Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 09/20/20

Area Forecast Discussion...UPDATED
National Weather Service Albuquerque NM
524 PM MDT Sat Sep 19 2020 .AVIATION... 00Z TAF CYCLE VFR prevails, winds calm overnight becoming terrain driven. Some haze still exists over parts of far eastern NM, mixing down to the sfc creating some hardly mentionable vis reductions. 24 && .PREV DISCUSSION...300 PM MDT Sat Sep 19 2020... .SYNOPSIS... Near to above normal temperatures and dry conditions will prevail through the weekend. A slight chance of showers and thunderstorms will favor the northern mountains each day through Monday, but little to no measurable precipitation is expected. Erratic and gusty winds will be possible with any storms that do develop. A back door front will dive into northern New Mexico Tuesday and progress southward into Wednesday, bringing the possibility of showers and thunderstorms to north central New Mexico. Otherwise, hazy skies will continue as smoke from western coast wildfires continues to filter into the state. && .DISCUSSION... SHORT TERM...(TONIGHT THROUGH SUNDAY NIGHT)... Upper high center has shifted to the south, with westerly winds aloft across northern New Mexico. Breezy to windy conditions were apparent over northeast New Mexico as well. Areas of haze from wildfire smoke will persist, with the HRRR Smoke model indicating the southeast third to half of the forecast area will be most affected. Similar to Friday afternoon, cumulus clouds have developed over the northern and some of the western high terrain this afternoon but no cells have been detected by radar as of this writing. Any that do develop should move to the east and will be mostly dry with gusty winds. Forecast models have reined in the small amounts of rain forecast over the northern high terrain on Sunday, thus Sunday afternoon may be similar to today although any cells will move more slowly to the east as the upper high starts to build back over New Mexico. Temperatures will be warmer than normal for most locales. LONG TERM...(MONDAY THROUGH SATURDAY)... Dry conditions and warmer temperatures will kick off the work week, with highs reaching near to several degrees above normal. Weak upper level disturbances may help to invigorate precipitation chances on Monday, but dry air will persist at lower levels. Little to no measurable precipitation is anticipated from this activity, but erratic gusty winds from virga will be possible. Despite the forecast of Tropical Storm Beta pushing inland earlier next week, little moisture is expected to reach the Land of Enchantment. However, an embedded disturbance in the eastern periphery of the ridge is expected to drop down Tuesday into north central NM. A backdoor front will then prog south into central and east central NM by Wednesday night. This will result in an increase in thunderstorm potential across the northern mts and eastern plains during the mid week. The upper level ridge will build and sustain over the western CONUS before centering across the Four Corners region on Thursday. Uncertainty lies after the ridge sets up, as a trough begins to move inland off the California coast. Models differ on the timing of these features and how exactly the trough will affect the position of the ridge. Nonetheless, dry conditions look to persist into the weekend, with temperatures remaining above average. 12 && .FIRE WEATHER... Upper high centered over southern New Mexico this afternoon with westerly winds aloft over northern New Mexico. The upper high builds back over New Mexico Sunday and Monday, with potential for some mid level moisture to work into the northwest third of the state Monday and Tuesday. A few dry showers and possibly a short lived thunderstorm with gusty winds will be focused over portions of the western and northern mountains this afternoon as well as Sunday afternoon. Best chances for localized wetting rain will be with convection over the northern mountains Monday and Tuesday. Most cells this afternoon and Sunday would move to the east, although more slowly on Sunday. There will be areas of fair to poor ventilation central and west Sunday and Monday. Ventilation improves overall Tuesday and Wednesday. Vent rates plummet Thursday and Friday as a strong ridge builds overhead, bringing dry weather. Temperatures will be near to above average. Areas of poor to fair overnight humidity recoveries are forecast over portions of the Rio Grande Valley westward Sunday night through Thursday night. && .ABQ WATCHES/WARNINGS/ADVISORIES... None. && $$
Area Forecast Discussion
National Weather Service Bismarck ND
945 PM CDT Sat Sep 19 2020 .UPDATE... Issued at 929 PM CDT Sat Sep 19 2020 Current forecast looks good. An occluded/cold front in eastern Montana is forecast to move to central North Dakota Sunday afternoon. At 02z/9 pm CDT regional radars show showers in Montana that correlate well with the RAP frontogenetic forcing along the front. East of this area, in far western North Dakota, we believe any radar return is mostly virga. So the better shower threat should come late tonight and Sunday as the baroclinic zone moves east. However, many CAM models, including the HRRR, track the forecast showers north into Canada tonight, probably along the track of an embedded short wave in the h500 flow. So overall the POPs on Sunday will be low for North Dakota. This is how the current forecast handles it so no changes needed. UPDATE Issued at 609 PM CDT Sat Sep 19 2020 Upper level smoke/haze continues across west and central North Dakota, but without significant visibility restrictions. An upper trough will approach from the west tonight, and this will bring a chance of showers, and possible thunderstorms to western North Dakota. The main F-G forcing moves into the region Sunday morning, so main threat of showers will be late tonight west into the central. But without significant moisture, we will leave the POPs low. Current forecast looks good. && .SHORT TERM...(This evening through Sunday) Issued at 246 PM CDT Sat Sep 19 2020 Slight chances for scattered showers and isolated thunderstorms highlights the short term forecast. This afternoon, surface height falls were ongoing as a surface low, currently placed in southeast Montana, slowly moves northeast. Aloft, the base of a negatively tilted trough is located over western Montana, as seen in water vapor imagery, with shortwave ridging ahead of the trough centered almost directly over North Dakota. As both features and the associated surface cold front move towards the forecast area, the chance of showers and a few isolated thunderstorms begins late this evening in western North Dakota, expanding east through the night. Chance of precipitation is rather low at this point, with modeled soundings continuing to show a mid-level dry layer that will likely keep some precipitation from making it to the surface. Steep mid- level lapse rates and instability values up to 500 J/kg support the mention of thunder, but still expecting just a few isolated, non-severe thunderstorms at most. This chance of showers and thunderstorms pushes east along the initial frontal boundary, ending in the James River Valley tomorrow morning. High-res models want to then bring some wrap around showers and possibly a few thunderstorms in the west and north central Sunday morning and afternoon as the center of the low moves over. Still not seeing much QPF-wise, so guessing that these will be very hit or miss, with any chances for precip quickly decreasing through the late afternoon and into the evening. Expecting it to be windy on Sunday in the wake of the frontal passage, with cold air advection and a well-mixed boundary layer. Winds will be strongest in western North Dakota, with sustained westerly winds around 25 to 30 mph, compared to only 20 mph in central North Dakota, and 15 mph in the James River Valley. Smoke aloft is thicker than it has been for the past few days, with a few surface obs in western North Dakota reporting visibility around 7 to 8 miles. However, the HRRR-smoke model shows substantial clearing of smoke aloft as this system rolls through and flow turns west-northwesterly. Because of this, opted to not extend haze any further past tonight. .LONG TERM...(Sunday night through Saturday) Issued at 246 PM CDT Sat Sep 19 2020 The extended forecast is highlighted by mostly dry weather and above average temperatures. As precipitation chances end Sunday night, we return to quiet and warm weather, with forecast highs on Monday in the mid 70s to lower 80s as flow aloft becomes more zonal. Tuesday currently looks even warmer, with highs in the low to mid 80s, but there`s still some uncertainty in whether smoke aloft returns to the area, which has limited high temperatures this past week. There is a slight chance for some showers and a thunderstorm or two late Tuesday into Wednesday morning, as a weak shortwave and surface cold front push through the forecast area. This looks to be the only real chance for precipitation through the end of the week, and even then it`s rather unimpressive, with the 12 UTC suite of models showing very little QPF, and latest GEFS plumes only have a few members at each site showing any QPF. In the wake of the cold front, expect Wednesday to be a bit cooler, before broad ridging returns and we warm back up for the end of the work week. Some uncertainty remains in how warm we will get for Friday and Saturday, seen with the increasing spread in 1 standard deviation for National Blend high temperatures. There are some hints that we`ll have a relative cool down as we head into next week, both in NBM probabilities and CIPS extended analogs. && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) Issued at 609 PM CDT Sat Sep 19 2020 VFR expected. A weak cold front will move from Montana to eastern North Dakota during the forecast period. The front will bring a wind shift from teh southeast to teh west. Otherwise, scattered showers, and an isolated thunderstorms are possible later tonight and Sunday. We mentioned some low level wind shear at KJMS between 07-12z. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...WAA SHORT TERM...MJ LONG TERM...MJ AVIATION...WAA
Area Forecast Discussion
National Weather Service Des Moines IA
635 PM CDT Sat Sep 19 2020 .DISCUSSION.../Tonight through Saturday/ Issued at 241 PM CDT Sat Sep 19 2020 General Summary... The 7 day forecast continues to be devoid of major widespread issues. Windy conditions will prevail today and especially Sunday, when southerly wind gusts up to around 40 mph will be possible across portions of northwest Iowa. Temperatures will continue to slowly rise through the weekend and to start the week, yielding widespread highs in the low to mid 80s by Tuesday. Precipitation chances continue to be scant at best, only clipping northern Iowa Sunday night and Wednesday night. Additional Details... The main concern within the forecast period resides at the beginning of it, revolving around strong winds and elevated fire weather. As the surface high continues to slowly push eastward across the southern Great Lakes region, low pressure will continue to build in to the northern Rockies front range and Northern Plains ahead of the pivoting PNW upper level wave. Increasing surface pressure gradient and deeper mixing has already yielded breezy southerly wind conditions across portions of eastern South Dakota, eastern Nebraska, southwest Minnesota, and northwest Iowa. Majority of winds have fallen in line with hi-res soundings, yielding sustained winds predominantly in the 10 to 20 mph range with gusts 20 to near 30 mph within the state. Winds will peak over northwest Iowa Sunday afternoon with expected 20 to 25 mph sustained and gusts 30 to 40 mph. Do not anticipate need for a wind advisory with current available guidance and soundings, through would not surprised to see a couple locations briefly meet advisory gust criteria. Smoke will continue to linger aloft, obscuring sky conditions. The large scale upper level pattern will remain fairly conducive for at least some additional smoke to stream across the area into the week, but fortunately should also see overall concentrations/obscuration reduce, as depicted in the extended HRRR Smoke runs and extrapolating based on synoptic model flow patterns. Some minor concentrations may reach the surface, but does not appear to be enough to raise concerns for visibility restrictions or hazardous air quality. The same story also continues on the temperature and precipitation front. As the PNW upper wave continues its pivot and trek northeastward into Canada over the next 24 to 36 hrs, amplified ridging will continue to move across the region. That plus the increased southerly flow will work in tandem to boost highs into the upper 70s to lower 80s Sunday and widespread low to mid 80s for much of the week. With the PNW wave trekking into Canada, the bulk of the forcing will remain north of the area, with the best opportunity for anything across far northern Iowa near a weakening boundary as the LLJ increases Sunday night. Do not hold your breath though, showers likley to be spotty and will lack ability to provide substantive rainfall. Dry conditions will then prevail through mid-week within broad upper ridging/zonal flow. Early in the week, a big upper low will slide into the Gulf of Alaska, and ejected short wave energy is slated to affect the area Wednesday night in the form of an open upper level wave and surface low. This will be our best chance for precipitation, albeit not a great one. The core of the lift and precipitation chances continues to be anticipated north into Minnesota, leaving our best chances along/near the surface front, yielding low end shower chances at this point within the forecast. && .AVIATION.../For the 00Z TAFS through 00Z Sunday evening/ Issued at 635 PM CDT Sat Sep 19 2020 Widespread VFR conditions to persist for entire forecast period. Smoke layer will continue at or above 20kft. Surface winds will be from the south to southeast and quite gusty by Sunday afternoon. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ DISCUSSION...Curtis AVIATION...Cogil
Area Forecast Discussion
National Weather Service Grand Forks ND
1016 PM CDT Sat Sep 19 2020 .UPDATE... Issued at 1012 PM CDT Sat Sep 19 2020 No changes to the forecast this evening. Using the vertically intergrated smoke from the HRRRx it is doing a good job and at 00z the thicker smoke area was just entering Grand Forks. That was noticed at sunset. It has the high level smoke overspreading the area overnight into Sunday....though diminishing behind a front from west to east late Sunday aftn/night. 00z models coming in show very little in terms of precipitation...some CAPE exists but smoke will be dense enough so that the high temps given by model data of near 80 will not be achieved and therefore CAPE will be less. Plus there will be considerable high level clouds and some mid level clouds as well. southeast winds will keep temps much milder than past nights with lows mostly in the 50s. UPDATE Issued at 658 PM CDT Sat Sep 19 2020 Thicker smoke shown nicely on visible pic heading slowly northeast and this will spread over the area by morning. HRRR smoke forecast products indicate a hazy/smoky sky Sunday. There will also be high clouds increasing overnight and remaining over the area Sunday. Some mid clouds too along eastward moving front. This will mean Sunday will be a cooler day than today. Also windy Sunday with winds in the 15-25 kt range. && .SHORT TERM...(This afternoon through Sunday night) Issued at 328 PM CDT Sat Sep 19 2020 Minimal impacts from weather expected through the short term periods, with main focus on complications from smoke and eventually isolated showers/storms (weaker) on Sunday. Regarding smoke aloft: Smoke aloft has remained within the diffluent region behind ridge axis where flow is more from the southwest aloft, and has been slower to overspread our CWA/impact temps. This has resulted in highs a bit warmer than forecast closer to what original NBM had pre smoke-adjustment. Cold front Sunday should scour out smoke and mid level clouds will eventually have more of an impact on temp trends than smoke later in the day. Still some suppression of highs is still possible (difference between upper 70s and low to mid 70s). Tonight-Sunday night: Negatively tilted trough axis eventually shifts across North Dakota and northwest MN west to east late tonight through Sunday evening, with a cold front midday through the afternoon Sunday. Strong signal in forcing aloft and steep mid level lapse rates/elevated instability axis of 500-1000 J/KG raises possibility of thunderstorms along/ahead of frontal zone. Convective temps will be in the lower 80s and even if smoke/cloud cover impacts are minimal it may be difficult to overcome the CAP. Considering limits of low level moisture advertised and strong CAP even elevated storms would be weaker despite the forcing/increasing deep shear profiles. HREF/NBM/GEFS show very weak and isolated signal in our CWA for showers or weaker thunderstorms through Sunday evening. There is a secondary lobe of positive vorticity shown to rotate along the International border in ND, closer to the main upper low and cold pool aloft. This activity would likely be tied more to diurnal heating (assuming there is post frontal clearing pre-sunset) and CAPE would be significantly lower in the post frontal air mass. I have low confidence in any one location observing measurable precip late tonight-Sunday evening, but it was reasonable keeping mention in forecast. If there are a few showers/storms they should be isolated and weaker in nature. .LONG TERM...(Monday through Saturday) Issued at 324 PM CDT Sat Sep 19 2020 The main story for next week is the very good chance of above normal temperatures through the majority of the week with some days possibly bringing a summer-like warmth. Climatologically speaking, normal temperatures range from the low 40s to mid 60s during this time of year. Expected temperatures this week range from the 50s to 70s, some days possibly into the 80s. Guidance supporting this claim are the strong signal of ensemble probabilities over 60% for anomalously warm temps aloft moving out of the continental west underneath quasi-zonal upper flow through mid week shifting towards upper ridging over the central CONUS by late week. NAEFS percentiles brings H7-H8 temps into the 90th percentile range over the Northern Plains, more notably late Tuesday and into next weekend. This conceptually makes sense as deterministic guidance and numerous ensemble members bring a thermal ridge over the region ahead of one or more weak cold fronts. The only fly in the ointment to hinder maximizing temp potential will be the chance for smoke aloft to prevent full diurnal heating. While mid and upper level flow does source air mass from the western CONUS where numerous fires still exist, the potential for smoke over the area will remain unknown outside of the 24-48 hour window. With the passage of the aforementioned cold fronts, there will be some chance for scattered thunderstorms, although confidence is low in this potential due to warm temps aloft and meager moisture return into the Northern Plains providing decent capping inversion. Additionally, a few breezy days are anticipated just ahead and behind the cold fronts, particularly post frontal winds out of the northwest and west on Monday. && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) Issued at 658 PM CDT Sat Sep 19 2020 Haze/smoke will spread northeast tonight. There will also be an increase in high level moisture ahead of the 500 mb trough which will move in Sunday aftn. Overall VFR conditions, as dont expect vsbys to be impacted blo 7 sm but overall conditions not as clear as today. Gusty south winds 15-25 kts, gusts over 30 kts in the RRV. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...None. MN...None. $$ UPDATE...Riddle SHORT TERM...DJR LONG TERM...CWJ AVIATION...Riddle
Area Forecast Discussion
National Weather Service Marquette MI
802 PM EDT Sat Sep 19 2020 .SHORT TERM...(This evening through Sunday) Issued at 346 PM EDT SAT SEP 19 2020 Water vapor imagery and RAP analysis show a mid-level trof over the Pacific NW into the northern Rockies, a ridge shifting out over the Plains and a trof over eastern N America. A fairly well-defined shortwave diving into the departing eastern trof is skirting ne Lake Superior. This wave has supported -shra across northern and eastern Lake Superior today. SW edge of this pcpn has brushed the tip of the Keweenaw and Luce County with sprinkles/-shra. Otherwise, clouds have dominated across the northern and eastern fcst area today with skies trending to mainly sunny toward the WI/MI stateline. Temps range from the 50s under the clouds to the low/mid 60s where skies are mostly sunny. Some -shra or sprinkles will continue over the far eastern fcst area for a few more hrs in association with the aforementioned shortwave diving se into the departing eastern N America trof. Otherwise, with the pattern progression, healthy height rises will occur across the Upper Lakes as the the Plains mid-level ridge shifts e, arriving over the fcst area during Sun. This will support dry weather and clear to partly cloudy skies. Where winds become more decoupled tonight, interior central, temps will fall toward 40F. Temps will range up to around 50F near Lake Superior. Under waa on Sun that pushes 850mb temps to 10C e and 14C w, high temps will reach the 60s across the board. Temps will top 70F at some locations over the w under approaching thermal ridge. Winds will become breezy on Sun as pres gradient tightens btwn 1035mb high pres to the e and sfc trof moving across the northern Plains. Fcst soundings indicate building mixed layer will support gusts easily to 20-30mph. Gusts to 30-35mph are expected over the w into the n central. Wouldn`t take much increase in mixing heights to increase gusts further. The southerly winds up Lake MI on Sun will lead to a mdt to potentially high swim risk for the beaches of Schoolcraft County. .LONG TERM...(Sunday night through Saturday) Issued at 429 PM EDT SAT SEP 19 2020 Current mid-level pattern shows a pseudo-omega geopotential height pattern with a troffing over the Great Lakes that brought the blo- normal temps we saw this week and another trof moving inland over the Pacific NW with ridging between the two. By the start of the longterm period, this ridge shifts east over the Great Lakes as the current trof over the Great Lakes moves to the Atlantic Coast where models and NHC have it phasing with Hurricane Teddy at the start of next week. After Teddy moves north towards Atlantic Canada, the ridge begins to shift east over towards New England and the central CONUS flow becomes less amplified. Heading into the second half of this upcoming week, models suggest a shortwave to move through the Upper Great Lakes region Wednesday night into Thursday, which looks like our next legitimate shot at widespread mentionable precipitation. Overall, temperatures look to stay near or above normal for the longterm period with troffing and negative height anomalies over the Pacific forcing downstream ridging and positive height anomalies over the CONUS, favoring the above normal temperatures. A shortwave trof moving through Canada to the north will bring a sfc trough over Upper Michigan bringing just a slight chance of some showers. Model soundings aren`t as promising as some raw model output suggests, so did lower the PoPs some from the going fcst, keeping just the slight chance PoPs across the west half Sunday night, and over the Keweenaw Monday morning. With this trough, a 50kt LLJ will also pass over Upper Michigan, which should keep things windy on Monday, and uncertain on the wind over night. High- res models certainly suggest gusty conditions to linger across the higher terrain and and downslope-favored areas as often seen with the WAA regimes. Increased the marine winds as well during this period, some uncertainty but increased them manually using top of BL winds. Breezy conditions diminish Tuesday with a ridge of high pressure moving through. With warm return flow, above normal temperatures are expected with dry conditions. The next shot at precipitation comes Wednesday night into Thursday as a shortwave trough and associated cold front pass through the UP. Have left thunder chances out of the fcst for now, but there is some modeled CAPE. Models show pretty good agreement in timing of this wave, but left the NBM chance PoPs for now considering it is still on day 5. && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) Issued at 758 PM EDT SAT SEP 19 2020 With dry low-levels persisting, VFR conditions will prevail at KIWD/KCMX/KSAW thru this fcst period. During Sun morning, winds will become gusty to 20+kt at all terminals with a further increase in winds during the afternoon. && .MARINE...(For the 4 PM Lake Superior forecast issuance) Issued at 346 PM EDT SAT SEP 19 2020 Tightening pres gradient btwn rather strong high pres over southern Quebec/New England and low pres moving from Saskatchewan to Hudson Bay will lead to brisk southerly winds over much of Lake Superior for the next couple of days. Typical for this wind direction, the strongest winds will occur mainly over the e half of Lake Superior. Winds tonight/Sun should mainly be under 20kt over the w and 20-25kt over the e. Winds of 20-30kt will be common Sun night/Mon, again strongest over the e where a few gale gusts may also occur at some of the high obs platforms. Pres gradient will then quickly slacken, resulting in winds settling back to under 20kt Mon night and then to under 15kt on Tue as a high pres ridge arrives. Winds will increase a bit on Wed, but remain under 20kt. There may be a further increase in winds on Thu in the wake of a cold front, but trends are toward a weaker front and thus weaker winds with its passage. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... None. Lake Superior... None. Lake Michigan... None. && $$ SHORT TERM...Rolfson LONG TERM...JAW AVIATION...Voss MARINE...Rolfson
...Updated Aviation Forecast Discussion...

.DISCUSSION... Issued at 325 PM CDT Sat Sep 19 2020 Main forecast problem is wind in the short term. Northwest upper flow over the region will switch to westerly and southwesterly as ridge builds to our south. Near surface pressure gradient will continue through Sunday, meaning strong surface winds with gusts 30-35 kts. But not high enough for an advisory. Smoke from fires will continue over the area and according to the HRRR may be thicker on Sunday. The near ground smoke may also mix down due to subsidence near front moving across the area from the northwest. This will impact the far northwest part of the OAX County Warning Area. Warmer temperatures start tomorrow and continues through the work week with highs in the 80s. The forecast is dry throughout the entire week. The next best chance of rain is late next weekend. && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) Issued at 630 PM CDT Sat Sep 19 2020 VFR conditions will continue through the forecast period. Winds will remain southerly, occasionally gusting up to 20-30 kts. LLWS will be possible at KOFK from 03Z-15Z Sunday, and could sneak into KLNK and KOMA between 04Z-15Z. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...None. IA...None. && $$ DISCUSSION...Smith AVIATION...KG
Area Forecast Discussion
National Weather Service Pocatello ID
857 PM MDT Sat Sep 19 2020 .SHORT TERM...Rest of Tonight...The latest radar imagery was showing an area of weak convection northwest of Mud Lake working east toward Dubois ahead of the core of a well defined upper low on H2O satellite imagery. The latest HRRR and NAM both maintain convection across that region into Island Park through midnight-3AM. Thus am not going to get in to big of a hurry to reduce or remove the precipitation potential across the NE mountains this evening. No changes planned at this time. See the previous discussion below. Huston Isolated Showers and thunderstorms have already developed over the Central Mountains this afternoon while the earlier line of showers from this morning exits into western Wyoming. Several short term models show a developing line of showers/thunderstorms during the mid- afternoon hours across the Arco Desert/Upper Snake River Plain tracking southeastward across the I-15 corridor and Idaho Falls to Rexburg. Within the organized line would be the potential for small hail and gusty winds while it continues it trek toward the Teton Valley early this evening. Out ahead of this line, isolated thunderstorms are possible this afternoon as well, including the southern highland areas all the way to eastward to Bear Lake. Eastern Magic Valley area and South Hills areas area least likely to see thunderstorm develop but are expected to see gusty west or northwest winds. Improvement to wind speeds and decreasing chances of thunderstorms are forecast between 8 pm and 10 pm. .Sunday through Tuesday...Zonal flow will allow for mild temperatures and generally light winds this forecast period. A ridge of high pressure begins to build back into the area from the south by Monday, which will shift our winds back from the southwest and begin to increase temperatures slightly. This time period is expected to be precipitation free. ND .LONG TERM...Tuesday through Saturday. A weak system will pass east south of Idaho but expect a chance of showers and thunderstorms in the far eastern part of the state near the Wyoming border. Will be dry Wednesday and Thursday with the chance of showers returning mainly to the central mountains and eastern highlands. Temperatures will be above normal through Friday with cooling expected by Saturday as the next system works east. Low confidence at the end of the long term period as models greatly different with GFS slower and wetter and European model drier and weaker with the end of the week system. Winds may increase by Friday into Saturday as well. GK && .FIRE WEATHER... Isolated to widely scattered thunderstorms will be possible through sunset tonight with some breezy conditions as well. Gusts of 20 to 30 mph will be possible especially in zones 410. Brunt of thunderstorm activity will be in zones 475, 476, 422, 410 and 411. All locations will see at least isolated activity. Humidity is way up today and should remain so through Sunday. Temperatures will begin to moderate Sunday and remain above normal through next week. Next chance for showers will be in the far east Tuesday mainly zones 413, 410 and 411. Could be breezy as well Tuesday but not expecting highlights as humidity stays above 15 percent. GK && .AVIATION...Showers and thunderstorms have developed this afternoon and have vicinity at all sites with SUN, BYi and DIJ most likely to see on station but can`t rule out anywhere. Will have 10 to 20 knot sustained winds through sunset at all sites before dying down. Will have clear skies throughout the day Sunday with up valley 10 to 15 knot afternoon winds at PIH and IDA. GK && .AIR STAGNATION...Air Quality concerns from regional wildfire smoke look to improve today as a low pressure trough moves through our area and flow turns more westerly. This essentially `closes off` flow from the CA wildfires for the time being. Keep in mind though that smoke from local wildfires will certainly still impact the air quality. This pattern of a general westerly flow looks to continue through Monday before gradually opening back up again from the southwest. ND && .PIH WATCHES/WARNINGS/ADVISORIES...None. && $$
Area Forecast Discussion
National Weather Service Reno NV
410 PM PDT Sat Sep 19 2020 .SYNOPSIS... Although smoke and decreased air quality from wildfires will continue to impact portions of eastern California and western Nevada, many areas will see better air quality with just some general haze through at least Sunday. High temperatures return to slightly above average for the bulk of next week. Dry conditions with periods of breezy winds are expected next week. && .DISCUSSION... The key features of the forecast into next weekend: * Smoke! I know...a big surprise. * Potential for elevated breezes with fire weather issues and a return to more areas of smoke/poor air quality Monday-Tuesday, and late next week. * Above average high temperatures Sunday through at least Thursday. While denser smoke and poor air quality have decreased dramatically in coverage across eastern California and western Nevada yesterday and today due to a turn to more north-east flow, a general haze persists. Most areas are currently experiencing good to moderate air quality per `` with just a few pockets of poorer air quality in Mono County. This general trend is forecast by the HRRR to continue this weekend with light north to east flow in the low levels. Unfortunately for smoke coverage as well for fire concerns, winds are expected to increase from the southwest and west Monday and Tuesday afternoon and evening as weak low pressure moves into the Pacific Northwest. While it is too far out to nail down details (not in forecast yet) of smoke coverage, the wind flow brings the solid potential for more smoke to pour into western NV and eastern CA if the Creek and North Complex fires remain active. Isolated pockets of critical conditions are possible Monday afternoon, with the potential for more widespread critical conditions along the Sierra Front northward on Tuesday. Wednesday and Thursday, lighter winds return and temperatures reach their peak (mid 70s-near 80 Sierra valleys, mid-upper 80s lower valleys of western NV) as high pressure builds overhead. However, another trough moves into the Pac NW late next week and into the following weekend for another round of increased breezes. Again, that will be of note for fire weather concerns as well as for possibly increased smoke production. Temperature-wise, there is less confidence in readings late next week. The blend of ensembles/models at that time show a high temperature range of 10 or more degrees in some spots. The current forecast is in between the two possible extremes...but keep in mind that highs late next week could be several degrees warmer or cooler depending on the timing and strength of the Pac NW trough. -Snyder && .AVIATION... A light northeasterly pressure gradient is laying over the region with little supporting flow aloft. This will keep surface winds easterly through the night for ridges with light to calm drainage winds for valley locations. Heating Sunday will support a southwesterly wind late in the afternoon, but speeds will remain light. Southwest winds increase Monday/Tuesday afternoons with gusts around 25kts for all terminals. Otherwise, visibility will have some restriction for most locations, especially MMH, due to varying degrees of smoke and/or haze. With light flow tonight and Sunday resulting in diffuse smoke transport, visibility will not be degraded below VFR for most area terminals. This may change Monday depending on fire activity and how much smoke builds in the central California valley over the weekend. Slantwise visibility will be lower than prevailing surface VIS as well. MMH could see an MVFR smoke layer if smoke from the Creek Fire more efficiently spills across the Sierra crest the next couple of days. Boyd && .REV Watches/Warnings/Advisories... NV...None. CA...None. && $$ For more information from the National Weather Service visit...