Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 09/10/22

Area Forecast Discussion
National Weather Service Binghamton NY
935 PM EDT Fri Sep 9 2022 .SYNOPSIS... Above average temperatures are expected today and Saturday under partly to mostly sunny skies. The next system moves in Sunday, with increasing cloud cover, falling temperatures, and chances for showers. Rain shower chances continue into early next week. && .NEAR TERM /THROUGH SATURDAY/... 930PM Update... Skies have cleared now that the sun is down and heating has subsided. This is expected to continue through the overnight hours before scattered clouds begin to work their way back into the area from the southwest Saturday morning and thicken up by the late afternoon ahead of the next low pressure system. Tonight, temperatures will drop to the mid to upper 50s with a few sheltered spots may dip into the low 50s. Highs on Saturday will be a few degrees warmer than today as SW flow returns to the area. Expect the low to mid 80s across the valleys with upper 70s at higher elevations. 630 PM Update... Another look was given to the overnight temperatures to see if radiational cooling might knock temps down a few degrees lower than guidance. It looks like winds just above the surface will pick up later this evening, allowing for mixing to occur overnight and counteract the effects of radiational cooling from a clear sky. Because of this, lows were not adjusted from the afternoon forecast package. The forecast remains on track. 230 PM Update... Sunny skies will be present the rest of this afternoon. However, the sky may not look as blue as a typical clear day as elevated smoke from wildfires out west sits over the region. This smoke will remain elevated and is not expected to have any impacts to conditions at the surface. HRRR smoke shows that this smoke will hang around until late tonight. A ridge of high pressure will be present over the region for this period, resulting in dry conditions until late Saturday night/early Sunday morning. After reaching the upper 70s to mid 80s this afternoon, temperatures will fall into the 50s and low 60s overnight. Other than the aforementioned elevated smoke, skies will be clear. Fog that develops tonight should remain in the valleys and not spread out like it did last night. Visibilities will be reduced though where fog develops. Fog clears out a couple hours after sunrise with sunny skies expected through the morning hours. Southwest flow will advect moist air into the region, and high clouds move in during the afternoon, resulting in partly sunny skies. Temperatures will be around the same as today, upper 70s to mid 80s. Heading into the overnight, a shortwave moves up the ridge and will bring a chance for showers to the western portions of the Twin Tiers and Wyoming Valley after midnight. There are some timing differences between model guidance and the arrival of these showers, so the NBM and HREF were followed for PoPs. Sky cover also increases ahead of this shortwave, leading to mostly cloudy skies. Temperatures Saturday night will be slightly warmer, only falling into the upper 50s to mid 60s. && .SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/... 230 PM Update... Main concerns in the short term are focused on the potential for rain Sunday and another round of showers and storms Monday. A large area of low pressure over the Northern Plains will start off as an open wave Saturday night and slowly rotate to the east through the Midwest and Great Lakes Sunday into Monday...becoming cutoff from the primary synoptic flow. This storm system will be able to draw a deep layer of moisture across the mid Atlantic region into parts of the Northeast on Sunday. The increasing moisture and overall warm advection regime will cause cloud cover to increase rapidly early Sunday morning. Rain is expected to develop to the south and gradually spread north through the day. The axis of highest PW values nudging in from the south will top out around 1.75 to 2 inches...which is roughly 1-2 standard deviations above normal. This rich and humid air mass will allow for some efficient rainfall during the day Sunday and into Sunday evening before the ribbon of moisture moves off the coast. The stronger dynamical forcing will remain closer to the upper low to the west and instability will be limited as well, so conditions will only be marginal for heavy rainfall on Sunday. Much of the region will likely see scattered showers on and off through the day and into the evening hours. Highs in the afternoon will top out in the 70s...and then only drop only into the upper 50s and 60s Sunday night given the amount of cloud cover persisting into Monday morning. The upper low will be approaching from the west Monday morning and move into the IN/OH area by Monday afternoon. A secondary warm front will lift north across the mid Atlantic on Monday, which will allow for strong layer lifting over PA and into NY. The deepest moisture will still be centered off the coast, but stronger forcing from the approaching upper low and jet streak rounding the base of the low will provide the necessary ingredients for another round of showers through the day. There will also be a weak to moderate amount of instability present by Monday afternoon which will help generate convection and scattered thunderstorms. Deep layer shear is expected to hold off to the w/sw on storms are not expected to be severe at this time, but some heavy downpours are not out of the question. High temperatures are expected to rise into the mid to upper 70s close to 80 around Syracuse and Scranton on Monday. && .LONG TERM /TUESDAY THROUGH FRIDAY/... 230 PM update... The cutoff low over Ohio Monday evening will speed up and lift to the northeast across the eastern Great Lakes into southern Quebec by late Tuesday/early Wednesday. As this occurs scattered rain showers are possible across much of the region...especially Monday night through Tuesday evening on the front end of the system and as it passes through. The cold air at the center of the upper low as it moves across central NY/ne PA should cause steep low/mid level lapse rates to become favorable for isolated thunderstorms. Severe weather is not expected. Then, on the back side of the system, a drier and cooler air mass will settle in with some lake enhanced showers firing off downstream of Lake Ontario into Wednesday. High pressure really starts to dominate the region by Thursday with skies clearing off and temperatures rebounding. Highs on Tuesday should be able to climb into the mid to upper 70s, but with the cooler air sliding in from the west/nw, lows Tue night may fall into the lower to mid 50s. A bit more sun on Wednesday should bring temperatures back into the 70s once again, but with much lower humidity expected. Wed night may be the coolest night with lows dropping into the upper 40s in some higher elevations and lower to mid 50s for most other areas. && .AVIATION /02Z SATURDAY THROUGH WEDNESDAY/... Mostly VFR conditions are expected through the period, however fog will likely develop at ELM and RME overnight into early Saturday morning. Any fog will bring IFR restrictions through Saturday morning until an hour or two after sunrise. Otherwise, skies will be mostly clear with some mid-level cumulus over the region during the afternoon and some high clouds also move in from the south tomorrow evening ahead of the next system. Outlook... Saturday night...Mainly VFR. Sunday through Tuesday...Chance for rain showers and associated restrictions. Afternoon thunderstorms will be possible Monday and Tuesday afternoon. Wednesday...Lingering showers for SYR and RME Wednesday morning. Otherwise, mainly VFR. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...None. NY...None. && $$ SYNOPSIS...BTL NEAR TERM...BTL/JTC SHORT TERM...AJG LONG TERM...AJG AVIATION...MPK
Area Forecast Discussion
National Weather Service Boise ID
913 PM MDT Fri Sep 9 2022 .DISCUSSION...An upper level ridge will rebuild over the region over the short term. With slightly warmer temperatures possible, smoke may keep temperatures a few degrees lower than forecast. Smoky conditions will continue over the next several days with little change expected. && .AVIATION...Smoke reducing visibility. Surface winds: variable 10 kt or less becoming E-SE 10-15 kt Saturday. Winds aloft at 10k feet MSL: NW 10-20 kt, decreasing to 5-15 kt Saturday. Sunday Outlook...Smoke reducing visibility. Surface winds variable 10 kt or less, becoming E-SE 5-15 kt in the afternoon. && .AIR STAGNATION...Smoky conditions will continue over the next several days with little change expected. Some improvement may come early next week as shower chances increase. && .PREV DISCUSSION... SHORT TERM...Tonight through Sunday night...Today`s cool surface air mass and supporting upper trough will move off to the east tonight as an upper ridge approaches from the Pacific. This will lead to a warming trend that will peak on Sunday when the ridge passes overhead. Smoke from wildfires has become thick enough to require an Air Quality Advisory from the Idaho Department of Environmental Quality. The Advisory will last through 3 PM MDT Monday. With the HRRR smoke model showing smoke persisting under the incoming upper ridge, it is likely that all areas will remain smoky all the way through, thickest in northern parts of our CWA. Already the smoke is thick enough to lower daytime temperatures and we have lowered our forecast highs for both Saturday and Sunday about 1 degree in the south to 3 degrees in the north. Northwesterly surface winds today will become light to locally moderate easterly Saturday as a surface high pressure area moves to our east while a surface thermal trough forms to our west. On Sunday the surface thermal trough will be right over our CWA with light winds converging into it from the east and west. Moisture from Hurricane Kay off northern Baja California will work northward this weekend, reaching southern Harney and southern Malheur Counties early Monday morning. Clouds will increase in those counties but the rest of our CWA should stay clear, but smoky, through Sunday night. LONG TERM...Monday through Friday...The ridge from the weekend will continue to slide east through Idaho on Monday, allowing additional south to southwest flow over the region. Moisture remnants from Tropical Cyclone Kay are anticipated to move over the forecast area on Monday. Influence and coverage of this moisture will be influenced by a presence of a trough, which could limit shower presence. Confidence on development of showers on Monday is not overly high. The wave associated with the inland remnants of Kay will lift across the area on Tuesday, which looks to be another day of a challenged forecast. The speed of this trough varies per model, again influencing moisture location and intensity across the forecast area. Following this system, another wave of low pressure along the Pacific coast will move into the Pacific Northwest later in the week, after Wednesday and potentially as late as Thursday. Timing and resulting moisture will depend on the final track of this system. Potentially drier conditions anticipated Friday after the departure of that later trough. Overall, the long term forecast looks to have periods of showers and thunderstorms, with thunderstorm coverage mainly anticipated on and after Tuesday. Temperatures across the region will return to near normal on Tuesday, with values cooling to below normal by Thursday. && .BOI WATCHES/WARNINGS/ADVISORIES... ID...Fire Weather Watch from Sunday afternoon through Sunday evening IDZ402-403-421. OR...None. && $$ DISCUSSION...KA AVIATION.....JT AIR STAGNATION...KA PREV SHORT TERM...LC PREV LONG TERM....KB
Area Forecast Discussion
National Weather Service Boston/Norton MA
1015 PM EDT Fri Sep 9 2022 .SYNOPSIS... High pressure will continue to dominate our weather through this weekend with dry weather and seasonable late summer temperatures, although we will see a milky haze from wildfire smoke aloft. In addition, swells from distant Hurricane Earl will bring rough surf and a high risk of rip currents at the ocean beaches. Our weather will turn wet early next week with showers and thunderstorms at times. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... No major changes to the ongoing forecast this evening. Did tweak temperatures overnight to reflect observed trends. 745 PM Update: Forecast looks to be in great shape with no significant change needed at this time. High pressure established across Southern New England with clear skies, a dry air mass and light to calm winds. Sets the stage for strong radiational cooling now that the sun has set. As noted earlier, little to no lower level moisture evident in model forecast soundings supports mainly clear weather for many except at times in the river valleys late in the overnight. Lows look on track with no changes needed there as well. Previous discussion: Satellite loop shows clear skies throughout SNE this afternoon as high pressure remains in control. We may see some diurnal cumulus form near some of the higher terrain until sunset, but that`s about it. Starting to see some evidence of western wildfire smoke on GOES-16 Airmass RGB making its way into southern Canada and approaching the Northeast, much like HRRR forecasts indicate. It`s possible we may be in for a reddish sunset tonight and especially during sunrise Saturday. Otherwise, we`re in for another night of ideal radiational cooling conditions with a dry airmass, clear skies, and light winds. Model cross sections don`t show a lot of lower level moisture than they have past few nights, so any fog/low clouds should be fairly localized and limited to interior valleys. Sided with cooler MOS guidance for lows tonight, mainly in 50s to lower 60s. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/... 100 PM Update: * High surf/dangerous rip currents Saturday at ocean beaches For those planning a trip to the beach Saturday, be aware that we expect high surf and dangerous rip currents at ocean beaches (both South Coast/Islands and on the North Shore). Remember that most beaches are no longer staffed with lifeguards for the season since we are now past Labor Day. It will also be dangerous to view the surf from jetties or the coastline, so be sure to stay a safe distance away! It`s quite possible an elevated rip current threat will persist Sunday too. A High Surf Advisory remains posted Saturday for the ocean beaches along south coast of RI and MA, including Cape Cod and the Islands. Offshore buoys are reporting long period swells of 7+ ft, from combination of low pressure over North Atlantic and some contribution from distant Hurricane Earl. These swells are expected to peak early Saturday morning and will bring rough surf and dangerous rip currents to ocean beaches. We added the North Shore as well (coastal Essex County) for Saturday since model wave guidance pushes these higher SE swells westward toward Cape Ann during the day. Areas from Boston south to Plymouth County should be spared of these higher swells due to shadowing effects from the Cape. Otherwise, high pressure will bring another day of sunshine and slightly warmer temperatures (80s), except along immediate coast where sea breezes will keep it a little cooler. Saturday night will be another night of clear skies and light winds, but slightly higher dewpoints means low temperatures will run a little milder, mainly in 60s. && .LONG TERM /SUNDAY THROUGH FRIDAY/... Highlights: * Increasing clouds but continued dry for Sunday. Rip currents due to swell from distant Hurricane Earl may continue to affect the coastlines. * Unsettled Mon and Tues with showers and embedded t-storms. While severe weather not anticipated, could have localized downpours. Temps cool to more seasonable levels. * Drier weather returns for mid to late week with cooler than normal temperatures for late Sept. Details: Sunday: Deep layer ridge remains established across SNE early on Sunday, but recent runs in guidance shows a tendency to weaken the ridge sooner than prior indications. Per model forecast soundings this doesn`t translate to rain chances on Sunday, with a good amount of unsaturated air below 500-600 mb. Shown mostly cloudy skies but a lot of this cloudiness should be of the mid- level cloud type with dry weather for the daytime hrs. Clouds continue to increase Sunday evening as ridge axis shifts eastward, allowing for rising moisture levels and some mid/upper level support for increasing rain chances across western MA/CT. Cooler highs in the mid 70s to around 80 for the western interior areas and along the immediate coastline, with warmer mid-80s highs in the coastal plain. Lows mainly low to mid 60s with an uptick in humidity level. Note that we may still have some lingering swell from distant Hurricane Earl that could continue a risk for rip currents into Sunday; though it won`t necessarily be a great beach day (at least compared to Sat) but keeping awareness high as beaches become less staffed with lifeguards in the post Labor Day period. Monday through Tuesday Night: Still anticipating a couple days of wet weather as a plume of elevated PWAT values (1.5-1.7" / 1.5-2 standard deviations above normal for mid-Sept) interacts with height falls associated with a closed but gradually deamplifying low across the Gt Lakes. Some instability is noted in some models, most bullishly in the NAM with CAPE with about 800-1000 J/kg. In addition, in conjunction with the high PWAT values we do also see warm cloud depths in the 12kft to 13kft range favorable for efficient downpours through warm rain microphysical processes. Probably won`t see severe weather given modest to borderline- supportive vertical wind profiles; these profiles also are strong enough from a storm-motion perspective to keep showers/embedded storms moving. Kept PoP at high chance to low likely for now but could see a need to increase these in coming day pending continued consistency in subsequent guidance. Closed low deamplifies Tue night as it moves NE into northern New England, swinging a cold front through SNE Tue night into early Wed AM, tapering off rain chances. Temperatures trend cooler than normal on the highs (mid 70s-near 80) owing to cloudiness/rain and reduced sunshine but milder than normal low (mid 60s) due to the same influences at night. Wednesday through Thursday Night: Other than some spotty light rain showers across northern MA, many areas are generally dry. While dry weather prevails, a shot of colder air (850 mb temps in the mid to upper single digits C) and high pres in control, it could support some cool nights with much lower humidity in this period. Highs also look to trend cooler than normal, in the mid to upper 70s. && .AVIATION /02Z SATURDAY THROUGH WEDNESDAY/... Forecaster Confidence Levels: Low - less than 30 percent. Medium - 30 to 60 percent. High - greater than 60 percent. High confidence. VFR through Saturday night. Expect some localized MVFR/IFR in patchy valley fog tonight and again Saturday night, but it should be less widespread than past few mornings. Light winds will allow for coastal sea breezes Saturday. KBOS Terminal...High confidence in TAF. KBDL Terminal...High confidence in TAF. Outlook /Sunday through Wednesday/... Saturday Night through Sunday Night: VFR. Monday: Mainly VFR, with local MVFR possible. Chance SHRA. Monday Night: Mainly VFR, with local IFR possible. SHRA likely. Tuesday: Mainly VFR, with local IFR possible. Breezy. Chance SHRA. && .MARINE... Forecaster Confidence Levels: Low - less than 30 percent. Medium - 30 to 60 percent. High - greater than 60 percent. 100 PM Update: High confidence. High pressure will remain over waters through Saturday night. NE winds will diminish tonight, followed by lighter winds and coastal sea breezes Saturday, then light southerly winds Saturday night. SCAs remain posted for rough seas on outer waters and for RI/Block Island Sounds. Seas peak Saturday morning, mainly due to SE swell, and begin to subside Saturday night. Please refer to the discussion on High Surf Advisories in Short Term section above. Outlook /Sunday through Wednesday/... Saturday Night: Winds less than 25 kt. Local rough seas. Sunday through Sunday Night: Winds less than 25 kt. Seas up to 5 ft. Monday: Winds less than 25 kt. Areas of seas approaching 5 ft. Slight chance of rain showers. Monday Night through Tuesday: Winds less than 25 kt. Seas locally approaching 5 ft. Chance of rain showers. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...High Surf Advisory from 6 AM to 6 PM EDT Saturday for MAZ007. High Surf Advisory until 6 PM EDT Saturday for MAZ020-022>024. RI...High Surf Advisory until 6 PM EDT Saturday for RIZ006>008. MARINE...Small Craft Advisory until 8 AM EDT Saturday for ANZ232. Small Craft Advisory until 6 PM EDT Saturday for ANZ235-237. Small Craft Advisory until 8 AM EDT Sunday for ANZ250-254>256. && $$ SYNOPSIS...Belk/Loconto/JWD NEAR TERM...Belk/Loconto/JWD SHORT TERM...JWD LONG TERM...Loconto AVIATION...Belk/Loconto/JWD MARINE...Loconto/JWD
Area Forecast Discussion
National Weather Service Caribou ME
936 PM EDT Fri Sep 9 2022 .SYNOPSIS... High pressure will prevail tonight through the weekend. A weak cold front will stall north of Maine Monday. Low pressure from the west will approach Tuesday and move over the area Wednesday. && .NEAR TERM /THROUGH SATURDAY NIGHT/... 928 PM update...Dropped overnight lows a degree in two in line with trends from recent nights. With the longer nights this time of year and dew points in the upper 50s to lower 60s, areas of fog appear destined to form again after midnight in river valleys under a steep and shallow radiation inversion. The other item of interest for Saturday besides unseasonably warm and humid conditions will be smoke. Smoke from western fires is expected to create hazy conditions throughout Saturday based on METSAT trends and HRRR guidance. The smoke is above 5000 feet. High pressure will remain over the region for tonight and Saturday, making for clear skies and calm winds. For tonight, HREF and SREF models indicate another round of valley and river fog in the late hours. Some higher terrains could see encroaching patchy fog in the early morning hours on Saturday. The warm airmass at 925mb will stick around the area through tonight with temps around 18C. This with the thin layer of mid level clouds push temps into the upper 50s tonight. By Saturday, ample sunshine after the initial morning fog. Once that burns off, sun and the warm airmass will push temps to above average values for this time of year. Expect highs in the low 80s with calm winds. For Coastal Downeast, the very distant Hurricane Earl will affect seas on Saturday, creating 13-15 second swell, which will generate some dangerous waves along the coast. A High Surf Advisory has been issued beginning in the early morning Saturday and ending late Saturday evening. && .SHORT TERM /SUNDAY/... H5 ridge will be firmly entrenched over the CWA on Sunday. With high pressure at the surface accompanied by clear skies and light winds another round of river valley fog is expected Sat night into Sun morning. High cirrus will move into fm the west shortly after daybreak and spread east during the day. However expect cirrus will be thin enuf drg the day to have little impact on temps with highs well into the 80s over inland locations. Temps wl obviously be cooler where fog tends to hang on longer in the morning. Cold front will be dropping south thru Quebec drg the day before slowing down and essentially weakening in place btwn 06-12z Monday to the north of the border. This wl result in cloudy skies and should prevent valley fog fm developing Sun night along with warmer min temps Mon morning. With boundary lurking acrs the north cannot rule out an isold shower developing over the St. John Valley in the afternoon. GFS indicates a fairly potent s/wv moving thru the state drg the afternoon but rmng operational runs do not indicate this, including it`s ensemble mean and have discounted this soln. && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... Our focus Monday night into Tuesday will be on an upper low lifting out of the Great Lakes and toward the Northeast. The upper low will cross into the southern Great Lakes Monday night as a weak surface low and occlusion approaches the Mid-Atlantic coast. Moisture lifting north ahead of the occlusion will bring increasing clouds Monday night. The occlusion will begin to push into our region on Tuesday as the upper low slides into the eastern Great Lakes. This will likely bring showers late Tuesday into Tuesday night. Both the GFS and ECMWF indicate there may be some mid level convection supported by humid air advecting north beneath upper level divergence and cooling associated with the approach of the upper low. This could make rainfall amounts quite variable across the area with widespread light to moderate rain and locally heavier rain where the convection sets up. Showers will continue Tuesday night then diminish on Wednesday as the low lifts out to the northeast. A surge of much cooler air will follow Wednesday night into Thursday as high pressure approaches and pushes Canadian air south across our region. High pressure will crest over the area Thursday night bringing a clear, calm and cold night possibly with some Frost in the colder northern valleys. A mostly sunny and seasonably cool day should follow for Friday with high pressure remaining over the area. && .AVIATION /02Z SATURDAY THROUGH WEDNESDAY/... NEAR TERM: Mainly VFR conditions tonight in light and variable winds. Early morning IFR/LIFR in low terrain terminals due to areas of fog. For Saturday, ample VFR conditions with light and variable winds. SHORT TERM: Monday night...VFR Lowering to MVFR or IFR Downeast and MVFR over the north. Light S wind. Tuesday IFR downeast, MVFR possibly lowering to IFR north. Light SE wind. Tuesday night...IFR, Possible S LLWS. S wind. Wednesday. IFR improving to VFR Downeast and MVFR north. Light S wind becoming NW and gusty late. && .MARINE... NEAR TERM: Winds will remain below SCA, however, Hurricane Earl will cause seas to increase throughout tonight into Saturday. Long period swell waves of 13-15 sec will build in generating wave heights of 5-7 ft in the outer waters and up to 5 ft for intracoastal waters. Thus a Small Craft Advisory has been issued beginning tonight through Saturday evening. SHORT TERM: Wind and seas are expected to be below SCA Tue night through mid- week. However, a cold frontal passage may result in some brief wind gusts up to 25 kt on Wed. Humid air over the waters and showers may lower vsby Tue into Tue night. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...High Surf Advisory from 5 AM to 8 PM EDT Saturday for MEZ029- 030. MARINE...Small Craft Advisory until 11 PM EDT Saturday for ANZ050-051. Small Craft Advisory from 6 AM to 8 PM EDT Saturday for ANZ052. && $$ Near Term...LaFlash/MCW Short Term...Buster Long Term...Bloomer Aviation...LaFlash/MCW/Buster Marine...LaFlash/MCW/Buster
Area Forecast Discussion...UPDATED
National Weather Service Morristown TN
1034 PM EDT Fri Sep 9 2022 ...New UPDATE... .UPDATE... Issued at 1018 PM EDT Fri Sep 9 2022 Forecast appears to be in good shape. Made only some slight adjustments to PoPs and winds over the next few hours, and largely blended towards the previous forecast from late tonight through the daybreak time frame. Regional radar imagery shows some light returns moving NW from SC and GA towards our CWA. Have been hard pressed to find any rainfall reaching the surface on surface obs this evening, outside of northwest AL, so did go ahead and lower PoPs through the next several hours to come in line with the more recent runs of the HRRR. Otherwise, as mentioned, largely blended back towards the previous forecast after 06z-09z or so. Continue to agree with the day shift that there`s a possibility that some advisory level wind gusts could be seen in the mountains later tonight. Increasing southeast H85 flow through the overnight hours will provide some gusty winds to the higher terrain, and the latest HRRR and even NBM guidance show some mountain wave- like signatures extending away from the mountains and into the TN valley after midnight. However, lack of more supporting features (strong inversion above mountaintop level, strong pressure gradients across the Appalachians, etc) give me enough pause to forego issuing an advisory at this time. Think the stronger wind gusts will be more the exception than the rule, although breezy conditions are expected in the higher terrain. && .SHORT TERM... (This evening through Saturday) Issued at 256 PM EDT Fri Sep 9 2022 Key Messages: 1. Area of showers and perhaps a few rumbles of thunder will lift north across the area tonight into Saturday. 2. Gusty winds in some of the higher elevations and foothills of the E TN mountains tonight into early Saturday. Discussion: In the upper levels, a closed low over the lower Mississippi Valley will slowly drift northwest and weaken. Lower levels will feature southeast flow that will strengthen tonight and then weaken a bit and turn more southerly. A band of isentropic lift will surge north across the area later tonight into Saturday and will be the primary focus for rain across our area. Convective energy looks very limited at best, so will include no more than a slight chance of thunder in the forecast. There will be plenty of available moisture with PW values approaching 2 inches across much of the area. However, the band should move quickly enough to keep flooding risk low most areas. In addition, the low level flow will be downsloping into the northern/central valley areas which will also help to keep precip amounts lower in those areas. However, some heavier showers may linger long enough to produce isolated localized flooding, so will keep the mention of localized flooding that is already in the HWO. The 850 mb jet will be southeast and approach 30 to 40 kts tonight into early Saturday. Looking at the vertical wind/temperature profile and the overall pattern, it does not look very favorable for mountain wave enhancement. While it looks marginal for a east TN mountain/foothills wind advisory, still do expect some strong wind gusts in the normally favored locations tonight into Saturday morning and this will be mentioned in the HWO as well. && .LONG TERM... (Saturday night through next Friday) Issued at 256 PM EDT Fri Sep 9 2022 Key Messages: 1. Unsettled, wet weather continues Sunday into Monday ahead of a cold front. 2. Cold front moves through Monday with dry and seasonable weather expected most of next week. Discussion: At the start of the extended period, an open wave will be in the process of phasing with a northern stream wave that will dig into the midwest. This northern stream wave will eventually become cutoff on Sunday with an upper low meandering across the Midwest and into the Ohio Valley into early next week. Southerly flow in the boundary layer will keep a moist airmass in place Sunday into Monday while mid level PVA and upper level divergence keeps synoptic scale ascent across the area for likely or higher PoPs. A front will progress through the area Monday with much drier air in its wake. Precipitation chances will be tapering off from west to east on Monday with the highest chances being along and east of I-81, across portions of northeast Tennessee and southwest Virginia. The upper low begins to move off toward the northeast Monday night into Tuesday. Behind this feature, heights will begin to increase as ridging sets up across the plains and MS River Valley. This will keep conditions dry Tuesday through Friday with temperatures near normal. && .AVIATION... (00Z TAFS) Issued at 756 PM EDT Fri Sep 9 2022 Expect VFR flight categories to continue until late tonight for KCHA and probably into the morning hours for KTYS and KTRI. Current guidance shows band of showers lifting north into the TN valley between 09z and 11z. Easterly flow across the Appalachians will likely hinder showers moving north through KTYS and KTRI so have trended TAFs accordingly. Ceilings are expected to fall to IFR levels at KCHA but may be slow to lower further north due to downslope flow counteracting increasing low level moisture. && .PRELIMINARY POINT TEMPS/POPS... Chattanooga Airport, TN 84 68 77 70 / 20 80 80 50 Knoxville McGhee Tyson Airport, TN 84 67 78 68 / 20 70 70 50 Oak Ridge, TN 85 66 76 67 / 20 70 80 50 Tri Cities Airport, TN 81 63 76 65 / 10 40 80 60 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$ SHORT TERM...CD LONG TERM....Diegan AVIATION...CD
Area Forecast Discussion
National Weather Service Portland OR
323 PM PDT Fri Sep 9 2022 .SYNOPSIS...A strong east wind event is on tap for today into early Saturday. This will bring critical fire weather conditions, above normal temperatures, and smoke and haze in various quantities for different parts of the area. A southerly flow reversal Sunday into Monday will lead to a strong onshore push which will replenish moisture for lower elevations, along with a cooling trend next week. && ..DISCUSSION (through Thursday)...Water vapor satellite imagery at 3 PM shows tremendously dry mid levels as northeast flow continues across Oregon and Washington behind an upper trough which is diving southeastward towards the Great Basin. Below normal temperatures continue as the cool air mass associated with this trough has become entrenched across eastern Oregon and Washington, while west of the Cascades temperatures are running a solid 10 degrees above normal as east flow is downsloping across the Cascades. The North Bend minus Spokane pressure difference has increased to 15.4mb as of 2PM (which is over-performing a bit from what guidance has suggested), and unsurprisingly wind speeds have spiked in response. Gusts to 40 mph have been observed in many locations, including at PDX with the onset of the easterly surface flow this morning from the Gorge. Overall, HREF is suggesting peak gusts for most areas will be 10-15mph less than they were during the 2020 Labor Day event, so we`ll continue to message the possibility of gusts to around 25-35mph across much of the Willamette Valley, 35- 45mph near the Portland/Vancouver Metro, and 45-55mph across the high Cascades and exposed areas in the Foothills this evening. Overnight tonight, the event will turn into more of a classic gap flow event, where areas within and downwind (i.e., west) of the gaps in the Cascades and Coast Range - most notably the Columbia River Gorge - will experience their highest winds. The mean of the HREF ensemble is suggesting gusts to 50+mph through the west end of the Columbia River Gorge tonight, which seems reasonable given the forecast maximum pressure difference of roughly 8mb from Astoria to the Dalles for early Saturday morning. The CAMs have not been doing a great job of resolving where the best mixing of strong winds a few thousand feet above the surface will reach the ground thus far during this event, and so it`s doubtful they will do well tomorrow either. Still, it`s worth noting they`re suggesting another burst in the northern lowlands when surface heating begins tomorrow morning. This seems like a reasonable possibility given forecast soundings are advertising still a fair amount of wind even just a thousand feet above the ground at that time, though the strong winds aloft will be quickly easing as the gradient weakens with the northeastward shift of the coastal thermal trough and resultant moderating temperatures east of the Cascades. As a surface low moves up the coast Saturday and Saturday night, a southerly flow reversal will overspread the forecast area from the southwest to bring in cooler conditions and increase low level moisture, finally assuaging some fire weather concerns for many (but not all) areas; more details on that follow in the fire weather discussion. The other concern is wildfire smoke. DEQ`s website suggests air quality has deteriorated into the moderate category for many locations, including (1) the Portland Metro where smoke has entered the area from wildfires to our north and east, and (2) the Eugene and Corvallis areas where smoke has arrived from primarily the Cedar Creek Fire near Oakridge. The particulates resulting in this reduced air quality are PM2.5, which are particularly hazardous to human health, so staying inside and keeping windows closed if possible is recommended. It is uncertain what will happen with air quality across the area tonight into tomorrow, but the HRRR smoke model suggests additional smoke will filter into the region from the east due to the strong winds. Saturday will also be a hot day, and some locations will have the potential to experience record high temperatures as readings climb into the mid to upper 90s inland and low 80s to locally 90 along the coast. NBM continues to hint at this potential heat for coastal communities as it advertises a 60% chance for highs above 85 degrees at Astoria. The one exception to the heat inland will be in parts of Lane County where the smoke concentration is the greatest and high temperatures could be cut several degrees short by the smoke`s limiting effect on incoming short wave radiation. The CAMs are hinting that some convection could fire along the leading edge of the cold front from the offshore low Saturday evening, though no members of either the EPS or GEFS ensembles are putting QPF anywhere in the area and soundings suggest the moisture will be above 600mb (except along the coast where there will be some marine moisture). Given the conflicting data, a 20% chance for showers was added to much of the area tomorrow evening/night, meaning there will be a four times greater probability that rain will not fall than that it will. Anything that falls will likely only be a few sprinkles, as is often the case with virga. Sunday, onshore flow keeps the area much cooler compared with Saturday, and the southwest to west flow should drive much of the smoke out except in the immediate vicinity of fires. (Unfortunately, this could result in a wave of low level smoke surging up the Willamette Valley into southern Washington Saturday night into early Sunday morning. But even so, the front is likely to loft whatever low level smoke is present so that it is no longer concentrated near the surface.) The upper low finally passes above the area Monday, deepening the marine layer and likely resulting in drizzle for low elevations both Monday morning and possibly Tuesday morning as well. The EPS ensemble even has several members producing QPF for PDX Monday morning, indicating the drizzle could reach inland locations too. Overall, the pattern for early to mid week next week looks much cooler; according to cluster analysis there isn`t a whole lot of spread among the ensemble members in the upper level synoptics, and according to NBM there isn`t much spread in the low level weather conditions forecast by those members either. NBM gives around a 75-8 5% chance that highs will not surpass 80 Tuesday through Thursday of next week. -Bumgardner && .FIRE...Significant offshore wind event is underway this afternoon as a well defined thermal trough resides along the CA and OR coasts while surface high pressure builds over the Columbia River Basin, promoting moderate to strong east winds over much of northwest OR and southwest WA. Relative humidity values are generally in the teens across the area with a few obs showing single digits in Willamette National Forest. Red Flag Warnings remain largely on track with respect to timing and forecast details. Expect winds to peak tonight into early Saturday over the higher terrain and through the Gorge, with some gusts to 50 mph over exposed terrain in the Cascades and 40-45 mph gusts in the Gorge and over favored terrain in the Coast Range. For Willamette Valley, have tweaked the wind forecast upward in the northern valley this evening based on a few gusts to around 40 mph coming out of the Gorge into PDX this afternoon. Otherwise, still generally expecting winds to max out around 35 mph in the rest of the valley this evening, with a relative lull overnight and winds then picking back up Saturday morning. Overnight recoveries will be poor throughout the area, struggling to reach 30 percent in most locations and especially in the Cascades. Winds should diminish relatively quickly on Saturday night as the thermal trough develops into a closed low and pushes offshore, weakening the gradient. This will yield improving although still relatively dry conditions for Sunday. /CB && .AVIATION...00Z TAFs: Strong easterly winds continue throughout the area with gusts as high as 45 kt at the highest terrain, and around 30 kt through the Willamette Valley. Currently receiving reports of LLWS but due to the uniformity of the wind speeds, have omitted from the forecasts. Satellite imagery shows widespread smoke from the Cedar Creek Fire pushing eastward over the southern Willamette Valley including KEUG and KSLE. Seeing some reductions to visibility due to smoke and haze, and there still remains the possibility of seeing IFR level conditions if smoke settles to the surface. Elsewhere, will likely see some smoke aloft or haze due to nearby fires, but not expected to be nearly as concentrated. Could see some eddies forming on the leeward side of the mountains due to downsloping and warming, although confidence is low. Easterly winds will strengthen downstream of the Columbia River Gorge at KTTD and Coast Range gaps such as KTMK and KAST through 06-09z Saturday before gradually weakening thereafter. For detailed Pac NW aviation weather information, go online to: KPDX AND APPROACHES...VFR conditions will persist through the next 24 hours. Will see very gusty easterly winds with speeds upwards of 35 kt at times. Reports of LLWS below 2000 ft at +/- 10 kt, but due to a lack of directional shear, have not included in the TAF. Winds will ease slightly after 10Z Saturday, but not expected to reduce significantly until later Saturday morning. -Muessle && .MARINE...A closed area of low pressure continues to push northward along the coastline which, when combined with high pressure inland, is creating very strong offshore flow. Expecting gusty winds around 15 to 20 kt with gusts up to 25 kt throughout all of the waters, easing from the inner waters westward starting early this evening. Winds have been slow to increase today, but have been sitting right along the Small Craft Advisory wind threshold. However, seas remain elevated with hazardous, choppy seas. Generally seeing seas around 7 to 9 ft at 9 to 10 seconds throughout the waters. These conditions will persist through the evening, when they will begin to ease to closer to 5 to 7 ft. Will continue the Small Craft Advisory due to a combination of winds and hazardous seas. After this east wind event, will see a wind reversal as onshore flow returns on Sunday. A southwesterly flow will usher in monsoonal moisture from the decaying tropical storm off of the California Coast. Could see slightly elevated winds at that time, but do think they will be marginal. High pressure builds once again bringing a typical summertime pattern to the region. -Muessle For information about upcoming marine zone changes, go online to: && .PQR WATCHES/WARNINGS/ADVISORIES... OR...Red Flag Warning until 8 PM PDT Saturday for Central Oregon Coast-North Oregon Coast. Red Flag Warning until 11 PM PDT Saturday for Central Oregon Cascade Foothills-East Slopes of the Central Oregon Coast Range-Mt. Hood National Forest West of Cascade Crest-North Oregon Cascade Foothills-North Oregon Coast Range- Willamette National Forest-Willamette Valley. WA...Red Flag Warning until 8 PM PDT Saturday for South Washington Coast and West Willapa Hills. Red Flag Warning until 11 PM PDT Saturday for Clark County Lowlands-East Willapa Hills-Eastern Gifford Pinchot National Forest Mt Adams Ranger District-Extreme South Washington Cascades and Foothills. PZ...Small Craft Advisory from 3 AM to 8 AM PDT Saturday for Columbia River Bar. Small Craft Advisory until 9 AM PDT Saturday for Coastal waters from Cape Shoalwater WA to Cascade Head OR out 10 nm-Waters from Cascade Head to Florence OR from 10 to 60 nm. Small Craft Advisory until 3 AM PDT Saturday for Coastal waters from Cascade Head to Florence OR out 10 nm. Small Craft Advisory until 3 PM PDT Saturday for Waters from Cape Shoalwater WA to Cascade Head OR from 10 to 60 nm. && $$ Interact with us via social media:
Area Forecast Discussion
National Weather Service Reno NV
301 PM PDT Fri Sep 9 2022 .SYNOPSIS... Warm daytime temperatures will be present through the weekend, but cooler days are in store for next week. Shower and thunderstorm activity will be present for areas in the Sierra Nevada as a tropical system migrates northward. Chances for showers and storms remain through early week before the moisture exits to the east later in the week. && .SHORT TERM... Smoke from surrounding wildfires, especially from the Mosquito Fire actively burning on the western Sierra slopes, has quickly become a major concern for northern CA and western NV communities. Smoke will continue to impact the region for the foreseeable future with degraded air quality and significant visibility reductions. Recent HRRR smoke forecast guidance indicates major smoke impacts for the Martis Valley, Carson Valley, and Tahoe Basin this afternoon. Light winds overnight will provide little relief, as smoke looks to linger in these areas into tomorrow morning. A wave of near-surface smoke looks to push east of the Sierra crest tomorrow afternoon, with potential for widespread air quality impacts even into the Greater Reno-Sparks area. If you have outdoor plans this weekend, consider postponing or cancelling them to days with better air quality as unhealthy to very unhealthy AQI is likely. For latest air quality in your location, please visit Another round of isolated thunderstorms are possible this afternoon, mainly for the Eastern Sierra. Biggest concerns for any storms that develop include dry lightning strikes outside of precip cores and gusty outflow winds up to 50 mph. Thunderstorm chances increase on Saturday for most areas south of US-50 as Tropical Storm Kay tracks into southern CA and pushes moisture northward along the Sierra. Storms look to develop early tomorrow afternoon, taking a northwest track through the evening. These storms will likely be wetter in nature, with localized areas of heavy rain possible. Rainfall amounts will be generally on the lighter side, up to 0.01", however the rainfall rates in terrain driven showers could produce wetting rains of up to 0.25". The areas of main concern are for Mono, Mineral and even as far north as Alpine County. This calls to attention burn scars in elevated terrain, since showers in those areas will be the most efficient rain makers. A gradual cooling trend continues today, with highs finally below 100 degrees! However, highs through tomorrow will remain above- average for this time of year. -Whitlam .LONG TERM... Sunday into Next Week... One thing that is certain in the extended forecast, temperatures will be moderating towards seasonable averages. Sunday kicks off a series of lowering daytime highs, with western Nevada valleys starting to see upper 80s to low 90s. Sierra locations will be refreshed to see 70s and even some 60s! Throughout the week this trend continues, and by midweek lower valleys will hover in the low 80s. A low moving into the Pacific Northwest has already begun to shift our airmass, allowing for the influx of cooler temperatures. So if you`re waiting to be rewarded for your perseverance through the recent heatwave, your patience won`t have to be prolonged. Winds will be light through early afternoon, before the typical afternoon breezes gust to around 25 mph. Monday will be a similar situation, although the wind field will be influenced from the south by flow associated with a tropical system. This southerly flow will become more westerly as the system lifts into the Great Basin into the latter part of the week. As the system begins an eastward trajectory by midweek, winds look to become stronger during our late day breezy period. One other consideration will be gusty outflows associated with any showers and storms that form in the eastern Sierra. Now for the lower confidence items in the forecast... Smoke from the Mosquito Fire will continue to dominate area skies, with fluctuating air quality values. This afternoon, the Tahoe Basin and Carson Valleys are being impacted by poor air quality. The smoke projections are dependent on the behavior of the fire as well as wind speed and direction. We are good at predicting winds, but we cannot predict how a fire will behave. The moral of the story is the forecasts for smoke plumes will vary daily. For now, we have seen extreme fire behavior that has created the dense smoke overhead, and we anticipate the trend to continue for the foreseeable future. The next item of concern is the tropical system streaming northwestward along the southern Pacific coast. Recent ensemble guidance suggests a weakening system as we go forward in time, which lessens our chances of getting significant rainfall this far north. Tropical Storm Kay is projected to move further out to sea, and into cooler waters, which will further the weakening process. Areas along the Sierra Nevada mountains will see the most impacts from this system. Higher terrain will help to squeeze out the moisture as the topographical lift provides additional forcing. For Sunday into Monday, chances range from 45-65% for Mono County, but even the Tahoe Basin could see chances around 40%. Lower elevations may only see some cloud cover, although with the smoke coverage, it could be hard to distinguish cloud layers from the smoke. The shower chances dwindle to 30-40% into midweek, as the system gets moved eastward over the Great Basin after being swept into the main flow. We sure could use some of this tropical moisture to surge further northward and help us out with the Mosquito Fire, but it doesn`t seem likely at this time. -HRICH && .AVIATION... Smoke and haze will continue to impact most regional terminals through the weekend. MVFR and occasional IFR conditions are possible for KTVL/KCXP/KMEV after 00 UTC as high concentrations of near- surface smoke from the Mosquito Fire pushes east of the Sierra crest. Additional waves of dense smoke are expected each afternoon and evening this weekend. Otherwise, haze will impact slantwise visibility for all terminals. Isolated thunderstorms are possible this afternoon for Mono and southern Mineral counties, which may impact KMMH. Storms look to produce little rain today, but they are capable of producing gusty, erratic outflow winds between 30-40 kts. Thunderstorm chances expand northward to the US-50 corridor on Saturday, with potential to impact KMEV/KMMH. These storms look to produce heavier rains, which may lead to mountain obscurations and reduced vis/cigs. -Whitlam && .CLIMATE... As we close the book on this unparalleled early September heat wave, the number of records set at Reno are plentiful: * New Daily Record Highs: 7 days in September with new records set, plus 2 more days on August 30-31 with tied record highs. The record of 106 on 9/6 blew past the previous record on that date by an impressive 10 degrees! * Warmest September Temperature: 106 degrees on 9/6. This surpassed the highest temperature ever reported in September (and even August), and was equal to the 4th hottest day in Reno`s climate history. * Latest Calendar Day with 100+ degrees: Set on 9/8/2022, three days later than the previous record from 2020. * Total number of 100+ degree days in September: 8 days. Prior to 2022, only 8 100+ degree days occurred in September through the ENTIRE climate history of Reno, going back to 1888. * New Daily Record High Minimums: A total of 5 record high minimum temperatures were set and 2 were tied between 8/30 and 9/8. * Warmest minimum temperature for any September day: 69 degrees on 9/7, surpassing the previous record of 67 degrees. * Consecutive 100+ degree days: 9 days, from 8/31 through 9/8. This is the third longest such streak, just short of two 10-day streaks which occurred in July 2005 and July 2021. * Total number of 100+ days in a calendar year: 22 days, equaling the record total set just last year. && .REV Watches/Warnings/Advisories... NV...None. CA...None. && $$