Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 06/26/18

Area Forecast Discussion
National Weather Service Sioux Falls SD
1054 PM CDT Mon Jun 25 2018 .SHORT TERM...(This evening through Tuesday) Issued at 339 PM CDT Mon Jun 25 2018 Currently, satellite imagery is showing the upper low just about in the middle of Nebraska, with a surface low centered in southeast Nebraska. The various models are in good agreement in bringing the upper low eastward to along the Missouri River of Nebraska and Iowa by 06Z Tuesday, moving into northeast Iowa by Tuesday afternoon. The main concern late this afternoon and evening is of course the potential for heavy rain, or at least pockets of heavy rainfall. The chances for severe weather in northwest Iowa and adjacent locations are becoming more remote as the clearing line has remained to the south, not allowing for a destabilization of the atmosphere. With the upper low slow close, would not be surprised to hear reports of a few funnels late this afternoon along and south of I 90 due to vorticity, but the threat for bona fide tornadoes is extremely low. The rainfall threat remains however, but this upper low is quite different then the upper low of last Wednesday and Wednesday night. First of all is not quite as strong. Secondly, the strongest dynamics are mainly confined to the time frame of right now through mid this evening, as QG forcing pinwheels northward from the upper low and extends from our eastern zones, back into southwest Nebraska at 00Z. However the QG forcing greatly decreases in strength between 00Z and 06Z tonight. So there is a question on just how heavy the rainfall will be. If we did not already receive a ton of rain in the previous week, we would not need a flash flood watch this evening as there will likely not be the barn burner 3 to 7 inch amounts which have been common recently. Instead, current thoughts are that there will be pockets of heavier rainfall when cells would happen to train for a couple of hours allowing local amounts to top an additional two inches through midnight. However believe widespread amounts will be in the three quarters of inch to inch and a half range. And the heavier amounts will be confined to along and south of I 90. The individual cells bringing the heaviest rainfall should be fairly progressive as the whole thing lifts northward, before weakening late this evening. Earlier, already extended the flash flood watch area in time through 04Z this evening. After 04Z, the various CAMs show a great decrease in rainfall both in coverage and intensity. In fact, the HRRR and HRRRx really keep the heaviest rainfall confined to the MO River valley. On Tuesday on the backside of the upper low, lingering showers and isolated thunderstorms will be a threat mainly east of the James River valley. Sounding profiles are moist through 4km with mid level temperatures near 700mb less than +10C. So therefore it will not take much to get a shower going here and there. But the activity will be isolated to scattered as forcing by Tuesday is limited. Temperatures are forecast to be moderately cool for this time of year with the amount of moisture present, and highs should be in the 70s, with perhaps lower 80s in south central SD zones. .LONG TERM...(Tuesday night through Monday) Issued at 339 PM CDT Mon Jun 25 2018 By mid week, an upper ridge of high pressure begins to redevelop over the south central United States which will provide rising heights for our area. There may possibly be a weak wave riding over this ridge Wednesday night worth a few pops, but overall chances for rainfall are real skittish until Saturday or Saturday night. This is due to an upper trough of low pressure moving into the intermountain west late this week, then toward the western plains on Saturday and Saturday night. Saturday will feature an unstable southwest flow aloft in our area, and the corresponding warm air advection should help to kick off showers and thunderstorms. The storms should be progressive however as the corresponding low level wind shift is moving from west to east as the upper wave also moves eastward. So at this time, this feature may not exacerbate the on going flooding. With the building ridge, it will become quite warm and humid, especially on Thursday and Friday where moist dew point values will help to produce widespread heat index values in the 90s to around 100 degrees. && .AVIATION...(For the 06Z TAFS through 06Z Tuesday night) Issued at 1049 PM CDT Mon Jun 25 2018 Scattered rain showers with isolated thunderstorms will be possible during the early overnight hours. By daybreak Tuesday, most showers are expected to end, with low cloud decks and patchy fog over much of the region. Fog will dissipate during the morning, and cloud decks will rise and decrease in coverage during the day. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...None. MN...None. IA...None. NE...None. && $$ SHORT TERM...MJ LONG TERM...MJ AVIATION...VandenBoogart
Area Forecast Discussion
National Weather Service Wilmington NC
1013 PM EDT Mon Jun 25 2018 .SYNOPSIS... A weak front will remain stalled over the area through Tuesday before Atlantic high pressure rebuilds. Another front may drop into the area Friday before dissipating. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... As of 1000 PM Monday...After collaboration earlier with SPC, we believe the low levels were overturned so strongly by earlier convection that there is now insufficient energy for severe thunderstorms overnight. Relatively steep lapse rates aloft still exist and will probably fuel the continuation of showers and thunderstorms, but the probability of future severe weather has dipped below the threshold needed for a watch. High PoPs (70-100 percent) remain in the forecast for the next few hours, with gradually drying conditions overnight. Discussion from 845 PM follows... Another active afternoon and evening with widespread showers and thunderstorms, feasting on boundary interactions and CAPE of 2000-3000 J/kg. Wind damage again appears to be the primary severe weather mode as the only report of hail was dime size in Columbus County around 700 pm. Convection so far has been primarily surface based, but a subtle increase in 900-650 mb westerly winds is advecting in a hot airmass that was strongly heated across central and western South Carolina all day. These relatively steep lapse rates aloft now encountering our very moist low levels should maintain elevated CAPE values of 1500-2000 J/kg through midnight. A broken squall line moving across the Piedmont counties should reach I-95 in the next 1-2 hours. Additional wind damage is quite possible with these storms. HRRR trends have been toward less of an organized severe potential as this activity moves on toward the coast overnight, however as we saw last night steep mid-level lapse rates seem to be a significant determining factor in how tenacious convection will be to continue on after dark. The next challenge (besides more warnings coming up in the next few hours) will be determine how long and for what areas to do a local extension of the Severe Thunderstorm Watch. -TRA Discussion from 300 PM follows... A Severe Thunderstorm Watch is in effect for the entire area until 10 PM tonight. A cold front is currently moving south into the area. Based on surface observations, it appears the location of the front as of 4 PM is near the NC/SC border. Convection is currently being driven in two different locations. The first is for the coastal counties, due to the sea breeze moving inland. The second is further inland, which is due to a mid-level impulse approaching from the west. The expectation is for convection to increase for both areas, with the inland convection becoming more dominant as we head into the evening. There is plenty of instability in place, especially with temperatures well into the 90s and dew points in the lower 70s. SPC Mesoscale Analysis currently shows MLCAPEs ~2,500 J/kg across the southernmost tier of the CWA. MLCAPEs are forecasted to increase over the next few hours with a band ~3,000 J/kg across the southernmost tier of the CWA and along the coast. Low level lapse rates are steep, up to 8 C/km. PWATs are also around 2". All of these and more will help increase the convective potential over the upcoming hours. The main threat will be damaging winds. But small hail will also be possible. Heavy rain should also be expected in these storms. Though, they appear to be moving at a decent rate, which will help to limit the flooding potential. However, any training or backbuilding of storms over the same locations would cause issues. The POPs generally reflect the timing of multiple CAMs and radar trends. The worst conditions are expected in the evening, then improving as the bulk of activity moves offshore. Though, remnant showers should persist well into the night, especially for the coastal counties. Overnight lows will generally range from 70-75 degrees. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/... As of 300 PM Monday...A relatively active pattern is likely to persist into Tuesday as a weak front remains stalled over eastern NC while a series of upper shortwaves move through the area. Somewhat drier, more stable air will shift in from the north as surface high pressure builds down the Eastern Seaboard. Better instability will exist across the SC Pee Dee region which will be south of the front. We show 40-50% PoPs Tuesday into Tuesday evening, diminishing Tuesday night as the greatest upper vorticity energy moves southeast of the area. A marginal severe threat will exist mainly along the NC/SC border and the Pee Dee region where the best instability will exist. High temps will be noticeably cooler given the weak cold air advection. Temps will top out in the upper 80s with heat indices in the mid to upper 90s. Temperatures will gradually warm Wednesday through Thursday as the upper ridge builds toward the eastern United States. Mainly diurnal convection is expected each day with the sea breeze the main driver, though weak shortwave energy could also drive some convection. Heat indices may be back above Heat Advisory criteria again on Thursday. && .LONG TERM /THURSDAY THROUGH MONDAY/... As of 300 PM Monday...A large upper ridge will build over the area Thursday night through Sunday before shifting east of the area early next week. Hot and muggy conditions are expected through Sunday, with the potential for Heat Advisories. Mainly diurnal convection is anticipated each day. Slightly cooler temps will occur Monday into Tuesday as stronger onshore flow develops. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/... As of 00Z...Convection is ongoing and rather chaotic at this time. There will be outflows that will trigger new convection for the next 2-3 hours. Later tonight, a more organized area of convection will move into the western CWA around 03Z, but will start to weaken by 06Z. Leaning on the HRRR model for this. Tuesday, mainly cloudy skies with a mainly northerly wind. Post frontal stratus is expected. Extended Outlook...Scattered showers and tstms will affect all terminals Tuesday night. Brief period of MVFR ceilings possible at NC terminals Tue night. Otherwise mainly VFR outside brief restrictions in scattered showers/tstms. && .MARINE... NEAR TERM /THROUGH TONIGHT/... As of 845 PM Monday...Winds are almost exclusively driven by thunderstorm outflows at the moment. The overall synoptic wind is southwest for areas south of Cape Fear, and more easterly north of Cape Fear, as a weak front is attempting to settle south along the coast. We likely won`t see these winds settle down until several hours after thunderstorms dissipate late tonight. Discussion from 300 PM follows... A cold front will move south into the area, then stall over the coastal waters. North of the front, expect light winds, generally from the north. South of the front, expect light winds, generally from the south. Seas will range from 2-3 ft. SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... As of 300 PM Monday...Brief period of E to NE flow over the NC waters Tuesday into Tuesday night before Atlantic high pressure rebuilds and flow becomes southerly. LONG TERM /THURSDAY THROUGH FRIDAY/... As of 300 PM Monday...SW flow Thursday into Thursday night, becoming variable Friday as a weak front drops into the waters. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...None. NC...None. MARINE...None. && $$ SYNOPSIS...TRA NEAR TERM...TRA SHORT TERM...99 LONG TERM...99 AVIATION...DL
Area Forecast Discussion
National Weather Service Indianapolis IN
1151 PM EDT Mon Jun 25 2018 .UPDATE... The AVIATION Section has been updated below. && .SYNOPSIS... Issued at 340 PM EDT Mon Jun 25 2018 Showers and thunderstorms will increase in coverage through midweek as an upper low and associated surface wave track across the Great Lakes. Once this feature passes on late Wednesday...drier conditions will return with a transition to hotter and more humid conditions by late week into the weekend as a broad upper ridge expands into the Ohio Valley. && .NEAR TERM /Rest of This Afternoon and Tonight/... Issued at 340 PM EDT Mon Jun 25 2018 Back edge of the rain associated with the wave tracking east through Kentucky continues to pull away from southeast counties this afternoon. Additional showers have developed in the wake of this system however across the southwest half of the forecast area. Obs analysis is suggestive that a weak surface wave may be the culprit and radar interpolation supports this with showers rotating slowly counterclockwise. Clouds had encompassed much of the area and were keeping temperatures down as a result. Most locations remained in the 70s as of 19Z. The primary focus right out of the gate is with the new shower development which most model data is not handling well. Recent runs of the HRRR are beginning to pick up on the feature. Should see a gradual decrease in shower coverage over the next few hours as the wave shifts east and narrow ridging aloft expands into the area by early this evening. Will carry chance pops for the next few hours over the southwest half of the forecast area to account for current showers. With the instability gradient focused closer to the Ohio not anticipate any impacts from thunder through early evening. High pressure centered over the eastern Great Lakes continues to maintain a dry easterly flow into parts of the region and is effectively blocking the warm front draped from central Missouri into western Kentucky from making any progression to the northeast. That will hold for much of tonight as the high drifts slowly southeast into New England. While chances for rain will begin to slowly increase...still appears the bulk of more substantial convection will largely remain southwest of the region overnight. Expected convective development in association with another wave aloft over eastern Missouri this evening is likely to track along the instability gradient and dive southeast into the lower Ohio Valley and eventually the Tennessee Valley. This is further supported by a low level jetlet nose into western Kentucky and Tennessee. CAMs hint at the lower Wabash Valley likely being clipped again by this complex late this evening and will carry highest pops in southwest counties. Despite the dry easterly flow persisting through the lower levels tonight...a vorticity lobe aloft ejecting out from the upper low moving through the Missouri Valley will drift across the region before weakening overnight and could produce isolated to scattered convection focused primarily across the southwest half of the forecast area. Will carry low chance pops to cover. Temps...considering the cloud cover and potential for at least isolated convection tonight...much prefer the warmer MAV guidance for lows in the mid and upper 60s. && .SHORT TERM /Tuesday through Thursday/... Issued at 340 PM EDT Mon Jun 25 2018 Forecast challenges continue to focus on an uptick in rain and storm chances through late Wednesday before the transition to the hotter and more humid pattern develops late in the short term and especially beyond into the extended period. The departure of the surface high off to the east will finally allow the warm front to lift north through the region Tuesday and introduce an influx of deeper moisture into the Ohio Valley. Meanwhile...the aforementioned upper low over the Missouri Valley will track E/NE into the Great Lakes by Wednesday. A surface wave associated with the upper feature will track in tandem eventually pulling a trailing cold front through the area on by late Wednesday. The combination of these features will bring a steadily increasing threat for showers and thunderstorms Tuesday and Wednesday...with peak coverage and impacts likely to come Tuesday evening into Wednesday morning. The combination of the warm front lifting north and increasing diffluent flow aloft ahead of the upper low will promote convective development Tuesday. The atmosphere at least initially on Tuesday will only be weakly unstable as cloud cover is likely to hamper heating. That will be enough for thunderstorm development but overall intensity will likely remain subsevere into Tuesday afternoon. Once the warm front lifts through the area however... moisture and instability will increase going into Tuesday evening. Mid and upper level flow will intensify as an upper jetlet wraps around the front end of the low. Additionally...a 35-40kt low level jet will expand across the area Tuesday night. With both BL shear and helicity values increasing as the upper low approaches in addition to what is mentioned above...the airmass will become much more favorable for robust convection going into Tuesday night. Some of the hi-res guidance seems to be favoring this thinking with afternoon convection developing to the west of the region and migrating into the area mainly after dark. Presence of the enhanced flow at 850mb should maintain convection all night. Sounding analysis indicated thermodynamic profiles are not perfect...but certainly support potential for strong to severe storms with convection Tuesday night. Precip water values near 2 inches and the 850mb jet still make heavy rain the primary threat into Wednesday morning. Scattered convection will persist on Wednesday but gradually transition to the east into the afternoon as the front sweeps across the area and the upper low and surface wave shift east. Will maintain chance pops for much of the day but anticipate the entire area will be dry by early evening. The remainder of the short term will see the transition commence to the hotter and more humid pattern set to encompass the Ohio Valley by late week into the weekend. The ridge aloft centered over the southern Rockies will expand east with heights aloft rising substantially from late Wednesday through Thursday evening. The core of the ridge will build into the area by Friday. High pressure will maintain dry weather Wednesday night and Thursday. Some hints that central Indiana may briefly align in northwest flow as the heights expand just outside the short term Thursday night with the possibility for convection riding along the ridge periphery. More on this in the Long Term section. Temps...have trimmed temps back a bit from previous forecasts Tuesday as clouds and convection will likely keep highs primarily in the lower to mid 80s. Low level thermals support gradually warming temperatures for the rest of the short term with many areas approaching or reaching 90 on Thursday. A model blend worked well for overnight lows. Wednesday night may bring slightly cooler weather as winds briefly turn northerly in wake of the frontal passage Wednesday. Beyond that point however...all signs point to lows primarily in the 70s going into the extended period. && .LONG TERM /Thursday night through Tuesday/... Issued at 202 PM EDT Mon Jun 25 2018 Lack of model consensus will lead to a low confidence forecast for much of the long term. That said, good confidence that an upper ridge will reside over the Mississippi Valley Thursday night. Central Indiana will be on the periphery of this ridge and fast upper flow over the Great Lakes and Canada. This will mean central Indiana will be in northwesterly flow and models suggest an MCS could move in overnight Thursday night and or Friday from Iowa and northern Illinois. Still, confidence is low enough that small blend PoPs will be accepted. After that, most of the weekend should be dry and warmer as the upper high settles over the Ohio Valley and later northeastern states. Prefer the GFS that is slower to move the ridge out to sea. At any rate, by Sunday and especially next Monday, the ridge will be suppressed with a few storms possible along the periphery of southwest flow aloft. Confidence in hot temperatures with highs in the 90s through most of the weekend. With a soupy atmosphere, good chance we will see some heat headlines for the weekend. && .AVIATION /Discussion for the 26/06Z TAF Issuance/... Issued at 1147 PM EDT Mon Jun 25 2018 Showers and thunderstorms will overspread central Indiana from southwest to northeast tonight due to an upper wave. Some MVFR ceilings have been drifting into the area over the last hour, but flight conditions should generally be at VFR levels outside of any convection. Any showers and thunderstorms that do form though could result in quick deterioration to MVFR or worse conditions. Meanwhile, winds will generally be southeasterly at 5 to 10 kts. && .IND WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SYNOPSIS...Ryan NEAR TERM...Ryan SHORT TERM...Ryan LONG TERM....MK AVIATION...TDUD
Area Forecast Discussion
National Weather Service Jacksonville FL
902 PM EDT Mon Jun 25 2018 .UPDATE...Storms developed over central Ga this afternoon and now are moving south across the Alatamaha River. Southeast Ga remains moist and unstable enough to keep convection going...possibly reaching near the Ga-Fl border this evening per the HRRR model. Expect a weakening trend as instability slowly fades with convection ending shortly after midnight. Isolated convection over the Suwannee Valley of ne Fl with the seabreeze should wind down by midnight. && .AVIATION...VFR conditions will prevail tonight through Tuesday morning. Storms currently over se Ga may affect SSI mainly between 02z-06z. && .MARINE... Southwest winds at 15 knots or less with afternoon sea breezes forming near the coast Tuesday afternoon. Seas in 2-4 foot range. Rip Currents: Low risk. && .PRELIMINARY POINT TEMPS/POPS... AMG 74 94 74 93 / 50 40 20 30 SSI 78 89 78 90 / 40 40 10 30 JAX 75 94 75 93 / 10 30 10 40 SGJ 76 91 75 90 / 10 30 10 30 GNV 73 93 74 92 / 30 40 30 40 OCF 73 92 74 90 / 30 40 30 30 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...None. GA...None. AM...None. && $$ Zibura/Kennedy/Wolf
National Weather Service Jackson KY
815 PM EDT Mon Jun 25 2018 .UPDATE... Issued at 801 PM EDT MON JUN 25 2018 Rain dissipated quickly throughout the late afternoon and early evening across eastern Kentucky. This led to an update of the pop and weather grids, diminishing the pops quicker to match up with the radar trends, and removing predominate thunder and heavy rain wording. Even now, the scattered pops across the CWA are probably too high, and will likely be lowered in the upcoming update. In conjunction with the loss of rain, all urban/small stream advisories and the flash flood warning were allowed to expire on time. After coordinating with RLX, the flash flood watch was also cancelled, since no other flooding threats are in place for this evening. Some of the hi-res models try to bring in a swath of something between 6 and 8Z in the southern CWA, but it should have weakened drastically by the time it reaches us, and only result in some scattered showers. The HRRR also points at another round of showers and maybe a rumble of thunder near dawn on Tuesday. Will continue to monitor the model trends and update the overnight forecast as necessary. Expect that this will likely lower pops across the CWA for the overnight if any changes are made. Finally, loaded the latest observations into the near term portion of the forecast to make sure the temps, dew points, and winds were on track with the current conditions. All updates have been published and sent to NDFD/web. A new forecast package was also sent out to remove the flood watch and heavy rainfall wording. && .SHORT TERM...(This evening through Tuesday night) Issued at 430 PM EDT MON JUN 25 2018 20z sfc analysis shows a meso high moving through eastern Kentucky in association with the last of the MCS induced showers and thunderstorms. Many locations picked up several inches of rain with the earlier rounds of convection and some localized flooding remains possible with this latest batch for the southern parts of the area. To the north, the heaviest rains fell earlier in the day but there is another final batch of rain looking to develop over north central Kentucky and then sliding east into the area late this afternoon. In addition to the heavy rain, a few of the storms produced damaging wind gusts with numerous reports of trees down - again mainly across the southern parts of eastern Kentucky. To deal with the ongoing, but waning, convection have issued the zones with a pre-first period. Currently, temperatures are in the low 70s with the rain areas while they have rebounded into the low to mid 80s for the southwest parts of the area. Dewpoints remain high with readings in the upper 60s and lower 70s most places. Meanwhile, aside from the storm related gusts, the winds have been light and variable. Thanks to the storm clusters plenty of clouds remain, though just now some clearing is starting to move into the western Cumberland Valley. The models are in fairly good agreement aloft through the short term portion of the forecast. They all depict an MCV moving through eastern Kentucky late this afternoon into the early evening. Some ridging builds in briefly late tonight into Tuesday morning ahead of a closed low trough moving out of the Central Plains and into the Upper Midwest - heading into the Great Lakes that night sending lower heights into Kentucky toward the end of the short term. Given the mesoscale nature of the features affecting the forecast in the near and short term have strongly favored the higher resolution HRRR and NAM12 for details. Sensible weather will feature showers and limited storms for several more hours and then a threat for left over development for a couple of hours beyond that and into the evening. The boundary that helped to spawn the storms of last night and today remains in place, though, so that a few additional storms and showers will be possible towards dawn. Lingering boundaries and the front starting to move back north looks to be enough for additional storms generated by the sfc instability and falling heights aloft. The weather would then settle well into the night before the actual cold front approaches late with additional showers and storms anticipated toward dawn Wednesday. Started the grids with the CONSShort and ShortBlend making a few adjustments for spot temperatures each night. Adjusted the PoPs, as well, to linger the convection a bit longer into the evening and then to add more of a diurnal component for Tuesday afternoon`s grids. .LONG TERM...(Wednesday through Monday) Issued at 335 PM EDT MON JUN 25 2018 The models are very good agreement aloft through the extended portion of the forecast. They all depict the departure of a decent trough from the Great Lakes and Ohio Valley at the start of the period. As it exits a fair amount of energy will trail behind through Thursday. Strong ridging then builds northeast from the Southern Plains into Kentucky through the end of the work week. By the weekend this ridge will be right over Kentucky with its suppressive effects in full swing. Only gradually will the core of this ridge shift east through the area later in the weekend and to start next week. Late in the period the ridge may be far enough east that some mid level energy is able to approach from the northwest. Given the excellent model agreement aloft confidence is rather high in the blended model output for the extended portion of the forecast - provided that it adheres to the tenants of strong ridging over the weekend. Sensible weather will feature another round or two of thunderstorms associated with the unseasonably deep sfc low moving through the Great Lakes with a cold front extended south through Kentucky on Wednesday. This boundary should clear the CWA that night with left over moisture and still some energy around aloft enough to keep a small chance for convection in the forecast Thursday. High pressure at the sfc and strong ridging aloft should then shut down convection for the end of the week and into the weekend with mid level warmth providing a hearty cap. Can`t rule out a late day storm in southeast parts of the area on Sunday, but most places should stay dry. Due to the ridge heat and humidity will build resulting in heat indices around 100 degrees or higher through the weekend. Will continue to highlight this in the HWO and social media messaging. For Monday, the ridge will be off to the east allowing more return flow and with less of a cap in place so that some afternoon, diurnally driven, storms will be possible along with not quite as oppressive heat and humidity. As for temperatures in the extended, made mainly just some very small terrain based and spot adjustments to the lows each night with some increase with the highs for Friday through Sunday with the ridge. Did not deviate far from the blended PoPs through Thursday while emphasizing the diurnal trends. After that, dropped the PoPs to sub 15% in accordance with the dominant capping 5h ridge. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) ISSUED AT 814 PM EDT MON JUN 25 2018 Bit of an uncertain forecast. Heavy rains that swept through eastern Kentucky earlier have since dissipated, but have left abundant llvl moisture and low hanging clouds in their wake. As we head into the overnight, wouldn`t be surprised if this moisture leads to fog development, even with some clouds present. The question is how much fog and what impacts will it have, especially at the TAF sites. Kept TAF sites MVFR for VIS overnight, along with continued IFR CIGS, but expect this to be variable and could even be worse in some locations. Will update as we begin to see the fog develop and it`s impacts overnight. Shower/thunderstorm development is expected once again during the day tomorrow, with generally MVFR CIGS. Exact timing/impacts of these showers and thunderstorms is still unknown, so kept VFR VIS at this time. Winds will be light and variable through the period, outside of any thunderstorms that develop. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JMW SHORT TERM...GREIF LONG TERM...GREIF AVIATION...JMW
Area Forecast Discussion
National Weather Service Newport/Morehead City NC
1020 PM EDT Mon Jun 25 2018 .SYNOPSIS... A frontal boundary will be stalled just south of the area through Wednesday with an area of low pressure moving along it. The low and front will move northeast Thursday, and then another cold front will move in from the northwest Friday. High pressure will build in over the weekend. && .NEAR TERM /Overnight/... As of 1020 PM Mon...A few showers/storms forming across SW zones in association with outflow from earlier storms in SE NC, will increase in coverage across E NC overnight as shortwave energy rides ESE along stalled front and outflow boundary residing across the southern zones. Should be fairly decent coverage of precip, though not expecting much severe. With MLCAPE still above around 1000 J/KG and effective shear +25kt, cannot rule out an iso strong to severe storm with main threat a damaging wind gust, though main threat overnight will be heavy rain and localized flooding. Previous discussion... As of 730 PM Mon...Initial area of thunderstorms staying mainly s and w of the FA. Main area of interest continues to be MCS moving through Piedmont of NC, and will likely move into the Coastal Plain around 10-11 PM, and thus delayed higher pops until then. No other changes. Previous discussion... As of 430 PM Monday...Based on latest NAM and HRRR, increased POPs to likely to categorical over southern 2/3 of area overnight. /Previous discussion/ As of 300 PM Monday...Cold front has stalled over Carteret and Onslow counties where it has run into sea breeze. Only light showers currently over northern sections but scattered storms developing upstream and line of strong to severe storms moving across mountains. Previous forecast update generally on track with scattered activity next few hours, and then more widespread activity moving in after 5 PM. HRRR continues to indicate lull 8-11 PM then line moving through into overnight hours. With front stalled across southern sections, some potential for strong to severe storms mainly this evening and highest along and south of Hwy 70. Stuck with previous forecast of chance north to likely south for POPs but may increase based on latest radar and meso model trends at issuance time. QPF forecast will indicate 0.5 to 1 inch amounts for southern half of area but higher amounts likely with any repeating storms. Min temps mainly low to mid 70s. && .SHORT TERM /TUESDAY/... As of 330 PM Monday...Models in decent agreement that front will be stalled just south and west of area with weak wave development due to continued shortwave energy from W-NW. ECMWF is a bit further north with shortwaves and then has wave lifting into coastal plains allowing warm sector push back over SW half of area during late afternoon. Leaned to GFS/NAM with clouds/precip expected to keep front just to south. Will have POPS from chance north to likely south with just a marginal threat of strong to severe storms over extreme SW sections. Clouds and onshore flow likely keeping max temps in lower 80s. && .LONG TERM /TUESDAY NIGHT THROUGH MONDAY/... As of 435 am Monday... The cold front will be to the south of the area with high pressure building into the area, while a weak low is forecasted to develop along the frontal boundary to the south...bringing rain across the area. High pressure will rebuild into the region through early next week. Tuesday night-Wednesday... The frontal boundary will be to the south of the area, while a shortwave aloft moves along where the boundary is located...resulting in a weak low developing. Unfortunately, models are struggling with the development, location and timing. Overall, expect cloudy and rainy conditions Tuesday and lingering into Wednesday. Temperatures will be cooler on Tuesday due to cloudy and rainy conditions, expect in the low 80s Tue and increasing Wed to the mid 80s inland and low 80s beaches. Thursday-Monday... A mid to upper level shortwave will move across the area Thursday resulting in additional showers/thunderstorms. Then a weak cold front pushing through Friday with high pressure building across the region afterward. This will allow for diurnally driven scattered showers and thunderstorms across the area for each day. Expect temperatures to return back into the 90s inland and mid/upper 80s along the OBX. && .AVIATION /02Z TUESDAY THROUGH SATURDAY/... Short Term /through 18Z Tuesday/... As of 730 PM Monday...VFR will prevail next few hours, then periods of sub-VFR likely showers/tstms moving NW to SE over TAF sites in the evening. Some storms could be severe with damaging wind gusts mainly south of KPGV. Precip will diminish to scattered to numerous showers overnight and continue into Tuesday with front stalled south of area. NE-E flow expected to result in MVFR CIGs developing overnight and continuing into Tue morning as well. Long Term /Tuesday night through Friday/... As of 330 PM Monday...sub-VFR likely Tue night into early Wed, then improving to VFR rest of period outside of mainly diurnal showers and storms. && .MARINE... Short Term /through Tuesday/... As of 330 PM Monday...Cold front has pushed to between Ocracoke Inlet and Cape Lookout with N-NE winds around 10 KT to north and SW 10 KT to S. Front expected to stall until late evening, and then push south overnight aided by showers/storms moving through from NW. Front will then stall south of area Tuesday with weak low pressure development resulting in easterly flow around 15 KT most of waters. Seas 2-3 ft tonight will build to 3-4 ft Wednesday. Long Term /Tuesday night through Friday/... As of 415 AM Monday...Winds will veer to SE Tue night into Wed and becoming S/SW 5-15 kt Thursday. Friday winds will briefly become northernly as a weak frontal boundary pushes through most of the area before winds veer back to the SE 5-10 knots late Friday. Seas generally be 2 to 4 ft for most of the period, except Wednesday where seas 3 to 5 ft. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...None. MARINE...None. && $$ SYNOPSIS...JBM NEAR TERM...JBM/TL SHORT TERM...JBM LONG TERM...BM AVIATION...TL/BM MARINE...JBM/BM
Area Forecast Discussion
National Weather Service Paducah KY
724 PM CDT Mon Jun 25 2018 .UPDATE... Issued at 724 PM CDT Mon Jun 25 2018 Updated aviation section for 00z TAF package. UPDATE Issued at 555 PM CDT Mon Jun 25 2018 Minor adjustments to reflect slower initiation of convective activity this afternoon and early this evening. Most of the convection is starting to develop along the convergence zone/instability axis running from Perry County Illinois to Muhlenberg County Kentucky, with minor development over southeast Missouri west of Ripley and Carter counties. Although the severe potential remains, decided to remove severe wording from the gridded and text forecast late this afternoon and very early this evening due to the delay in upscale growth of thunderstorms at this time. Made some other minor PoP/Weather updates to reflect movement of thunderstorms along the boundary later this evening and overnight. && .SHORT TERM...(Tonight through Wednesday night) Issued at 243 PM CDT Mon Jun 25 2018 Satellite and surface observations continue to depict a slowly shifting northwest to southeast surface boundary advecting northeastward through the WFO PAH forecast area. At 1 pm CDT, LAPS depicted the boundary from near Pinckneyville IL onward to Sturgis and Greenville KY. Most of the towering cumulus is showing up along the convergence zone, where surface CAPE`s are running between 1500 j/kg to 2000 j/kg at 19z Monday. The highest CAPE values (around 3500 j/kg) was noted along the MS river in Mississippi Co. Missouri. The NAMNest is most similar in suggesting convective potential into west Kentucky, while the NAM12 and HRRR model runs are best representative of the development of convection over southeast Missouri. May make a last minute change to reflect a blend of these solutions. The suggestion is that multicell storms that develop over the foothills over southeast Missouri will congeal into a linear mode/broken squall line this evening. Do not anticipate much significant activity until after 21z (4 pm CDT) with the main convective line exiting to the east around midnight or 1 am Tuesday. The next round of showers and thunderstorms should expand east across the area between 4 am and 10 am on Tuesday. The lowest forecast confidence lies with the range of PoP solutions for Tuesday afternoon and evening. Even SPC`s Day 2 Outlook is conditional on antecedent cloud cover and atmospheric stabilization during this time period. At this time, the forecast rain chances may be too high for Tuesday afternoon and evening as compared to the 12km NAM-WRF solution. Anticipate the most forecast changes in the next 12 hours will be with this time period. Going into Tuesday night and Wednesday, the signal for pre- frontal/frontal convergence and lift should lead to a transition of PoP/Weather from west to east through Wednesday evening, as a warm layer builds in with the ridge and caps the potential for convection. Heat index values should top out near 100 in the delta region of southeast Missouri on Tuesday afternoon, with 100 to 105 degrees expected over southeast Missouri and the Purchase area of west Kentucky from late morning to late afternoon on Wednesday. The exact coverage will depend on lingering cloud cover and temperature recovery during the day. .LONG TERM...(Thursday through Monday) Issued at 243 PM CDT Mon Jun 25 2018 The primary concern during the long term period is heat. A potentially high-impact heat wave is expected Thursday into the weekend. The potential for increasing moisture later in the weekend into early next week could blunt the heat wave beyond day 5, but there is still some model variability at that time range. A strong 500 mb high will build over the lower Ohio Valley on Thursday, with the 594 dm center nearly overhead. This high is likely to suppress convection and even cloudiness. A west-southwest low level wind flow will advect hot air into our region, with 850 mb temps climbing into the lower 20s Celsius. Surface highs will range from the lower 90s in sw Indiana and the KY Pennyrile region to the mid 90s further west. Heat indices near 110 are possible in the west. The high will drift slowly eastward Friday through the weekend, then become stationary over the Appalachian Mountains. The chance of an isolated storm will slowly increase through the weekend. Subsidence will decrease ever so gradually as our region becomes located on the southwest periphery of the deep-layer high. Although forcing will be very weak, the magnitude of the instability could drive some isolated afternoon convection. The moisture will have little if any impact on temps Friday, when highs will be in the mid 90s everywhere. There could be a more noticeable impact by Sunday, although heat indices are still forecast to exceed 100 degrees. Early next week, the 500 mb high center will move off the Atlantic coast. However, the southwest extension of the ridge axis will be over the lower Ohio Valley. This ridge will be responsible for persistently hot conditions, however it is possible that isolated to scattered diurnally driven storms could blunt the impact of the heat. && .AVIATION... Issued at 724 PM CDT Mon Jun 25 2018 Isolated to scattered shra/tsra possible until around 07z, especially at KEVV/KOWB, then again after 11z at all TAF sites, but these times are current best estimates. VFR conditions will be predominant through the TAF period, with brief MVFR conditions possible in and near shra/tsra. Winds will be variable around 5 kts at KEVV/KOWB, and south at 4 to 9 kts at KCGI/KPAH. && .PAH WATCHES/WARNINGS/ADVISORIES... IL...None. MO...None. IN...None. KY...None. && $$ SHORT TERM...Smith LONG TERM...MY AVIATION...RST
Area Forecast Discussion
National Weather Service Blacksburg VA
1145 PM EDT Mon Jun 25 2018 .SYNOPSIS... A weak cold front will push south across our area and stall to our south through tonight. High pressure aloft will then build over the eastern U.S. during the later half of the week resulting in hotter and humid conditions along with the threat of diurnally driven showers and thunderstorms. && .NEAR TERM /THROUGH TUESDAY/... As of 1145 PM EDT Monday... Made some quick adjustments to existing forecast to increase threat of precipitation across northern portion of forecast area to account for expanding area of showers in isentropic zone. This area a bit further north than higher resolution models originally depicted...basically at point where depth of cool pool and warm moist advection overrunning it reaches level of free convection (LFC). Forecast soundings in this region show only very shallow positive area, but one with some vertical depth, so despite limited overall convective available potential energy, showers breaking out along nw-se LFC axis. Models suggest that slow southwestward trend may occur as the night progresses as depth of cool pool forces LFC further to the SW, so will maintain trend for higher threat of precipitation slipping a bit SW with time per earlier forecast. Otherwise, no changes needed at the present time. As of 815 PM EDT Monday... Made some changes to the near-term grids to reflect impact of cooling associated with progressive line of showers and thunderstorms that is now moving southeast and out of the southern portion of the Blacksburg forecast area. Although severe threat has ended, many of the higher resolution models indicating that redevelopment of light showers across at least the southwestern third of the forecast area is expected as the night progresses as weak southwestern isentropic lift returns on the backside of the departing mesoscale vorticity complex (MCC) while the cool air wedging amplifies with building surface high pressure to the north. This already well reflected in the existing gridded forecast. However, a more stratified environment with limited convective positive positive energy in mid levels, and only lackluster warm moist advection over deepening cool pool would argue that overall rainfall amounts for the rest of the night will be on the light side. Lighter precipitation amounts for the overnight period reflected in 18Z NAM Nest, 21Z RAP, and 22Z HRRR models - a far cry from the bullish convective maxima of the earlier runs of the ECMWF and Canadian models - which did not at all anticipate the extent of post-MCC stratification that now resides over the Blacksburg forecast area. Will therefore lower total amount of precipitation for the overnight period to about half of what was earlier forecast - more in line with latest hi-resolution models. Otherwise, rest of forecast still appears to be on track, so no other noteworthy changes needed at the present time. As of 308 PM EDT Monday... A series of remnant Mesoscale Convective Vorticity Centers (MCVs) will move from Kentucky toward our region around the southwestern periphery of a midlevel trough over New England. MCV over eastern Kentucky will travel east this afternoon into tonight. SPC Mesoscale analysis at 18z showed that surface based CAPEs have climb to 1to 2K J/kg and LIs are minus 1 to minus 3. The best supercell composite parameter is to our west across Kentucky and to our south in central North Carolina. With a weak cold front pushing south across our area and stalling to our south tonight. Expected scattered showers and thunderstorms to develop this afternoon into tonight. SPC Day One convective outlook has a slight risk across southwestern portions of the forecast area. Multicell clusters will be the primary convective mode, with the potential for wind damage with downbursts through this evening as storms coalesce on outflows and move southeast. Shaped pops this afternoon into tonight towards a blend of the HRRR and NAM. As the main system passes by this evening, surface trough moves further off shore and surface ridge becomes established with high pressure setting up a warm-season wedge. In other words, sagging frontal boundary becomes a wedge front Tuesday morning with some upslope clouds, showers and patchy fog. While some of the rain may be heavy with thunderstorms, rather high flash flood guidance values and coverage precludes any need for a watch at this point. Under cloudy skies, low temperatures tonight will range from the upper 50s in the northwest mountains to the upper 60s in the piedmont. Wedge conditions should exist on Tuesday with easterly/southeast convergent flow supporting greater coverage of clouds and showers in the western mountains. Higher PWAT values will be transported northwestward from the Carolinas. There is enough instability to support some scattered thunderstorms especially in the west. The day two convective outlook has posted a marginal risk for severe thunderstorms on Tuesday near the frontal boundary and across the higher terrain across southwest portions of our forecast area. The main threat is potentially damaging wind gusts. High temperatures Tuesday will vary from the upper 60s in the northwest mountains to around 80 degrees in the piedmont. Forecast confidence during this part of the forecast is moderate. && .SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/... As of 303 PM EDT Monday... This portion of the forecast will be characterized as an active weather pattern. An upper level shortwave trough will approach the area Tuesday night into Wednesday, and then cross the region late Wednesday afternoon and evening. Showers and thunderstorms are expected during this entire time period with the best chances Wednesday afternoon and evening associated with the passage of the main trough axis and surface cold front. The latest Day 3 Convective Outlook at SPC places a Marginal risk of severe weather across the far western sections of the region, with damaging winds being the greatest threat. By Thursday, the main trough axis will be to our east, but precipitation chances will linger one final disturbance wraps into the area on the backside of the main system. Look for primarily isolated to scattered showers across western parts of the region. Northwest flow downslope conditions east of the crest of the Blue Ridge will limit any development there. Temperatures during this portion of the forecast will trend milder each day with readings a few degrees above normal by Thursday. Forecast confidence during this part of the forecast is moderate to high. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... As of 1245 PM EDT Monday... Thursday night into Friday will be the time frame where an upper level ridge starts to build into the region. This feature is expected to strengthen, broaden, and become centered over the area by the the end of the weekend. The result will be increasing heights/temperatures across the region. While not zero, precipitation chances will be on the low side. and limited to a few locations across the mountains where the combination of diurnal heating and weak orographical influences may help fuel showers and storms. Heat index values are forecast to be in the low 100s both Saturday and Sunday afternoon over parts of the Piedmont region. On Monday, precipitation chances will increase a bit across mainly western parts of the forecast area. The center of the upper ridge is expected to shift east, and this in turn will help lessen the strength of the capping inversion. Temperatures during this portion of the forecast are expected to be around five to ten degrees above normal. Forecast confidence during this portion of the forecast is moderate to high. && .AVIATION /04Z TUESDAY THROUGH SATURDAY/... As of 815 PM EDT Monday... Deepening cool moist wedge building southwest over the Blacksburg forecast area as high pressure builds north of the region will clash with warmer and more moist air that will be lifted northeast over the cool pool - resulting in gradual lowering of ceilings and visibilities over the entire Blacksburg forecast area as the night progresses. Most areas should experience IFR flight conditions well before daybreak - and likely even as early as late evening/around midnight from Bluefield to Blacksburg, and points south along the eastern flanks of the Blue Ridge which experienced a soaking rain earlier in the day. LIFR flight conditions with obscuration of the higher ridges is likely along the eastern flanks of the Blue Ridge by late tonight as upslope flow intensifies with cool pool. Also expect to see redevelopment of showers/light rain and even some drizzle in upslope areas as the night progresses as warm and moist air is lifted northeast over deepening cool pool. Precipitation most likely along and southwest of a line from Lewisburg through Roanoke to Danville. The low level wedge expected to remain in place on Tuesday, and despite drying aloft, expecting that sub-VFR ceilings will likely persist for much of the day along with some added shower coverage - especially in southern and western sections. Medium confidence in ceilings, visibilities and winds during the TAF period. .Extended Aviation Discussion... Low cigs likely to persist within the wedge Tuesday night with sub-VFR conditions in spotty light rain or drizzle also possible. The wedge should scour out on Wednesday as another low pressure system arrives from the northwest with added showers and stronger storms possible by Wednesday afternoon. Strong high pressure will follow this feature for the end of the week with widespread VFR expected outside of early morning patchy valley fog and perhaps isolated storms across the mountains Thursday into Friday. Outside of a few MVFR showers in the southwest portion of the forecast area, VFR conditions should prevail Saturday. && .EQUIPMENT... As of 155 PM EDT Monday... The NOAA weather radio transmitter in Hinton, West Virginia that is WXM72 and broadcasting at a frequency of 162.425 MHz is off the air. Parts are on order to repair the transmitter, but there is no known time of restoration. We apologize for any inconvenience. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...None. NC...None. WV...None. && $$ SYNOPSIS...JH/KK NEAR TERM...KK/WERT SHORT TERM...DS LONG TERM...DS AVIATION...JH/KK/WERT EQUIPMENT...
Area Forecast Discussion
National Weather Service Las Vegas NV
240 PM PDT Mon Jun 25 2018 .SYNOPSIS...An area of high pressure over the Desert Southwest will keep hot and dry conditions in place through Wednesday. A trough of low pressure will move across the western states Thursday and Friday leading to increasing southwest winds and temperatures pulling back several degrees going into the weekend. && .SHORT TERM...through Wednesday night. Little change in the weather can be expected through Tuesday night and the most noteworthy concern will be fairly dense smoke over northern Inyo and Esmeralda counties from the Lions Fire near Mammoth. According to the HRRR Surface Smoke forecast, more diffuse smoke will be observed over northwest San Bernardino County and also portions for southern Nevada and northwest Arizona. However, it should not be dense enough to mention in the forecast. Wednesday will see a moderate increase in winds as the leading edge of an incoming Eastern Pacific trough begins to influence the area. South- southwest gusts of 25-30 mph will be fairly extensive. High and low temperatures will stay fairly consistent before the downward trend develop the latter half of the week. .LONG TERM...Thursday through Monday. The strong high pressure that will bring the above normal temperatures early in the week will be shoved east as a trough pushes into the west coast. This will bring a cooling trend that is expected to last into the weekend. Temperatures are forecast to be right around normal with little in the way of clouds. With the approaching trough, southwest winds are forecast to increase Thursday afternoon across much of the area. Most places will see winds between 25-35 mph which will lead to fire weather concerns. Winds will be lighter across the area Friday with the exception of Mohave County where a few gusts over 30 mph will still be possible. Winds will be lighter over the weekend as the area will be sandwiched between high pressure off the coast and low pressure to the east. && .AVIATION...For McCarran...Mostly clear conditions, except for some diffuse smoke from distant wildfires, will continue through Tuesday with high temperatures around 108-110. A south-southwest component around 10 knots will occur in the evening and overnight hours. East- southeast wind components occasionally gusting around 15 knots can be expected during the afternoon hours. For the rest of southern Nevada, northwest Arizona and southeast California...Smoke from a wildfire in the Sierra Nevada will affect flight visibility across Inyo County. Otherwise, no weather or significant clouds expected. South to southwest winds around 20 knots during the afternoons, with lighter winds overnight. No weather or significant clouds expected. && .FIRE WEATHER...Elevated fire weather conditions can be expected by Wednesday afternoon as a Pacific Trough begins to move inland. South-southwest gusts of 25 to 30 mph will be fairly extensive across the region Wednesday afternoon with single digit relative humidity values. Critical Fire Weather conditions are a concern across much of southern Nevada and northwest Arizona by Thursday afternoon as the trough moves inland potentially leading to extensive gusty southwest winds 30 to 40 mph. && .SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report any significant weather or impacts according to standard operating procedures. && $$ SHORT TERM/AVIATION/Fire Weather...Adair LONG TERM...Gorelow For more forecast information...see us on our webpage: or follow us on Facebook and Twitter