Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 09/24/18


Area Forecast Discussion
National Weather Service Denver/Boulder CO
1000 PM MDT Sun Sep 23 2018 .UPDATE... Issued at 955 PM MDT Sun Sep 23 2018 Spotty high based mainly virga showers are now popping up over the far northwest corner of the CWA (extreme Jackson County around the Ryan Wildfire). Radar returns are weak at most. Main concern with this leading batch of showers will be gusty winds which the Ryan Fire IMET has been made aware of. Farther west over northwest Colorado, showers are a bit more numerous and cloud bases are a bit lower with smaller temp/dewpoint spreads. But, the underlying cloud layer with these showers would support more wind than wetting rainfall. Expect this shower activity to reach western portions of the CWA between 12-3 AM tonight. However, the main batch of showers associated with the mid-level trough and jet are still back over northeast Utah at this hour. They don`t look all that impressive on radar. At their present rate of forward motion, should see main batch of showers passing over the northern mtns between 1-5 AM and over the n-central mtns around Summit County area and the northern Front Range foothills between 3-7 AM MDT. Furthermore, the sfc cold front now moving ewrd thru south- central Wyoming is still timed to jump the Continental Divide and then slide south and east acrs nern Colorado during the pre-dawn hours. A shift to gust northerly winds and a modest jump in dewpoint will mark it passage thru the Denver metro area around 5 AM. Really do not see much of a chance for precip east of the mtns as temp/dewpt spreads should remain relatively large. What may be more noticeable will be the wildfire smoke that will spread down from Wyoming behind the front. Do not expect to see visibilities in the smoke much below 5-6 miles, although can`t rule out pockets of heavier smoke and VSBYs down to 2-3 miles early to mid morning. Have made adjustment to the forecast grids to account for this time line. && .SHORT TERM...(This evening through Monday) Issued at 322 PM MDT Sun Sep 23 2018 Lots of shallow convection upstream over western Colorado and Utah, but it`s still dry enough to limit CAPE and there is still very dry air above this convective layer. As a result these clouds shouldn`t produce any precipitation. Deeper bands further north will shift eastward, clipping northern Colorado later tonight into Monday morning as the associated trough moves past. The environment is still pretty dry overnight. Around sunrise the cold front will drop across the plains, bringing a bit more moisture but still nowhere near saturation. This moisture and convergence will help keep cloud cover through the day, but it will still probably not produce much shower activity. Current forecast has chance PoPs over the northern mountains and isolated showers/storms mainly near the northern border on Monday. This still looks good. It should be cold enough for the precip that does fall to be snow in some areas above timberline, but not expecting it to go any lower. Forecast temperatures look good. We did increase winds a little and lower humidities a little in the mountains again--more in the fire weather section below. Also of note is that the cold front will likely bring in smoke at low level that the Ryan wildfire produces overnight. The HRRR smoke model shows this pattern well, but is likely overdoing the smoke production, especially the plume from the more southern Silver Creek fire. Even given this, the pattern of low level smoke being advected from the Laramie/Cheyenne area southward behind the front seems likely. Laramie has still had visibilities of 5-10 miles and we`re further away, so probably not that low here, but it may well be the smokiest we`ve been this summer in Denver. The smoke should gradually mix out and be blown away as winds turn more toward the east and southeast in the afternoon, but this could be a slow process. For now, we`ll add the mention of smoke in the morning for Denver northward across Weld county. .LONG TERM...(Monday night through Sunday) Issued at 322 PM MDT Sun Sep 23 2018 Monday night into Tuesday, a moderate to strong west/northwesterly flow aloft will be over the area. The first short wave trough will pass to the north and east of CO by 00z Tuesday. The best chance of showers at that time will be over the far northeast plains. Mid level cold air advection will drop the 700 mb temperatures from 10C Monday afternoon to 4C Tuesday aftn. Although it will be cooler it will remain dry in the mountains west of the Continental Divide. A cold front post-frontal upslope along the Front Range/Palmer Divide may allow for some light showers in and near the foothills southwest of Denver by late Tuesday. It will remain cool on Wednesday over the northeast plains, with only a slight chance of showers over the Palmer Divide early. Dry elsewhere across the cwa. Weak to moderate mid level qg descent sweeping across the state Wednesday afternoon and evening. Mid level warming will start to develop late Wednesday and continue with a gradual warming trend the rest of the week. A dry northwesterly flow aloft with a ridge to the west through Friday then more of a zonal flow aloft over the weekend. && .AVIATION...(For the 06Z TAFS through 06Z Monday night) Issued at 955 PM MDT Sun Sep 23 2018 Light and variable winds in the denver metro area as of 2145z should transition to a more typical south-southwest drainage wind pattern in the next couple of hours with pressure falls across southern Wyoming ahead of a cold front. This cold front is expected to slip across southeast Wyoming after midnight, then drop south across northeast Colorado late tonight. Latest model guidance points to a 11Z arrival time in the Denver metro area. The air near the ground behind this front appears quite dry. So, the chance for precipitation in the Denver area with frontal passage appears quite low at this time. What most likely will accompany the front will be northerly winds bringing smoke down from wildfires upstream from here, such as the Ryan Wildfire. It is possible that VSBYS in the Denver area could fall to the 4-6 mile range due to the smoke during the early to mid-morning hours. By late morning, a shift to southeast wind should dispatch most of this smoke before noon. && .FIRE WEATHER... Issued at 955 PM MDT Sun Sep 23 2018 The Red Flag Warning for FW zones 211..213 and 217 in Jackson, Grand and Summit Counties expired at 8 PM MDT this evening. Its possible this warning could be reissued for this same area tomorrow afternoon should the latest model data support this action. Otherwise, high based mostly dry showers passing over the Ryan and Silver Creek Wildfires overnight may produce gusty and erratic wind gusts to 30 mph. Fortunately, rising RH values overnight in advance of the weather system presently passing over Utah should reduce the risk of large fire growth. && .BOU WATCHES/WARNINGS/ADVISORIES... None. && $$ UPDATE...Baker SHORT TERM...Gimmestad LONG TERM...Cooper AVIATION...Baker FIRE WEATHER...Baker
Area Forecast Discussion
National Weather Service Columbia SC
905 PM EDT Sun Sep 23 2018 .SYNOPSIS... Surface and upper ridge offshore will continue to extend into the region through Tuesday as a frontal bounday dissipates over the northern Midlands. Another front will move into the region mid to late week. These factors will lead to increasing precipitation chances by mid week but temperatures remain above normal until next weekend. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... Surface and upper ridge off the coast will continue to ridge into the area through tonight. A backdoor cold front appears to move into the northern Midlands tonight and possibly wash out in the Piedmont. There could still be isolated showers across the northern Midlands near the front. Continued onshore flow could also bring a few showers to the CSRA tonight. Expect more clouds overnight as PWAT increases 1.5 to 2.0 inches. Kept overnight low in line with guidance consensus...in the upper 60s and lower 70s. && .SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/... Upper ridging over the western Atlantic will promote southwesterly upper flow over the region Monday and Tuesday. A slow moving back door front will be in the area on Monday with wedge conditions possible in its wake. Moisture will increase with precipitable water values around peaking at 1.8 to 2.0 inches on Monday. Have continued with chance pops given the deeper moisture and frontal boundary in the area, although QPF should be light. The front will be south of the area on Tuesday with drier air in place so slight chance pops appeared adequate. High temperatures on Monday are forecast closer to seasonal norms than in recent days, in the lower 80s north and middle to upper 80s south. On Tuesday, highs will be a little warmer with less showers around, in the middle 80s to around 90. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... Upper ridging off the East Coast will weaken Wednesday and Thursday with southwesterly flow aloft becoming more zonal by Friday and into the weekend as an upper trough moves into the Upper Midwest and then Great Lakes regions. A cold front will approach the forecast area on Friday and may stall through Saturday. Moisture will deepen across the area ahead of the front. Have continued to indicate mainly chance pops. High pressure expected to return by Sunday with lower pops. Expect to see a gradual cooling trend through the long term with highs around 90 on Wednesday and in the low to mid 80s by Sunday. && .AVIATION /01Z MONDAY THROUGH FRIDAY/... High confidence for VFR conditions through this evening. Winds will become light and variable through the night. A frontal boundary will be slowly pushing southward out of North Carolina overnight, with is expected to remain north of all taf sites until late Monday morning. South of front, models still hinting at the potential for fog and stratus development. Latest hrrr models is showing an increasing chance for ceiling restrictions now across portions of the Midlands ahead of the southward moving front, with some possibility also across the CSRA. Have indicated restrictions at AGS/DNL after 06Z, and at CAE/CUB towards morning. Should see VFR return to all sites by midday Monday as boundary layer mixing increases. Scattered showers will be possible Monday, but confidence in timing and coverage remain too low to include in TAFs. EXTENDED AVIATION OUTLOOK...Restrictions possible each day in late night/early morning fog/stratus and mainly afternoon and evening showers and thunderstorms as a frontal boundary will stall across the area this week. && .CAE WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. && $$
Area Forecast Discussion
National Weather Service Cheyenne WY
855 PM MDT Sun Sep 23 2018 .UPDATE... Issued at 848 PM MDT Sun Sep 23 2018 8 pm Update. Made some adjustments to POPs using latest hi-res model guidance. HRRR and NAM Nest show showers developing between 06-08z moving over southeastern Wyoming. Most areas could see a sprinkle or two overnight but wetting rain does not look highly favorable. The best shot looks to be the mountain peaks in far southern Wyoming near the Colorado border. Other updates include the addition of smoke and haze as the Ryan Fire continues to burn. Should see the rain reduce that some through the day tomorrow. Along the same lines, winds were increased slightly with the latest guidance. This pushed some area toward more critical Fire Weather COnditions and the Red Flag Warning was expanded as a buffer. && .SHORT TERM...(This evening through tuesday night) Issued at 200 PM MDT Sun Sep 23 2018 Fire weather will continue to be the main concern Monday, then a break expected Tuesday. Currently pretty quiet across the CWA weatherwise with some cumulus spreading across the area in southwesterly upper flow. A upper shortwave will move across the area overnight into early Monday setting off widely scattered showers and maybe a few tstms. It will also push a cool front across the CWA later tonight and bring about 10-15 degrees of cooling Monday, especially east of the mtns. Still breezy out west Monday afternoon. A better coverage of showers/tstms expected Monday afternoon and evening over the plains as another shortwave nears the area. A second push of colder air moves into the area in the wake of the second shortwave Monday night with dry and mild conditions Tuesday along with light winds. Chilly night Tuesday night under mainly clear skies and light winds as a surface high settles down the northern and central Plains with many areas falling into the 30s. .LONG TERM...(Wednesday through Sunday) Issued at 200 PM MDT Sun Sep 23 2018 The latest medium range models are in good agreement depicting a northwest flow aloft Wednesday and Thursday, transitioning to west to southwest next weekend. Little to speak of in terms of sensible weather, aside from a cold frontal passage Wednesday night. Cooler than normal temperatures Wednesday and Thursday will moderate to above normal Friday through Sunday. Breezy conditions will occur each afternoon west of the Laramie Range, which will maintain the elevated fire danger. && .AVIATION...(For the 00Z TAFS through 00Z Monday evening) Issued at 531 PM MDT Sun Sep 23 2018 Forecast for today and tonight VFR to MVFR at times with some rain showers and smoke/haze from ongoing wildfires. Gusty southwest winds will continue though the early evening as an area of low pressure strengthens over southeastern Wyoming. Ceilings will begin to drop as a stalled coldfront slowly moves its way south. Scattered showers and isolated thunderstorms will develop overnight and early tomorrow. VCSH was introduced to many TAF sites, but lack of agreement on short term guidance precludes the inclusion of thunder at this time. Northwest to northeasterly winds behind the front will change early tomorrow morning and continue through the day. && .FIRE WEATHER... Issued at 848 PM MDT Sun Sep 23 2018 Yet another day with critical fire weather conditions expected Monday but mainly over Albany and Carbon counties. A cold front will pass across the area overnight with widely scattered showers and a few evening storms possible across the area. A second surge of cooler air will arrive Monday night and should bring a respite to the critical fire conditions for Tuesday. Elevated concerns then look to return over western districts beginning on Wednesday. Added Zones 302 and 309 to the Red Flag Warning replacing the previous Fire Weather Watch. While condiitons are Marginal, strong winds and marginal humidity may allow extreme Fire Behavior. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...Red Flag Warning from noon to 8 PM MDT Monday for WYZ302>309. NE...None. && $$ UPDATE...AL SHORT TERM...RE LONG TERM...MAJ AVIATION...AL FIRE WEATHER...AL
Area Forecast Discussion
National Weather Service Green Bay WI
648 PM CDT Sun Sep 23 2018 Updated aviation portion for 00Z TAF issuance .SHORT TERM...Tonight and Monday Issued at 249 PM CDT Sun Sep 23 2018 The latest RAP analysis and satellite/radar imagery show a cold front stalling out over far northern WI and the Upper Peninsula early this afternoon. This front has brought in some low stratus over Vilas county, and scattered to broken cumulus over northern WI. Meanwhile, clear skies are prevailing across east-central WI all the way to a low pressure system over eastern South Dakota. As the front over the U.P. border returns northwards, forecast concerns mainly revolve around clouds and temps in the short term. Tonight...As an elongated low pressure system moves from eastern SD to northern MN, the stalled cold front will return north across the U.P. and Lake Superior. Some clouds above 15 kft will likely push into northern WI ahead of the low, but most areas will continue to see mostly clear conditions persist. The pressure gradient will tighten across the region, and the resultant increase of boundary layer winds should limit fog potential. Did lower temps a tad in the cold spots. But otherwise, lows should fall into the middle 40s to lower 50s. Monday...The low pressure system will continue to move north into Ontario while pushing a cold front across Minnesota. South/southeast winds will increase ahead of the front, and should push highs into the upper 60s to middle 70s. However, the south winds will also start to draw in increasing amounts of Gulf moisture. This should result in more cloud cover and humid conditions arriving for the afternoon. But precip chances should remain south and also west of the region through early evening. .LONG TERM...Monday Night Through Sunday Issued at 249 PM CDT Sun Sep 23 2018 A cold front will move through the area Late Monday night into Tuesday, bringing showers and a chance of thunderstorms. On Monday night, pops will be highest in the northwest, near the cold front. Models have trended east with a surge of tropical moisture during the evening, so most of that rain should miss us. On Tuesday, the main focus should be over the southeast half of the forecast area, where the slow frontal passage will still be occurring. Instability is progged to be fairly weak during most of the event, except Tuesday afternoon in the Fox Valley/Lakeshore region, when CAPE may reach 500-1000 j/kg. With deep layer shear of 45-55 knots and upper divergence with the RRQ of a 120 knot jet streak coincident with the instability axis, a few strong storms cannot be ruled out. The cold front should be east of the region by Tuesday night, but the RRQ will linger over eastern WI during the evening and a strong upper level trough is forecast to move through the region late Tuesday night into Wednesday morning. Will need to keep some small pops in eastern WI Tuesday evening, and across far northern WI into Wednesday. Another cold front is forecast to arrive late Wednesday night into Thursday, along with the next chance of showers. Other than mid-level lapse rates of 6.5 to 7 C/KM over northern WI Thursday afternoon, models show little instability to work with. Will only mention a slight chance of storms over north central and far northeast WI Thursday afternoon, aided by the passage of a short- wave trough. High pressure may bring a brief dry period for the end of the work week, but models strongly disagree on the arrival time of precipitation for the weekend. The ECMWF model keeps dry weather in place through Friday night, while the GFS has a much wetter look through the entire weekend. Temperatures will be above normal Monday night into Tuesday, then below normal for the rest of the extended period. && .AVIATION...for 00Z TAF Issuance Issued at 647 PM CDT Sun Sep 23 2018 Generally good flying weather across central and northern WI through this TAF period. Mid and high clouds are expected to increase tonight as the surface pressure gradient tightens. This will help to keep wind speeds from becoming calm and variable and also limit the overall temperature decrease tonight, allowing for a reduced fog potential. Late in the TAF period, Monday afternoon, there may be some afternoon CU that develops, possibly giving a broken MVFR ceiling at times. Additionally, low level wind shear may increase late tonight over north-central WI, but it doesn`t appear significant enough to include at any of the TAF sites with this issuance. && .MARINE...Increasing southeast winds and favorable fetches will lead to building waves on Lake Michigan late tonight into Monday morning. Waves are expected to peak along the Lake Michigan shoreline in the 09-13z time period at 4 to 4.5 ft. A small craft advisory has already been issued, and will issue a beach hazard statement for the morning hours north of Manitowoc. Gusty southwest winds could also generate conditions that are hazardous to small craft on Thursday and Thursday night. && .GRB WATCHES/WARNINGS/ADVISORIES... Beach Hazards Statement from 1 AM CDT Monday through Monday morning for WIZ022-040. && $$ SHORT TERM.....MPC LONG TERM......Kieckbusch AVIATION.......Cooley
Area Forecast Discussion
National Weather Service Lake Charles LA
936 PM CDT Sun Sep 23 2018 .DISCUSSION... Wx map shows very little pressure gradient over the region, with light east to southeast winds. Aloft, a broad low at 700mb, with a trough reflection at 500mb over E TX yielding enough lift in this juicy tropical atmosphere (00z LCH sounding PW at 2.33") to continue scattered showers & isolated thunderstorms this evening. Per latest HRRR & 00z NAM12 guidance, this will likely increase over LA after midnight, especially along and south of I-10 into the coastal waters. Forecast update included tweaking QPF and chances of SHRA/TSRA this evening and the overnight and early morning hours Monday. Remainder of forecast on track. DML && .PREV DISCUSSION... /issued 653 PM CDT Sun Sep 23 2018/ AVIATION...A weak front has worked to around the Sabine River this afternoon with a few showers noted along the boundary. With the boundary in the region tonight, and moisture remaining high, low ceilings are expected to develop late tonight. Ceilings will gradually improve during Monday morning, however showers will increase in coverage as well. Winds will light and generally vrb tonight and become sw Monday. PREV DISCUSSION... /issued 404 PM CDT Sun Sep 23 2018/ DISCUSSION... Weak SFC front remains over E TX, stretching N-S very near a Beaumont to Lufkin line and on to low pressure centered west of Tyler. Aloft, upper trof remains over east TX. Ongoing isolated to scattered shower activity will continue into early evening before largely dissipating inland, and in a familiar pattern, continue over the Gulf waters and increase in coverage during the overnight hours across coastal LA. This activity will subsequently expand northward through Monday into East Central LA, with E TX seeing a reprieve thanks to some relatively drier air pushing in from the west as the upper trof and associated SFC features weaken and begin to lift out to the NE. As the trof continues to pull away on TUE, MSTR will return to E TX around a WWD expanding sub-tropical ridge over the Gulf, with areawide scattered showers and thunderstorms expected. Scattered to numerous showers and thunderstorms are tap WED and THU as global models continue to depict an upper trof digging into the Central CONUS, sending a weak frontal boundary into the region. Rain chances decrease a bit FRI and SAT as the front washes out and a deep layer ridge builds over the SE CONUS, with even lower chances SUN as this feature builds WWD. Temperatures through the period will continue to average well above seasonal normals. 13 MARINE... High pressure extending into the northwest Gulf will maintain a light south to southeast flow to start the coming week. A weak front sagging into the area Wednesday will result in variable and at times northerly winds through Thursday, with a more prevailing east to southeast flow developing on Friday as the front dissipates and high pressure strengthens over the Mid Atlantic. 13 && .PRELIMINARY POINT TEMPS/POPS... AEX 72 88 72 90 / 50 60 20 40 LCH 74 88 74 88 / 50 60 30 50 LFT 74 89 74 89 / 50 60 40 60 BPT 74 87 75 88 / 50 40 30 50 && .LCH WATCHES/WARNINGS/ADVISORIES... LA...None. TX...None. GM...None. && $$ PUBLIC...08
Area Forecast Discussion
National Weather Service Marquette MI
645 PM EDT Sun Sep 23 2018 .SHORT TERM...(This evening through Monday) Issued at 403 PM EDT SUN SEP 23 2018 WV imagery and RAP analysis indicated a shortwave trough moving through the northern Rockies with nearly zonal mid/upper level flow downstream across the rest of the northern CONUS. At the surface, the cold front that moved through most of Upper Michigan last night has stalled near KESC-KIMT. Abundant low clouds persisted across the north with temps in the mid to upper 40s while sct-bkn cu prevailed over the south allowing temps to climb into the lower to mid 60s. Upslope easterly flow into north central Upper Michigan still supported some patchy drizzle in the higher terain along with some fog. Tonight, a southerly low level jet will increase over the area tonight in response to deepening low pressure ahead of the advancing nrn Rockies shrtwv. Some pcpn may develop with the WAA pattern but models 295k-305k isentropic progs suggest that mid level moistening will remain north of Upper Michigan with mainly just low level moisture persisting. So, no more than drizzle would be expected where se to s flow upslopes, especially over the nrn Keweenaw peninsula. Otherwise, temps will remain steady or slowly rise tonight north as the winds veer. Monday, any remaining low clouds or fog should dissipate during the morning as low level mixing increases. Sunshine and WAA with gusty southerly winds to around 25 mph will help push temps to around 70, especially where downslope flow prevails near Lake Superior. .LONG TERM...(Monday night through Sunday) Issued at 339 PM EDT SUN SEP 23 2018 No significantly impactful weather expected in the long term as fairly typical fall conditions persist. A low will pass N of the CWA, dragging a cold front/trough across the area Mon night into Tue morning. Best resulting rain coverage should be over the western CWA, with more scattered coverage elsewhere. A couple of shortwave troughs moving through the region Tue evening and Wed may bring some rain showers, but coverage is uncertain. 850mb temps drop down around 1-2C Tue night and Wed, so WNW winds may lead to some isolated to scattered showers downwind of Lake Superior. A stronger trough will then move through the area Thu, bringing chances for showers Thu into Thu night. Lake effect rain showers are possible Fri as models show WNW flow with 850mb temps around or less than 0C. Lots of uncertainty next weekend as models differ significantly, but could see continue off and on chances for rain. High temps of 55-65 Tue will fall into the 50s for the most part Wed through Sun (may not even get above 50 in spots Fri and Sat. Lows over the interior will be in the 30s Tue night through Sat night, with Fri and Sat night looking coldest. Frost will be possible at times, but potential will need to be fine tuned as precip and cloud cover can be better sorted out. && .AVIATION...(For the 00Z TAFS through 00Z Monday evening) Issued at 645 PM EDT SUN SEP 23 2018 Abundant low-level moisture and upslope winds will support IFR/LIFR conditions through tonight at KCMX/KSAW. Downsloping will continue at KIWD and allow VFR conditions through the period. KCMX will improve to MVFR late tonight and to VFR by Mon afternoon. KSAW will maintain upsloping tonight but should improve to MVFR early Monday morning as winds become southerly and VFR by late morning. && .MARINE...(For the 4 PM Lake Superior forecast issuance) Issued at 403 PM EDT SUN SEP 23 2018 Another cold front will approach from the west on Mon, and this will keep winds mostly in the 20-30kt range, though the strongest winds will shift to eastern Lake Superior tonight and Mon as winds become southerly. There could be some gale force gusts over the eastern part of the lake on Mon. With passage of the cold front Mon night/early Tue, winds will shift to the nw at 15-25kt for Tue, strongest over the e half of the lake. May be able to slip in a day with winds mostly under 20kt on Wed before the next low pres system moving e toward northern Ontario brings stronger winds of 20-30kt again on Thu. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... None. Lake Superior... Gale Warning until 9 PM EDT /8 PM CDT/ this evening for LSZ162. Lake Michigan... None. && $$ SHORT TERM...JLB LONG TERM...Titus AVIATION...07 MARINE...JLB