Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 08/10/18

Area Forecast Discussion...UPDATED
National Weather Service Albuquerque NM
549 PM MDT Thu Aug 9 2018 .AVIATION... 00Z TAF CYCLE A healthy crop of tstms have formed over the northern and western high terrain. Tstms will generally move south into valley locales producing one to two hour long periods of MVFR conditions. Thunderstorms will be capable of producing moderate to large hail, frequent cloud to ground lightning, and gusty erratic winds. VCTS can also produce strong gusty erratic winds. The eastern plains are expected to also get their fair share of tstm activity between now and 09Z. Areas from KLVS to KSXU to KTCC could see a passing tstm between 01Z to 04Z, with storm coverage pushing south to KCVN to KROW 03Z to 06Z. Tstm activity is expected to fully diminish by the early morning hours, with remnant high cirrus over much of the state. Tomorrow will see another round of afternoon tstms forming over the higher terrain and potentially along any sfc boundaries over eastern NM. 24 && .PREV DISCUSSION...246 PM MDT Thu Aug 9 2018... .SYNOPSIS... An active end to the work-week is underway, with thunderstorms developing further west across the state compared to the past few days. Storms this evening will be capable of producing locally heavy rainfall and localized flash flooding. More storms are forecast Friday, with high temperatures below normal thanks to rain-cooling and additional cloud cover. Look for continued rain chances through the weekend, though trending down some from Friday. High pressure will strengthen over the region next week, leading to an uptrend in temperatures. However, decent chances for storms look to persist for the foreseeable future. && .DISCUSSION... The upper high is pulling away, as evidenced by the pressure height falls noted on the 12Z upper air analysis, and was centered over Nevada at 12Z. PWATs are trending up across central and western New Mexico and were near 1" on the KABQ upper air sounding this morning. An increase in storm coverage is expected this afternoon, especially across central and west central New Mexico where storms have not been as plentiful that past couple of days. South or southwest steering flow will take storms off of the central mountain chain over the Santa Fe and Albuquerque Metros this afternoon/evening. Both the 12Z and 18Z NAM, and the last several runs of the HRRR show the eastern highlands, Estancia Valley, the Sandia/Manzano Mountains and perhaps portions of the south central highlands getting hammered this evening and these are the areas where we have our highest evening PoPs. The Flash Flood Watch is still in effect and will be left as-is this forecast cycle given no compelling evidence for change. Another crop of storms with scattered to numerous coverage is forecast for Friday, but instability will be more limited with daytime temperatures forecast to be 3 to 8 degrees cooler than today`s. Look for a downturn Saturday, thanks in-part to some drying of the atmosphere. Sunday may tick back up in terms of storm coverage, with the upper high over Utah and a weak upper low over the TX Panhandle. Northerly steering flow on Sunday would once again take storms off the higher terrain late day over the Santa Fe and Albuquerque Metros. Both the 12Z operational runs of the ECMWF and GFS show the upper high building over AZ/NM next week, leading to an uptrend in temperatures back to above normal most areas by Wednesday or Thursday. The GFS shows a weaker high, with daily rounds of storms persisting. Our forecast is closer to the GFS at this time. 11 && .FIRE WEATHER... Scattered to numerous showers and thunderstorms will be found over much of the forecast area for the remainder of the day and into tonight, especially along and east of the central mountain chain. After receiving wetting rainfall in several locales, tonight`s RH recovery should be good to excellent across most of the state. A continued moist southeasterly flow at the surface should keep sufficient moisture in place for more scattered to numerous storms on Friday. Temperatures will run a few to several degrees below average Friday afternoon in all areas except the northwest plateau. This weekend high pressure aloft will stretch about a southwest to northeast oriented axis, wrapping dry air into northern NM on Saturday. A weak upper low will take shape over west TX, keeping some mid level moisture in far eastern NM, but overall a downtrend in storm coverage is expected Saturday. Temperatures will not alter much Saturday, but could gain a degree or two on Sunday. A disturbance aloft is then expected to enter northern NM Sunday with additional storms accompanying and eventually spreading into the western tier of the state through the evening. The weather next week will be characterized by a gradual exit of the weak low over west TX while high pressure remains ill-defined, struggling to re-establish itself over the Great Basin. This will keep daily thunderstorm chances going with temperatures approaching normalcy. 52 && .ABQ WATCHES/WARNINGS/ADVISORIES... Flash Flood Watch until 4 AM MDT Friday for the following zones... NMZ508-512>515-521>523-528-529-532-533-537. && $$
Area Forecast Discussion
National Weather Service Amarillo TX
635 PM CDT Thu Aug 9 2018 .AVIATION... VFR for all three terminals for the 00Z TAF period. KAMA does have a PROB30 group for the last six hours of the period, when it may fall to MVFR if impacted by thunderstorms. Winds will gradually become light and variable in the beginning of the period until about 18Z when the winds pick up to 10-15 kts out of the east to southeast. KDHT and KGUY may be impacted by and isolated thunderstorm towards the end of the period but confidence is low. 36 && .PREV DISCUSSION... /Issued 357 PM CDT Thu Aug 9 2018/ DISCUSSION... Convection developing this afternoon along the axis of an east to west shortwave trough located across the northern and central Texas Panhandle. Convection expected to continue pushing slowly south into the evening hours and then dissipate or move out of the forecast area by 03Z to 06Z Friday. Recent CAMs and latest RAP continuing to show convection redeveloping after 06Z to 08Z Friday across the Interstate 40 corridor southward. Focused POPs for tonight mainly across the southern half or so of the Panhandles. Upper flow transitions to northerly to northeasterly tonight and Friday as the upper trough digs south and west across the Panhandles and an upper high builds northeast across the Great Basin region and the northern Rockies and northern Plains states. Closed upper low develops over the southern Plains states this weekend and moves westward across the Panhandles or in the vicinity of the forecast area by early and middle of next week. Weak frontal boundary to push south across the Panhandles Friday and Friday night and then remains quasi-stationary near or across portions of the Panhandles over the weekend. Convection chances to continue tonight through the weekend and into the early and middle of next week. Confidence low as to timing and location of where convection will develop, however it appears that the best chances should be over the central and southern Texas Panhandle through Saturday night and then shifting to most or all of the forecast area by early and mid next week. Schneider && .AMA Watches/Warnings/Advisories... TX...None. OK...None. && $$ 36/89/
Area Forecast Discussion
National Weather Service Austin/San Antonio TX
747 PM CDT Thu Aug 9 2018 .UPDATE... Scattered showers and storms continue across the Edwards Plateau and northern Hill Country. Increased PoPs slightly in this area for the next few hours. Latest runs of the HRRR continue to decrease activity shortly after sunset. Otherwise, no major changes were needed to the current forecast. && .PREV DISCUSSION... /ISSUED 648 PM CDT Thu Aug 9 2018/ AVIATION... VFR at all TAF sites this evening and into tonight. A weak boundary and associated convection across the Hill Country and Edwards Plateau should remain to the north of TAF sites tonight. The typical summertime morning stratus is expected again tonight, but with weaker winds from the southeast, stratus will not likely make it all the way to KAUS. MVFR conditions are still expected at KSAT/KSSF. KDRT will remain VFR throughout the TAF period. PREV DISCUSSION... /ISSUED 321 PM CDT Thu Aug 9 2018/ SHORT TERM (Tonight through Friday Night)... A weak outflow boundary across northeast Texas that extends to the southwest into central Texas is forecast to combine with another boundary coming down from the northwest to develop a convective line over the Hill Country and Edwards Plateau later this afternoon. Several HiRes and even some of the regional and medium-range models agree on this scenario. In addition, the typical seabreeze activity should increase within this hour and affect parts of the Coastal Plains and southeast counties. Most HiRes models keep the stronger activity just to the north of the Hill Country for the evening period. However, later tonight/overnight period, an organized mesoscale convective system is forecast to develop and affect the Hill Country and especially Llano and Burnet Counties. Some storms could be strong and produce isolated heavy downpours and wind gusts of 40 to 50 mph. An upper level trough axis will remain just to the north of the Hill Country on Friday and will aid for a new round of scattered showers and isolated thunderstorms mainly across the southern Edwards Plateau and Rio Grande Plains. Also, the typical seabreeze convection is once again expected across the Coastal Plains and southeast counties. LONG TERM (Saturday through Thursday)... The unsettled weather persists this weekend into Monday of next week with several rounds of moderate to heavy rainfall episodes mainly across the Edwards Plateau and Rio Grande Plains. The I-35 corridor area is expected to get some activity during the period with best chances on Saturday night into Sunday morning and again Sunday night into Monday morning. Some shower and storm activity is possible Monday and Tuesday as an upper level disturbance departs the area. The upper level disturbance responsible for the extended period of rain chances finally pushes to the northeast and away from the area with rain chances coming to end mid-week. Storm total rainfall amounts across the Edwards Plateau and Rio Grande could range from 1 to 3 inches with isolated 4 inches. Areas along and east of Interstate 35 are expected to get one inch or less. && .PRELIMINARY POINT TEMPS/POPS... Austin Camp Mabry 77 95 75 93 75 / 30 40 40 40 60 Austin Bergstrom Intl Airport 76 95 75 93 74 / 30 30 40 40 60 New Braunfels Muni Airport 75 95 74 93 74 / 20 20 40 40 60 Burnet Muni Airport 74 92 73 90 72 / 60 60 50 50 60 Del Rio Intl Airport 78 99 77 93 75 / 20 20 40 40 60 Georgetown Muni Airport 76 95 74 92 73 / 50 50 50 40 60 Hondo Muni Airport 74 98 74 96 74 / 20 20 30 30 60 San Marcos Muni Airport 75 96 75 93 75 / 20 30 30 40 60 La Grange - Fayette Regional 77 96 76 94 76 / 10 30 20 50 40 San Antonio Intl Airport 77 96 76 94 76 / 10 20 30 30 60 Stinson Muni Airport 76 97 76 95 77 / 10 20 20 30 60 && .EWX WATCHES/WARNINGS/ADVISORIES... None. && $$ Mesoscale/Aviation...YB Synoptic/Grids...Hampshire
Area Forecast Discussion...UPDATED
National Weather Service Fort Worth TX
753 PM CDT Thu Aug 9 2018 .AVIATION... /00Z TAFs/ After the initial Denton County storm this afternoon, the bulk of the convective activity was south of the Metroplex TAF sites (Arlington the primary exception). However, the dancing outflow boundaries throughout the TRACON are finding particularly unstable air, and a few thunderstorms rooted in the mT boundary layer will occur through nightfall. Despite the chaotic wind field, for ease of operations, DFW/DAL are in south flow, inbound traffic avoiding the thunderstorm clusters south of the Metroplex. While storm impacts at any metro TAF site would be quite brief, some in-flight slaloming will be required early this evening. A low-level trough will remain draped across the Metroplex overnight. This will promote some upglide, but the main corridor of warm/moist advection will be oriented through Central Texas into East Texas. Despite being worked over late this afternoon, this buoyant inflow beneath steep lapse rates aloft will promote the redevelopment of thunderstorms across Central Texas later this evening. This will maintain impacts to south departures and incoming traffic through both Glen Rose and Cedar Creek. Eventually, showers may develop closer to the Metroplex, but probably not until the predawn hours, at which point boundary layer parcels are unlikely to be involved. In addition, with more widespread convection to the south literally stealing its thunder, these shallower updrafts across North Central Texas will have less favorable lapse rates, and the Metroplex TAFs will carry only VCSH Friday morning. In the short term, the wind field will continue to be governed by outflow. With the proximity of surface troughing, light easterly winds will likely take hold this evening within the Metroplex. Veering southerly flow will then overwhelm this late tonight and prevail through Friday. With a moisture-rich boundary layer still in place on Friday beneath weak troughing aloft, some redevelopment of thunderstorms should occur at peak heating. The weak surface wind field will allow residual boundaries to linger. With much of the forcing on the mesoscale, initiation will be largely dictated by the location of these boundaries, which may be determined by the nocturnal activity that has yet to occur. While the timing of this convection would be focused during the typical late afternoon peak heating period, uncertainties about location will preclude any introduction of Friday afternoon thunder in the TAFs at this time. 25 && .SHORT TERM... /Issued 347 PM CDT Thu Aug 9 2018/ /This Afternoon and Tonight/ The main challenge in the short term forecast period will be the location and coverage of precipitation. For the rest of this afternoon, it appears that locations south of I-20 will stand the best opportunity for showers and thunderstorms. A few storms will be possible near the Highway 380 corridor this afternoon as well. Overnight tonight, storm chances will increase quite noticeably across the Concho Valley and into Central Texas. This afternoon, there has been a relative lull in convective activity from about noon through the 3 PM time frame. A broad surface trough continues to slide southward through the forecast area with an mesoscale convective vortex or MCV noted across the Concho Valley. Agitated CU was noted from near a Gatesville to Athens line and I`ve nudged PoPs into the 50 percent category here. There will be a risk for strong to near severe downbursts given large amounts of DCAPE and a very hot and well-mixed boundary layer. A small thunderstorm cluster was noted just north of the Highway 380 corridor in response to just daytime heating. The cessation of this convection will be interesting, but in general, it should decrease after sunset. Overnight tonight, showers and thunderstorms should blossom across Central Texas and the Concho Valley. RAP and NAM guidance continue to support strong isentropic ascent along the 305K theta surface. As noted yesterday, the NAM has done a pretty good job of handling the overnight LLJ and I see no reason to disregard its output tonight. 925mb winds will climb into the 30 to 35 knot range and glide atop the surface trough. There may be some additional assistance from the aformentioned MCV and this should help fuel widespread to numerous convection across Central Texas. HREF members concur with this assessment and mean QPF values are quite aggressive across this area with rain totals in excess of 4". I`m not completely sold on this potential, but given the very moist regime (characterized by 2" PWATs) and the unseasonably strong LLJ, it`s not out of the realm of possibility. I`ve inserted "heavy rain" wording into the western portions of Central Texas tonight and there could be a low end flood threat, especially across some of the more flood prone areas in Central Texas. Elsewhere, there will be a chance for a lower coverage of showers and thunderstorms. Overnight low temperatures will fall into the 70s areawide. There may be a low potential for some patchy fog along the Red River where skies. Bain && .LONG TERM... /Issued 347 PM CDT Thu Aug 9 2018/ /Friday through next Thursday/ Showers and thunderstorms may be ongoing at the start of the long term period Friday morning, forced by robust isentropic ascent/warm advection over-topping a diffuse remnant outflow boundary/wind shift across Central Texas. Recent hi-res guidance is in decent agreement in depicting fairly high precipitation coverage across Central Texas and up to about the I-20 corridor through the morning hours, and this seems reasonable given the anticipated magnitude of lift and copious amounts of moisture. We`ve increased PoPs to 70% across a good chunk of our Central Texas counties Friday morning. PWATs are forecast to push 2" in spots here, so heavy rainfall will be possible. In addition, upwind corfidi vectors of less than 5-10 kts or so, becoming increasingly boundary-parallel portend some risk for training/backbuilding cells. Relatively high 1 and 3-hour flash flood guidance across Central Texas reduce our concern for widespread flash flooding at this juncture, but some localized hydrological concerns may arise generally south of I-20 through the morning hours. This initial round of convection should diminish into the early- afternoon as the initiating ascent peters out as the low-level wind field relaxes. Given the anticipated convective coverage across Central Texas, re-development of showers and storms during the afternoon is in question, so we`ve reduced PoPs a bit across the last few rows of counties. Additionally, if this complex exhausts a robust enough outflow, it could even hamper convective chances north of I-20 later in the day. High temperatures will also obviously hinge on the placement of left over cloud cover and mesoscale boundaries. The warmest conditions should occur near the Red River, while locales south of I-20 may have a hard time getting into the 90s. A similar scenario may unfold Friday night into Saturday morning as moist upglide gets cranking once again, and so high-end chance PoPs will be advertised across much of North and Central Texas. These may need to be increased as confidence in the placement of pertinent mesoscale features increases. Over the weekend, upper level troughing will become more established across parts of West Texas. This will keep a persistent fetch of deep southerly flow and associated moisture transport going across the western half of Texas. The brunt of large scale ascent looks like it will remain just west of our forecast area by the end of the weekend and into early next week, and a fairly tight PoP gradient has been introduced from west-to- east starting on Sunday. Both the GFS and ECMWF show some pretty dry air punching into our southeastern and eastern counties during this time frame, and today`s mid-range ensemble guidance is similarly advertising the lowest precipitation chances east of the I-35 corridor. Assuming this upper low doesn`t pivot any farther west than currently advertised, some of our far western counties may benefit from decent wetting rains Sunday-Tuesday. By the middle of next week, the persistent upper troughing and associated broad cyclonic flow overhead may begin to break down as the southwestern US subtropical ridge attempts to build back eastward. Temperatures should rebound into the mid and upper 90s Wednesday and Thursday, and PoPs will quickly trend downward through this period. Carlaw && .PRELIMINARY POINT TEMPS/POPS... Dallas-Ft. Worth 77 92 73 89 74 / 50 50 50 30 60 Waco 73 93 72 90 74 / 70 70 50 50 60 Paris 73 93 72 89 71 / 20 30 30 30 30 Denton 74 93 70 88 72 / 40 40 50 30 50 McKinney 74 93 72 89 73 / 40 40 40 30 50 Dallas 78 93 75 91 75 / 50 50 50 30 60 Terrell 75 93 73 90 73 / 40 50 50 30 40 Corsicana 75 91 73 90 73 / 50 70 50 50 50 Temple 73 93 74 91 72 / 70 70 50 50 60 Mineral Wells 74 91 70 86 71 / 50 50 50 40 60 && .FWD WATCHES/WARNINGS/ADVISORIES... None. && $$ 25/05
Area Forecast Discussion
National Weather Service Houston/Galveston TX
1032 PM CDT Thu Aug 9 2018 .DISCUSSION... Storms have dissipated and cirrus remains over parts of the area. Storms along the outflow boundary near the cold front have been weakening steadily and dissipating. Expecting that a few showers or thunderstorms could develop along the outflow near RYW-ACT- PSN though weak subsidence could minimize the chances for development. Will carry slight chances across the northern counties. Also toward sunrise may see a few showers over the Gulf and into the coastal counties. Patchy light fog possible near CXO/LBX near sunrise but probably more a matter of MIFG. On a different note...After the rains of Friday and Saturday Saharan dust blowing out of the Caribbean should move into SETX on Sunday and linger through Tuesday with upper ridging and drying out the rain chances. Last but not least is the potential for great Perseid meteor shower watching this weekend with mostly clear skies after midnight. Perseids already started tonight and should probably peak Saturday or Sunday. 45 && .PREV DISCUSSION... /ISSUED 654 PM CDT Thu Aug 9 2018/ AVIATION... Radar imagery shows most of the remaining showers and thunderstorms continuing to fizzle out across the region. VFR conditions should prevail through the morning hours with some sites such as CXO/LBX potentially seeing some patchy fog in the early morning hours, similar to the last few days. Winds should stay up for the next few hours at CLL with a tighter pressure gradient in place over our northwestern zones as the trough axis moves southward this evening. Some of the short term/global guidance is hinting at the possibility of some early morning convection associated with this boundary. At this time, just not confident enough that the precipitation will make it that far south so have kept the TAFs dry overnight. Convection tomorrow should begin a little earlier across the area, and spread inland by early afternoon. The typical diurnal summer wind pattern will continue, with winds light and out of the southwest tonight turning out of the southeast by the afternoon hours tomorrow. Gusty conditions will be possible beneath stronger storms in the afternoon. Hathaway PREV DISCUSSION... /ISSUED 340 PM CDT Thu Aug 9 2018/ NEAR TERM [Through Tonight]... Watching thunderstorm development today has been interesting purely from a visible satellite perspective. GOES 16 VIS around 15-16Z showed two areas of enhanced cumulus that eventually led to thunderstorm activity. The first was down along the coast and currently see activity from Wharton to near Sugar Land. Another cluster exits east of Houston IAH to HOU. Outflow boundaries from this convection could initiate new storms over the next hour or two. The second area of enhanced cumulus was from near Columbus northeast to Conroe and Lufkin. This activity has not been as strong and with more pulse increases in intensity. HRRR model runs were not that bad with this evolution and timing so far and based on that, overall trend should be for convection to decrease in coverage after 22Z this evening. Near term forecast has been updated for these trends and the PoP forecast tries to capture areas of convection with higher PoPs. Tonight the main issue will be convection that forms north of the area and then pushes south. Overall model guidance for tonight and even tomorrow are very different. Overall thinking is for rain chances to decrease tonight with loss of day time heating and instability, but forecast will keep some thunderstorm chances for areas north of Conroe to account for any new storm development. Overpeck SHORT TERM [Friday Through Friday Night]... Friday`s forecast looks to be quite uncertain based on model guidance so we will need to go off of what we do know from latest analysis and guidance. None of the WRF model runs have a good working scenario for Friday since convection will be mesoscale driven from any outflow boundaries generated from overnight thunderstorm activity. There is an upper level low over the Ozarks currently and its trough axis is expected to push into east Texas as it stretches out with the low moving east. This does lower heights and may allow for some weak large scale ascent. Models do show precipitable water values holding around 2 inches so given some heating and some lift on the synoptic scale, it reasons to keep some 40 to 60 PoPs in the forecast. The main question is where those higher rain chances may end up and that`s where we will have to go with a blend of the best guidance so far. Generally this looks to be along the coast but then also across the northern areas from College Station over to Livingston. Houston will be stuck in the middle but likely have better rain chances due to mesoscale boundary interaction similar to today. Short term hazards and impacts remain relatively the same with brief heavy rainfall with maybe an inch of rain an hour rain rate, lots of lightning and downburst winds. The severe potential looks rather low at this time given the pulse nature of the convection and overall lack of high instability. WPC has a marginal/slight risk of excessive rainfall basically for the northern most areas from the Brazos Valley to east Texas. This basically accounts for any thunderstorm activity that forms north of the area and moves south. The main issue here will be if multiple rounds of storms form and move over the same area. Overpeck LONG TERM [Saturday Through Thursday]... The cutoff low remains centered over the Panhandles in the Southern Plains on Saturday, as ridging remains over the Gulf. The continued source of lift from the lower heights aloft will continue the wet trend through the weekend. Showers and thunderstorms are the most likely in our northeastern counties on Saturday near where the front stalls. Our risk for excessive rainfall remains marginal on Saturday, as the main focus for heavy rain will be beneath the upper level low in Central Texas. Rain totals over Southeast Texas will be around 1 inch, with locally higher amounts near 2-3 inches possible in the Piney Woods region. Ridging gradually builds westward into the northwestern Gulf on Sunday and will help dampen rain chances early next week. Despite surface high pressure approaching from the east, a weak to moderate onshore flow will periodically pull in moisture from the Gulf, allowing for a slight chance for diurnal showers and thunderstorms beginning Tuesday. Otherwise, expect temperatures just above climatological average with highs in the mid 90s and lows in the upper 70s next week. Guidance diverges on the pattern for late next week, as the ECMWF has another trough digging into the Southern Plains while the GFS is not as aggressive and keeps the trough in the Central Plains. Kept POPs near 30 for Thursday to account for the uncertainty. This will be the feature to watch for the next several days. 22 MARINE... Light to moderate winds are expected over the next several days until stronger onshore winds develop Sunday. These stronger onshore winds will persist into next week with seas of 3 to 5 ft expected. Caution flags may be needed particularly Sunday night into Monday for the most western/southwestern coastal zones. Seas could potentially be higher both in and near showers or thunderstorms with slight chances into next week. Randall && .PRELIMINARY POINT TEMPS/POPS... College Station (CLL) 76 95 75 93 75 / 20 40 40 60 40 Houston (IAH) 78 93 78 92 77 / 10 60 20 60 30 Galveston (GLS) 82 88 81 88 82 / 10 60 20 50 20 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ Discussion...45
Area Forecast Discussion
National Weather Service Wilmington OH
936 PM EDT Thu Aug 9 2018 .SYNOPSIS... High pressure this evening will be pushed to the south as a weak cold front noses into the region from the north tonight and Friday. Showers and thunderstorms will occur as this front and an upper level trough pushes through the region. On Saturday, high pressure will build over the Upper Midwest and then help usher in a drier and cooler airmass for Sunday. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... Southward-progressing convection over NE Indiana / NW Ohio is making it a little bit further than previously anticipated, although the trend toward warmer cloud tops and gusting-out has been pronounced over the past 30-60 minutes. Nonetheless, some increases to the PoPs were necessary in the northwestern sections of the ILN CWA. Recent observations have had peak gusts generally in the 20-30 knot range, suggesting that no statements will be necessary unless an unexpected strengthening were to occur. Otherwise, generally dry conditions should continue overnight. Temperature trends were updated slightly cooler in the near term, but min temps still look fairly reasonable, especially with some cloud debris spilling into the area. Widespread fog appears unlikely, with HRRR visibility signals generally good, and less near-surface saturation in various model soundings compared to last night. Previous discussion > Lower level cloud cover will dissipate fairly quickly this afternoon. Cirrus spilling into the region from the southwest will affect the southern CWA this evening and overnight. Showers and thunderstorms will be possible northwest of the CWA tonight and could nose towards the I-70 corridor before daybreak. It`s more likely that cloud cover will be more substantial later overnight, spreading south over the CWA. Lows tonight will once again be limited to the dewpoints which are running in the mid to upper 60s. A few cold pool areas could drop lower, and valley fog will once again be found in river valleys and low-lying areas. The cloud cover coming in from the north should limit this fog to the southern half of the CWA overnight. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/... A weak cold front will cross south through Ohio and interact with an upper level trough to create showers and thunderstorms. The best chance lies in central Ohio but any portion of the CWA will see a chance for activity, peaking in the afternoon and early evening. A shortwave within the upper trough will be strongest southwest of metro Cincinnati and east through the Kentucky/Tennessee border. The rest of the Ohio Valley will see shortwave energy underneath the trough interact with some daytime heating everywhere and a surface frontal passage in the east. A very muddled upper pattern will occur with energy found in pockets over the region Friday night. Activity should be on the decrease through the night but some storms will persist and cannot be definitively ruled out just about anywhere over the CWA at this moment in time. Highs Friday will be a little cooler - lower to middle 80s under cloud cover, with overnight lows from the lower 60s behind the front in the north to the middle 60s south of the I-70 corridor and upper 60s along and south of the Ohio River. && .LONG TERM /SATURDAY THROUGH THURSDAY/... For Saturday into Saturday night, a frontal boundary draped across the region will slowly sag southeast. Meanwhile, as an upper level ridge amplifies northeast into the northern Plains and south central Canada, downstream mid level troughing will develop across the Great Lakes and Ohio Valley. A chance of showers and thunderstorms will continue Saturday into Saturday evening, then pcpn should taper off during the overnight period with the loss of diurnal heating and frontal convergence. Highs in the lower 80s will drop into the lower to mid 60s. For the period Sunday into Monday, the biggest change among the operational models has been the placement of the mid level closed low center over our region. The latest ECMWF is closing the center of circulation farther west then the NAM, GFS, and CMC. The ECMWF solution would favor a greater chance of showers/storms while the other models would result in a much lower chance or even a dry solution over some parts of the area. Have made a compromise which is to keep a slight chance/low chance of showers/storms continuing, mainly during the afternoon and early evening hours. Will continue to monitor later model runs should more adjustments be needed. Highs Sunday and Monday will range from the upper 70s to the lower 80s with lows Monday morning in the lower to mid 60s. For Tuesday into Tuesday night, it still appears that the upper level closed low will get "kicked" to the east from upstream upper level energy pushing into Ontario as well as the central/southern Plains. At the surface, high pressure will traverse west to east across the Ohio Valley. Have gone with a dry forecast for this period. However, there will likely be increasing clouds Tuesday night ahead of the central/southern Plains system. Highs in the lower to mid 80s will drop into the mid and upper 60s by Wednesday morning. For the remainder of the extended, Wednesday into Thursday, aforementioned upper level energy will move into the Ohio Valley along with a frontal boundary. This will bring the next good chance of showers and thunderstorms to our area. Highs again will range from the lower to mid 80s with lows in the mid and upper 60s. && .AVIATION /01Z FRIDAY THROUGH TUESDAY/... Storms moving into northern Ohio are expected to dissipate before reaching the TAF sites, so a dry forecast will be maintained overnight and into tomorrow morning. Some MVFR fog will be possible at a few of the sites (with LIFR fog at KLUK). There is also a small chance of stratus development, as occurred in patches last night, but confidence is currently too low to include in the forecast. Clouds will increase tomorrow, with showers and thunderstorms developing during the afternoon. A VCSH has been included for all TAF sites, and future issuances will likely need a period of prevailing showers, once the timing and location forecast is a little better known. OUTLOOK...Thunderstorms will remain possible at times through Monday, with the greatest chances during the afternoon and evening. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...None. KY...None. IN...None. && $$ SYNOPSIS...Franks NEAR TERM...Franks/Hatzos SHORT TERM...Franks LONG TERM...Hickman AVIATION...Hatzos
Area Forecast Discussion
National Weather Service Indianapolis IN
1040 PM EDT Thu Aug 9 2018 .UPDATE... The Aviation Section has been updated below. && .SYNOPSIS... Issued at 354 PM EDT Thu Aug 9 2018 A frontal zone will approach the area late tonight into Friday, bringing chances for storms at times Friday into Saturday. An upper level trough will follow later in the weekend, which may produce a few showers and storms before high pressure allows a brief break at the start of the week. && .NEAR TERM /Rest of Tonight/... Issued at 1000 PM EDT Thu Aug 9 2018 Based on southeast trajectory and weakening of the southern end of storms across northern Indiana, still think these cells will stay just north of the forecast area, and thus no changes being made to the PoP forecast at this time. Increased cloud cover some across the northern counties for much of the night and also the southeast counties near daybreak. Otherwise no other appreciable changes made as forecast is on track. Previous discussion follows... Model blend appears to be overdoing extent of convection thus far today, particularly the GFS, and this has contaminated forecast builder initialization. Expect that the most vigorous convective development currently ongoing across southern Wisconsin, along the axis of strongest instability pooled ahead of the boundary, will be the main focus for the late afternoon and evening, and HRRR suggests this activity will largely dissipate before making it into central Indiana. Will go dry tonight and monitor the progress of the northern activity. Temperatures will likely be slightly warmer than last night owing to more cloud cover, but between blends being a bit too warm recently, and compared to persistence, felt that consensus numbers were slightly too warm. && .SHORT TERM /Friday through Sunday/... Issued at 354 PM EDT Thu Aug 9 2018 The highest chances for storms will come Friday afternoon and evening with the presence of the surface frontal zone and an upper level wave pushing through the region. Activity associated with the boundary and a secondary upper wave may persist into Saturday and additional chances will be necessary Sunday as the upper wave drops into the area and potentially closes off. A significant severe threat is unlikely at this time. Consensus temperatures appeared a bit warm given numbers today and expected low level thicknesses through the period, as well as potential for expansive cloud cover and precipitation. Made downward adjustments each day. && .LONG TERM /Sunday night through Thursday/... Issued at 237 PM EDT Thu Aug 9 2018 Ensembles suggest a cutoff upper low over the Ohio Valley will drift off to the east early next week, followed by a more substantial trough that may move into the area by the middle of next week. Could be some diurnally driven shower activity on Monday afternoon, especially over the eastern zones associated with the cutoff low. However, ensembles are very bullish on the precipitation threat this far west. Will leave some chances PoPs for Monday in those areas for now. Otherwise, appears a better precipitation threat may arrive by the middle of next week, as a stronger trough moves along the northern parts of the country. Will add some PoPs for next Wednesday and Thursday to cover this potential. && .AVIATION /Discussion for 100300z TAF issuance/... Issued at 1040 PM EDT Thu Aug 9 2018 Updated current conditions only. Previous discussion follows... Quiet weather tonight and VFR conditions expected at the sites as convection should stay well north or south of the sites. A very slim chance a shower/storm makes it south enough to impact KLAF, but certainly not enough to include. A front slowly sinking through the area will bring some chances for storms on Friday, but the probability is low enough to leave out at this time. Will include a deck of few to scattered clouds around 2000 to 4000 ft during the late morning through the afternoon with this front. && .IND WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...Nield NEAR TERM...Nield/CP SHORT TERM...Nield LONG TERM...JAS AVIATION...CP
National Weather Service Jackson KY
1154 PM EDT Thu Aug 9 2018 .UPDATE... Issued at 1154 PM EDT THU AUG 9 2018 The latest scans of the WSR-88D radar shows that much of the shower activity has now diminished this hour. We are watching some activity in the Tennessee Valley that will move into portions of the Lake Cumberland region over the next several hours. The forecast looks on track and only minor changes were needed to blend in the latest obs and trends. UPDATE Issued at 911 PM EDT THU AUG 9 2018 The latest radar trends have shown a weakening of any of the isolated showers and thunderstorms that developed this evening. These showers seemed to be tied to some weak boundary interaction which shows up well on the SPC Meso data. Given the trends will take thunder out of the grids and HWO through the this evening into much of the night. The guidance remains in favor of a disturbance progressing northeast out of the Tennessee Valley into eastern Kentucky toward dawn. Only minor edits were made toward the latest trends at this time. UPDATE Issued at 651 PM EDT THU AUG 9 2018 The latest WSR-88D radar scans are showing a few isolated showers tracking across portions of the area this evening. However, did keep the mention of thunder since there has been some signs of ice when looking at the MRMS VII product. These will subside as we loose the daytime heating, but more activity remains possible toward dawn as an upper level disturbance approaches. Overall these were mostly minor updates to the grids and also made updates to temperatures, dewpoints, and winds with the latest obs and trends. && .SHORT TERM...(This evening through Friday night) Issued at 304 PM EDT THU AUG 9 2018 Seeing a rather complicated surface pattern this afternoon. There is a quasi-stationary frontal boundary aligned from the Ohio Valley down to the Arklatex region. Mid/upper level charts show a trough over the eastern CONUS and models drop additional energy in the form of shortwaves southward out of Canada which tend to maintain this feature through the short term. In general the HRRR has been handling the less organized convective activity poorly, but has managed to capture the more obvious line of showers and thunderstorms crossing Tennessee and south central Kentucky this morning. HRRR has been consistently moving this activity eastward but weakens the northern end considerably as it passes through our southern most zones through the afternoon. RAP/NAM solutions follow this scenario as well, but most models show a general redevelopment of rain through the overnight as as a shortwave trough enters into the lower Ohio Valley. Reflected surface wave looks quite weak and undefined. Lower level wind field is also quite weak but there may be a few hours of upper level support leading up to dawn from the right entrance region of a jet streak over OH/WV that may help with some lift aloft. Whats left of the surface front appears to wash out with time. Most of any rainfall through the short term should be associated mainly with relatively weak synoptic features interacting with mesoscale forces and diurnal heating. Thus convection will be mainly diurnally driven. PWATs increase considerably through the overnight into Friday morning and more significantly across our south, up around 1.8 to 1.9 inches. Storm motion drops off to less than 10 kts as well. Freezing levels remain respectfully high at around 13 kft and CAPES are favorable for warm rain processes. Suspect there could be some low centroid heavy rainers as a result towards dawn and through much of the day Friday. Temperatures will be moderated through the period as well with cloud cover and an increased threat of rain keeping overnight lows up and afternoon highs down a bit. .LONG TERM...(Saturday through Thursday) Issued at 304 PM EDT THU AUG 9 2018 A shortwave trough will slowly push across the area over the weekend, but lack of significant forcing will yield only scattered showers and storms each afternoon. The threat on Sunday will shift exclusively into southern and southeast Kentucky before pushing south Sunday evening. As we head into early next week, the period is looking drier, especially on the 12z GFS. The ECMWF keeps some small chances in the afternoons, but will limit pops to only slight chances for Monday through Wednesday. A more organized system may arrive next Thursday, but details are fairly questionable at this time range. We may warm up nicely into the middle of next week pending the strength of the late week system. Highs through next week will stay fairly close to normal in the low to mid 80s. with overnight lows staying the 60s. && .AVIATION...(For the 00Z TAFS through 00Z Friday evening) ISSUED AT 743 PM EDT THU AUG 9 2018 We are seeing some isolated shower activity this evening, but these showers are expected subside through the evening. The only site the could see issues from these at this point would be JKL, but have left mention out for now given the up and down nature of this convection. Did keep the mention of lowering CIGs and VIS at all the sites again tonight, but a little concerned on how this will evolve at SME/LOZ given the potential for showers toward dawn. Also, did opt to TEMPO JKL given the potential for valley fog to creep into the TAF site. Overall have all the sites seeing at least IFR conditions or lower at times tonight through Friday morning. We should see some improvement through the day, but a upper level disturbance will bring the chances for showers and thunderstorms through the morning and afternoon Friday. For now left the mention of VCSH from previous forecast cycle. Winds will remain light through the TAF period. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...DJ SHORT TERM...RAY LONG TERM...KAS AVIATION...DJ
Area Forecast Discussion
National Weather Service Medford OR
838 PM PDT Thu Aug 9 2018 .DISCUSSION...Smoke continues to be the main feature of concern across southern Oregon and northern California. Visibilities have been ranging from three quarters of a mile to a mile and a half over the past few hours. This poor air quality will continue again for one more night and morning before a dry cold front comes through tomorrow evening and makes things a little less hot. The winds will pick up tomorrow and will help drive the smoke to the east-- at least briefly. With the evening update package, my only changes are to expire the heat advisory and to ponder the necessity for any fire weather products for tomorrow. Otherwise, the current forecast looks good, and the previous discussion will provide the details of the forecast. -Schaaf && .AVIATION...For the 10/00Z TAFs...Marine stratus mainly along the coast but beginning to push back inland. Starting first in the Coos Bay/North Bend area. A bit of a hole around Cape Blanco but that will fill in over the next few hours. Confidence is high that the stratus will come back onshore with widespread MVFR ceilings and visibility and last through the night. A large closed low offshore will approach the coast overnight. Generally, this increases the depth of the marine layer which makes for a low ceiling and drizzle situation rather than for fog. Inland, we do not expect stratus will penetrate as far inland as Roseburg tonight, but it should be close and between 5am and 9am Friday there is fair uncertainty as to possible ceilings near 2000 ft. Smoke is the contributer to MVFR weather at Medford, Klamath Falls and much of southwest Oregon. The latest 24-hr forecasts reflect similar trends as observed yesterday...deteriorating at evening and remaining MVFR range overnight, then improving some by late morning Friday. Stavish/JBL && .MARINE...Updated 815 PM PDT Thursday 09 August 2018...Light winds and seas continue through Friday, then a weak front will pass through Friday night into Saturday morning. North wind develops through Saturday afternoon. Small craft advisory winds are possible south of Cape Blanco Saturday night and these winds increase through Sunday with a strong thermal trough over the south Oregon coast. The thermal trough and winds weaken a but Monday, then even more Tuesday. Stavish. && .PREV DISCUSSION... /Issued 236 PM PDT Thu Aug 9 2018/ SHORT TERM...The high pressure ridge over the area, which is bringing very hot temperatures to inland areas, will shift eastward on Friday as an upper trough moves into the Pacific Northwest coast. Today, one of the main concern is with heat impacts across inland areas. Temperatures are on track to be similar or slightly higher than yesterday. A heat advisory (NPWMFR) remains in effect through this evening for areas in southern Douglas, Josephine, Jackson, central Siskiyou and Lake counties where highs are expected to rise into the upper 90s and low 100s. A second concern today is with breezy winds and dry conditions. Across portions of Northern California, breezy winds and dry humidities are expected this afternoon and evening, bringing increased fire danger. A red flag warning (RFWMFR) is in effect for these conditions. On Friday, the upper trough will move into the Pacific Northwest coast bringing slightly less warm temperatures. Gusty winds and continued dry humidities will bring additional fire weather concerns, especially to Northern California and areas east of the Cascades. Models are in good agreement showing the upper trough continuing to move inland Saturday then shifting northeast on Sunday. Overall, models have trended slightly slower with the upper trough moving inland on Friday with the trough pushing into the coast late in the day and into the evening. With this trough moving onshore, expect temperatures to lower about 3 to 6 degrees across inland areas. Although the forecast trough progression inland is slower than previously shown, models are still in good agreement that winds will increase late in the day Friday and into the evening across inland areas. The strongest winds are expected in the Shasta Valley and east of the Cascades, where gusty southwest winds will develop. The combination of gusty winds and very dry daytime humidities may bring critical fire weather conditions to these areas. So, fire weather watches remain in effects for portions of central and eastern Siskiyou, Modoc, Lake and Klamath counties. Other inland areas from the Cascades west will also see breezy to gusty west winds late Friday afternoon into Friday evening. Additionally, transport winds aloft will increase during the day. The 12z high resolution HRRR model shows smoke decreasing over the area as it is transported to the east and northeast Friday afternoon. So expect some improving conditions, including to areas west of the Cascades. Of note though, local wildfires will continue to bring some smoke impacts to areas downwind of the fires. So expect that any improvement in smoke over the area will be brief. Smoke is expected to increase again Saturday afternoon and evening as northwest to west surface and transport winds return. An air quality advisory (AQAMFR) remain in effect due to the impacts of wildfire smoke for areas in southwest Oregon. Smoke impacts are also likely into Northern California. Along the coast, the upper trough passage will bring a deepening marine layer Friday into Saturday morning. This may result in isolated showers or light drizzle along with patchy fog near coastal areas. Also the marine layer is expected to spread inland and bring clouds into portions of the Umpqua basin Friday night into Saturday morning, including at Roseburg. Models indicate the depth of marine layer extending up to around 1500 to 2000 ft elevation Friday night and Saturday. So, overall, expect the clouds to stay north of the Umpqua divide. Saturday will likely be the least hot day for inland areas with temperatures forecast in the 80s to near 90 for most inland valleys. On Sunday, the upper trough will lift northeast. Meanwhile,at a surface, a thermal trough will develop along the coast. This pattern will bring a warming trend to inland areas. Guidance indicates temperatures will warm into the lower to mid 90s across western valleys but depending on smoke levels, these temperatures may be slightly lower. With the surface thermal trough along the coast, also expect breezy northeast winds over the coastal mountains with lighter northeast winds over the inland mountains Saturday night into Sunday morning. In the afternoon the winds will change to north to northwest over the area. With a mix of northeast to northwest winds, expect areas of smoke from nearby wildfires to continue to bring smoke and air quality impacts to inland areas. LONG TERM...Monday through Thursday, an upper ridge will build over the region early next week then weak shortwaves may move up from the south to southwest by mid week. As the ridge builds, expect temperatures to warm up Monday and Tuesday across inland area with highs warming back into the mid to upper 90s across western valleys and in the upper 80s to near 90 for valleys east of the Cascades. By Wednesday, models are indicating some weak upper shortwaves and mid level moisture moving into the area from the southwest. There is lower confidence on the details of these disturbances as models show significant run to run variability. Also a significant variable is whether any upper and mid level moisture originating from Tropical Storm John moves up into northern California and southern Oregon. So, will continue to monitor this with future model runs. FIRE WEATHER...Updated 200 PM PDT Thursday, 9 August 2018... Hot and dry weather will continue for the next couple of days. The models continue to trend slower with the progression of the upper low Friday into the weekend. The slower arrival of the upper low will lessen the gusty winds and low relative humidity threat into this evening. This is especially the case in the Shasta Valley. Winds are still expected to increase some later this afternoon into this evening in the Shasta Valley, but they are not expected to be strong and thus Red Flag conditions won`t be met. Therefore we decided to cancel the Red Flag Warning for fire zone 281. The Red Flag Warning remains in effect for portions of of Fire zone 285, but there`s increasing evidence it will affect a small area and adjustments were made to the coverage area. Details on this can be found at RFWMFR. The upper low will push closer to the Oregon coast Friday. Models are in pretty good agreement showing 700mb winds increasing Friday afternoon. This along with surface heating will allow some of the stronger winds to mix down at the surface. Also with the slower arrival of the upper low. Temperatures, especially east ofthe Cascades could be similar to what they are today. At the same time relative humidity will be low, thus a Fire Weather Watch remains in effect for Friday afternoon and evening. The coverage area for the watch has been left unchanged. For details on the watch please see RFWMFR. South to southwest winds will increase further Friday afternoon ahead of and with a dry cold front. It will likely result in critical conditions across the east side bringing low RH and strong, gusty winds. Winds could gust 30 to 40 mph there with RHs around 10%. West side areas will not be quite dry enough to reach warning criteria, but gusty northwest winds will also be stronger than normal and are likely to increase fire activity. The decision was made to keep the watch and not upgrade at this time due to the models trending slower with the arrival of the upper low. Heat: The inland warming trend will continue and reach a peak on Friday. Wildfire smoke has been a hindrance to heating (typically by around 3 to 5 degrees), but high temperatures will still be about 10 degrees above normal. We`ll have a one day cool down with temperatures about 10 degrees cooler, before they rebound on Sunday and then edge up again early next week. Lightning: Model guidance is generally indicating moisture sufficient for thunderstorms to be lacking through at at least the start of next week. By next Tuesday, there may be sufficient mid level moisture and instability to bring a threat of thunderstorms, but this is still a long ways out and the details on timing and locations of storms could change. -Petrucelli && .MFR WATCHES/WARNINGS/ADVISORIES... OR...Heat Advisory until 9 PM PDT this evening for ORZ023-024-026. Fire Weather Watch from Friday afternoon through Friday evening for ORZ624-625. Heat Advisory until 9 PM PDT this evening for ORZ031. CA...Fire Weather Watch from Friday afternoon through Friday evening for CAZ281. Heat Advisory until 9 PM PDT this evening for CAZ081. Fire Weather Watch from Friday afternoon through Friday evening for CAZ284-285. Red Flag Warning until 9 PM PDT this evening for CAZ285. Pacific Coastal Waters...None. $$
Area Forecast Discussion
National Weather Service San Francisco Bay Area
433 PM PDT Thu Aug 9 2018 .SYNOPSIS...High pressure over the west will maintain very warm to hot conditions across the interior. Meanwhile, cooler conditions will persist near the coast due to a persistent shallow marine layer and moderate onshore flow. Slightly cooler temperatures are expected by this weekend as high pressure weakens. && of 1:44 PM PDT Thursday...Satellite imagery shows skies have cleared and stratus has retreated to out over the ocean. Current temperature trends are running warmer than yesterday at this time by as many as 10 degrees, with readings ranging from the lower 60s to lower 70s at the coast, the 70s to mid 80s around the Bay, and the 90s to near 102 inland. Expect a repeat tonight with a shallow marine layer near the coast, locally dense fog is expected at the coast Friday morning. High pressure will keep the warm/hot temperatures through Friday before gradual and slight cooling arrives over the weekend when the upper ridge weakens. Air quality should show some improvement over the weekend as well when onshore winds strengthen and become more southwest. Although a cooling trend is indicated, highs across inland areas will still be quite warm with mid to upper 90s expected. High pressure aloft will then rebuild westward from the desert southwest early next week for inland highs edging back to over 100 degrees by Thursday or Friday. && of 04:33 PM PDT Thursday...For 00z tafs. VFR conditions will continue through the evening as stratus resides along the immediate coast. Slantwise visibility issues will persist due to smoke and haze from multiple wildfires. Latest HRRR smoke forecast suggests some possible relief overnight in vertically integrated and near surface smoke across the Bay Area. Coastal stratus is expected to return tonight in similar fashion to what was observed last night with only minor differences. Patchy dense fog and drizzle possible through the early morning along the coast. Winds will remain generally light through the period with locally higher winds and gusts in the afternoon/evening at KSFO. Vicinity of KSFO...VFR through the period aside from patchy IFR cigs overnight and into the early morning. Smoke/haze affecting slantwise vis will continue to be a concern, although HRRR smoke model suggests some overnight relief. Breezy winds remain a possibility into the early evening before diminishing overnight. Onshore winds will increase again tomorrow afternoon. SFO Bridge Approach...Same as terminal. Monterey Bay Terminals...Another early return of stratus is expected. LIFR/VLIFR cigs overnight into tomorrow morning along with patchy dense fog. Generally light winds through the period. && of 02:31 PM PDT Thursday...Breezy northwest winds will prevail with locally stronger gusty winds along the coast, especially near coastal gaps and north of Point Reyes and south of Point Sur. A pair of southerly swells generated by tropical systems to the south will move through the coastal waters through the coming days. && .MTR WATCHES/WARNINGS/ADVISORIES... .Tngt...SCA...SF Bay until 9 PM SCA...Pigeon Pt to Pt Pinos 0-10 nm until 9 PM SCA...Pt Pinos to Pt Piedras Blancas 0-10 nm until 3 AM SCA...Pt Arena to Pigeon Pt 10-60 nm until 3 AM SCA...Pt Arena to Pt Reyes 0-10 nm && $$ PUBLIC FORECAST: Sims AVIATION: AS MARINE: DRP Visit us at Follow us on Facebook, Twitter, and YouTube at:
Area Forecast Discussion
National Weather Service Nashville TN
832 PM CDT Thu Aug 9 2018 .UPDATE... FOR EVENING DISCUSSION. && .DISCUSSION... A few showers and thunderstorms have developed in western areas tonight ahead of the upper shortwave trough. Short term models such as the HRRR and NAMNest want to develop a MCV type feature across the area overnight, mainly for areas north of I-40 and east of I-65. Went ahead and raised pops slightly to reflect CAM consensus. Also added in mention of patchy fog as earlier rains provided more surface moisture and areas may see some fog development overnight. Other than that, no major changes to the forecast this evening and overnight. && .AVIATION... 00Z TAF DISCUSSION. VCSH/-SHRA to affect all airports this TAF period with scattered showers this evening at CKV/BNA/MQY. Cannot completely rule out a VCTS at BNA/MQY but storms should mainly remain south of those airports. Overnight, models consistent in bringing -SHRA to CSV, with more VCSH at BNA/MQY/CSV on Friday. Cigs to remain mainly VFR but periods of MVFR visibility anticipated at CKV/CSV late tonight. && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ DISCUSSION......Barnwell AVIATION........Shamburger
Area Forecast Discussion
National Weather Service Tucson AZ
202 PM MST Thu Aug 9 2018 .SYNOPSIS...Abundant moisture and favorable flow will provide an active period for thunderstorms with locally heavy rainfall at times into early next week. Daytime temperatures will also trend near or below seasonal normals. && .DISCUSSION...The considerable cloudiness this morning and early this afternoon had delayed the onset of scattered showers and thunderstorms today. Latest HRRR solution had backed off on the amount of activity projected for this evening and tonight. The HRRR model also showed a much later start to the showers and thunderstorms, with most of the activity occuring across southeast Arizona after 03Z Friday. Despite this delay, the possibility of blowing dust in the lower deserts was still not out of the question. Thus, will keep the Blowing Dust Advisory posted until 10 PM MST this evening. Otherwise, models keep a favorable flow pattern across the region for daily showers and thunderstorms through at least early next week. Thereafter, the high pressure ridge centered north of the area will shift southward next week with warming aloft limiting thunderstorm activity a bit. High temperatures will also return to normal readings. && .AVIATION...Valid through 11/00Z. Scattered TSRA/SHRA this evening and overnight into Friday. Otherwise, SCT-BKN cloud bases generally 8k-15k ft AGL. WLY/SWLY SFC winds this afternoon will remain less than 15 kts, but gusty erratic outflow winds to 40 kts will be possible in and around stronger TSRA. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...The weather pattern will remain favorable for daily showers and thunderstorms into next week. Daytime temperatures will remain below normal through the weekend, before warming back to normal Monday through the rest of next week. Terrain driven 20-ft winds at less than 15 mph, except for in and around thunderstorms where strong outflows may occur. && .TWC WATCHES/WARNINGS/ADVISORIES... Blowing Dust Advisory through 10 PM MST this evening for AZZ501- 502-505. && $$ Visit us on Facebook...Twitter...YouTube...and at