Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 11/22/20

Area Forecast Discussion...UPDATED
National Weather Service Columbia SC
656 PM EST Sat Nov 21 2020 .SYNOPSIS... High pressure will keep dry weather over the region through Sunday. Warming trend continues this weekend. A series of cold fronts expected to cross the region early into the middle of next week. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... Upper high centered just to our SE, with surface ridge axis across our region, providing fair weather and light winds. Late tonight, the upper ridge will shift east with upper trough approaching from the west. Models indicate a surface trough developing offshore with some isentropic lift commencing. This may spread some stratocumulus into our southern FA late tonight. Some high level cloudiness may stream in from the west late tonight as well. Patchy fog potential in areas where skies remain mostly clear. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY NIGHT/... Upper ridge axis shifts offshore Sunday with an approaching upper trough and lowering 500mb heights over the area. The model show an increasing low level onshore flow into the eastern portion of SC. There will be deeper mid/upper level moisture in increasing sw flow aloft. PWATs will increase to around an inch. Coastal trough may lead to a slight chance of showers late Sunday into sunday night, mainly in the eastern area but a lack of significant forcing will limit shower coverage. Model time sections show plenty of cloud cover Sunday into early Monday and this will trend temperatures downward slightly from the recent unseasonably warm temperatures. Cold front moves through late Sunday night, keeping chances of showers in the east where moisture will be higher with a cooler, drier airmass moving in behind the front. Clouds through most of the night and mixed boundary layer will keep lows in the upper 40s and low 50s. High pressure will ridge southward into the region on Monday through Tuesday. This will produce clear skies and pleasant temperatures with a slight cool down Monday into Tuesday. More favorable radiational cooling conditions Monday night, although a weak low level jet will keep lows in the upper 30s to around 40 degrees across the area. As high pressure builds offshore Tuesday night low level flow will become more east/southeast and moisture will gradually begin to increase over the area. Expect slightly milder temperatures Tuesday night with lows from 40 to 45 across the area. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... Amplified pattern will remain in place. Another upper ridge begins to slide off the coast Tuesday night into Wednesday as deep trough ejects from the Four Corners region and lifts northeast and closes off across the Midwest through Wednesday. Associated surface low pressure and cold front expected to move into the region Wednesday night into Thursday. Both ECMWF/GFS in decent agreement that front will push through the region, but have a difficult time pushing southward. As flow remains zonal/southwest behind the front. Have continued with chance pops with the associated front Wednesday night into Thursday. Temperatures will likely remain slightly above normal through the end of the week. Differences begin to appear in the models as the weekend approaches. Models indicate a major system trying to develop across the southwest portion of the country and head eastward by the weekend into early next week. && .AVIATION /00Z SUNDAY THROUGH THURSDAY/... VFR conditions expected through 06z or so but then possible restrictions in fog through the predawn hours. Surface high pressure continues to prevail over the region but low level moisture continues to slowly increase with the southeasterly surface winds off the Atlantic. Winds will be near calm overnight with mostly clear skies although some patchy cirrus moving in from the west does complicate the forecast a bit. Mixed signals again in the guidance with HRRR and MAV/LAV not really showing much fog but the MET guidance is hitting it hard again with IFR/LIFR vsbys and our local radiational fog scheme is also hinting at possible IFR vsbys around 12z. Also late tonight the southeasterly flow will allow a weak surface trough along the coast to move inland and bring some stratocumulus clouds after 10z. Given the uncertainty in clouds but also understanding little change in air mass other than some increased low level moisture, will bring in MVFR vsbys at 09z at CAE/CUB with tempo IFR vsbys through 12z. Introduce fog a bit earlier at AGS given proximity to the river and dewpoint depressions already at 6 degrees. Less confidence at OGB so only carrying a tempo group there. Vsbys should improve by 13z back to VFR and some VFR cigs expected to spread over the region with weak isentropic lift associated with the weak surface trough. Possibly some MVFR cigs at OGB/AGS/DNL during the day but confidence is low. EXTENDED AVIATION OUTLOOK...Restrictions in late night/early morning fog/stratus possible through Tuesday. && .HYDROLOGY... Minor flooding continues along the shoreline of Lake Wateree. Area reservoir operators continue to move water through the Catawba/Wateree basin and expect the lake level to remain above flood stage tonight and fall below flood stage on Sunday. && .CAE WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. && $$
Area Forecast Discussion
National Weather Service Green Bay WI
506 PM CST Sat Nov 21 2020 Updated aviation portion for 00Z TAF issuance .SYNOPSIS... Issued at 225 PM CST Sat Nov 21 2020 A light mix of precipitation across mainly north-central and central Wisconsin tomorrow, with a more substantial round of precipitation (much of it wintry) likely Tuesday into Tuesday night. The upper flow across North America was initially fairly flat. The pattern will be slowly progressive and gradually gain amplitude during the upcoming work week. There will also be a trend toward increased splitting of the westerlies, at least at times. The pattern will result in two substantial shortwaves crossing the region, likely resulting in AOA normal amounts for the period. Daily temperature departures from normal will be modest, though generally on the above normal side of the ledger. && .SHORT TERM...Tonight and Sunday Issued at 225 PM CST Sat Nov 21 2020 The latest RAP analysis and satellite/radar imagery show high pressure centered over the western Great Lakes early this afternoon. Patches of clouds below 2000 ft lingered through much of the morning over northwest WI and parts of north-central WI, but is only slowly eroding early this afternoon. Looking upstream, the next storm system is moving into the Dakotas. As this storm system moves into the region, light precip chances are the main forecast concern through Sunday afternoon. Tonight...High pressure will gradually shift to the east, but will continue to have plenty of influence on our sensible weather. The evening should be clear and calm for most locations. Mid and high clouds will increase from west to east after midnight, but forecast soundings indicate that the layer below 10 kft will remain dry. Inherited a forecast that went below the national blend for low temps, and see no reason to stray significantly. Lows ranging from mid to upper teens in the north to upper 20s near Lake Michigan. Sunday...Shortwave energy will be digging into the region. Moisture through the column continues to look limited and disjointed. But deep enough saturation looks to occur by midday over central to north-central WI for a chance of light rain and snow. The chance of light rain and snow will then spread northeast over the course of the afternoon, and remain mainly north and west of the Fox Valley. Perhaps a couple tenths of snow accumulations are possible over the northwoods, but no travel impacts are expected. High temps will range from the mid 30s north to the low 40s over the southern Fox Valley. .LONG TERM...Sunday Night Through Saturday Issued at 225 PM CST Sat Nov 21 2020 Precipitation from Sunday will probably linger into Sunday night. Mid-level moisture may get stripped out sufficiently to result in some FZDZ. NW flow across Lake Superior may also keep some light precipitation going in north-central into far northeast Wisconsin for much of the night. The main precipitation event during the period will occur Tuesday into Tuesday night. A fairly substantial full-latitude trough will initially head east from the West Coast, but undergo some splitting as it progresses across the country. That will add an additional layer of uncertainty to the forecast and make pinning down details difficult. Will hold off on getting too specific with the precipitation forecast and handle primarily with a mention of the possibility of hazardous travel condition in the HWO for now. At this point, central into north-central Wisconsin seem most at risk of receiving at least a few inches of snow. Precipitation could linger into Wednesday in eastern Wisconsin, though it may be just warm enough for that precipitation to fall as mainly rain. Quiet weather should return for the rest of the forecast period, including Thanksgiving Day. A significant system may affect the area just beyond the end of the period, but its track and intensity will depend on if/when/how much phasing of the streams occurs and so the models will probably have some difficulty honing in on the evolution of that system until we get much closer to the event. && .AVIATION...for 00Z TAF Issuance Issued at 506 PM CST Sat Nov 21 2020 VFR conditions and winds under 10 kts remain expected through Sunday morning. Clouds will increase and lower late tonight through Sunday as a weak trough tracks through the western Great Lakes region. The trough will likely cause CIGS to lower to MVFR across central and north-central Wisconsin Sunday afternoon, with a chance for precipitation. Precipitation chances look to be too low across central Wisconsin during that period, however will add a PROB30 group for RHI given the better chance for -RASN to hit the ground. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS.......Skowronski SHORT TERM.....MPC LONG TERM......Skowronski AVIATION.......Kurimski
Area Forecast Discussion
National Weather Service Lincoln IL
847 PM CST Sat Nov 21 2020 .SYNOPSIS... Issued at 847 PM CST Sat Nov 21 2020 A cool and rainy night is in store across central and southeast Illinois with low temperatures dropping into the upper 30s and lower 40s. The rain will taper off and come to an end from west to east Sunday morning, followed by mostly cloudy but dry conditions during the afternoon. && .UPDATE... Issued at 847 PM CST Sat Nov 21 2020 02z/8pm surface analysis shows a 1020mb low over southwest Missouri...with a large area of overrunning rain stretching from the Ozarks northeastward into central Illinois. Local radar indicates the heaviest/steadiest rain currently along/just north of the I-70 corridor, although another rain band has formed further north along a Rushville to Bloomington line. All models suggest the rain will become widespread across all of central and southeast Illinois from late evening through the overnight hours before coming to an end from west to east by midday Sunday. Made some minor adjustments to hourly PoPs, but the overall forecast is right on track. Am expecting a rainy/cool night with lows ranging from the middle 30s far north around Galesburg and Lacon to the middle 40s south of I-70. && .SHORT TERM...(This evening through Sunday) ISSUED AT 357 PM CST Sat Nov 21 2020 The return of rainfall has begun across the region. Seeing almost two bands of precipitation, one across the I-70 corridor, and the other north of the I-72 region. The northern band has not reported much reaching the ground, while the southern band is slightly stronger reflectivity, with reports of rainfall in the bottom 6 CWA counties. This stream will continue to flow through the area depicted, creating the potential for heavy rainfall across the southern CWA. The associated frontal boundary remains just south of the Ohio River, and is expected to lift slightly north overnight as the Low pressure core moves into the mid-Mississippi River Valley. The track of the core is forecast to remain south of the CWA, through the Ohio River Valley overnight. This will hold the heaviest rainfall across southern Illinois, with the chance of up to 1.50 inches possible south of the I-70 corridor. As this system exits the region Sunday, expect lingering shower activity through the morning...with ending times through the early afternoon across central and eastern Illinois. Temperatures will remain seasonal through Sunday, with highs forecast in the mid to upper 40s, while tonights lows only dip into the mid 30s far north, while in the mid 40s across far south. .LONG TERM...(Sunday night through Saturday) ISSUED AT 357 PM CST Sat Nov 21 2020 Dry weather is expected to develop across the Midwest Sunday night through most of Monday, as High pressure quickly builds across the Midwest. This will be short lived, as another advancing system tracks into the Midwest again Monday night into Tuesday. This will push the High off to the east, bringing the return of WAA to the region. There is signals of WAA rainfall arriving overnight Monday into Tuesday, with a lull in activity anticipated Tuesday afternoon. Like this system coming through tonight, the main bands of precipitation and heaviest rainfall is likely to occur Tuesday night into early Wednesday morning. The main difference in forecast models, is that the track of the Low core with this system will be through northern Illinois, possibly clipping the IL River Valley. This will mean the heaviest rainfall from this system will track through our coverage area. Models indicate 1-2 inches of total precip from this event, however these numbers typically decrease closer to the arrival of the system. High pressure is then forecast to return across the region mid- week, lingering through the end of the week. A few models hint at another system approaching the region from the south towards the end of the forecast period, however this will be left out of discussion currently as models do not have great collaboration. Temperatures through the upcoming week remain seasonal, with highs through the week in the 50s, and lows dropping to the 30s and 40s. && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) Issued at 550 PM CST Sat Nov 21 2020 A wave of low pressure will spread low clouds/precip across central Illinois this evening. 2330/530pm radar mosaic shows light showers developing along/south of a KBMI to KUIN line. With an initially dry boundary layer, it will take awhile before the atmosphere moistens sufficiently to support precip reaching the ground and even longer for ceilings to lower substantially. Based on NAM forecast soundings and HRRR forecasts, it appears ceilings will lower to MVFR at all sites except KPIA between 04z and 06z...then further northwest to KPIA by around 08z. As light rain continues, IFR ceilings will develop everywhere except KPIA late tonight into Sunday morning. Once the rain departs, a low overcast will persist...until ceilings rise back to VFR west of the I-55 corridor after 20-22z Sun. Winds will initially be NE at 5-10kt, then will switch to N/NW after FROPA Sunday afternoon. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...Barnes SYNOPSIS...Barnes SHORT TERM...Baker LONG TERM...Baker AVIATION...Barnes
Area Forecast Discussion
National Weather Service Pueblo CO
312 PM MST Sat Nov 21 2020 .SHORT TERM...(This evening through Sunday) Issued at 312 PM MST Sat Nov 21 2020 This afternoon there are still a few low clouds near the eastern border, while a few instability showers/clouds can be seen over the mtns and high valleys. The HRRR has be persistent in showing a batch of showers moving off the southern Sangre de Cristo mtns this evening, and then eastward across Huerfano and Las Animas Counties and into Baca County through the evening. The GFS also shows this area of showers, so will go with some scattered showers in these areas this evening. Low clouds are expected to back into the southeast plains tonight but at this time are not expected to move into the KCOS or KPUB areas. By 12Z the forecast models show the potential for low clouds shifting southward and being mainly over Las Animas, Baca and Huerfano Counties. Otherwise dry weather is expected tonight as an upper ridge starts building toward the area from the west. Sun the upper ridge will move over CO but will be quickly followed by the next disturbance. Most of the day Sun will be dry, but then ahead of the the disturbance moisture will increase in the afternoon and by late afternoon it looks like there will be some showers along the Continental Divide, mainly over the eastern San Juan mtns. Temps on Sun looks a little cooler, with highs in the 40s to lower 50s over the plains, and mostly in the 40s in the high valleys, with upper 30s to mid 40s in Teller County. .LONG TERM...(Sunday night through Saturday) Issued at 312 PM MST Sat Nov 21 2020 Sunday night through Tuesday...The first upper low pressure system to affect the region will initially approach as an open longwave trough, with a nearly constant southwest feed of moisture across the Four Corners Sunday night through Monday morning. This will bring snow to the higher terrain along the Continental Divide as well as the Sangres, while the rest of the forecast area will likely just experience increased cloudiness. Monday evening the system begins to strengthen as it crosses into the Great Basin and Rockies, with an associated cold front pushing south into CO Monday night. The system will then continue crossing CO through Tuesday, exiting to the east into Kansas that night. At this time, total forecast snow amounts over the southwest mts range from a foot to a foot and a half of new snow, while the peaks of the central mts and the Sangres could see 6 to 12 inches of new snow. Minimal amounts are expected over the Wets, Rampart Range and Monument Hill, but this will need to be monitored for any possible movement changes as snowfall in these areas would be tied to the associated cold front late Mon night. Somewhat pleasant temps are anticipated across much of the region on Monday, but with the frontal passage, highs on Tuesday will be 10 degrees cooler across the high valleys, and 20 degrees cooler across the plains. Wednesday...Colorado will be between systems on Wed, with dry and mild conditions forecast across the region. Maximum temps are expected to be in the 40s and 50s for most areas. Thursday through Saturday...Long range models are showing some variance with the timing of the next system to affect the forecast area. GFS is indicating an upper trough crossing the region Thu and Fri, while the EC paints a slightly slower, and stronger, solution with a closed low crossing AZ and NM Fri and Sat. Obviously, confidence on timing is low though the one common denominator is a system affecting Colorado on Fri, and the extended procedure indicates the highest pcpn chances on Fri with highs in the 30s and 40s. Stay tuned as the models start to fine tune the system over the Thanksgiving holiday. Moore && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) Issued at 312 PM MST Sat Nov 21 2020 VFR conditions and dry weather are expected at KPUB the next 24 hrs, and winds will generally be 10 kts or less. KCOS could see some showers in the vicinity very early this evening, otherwise dry weather is expected with winds mostly under 10 kts, however south winds Sun afternoon should be 10-15 kts. KALS could see a few showers in the vicinity very early this evening, otherwise dry weather and light winds are forecast, although southerly winds Sun afternoon could increase to 10-15 kts. && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...28 LONG TERM...MOORE AVIATION...28