Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 07/13/20

Area Forecast Discussion...UPDATED
National Weather Service Albuquerque NM
534 PM MDT Sun Jul 12 2020 .AVIATION... 00Z TAF CYCLE Convection will steadily taper off this evening with stronger to severe storms lasting longer into the evening over the eastern plains. MVFR conditions can be expected with any passing storm with frequent lightning, hail, erratic gusty winds, and locally heavy rainfall. KTCC and KCAO are still in line for a TS hit this evening. It is looking less likely any meaningful east canyon wind will reach KSAF and KABQ, but can`t rule out the direction change out of the east late this evening. Another round of showers and storms can be expected to start near mid-day Monday, with stronger storms focusing over eastern NM. Drier storms across the west will produce gusty outflow winds and could blow around some dust as well. 24 && .PREV DISCUSSION...310 PM MDT Sun Jul 12 2020... .SYNOPSIS... Isolated to scattered severe thunderstorms will be possible across northeast and east central New Mexico during the afternoon and early evening hours today. The primary hazards will be large hail and damaging winds. Meanwhile, near-record to record breaking heat will continue across northern and central New Mexico through Monday. By midweek, the high pressure system will center over central Texas, allowing moisture to wrap around the system into New Mexico. This will offer some heat relief, as well as an increase in shower and thunderstorm coverage each afternoon. && .DISCUSSION... SHORT TERM...(TONIGHT THROUGH MONDAY NIGHT)... Another uptick in shower and storm activity this afternoon, and some of the storms in northeast and east central New Mexico could become strong to severe with large hail and damaging winds. HRRR suggests most of the convection will taper off by late this evening. There may be a slight downturn in the number of showers and storms on Monday as the upper high center drifts to the south and east, although there will be potential for a few strong to severe storms Monday afternoon/evening over northeast New Mexico. Stronger westerly winds will be more noticable along and north of I-40. High temperatures Monday afternoon will continue to be hotter than normal, and may still be near record values over portions of the east and in the Northwest Plateau. Added a few zones to the existing heat advisory for Monday afternoon. LONG TERM...(TUESDAY THROUGH SUNDAY)... The Four Corners high begins to pivot eastward, as a broad trough passes through the central Rockies on Tuesday. Embedded mid level disturbances around the ejecting Four Corners high in conjunction with moisture recycling and daytime heating will contribute towards afternoon thunderstorm development. An ejecting shortwave will maintain a corridor of amplified west/southwesterly flow above far northeastern New Mexico where a moist and unstable airmass exists. At the sfc, a boundary will push southward from the CO plains, before stalling near the NM/OK borders. Anticipate that storms will fire along this boundary and across the higher terrain, before pushing eastward. Intensity of these storms will be dependent on the how prior convection affects the boundary layer. Currently, the NAM suggests CAPE values between 1000-1500 J/kg combined with 30-35 kts of effective bulk shear, suggesting that ingredients are coming together for a potentially favorable severe environment. Resolution of the mesoscale features and their alignment with the synoptic setup in future runs of the numerical models will help to shape up the event. Even in the wake of the departing high aloft, excessive heat will be a concern, especially across the central highlands and southeast New Mexico. By midweek, the high centers itself over central Texas, allowing southerly flow to become dominant and the monsoon plume to position itself over New Mexico. This will support cooler temperatures with increased daily storm coverage moving into the end of the workweek. Moving into the weekend, guidance is suggesting that the high will begin to elongate, stretching from the ArkLaTex region back into the Desert Southwest. This is a departure from previous runs, which depicted the high retrograding back into New Mexico. Resolution of this feature will determine whether the potential for showers and thunderstorms and relief from excessive heat will continue. 99/12 && .FIRE WEATHER... The area of high pressure aloft which has recently gripped New Mexico will slowly weaken and shift to the east and south this week, allowing more moisture to invade western and northern New Mexico. This subtle pattern change will lead to gradually cooler daytime highs and increasing areal coverage and number of wetting showers and storms. In addition, a moist surface boundary Tuesday evening will assist with shower and storm development over northeast New Mexico. Some dry convection with erratic and gusty winds will continue to occur over western and central New Mexico Monday and Tuesday before becoming wetter. Cell motion will be generally to the east this afternoon and evening and again on Monday. Latest extended forecast models suggest the upper high center will stay put east of New Mexico through the next 7 days, so afternoon and evening showers and storms will be a daily feature. 99 && .ABQ WATCHES/WARNINGS/ADVISORIES... Heat Advisory from noon to 8 PM MDT Monday for the following zones... NMZ231>240. Heat Advisory until 8 PM MDT this evening for the following zones... NMZ201-209-219-220-225-236>238. && $$
Area Forecast Discussion
National Weather Service Billings MT
739 PM MDT Sun Jul 12 2020 .UPDATE... Updated forecast to adjust timing and coverage of precipitation into the area this evening. Livingston already reporting on and off rain and that area extends north toward Harlowton and Ryegate. Expecting scattered showers in the region the rest of this evening with a slight shift east with time as trough shifts east. Rest of forecast on track. Frieders && .DISCUSSION... Tonight through Monday night... Surface cold front was difficult to discern this afternoon and was likely moving through the area in pieces, with radar/satellite showing a boundary pushing into NE Yellowstone County, and two different boundaries in Big Horn County. Temps were in the 80s and 90s across the area and RH`s ranged from the single digits and teens S and W, to the 30s far SE and N. Expect RH`s to drop further in the E as NW wind shift moves into this area. So far, winds were not too gusty across the area, except in the W where they were gusting into the 20s. Large mass of clouds has been moving ENE through NW MT and is associated with the jet. Jet will bring upper divergence to the area tonight and will combine with the 700 mb front and a second frontal surge to bring increasing clouds and chances for evening showers and thunderstorms to much of the area. Best CAPE will be over Fallon/Carter Counties with HRRR showing MLCAPE of 1000 j/kg or less over Fallon and higher CAPE over Carter. Wind shear will be fairly strong over these areas so cannot rule out a strong storm. Expect showers to become more numerous after 06Z. Monday will be much cooler under cyclonic flow and jet divergence. There was not much CAPE. There will be scattered showers from around KBIL SW in the morning. Showers will spread E in the afternoon with a slight chance of thunderstorms. Highs will only be in the 70s, and cold advection will create breezy conditions. Cold advection continues Mon. night, and showers and isolated storms will move into SE MT and decrease in coverage. Arthur Tuesday through Sunday... Flow aloft is mostly zonal on Tuesday and slightly cyclonic and heights continued to be suppressed with temperatures below normal. Models have shifted shower and thunderstorm activity a bit further south with the one threat area continuing to be southern Powder River and Carter counties. Wednesday pattern is similar with the activity further south and east of the area which means a dry forecast for the area. Thursday has temperatures back into the 90s as heights start to build with short lived ridging breaking down on Friday as a disturbance tracks north of the area. Friday and Saturday do not see any significant cool down but clouds increase as do chances for thunderstorms as pieces of monsoonal moisture move across the area from the west. These storms will likely be high based and produce little moisture. borsum && .AVIATION... VFR conditions will prevail. Showers will become more numerous overnight for most areas before tapering off Monday morning. Additional scattered showers and isolated thunderstorms will affect areas in and near the mountains on Monday afternoon, including KSHR. Local mountain obscurations will occur with any showers. Frieders && .PRELIMINARY POINT TEMP/POPS... Mon Tue Wed Thu Fri Sat Sun ----------------------------------------------------------- BIL 060/077 051/080 053/087 057/092 061/092 060/088 059/085 53/T 10/U 00/U 00/U 11/B 23/T 32/T LVM 053/075 043/079 046/085 050/090 053/088 052/087 052/084 52/W 10/U 00/U 00/U 12/T 23/T 22/T HDN 060/078 051/082 051/089 055/093 059/094 060/090 058/087 32/T 10/U 00/U 00/U 01/U 22/T 22/T MLS 060/078 051/081 053/087 057/091 061/093 062/088 058/084 42/W 11/U 00/U 00/U 11/U 22/T 32/T 4BQ 060/079 051/080 052/087 056/092 060/096 059/090 059/085 11/B 22/T 10/U 00/U 01/U 21/U 33/T BHK 058/078 048/079 050/085 054/090 058/094 058/087 057/083 41/B 11/U 10/U 00/U 11/U 21/U 42/T SHR 056/078 050/080 050/088 053/093 058/096 058/091 056/086 14/T 33/T 20/U 00/U 01/U 22/T 33/T && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...None. WY...None. && $$
Area Forecast Discussion
National Weather Service Dodge City KS
543 PM CDT Sun Jul 12 2020 ...Updated aviation section... .SHORT TERM...(This evening through Monday) Issued at 344 PM CDT Sun Jul 12 2020 The primary forecast challenge will be tonight`s thunderstorm chances, coverage, severity. Thunderstorms were already underway across the terrain-favored areas of eastern Colorado. There was pretty good CAPE+Shear combination out there, supporting a Slight Risk from the SPC. The main question will be how far east/southeast a mesoscale convective system (MCS) will make it late tonight, before weakening. Low level moisture will certainly not be a problem, as there were mid-upper 60s dewpoints across much of southwest and west central Kansas late this afternoon. Middle tropospheric winds were out of the west-northwest this afternoon across Colorado and western Kansas. Once a MCS (or two) becomes established it should move southeast late tonight along the low level moisture axis, which is oriented fairly closely to the cloud- bearing deep tropospheric flow field, so at least one MCS should survive well into the night. Numerous models support MCS activity continuing well into the night whether it be QPF fields from global models or QPF/Composite Reflectivity from some of the various high resolution convective-allowing models. The exception (at least until the most recent 19Z run that was just rolling in) was the NCEP HRRR which struggled to maintain an MCS east of the KS-CO border. The Experimental HRRRv4, however, did maintain at least one MCS on its morning runs. On Monday, a deeper leeside trough will develop across eastern Colorado, resulting in slightly stronger surface winds from the southeast. The mid tropospheric flow will be out of the due west on Monday, as a polar jet stream trough moves across southern Canada along/just north of the International Border. This will be another good setup for eastern Colorado storms late in the day, which will again evolve into one or more MCSs later in the evening as storms move east and the nocturnal low level jet increases. We have 20-40 POPs in the grids for Monday Night, however these may need to be increased as confidence increases on MCS maintenance parameters across southwest Kansas after dark. .LONG TERM...(Monday night through Sunday) Issued at 344 PM CDT Sun Jul 12 2020 The cold front tied to a polar jet stream trough up north will push south across Kansas on Tuesday. There are timing uncertainties, but as of this forecast cycle, we will maintain mid-upper 90s for highs Tuesday south of the Arkansas River with upper 80s to around 90 for a high up along I-70. Yet another evening/late night MCS will probably develop just north of the surface front Tuesday Night, where dewpoints should be in the upper 60s to lower 70s. MCS outflow Tuesday Night/early Wednesday will most certainly aid in pushing the polar front south southwest Kansas during the day Wednesday. Moist, post-frontal upslope will develop again Wednesday afternoon/evening with more MCS activity Wednesday Night. Given this, nightly POPs of 20-40 percent will be in the forecast through mid-week. Much of western Kansas could see a couple inches of rain out of the combined multi-night MCS opportunities through Wednesday Night. The pattern will start to change by Thursday, per latest global model signals, with the summer subtropical ridge finally winning out and expanding its influence across the southern and central Great Plains. This should also transition our sensible weather into a hotter pattern with more widespread 100+ degF afternoons possible (Thursday and beyond). && .AVIATION...(For the 00Z TAFS through 00Z Monday evening) Issued at 541 PM CDT Sun Jul 12 2020 A few thunderstorms will be possible around the DDC, GCK, and LBL terminals this evening. Otherwise expect VFR conditions through tomorrow. Winds will be from the southeast overnight shifting to more of a southerly direction around mid morning. && .PRELIMINARY POINT TEMPS/POPS... DDC 68 95 69 96 / 40 0 20 10 GCK 66 98 67 95 / 40 10 30 10 EHA 68 100 67 97 / 40 30 40 10 LBL 68 101 68 100 / 50 10 30 0 HYS 68 94 70 90 / 10 0 20 10 P28 69 94 73 99 / 20 10 10 10 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Umscheid LONG TERM...Umscheid AVIATION...Springer
Area Forecast Discussion
National Weather Service Peachtree City GA
1010 PM EDT Sun Jul 12 2020 .UPDATE... MCS has moved through the SW portions of the state with some wind damage reports associated with it. Behind it, just some trailing stratiform but it too should be exiting quickly with no additional pops for the central sections. Another much weaker line is currently moving through portions of Tennessee. HRRR and WRF disagree on evolution with HRRR dying it out prior to arrival while the WRF brings it into far north GA. Will carry low end chance pops for the far north with this update. Otherwise, no changes planned. Deese && .PREV DISCUSSION... /issued 315 PM EDT Sun Jul 12 2020/ SHORT TERM /Rest of today through Monday Night/... Tricky near term fcst as the persistent MCS propagating southward across Alabama continues to stay just west of the CWA boundary and has primarily allowed the lofted mid/upper cloud shield to extend across north GA so far limiting diurnal destabilization. While this complex should follow along the tight instability axis still west of the area, the leading edge and outflow could aid its environment and end up pushing into western portions of central GA late this afternoon into evening. Also watching possible isolated convective development behind this system later this evening as the upper wave axis traverses the area mainly in the 00-06z period and holding onto some chance pops accordingly but uncertainty remains high. Any residual moisture from the MCS could end up advecting in some lower stratus or possible fog into parts of the western CWA for Monday morning with the light low level westerly fetch so will need to monitor evening trends as well. Monday looks less impactful as the enhanced moisture and aforementioned shortwave axis will allow some slight to chance pops more confined to southern and eastern portions of central GA, otherwise isolated chance for orographically enhanced convection in the northeast mtns and rest of area should remain dry under NW ridging. Temps thru period should remain right near climo norms and expecting highs Monday generally in low 90s north to mid 90s south. Baker LONG TERM /Tuesday through Sunday/... Upper level ridging will slowly build eastward into the Tennessee Valley through the long term periods. A weak surface boundary will linger over portions of central and south Georgia through mid week but will have limited moisture to work with. This pattern will lend itself to isolated to scattered diurnally driven showers and thunderstorms through the work week with afternoon highs in the 90s across much of the area, with mid to upper 90s across a large portion of the forecast area Tuesday through Friday. Heat indices will be near 100 across portions of north GA with 100-105 across central GA through next weekend. Although long term models are in pretty good agreement, GFS continues to trend toward a wetter pattern Thursday and beyond, with POPs likely on Sunday. Atwell AVIATION... 18Z Update... Initial VFR conditions with possible few cu 4-6 kft and some mid/upper level cigs from cloud shield of convective complex pushing southward across Alabama. Think most storm activity should stay west of the sites except for perhaps CSG after about 20/21z but will carry VCSH and tempo SHRA for near ATL. Cannot rule out some evening isolated development with main upper wave axis but confidence still low on and will monitor trends. Some MVFR cigs could flirt with sites near ATL and CSG Monday morning but greater chance for CSG. Winds mainly NW to SW 5-8 kts with 3-5 kts overnight (calm in south). Precip chances too low for Monday so just mainly SCT cu 4-6 kft. //ATL Confidence...18Z Update... Low on shower/storm potential this afternoon and evening. High on all else. Baker && .PRELIMINARY POINT TEMPS/POPS... Athens 70 93 71 95 / 10 20 10 10 Atlanta 71 91 71 93 / 10 10 10 10 Blairsville 64 84 63 87 / 20 20 10 10 Cartersville 68 90 67 93 / 10 10 10 5 Columbus 73 94 73 97 / 40 20 10 10 Gainesville 70 89 69 91 / 10 10 10 10 Macon 73 94 72 96 / 20 20 10 10 Rome 69 90 68 94 / 5 10 10 5 Peachtree City 70 91 69 94 / 20 10 10 10 Vidalia 75 95 74 97 / 20 50 20 20 && .FFC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Deese LONG TERM....Atwell AVIATION...Deese
Area Forecast Discussion
National Weather Service Huntsville AL
840 PM CDT Sun Jul 12 2020 .NEAR TERM...(Tonight) Issued at 840 PM CDT Sun Jul 12 2020 Showers and thunderstorms in middle and southwest TN persist within a narrow ridge of convective instability ahead of the cold front. There remains a bubble of more stable air over much of north central and northeast AL into eastern portions of southern middle TN. With 6km bulk shear values of 25-35kt, the updrafts continue to persist as the front moves south. However, HRRR runs continue to project a decay and dissipation of thunderstorms as they arrive in our forecast area over the next few hours. Will keep a low PoP in thru 06Z. The other impact weather to address tonight is the potential for fog. Temp/dew point spreads will continue to narrow overnight with light flow. Despite the weak frontal passage, rainfall from earlier today and a generally mostly clear sky suggest a good potential for fog later tonight. The Bufkit sounding fog tool also supports fog over stratus at this point. .SHORT TERM...(Monday through Tuesday night) Issued at 222 PM CDT Sun Jul 12 2020 The first part of the upcoming work week looks to be fairly dry and warm over the TN Valley as a ridge continues to build eastward and towards the area. Subsidence associated with the ridge, along with dry air filtering within northwest surface flow, will keep rain chances very low. Temps will increase each day, with highs on Monday in the upper 80s and then warming into the lower 90s on Tuesday. Overnight lows will fall into the upper 60s to lower 70s. .LONG TERM...(Wednesday through Saturday) Issued at 222 PM CDT Sun Jul 12 2020 The warming trend will continue through the remainder of the work week as the ridge becomes anchored over the Mississippi Valley. Surface winds will shift to the south, allowing moisture to filter into the region. Afternoon convection will return to the area each afternoon in the long term period as the combination of ample moisture and weaknesses in the ridge lends at least some aid to any mesoscale boundaries. Given the lack of any large scale forcing, will cap PoPs in the slight chance to chance categories. The real focus during the latter part of the week will be the warming temperatures. As we continue to see mid and upper level height rises, along with the southerly surface flow, highs will warm each afternoon into the lower to mid 90s. Combine these highs with the moisture in place and heat index values look to top out above 100 degrees in many locations. Overnight lows will generally fall into the lower 70s, though some locations may struggle to drop below the mid 70s by Thursday and Friday nights. && .AVIATION...(For the 00Z TAFS through 00Z Monday evening) Issued at 545 PM CDT Sun Jul 12 2020 A cold front pushing southeast through central KY into northwest TN was producing a few thunderstorms. These will encounter more stable air over southern TN and north AL late this evening (after 02-03Z), but will not totally rule out that these make it into the area. Have left them out of the KHSV and KMSL TAFs for now however, and will amend as necessary. Fog is forecast to develop late tonight into early Monday morning. Have indicated 1/2SM FG at KHSV and 3/4SM BR at KMSL from 10-13Z. It is possible the FG could develop earlier, and will address this in future updates as necessary. VFR conditions are expected after 13Z with north flow around 5kt occurring behind the cold front. && .HUN WATCHES/WARNINGS/ADVISORIES... AL...NONE. TN...NONE. && $$ NEAR TERM...17 SHORT TERM...73 LONG TERM...73 AVIATION...17 For more information please visit our website at
Area Forecast Discussion
National Weather Service San Diego CA
135 PM PDT Sun Jul 12 2020 .SYNOPSIS... After a scorching hot weekend, cooling will spread into the coastal and valley areas Monday and Tuesday as high pressure aloft weakens, onshore flow increases and the marine layer deepens. The heat will continue through Monday in the Deserts where an Excessive Heat Warning remains in effect. Seasonal summer weather will prevail Wednesday through Friday as a weak trough stalls along the West Coast. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... Temperatures soared again today and reached the nearly the same levels as yesterday in many valley, mountain and desert areas. Scorching heat baked the deserts where at 1 PM the temperature at Palm Springs was 114F and Thermal was 113F. The record high for both sites is 120. Here are some of record highs for other areas that may be tied or broken today: Big Bear (91) Anaheim (98) Ramona (99) Alpine (101) Riverside (107) Borrego (116) Palm Springs (120) Thermal (120) On Monday the heat will relent west of the mountains as the ridge aloft weakens, a coastal eddy deepens the marine layer, and the onshore flow will be a little stronger. It will still be quite warm in the Inland Empire with highs in the mid 90s, but triple digit heat is unlikely. The mountains will also be warm again tomorrow with highs in the 80s and low 90s. In the deserts, the heat dome associated with the upper ridge will last one more day, and a Heat Warning remains in effect through 8 PM Monday. Highs will be around 105 in the High Deserts and 115F in the Lower Deserts. Temperatures return to their seasonal averages in all four climate zones Tuesday through Friday when a weak trough stalls along the West Coast. Marine layer clouds will be more widespread over the coastal waters and spread across the coastal zones into the western valleys each night before retreating back to near the coast each day. Cumulus formed over the mountains during the heat of the afternoon today, but the atmosphere has been too stable for deep growth through 1 PM. Neither the WRF nor the HRRR output any showers through this evening, but some of the HREF runs from SPC have small chances of convection through early evening. The long range outlook for next weekend and beyond shows a nearly stationary east-west oriented ridge centered over KS/OK. Weak troughiness persisting along the West Coast will limit the westward extent of the most intense heat, and temperatures will be at or a little above average through July 22nd in our area. This pattern will also limit the monsoon potential over Southern California. && .MARINE... Patchy fog for portions of the coastal waters this evening through Sunday morning, though confidence still somewhat on the low end. Some areas may experience visibility of less than 1 nm. Otherwise, no hazardous marine conditions are expected through Wednesday.Strong upper-level ridges are in place over the EastPac and the Southern Plains states, leaving a weak trough position prevailing along the West Coast. This maintains onshore flow and a shallow marine layer over SoCal. The pattern retrogrades late in the week into next weekend, resulting in warming but still mostly dry with SW flow aloft. && .AVIATION... 112010Z...Coast/Valleys...SCT-BKN clouds AOA 10-20K ft MSL this afternoon into tonight. Moderate confidence continues for patchy low clouds returning tonight after 08Z. Looking like low clouds could make it to VCTY KSAN 07-09Z, and closer to 10-12Z near KSNA. A coastal eddy will slowly spin up brining in low clouds more widespread in coverage tonight. Visibility 1-3 sm where clouds/fog intersect terrain. Other areas may see vis 4-5 sm in BR through the early morning as well. Moderate confidence on cigs clearing by 14- 16Z Sunday morning. Mountains/Deserts...SCT CU/ISO TCU may developing over the mountain crests this afternoon with bases near 8000 ft MSL and tops to 20000 ft MSL, dissipating near sunset. Some of these mid level clouds 15,000 ft MSL will prevail through the night and into Sunday morning. && .MARINE... Patchy fog for portions of the coastal waters this evening through Sunday morning, though confidence still somewhat on the low end. Some areas may experience visibility of less than 1 nm. Otherwise, no hazardous marine conditions are expected through Wednesday. && .SGX WATCHES/WARNINGS/ADVISORIES... CA...Excessive Heat Warning until 8 PM PDT Monday for Apple and Lucerne Valleys-Coachella Valley-San Diego County Deserts- San Gorgonio Pass Near Banning. Heat Advisory until 8 PM PDT this evening for Orange County Inland Areas-Riverside County Mountains-San Bernardino County Mountains-San Bernardino and Riverside County Valleys-The Inland Empire-San Diego County Mountains-San Diego County Valleys-Santa Ana Mountains and Foothills. PZ...NONE. && $$ PUBLIC...Moede AVIATION/MARINE...APR