Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 11/21/22


Area Forecast Discussion
National Weather Service Gray ME
1042 PM EST Sun Nov 20 2022 .SYNOPSIS... Scattered snow showers will diminish south of the mountains early this evening while remaining numerous across the mountains through tonight. Another area of low pressure will pass north of the area late Monday and Monday night, bringing more gusty winds and another round of snow showers toward the mountains, some of which could again be heavy. After a relatively quiet mid-week period, a storm system is likely to impact our area late in the week... although its impacts remain quite uncertain at this time. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... 0340z Update... After a second burst of strong winds this evening, winds should begin to diminish somewhat again shortly. Temperatures may fall into the single numbers by morning across the north and teens in the south. The cloud cover and snow shower activity will also continue to diminish across the north as we move through the night per latest HRRR solution as well as satellite and radar trends. 0025Z Update... Latest update was to increase pops for southernmost New Hampshire near the Massachusetts border to account for a large and long lake effect snowband coming in off Lake Ontario this evening. Update... Webcams and latest radar imagery continues to show snow showers in the mountains and foothills, occasionally making a run for the coastal plain from time to time. Latest HRRR has this precipitation this evening over the mountains before gradually diminishing during the overnight hours. Have made minor adjustments to pops for the near term portion of the forecast as well as temperatures and surface dew points. Winds will continue to gradually back off from their afternoon intensity during the overnight period. Prev Disc... Isolated to scattered snow showers will continue south of the mountains through the rest of this afternoon but will continue to diminish in coverage as we lose diurnal instability. However, toward the mountains, snow showers will remain numerous into at least this evening with the ongoing upslope flow following the passage of the upper trough axis. With how poorly guidance has performed so far, I will leave in at least a scattered mention of SHSN through most of the overnight hours across the mountains before gradually tapering off PoPs toward daybreak as high pressure builds in. There continues to be the possibility of a few heavy snow showers or squalls with all of this activity, which could bring brief but very rapid reductions in visibility and gusty winds to 40 mph. Even outside of snow showers, gusty winds of 25 to 35 mph will continue well into this evening, possibly exceeding 40 mph on occasion, bu will slowly diminish through the overnight hours. Flow aloft will transition to northwest as the upper trough continue to move east, and the strong cold air advection will carry in some of the coldest air of the season so far. Have not gone quite as cold as some guidance on low temps since we should stay pretty well mixed through the night. That said, widespread lows in the teens are expected with some embedded single digits, especially farther north. However, wind chills will be in the single digits, perhaps even a few degrees below zero. && .SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/... The upper low will continue to scoot across the Canadian Maritimes allowing a ridge of high pressure to build over New England to start off Monday. We`ll start off mostly sunny with the ridge overhead, but the ridge will quickly shift east through the morning and afternoon as another shortwave trough and cold front approach, eventually crossing through the area during the evening and overnight hours. Ahead of this wave, clouds will increase through the day as well as winds aloft, and winds are expected to again become gusty in the afternoon and evening hours. While not looking quite as strong as today, gusts to 25 to 35 mph look reasonable based on forecast soundings, possibly a couple reaching 40 mph at times. Increasing lift and moisture with the approaching trough will get another round of mountain snow showers going by late afternoon or early evening, and once the front and trough axis cross, upsloping snow showers are expected to increase in coverage and continue through the overnight hours. Not unlike today, steep lapse rates and sufficient moisture in the low-levels along with some instability could result in some heavier snow showers and possibly a snow squall or two toward the mountains and foothills. It`ll be another chilly night with lows in the teens to lower 20s. && .LONG TERM /TUESDAY THROUGH SUNDAY/... The overall upper air pattern is expected to amplify a bit later this week into the weekend, although a potentially impactful late- week system is still proving quite difficult to pin down with a significant spread in model solutions. Thus while moderate to high confidence in the forecast exists through the middle of the week... that quickly drops off late in the week with solutions ranging from yet-another-clipper to a big coastal storm with a wallop of warm, moist air... and anything in between. Of note, the GFS/GEFS continue to be wildly different from the ECMWF/EPS and CMC/GEPS Starting Tuesday... flow aloft flattens out somewhat in the upper levels, which allows high pressure centered over the Mid- Atlantic to spread northward into our area. A modest southwesterly return flow develops as a result, with a warmer day under mostly sunny skies in the 30s to mid-40s... except perhaps lagging back in the 20s in the western Maine Mountains where the return flow doesn`t quite reach. The PGF between low pressure over eastern Canada and high pressure to our south doesn`t relax enough to go all-in on strong radiational cooling for Tuesday night, especially toward the north amid modest pressure falls... so have stuck with the multi-model blend for the most part, except to blend in slightly cooler temps in the sheltered valleys... bringing lows into the teens and 20s, near 30 at the immediate coast. A broad upper level trough centered over northern Quebec / Newfoundland swings an axis across Wednesday with little fanfare for New England, other than snow shower potential in the higher terrain near the international border but also spreading down through the Whites and Blues through the day as a cold front sinks south and allows for some low/mid- level moisture convergence. Confidence in the overall pattern drops off precipitously Thursday through the end of the forecast with large disparities in the major model suites. Of note... there is considerable difference in the handling of a longwave trough as it exits the Rockies Thursday into Friday. Euro and Canadian suites have held this long wave together... painting an amplified pattern across the eastern CONUS through the end of the week and weekend with a big coastal developing. Meanwhile the American has cut off low pressure in the southern Plains or southern Rockies with a far less amplified, clipper-type low pushing across in recent runs... although the latest 12Z deterministic GFS has trended slightly toward keeping the trough together with a more amplified pattern. Though, even the more amplified cluster of solutions have their own gamut of potential scenarios with differences in trough orientation as it reaches the coast, which has big implications for what sort of mid-level jet and associated temperatures/forcing we`ll have to work with. All this to say... while precipitation is likely Friday and Saturday, the details beyond that remain quite uncertain besides a higher likelihood of frozen precipitation in the mountains, as usual. Thursday, while very much reliant on how strongly upper level ridging builds in and reinforces Canadian high pressure at the surface (stronger in a more amplified solution)... is not expected to be impactful, except when considering the antecedent airmass and strength of the CAD should a coastal low come to fruition. Otherwise it will likely be cooler than Wednesday with a greater northerly component to flow. Some signals we`ll be looking for in the coming days, assuming a more amplified pattern comes together like cluster analysis and a majority of members suggest: configuration and orientation of the upper-level trough and associated jets, which will drive about every other ingredient and dictate the track of the storm; amplitude and orientation of the mid-level circulation and jet, which would rely heavily on the upper-level dynamics and drive mesoscale precipitation processes along with ptype; and strength of antecedent CAD through the low- and mid-levels, which would also inform ptype (stronger CAD = more frozen precip) and determine if this storm takes on classic Nor`easter characteristics. && .AVIATION /04Z MONDAY THROUGH FRIDAY/... Short Term...Can`t rule out a brief snow shower at AUG/PWM/RKD through this 21-22Z or so, but most of the snow showers will remain farther north toward the mountains and HIE. Some of these could produce brief but very rapid IFR visibilities. Elsewhere, VFR conditions are expected through tonight with brisk W/WNW winds continuing into this evening before slowly diminish through tonight. High pressure will bring VFR to all sites on Monday, but another low pressure will move through late Monday into Monday night bringing more gusty winds as well as snow showers toward HIE. Long Term...VFR prevails Tuesday through Thursday with a non- zero threat of on- and-off MVFR for KHIE with SHSN. Confidence is quite low for the end of the week, however a storm system crossing New England is expected to bring a period of flight restrictions Friday and Saturday, perhaps into Sunday in some locations. Some solutions suggest strong winds, significant reductions in visibility, and lowered ceilings. && .MARINE... Short Term...Solid Gale conditions will continue through tonight before a brief lull on Monday. Another low pressure passing north of the waters and the passage of a cold front will bring another period of Gale conditions from Monday evening through early Tuesday. Long Term...High pressure builds into the waters from the south through the mid-week period which will allow conditions to improve over the waters... with winds and seas falling below SCA thresholds by the end of the day Tuesday. A significant coastal storm may develop late in the week with a period of active seas at any rate as we head into the weekend. Stronger solutions produce at least Gale force winds... however confidence is quite low at this time. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...None. NH...None. MARINE...Gale Warning until 7 AM EST Monday for ANZ150>152-154. Gale Warning until 1 AM EST Monday for ANZ153. && $$ NEAR/SHORT TERM...Cannon LONG TERM...Casey
Area Forecast Discussion
National Weather Service Midland/Odessa TX
631 PM CST Sun Nov 20 2022 ...New AVIATION... .SHORT TERM... (This afternoon through Monday night) Issued at 225 PM CST Sun Nov 20 2022 Main concern overnight is whether or not FG/FZFG will form. Clouds will modulate the development of FG/FZFG and indications are that clouds will clear from w to e in the afternoon/early evening to early morning, respectively. HRRR VSBY forecast is aggressive with other data, like NAM12, favoring the Pecos River Valley. It make some sense that areas which received measurable precip this morning, like the srn PB, will also have greater potential of FG/FZFG. Consensus is that lows will below freezing most all areas, so FG that develops early will transition to FZFG, except parts of srn PB. Winds will be light and some locally dense FG is certainly possible and have opted to include in Pecos River Eddy Co and srn PB. Otherwise temps will slowly warm up into M50s-U50s Mon PM with an abundance of sunshine. Another cold morning Tue with FG/FZFG a possibility, generally across srn areas. && .LONG TERM... (Tuesday through Saturday) Issued at 225 PM CST Sun Nov 20 2022 The extended portion of this forecast will consist of a slight warming trend with cool, dry weather expected. Zonal flow aloft and continued southerly sfc winds on Tuesday and Wednesday will bring high temperatures back into the low 60s for most locations. However, our streak of days with below normal temperature in Midland should continue through at least Friday as a dry cold front is progged to arrive on Thanksgiving Day. This front will not be arctic in origin and will only serve to knock temperatures down by a few degrees on Thursday and Friday. The cold front will also bring much drier air into the region, resulting in dew points falling into the 20s and 30s making for some crisp weather. By next weekend, temperatures will rebound well above normal as westerly downsloping winds increase across the forecast area, promoting highs in the upper 60s to low 70s. All long range models are now showing a dry forecast through next weekend, so kept grids dry through the extended. -Salerno && .AVIATION... (00Z TAFS) Issued at 538 PM CST Sun Nov 20 2022 All TAF sites but FST are now VFR and FST should become VFR by 06Z. Models show considerable uncertainty as to whether or not MVFR or IFR conditions will redevelop later tonight. Several different models show HOB dropping to low MVFR or IFR with more uncertainty for the other TAF sites so have introduced IFR CIGs for now only at HOB. A south to southwest wind direction does not favor very low VIS so this is a lesser concern right now. Hennig && .PRELIMINARY POINT TEMPS/POPS... Big Spring 30 58 33 62 / 0 0 0 0 Carlsbad 26 57 29 60 / 0 0 0 0 Dryden 35 54 37 56 / 0 0 0 0 Fort Stockton 31 58 33 64 / 0 0 0 0 Guadalupe Pass 30 52 34 56 / 0 0 0 0 Hobbs 25 57 30 60 / 0 0 0 0 Marfa 23 57 26 62 / 0 0 0 0 Midland Intl Airport 28 57 32 60 / 0 0 0 0 Odessa 29 57 32 60 / 0 0 0 0 Wink 26 57 29 61 / 0 0 0 0 && .MAF WATCHES/WARNINGS/ADVISORIES... TX...None. NM...None. && $$ SHORT TERM...49 LONG TERM....24 AVIATION...10