Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 03/16/17

Area Forecast Discussion
National Weather Service Bismarck ND
854 PM CDT Wed Mar 15 2017 .UPDATE... Issued at 852 PM CDT Wed Mar 15 2017 Main areas of concern for this update are temperatures and precipitation chances. H85 warm air advection will continue across western and central North Dakota tonight. This in combination with the clouds should help keep temperatures from falling off too much overnight. Will show some small temperature fluctuations in the hourly temperature forecast, but overall do not expect readings to change too much in most locations. Decided to keep the slight chance pop in the southern James River Valley. The latest HRRR suggests there could be light precipitation in the southeast part of the state, while the RAP and 16.00Z NAM look drier. The 00z Bismarck sounding had quite a bit of dry air above H9 to overcome, so it appears this could be more of a virga/sprinkle type of situation. UPDATE Issued at 614 PM CDT Wed Mar 15 2017 Main adjustment for this update was to increase hourly temperatures in the southwest part of the state late this afternoon. Some spots in the southwest have climbed into the 50s and lower 60s which was warmer than our hourly temperature forecast. Will continue to monitor local radars to see if any light precipitation tries to develop this evening in the southern James River Valley as per the GFS and NAMNEST. The high resolution short term models have generally been dry in that region and focus more on the next round coming from eastern Montana. Will hold onto the slight chance small pop for now in the southern James River Valley which reflects the lower confidence in that area. && .SHORT TERM...(This evening through Thursday) Issued at 203 PM CDT Wed Mar 15 2017 A warm front will move push through late this evening, ramping up warm air advection significantly. Some models (GFS, SREF, NAMNEST)indicate some light precipitation will impact the southern James Valley along with this warm push. If this pans out some light freezing rain will be possible around midnight with surface temperatures still below freezing. Confidence isn`t high enough at this time to warrant anything more than a slight chance. Breezy westerly winds will develop tomorrow as a cold front swings through late morning west and early afternoon east. Even though we will likely be cloudy for the majority of the day, those westerly winds will mix down much warmer air aloft leading to temperatures in the 40s and 50s. A surface low will pass just north of North Dakota Thursday/Friday with the cold front trailing down through North Dakota. Most of the global models have some light rain following the front Thursday. At this time it appears northern North Dakota has the best chance of seeing some light rain due to the location of surface low and best forcing. .LONG TERM...(Thursday night through Wednesday) Issued at 203 PM CDT Wed Mar 15 2017 The long term will be a roller coaster with a series of waves moving through the region. Overall this will maintain a mild weather pattern with several passages of pacific cold and warm fronts. Friday will be a windy day with 20 to 30 mph northwesterly winds as strong cold air advection and pressure rises move into the region. The western upper level ridge builds back up again into the Dakotas Saturday, followed by another strong clipper moving east across southern Canada Sunday/Monday. There may be a quick shot of rain or snow Sunday/Sunday night. The models depict a storm system moving into the west coast Monday night and deepening over the west coast Tuesday. This system could bring us at least a couple of days worth of rain or snow beginning Tuesday night, though models differ greatly on phase and placement of the system. Temperatures will be variable, with highs ranging from the 30s to the 50s. && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 614 PM CDT Wed Mar 15 2017 The short term models still suggest the potential for mvfr to ifr cigs, primarily towards KJMS for tonight. MVFR cigs could also develop Thursday afternoon in northern parts of the state. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...CK SHORT TERM...AJ LONG TERM...AJ AVIATION...CK
Area Forecast Discussion
National Weather Service Cheyenne WY
828 PM MDT Wed Mar 15 2017 .UPDATE... Issued at 809 PM MDT Wed Mar 15 2017 Subsidence associated with a weak upper level PV anomaly passing to the north along with deeply mixed boundary layer will allow westerly winds to increase to near 25 mph with gusts to 40 mph by late Thursday even into the SW Nebraska Panhandle. Latest short range models are consistent in bringing in critical RH values around 15 percent in this same area with the HRRR time-lagged ensembles giving a 90 percent probability of critical fire weather conditions. One caveat is the potential for more cloud cover associated with the shortwave which would reduce the amount of insolation and prevent RH from reaching critical thresholds. In light of all this, decided to go with a Fire Weather Watch for zone 313 to allow the later shifts to monitor trends in the cloud cover. && .SHORT TERM...(Tonight through Friday Night) Issued at 243 PM MDT Wed Mar 15 2017 High clouds continuing to stream across much of the CWA but clearing from the west with the upper ridge moving slowly east into the Rocky mtn area. The ridge will move across the area while weakening overnight leaving a generally zonal flow over the CWA Thursday through Friday. Another warm day across the CWA Thursday with plenty of sun and dry downslope flow. Max temps will be in the 70s east of the mtns...nearing 80 across the southern Neb Panhandle. A cool front will sink south across the plains Thursday night as a shortwave moves across the northern Rockys into the northern plains. Dry air will preclude pcpn for the most part though a few light showers not out of the question Thursday evening over northern parts of the CWA closer to the shortwave. Friday will be dry and cooler especially over the plains where max temps should be about 15 degrees cooler from Thursday. .LONG TERM...(Saturday through Wednesday) Issued at 243 PM MDT Wed Mar 15 2017 A warm and dry weekend is ahead with upper-level ridging remaining in place and H7 temperatures in the +6C to +8C range. Larger scale subsidence will yield little or no chance for precipitation. Highs will likely be in the 70s along/east of I25, and possibly even low 80s in the southern NE Panhandle or Platte River Valley. Mid-level flow remains westerly through early next week, but a cold front is expected to push temperatures back into the mid/upper 50s for much of the area. May see a period of showers in the mountains and over our northern zones with the fropa, but overall the weather pattern will remain quiet. && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 551 PM MDT Wed Mar 15 2017 VFR conditions expected to prevail through the TAF period. Main forecast concern will be a period of stronger wind gusts on Thursday as a shortwave passes to the north. Could see westerly gusts to 35 kt for a few hours beginning in the late morning over the western TAF sites and during the afternoon for the Nebraska terminals. && .FIRE WEATHER... Issued at 809 PM MDT Wed Mar 15 2017 A period of enhanced fire weather conditions are possible late Thursday morning into the afternoon for parts of the SW Nebraska Panhandle. Winds will be increasing ahead of a shortwave passing to the north with afternoon RH values between 15 and 20 percent. Decided it would be prudent to issue a Fire Weather Watch where fuels are driest and where dewpoints are progged to be the lowest Thursday afternoon in zone 313. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...None. NE...Fire Weather Watch from Thursday morning through Thursday evening for NEZ313. && $$ UPDATE...DEL SHORT TERM...RE LONG TERM...CLH AVIATION...DEL FIRE WEATHER...DEL
Area Forecast Discussion
National Weather Service Grand Forks ND
1001 PM CDT Wed Mar 15 2017 .UPDATE... Issued at 1001 PM CDT Wed Mar 15 2017 With newest NAM, RAP, and HRRR runs am less impressed with precip chances in the south for the 06Z to 12Z time frame. Started trending back on POPs a bit, but will wait for the GFS and another high res cycle before pulling them completely. South winds and clouds have keep temps in the upper 20s and low 30s, dropping a bit into the 20s later tonight. && .SHORT TERM...(This evening through Thursday) Issued at 234 PM CDT Wed Mar 15 2017 The primary forecast challenge for the short term period will be freezing rain potential for late tonight into the day tomorrow, before an A.M. wintry mix...or freezing rain...turns over to all rain as temperatures climb into the upper 30s by noontime and into the low 40s across the south by mid afternoon. Models continue to indicate a band of precip beginning to develop across eastern SD into s cntrl ND late in the evening (GFS/GEM) to early morning period (NAM)...however the high res models continue to be much drier or void of precip in the overnight period, although latest RAP has began to indicate precip across SE NoDak tomorrow morning (early runs were showing precip developing earlier in the overnight period). With uncertainty in timing and northward extent, prefer blended solution with best chance for development in the 09Z to 15Z timeframe across SE ND. Ice accumulation models do indicate a couple hundredths of an inch across Ransom/Sargent/Richland counties...which agrees with latest WWD guidance. Therefore this will need to be monitored closely for potential impacts during the Thu morning commute...mainly south of the I 94 corridor. Overnight lows across west will be impacted by some cloud cover and 10 to 15 mph winds overnight, with the eastern zones remaining mostly clear but breezier than last night. Temps will be much warmer across the east, generally in the low 20s, as opposed to near zero in areas last night. Although QPFs decrease east of the valley, a wintry mix could cause some areas of slick spots later into the day. ForecastBuilder is showing freezing rain or sleet through noontime east of the valley, and then a gradual change over to rain...which is supported by latest BUFKIT soundings and GFS plume models. A low pressure system moving across southern Canada will bring increased chances of precipitation across the far north late in the period into the early long term period (see discussion below). .LONG TERM...(Thursday night through Wednesday) Issued at 234 PM CDT Wed Mar 15 2017 The main concerns in the extended forecast are 1) chances for light rain, and perhaps freezing rain/mix in parts of NW MN, Thursday night into Friday and 2) temperature variations due to the active zonal pattern aloft. Thursday night into Friday, a surface low/upper level wave passes by just north of the international border, bringing precipitation chances to an area along/north of US Hwy 2 and generally along/east of the Red River. With relatively warmer air brought in on Thursday by southerly flow, mainly light rain is expected Thursday evening. Chances for light freezing rain/drizzle/wintry mix will creep in overnight and into early Friday morning, especially for areas northeast of a Hallock-Bemidji line, as temps cool aloft behind the cold front. However precip amounts will be quite light, generally a tenth of an inch or less, so very little, if any, ice accumulation is expected in those areas and impacts should be minor. As this system clears out, cooler northwest flow will bring temps to near or slightly above normal values with breezy conditions for the rest of Friday/Friday night. With the next upper ridge and its associated surface low developing in the Northwest and high pressure rushing through the Northern Plains Saturday, temperatures will warm considerably from Saturday to Sunday. Sunday and Monday will be the warmer days for the next week. On Sunday, expect high temps in the 40s to 50s. Maintained some slight chances for rain in the northern half of the forecast area Sunday due to uncertainty in a mid level dry layer. On Monday, highs will still likely be in the upper 30s to 40s. Early next week looks relatively dry with cooler air and high pressure pushing in for Tuesday. && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 636 PM CDT Wed Mar 15 2017 Some MVFR stratus has started to move into the southern forecast area this evening. This has started to creep into the KFAR area, although do not think it will last long. Have a TEMPO group for MVFR conditions but think all sites will be back to VFR by mid evening for the rest of the night. Increasing mid and high clouds will move in from the west tonight and tomorrow morning, with more MVFR stratus coming in towards the end of the period. Have most sites down below 1500 with a few below 1000 by late tomorrow afternoon. Some light precipitation will be possible, but models are inconsistent with the first round that will lift across western MN during the morning, slightly better with precip across the north late in the period. Have a VCSH at KDVL for now and can add more precip for later issuances as things become more clear. South to southeast winds will stay around 10 to 15 kts. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...None. MN...None. && $$ UPDATE...JR SHORT TERM...Speicher LONG TERM...BP AVIATION...JR
National Weather Service Jackson KY
1035 PM EDT Wed Mar 15 2017 .UPDATE... Issued at 1035 PM EDT WED MAR 15 2017 GOES 16 IR and low level water vapor indicating the area of CU continues to erode in the far east this evening. Most of the guidance wants to hang on to clouds a bit longer, but at this point keep at best a few to scattered through the night in the grids. That said the biggest issue tonight will be how low do we in fact go low temperature wise. Earlier this afternoon GOES 16 VIS/NIR bands did show areas that received snow showers/squalls yesterday into yesterday evening. This is in fact playing a important role in temperatures this evening where a swath from Bath County southeast to Letcher County are cooling much quicker under clear skies and maximized radiational cooling. Interestingly enough the HRRR has a decent handle on the location of this and therefore leaned in that direction. The other issue will be the fact that the surface high will not truly crest across the region. Therefore think this lowest temperatures will occur in the SW toward to Lake Cumberland region where best chances of decoupling will occur. The MAV/MET have this thought and therefore leaned in that direction for the far eastern valley spots. Otherwise more minor changes were made to align grids with latest obs and trends. UPDATE Issued at 741 PM EDT WED MAR 15 2017 GOES 16 IR showing CU continuing to erode across eastern KY, as an area of high pressure builds east into Western TN. This surface high will also aid in weakening the pressure gradient and mixing will also decrease resulting in decreasing winds through the night. This will lead to quite the chill across the region, with NAEFS suggesting upper levels temperatures approaching 4 STD below normal for this time of year. Overall the forecast grids are in good shape with more minor adjustments needed this update. && .SHORT TERM...(This evening through Thursday night) Issued at 333 PM EDT WED MAR 15 2017 Satellite shows an extensive cumulus/stratocumulus field across eastern KY, and radar shows some possible flurries mainly in the northern and eastern part of the area. However, have not seen any flurries or snow showers on web cams today, and radar trends have been diminishing. Will carry a few more hours of flurries in parts of the north and east before ending early this evening. High pressure will build into the TN Valley tonight. This combined with the loss of daytime heating will result in a decrease in clouds after sunset. With mostly clear skies and lighter winds tonight expect a ridge valley temperature difference to develop. This was not depicted in the initialized grids but it was in the previous forecast so have lowered temperatures in the colder valley areas for tonight which is more in line with the previous forecast. As high pressure slides east on Thursday temperatures will slowly warm, but remain below normal. As warm air advection kicks in Thursday night and the valleys decouple should see another ridge valley temperature split develop. The pattern Thursday night is more conducive to a significant ridge and valley difference than tonight`s. It is very possible that the ridge valley temperature difference depicted for Thursday night in the forecast grids is not great enough, so would not be surprised to see this modified in the coming forecasts. Thursday night will see temperatures once again well below freezing, so will need to issue another freezing warning. May see some light precipitation develop by early Friday morning in advance of an approaching warm front. Temperatures will be rising late Thursday night and early Friday morning, but it is possible the precipitation may start early enough that a brief period of wintry precipitation could occur before changing to rain on Friday. .LONG TERM...(Friday through Wednesday) Issued at 500 PM EDT WED MAR 15 2017 The models are in good agreement aloft through the extended portion of the forecast. They all depict a brief relaxation of the pattern over Kentucky on Friday ahead of the next trough rolling toward the Great Lakes. This will bring another round of falling heights and mid level energy to the Ohio Valley for late Friday into Saturday. In fact, the core of this trough will actually cut right through eastern Kentucky later that day and into the night - most impactful from the ECMWF than the GFS. This trough then moves off to the east by Sunday morning with rising heights to follow for the state. We can then look forward to slight ridging through the rest of the weekend and into Monday morning. This does weaken with time, though, so that by Monday night northwest flow will bring renewed batches of energy to our region south of a large and dominant low over the Hudson Bay. Falling heights will be the rule through mid week as the Canadian low shifts its influence south to the Great Lakes with prolonged northwest flow continuing along with some energy breaking off and making it south into Kentucky. The northern low then eases off to the east on Wednesday. Given the model agreement will favor a general blend with higher than normal confidence in the broad overall pattern. Sensible weather will feature departing cold air on Friday morning with chilly valleys mixing out towards dawn. This may yet have sub freezing readings around as the next wave of WAA pcpn moves in just after sunup. Accordingly there is some concern for a mixture of light p-types at the onset. For now, though, will keep it clean as just a rain/snow mix, though some sleet or a brief period of freezing rain in the valleys cannot be ruled out. Temperatures will warm through the day, Friday, getting up back into the 50s as a prolonged period of showers sets up lasting through a much milder Friday night. The pcpn chances will come to an end by midday Saturday as a slow moving cold front presses southeast of the area bringing in another bout of cold, but not frigid, air. This chilly air will moderate later Sunday into Monday before another system from the Southern Plains approaches and slides into Kentucky bringing another shot at rains through Tuesday. Drier and again cooler air follows for Wednesday. Made some minor adjustments to lows for a couple of the nights based on terrain differences, but for the most part went along with the blended starting point for temps through the extended. As for PoPs - tightened them up with the arrival early Friday morning and then upon departure Saturday morning. && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) ISSUED AT 720 PM EDT WED MAR 15 2017 The upcoming period will remain VFR with an area of SCT to BKN CU at around 5 KFT to start the period. Based on SAT trends this area of CU will continue to erode from west to east and already seeing clearing skies at SME/LOZ. High pressure across Western TN will build east into Middle TN tonight and keep the mostly clear skies going through the remainder of the TAF period. Winds could remain gusty in the east for a hour, but the gradient will relax and some will decouple thanks to high pressure build east. && .JKL WATCHES/WARNINGS/ADVISORIES... Freeze Warning until noon EDT Thursday for KYZ044-050>052- 058>060-068-069-079-080-083>088-104-106>120. Freeze Warning from 9 PM Thursday to 9 AM EDT Friday for KYZ044- 050>052-058>060-068-069-079-080-083>088-104-106>120. && $$ UPDATE...DJ SHORT TERM...SBH LONG TERM...GREIF AVIATION...DJ
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
659 PM CDT Wed Mar 15 2017 .SHORT TERM...(This evening through Thursday) Issued at 300 PM CDT Wed Mar 15 2017 Early afternoon visible satellite imagery together with RAP13 surface analysis showed high pressure and clear skies across most of Minnesota and Wisconsin. Despite the light winds, temperatures warmed above freezing at most locations along and north of I-94, with cooler temperatures near I-90 where there was more snow cover. Over the next 24 hours the ridge of high pressure will shift eastward and warm air advection will move from the Dakotas into western MN and lead to isentropic ascent, mid level clouds, and some light precipitation on Thursday. The narrow band of precip will only be a few hundredths, but could see some mixed precipitation in the morning across western Minnesota based on the thermal profiles. Temperatures should warm close to 40 by Thursday afternoon as the precipitation changes over to all rain. .LONG TERM...(Thursday night through Wednesday) Issued at 300 PM CDT Wed Mar 15 2017 The longer term concerns are timing of a couple of fast moving fronts across the region and overall temperature trend. Initial cold front sweeps across the region Thursday night into Friday morning. We should see stratus lift into the cwa thursday evening per trend of 0.5Km condensation pressure deficits on most deterministic runs indicate saturation developing. SREF probs for <3 and <1sm are quite high >60% ahead of this feature. Models are not overall positive on QPF for the front...with any real chance of measurable over the far eastern cwa Thursday night. Models indicate could be a light mix...with surface temperatures forecast close to freezing and an elevated warm layer associated. Somewhat cooler air follows the front with a warming trend expected into the weekend. Forecast highs will be determined by the amount of snow cover that remains over the area. Much of it should be gone by later Sunday. The next front is forecast to move through Sunday night into Monday but models are trending dry at the moment. The 12z ECMWF which remains more progressive and weaker with the much of the energy rides north of the cwa. && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 659 PM CDT Wed Mar 15 2017 Narrow band of MVFR cigs that has been slowly moving across western MN during the afternoon is the first problem. 18z NAM and RAP soundings show this band making it to at least MSP, so brought it in at STC/MSP, left it out of RNH/EAU for now, but would get to these fields after 6z, so we`ll watch this cloud banks trend before bringing into WI. There is another batch of mainly mid- level clouds to about I-29 and this will work across the area tonight through Thursday morning. Biggest limiter for precip with these clouds is deep and dry sub-cloud layer, but looks like enough moistening happens Thu afternoon to start generating some precip in eastern MN/western WI, so introduced some vcsh to STC/MSP/RNH. Toward the end of the period, the NAM/GFS show the low levels moistening enough ahead of a front moving into western MN to allow low stratus to form. In all likelihood, the models are overdoing this moisture, so have a bit more conservative approach to the end of the TAF periods then the MAV/LAV and especially MET have. KMSP...MVFR clouds to the west have showed no signs in slowing down, so timed them in at about 5z. They have been hanging out at locations to the west for about 3 hours, so they will be out before the morning push starts. Confidence low on precip reaching the ground, but the threat is enough to allow for the introduction of a VCSH. Low confidence on CIGS in the final 6 hours. GFS/NAM would say we go IFR/low MVFR, but suspect that is over done. /OUTLOOK FOR KMSP/ Fri...MVFR/-SHRA possible early, then VFR. Wind NW at 10g25kt. Sat...VFR. Wind NW at 10kt. Sun...VFR with MVFR possible. Wind S at 15g25kt. && .MPX WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. && $$ SHORT TERM...JRB LONG TERM...DWE AVIATION...MPG
Area Forecast Discussion
National Weather Service San Angelo TX
1103 PM CDT Wed Mar 15 2017 .AVIATION... /06Z TAFS/ MVFR/IFR ceilings will develop at all sites early Thursday morning. VFR conditions will return to all sites by late morning or early afternoon. South winds of 6 to 12 knots overnight, will increase to 12 to 18 knots, with higher gusts, by late morning. && .PREV DISCUSSION... /issued 613 PM CDT Wed Mar 15 2017/ AVIATION... /00Z TAFS/ Stratus currently across the Interstate 10 corridor will spread north this evening, resulting in MVFR/IFR conditions first at the southern 3 sites, then spreading to KABI and KSJT by late evening or early Thursday morning. VFR conditions will return to all sites by late morning or early Thursday afternoon. Expect south winds of 6 to 12 knots overnight, increasing to 12 to 18 knots, with higher gusts, by late morning or early afternoon. PREV DISCUSSION... /issued 352 PM CDT Wed Mar 15 2017/ SHORT TERM... (Tonight and Thursday) Low level moisture continues to stream northward across West Central Texas this afternoon, with low clouds persisting from I-10 northward into the Concho Valley and Heartland. Clouds finally starting to lift and break up, allowing a little more sunshine and for temperatures to start climbing towards forecasted values. Cloud cover will return tonight, with the HRRR and the TTU WRF showing a little bit of drizzle or very light showers across the Northwest Hill Country. Will continue the mention of drizzle in the forecast for down there. Otherwise, cloud cover will keep temperatures a few degrees warmer over what we saw this morning, with lows in the mid and upper 50s. Similar day upcoming on THursday, with morning low clouds giving way to some afternoon sunshine. Temperatures will eventually be pretty close to what we are seeing today, with highs in the mid and upper 70s. Although it may take until late afternoon to get there. LONG TERM... (Thursday Night through next Wednesday) Warm and above normal temperatures are expected to prevail through the middle of next week for our area, with occasional shortwave ridging aloft. Winds will be mostly from the south during the next several days. A weak cold front could sag south into our far northern counties Friday night before stalling, then lifting back north as a warm front on Saturday. The possibility of showers and thunderstorms with this front looks to be just north and northeast of our area. Early next week, a cold front is progged to move south into the northern and western parts of our area on Tuesday before stalling. The GFS indicates a possibility of showers and thunderstorms with this front, and is faster with the timing than the ECMWF. With low certainty, keeping PoPs below 15 percent and will monitor model trends and consistency. Temperatures should be several degrees cooler behind this front across the northern part of our area. A deep upper trough is progged to move east across the western and southwestern CONUS on Wednesday, and across the Rockies Wednesday night. With an unstable airmass progged over our area with the approach of this system and associated cold front, the chance for thunderstorms could be increased by Wednesday night. && .PRELIMINARY POINT TEMPS/POPS... Abilene 57 78 59 85 / 5 5 5 5 San Angelo 58 77 59 85 / 10 10 0 5 Junction 59 77 60 81 / 10 10 5 5 Brownwood 55 75 58 83 / 10 10 5 10 Sweetwater 59 77 59 85 / 5 5 0 0 Ozona 58 77 58 83 / 10 10 5 5 && .SJT WATCHES/WARNINGS/ADVISORIES... None. && $$ Daniels