves inland. Thus, expect a cloudy start to the day Friday with cooler afternoon temperatures inland. Occasional drizzle is expected on the coast and west slopes of the coastal mountains Fri morning due to lifting of the moist marine layer. The clouds will clear Fri afternoon. The flow aloft becomes NW behind the upper trough Friday afternoon which should clear the haze from the wildfires. The HRRR smoke model depicts this quite well as the smoke is advected to the east over the next 12 hours. The upper level trough will move into the northern Rockies by Sat morning with an upper level ridge moving into the Pacific Northwest. This will bring pleasant weather for the upcoming weekend with inland temperatures in the low to mid 80s and coastal temperatures in the 60s. An upper low will undercut this ridge and move over the Pacific NW on Sunday, which may bring a slight chance of thunderstorms to the southern Cascades late Sunday into Monday. The upper low will result in the steering flow becoming southerly, which could bring smoke into the region once again from the wildfires in southern Oregon. /tw .LONG TERM...Sunday night through Friday...Models are showing an upper-level trough with a closed low approaching Sunday night and sitting right over us on Monday. With most of the GEFS ensembles also showing this feature in relatively the same place, this increases confidence in this feature for Sunday night into Monday. With the location of the closed low, the cooler air aloft with the still fairly hot surface temperatures will help to destabilize the atmosphere and could generate showers and perhaps a few thunderstorms anywhere from the Coast Range east toward the Cascades Monday afternoon and evening. The upper-level low retreats westward offshore on Tuesday, which means southerly flow over the area and maybe even some offshore surface winds on Tuesday. If surface winds turn offshore, we may see Tuesday get hotter than Monday. By Wednesday, the upper-level trough finally kicks through from the southwest, which pattern-wise may suggest another shot at showers or perhaps even thunderstorms, but the better chance will be north of our area. Right now, holding off as the models aren`t showing any showers on Wednesday, likely due to the track being farther north. Later next week, flow starts to become more zonal, which should bring back more seasonably normal temperatures. -McCoy && .AVIATION...The widespread MVFR stratus across the region this morning has now scattered out in most places. Expect widespread VFR conditions through the rest of the afternoon. There are some mid-level convective clouds showing up on satellite and radar this afternoon. There is a slight chance that a couple of thunderstorms will develop over the Cascades or Oregon Coast Range later this afternoon or this evening. An upper level trough will move onshore tonight, deepening the marine layer even more than we saw last night. MVFR cigs to spread back onto the coast by 03Z this evening. The deeper marine layer should allow for an extensive marine stratus push into the interior going into Fri morning, with widespread MVFR cigs expected to develop by 12Z- 14Z. MVFR cigs will likely last until around midday. KPDX AND APPROACHES...VFR conditions continue through the rest of today and much of tonight. MVFR stratus likely returns to the terminal by 10Z-12Z and remains through most of tomorrow morning. Pyle && .MARINE...Expect little change to the overall weather pattern through the first half of next week. High pressure will remain over the NE Pac, while thermal low pressure remains over northern California and southern Oregon. This will result in persistent northerly winds over the coastal waters. The winds will become gusty over PZZ255/PZZ275 during the afternoon and evening hours each day through Saturday. A small craft advisory is in effect for these zones today, with another one for tomorrow. Upper level low pressure will approach later in the weekend and early next week. This will weaken the NE Pac high, which should result in lighter winds. Winds will remain 5 to 7 ft through the end of the week, with seas dominated by fresh NW swell with a period of 9 to 11 seconds. Seas drop down closer to 5 ft over the weekend. Pyle && .PQR WATCHES/WARNINGS/ADVISORIES... OR...None. WA...None. PZ...Small Craft Advisory for winds from 2 PM this afternoon to 2 AM PDT Friday for Coastal Waters from Cascade Head OR to Florence OR out 60 NM. && $$ Interact with us via social media: This discussion is for Northwest Oregon and Southwest Washington from the Cascade crest to 60 nautical miles offshore. This area is commonly referred to as the CWA or forecast area.