Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 01/24/18

Area Forecast Discussion
National Weather Service Aberdeen SD
904 PM CST Tue Jan 23 2018 .UPDATE... Issued at 903 PM CST Tue Jan 23 2018 Have slowed down the onset of fog, and shifted it farther east, given the slow movement of the upstream low clouds and fog and model guidance. Otherwise, few additional changes were needed to the ongoing forecast. && .SHORT TERM...(This Evening through Wednesday Afternoon) Issued at 317 PM CST Tue Jan 23 2018 The forecast challenge tonight into Wednesday will be whether or not fog and/or low stratus forms over the CWA for a third consecutive night, and its impacts on temperature. Currently, temperatures are holding in the 20s across the eastern third of the CWA, where low stratus clouds and patches of fog persist. The sun is shining through some high clouds across the western two-thirds of the CWA, where temperatures are warming into the 30s and 40s. The high clouds are associated with an upper level wave working through the region. Once that wave/cloudiness moves southeast of the region, another clear sky night on light (albeit westerly component) winds will be in play. And, there will probably be adequate low level moisture still around tonight in the nocturnal boundary layer to aide in more fog or low stratus development, especially within and between the Missouri and James River valleys and up on the Prairie Coteau. East of the Coteau may end up being more stratus than fog. Since there is support from the RAP in BUFKIT, along with several other numerical guidance data sets, opted to stick with fog mention in the weather grids for tonight into the first half of the day Wednesday. Similar to last night, temperatures should not drop off much more than perhaps 5 to 10 degrees underneath cloudy areas tonight. Clear areas may be able to drop closer to 15 to 20 degrees before stabilizing in fog/stratus environment, with a slow temperature rebound expected on Wednesday, if fog/stratus tonight pans out. .LONG TERM...(Wednesday Evening through Tuesday) Issued at 317 PM CST Tue Jan 23 2018 When the period opens Wednesday night, a large upper level ridge of high pressure is beginning to build into the region. By Friday morning, the upper ridge has shifted east and is being replaced by a large/broad upper level trough of low pressure. By Sunday morning, we`re right back where we started when the period opened, with another upper level ridge trying to build into the region from the west. However, the 12Z GSM deterministic solutions all agree today on this next upper level ridge being suppressed while it works into the middle of the country and for a brief period heading into day 7, there could actually be nearly zonal flow over the region. In this continued progressive pattern of ridge/trof/nearly zonal flow, the forecast is still basically a dry forecast. The warming trend still shows up in the deterministic low level thermal progs as well as ensemble guidance through Friday. The onset of the broad longwave upper trof still progs a cold frontal passage through the CWA late in the week, with temperatures cooling back down to near, or perhaps just below, climo normal for the weekend. The suppressed ridge/nearly zonal flow set-up for early next week potentially ushers a quick turn around back into some well above climo normal temperatures by Tuesday. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday Evening) Issued at 534 PM CST Tue Jan 23 2018 Confidence is growing that ABR will join ATY in the IFR category by around 06Z tonight as additional low level moisture sinks south from ND. MBG will be on the western edge of this low cloud/fog field, and am less confident that it will occur. Took out much of the fog potential at PIR for now, but it may be able to slip in around 09Z Wednesday. Winds should be around or below 10kts through the period. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...None. MN...None. && $$ UPDATE...KF SHORT TERM...Dorn LONG TERM...Dorn AVIATION...KF
Area Forecast Discussion
National Weather Service La Crosse WI
533 PM CST Tue Jan 23 2018 .SHORT TERM...(This evening through Wednesday) Issued at 316 PM CST Tue Jan 23 2018 At 2 PM, there was an area of sunny skies from northeast Minnesota south into north-central Iowa. A bit of this clearing is creeping into parts of Dodge County in southeast Minnesota. Temperatures ranged from the teens to mid-20s. The 23.12z models are in agreement that a short wave trough will move southeast through Iowa and Missouri tonight. With the air mass dry across the region, most of the models are in agreement that we will remain dry. The one exception is the RAP which tries to generate some flurries south of Interstate 90. For the time being, just stayed with the dry forecast. On Wednesday, the models show that another short wave trough will move southeast across northern Minnesota and Wisconsin. Like its predecessor, the air mass looks too dry for precipitation. .LONG TERM...(Wednesday night through Tuesday) Issued at 316 PM CST Tue Jan 23 2018 The main story for the extended forecast is warmer temperatures, especially on Friday. Upper level ridging and southerly flow build into the region Thursday into Friday resulting in much warmer temperatures. 925 mb temperatures are expected to warm to +3 C to +6 C during this timeframe. Plan on high temperatures on Friday ranging from the lower and mid 40s across portions of north-central Wisconsin to around 50 over far southwest Wisconsin and portions of northeast Iowa. A weak cold front slides through the region Friday night into Saturday cooling highs back into the 30s to around 40. Another surge of warm air is possible on Tuesday ahead of the next system. There are signals way out in the extended that temperatures could cool significantly going into the first week of February but it`s a little early to nail down specifics. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 533 PM CST Tue Jan 23 2018 Rather difficult ceiling forecast for this set of TAFs. Satellite currently showing a break in the clouds over southeast Minnesota into central Iowa that is working slowly east. This has allowed the skies to clear at KRST but additional low clouds west of this clearing with MVFR ceilings are also working slowly east. Looking at forecast soundings from the 23.18Z NAM would expect the lower clouds from the west to spread back in with this moisture then getting trapped beneath the inversion and remaining through Wednesday. The clearing could also allow some fog to form overnight with light winds and lots of low level moisture in place from the recent precipitation. For KRST, plan to show VFR conditions this evening with some fog then forming overnight and the lower clouds moving back in for a return to MVFR for the overnight through Wednesday. For KLSE, expecting the current MVFR ceiling to move out by mid evening with VFR overnight before the lower clouds and MVFR ceilings move back in during Wednesday morning. && .HYDROLOGY...Through Saturday Issued at 316 PM CST Tue Jan 23 2018 Elevated river levels will continue to recede across portions of northeast Iowa, southeast Minnesota, and southwest Wisconsin over the next few days. Be alert for possible ice jamming over the next few days and localized high water or minor flooding. More ice jams are possible on Friday as temperatures surge into the 40s to possible lower 50s. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. IA...None. && $$ SHORT TERM...Boyne LONG TERM...Wetenkamp AVIATION...04 HYDROLOGY...Wetenkamp
Area Forecast Discussion
National Weather Service Gray ME
1029 PM EST Tue Jan 23 2018 .SYNOPSIS... Temperatures have struggled upward all day...finally reaching near freezing. After widespread freezing rain of one to two tenths...precipitation is coming to an end from west to east late this afternoon and early this evening. Any remaining showers will transition to snow in the mountains...while to the south dries out. Temperatures will remain fairly steady this evening...climbing with the cold front around midnight before slowly falling towards sunrise. Near normal temperatures are expected Wednesday...with much colder overnight temperatures Wednesday night. High pressure builds in for the remainder of the week. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... 1030 PM Update...Have adjusted temperatures, sky cover, and winds a little bit for the overnight hours. However, no big changes have been made. The last band of rain is quickly moving eastward and out of the area. It should clear the mid coast around midnight...maybe a bit after. Rapid clearing is taking place behind the batch of rain (except across far western and northern zones). This may lead to some radiational fog for a time before winds increase. Slippery conditions are also expected on untreated surfaces overnight, especially where it clears and and stays calm. 805 PM Update...Have allowed the remaining winter weather advisories expire on time at 8 pm. Most locations have risen to between 32 and 33 degrees at this time. However, we do expect many slippery areas to continue overnight - especially in areas that clear out after midnight and the winds stay calm. This could lead to a quick refreezing of some surfaces - especially secondary roads, parking lots, and sidewalks. In the meantime we do have one more band of mostly rain to move through. This will move through quickly - likely lasting around 1 hour at any given location through 03-04z and could be accompanied by an isolated rumble of thunder. Winds may pick up somewhat with or immediately behind this band which could cause some more branches to fall and cause power outages. 610 PM Update...Have updated mainly PoPs for the next 3 hours or so as a strong short wave trough will swing through with a relatively short-lived band of showers. This can currently be seen near the NY/VT border. The latest run of the HRRR has a pretty decent handle on it, so updated the PoPs to reflect the HRRR for the most part. Most locations are at or just above freezing at this time, so this should mainly be in the form of rain. However, some spots are still just below freezing (especially in the advisory area) so some additional minor ice accretion will be possible until about 03z or so. Thereafter, a clearing trend is expected. Otherwise, have cancelled the wind advisory for the mid coast, as 40 kt gusts are not foreseen at this point. 5 PM Update...Have extended winter weather advisories until 8 pm where temperatures are still around or just below freezing. This includes interior portions of our Maine zones and Carrol County NH. Have cancelled Coos County as most areas are now above freezing. In any event, the precipitation will come to an end over the next couple of hours, with power outages possible through that time. Previously... Back edge of the precip has reached the CT River Valley this hour...and will continue to pull Ewd into the late afternoon/early evening. WAA and latent heating has pulled surface temps up to just about freezing in most locations. There are pockets...especially across the interior of Wrn ME...that remain below freezing and will continue to see occasional freezing rain into the early evening. For that reason the winter wx advisories there remain in place. Across Srn NH and coastal Wrn ME I have allowed those advisories to expire. Where the warm front has made it onshore around Midcoast ME there remains a threat for strong Sly wind gusts. So far RKD has been fairly benign winds...but just offshore at MISM1 wind gusts above 40 kts have been observed. I will keep the wind advisory in effect for this threat. Temps should remain fairly steady into the evening ahead of the approaching cold front...back across central NY. The upper level front is quickly moving E...with dry slot bringing some clearing to far Wrn zones before sunset. With the approach of the front...deeper mixing will help overturn the low level cold and temps should rise to their daily max around the 06z time frame. Temps slowly fall after that...with strongest CAA delaying until Wed. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/... Wly CAA flow will dominate Wed and Wed night. Temps are not expected to rise too much from morning readings Wed as the colder air moves in. Winds may gust as high as 30 knots at times in the afternoon. I would not be surprised to see this lead to a few scattered outages in places where ice remains stuck to tree limbs. Temps continue to fall overnight...but gradient winds will keep readings closer to model raw 2 m temps than cooler MOS values. Upslope snow showers will continue thru the day and into the overnight with some light accumulations in the higher terrain. && .LONG TERM /THURSDAY THROUGH TUESDAY/... The deterministic model solutions remain in decent agreement on the long wave pattern through the middle of next week. The pattern will remain progressive and begins to amplify with time. A steady progression of troughs and ridges across the forecast area will result in several sharp swings in temperature between well below and well above normal readings as we see a parade of disturbances cross the forecast area. In the dailies...A shortwave impulse will deliver a reinforcing shot of cold air to the area for Thursday and Thursday Night. The cold begins to ease on Friday as ridging and rising heights arrive. A warm front lifts north across the area Friday night with a southerly flow and well above normal temperatures arriving for the weekend. The more progressive GFS was again discarded as an outlier with the approaching frontal system in favor of the slower ECMWF/CMC- Global solutions...which bring the front and steadier band of precipitation across the forecast area late Saturday Night and Sunday. If the warmer ECMWF/CMC-Global are correct...then a multi day period of well above normal temperatures coupled with one to two inches of rain could cause some hydro issues given current ice jam situation. Colder air begins to filter into the area by Monday behind this system along with a return to below normal temperatures for the start of the new work week. && .AVIATION /04Z WEDNESDAY THROUGH SUNDAY/... Short Term...Once cold front moves thru the winds become Wly and will help to dry out the low levels. VFR conditions are expected to quickly return late tonight. Upslope flow in the mtns will keep HIE MVFR with VCSH. Long Term... Sat Night - Sun...MVFR with areas of IFR in Rain and fog. && .MARINE... Short Term...Strong SCA conditions are expected thru Wed night. Long Term... Thu - Fri...Small Craft conditions are likely outside the bays. Sat...Small Craft conditions are likely...with gusts approaching gale outside the bays. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...None. NH...None. MARINE...Small Craft Advisory until 9 PM EST Wednesday for ANZ150>154. && $$ NEAR TERM...Ekster SHORT TERM...Legro LONG TERM...Schwibs AVIATION...Legro/Schwibs MARINE...Legro/Schwibs
National Weather Service Jackson KY
954 PM EST Tue Jan 23 2018 .UPDATE... Issued at 954 PM EST TUE JAN 23 2018 A short wave trough will continue to rotate through the Ohio Valley through the overnight. Some lighter echoes have developed across eastern Kentucky over the past hour. Expect isolated to scattered rain/snow showers to continue into the overnight, before diminishing towards dawn, as forcing exits to the east and northeast. Have raised the low temperatures a tad across eastern Kentucky, as readings will be slower to cool off given the extensive cloud cover across the area, and lack of much colder air upstream. Wind gusts have also subsided this evening, as the pressure gradient gradually relaxes across the region. While a dusting of snow on elevated surfaces across the higher ridgetops will be possible through the overnight, given the lagging warmer ground temperatures, little or no impacts are expected. Updates have been sent. UPDATE Issued at 651 PM EST TUE JAN 23 2018 The forecast is on track. Merely freshened up the hourly temperatures and dew points into this evening based on the latest trends in observations. && .SHORT TERM...(This evening through Wednesday night) Issued at 415 PM EST TUE JAN 23 2018 A shortwave trough was moving through the eastern Great Lakes and OH Valley and into the Appalachians this afternoon while a shortwave ridge was over parts of the MS Valley with another shortwave upstream over the Plains. Cumulus and stratocumulus was well entrenched over the lower OH Valley, MS Valley, and Great Lakes. Some radar returns are upstream over parts of IN and central KY where mainly sprinkles or flurries are possibly occurring. Short term model guidance such as the HRRR brings a shortwave trough/500 mb vort max across the region this evening and an associated surface trough. Cold advection is continuing with the coldest air with this airmass anticipated late tonight and into the day on Wednesday as the second upstream shortwave trough moves through. Moisture is expected to remain at the low levels near and below 850 mb and low clouds should persist through at least Wednesday evening. The trough departs to the northeast on Wednesday night with mid level heights rising across the Southeast and into the Lower OH Valley and TN Valley regions. Omega peaks on time height sections this evening and again on Wednesday morning to early afternoon as the two shortwaves move through when rain or snow shower or flurry or sprinkle activity should peak. After early this evening, the atmosphere should be sufficiently cold enough for either isolated snow showers or flurries. With the 850 mb temperatures in the -5C to -10C range and cloud cover anticipated, below normal temperatures are expected for highs on Wednesday. Skies should gradually clear on Wednesday night, but NAM guidance suggests clouds should linger the entire night. If skies were to remain mostly clear to clear the valleys in the Cumberland Vally could end up around 20 or the upper teens. .LONG TERM...(Thursday through Tuesday) Issued at 257 PM EST TUE JAN 23 2018 The extended will start off with a period of warm and dry weather to end out the week and into the upcoming weekend. A ridge of high pressure will prompt south to southwest winds which in turn will transport warm air off the Gulf of Mexico into the Tennessee and Ohio valley regions. The next chance of rain for eastern Kentucky will arrive in the area late Friday night, as a cold front approaches from the Plains. The trend in the latest model data is for a faster west to east progression of this weekends weather system, and the forecast will reflect this. Rain showers should gradually overspread the area on Saturday, and will be most widespread from Saturday evening through Sunday evening, as a cold front moves across the region. The precipitation will taper off Sunday night, as the front moves further from our area. Temperatures should fall to the point where some snow will mix with the rain Sunday night. Flurries and a few snow showers are then expected across the area from around dawn on Monday through early Monday morning. Any remaining precipitation should be exiting the area by late Monday morning. After that, the weather should be dry across eastern Kentucky through Tuesday. Temperatures in general should be above normal in the extended. Daytime highs should be in the 50s Friday through Sunday, with nightly lows ranging from the mid 30s through the lower 40s Friday night, and in the lower 40s for Saturday night. These two warm nights are expected to be sandwiched by two colder nights when temperatures will be in the upper 20s and lower 30s(Fri night and Sun night). && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) ISSUED AT 651 PM EST TUE JAN 23 2018 Ceilings will lower to MVFR from west to east through this evening, as an upper level disturbance moves across the Ohio Valley. Some light rain/snow showers may be seen at times this evening; however, expect this activity to remain light enough to not cause much in the way of visibility restrictions. Precipitation will taper off later tonight, with MVFR ceilings likely hanging on through the rest of the period. West winds of around 10 kts, with a few gusts of 15 to 20 kts at times through early this evening, will gradually diminish overnight and into Wednesday. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...GEOGERIAN SHORT TERM...JP LONG TERM...AR AVIATION...GEOGERIAN
Area Forecast Discussion...UPDATED
National Weather Service North Platte NE
518 PM CST Tue Jan 23 2018 .SHORT TERM...(Today and tonight) Issued at 332 AM CST Tue Jan 23 2018 A midlevel disturbance across ern WY/wrn SD will move through wrn/ncntl Neb today. The RAP, HRRR, NAM-nest and ECM suggest scattered flurries. Consensus model data was the basis for the snow flurry forecast which places the flurries across northern Neb. The NAM-nest, the most aggressive model, would drive the flurry activity south to Interstate 80. A blend of the HRRR and RAP models plus bias correction produces highs in the lower to upper 30s. This is about 3 to 5 degrees cooler than the straight guidance blend. Snow cover and cloud cover are the driving forces behind the temperature mark down. Also, the h850mb temperature advection is neutral today and tonight. Clearing skies should develop tonight with a continuation of generally light northwest winds. A blend of bias corrected guidance produces lows mostly in the teens, near 10F in the Platte valleys. .LONG TERM...(Wednesday through Monday) Issued at 332 AM CST Tue Jan 23 2018 Generally quiet weather is anticipated through midweek as an upper ridge progresses from the Rockies to the Plains. Temperatures moderate into the lower 40s Wednesday with the help of downslope flow and sunny skies. The heart of the ridge arrives Thursday with H85 temps pushing 12C, which should translate to highs in the 50s for parts of the area. Continued the trend of keeping temps below guidance due to snow cover. A lead shortwave drags a cold front through the region on Friday, and a follow-up shortwave crosses the Plains on Sunday. Still expecting dry passages as the systems are moisture starved and forcing is short-lived. With a real lack of Arctic air upstream, the cooldown will only result in highs in the mid/upper 30s and lows in the mid/upper 10s, which is right around climo norms. The only concern during this period is the potential for large snow melt through Thursday and refreezing each night as lows drop into the teens. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 517 PM CST Tue Jan 23 2018 Visual flight rules with northwest winds less than 10kts && .LBF WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...CDC LONG TERM...Snively AVIATION...Power