Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 01/06/20

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
521 PM AKST Sun Jan 5 2020 .UPDATE...Latest GOES 17 imagery indicates a blossoming area of precipitation in the northern Gulf. Short term model analysis from the RAP indicate a strengthening low level front extending from Icy Bay southward into the central Gulf. There are hints of a weak surface wave development along the front on satellite. Course resolution models seem to be struggling with these features, all of which are further west than models have initially placed them. Strengthening frontogenesis in the 850-700mb layer combined with steep lapse rates noted on the 00Z Yakutat RAOB will lead to a period of heavy snowfall rates for the NE Gulf Coast this evening. Thus have extended the Winter Weather Advisory to include Yakutat for an additional 3 to 5 inches. Should the system hang up to the west even further, a warning may certainly be justified but will continue to monitor through the evening hours. && .PREV DISCUSSION...ISSUED AT 3 PM SUNDAY... SHORT TERM.../Through Monday night/...A low over the far northern Gulf will push a weather trough across the northeast gulf coast and northern inner channels tonight. Accumulating snow has been fairly steady through the day in Yakutat. A weak low will form over the eastern gulf along the trough and enhance precipitation rates as the complex approaches the outer coast of the Panhandle tonight. Overnight totals are still expected to be around 4 inches for Gustavus and 3 to 5 inches for Elfin Cove. Previously issued winter weather advisories remain in place for those two zones. Model analysis indicated NAM as an outlier for the follow on system on Monday. Have therefore sped up the progress of this system using a blend of GFS and the Canadian models for PoP and QPF. Based on current and short range predicted temperatures, this will also be a snow event. Generated 3 to 5 inches of snow for Juneau, Douglas, and Mendenhall Valley, so have issued a winter weather advisory for the Juneau zone from 6PM Monday night to 6AM Tuesday morning. Lesser amounts of accumulating snow elsewhere from Sitka northward. LONG TERM.../Tuesday through Sunday/ As of 10pm Saturday. The region looks to remain primarily in the winter season this coming week as we stay on the cold side of the jet stream. A few weather systems look to pass by with a warm wedge of air, but are expected to pass quickly with only the southern outer coast having the potential for a change to rain/mix. A low passing by to the south on Tuesday will cause northerly outflow winds to increase. A separate weak low over the northern gulf coast and associated trough will likely cause snow showers in the Yakutat area on Tuesday. This band then gradually moves east over the central panhandle through Tuesdays night and Wednesday, keeping the chance of snow showers in the forecast. Placement of smaller circulations/enhancement along the trough is less certain, so limited POP for that reason. A low tracking east across the southern Gulf of Alaska on Thursday will be the main weather maker for the week. A warm wedge of air with this system will likely cause a change to rain on the south side of the system, but accumulating snow on the north side. Models have differed on placement of the low, so confidence in where that rain/snow line ends up is not high. Went with a change to rain for the far southern areas, including Ketchikan, but remaining all snow for Petersburg/Wrangell. Offshore flow further north will limit snow accumulations, which is where Juneau falls. Timing of when the brief warm up happens will also play a factor, ie. during the day Thursday or overnight/Friday morning. This low passing over the southern panhandle will again cause north winds to increase through the northern inner channels. Went slightly above model guidance on temperatures for downslope areas like Skagway and downtown Juneau. .AJK Watches/Warnings/Advisories... PUBLIC...Winter Weather Advisory from 6 PM Monday to 6 AM AKST Tuesday for AKZ025. Winter Weather Advisory until 3 AM AKST Monday for AKZ022. Winter Weather Advisory from 9 PM this evening to 6 AM AKST Monday for AKZ020. Winter Weather Advisory until 3 AM AKST Monday for AKZ017. MARINE...Small Craft Advisory for PKZ041>043-051-052. && $$ DEL/Fritsch/Ferrin Visit us at
Area Forecast Discussion
National Weather Service Cleveland OH
957 PM EST Sun Jan 5 2020 .SYNOPSIS... A quick clipper moving across the Great Lakes to Ontario this evening will take a cold front east across the area tonight. Weak high pressure will build over the Ohio Valley briefly on Monday before a weak low pressure system moves northeast across the Ohio Valley on Tuesday. A trough will linger across the eastern Great Lakes through Wednesday until high pressure shifts east across the lakes Wednesday night. && .NEAR TERM /THROUGH MONDAY NIGHT/... The main changes to the update late this evening are to the temperatures. Temperatures have steadily risen across Ohio tonight with many locations in the lower 40s. Have brought overnight lows up a few degrees as temperatures are not expected to fall into the upper 20s but rather low to mid 30s. Otherwise, snow/melting snow is falling across the snow belt and will continue through the overnight. Previous Discussion... The key tonight will be to watch the surface temperatures this evening. Temperatures have nudged little so far today with the extensive cloud cover and have only recently rose to the upper 30s across western OH. Elsewhere we will hold in the lower/mid 30s through the remainder of the afternoon. The RAP has the best handle on the current situation and raises temperatures across the east through the evening after dark and this seems reasonable considering the increasing southerly winds this evening. Therefore will have to have a rain/snow mix mentioned across the west and far south with a transition to all snow overnight for any remaining precipitation. The breezy conditions will continue through the night with gusts around 35 MPH into Monday morning. This sharp, well defined clipper responsible for tonight`s weather will essentially just brush the local area. The steadier/isentropic lift snow will still take place across the lake/northeast OH/northwest PA and into NY beginning as early as late this afternoon. Elsewhere more scattered snow showers will work east with/behind the cold front tonight. Outside of the snowbelt a quick coating of snow is possible with the passing snow showers. Across the higher terrain of OH we may be able to squeeze out a inch (two at most). Across northwest PA with the colder temperatures and a longer potential duration of snow showers, accumulations will likely be 1 to 3 inches inland with a few 4 inch reports possible. Will keep the quick transition between systems and for Monday high pressure will be building across the Ohio Valley. Minor lake effect component with westerly flow, marginal temperatures, and a brief window will linger snow showers across NW PA through a good portion of Monday. Light additional accumulations possible. Highs Monday will still run slightly above normal with mid/upper 30s expected again. The ridge builds overhead for Monday night with fair weather and temperatures that will dip down into the 20s. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... An upper level trough will swing through the Great Lakes region Tuesday into Wednesday as an upper level ridge builds across the Plains. The ridge will move east over the local area as trough retreats to the east. This will allow dual low pressure systems to move east ahead of the upper level trough. First low pressure system will move east through central Ontario, Canada and the second low will move east across the Ohio and Tennessee Valleys. A cold front is progged to move southeast across the local area Tuesday night with a reinforcing cold front expected Wednesday. Mainly some lake effect snow shower activity is expected with the fronts across the northeast portion of the forecast area. Otherwise, not expecting any precipitation across the rest of the area. Cold air advection will follow the front late Tuesday night and even more so on Wednesday morning as a glancing blow to the area. Highs Tuesday will be in the 40s in advance of the surface low pressure followed by lows in the 20s Tuesday night as cold air advection begins. Highs Wednesday will likely occur late morning or early afternoon around 30 degrees and then fall back into the 20s during the evening. && .LONG TERM /THURSDAY THROUGH SUNDAY/... Upper level ridge across the area will move east of the area Thursday night allowing broad upper level trough to push east toward the region. This trough will deepen and become positively tilted resulting in cyclogenesis over northern Texas and Oklahoma by Thursday night. The surface low pressure system will eject northeast into the eastern Great Lakes region by Saturday afternoon. A fairly strong conveyor belt of warm moist air will develop to the east of the low pressure track. This warm moist air will be transported from the Gulf of Mexico northeast into the forecast area. Upper level dynamics and current track of the low could place the local area in an area of potentially heavy rain Friday. The GFS model at this time seems to be the wettest with a series of waves moving northeast across the area Friday through Sunday. The European appears to be more progressive and does not linger heavy precipitation threat into the weekend. The Canadian model is a bit closer to the GFS at this time. Therefore, will hold off on mentioning anything in the hazardous weather outlook for heavy rain due to uncertainty in the models this far out. Even so, the potential for a period of heavy rain is possible Friday and will begin to advance precipitation into the local area Thursday night and keep a mention through the weekend. Due to the warm air advection Friday, temperatures will push the 60 degree mark as of now with slightly cooler temperatures Saturday in the 50s and then the 40s by Sunday. Otherwise, 30s to lower 40s expected Thursday night, 40s Friday night, followed by lower to middle 30s Saturday night as cold air advection begins to push east. && .AVIATION /00Z Monday THROUGH Friday/... Much of the area is VFR this evening with the exception for some snow entering portions of NE OH and NW PA. Expect ceilings to fall to MVFR with a clipper moving through the region to the north. The most pessimistic ceilings will be in the KERI area where snow may bring some periods of IFR overnight. Snow may impact KCLE, KYNG, and KCAK overnight, but just will have a MVFR mention for now. As the clipper departs on Monday, skies will clear from the west and ceilings will lift to VFR before scattering out completely. Aside from the snow, the most impactful item in the TAFs will be the winds. Winds will become more westerly overnight. Wind gusts of 25 to 30 knots are expected through Monday afternoon with the clipper passage. .OUTLOOK...Non-VFR possible Tuesday night into Wednesday morning. Widespread non-VFR likely Thursday night through Friday. && .MARINE... Dropped the small craft advisory for this afternoon as winds diminished and shifted to a southwest direction. However, as winds increase again later his evening, will need to hoist the small craft advisory once again. Winds should top out at 30 knots and continue through Monday night and diminish Tuesday morning. Generally light southwest flow is expected Tuesday afternoon but this will also be short lived as winds increase from the west by Tuesday night and continue into Wednesday night when winds diminish for a period of time. Low pressure will begin to move northeast toward the lake Thursday night into Friday and cause winds to increase from the southwest. Will need to monitor this for possible gales if the storm system increases considerably over what is being progged at this time. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...None. PA...None. MARINE...Small Craft Advisory until 10 AM EST Tuesday for LEZ145>149. Small Craft Advisory until 10 PM EST Monday for LEZ142>144. && $$ SYNOPSIS...Oudeman NEAR TERM...Oudeman/Sefcovic SHORT TERM...Lombardy LONG TERM...Lombardy AVIATION...Sefcovic MARINE...Lombardy
Area Forecast Discussion
National Weather Service Marquette MI
658 PM EST Sun Jan 5 2020 .SHORT TERM...(This evening through Monday) Issued at 401 PM EST SUN JAN 5 2020 GOES water vapor and RAP analysis show a shortwave trough across Upper Michigan as the ongoing snow showers show some cyclonic signatures via satellite. Some of the heaviest snow of the day is currently over the Keweenaw and Marquette county. Webcam`s across the east don`t necessarily confirm or deny any amount of Lake Michigan enhancement yet; however, model 850 temps are about -7C to - 8C with the preferred wind direction just starting to occur. As for snowfall accumulations, seems to be right on track with a recent spotter report in Norway had 1.5 inches. Although the trough axis has slowed down on approach, still expecting -SN to begin to diminish in the next few hours, especially after 00Z in the west and along the WI border. The bigger question heading into tonight is the how much lake enhancement is seen of Lake Michigan and what LES develops in the NW wind LES belts across the west. For the west, 850 temps fall to near -12C before beginning to warm back up into Monday morning. At the same time, model soundings indicate some subsidence moving in as DGZ saturation ends with lowering inversions. As it stands, seems like there will be some LES snow early on, ending relatively early into tonight. For the Lake Michigan band, the window for lake enhancement to occur is roughly through 00Z before winds veer more to the NW. With this, have made a few small changes to the going forecast with fairly similar snowfall accumulations expected...with a little extra across the Keweenaw. Through tomorrow morning, going to see an additional 2 inches across the Keweenaw, with the potential of up to 4 inches should LES develop and linger. For the east, 2 to 4 inches with the potential for up to 6 inches with some LES developing on the back end tomorrow morning as inversions remain slightly higher for a little longer. On Monday, heights will begin rise as drier air begins to settle across the area. Any remaining showers and associated PoPs cut out quickly during the morning as skies clear from the SW into the afternoon. .LONG TERM...(Monday night through Sunday) Issued at 312 PM EST SUN JAN 5 2020 Active weather pattern becomes amplified throughout the week with overall temperature trends fluctuating between sharp cold downs and brief warm ups. Of course, with these highly-variable temperatures from day to day will come chances for wintry precipitation, including accumulating LES especially early/mid week across the west to northwest wind snow belts. More on that below! Tuesday night through the Wednesday time period will turn sharply colder as an arctic front pushes east across the Upper Michigan. Locations across western Upper Michigan will likely see their high temperatures during the day on Tuesday occur that morning, with falling temperatures expected through the afternoon hours. Combo of the colder air arriving and gusty winds will make conditions feel much colder U.P. wide. Tuesday night into Wednesday lows look to fall into the single digits to lower teens. Lingering gusty northwest winds will allow wind chills to range from near zero to 15 below, coldest across the west and central. Lingering LES and resulting clouds across the northwest wind snow belts will help keep temperatures somewhat modified and on the "warmer" side. By Wednesday, temperatures rebound into the teens with wind chills improving throughout the day. Along the front, Tuesday morning through that afternoon, expect a narrow band of snow to push across the Upper Peninsula. It could bring a quick burst of one-half of an inch of snow or slightly more in spots. Behind the arctic front expect LES showers to fill in across the west to northwest wind snow belts that afternoon and lingering through much of Wednesday. SLRs during this time period look to remain below/around 20:1, not terribly fluffy for LES standards due to the combo of the colder arctic air mass pushing lift outside of the DGZ and the likelihood of dendrite fracturing with gusty winds expected throughout the depth of the convective layer. Still expect at least moderate LES across the west wind snow belts, especially the Keweenaw Peninsula on Tuesday, and then the northwest wind snow belts Tuesday evening through at least mid-day Wednesday. Snowfall accumulations look to remain fairly tame, perhaps 3-4`` with pockets of higher amounts of 6-8`` over the Keweenaw and around/east of Munising, but the smaller snowflake sizes that are typical of these types of arctic air outbreaks will be efficient at reducing visibilities. Not to mention the blowing snow/drifting snow concerns given the gusty winds, so do expect there will at least be impacts to travel across the west to northwest wind snow belts Tuesday into Wednesday. By Wednesday night, any lingering LES will push offshore with southwest flow aloft starting to lift into the region, bringing with it much warmer air. This warm air advection arrives ahead of the next shortwave and developing surface low progged to lift across the Upper Great Lakes Thursday into Friday. Models are in fairly good agreement with the overall track of the system taking the surface low up and over Lake Superior, but not in good agreement with how overall precipitation chances will play out. The GFS is by far the most robust with bringing the gulf rich moisture northward by mid- day Thursday, followed by the ECMWF which is a bit further delayed and the the Canadian which is even more delayed and doesn`t really doesn`t bring much in the way of any precipitation. If widespread precipitation can get this far north before the system passes over the region, will need to monitor the trends/strength of the warm nose and any potential impacts to p-type. After the system passes through expect lingering LES across the west wind snow belts Friday/Friday night and the northwest wind snow belts Saturday/Saturday night as colder air spills across the region. By the end of the weekend/early next week, medium-range models show the potential for another low pressure system developing in the lee of the Rockies and lifting northeast across the Upper Great Lakes. && .AVIATION...(For the 00Z TAFS through 00Z Monday evening) Issued at 655 PM EST SUN JAN 5 2020 Mainly MVFR conditions are expected at KIWD and KSAW this evening along with gusty westerly winds. Higher terrain enhanced wind gusts at KCMX to around 40 knots will result in more blowing snow with IFR vsby. In additional some light lake effect snow may also develop. Otherwise, drier air moving in overnight will bring VFR conditions at KIWD/KSAW. && .MARINE...(For the 4 PM Lake Superior forecast issuance) Issued at 413 PM EST SUN JAN 5 2020 NW gales tonight up to 45 kts will relax by tomorrow morning across the west, lingering in the east through the afternoon. Winds will then back to the SW on Monday night with gales up to 35 kts. Winds will then back to the NW again on Tuesday evening, increasing to gales up to 40 knots on Tuesday night. With colder air filtering in across Lake Superior Tuesday night, heavy freezing spray will be likely. Winds relax on Wednesday before increasing again from the southeast on Thursday with gales up to 35 kts possible across the eastern half of Lake Superior. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... Winter Weather Advisory until 7 AM EST Monday for MIZ006-007-014- 085. Winter Weather Advisory until midnight EST tonight for MIZ001- 003. Lakeshore Flood Advisory from midnight tonight to noon EST Monday for MIZ006-007. Lake Superior... Gale Warning until 4 PM EST Monday for LSZ248>251-265>267. Gale Warning until noon EST /11 AM CST/ Monday for LSZ241>245- 263-264. Gale Warning until 7 AM EST /6 AM CST/ Monday for LSZ162-240. Lake Michigan... None. && $$ SHORT TERM...JAW LONG TERM...Ritzman AVIATION...JLB MARINE...JAW
Area Forecast Discussion
National Weather Service Shreveport LA
815 PM CST Sun Jan 5 2020 .UPDATE... While the diurnal trend is slightly off in a few locations, most of the short term guidance is in good agreement regarding overnight low temperatures. As such, no update is needed at this time. /44/ && .PREV DISCUSSION... /issued 528 PM CST Sun Jan 5 2020/ AVIATION... VFR conditions are expected for the entire TAF period. A wind shift can also be expected past 06/08z (starting at our western TAF sites) to a more West/Northwest direction following a cold front. /44/ PREV DISCUSSION... /issued 402 PM CST Sun Jan 5 2020/ SHORT TERM.../Tonight through Monday Night/ Much above normal temps have been observed with 21Z temps near or having already exceeding 70 degrees across much of the region under strong insolation and SW sfc winds. Meanwhile, the afternoon sfc analysis indicates that the earlier indicated inverted sfc trough has washed out across extreme SE OK/Wcntrl AR, although another weak sfc trough continues to make steady progress SE into Srn OK and Wrn AR, with the leading edge of this bndry extending from near a DTO, to HHW, to just N of McCurtain County, to MEZ and RUE. This bndry remains progged to continue easing into portions of extreme NE TX and SW AR this evening in VC of the I-30 corridor before become stationary, with a shallow lyr of low level moisture progged to continue gradually building N into portions of Deep and SE TX into Cntrl and Ncntrl LA late tonight through much of Monday. The short term progs are not very keen on patchy FG development tonight, although the HRRR does hint at some patchy FG near/after 12Z Monday over portions of SE and possibly Deep E TX into the Lower Toledo Bend Country of Wcntrl LA. Given the scarcity though, have omitted FG mention in the forecast, although light SSW winds S of the sfc bndry should result in milder temps tonight compared to what was observed this morning. However, believe the NBM is again too cool with min temps given the extent of mixing and weak moisture advection S of the bndry, and have continued to trend min temps just a bit above the NBM and near the MAVMOS with the coldest temps expected N of the bndry over extreme NE TX/SE OK/Nrn sections of SW AR. Little movement in this bndry is expected Monday, with another day of above normal temps expected over Lower E TX/N LA, where low level moisture advection will continue through the day. A shallow cu field may develop over Lower Toledo Bend into portions of Ncntrl LA by mid to late morning Monday, but the short term progs have trended less with this shallow lyr of moisture, before the aforementioned sfc bndry across the Nrn zones is reinforced SE as a cold front as a progressive shortwave trough quickly translates into the Srn Plains in the late afternoon and into the Lower MS Valley by 06Z Tuesday. The short term progs have continued the trend this morning with the moisture depth even more shallow than what has been depicted, with none of the guidance suggesting enough moisture/large scale ascent for any QPF. Given this good agreement, have taken out the low pops for Ncntrl LA Monday night, with the front expected to clear the region shortly after 06Z Tuesday. Weak cold advection will follow the fropa Monday night as any residual post-frontal stratocu gradually clears Srn AR/N LA/extreme Ern TX, and have trended min temps near of not a tad warmer than the NBM given the MOS trends and potential for post- frontal cu. However, the sky should clear the SE zones prior to daybreak Tuesday, with near seasonal temps expected for the Tuesday/Wednesday timeframe. 15 && .PRELIMINARY POINT TEMPS/POPS... SHV 44 68 40 59 / 0 0 0 0 MLU 44 68 41 58 / 0 0 10 0 DEQ 35 58 32 58 / 0 0 0 0 TXK 39 60 36 57 / 0 0 0 0 ELD 40 62 37 58 / 0 0 0 0 TYR 42 64 38 59 / 0 0 0 0 GGG 42 65 39 60 / 0 0 0 0 LFK 45 71 41 61 / 0 0 0 0 && .SHV WATCHES/WARNINGS/ADVISORIES... AR...None. LA...None. OK...None. TX...None. && $$ 15/44