Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 10/28/19

Area Forecast Discussion
National Weather Service Duluth MN
628 PM CDT Sun Oct 27 2019 .SHORT TERM...(This evening through Monday night) Issued at 332 PM CDT Sun Oct 27 2019 Cooler temperatures will be the trend in the short term following the passage of a cold front earlier this morning, along with mostly cloudy skies overnight. Low level moisture will continue to be trapped under an inversion, and with the thermal profile cooling this evening into tonight, along with enough mixing, there may be just enough forcing to squeeze out some sprinkles this afternoon turning into snow flurries this evening into tonight. HRRR and RAP forecast soundings show the top of the boundary layer hovering near the dendritic growth zone for much of the night, which suggests that flurries will be possible. These types of setups seem to favor horizontal roll convection with low-level stratocumulus clouds, and this organization is suggested in model reflectivity as well. The best chance at seeing flurries or light snow showers will be in northeast Minnesota as 500-mb cyclonic vorticity advection slowly pivots across northern minnesota concurrent with a 250-mb jet max. Temperatures will cool down into the 20s tonight. There will likely be some partial clearing of the clouds later tonight as drier air moves in, which may allow for some areas to reach the lower 20s, while areas that remain under clouds will reach the mid 20s. Winds will become light as the pressure gradient weakens overnight. On Monday, a mix of clouds and sun is expected for most of the region with temperatures only reaching the mid 30s under cool westerly flow. Clouds will increase across northwest Wisconsin in the afternoon into the overnight as a shortwave trough swings through, followed by a clearing trend from west to east later in the night. There could be a period of light snow in portions of northwest Wisconsin, especially in Price and Iron counties, that may bring a light dusting of snow. .LONG TERM...(Tuesday through Sunday) Issued at 332 PM CDT Sun Oct 27 2019 Fairly quiet conditions and below normal temperatures are expected for the extended. Focus remains on a potential late week system that may bring accumulating snowfall to parts of the Northland. An upper low will be over southwestern Hudson Bay at the start of the extended with a trough extending southwest to another low over the Intermountain West. To the east, surface low pressure is expected to be located over lower Michigan with a vorticity maxima traversing the Northland. This may lead to some light snow across parts of northwest Wisconsin, but overall trends keep the bulk of this system away from the Northland. As the upper trough to the west moves through later Tuesday, a weak cold front will work across the region and may bring a few light snow showers to areas along the International Border Tuesday afternoon and night. High pressure will then move in later Tuesday and remain in place into Thursday as a second upper trough moves over the Northern Plains and into the Northland Wednesday night. Skies should remain fairly clear, however, allowing for good radiational cooling conditions both Wednesday and Thursday mornings with readings in the teens and 20s. Highs Wednesday will be right around freezing. The trough will then move through on Thursday as an upper low moves from the Central Plains to the Mid-Mississippi Valley. The GFS and ECMWF remain in fairly good agreement bringing the surface low from the lower Ohio Valley into southwestern Ontario Thursday night. The 27.12 runs of both models have shifted the track a bit to the east on this run, which keeps the effects of the system to our south and east and brings no QPF to the CWA. The past few runs of both the GFS and ECMWF have been waffling east and west with the location of the low from run to run, so certainly not ready to go with a dry forecast based on one model run when it won`t take a huge shift in the track to bring effects to the area. Some of the GFS ensemble members track the low much further to the west across Wisconsin and into Upper Michigan, so we are far from being out of the woods yet in terms of accumulating snowfall. As such, we continue to run with NBM guidance until a more consistent solution presents itself. A shortwave then drops out of Canada heading into the weekend that will bring light precipitation chances to the Northland. Highs will be in the 30s for the end of the week and weekend with lows in the 20s. && .AVIATION...(For the 00Z TAFS through 00Z Monday evening) Issued at 628 PM CDT Sun Oct 27 2019 Mainly VFR cigs at the start of the forecast. However, there are pockets of MVFR cigs in the vicinity of the snow showers/flurries/drizzle dotting the landscape. Will leave out these lower cigs due to low confidence and carry VFR through the forecast. Gusty winds will diminish by 02Z. && .MARINE... Issued at 332 PM CDT Sun Oct 27 2019 No hazardous conditions are expected across western Lake Superior over the next 48 hours. Winds will gradually become westerly tonight at 6 to 12 knots before becoming southwesterly on Monday at 10 to 15 knots. Winds will remain southwesterly on Tuesday at 10 to 15 knots. Waves through the period will be under 2 feet. && .PRELIMINARY POINT TEMPS/POPS... DLH 25 35 23 37 / 20 10 0 10 INL 24 34 21 34 / 0 0 0 0 BRD 24 35 23 36 / 0 0 0 10 HYR 25 36 23 40 / 0 10 20 10 ASX 27 38 25 42 / 10 10 10 10 && .DLH WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. LS...None. && $$ SHORT TERM...JS LONG TERM...BJH AVIATION...GSF MARINE...BJH
Area Forecast Discussion
National Weather Service Lincoln IL
907 PM CDT Sun Oct 27 2019 .SYNOPSIS... Issued at 345 PM CDT Sun Oct 27 2019 After a sunny and pleasant fall day today across Illinois, a cold front will push southeast into central IL during tonight, and stay over the area on Monday. This will increase low clouds from the northwest during tonight, with patchy fog possible overnight into mid Monday morning east of the IL river. A cloudier day is in store on Monday, with an increasing chance of light rain over central and northwest IL late Monday afternoon and Monday night. Light snow could mix in with the rain northwest of the IL river overnight Monday night. Lows overnight will range from 38 to 45 degrees, coolest by Galesburg. Highs Monday will range from the upper 40s and lower 50s northwest of the IL river, to the mid to upper 60s in southeast IL. && .UPDATE... Issued at 907 PM CDT Sun Oct 27 2019 Monitoring two area of clouds this evening and working on timing them into the CWA overnight. First area seen on satellite is over central MO where clouds have finally begun to develop along the approaching cold front. These clouds are expected to continue to develop to the northeast across parts of central IL late tonight. Second area of clouds is over southeast MO. HRRR has these clouds advecting northward overnight and reaching into central IL toward morning, but in southeast portions of the CWA. These two areas will combine during the early morning hours, covering the whole CWA around 6-7 am. So have made some adjustments to cloud cover and lower high temps in the southeast for tomorrow. Will be sending out an update shortly, but not sure it will change wording of forecast all that much. && .SHORT TERM...(This evening through Monday night) ISSUED AT 345 PM CDT Sun Oct 27 2019 20Z/3 pm surface analysis shows 1017 mb high pressure over MS and ridging into the TN and Ohio river valleys. This was providing a sunny afternoon across the area with SSW winds 5-15 mph giving seasonable temps of 60-65F. Aloft a 592 dm 500 mb high was over the Southeast Atlantic coast while upper level trof extending from central Canada back into the central Rockies and into CA. IL was in a sw upper level flow so an active weather pattern lies ahead this work week. Latest CAMs bring a cold front from southeast IA and nw MO se toward the IL river by early overnight and becoming quasi- stationary in central IL later tonight into Monday. Post frontal low stratocumulus clouds over central/western IA and nw MO will likely move into central IL during overnight into Mon morning and linger thru Mon night. Some patchy fog possible east of the IL river overnight into mid Mon morning with low level moisture trapped in a low level inversion and light winds. Could be some isolated very light rain or sprinkles in west central and nw IL late tonight. Lows overnight mostly 40-45F with upper 30s by Galesburg. Models have trended wetter Mon afternoon over areas from I-55 nw and have chance pops of light rain late Mon afternoon along and west of the IL river, with likely to categorical pops from I-55 west Mon evening. This due to increase forcing on cool side of frontal boundary over central IL on Mon afternoon and into Mon night. Highs Mon range from upper 40s by Galesburg to mid to upper 60s in southeast IL. Lows Mon night range from mid 30s over the IL river valley, with light snow possible with the light rain nw of the IL river overnight Mon night. Milder lows in the low to mid 40s in eastern IL with upper 40s by Lawrenceville. .LONG TERM...(Tuesday through Sunday) ISSUED AT 345 PM CDT Sun Oct 27 2019 Quiet weather returns briefly on Tuesday as IL will be in between weather system, and forcing weakens behind the front by Tue morning and weakening cold front exiting east of IL into eastern parts of the Great Lakes and Ohio river valley by Tue afternoon. A fair amount of clouds linger on Tue especially from the IL river east with some sunshine possible west of the IL river Tue afternoon. Highs Tue range from the mid 40s over the IL river valley, to 55-60F in southeast IL. Medium range models continue to dig an even stronger upper level trof over the Rockies by mid week and eject some moisture ne into central IL during Tue night and Wed. Again areas from the IL river nw will see a chance of mixed pcpn overnight Tue night into early Wed though little or no snow accumulations. Lows Tue night range from near freezing at Galesburg to mid to upper 30s over much of central IL and lower 40s in southeast IL. Highs Wed range from lower 40s nw of the IL river to the low to mid 50s in southeast IL. The main storm system to eject ne on Thursday and bring the highest chances of pcpn from Wed night and Thu evening. Between 1-2 inches of rain possible especially east of the IL river with locally higher amounts possible in southeast IL. Much colder air arriving during Thu night to change rain to snow showers and could be some light snow accumulations then as ECMWF model had trended colder during that time from. A widespread freeze likely to end our growing season later Thu night with lows 27-32F. Dry and cool weather expected Friday thru next Sunday with highs in the low to mid 40s Friday and moderating a bit to upper 40s and lower 50s by Sunday. && .AVIATION...(For the 00Z TAFS through 00Z Monday evening) Issued at 637 PM CDT Sun Oct 27 2019 Skies are clear at all sites, but clouds will be moving in tonight. Satellite loops show clouds slow progressing across eastern IA behind a cold front. Thinking is that some VFR clouds will arrive around midnight at PIA and then later at other sites. However, MVFR cigs around 2-2.5kft will follow a few hours after the clouds move in, followed by cigs below 2kft toward morning and then lasting through rest of day. Winds will be southwest to start and then become northerly to light and variable as the front moves into the area and stalls over central IL. Northeast winds are expected behind the front at PIA, with variable winds at the other sites. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...Auten SYNOPSIS...07 SHORT TERM...07 LONG TERM...07 AVIATION...Auten
Area Forecast Discussion
National Weather Service Paducah KY
703 PM CDT Sun Oct 27 2019 .UPDATE... Issued at 702 PM CDT Sun Oct 27 2019 Given the expansive overcast already invading the region from the south early this evening, adjusted the forecast over the next 24 hours to reflect more sky cover than originally forecast. This had the effect of reducing (but not eliminating) the anticipated fog coverage overnight, in addition to raising temperatures tonight and lowering temperatures on Monday. Used a blend of the CONSShort and Experimental HRRR data, and blended into the NBM (National Blend of Models). Further adjustments may be necessary. Remainder of forecast is unchanged from prior. && .SHORT TERM...(Tonight through Tuesday) Issued at 200 PM CDT Sun Oct 27 2019 Potential exists for fog tonight, perhaps locally dense. MOS indicates points west will be more conducive to fog formation/density, but all sites are susceptible. Per collab with neighbors, will highlight via SPS/HWO, vs headline. It may take til mid-late Monday morning to scour remnant low cloud/fog out, and burn thru the inversion. There is some model disagreement on whether there will be any cloud above a frontal boundary makes its appearance on our northwest border. Since most of the moisture advection/pcpn appears to lag the front, will increase clouds west to east with time, but be a little more gradual and less aggressive certainly with any pops introduced in the short term forecast. Pending collab., may yield late Monday night as we lean into Tuesday`s small pop mention in our northwest. Temps tonight in the 40s should recover into the 60s tmrw, pending the aforementioned cloud clear out/slow beginning (west), while they may push 70 south/east. More cloudiness/small pops appear thereafter, so Monday night lows range from mid 40s-around 50. Tuesday temperatures should show a more substantial gradient from 50s on our northwest/behind the front, to around 60 bridging across the boundary/nearer the Ohio river, to approaching 70 again in the warm sector ahead of the boundary in our south/east. .LONG TERM...(Wednesday through Sunday) Issued at 200 PM CDT Sun Oct 27 2019 The extended period begins with a positively-tilted midlevel trough located over the Four Corners region, with the PAH CWA under the influence of strong southwesterly flow. At the surface, a stationary front will be parked to our southeast, oriented southwest to northeast across western Tennessee into central Kentucky. Ripples of energy in this southwesterly flow will yield increasing chances for showers Wednesday. The midlevel trough will eject from the Four Corners region and move through the Central Plain/Midwest through Friday. Surface low pressure will develop over the ArkLaTex area and move northeastward through the Lower Ohio Valley along the stationary boundary. Models are in good agreement that this low will track to our south and east. This will put us on the cooler side of the system, which will preclude a severe weather threat for our area. Main concerns with this system are precipitation amounts and timing the end of the precipitation Thursday evening. Despite being on the back side of the low, precipitable water values will once again be two or more standard deviations above normal for late October, per the latest GFS ensemble mean. Some models like the 12z GFS place our region in a favorable area of upper-level divergence Thursday, which could enhance rainfall rains as well. For precipitation totals, leaned heavily on WPC guidance, with a blend of NBM. This yielded storm total amounts of 1.5 to 2.5 inches. This will be over a fairly long period, so flash flood concerns are low at this time. However, given that we are suddenly soggy again, there may be flooding issues in low-lying spots or in poorly-drained locations. POPs decrease across the region late Thursday afternoon and evening, but the rain may not be clear of a good portion of the area for Trick-or-Treat time. Additionally, winds will pick up quite a bit in the wake of the departing low, sustained at 15-20 mph with gusts of 25 to 30 with temperatures in the mid 40 to mid 50s, as colder air works in. Cold high pressure will dry us out for Friday into next weekend. There will be a gradient in temperatures Wednesday-Thursday, with highs ranging from the lower 50s in the northwest to the middle 60s in the southeast. Behind the front, highs will only reach the upper 40s to lower 50s, with slowly moderating temperatures for the weekend. There remains a possibility of widespread subfreezing temperatures for next weekend. && .AVIATION... Issued at 554 PM CDT Sun Oct 27 2019 Late today, the leading edge of low clouds was from KPOF to KUCY to KBNA. Trajectories around 1500 ft off in house model data suggests a northward movement tonight, bringing MVFR cigs back across the region, especially from 06z on at the Terminals. Winds will be light as well. MVFR vsbys cannot be ruled out. A lot of that will depend on the cloud cover. The lower cigs will likely hang around Monday, with some improvement in base heights. Winds should be light from the south. && .PAH WATCHES/WARNINGS/ADVISORIES... IL...None. MO...None. IN...None. KY...None. && $$ UPDATE...RJP AVIATION...08