Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 05/11/19

Area Forecast Discussion...UPDATED
National Weather Service Amarillo TX
703 PM CDT Fri May 10 2019 .AVIATION... For the 00Z TAFs, MVFR cigs will persist through this evening, eventually becoming IFR late tonight into mid morning Saturday at the terminal sites. Cigs should improve to VFR around mid afternoon on Saturday. 02 && .PREV DISCUSSION... /Issued 257 PM CDT Fri May 10 2019/ SHORT TERM...Today and Tonight... Light rain showers are beginning to fill in the southwestern Texas Panhandle and will continue to progress northeast through the afternoon. Light snow is possible mainly in the far western Panhandles where temperatures remain in the mid to upper 30s. No accumulations are expected to occur with any light snowfall. Cloudy skies will persist all day today and through the morning hours Saturday. A shortwave trough will be over the central Rockies tonight and continue to provide light rain showers across the eastern half of the Panhandles. Meanwhile, the RAP 500mb heights and midlevel GOES16 satellite water vapor shows a midlevel closed low over the south central coast of California and is in agreement with all the models. Temperatures tonight will be slightly warmer ranging from the upper 30s in the northwest Texas and Oklahoma Panhandles to the upper 40s in the southeast Texas Panhandle. Rutt LONG TERM...Saturday through Friday... Fairly uneventful forecast with chances for showers and non-severe thunderstorms through Monday night, followed by dry weather through Thursday night. Potential for severe thunderstorms to resume Friday. Models and ensembles have maintained their depiction of evolution existing split flow. Closed mid-level low in southern stream over central California today retrogrades into Pacific before coming ashore early Saturday evening north of the Baja spur. Steady eastward movement of closed low across northern Mexico will continue through Sunday night. By late afternoon Monday system crosses Rio Grande and moves close to Midland. Circulation wanes Monday night and Tuesday with system becoming an open positively- tilted wave which clears the southeast Texas Panhandle Tuesday afternoon. Meanwhile, Texas and Oklahoma Panhandles will be influenced by northern stream trof Saturday and Saturday evening. Main trof axis passes Saturday evening, with northwest flow aloft then prevailing through Sunday evening. Flow weakens Monday and Monday night as remnants of aforementioned southern stream system are absorbed. Modest amounts of moisture and instability warrants mention of showers and thunderstorms Saturday through Monday night, with southern sections generally favored, owing to expected higher amounts of moisture being available. Ridge builds across Rockies Tuesday through Wednesday, with northwest flow across the Panhandles. Ridge moves across Panhandles Thursday and Thursday night. By Friday morning, a digging trof emerges from the eastern Pacific. Strengthening southwest flow on Friday will likely lead to increasing chances for organized and possibly severe thunderstorms through the weekend. Cockrell && .AMA Watches/Warnings/Advisories... TX...None. OK...None. && $$
Area Forecast Discussion...UPDATED
National Weather Service Austin/San Antonio TX
825 PM CDT Fri May 10 2019 .UPDATE... Seeing an uptick in elevated convection this evening across just to the east and south of San Antonio as well as across far northern areas of the CWA. Models did not capture this activity south and east of San Antonio well, and have updated forecast to raise PoPs through the evening across this region as it continues to expand and lift northeast. MUCAPE values near 1000 J/kg supporting a few stronger updrafts with lightning occurring in this activity. MRMS has been estimating pockets of rainfall rates nearing 1" per hour. Recent runs of the HRRR as well as Texas Tech 4 KM show increasing coverage of showers across western areas of the CWA between Midnight- 3AM as main forcing comes out of Mexico, then expanding into central areas of the CWA/I-35 corridor between 3AM-6AM, then east of the I-35 corridor through Saturday morning. Have increased PoPs slightly in some areas to account for this. We will maintain the Flash Flood Watch for the time being. As mentioned in previous forecast this is highly conditional on seeing expanding coverage of elevated convection overnight. If this does occur, some pockets of rainfall up to 1 inch could be possible (as evident with current rainfall rates mentioned above that are ongoing this evening). Very difficult to pinpoint where these pockets could occur, but out of abundance of caution the Flash Flood Watch will remain in place given some locations that are currently very sensitive to any additional rainfall resulting in very quick runoff. && .PREV DISCUSSION... /ISSUED 648 PM CDT Fri May 10 2019/ AVIATION... /00Z TAFS/ CAMS models show a minimal amount of deep layer convection affecting the I-35 terminals this evening, so have pulled back on the VCTS and favored the best chance of thunder to be 09Z to 12Z to reflect recent HRRR and NAM runs. Expect a gradual descent of low cigs to ifr toward midnight with a few pockets of lifr conditions by 09Z. Meanwhile at DRT shower activity looks minimal for the evening with model consensus showing mainly showers possible from 06Z to shortly after daybreak. Subsidence could work its way into this area at daybreak, so some brief vlifr conditions may need to be considered in later updates. A slow improving trend is expected through midday, with all the low level moisture expected to keep a prevailing mvfr cig through the daytime hours along I-35. PREV DISCUSSION... /ISSUED 342 PM CDT Fri May 10 2019/ SHORT TERM (Tonight through Saturday Night)... Conditions are expected to begin gradually trending drier for South Central Texas in the short term portion of the forecast. A few showers have been able to develop across the Rio Grande Plains this afternoon and into the Edwards Plateau, but most areas will not see rain through the early evening hours. SPC Mesoanalysis this afternoon shows a mid-level wind speed maxima associated with a disturbance over northern Mexico lifting into Southwest Texas. As this speed max lifts farther to the northeast, reaching the Rio Grande Plains, scattered showers and thunderstorms are expected to develop across the Edwards Plateau and Hill Country late this evening or early Saturday morning. Despite a stable boundary layer behind yesterday`s cold front, over 1000 J/kg of MUCAPE, long, skinny CAPE profiles (encouraging water loading of updrafts), and forecast precipitable water values near 1.5 inches per forecast soundings from Austin and Waco, will allow for a locally heavy rain threat to linger with overnight storms. The tricky aspect will be where these actually develop as model guidance has placed an axis of higher 1-1.5 inch rainfall amounts anywhere from the I-35 corridor to the Hill Country to north of Waco throughout the day. Based on lower flash flood guidance values and their proximity to this potential higher rainfall axis, Burnet, Williamson, Blanco, Travis, and Hays all appear to have at least some threat for isolated minor or flash flooding overnight. This is highly contingent on how close to the region this higher rainfall axis is able to develop, however. Additional attention will have to be paid to the stalled frontal boundary located along the Middle Texas Coast and bisecting the Houston metro as increasing forcing for ascent results in another thunderstorm complex developing close towards the Texas coast by Saturday morning. While this boundary is expected to stay just east of the region through Saturday night, will also have to watch for a secondary heavy rain threat for the Coastal Plains counties in case any kind of convective interaction with the front (outflow/cold pool development) nudges it closer to the region. The passage of the disturbance from Mexico should allow for rain to end from west to east during the day on Saturday, with Saturday afternoon activities for most of the region likely dry. Regarding the Flash Flood Watch, have opted to continue it with a (highly) conditional threat for additional rainfall overnight. As was noted earlier, the far western and far southeastern counties of the watch are the most sensitive at this point. Should rain fall farther north or east of the region, the Flash Flood Watch will likely be able to be cancelled before the Saturday evening expiration. Otherwise, expect cool temperatures to continue overnight with lows in the 50s to low 60s and highs in the 70s to near 80 on Saturday. Saturday night lows are forecast to fall into the mid 50s to mid 60s and will have to watch for the potential of some patchy fog development given recent rainfall and some clearing of cloud cover. LONG TERM (Sunday through Friday)... Generally dry conditions will linger into Sunday, but the approach of a closed low from Baja California will allow for low rain chances to creep back into the Rio Grande Plains by Sunday afternoon. Rain chances will then spread back across the region from west to east Monday through Wednesday as this disturbance lifts into North Texas and shifts east of the state as an open wave. Shortwave ridging will allow for drier conditions to settle back into the region mid-week. Rain and cloud cover will keep temperatures below seasonal normals through the middle of next week with some moderation by late next work week as ridging builds overhead. && .PRELIMINARY POINT TEMPS/POPS... Austin Camp Mabry 57 74 59 78 59 / 60 30 - - 10 Austin Bergstrom Intl Airport 57 74 56 79 58 / 60 40 - - - New Braunfels Muni Airport 58 77 57 79 59 / 60 30 - 10 10 Burnet Muni Airport 54 72 55 76 57 / 60 30 - 10 10 Del Rio Intl Airport 58 80 62 79 64 / 40 - - 30 30 Georgetown Muni Airport 55 72 54 77 58 / 60 30 - - - Hondo Muni Airport 59 78 59 81 61 / 60 20 - 20 20 San Marcos Muni Airport 58 75 58 79 58 / 60 40 - 10 10 La Grange - Fayette Regional 62 76 61 80 60 / 60 60 - - - San Antonio Intl Airport 58 76 60 79 60 / 60 30 - 20 10 Stinson Muni Airport 61 77 61 79 61 / 60 30 - 20 10 && .EWX WATCHES/WARNINGS/ADVISORIES... Flash Flood Watch through Saturday evening for Atascosa-Bastrop- Bexar-Blanco-Burnet-Caldwell-Comal-De Witt-Fayette-Gonzales- Guadalupe-Hays-Karnes-Kendall-Lavaca-Lee-Travis-Williamson-Wilson. && $$ Aviation...Oaks Short-Term/Long-Term...Runyen
Area Forecast Discussion
National Weather Service Paducah KY
927 PM CDT Fri May 10 2019 .UPDATE... Issued at 927 PM CDT Fri May 10 2019 Tracking some scattered light showers mainly impacting the southern Pennyrile region of west KY. Raised PoPs to cover the scattered nature of this activity but it should be moving out of the area shortly after midnight. Other activity that we are watching is now moving northeast out of Arkansas up into parts of southeast MO. This batch of precipitation will continue moving northeast and impact parts of SEMO and maybe far west KY late this evening, but is forecast to slowly dissipate as it moves northward. We have added PoPs to these areas. Taking a peek at the 00Z model data that is trickling in, it appears as though precipitation may be moving in a bit quicker than originally thought for tomorrow and western parts of the area will be dealing with morning showers. The midnight shift will be taking a more comprehensive look at this during the overnight hours. && .SHORT TERM...(Tonight through Sunday night) Issued at 245 PM CDT Fri May 10 2019 A rather cool and wet Mothers Day weekend is in store for our region. There are still some significant differences in the model mass fields, but they do not seem to affect our sensible weather. Even the model qpf fields have come into fair agreement, despite differences in the track and strength of the system. First things first, an area of rain is currently tracking northward into western Tennessee this afternoon. The hrrr and rap briefly bring this rain into western Kentucky early this evening before moving it out. A small pop will be added for west Kentucky late this aftn and early evening to account for this rain. The arrival of the main rain shield will be on Saturday morning for most of our area as another upper level shortwave ejects northeast from the southern Plains. The models differ on the track and strength of the associated surface low. It appears the low will be quite weak, passing northeast across western Tennessee on Saturday evening. The 850 mb low or trough is forecast to be along the lower Ohio Valley, which will result in a weak southerly flow of elevated warmth and instability. Some thunder will be kept in the forecast for Saturday afternoon and evening in the 850 mb warm sector. Model qpf guidance has been consistently trending downward, and it appears most places will receive well under an inch. There will be a fairly strong temp gradient Saturday. Highs will be only in the 50s along and west of a kmvn to kcgi corridor, where rain and north winds will dominate. On the other end of the spectrum, highs in the khop area should be well up in the 60s, where rain may not start until mid afternoon and winds will be more easterly. Sunday should be a rather cloudy day despite drier northwest winds on the back side of the departing system. A strong upper level disturbance in the northern branch of the jet will close off into a deep low over the upper Mississippi Valley. This low will move east into the Great Lakes area on Sunday night. Impulses rotating around the back side of the low will bring small chances of showers Sunday into Sunday night. Cold air aloft associated with the upper low could enhance the showers Sunday afternoon/evening. .LONG TERM...(Monday through Friday) Issued at 245 CDT Fri May 10 2019 The medium range guidance is in reasonable agreement for next week and has been fairly consistent for the last few days now. The weekend storm system will slowly pull away from the region Monday, and a few showers may linger into the morning hours. Behind this system we will be under northwest flow aloft through Thursday, but ridging will build over the region on Friday, as a large trough pushes onto the west coast. The only potential weather-maker through the week will be a clipper system and possible cold frontal passage Wednesday into Wednesday night. The medium range models have been pretty consistent with a frontal passage in this time-frame for a few days, but the strength of the upper system and push with the front have varied and continue to vary amongst today`s 12Z guidance. Moisture return ahead of the cold front will be very limited, but the GFS eeks out just a bit of surface-based instability Wednesday afternoon and evening, so a thunderstorm or two will be possible. The GEM is the strongest with the upper system and has decent flow aloft, so a strong storm cannot be completely ruled out, if any can get going. Given the uncertainty in the details, will limit PoPs to low chance levels and limit the mention in the HWO to locally heavy downpours and lightning. Dry surface high pressure will keep the area dry and cool Monday and Tuesday. Temperatures will start out well below normal on Monday and slowly climb to near normal levels for the last half of the week. && .AVIATION... Issued at 650 PM CDT Fri May 10 2019 As cool low level air undercuts southwesterly flow aloft, surface winds less than 12 knots will be out of the northeast most of the next 24 hours. Pesky MVFR cigs may hang over parts of western KY (especially near the TN state line) this evening with the passage of a low pressure area through central TN. TAFs will be amended as appropriate. MVFR cigs will become more likely over the southern half of the region by daybreak, and over the northern half by afternoon. Meanwhile, the next impulse in the flow aloft will cause showers to move in from the west starting around daybreak. While VFR vsbys in rain are forecast at this time, MVFR vsbys are possible in heavier pockets of rain, mainly in the afternoon. The probability of lightning was too low to include in the TAFs at this time. && .PAH WATCHES/WARNINGS/ADVISORIES... IL...None. MO...None. IN...None. KY...None. && $$