Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 12/03/17

Area Forecast Discussion
National Weather Service Columbia SC
1014 PM EST Sat Dec 2 2017 .SYNOPSIS... A weak front has stalled just south of the area. Dry high pressure takes control Sunday. A strong cold front will affect the area around the middle of next week, with much colder air settling over the region by the end of the week. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... For the overnight period, Lingering low level moisture, along with weak isentropic lift, will help to keep low stratus across the area. The addition of light winds may allow at least some patchy fog to develop late. Dry conditions expected with lows in the 40s. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/... Upper ridge will cross the region in the Sunday-Monday time frame. Surface high pressure will also be over the region. Still expect dry with moderating temperatures. Afternoon highs will be in the 60s with overnight lows in the 40s. && .LONG TERM /TUESDAY THROUGH SATURDAY/... Models still showing rather significant changes to the upper pattern, with a deep east coast trough setting up through the end of the week. The surface high will move off the coast by Tuesday with a strong cold front approaching from the west through the day. Expecting Tuesday to be rather mild, with readings in the 70s. The front will move into the area Tuesday night, then moving east of the cwa Wednesday morning. Best chance for rainfall associated with the front should be late Tuesday, lasting through a portion of Wednesday. Drier air should filter in Wednesday night through Friday. Behind this front, the region will see a return of much colder air. Overnight lows by the end of the week will near or below freezing, with daytime highs only in the 50s. && .AVIATION /03Z SUNDAY THROUGH THURSDAY/... Fog and low stratus expected to develop during the late evening and overnight. Moderately high confidence for IFR and LIFR conditions after 06z to 14z. Lower clouds beginning to re-develop across the area early this evening. Satellite trends suggest decreasing higher level clouds overnight. With high low-level moisture...light winds and minimal dew point depressions should lead to fog development. The latest HRRR and LAMP suggest widespread fog after 06z and this seems reasonable. Fog and stratus should diminish by around 15z with scattered or clear skies in the afternoon. The winds will be light mainly from the north through the day. EXTENDED AVIATION OUTLOOK...It should be drier Sunday night into Monday with ridging more dominant. Moisture will increase again on Tuesday, and a strong front will move through Tuesday night/Wednesday. && .CAE WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. && $$
Area Forecast Discussion...UPDATED
National Weather Service Austin/San Antonio TX
805 PM CST Sat Dec 2 2017 .UPDATE... Updated to re-establish hourly temp trends as well as expand fog coverage overnight through Sunday morning. Short term guidance suggests developing low stratus overnight with the potential for lowering ceilings into fog layer. Available consensus, LAMP, and HRRR guidance indicate visibilities dropping below 2 miles by daybreak through a good portion of the Hill Country and along and east of I-35. There is the potential for some areas of dense fog, but confidence in this is slightly lower. && .PREV DISCUSSION... /ISSUED 528 PM CST Sat Dec 2 2017/ AVIATION DISCUSSION...FOR 00Z TAF PERIOD... While VFR is expected through the rest of the evening and through midnight, poor flying conditions are expected not long after. A surge of low level moisture will blanket the region in IFR or worse CIGs from the south and spread through all TAF sites by daybreak. Guidance suggested IFR BR as well but did not go as significant with high clouds around tonight. CIGs will linger through much, if not all, of the morning hours as well before improving slowly into the afternoon hours, eventually reaching VFR by mid to late afternoon. PREV DISCUSSION... /ISSUED 315 PM CST Sat Dec 2 2017/ SHORT TERM (Tonight through Sunday Night)... An approaching Pacific disturbance looks impressive on satellite as it moves into Nrn Mexico. The low level moist layer over South Central TX deepens rapidly tonight while model soundings forecast a dry layer aloft to maintain capping to limit rain potential to mostly a slight chance through daybreak Sunday. With limited moisture and increasing nocturnal winds increasing up the Rio Grande Plains tonight, some slightly better chances for showers would seem probable over and NW of the southern escarpment with rain chances ramping up around daybreak over the Coastal Prairies/Rio Grande plains in a deepening low level moisture layer. The upper disturbance moves quickly across TX Sunday with not much opportunity for moisture loading. Will keep out mention of convection with this system, although an isolated clap of thunder could not be ruled out for Sunday. In the wake of the disturbance, progressive zonal flow aloft and a stronger upstream disturbance leads to only minor changes in the surface winds and continued onshore fetch of Gulf moisture and more chances for overnight streamer showers Sunday night. Temps the next couple nights should remain well above normals for early Dec. LONG TERM (Monday through Saturday)... The stronger upstream system mentioned in the short-term discussion initially arrives partially with a strong shortwave passing well to the north of the area Monday. While this can often lead to downsloping, mid level transport of Pacific moisture could present a weaker cap, especially by Monday night. Isolated thunder will be possible Monday into early Tuesday, with perhaps the best chance along the strong front forecast to move into the area at daybreak Tuesday. The initial post-frontal push should bring strong cooling and drying which should curb rain chances. Upstream energy hung over the SWrn US will move into W TX Tuesday night with cold rain showers expected to move into South Central TX Wednesday into Wednesday night. Model PoPs indicate rains are likely, but continued low level drying indicated by only a slight rebound in forecast surface dewpoints has us capping PoPs into a chance category for now. Late Wednesday night, mid level cooling and weak isentropic lift could generate a brief R/S mix over the Southern Edwards Plateau and Wrn Hill Country before precip chances decrease N-to-S late Thursday Morning. Light freezes should be possible over the Hill Country and the adjacent valleys just S/E of the escarpment Thursday and Friday mornings. Nly flow aloft and light surface winds next Saturday should lead to another cool day before a warming trend resumes next Sunday. && .PRELIMINARY POINT TEMPS/POPS... Austin Camp Mabry 60 73 66 80 55 / 10 30 30 40 50 Austin Bergstrom Intl Airport 58 74 66 80 57 / 10 30 30 40 50 New Braunfels Muni Airport 60 75 66 81 59 / 20 30 30 40 30 Burnet Muni Airport 58 72 64 78 51 / - 20 20 20 40 Del Rio Intl Airport 60 75 61 78 55 / 20 30 - 10 - Georgetown Muni Airport 58 73 65 79 53 / - 20 30 30 40 Hondo Muni Airport 60 77 63 81 59 / 20 30 30 20 20 San Marcos Muni Airport 59 75 66 81 59 / 20 30 30 40 40 La Grange - Fayette Regional 57 76 66 81 60 / 20 40 30 40 40 San Antonio Intl Airport 61 76 66 81 60 / 20 30 30 30 30 Stinson Muni Airport 62 77 66 82 61 / 20 30 30 30 20 && .EWX WATCHES/WARNINGS/ADVISORIES... None. && $$ Mesoscale/Aviation...TB3 Synoptic/Grids...Runyen Public Service/Data Collection...Treadway
Area Forecast Discussion
National Weather Service Green Bay WI
507 PM CST Sat Dec 2 2017 Updated aviation portion for 00Z TAF issuance .SYNOPSIS... Issued at 205 PM CST Sat Dec 2 2017 Another mild and dry day Sunday, then turning windy and colder early next week. The fast low-amplitude flow that has been in place across the northern CONUS and southern Canada the last few days will undergo significant amplification the next several days as strong ridging develops near the West Coast. A deep trough will develop downstream over central and eastern North America. Once in place, the new large-scale pattern looks pretty stable, and is likely to persist through the rest of the forecast period and beyond. Day to day changes during that time will likely be the result of variations in the depth/sharpness/location of the eastern North American long-wave trough caused by shortwaves moving through the pattern. Temperatures will remain 15-22 F degrees above normal through Monday, then drop back to 5 to 10 F degrees below normal by mid- week, remaining there for the rest of the period. The bulk of the precipitation will occur as a strong cyclone crosses the region early next week. That system looks like a pretty good precipitation producer for early December, though having the dry slot driving right through the forecast area will probably hold amounts back somewhat. Normal precipitation for a week at this time of year is roughly 0.40 inch. It`s reasonable to expect that most of the area will end up with somewhat close to that. && .SHORT TERM...Tonight and Sunday Issued at 205 PM CST Sat Dec 2 2017 The latest RAP analysis and satellite/radar imagery show an area of low pressure exiting eastern Lake Superior while high pressure stretches across the central Great Plains. Weak shortwave energy moving across South Dakota is generating an area of scattered to broken cirrus, which is moving across southern Minnesota and the southern half of Wisconsin. Should see this cirrus move across areas generally south of route 29 this afternoon. Otherwise, the 12z regional sounding analysis shows very dry air present below 700mb across the Plains and northern Mississippi. Therefore, forecast concerns mainly revolve around clouds and temps in this portion of the forecast. Tonight...High clouds associated with the shortwave are expected to depart during the evening, leaving mostly clear skies for much of the night. With winds expected to become light and variable, stuck with temps below the multi-model blends. High clouds are anticipated to increase late from the west, but do not think will have a big impact on temps. Lows ranging from the lower 20s north to low 30s near the Lake. Sunday...Mid and high clouds will continue to thicken as they invade from the west. Though the Gulf will start to open, deeper moisture will take time to move into the region, and will likely not make it into Wisconsin until Sunday night. Will still see skies become mostly cloudy after a partly cloudy or filtered sunshine start to the day. Mild highs ranging from the mid 40s to low 50s. .LONG TERM...Sunday Night Through Saturday Issued at 205 PM CST Sat Dec 2 2017 The primary weather maker during the period will be the strong cyclone forecast to emerge from the northern or central Rockies Sunday and track to southern Ontario by Tuesday morning. The system is expected to bring widespread precipitation, though as already mentioned amounts will probably be held down by having the dry slot directed into the area. The main impact of the system for most of the area will be wind. Would not be surprised to get some gusts of 45-55 mph right along and behind the cold front on Monday night. Strong west to southwest winds will continue into Tuesday. Colder air wrapping around the cyclone will cause lingering showers to change to snow Monday night. There is some uncertainty over how much precipitation will still fall over north-central Wisconsin after the changeover. Even an inch or two of snow could make for very difficult travel conditions across the north Tuesday given the wind. At this point, it just looks like scattered snow showers and flurries elsewhere, with minimal accumulation. The remainder of the period will be spent under cold cyclonic flow as disturbances rotate through the long-wave trough near the region. Some of those could produce an inch or two of snow and begin to establish a snowcover across the region, but the specifics of when that would occur are tough to gauge this far out. Temperatures, especially at night, could be colder if a widespread snowcover becomes established. && .AVIATION...for 00Z TAF Issuance Issued at 507 PM CST Sat Dec 2 2017 Good flying weather through tonight with only scattered high clouds to go along with winds under 10 kts. Clouds return on Sunday and will gradually thicken/lower ahead of the next system approaching from the west. Adverse flying weather is not expected to arrive until Sunday night. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS.......Skowronski SHORT TERM.....MPC LONG TERM......Skowronski AVIATION.......Kurimski
Area Forecast Discussion
National Weather Service Wilmington OH
935 PM EST Sat Dec 2 2017 .SYNOPSIS... High pressure will keep the region unseasonably warm and dry through the weekend. A strong cold front will move east across the area Monday night into Tuesday, bringing in an area of rain showers. A much colder airmass will then settle into the region behind the front, leading to well below normal temperatures into next weekend. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... Mid and high clouds continue to move across the region. Recent RAP runs continue to suggest that there will be one more increase in mid cloud across the far east/southeast counties later tonight as a short wave quickly moves through. Given temperatures trends thus far, have bumped temperatures down a bit. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/... The center of the surface high will begin to work to the east on Sunday. With only some patchy cirrus expected, skies will be mostly sunny. Weak southerly flow will allow the temperatures to warm to about 10 degrees above normal. Highs will range from the lower to mid 50s in the north to the upper 50s in the south. && .LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/... As has been advertised for awhile now, the upper level pattern will become highly amplified during the extended period. This will result in above normal temperatures to begin, then trending downward to below normal readings through the end of next week. For Sunday night into Monday night, a mid level trough will dig and carve itself out across south central Canada and into our region. This scenario will result in deepening low pressure which will track northeast across the northern Plains and into Ontario. As this occurs, a cold front will move east into our region Monday night. Cloud will increase through Monday, with the threat of showers ramping up Monday night in the moist ascent/lift. Under increasing southerly flow, highs will warm into the upper 50s north to the lower 60s south. Lows will be frontal position dependent, but should range from the upper 40s west to the lower 50s east. The cold front is expected to be progressive, and is now expected to be out of the area by Tuesday afternoon, showers will come to end. With CAA, highs will occur early west, then slowly fall, with a slight rise east, then slowly falling. A secondary cold front is expected to move southeast through the region Tuesday night into Wednesday. This will bring colder air, but precipitation is lacking. It will be much colder by Wednesday with highs in the 30s. For the remainder of the week, s/wv energy in the highly amplified flow will allow the large scale upper level trough to remain, keeping cold air in place. There continues to be timing issues with some of this energy with the GFS bringing a piece through the region Friday/Friday night, while the ECMWF is delayed by about a day. As a result, will keep temperatures cold, highs in the 30s/lows in the 20s with a chance of snow showers, mainly Friday night into Saturday. && .AVIATION /03Z SUNDAY THROUGH THURSDAY/... Main question is whether any ground fog will occur at KLUK tonight. Temperatures are starting out warmer and if there were any wind, it would be coming from an unfavorable direction. But cannot completely rule out some visibility restrictions there. Otherwise VFR will prevail across the region with just some mid and high clouds. Winds will remain light through the period eventually coming out of the south on Sunday. OUTLOOK...MVFR/IFR conditions along with gusty winds are likely Monday night into Tuesday. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...None. KY...None. IN...None. && $$ SYNOPSIS...JGL/Sites NEAR TERM... SHORT TERM...Sites LONG TERM...Hickman AVIATION...
Area Forecast Discussion
National Weather Service San Francisco Bay Area
430 PM PST Sat Dec 2 2017 .SYNOPSIS...A weak low pressure trough will pass across Northern California today with rain chances expected to mostly remain north of the Golden Gate tonight. Longer range trends suggest dry and cooler temperatures over the weekend into early next week, followed by warmer temperatures later in the week. && of 01:28 PM PST Saturday...Cloud cover continues to increase across the region as a cold front approaches from the north. The increased clouds have kept temperatures in check with afternoon temperatures in the 50s to lower 60s. The afternoon temperatures are noticeably cooler than yesterday afternoon, 5 to 10 degrees cooler. The most active part of the forecast will be the next 24-36 hours as a cold front is forecast to move through the region. Models have been pretty consistent with bringing a slight chance for rain to the North Bay for several days now, but the uncertainty was how far south would it rain. The 12Z model suite has followed recent trends to push rain chances a tad southward. The hi-res HRRR and WRF bring a few showers as far south as Monterey tonight/early Sunday. Moisture may be a little lacking through the column for that to happen, but a few showers down to SF Bay seem more likely. Therefore, updated forecast for 15-20% pop south to near Redwood City. None the less, rainfall amounts will be light across the entire area. Highest totals will be a few hundredths or a tenth across the North Bay. Instability with the front appears to be limited, but it does have a colder airmass associated with it at 700-500mb. Additionally, wetbulb zero heights actually drop below 3k feet across far Northern Sonoma/Napa County. If things would line up just right some frozen precip could be possible over the highest peaks, but conf is too low to add winter weather to grids. High pressure ridges behind the front Sunday night and Monday. Offshore gradients ramp up to greater than 11mb (SFO- WMC), which is pretty decent for gusty winds. WRF 925mb winds actually hit about 40kt across the higher terrain. It will be borderline for any type of wind advisory, but later shifts will need to take a closer looks. Winds diminish Monday evening and become even lighter by Tuesday morning. The clearing skies and weakening winds will lead to some chilly mornings next week. Otherwise, building high pressure will translate to a warming and drying trend. In fact, temps in the 70s will be possible the middle of next week for interior Monterey/San Benito Counties. Latest CPC 8-14 outlook keeps much of CA below normal for rainfall Dec 10-16. A side note, GOES16 has officially gone `dark`. GOES16 is currently moving to is final location of 75 deg W or the longitude of Philadelphia. The move is expected to take about ten days and will not be sending satellite data during its move to protect the sensors. The satellite should be fully operational around December 20. && .AVIATION...As of 4:30 PM PST Saturday...For 00Z TAFs. It`s VFR with mainly high clouds except locally haze is reducing visibilities to MVFR. Radar is just beginning to show high based light rain echoes reaching northern Sonoma county. The Cazadero profiler shows rain evaporating at approx 11 thousand feet. 00Z tafs carry on forecast for a cold front moving southeast tonight bringing lowering cigs and chance of rain to the North Bay overnight, light rain possibly reaching a little farther south into Sunday morning. Vicinity of KSFO...VFR conditions will prevail into this evening with cigs lowering to MVFR after 04z. Tempo group MVFR cigs 04z-08z and another tempo for light rain showers and MVFR cigs 08z-12z. Models trending a bit more south compared to previous output indicating rain chances could move a little farther south. Light winds this evening will increase near time of frontal passage. SFO Bridge Approach...Similar to KSFO. Monterey Bay Terminals...VFR conditions will prevail through the forecast period with mainly high clouds expected ahead of the approaching frontal system. Precipitation associated with this front may move farther south. A mention of showers remains out of the TAF for now. Mainly light winds. && of 3:26 PM PST Saturday...Moderate northwesterly winds expected across the coastal waters through the remainder of the weekend and into early next week. Winds will accompany the passing front and persist in its wake. Northwesterly swells in the 9 to 11 ft range at 15 seconds will prevail. && .MTR WATCHES/WARNINGS/ADVISORIES... .Tngt...SCA...Pigeon Pt to Pt Pinos 0-10 nm from 12 AM SCA...Pt Arena to Pigeon Pt 10-60 nm SCA...Pt Pinos to Pt Piedras Blancas 0-10 nm SCA...Pigeon Pt to Pt Piedras Blancas 10-60 nm from 9 PM SCA...Pt Arena to Pt Reyes 0-10 nm from 7 PM SCA...Pt Reyes to Pigeon Pt 0-10 nm from 9 PM && $$ PUBLIC FORECAST: MM AVIATION: Canepa MARINE: CW Visit us at Follow us on Facebook, Twitter, and YouTube at:
Area Forecast Discussion
National Weather Service Shreveport LA
936 PM CST Sat Dec 2 2017 .UPDATE... High thin clouds continue to move into the region from the west late this evening but the cirrus is not stopping late evening temperatures from dropping dangerously close to fcst min temps, especially across our eastern most zones. For this reason, had to adjust overnight min temps across our eastern parishes of Northeast Louisiana as well as some of our Southwest Arkansas Counties. Beginning to see some patchy fog across our southern zones as well where the cirrus is the very thin and hourly temp/dewpt depressions are near zero. This is in pretty good agreement with the HRRR which is showing the potential for the fog to expand into portions of East Central La into Deep East Texas. For this reason, have also added some patchy fog to the grids mainly along and south of a line from LFK to near MLU for the remainder of the night into the mid morning hours on Sun. Other changes included a slight adjustment to dewpoint and RH grids to mimic current and fcst trends. Otherwise, no other changes were necessary to the forecast. Update out shortly...13. && .PREV DISCUSSION... /issued 640 PM CST Sat Dec 2 2017/ AVIATION... For the 03/00Z TAFs, VFR conditions are expected to continue at our area terminals this period aside from brief vsby restrictions due to patchy early morning fog at LFK and possibly a few other sites. Otherwise, look for more mid clouds but mostly high clouds to stream into the region ahead of an upper level low ejecting across Baja into northern Mexico. Winds will remain light to near calm overnight and generally from the SE between 5-10 kts during the daytime hours. Lower clouds may also begin to creep into the picture toward the end of this period but may hold off until after 04/00Z. /19/ && .PRELIMINARY POINT TEMPS/POPS... SHV 51 75 58 76 / 0 10 10 50 MLU 46 72 54 77 / 0 0 10 20 DEQ 48 75 55 72 / 0 0 20 70 TXK 53 73 57 73 / 0 0 20 70 ELD 48 72 54 74 / 0 0 10 50 TYR 51 74 60 75 / 0 20 20 60 GGG 51 75 58 76 / 0 10 20 60 LFK 49 74 61 78 / 0 20 20 60 && .SHV WATCHES/WARNINGS/ADVISORIES... AR...None. LA...None. OK...None. TX...None. && $$ 19/13
Area Forecast Discussion
National Weather Service Tucson AZ
139 PM MST Sat Dec 2 2017 .SYNOPSIS...Dry conditions will prevail into next Friday. Daytime temperatures will remain well above normal this weekend followed by a cooling trend Monday into Tuesday. Expect no significant daily temperature changes Wednesday into Friday, although gusty east winds will occur at times. && .DISCUSSION... The core of the slow moving area of low pressure is over the Gulf of California as of 20Z and remains on track as it approaches southeast Arizona. Biggest impact with this low has been mostly cloudy skies although Nogales did manage to squeeze out a trace of rain earlier today with a few passing showers. HRRR maintains the idea of a few widely scattered showers/sprinkles through late afternoon/evening (mainly to the east of Tucson). I made some slight areal/temporal adjustments to PoPs and Wx for this evening based on the last few runs of the HRRR and observational trends, but nothing substantial. Look for highs to top out in the mid 70s (generally on par with that we`ve seen the past few days). Upper low will depart the area on Sunday with some lingering cloud cover possible in the morning. Mostly sunny skies are expected through the day tomorrow but clouds will increase once again late in the day. This time, a system moving onshore through the Pac NW will be the responsible party and will sweep through the Great Basin and into the Four Corners Monday/Tuesday. Precip chances with this system remain nil thanks to its over-land trajectory and positioning well north of the forecast area. Varying amounts of cloud cover along with a drop in temperatures will be the most sensible impacts with this system. Highs will retreat into the mid/upper 60s at times this week which is generally right where they should be for early December. A secondary trough will bring a round of breezy winds to the area later in the week. Some clouds are possible Wednesday/Thursday in advance of this low as moisture gets pulled northward into Arizona. Could even see enough moisture to squeeze out some virga/sprinkles in far southeast Arizona coincident with the passage of the trough but at this point it looks to be of minimal impact. Winds will increase on Thursday as even cooler air is advected into the area. Last few runs of the NBM is suggesting mid 60s for highs to close out the week. Deterministic guidance is a bit warmer but only by a degree or two. Regardless, cooler temps look like a safe bet to close out the week. Sub freezing temps also look like a safe bet in the higher terrain locations east of Tucson, with desert lows falling into the upper 30s. && .AVIATION...Valid thru 04/00Z. Isolated -SHRA may occur mainly S to SE of KTUS through this evening. Otherwise, expect SCT clouds around 8k-12k ft AGL and layered cloud decks above 15k ft AGL today with slow clearing from west to east overnight into Sunday morning. Surface wind will be variable in direction less than 12 kts through the period. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...There is a slight chance of showers mainly south to southeast of Tucson this afternoon and evening. Otherwise, dry conditions prevail through next Friday. 20-foot winds will be terrain driven at generally less than 15 mph through Tuesday, with gusty east winds at times next Wednesday and especially Thursday. && .TWC WATCHES/WARNINGS/ADVISORIES...None. && $$ Visit us on Facebook...Twitter...YouTube...and at