Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 10/06/20

Area Forecast Discussion...UPDATED
National Weather Service Albuquerque NM
457 PM MDT Mon Oct 5 2020 .AVIATION... 00Z TAF CYCLE Upper high centered over AZ to shift over the Four Corners next 24 hrs. SFC low over ern NM at 23Z to also move swd, with a nly wind shift progressing through ne and east central NM between 06/00Z and 06/12Z. Haze may briefly become more impactful over ne and east central NM along the nly wind shift boundary based on the HRRR Smoke model, otherwise will remain elevated with the greater concentration over the ern half of NM prior to 06/15Z. Occasional nwly gusts to around 35kt along the central mt chain and in nw NM to diminish aft 06/02Z. && .PREV DISCUSSION...325 PM MDT Mon Oct 5 2020... .SYNOPSIS... Critical fire weather conditions across the Sandia and Manzano mountains and much of Torrance County will subside tonight with decreasing winds. Near-record to record warmth will continue through the remainder of this week as strong high pressure drifts east over New Mexico. Southwest breezes will begin increasing by Friday then especially on Saturday as a storm system approaches from the west. Much colder air with strong winds, valley rain showers, and mountain snow are possible for northern New Mexico by Sunday. && .DISCUSSION... SHORT TERM...(TONIGHT THROUGH WEDNESDAY)... High pressure centered over Arizona will migrate east tonight before centering over northern NM Tuesday night. A shortwave will descend into far northeastern NM, allowing a weak, dry backdoor front to dip into eastern NM tonight. With lighter flow aloft, temperatures are expected to be slightly cooler than today`s readings, due to less compressional warming by downslope flow. That said, near record and some record breaking temperatures are possible for a few locales. Meanwhile, smoke and haze will be transported over NM, affecting areas north of I-40 and east of the central mts, along with portions of far SW Catron county. The ridge of high pressure aloft will remain over NM Tuesday night and Wednesday, allowing warm temperatures and dry conditions to persist. LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)... The 588dm H5 ridge axis over NM Wednesday will weaken to near 585dm by Thursday as a weak trough axis drifts west from TX and a strong upper trough approaches the west coast. Flow aloft will back to the southwest and increase Friday as the upper trough inches eastward into central CA. This gradual change to the upper level pattern will result in little change to sensible weather conditions over NM, other than to increase winds slightly across the state. Temps will remain above normal with near-record to record highs each day this week. Overnight lows will still be chilly with clear skies, light winds, and very low humidity. Haze may actually increase over the state by the end of the week as flow aloft shifts more directly from larger fires still burning over CA. The aforementioned storm system approaching the west coast is trending toward a more active scenario within the Great Basin and central Rockies by the weekend. The initial upper low is shown by nearly all guidance to eject eastward and weaken to an open wave near the Four Corners by Saturday. The main impact from the initial wave will be wind with widespread breezy to locally windy conditions likely. A secondary, larger upper level trough then surges southeast into the western CONUS as a potent 160 kt speed max arrives from the Gulf of AK. This second storm system is shown to follow in the wake of the intial upper wave and develop into a potential closed low over the central Rockies by Sunday. Guidance is coming into better agreement and is trending a tad farther south, colder, and slightly wetter for northern NM. The greatest confidence at this time is for significantly colder temperatures and strong winds across NM. 12/33/Guyer && .FIRE WEATHER... High pressure aloft builds back over NM from the west on Tuesday. Light winds with well above average temperatures for early October will be the rule through the remainder of the work week. Weather prediction models agree that a strong upper-level trough will bring increasing winds with chances of precipitation including mountain snow during the weekend. Critical fire weather condtions are possible Saturday as southwest winds increase ahead of the associated surface cold front. 12/33 && .ABQ WATCHES/WARNINGS/ADVISORIES... Red Flag Warning until 6 PM MDT this evening for the following zones... NMZ107. && $$
Area Forecast Discussion
National Weather Service Boise ID
838 PM MDT Mon Oct 5 2020 .DISCUSSION...It was a beautiful day across much of southeast Oregon and southwest Idaho, with wildfire smoke confined mainly to areas near the Nevada border and near local wildfires. Clear skies will allow for cool overnight temperatures, but nothing out of the ordinary for early October. Southwest flow aloft will develop on Tuesday, bringing smoke from California back across our area during the afternoon. Southwest flow will continue into Wednesday with smoke continuing to increase. High temperatures will remain around 10 to 15 degrees above normal. The forecast remains on track and no updates are planned this evening. && .AVIATION...Mainly VFR. Smoke layers near the Nevada border tonight, spreading north across most of the area on Tuesday, locally reducing visibilities to MVFR. Surface winds variable around 5 kts overnight becoming SW around 10 kts on Tuesday. && .PREV DISCUSSION... SHORT TERM...Tonight through Wednesday night...Most of the smoke from the California wildfires has retreated south to the Nevada border. There is also smoke in the west central Idaho Mountains due to wildfires there. Latest HRRR begins to bring the California smoke back into our CWA later Tuesday and with expected west-southwesterly flow aloft that trend will continue into Wednesday. Low temperatures will be a little cooler tonight then hold steady Tuesday night and Wednesday night. High temps Tuesday will be like today, then a couple degrees warmer Wednesday. Light winds through Wednesday night. Except for the smoke skies will be generally cloudless. LONG TERM...Thursday through Monday...An upper level trough will approach the region on Thursday and split from the jet stream on Friday as it moves into central CA. Our area will see increasing high clouds on Thursday and Friday, but little precipitation. Temperatures will gradually cool Thursday and Friday with increased clouds. A cold front will move into the region on Saturday with showers and lowering snow levels to around 6500-7000ft. Precipitation amounts of 0.75-1.00in over the mountains, with generally less than 0.50in in the valleys, are possible with this system. Cool northwest flow will continue behind the system, but shower chances will go down, as the bulk of the activity will generally be north of Baker City and McCall. && .BOI WATCHES/WARNINGS/ADVISORIES... ID...None. OR...None. && $$ DISCUSSION...ST AVIATION.....JT PREV SHORT TERM...LC PREV LONG TERM....KA
Area Forecast Discussion
National Weather Service Boston/Norton MA
1034 PM EDT Mon Oct 5 2020 .SYNOPSIS... High pressure builds in tonight bringing mostly dry conditions into early Tuesday. Continued mild Tuesday with a risk for a few showers. Warm and windy with a risk of scattered showers Wednesday afternoon into the evening as a cold front moves through. Dry and much cooler to end the week, but will remain windy on Thursday. Temperatures trending above normal over the weekend as high pressure moves to the east. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... 1030 PM Update... Much of the forecast is on track with a 7000 ft deck over much much of Western MA. Nudged the forecast toward the latest GLAMP guidance and it appears that the 850-925 mb RH field per the RAP 13 model is a rather good proxy for the sky cover. As a result of the cloud cover, lows tonight only dip into the mid 40s to low 50s, which is milder than recent chilly nights but right about climatological normal for early October. Also could see locally dense fog in the typical fog-prone interior valley locations after midnight, but otherwise a mild and quiet night of weather. PREVIOUS DISCUSSION... Clouds continue to decrease as drier air moves in above 700 mb. Lingering low level moisture has allowed for plenty of diurnal cumulus mixed with sun this afternoon. High pressure moves into southern New England overnight as a 500 mb ridge builds aloft. At the surface easterly flow becomes southerly/southwesterly during the late evening and early overnight hours. Given the lingering moisture below 700 mb and the warm advection pattern we can expect low clouds building back in with some patchy fog development as well. Given the wind trajectory and moisture plume, the Cape and Islands may actually stand the best chance of missing out on the fog and low clouds this time. Dewpoints in the upper 40s and low 50s will keep low temperatures in that range as well. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/... Mostly dry day on Tuesday with mild, seasonable temperatures. Normal highs in early October are in the 60s which is right around the current forecast. Looking aloft we see the ridge axis crossing the region early Tuesday morning, so heights will begin to fall ahead of an approaching trough over the mid-west. Through this flow a weak disturbance/vort max passes, and this together with a weak low level jet and WAA aloft may squeeze out some scattered light showers over western/central New England. Moisture is lacking, though, so not expecting much out of it. Model soundings do show mixing up to 850- 900 mb which would allow some of that jet to mix down bringing gusts 15-20 mph in the afternoon. The stronger winds come overnight toward Wednesday morning as the approaching trough and sfc low tighten the pressure gradient bringing stronger wind gusts. Strongest wind gusts overnight would be over the waters where the inversion is less pronounced. This will lead to increasingly rough seas for area waters. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... Highlights * Mild, windy Wednesday with afternoon/evening scattered showers. Possibly a few isolated thunderstorms. * Drier and cooler Thursday and Friday. Still windy on Thursday. * Above normal temperatures expected this weekend. Wednesday and Wednesday night... A potent positively tilted shortwave trough will dig from the central Great Lakes early on Wednesday into New England by the evening. The shortwave lifts offshore Wednesday night. At the surface low pressure will move across Ontario and Quebec into northern New England by the evening. Associated with the low a cold front will sweep through southern New England during the afternoon and into the evening. Good consensus amongst guidance with the frontal passage through the region during the afternoon and into the evening. The main concerns as this front slides through are gusty winds. Expecting a 40-50 kt 850 hPa low level jet ahead of the front. Should see some 20-25 kt gusts mixing down across the interior per 0-1 km nearly adiabatic lapse rates and winds within that range. Gustier across Cape Cod and the Islands with gusts of 25-30 kts. Will need to watch if we can tap into gusts up to 1.5 km AGL where speeds are 5-10 kts higher in both locations. Gusty winds continue at night as the strong low level jet remains along with a tight pressure gradient. Expect the front to bring in scattered showers during the afternoon and into the evening. Cannot rule out isolated thunderstorms as there is quite cold air aloft at 500 hPa with values ranging from - 25 to -15 degrees Celsius. In addition, low level lapse rates are roughly 6-8 degrees Celsius per km with mid level lapse rates around 6-7 degrees Celsius per km. Does appear there is roughly a few hundred J/kg of MUCAPE. Bulk shear values are around 70-90 kts in the 0-6 km layer. K index values are roughly 20-30, so moisture could be a limiting factor. Still will need to keep an eye on as the CWA is on the periphery of the latest SPC Day 3 Outlook. Temperatures will be mild with 925 hPa flow roughly out of the west. This should promote some downsloping, but given the increased cloudiness have only bumped up to the 75th percentile of guidance. Highs generally range from the upper 60s to the mid 70s with the warmest readings in the CT and Merrimack Valley. Winds shift to the northwest and advect in a much cooler airmass at night. Should see 0 to +5 degree Celsius cooler air advect in. Low temperatures fall into the 40s across the interior and the low to mid 50s along the coastal plain. Thursday and Friday... Mid level ridge axis builds from the Northern Plains/Upper Mississippi River Valley early on Thursday eastward into the central/eastern Great Lakes on Friday. At the surface high pressure nudges into the region from the central Great Lakes on Thursday and builds in from just south of the region on Friday. Gusty winds continue on Thursday due to the tight pressure gradient from the exiting front and high building in. Colder air will continue to advect into the region due to northwesterly flow aloft. Should see -5 to 0 degree Celsius 850 hPa filter in. Will feel much cooler with high temperatures ranging from the mid 50s to the mid 60s. The pressure gradient really relaxes Thursday night into Friday morning as the high builds further east. This will bring an end to the gusty winds and keep skies relatively clear. Looks like a strong radiational cooling night, so have nudged down lows to the 25th percentile of guidance. Am uncertain on how quickly the gusty winds subside, but may need to go colder in future updates. Based on the current forecast it is not out of the question that Frost/Freeze headlines will be needed. Lows generally in the 30s across the interior and low to mid 40s along the coast. Dry and quiet weather across the region on Friday. Still a bit cool as winds aloft do not shift to a westerly direction advecting in milder air until late in the day. Temperatures will be similar to Thursday with readings ranging from the mid 50s to the mid 60s. Saturday and Sunday... Ridge axis builds over the region Saturday and slides east of the region on Sunday. As the high shifts to the east of southern New England will see much milder air advect in. Confidence in the forecast remains high for Saturday, but less certain on Sunday as there are questions how tropical cyclone Delta interacts with things as it moves inland. Have kept the NBM guidance due to the significant differences in this window, which bring us slight chances of rain. High temperatures on both days will be above normal for this time of year with westerly/southwesterly flow at 850 hPa. This brings in 10 to 15 degree Celsius air. Readings range from the mid 60s to the mid 70s. && .AVIATION /03Z TUESDAY THROUGH SATURDAY/... Forecaster Confidence Levels... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Tonight...High confidence. MVFR to IFR conditions developing across much of the interior generally around and after 06Z. Could see some patchy dense fog especially across the CT River Valley. Cannot completely rule out MVFR ceilings across the south coast, but think best chance is further west where there is more moisture. Winds generally less than 5 kts out of the SE/S. Tuesday...High confidence MVFR to IFR conditions during the morning with light scattered showers. Conditions improving to VFR during the afternoon. Winds out of the S at 5 to 10 kts with gusts around 15 to 20 kts. Tuesday night: High confidence. VFR with light S/SW winds becoming breezy along the south coast terminals 10 to 12 kts, gusting to 20 to 25 kts by 12Z. KBOS Terminal...High confidence in TAF. KBDL Terminal...High confidence in TAF. Outlook /Wednesday through Saturday/... Tuesday Night: VFR. Breezy. Wednesday: Mainly VFR, with areas MVFR possible. Windy with gusts up to 35 kt. Chance SHRA. Wednesday Night: VFR. Windy with gusts up to 35 kt. Thursday: VFR. Windy with gusts up to 30 kt. Thursday Night through Friday: VFR. Breezy. && .MARINE... Seas over the southern waters come down through the night tonight. As a result, have cancelled the remaining SCAs for tonight. By Tuesday morning, southerly winds will be on the increase with gusts up to 25 mph possible with building 5-7 ft seas especially for the northern outer waters by Tuesday afternoon. A Small Craft Advisory goes is in effect for the northern waters Tuesday afternoon and overnight. A cold front then crosses the waters late Wednesday with winds shifting to the west and gale force conditions possible through Thursday. Outlook /Wednesday through Saturday/... Wednesday: Low risk for gale force winds with gusts up to 40 kt. Seas up to 5 ft. Chance of rain showers. Wednesday Night: Moderate risk for gale force winds with gusts up to 35 kt. Rough seas up to 9 ft. Thursday: Low risk for gale force winds with gusts up to 35 kt. Areas of rough seas. Thursday Night: Moderate risk for Small Craft Advisory winds with local gusts up to 30 kt. Areas of rough seas. Friday: Winds less than 25 kt. Areas of seas approaching 5 ft. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...Small Craft Advisory from 2 PM Tuesday to 8 AM EDT Wednesday for ANZ250. && $$ SYNOPSIS...BL/BW NEAR TERM...BL/BW/Chai SHORT TERM...BW LONG TERM...BL AVIATION...BL/BW MARINE...BL/BW/Chai
Area Forecast Discussion
National Weather Service Grand Forks ND
1012 PM CDT Mon Oct 5 2020 .UPDATE... Issued at 1012 PM CDT Mon Oct 5 2020 Only forecast change was adjust for high clouds increasing a bit faster in our northwest and carrying this faster timing thorugh the rest of the night in line with latest short range guidance. Still expect no impactful weather through early Tuesday morning, and forecast is on track for the night, with no impactful weather through early Tuesday morning. Will still need to monitor latest data as it comes in tonight for fire weather potential and whether a wind advisory will need consideration for Tuesday afternoon. UPDATE Issued at 707 PM CDT Mon Oct 5 2020 A few diurnally driven sprinkles are lingering, but these returns are mainly associated with virga (not reaching the ground). Expect this to continue to fall apart over the next few hours due to recent sunset/loss of daytime heating. Winds should also follow a decreasing trend. No impactful weather expected, and other than adjustments for near term trends forecast is on track. && .SHORT TERM...(This evening through Tuesday night) Issued at 305 PM CDT Mon Oct 5 2020 The main impact expected for the short term will be fire weather concerns on Tuesday afternoon into early Tuesday evening. Gusty northwest winds will decrease again this evening with minimal cloud cover expected. These winds will ramp up again pretty quickly Tuesday morning, with the strongest period being Tuesday afternoon into early Tuesday evening. Thinking that temperatures will be on the higher side of guidance during that period, dew points will be on the lower side, and wind speeds/gusts will be on the higher side. Blended in a lot of the HRRR to drive temperature and dew point grids, which did well today (and past days as well). Model soundings even show the potential for mixing down warmer/drier/windier conditions. Made several calls to fire weather officials today, and the word is that fuels are dry. For that reason, coordinated with SPC and adjacent forecast offices and issued a fire weather watch for most of eastern North Dakota. Also added a highlight of near critical fire weather conditions for the southern Red River Valley and the northwest quarter of Minnesota. Like today, winds should die down again Tuesday evening, but not completely. This will help keep temperatures from falling too far. .LONG TERM...(Wednesday through Monday) Issued at 305 PM CDT Mon Oct 5 2020 A change in the synoptic pattern will favor dry and warm conditions through the remainder of the week while a suggested a shift towards wetter conditions is forecast early next week. Although, confidence is low in details regarding this late period change towards wetter conditions. Upper troughing near ON begins to shift east allowing increased heights to overspread the Northern Plains. This will continue seasonably average to well above average temperatures as warm air masses from the High Plains/central Rockies advects over the region underneath ridging aloft. High temperatures Friday into the weekend look to be well into the 70s area wide, with even a chance of breaking into the low 80s showing up in some GEFS members as well as the 75th percentile of max temps via NBM. There is a chance these temps continue into the weekend, but ultimately will depend on other factors unknown at the moment like the development of a potential system into next week as well as cloud cover. Ensemble members as well as deterministic guidance progs the development of a system over the north-central CONUS/southern CAN getting to early next week. Several member variants also want to develop then stall the system near central North America meaning perhaps more than one day of with precip chances early to mid next week. With at least a brief period of southwesterly flow aloft over the region ahead of this potential system, there is some moisture that advects back into the region despite the continued NW flow of late whisking away moisture content to the Deep South. Further details on amounts lack confidence, although there is a wide spread within ensemble guidance ranging from just a few hundredths to several inches. Details will become clearer in the coming days. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 707 PM CDT Mon Oct 5 2020 VFR conditions are expected through the TAF period across eastern ND and northwest MN, and while virga or a few sprinkles can`t be ruled out in northwest MN through 08Z impacts at terminals are unlikely. Gusty west-northwest winds should decrease as well this evening, but an increasing trend from the west-southwest is expected during the day Tuesday with strongest afternoon gusts in northeast ND 35 kt (possibly higher at KDVL). && .FGF WATCHES/WARNINGS/ADVISORIES... ND...Fire Weather Watch from Tuesday afternoon through Tuesday evening for NDZ006>008-014>016-024-026>030-038-039-054. MN...None. $$ UPDATE...DJR SHORT TERM...Godon LONG TERM...CJ AVIATION...DJR
National Weather Service Hastings NE
1014 PM CDT Mon Oct 5 2020 .UPDATE... Issued at 1003 PM CDT Mon Oct 5 2020 Red Flag Warning was allowed to expire as scheduled. Winds have diminished and humidities have rebounded back into the 40 to 50 percent range across the area. && .DISCUSSION...(This evening through Monday) Issued at 226 PM CDT Mon Oct 5 2020 If it is warm, dry fall weather you like, the next 7 days should be good for you. It`s a warm early October day over the area with mid-afternoon temperatures ranging from the lower 70s to the upper 80s from east to west across the forecast areas. An area of high level smoke from CO/WY fires continues to thin and move east allowing temperatures to finally reach closer to maximum high potential. Within the first 6 hours, the main issue is the fire weather concerns driven by low relative humidity and the advance of a cool/cold front/trough just slipping into the western forecast area at this time. Winds will shift to the west/northwest and may be pick up for 1 to 3 hours behind that trough causing increased fire concerns. Also, some haze with visibility restrictions have worked into north central Kansas. Have included a short period of haze associated near/with this area current area in the southern forecast and used the HRRR near surface smoke as a proxy. The haze will settle along the light wind surface winds within the trough axis through the early evening...before north winds push it out and mix up the lower atmosphere. The forecast is technically dry through Monday. At least through Sunday night, there appears to be very little risk if any of precipitation. Temperatures will be well above normal with 80s common. Temperatures may see some daily influence of high level smoke from the CO/WY fires which will likely flare up each afternoon/evening...trailing the smoke across the forecast area some 12-18 hours later. That could knock temperatures down a few degrees or delay warming each day. After the front passes this evening, surface winds go right back to a dry, warming west/southwest flow Tuesday. Another front will drop down Wednesday and bring a pretty stiff north/northeast breeze for a time during the day. Temperatures are forecast to be cooler Wednesday, but we may not be cool enough, especially in the northeast forecast area. Then, south winds kick in Thursday but so do some mid/high clouds. Temperatures will be warm again but may be tempered by the clouds during the day a bit. As we get deeper in the week/weekend, temperatures remain warm but low level moisture will be on the increase some. In fact, it may be humid in some areas this weekend, especially east/south of the Hastings/Grand Island area. We haven`t said that in awhile. As mentioned, the forecast is dry, but signs of potential moisture are lurking next Monday night, Tuesday and Wednesday. Temperatures will also be cooling and we start to see that already on next Monday by at least trimming things back to near normal. Also, some rain/snow is likely across the CO/WY fire area by Sunday night. That should help with containment and lesson the smoky sky impacts of those fires next week. && .AVIATION...(For the 00Z KGRI/KEAR TAFS through 00Z Wednesday) Issued at 630 PM CDT Mon Oct 5 2020 VFR conditions are expected through this period. Other than high level smoke, skies will be mostly clear. Winds will shift to the north this evening as a surface trough moves through. Winds will increase on Tuesday, shifting to the southwest by midday. Gusts over 20kts are expected in the afternoon. && .FIRE WEATHER... Issued at 226 PM CDT Mon Oct 5 2020 The Red Flag Warning continues for 5 counties in the northwest portion of the forecast area until 8 pm this evening. Relative humidities will drop the next couple of hours as a west/northwest wind settles into the area. The wind speed of 20 to 25 mph has always been borderline on this event, as the trough/front slowly slide into the area. However, if those winds can get up to speed even for 1 or 2 hours, conditions would be pretty critical in the warned area. The rest of the forecast area isn`t exactly out of the woods should a fire develop but relative humidities generally aren`t as low. The fire weather concerns are here all week in some manner simply because we have such warm temperatures. It is interesting to note the moisture increase by Thursday which really prevents a lot of the forecast area from reach Red Flag criteria later in the week. There could be a sharp western edge over the western forecast area west of Kearney to Phillipsburg which will be worth watching from time-to-time. Point weather is an issue, but maybe not quite a bad as it first looked a few days ago. Nonetheless, the importance of careful fire use and/or adhering to local burn bans and policy can`t be overstated the next 7 days. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ UPDATE...Mangels DISCUSSION...NOAA/NWS/Moritz AVIATION...Mangels FIRE WEATHER...NOAA/NWS/Moritz
Area Forecast Discussion
National Weather Service Goodland KS
605 PM MDT Mon Oct 5 2020 .UPDATE... Issued at 605 PM MDT Mon Oct 5 2020 The Red Flag Warning that was in effect until 00z has been allowed to expire on time. Critical fire weather conditions are no longer expected. && .SHORT TERM...(This evening through Tuesday) Issued at 144 PM MDT Mon Oct 5 2020 Northwest flow continued over the region today with an upper ridge over the west coast and a shortwave trough progressing from the northern Plains to the Upper Midwest. At the surface, a cold front was draped across western Nebraska and approaching the area. At 1:30 PM MT, temperatures mainly ranged in the 80s with west winds shifting to the northwest and increasing. Gusts up to 30 to 35 mph were reported along the Colorado and Nebraska borders. Smoke and haze have been observed across much of the area, with visibilities as low as 4 miles in McCook, Nebraska during the morning. As winds increase through the afternoon and the cold front comes in to the forecast area, smoke from wildfires in north central Colorado and south central Wyoming should get pushed south of the region by the early evening. Otherwise, expect winds to decline after sunset with temperatures mainly in the 40s overnight. On Tuesday, the upper ridge slides eastward onto the Rockies. Relative humidity values will be at 15 percent or less along and west of a line from Trenton, Nebraska to Sharon Springs, Kansas with values of 16 to 20 percent elsewhere. Fortunately, southwest winds look to be relatively light through the day at about 10 to 15 mph and a fire weather highlight does not appear necessary at this time. However, smoke from wildfires west of us does look to return to the northwestern portion of the region Tuesday afternoon into the evening. For Tuesday night, low temperatures are slightly warmer, in the 40s and low 50s. .LONG TERM...(Wednesday through Sunday) Issued at 303 PM MDT Mon Oct 5 2020 At the beginning of the forecast period, models show an upper air high just SE of the CWA with a weak low over western TX on Wednesday. During Wednesday evening, the low begins to travel northeast as the high transitions to an upper air ridge as it travels east. Forecast guidance shows the low transitioning to an upper air trough and reaching SE of the CWA by Thursday night/Friday morning with the CWA having a generally westerly flow aloft due to influence of a small ridge behind the trough. Models begin to show some discrepancy going into Saturday with the timing of a low coming in from the west ahead of a larger trough. The ECMWF shows the low over the CWA on Saturday evening and then continuing eastward. GFS shows the low reaching only central CO before being absorbed into the larger trough on Saturday night/Sunday morning. The model discrepancy continues with the large trough behind the aforementioned low in regards the trough`s placement and timing. The ECMWF shows that the front end of the trough will reach the western portion of the CWA by Sunday afternoon with its base extending near where NM/OK/TX meet. The GFS shows the front part of the trough reaching the western counties of the CWA by the Sunday morning hours with the base of the trough extending down into central NM/TX by Sunday evening. While both models show a NNW flow over the CWA by Sunday evening, the GFS also shows a feature that the ECWMF does not: a 914mb low at the base of the trough causing weaker and westerly turning upper air winds in the western CWA counties. This situation will be monitored in the coming days to see if models come into better agreement as this trough feature will have a major effect on the CWA weather pattern at the beginning of next week. At the surface, the Tri-State area expects to see dry conditions continue until the end of this week followed by a small possibility of precipitation for the far NW part of the CWA at the beginning of next week. Northern Yuma and NW Dundy counties may see a slight chance for showers ahead of a cold front passing through the area on Sunday evening. Elevated fire weather conditions are possible for areas along and west of KS-25 during the afternoon for Wednesday through Saturday with Sunday afternoon showing similar chances for the CO counties of the CWA. RH values are expected to be below 20% for these areas on these days. Forecast wind speeds remain below criteria to support fire weather on Wednesday, Friday, and Saturday. However, Thursday may see wind gusts reaching 25 mph in Cheyenne CO, Wallace, and Greeley counties while wind gusts may surpass 25 mph in the west of KS-27 on Sunday. This situation will be monitored in case wind speeds increase. The Tri-State area expects to have high temperatures in the middle to upper 80s Wednesday through Friday followed by highs in the lower to middle 80s on Saturday and highs in the upper 70s to lower 80s on Sunday. Overnight low temperatures for the Tri-State area expect to be in the middle 40s to lower 50s for the entire forecast period. The far eastern parts of the CWA may see Thursday night lows reach the middle 50s while the far western CWA counties may see lows drop to the lower 40s on Sunday night. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 440 PM MDT Mon Oct 5 2020 KGLD, vfr conditions expected through the period. A north wind near 15kts at taf issuance will fall below 12kts by 02z then become light and variable from 05z-13z under a generally clear sky. For Tuesday a southwest wind under 10kts becomes 12kts with some higher gusts from 17z-21z then below 12kts after 22z. Smoke and some haze are forecast to reach the terminal from the west after 20z. Its unknown at this time whether visibility restrictions will take place due to the smoke but at this time the 18z HRRR near surface smoke forecast suggests no restrictions will take place. KMCK, sub vfr cigs from smoke are currently expected from taf issuance through early this evening but could last longer. Otherwise vfr conditions are expected through the period. A north wind around 13kts at taf issuance will fall below 12kts by 02z then light and variable from 05z-15z. From 16z southwest winds start to increase a bit with gusts around 20kts possible in the 19z-21z timeframe. After 22z southwest winds are expected to fall below 12kts. We will be monitoring the visibility through the night and assess whether its from wildfire smoke to our northwest or spider webs as has been the case recently. && .FIRE WEATHER... Issued at 144 PM MDT Mon Oct 5 2020 A Red Flag Warning remains in effect for a large portion of the forecast area through early this evening. With minimum relative humidity values around 10 percent along with northwest winds gusting to 35 mph this afternoon, any fires that start have the potential to spread rapidly. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ UPDATE...99 SHORT TERM...JBH LONG TERM...076 AVIATION...99 FIRE WEATHER...JBH
Area Forecast Discussion
National Weather Service Medford OR
907 PM PDT Mon Oct 5 2020 .DISCUSSION...Oregon DEQ put out an Air Quality Alert late in the afternoon that we disseminated in our hazard grids and AQAMFR message earlier. Smoke moving inland from the west and southwest will allow air quality to erode with smoke for the next several days. No other changes to the forecast are needed this evening. Upcoming shifts over the next several days will be focused on the weekend rain event and refining expected amounts, which will continue to be in everyone`s interests. MTS && .AVIATION...For the 06/00Z TAFS...Areas of MVFR/IFR conditions are expected to return to the coast north of Cape Blanco and into the Coquille and Umpqua valleys again late tonight into Tuesday morning. But, coverage will not be as widespread or as lengthy as it was Monday morning. Over the remainder of the area...VFR conditions will prevail through Monday night, except for patchy MVFR vsbys in wildfire smoke, mainly in southern Curry, Josephine, and western Siskiyou counties. -DW && .MARINE...Updated 800 PM PDT Monday 5 October 2020...Small craft advisory winds are occuring south of Cape Blanco, with steep seas over all of the southern Oregon coastal waters. The thermal trough responsible for these conditions will shift inland tonight. As a result, gusty north winds are expected to diminish early Tuesday, but steep seas will persist through Wednesday. After relatively calm conditions Wednesday night into Thursday, A series of fronts are forecast to pass through the area late Thursday into early next week. This will produce periods of increased southerly winds, likely resulting in at least advisory level conditions. -BPN/DW && .PREV DISCUSSION... /Issued 250 PM PDT Mon Oct 5 2020/ Satellite imagery this afternoon is showing that the stratus in the Umpqua Valley this morning has burned off. Sunny, warm conditions prevail across the forecast area, but persistent wildfire smoke continues to result in hazy, smoky conditions. Indeed, air quality is reduced, especially across northern California where many readings are in the unhealthy for sensitive groups (USG) or unhealthy categories. Farther north, in southern Oregon, some of this smoke is causing USG air quality in Josephine County, mainly due to the Slater fire. Latest HRRR smoke guidance does show near-surface smoke increasing as a whole tonight through tomorrow afternoon/evening across SW Oregon due to SSW winds becoming dominant. The upper ridge responsible for the recent spate of dry, warm weather will hold through at least the middle of this week. Marine stratus/fog will be limited tonight, but could affect coastal areas again and perhaps some areas of the Umpqua Basin. Due to lower October sun angles, we expect the wildfire smoke to have a fairly significant impact on expected daytime high temperatures tomorrow and Wednesday. Therefore, we have undercut guidance again for most areas by at least a couple of degrees, but by about 5-10 degrees for areas where thicker smoke is expected. We`ll likely see an increase in marine stratus/fog over the coastal waters and along the coast Tuesday night into Wednesday, but mainly sunny, hazy, smoky conditions will persist inland with fairly typical afternoon breezes, especially east of the Cascades. The flow aloft in the NE Pacific will split resulting in the development of a closed low offshore on Thursday. Expect an increase in high cloudiness from this system along with some cooling and also an increase in SSW winds east of the Cascades, but it should remain mostly dry. The closed low is expected to move into northern California, mainly south of our CWA Thursday night into Friday morning, but could graze SW portions of the forecast area with some light rain. Model guidance is still keying in on a strong trough and frontal system expected to arrive at the PacNW coast late Friday night, then sweep quickly through our forecast area on Saturday. This will bring a high probability of wetting rainfall to the entire forecast area with the highest odds, greater than 75%, along and west of the Cascades/Siskiyous. Odds are slightly lower farther south and east, but are still near or better than 50%. There will be some gusty winds in advance of this system, but it doesn`t appear, at least at this time, to be high wind producer. Rainfall rates are a concern due to the numerous burn scars from the summer/early fall fires. Right now, it looks like there will be a period of heavier rainfall with the front, perhaps 6 hours, from late Saturday morning through Saturday afternoon. Rainfall rates could reach 0.25"/hour, but probably will not be high enough to be a concern for flash flooding/debris flows. We`ll continue to monitor this and make updates. It should be noted that model guidance is showing some cold air aloft arriving Saturday evening, and convective indices support a slight chance of thunder along the coast. It probably doesn`t make it far enough inland, however, to reach any of the burned areas. Saturday night, the snow level lowers to around 6500 feet and if any precipitation is left over, there could be the first snowflakes of the season up at Crater Lake. It won`t amount to much though. Beyond that, models are showing the strong jet aimed mostly to our north Sunday into early next week with upper ridging developing near or off the California coast. Another disturbance could come through the area Sunday night into Monday, but it looks weak at this time. -Spilde FIRE WEATHER...Updated 2 PM PDT Monday, October 5th, 2020...Today through Wednesday will continue to be very warm and dry in the afternoons. A continuing strong inversion is likely to continue to result in seasonably cool overnight low temperatures in the valleys, but mild temperatures on the ridges, especially by October standards. Winds will trend higher east of the Cascades on Wednesday, and with humidity still low, this is an area of the concern in the forecast. At this point, winds and RH won`t quite reach critical thresholds, and smoke aloft will probably keep RH a bit higher than purely sunny skies would provide. Temperatures are likely to drop 5 to 10 degrees for highs Thursday as compared to Wednesday, and RHs will correspondingly edge upward as intervals of clouds increase Thursday and Friday. There are two main potential rainmakers this weekend. The first arrives Friday and the overall trend for the past several days has been for this rain to be focused from the California/Oregon border southward. Latest data still generally confirms this, so we expect potential for some rain in Siskiyou County as early as Thursday night. The next system is a well-defined front that`s poised to deliver significant, although potentially short-lived, precipitation across the forecast area Saturday. Overall, there`s still about a 75 percent chance in wetting rainfall across our Fire Weather Zones, particularly as the frontal boundary moves through Saturday into Saturday night. One last note...about winds with these systems. The strongest winds are expected ahead of the front late Friday night into Saturday morning (southwesterly) and behind the front Saturday night/Sunday (northwesterly). Keene/BTL && .MFR WATCHES/WARNINGS/ADVISORIES... OR...None. CA...None. Pacific Coastal Waters...Small Craft Advisory until 5 PM PDT Wednesday for PZZ350-356-370-376. $$
Area Forecast Discussion
National Weather Service Pueblo CO
608 PM MDT Mon Oct 5 2020 .UPDATE... Issued at 604 PM MDT Mon Oct 5 2020 Updated forecast to allow the Red Flag Warning to expire for fire weather zones 220, 226, 227, and 234. && .SHORT TERM...(This evening through Tuesday) Issued at 236 PM MDT Mon Oct 5 2020 Will leave the Red Flag Warning in effect through 6 PM today as RH values are below 15% in those areas and winds are, or are still expected to become breezy this afternoon. The HRRR is forecasting an increase in smoke over the southeast plains tonight, and over Teller, Fremont and Custer Counties. It`s uncertain how much that may affect visibilities, but there is the potential for visibilities to become lower than they already are. The HRRR then shows improving conditions along the eastern mtns and I-25 corridor in the mid to late morning hours Tue, and then improving (but not clearing) over the far southeast plains later in the day. Otherwise, dry weather will continue tonight and Tue, with highs on Tue being above average. .LONG TERM...(Tuesday night through Monday) Issued at 236 PM MDT Mon Oct 5 2020 Wednesday through Friday...Warm and dry conditions will persist under the upper-level ridge that continues to dominate the area. It is expected to flatten somewhat on Thursday before amplifying on Friday, although it should not impact the current weather pattern much. Afternoon highs will be fairly consistent, sitting around 90 over the east plains, mid-70s in the valleys and high 60s over the higher terrain. Nighttime lows will continue their current trend, typically ranging from the mid-40s out east to lower 30s in the valleys. Saturday-Monday...A trough of low pressure is expected to make its way onto the Western Coast early Saturday. This will initially assist in amplifying the existing ridge over CO before the low begins to propagate eastward. The low should move through the area starting Sunday afternoon-evening, bringing with it an increased chance of precipitation over the higher terrain that quickly begins to move east on Monday. While most models have begun to agree on the timing of the trough moving through, the intensity of the low and resulting precipitation is contested between models, specifically the GFS and the ECMWF. The ECMWF has a less intense low moving with the base of the trough, swinging through late Sunday night, while the GFS sticks to a stronger cutoff low that digs further down into New Mexico. Will have to continue to monitor the progression of model trends through the remainder of the week, as the plains will have a much better chance at some much-needed precipitation if the trends favor the GFS solution, although the highest chances for showers still remain over the mountains. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 236 PM MDT Mon Oct 5 2020 KALS is expected to have VFR conditions and dry weather through the forecast period. KCOS and KPUB will have dry weather through the forecast period. Forecast models indicate increasing smoke at these sites this evening, and remaining over the area into about midmorning Tue. If the smoke does increase, there will be the potential for reduced visibilities, in the MVFR category. Winds will become light tonight, and then Tue afternoon, south to southeast winds of 10-15 kts are likely && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...HODANISH SHORT TERM...28 LONG TERM...GARBEROGLIO AVIATION...28