Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 12/27/17

Area Forecast Discussion
National Weather Service Wakefield VA
913 PM EST Tue Dec 26 2017 .SYNOPSIS... A cold front will drop through the region tonight with weak low pressure pushing off the Carolina coast Wednesday. Meanwhile, arctic high pressure builds across the Eastern Great Lakes and New England Wednesday and Thursday. Another weak low pressure system develops off the Southeast coast Thursday night through early Friday, before arctic high pressure returns for next weekend into the new year. && .NEAR TERM /THROUGH WEDNESDAY/... Latest MSAS has weak low pressure moving east along the Mason- Dixon line with the trailing cold front extending sw ivof I81 corridor. Meanwhile, high pressure was located over nern NC with another weak area of low pressure over the NC mts. Closer to home, BKN-OVC AC deck aoa 12K ft has overspread the region in advance of these weather features. Temps dropped quickly after sunset but have since leveled off with the increase in cloudiness. Waited to see the 00Z NAM, but it now agrees with the high res models in keeping most if not all the AKQ forecast area dry through 12Z. Any pcpn associated with the front remains mostly aloft as the front crosses the area due to the dry low levels. Any pcpn assctd with the developing coastal low remains along and just south of the Albemarle sound through 12Z. Thus, the only pcpn possible would be some very light snow/flurries across srn Bertie NC cnty around sunrise, otw mstly cldy and dry. Given the cloudiness, bumbed up mins a a degree or two. Lows in the 20s. PVC DSCN: A dampening shortwave trough will push across the Ohio Valley this evening, before sliding across the Carolinas on Wednesday. This feature will interact with the aforementioned cold front, spinning up a weak low/coastal front. 12z/26 NAM/CMC/ECMWF each are a bit wetter with the overrunning moisture, with the GFS lagging behind showing little or nothing. However, much of the deep moisture and lift remains just to our SE. Our official QPF has increased slightly over our SE sections, with precipitation expected in the mid to late morning timeframe across far NE NC and coastal SE VA, and pops have been increased to high end chc/likely during this midday time period. Thermal profiles aloft support light snow at the outset across the entire area. However, warmer air just aloft (H8-85) could allow for some light sleet/graupel mixing in before any mixed precipitation turns over to rain by late morning. PoWT grids do indicate a small chance of some freezing rain along (and mainly S) of the Albemarle sound, and accordingly some FZRA mention was considered. However, given very light QPF and the timing, we have stuck with frozen dominant P-type, and hence no winter wx headlines at this time. Should also note that precipitation could turn back to snow briefly by early afternoon in strong CAA before ending, again with little or no accumulation given relatively warm ground and light QPF. Farther N, highs should only rise into the low/mid 30s under a partly to mostly cloudy sky. Have also allowed for a period of flurries over northern tier, mainly north of a FVX-RIC-WAL line. Even in the dry airmass, northern stream shortwave, ongoing strong CAA and strong upper jetmax crossing could be enough to wring out a few light snow showers. HRRR has begun to catch on to this potential, for what it`s later shifts will be keeping an eye out for this potential early tomorrow morning. Measuring unlikely, so will hold pops out for now. && .SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/... Strong (cold) 1040+ mb arctic high pressure will build across the Ern Great Lakes Wednesday night into Thursday and continue to nudge into the area. This will bring a cold/dry day with partial clearing. Have continued to undercut MOS guidance for this period, with forecast highs only in the upper 20s N to mid 30s SE, after morning lows in the low/mid teens N to the low 20s SE. There is the potential for wind chill values of 0-5 above early Thursday morning over the MD Ern Shore if enough wind persists. 12z Model guidance continues to trend drier and more suppressed with the wave that pushes off the Southeast coast Thursday night into early Friday. The GFS remains an outlier in handling this system, and even it is showing little or no QPF for the lower Mid-Atlantic at this time with the exception of some light QPF over NE NC. Dropped POP back to slight to low end chance for some snow showers. QPF will be light and hence any snow accum will be minimal. Lows Thursday night range from the upper teens/around 20F N to the upper 20s far SE under a mostly cloudy sky. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... Long term period will be dominated by cold NW flow across the region, as broad upper trof persists over the eastern 2/3rds of the U.S. Models still not in synch with regard to the tangible weather scenario in the Friday night through Monday time frame. 12Z ECMWF continues its trend of bringing a system across the Great Lakes, and developing a surface low off the mid Atlantic coast Sat/Sat night. This system intensifies far enough offshore to limit any light snow to the northern portions of the area on Saturday. GFS continues to suppress this system in lieu of a shortwave that rotates around the main upper trof Sunday into New Years Day. WPC has negated this solution in favor of the ensemble solutions, and thus have mainly used WPC blended solution for the Friday night through Monday time period. This means a generally dry period, but quite cold, with temperatures well below normal through the period. By day 7, next Tuesday, all models suggest dry but continued cold weather across the region. Temperature-wise, it will be a cold period, with high temps most areas not getting out of the 30s from Saturday through Tuesday. Exception will be SE portions of the area, where temps could get to or just above 40 degrees on Saturday. Low temps mainly in the 20s Friday night, dropping mostly into the teens /except around 20 near the coast/ Saturday night through New Years night. Min temps in the 20s again by next Tuesday night. && .AVIATION /02Z WEDNESDAY THROUGH SUNDAY/... VFR conditions across the region with mid and high clouds and light wind. A dry cold front will push through the region late tonight with the wind increasing and veering around to the N. Weak low pressure will form just offshore of the Carolina coast Wednesday bringing a 20-40% chc of light snow or a light rain/snow mix to far SE VA/NE NC region. Outlook: Strong high pressure builds N of the region late Wed/Thu. Weak low pressure remains offshore Thursday night into early Friday. Another cold front pushes across the area Friday night with high pressure returning Saturday. && .MARINE... Marine conditions are pretty tranquil this afternoon. With high pressure over the area, winds are at or below 10 kt most areas. Shortwave trof and associated surface low moves off the coast and begins intensifying by Wednesday afternoon, resulting in a significant increase in winds late Wednesday afternoon through Thursday midday/afternoon. Will be issuing a SCA during this period with the 4 pm forecast issuance. Beyond Thursday afternoon, the next threat for SCA conditions looks to be Saturday night into Monday, as yet another period of cold air advection ensues. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...None. NC...None. VA...None. MARINE...Small Craft Advisory from 1 PM Wednesday to 10 AM EST Thursday for ANZ635>638. Small Craft Advisory from 1 PM Wednesday to 1 PM EST Thursday for ANZ630>632-634. Small Craft Advisory from 4 PM Wednesday to 7 PM EST Thursday for ANZ633-652-654-656-658. Small Craft Advisory from 4 PM Wednesday to 4 PM EST Thursday for ANZ650. && $$ SYNOPSIS...MAM NEAR TERM...MPR/MAM SHORT TERM...AJZ/MAM LONG TERM...WRS AVIATION...MAM/JEF MARINE...WRS
Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
1049 PM EST Tue Dec 26 2017 .SYNOPSIS... A series of very cold and dry Arctic high pressure systems will be the primary weather feature across the region through mid-week next week. However, a slight chance of very light wintry precip exists over the southern Georgia and Carolina Piedmont Wednesday morning and a chance of light wintry precip is possible across the entire region Sunday night into Monday. && .NEAR TERM /THROUGH WEDNESDAY/... As of 1020 PM EST: Still fair across the region for the time being, but our concerns about the srn fringe of the fcst area remain unchanged. Upstream radars show light precip development reaching up into nrn MS and moving into the nrn half of AL. It is worth mentioning the models have a decent handle on this development and still just skirt the nrn edge of the precip across the Lakelands. The problem is that relatively clear sky has allowed temps to fall below 32F in parts of that region, specifically Greenwood, while the air mass was also dry, but not as dry as farther north. The 21Z SREF continues to show the potential for precip on the order of only a few hundredths, with a favored precip type of rain, because the model suggests that temps will actually rise a bit once thicker cloud cover moves in, raising wet bulb temps above 32F. As of this time there is no clear indication that precip will present a problem across that region, so an advisory will not be issued. However, this will have to be monitored overnight and one might still be needed if the favored precip type becomes freezing rain. Otherwise, water vapor imagery and initialized RAP heights show a broad but shallow trough over the eastern U.S. early this evening. Weak vorticity lobes embedded in the resulting westerly flow aloft will approach the forecast area and cross the region late tonight. Meanwhile, a 150 kt 300 mb jet streak will pass just north of the forecast area overnight, with a brief window of weak upper level divergence occurring around daybreak south of the jet axis. Finally, some very transient low level upglide may develop toward daybreak in the 900 to 850 mb layer over the lower piedmont to complete the weak forcing picture. Moisture is expected to be quite limited, but now all of the operational models are bringing some low-end measurable QPF amounts to the southeast fringe of the forecast area, and the 12Z ECMWF has become even a bit more troubling (wetter). Surface wet bulb temperatures will likely be right around the freezing mark across the far southern piedmont, and perhaps closer to 30 degrees southeast of Charlotte. Will thus feature some slight chance to chance PoPs for sleet or light freezing rain in a 6-hour window around daybreak Wednesday morning. Will not include any accumulations given the dry profiles and limited model PoP and QPF, but it bears watching in case a short fuse statement or advisory is needed should QPF trend further upward. Will mention in the HWO. Westerly flow will continue through Wednesday but with little to no additional forcing. The reinforcing cold front will begin pushing southward across the northern tier of the forecast area late Wednesday. Improving afternoon insolation should permit at least the southern tier to warm slightly above Tuesday max temp values. && .SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/... As of 200 PM EST Tuesday: The strong and cold high pressure centered over the Great Lakes Region on Wednesday night will build down the east side of the Appalachians in a cold air damming pattern on Thursday. This will lead to well below normal highs on Thursday generally in the lower to middle 30s. The colder air will be very dry with dewpoints in the single digits. This overall dryness will limit the precipitation potential in our forecast area from a weak low off the coast. This forecast will continue the trend of reducing precipitation and will only include a slight chance of snow/sleet Thursday afternoon and evening in the southern portions of the forecast area. The cold air damming will break up by Friday allowing temperatures to climb into the 40s outside the highest elevations. Conditions will remain dry Friday. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... As of 230 PM EST Tuesday: The medium range forecast still carries much greater than usual uncertainty, with poor model-to-model and run-to-run agreement on numerous longwave features and storm systems. The beginning of the period has become slightly less controversial, with a strong and now dry surface high centered over the northern plains exerting its influence on our area Friday night through early Sunday. The GFS carries a clipper system through the Appalachians Saturday, but the best QPF response remains just to the north of our forecast area, and sensible weather here remains dry. The fun begins Sunday afternoon, with the 12Z GFS depicting the development of a cold wedge of high pressure extending down the southern Appalachians with some moisture being shunted northward over the wedge as a Gulf low undergoes cyclogenesis near the Big Bend of Florida Sunday night and Monday. The 12Z ECMWF has a much less intense low much farther to the south, with absolutely no QPF response in our area. The drying trend from earlier this week seems to be repeating itself once more, so opted to keep my thinking consistent with previous shifts and keep pops to slight chance or less outside of the mountains Sunday night through the day on Monday, with just a few hours of chance pops in the NC/GA mountains early Monday morning. If there is any QPF, profiles will be cold enough to support almost entirely snow in the NC mountains, with some light rain/snow mix possible outside of the mountains. If the favorable drying trend continues, this system will likely be very low or no impact. The last area of controversy in the medium range is the temperatures late in the weekend and early next week. The GFS is carrying a very deep longwave troughing pattern for the eastern seaboard, and persistent, close to record-breaking cold temperatures would be possible if this verifies. The ECMWF is quite chilly, but not nearly as cold as the GFS. Opted for a model blend for the public forecast, which, though cold, is not the bone-chilling solution possible in the highly amplified GFS. Will wait for better model agreement to determine any possible impacts across the area from persistent cold temperatures. && .AVIATION /04Z WEDNESDAY THROUGH SUNDAY/... At KCLT and Elsewhere: VFR through the period. Light wind direction causing minor problems at TAF time. Opted to keep wind direction just N of E for the first few hours, but guidance still veers the wind to ESE during mid evening. Obs show a VFR ceiling over the Midlands of SC, which could brush past KCLT at that time. Will keep some sct clouds but not a ceiling around 045. Wind will come back to NE in the early morning hours and then will strengthen from the N midday Wednesday. Most models have very light precipitation breaking out from Greenwood SC to Chester to Monroe NC, but staying well southeast of all the TAF sites around daybreak. There is some minor concern that it could reach as far N as KCLT, but the models continue to slowly back off and it was not included. Outlook: Dry and cool high pressure should remain the dominant weather feature through late week and into the weekend. Another small chance for wintry precipitation exists for the lower piedmont late Thursday into early Friday, as coastal low pressure forms, though confidence is low. Present indications are for a mainly dry forecast with any wintry weather shunted to the southeast. Confidence Table... 15-21Z 21-03Z 03-09Z 09-12Z KCLT High 81% High 82% Med 68% Low 56% KGSP Med 70% Med 75% High 83% Med 64% KAVL High 94% High 85% Med 70% High 87% KHKY High 100% High 83% Med 66% High 100% KGMU Med 76% High 86% High 85% Med 63% KAND Med 76% Med 65% High 90% Med 61% The percentage reflects the number of guidance members agreeing with the scheduled TAF issuance flight rule category. Complete hourly experimental aviation forecast consistency tables and ensemble forecasts are available at the following link: && .GSP WATCHES/WARNINGS/ADVISORIES... GA...None. NC...None. SC...None. && $$ SYNOPSIS...JMP NEAR TERM...HG/PM SHORT TERM...SW LONG TERM...Carroll AVIATION...PM
Area Forecast Discussion
National Weather Service Houston/Galveston TX
857 PM CST Tue Dec 26 2017 .UPDATE... Retooled temperature trends for obs, but with diurnal ranges this week being so small, the changes are cosmetic. Given the strong drizzle signature on radar and several -DZ obs around the area, have added drizzle and made it the primary precip type along with some light rain early on, transitioning back towards light rain showers tomorrow. Not entirely sure we`ll make this transition fully to showers given the structure of HRRR soundings, but will conservatively drop the drizzle in tomorrow`s grids for now. Luchs && .PREV DISCUSSION... /ISSUED 553 PM CST Tue Dec 26 2017/ AVIATION... Low ceilings and fog (mainly IFR) along with periods of -RA or -DZ are expected this evening and overnight. Look for increasing north winds overnight. Anticipating slowly improving ceilings late tomorrow morning through tomorrow afternoon from north to south along with a decreasing risk of -RA/-DZ. 42 PREV DISCUSSION... /ISSUED 346 PM CST Tue Dec 26 2017/ DISCUSSION... Low amplitude trough and associated ascent continues to shift away from east TX this afternoon, pulling weak showers with it. Surface low along coastal front remains off the upper TX coast which will also likely shift e-ne before weakening this evening. As this occurs, we will see winds become more nely across the area which should also help lift fog over the near shore/bays. This will also aid in shifting reinforcing cold front now moving into central TX offshore tonight. Expect this will keep temps well in the 40s tomorrow along with brisk northeast winds and cloudy skies. PoPs wednesday will be less certain with general zonal flow and potential for another subtle disturbance coming out of nrn Mexico. Will keep chance PoPs in play for now. Overall should see a trend towards somewhat warmer weather into late week/early weekend before yet another cold front ushers in return to much below normal temps to start the New Year. This next front also brings significant uncertainty as both Euro and GFS remain markedly different with how they handle the arctic intrusion. GFS continues to drive significant cold air intrusion straight down the high plains, while the Euro takes the surface ridge more towards the southeast/mid atlantic. This leads to quite a bit of difference in the temp forecast over southeast TX, and leads to very low confidence in the extended forecast as a whole. Have opted to keep a compromise for temps after the weekend front, but should GFS verify we could be much colder. Evans MARINE... Patchy fog will persist into the evening hours, but doubt there will be any prolonged periods of vsbys less than 2nm. They should improve overnight as northeast/north winds start increasing. Speeds will gradually increase to advisory levels overnight and will hoist an SCA starting at 3am. The persistent e/ne wind has given water levels a bit of a boost and they`re currently running 1-2 feet above normal. They`ll likely remain above normal for several days but am not expecting levels nearing any coastal flood impacts. Winds will veer to more of an easterly direction later in the week as high pressure moves away. Expect another front this weekend, but confidence in timing/strength is quite low at this time. 47 && .PRELIMINARY POINT TEMPS/POPS... College Station (CLL) 38 42 36 46 39 / 40 30 30 10 10 Houston (IAH) 42 45 37 49 40 / 50 50 30 20 20 Galveston (GLS) 46 48 43 51 46 / 50 40 40 20 20 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...Small Craft Advisory from 3 AM to noon CST Wednesday for the following zones: Coastal waters from Freeport to the Matagorda Ship Channel out 20 NM...Coastal waters from High Island to Freeport out 20 NM...Galveston Bay...Matagorda Bay...Waters from Freeport to the Matagorda Ship Channel from 20 to 60 NM...Waters from High Island to Freeport from 20 to 60 NM. SMALL CRAFT SHOULD EXERCISE CAUTION until 3 AM CST Wednesday for the following zones: Coastal waters from Freeport to the Matagorda Ship Channel out 20 NM...Coastal waters from High Island to Freeport out 20 NM...Galveston Bay...Matagorda Bay. && $$ Discussion...25
National Weather Service Jackson KY
1040 PM EST Tue Dec 26 2017 .UPDATE... Issued at 1040 PM EST TUE DEC 26 2017 Grids refreshed with latest observations. The forecast is still on point with colder temperatures beginning to make their way into the northwestern portion of the CWA. Any potential for flurries will be in the northern part of the CWA. However, potential is decreasing as seen in the latest HRRR run which shows no returns in our CWA but minimal snow to the north. Left flurries in the grids for now as they taper out through the night. UPDATE Issued at 649 PM EST TUE DEC 26 2017 Ingested current observations to freshen up grids. No major changes needed since forecast is on track for the onset of the colder air coming into the CWA later tonight as well as the ongoing potential for some snow flurries. && .SHORT TERM...(This evening through Wednesday night) Issued at 340 PM EST TUE DEC 26 2017 The latest surface map features an exiting arctic front into the Tennessee Valley. High pressure is centered across the northern Plains, with very cold air gradually building southeast into the lower Ohio Valley. Aloft, broad cyclonic flow remains in control across most of the CONUS. Another mostly cloudy day has been on tap for eastern Kentucky, with temperatures ranging from the low to mid 30s across the area. Clouds and some flurries will be seen across eastern Kentucky tonight, as another weakening impulse traverses the cyclonic flow aloft. Some of the higher resolution models suggest a glancing blow of measurable snowfall north of I-64, but given the dry low levels and weakening trend to the mid-level short wave, will keep POPs low. Temperatures will drop to around 10 degrees, or slightly lower by dawn Wednesday morning north of I-64. A gradient of warmer readings will be found towards the Tennessee/Virginia border, where lower 20s will be more common. Skies will clear out on Wednesday, with the arctic high building in stronger. Highs will remain in the 20s for most locations. Mostly clear skies hold on into Wednesday night, setting the stage for single digit temperatures in the valleys by early Thursday morning. .LONG TERM...(Thursday through Tuesday) Issued at 340 PM EST TUE DEC 26 2017 Good agreement in the mid/upper solutions through the first 24 to 36 hours of the extended. Models diverge thereafter leading to an overall low confidence in the forecast. While some general, more qualitative descriptions can be made about the pattern, differences in the mid/upper level flow are significant enough that there is not much point in detailing features closer to the surface. Broad cyclonic flow across the CONUS dominates the pattern with a couple disturbances to deal with through the extended. There seems to be an overall trend towards a more amplified pattern by the end of the period or perhaps just beyond. First mid level disturbance passes through the Ohio Valley by Friday with the potential of a more significant shortwave trough passing through the region over the weekend. The 12Z GFS is also much slower and deeper with it`s version of the shortwave trough, if it is even the same feature. Consequently the GFS produces a much stronger surface wave and more significant sensible weather at the end of the extended. Will add that the GFS is a strong outlier with much better agreement between the 12Z ECMWF and Canadian. For now will stay with the blends and consensus in guidance for sensible weather. That said, the only thing we can say with any certainty is that we will experience well below normal temperatures with daily highs generally running between 25 and 35 F. Overnight lows will run mainly in the teens, though some single digits will be possible late in the period. The aforementioned disturbances will produce an occasional chance for some light snow over portions of the forecast area. At this time do not see anything worth highlighting with respect to potential snowfall accumulations. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) ISSUED AT 645 PM EST TUE DEC 26 2017 VFR conditions will prevail through the period along with some passing mid and high cloud cover. A few flurries may be seen tonight - mainly in the northern aviation sites; however, these will be light enough to not cause much in the way of visibility restrictions. Look for the clouds to thin out during the day on Wednesday. Winds will remain around 5 kts or less, generally from the north. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...CGAL SHORT TERM...GEOGERIAN LONG TERM...RAY AVIATION...GEOGERIAN/GREIF
Area Forecast Discussion
National Weather Service Louisville KY
836 PM EST Tue Dec 26 2017 .Forecast Update... Issued at 834 PM EST Tue Dec 26 2017 The much colder air is making its way to the south this evening. Temperatures across portions of southern IN have fallen into the teens and will continue to drop into the single digits tonight. Temperatures across central KY will follow suit through the night with lows in the single digits to teens. The radar over the last hour or so has shown a drying trend. We could still see some flurries or very light snow over the next couple hours across southern IN and far north central KY, but it should have no impact. The forecast was updated to pull the mention of snow and flurries a bit to the north. Otherwise, only minor changes were made to temps. && .Short Term...(This evening through Wednesday night) Issued at 259 PM EST Tue Dec 26 2017 A disturbance near Kansas City this afternoon will slide eastward and roll across the Ohio Valley this evening. NAM and GFS show weakening upper level divergence and frontogenetical forcing as this feature approaches, and regional radar depictions upstream have indeed been showing decreasing dBZs. Most surface observing sites over southern Illinois and southeastern Missouri have shown little if any snow at the ground. However, there has also been a recent uptick in snowfall in a band from central Indiana to southeast Illinois. The RAP and HRRR bring higher chances of snow into southern Indiana and far north central Kentucky this evening. So, will still bring in a small PoP for those areas this evening. Lift appears weak and surface dew point depressions will be on the order of 10 to 15 degrees so any snow that does fall will be very light and dry. Nevertheless, a light dusting will be possible on the cold ground this evening especially north of the Ohio River. Wednesday and Wednesday night arctic high pressure will advance from the Missouri Valley to the Great Lakes, providing us with plenty of sunshine during the day Wednesday but with chilly temperatures. Morning lows will range from the single digits along and north of I- 64 to the middle teens in southern Kentucky. Afternoon highs will be in the teens in Indiana and 20s in Kentucky. Wednesday night mid and upper clouds will increase ahead of a weak upper trof over the Plains, but it will still be a cold night with the heart of the cold dome of high pressure moving through, resulting in single digits and lower teens for lows. Because the center of the high will miss us to the north, we will maintain a breeze on the order of 5 to 10 mph tonight and Wednesday. With the frigid air in place, even flow this light will still take wind chills below zero tonight and tomorrow night in southern Indiana and north central Kentucky. .Long Term...(Thursday through Tuesday) Issued at 313 PM EST Tue Dec 26 2017 After some dry, cold weather on Thursday and Friday with high surface pressures in place, a clipper system is progged to push through the Ohio Valley Friday night. This may drop a dusting of snow on southern Indiana and north central Kentucky as it rolls through. There are significant differences in the models for this weekend`s weather with the GFS showing a much wetter solution than the drier ECMWF and GEM. The operational GFS is quite a bit wetter than most of the model`s ensemble members and is wetter than the mean as well. Based on this and the performance of the GFS`s QPF fields at long range over the past week or two, am inclined to lean more toward the drier EC/GEM. Looking at the EPS, most of the perturbations are indeed dry this weekend. As a result, will stick with low PoPs in the chance category, which also happens to be in good agreement with the previous forecast. Wind chills New Year`s Eve, as well as the following two nights, will be a few degrees either side of zero, so people heading out will need to be sure to bundle up good. Taking a glance farther ahead...right now it looks like the cold will hold on through about the first 6 days of January before beginning to lose its grip during the second week of the month. && .Aviation...(00Z TAF Issuance) Issued at 614 PM EST Tue Dec 26 2017 A weak disturbance will move through the region this evening bringing with it some light snow. The latest trends show that most of this activity should stay to the north of the TAF sites. It now looks like LEX may have the best chance for some flurries or very light snow over the next few hours so will carry VCSH there. Otherwise, will take out the mention of precipitation at SDF and HNB. Skies will be clearing from the north late tonight into early tomorrow morning. VFR ceilings should prevail prior to the clearing. Winds tonight and tomorrow will be out of the north around 7-10 knots. && .LMK WATCHES/WARNINGS/ADVISORIES... IN...None. KY...None. && $$ Update...EER Short Term...13 Long Term...13 Aviation...EER
Area Forecast Discussion
National Weather Service Memphis TN
856 PM CST Tue Dec 26 2017 .UPDATE... Looking at the latest KGWX radar images, light rain is pushing into areas of North Mississippi between Charleston and Calhoun City. Current temperatures range from the upper 30s to the lower 40s across this area. The HRRR continues to show precipitation skirting this area from Charleston over to Aberdeen, possibly as far north as Tupelo into the overnight hours. Concerned that precipitation will change over to freezing rain and/or sleet as temperatures drop to or slightly below freezing. Will update to add rain chances for the remainder of the evening hours and change precipitation type to rain, freezing rain or sleet after midnight. Will hold off on any winter weather advisory at this point, but one may be needed if precipitation does indeed change over. KRM && .DISCUSSION... /issued 322 PM CST Tue Dec 26 2017/ Guidance has trended toward less of an impact from any wintry precipitation both tonight and next weekend. However, it still looks like we will continue to deal with very cold temperatures. Some temperatures may be as much as 20-25 degrees below normal early next week. Overnight, WPC has removed any accumulating rain/snow/sleet/ice from their graphics across North Mississippi. Models still show some chance for snow or sleet. The GFS features a warm nose of around 2-2.5 degrees F which would likely result in snow while the NAM has a much warmer warn nose over 5-6 degrees which would likely result in sleet. Nevertheless it looks like a short lived event only impacting a small portion of the Midsouth along a line from South Monroe county to South Coahoma county. Any precipitation that develops will not likely begin until after Midnight and should exit the Midsouth by sunrise. Will maintain 30% or less pops with no accumulation. Today through the weekend and into early next week the pattern essentially remains unchanged. A broad deep trough that spans most of the country will remain in place centered roughly over the Great Lakes. This pattern will allow a steady flow of Arctic air to sweep across West Canada into the Northern Plains and eventually the Ohio and Mississippi River Valleys. We probably won`t see dew points above the low 20s any time over the next 7 days with the lowest dew points in the single digits tomorrow and Thursday or even below zero early next week. High temperatures may even remain in the teens early next week with low temperatures below 10 degrees across much of the Midsouth. The GFS is about the only model holding on to the Wintry Precipitation next weekend. Not ready to completely remove pops for the weekend, but lowered them considerably and reduced the duration to only Sunday into Sunday night as a Cold front sweeps across the area. 30 && .AVIATION... An MVFR deck over SW KY/MO bootheel and parts of NW TN will move south into KMKL/KJBR this evening and into KMEM and KTUP later tonight. Overrunning ahead of a reinforcing cold front may result in some light sleet at KTUP late tonight. Northeast winds will be on the increase to 12 kts with higher gusts by morning with conditions becoming VFR area-wide mid-morning Wednesday. && && .MEG WATCHES/WARNINGS/ADVISORIES... AR...None. MO...None. MS...None. TN...None. && $$
Area Forecast Discussion...UPDATED
National Weather Service San Angelo TX
620 PM CST Tue Dec 26 2017 .UPDATE... After getting a few reports of light accumulations of freezing drizzle across parts of the Big Country, and temperatures about to fall into the 20s for the area, have elected to go ahead and issue a Winter Weather Advisory for freezing drizzle for the Big Country. This will mainly affect bridges and overpasses across areas generally along and north of the I-20 corridor. With drier air advecting south into the area later tonight, likely putting an end to the drizzle, have the advisory in effect until 3AM. 20 && .PREV DISCUSSION... /issued 511 PM CST Tue Dec 26 2017/ AVIATION... /00Z TAFS/ IFR/LIFR ceilings are occurring at all sites early this evening and are forecast to persist through the overnight hours. In additions, ares of fog will also result in reduced visibilities. Patchy freezing drizzle may develop across mainly the Big Country this evening, possibly affecting KABI. Most of the drizzle if forecast to taper off after midnight. MVFR ceilings are forecast to develop at all sites by late morning Wednesday, then persisting through the afternoon hours. PREV DISCUSSION... /issued 305 PM CST Tue Dec 26 2017/ SHORT TERM... (Tonight and Wednesday) .Very cold temperatures with areas of freezing drizzle across the Big Country...Concho Valley and N. Crockett County tonight. Watch out for icy bridges and overpasses... Very cold air continued to move into West Central Texas. The Texas Tech West Texas Mesonet indicated temperatures of 27 degrees at Knox City, with 28 at Aspermont and Haskell. It was 33 and 35 degrees at Sweetwater and Abilene. Light drizzle, some freezing, was indicated by the Dyess AFB radar. Short range models, including the HRRR and NAM, indicate areas of light drizzle this evening, tapering off toward midnight as isentropic lift of warm air over cold air at the surface, weakens. Icy bridges and overpasses will be the main concern tonight, especially along and north of I-20, where temperatures will be in the 20s. Freezing drizzle amounts will be mainly trace amounts, but even these amounts could produce hazardous conditions. With current temperatures in the teens in the Panhandle and Western Oklahoma, sows tonight will be lower and mid 20s in the Big Country with lows near 32 along the I-10 corridor. Went 2-3 degrees cooler than most short range MOS guidance Wednesday with cloudy skies and strong cold advection. LONG TERM... (Wednesday Night through New Years Day) Looks like mainly quiet weather across the area for mid to late week. Temperatures will recover into the 50s for highs and lows mainly in the 30s. The next strong cold front will move south across West Central Texas Saturday, bringing much colder temperatures Sunday and New Years Day as an arctic airmass settles over the area. The GFS indicates a near 1060 MB surface high over the Central Plains and the ECMWF has a near surface 1045 MB(probably the right value) over the upper Midwest, and a more shallow arctic airmass over our area. For now, spitting the guidance between the very cold GFS and much warmer ECMWF for our area. Highs will be in the mid 30s and 40s Sunday through Tuesday with lows in the teens and 20s New Years and Tuesday mornings. && .PRELIMINARY POINT TEMPS/POPS... Abilene 24 33 29 50 / 20 10 5 0 San Angelo 29 34 32 55 / 20 10 5 5 Junction 34 37 33 54 / 20 20 5 5 Brownwood 30 33 30 47 / 30 10 5 5 Sweetwater 23 32 29 52 / 20 10 5 0 Ozona 32 36 34 53 / 20 20 5 5 && .SJT WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory until 3 AM CST Wednesday for Callahan- Fisher-Haskell-Jones-Nolan-Shackelford-Taylor-Throckmorton. && $$