Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 08/12/20

Area Forecast Discussion
National Weather Service Boise ID
843 PM MDT Tue Aug 11 2020 .DISCUSSION... Scattered showers and isolated thunderstorms developed in southern Harney and Malheur Counties earlier this afternoon, and have tracked northeastward into the Owyhees and Upper Treasure/Magic Valleys this evening. Wind gusts have peaked to 45-55 mph with stronger thunderstorms in southeast Oregon. Outflow ahead of the storms arrived at the Caldwell and Boise metro areas around 7:30 PM MDT, which created a wind shift to S-SW and produced wind gusts to 20-25 mph briefly. Current activity is starting to decrease with the sunset. Cloud cover will start to break up overnight in time for some viewing hours of the Perseid meteor shower, but smoke and dust blown into the area from northern California wildfires and from our outflow winds may create visibility restrictions. A cold front is still on track to arrive Wednesday afternoon and evening, which will bring an additional wave of cloud cover and cooler temperatures. A slight chance for sprinkles/rain shower is in the forecast associated with the frontal passage in the afternoon/evening timeframe. Dry and cooler temperatures are then expected Thursday. && .AVIATION...VFR. Isolated showers and thunderstorms south of a line from KBNO to KONO to KSUN. Surface winds: variable 10 kt in the Snake Plain and mountains, SW-W 10-30 kt in southeast Oregon through 06Z, then decreasing. Thunderstorms may produce gusty erratic outflow winds up to 40kt through 06Z. Winds aloft at 10k feet MSL: W- SW 15-25 kt increasing to 25-35 kt by 12z/Wed. && .PREV DISCUSSION... SHORT TERM...Tonight through Thursday...At 2 PM MDT a few rain showers have moved across the Nevada border. A thunderstorm was noted in southern Harney County. Early morning HRRR brought pcpn as far north as Boise this evening but latest HRRR has shifted the northern limit southward about 20 miles. Still, if showers or thunderstorms get that close the Boise area will feel outflow winds. However latest HRRR has also weakened its wind gust forecast. Earlier it had gusts to 50 mph in se Malheur County late today, then across the Owyhees and Mountain Home early this evening, and Fairfield by sunset. Now it still has gusts in the Owyhees and north to Marsing 6-7 PM MDT, but much weaker east of there. Our forecast will keep the northern limit of showers and thunderstorms this evening at Rome/OR through Mountain Home to Fairfield. Outflow gusts to 30 mph may reach Boise from the south this evening. On Wednesday any convective activity will shift to Twin Falls County, then exit east Wednesday night. Meanwhile, a Pacific cold front will pass through eastern Oregon Wednesday morning and western Idaho Wednesday afternoon. Front will bring breezy west/northwest winds, cooler temps, and clouds, but only a few sprinkles to the higher northern mountains. Continued dry elsewhere. Highs Wednesday will be 75 to 80 in Baker and Valley Counties but still near 90 in southern valleys. Mostly sunny, breezy, and cooler again in all areas Thursday as the upper trough moves through. Clear and cool Thursday night. LONG TERM...Friday through Tuesday...A warming trend to above normal temperatures is expected as a strong ridge expands over the Western US by Sunday. Temperatures will warm to near record highs by Sunday with temperatures around 10-15 degrees above normal. Monsoon moisture may eventually get wrapped up in the ridge with thunderstorm chances increasing after Sunday. && .BOI WATCHES/WARNINGS/ADVISORIES... ID...Red Flag Warning from 1 PM to 9 PM MDT Wednesday IDZ423. OR...None. && $$ DISCUSSION...SH AVIATION.....SP PREV SHORT TERM...LC PREV LONG TERM....KA
Area Forecast Discussion
National Weather Service Denver/Boulder CO
954 PM MDT Tue Aug 11 2020 .UPDATE... Issued at 944 PM MDT Tue Aug 11 2020 Skies are slowly clearing and weather looks to be calm overnight. Hot and dry conditions are expected to persist tomorrow, which elevates the fire danger. Smoke from the fires in the mountains should also impact the area again tomorrow. && .SHORT TERM...(This evening through Wednesday) Issued at 311 PM MDT Tue Aug 11 2020 Latest GOES-16 and area radars showing a broken line of strong storms moving westward from Lincoln and Washington Counties, with additional storms to the northeast across Phillips and Sedgwick Counties. The HRRR had the convective evolution pegged 24 hours prior to now. Expect the broken line of storms to continue moving east. By 5 PM the storms should be east of our area. The strongest storms across the far northeast plains could have small hail and 50 mph gusts. For the high country and Palmer Divide, expect high based showers, through 8 PM with gusty winds and probably no rainfall. Smoke from the Garfield County fires will continue into Wednesday morning, and become more pronounced near the surface after 10 PM tonight, especially west of the Divide in Grand and Summit Counties. Park County, the eastern foothills, and Denver metro will also all see an increase in the smoke at the surface and aloft after midnight. The ridge of high pressure is parked over New Mexico through Wednesday with the ridge axis extending across central Colorado. Winds aloft will be west or slightly north of west, continuing to advect smoke into our area. By Wednesday afternoon the smoke should be confined to the mid and upper levels and not as much near the surface until once again a nocturnal inversion develops late evening and traps the smoke closer to the ground. Despite the smoke, temperatures will still reach the mid 90s across the plains, with slightly cooler temps in the mountain valleys vs. today. Highs should be in the upper 70s in the valleys and near 60 at timberline. In terms of convective potential, it will continue to be extremely dry throughout the depth of the atmosphere with the ridge overhead and weak downslope flow out of the west. Precipitation chances will be 10% or less for most of the area, just expecting high based virga showers with gusty winds and very little if any rainfall reaching the ground. The exception will once again be the far northeast plains where surface dewpoints will remain in the mid 50s with low-level southeast flow, shielded from the drying downslope to the west. Convection may form along the moisture convergence boundary mid afternoon and if so, there is around 2,500 J/kg CAPE available for marginally severe storms across the far northeast corner of Colorado. Deep layer shear remains weak (20 kts) so marginally severe hail and wind gusts to 60 mph are the possible impacts. .LONG TERM...(Wednesday night through Tuesday) Issued at 311 PM MDT Tue Aug 11 2020 An upper level high will remain over Arizona and New Mexico, with mainly westerly flow aloft, over the area Thu and Fri. Overall, there isn`t much moisture, however can`t rule out a slight chc of high based storms, over the higher terrain, especially on Fri. Highs both days will remain in the 90s to around 100 both days over nern CO. For the weekend, the upper level high will begin to retrograde, with the flow aloft becoming more northwesterly. On Sat, it will remain hot, with just a slight chc of aftn storms, over the higher terrain. By Sat night, a cool front will move into nern CO. The ECMWF has MLCAPE in the 2000-2500 j/kg range over the far nern plains, with convection developing along the front, Sat night. Meanwhile, the GFS has virtually no MLCAPE, with no tstm activity over the plains. On Sun, it will be cooler with highs lowering back to more seasonal levels. There are substantial differences with respect to low level moisture and instability over nern CO. The ECMWF has MLCAPE in the 2000-2500 range with a chc of storms across nern CO. On the other hand, the GFS has far less MLCAPE with limited tstm potential. && .AVIATION...(For the 06Z TAFS through 06Z Wednesday night) Issued at 944 PM MDT Tue Aug 11 2020 The outflow from convection to the north and east seems to be weakening and winds are expected to turn to normal drainage for the night. Skies are slowly clearing. There will more haze tomorrow due to fires in the mountains. && .FIRE WEATHER... Issued at 311 PM MDT Tue Aug 11 2020 It will remain hot and dry with elevated fire danger on Wednesday, however, winds will be light. Fire danger will increase over the higher terrain, north of I-70 on Thursday, as wind speeds will increase. && .BOU WATCHES/WARNINGS/ADVISORIES... None. && $$ UPDATE...Direnzo SHORT TERM...Schlatter LONG TERM...RPK AVIATION...Direnzo FIRE WEATHER...RPK
Area Forecast Discussion...Updated
National Weather Service Billings MT
838 PM MDT Tue Aug 11 2020 .UPDATE... Updated forecast this evening mainly for area of weak thunderstorms over SC Montana producing gusty outflow winds. This activity which extends from the southern Paradise Valley to eastern Yellowstone county should dissipate over the next hour or so as it moves into Rosebud county. Wind gusts of 40 to 50 mph have been reported from time to time with this activity, but generally gusts have been in the 20 to 30 mph range. A few strong to severe storms are holding fairly stationary over northeast Carter county. This activity should move shift east of the area over the next hour or so as well. The Bear Creek fire along the SW MT/ID border is produce a large plume of smoke that has pushed all the way into SC MT this evening. Reports from Livingston and Bozeman of smoke at the surface with Livingston showing visibility restricted to 6 miles at the airport. Added mention of smoke to the forecast overnight for areas under this plume. Rest of the forecast on track for tonight. Red Flag warning continues for most of the region starting late tomorrow morning. Chambers && .DISCUSSION... Tonight through Wednesday Night... Current surface analysis shows a surface boundary (dry line?) in western Custer/Powder River counties. There is a subtle shortwave moving thru southeast MT, where MLCapes east of the boundary are 500-1000 j/kg. Shear is fairly weak, but southeast surface winds have increased near the Dakotas border, and we have recently seen an uptick in cumulus development along the convergent area. Add it all up, and we could see a brief line of t-storms in our far east over the next few hours...thru 01z if the latest HRRR is to be believed. These storms should remain sub-severe, but cannot rule out some small hail and gusty winds, so a heads up for those with outdoor plans in the area. Further west, isolated t-storms developing over and spreading off the mountains should be high- based and generally weak...but have the potential to produce gusty surface winds. All of this activity should diminish this evening, leading to dry/quiet weather late tonight and Wednesday morning. An upper level low is over BC with a shortwave dropping along the coast. Pre-frontal warming ahead of this wave will push temps well into the 90s tomorrow, which looks like the hottest and driest day of the week. Synoptic scale ascent will combine w/ steep low-mid level lapse rates to bring a risk of high-based t-storms across our region in the afternoon and evening. The combination of hot temps, low humidity, breezy/mixed winds and increasing t-storm activity has led to the issuance of a Red Flag warning from 11 am to midnight tomorrow for most of our fire zones. It will be interesting to watch the morning to early afternoon wind shift moving across our east, which will be followed by a period of deep mixing and significant boundary layer drying. Latest models suggest dew points in the 20s to low 30s, which with temps near 100 degrees would put humidity below 10 percent near places like Forsyth, Miles City and Broadus. This will obviously be problematic for existing fires. Wednesday night cold front will bring a shift to modest northerly winds, mainly after sunset. Could see some lingering overnight showers in our west, and nighttime RH recoveries will be a bit better as we advect in the cooler air. JKL Thursday through Tuesday... Overall, a quiet and mostly hot extended forecast in store. An upper trough will move over the forecast area Thursday afternoon and evening. This will result in temperatures about 10 to 15 degrees cooler than Wednesday along with a slight chance for a shower or thunderstorm during the afternoon into the evening with the evening hours having a slightly higher chance. Afternoon humidities will be slightly higher in the lower 20s along with light winds. A zonal flow aloft will prevail Friday into early Saturday ahead of another front that will move southeast across the eastern portions of the state late Friday night/Saturday morning. This will usher in gusty northwest winds during the day Saturday across mainly the eastern portions of our forecast area from about Rosebud County eastward. So this will be another day for fire weather concerns. Models then begin to build a strong ridge Sunday into the middle portions of next week which will result in hot temperatures returning. However, there are some indications that some monsoonal moisture make works itself under the ridge, something we have not seen much of yet this season. Hooley && .AVIATION... Isolated thunderstorms will continue through late evening across SC MT and far SE MT before dissipating. Local MVFR conditions and wind gusts to 40kts are possible with the SC MT storms, with IFR in heavy rain, hail and gusts to 50kts are possible with the SE MT storms. A plume of wildfire smoke is already reducing visibility at KLVM and KBZN. Expect visibility as low as 5sm at times as far east as Treasure and Big Horn counties (including KBIL) due to this plume of smoke overnight into Wednesday morning. Chambers && .PRELIMINARY POINT TEMP/POPS... Wed Thu Fri Sat Sun Mon Tue ----------------------------------------------------------- BIL 063/095 059/085 056/087 056/082 054/087 057/093 062/093 22/T 31/B 30/U 10/U 00/U 01/U 11/B LVM 053/092 051/083 047/086 047/085 047/089 052/094 056/092 23/T 33/T 20/U 00/U 00/U 01/U 12/W HDN 059/098 057/087 055/088 055/083 052/089 056/094 060/094 22/T 31/U 30/U 10/U 00/U 00/U 11/B MLS 064/100 062/086 058/085 056/080 053/084 057/090 061/092 10/U 30/U 50/U 10/U 00/U 00/U 01/U 4BQ 062/098 061/088 058/086 057/083 053/086 058/091 060/093 11/U 20/U 30/U 10/U 00/U 00/U 01/U BHK 061/097 059/087 055/085 054/081 049/082 052/087 055/089 32/T 20/U 51/U 11/U 00/U 00/U 01/U SHR 058/097 056/089 053/087 053/083 050/087 054/093 058/093 12/T 21/U 20/U 00/U 00/U 01/U 12/W && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...Red Flag Warning in effect until 9 PM MDT Wednesday FOR ZONE 117. Red Flag Warning in effect from 11 AM Wednesday to midnight MDT Wednesday night FOR ZONES 123>132. WY...Red Flag Warning in effect from 11 AM Wednesday to midnight MDT Wednesday night FOR ZONES 274-284. && $$
Area Forecast Discussion...UPDATED
National Weather Service Corpus Christi TX
1040 PM CDT Tue Aug 11 2020 .DISCUSSION... Updated wind over the Coastal Waters to SCEC (15-20kt) for tonight given recent observations and HiResW-NMM, GFS, and RAP deterministic output for the 03-09z Wednesday period. && .PREV DISCUSSION... /Issued 635 PM CDT Tue Aug 11 2020/ DISCUSSION... Note Aviation Discussion below corresponding to the 00z TAFs. AVIATION... VFR conditions expected during the period, except for a mixture of MVFR and VFR ceilings/visibilities over the Coastal Plains during the 09-14z Wednesday period. Weak/moderate onshore flow this evening/early tonight, then becoming light/variable through early Wednesday, then transitioning to moderate/breezy onshore flow by late Wednesday afternoon. Significant precipitation is not expected during the period. PREV DISCUSSION... /Issued 234 PM CDT Tue Aug 11 2020/ SHORT TERM (Tonight through Wednesday night)... A quiet hot 36-hours is ahead for us with a surface high over to our east with ridging aloft dominating throughout the period. Rain chances diminished earlier this afternoon and will remain absent through the evening. Winds at 925mb are shown to take a more southwesterly orientation heading into tomorrow morning and will result in drier air aloft along with a stronger cap and weaker PWAT values. Therefore, have kept silent PoPs for the entire CWA for Wednesday and Wednesday night as conditions are more unfavorable than today. Temperatures are expected to be a couple degrees warmer Wednesday with SPS conditions likely as heat indices range from 105 to 109 degrees with isolated higher amounts possible. Close monitoring is needed for potential heat advisory conditions, especially over the Coastal Plains. LONG TERM (Thursday through Tuesday)... Not much deviation from the previous long-term forecast. The upper level ridge remains over the region through the end of the work week. With dry air aloft and lower than average PWAT values, rain chances will be very limited. The Victoria Crossroads area could see an isolated storm or two along the sea breeze. Looking into the weekend and next week a trough digs south into the Ohio Valley, and will cause the ridge to shift slightly west. An inverted trough slides into the area from the south. Kept PoPs around 20-30 percent as the lack of moisture may limit precipitation at the beginning of the weekend. PWAT values begin to increase by the end of the weekend into next week. Rain chances look more probable by that point as an H5 shortwave approaches the region. The GFS and Euro both suggest a weak cold front early next week. With it being near the end of the period, we will see if the models hold onto this. Hot and humid conditions persist through the extended period. Daily SPSs likely needed with heat indices ranging from 105-109 and a few locations briefly reaching values at or above 110 degrees. MARINE... Generally weak to moderate onshore flow will persist through the period. Brief moderate winds can be expected across the bays and nearshore waters south of Port Aransas each afternoon. Isolated showers and thunderstorms will be possible at times through the work week. Rain chances will increase as we head into next weekend and early next week. && .PRELIMINARY POINT TEMPS/POPS... Corpus Christi 78 96 77 95 77 / 10 10 0 10 0 Victoria 78 98 77 97 76 / 0 10 0 10 0 Laredo 78 102 77 102 77 / 0 0 0 0 0 Alice 76 99 75 99 75 / 0 0 0 10 0 Rockport 82 94 82 94 82 / 10 10 0 10 0 Cotulla 77 102 77 103 76 / 0 0 0 0 0 Kingsville 77 98 76 97 76 / 0 0 0 0 0 Navy Corpus 82 92 81 93 81 / 10 10 0 10 0 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...None. GM...None. && $$ WC/87...SHORT TERM
Area Forecast Discussion
National Weather Service Des Moines IA
642 PM CDT Tue Aug 11 2020 .DISCUSSION.../Tonight through Tuesday/ Issued at 252 PM CDT Tue Aug 11 2020 The main forecast concern was focused on the continued somewhat active weather pattern throughout the week and into the weekend. Not great agreement with the models wrt to convection this week and seems the ECMWF is the outlier and wettest model run through Friday. Leaned closer to the hires models through Wednesday which was a trend downward with storm chances other than over northern Iowa. Then closer to the GFS late in the week. Surface high pressure remains over the Great Lakes and keeps any shortwave off to the west of the forecast area tonight into Wednesday. Lowered pops considerably across the forecast area but left low end pops over the west to north per latest NAM as well as the 11.18z HRRR and RUC suggesting convection trickling into northwest part of Iowa by Wednesday morning. Overall, low confidence with much development due the decent dry air entrainment from the surface high pressure to the east, weak lift, and the instability axis remaining in western Iowa. Couldn`t completely rule out and isolated elevated strong storm later Wednesday, but the overall widespread potential is low. Thursday...The ECMWF has another shortwave cutting across the state Thursday and it has been fairly consistent with this trend. That being said, the GFS has also been fairly consistent with the northern trend and thus keeping the state dry on Thursday. The timing of the ECMWF would suggest some severe weather potential as it passes through the state during the afternoon hours. Instability is 2000-3000 J/kg but shear remains weak throughout the day Thursday per GFS. Plus, the better moisture convergence is suggested to be in Minnesota and possible over far northern Iowa. Friday through Sunday...large upper ridge remains in place over the southwest CONUS and there is a hint of a weak cold front to pass through the region Saturday. Obviously timing remains questionable, but the lack of significant frontogenetical forcing and moisture with this system, low confidence with the storm chances and thus the severe threat. Much cooler temperatures by the early part of next week. && .AVIATION.../For the 00Z TAFS through 00Z Wednesday evening/ Issued at 642 PM CDT Tue Aug 11 2020 Few concerns early. Warm air advection returns to northwest Iowa aft 06z and -tsra may develop into northern sites aft 11z nearing KFOD by 16z and possibly KMCW by 15z. Coverage still uncertain. Otherwise light winds through 12z with some mixing aft 15z and generally mid to high level ovc with VFR conditions. Will monitor any lower cigs and wx trends for next package. /rev && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ DISCUSSION...Podrazik AVIATION...REV
National Weather Service Eureka CA
333 PM PDT Tue Aug 11 2020 .SYNOPSIS...Warm, dry conditions will continue through Friday across interior areas. Overnight clouds and fog will dissipate during the late morning along the coast, leaving sunny skies and mild temperatures during the afternoon. A warming trend is expected Friday through the weekend, with a slight chance of thunderstorms over the weekend. && .DISCUSSION...Benign summertime conditions continue throughout the region today, with sunny skies and warm temperatures across inland areas, and stubborn shallow marine clouds along the immediate coast. While temperatures may be a few degrees lower than they were yesterday at this time across interior valleys, it is hardly noticeable as they have nonetheless climbed well into the 90s to near 100 degrees in some places. This slight moderating trend will continue Wednesday and Thursday, although afternoon temperatures will continue to reach near seasonal averages each day. Skies will also continue to be mostly clear through Friday across inland areas. Temperatures will begin a warming trend Friday, likely climbing back to between 95 and 105 throughout interior low elevations. Along the coast, a very shallow marine layer is expected to persist through the end of the week. As such, shallow stratus clouds and fog are expected to only reach between 500-1000 feet in elevation along the immediate coast, with local visibility reductions due to fog possible all the way down to sea level. This will occur during the overnight and morning periods tonight through potentially Thursday night, with a relatively quick burnoff expected during the morning. Much drier air is expected to move through the area early Friday, which should help to scour out these clouds almost completely. This may also result in slightly warmer temperatures in coastal communities as well. On Saturday, a weak disturbance moving in from the southwest may bring enhanced moisture, lift, and instability to the area, with the potential to produce afternoon thunderstorms. Uncertainty remains very high at this stage, but have introduced slight chances for thunderstorms across primarily the interior mountainous areas along and east of South Fork Ridge. Otherwise, slightly above normal temperatures will also continue Saturday and Sunday, with a slight retreat back to near seasonal averages Monday and beyond. Additional opportunities for thunderstorms appear possible early next week, but probabilities remain too low to include in the official forecast at this time. /BRC && .AVIATION...Widespread stratus and fog blanked the coastal waters and adjacent land areas this morning. This cloudiness eroded fairly quickly on the inland edge, but periods of onshore flow kept the immediate coastal areas BKN-OVC. Clouds N of Cape Mendocino have also eroded on their W flank as gusty northerlies continue. Low clouds are more expansive over the coastal waters S of Cape Mendocino. The ACV profiler indicates the marine layer has deepened to over 3000 ft through the day, with the Bodega Bay profiler indicating a marine layer a bit shallower (a shade below 3000 ft). Expecting similar conditions tonight with an expansion of stratus and fog along the coast. A brief ceiling advected into KUKI from the S this morning, and the HRRR hints that this might be a bit more likely Wednesday morning. Winds will be generally light over land. /SEC && .MARINE...Northerly winds will continue to gradually diminish overnight, with the strongest winds continuing downwind from Cape Mendocino. Advisory level seas will continue through the downtick in winds until northerlies again increase Wednesday night and Thursday. As a result, have extended the Small Craft Advisory for the outer waters into Thursday night. Winds and seas may increase enough over the N outer waters to warrant a Gale Watch or Hazardous Seas Watch, but will defer this decision to the next shifts. Mid-period NW swell and long period SSW swell will gradually decay over the next couple of days. Otherwise, seas will be dominated by short period waves. /SEC && .EKA WATCHES/WARNINGS/ADVISORIES... CA...None. NORTHWEST CALIFORNIA COASTAL WATERS...Small Craft Advisory until 1 AM PDT Friday for PZZ470-475. && $$ Visit us at Follow us on Facebook and Twitter at: For forecast zone information see the forecast zone map online:
Area Forecast Discussion
National Weather Service El Paso TX/Santa Teresa NM
512 PM MDT Tue Aug 11 2020 .AVIATION...00Z TAF CYCLE VFR conditions generally expected. Showers are trying to develop in the vicinity of KELP as an outflow moves east to west. A lightning strike or two cannot be ruled out with brief impacts possible at the airport within the next hour or so (by 01z). Otherwise, SCT mid clouds expected for the region with light and variable winds. && Brown .PREV DISCUSSION...300 PM MDT Tue Aug 11 2020... .SYNOPSIS... High pressure aloft will be centered over the Borderland through the end of the week, which will suppress most thunderstorm development and result in afternoon temperatures near or at record levels. A few storms may succeed in developing over the higher mountains or in far southwestern New Mexico, but most locations will remain dry. The upper high will then migrate west and northwest over Arizona on the weekend and over Utah early next week, with temperatures not quite as hot and enough moisture for a few thunderstorms area wide. && .DISCUSSION... .SHORT TERM...Tonight and Wednesday... Any isolated shower, storm, or breezy outflow activity will die off after sunset, or shortly thereafter. Warm temperatures continue into the overnight, especially El Paso county and portions of the Rio Grande valley south of El Paso, where the Heat Advisory continues until early Friday. Elsewhere temps remain seasonably above average. For Wednesday, extended range HRRR is quite bullish on activity, as usual, but does show the preferred areas of convection pretty well I feel. The Gila, Sacs, southern Otero, and the terrain of Hudspeth county. Might be a slight uptick in moisture levels tomorrow, by slight I mean ever so slightly in the mid levels, so this "threat" seems plausible. In any event, have POPs across the terrain regions of the CWA mainly, but can see a few POPs leaking into adjacent lowland locations, and maybe even the Bootheel. Nevertheless, the ridge overhead will suppress a lot of this activity, both in coverage and intensity, and of course, temperatures will rise into the low 100s to near 105 degrees most lowland locations (with 850 temps fcst a bit higher than Tuesday suggesting warmer temps than Tuesday). && 35 .LONG TERM... Record heat continues Thursday and Friday with the upper high centered directly overhead. Moisture tries to seep in from Sonora and southeast AZ at times, so a few storms are possible west of the divide, yet they will struggle under the high. But things might improve slightly over the weekend as the upper high migrates westward over AZ. This will take the edge off of record heat (though still hotter than normal) and allow an upper impulse or two to drop southward around the front side of the high. We`ve seen this already earlier in the summer, and though it is not a classic monsoon pattern we will take whatever storms this can generate. It might even get better early next week as the models drift the upper high over southern UT. Meanwhile a decent upper trough drops down into the plains states...a set-up for weak backdoor fronts. That could bring temperatures down closer to normal (but still hot because it`s August) and increase thunderstorm coverage a bit. We`re not talking about a nice monsoonal outbreak of storms, but definitely better than the current scenario. && 01 .AVIATION...Light to mildly breezy winds (G15-20KT) through the afternoon hours at KDMN, KTCS, KLRU. Otherwise, FEW-SCT120-150 with mainly terrain storms and VFR conditions expected at terminals. Cannot rule out a breezy outflow as well. && 35 .FIRE WEATHER... Upper ridge will remain in the vicinity of southern NM through the end of the week. Consequently, thunderstorm chances will be rather isolated with mainly terrain storms, and temperatures 8-15 degrees above average. Warm temperatures and slightly better storm chances expected through the weekend for all locations, but only an iso to sct mtn and iso lowland threat. Early to mid next week may provide even better storm chances as the upper level high jogs to the northwest of the area. All the while, outside of thunderstorms, winds remain light to mildly breezy each afternoon. Min RH 10-15% lowlands and 15-25% area mtns with ventilation a mix of Poor to Good through the early weekend. && 35 && .PRELIMINARY POINT TEMPS/POPS... El Paso 77 105 77 105 / 0 0 0 0 Sierra Blanca 70 99 69 100 / 10 10 0 0 Las Cruces 71 103 71 102 / 0 0 0 0 Alamogordo 71 104 73 104 / 10 10 0 10 Cloudcroft 55 80 56 80 / 10 20 0 30 Truth or Consequences 72 101 71 102 / 0 10 10 10 Silver City 67 96 67 96 / 0 10 0 20 Deming 68 104 70 104 / 0 0 0 0 Lordsburg 69 102 71 102 / 0 0 0 10 West El Paso Metro 77 106 78 107 / 0 0 0 0 Dell City 71 105 71 105 / 10 10 10 0 Fort Hancock 75 106 75 107 / 0 0 0 0 Loma Linda 73 98 73 99 / 10 0 0 0 Fabens 76 105 77 105 / 0 0 0 0 Santa Teresa 72 104 74 104 / 0 0 0 0 White Sands HQ 74 103 75 104 / 0 0 0 0 Jornada Range 71 102 72 102 / 0 10 10 0 Hatch 70 103 71 104 / 0 0 0 0 Columbus 73 104 74 105 / 0 0 0 0 Orogrande 73 104 74 104 / 0 0 0 0 Mayhill 61 90 61 91 / 0 20 0 30 Mescalero 59 90 60 91 / 10 20 0 30 Timberon 59 89 59 89 / 0 20 0 20 Winston 60 93 60 93 / 10 20 10 30 Hillsboro 68 101 68 101 / 0 10 0 20 Spaceport 69 102 70 102 / 0 0 0 10 Lake Roberts 60 94 60 94 / 10 20 0 30 Hurley 67 98 66 99 / 0 0 0 20 Cliff 63 101 64 102 / 10 10 0 20 Mule Creek 67 97 67 97 / 10 20 0 20 Faywood 68 99 68 99 / 0 10 0 20 Animas 68 103 69 104 / 0 0 0 10 Hachita 67 102 69 103 / 0 0 0 0 Antelope Wells 68 101 69 102 / 10 0 0 10 Cloverdale 65 96 68 97 / 10 10 0 10 && .EPZ WATCHES/WARNINGS/ADVISORIES... NM...None. TX...Heat Advisory until 8 AM MDT Friday for TXZ418-419-423-424. && $$ 35-Delizio/01/34
National Weather Service Hastings NE
753 PM CDT Tue Aug 11 2020 ...Short Term and Aviation Update... .UPDATE... Issued at 752 PM CDT Tue Aug 11 2020 Mainly regarding some forecast tweaks for the rest of tonight (and some comments about Wed-Wed night): - Although still feel that the probability of MOST of our coverage area (CWA) seeing rain/thunderstorms tonight is fairly low, latest radar trends and short term models (such as HRRR) are now more suggestive that at least isolated-scattered activity will "survive" into especially the western/northern one-thirds of our CWA (as opposed to pretty much completely dying out before reaching our borders as models earlier today were more suggestive of). - As a result, have slightly increased the areal coverage of low rain/storm chances (PoPs) for this evening, with at least a small chance assigned to most all areas mainly west of an Osceola-Hastings-Osborne KS line through 06Z/1AM. For the late night/early AM hours (after 06Z) have confined any small thunderstorm chances to some areas north of I-80, but with subtle hints that at least spotty/pesky activity could linger or develop here or there, have maintained a generic "chance of sprinkles" through the late-night all areas to at least imply that the forecast is not guaranteed dry. - As for possible storm intensity this evening, still feel the odds of legit severe activity is relatively low (in agreement with SPC Day 1 outlook), but have updated our Hazardous Weather Outlook (HWOGID) to at least acknowledge that a few strong storms (gusty winds/maybe small hail) cannot be ruled out. Per radar and HRRR trends, our main concerns for a few strong storms through 06Z might end up targeting both our southwestern and also northern counties, with a relative minimum of concern in between (including the I-80 corridor/Tri Cities area. In closing, want to reiterate/reinforce what preceding day shifter stated below: this is not a very straightforward forecast for the next 24-36 hours. Thanks to a series of subtle disturbances working through the flow aloft, various models are truly all over the place with their placement/timing of convection, especially for Wednesday daytime-night. Will defer to upcoming night shift to make forecast adjustments to these Wed periods, but I`d advise to just expect at least modest changes/possible curveballs to be thrown in this tricky pattern, not only with our own official forecasts for our CWA, but also with upcoming Day 1 SPC severe storm outlooks. && .SHORT TERM...(This evening through Wednesday) Issued at 226 PM CDT Tue Aug 11 2020 Unfortunately this is not a very straightforward forecast for the next 36 hours. Thunderstorms are the main forecast concern through tonight and tomorrow, but details on coverage and timing remain somewhat uncertain. Currently, we are seeing showers and thunderstorms starting to develop over western Nebraska and northern Colorado. These storms will have an unstable environment to strengthen in for the next several hours, but models generally agree that storms will decrease in intensity/coverage as they move into central Nebraska and Kansas overnight. Large portions of the area will end up seeing little to no precipitation through tonight. Heading into tomorrow, short-term models seem to be picking up on some remnant outflow or MCV features to help spark some redevelopment during the day. There is still considerable uncertainty as each model differs on their depiction and timing, with some showing showers/storms redeveloping as early as mid- morning. The overall consensus is for thunderstorms to redevelop in the afternoon, though. Diurnal heating should result in MUCAPE to around 4000j/kg by late afternoon, and bulk shear is forecast to be 20-30kts. This could support some strong to marginally severe updrafts as storms move through the area into the evening. .LONG TERM...(Wednesday night through Tuesday) Issued at 226 PM CDT Tue Aug 11 2020 Models have trended drier for Thursday and Thursday night, likely a result of increased inhibition from rising temperatures aloft. As a result, we now have a dry forecast for this period. Highs should be around 90 in most locations and some spots may have heat indices approach 100 degrees. Friday is still expected to be the warmest day of the week before a cold front pushes in from the northwest. Widespread highs in the 90s are expected, but for now, it looks like we will remain short of heat advisory criteria. Chances for thunderstorms return Friday evening into Saturday as the cold front moves through the area. There is some uncertainty on the strength and timing of this front, but we still have several days for the models to work out the specific details. We will cool off somewhat Sunday through Tuesday, with current forecast calling actually calling for highs in the upper 70s and low 80s each day. This is largely due to the shift to more northwesterly flow aloft, which will also provide periodic slight chances for rain and thunderstorms into the beginning of next week. && .AVIATION...(For the 00Z KGRI/KEAR TAFS through 00Z Thursday) Issued at 752 PM CDT Tue Aug 11 2020 Confidence remains fairly high in VFR ceiling/visibility through the period (despite a decent amount of mid-high level cloud cover), and is also high in dry/storm-free weather through the vast majority of the period. That being said, compared to previous TAF cycle there is probably slightly more concern that a few showers/storms could drift through the general vicinity of the terminals later this evening. That being said, confidence is still fairly low in this possibility, so am only hinting at it with a generic "vicinity shower" (VCSH) mention 03-06Z KEAR/04-07Z KGRI. Beyond this, have left the remainder of the period void of any official rain/thunderstorm possibility for now given low probability/low-confidence, but this is not a guarantee to remain the case in future issuances as various models hint that at least spotty convection could be in the area at some point during the daytime Wednesday (with perhaps better chances Wed evening just beyond this valid period). As for winds, no major issues anticipated. Aside from any possible thunderstorm outflow influences, direction should be fairly consistent from the south- southeast. Sustained speeds should prevail under 11KT through most of the first 15 hours, before picking up a bit through much of the day Wednesday with sustained speeds closer to 15KT and gust potential 20+ KT. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ UPDATE...Pfannkuch SHORT TERM...Mangels LONG TERM...Mangels AVIATION...Pfannkuch
Area Forecast Discussion
National Weather Service North Platte NE
637 PM CDT Tue Aug 11 2020 .SYNOPSIS... Issued at 313 PM CDT Tue Aug 11 2020 At 20Z, surface low pressure extended from far eastern WY south along the Front range of CO. Storms have already initiated east of this leeside surface trough into the western panhandle and near Akron CO. Isolated elevated still lingered over the central Sandhills. temperatures have risen above 90 near and west of Highway 83 to as warm as 96 at Imperial, with mid 80s further east. && .SHORT TERM...(This evening through Wednesday night) Issued at 313 PM CDT Tue Aug 11 2020 Tonight... Storms initially near and west of Highway 61 will spread east mainly across north central Nebraska. This has been indicated by the HRRR, RAP and NAMNest models. Further south across southwest Nebraska into Custer County, POPs were lowered to a slight chance or isolated coverage. All the activity should begin to diminish after 03Z and exit the eastern areas soon after 06Z. There is a Slight Risk for severe storms for areas west of Ogallala through Springview and a marginal Risk to the east. Damaging winds looks to be the greater threat, although large hail to 1 inch diameter also possible. Wednesday and Wednesday night... A disturbance currently in eastern Utah will reach the western Sandhills Wednesday afternoon. Strong heating with highs reaching the mid and upper 90s over the western Sandhills along with a surface dryline in place will be a focus area for storm initiation. MUCAPEs west of Highway 83 1500-2500 J/KG and 2500-5000 J/KG to the east, modest deep layer shear 20-25KT, and steep mid level lapse rates would support strong to severe storms soon after initiation. A slight risk for severe storms is forecast from southern Cherry County southeast across most of southwest and central Nebraska. This has consistently been indicated by the GFS and ECMWF the past few days. An organized thunderstorm cluster may form, with an increasing damaging wind threat southeastward during the evening. .LONG TERM...(Thursday through Tuesday) Issued at 313 PM CDT Tue Aug 11 2020 Thursday through next Tuesday... Thunderstorm development late Thursday afternoon is conditional, and contingent upon a fairly strong cap breaking. Forecast soundings indicate CIN weakening to 150 to over 300 J/KG while SBCAPEs range from 2500-near 5000 J/KG. Deep layer shear is also weak at 10-15KT. Not expected any thunderstorm development at this time, for a dry forecast. On Friday, a weak front will move through most of the area, with a slight chance for storms Friday evening across eastern areas. Saturday, a trough moving across the Northern Plains will bring a weak cold front into the area for afternoon and overnight chances. This will bring a cooldown to the 80s for Sunday through Tuesday. The period look mainly dry as northwest flow becomes established, from an upper ridge intensifying across the Desert Southwest and an upper trough deepens across the Great Lakes/Midwest. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 628 PM CDT Tue Aug 11 2020 Main concern for the TAF period will be convection chances at VTN and LLWS at LBF. Convection currently to the west of VTN should progress towards the terminal and arrive around 12/03Z. Have included TSRA though confidence is only moderate in direct impact to the terminal at this time. Will monitor for possible amendments as confidence grows. There could be LLWS at VTN and LBF overnight, but have only included it at LBF for now due to low confidence at VTN. The LLWS should end at LBF towards sunrise Wednesday. Otherwise, expect VFR CIGs, with the exception of a low possibility of near MVFR in any convection impacting VTN. && .LBF WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Roberg SHORT TERM...Roberg LONG TERM...Roberg AVIATION...Brown
Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
819 PM CDT Tue Aug 11 2020 .UPDATE... 819 PM CDT Only a couple of minor tweaks to the going forecast this evening, mainly to increase sky cover account extensive (but relatively thin) cirrus across the region, and to lower mins just a bit in a few of our typically cooler spots across north central IL. Evening surface analysis places high pressure across northwest and north central IL. Thermodynamic profiles are fairly dry, per ILX 00Z sounding and RAP analysis, with the exception of upper levels above about 350 mb where an extensive layer of high clouds has been streaming northeast from convection over western Missouri. While this layer fairly thin across the north/northwestern parts of the forecast area, have increased sky cover to partly/mostly cloudy especially for this evening. Should see a decrease in these high clouds across the northwest later tonight, as convection drifts east into the lower Ohio Valley. Also, lowered min temps just a bit into the mid-50s for a couple of our usually coolest spots west of the Chicago metro area. Afternoon dew points mixed to those values there this afternoon, and calm winds and eventually mainly clear skies later tonight should be favorable for decent radiational cooling. While some patchy shallow ground fog is possible in some spots, drier conditions tonight should prevent widespread fog from developing. Otherwise, going forecast looks to be in great shape, with pleasant weather continuing Wednesday. Updated forecast products available. Ratzer && .SHORT TERM... 259 PM CDT Through Wednesday night... With a drier airmass moving in behind yesterday`s impressive derecho, quiet conditions will continue through tomorrow as high pressure centers over the area this evening. Winds will becoming light and variable and low temperatures drop into the mid to upper 50s, with low to mid 60s in the metro. Some residual low-level moisture and expected cooling could result in some patchy shallow fog in low spots outside of the metro. Cirrus clouds will try to lift into the area from a system in southern Missouri, but any precip associated with this will remain to the south of our area. The surface high lifts northeast slightly into the upper Great Lakes with winds turning easterly during the day on Wednesday. Subsidence aloft and high pressure at the surface should help limit any precip chances through Wednesday. Temperatures during the day will be slightly warmer than today with highs in the mid 80s. East winds will result in cooler temps near the lake in the upper 70s. Petr && .LONG TERM... 259 PM CDT Thursday through Tuesday... Upper level ridge overhead will result in dry conditions into Thursday. There could be a few spotty diurnal showers so held onto some slight chances across our far southwest in the afternoon. A wave moves overhead Friday, but the instability and moisture axis looks to remain off to the west. Kept some low chance PoPs for Friday, but not expecting any significant weather from this. Highs will be fairly steady through the end of the work week with highs in the mid to upper 80s. The ridge breaks down as a trough moves into the upper Great Lakes with an associated cold front pushing expected to move through the area. This could lead to seasonably cool temperatures in the 70s toward early next week. Persistent northerly winds behind the front will result in gusty winds off of the lake and building waves and will need to be watched if this signal persists. Petr && .AVIATION... For the 00Z TAFs... Very quiet aviation weather over the next 24-30 hours, with no forecast concerns. Surface high pressure as developed into northwest IL early this evening, in the wake of yesterday`s severe storms and overnight cold frontal passage. Generally light variable winds are expected through tonight in the vicinity of the surface high center, with the exception of light easterly winds this evening across the Chicago terminals with the decaying diurnal lake breeze circulation. VFR conditions will prevail, with only a period of some cirrus this evening off of convection with a mid-level wave well to our southwest across Missouri. Similar conditions are expected Wednesday, with the high drifting slowly east across the region. Winds should become easterly with mixing after sunrise, with a slight lake push in the afternoon for the Chicago terminals. Dry thermodynamic profiles should result in mainly clear skies across the region. Ratzer && .LOT WATCHES/WARNINGS/ADVISORIES... IL...None. IN...None. LM...None. && $$ Visit us at Follow us on Facebook, Twitter, and YouTube at:
Area Forecast Discussion
National Weather Service Nashville TN
808 PM CDT Tue Aug 11 2020 .UPDATE... FOR EVENING DISCUSSION. && .DISCUSSION... Diurnal storms are fading away with all of Middle Tennessee dry at the moment. Short term models indicate that a couple scattered showers and storms are possible overnight, so slight chance PoPs were left in for the majority of the CWA. Some patchy fog will also be possible after midnight. Hourly PoPs were adjusted along with minor cloud cover changes. Otherwise, the current forecast looks good. && .AVIATION... 00Z TAF DISCUSSION. Lack of cumulus on satellite and recent HRRR model runs indicate SHRA/TSRA are over for today at airports with VFR conditions expected this evening. Fog developing overnight will bring MVFR/IFR visibility to CKV/MQY/CSV. Another round of SHRA/TSRA is anticipated on Wednesday afternoon at all airports. Light north or calm winds tonight will become light and variable on Wednesday, but predominately northwest. && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ DISCUSSION......Reagan AVIATION........Shamburger
Area Forecast Discussion
National Weather Service Shreveport LA
938 PM CDT Tue Aug 11 2020 .UPDATE... Made rather significant updates to the forecast for not only the remainder of the overnight period but into Wednesday as well in the POP department. This is by far a very uncertain forecast but all the ingredients are there for a possible heavy rainfall event overnight near and north of the I-30 Corridor and further south and east through the morning hours on Wednesday. Regional radar mosaic over the last hour or two has shown a decreasing trend to convection across our northwest zones but an uptick in convection just northwest of our region. At the surface, residual outflow boundary from earlier convection this afternoon continues to drift southward and as of 02z was located near a Monroe, Louisiana to Caddo Lake to near Pittsburg and Suphur Springs, Texas line. Convection for the most part this evening has been non-existent along the leading edge of this outflow boundary but instead, has been focused along an elevated boundary in the 850-700mb layer with the convection moving slowly south and east in northwest flow aloft. Forcing associated with this elevated boundary was also prevalent at 500mb in the form of an upper level trough which appears to be much stronger than earlier progs were suggesting. Couple these features with PWATS near 2 inches, MUCAPE values in excess of 1000J/kg across our northwest third and an expected 850mb jet near 30kts or so continuing to feed the trough and you have the ingredients for heavy rainfall. The 00z WRF is hinting at this scenario and is very close to the latest HRRR and earlier runs of the HREF and several of CAM runs leading to even greater support. The uncertainty is just how far south this convection will come through sunrise in the morning and then after sunrise. For this update, raised pops considerably across our northern zones through the remainder of the night through sunrise with a mention of locally heavy rainfall near and north of the I-30 Corridor during this time period tapering pops back to slight chance variety nearer to the I-20 Corridor of NE TX and N LA. Then for Wednesday, again increased pops to high end likely variety across our NE half, tapering pops back to slight chance near the I-20 Corridor of NE TX and low end chance variety nearer to the Northern Louisiana portion of the corridor. Also kept the heavy rainfall wording through the post sunrise hours on Wed across our northeast with slight chance to chance pops areawide by Wed Aftn. Update already sent...13. && .PREV DISCUSSION... /issued 442 PM CDT Tue Aug 11 2020/ AVIATION... Very uncertain terminal forecast through the next 24 hours as the spread remains wide as to convective evolution overnight and/or placement. Regional radar mosaic attm showing scattered pulse type convection northwest of the I-30 Corridor that has continued developing in the wake of a southward moving outflow boundary. Progs are split on the progress of this boundary southward to near the I-20 Corridor overnight before stalling with widespread convection developing in its wake, possible affecting the TXK/TYR/GGG and ELD terminals. For the 00z TAF package, will only prevail VCTS with the TXK terminal for now, delaying VCTS to closer to midnight for TYR/GGG/SHV and ELD. Added TEMPO groups for MVFR ceilings and MVFR VSBY restrictions through much of the late night and morning hours on Wed for these TAF sites as well before taking out any VCTS mention by late morning through the tail end of the TAF period. 13 && .PRELIMINARY POINT TEMPS/POPS... SHV 77 93 75 97 / 20 50 10 20 MLU 77 95 75 96 / 20 50 20 40 DEQ 72 91 71 95 / 80 70 10 10 TXK 74 89 73 94 / 70 70 10 10 ELD 74 91 72 94 / 40 70 20 30 TYR 77 97 76 99 / 20 30 0 0 GGG 76 95 75 97 / 20 40 0 10 LFK 76 98 75 100 / 10 30 0 10 && .SHV WATCHES/WARNINGS/ADVISORIES... AR...None. LA...None. OK...None. TX...None. && $$ 13/13
Area Forecast Discussion
National Weather Service Tulsa OK
953 PM CDT Tue Aug 11 2020 ...UPDATE... .DISCUSSION... Active day with pockets of very heavy rainfall (3 to 5 inches) noted across parts of southeast OK. Convection has been on the decrease over the past few hours, although recent HRRR runs suggest that showers/storms may fester across parts of far southeast OK well into the overnight hours. Will let the majority of the flash flood watch expire at 10 pm, but extended the watch for Pushmataha and Choctaw counties until 4 am. && .PRELIMINARY POINT TEMPS/POPS... TUL 72 93 73 96 / 10 10 20 10 FSM 71 92 72 96 / 30 30 10 20 MLC 72 92 74 95 / 50 20 10 10 BVO 70 91 72 93 / 10 10 20 20 FYV 68 89 69 91 / 20 20 10 20 BYV 68 91 68 93 / 10 20 20 20 MKO 70 90 72 93 / 10 20 10 10 MIO 69 91 71 93 / 10 10 20 20 F10 70 90 72 94 / 10 10 10 10 HHW 73 93 74 97 / 80 30 10 10 && .TSA WATCHES/WARNINGS/ADVISORIES... OK...Flash Flood Watch until 4 AM CDT Wednesday for OKZ049-053. AR...None. && $$ SHORT TERM...18