Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 09/09/18

Area Forecast Discussion
National Weather Service Bismarck ND
857 PM CDT Sat Sep 8 2018 .UPDATE... Issued at 857 PM CDT Sat Sep 8 2018 Latest surface map shows the pre-frontal boundary slowing as it moves out of western North Dakota. This is indicated by the lack of a windshift to the northwest behind the pre-frontal passage, and thunderstorms continuing to exhibit a pulse type mode. Thunderstorms have remained sub-severe and think this will continue to be the trend overnight as Effective Shear should remain in the 20kt to 30kt range. The RAP indicates that southeast to southerly winds will continue for all but the far west overnight as the convection outruns the weakening surface trough. Will be monitoring elevated convection overnight as 850mb southerly flow continues to meet up with a 700mb shortwave over north central North Dakota, including the Turtle Mountains. This is where the bulk of the showers/thunderstorms will occur. An isolated shower or thunderstorm grazing south central ND/Bismarck vicinity is possible by around midnight. Otherwise, should be drier across the far west. Adjusted PoPs based on the latest radar, HRRR and RAP13. UPDATE Issued at 552 PM CDT Sat Sep 8 2018 Showers and isolated thunderstorms developing along a pre frontal trough across western North Dakota per regional radar. Effective shear generally in the 20kt to 25kt range per SPC Mesoanalysis. Thus far, the structure of the thunderstorms have been straight up and down and would expect this to continue far west. A 700mb shortwave in northeast Montana will shift into northwest North Dakota this evening which may have a play into stronger thunderstorm development and possible isolated severe. Current forecast on track. && .SHORT TERM...(This evening through Sunday) Issued at 257 PM CDT Sat Sep 8 2018 The focus the next 36 hours is on marginal severe-storm risks in western ND this afternoon and evening, and centered on the south central into the southern James River valley late Sunday. As of 19 UTC, a broad warm sector is in place across most of the area south of a warm frontal zone that extends from near Regina toward Rolla, and east of a strengthening, north-south-oriented pre-frontal pressure trough near the ND-MT state line. Surface observations reveal mixing-lowered dewpoints in the mid 40s F in southwestern ND. However, subtle sheltering by cirrus decks and modest advection of slightly greater low-level moisture content in western SD will likely offset the impacts of mixing at least somewhat in southwest ND the rest of the afternoon. Moreover, in northwest ND, slightly more backed surface winds drawing on the relatively-greater moisture content marked by surface dewpoints in the lower to middle 50s F in central ND, and greater cloud- cover-related sheltering of the boundary layer will likely aide in the maintenance of higher boundary layer moisture content. The net effect should be a north-south axis of weak MLCAPE ranging from 500-1000 J/kg in western ND this afternoon and early evening as forecast by most model guidance including recent RAP cycles. Forecast soundings suggest that MLCIN will not be minimized until late afternoon, but GOES-16 visible satellite imagery reveals gradually-deepening cumulus near the surface trough in eastern MT concurrent with increasing confluence in surface wind fields and an approaching shortwave trough, suggesting that initiation will indeed occur in time. Having said that, disparity exists in various CAM cores, with recent ARW-core HRRR simulations and NMM- based HREF members more aggressive with convective initiation than ARW-based members of the 12 UTC HREF, including the NSSL WRF and EMC WRF-ARW. The consensus of this guidance supported PoPs of 20 to 40 percent in western ND in the late afternoon and early evening, and then over central ND tonight. We are increasingly skeptical of the ability for convection to be maintained in any organized fashion into the central part of the state, though, as weak background forcing will be in place as the synoptic-scale pre-frontal trough is expected to only slowly advance eastward. Moreover, boundary layer cooling is likely to be ongoing by the time convection is able to propagate into central ND, further reducing already-weak bouyancy. We are still advertising the risk of a few strong to marginally severe storms in western ND through this evening in respect to steep low- and midlevel lapse rates and effective-layer shear on the order of 30 kt in support of multicellular storms. Given the orientation of deep-layer wind fields to the surface trough, the initial convection may be semi-discrete, though the tendency for outflows to spread from convection given a dry and deeply-mixed boundary layer and multicellular organization may tend to yield upscale growth in time, before updrafts weaken by mid evening. On Sunday, a shortwave trough moving through southern Canada is expected to shift a cold frontal zone eastward, but the buoyant sector will likely still encompass areas along and southeast of a line from Harvey to Bismarck/Mandan and Lemmon in the mid to late afternoon. The consensus of 12 UTC models calls for around 1000 J/kg of MLCAPE given surface dewpoints in the lower 60s, and effective-layer shear may approach 30 kt. That will support another marginal risk of severe storms in south central ND into the southern James River valley. Highs will be cooler area-wide (generally 75 to 80 F), and given the potential for cloud cover heralded in forecast soundings, there is some uncertainty with regard to whether advertised instability will be realized. That being said, the consensus of both convection-parameterizing and convection-allowing model guidance strongly supports storms in the late afternoon and evening. .LONG TERM...(Sunday night through Saturday) Issued at 257 PM CDT Sat Sep 8 2018 An active weather pattern is expected in the long term forecast period, with near or slightly above temperatures favored along with a few chances for showers and thunderstorms. The 500 mb pattern is forecast to be characterized by a mean trough in the northwestern United States in between positive height anomalies in the northeast Pacific and the East Coast. The 00 and 12 UTC global deterministic and ensemble guidance suggests one shortwave trough and attendant cold front likely crossing the region late Tuesday. Given that, the Monday and Tuesday time frame could be the warmest days of the week as a response to the pre-wave warm air advection pattern. There will be a chance of convection with this feature, though both the GFS and ECMWF and their ensembles suggest the front will likely be east of the local area before surface-based storms are able to form Tuesday afternoon. Thereafter, a cooler air mass may arrive for the midweek period. Southwest flow is expected to strengthen by late week as the trough in the northwest United States deepens, which may yield increasing precipitation probabilities in western and central ND. However, the amplitude of the synoptic-scale trough is an uncertain forecast element at this time. The 00 UTC ECMWF and ECMWF ensemble, and to some extent the FV3-GFS, portrayed a much more amplified trough and resulted in warmer temperatures and greater convective opportunities by next weekend. However, the 00 and 12 UTC GFS and the 12 UTC ECMWF suggest a much more progressive and less amplified pattern, and therefore they are simulating a cooler regime, especially by late next weekend. For now the the multi-model consensus is the most reasonable forecast, which calls for highs around 70 F by Friday along with modest PoPs. && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) Issued at 552 PM CDT Sat Sep 8 2018 Showers along a pre-frontal trough will affect KISN/KDIK/KMOT with a tempo group added to these terminals through 06z Sunday. A vcsh at KBIS and KJMS for the remainder of the tonight period. Low Level Wind Shear will affect KMOT from 02Z through 15Z Sunday. An are of mvfr clouds are forecast into KBIS/KJMS from 12z Sunday until 16Z at KBIS and 21z Sunday at KJMS. Expect a round of showers/thunderstorms developing Sunday afternoon and evening between KBIS and KJMS. Low clouds lingering into KJMS may Details on this still too far out. && .FIRE WEATHER... Issued at 257 PM CDT Sat Sep 8 2018 Near-critical fire weather conditions are occurring in southwest ND this afternoon due to strong south winds and relative humidity values as low as 20 percent in some areas. However, cloud cover is increasing from the west and will likely temper conditions during the late afternoon. That, combined with adjective fire danger ratings in the moderate category in many areas, kept us from issuing a Red Flag Warning. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...KS SHORT TERM...CJS LONG TERM...CJS AVIATION...KS FIRE WEATHER...CJS
Area Forecast Discussion
National Weather Service Columbia SC
1037 PM EDT Sat Sep 8 2018 .SYNOPSIS... A weak cold front will approach from the north late tonight but likely stall across North Carolina on Sunday. Expect a continued chance of mainly afternoon and evening thunderstorms next few days with the chance for scattered thunderstorms with near normal temperatures. Tropical Storm Florence could affect the weather by the second half of next week. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... Weak upper-level ridging continues across the area. A cold front is forecast to remain just north of the area in North Carolina overnight. Expect most convection associated with the front will remain north of the forecast area as indicated by the HRRR. Have forecasted just slight chance pops in the north part. High low- level moisture in the low-level southeasterly flow combined with nocturnal cooling may result in fog toward sunrise. SREF probabilities were highest in the southeast section. Expect low temperatures again in the lower 70s. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/... The area will remain in the warm sector ahead of a low pressure system Sunday and Monday. Despite moist southerly flow, mid- level ridging will continue to limit convection Sunday. The greatest chances for storms will be to the southeast along the sea breeze, and across the Upstate closer to the front. As the cold front approaches from the west Monday, precipitation chances should increase, and could become likely from the central Midlands westward. Models also give some indication that a shortwave trough could move up from the southwest, increasing convection across the eastern Midlands as well. Temperatures will remain above normal through this period with highs in the low to mid 90s and lows around 70. && .LONG TERM /TUESDAY THROUGH SATURDAY/... The big unknown at this point for the longer term period continues to be Tropical System Florence. Please refer to the NHC for the latest track and intensity guidance. Much uncertainty exists due to the unknowns surrounding the final track of the hurricane. Have kept a chance of convection each day per model consensus and latest WPC guidance. Have also leaned towards WPC for wind guidance. && .AVIATION /03Z SUNDAY THROUGH THURSDAY/... VFR through 06Z. There is some potential for some fog during the early morning, although cross-over temperature suggest a lower threat for radiation fog. The Lamp and HRRR suggest higher fog probabilities at AGS and OGB terminals 08Z-13Z. Mainly VFR conditions expected at all TAF sites after 13Z. Convection may be a bit more widespread Sunday afternoon, so have included VCSH at all sites. EXTENDED AVIATION OUTLOOK...Abundant low-level moisture and onshore flow will continue the potential for late night and early morning stratus. Flight restrictions are possible in scattered afternoon/evening showers and thunderstorms. Any potential impacts from Tropical Storm Florence will not be in the area until Thursday. && .CAE WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. && $$
Area Forecast Discussion...UPDATED
National Weather Service Duluth MN
635 PM CDT Sat Sep 8 2018 .UPDATE... Issued at 635 PM CDT Sat Sep 8 2018 Please see the 00Z Aviation discussion below. && .SHORT TERM...(This evening through Sunday) Issued at 357 PM CDT Sat Sep 8 2018 A quiet short term continues through the next 24 hours as a ridge of high pressure slides off to the east, and a low pressure system develops over Saskatchewan and slowly pushes a cold front towards the area. Southeast winds have already developed over the area, and should keep temperatures from dropping off as much as they did last night, and have raised min Ts slightly. Southeast winds will pick up for Sunday and expect highs to warm as well. Dewpoints will increase some, and it will feel a bit more humid than today. However, without having the front closer or having a good leading shortwave to initiate convection have kept all pops out of the forecast area for the daytime. .LONG TERM...(Sunday night through Saturday) Issued at 357 PM CDT Sat Sep 8 2018 The main areas of focus for the extended forecast continue to be a more active weather pattern for the upcoming week, with temperatures near to above average. Sunday night and Monday will have increasing chances for showers, and possibly a thunderstorm, as a mid-level trough and attendant surface cold front move into the Northland. Some clear skies will linger over northwest Wisconsin through at least sunrise on Monday, so temperatures could be a little on the chilly side due to radiational cooling. Lows over northwest Wisconsin will dip in the lower to middle 40s. In general, a brief respite from precipitation is anticipated on Tuesday before more widespread chances for precipitation return for Tuesday night and Wednesday. Gusty southerly flow on Tuesday will bring some warmer temperatures, with most areas seeing temperatures nearly 5 to 10 degrees above average. Winds between 20 to 30 mph should usher in high temperatures in the middle to upper 70s across much of the Northland. A 35 to 45 knot low-level jet will make its way into the region, enhancing low-level warm air advection, and lift for precipitation as well. Model trends are now indicating a more active pattern for the latter half of the upcoming week, due in part to a shifting flow pattern aloft. A large longwave trough deepens over the northwestern United States, with large scale ridging over the eastern United States. This ridge, along with the influence of what is currently Tropical Storm Florence, will act to block the flow, placing the Northland under a strong upper-level jet and west to southwesterly flow, which will allow a series of mid-level impulses to impact the region. The GFS, ECMWF, and GEM synoptic-scale models all show repeated rounds of precipitation over the Northland, with some subtle differences in the spatial coverage and timing of precipitation, but the overall picture for this pattern appears similar. Instability during this period doesn`t appear to be too favorable for severe storms, with MUCAPE values generally around 500 to 1500 J/kg through the period, although a strong storm or two can`t be ruled out. However, repeated rounds of rainfall, and Pwat values progged by the GFS in the 1.4 to 1.9" range should provide ample moisture for a heavy rainfall scenario, particularly if the low-level jet is in play. The most likely time frame for heavy rainfall will be Friday into Saturday. Generally, temperatures for the rest of the week will be in the lower to middle 70s, still above normal for this time of the year. The average high is in the upper 60s. && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) Issued at 635 PM CDT Sat Sep 8 2018 High pressure will influence the region as it builds into western Quebec. A developing low will move into the Northern Plains tonight and on Sunday. Expect VFR conditions overnight. A strong low level jet will develop across western Minnesota due to the approaching low and departing high. This will bring low level wind shear to INL/BRD between 06Z until approximately 14Z. Expect the mixed layer to grow on Sunday and gusty winds to develop as the low moves eastward on Sunday. Utilized a combination of NAM and RAP guidance in the latest TAF set. && .PRELIMINARY POINT TEMPS/POPS... DLH 47 68 50 71 / 0 0 10 20 INL 51 73 54 72 / 0 0 60 20 BRD 51 71 54 73 / 0 0 30 20 HYR 44 70 46 72 / 0 0 0 10 ASX 46 71 48 73 / 0 0 0 10 && .DLH WATCHES/WARNINGS/ADVISORIES... WI...Beach Hazards Statement until 8 PM CDT this evening for WIZ001. MN...Beach Hazards Statement until 8 PM CDT this evening for MNZ037. LS...Small Craft Advisory until 10 PM CDT this evening for LSZ146>148. Small Craft Advisory until 4 AM CDT Sunday for LSZ143>145. Small Craft Advisory until 10 AM CDT Sunday for LSZ140>142. && $$ UPDATE...WL SHORT TERM...LE LONG TERM...JTS AVIATION...WL
Area Forecast Discussion
National Weather Service Des Moines IA
616 PM CDT Sat Sep 8 2018 .SHORT TERM.../Tonight through Sunday/ Issued at 310 PM CDT Sat Sep 8 2018 Confidence: High Remnants of Gordon continue to exit the region to the east of Iowa and now over Illinois/Indiana as the upper level wave shifts east, taking the system away from Iowa within easterly flow. Ridging aloft and at the surface will take over for the next 24 hours with gradual return of east southeast surface winds with time. Weak cold air advection has been making inroads across eastern Iowa this afternoon...providing the region with a pleasant day despite mid to upper level cloud cover lingering over the southeast half of the forecast area at this time. By tonight the ridge axis will be moving across the area with light winds over most of the region. This will allow for a rather cool Sunday morning with lows in the 40s to the lower 50s. There is one uncertainty tonight in a rather high certainty forecast...with ample soil moisture, light winds and cool temperatures expected...fog may become an issue over portions of our area due to radiational cooling. Hires ARW/NMM favoring low lying river valley regions but even urban areas may see brief period of fog between 10 to 13z. The HRRR is not picking up on any fog potential for now By afternoon only a slight rise in H850 temperatures is anticipated as the ridge slowly slides east. Highs should hold in the lower 70s for the afternoon with a few fair weather cumulus. .LONG TERM.../Sunday night through Saturday/ Issued at 310 PM CDT Sat Sep 8 2018 Confidence: Medium to High Main challenge for the extended will be extent of possible impacts from several northern stream shortwaves that attempt to pull weak cool fronts through the region. High pressure ridge axis aloft and at the surface is anticipated to move little from the Great Lakes to Southern Plains over the next 5 to 7 days. This is in part due to Hurricane Florence approaching the eastern seaboard...which will result in a slowing in the pattern...eventually developing a blocking pattern for the central portions of the country. The tropical system is expected to be nearing the southeast US coast around 00z Friday of next week with some uncertainty regarding the movement of the system thereafter. Consensus remains modest between the operational GFS/Euro with the Euro showing a consistent signal to bring the storm inland over the mid-Atlantic/southeast states. Though the central US will not see any direct effects of the storm... the track will help logjam the upper level pattern forcing most of the western Plains shortwaves north into Canada along with a tendency to weaken any system heading east. Tuesday and Wednesday two weak waves will move across western Iowa with accompanying warm air advection. The pronounced east northeast flow through Tuesday should limit moisture over much of the region. Also the Gulf of Mexico is essentially shut down for now as the expansive Ohio Valley/Great Lakes ridge remains in place. The result will be continued limited chances for rain/thunder over our forecast area through Wednesday. Beyond Wednesday there is actually a retrogression of the upper level pattern which will force any Plains shortwave energy farther northwest of the area for the remainder of the forecast period. During the period building heights and warming H850 temperatures as southern Plains dry air moves back into the region should promote high temperatures well into the 80s by late week into next weekend and some adjustments to forecast highs may be needed over the next few days. The below normal temperatures we are seeing today will become near to slightly above normal again with the rise by the end of the week. && .AVIATION.../For the 00Z TAFS through 00Z Sunday evening/ Issued at 616 PM CDT Sat Sep 8 2018 Mainly VFR conditions expected with mainly clear skies and winds to diminish out of the east to northeast. Could see some fog late tonight toward sunrise so did introduce some MVFR VSBYS. Low confidence in the fog at this time. However if the fog does develop could see some dense fog and then VSBYS would likely fall into IFR or lower. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ AVIATION...Beerends
Area Forecast Discussion
National Weather Service Wichita KS
650 PM CDT Sat Sep 8 2018 .SHORT TERM...(This evening through Tuesday night) Issued at 244 PM CDT Sat Sep 8 2018 Still seeing some very light showers for areas east of the KS Turnpike as main shortwave makes slow progress into south central KS. Remnants of Gordon look to have shifted further east of the forecast area today, keeping most of the heavier showers to the east as well. Low levels remain very moist, with low clouds and stratus over most of the forecast area, as wraparound remnant moisture remains high. So not expecting any clearing in the low clouds until better mid level drying associated with the shortwave moving east of the area occurs late this evening over overnight. As with the previous few nights, high soil moisture and very moist low layers will probably lead to some fog formation across portions of central KS after midnight. Latest SREF data and RAP bufkit soundings hint that some of the fog may become dense early Sun morning, especially near KSLN and possibly south between I-135 and the KS Turnpike into KICT. Will let the evening shift look at things further before going with a dense fog advisory, but the potential is there, if any clearing occurs across central KS early Sun morning. So plan on going with patchy/areas of fog for now. Cloud cover will be stubborn to clear off during the morning hours on Sun, but drying and subsidence in the wake of the shortwave moving across the area, will lead to the low layers finally drying out for the afternoon hours on Sunday. With morning cloud cover temps will again struggle to climb out of the middle 70s as surface dewpoints will remains fairly high and soil moisture will be high. Could see another round of patchy fog for Mon morning, given the high soil moisture from recent rainfall, especially for areas east east of the KS Turnpike underneath the ridge axis that will be situated over the eastern half of Kansas. So will go with a mention of patchy fog again for late Sun night into early Mon. Southerly flow and a warming trend will begin for Mon, as the ridge axis moves east of the area. Ketcham .LONG TERM...(Tuesday through Saturday) Issued at 244 PM CDT Sat Sep 8 2018 Dry weather is expected for most of the work week with the upper flow becoming more zonal or slightly back out of the SW. Medium range models show a lee side trough developing in wrn KS with a gradually tightening of the pressure gradient as we move into the middle of the week. This will lead to some breezy conditions across central KS by Wed-Fri. Ketcham && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) Issued at 639 PM CDT Sat Sep 8 2018 Primary concern through Sunday morning will be low clouds and the potential of fog. Low level drying is finally beginning to take shape early this evening as evidenced on satellite by an area of clearing over NE KS. Recent surface obs in this area show VFR conditions for a change and these improved conditions should begin to work into central KS over the next several hours. The question, then, is how quick does the clearing occur and will there be enough time for BR/FG development. Given the ongoing clearing, confidence in the development of BR/FG is increasing and the latest TAF issuance reflects this (ie. changing TEMPO groups with BR to FM groups). There is certainly some potential for LIFR conditions in FG overnight, especially near KRSL/KGBD/KSLN/KHUT where clear skies look to last the longest. We`ll closely monitor this potential and adjust the TAFs accordingly should confidence increase. For KICT/KCNU, it is less certain how quick the clouds will clear (if at all at KCNU) and the BR/FG potential is lower there for now. Low clouds and any fog should begin to mix out from west to east on Sunday. - Martin && .PRELIMINARY POINT TEMPS/POPS... Wichita-KICT 60 76 58 80 / 10 0 0 0 Hutchinson 58 76 57 80 / 10 0 0 0 Newton 57 75 56 78 / 0 0 0 0 ElDorado 57 74 55 78 / 0 0 0 0 Winfield-KWLD 59 76 57 79 / 10 0 0 0 Russell 58 76 58 81 / 10 0 0 0 Great Bend 58 76 57 81 / 10 0 0 0 Salina 57 76 56 80 / 10 0 0 0 McPherson 56 76 56 79 / 10 0 0 0 Coffeyville 61 75 58 79 / 0 0 0 0 Chanute 59 74 57 78 / 0 0 0 0 Iola 58 74 56 77 / 0 0 0 0 Parsons-KPPF 60 75 58 78 / 0 0 0 0 && .ICT WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...Ketcham LONG TERM...Ketcham AVIATION...RM
National Weather Service Jackson KY
1110 PM EDT Sat Sep 8 2018 .UPDATE... Issued at 1110 PM EDT SAT SEP 8 2018 Updated the forecast package for latest trends in PoPs and temps. Surface warm front will begin to edge northward between now and dawn. PoPs south of this feature were lowered for the remainder of the night as most of activity through the evening has been along and north of the front. HRRR has had a good handle on things thus far and suggest this trend will be the case through the remainder of the night. However, cold front to west is making a move eastward as well. Thus PoPs will be gradually rising from the west through early morning Sunday. Finally, band of very heavy rainfall (nearly a half inch fell in 5 minutes at Frankfort mesonet) accompanied by gusty winds of 30 to 40 mph continues to march eastward at a somewhat slower pace than one might expect. It has been showing signs of weakening over the past hour. If this line holds together it should reach our Bluegrass counties by around midnight. Will be watching this feature closely as it pushes into our area for possible hydro issues and/or special statements. UPDATE Issued at 841 PM EDT SAT SEP 8 2018 Moisture continues to stream into the area. A surface warm frontal boundary is draped across eastern Kentucky, roughly stretching from Whitesburg to Mount Vernon. The warm front is expected to gradually lift northward Sunday morning. Until then this feature will continue to be a focus for isolated to scattered shower and thunderstorm activity through the overnight. WPC has placed portions of Fleming and Bath counties in a moderate risk for flash flooding over the next 3-6 hours due to a couple of training bands of heavy precipitation upstream. Will be watching these carefully as they approach and possibly pass through our Bluegrass counties. Mason County mesonet has already pick up nearly three inches, half of that total through mid-day and the other half through the evening. Seeing estimates of similar totals for a few locations up in that area. Updated grids for latest observations and will freshen up the zone package. Otherwise forecast is on track. && .SHORT TERM...(This evening through Sunday night) Issued at 352 PM EDT SAT SEP 8 2018 Current conditions across the area feature a warm front set up across the area as strong convection has developed along and north of it this afternoon. Due to heavy rainfall this morning north of I-64 and the expected convection this evening, some FFG is a bit lower in the north. Given model soundings in the short term with PWATs in the 2 inch range and skinny CAPE profiles, have decided to issue the Flash Flood Watch starting this afternoon and continuing into Sunday evening. Expect precip in the north to weaken and and become more stratiform with a steady rainfall into the night but still putting down some decent amounts. Later tonight, the front will begin to push east into central Kentucky. This will bring a bit more forcing into the the area and thus a bit more efficiency in the precip amounts and with a saturated air mass in place across the area, flash flooding will certainly be possible. The continued heavy rainfall chances will continue into Sunday as the front pushes east. While the NAM seems to be over doing QPF amounts, models do suggest a slower passage of the front as it crosses eastern Kentucky. This will make for moderate to heavy rainfall amounts over a prolonged period of time. The front finally pushes into eastern Kentucky by 00z. Thus will keep the watch out through 00Z Monday. In fact, with the front still hanging out across central portions of eastern Kentucky, another day of strong storms is possible. Some areas in the south will see some breaks allowing some instability to build south of the warm front and even as the cold front pushes east across the area. By Sunday night, as the front pushes into far eastern Kentucky, much of the heavier precip will come to an end. Thus will insert lower chance pops behind the front as much of the precip winds down. Some fog may be possible behind the front for Monday morning. Overall, a wet short term, period of the forecast is likely with flash flooding possible. .LONG TERM...(Monday through Saturday) Issued at 326 PM EDT SAT SEP 8 2018 At the start of the period an upper level low pressure system will be over northern MI with surface low pressure in southeast MI. A cold front trailing from the surface low will be in the far southeast part of the forecast area. The front will slowly push southeast of the forecast area on Monday, before stalling in the Appalachians. There is good model agreement that upper level high pressure over the western Atlantic will build west through the middle to latter part of the week. This will result in rising heights back into our area. The front that will have pushed southeast of KY on Monday will likely meander back to the northwest by midweek. By late in the week the front will still be in the area but will become increasingly diffuse. All eyes will be on the Atlantic during the coming week as Hurricane Florence makes its way west under the large mid/upper level high pressure system sprawled from the western Atlantic into the eastern U.S. There is still considerable uncertainty with the path of the hurricane and what if any impact it will have on our weather by next weekend. The threat of showers and thunderstorms will remain in the forecast through the week as the already noted front moves through the area, stalls, and then likely returns by mid week. However, any showers and storms will mainly be diurnally driven and should only be isolated to scattered in nature. Temperatures will be a little cooler to start the week with the front having passed to our southeast, but temperatures will climb to well above normal readings again by the middle and latter part of the week. && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) ISSUED AT 841 PM EDT SAT SEP 8 2018 Moisture continues to stream into the area. A surface warm frontal boundary is draped across eastern Kentucky, roughly stretching from Whitesburg to Mount Vernon. This feature continues to be a focus for shower and thunderstorm activity this evening. CIGS are considerably lower along and north of this boundary. And of course VSBYS lower as showers and thunderstorms pass any given location. In general a bad night to be out flying in this area. Stayed close to guidance for terminal forecasts. That being said looking for showers on and off through the overnight. Can not rule out some rumbles of thunder here and there. Do expect a relative lull in showers late tonight into the pre-dawn time frame. But shower and thunderstorm activity picks back up through the day tomorrow ahead of a cold front as it bears down on our area from the west late in the day. Light east- southeast winds will become more southerly with time as the surface warm front gradually lifts northward through the early morning Sunday, generally after sunrise for our eastern and northern most sites, just a few hours before sunrise for our southern most terminals. && .JKL WATCHES/WARNINGS/ADVISORIES... Flash Flood Watch through Sunday evening for KYZ044-050>052- 058>060-104-106>112-119-120. && $$ UPDATE...RAY SHORT TERM...SHALLENBERGER LONG TERM...SBH AVIATION...RAY
Area Forecast Discussion
National Weather Service North Platte NE
710 PM CDT Sat Sep 8 2018 .SHORT TERM...(This evening through Sunday) Issued at 207 PM CDT Sat Sep 8 2018 A northern stream trough will keep low level moisture and stratus over the forecast area tonight. In addition, there will be a slight chance for showers and a few thunderstorms. The 12z GFS look to high on QPFs, and favored the drier NAM, and latest HRRR and RAP runs. Chances look to remain mainly north of I80, and west of Burwell, Stuart and Naper. Low fairly mild in the upper 50s. On Sunday, lingering showers possible until 10 am cdt, from North Platte northeast through Ainsworth and Bassett. Otherwise, widespread stratus will erode from west to east. South winds will increase to 10 to 20 mph, as the surface pressure gradient tightens up. Highs to reach around 85 northwest sandhills to around 75 far southeast zones, which remains near the previous forecast. .LONG TERM...(Sunday night through Saturday) Issued at 207 PM CDT Sat Sep 8 2018 Another northern stream disturbance Sunday night will bring a slight chance for showers or a few thunderstorms to mainly Keya Paha and Boyd counties. Beginning Monday, zonal flow aloft will become increasingly southwesterly as the week progresses, along with a warmup to above normal highs. Highs Monday in the low to mid 80, will range in the mid to upper 80s Tuesday through Friday, then back in the low to mid 80s Saturday. Dry in the extended, except for a slight chance for thunderstorms Tuesday evening in north central Nebraska. && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) Issued at 710 PM CDT Sat Sep 8 2018 Low cloudiness will push into western and north central Nebraska overnight with IFR ceilings developing at the KLBF terminal after 05z Sunday. MVFR ceilings will set in across northern Nebraska overnight. Skies will gradually clear Sunday afternoon at both terminals. && .LBF WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...Roberg LONG TERM...Roberg AVIATION...Buttler
Area Forecast Discussion
National Weather Service Medford OR
857 PM PDT Sat Sep 8 2018 .SHORT TERM...A low pressure system is located well to the northwest off the British Columbia coast with zonal flow aloft over the area tonight into Sunday. As the low moves into the British Columbia coast, a cold front will push into the Pacific Northwest coast Sunday evening and night. Models continue to show that this front will bring light showers to the southern Oregon coast and inland over Coos and portions of Douglas County Sunday night and Monday morning. Also expect this system to bring a cooling trend on Monday. High temperatures are expected in the 70s to around 80 for inland areas on Monday. Additionally some east side valleys may see lows in the mid to lower 30s Monday morning. With the front, also expect breezy northwest winds across many inland areas, including from the Cascades east and into the Shasta and Rogue valleys, late Monday afternoon and Monday evening. Areas of smoke are expected tonight and Sunday downwind of wildfires. This will bring smoke impacts into Joesphine, Jackson and Siskiyou counties with lesser impacts into Klamath, Lake and Modoc counties. Areas of smoke are likely to continue into Monday as well. However, some improvement is expected late Monday as the front moves into the area, bringing cooler temperatures and increased winds aloft to transport smoke out of the area. Tuesday into Wednesday, models show and upper trough settling over the area with an upper low moving down the Pacific Northwest. This pattern is expected to bring additional cooling to the area and more fall-like temperatures. Light showers are also possible over area west of the Cascades, with best chances along the coast from Cape Blanco northward and across Douglas county. Models continue to show variability on how much shower activity will progress inland south of the Umpqua Divide and east of the Cascades. So confidence in any showers for these areas remains low. && .AVIATION...For the 09/00Z TAFs...Stratus and fog with IFR to LIFR ceiling and visibility will be common along the coastal strip through the night, especially north of Cape Blanco. Stratus will also gradually build into the western Umpqua Basin and may make it right up to KRBG by morning. Elsewhere, conditions will be VFR with the exception of those areas affected by smoke. Current high resolution smoke models show this to continue be from Grants Pass to KMFR and to a lesser degree KLMT. Visibility restrictions due to smoke in these areas will vary greatly through the night, but conditions are generally expected to remain MVFR or better. MVFR and local IFR visibilities are also expected tonight and Sunday in Siskiyou county, including at KSIY and KMHS. Periods of MVFR visibilities may also occur east of the Cascades in Klamath County. -CC/Wright && .MARINE...Updated 800 PM PDT Saturday, 8 September 2018... Relatively weak winds and low seas will persist into Sunday morning. Northwest swell will increase Sunday into Monday night, but will not become steep. A series of weak fronts will move across the waters next week with seas slowly trending slightly lower Tuesday into Friday. -DW/Wright && .PREV DISCUSSION... /Issued 239 PM PDT Sat Sep 8 2018/ DISCUSSION...High pressure has built into the region behind a departing cold front, but an upper level low has taken up residence off the coast of the Queen Charlotte Islands of British Columbia. This will keep cool onshore flow over our forecast area for the next few days. It also means a few impulses will pass over the area as they orbit the low, and these will provide reinforcing shots of cool air, and at least a couple of chances for rain for portions of the area. For smoke, this pattern will mean relief for most areas, both by blowing away the accumulated smoke and by toning down activity on many of the local wildfires. However, west winds do mean that areas in the vicinity and to the east of the fires will still remain under the plumes, and therefore will not fully clear. HRRR smoke models continue to push smoke from the Klondike and Natchez fires into the Illinois, Applegate, and Rogue Valleys, while smoke from the Delta fire streams into the area around Mount Shasta City and southeastern Siskiyou County. With the next front`s arrival late Sunday and into Monday, it is possible much of the smoke production and fire activity will have died down enough to more significantly clear the air. This front appears a bit more robust than the last when it comes to moisture, and we have increased the chances of light rain along the coast and into the Umpqua Basin Sunday night and Monday morning. Those south of the Umpqua Divide and east of the Cascades will not be so lucky, as the weak front will wash out as it crosses onshore, and the bulk of moisture and lift will stay well to the north. The same can be said of the next, very similar front due into the area Tuesday into Wednesday. While moisture will be limited and most areas should remain dry, the effects of the fronts will be felt by all when it comes to temperatures, as highs on Monday through Wednesday are expected to be 5 to 10 degrees below normal for this time of year. In fact, it is possible that very few places in the forecast area will reach 80 for a high Tuesday, and nighttime lows in our usual cool spots may make a good run for the freezing mark. As a result, some locations, such as Tulelake, may need to be on the lookout for frost/freeze conditions beginning Monday morning. The low itself finally drops south into the region Wednesday into Thursday, before opening up and sliding inland late in the week. This will keep a chance of showers in the area Wednesday night into Thursday. With the trough passing overhead, it is even possible that an isolated thunderstorm could develop along and east of the Cascades in the afternoons, but chances are the area will only see light showers, as once again moisture inflow and overall instability are limited. Heading into the weekend, models are coming into much better agreement than we have seen over the past several days. Both the GFS and ECMWF solutions show a ridge building into the area from the south Friday into the weekend, with a thermal trough redeveloping along the coast. This pattern would produce dry east winds and a return to near or slightly warmer than normal highs for Friday and Saturday, so the forecast has been changed to trend towards this idea. -BPN && .MFR WATCHES/WARNINGS/ADVISORIES... OR...None. CA...None. Pacific Coastal Waters...None. $$ CC
Area Forecast Discussion
National Weather Service New York NY
1046 PM EDT Sat Sep 8 2018 .SYNOPSIS... The area will remain under the influence of high pressure to the north and a stationary front to the south through Sunday. The front then begins to move northward as a warm front Sunday night, lifting north of the area Monday night. An approaching cold front will then stall or dissipate across the area Tuesday into Wednesday. High pressure builds to the north of the area for the end of the week. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... Just a few minor adjustments to account for the bulk of the light rain moving off to the east. Therefore conditions will dry out from NW to SE the next couple of hours. Additionally, slight adjustments were made over the next 6 hours with respect to wind. HRRR and GLAMP blend was used here as this guidance was lining up better with current conditions. With the stationary front remaining south of the area and an upper trough slowly approaching from the west, an overrunning pattern remains over the area with occasional light showers expected through the night, particularly across coastal areas. Precipitation chances may briefly decrease across the Lower Hudson Valley and Connecticut this evening as high pressure builds to the north, advecting drier air southward. However, confidence is low in this scenario, as precipitation has continued to redevelop through much of the day. Otherwise, temperatures will remain below climatological normals through the night, despite overcast skies, as cooler Canadian air is advected into the area and onshore flow persists. The high risk of rip currents on the ocean beaches continues into tonight, with waves and swell increasing well ahead of tropical cyclone Florence. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/... Winds strengthen through the day on Sunday as the stationary front to the south begins to slowly move northward, strengthening the pressure gradient between the high pressure to the north. Cloudy conditions are expected to persist, especially with opaque cirrus ahead of the remnants of tropical cyclone Gordon to the west. Similar to Saturday, an overrunning pattern will lead to the chance for off and on showers through the day, gradually increasing into the night. Have delayed the onset of likely precipitation, as more recent deterministic and high resolution models suggest an initial struggle to saturate drier low levels, with the Canadian high pressure remaining to the north. As the upper trough nears and attendant front moves closer to the area, chances of showers will increase overnight and towards day break, with moderate to heavy rainfall possible at times, particularly to the north and west of the city. The high risk of rip currents on ocean beaches continues into Sunday and Sunday night. A high surf advisory is now in effect for Sunday and Monday. && .LONG TERM /MONDAY THROUGH SATURDAY/... A confluent flow between the southern and northern branches of the polar jet will retreat to the northeast along with strong surface high pressure over the Canadian Maritimes. The cool, dry air over New England and a southern branch low over the Great Lakes will result in deep-layered warm advection across the region Monday with a moderate rainfall event. This will be more of a stratiform rain, but weak elevated instability may allow for an isolated afternoon/evening thunderstorm. A warm front works north of the area Monday night with the return of a warm, muggy airmass as winds become southerly. Precipitation will become more scattered and convective in nature Monday night through Wednesday. A weakening cold front will then move into the area Tuesday afternoon. There is some uncertainty as to whether or not the boundary passes just east of the area, or dissipates across the region through midweek. The associated southern branch shortwave trough dampens as it lifts northeast of the region and the western Atlantic ridge expands westward into the Ohio Valley. This in turn will likely suppress convection for the second half of the week with high pressure building to the north of the region. Easterly flow will likely develop and bridge across whatever is left of the front. The aforementioned upper level ridge will also become a big player in the future track of Tropical Cyclone Florence. Global models do differ in the magnitude of the western Atlantic ridge with a potential weakness developing late next week near the eastern seaboard. The latest official forecast from the National Hurricane Center takes the system westward toward the southeast and Mid Atlantic coasts toward the second half of next week. Outside of a prolonged period of swells, resulting in rough surf, dangerous rips currents, and beach erosion, it is still too early to determine if the region will experience additional impacts. To maintain good situational awareness, please refer to the latest official forecast from the National Hurricane Center ( Temperatures moderate through the period with highs in the 70s Monday, to the lower and middles 80s for the rest of the week. && .AVIATION /03Z SUNDAY THROUGH THURSDAY/... Canadian high pressure builds to the north through Sunday morning as a frontal boundary remains across the mid Atlantic region. The high retreats to the northeast Sunday afternoon as the frontal boundary begins to move north as a warm front. VFR through the forecast period. Light rain has pushed south of all terminals. Conditions should remain mainly dry through at least 06Z, however, rain showers will slowly move back overnight, so added VCSH after 06Z for metro terminals, with later times for all other terminals. Better chances for rain after 20Z Sunday for the metro terminals. N to NE winds 10-15KT shift to the NE to E overnight with occasional gusts as high as 20KT through this evening. Winds increase to around 15 to 20KT on Sunday afternoon with up to 25KT by after 20Z. .OUTLOOK FOR 00Z SUNDAY THROUGH THURSDAY... .Sunday night-Monday...MVFR, with IFR possible. Rain, locally heavy at times possible. E-SE winds 15-20KT, G20-30KT. .Monday night-Tuesday...MVFR possible and a chance of showers/tstms. SW winds G15-20KT possible. .Tuesday night-Thursday...MVFR possible in a chance of showers/tstms. && .MARINE... Conditions will steadily deteriorate through the weekend, particularly on the ocean, as swell builds and northeasterly to easterly winds increase. The strongest winds are expected Sunday night into Monday, and a gale watch is now in effect for the ocean waters. SCA-level winds are expected elsewhere beginning Sunday night. Winds will diminish late Monday, however seas will remain well above SCA levels on the ocean due to long period swells being generated by Tropical Cyclone Florence. To maintain good situational awareness, please refer to the latest official forecast from the National Hurricane Center ( && .HYDROLOGY... Around one to two inches of rain with locally higher amounts is fcst Sun thru Mon ngt, with the greatest amounts expected across northeastern NJ into the Lower Hudson Valley. Although the main threat right now is for minor urban and poor drainage flooding, a more significant flood risk will be possible if the axis of hvy rain ends up further e than expected attm. Any tstms Tue-Fri will be capable of producing locally hvy rain. && .TIDES/COASTAL FLOODING... Minor coastal flooding is possible with this evening and again during the morning high tide cycles across portions of the south shore back bays of Kings, Queens and Nassau counties. The combination of increasing astronomical tides from a new moon occurring Sunday, an increasing easterly flow and building SE swells will bring the potential for more widespread minor to locally moderate coastal flooding beginning late Sunday and persisting into early next week. Tidal departures of 1 to 1 1/2 ft are all that is needed at most locations for minor coastal flooding benchmarks to be met, however some of locations on the south shore of Long Island and western LI Sound only need between 1/4 and 3/4 ft. && .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...High Rip Current Risk through Sunday evening for NYZ075-080- 081-178-179. High Surf Advisory from 11 AM Sunday to 6 PM EDT Monday for NYZ075-080-081-178-179. NJ...None. MARINE...Small Craft Advisory from 6 PM Sunday to 6 PM EDT Monday for ANZ330-335-338-340-345. Gale Watch from Sunday evening through Monday afternoon for ANZ350-353-355. Small Craft Advisory until 6 PM EDT Sunday for ANZ350-353-355. && $$ SYNOPSIS...MD/DW NEAR TERM...JE/DW SHORT TERM...MD LONG TERM...DW AVIATION...JP MARINE...MD/DW HYDROLOGY...MD/DW TIDES/COASTAL FLOODING... EQUIPMENT...
Area Forecast Discussion
National Weather Service Pueblo CO
608 PM MDT Sat Sep 8 2018 .UPDATE... Issued at 600 PM MDT Sat Sep 8 2018 Updated to adjust sky cover and fog potential across the Plains for tonight into Sunday morning. Most models are in agreement that low stratus and area of fog are expected to develop, especially given the low level flow and similar conditions to last night. No other changes at this time. Mozley && .SHORT TERM...(This evening through Sunday) Issued at 301 PM MDT Sat Sep 8 2018 Relatively tranquil and mild conditions currently gracing southern Colorado with recent GOES imagery indicating developing cumulus fields over many western mountain locations. Latest data indicate that next upper disturbance moving into northwestern Colorado with recent lightning strikes noted over far northeastern Utah. Incoming HRRR computer simulation indicates that isolated primarily higher terrain showers and thunderstorms will be possible over southern Colorado from this afternoon into this evening, while recent NamNest solution is slightly more aggressive with precipitation over higher terrain locations generally along and west of the Interstate 25 corridor into this evening. So for sensible weather, will depict isolated primarily higher terrain thunderstorms into this evening. In addition, conditions again favorable for areas of low clouds/fog over eastern sections from later this evening into Sunday morning. For now, will trend with low cloud development over far eastern locations before midnight, with west-ward push into/near portions of the Interstate 25 corridor a few hours after midnight. Then, low cloud conditions expected to improve as the morning progresses Sunday morning with far eastern sections the latest to experience improvement. For Sunday, next upper disturbance is expected to rotate across the forecast district and will be capable of producing next round of isolated to scattered primarily afternoon into evening showers and thunderstorms. In addition, gradient winds are expected to remain light during the next 24 hours, while maximum temperatures on Saturday are projected to run near to a few degrees warmer than values noted Saturday. .LONG TERM...(Sunday night through Saturday) Issued at 301 PM MDT Sat Sep 8 2018 ...Some Lingering Moisture Monday then Mainly Hot and Dry... Models still have a little bit of lingering moisture over the forecast area Monday as a very weak upper level disturbance moves across. However, the airmass will be drying out in the lower levels with dewpoints generally in the 30s or less from the I-25 corridor westward. Dewpoints will be higher east of the corridor but the airmass will be too stable for storms. So, there will be some isolated afternoon and evening storms along and west of the I-25 corridor Monday but little activity east of the corridor. The primary storm threats will be lightning and gusty winds. On Tuesday, forecast models have dry southwest flow spreading into Colorado, boosting temperatures and decreasing storm chances. The chance for storms will be just about zero on Tuesday. An isolated storm may find a way to fire along or near the Kansas border during the afternoon but confidence is pretty low. Temperatures Tuesday afternoon will climb back to midsummer levels. Wednesday through Saturday will be hot and dry with temperatures holding at midsummer levels through the period. The heat won`t be quite as bad as midsummer, though, as the nights will be a little longer and cooler than midsummer. With hot and dry weather in the forecast, now is a good time to think about how fire danger levels might change in the weeks ahead. This is the time of year when daily afternoon showers decrease and periods of dry weather increase. As a result, it`s also the time of year when grasses begin to dry out. If we fail to see some decent amounts of wetting precipitation from time-to-time, we`ll see fire danger levels escalate once again. Guess it`s time to hope for the best but prepare for the worst. Any fire mitigation that could be done where you live? && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) Issued at 301 PM MDT Sat Sep 8 2018 Overall, VFR conditions are anticipated over the TAF sites into this evening, with recent HIRES model solutions continuing to indicate that isolated showers and thunderstorms will be possible near but not directly impacting the TAF sites into this evening. In addition, recent HIRES models indicating that stratus is expected redevelop over the far southeast Colorado Plains later this evening and push west towards the I-25 corridor after 09Z tonight with KPUB having the highest potential to notice some low cigs/etc. with this development. Computer simulations then project that VFR conditions will return to far eastern locations of southeastern Colorado by later Sunday morning with next round of isolated to scattered showers and thunderstorms then impacting southern Colorado from Sunday afternoon into Sunday evening as next shortwave impacts the area. && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...MOZLEY SHORT TERM...77 LONG TERM...LW AVIATION...77
Area Forecast Discussion
National Weather Service Blacksburg VA
841 PM EDT Sat Sep 8 2018 .SYNOPSIS... A wedge of cool air will surge south through the region tonight resulting in lingering showers as well as patchy drizzle into the early morning hours of Sunday. The wedge will remain in place through Sunday with a continued chance for showers through the latter portion of the weekend. Low pressure crossing from the Ohio Valley through New England will erode the wedge on Monday then stall a weak front over the Mid Atlantic Tuesday and Wednesday, before Florence begins to impact parts of the East Coast late in the week. && .NEAR TERM /THROUGH SUNDAY/... As of 830 PM EDT Saturday... Cold front near the Blue Ridge should continue to surge southwest through the region overnight reaching southern sections by morning. This will result in a quick 10-15 degree drop in temperatures along with a round of gusty northeast winds. Convergence zone just ahead of the boundary continues to help fire heavy rain producing convection per lingering decent instability across southern and southwest sections. Latest HRRR continues to develop showers/storms along the front over the far southern sections with some of this becoming elevated upon crossing into the cooler air to the north. Expect once the shallow cool pool undercuts the rest of the convection will gradually see a transition from showers to more stratiform nature light rain/drizzle after midnight. Thus adjusted pops to account for more coverage east and less west where the earlier band continues to stay just off to the west. Also slowed down the switch from convective mode over the south/west a few hours but maintained overall high chance to likely pops through early Sunday. Kept low temps close to previous with only a small bump up in lows across the south at this point. Previous discussion as of 230 PM EDT Saturday... Showers and thunderstorms have developed ahead of a developing wedge pushing down from the south. Precipitable water values remain elevated so the threat of excessive rainfall and localized flooding remains. Additionally, even though the dynamic environment is weak there will be a good amount of low level shear in the vicinity of the wedge front so expect some degree of organization to convection later this afternoon. As the wedge pushes down in earnest this evening this will enhance convergence and isentropic lift and continue with a good chance of showers overnight. The wedge remains in place through Sunday with weaker isentropic lift continuing showers and some drizzle through the day. There will be some destabilization on the western/southern edge of the wedge tomorrow but the better chances for thunder will be just outside of our region. Temperatures tonight will range from the mid/upper 50s from the Alleghany Highlands to the low/mid 60s elsewhere. Highs Sunday will be in the low to mid 60s in the heart of the wedge, rising to the mid 70/upper 70s west of the Blue Ridge and from Southside to the NC foothills. && .SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/... As of 1151 AM EDT Saturday... The weather will remain unsettled Sunday evening into Sunday night. Southwest flow at 500 mb continues and upper diffluence increases over the Mid-Atlantic region along with lift under the left entrance region of an upper jet streak. A warm front will lift north across the region. The low level southwest flow will erode wedge late Sunday night into Monday morning. Low temperatures Sunday night will range from the upper 50s in the mountains to around 70 degrees in the piedmont. The warm front continues to lift north on Monday as a cold front approaches from the west. The warm, humid, summerlike air mass returns to our area with high temperatures Monday from near 70 degrees to the mid 80s in the piedmont. Scattered showers and thunderstorms mainly afternoon and evening are expected. With the loss of solar heating, most of the convection will diminish Monday night. Areas of low clouds and fog will develop Monday night into Tuesday morning. Low temperatures Monday night will feature readings from around 60 degrees in the northwest mountains to the lower 70s in the piedmont. Frontal boundary will stall across the region Tuesday into Tuesday night with showers and thunderstorms likely. The backing of the low-level flow Tuesday into Wednesday could permit some heavy showers to form in upslope areas on the east side of the mountains as moisture deepens in the profiles and precipitable water values. High temperatures will moderate into the lower 70s in the west to the mid 80s in the east. Low temperatures Tuesday night will generally be in the lower 60s to the lower 70s. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... As of 1151 AM EDT Saturday... All eyes on the Atlantic as Florence, likely a strong hurricane after intensification on Sunday, appears to be posing an increasing threat to the southeastern US coast, but there is still lots of time for that to change. Please refer to the latest NHC advisory on Florence for details on strength, movement and track. Strong upper ridge dominates just off the mid-Atlantic coast with associated surface high pressure over the East Coast, which may make it hard for the storm to turn north for awhile. The strength and shape of the blocking upper high will dictate where Florence will track. In any case, warmer conditions each day under the ridge and enough moisture to result in diurnal and mainly mountain afternoon and evening convection. Low level boundaries and moisture convergence will create scattered showers and thunderstorms. If Florence does indeed head in the direction of the Carolina coast and even inland into Virginia, that would result in maybe a day of sinking motion and lack of precipitation perhaps around Wednesday or Thursday. The range of possibilities of actual track still extends from Florida northward to at least the Mid-Atlantic which includes a chance of it recurving just offshore. If Florence ends up heading in our direction we could experience impacts as early as Thursday, but more likely Friday, from increasing north to northeast winds and then eventually heavy rain. The major point to make at this time regarding Florence is that while it is way too soon to have much confidence in whether or not it will impact the RNK county warning area, everyone needs to keep a close eye on forecasts of Florence from the National Hurricane Center and the NWS office like ours over the weekend. By Monday of next week we should have a much better handle on the track of Florence and who will/will not be impacted by this major hurricane. A track through South Carolina into western North Carolina and then into southwest Virginia would be the worst case scenario for us, while a further eastward track along the coast would have considerably less impact on our region, perhaps no more than just gusty north winds. Now is the time to begin considering what preparations need to be made should Florence directly impact our area. For the medium range forecast, the consensus guidance which is consistent with an extrapolation of the official NHC forecast suggests the storm would move into eastern VA by late Thursday into Friday, so the wind and PoP forecast grids reflect that idea for now, but with wind speeds toned down considerably from what they would be should Florence actually take a further westward track. There still is a great deal of uncertainty in extended forecast. Stay tuned throughout the days ahead as the forecast is likely to change several times in the next few days. && .AVIATION /00Z SUNDAY THROUGH THURSDAY/... As of 650 PM EDT Saturday... Scattered showers thunderstorms will continue to affect TAF sites into late this evening, espcly along the corridor from KLWB to KLYH and KDAN where coverage looks to be the most widespread. Will include a prevailing group for shra/tsra pending locations of showers in regards to the terminals at release. Otherwise continuing with a VCTS/VCSH mention and including a TEMPO group as well where sub-VFR looks to be rather brief. A wedge of cool air will push south behind a passing cold front overnight with this boundary reaching the Blue Ridge locations by midnight and much of the rest of the region in the early morning hours of Sunday. This will bring more widespread IFR/LIFR conditions behind the front with winds becoming east/northeast and a bit gusty mainly east of the Blue Ridge. Isentropic lift over the wedge will keep some showers around before gradually tapering to drizzle and fog. There may be some improvement in conditions late in the period but with a solid wedge in place will opt to stay with mainly IFR/LIFR conditions through much of Sunday as well. High confidence in precipitation and developing IFR/LIFR conditions. Extended Discussion... A wedge will remain in the area into Sunday night, so Sunday night will likely again have widespread IFR/LIFR conditions. The wedge erodes Monday with scattered MVFR showers and thunderstorms. MVFR and IFR thunderstorms are likely on Tuesday and Wednesday. May see overall VFR return Thursday pending the timing of Florence with much of the region still west of this system until late week. Confidence average for all elements through Tuesday. Below average confidence Wednesday into Thursday. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...None. NC...None. WV...None. && $$ SYNOPSIS...JH/MBS NEAR TERM...JH/MBS SHORT TERM...KK LONG TERM...KK AVIATION...AMS/JH/MBS