Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 09/26/21

Area Forecast Discussion
National Weather Service Boston/Norton MA
1003 PM EDT Sat Sep 25 2021 .SYNOPSIS... Low pressure southeast of Nantucket moves northwest along a stalled front overnight. Showers and an isolated thunderstorm are likely overnight, mainly across Rhode Island and eastern Massachusetts. Dry by late Sunday morning. Showers possible Monday and Tuesday as a series of fronts move through. Cooler and drier mid-week. Unsettled conditions possible late in the week with low pressure passing offshore. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... Based this update largely on the last few runs of the HRRR and RAP. favor the idea of these guidance that scattered showers will become more widespread after midnight. Still thinking the majority of showers stay towards the east coast. Instability and lapse rates remain limited, but cannot dismiss the idea of a thunderstorm or two. The main outcome of those would be downpours. Minor tweaks to temperatures to bring them back in line with observed trends. 630 PM update... Latest visible satellite imagery clearly depicts a low pressure center about 200 miles off the coast of Maryland. The latest MSLP analysis from the RAP resolves this feature quite well. Latest guidance from 18Z HREF, 21Z RAP , and the consensus of the short- term forecast models (CONSSHORT), have shifted the axis of heaviest rainfall slightly east for this evening. Update the forecast grids to reflex this change. Still expecting to see rainfall amounts in the .5 to .75 inch rain with isolated higher amounts possible over east/southeastern MA. Model soundings from the RAP also depict modest instability overnight that could support a few rumbles of thunder. Other than the slight eastward shift of heaviest rainfall, the previous forecast remains on track. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/... 325 PM update... Any showers move offshore before 9 or 10 AM Sunday morning, as low pressure pulls out to the northeast. Sunday will then turn out mainly sunny with near normal temperatures...highs mainly 70 to 75. With the low pressure strengthening to our northeast and with strong high pressure building in from the Tennessee Valley, winds will turn to the west-northwest and may gust to 10-20 mph. Clear skies are forecast for Sunday night, with drier air allowing for good radiational cooling. Overnight lows should drop to the lower 50s except upper 40s northwest MA and mid or upper 50s Cape Cod and the islands. && .LONG TERM /MONDAY THROUGH SATURDAY/... 325 PM update... Highlights... * Showers possible Monday and Tuesday as a series of fronts move through southern New England * Cooler/drier conditions beginning mid-week in the wake of a cold frontal passage on Tuesday * Wet/unsettled conditions possible late week with a passing off- shore low. Monday and Tuesday... Deep southwest flow will keep temperatures and humidity slightly above normal on Monday and Tuesday. Increasing moisture on Monday from persistent southwest flow will support isolated showers Monday afternoon as a warm front lifts through southern New England. On Tuesday we`ll see higher precipitation chances as a stronger cold front pushes through southern New England Tuesday afternoon. Modest CAPE (200-400 J/kg) and 0-6 km shear (25-30 knots) may support some isolated thunderstorms as well. Behind the front, northwest flow users cooler/drier air into southern New England along with more fall like conditions for mid-late week. Wednesday into next weekend... Strong cold air advection and deep north/northwesterly flow behind Tuesday`s cold front will usher cooler/drier air into southern New England. This will have the area feeling much more like fall with daily high/low temperatures in the mid 60s/upper 40s respectively. Expect these conditions to persist through at least Thursday as deep north/northwest flow is forecast to prevail by the majority of the deterministic/ensemble models. By Friday we start to see some spread in the deterministic model guidance with respect to precipitation chances from a passing offshore low. The GFS solution takes this low well offshore and into Nova Scotia late week, while the EURO takes the low inland producing cool/wet conditions for Friday. Ensemble guidance offers little improvements in confidence as there is a split in the EC/GEFS members with respect to wet/dry conditions. Thus, have leaned on the NBM which places slight chance PoPs across the region for Friday. Much of next weekend`s forecast will hinder on whether or not this low traverses inland. Should that be the case we`ll be dealing with cool/wet fall like conditions. In the alternative scenario where the low stays more off shore we`ll be dealing with cool/dry fall like conditions. We`ll have a better idea of what to expect as the path of this off-shore low becomes more clear in future model runs. Stay tuned for additional details. && .AVIATION /02Z SUNDAY THROUGH THURSDAY/... Forecaster Confidence Levels. Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Tonight...Moderate confidence. Mainly VFR across western terminals. MVFR developing in central sections, with IFR developing across eastern terminals. Showers likely across northeast CT, RI and central and eastern MA as low pressure advances from off the Delaware coast to southeast MA. An isolated thunderstorm cannot be ruled out after 04Z across eastern RI and eastern MA. Areas of fog, especially RI and eastern MA. Fog may be locally dense along the eastern MA coast. Sunday...High confidence. VFR west. MVFR/IFR and any showers ending by mid morning in eastern sections, rapidly becoming VFR by 16Z. W to NW winds gusting up to 15-20 kt. Sunday night... High confidence. VFR. KBOS Terminal...Moderate confidence, due to timing of IFR and possible fog/showers. Have not included thunder in the TAF but isolated thunder not out of the question around 06-10Z. KBDL Terminal...High confidence. Outlook /Monday through Thursday/... Monday: VFR. Breezy. Monday Night: VFR. Breezy. Chance SHRA, isolated TSRA. Tuesday: VFR. Breezy. Chance SHRA, slight chance TSRA. Tuesday Night: VFR. Wednesday through Wednesday Night: VFR. Breezy. Thursday: VFR. Breezy. Slight chance SHRA. && .MARINE... Forecaster Confidence Levels. Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Low pressure will consolidate along a stalled front somewhere over far southeastern MA late tonight, then move northeast and intensify away from our region on Sunday. Showers are likely, along with visibilities frequently below 1 nm overnight over the waters. An isolated thunderstorm cannot be ruled out late tonight. Visibility improving as winds shift to the west-northwest on Sunday and any rain showers come to an end in the morning. Winds may gust to 20-25 kt. Seas will continue to be in the 5 to 6 ft range over the outer waters through Sunday night. So, Small Craft Advisories have been extended for most outer coastal waters through Sunday night. Outlook /Monday through Thursday/... Monday: Low risk for Small Craft Advisory winds with gusts up to 25 kt. Seas up to 5 ft. Monday Night: Low risk for Small Craft Advisory winds with gusts up to 25 kt. Seas up to 5 ft. Chance of rain showers, slight chance of thunderstorms. Tuesday through Tuesday Night: Winds less than 25 kt. Areas of seas approaching 5 ft. Chance of rain showers, slight chance of thunderstorms. Wednesday: Winds less than 25 kt. Seas up to 5 ft. Slight chance of rain showers. Wednesday Night: Winds less than 25 kt. Seas up to 5 ft. Chance of rain showers. Thursday: Low risk for Small Craft Advisory winds with gusts up to 25 kt. Rough seas up to 8 ft. Chance of rain showers. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...Small Craft Advisory from 6 PM Sunday to 6 AM EDT Monday for ANZ235-237. Small Craft Advisory until 6 AM EDT Monday for ANZ250-254-255. Small Craft Advisory until 6 AM EDT Monday for ANZ256. && $$ SYNOPSIS...RM/GAF NEAR TERM...Belk/RM/GAF SHORT TERM...GAF LONG TERM...RM AVIATION...Belk/RM/GAF MARINE...Belk/RM/GAF
Area Forecast Discussion
National Weather Service State College PA
1051 PM EDT Sat Sep 25 2021 .SYNOPSIS... Early fall weather will be in full swing across central PA with seasonably warm days, refreshingly cool nights, and little to no rainfall through the end of the month. && .NEAR TERM /UNTIL 7 AM SUNDAY MORNING/... Regional radar loop at 03Z shows a fairly solid line of showers over the central part of the state associated with approaching cold front. Strong large scale forcing ahead of deep upper trough will likely sustain at least a broken line of showers moving through the eastern part of the forecast area late this evening. Radar trends and latest HRRR support the chance of a shower over all but the Harrisburg area south and east, as the front moves through late this evening. Breaking clouds and light winds will likely allow valley fog to develop across the Allegheny Plateau late tonight. Further east, a tighter pressure gradient will likely result in enough of a breeze to preclude significant fog formation. Guidance continues to support low temps from the mid 40s over the Alleghenies, to the mid 50s over parts of the Lower Susq Valley. && .SHORT TERM /7 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/... Surface ridge and associated low-pwat air mass over the area should ensure fair weather Sunday. Model soundings indicate mixing to 800mb, where progged temps of around 3C support highs from the mid 60s over the Alleghenies, to the low 70s in the Susq Valley. RH time sections generally indicate a sunny to mostly sunny day. However, some mid level cloudiness is likely to spill into northwest Pa late in the day associated with a warm front lifting into the Grt Lks. Fair weather should last through Sunday night. However, do expect varying amounts of cloud cover over northern Pa associated with warm front lifting through the Grt Lks. Can`t completely rule out a light shower/sprinkle across the northern tier counties, but have kept POPs below 15pct. An active southwest breeze should result in a somewhat milder night than tonight, with lows mainly in the low to mid 50s. && .LONG TERM /MONDAY THROUGH SATURDAY/... Monday could have temperatures a few degrees above normal as a ridge of high pressure set up overhead. SW flow at the surface and sunny skies will allow temperatures to get up into the 70s across the area, and near or just above 80 in south central PA. A shortwave and associated cold front will approach from the north Monday afternoon, but model guidance only supports light qpf and scattered/isolated pops. The best chance of rain comes Tuesday, as the cold front crosses over PA. More scattered showers and storms will be possible during peak heating Tuesday with enough forcing from the front. All guidance supports slightly below normal temperatures the second half of next week, as upper trough axis swings over the area. At the surface, Canadian high pressure and associated dry air mass appears likely to bring fair weather into at least the beginning of next weekend. && .AVIATION /03Z SUNDAY THROUGH THURSDAY/... VFR showers are dwindling and should cease within the next couple of hours. Post-frontal upslope/westerly flow should lower cigs to MVFR at KBFD and KJST later this evening and into early tonight. Conditions return to VFR by 15Z with west-northwest winds (270-310 degrees) picking up and gusting up to 20kts into Sunday afternoon. Gusty winds die down by 22z tomorrow. Outlook... Sun...VFR, gusty afternoon winds. Mon...VFR/no sig wx. Tue...Predominantly VFR with a few passing showers/iso t-storm possible associated with FROPA. Wed-Thu...VFR/no sig wx. && .CLIMATE... Harrisburg`s latest 90-degree day on record is Oct. 7 in the 1941. With summer in the rearview mirror and given the fall pattern going forward, it`s probably safe to say that there won`t be any more 90 degree days this year. So in 2021, Harrisburg likely finishes with 34 days where the maximum temperature was >= 90F. That ties 2010 and 1955 with the 14th highest on record. The top 3 are 1966 (60), 1944 (48), and 1943 (46). h/t @ajuklo for the callout on Twitter. More interestingly, 2021 currently ranks 2nd for the number of days with minimum temperatures >= 70F in Harrisburg. The top 3 are 2020 (50), 2021 (48), and 2016 (42). 8 of the top 10 years are in the 2000s. Those warm summer nights... && .CTP WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Steinbugl NEAR TERM...Fitzgerald SHORT TERM...Fitzgerald LONG TERM...Fitzgerald/Wagner AVIATION...Steinbugl/Gutierrez CLIMATE...
Area Forecast Discussion
National Weather Service Dodge City KS
447 PM CDT Sat Sep 25 2021 ...updated aviation... .SHORT TERM...(This evening through Sunday) Issued at 102 PM CDT Sat Sep 25 2021 For tonight a surface low in eastern Colorado will progress towards the state line by morning. Winds in the 850 mb levels will increase out of the southwest to 30-40 kts tonight bringing in 23-25(C) air over southwest Kansas by morning. This should bring decent mixing through the overnight hours and as a result overnight lows should fall back into the upper 50s to lower 60s. Sunday the main concern will be the red flag potential in our southeast. We should have decent sunshine throughout the day until high clouds start to move in the late afternoon and evening from an upper low in the desert southwest. The surface low should move northeast into Nebraska which will tighten the pressure gradient especially for areas along the Oklahoma border. We should have efficient heating with southwest winds through the day and drier ground. Plus the vegetation has browned up which could lead to a better fire weather environment especially in the Red Hills. All of the short term models are outlooking relative humidity values in the 10-15% by mid afternoon. Southwest winds in the afternoon will most likely be in the 20-30 mph sustained range with gust potential to 40 mph. High temperatures I went with NBM90th as a start which was mid 90s but bumped up the temps a few degrees to the upper 90s to get closer to the 12Z HRRR idea for highs...and it wouldn`t surprise me if we could get a 99 or 100 degree high somewhere in southwest Kansas in the afternoon. .LONG TERM...(Sunday night through Saturday) Issued at 156 PM CDT Sat Sep 25 2021 Overall the long term looks like a wet weather pattern especially as we get to the middle and end of the workweek with WPC guidance showing a good swath of at least 1 inch of rain for most of southwest Kansas from the day 5-7 periods. The first chance of rain could be coming from Tuesday night into Wednesday morning as an upper low in the desert southwest moves to the northeast and turns into a longwave trough. The trough will pass along the Kansas-Colorado border and with a couple of days of south to southeast winds we should have enough gulf moisture to develop some scattered showers and thunderstorms. Wednesday through Saturday a slow moving or blocked upper low will move from the desert southwest through the Rockies. With southeast winds at the surface and shortwave rotating around the main low near the Kansas-Colorado border we should expect several days worth of rain and storms. With the cloud cover expected as well as the rain high temperatures during this time will be in the upper 60s to low 70s. && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) Issued at 444 PM CDT Sat Sep 25 2021 VFR is expected through TAF pd. A 40-50 kt LLJ will develop overnight and could lead to overnight LLWS across the terminals. Lee troughing and mixing will continue tomorrow. As a result, stronger southwesterly winds of 15-24 kt are expected with gusts of 25 to 30 kt. This is particularly true for KLBL and KDDC. && .FIRE WEATHER... Issued at 204 PM CDT Sat Sep 25 2021 Red flag warning will be in effect for Clark, Comanche, and Barber counties for tomorrow afternoon as wind speeds out of the southwest will be 20-30 mph with gusts to 40 and relative humidity values fall to 10-15%. We will also see close to red flag conditions for areas along and east of a Liberal to Larned line for Sunday afternoon. Even with some areas that still have green grass there is enough curing that would give plenty of fuel for any wildfires that could develop. && .PRELIMINARY POINT TEMPS/POPS... DDC 61 97 61 93 / 0 0 0 0 GCK 57 98 57 92 / 0 0 0 0 EHA 62 94 59 92 / 0 0 0 10 LBL 61 95 60 94 / 0 0 0 0 HYS 58 97 58 91 / 0 0 0 0 P28 62 96 64 94 / 0 0 0 0 && .DDC WATCHES/WARNINGS/ADVISORIES... Red Flag Warning from 1 PM to 7 PM CDT Sunday for KSZ088>090. && $$ SHORT TERM...Tatro LONG TERM...Tatro AVIATION...Sugden FIRE WEATHER...Tatro
Area Forecast Discussion
National Weather Service Duluth MN
657 PM CDT Sat Sep 25 2021 .DISCUSSION...(This evening through Friday) Issued at 317 PM CDT Sat Sep 25 2021 Summary: some chances of light rain showers are in place tonight across the MN Arrowhead and over far northern Wisconsin. Then, a blocking pattern will keep conditions quiet across the Northland through mid-week before a trough brings another chance of showers, and perhaps some thunderstorms, Thursday into Friday. The Northland will continue to be on the leeward side of a longwave upper-level trough, which will help usher in some weak positive vorticity advection across the region. As one lobe of PVA moves off to the east, we expect a secondary impulse to dive southeastward across the northeastern portions of the region. The RAP model is progging a band of 925-850 mb layer FGEN to traverse the aforementioned areas tonight, increasing chances of light rain showers. Precipitation chances will ramp down after sunrise Sunday morning, leading to a dry day Sunday. High temperatures Sunday will warm into the lower to middle 70s. For Monday through Wednesday night, dry conditions will continue as an omega blocking pattern develops in the upper-levels per the GFS/ECMWF/GEM global models. Temperatures will be around or above normal during this time frame, thanks to southerly return flow around a surface high pressure system. Highs are expected to warm into the upper 60s into the 70s. The next opportunity for showers, and perhaps some thunderstorms, will be Thursday into Friday, as an elongated upper-level trough translates eastward. Southerly return flow around the departing surface high will help support increased theta-e advection, as well as higher PWAT values, generally >90% of climatology per the NAEFS. The large-scale forcing looks fairly weak, and instability is slim to none ahead of the trough, so there will be chances of showers, but there`s a good bit more uncertainty regarding any thunderstorms. A few more impulses embedded within the trough will keep chances of showers over the region for Friday and Saturday, but uncertainty remains on timing and spatial coverage this far out. && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) Issued at 657 PM CDT Sat Sep 25 2021 VFR conditions are expected through the TAF period. A passing wave will bring -shra to far northern MN overnight, which may affect KINL and KHIB, lowered visibilities/ceilings are not expected with it. The wave will also bring a period of stronger winds aloft, bringing LLWS to the terminals overnight as well. These are expected to move out of the area by 13z, with quiet conditions lingering for the remainder of the forecast. && .MARINE... Issued at 317 PM CDT Sat Sep 25 2021 Breezy conditions will continue across western Lake Superior this afternoon, thanks to a tight surface pressure gradient situated across the region. Westerly winds will be their strongest along the Bayfield Peninsula northeast towards the Outer Apostle Islands, with gusts up to 25 knots. Wave heights in these areas should also range between 3 to 5 feet. Due to these conditions, a Small Craft Advisory will continue for these areas through 7 PM CDT tonight. Winds near the Twin Ports have struggled to reach Small Craft Advisory criteria today, and winds aren`t expected to strengthen to that criteria at this time. Thus, we have decided to cancel the advisory for those areas. Winds and waves are expected to weaken this evening, continuing to be from the southwest. Light and variable winds are expected for Sunday, eventually turning more northeasterly Sunday evening, continuing into Monday morning. && .PRELIMINARY POINT TEMPS/POPS... DLH 49 73 48 66 / 10 0 0 0 INL 47 70 43 69 / 30 10 0 0 BRD 50 78 48 73 / 0 0 0 0 HYR 45 74 45 72 / 10 10 0 0 ASX 48 76 46 68 / 20 10 0 0 && .DLH WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. LS...Small Craft Advisory until 7 PM CDT this evening for LSZ146-147- 150. && $$ DISCUSSION...JTS AVIATION...LE MARINE...JTS
National Weather Service Hastings NE
640 PM CDT Sat Sep 25 2021 .DISCUSSION...(This evening through Saturday) Issued at 300 PM CDT Sat Sep 25 2021 Primary forecast challenges are warm (well-above average) temperatures next few days, then chances for rain middle of next week. Summary: Dry conditions and summer-like temperatures will prevail for the next several days. In fact, may get within a few degrees of record high temps on Sun. Despite the hot temps, looks like we`ll avoid significant fire wx concerns owing to mostly light winds and somewhat elevated dew points. Focus will then shift to increasing rain chances as early as Tue night/Wed, but esp. Wed night into Thu as a cold front moves into the area. Both deterministic GFS/EC and their respective ensembles are in good agreement showing the rain chances to be fairly decent and widespread. There`s some uncertainty as to how late into the week the rain chances will linger, but confidence is higher that temps will return to more seasonable, but likely still mostly above average, levels. There`s really not a whole lot to talk about for the next few days other than the well-above normal temperatures. Current forecast high temps for Sun are within a few deg of records, but don`t think we`ll quite get there as mixing doesn`t appear particularly strong or deep. Incr temps 1-3 deg across the board for next few days given drying ground and H85 temps well above climo, but I`ll let mid- shift assess how temps did today and determine if additional upward adjustment is needed. Going highs are already near NBM 90th percentile, so not much room for an incr. As mentioned above, fire wx doesn`t look particularly concerning as local area will be in close proximity to sfc trough and greatest pres gradient remains S/SE of the CWA. The exception to that will be over the next few hrs this aftn. Temps are overachieving slightly, as is the drop in Tds, and we`re seeing wind gusts averaging around 25 MPH. With field work on the incr, just didn`t feel comfortable not having at least a mention of elevated fire wx conditions for this aftn, so just updated the HWO. Went on the drier side of guidance (CONSSHORT/15Z RAP blend) for Tds on Sun given today`s trends. Focus then shifts to our upcoming rain chances next week. Both 12Z GFS and EC are in good agreement in bringing cold front into CWA at some point Wed aftn/eve along with scattered to widespread shwrs/storms. Ensemble data also shows high probs for appreciable and widespread QPF, so not surprised to see blend jump to likely PoPs in the Wed aftn thru Thu time frame. This system has the potential to be the greatest rain event in terms of overall coverage of rain amnts >0.5" in quite some time. Will have to watch for some svr storms with initial fropa Wed aftn/eve as that`s when we`ll have greatest instability. However, plan view bulk shear plots suggest greatest shear may tend to be largely behind the front itself and removed from best instability. Something to watch over the coming days. Still some uncertainty as to how long PoPs will persist into late next week, and this will all revolve around details regarding energy that may bec cut off over SW CONUS and gradually eject NE. EPS QPF progs have ticked up over last run or two, but op EC is more aggressive with QPF coverage/persistence than GFS. At any rate, looks like we`ll have pcpn chcs continue thru the end of the week, and likely well into next weekend, but confidence on details is definitely low attm. Much more confident in the return to near to slightly above normal temps behind the cold frontal passage. Significantly cold air will be hard to come by given Pacific nature of these systems, but of course cloud/pcpn coverage will play a significant role in temp details. && .AVIATION...(For the 00Z KGRI/KEAR TAFS through 00Z Monday) Issued at 608 PM CDT Sat Sep 25 2021 VFR conditions are expected through the period with winds relaxing near the ground overnight as the pressure gradient weakens and stronger winds aloft decouple. Overnight...expect steady winds out of the southwest around 1KFT near 40 KTS...and added some LLWS from roughly 26/04Z-26/14Z to cover this. Other than a few passing high clouds at times...skies should remain mostly clear through the period. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ DISCUSSION...Thies AVIATION...Rossi
Area Forecast Discussion...CORRECTED
National Weather Service Gray ME
1045 PM EDT Sat Sep 25 2021 .SYNOPSIS... The cold front will remain stalled to our east into tonight, and will bring some scattered showers to areas along the coast East of Portland. Another round of moderate to heavy rain is possible early Sunday into Sunday after noon mainly across SW and central Maine. Cooler, more seasonal are expected Monday through the middle of the week. There is a chance for scattered showers Monday and Tuesday as an upper low sits and spins jut to our north. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... 1035 PM Update...The going forecast remains largely unchanged at this hour as latest observational data and model information continues to line up with forecast PoPs and QPF overnight. A SFC trough oriented on and near the coastal plain continues to be the dividing line between a tropical air mass to the east and a drier air mass to the west. As a long wave trough with embedded short waves impinge on the forecast area tonight we are continuing to expect the development of showers and isolated thunderstorms on the coastal plain northward into portions of central Maine after midnight. There is still uncertainty where exactly the max QPF axis will be, as it is expected to be quite narrow. It`s even possible that the heaviest rain stays just offshore or over the islands. However, current model consensus and meteorological observation trends support a general S-N swath of heavy showers with 1-3" possible in sub-swaths from roughly Portland to Augusta to Skowhegan. Heaviest precipitation expected 3 hours either side of 12z. Localized flooding will be possible in this area. 650 PM Update...Have updated the forecast mainly to tighten up forecast PoP gradient for the overnight hours and shift the highest PoPs a smidge to the east following the latest hi-res guidance. This lowers PoPs significant in places like southern and central NH overnight, except for the immediate Seacoast. Previously... A front remains draped across the eastern edge of the forecast area, with coastal York county, Cumberland, Androscoggin, Kennebec, and the midcoast remaining in a warm moist airmass. Dewpoints are in the 60s here with cloud cover. Meanwhile a completely different world across NH where skies are clear and dewpoints are in near 50. This dichotomy will continue through the next day or so as the front stalls, and even retrogrades slightly. For the eastern areas, radar and satellite imagery show a band of showers developing along and just east of the surface boundary and these showers will move north and fill in bringing rain to Penobscot bay and points just west. While the individual cells are small they will continue to move along the frontal surface and this training presents a small threat for flash flooding through evening. Now for something completely different; west of the front will remain dry with clear skies to start off overnight. These clear skies will allow temperatures to drop into the upper 40s with widespread fog once again forming in the river valleys. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/... Sunday a new player arrives to join our existing boundary. A short wave over the Great Lakes will approach from the west, and this interaction will pull the moisture back further west, backing right up into the White mountains. The CT river valley will likely still remain on the `dry side` but overall expect coverage of showers to increase due to this interaction. Have kept the highest amounts from Portland east, where up to 2 inches is possible. However expect the drop off to nearly nothing to be quite abrupt and most of the area will see less than a quarter inch. This tight gradient is well represented in the HREF and HRRR forecasts and have leaned on those for the placement of the boundary. Most of the rainfall will move through early Sunday morning, with the front starting to push out by mid day. By Sunday night the westerly flow aloft will finally kick out our lingering surface boundary and make way for the drier air to move in across the CWA. With so much moisture in place it`ll take more than a single evening to dry out and thus fog is likely across the region on Sunday night. && .LONG TERM /MONDAY THROUGH SATURDAY/... Latest models showing a little less amplifies 500 MB pattern across N Hemisphere for next week, but still with some significant blocking in place, and dominant Atlantic ridging. Still, downstream blocking over the N Atlantic and Rex block to our N extending to E of Hudson Bay will allow for 500 MB low to close off just to out N, and stay in the vicinity of the CWA through the week. Models have been fairly consitent with the forecast for the first half of the week, but change from run to run as to how that closed low interacts with energy coming in from the NW, and upstream and downstream blocking, so confidence beyond Tue begins dropping. Mon/Tue will see that 500 MB close off to out N, allowing cooler air to work in, along with some clouds, especially in the mtns, and maybe a chance showers Monday afternoon/evening and Tuesday evening. Monday will see a sfc cold front work through, so this will be the better chance for showers across the nrn 2/3 of the CWA. Highs Monday range from 65-70 in the N to the low to mid 70s in the S. On Monday the cold front will have settle S of the mtns, but will likely still be crossing srn zones, so lows in the N will be in the mid 40s, but in the mid to upper 50s in the S. The from stalls a bit near S NH and the Me coast, and there may be a few showers here on Tuesday, and more in the way of clouds, with highs 60-65 in the N, and in the upper 60s to around 70 in the S. For Wed/Thu and maybe into Fri, will be dealing with the closed low as it shifts S across the region, with cooler temps /maybe even a hair below normal for highs/, and the possibility of bouts of showers, but timing where and when at this point is really a game of chance. We`ll call it unsettled, but not expecting any day would be a washout. Depending on where that closed low ends up could see ridging developing over the top of it and a warming trend for next weekend. && .AVIATION /03Z SUNDAY THROUGH THURSDAY/... Short Term...The tale of two airmasses is most noticeable in the aviation impacts. The eastern portion of the CWA remains shrouded by clouds, as some locations struggle to even exceed MVFR ceilings. Meanwhile the western part of the CWA is clear with VFR conditions. Overnight will see flight category decreases across the area, but for opposing reasons. In the east, the clouds will slightly to mainly MVFR with scattered showers and even a rumble of thunder in heavy rain briefly resulting in IFR. Meanwhile across the western portion of the area, clear skies will give way to IFR and valley fog overnight. Long Term...Mainly VFR in the extended from Monday through Thu. Will see some MVFR cigs in the mtns at times along with some showers. These are possible in the south as well es[especially Monday night. && .MARINE... Short Term...Seas remain below 5ft currently with the front draped across the eastern portion of the waters. However, on the outer waters, we expect 5 footers to arrive after midnight, and gusts around 25 kt in CAA Sunday morning. Therefore, a SCA has been issued for the outer waters, albeit a low-end one. Long Term...Winds/seas stay mostly below SCA levels through Thursday. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...None. NH...None. MARINE...Small Craft Advisory from 4 AM Sunday to midnight EDT Sunday night for ANZ150-152-154. && $$ NEAR TERM...Ekster SHORT TERM...Curtis LONG TERM...Cempa
Area Forecast Discussion
National Weather Service New Orleans LA
949 PM CDT Sat Sep 25 2021 .EVENING UPDATE... No updates planned this evening. Clear skies and light north to northeast winds across much of the area. 00z LIX sounding remains supportive of lows in the 50s across the north half of the CWA, similar to this morning. If anything, current forecast might be a degree or two on the warm side. 35 && .PREV DISCUSSION... /issued 634 PM CDT Sat Sep 25 2021/ AVIATION (00z TAF package)... VFR conditions expected at all terminals through the forecast period. While there is a non-zero threat of reduced visibilities due to fog at several terminals (KHUM/KBTR/KMCB), threat isn`t high enough to mention in the forecast at this time. 35 PREV DISCUSSION... /issued 316 PM CDT Sat Sep 25 2021/ SHORT TERM (This evening through Monday Night)... No complaints in the forecast yet again as clear, comfortable and calm conditions persist going into this evening and into the overnight hours. Current overview of the US shows a very quick moving trough and attendant surface cold front swinging east from the Midwest into the northeast. This cold front will lose steam pushing south, perhaps making it as far south as north or central Mississippi later tonight/early Sunday before undergoing frontolysis becoming parallel to the mean low to mid-level flow in place. No major impacts to our region other than another reinforcing high building into the southeast behind this decaying front. Did make some minor adjustments to overnight lows Sunday morning once again as deterministic NBM is a little too warm in an area dominated by strong tropospheric subsidence and surface radiational cooling processes. Holding onto the very lowest end of the NBM ensemble spread which keeps us in the mid to upper 50`s again/low to mid 60`s southshore - similar to what we saw this morning. Also seeing some guidance hinting at the potential for patchy fog generally for western areas from New Roads southeast to Reserve, and also around McComb likely due to some members trying to bulge a slight increase of dewpoints along ESE light flow into this region. Nothing that will be too noticeable, but enough to aid in fog formation given the combination of a cooler bias in temperatures with this slight uptick in moisture. Not anticipating widespread, dense fog but patchy fog has been included in this area for now. Otherwise, Sunday promises to be another gorgeous day. HRRR RICAPS hints at more upper-level cirrus around the H2 to H3 layer yet again from moisture advection out ahead of a closed upper-level low over SE CA/SW AZ. No other major adjustments were needed this weekend as nice weather will persist. Starting out the new work week on Monday, the same aforementioned upper-low over the southwest, blocked underneath large-scale ridging over the west drifts east into the Rockies, with a noticeable subtropical feed of moisture in the upper-levels spreading over the lower MS valley region. This will lead to an increase in mid-level altocumulus/upper-level cirrus. But overall, still a real nice day regardless. Meanwhile at the surface, the reinforcing high continues to drift east enough to allow for the attendant 850mb ridge to follow into the far eastern Gulf. This will help promote a slow, but steady moistening trend beginning at the surface, and eventually extending in vertical depth with time. Dewpoints return into the low to mid 60`s on Monday, with slightly warmer afternoon highs reaching the mid to a few upper 80`s. The deepest fetch of Gulf moist transport will begin to our west over east TX/ west LA, where showers and a few storms will break out in a pattern dominated by WAA and a veering low-level wind profile. Otherwise, we stay dry through Monday night. LONG TERM (Tuesday through Friday Night)... Going into Tuesday, the ridge out west begins to steepen and amplify thanks to deep troughing building into the Pacific NW and a closed upper-level low meandering over southeastern Canada. This will lead to this same upper-low over the southwestern US to become absorbed/stretched out in an increasing SW to NE flow within the upstream portion of the ridge. What this in term does is keeps a generalized weakness in the upper-level heights over the southern Plains into the Arklatex region, where already a tongue of deep Gulf moisture resides. Given messy mid-level impulses and PVA in an unstable surface and moist environment, rounds of messy/disorganized showers and storms will persist over this area and increase in coverage with time. The question remains on how far east can any of this activity make it into our area. A closer look at GFS soundings shows a bit of a different story compared to our concerns we had yesterday, with enough deep moist ascent in place to erode any lingering subsidence in the lowest levels. Combined with moistening in the mid to upper troposphere, this could be enough to squeeze out some showers at times on Tuesday. Perhaps beginning as stratiform showers/virga early in the day but may be increasing in coverage thereafter. NBM caught on this flip by increasing PoPs more into the 30-60% range for the western half of the CWA. But we are still seeing precipitation struggle to make it further east than I-59 across coastal MS as subsidence continues to remain strong in this region. Likely leading to any stratiform showers (elevated on radar) to decay eventually and dry out not making it too far east. This will likely be a very sharp PW gradient ranging from around or just above 2" for the Atchafalaya basin to 0.75 to 0.8" across the MS coast. Where this gradient sets up continues to change so will keep a low confidence mention in this portion of the forecast going. Generally the same story for Wednesday and Thursday as better shower and storm chances remain across western areas, less for eastern. The upper-level pattern turns a bit chaotic in this time frame with weak ridging taking over a large part of the US and the Pac NW trough digs deep into the southwestern US and breaks off from the main trough exiting into southern Canada. For us, we just stay parked underneath broad 588dm ridging meaning quiet/calm and mostly dry conditions may end the week ahead with temperatures close to climo norms. KLG MARINE... Light winds and calm seas will prevail through the rest of this weekend and into early next week. Eventual wind shift from the east to eventual southeast can be expected early next week, persisting through the rest of the week with light showers possible, generally west of the MS river. KLG && .PRELIMINARY POINT TEMPS/POPS... MCB 55 84 59 85 / 0 0 0 0 BTR 56 84 59 85 / 0 0 0 10 ASD 55 86 60 86 / 0 0 0 10 MSY 64 85 67 86 / 0 0 0 10 GPT 58 84 63 84 / 0 0 0 0 PQL 56 84 60 85 / 0 0 0 0 && .LIX WATCHES/WARNINGS/ADVISORIES... LA...None. GM...None. MS...None. GM...None. && $$
Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
900 PM CDT Sat Sep 25 2021 .UPDATE... 900 PM CDT Made some relatively minor changes to the forecast this evening/early overnight primarily to increase cloud cover and slow our diurnal temperature drop-off. Early evening surface analysis depicts high pressure drifting southeast across the lower Missouri and lower Ohio river valleys. To the north across our forecast area, southwesterly low level flow was in place north of the ridge. In our very dry low level air mass, diurnal cooling/decoupling of the boundary layer allowed for a fairly quick drop in temps (into the 50s in some spots away from the Chicago metro) after sunset. However, a fairly extensive mid-level cloud deck has developed above about 12,000 feet this evening across much of the cwa at mid-evening which has limited radiational cooling and slowed our diurnal temp-drop. Guidance has not done a good job this afternoon/evening of depicting the extent of this BKN- OVC cloud cover, which 00Z RAOBs from DVN and GRB show as a relatively shallow saturated layer in the vicinity of 600 mb (the shallow nature likely related to poor model depiction). This correlates to the 305-310 K isentropic levels, which depict an area of relatively low condensation pressure deficits across northern IL/WI. With time tonight, this should spread off to the southeast, while the east-northeastward translation of the upper trough axis and upper level jet axis should also result in more widespread cloud cover shifting across northern WI-Lake MI and lower MI by the pre- dawn hours. With anticipation of the above evolution, I`ve boosted cloud cover across much of the cwa this evening, and slowed the hourly depiction of our diurnal temperature drop this evening/midnight. With expected decrease in cloud coverage after midnight, would expect to resume a decent cool-off in surface temps given dry low levels (surface dew points in the upper 30s/lower 40s). Therefore didn`t raise our expected overnight mins, just slowed our approach to them through the late evening/midnight period. Otherwise, going forecast into Sunday looks on track, and made no other significant changes this evening. Ratzer && .SHORT TERM... 239 PM CDT Through Sunday... As can be the case for periods during the season we are now in, the main forecast concerns are gusty winds and an elevated fire weather risk. A mild, breezy, and dry afternoon across the area this final Saturday of September. Relative humidity values as of 230 PM are in the 25 to 35 percentage range across most of the area, and may dip just a smidge more during peak heating. Going into this evening, the winds gusting to around 25 mph will ease quickly near sundown. Temperatures will drop from around 70 to near 50 by midnight, but then hold nearly steady as some wind is felt from a developing low-level jet overhead. Fast paced northwest flow aloft will continue over the Upper Midwest and Great Lakes regions the remainder of the weekend. The next jet maximum and perturbation will progress southeastward through these regions on Sunday, with a response in the low-level thermal ridge expanding into the area and the pressure gradient tightening. The combination of these will result in a warmer and windier day than today, with climatology favoring highs around 80. Some high clouds are likely, though how thick is of low confidence, and if not too think some 80 degree readings will be realized. Winds look to gust to 30 mph based on forecast soundings. Again if high cloud cover is not a factor, the dryness of the low-level air may result in higher PBL momentum transfer and gusts to near 35 mph. The Gulf of Mexico moisture remains cut off on Sunday, and so while the driest wedge of air over the region today will have passed, lower to mid 40s dew points are not at all hard to fathom given how low dew points are at present. This is on the lower range of the guidance solutions but in line with the HRRR and RAP which both preformed admirably with dew points today. This results in humidity values of 20 to 35 percent, with lowest values again along/north of I-80 in northern Illinois. This will be elevated to near-critical fire weather risk, especially over the driest ground conditions in north central Illinois. For more, see the Fire Weather Discussion below. MTF && .LONG TERM... Sunday Night through Saturday... 200 PM...No significant forecast concerns through the end of next week. Southwesterly winds may still be gusting into the mid 20 mph range Sunday evening as they slowly diminish through the night. These stronger winds will allow temps to slowly fall during the evening with lows by Monday morning in the upper 50s/lower 60s for most areas. The concern for Monday has been the timing of a cold front that will move across the area later in the afternoon into the evening. The faster ECMWF/NAM 24 hours ago have slowed and are in line now with the GFS. This increases confidence for highs to be well into the 80s on Monday, especially starting from the lower 60s in some areas. Its possible some areas will reach the upper 80s. The front will be aided by the lake and much of the guidance shows it moving quickly inland during the late afternoon, possibly reaching the I-80 corridor by sunset. Have adjusted hourly temp/wind grids for this trend but changes/refinements can still be expected as later model runs adjust timing. Temps will fall quickly into the 70s behind this front and possibly into the upper 60s by early evening. From Tuesday through the end of next week, dry weather is expected. High pressure slowly moving south over the eastern Great Lakes will remain the dominant weather feature for our area keeping precip chances to our west/northwest along with southeast winds and likely afternoon lake breezes. Temps expected to be above seasonal normals for late September/early October. cms && .FIRE WEATHER... 239 PM CDT Low relative humidities combined with west winds gusting to 30 to possibly 35 mph during Sunday late morning and afternoon will result in an elevated wildfire danger. Critical fire weather conditions are possible across primarily north central Illinois, with a possible limiting factor being slightly higher RH Sunday afternoon. See the Short Term Discussion for more details regarding forecast parameters. Kluber/MTF && .AVIATION... For the 00Z TAFs... Aviation Weather Concerns for 26/00Z TAFs: * Winds decreasing quickly this evening, but increasing again early Sunday morning. Surface high pressure with a tight pressure gradient has kept our winds gusting into the mid to upper 20 kt range from the west. A very dry atmosphere is expected to lead to temperatures decreasing rapidly after sunset, allowing winds to decrease this evening. A broken deck at around 10,000 to 15,000 ft will move in overnight, primarily east of I-57. Strong southwesterly winds are expected to return Sunday morning, with gusts into the lower 20 kt in the morning, increasing to upper 20s, and possibly lower 30 kt in the afternoon. A low-level jet is expected to set up Sunday evening, so although winds are expected to decrease a bit after sunset, I expect southwesterly winds will be gusting into the upper teens throughout Sunday evening. BKL && .LOT WATCHES/WARNINGS/ADVISORIES... IL...None. IN...None. LM...Small Craft Advisory...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744- LMZ745...3 AM Sunday to 10 PM Sunday. && $$ Visit us at Follow us on Facebook, Twitter, and YouTube at:
Area Forecast Discussion
National Weather Service Melbourne FL
1025 PM EDT Sat Sep 25 2021 .DISCUSSION... Scattered showers and lightning storms occurred this afternoon and early evening, mainly across the Treasure Coast. These showers generally moved southward around 10 mph. Convection dissipated shortly after sundown in ECFL, however, scattered showers continue to move across the western side of the peninsula tonight. Drier air has filtered in across the north, with PW values around 1", and the HRRR model has steadily backed off convection chances for the local area tonight. Thus, have taken out rain chances over land for tonight and lowered rain chances across the Atlantic. Less humid this evening, with dewpoints in the upper 60s to low 70s under partly cloudy skies. Forecast remains on track, with overnight lows in the upper 60s to low 70s and will remain mostly dry tonight. && .AVIATION...VFR conditions prevailing through the period. Dry conditions expected through tomorrow, with only a slight chance of showers and storms along and inland from the Treasure Coast. NE flow continuing through the period, diminishing this evening, before increasing again tomorrow morning into the afternoon. Winds along the coast tomorrow around 10-12kts. && .MARINE...Scattered showers and lightning storms occurred over the Treasure Coast Atlantic waters this evening. Cell movement was generally to the south around 10 KT, with showers and storms dissipating shortly after sundown. Drier air has filtered into the local area, lowering overall rain chances tonight. Current buoy 41009 observations show seas are around 3 ft with ENE winds around 8 KT. Winds will be northeast around 5-10 KT tonight, with seas around 3-4ft across the Atlantic waters. && .PRELIMINARY POINT TEMPS/POPS... DAB 70 86 69 86 / 0 0 0 0 MCO 71 90 70 90 / 10 10 0 0 MLB 73 86 72 86 / 10 10 0 10 VRB 73 87 71 87 / 10 20 0 10 LEE 71 90 70 91 / 10 10 0 0 SFB 69 88 67 89 / 10 0 0 0 ORL 71 88 69 89 / 10 10 0 0 FPR 71 86 70 86 / 10 20 0 10 && .MLB WATCHES/WARNINGS/ADVISORIES... FL...None. AM...None. && $$ SHORT TERM...Watson IMPACT WX/RADAR....Cristaldi AVIATION...Leahy
Area Forecast Discussion
National Weather Service Phoenix AZ
455 PM MST Sat Sep 25 2021 .UPDATE...Updated Aviation Discussion. && .SYNOPSIS... A slow moving low pressure system will bring unsettled weather conditions across the region through this weekend, and possibly into Monday. Chances for showers and isolated thunderstorms will continue through much of this weekend with the best time frame for thunderstorms and any heavy rainfall occurring on Sunday. Lingering chances for rain are expected across eastern Arizona through at least Monday before another weather system likely brings more rainy weather during the latter half of next week. Below normal temperatures are also anticipated for much of the area through at least the middle part of next week. && .DISCUSSION... A closed low is evident on water vapor imagery south of San Diego and just west of the Baja Peninsula. This low pressure system will migrate slowly eastward the next few days, bringing below normal temperatures along with a chance of showers and thunderstorms to the Desert Southwest. Latest satellite imagery reveals the light rain and clouds from earlier this morning have generally lifted northward, resulting in mostly sunny skies across the lower deserts. Meanwhile, latest mesoanalysis depicts a nearly homogeneous area of PWATs across the Sonoran Desert. Instability has been struggling to materialize, given the relatively cool conditions in the lower levels. Only exception has been across portions of southeastern Arizona, where the CU field appears healthier. General consensus from the HREF is that afternoon and evening convection will be favored across southeastern Arizona and the Mogollon Rim. A few storms will also be possible along a line stretching northeastward from Kaka to Globe, while probabilities for rain will initially be quite low in the Valley. Short-term models remain in good agreement organized showers wont develop until the aforementioned upper low drifts eastward and vorticity and jet-forced ascent increases. However, latest trends in the HRRR suggest this wont occur until around midnight. Thereafter, shower and thunderstorm activity will likely blossom across portions of south-central Arizona, followed by another break in the activity later Sunday morning. As the upper low moves towards central Arizona Sunday afternoon, instability will likely increase. Latest HREF indicates a widespread area of 1000+ J/kg SBCAPE, which will support the redevelopment of showers and thunderstorms. Areas generally south of Phoenix will be favored for strong wind gusts, however all storms will be capable of producing heavy rain and localized flash flooding. && .PREVIOUS DISCUSSION... For Sunday night and Monday, the upper level low center is forecast to slowly track into western New Mexico, but we are likely to see several vorticity lobes wrapping around the western side of the low affecting the eastern half of Arizona. This will bring additional chances of showers and thunderstorms, but coverage should be more limited and the rainfall threat will be diminishing. Rain chances on Monday are likely to extend as far west as Maricopa County, but better chances will be seen east of Phoenix. Temperatures this weekend and Monday will remain somewhat on the cooler side, especially Sunday and Monday when the Phoenix area is likely to only top out in the mid to upper 80s. The western deserts should remain a bit closer to normal readings, but still likely five degrees or so below normal. The unsettled weather pattern should persist through the rest of next week as models continue to shift toward a deep Pacific trough quickly approaching our region from the northwest on Tuesday before possibly stalling out over our region during the latter half of next week. Model ensembles are in much better agreement showing this trough hanging around for several days next week likely bringing additional cooling and more wet weather. So far models show this next system is likely to carry less moisture than the current one, but it should be a colder system. Stay tuned, as the forecast details are likely to change and get refined as the storm system draws near. && .AVIATION...Updated at 2355z South-Central Arizona including KPHX, KIWA, KSDL, and KDVT: The next 24-30 hours will have multiple aviation weather concerns as chances for showers and thunderstorms increase. For the rest of this evening and night, winds are expected to follow typical diurnal trends with afternoon westerlies becoming easterly around 06z. Wind speeds will generally remain AOB 10 kts. Convection and associated impacts are most likely to remain south and east of the terminal area with less than a 10% chance for a shower, storm, or outflow. However, confidence remains high enough to maintain VCSH and PROB30 for thunderstorms early Sunday morning, primarily between 9z to 14z, although activity could linger in the vicinity through a few hours later. Thunderstorms can produce downbursts, heavy rain that reduces visibility, and extended periods of v winds with multiple weak outflows. Otherwise, southeasterly winds are expected to predominate prior to and during the morning convection. Cigs will likely drop between 090-110 although periods of lower cigs near 050 cannot be ruled out. Showers and storms are expected to clear out through the late morning and early afternoon hours. Confidence in wind directions during that time are uncertain and may depend on how the morning activity clears. Periods of N/NNE winds are emerging from model guidance but with decent variability in timing and areal extent. Confidence is high enough to introduce another period of VCSH and PROB30 for late Sunday afternoon (KPHX) as activity moves in from the S-SW. Thunderstorms will contain the aforementioned threats once again but storm movement may create a slightly higher blowing dust concern with outflows that move from south to north. Southeast California/Southwest Arizona including KIPL and KBLH: For the rest of this evening, generally light winds AOB 9 kts will prevail with directions favoring the south to southeast. Extended periods of very light and variable winds are likely during the overnight and early morning hours at KIPL. Chances for storms and related impacts, including outflows, at any time is too low for mention in the TAFs but chances for those increase to 20% by Sunday late morning-afternoon. && .FIRE WEATHER... Monday through Friday: An unsettled weather pattern will be in place for much of the period with lingering rain on Monday across eastern and central Arizona followed by a brief break on Tuesday. Another weather system will then likely affect the region during the latter half of the week bringing additional chances for wetting rains. Moisture levels will remain quite elevated for much of the period with min RHs mostly above 30% each day through Wednesday before dropping off slightly late next week. Winds will be fairly light most days with typical afternoon breezes that will favor local diurnal/terrain influences. && .SPOTTER INFORMATION STATEMENT... Spotters should follow standard reporting procedures. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...None. CA...None. && $$ DISCUSSION...Hirsch PREVIOUS DISCUSSION...Kuhlman AVIATION...12 FIRE WEATHER...Kuhlman
Area Forecast Discussion
National Weather Service Riverton WY
454 PM MDT Sat Sep 25 2021 .SHORT TERM...This evening through Sunday night The ridge, which started to build yesterday, becomes well established today across the region. This will lead to much above normal temperatures and continuing dry weather through the weekend. The main concern will be the elevated to critical fire weather conditions across southern zones. Today will see fairly breezy southwest winds across the usual Wind Corridor during the afternoon. The Red Flag Warnings across this area will stand through 7 PM this evening. The question will be whether or not to issue for the same areas tomorrow, due to similar conditions expected. Winds will be gusty, but yet marginal today, and depending on how the event verifies today, it could go either way. Models are not as excited about winds tomorrow, so if today is marginal, tomorrow will likely be even more so. Did bring winds up a bit from the HRRR forecast for today and tomorrow, but still getting only marginal conditions. Will hold off on extending any highlights until the next shift. Could reasonably see extending Zone 280 and 289, as this is where the wind will be strongest tomorrow and perhaps an RFD elsewhere. .LONG TERM...Monday through Saturday Dry and warm conditions continue across the Cowboy State, as the flat ridge shifts eastward over the Northern/Central Plains and becomes more amplified Monday. This will be in response to a closed low, that will move onshore over British Columbia Monday. Elevated fire conditions will continue during this time as well, as temperatures remain above normal. Southwest flow aloft will also become more predominant, as a result of this pattern. The closed low will become an longwave open trough and weaken Tuesday, as it makes its way over the PACNW. This system could bring precipitation across western and southern portions Tuesday, as most of the energy associated with this system gets shunted northeastward by the ridge (that will be over the Upper Midwest). Precipitation chances then spread eastward Tuesday night, as the associated cold front moves through the area. These chances will continue through the day Wednesday, as the supporting trough exits into central Canada and the front begins to stall. There remains some discrepancies between the GFS and ECMWF, with regard to the amount of available moisture. The GFS is much more generous with the precipitation Wednesday. This is mainly due to an upper low that will be over CO ahead of the incoming trough. This low will have some residual monsoonal moisture and could also be advecting in Gulf moisture by Tuesday. Current solutions have this low impacting the Front Range and High Plains. With that said, precipitation amounts do not look promising. However, temperatures will return to more seasonal readings Tuesday west of the Divide, as a result of the increasing cloud cover. Cool to mild temperatures will be in place Wednesday, as a result of the cold front. The trough becomes stretched, with the southern end of the longwave trough closing off over the Four Corners and becoming a cutoff low Thursday. The pattern becomes very disorganized over the Rockies, as a result. Conditions look to be dry and seasonal over the Cowboy State Thursday and Friday, with chances for precipitation possible on Friday. This would be if the cutoff low starts to migrate northward. && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) Issued at 453 PM MDT Sat Sep 25 2021 VFR conditions with clear skies will continue through the TAF period. Winds decrease quickly after sunset. Winds will increase again between 19Z and 21Z, with west to southwest gusts of 20 kt at KRKS and KCPR. Please see the Aviation Weather Center and/or CWSU ZDV and ZLC for the latest information on smoke, icing, and turbulence forecasts. && .FIRE WEATHER... The ridge becomes established today across the region, resulting in unseasonably warm temperatures and dry weather through Tuesday. Southwest winds will be breezy both today and tomorrow across the south, but today will see the stronger winds. The Red Flag Warnings remain in effect through 7 PM tonight. Could see additional Red Flag Warnings added for tomorrow, though winds will be much more on the marginal side, so holding off for now. Monday will see much of the same conditions with winds on the light side of marginal. Tuesday could be the more interesting day, as a cold front will sweep across the region ahead of the next system. Winds will be quite gusty with the frontal passage, but the RH will be the bigger question and any issuance of highlights will depend on the timing of the front and amount of available moisture behind it. && .RIW WATCHES/WARNINGS/ADVISORIES... Red Flag Warning until 7 PM MDT this evening for WYZ277-279-280- 289. && $$ SHORT TERM...Hensley LONG TERM...LaVoie AVIATION...LaVoie FIRE WEATHER...Hensley