Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 07/17/21

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
925 PM CDT Fri Jul 16 2021 .UPDATE... Issued at 923 PM CDT Fri Jul 16 2021 Area of showers and thunderstorms beginning to move through Jones county at this hour, and may hold together long enough to make it to Lyman county. Have increased the POPs for the next few hours for that area. Otherwise, no changes made to the forecast at this time. && .SHORT TERM...(This Evening through Saturday Night) Issued at 228 PM CDT Fri Jul 16 2021 Convection chances/coverage are the main challenges for the short term. For this evening very evident s/w moving into central South Dakota will remain the main focus for convection into the evening hours. A developing LLJ may help maintain activity into the evening hours post sunset. The main threat for severe is probably located mainly west river, where a little stronger winds aloft are progged overtop higher instability. Latest HRRR maintains development of an MCS forming over southwest SD, and then moving southeast overnight. For the most part Saturday will be dry, but as moisture/instability increase again over the central/western part of the state, more storms are expected. Once again shear appears modest, but MLCAPE progs suggest pretty unstable atmosphere toward evening. CAMS are a tad more aggressive in bringing some convection east of the Missouri river during the mid to late evening hours Saturday. As mid-level heights build over the region this weekend, temperatures will be on the uptick. .LONG TERM...(Sunday through Friday) Issued at 228 PM CDT Fri Jul 16 2021 The tale of the extended period is very warm temperatures where highs will be in the 90s for most of the region most days. Sunday is the main exception as showers/thunderstorms may be ongoing from a passing shortwave. Once this system clears out by Sunday night, high pressure builds into the region. Combined with southerly flow at the surface, temperatures will shoot right back into the 90s for Monday through the remainder of the workweek for most areas. Conditions will be very unpleasant as daytime dewpoints will be in the 60s for most of the area through Monday and remain in the 60s for most areas east river for the remainder of the period. Breezy conditions are possible at times during the middle of next week. Combined with slightly lower RH values in the middle of the week, this will lead to elevated fire weather conditions for much of the forecast area. && .AVIATION...(For the 00Z TAFS through 00Z Saturday Evening) Issued at 624 PM CDT Fri Jul 16 2021 Terminals KABR,KATY,KPIR,KMBG For the most part, VFR conditions will prevail across the area tonight and Saturday. There is a small chance for some thunderstorm activity to affect the far southwestern part of the area later this evening, but this activity should remain south of KPIR. By mid to late afternoon Saturday, may see some scattered thunderstorm development over central South Dakota, but will not mention in the KMBG or KPIR TAFs at this time due to the uncertainty. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...None. MN...None. && $$ UPDATE...Parkin SHORT TERM...TDK LONG TERM...Telken AVIATION...Parkin
Area Forecast Discussion
National Weather Service Bismarck ND
944 PM CDT Fri Jul 16 2021 .UPDATE... Issued at 936 PM CDT Fri Jul 16 2021 The main show this evening has been a storm that formed near Beulah which has dropped south-southwest and is now passing between Richardton and Hebron. This storm has produced hen egg size hail, but has pulsed up and down in strength a few times. The area it has been moving through is a more or less north to south corridor of elevated instability, but it is getting into an area of a little less deep layer shear. With that said, it still remains severe though with the loss of shear intensity may be easing. For the remainder of tonight, still concerned with some thunderstorms developing with the low level jet increasing. Enough instability will be around for some storms to get strong, with maybe a severe storm or two. UPDATE Issued at 638 PM CDT Fri Jul 16 2021 Some storm shave developed over the southwest, though recently a new storm has developed near Hazen. The southwestern storms have remained tame as lower instability is noted over that area, but as you go east, instability increases until you reach near the Highway 83 corridor. High-res models have been increasing coverage some as we go through the evening and overnight over this aforementioned area, but with how crummy they did earlier in the day will have to wait and see a bit to see how this pans out. With that said, have expanded the low storm chances further east as we get into the overnight hours. && .SHORT TERM...(This evening through Saturday) Issued at 345 PM CDT Fri Jul 16 2021 Chances for thunderstorms increase this evening and then again overnight tonight for portions of western and central North Dakota. A few thunderstorms may become severe with quarter size hail and 60 mph wind gusts possible. Another round of thunderstorms is possible again late Saturday afternoon and evening. A building upper level ridge over a broad surface low, located over eastern Montana, was evident on water vapor imagery this afternoon with a series of weak impulses moving through the axis. At the surface, dew points have climbed into the mid 60s across central North Dakota, with a sharp drop-off in dew points near the Montana border. Coinciding with the eastward progression of the ridge, mid level lapse rates are steeping from west to east, with 7.5 C/km to near 8.5 C/km over the west. Moderate to strong instability is developing this afternoon with the overlap of richer boundary layer moisture and lapse rates aloft. Despite rising mid level heights with the building ridge, good agreement exists in the elimination of convective inhibition near the surface low over western North Dakota as the boundary layer mixes out this afternoon. Overall ascent is modest but convergence and differential heating should be adequate for some convective initiation. Effective bulk shear is on the weaker side for organized convection, but should be enough to combine with 1500-2500 J/kg of MLCAPE to encourage a few potentially severe thunderstorms. Quarter size hail and localized 60 mph wind gusts will be possible with stronger thunderstorms. Then overnight the focus for ascent shifts towards elevated based nocturnal initiation, on the nose of warm air advection in the 850-700mb layer. Though the various convection allowing model cores are scattered in placement, most are producing some sort of overnight convection. MUCAPE may remain high enough with cloud layer shear of around 30 kts to allow some storms to produce hail nearing severe criteria. After lingering convection Saturday morning, the persistent pattern may produce another round of thunderstorms near the western surface low in the late afternoon. A discrepancy in solutions remains between CAMs, though the main outlier continues to be the HRRR which keeps tomorrow dry compared to other available models. Forecast soundings across the board look uncapped for the most part, with the HRRR producing a deeper mixed boundary layer (a known tendency) which may be preventing initiation within the model. Thus the reasonable outcome is more likely thunderstorm initiation tomorrow evening, though with some question about coverage considering the mid-level height rises. Again the CAPE/shear parameter space should provide an environment for isolated severe thunderstorms if conditions align. Temperatures Saturday become hot in the afternoon with highs in the 90s across the west and central with a few points of the far west possibly reaching 100. .LONG TERM...(Saturday night through Friday) Issued at 345 PM CDT Fri Jul 16 2021 The persistence of above normal temperatures highlights the long term forecast period. Into next week, the upper level pattern is highlighted by the amplified ridge over the Rockies, with climatologically high mid- level heights over the Northern Plains. This pattern will maintain above normal temperatures with a few low predictability chances for convection as impulses run through the ridge axis. Each day will feature widespread highs in the 90s, with hottest temperatures in the west through mid-week. Several days of highs crossing the 100 F threshold are possible for some areas as well, for the west during the first portion of the period and then possibly in the central later in the week. Though forecast max heat indices remain below advisory criteria due to relatively lower humidity, the prolonged period of hot temperatures is still notable. && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) Issued at 638 PM CDT Fri Jul 16 2021 Isolated thunderstorms are possible over the area overnight. Have mentioned VCTS in the KDIK and KBIS TAFs where confidence is a bit higher. Over other locations, will withhold mentioning for now. Some storms may linger into the morning hours over the north. Thunderstorm chances return from west to east again Saturday afternoon. Did not mention this in current TAF package given there is still a fair amount of uncertainty on timing and coverage. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JJS SHORT TERM...AE LONG TERM...AE AVIATION...JJS
Area Forecast Discussion
National Weather Service Dodge City KS
608 PM CDT Fri Jul 16 2021 ...updated aviation section... .SHORT TERM...(This afternoon through Saturday) Issued at 111 PM CDT Fri Jul 16 2021 A mostly quiet weather night is expected across the FA. The main exception to this is across Hamilton and Kearny counties, perhaps up to Scott county and points southward. There will be a chance of mid evening storms in this area. Storms are expected to develop along the higher terrain of eastern Colorado and then slowly propagate to the south or perhaps south-southeast. Bulk shear is slightly stronger today around 30-35 kt. The main threats with the storms will be damaging convective outflows of 60-70 mph and heavy rainfall. Perhaps some hail too with the slightly stronger shear that is in place. Have the highest pops during the evening across Hamilton and Kearny counties to account for this anticipated storm evolution. It should be a mid to late evening event, so prior to 6 or 7 pm, much of the FA should remain storm free. Since anticipated storm motion is to the S or SSE, much of the rest of the area should be in the clear. There was a secondary concern of storms forming across the Nebraska panhandle and then drifting towards central Kansas, however, confidence on this actually occurring is low. Otherwise, the rest of the forecast is ho-hum weather. Overnight lows look to be seasonal with values mainly in the 60s. For Saturday, a mid level ridge starts to amplify across the Central Rockies. The net result is even weaker flow at the mid and upper levels of the atmosphere. PWATs will continue to remain over an inch, so there will be moisture and instability in place for storms. Confidence on exact placement of storms in the weak flow regime is low. As a result, have broad brush pops across the FA. Activity should remain isolated to widely scattered, so there is a higher chance you`ll remain dry than seeing a storm over you. Otherwise, near normal highs are expected with values in the 90s. .LONG TERM...(Saturday night through Thursday) Issued at 111 PM CDT Fri Jul 16 2021 The center of the mid level ridge on Sunday starts to head north during the day. This may help us with a slightly higher areal coverage of storms. The slight chance to chance pops looks reasonable for now. Temperatures will continue to remain near or perhaps a few degrees below normal to close out the weekend. It will still be warm nonetheless. For Monday, the mean center of the mid level ridge is still expected to be northwest of the FA. Again, a similar weather pattern is expected to continue with warm temperatures and isolated storms. As the ridge heads north, low level northeastern flow may develop on the eastern side of the ridge. This may help to keep temperatures more in the 80s versus the 90s for Monday through Wednesday. The main caveat to this is the intense July Sun, which could offset this cooler low level flow. Regardless if its in the 80s or the 90s, the end result is still the same with the Summer weather continuing for the rest of the extended period. There still is a trend in the long range models to shift the ridge closer to our area by the end of the business week. This could result in dry conditions and seasonally hot highs dominating. && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) Issued at 606 PM CDT Fri Jul 16 2021 The challenge for the overnight is where the opportunity exists for convection. The forecast area is downstream from ongoing surface based convection over eastern Colorado. The atmosphere will decouple with time this evening however steep mid level lapse rates and instability should support several model solutions which allow clusters of thunderstorms to continue southeast across the heart of west central and southwest Kansas. This shouldn`t offer much of a severe threat but rather locally moderate to heavy rains and frequent lightning. Hopefully The 00 model runs will offer more clarity for the convection late this evening and overnight as the HRRR at this time is at odds on location with everything else. && .PRELIMINARY POINT TEMPS/POPS... DDC 68 93 68 92 / 30 30 20 30 GCK 65 92 66 90 / 30 20 20 30 EHA 67 94 67 92 / 20 20 20 20 LBL 68 93 67 91 / 20 20 20 30 HYS 66 90 67 88 / 30 20 20 40 P28 70 93 70 91 / 10 20 20 40 && .DDC WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...Sugden LONG TERM...Sugden AVIATION...Russell
National Weather Service Hastings NE
629 PM CDT Fri Jul 16 2021 ...AVIATION UPDATE... .DISCUSSION...(This evening through Friday) Issued at 320 PM CDT Fri Jul 16 2021 Clouds continue to slowly diminish this afternoon. Temperatures have been a little slow to warm, but as there is more sunshine, they should rebound. Thunderstorms are expected to develop later this afternoon on the high plains, then move to the southeast during the evening hours. Models all have a little different location and timing for the thunderstorms, as well as the path that they will take. All of the models have the convection diminishing as it moves to the east, but just how far to the east does it get and what it looks like when it does get to the forecast area are a little questionable. Have kept some low PoPs mainly in the northwest and north through the night. A few of these storms could be strong, but should weaken as they get into the forecast area. There is a small chance there could be a few showers and thunderstorms in the far north/northeast during the morning hours on Saturday. Otherwise, clouds should diminish during the day on Saturday and temperatures warm into the 80s. The next upper level wave moves into the area Saturday night. This convection will also start on the high plains and move into the area during the evening and overnight, but this will be a little further to the east and models all put some convection across the forecast area Saturday night through Monday. Not expecting there to be precipitation all of the time through the entire weekend, but there could be some on and off thunderstorms. These have the potential to be strong to severe at times, but timing them is still a little bit of a challenge. Saturday night into Sunday night have the best chance for there to be rain and most locations should see some rainfall from this system. Temperatures through Monday will be mainly in the 80s. Monday night through Friday appears to be a dry period. An upper level ridge to the west builds into the area and an upper level low develops in the southern plains. Expect dry conditions as the ridge moves over and the temperatures should be on a steady increase from the lower to mid 80s on Tuesday to the lower to mid 90s by Friday. && .AVIATION...(For the 00Z KGRI/KEAR TAFS through 00Z Sunday) Issued at 625 PM CDT Fri Jul 16 2021 Main concern this period is whether or not the terminals will see some shower/thunderstorm activity overnight. Right now confidence is fairly low because based on model data, a lot will depend on what forms (or doesn`t form) over the NE Panhandle in the next few hours. If the HRRR is to be believed then both terminals could see some activity after about 08Z. Should things stay calm in the Panhandle, then most of the area will likely remain dry. Winds are expected to remain rather light and variable through the end of the period, and VFR conditions are expected to remain. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ DISCUSSION...JCB AVIATION...Shawkey
Area Forecast Discussion
National Weather Service Wichita KS
1001 PM CDT Fri Jul 16 2021 .UPDATE... Issued at 1000 PM CDT Fri Jul 16 2021 Isolated diurnally driven storms have waned across south central KS, or have shifted southwest into OK. But as the late evening continues, latest RAP model shows 850-700h moisture transport looks to gradually increase across south central KS. This will lead to renewed convection developing across south central KS, late this evening and overnight. Already seeing signs of this development, with some isolated showers/storms developing just to the southeast of KICT. Think this renewed convection is just the start, with widely scattered showers and storms expected to keep developing overnight. The moisture transport isn`t as strong as last nights, so do not think the storms will be as widespread as last night. Ketcham && .SHORT TERM...(This evening through Monday night) Issued at 349 PM CDT Fri Jul 16 2021 Main forecast challenge: Thunderstorm chances over the next few days. As of late this afternoon, a weak surface front extended from near the Oklahoma Panhandle across east-central Kansas to central Missouri. Will maintain a 20-30% chance of thunderstorms in south-central/southeast Kansas Tonight where modest 925-850 mb convergence is progged with higher precipitable water of 1.5-1.75 inches. Even though any storms that manage to develop are expected to be isolated to widely separated in coverage, they would be high-efficiency rainfall producers. Other convection clusters are expected to continue developing over the central High Plains through this evening, with a south-southeastward propagation overnight. Will maintain a 15-20% probability for thunderstorms in central KS for late tonight into Saturday morning, although better chances for storms should be over the High Plains. Otherwise not much change expected for Saturday-Saturday night with the front lingering over southern Kansas, with humid conditions and slight chances for a thunderstorm. The short-medium range guidance indicates that upper level high pressure will develop and strengthen over the Rockies Sunday into Monday, with a mean longwave upper trough in the eastern CONUS. A shortwave is progged to slide south-southeastward along the eastern periphery of the Rockies High, across the Central Plains Sunday into Monday. This shortwave will encounter anomalously high moisture across the Central Plains and should lead to higher chances of a thunderstorm complex or two moving through our forecast area. At this juncture, Sunday night appears to have the highest storm chances. This wave should also push the front southward out of Kansas by Monday. .LONG TERM...(Tuesday through Friday) Issued at 349 PM CDT Fri Jul 16 2021 Medium range models are in good agreement indicating that the Rockies upper-level high will tend to persist. After some modest relief from the heat and humdity early in the week, temperatures will slowly modify back to around seasonal climatology by Thursday/Friday. Will maintain dry weather during this period. && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) Issued at 821 PM CDT Fri Jul 16 2021 VFR conditions are expected for the first 6 to 10 hours. Lots of level moisture continues to linger across the forecast area, with this tropical airmass expected to linger into Sat as well. So as the early morning on Sat progresses, expect some MVFR cigs to develop across much of the forecast from 10-14z/Sat. Surface moisture remains high as well, which may lead to some MVFR vsbys developing across portions of central KS for Sat morning as well. Ketcham && .PRELIMINARY POINT TEMPS/POPS... Wichita-KICT 71 89 70 88 / 20 20 20 40 Hutchinson 69 90 68 89 / 20 20 20 40 Newton 69 88 69 87 / 20 20 20 40 ElDorado 69 88 69 87 / 20 20 20 40 Winfield-KWLD 70 90 70 89 / 30 20 20 40 Russell 67 90 68 88 / 20 20 40 40 Great Bend 69 89 68 87 / 20 20 30 40 Salina 68 91 68 90 / 10 20 30 40 McPherson 68 89 68 87 / 10 20 20 40 Coffeyville 69 88 70 89 / 30 20 20 30 Chanute 70 87 70 87 / 20 20 20 30 Iola 69 87 69 85 / 10 20 20 30 Parsons-KPPF 70 88 70 88 / 30 20 20 30 && .ICT WATCHES/WARNINGS/ADVISORIES... None. && $$ UPDATE...Ketcham SHORT TERM...JMC LONG TERM...JMC AVIATION...Ketcham
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
1022 PM CDT Fri Jul 16 2021 .UPDATE... Issued at 1022 PM CDT Fri Jul 16 2021 Updated for aviation discussion below. && .SHORT TERM...(This evening through Saturday night) Issued at 210 PM CDT Fri Jul 16 2021 Benign weather is expected this period as we remain under the influence of high pressure centered over the Great Lakes. Given the light winds and clear skies expected, to go along with a slight increase in surface dewpoints, did add a mention for some patchy fog tonight over south central and southeast MN up into western WI. This looks to be mainly confined to valleys and near bodies of water. Given the light south/southeast winds expected this period, expect smoke from Canadian wildfires to remain elevated and do nothing more than continue to offer us milky colored skies and colorful sunrises and sunsets. For highs tomorrow, stuck with something close to the NBM. It`s a couple of degrees warmer than today, which makes sense as little in the way of airmass change is expected, which means we`ll just be slowly warming things up on a daily basis. .LONG TERM...(Sunday through Friday) Issued at 210 PM CDT Fri Jul 16 2021 The extended period continues to look like a lot of nothing as far as active weather concerns, with the biggest thing of note being steadily increasing temperatures next week. The only chance we have of seeing any precipitation whatsoever would be with a back door cold front late Tuesday through Thursday, with the 12Z ECMWF much more apprehensive about the chance than the GFS/NBM. This front does already favor central MN and Duluth`s CWA instead of us, and I would not be surprised if subsequent model runs begin to remove this chance. We keep our northwest flow aloft, with temperatures reaching the upper 80s on Sunday, low 90s on Monday and Tuesday, with a chance for mid 90s in the metro and western MN on Wednesday/Thursday. Hazy skies will continue to remain a possibility due to upstream wildfires, however this will continue to remain an upper level feature and shouldn`t affect things at surface level. This trend of hot temperatures and lack of precipitation unfortunately looks to continue until the end of the month, with the large scale pattern not looking to change. && .AVIATION...(For the 06Z TAFS through 06Z Saturday night) Issued at 1022 PM CDT Fri Jul 16 2021 Main issue remains potential for fog late tonight. Light winds and maybe some residual moisture from the rain on Wednesday could lead to some fog for 2-4 hours, especially in eastern MN and western WI. Surface high pressure centered over eastern Lake Superior, with its influence extending almost to western MN, where return south- southeast flow is taking place. Also, smoke may eventually become more prevalent at the surface, so will need to watch for any reduced visibility similar to what happened last weekend. The HRRR smoke forecast indicates that to be a distinct possibility, but again, it is uncertain at this time whether visibility will be reduced. KMSP...There will probably be some fog in the Minnesota River valley in the morning, but otherwise, quiet weather is expected. Will have to watch to see if any of the smoke causes a visibility reduction on Saturday. /OUTLOOK FOR KMSP/ Sun...VFR. Wind SE 5-10 kts. Mon...VFR. Wind SW 5 kts. Tue...VFR. Wind SW 5 kts. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...None. WI...None. && $$ UPDATE...TDK SHORT TERM...MPG LONG TERM...TDH AVIATION...TDK
Area Forecast Discussion
National Weather Service Pocatello ID
151 PM MDT Fri Jul 16 2021 .DISCUSSION...Satellite imagery showing afternoon build-ups beginning across higher elevations of East Idaho early this afternoon. A few cells already developing into something the radar can see, and expect development to continue for the next several hours. Have maintained thunderstorm coverage in line with blend of the high-res models for the afternoon, with coverage dropping off after sunset. Dry low levels should be conducive for another round of strong gust potential. One more shortwave feature rotates through the Great Basin on Saturday, so East Idaho could see another round of afternoon/evening thunderstorms, mainly across southern portions of the region. Smoke has been less of a concern with good air quality across much of the Snake Plain and areas south. HRRR Smoke fields hold smoke to the central mountains, due to both fires there and being within the trajectory of the smoke from Oregon/California. Have allowed the HRRR smoke fields to populate that portion of the forecast without broad-brushing patchy values over the rest of the area. Moving into Sunday and Monday, center of upper high anchors over southwest Wyoming. South flow into East Idaho still indicative of a temperature increase. Interestingly, models are still picking up on a bit of mid-level moisture flow through the Great Basin for Sunday, and the 12Z NAM now showing a few thunderstorms Sunday afternoon. Numerical guidance still pushing 100+ temperatures for a large chunk of the area, with overnight temperatures trending upwards as well. Ensemble blends still trending below guidance, so kept the numbers a little above the blend, but below the higher guidance values. The additional moisture, and onset of the deeper monsoon moisture for Monday are a concern for limiting the top end of temperature potential. Heat Risk still quite elevated, so will keep the Excessive Heat Watch in place. Speaking of the monsoonal moisture, ensemble PWAT values spike up sharply in most if not all members starting Monday. Thunderstorm activity is expected to become more widespread through the middle of the week, potentially continuing through the end of the week as there is not much in the way of features to push the moisture stream away to the east. Temperatures are expected to moderate somewhat for Tuesday and beyond. DMH && .AVIATION... Have vicinity thunder at DIJ, BYI and PIH. Think coverage not as widespread as yesterday but will still have isolated development. Only have smoke visibility restrictions at SUN but keep at 6 statue miles. Other sites seem to have mainly gone to 10 miles or more for the most part and kept no visibility restrictions any longer. Winds generally light and 10 knots or less unless near any thunderstorm outflow. GK && .FIRE WEATHER... High Haines index red flag warning is in effect through tonight in zones 475 and 422. Mud Lick does not look as active today. Did not extend the warning so will let next shifts decide on Saturday into the weekend. Expect isolated thunderstorms today with some possible outflow over 30 mph but should not be as widespread as yesterday. Hot conditions will intensify over the weekend with the persistent Haines index of 6 continuing. Next week monsoonal flow will be the main feature and the threat for thunderstorms will be more extensive with a better chance for precipitation. GK && .PIH WATCHES/WARNINGS/ADVISORIES... Excessive Heat Watch from Sunday afternoon through Monday evening for IDZ051>059. Red Flag Warning until 7 AM MDT Saturday for IDZ422-475. && $$
Area Forecast Discussion
National Weather Service Portland OR
207 PM PDT Fri Jul 16 2021 .SYNOPSIS...A broad upper level trough remains over the Pacific Northwest through tonight. High pressure centered over The Great Basin will gradually expands north and west this weekend resulting in a gradual warming trend. Southwest flow aloft prevails the first half of next week, which will maintain dry conditions and slightly above normal afternoon temperatures. && .SHORT TERM...Tonight through Monday...IR Water Vapor imagery via GOES 17 shows a broad 550 mb upper level low in the Gulf of Alaska, with a broad upper level ridge across The Great Basin. These two systems will be the main synoptic systems which will dictate the weather through at least Monday. Model families are in good agreement that the low currently in the Gulf of Alaska will continue moving southeast along the Canadian coast, at the same time the upper level ridge across The Great Basin will build towards The Cascades. However, there are discrepancies within the model family ensembles as to just how these two systems will interact. The GFS, NAM, Canadian and NBM models have the upper level ridge becoming stronger, with the ridge axis pushing across the Cascades. The ECMWF and RAP on the other hand has the ridge axis staying further east of The Cascades, which would allow the low from the Gulf of Alaska to dig deeper into the Pacific NW. What should be noted is that both of these solutions will likely not result in any precipitation across the CWA. However, as the low moves closer to the Olympic Peninsula, there is a slight chance of some drizzle along the coast in the morning. Given that most model run are showing The Great Basin ridge becoming the more dominate feature through the start of next week, have chosen to keep daytime high temperatures in the mid to upper 80s inland and low to mid 60s along the coast. Also, expect the nighttime marine surges to become stronger as the low in the Gulf of Alaska slowly travels south. This will result in cloud cover along the Coast which will persist along the northern Oregon and southern Washington coast as well as push inland along the Columbia River Gorge towards the Portland/Vancouver metro area. One more thing to note is that the overall upper level flow will be from the south/southwest, this will result in some haze/smoke from the Jack Fire located in eastern Douglass County to impact portions of the Lane and Linn County Cascades for the foreseeable future. At this time am not expecting a significant wind shift which would cause smoke/haze from the Southern Oregon and Northern California fires to impact the Willamette Valley. /42 .LONG TERM...Monday night through Saturday...Little chance in the GFS and ECMWF deterministic runs and their ensembles through the upcoming week. The upper low along the Canadian Coast will continue to battle with the large-scale upper ridge firmly planted from the Great Basin to the Upper Midwest. Models show that the upper low will continue to get little closer to the Pac NW Tuesday and Wednesday, which will likely result in a slight cooling trend during the middle of the week. Models finally have the upper low moving into British Columbia Thursday. As we start getting into the latter part of the week, models have a period of zonal upper level flow developing Friday. However, models are showing the potential for a strong low from the Gulf of Alaska starting to exert influence across the Pacific NW as early as Sunday. The GFS has this system as a much stronger trough, while the ECMWF has a compact low over the same area. /42 && .AVIATION...Stable westerly flow aloft continues. Weakening front will push onshore later this afternoon, with another weak front arriving later tonight. Overall, not much in way of mid or upper clouds, but expect another surge of lower VFR and MVFR stratus along the coast this evening, persisting into Sat am. Will see patchy drizzle or light rain again, mainly north of Tillamook. Further inland, VFR this tonight, as residual scattered 3500 to 4500 ft clouds dissipate by 00Z. With the continued onshore flow, and remains of another front arriving later tonight, will see stratus with CIGS 030 to 040 reforming over the interior later this evening, mainly north of KSLE. This stratus will break up and dissipate later Sat am. For detailed regional Pac NW aviation weather information, go online to: KPDX AND APPROACHES...VFR with scattered clouds into early evening, then clearing. But, onshore flow continues, so will expect lower VFR deck reforming after 07Z. This stratus will persist into Sat am, breaking up after 18Z. && .MARINE...Weak front offshore will push onshore towards early evening. Another weak front farther offshore will push across the coastal waters later tonight. But, S to SW winds will stay under 15 kt for the most part, with seas 3 to 5 ft. High pres will rebuild across the offshore waters on Sat, and remain anchored in that position through the weekend into early next week. Meanwhile, thermal trough will hug the far south Oregon coast. This setup will maintain northerly winds on the coastal waters, with 10 to 20 kt. Strongest winds will be south of Cascade Head, and primarily in the afternoons/evenings. && .PQR WATCHES/WARNINGS/ADVISORIES... OR...None. WA...None. PZ...None. && Interact with us via social media:
Area Forecast Discussion
National Weather Service Phoenix AZ
459 PM MST Fri Jul 16 2021 .UPDATE... Updated Aviation section. && .SYNOPSIS... Abundant monsoon moisture will continue to bring daily chances for showers and thunderstorms across south-central and eastern Arizona with a tendency to favor the higher terrain of eastern Arizona. Storms will be capable of producing both locally heavy rain and strong winds. Temperatures overall will remain close to average through the middle of next week. && .DISCUSSION... Parts of Phoenix saw a fairly active start to the day this morning as isolated to scattered showers and thunderstorms developed across parts of the metro this morning. The majority of this activity was confined to central and eastern parts of the Valley, though a few spots in the west Valley did get in on some of the shower activity as well. Rainfall amounts generally remained below 0.25" inches for most locations while a few isolated locations saw upwards of 0.50" to locally close to 1" in parts of the southeast Valley. Officially, Phoenix Sky Harbor recorded 0.01" of rainfall this morning, bringing the total for the monsoon season so far up to 0.54". Currently, temperatures across the metro continue to warm up as current highs across the west Valley have climbed above 100 degrees and low to mid 90s across the east Valley (due to this morning`s rainfall). Meanwhile, visible satellite imagery shows mostly clear skies over the Phoenix metro this afternoon while strong convection continues over the high terrain to the east. The environment remains quite saturated across the region with 16.12Z PHX sounding recording a PWAT value of 1.92" and 1.93" on the 16.12Z TUS sounding, which are near or above record territory values for these sites on this date. Radar this afternoon shows strong convection over the high terrain east of Phoenix pushing through eastern portions of southern Gila County. Storms are slowly pushing toward the southwest under the influence of weak northeasterly steering flow. The main threat with these storms as they progress through Gila County this afternoon will be flash flooding, especially for burn scar areas. A Flash Flood Watch remains in effect until 11 PM MST for southern Gila County and portions of northeastern Maricopa County. Additional threats going forward through the afternoon across the high terrain will be strong, gusty winds and perhaps hail. Objective analysis this afternoon shows DCAPE values around 1,000 J/kg with the highest values situated to the west over south-central Arizona. HREF probabilities shows about a 50-60% chance for outflow winds to exceed 35 mph and less than a 10% chance for gusts to exceed 60 mph. Forecast uncertainty increases this evening with the westward progression of the ongoing convection into the lower deserts. Many of the 12Z HREF members show convection over Gila County dying off as it gets into the Valley. However, given the instability in place, with HREF guidance show MUCAPE values in excess of 1,000 J/kg, and little convective inhibition, the potential for getting showers and thunderstorms into the Valley will be possible with strong enough outflows. The HRRR continues to be one of the more aggressive CAMs with showing convection getting into the Phoenix area this evening. Strong, gusty winds, locally heavy rainfall, and lightning will be the primary threats with any convection that makes it into the metro area this evening. Additional shower activity can`t be ruled out going into tomorrow morning as well. .PREVIOUS DISCUSSION... Saturday will see a westward expansion of the monsoon moisture, mainly due to the increasing southeasterly flow from the upper level high repositioning itself to our northeast and the vort max/inverted trough continuing to track westward reaching southeast California Saturday afternoon. Subsidence behind the inverted trough is likely to limit storm chances across south- central Arizona initially on Saturday, while also bringing chances for some isolated storms as far west as southeast California. The stronger southeasterly flow may be enough for a complex of storms later in the day to track northwestward through southeast Arizona and maybe into south-central Arizona Saturday night, as hinted by the 06Z HRRR. A favorable southeasterly flow should persist across much of the region Sunday into Monday resulting in a northward expansion of monsoon moisture well into the Great Basin. Daily storm chances will exist across most of Arizona through at least early next week, favoring the typical high terrain areas each day. There will likely be at least a day or two where the lower deserts will be active, especially if the mid level easterly flow increases like what models continue to show for next Tuesday and Wednesday. Through next week, there are no signs of the monsoon letting up, in fact it will likely be more active than the current week has been. The temperature forecast is mostly an afterthought at this time, taking a backseat to our daily storm chances. NBM guidance has not changed much supporting near normal temperatures across the western deserts to slightly below normal across south-central Arizona. && .AVIATION...Updated at 0000Z. South-Central Arizona including KPHX, KIWA, KSDL, and KDVT: Thunderstorms have been slowly progressing westward across Gila and Pinal Counties. Given available moisture and associated instability, it is expected the outflows/gust fronts will be able to generate new storms progressively westward toward metro Phoenix. Key question is whether or not that propagation process will continue across the Valley floor this evening. Model guidance is something of a mixed bag with some indicating that process sustaining itself and others indicating storms falling apart away from the higher terrain. However, a mid afternoon sounding suggests that outflows will be able to overcome the remaining convective inhibition - if they are strong enough. There is relatively high confidence that outflows will overspread the Valley floor from the northeast and east roughly between 01Z and 04Z. In turn, it is anticipated that at least isolated storm activity will happen roughly between 02Z and 05Z. Thus, inserted TEMPO TSRA in the Phoenix area TAFs during that time. Anticipate ceilings will remain above 6kft AGL but it could be lower underneath a strong thundershower. Surface winds are anticipated to favor southeasterly but there may be a short time of variable directions but with speeds anticipated to be below 10kts. Then, outflows from the northeast and east are anticipated with gusts of 25-35kts. But, with subsequent storm development in the vicinity, there would be a period of highly variable and strong winds. It is highly dependent upon how robust that development winds up being which remains uncertain. Anticipate much more mild conditions by 06Z (if not sooner) with relatively light winds. Southeast California/Southwest Arizona including KIPL and KBLH: Winds will continue to favor south and southeasterly directions tonight and Saturday. At KIPL, anticipate a period of south- southwesterly this evening along with some gusts of 15-20kts before resuming southeasterly. Anticipate little cloudiness though there could be some cirrus from thunderstorm remnants emanating far to the east. && .FIRE WEATHER... Monday through Friday: Temperatures will generally be near seasonal averages as monsoon moisture remains in place over the region. Storm activity is anticipated to spread as far west as southeast California by early next week. Any storms that form will have good potential to produce wetting rain. Threats from storms will continue to involve locally heavy rainfall and flooding while an increase in strong gusty winds looks possible starting Sunday or Monday. Significant flooding may be experienced on previously burned areas of Gila County. Min RH levels are expected to remain in the 20-30% range most areas (30-50% higher terrain of south-central AZ). Max RH levels will be 35-60% most places (60-90% higher terrain of south-central AZ). Apart from thunderstorms, winds will favor familiar diurnal patterns. && .SPOTTER INFORMATION STATEMENT... Spotters should follow standard reporting procedures. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...Flash Flood Watch until 11 PM MST this evening for AZZ545-547- 552-555>558-560>563. CA...None. && $$ DISCUSSION...Smith PREVIOUS DISCUSSION...Kuhlman AVIATION...AJ FIRE WEATHER...Smith/AJ/Kuhlman
...Update to aviation forecast discussion...

.DISCUSSION... Issued at 350 PM CDT Fri Jul 16 2021 Cloud cover has been a little slow to dissipate, but per satellite it has been scattering more quickly in the last hour or so and should continue to do so this afternoon. As a result temperatures are still only around 80 degrees, but with increasing sunshine the next few hours they should rebound to the mid 80s, a few degrees warmer on the southwest edge of the CWA. Main challenges for this forecast package are timing and placing the weak shortwaves and associated shower/storm chances within the northwest flow rounding the edge of the upper ridge that remains stuck over the southwest US. Generally speaking, model guidance appears to have backed off on precip chances through tomorrow, at least for our area. The best chances this evening and tonight look to remain in southeast KS where a weak frontal boundary hangs around, although a few CAMs bring some storms pretty close to our east central KS areas. Also won`t completely rule out some fog redeveloping in eastern KS close to sunrise as forecast soundings keep enough BL moisture with morning lows close to crossover temps, but this could end up being mainly stratus for a brief period in the morning. RAP soundings seem to be more aggressive with fog, so will need to continue monitoring trends for better consistency. The next wave coming out of NE tonight into tomorrow appears to keep the better forcing toward central KS into the morning hours, with only slight chances for storms through the afternoon. There may be just enough of a cap for the majority of the area to preclude any precip, but have maintained small PoPs along the southwest edge of the area where it looks just a bit weaker. Rain chances improve somewhat Sunday into Monday with the next perturbation, which looks to be a bit stronger and more focused over northeast KS. As these disturbances move through the flow, the ridge will continue to amplify over the western US and eventually the axis should move east toward the Plains. This keeps a dry forecast for the rest of next week beyond Monday. These rising heights will allow for a slight warm-up into the end of next week, but in the meantime expect temps to hold fairly steady with highs in the 80s and lows in the 60s. && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) Issued at 630 PM CDT Fri Jul 16 2021 VFR conditions now through at least part of the overnight period. There appears to be a good enough level of confidence in a few hour period where at least patchy fog develops and could impact the terminals through 12Z time frame and through 13-14Z before scattering out and lifting to a stratus deck that lingers into the early afternoon. && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ DISCUSSION...Picha AVIATION...Drake
Area Forecast Discussion
National Weather Service Las Vegas NV
820 PM PDT Fri Jul 16 2021 .SYNOPSIS...A brief dry period for most of the area tonight and Saturday before showers and thunderstorms begin to return on Sunday and remain a concern through the week. More seasonal temperatures expected through the period as well. && .UPDATE...Thunderstorm activity is drawing to an close this evening as the sun sets. At 8 pm, a cluster of storms east of Phoenix remained quite active. The HRRR brings an outflow boundary generated from this activity into southern Mohave County after 9 pm this evening with gusty winds of 20-30 mph. The winds move north along the Colorado River Valley and across southern and central Mohave County into Clark County by 1 am where the boundary is then forecast to dissipate. There is also a small chance that a thunderstorm develops along the boundary as it moves into southern Mohave County but confidence is low. Elsewhere in our area, expect a mostly clear and quiet night. The forecast with an updated overnight period is out. && .PREVIOUSLY ISSUED DISCUSSION... .SHORT TERM...Tonight through Sunday The next few days will see reduced thunderstorm activity for a large portion of the CWA. Mohave County being the exception. This will essentially be one day of rest before a surge of moisture and upper level disturbance from the south brings the threat of more impactful thunderstorms on Sunday. Activity may begin as early as Sunday around midnight in southern portions of the CWA around Lake Havasu, Laughlin and Bullhead City. This moisture flows north during the day bringing a chance of thunderstorms with increased rain rates to the entire area by Sunday afternoon. .LONG TERM... Much of this afore mentioned moisture will loiter over the area on Monday through the end of the week. However, Monday through Wednesday are likely to see more isolated development across the area due to lack of real forcing and no reinforcing moisture surges from the south. This changes some on Thursday through Friday. Most ensemble model guidance are indicating a healthy moisture surge on these days. Storm activity will pick up as a result and we are likely to see an impactful end to the work week. && .FIRE WEATHER...Dry conditions along the eastern Sierra combined with potential thunderstorm development on Sunday prompted the issuance of a Fire Weather Watch for Fire Weather Zone 226 Sunday through Sunday night. Fuel values are historically dry in the Sierra. There are also a number of wildfires ongoing. With potential effects on resources the early notification of these conditions is warranted. && .SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report any significant weather or impacts according to standard operating procedures. && $$ UPDATE...Salmen DISCUSSION/AVIATION...Lericos For more forecast information...see us on our webpage: or follow us on Facebook and Twitter