Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 05/16/18

Area Forecast Discussion
National Weather Service Dodge City KS
701 PM CDT Tue May 15 2018 ...Updated Aviation Section... .SHORT TERM...(This afternoon through Wednesday) Issued at 1212 PM CDT Tue May 15 2018 All precipitation has cleared off the radar scope as of midday for a temporary break from the action, but this won`t last long. A subtle boundary is seen on satellite/radar imagery sinking south of Dodge City as of noon, with north winds near 20 mph in its wake. This boundary will play an important role in convective evolution this evening. A rather extensive cumulus field is evident, much of it generating off the heavy rain/hail swath across the northern zones from last night`s spectacular storm. Despite the clouds and north winds, temperatures will warm easily through the 70s this afternoon. Most if not all locations will remain dry through 5 pm. Another active round of thunderstorms is expected tonight, with some again producing severe wind and hail. SPC has been trending its marginal/slight categorical risks further NW toward our SW zones, and we agree with this thinking. Virtually all short range models generate convection off the Palmer Divide and/or the Raton Mesa in Colorado/New Mexico mid afternoon, and subsequently spread storms eastward into Kansas through tonight. We have high confidence on this general outcome. The catch is, how many storms? What will be the storm mode be? Where exactly do they track? How severe will they be when they get to Kansas? As we learned last night, we only need one storm to make for a long night. 12z NAM is quite aggressive, spreading convection across areas west of US 83 this evening. Trend of HRRR iterations has a squall line arriving at Morton county by 7 pm, then progressing NE toward Dodge City by 10 pm. This NEly trajectory makes sense, with 500 mb flow a bit south of due west. CAPE and shear combination will again support convection and allow it to persist well into Kansas. Consensus of short term models suggest large hail and/or damaging wind is most likely across the SW counties through midnight, and this is where severe wording was included in the grids. Again tonight, the tornado risk is very low. That said, I am concerned with boundary across the southern zones. If a discrete supercell can anchor on that boundary ahead of the developing squall line (something the HRRR is starting to suggest) than a brief tornado can`t be ruled out. Along with WFO Amarillo, increased pops to the likely category along the Oklahoma border. Lows tonight in the 50s after storms move NE, congeal or exit SW KS. Wednesday...Upper flow configuration changes, as ridging amplifies over the spine of the Rockies, in response to 565 dm closed low entering central California. Moisture and instability will be maintained through the afternoon, as SEly boundary layer flow maintains upper 50s and lower 60s dewpoints. NAM suggests some showers may persist well into the morning across the NE zones, with most areas dry most of daylight Wednesday. Best chances for initiation of new convection appears to be along the CO/KS line late in the afternoon. SPC`s marginal 5% wind/hail probability along/west of US 83 appears reasonable. Temperatures warm a couple more degrees into the lower 80s. .LONG TERM...(Wednesday night through Tuesday) Issued at 155 PM CDT Tue May 15 2018 Upper low at 564 dm near Reno, Nevada sunrise Thursday will only crawl eastward across Nevada during daylight Thursday. The resultant sharp ridge axis will be on top of SW KS Thursday morning, with SW flow resuming aloft by afternoon. SE surface winds will increase noticeably Thursday afternoon, as moisture flux is maintained. Model blend and 12z ECMWF show thunderstorm coverage favoring the NW zones late Thursday, and some of these will be contenders for large hail/damaging wind production. Marginal 5% hail/wind probabilities from SPC are well placed across the CWA. ECMWF progs CAPE on the order of 2500-2800 across the NW zones, and surface dewpoints to the lower 60s, where severe wind/hail are most probable Thursday afternoon. Temperatures Thursday night/Friday morning will hold in the 60s, courtesy of a strong low level jet and strong S/SE winds. Moisture influx into SW Kansas Friday morning will be strong, with a probable morning thunderstorm complex ongoing in Nebraska. The risk of severe weather is apparent Friday, as models continue to develop a potent synoptic set up for tornadic supercells Friday afternoon. Broad trough over the Rockies will only slowly expand eastward through the day, with vort maxes/jet streaks rotating around the SE periphery of the trough and interacting with a well established dryline. Leeside cyclogenesis will be impressive beneath the strengthening SW flow aloft, with 12z ECMWF placing a 996 mb surface low near Syracuse 7 pm Friday. Initial indications are dryline will punch to roughly US 283, with rich 60s dewpoints established in the warm sector east of the dryline and south of a warm front across the northern zones. Various CAPE/shear/EHI progs from various models strongly suggest severe thunderstorms at least across the NE 1/2 of SW KS, with very large hail and tornadoes possible. As a start, have already included severe wording in the grids for Friday afternoon and evening. Cold frontal passage Friday night through Saturday will usher in noticeably cooler temperatures (only lower 70s Sunday afternoon), lower humidity, and an end to rain/thunderstorm chances. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 653 PM CDT Tue May 15 2018 The main challenge in aviation weather will be timing and duration of thunderstorms overnight. We expect at least a small mesoscale convective system to affect GCK, DDC, and LBL terminals. The latest TAF will include a 4-hour period of VCTS, with activity winding down in the 09-12z time frame. Winds throughout the period will be fairly light, less than 12 knots expect near thunderstorms. There is probability of any sustained IFR or MVFR ceiling, so the ceiling/visibility will remain VFR. && .PRELIMINARY POINT TEMPS/POPS... DDC 59 82 59 85 / 60 30 10 10 GCK 58 81 58 85 / 60 20 10 20 EHA 55 84 57 89 / 80 20 10 10 LBL 57 83 60 89 / 80 20 10 20 HYS 57 80 58 84 / 20 20 10 10 P28 61 84 61 88 / 40 40 10 10 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Turner LONG TERM...Turner AVIATION...Umscheid
Area Forecast Discussion
National Weather Service Austin/San Antonio TX
711 PM CDT Tue May 15 2018 .AVIATION... A line of SHRA/TSRA is moving south across the eastern Hill Country. Have replaced the PROB30 for KAUS with a VCTS from 02z to 06z as the line passes just west of the site. Will monitor its progress for possible impacts to KSAT/KSSF. TSRA over the Serranias del Burro should remain over that higher terrain until dissipation and have removed mention from KDRT. VFR skies will prevail going into the overnight, except brief MVFR or lower CIGs/VSBYs in SHRA/TSRA. MVFR CIGs will develop later tonight, closer to morning and mix out to VFR around mid morning on Wednesday. Wind gusts to 50 KTs are possible with the SHRA/TSRA, otherwise S to SE winds 5 to 12 KTs will prevail. && .PREV DISCUSSION... /ISSUED 301 PM CDT Tue May 15 2018/ SHORT TERM (Tonight through Wednesday Night)... There are still a lot of uncertainties regarding the short-term forecast as is usual the case with these subtle disturbances within northwest flow aloft. The best upper support for convection will be just to the north of our area and this is where some convection has already developed. We will have to watch these areas for possible south or southeast movement into our CWA late this afternoon and evening. First, scattered thunderstorms have developed to the west of Val Verde County near the dryline. As these storms become sustained, 700-300 mb mean winds from the west could bring this activity into Val Verde County around 5-7 PM. Will forecast 20/30 PoPs this evening for the northern Rio Grande Plains for this potential activity. A second area of storms is developing near a surface low northeast of Midland. The best potential for these storms to make it to the CWA would be for them to congeal into a small complex that would become cold-pool dominated. Forward-propagation vectors point to the southeast by 00z and this would bring the potential storms into the northern Hill Country after 00z. The latest HRRR does support this scenario and the latest satellite imagery looks promising for additional development needed for cold-pool generation. A third area of storms is located southwest of Fort Worth and these storms are moving stationary. Think these could eventually move southeast and clip the CWA later this afternoon, but probabilities are pretty low as these are a little too far east. A fourth area of storms is currently near the TX/OK border and does have a developed cold pool associated with the storms moving to the south as evident on the latest visible satellite imagery. Current movement of the boundary is to the south and the latest HRRR moves this system SSE through the evening hours into the northeastern CWA around 4-6z. The third area of storms mentioned could impact the storms are they may cut off the boundary. The HRRR does not have the third area as robust as currently occurring. Will forecast 20 to 40 PoPs for north and northeastern CWA for tonight. Any storms that do move into the CWA this evening should be in a weakened state as the boundary layer slightly cools and inhibition increases. A strong storm or two will be possible initially and the SPC has the northern Hill Country and Edwards Plateau in a marginal risk of severe storms. By morning, lows will be in the upper 60s to lower 70s with patchy fog possible in the Coastal Plains. Most of tomorrow will remain dry but there could be additional storms develop northwest of our CWA that move into the Edwards Plateau and northern Hill Country in the late afternoon or evening hours. Overall, think the coverage of storms will be less as shortwave ridging begins to move into the area. Highs tomorrow will be in the lower 90s to upper 90s with the higher values along the Rio Grande. LONG TERM (Thursday through Tuesday)... Shortwave ridging will be the main player for the beginning of the long-term forecast. Dry and hot weather is expected Thursday through Saturday. 850 mb temps along the Rio Grande will be up to 26C Thursday afternoon and we should see the first 100 degree day of the season for Del Rio Thursday with middle 90s along the I-35 corridor. 850 temps will cool slightly Friday and temps should be a degree or two cooler. As the ridge slides to the east Sunday, storm chances will return to the forecast for the northwest CWA Sunday and Monday. && .PRELIMINARY POINT TEMPS/POPS... Austin Camp Mabry 71 94 70 95 71 / 30 - 10 - 0 Austin Bergstrom Intl Airport 68 92 66 93 69 / 30 - 10 - 0 New Braunfels Muni Airport 68 92 66 93 68 / 20 0 - 0 0 Burnet Muni Airport 70 92 68 93 69 / 40 20 20 - 0 Del Rio Intl Airport 73 98 73 100 73 / 30 - - 0 0 Georgetown Muni Airport 70 93 68 93 69 / 30 20 20 - 0 Hondo Muni Airport 70 94 67 96 67 / 20 - - 0 0 San Marcos Muni Airport 69 92 66 93 69 / 20 0 - - 0 La Grange - Fayette Regional 70 92 68 93 71 / 20 0 - - 0 San Antonio Intl Airport 71 92 70 95 70 / 20 0 - 0 0 Stinson Muni Airport 70 93 69 96 70 / 10 0 - 0 0 && .EWX WATCHES/WARNINGS/ADVISORIES... None. && $$ Mesoscale/Aviation...04 Synoptic/Grids...Williams Public Service/Data Collection...YB
Area Forecast Discussion...UPDATED
National Weather Service Fort Worth TX
949 PM CDT Tue May 15 2018 .UPDATE... Earlier strong-severe convection which tracked southward across our western counties this afternoon and evening has really worked over this portion of our forecast area with a local minimum in CAPE. This, combined with nocturnally increasing convective inhibition, should work to help steadily dissipate the ongoing line of showers and storms currently approaching our far western row of counties (Eastland to Young). Brief gusty winds, small hail, and cloud to ground lightning will be the main threats with this activity. Have pared back PoPs across much of the forecast area this evening, leaving the highest values west of an Olney to Eastland line as this aformentioned activity decays. The next feature we`ll be watching is an ongoing complex of storms moving swiftly into the eastern Texas Panhandle. This activity may be aided by a subtle mid-level ripple in the flow, with an associated 40-50 kt wind maxima at 500 mb noted in regional upper-air mesoanalysis. These storms presently reside within a somewhat more favorable thermodynamic environment, characterized by steeper mid-level lapse rates and better low- level moisture. The current thinking is that this complex will gradually start to turn a bit more towards the south as it heads towards a developing low-level jet. That said, 925-850 mb winds are not forecast to be all that strong (25-30 kts), and convection will have to contend with previously convectively processed air as it approaches North Texas after midnight. We`ve expanded low PoPs a bit farther towards the south and west to catch the additional southward development, but precip chances will remain fairly low with the idea that this activity will be gradually weakening, exhausting a gusty outflow, and leaving us to contend with just a convective carcass late tonight and early Wednesday morning. We`ll continue to closely monitor trends and upstream convective vigor this evening, however. Updated products have been transmitted. Carlaw && .AVIATION... /Issued 631 PM CDT Tue May 15 2018/ /00Z TAFs/ Concerns--Evening convection and brief N flow. Convection has been weakening over North Texas...and this trend should continue after sunset with the loss of daylight heating. Given that a weak outflow boundary continues to hang around just north of the Metroplex terminals...will allow VCTS to ride through 16/0200Z (will also mention TEMPO 04008KT as we could see some brief...but light N flow). Heading into the overnight...the next round of convection (presently over northeast New Mexico and into the Texas Panhandle) will move into western North Texas after midnight...but this convection is expected to weaken before making it to the Metroplex. VFR will prevail through the forecast period. Godwin && .SHORT TERM... /Issued 308 PM CDT Tue May 15 2018/ There are two areas of convection that will be of concern to the forecast through the evening hours. The first area is an MCS that developed earlier this afternoon over western Oklahoma, that as of about 2:25 PM CDT is roughly 30 miles north of the Red River. These storms should cross the Red River and enter Montague and Cooke Counties during the next couple of hours. The environment ahead of these thunderstorms is characterized by SBCAPE of 2,000+ J/kg and surface dewpoints near 70 F. A few damaging wind reports have already been received with these thunderstorms over Oklahoma, and conditions are favorable for them to maintain intensity as they continue south, reaching the Dallas/Fort Worth area by around 6:00 PM this evening. While widespread severe weather is not anticipated with these storms, a few storms will likely be strong with gusty winds and small hail possible. The second area of convection is a cluster of thunderstorms that has developed along a line from Mineral Wells to Comanche. Hi-res guidance is not handling these storms as well as the more organized storms in Oklahoma, but nonetheless they are in an environment of around 2,500 J/kg SBCAPE and surface dewpoints in the upper 60s, so they too should maintain their intensity for the next few hours. These storms are expected to merge into a cluster and move south to southeast at 10-15 MPH. These storms will bring a threat for gusty winds, frequent lightning, and heavy downpours to parts of Central Texas. A few storms could be severe with damaging winds and small hail possible. These storms should exit our county warning area around midnight tonight. Heading into the overnight, the forecast remains tricky as highres guidance has struggled all day with convective trends. Visible satellite imagery shows thunderstorms beginning to develop along the east side of the Sangre de Cristo Mountains in northern New Mexico. This is fairly in line with the HRRR which grows these thunderstorms upscale into an MCS quickly. This MCS is forecast to move across the Texas Panhandle, then drop southeast into the Red River Valley late tonight as it rides northwest flow aloft. These thunderstorms should weaken significantly before reaching our county warning area, but will maintain chance PoPs along the Red River after midnight as some scattered showers and thunderstorms may remain. The overnight severe weather threat should be minimal. Godwin && .LONG TERM... /Issued 308 PM CDT Tue May 15 2018/ /Wednesday through Tuesday/ Provided that storms impact most of the region tonight, the airmass should be fairly worked over Wednesday. Will keep a 20 percent chance of showers/storms over the entire area with the idea that any activity would either be isolated elevated morning showers or isolated surface based afternoon pop-up convection. Generally mostly sunny skies in the afternoon will help temperatures reach their highs of upper 80s in the north to lower 90s in the south. Once again more vigorous convection will develop to our west Wednesday afternoon. Although the atmosphere will not be quite as unstable as today, the mid level northwesterly flow does increase to 25-30 knots which should help this convective activity make it into the region after dark. No big squall lines are expected and this activity should stay isolated to scattered in nature so PoPs will be low and mainly over the western areas. Convection will dissipate as it heads into increasing inhibition in the heart of the CWA. Upper level ridging will begin to build over the region on Thursday, but it still looks like there will be another round of afternoon convection to our west and enough flow to potentially bring it into the western zones Thursday night. Otherwise temperatures will respond to the upper level ridging and increasing thickness values and warm to the 90-95 degree range across the entire region Thursday, Friday, and Saturday. Will keep the rain out of the forecast during this time period, even though convection will continue to fire daily in west Texas. This is because the upper level flow will become more southwesterly ahead of the next upper trough and storm motions should keep the convection to the northwest of the CWA. This trough will result in stronger low level flow from the south and southeast by Sunday, bringing a "cooler" fetch off of the Gulf. High temperatures will trend slightly downward Sunday into early next week. As the trough moves into the Plains the flow may be more favorable for West Texas convection to reach the CWA Sunday night and upper level forcing may be sufficient for some home grown convection to bubble up over the area on Monday. Will keep PoPs in the 20 percent range due to concerns about the system being too far north of the region and an increasing cap as the cooler Gulf airmass in the lowest few thousand feet helps strengthen the inversion. TR.92 && .PRELIMINARY POINT TEMPS/POPS... Dallas-Ft. Worth 70 90 70 91 72 / 20 20 20 10 10 Waco 68 93 68 94 70 / 20 20 20 10 10 Paris 66 86 68 88 69 / 50 20 20 10 10 Denton 67 89 69 91 71 / 20 20 20 10 10 McKinney 67 88 69 90 70 / 20 20 20 10 10 Dallas 71 91 72 92 73 / 20 20 20 10 10 Terrell 68 90 68 91 70 / 10 20 20 10 10 Corsicana 68 91 68 91 70 / 10 20 20 10 10 Temple 68 94 69 93 70 / 20 20 20 10 10 Mineral Wells 66 90 67 92 68 / 30 20 30 10 20 && .FWD WATCHES/WARNINGS/ADVISORIES... None. && $$ 90/58
Area Forecast Discussion
National Weather Service Goodland KS
509 PM MDT Tue May 15 2018 .SHORT TERM...(This evening through Wednesday) Issued at 245 PM MDT Tue May 15 2018 W/SW flow aloft will persist over the Central/Southern Plains through tonight. A small amplitude shortwave was noted upstream in northern NM at 18Z. This feature is expected to progress ENE into eastern CO and western KS this evening/tonight. An H85 ridge has developed over west/nw Kansas in the wake of elevated convection this morning. As a result, diurnal destabilization /CIN erosion/ will be delayed by several hours in comparison to yesterday. This will stifle convective development over the Tri-State area through the majority of the afternoon and allow a reservoir of moderate instability to build over the region by this evening - particularly in southeast CO and southwest KS. Simulated REF forecasts from the HRRR suggest there may be two areas of interest with regard to convective development late this afternoon and evening. 1) Convection will develop in northeast NM in assoc/w the aforementioned shortwave by mid-afternoon, then rapidly grow upscale into a linear MCS that propagates east across the TX/OK Panhandle ands portions of southeast CO/southwest KS late this afternoon and evening. Even if this occurs, the primary impacts would likely be confined south of Greeley/Wichita counties. 2) Convection will develop over the Foothills invof Denver late this afternoon (23-00Z) and propagate E/SE through eastern CO into western KS this evening/tonight. Deep-layer shear will be supportive of supercellular organization with an attendant large hail and damaging wind threat this evening, particularly if persistent deep convection results in the development of an MCV which fosters further organization/longevity - similar to what may have happened yesterday. Consequently, convection could persist will into the overnight hours, particularly if aided by DPVA attendant small amplitude shortwaves progressing into the area from the W/SW. Wednesday: The Tri-State area will be situated on the N/NE periphery of a shortwave ridge building atop the Rockies, and forcing will primarily be associated with small amplitude waves progressing into the region via W/WNW flow aloft. With lingering/ongoing convection possible mid/late Wed morning, it is difficult to diagnose the evolution of the thermodynamic env. Wed afternoon. As such, there is low confidence with regard to the convective forecast. At this time, anticipate that the best potential for isold/sct convection in northwest KS will largely occur after 00Z Thu. .LONG TERM...(Wednesday night through Tuesday) Issued at 245 PM MDT Tue May 15 2018 This period continues to look promising for rainfall chances, however the front has shifted north which will also shift rainfall chances further north. Behind the upper level short wave ridge Wednesday night will be round after round of short wave troughs in the southwest flow Thursday through Saturday. The first round of storms will occur late Thursday afternoon/early evening. An upper level short wave trough will deepen late Thursday afternoon/early Thursday evening over the dry line west of the Tri- State Area. Effective shear will be around 50kts, with surface CAPE of 3000 j/kg. Low level shear and helicity will be supportive of tornadic development from storms that form, due to the strengthening low level jet. The limiting factor will be the stabilizing environment by 9-10 PM MT despite the strong lift from the upper level short wave trough. The environment will also be supportive of generating giant hail (baseball size and larger) and wind gusts of 70 MPH. However there will only be a three, maybe four hour window of opportunity for severe weather before the environment begins to stabilize. By late evening the severe threat should be winding down. Storm coverage will increase to the north toward the Cheyenne Ridge. The storm activity will move east of the forecast area by early Friday morning. Friday a warm front/dry line will develop moving north. Models differ regarding how far north the boundary will move, which will of course influence where storms will fire as the next upper level short wave trough deepens over the front. South of the boundary there will be a narrow corridor where strong to severe weather thunderstorms may form. This corridor will move through with the boundary. Mean storm motion is across the boundary into the more stable environment, which suggests severe storms may not last all that long. Severe weather for this day does not look as promising as Thursday. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 506 PM MDT Tue May 15 2018 Scattered thunderstorms in eastern Colorado late this afternoon will move into northwest Kansas this evening. These may briefly impact KGLD with MVFR conditions, including gusty winds and lowered ceilings/visibilities. Storms will weaken as the evening progresses and not expected to impact KMCK at this time. Otherwise, VFR expected through the overnight hours and into Wednesday. There will be low chances for isolated thunderstorms late Wednesday afternoon. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...VINCENT LONG TERM...JTL AVIATION...024
Area Forecast Discussion
National Weather Service Lincoln IL
909 PM CDT Tue May 15 2018 .UPDATE... Issued at 905 PM CDT Tue May 15 2018 Low pressure advancing eastward across south-central Illinois will keep the potential of a few showers and isolated storms the rest of the night in our southern counties. Kept low chance or slight chance PoPs south of a line from Jacksonville to Mattoon overnight, with a generally receding trend from north to south. The low is expected to finally shift southeast of Illinois Wed morning, but could trigger additional showers and a few storms south of I-70 on Wed, but no significant weather is expected. Areas that received rain today could see some fog development later tonight into Wed morning. Not expecting dense fog, but reduction in visibility below 2 miles could occur in localized areas. Have added some fog to the forecast. Lows look on track to drop into the mid 50s toward Galesburg/Peoria, with mid 60s south of I-70. Updated forecast info will be available shortly. && .SHORT TERM...(This evening through Wednesday) ISSUED AT 300 PM CDT Tue May 15 2018 A cold front was pushing south toward I-70 at mid afternoon, and will push through southeast IL late this afternoon, getting south of highway 50 by 00z/7 pm. Isolated showers and thunderstorms were north of the front over central IL, with locally heavy rains between Springfield and Decatur and east of Greenview in eastern Menard county. Some instability behind front with LAPS showing CAPES of 1000-1800 J/kg southeast of the IL river and north of I-70 with fairly moist dewpoints in the mid to upper 60s, while 0-6 km bulk shear is 25-35 kts, highest over northern CWA. SPC day1 has marginal risk of severe hail and winds se of IL river rest of this afternoon through 00Z/7 pm. CAM models show isolated to scattered convection shifting into southeast IL by early evening and then diminishing late evening and overnight as frontal boundary pushes south of IL. Could be some patchy fog overnight in southeast IL per HRRR model, but with mostly cloudy skies prevailing there overnight, think this would limit fog formation despite lingering low level moisture and lighter winds. Lows overnight range from mid 50s from Peoria north to the mid 60s southeast of I-70. Continued a slight chance of showers and thunderstorms in southeast IL on Wed due to lingering moisture behind the front. Also have a weak upper level low/trof over se IA/ne MO Wed afternoon and this could develop isolated convection further north over MS river valley Wed afternoon. Highs Wed in the lower 80s. Less humid over central IL with dewpoints in the 50s, while dewpoints in the low to mid 60s in southeast IL. .LONG TERM...(Wednesday night through Tuesday) ISSUED AT 300 PM CDT Tue May 15 2018 Summertime weather pattern looks to continue through early next week across central and southeast IL, as temperatures remain above normal along with periodic chances of showers and thunderstorms, though most of the time it will be dry. Isolated shower or thunderstorm possible in southern 6 counties Wed evening, otherwise dry over CWA Wed night. Lows Wed night in the upper 50s and lower 60s, mildest in southern counties. The weak 576 dm 500 mb low drifting slowly over west central IL Thu could develop isolated convection again over southeast IL and near MS river valley in sw IL Thu afternoon. Highs Thu in the low to mid 80s and dewpoints in the mid 50s to lower 60s, highest in southeast IL. Carried isolated showers and thunderstorms in eastern IL on Friday especially Fri afternoon when chance pops near the IN border/Wabash river. This due to weak upper level low moving into west central IN by Fri afternoon. Highs 80-85F on Friday and dewpoints in the upper 50s and lower 60s. Isolated convection could linger near the Wabash river valley early fri evening, otherwise dry Friday night through Sat morning. A warm day in the mid to upper 80s Saturday with a few spots like Springfield approaching 90F with ssw winds. Have 20-30% chance of showers and thunderstorms over the IL river valley Sat afternoon, especially late, and into Sat evening. Good chance of showers and thunderstorms spreads east over CWA overnight Sat night into Sunday as a cold front pushes se from upper Midwest through IL. Chance of showers and thunderstorms diminish from nw to se during Sunday night. Weak high pressure building into the Great Lakes by Monday to return a bit cooler and drier conditions. Highs Sunday range from 75-80F northern CWA to mid 80s in southeast IL. Highs Monday of 75-80F over central IL and around 80F in southeast IL. Temps modify back up on Tue with highs in the low to mid 80s. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 655 PM CDT Tue May 15 2018 A draped band of scattered showers with isolated strong to severe thunderstorms had moved south of I-72 early this evening and expect central IL airports to be dry next 24 hours. A cold front has pushed south toward highway 50 and will push south of the Ohio river overnight. This boundary may develop more isolated convection Wed afternoon over southeast IL, and should stay south of I-72. Scattered cumulus clouds of 2.5-5k ft with broken to overcast mid level clouds of 8-12k ft expected tonight, though northern airports at PIA and BMI could go scattered mid to high level clouds overnight. MVFR vsbys with fog could occur along I-72 from 09-14Z Wed where rainfall occurred today, with PIA possibly getting to 5-6 miles. Will also need to watch for possible MVFR ceilings from 09-14Z along I-72 and possibly BMI as well. For now think these lower ceilings will be just south of I-72 but will need to watch. NE winds 10-17 kts early this evening along I-74 to diminish to 5-10 kts after dark and continue on Wed. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...Shimon SHORT TERM...07 LONG TERM...07 AVIATION...07
Area Forecast Discussion...Updated Aviation
National Weather Service Saint Louis MO
703 PM CDT Tue May 15 2018 .SHORT TERM... (Through Late Wednesday Afternoon) Issued at 344 PM CDT Tue May 15 2018 MCV drifting along the Missouri/Arkansas border is helping to spark off isolated/widely scattered showers and thunderstorms this afternoon. Expect this activity to increase in areal coverage a bit as low-mid clouds move northeast allowing for some stronger insolation and destabilization of the boundary layer. RAP meso- analysis is showing up to around 1000-1500 J/Kg MLCAPE this afternoon/evening before sunset, so a few stronger storms with gusty winds and some hail are possible. Should see convection diminish after sunset. The MCV will continue moving east tonight and a weak cold front will drift through the forecast area. Looks MOS guidance and forecast soundings are showing stratus and possibly some fog in vicinity of the front as it moves through...much like what occurred over Iowa last night. The lingering cloud cover on Wednesday will probably keep temperatures down in the upper 70s and low 80s. Most guidance is also hinting at some diurnal convection across southeast Missouri into southern Illinois. Carney .LONG TERM... (Wednesday Night through Next Tuesday) Issued at 344 PM CDT Tue May 15 2018 A broad trof of low pressure that`s currently over the northeast Gulf will get pulled up into the mean mid-latitude flow over the Lower and Mid Mississippi Valley on Thursday and an upper ridge will build up north of it across the Upper Midwest. This will create a quasi-rex block over the Central U.S. which will clog up the pattern for the latter half of the week and into the weekend. Our area should be on the western side of the trof over the Mid Mississippi Valley in northwest flow aloft. There could be some diurnal convection Thursday and Friday afternoon, but nothing organized looks likely. The pattern breaks Saturday night and becomes more zonal by Saturday/Saturday night. Medium range guidance brings another shortwave and front into the Mississippi Valley Saturday night/Sunday and pushes the front south through our forecast area Sunday afternoon/evening. Should see some precipitation along and ahead of the front...primarily Saturday night into Sunday. Temperatures through the period continue above normal with highs mainly in the 80s and lows in the upper 50s to low and mid 60s. Carney && .AVIATION... (For the 00z TAFs through 00z Wednesday Evening) Issued at 649 PM CDT Tue May 15 2018 Showers and thunderstorms continue to slowly sag southward along a boundary this evening, generally stretching from Quincy through Litchfield and Vandalia. Thunderstorms will lose their punch as the sun sets and surface heating wanes. Main concern tonight will be MVFR cigs. Some guidance brings in IFR cigs just south and west of KSTL and KCPS. This will need to be monitored overnight with later updates possibly including IFR cigs early and mid-morning hours Wednesday. Conditions are expected to improve during the day Wednesday with VFR condition and winds generally 10 kts or less. SPECIFICS FOR KSTL: Continue to watching showers and thunderstorms weaken and sag southward along a slow moving boundary. Limited TAF to mention VCSH with waning support of storms after sunset and waning surface heating. Main concern overnight will be MVFR cigs from 1k to 1.5k ft in the early to mid-morning period. May need adjust should trends continue to show, but for now, confidence is still less than likely with lowest ceilings just south and west of KSTL. Otherwise, we improve to VFR by early Wed. afternoon with light winds generally less than 10 kts. Maples && .LSX WATCHES/WARNINGS/ADVISORIES... MO...None. IL...None. && $$ WFO LSX
Area Forecast Discussion
National Weather Service Memphis TN
921 PM CDT Tue May 15 2018 .UPDATE... Showers and thunderstorms continue across portions of North Mississippi and West Tennessee near the Tennessee River. This activity should gradually push east. However, the HRRR shows some redevelopment of showers over North Mississippi and West Tennessee just before sunrise. Thus, will leave 30-40 POPS east of the Mississippi River. Will update to remove some evening wording, otherwise forecast looks good. KRM && .DISCUSSION... /issued 333 PM CDT Tue May 15 2018/ Temperatures at 3:00 PM are in the low to middle 90s across most of the Midsouth. The exceptions are in Northeast Arkansas where clouds have moved in and in isolated parts of North Mississippi and West Tennessee where a line of thunderstorms has cooled things off a bit. A ridge responsible for the abnormal heat of late continues to break down allowing for the development of thunderstorms this afternoon and will lead to slightly cooler conditions tomorrow. Showers/thunderstorms first initiated over Northeast Mississippi but we are currently seeing additional development over the Mississippi Bootheel and Northeast Arkansas. A series of weak troughs will move through general zonal flow tonight and tomorrow. The first of these features may help to keep thunderstorms ongoing through the night tonight, and the likely enhance ongoing activity and or result in redevelopment tomorrow. Most of the Midsouth should see some rainfall over the next 36 hours. Due to the convective nature of the storms, localized areas could see over one half of an inch or rain, but county wide average totals will likely be much less. Consider yourself lucky if you receive more than a few tenths of rain. Localized gusty wind and frequent lightning may accompany the stronger storms. An isolated severe thunderstorm can`t be ruled out. A weak upper level low over the Northern Gulf will drift inland tomorrow into Thursday. This feature combined with a weak broad trough over the Mississippi River should keep at least marginal rain chances around through the end of the work week...likely highest over Northeast Mississippi and near the Tennessee River in West Tennessee. A few strong storms are possible, with the greatest threat being localized gusty wind. Over the weekend, the Gulf Low and broader trough over our area should all begin to shift East. As a result, drier conditions are expected Saturday, with warmer temperatures returning area wide. Highs are expected to climb back into the low 90s. Another cold front should approach the Midsouth late in the weekend ushering in another round of showers and thunderstorms. Behind the front, high temperatures early next week should drop back into the low to middle 80s. 30 && .AVIATION... A slow moving/weak upper disturbance over Arkansas will track through the Mid-South over the next 24 hours. Isolated to scattered SHRAs and TSRAs will gradually dissipate this evening and then redevelop early Wednesday afternoon mainly east of the MS River. Patchy MVFR vsbys near sunrise at TUP...MKL and JBR. Winds light and variable overnight and then light northwest on Wednesday. SJM && && .MEG WATCHES/WARNINGS/ADVISORIES... AR...None. MO...None. MS...None. TN...None. && $$
Area Forecast Discussion...UPDATED
National Weather Service Mobile AL
848 PM CDT Tue May 15 2018 .DISCUSSION...See updated information for land areas below. && .UPDATE...Sent a quick update to the public products to decrease the chance the showers and thunderstorms for the remainder of the night as convection has been very limited. Have not completely removed the chance of precipitation as still expect a return of at least isolated rain showers and storms overnight as the upper low pressure system over the Florida Great Bend region lifts north, and remnant surface boundaries remain across the forecast area. Other weather elements are trending as forecast through the remainder of the night. Updates sent. /22 && .PREV DISCUSSION... /issued 641 PM CDT Tue May 15 2018/ DISCUSSION...Updated for latest aviation discussion below. AVIATION... 00Z issuance...VFR and mostly dry conditions will prevail through 16.24z. East to southeast winds around 6 knots early this evening will become calm to light and variable overnight into Wednesday morning. Light north to northwest winds around 6 knots will develop by 16.15z. Sea and bay breeze development along the coast around 16.20z will allow the winds to turn to a light southerly flow at KPNS and KBFM, while remaining from the northwest at KMOB. /22 $$ PREV DISCUSSION... /issued 326 PM CDT Tue May 15 2018/ NEAR TERM /Now Through Wednesday/...Scattered showers and thunderstorms will develop through about mid evening today with the best coverage over the eastern half of the forecast area through mid afternoon followed by better coverage a little further west including inland areas of SE MS stretching southeastward to the Al coast. Similiar to the last couple of days gusty straight line winds, frequent lighting and short periods of very heavy rain will be the main threats with the stronger thunderstorms. Surface base capes continue to range from 1000 j/kg to the east to about 2500 j/kg to the west currently this afternoon with slightly lower lapse rates in the boundary layer compared to the last 2 days. A distinct warm nose at around 18kft is also present with both the RAP and NAM12 model soundings which support the lower lapse rates in the boundary layer. For the big picture the main upper low over the Northeast gulf this afternoon will continue to drift north and become absorbed with a passing short wave trough tracking eastward across the lower part of the country through Wed afternoon. Near the sfc a weak area of low pressure continues near the upper system progged to drift northwest and meander through Wed afternoon. Some of the hi-res model data depict better thunderstorm development around this weak system overnight and early Wed generally south of Panama City and Port St Joe drifting northward towards the coast through Wed afternoon. As a result if this solution is close expect little to no impact to our counties near the coast through Wed afternoon. Temperatures will continue to be on the warm side tonight through Wed afternoon. Lows tonight will range from the mid to upper 60s for most inland areas and the lower to middle 70s along the immediate coast. Highs Wed will range from the mid to upper 80s generally over the eastern half of the forecast area and the lower to middle 90s to the west. 32/ee SHORT TERM /Wednesday night Through Friday night/...An upper trof persists over the central Gulf coast region through the period while a modest and broad extratropical surface low over the northeast Gulf drifts northward into the central Gulf coast states through Thursday and evolves into a surface trof oriented east-west over the area. The surface trof weakens over the area on Friday then dissipates Friday night. Given that the surface low now looks weaker and changes to a broad surface trof over the area later in the period, coverage of convection each day now looks to be limited to scattered at best. So, will have good chance pops for the entire area on Thursday then for Friday will have good chance pops over the eastern portion with chance pops over the remainder of the area. A moderate risk of rip currents continues through the period along with daytime highs a few to several degrees above normal. /29 LONG TERM /Saturday Through Tuesday/...The upper trof over the area weakens through Monday and shifts into the extreme southeast states. A shortwave trof meanwhile advances from the southern Plains and moves to near the lower/mid Mississippi river valley by Tuesday. A surface ridge remains over the northern Gulf through the period and promotes a light onshore flow. With this pattern, expect scattered convection to develop each day across much of the area. Daytime highs will be generally a few degrees above normal. /29 MARINE...A broad upper low centered over the Northeastern Gulf will move north and become absorbed by a mid to upper trough tracking eastward over the lower part of the country through late Wed. A weak surface low will move northwest of the upper system and weaken just east of the marine area late Wed into Thu. Isolated to scattered thunderstorms are expected to continue over the marine area through much of the week with the best coverage near the coast and further offshore to the east. 32/ee && .MOB WATCHES/WARNINGS/ADVISORIES... AL...None. FL...None. MS...None. GM...None. && $$ This product is also available on the web at:
Area Forecast Discussion
National Weather Service Charleston WV
930 PM EDT Tue May 15 2018 .SYNOPSIS... Unsettled weather pattern continues through the week with daily thunderstorm chances in a warm and humid air mass. && .NEAR TERM /THROUGH WEDNESDAY/... As of 930 PM Tuesday... Updated the forecast based on current radar trends. As of 340 PM Tuesday... The latest surface map features a wavy cool front aligned from east to west across the Ohio Valley. Convection has been organizing along the boundary, with the most significant activity occurring towards New England. Aloft, an upper level low continues to spiral across the eastern Gulf of Mexico, advecting moisture into the region through the day. So far, convection has been isolated across the area; however, given the heating and weakening cap, expect coverage to increase through late this afternoon and early this evening, with isolated strong to severe storms possible. The latest HRRR has also been playing up clusters of convection moving in from central Ohio, affecting the Parkersburg area in the 5-6 pm time frame. Depending upon the evolution of the outflow associated with this activity, further convection may build downstream into the area, where some locations had seen heavier rainfall from yesterday. This would pose an isolated flash flooding threat, but there is not enough confidence for a watch, as the outflow looks to be fairly progressive as it moves through the area. Convection will diminish past midnight, with lows generally in the 60s, with low clouds and fog likely forming in the wake of the rainfall. Convection will fire up once again on Wednesday, as general troughiness takes hold across the Ohio and Tennessee valleys. Will continue with likely POPs for most locations. Highs will be cooler, generally upper 70s to lower 80s. Again, an isolated flash flooding threat will be possible, with less of a threat of severe, given the weaker shear and instability in place. && .SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/... As of 340 PM Tuesday... Active pattern continues through the short term. We also continue to find ourselves between a frontal boundary that will drop into the area from the north tonight before stalling, and a tropical system to our south. Moisture will continue to stream northward into the southern Appalachians with the surface frontal zone providing a focus for fairly widespread but mainly afternoon and evening shower and thunderstorm activity. Sensible weather should remain unsettled and while not hot, muggy and warm with a small diurnal trend. Afternoon highs Thursday will climb into the 70s to near 80 and overnight lows in general will fall into the mid 60s though some of the typically cooler valleys may get closer to 60. && .LONG TERM /FRIDAY THROUGH TUESDAY/... As of 340 PM Tuesday... Tropical wave or low in the deep south finally gets picked up by the westerlies and lifts northward into New England by Sunday. That leaves us under the sole influence of northern stream disturbances through the remainder of the forecast. Synoptically, disturbances will continue to track across the Great Lakes and Ohio Valley but a more westerly flow aloft may allow for a bit more sunshine and warmer temps between disturbances...and then the occasional threat of showers and thunderstorms with each disturbance. Again, temperatures remain above normal. && .AVIATION /01Z WEDNESDAY THROUGH SUNDAY/... As of 735 PM Tuesday... Showers and thunderstorms will be scattered across the area this evening, causing restrictions. Conditions will generally be VFR outside of the precipitation. Areas that receive rainfall could see some fog overnight, especially protected valleys. Showers and thunderstorms can be expected again on Wednesday, with generally VFR conditions outside of the precipitation. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z THURSDAY... ALTERNATE SCENARIOS: Timing of showers and thunderstorms could vary. Timing, location, and density of fog overnight could vary. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. UTC 1HRLY 10 11 12 13 14 15 16 17 18 19 20 21 EDT 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17 CRW CONSISTENCY H H H H H H H H H H M M HTS CONSISTENCY H H H H H H H H H H M M BKW CONSISTENCY H H H H H H H H H H M M EKN CONSISTENCY L L M M H H H H H H M M PKB CONSISTENCY H H H H H H H H H H M M CKB CONSISTENCY H H H H H H H H H H M M AFTER 00Z THURSDAY... Brief periods of IFR possible in showers and storms through the week. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...None. OH...None. KY...None. VA...None. && $$ SYNOPSIS...99 NEAR TERM...RPY/99 SHORT TERM...99 LONG TERM...99 AVIATION...RPY