Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 11/07/17

Area Forecast Discussion
National Weather Service Burlington VT
702 PM EST Mon Nov 6 2017 .SYNOPSIS... Rain over southern Vermont will come to an end early this evening as a cold front exits the area to the east. We will still keep quite a bit of clouds around tonight with northwest winds bringing colder air into the region. High pressure builds into the region Tuesday into Wednesday for dry weather...but below normal temperatures. We briefly return to normal conditions on Thursday...but a trough of low pressure will bring a noticeable change to our weather with rain showers changing to snow showers and temperatures well below normal heading into the weekend. && .NEAR TERM /UNTIL 7 AM TUESDAY MORNING/... As of 643 PM EST Monday...Going forecast is in good shape with just some minor tweaks made to sky cover for the overnight. Latest HRRR has a very good handle on the areal coverage and depth of 1000-850MB moisture currently driving the low clouds across the region. Overnight, this moisture whittles away while upstream moisture stays north of the region. Not thinking this will have any effect on min temps, so left that intact. Previous Discussion...Cold front has yet to push south of the area this afternoon and as of 300 pm looks to be just south of a Montpelier to Middlebury line. South of this line a fairly widespread area of rain showers exists across south central and southern Vermont and should last over the area until early this evening when cold front finally moves east of the area. One item of note for tonight is there is still quite a bit of cloud cover over the area and feel it will not clear out as quickly as some of the data suggests. So have a much slower timing of clouds dissipating...but should eventually see some clearing after midnight. Lows will generally get down into the mid 20s to lower 30s with a few colder spots in the northern Adirondacks. && .SHORT TERM /7 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/... As of 257 PM EST Monday...a large area of high pressure builds into the region with dry weather expected through the entire time period. Flow aloft will generally be from the west and southwest through the period and temperatures will generally be below normal. Should still have some cloud cover around on Tuesday but Wednesday may be the day with more sunshine. && .LONG TERM /THURSDAY THROUGH MONDAY/... As of 331 PM EST Monday...While there are few timing differences in the medium ranged guidance, the consensus is setting up for an upper level trough to swing through just north of the Great Lakes and develop a northern stream surface low just north of the Ottawa valley. That low pressure system deepens and brings a cold front through the North Country with some light precipitation. Both the GFS/EC have the 0C 925/850mb temps well to the south so any precip that falls should be snow. The tightly packed thermal gradient will remain something to watch for as there could be enough dynamical support to generate some snow squalls but the good news with regards to impacts, is that the timing of the front will move through overnight limiting the overall impact of any such squalls. Temps will also be something to continue focusing on as a 1038mb high builds in over New York and New England and pushes the 925mb 0C line all the way to Virginia Friday night. Once again there are some timing inconsistencies so I`ve stayed closer to the more consistent EC with -6C to -12C at 925mb for lows Friday night and highs on Saturday. That leads to lows in the teens Friday night, highs in the 20s on Saturday except for areas near Lake Champlain which should warm to near freezing, and then single digits and teens overnight Saturday night. The pattern quickly moderates as zonal flow takes over and we warm back into the 40s for Sunday and Monday with lows in the 20s to 30s. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/... Through 00Z Wednesday...Cold front has finally cleared the area. MVFR ceilings continue through about 06z...before more noticeable clearing takes place. Winds will generally be from the northwest through the period at speeds of 10 knots or less. Outlook... Tuesday Night: VFR. NO SIG WX. Wednesday: VFR. NO SIG WX. Wednesday Night: VFR. NO SIG WX. Thursday: VFR. Slight chance SHRA. Thursday Night: VFR. Chance SHSN, Chance SHRA. Friday: Mainly VFR, with local MVFR possible. Slight chance SHSN. Friday Night: VFR. NO SIG WX. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...None. NY...None. && $$ SYNOPSIS...Evenson NEAR TERM...Evenson SHORT TERM...Evenson LONG TERM...Deal AVIATION...Neiles
Area Forecast Discussion
National Weather Service Columbia SC
616 PM EST Mon Nov 6 2017 .SYNOPSIS... High pressure in the forecast area will weaken tonight ahead of an approaching cold front. The front will be near the north part of the area Tuesday. It will sink just to the south Wednesday. Wet conditions will be associated with the front during the middle of week. Much cooler air will follow the front. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... Tonight a backdoor cold front will approach the extreme northern portion of the forecast. Although moisture will be increasing ahead of the front, we believe any showers will hold off until Tuesday morning. The RAP model also suggests shortwave energy will be moving east of the area late tonight which will help suppress development. Dense fog tonight seems unlikely due to increased mid-level cloudiness but cannot rule out some areas of fog, particularly in the CSRA. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY/... A frontal boundary will be near the northern portion of the forecast area on Tuesday. Expect the greatest chance of showers near the frontal boundary so have continued to indicate chance pops north and slight chance south. Confidence is lower than normal given the high spread in pop guidance. The MET has lower pops and keeps the front further north than the MAV. Model precipitable water values increase to around 1.6 inches by Tuesday afternoon which is around 175 percent of normal for this time of year. Instability appears weak Tuesday afternoon and evening with model LI values around -1 to -2. Have continued with mention of thunder Tuesday. It should remain warm south of the front Tuesday with highs in the mid 70s to lower 80s. Models show the boundary pushing south through the area Tuesday night and early Wednesday. Shortwave energy will cross the area on Wednesday enhancing rainfall potential. Have continued with likely pops. It will be cooler on Thursday behind the front and with clouds and rain in the area. Highs in the lower 60s. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... A southern stream trough will move from the Mississippi Valley region toward the Southeastern states on Thursday and shift off the coast on Friday. The frontal boundary will be along the coast on Thursday. Deep moisture will shift off the coast late Thursday into Friday as the trough pushes east. High pressure will ridge into the region for Friday and Saturday providing cool and dry conditions. Moisture may begin to increase toward the end of the period on Sunday and Monday. Temperatures will be near or below normal through the long term period. && .AVIATION /23Z MONDAY THROUGH SATURDAY/... Increasing low-level moisture may again bring visibility restrictions after 06Z Tuesday however mid-level cloudiness advecting east from the Upstate may preclude widespread dense fog. AGS and OGB will be the sites most likely to develop MVFR or lower visibilities. The backdoor front will approach the region late tonight and push into the northern forecast area near the end of the 24 hour TAF period. Showers and associated restrictions will be possible after 18Z Tuesday but confidence is low at this point. EXTENDED AVIATION OUTLOOK...Chance of rain with CIG/VSBY restrictions Wednesday through Thursday night as a front approaches. && .CAE WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. && $$ SYNOPSIS...99 NEAR TERM...99 SHORT TERM...99 LONG TERM...99 AVIATION...99
Area Forecast Discussion
National Weather Service Dodge City KS
758 PM CST Mon Nov 6 2017 .UPDATE... Issued at 757 PM CST Mon Nov 6 2017 Stratus dissolving rather quickly this evening. Lowered sky grids to 50% through midnight. Stratus trends tonight into Tuesday are uncertain, with competing forces from dry advection from the NE and upslope flow. If stratus fails to redevelop soon, low temperatures Tuesday will need to be lowered to the cold MET/MAV guidance (mid 20s). && .SHORT TERM...(This evening through Tuesday) Issued at 343 PM CST Mon Nov 6 2017 Water vapor loop and RAP analysis this afternoon showed a formidable shortwave trough along the northern branch of the upper level jet. This was diving southeast into southwestern Wyoming during the afternoon hours, with a few echoes showing up on radar mosaic across southeastern Wyoming. Response at the surface was becoming more noticeable as lowering pressure across southeastern CO with a 1007mb surface low centered from Trinidad, CO to east of Las Vegas, NM. Another surface weakness was developing across South Dakota. The South Dakota weakness will become squashed by much stronger anticyclogenesis at the surface across Montana tonight. This large surface high will expand southeastward rapidly tonight, which will actually help push drier surface air down into Nebraska and Kansas. The low level dry advection is expected to erode the lingering stratus on the east side overnight. Low level cyclogenesis tonight will be fairly weak, but still perhaps sufficient enough for development of patchy drizzle or even freezing drizzle across far west-central KS in the 06-12z time frame tonight. Several of the mesoscale models indicate this possibility, showing blotchy 0.01 inch QPF during this time frame along the CO-KS border north into northeastern CO. The upper level disturbance will continue to push southeast tonight, but stretching out as it enters the Rockies. This is now expected to limit 700mb frontogenesis tomorrow and tomorrow night to mainly eastern CO and adjacent far southwestern KS. POPs have been scaled back some across southwest KS, mainly northeast of a Garden-Dodge- Ashland line. Northeast of this line, there is an increasing likelihood that no precipitation will fall at all with this system. It does still appear, however, that around an inch of snow will fall in the far southwest, particularly Elkhart area. Most areas between Elkhart to Garden-Dodge will only see a few tenths of an inch of snow, if anything at all, given 1) strength of the surface high moving and associated low level dry air and 2) the track of the 500mb vorticity center tracking from western Colorado to the Texas Panhandle, keeping the best overall lift and attendant 700mb frontogenesis to the south of the southwest KS region. .LONG TERM...(Tuesday night through Monday) Issued at 119 PM CST Mon Nov 6 2017 A dry period is expected early in the period as medium range models indicate an upper level shortwave trough transitions southeast out of the Central Plains into the lower Mississippi River Valley, giving way to weak upper level ridging across the Intermountain West and a northwest flow aloft across the Western High Plains. With a significantly drier air mass settled across the region, any lingering precip chances due to the exiting upper level shortwave will quickly dissipate by Wednesday afternoon. The dry period will continue through Friday as the flow aloft becomes more zonal. Surface high pressure will shift eastward across the Central Plains Wednesday, returning a southerly flow to western Kansas. This will begin to slowly erode the colder airmass across the high plains with H85 temperatures climbing above 0C. Highs in the 40s(F) can be expected Wednesday afternoon. The warming trend will continue through the end of the week with highs pushing up into the 50s(F) Thursday with a few 60s(F) possible Friday. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 500 PM CST Mon Nov 6 2017 MVFR stratus cigs persist as of 23z, with a few breaks here and there. Complicated TAF package with regards to stratus trends, as strong surface high pressure builds into SW KS from the north. Expecting MVFR stratus to persist at the airports much of the night at all airports. A cold front with a reinforcing surge of cold/dry surface air will arrive around 12z Tue, increasing NE surface winds to 15-25 kts. Models show the stratus cigs slowly lifting into low end VFR at DDC/LBL daylight Tuesday, in response to dry advection in the boundary layer. MVFR stratus is most likely to hold at GCK, where VCSH was included after 18z Tuesday. Slim chance of drizzle or light snow at GCK after 18z, but kept out of the 00z TAFs with low confidence. Deeper in the incoming dry air mass, stratus may break completely at HYS after 18z Tuesday. && .PRELIMINARY POINT TEMPS/POPS... DDC 32 40 27 46 / 0 10 20 10 GCK 31 36 27 46 / 10 20 30 10 EHA 31 37 28 46 / 10 20 50 10 LBL 32 39 27 45 / 0 20 40 20 HYS 30 40 26 47 / 10 10 10 10 P28 35 45 30 47 / 0 10 30 10 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...Turner SHORT TERM...Umscheid LONG TERM...JJohnson AVIATION...Turner
Area Forecast Discussion
National Weather Service Goodland KS
432 PM MST Mon Nov 6 2017 .SHORT TERM...(This evening through Tuesday) Issued at 245 PM MST Mon Nov 6 2017 Main forecast issue will be an extended period of light freezing precipitation later on tonight into tomorrow morning. With stronger upslope today, clouds have held on longer with much cooler temperatures expected. Current satellite shows a rather dry air mass, above the saturated boundary layer moisture, over and upstream of our area. Fog just burned off in eastern Colorado. High resolution guidance, especially the Hrrr, is doing very well with current temperature and boundary layer moisture fields. The Hrrr caught the fog very well followed by the Rap. Freezing fog will redevelop roughly along and west of the Colorado border during the evening in advance of the develop precipitation does not look to start in the northern of our area until around midnight. With the westerly flow aloft, the expected deep dry air mass mentioned above will be slow to saturate. Nam forecast soundings were catching this reality of the thermal and moisture fields the best. So for most of the period from 06z tonight through the morning hours on Tuesday, the Nam is showing that there is no ice in the column, no elevated warm layer, and the sounding below 700 mb between -6 to -10C. So it looks like freezing drizzle and rain is expected from later this evening through the morning hours tomorrow. Precipitation amounts will be light, less than a tenth of an inch at this time, but most of that will be realized as ice. So as a result have issued a Winter Weather Advisory from 11 pm mountain tonight to noon on Tuesday for the western half of the area. It looks like the soundings get saturated deep enough to have ice in the column from late in the morning through the afternoon. So on top of any accumulating ice, will be a thin layer of snow. Temperatures will be going nowhere tomorrow and should not get out of the 30s. .LONG TERM...(Tuesday night through Monday) Issued at 410 PM MST Mon Nov 6 2017 H5 trough will move out of the region on Wednesday with a weakening ridge moving eastward out of the Great Basin. This will flatten as we head into Thursday, eventually becoming zonal going into Friday. A chance of snow or a freezing drizzle/snow mix will persist into the early morning hours on Wednesday, ending around sunrise. This will mainly be observed west of the Kansas/Colorado border and south of Interstate 70. Dry weather will prevail Thursday through Sunday with temperatures gradually warming each day. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 432 PM MST Mon Nov 6 2017 Light wintry precipitation may impact both terminals late tonight through Tuesday morning. Lowest cigs and best chance for any precipitation will be at KGLD where a period of freezing drizzle is expected transitioning to light snow and decreasing in coverage around 15Z. I have less confidence in these impacts at KMCK so I left FZDZ mention out during this update. I also can`t rule out brief drops to IFR cigs or vis, but trend for prevailing conditions is away from this and I kept CIGs about 1000ft AGL. VFR conditions are expected by the afternoon, however there is still a chance light snow could continue to impact either terminal into the afternoon hours Tuesday (though chances/confidence wasn`t high enough to keep this in the TAFs). && .GLD WATCHES/WARNINGS/ADVISORIES... KS...Winter Weather Advisory from 11 PM MST /midnight CST/ this evening to noon MST /1 PM CST/ Tuesday for KSZ001-002-013- 014-027-028-041-042. CO...Winter Weather Advisory from 11 PM this evening to noon MST Tuesday for COZ090>092. NE...Winter Weather Advisory from 11 PM MST /midnight CST/ this evening to noon MST /1 PM CST/ Tuesday for NEZ079-080. && $$ SHORT TERM...BULLER LONG TERM...TL AVIATION...DR
Area Forecast Discussion
National Weather Service Green Bay WI
518 PM CST Mon Nov 6 2017 Updated aviation portion for 00Z TAF issuance .SHORT TERM...Tonight and Tuesday Issued at 208 PM CST Mon Nov 6 2017 The latest RAP analysis and satellite/radar imagery show high pressure stretching from the northern Rockies into the western Great Lakes early this afternoon. A weak area of low pressure is moving east over western South Dakota, and is producing snow over eastern S.D. into southwestern Minnesota. Mid-level clouds are increasing across the southern two-thirds of Wisconsin, while last nights low clouds have retreated to the north shore of the Upper Peninsula. As this weak system moves across the region tonight, snow chances are the main forecast concern. Tonight...A sheared short-wave will move across the region, but weak lift and a lack of deep saturation will limit precipitation development. Progged soundings do moisten the sub-cloud layer below 5-6 kft, so think that some snowflakes could reach the ground though, mainly in the late evening to mid-overnight hours. Therefore, kept a chance of flurries over mainly north central WI, and a small chance of lake effect snow showers over northern Vilas county (winds are too westerly for any significant accumulations). Low temperatures should range from around 20 in north central WI to around 30 near Lake Michigan. Tuesday...High pressure will reassert itself as the shortwave departs to the east during the morning. As a result, clearing will progress from northwest to southeast through early afternoon. Despite abundant afternoon sunshine, temperatures will remain chilly, ranging from the upper 20s northwest to the upper 30s southeast. .LONG TERM...Tuesday Night Through Monday Issued at 208 PM CST Mon Nov 6 2017 Well below normal temperatures will continue on towards the weekend. A mid level trough will accompany another cold front Wednesday night into Thursday, for a chance to see some snowfall in northern Wisconsin. Some lake enhancement from Lake Superior will be possible for the far north affecting primarily Vilas and northern Forest counties. Northwesterly flow will continue through Thursday into Friday with the rest of the area remaining dry but much colder than normal. Any lingering snow showers will come to an end on Friday as the winds shift back towards the south. Expect a warming trend towards the end of the week and into the weekend, ahead of the next upper level trough. Active weather is expected Saturday into Sunday as high temperatures skirt around the freezing point. Mostly snow is expected in northern Wisconsin, with a chance to see some rain further south during the afternoon. Any precipitation that sticks around towards the end of the day on Sunday will return to snow. Highs will start in the 30s on Wednesday, before dipping into the 20s and upper teens on Thursday. A return to the 30s is in store over the course of the weekend. && .AVIATION...for 00Z TAF Issuance Issued at 515 PM CST Mon Nov 6 2017 Quiet weather and generally good flight conditions are anticipated during the next 24 hours, with just middle and high clouds passing through the region. Some Sc off Lake Superior may briefly work into north-central Wisconsin late tonight as low- level flow turns more northwesterly. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM.....MPC LONG TERM......Uhlmann AVIATION.......Skowronski
Area Forecast Discussion
National Weather Service Indianapolis IN
950 PM EST Mon Nov 6 2017 .UPDATE... The NEAR TERM and Aviation Sections has been updated below. && .SYNOPSIS... Issued at 254 PM EST Mon Nov 6 2017 A couple of waves will move along a front in the Tennessee Valley, bringing chances for rain to central Indiana tonight and Tuesday. High pressure will then provide dry weather through Friday. Another low pressure system will bring more rain chances for the weekend. Temperatures will remain below average. && .NEAR TERM /Overnight/... Issued at 950 PM EST Mon Nov 6 2017 Surface analysis late this evening shows weak low pressure in place over Arkansas. GOES16 shows clouds streaming east across Indiana within the flow aloft. Water Vapor shows a upper disturbance over middle Mississippi River Valley streaming northeast. Temps across the area were mainly in the 40s. Models suggest the upper wave to the southwest will continue to stream east and provide lift across southern Indiana as a surface low develops and strengths...passing along the Ohio River. HRRR suggests precipitation development overnight...mainly across the southern parts of Central Indiana. Thus have fine tuned pops a bit...focusing best pops mainly across the southern parts of Central Indiana. Given the expected clouds and rain...trended overnight lows warmer than the forecast builder blend. && .SHORT TERM.../Tuesday through Thursday/ Issued at 254 PM EST Mon Nov 6 2017 Models are close enough that the model blend initialization was accepted for most items. Decent forcing will be ongoing across the far southeast with the start of the Tuesday period so will go with likely PoPs there with chance or lower PoPs farther northwest. These will diminish during the morning as the forcing exits. Will go dry during the afternoon. Another system to the south will bring some PoPs to the far southwest Tuesday evening, but forcing is much weaker with this system. Will only go slight chance PoPs to low end chance PoPs there during the evening. Afterward high pressure will build in and keep conditions dry Wednesday and Wednesday night. A cold front will move in on Thursday, but with no moisture to work with, dry conditions should continue. Model blend temperatures look reasonable. && .LONG TERM /Thursday Night through Monday/... Issued at 227 PM EST Mon Nov 6 2017 A progressive and somewhat zonal upper flow will occur over the long term period. High pressure over the upper midwest Thursday night and early Friday will track east across the Great lakes brining cool and dry weather through early Saturday. A frontal system and low pressure will give us a chance of showers late Saturday into Sunday. The Canadian and GFS are a little faster with the best chances of rain being Saturday night and the Euro being a little slower with the best chances of rain occurring Sunday and early Sunday evening. Will go with a blend for now which is close to Superblend POPS. After Sunday it will be dry and cool as high pressure builds into the upper midwest and eventually our region. Concerning temperatures went near to slightly above...close to a Superblend MEX MOS blend. && .AVIATION /Discussion for the 070300 IND Taf Update/... VFR conditions are expected to continue the next several hours. Only minor changes to the ongoing TAF as MVFR Cigs should hold off until after 15Z. Previous Discussion Below /Discussion for the 070000Z Tafs/... Issued at 705 PM EST Mon Nov 6 2017 VFR Conditions are expected to deteriorate to MVFR/IFR CIGS overnight. A quick moving short wave was found across Southern Illinois and will push across the Ohio Valley tonight. Radar shows areas of rain over Western Kentucky and Illinois developing...pushing east within the flow. The bulk of this precip will remain close to the Ohio River, however best chances for impacts will be at the BMG TAF site...along with IFR conditions on Tuesday Morning as the surface low moves east across Kentucky. HUF and IND sites will mainly fall to MVFR conditions as the surface low passes to the south. Improvement to VFR is expected at all TAF sites by 21Z Wednesday as High pressure arrives from the northwest. && .IND WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...50 NEAR TERM...PUMA SHORT TERM...50 LONG TERM....JH AVIATION...JP
Area Forecast Discussion
National Weather Service Jackson MS
952 PM CST Mon Nov 6 2017 .UPDATE... Updated for evening discussion. && .DISCUSSION... Latest surface analysis indicates a stationary frontal boundary located over the extreme northwestern area of the CWA. Zonal flow aloft is allowing for only a slow southward progression of the front into the region, but nevertheless it is expected to continue its crawl through the area overnight and into tomorrow. Increasing cloudiness can be expected throughout the region tonight along with a slight chance of showers across the northern counties. Patchy areas of dense fog are possible after midnight across the southern counties, extending a bit farther northeast toward Meridian in eastern locations. Low temps will be in the mid to upper 60s across the CWA, with the chance for temps to cool a bit more in northwestern locations as cooler air filters in behind the front. /TH/ Prior discussion below: Tonight through Tuesday... Latest Rap and Satellite imagery showed flat ridging through the atmosphere. A stationary cold front was positioned just north of the forecast area where there was a big difference in temps. Readings south of the boundary were in the 70s and 80s to the north 50s and 60s. Area radars were picking up some showers north of the forecast area. For tonight latest CAM guidance shows some showers developing over our northern counties overnight. There may be some limited potential of some elevated convective potential. Guidance is also looking at some patch fog to develop generally along and south of interstate 20. It will be another mild night with above normal lows in the middle to upper 60s. Could see some near record high minimum temps overnight. For Tuesday expect the chances of rain to spread south to around the interstate 20 corridor as the cold front makes it way slowly to the south. There should be enough instability for some thunderstorms during the afternoon. At this time not seeing any strong thunderstorm potential. So as far as the short term is concern will keep the HWO clear at this time. Highs on Tuesday will range from the Lower 70s north to the lower 80s south./17/ Tuesday night through Sunday... Zonal flow will continue across the region and a cold front will slowly sag south across the area through Wednesday. This will continue to keep chances for rain and some storms in the forecast through Wednesday, with the highest chances of rain across central portions of the forecast area on Wednesday. Rainfall amounts of around 1-2 inches will be prevalent areawide, but it appears the greatest QPF amounts will be along the I-20 corridor. Given the relative dry nature of our weather pattern prior to this, flooding should not be an issue. Most of this rain should also not be very convective, which will also limit the potential for heavy rain and flooding. However, this rainfall should be much appreciated. By Wednesday night into early Thursday, the front will finally have a push to clear the region as a shortwave trough will push through. Rain will clear the southeast during the early portions of Thursday and a cooler, drier airmass will filter into the region. Temperatures through the end of the week into the weekend will feel a bit more like fall, with highs in the 60s and lows in 40s. By late in the weekend, another front will move through the region and bring another round of rain and storms with it. Behind this, shortwave ridging will once again move in. /28/ && .AVIATION... 00Z TAF discussion: VFR conditions early in the period will become MVFR by midnight and eventually IFR thereafter as low clouds and fog develop across the region. These conditions will linger through mid morning Tuesday followed by a slow rise in ceilings to MVFR. Showers and thunderstorms will develop in the vicinity of GLH, GWO, and GTR after midnight as a weak cold front moves into the area. The front will pass through these locations between 07/14Z and 07/18Z, but low flight categories will continue through the end of the period./26/ && .PRELIMINARY POINT TEMPS/POPS... Jackson 68 77 59 63 / 1 21 38 85 Meridian 65 79 60 65 / 1 21 29 84 Vicksburg 67 76 57 60 / 1 25 43 85 Hattiesburg 66 80 64 71 / 3 8 12 64 Natchez 67 77 59 63 / 1 13 40 73 Greenville 64 68 52 56 / 4 38 56 85 Greenwood 67 69 54 58 / 5 40 54 85 && .JAN WATCHES/WARNINGS/ADVISORIES... MS...None. LA...None. AR...None. && $$
Area Forecast Discussion
National Weather Service Melbourne FL
845 PM EST Mon Nov 6 2017 .UPDATE... ...Widespread low clouds with some areas of dense fog overnight... Tonight...A high pressure ridge over the northeast Gulf of Mexico and a weak inverted trough to our east will continue to provide northerly low level winds. This flow has certainly not been tapping any drier air, as afternoon dew points were in the mid-upper 60s, and even in the lower 70s along the coast. High pressure aloft should result in mostly clear skies, except along the Treasure Coast where some cloudiness and isolated showers will move down the Gulf Stream and push ashore. After 2 mornings with low stratus and fog, the pattern will remain favorable for another round to develop after midnight and become widespread. The HRRR model has been showing fog working down from the north with coverage similar to this morning, northward from about Okeechobee to Vero Beach. Cape Canaveral profilers show about 15 knot northerly winds in the boundary layer, so the lowest visibility should again be near/west of Interstate 4. Expect local/areas of dense fog to occur there in the pre-dawn hours. Don`t see anything substantial to change in the current forecast package. && .AVIATION... 00z TAFs were essentially unchanged from the previous set which somewhat mirrored what occurred early this morning. Areas of LIFR are expected again in the pre-dawn hours, especially ISM-MCO-SFB-LEE. Northerly winds may keep the low levels mixed enough to limit duration/extent of very low ceilings at the coastal terminals. && .MARINE... Tonight-Tuesday...Buoy 41009 has been reporting north winds around 12 knots most of the evening with seas close to 4 feet. Weak inverted trough is forecast to persist in the vicinity of the west wall of the Gulf Stream into Tue morning. This should maintain rather steady state winds and seas 3-4 feet. Widely scattered showers have been moving down the Gulf Stream and don`t anticipate any changes in that through Tue morning. && .MLB WATCHES/WARNINGS/ADVISORIES... FL...None. AM...None. && $$ Lascody/Sedlock
Area Forecast Discussion...UPDATED
National Weather Service Twin Cities/Chanhassen MN
601 PM CST Mon Nov 6 2017 .SHORT TERM...(This evening through Tuesday) Issued at 259 PM CST Mon Nov 6 2017 Very dry atmosphere in the lowest 5k has kept most of the measurable precipitation in far southwest Minnesota today. Area web cams have noted that portions of southwest Minnesota have seen a half inch to locally one or two inches of snow based on these web cams. Only favorable areas of receiving any measurable snowfall will occur along the Minnesota River Valley, south to the Iowa border through the early evening as this system continues to weaken. Any farther to the north, the drier air mass will keep most of the area precipitation free, with only a few flurries possible. Forecast concerns tonight relate to the current run of the HRRR, ESRL HRRR, and RAP which all noted some measurable snow this evening in west central Minnesota where another weak disturbance moves across the Dakotas. Although this is noted early this afternoon on regional satellite imagery in southern Montana, there remains no significant trigger for development of bands of light snow, only a few flurries at best in Minnesota. Later forecasters can see how well organized this system becomes this evening as it moves across the Dakotas. Otherwise, a slow decrease in the cloud cover is expected tonight, but temperatures will fall into the teens in central Minnesota, to the 20s elsewhere. .LONG TERM...(Tuesday night through Monday) Issued at 259 PM CST Mon Nov 6 2017 Precip wise, the weather for the next week looks fairly quiet, with the only meaningful chance for precip coming Saturday with what is increasingly looking like a minor system at best. For temperatures, it will be cold this week, especially Thursday, but a warmup back to and even above normal still looks on track for next week. Looking at the large scale, the dominate weather feature for this week will be an anomalously deep h5 low dropping down around Hudson Bay Thursday/Friday, which will bring us a hit of modified arctic air to end the week. For the weekend, we`ll see the flow flatten out, while next week the flow will become quite amplified in the Pacific, with a ridge building into the Bering Sea and a trough digging across the eastern Pac. This will send a ridge up our direction and finally give us a reprieve from this prolonged stretch of colder than normal weather that set in back on the 27th of October. Though cold, we`ll actually start out Wednesday in a warm sector ahead of a cold front passing through. GFS is quite a bit faster than the ECMWF and NAM with this FROPA and looks too cold for highs Wednesday, so favored the forecast toward the warmer ECMWF/NAM, with a decent shot at hitting 40 up to a Morris/St. Cloud/Chippewa Falls line. Moisture with the front is lacking and forcing with it`s parent upper wave in terms of PVA will be going from NW MN over to northern lower MI, so we`ll be getting a glancing blow from this, with only small chance for a quick hit of light snow behind the front (but ahead of the shortwave) north of I-94. Behind the front, h85 temps will be 10 to 20 degrees C below normal for Thursday, so although a good 20ish degrees below normal, current forecast highs in the upper teens to mid 20s for Thursday look good. Going into Friday, the question becomes how quickly does the warm air return as we get on to the back side of the Canadian high. GFS, which looks too quick with bringing the front in Wednesday also looks too quick with bringing the warm air back on Friday, so went closer to the ECMWF for highs on Friday, which are only a couple of degrees warmer than what is expected for Thursday. The one thing that may need to be changed in the coming days for Friday is to boost winds some as the pressure gradient gets cranking between the departing 1040mb high over the Great Lakes and the 1005mb low pressure trough moving across the Dakotas. Forecast soundings off the 06.12 GFS in western MN Friday show top end potential for sustained southeast winds in the 25-30mph with gusts to around 40 mph. For the weekend the flow will become more zonal as the Hudson Bay low lifts off toward Greenland. There will be at least one wave heading across the upper MS Valley this weekend, but models still disagree a bit on details. The key differences deal with a wave that will come onshore in the Pac NW on Friday. This wave will be splitting apart as it comes across the Rockies. The ECMWF keeps two distinct waves with this system, one going across southern Canada Friday night/Saturday, with a second southern stream wave tearing off and going from CO Saturday into the Ohio Valley Sunday. The GFS/GEM are not as aggressive with splitting this wave apart on Friday and instead bring a single wave across upper MS Valley Saturday that deepens to our east on Sunday. The net result is the ECMWF shows nothing happening, while the GFS/GEM continue to break out some light precipitation ahead of the wave Saturday, especially along/east of I-35, with the GFS warm enough to have the majority of that precip come as rain. So even if we do end up getting something, the probability of a high impact winter event looks pretty low. Sunday, we`ll see a surface ridge move through, which will help hold our temperatures in the 30s, but by Monday, we`ll see ridging building up out of the southern Plains which will send our highs back up into the 40s, with some 50s not out of the question as we go through the course of next week. In fact, when you look at the frequency of 50+ highs in the Twin Cities for the month of November, you have to go back to 1997 to find a November that produced zero highs at or above 50, with the fewest number of 50+ highs since then at 4, so we likely still have a couple of 50 degree highs left in us before we go all out winter mode. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 601 PM CST Mon Nov 6 2017 VFR conditions expected, except across southwest MN where MVFR cigs should develop a bit later this evening. A few flurries are also possible there through the evening. Drier air will work in from the north Tuesday with clearing skies expected mid morning onward. KMSP...No additional concerns. /OUTLOOK FOR KMSP/ Wed...VFR. Wind SW 5-10 kts, becoming northwest. Thu...VFR. Wind NW 10-15 kts. Fri...VFR. Wind SE 10-15 kts. && .MPX WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. && $$ SHORT TERM...JLT LONG TERM...MPG AVIATION...BORGHOFF
Area Forecast Discussion
National Weather Service Marquette MI
715 PM EST Mon Nov 6 2017 .SHORT TERM...(This evening through Tuesday) Issued at 258 PM EST MON NOV 6 2017 Water vapor imagery and RAP analysis show broad troffing from the nw CONUS to the Upper Great Lakes with a shortwave swinging across Manitoba. At the sfc, high pres is ridging from the Dakotas to Lower MI. Position of the high pres ridge combined with approaching shortwave over Manitoba has resulted in winds backing w to wsw today, causing light LES, mostly just flurries, to shift n. This has also allowed skies to clear out in areas where flow off Lake Superior has been lost. Short term part of the fcst will be affected by shortwave currently over Manitoba. This wave will swing across Lake Superior tonight, providing a brief period of weak synoptic forcing, mainly during the evening. As the wave passes, fcst soundings show a very brief lifting of the inversion which is initially based at 4-5kft. With Lake Superior sfc water temps roughly around 7C, air mass will be plenty cold enough to support LES as 850mb temps of -8 to -10C to start the evening fall to -12 to -13C by morning before moderating back to -8 to -10C by late Tue aftn. However, as has been the case since last evening, fcst soundings continue to show a well- mixed boundary layer (inverted-V profile) which is a negative for LES. The negative impact of the dry air/well-mixed boundary layer was evident this morning as LES remained light even with the 850mb temps of -10/-11C. So, while passing shortwave will give LES a bit of a boost as will the colder air arriving overnight, LES probably won`t produce more than an inch or two of accumulation where -shsn are most persistent. Longer fetch will provide better lake moistening of the boundary layer into the ne fcst area, so heavier shsn will affect that area. In addition, subtle wind shift as sfc trof drops across Lake Superior will lead to a band of at least mdt shsn moving onshore over the ne fcst area late tonight/early Tue morning, and that may end up producing the bulk of the snow accumulation. Increasingly anticyclonic low-level flow and lowering inversion will cause LES to diminish from w to e during Tue. Backing winds ahead of the next approaching low pres trof will also shift the lingering LES to the n with time and will allow for increasing sunshine from sw to ne. LES should end over the w in the early aftn and e of Grand Marais by evening. .LONG TERM...(Tuesday night through Monday) Issued at 316 PM EST MON NOV 6 2017 Overall, confidence has increased in the timing and magnitude of the first, early taste of winter across the Upper Great Lakes. This colder, arctic air is expected to impact the region Thursday through Friday and will bring moderate to heavy lake effect snow primarily across the northwest wind snow belts. Temperatures will warm back up towards seasonal this weekend into early next week, but precipitation chances may linger through the weekend. Tuesday night and Wednesday: Expect dry conditions to start off with increasing cloud cover as surface ridging briefly clips the region ahead of an advancing weak surface trough from the north. With colder air beginning to filter south along and behind this surface trough, expect 850mb temperatures to cool down enough for lake effect snow showers to begin in the west wind snow belts towards the end of the day on Wednesday. Wednesday night through Friday: Quasi-zonal flow is progged to become highly amplified across the Upper Great Lakes as a potent shortwave digs south from Canada. Due to the strong cold air advection along and behind this shortwave, expect moderate to heavy lake effect snow to develop initially in the northwest wind snow belts Wednesday night into Thursday. Further inland from Lake Superior, as the main shortwave digs across Upper Michigan snow will also be possible down to the Wisconsin border. By Thursday afternoon, snow across the interior central will diminish while lake effect snow continues as the main trough axis shifts east of the region. With 850mb temperatures progged to drop to around -20C at times, ample lake-induced CAPE and inversion heights approaching 10k feet will be more than sufficient to support a convective boundary layer. With the above mentioned cold air advection, forecast soundings also show ample lift and cloud depth through the DGZ, which will allow for efficient ice production, and thus higher snowfall rates. Therefore, have increased QPF and kept the trend of increasing SLRs, and thus accumulating snow, in the northwest wind snow belts to account for this Wednesday night through Thursday. Along with the accumulating lake effect snow gusty northerly winds will spread across the area, especially near the shore of Lake superior. This will likely result in reduced visibilities as SLRs should become high enough to transition over to fluffier snow. Late on Thursday through Friday, expect the lake effect to diminish from west to east across Upper Michigan as a strong arctic high pressure system slides across the region. Temperatures during this time period will definitely provide the first taste of winter for the region. The strongest cold air advection is expected to arrive during the day and overnight hours on Thursday. Therefore, expect temperatures to fall through the day on Thursday across much of the area. In fact, by the afternoon hours temperatures may only top out in the teens across portions of the west and central. Gusty northwest winds will make it feel even colder out, with wind chill temperatures only approaching the single digits to teens in some locations. Thursday night into Friday morning, overnight lows are expected to drop into the single digits across the interior west and central, and into the teens elsewhere. The combination of the cold air mass and lingering breezy winds will make conditions feel around or just below zero across the area during the overnight hours. The up and coming weekend through early next week: An active pattern is progged to develop this weekend into early next week, fostering additional widespread and lake effect precipitation chances. The above mentioned surface ridge will quickly slide east of the region and we will get back under a quick shot of return flow ahead of an approaching shortwave for Saturday. The medium-range models disagree on the strength of this wave, but with the main trough axis tracking across the region with broad warm air advection, this should foster widespread light snow on Saturday. As the main trough axis pushes east across Upper Michigan, another round of cold air advection will push southeast across Upper Great Lakes Saturday night into Sunday. This will allow any lingering widespread snow to transition to lake effect snow in the northwest wind snow belts by Sunday. Early next week, ridging is progged to build across the region and should favor a warm up. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 659 PM EST MON NOV 6 2017 VFR conditions at the TAF sites will give way to MVFR conditions in lake effect -shsn at KCMX and KIWD later tonight as a disturbance and associated sfc trof pass across the area and winds veer more to the nw across Lake Superior. Downslope nature of the wind at KSAW should maintain VFR conditions at that terminal. Westerly winds and increased mixing across the lake will lead to gusty winds above 20 knots at times at KCMX. Expect improvement to VFR at KIWD and KIWD by Tue afternoon as winds back sw and push lake effect bands north of these sites. && .MARINE...(For the 4 PM Lake Superior forecast issuance) Issued at 258 PM EST MON NOV 6 2017 Low pres trof will drop se across Lake Superior tonight. Ahead of the trof, westerly winds of 20-30kt will prevail with perhaps a few gale force gusts. In the wake of the trof, winds will diminish from w to e late tonight/Tue morning, leading to a short period of winds under 20kt. Winds will then quickly ramp up again from w to e Tue aftn/evening ahead of the next approaching trof. There should be a period of gales over portions of w and central Lake Superior Tue night. Winds will diminish a bit Wed. In the wake of the trof, a very cold air mass for this time of year may lead to gales on Thu, especially over the e half of Lake Superior. Winds will diminish from w to e Thu night/Fri, down to under 20kt for a time as a high pres passes. Winds will then ramp up again into Sat ahead of the next approaching low pres trof. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... None. Lake Superior... Gale Watch from Tuesday evening through Wednesday morning for LSZ242>244-263-264. Lake Michigan... None. && $$ SHORT TERM...Rolfson LONG TERM...Ritzman AVIATION...Voss MARINE...Rolfson
Area Forecast Discussion
National Weather Service Omaha/Valley NE
528 PM CST Mon Nov 6 2017 .SHORT TERM...(Tonight through Thursday) Issued at 248 PM CST Mon Nov 6 2017 WV imagery this afternoon showing that the large scale pattern has amplified a bit since yesterday in part to a positive tilt trof currently extending from the Pac NW into central Canada. At the surface...a large area of high pressure was in control over the majority of the eastern half of the CONUS. The going forecast is in pretty good shape...only minor tweaks needed. The chance for light snow continues over portions of the northern CWA tonight. Lift will increase withe approach of an elongated vorticity channel dropping out of the northern Plains. Upper level Qvec convg...per both the NAM12/GFS20...suggests lift via DPVA will be able to overcome the deep layer cold air advection settling in. At any rate...the potential for light snow accumulation will be focused over northern NE as well as extreme southern SD. All told...the HRRR and RAP12 advertise accumulations by events end Tuesday morning up to about half inch. Otherwise...Dry and cold Tuesday through Thursday with highs generally in the mid 30s-low 40s and lows in the low/mid 20s. .LONG TERM...(Thursday night through Monday) Issued at 248 PM CST Mon Nov 6 2017 No major changes planned in the extended periods. Dry and cold will be the rule heading into next weekend with highs in the mid 40d. Through next weekend both MAV/ECM MOS meteograms suggest a modest warming trend with highs topping out in the low 50s. Precip chances continue then Friday night/Saturday morning associated with a Pac NW shortwave trof crossing into the central Plains. As of now...dominate precip type is progged to be rain. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 527 PM CST Mon Nov 6 2017 At KOMA and KLNK, VFR conditions are expected through the TAF cycle. At KOFK, light snow may affect the site later tonight into Tuesday morning. Winds will remain light at all sites, with speeds mainly around 6kt or less and direction shifting from east/northeast to north and northwest by the end of the TAF cycle. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...None. IA...None. && $$ SHORT TERM...DEE LONG TERM...DEE AVIATION...Mayes
Area Forecast Discussion
National Weather Service Nashville TN
725 PM CST Mon Nov 6 2017 .UPDATE... FOR EVENING DISCUSSION. && .DISCUSSION... Latest radar imagery shows widespread light to moderate rain with a few embedded thunderstorms continues to spread eastward across Middle Tennessee, now entering the Upper Cumberland. Regional radar imagery shows activity still extends westward into Arkansas, so off and on rain with some lightning and thunder will continue through the night before ending from west to east after sunrise Tuesday morning. Have raised pops this evening and tonight in line with latest HRRR model runs. Surface observations show frontal boundary has sagged southward to just south of the Alabama border, with all of Middle Tennessee now in the stable cool surface layer north of the front. Temperatures will therefore remain steady or only drop slightly the rest of the night. OOZ OHX sounding shows elevated instability up to 250 J/Kg is present north of the front along with deep layer shear up to 55 knots, so cannot rule out an isolated strong storm or two with small hail overnight - mainly across southern counties closer to the surface front. && .AVIATION... 00Z TAF DISCUSSION. A boundary is situated across Southern TN and a low will ride along this boundary tonight and tomorrow. This will give the possibility for thunderstorms tonight area wide...with a few strong storms possible across the south. The main threat will be hail and wind. With the boundary in place all TAF sites will see mainly IFR conditions. It might even be LIFR around 12Z and in and around thunderstorms. Hopefully visibilities will improve after 18Z and ceilings will improve to MVFR around 00Z Wednesday. && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ DISCUSSION......Shamburger AVIATION........12
Area Forecast Discussion
National Weather Service Blacksburg VA
636 PM EST Mon Nov 6 2017 .SYNOPSIS... A cold front will travel east across the Appalachians into tonight. Behind the front, high pressure with much cooler air will then wedge down east of the mountains tonight. A series of waves will then ripple through the region and bring a good chance of rain to the forecast for Tuesday and again on Wednesday. && .NEAR TERM /THROUGH TUESDAY/... As of 635 PM EST Monday...Cold front roughly bisects the forecast area at this hour, extending from Fredericksburg southwestward into Amherst County on through the New River Valley into the eastern TN Valley in VA/TN. Still somewhat marginally unstable ahead of the front in the Piedmont to spark some scattered moderate showers through mid-evening. More significant change in sensible wx conditions awaits behind the front, with cooler/drier air and post-frontal stratus now beginning to plague much of the western Appalachians in WV and VA, with lowering trend in ceilings taking place in the New River Valley. Expect overall similar trends with lowering/thickening clouds initially west of the Blue Ridge, but later in the overnight in the Piedmont. May see some patchy fog in the western mountains develop as well as brief period of NW winds subside to calm, but winds likely stay up enough overnight in the Piedmont to mitigate any fog development there. Front more or less stalls near or just south of southwestern VA overnight as we await the weak mid-level impulse and strong burst of 925-700 mb warm advection now across western TN. 18z NAM/GFS guidance has started to speed up timing of rain closer to the pre-dawn hours. Will not make changes as yet, but it is possible that upward alterations to PoPs/Wx may be needed later this evening if trends continue. Previous near-term discussion issued at 304 PM follows... A cold front located in the mountains this afternoon will travel southeast this evening into tonight as a wave of low pressure lifts northeast into Tennessee by Tuesday morning. The combination of mixing and downsloping winds has scour out the low clouds with the lingering wedge east of the Appalachians. SPC Day One convective outlook has back off of the marginal threat for Virginia and trimmed back the general thunderstorms for the western mountains. The best threat for any severe thunderstorms will occur to our west from the Ozarks to parts of Tennessee and Kentucky. For our area, the threat severe weather is minimal with the weak thermodynamic parameters. Used a blend of the HRRR and Conshort for pops allowing for isolated to scattered convection this afternoon into this evening, then a expect a break in the action early tonight as high pressure over the upper midwest strongly wedges into the region. Added some patchy fog tonight especially in the western valleys. The wave moving out of the Mississippi valley will approach from the west late tonight. This wave will run over the top of the wedge and create enough lift to spread a chance of rain back into the west late tonight into Tuesday morning. Cooler air arrives with the wedge tonight. Low temperatures tonight will range from the lower 40s in the north to the mid 50s along the southern Blue Ridge mountains. The unsettled weather will continue into Tuesday as an initial upper level shortwave generating strong isentropic lift moves through The area. On Tuesday, PWAT values surge to 200% of normal and strong lift over the low level wedge should generate some moderate rains. Utilized WPCGUIDE for QPF with the heaviest noted across the northwest on the GFS and ECMWF. With these QPF values for Tuesday, any flooding issues would be minor. Because of the solid wedge in place, the best chance for thunderstorms will be confined to the far southwest/western portions of the forecast area where there is some instability and a small probability of CAPES reaching 500 j/kg. High temperatures on Tuesday will vary from the the mid 40s in the north to around 60 degrees in the far west. && .SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/... As of 304 PM EST Monday... Frontal boundary draped across the Gulf Coast States to the NC/SC coast will keep our weather on the wetter side this period as upper flow remains parallel to the front with little movement expected. Waves of low pressure will ride along the front and drive moisture northward into the Virginias into Wednesday night. The wetter period looks Tuesday evening, with a gradual shift southward in the precip coverage over time as a northern stream wave drives southeast into the Great Lakes by Thursday. Temperatures will remain on the cool side thanks to an easterly flow, with highs Wednesday and Thursday mainly in the 40s, with some 50s piedmont Thursday. By Thursday night, northern stream front will be riding east of us with clearing taking place as strong high pressure works into the Western Ohio Valley. Should be chillier by Friday morning with lows in the lower 30s with mid to upper 30s east. && .LONG TERM /FRIDAY THROUGH MONDAY/... As of 304 PM EDT Sunday... Cool high pressure will work from the Great Lakes/Ohio Valley Friday into the Northeast U.S. by Sunday. This will keep us dry and cooler than normal for the Friday-Saturday time frame, but return moisture ahead of the next front may bring a cold rain to us Sunday into early Monday. The pattern actually favors freezing precipitation as warmer air overrides the colder air but this far out will be having mainly rain, at times mixed with snow in the mountains late at night/early morning time frame. At the same time models show differences on the strength on the high and next system, with the GFS weaker. Another thought is November climatologically is not favorable for much ice of any consequence for our area. && .AVIATION /23Z MONDAY THROUGH SATURDAY/... As of 635 PM EST Monday... Generally VFR (except MVFR for Lewisburg and Bluefield) conditions as cold front makes eastward march across the Blue Ridge. May see a few showers from these but unlikely to develop to the point where they would cause significant restrictions. Conditions then deteriorate around 03z, becoming quite messy with poor flight conditions through the rest of the TAF period. Look for a west to east lowering in ceilings with post-frontal MVFR to LIFR stratus and associated MVFR to LIFR at times. Confidence is moderate on at least MVFR to IFR ceilings, but is lower on LIFR ceilings. May see periods of patchy mist or fog set in after midnight mainly in the western mountains. Have poor confidence on how low visibilities may get and when any fog may lift as OVC skies opens questions on radiational cooling. Offered a 2SM BR for Blacksburg, Lewisburg and Bluefield with this TAF. Winds appear too strong in the Piedmont for any mist or fog. After a brief period of NW winds 3-6 kts, expect a veer to northeast/east 4-8 kts in the Piedmont, but trend variable west of the Blue Ridge overnight. We will then await the warm front now making its way across the western TN Valley. 18z guidance brings 5-6 SM frontal rain into the region between 10-18z, with P6SM- type showers thereafter. Expect very limited change in ceilings overnight through Tuesday, with IFR to MVFR being common. Southwesterly 35-kt low-level jet overlying light east winds at surface may allow for occasional low-level wind shears particularly in the mountains of NC and far southwest VA but unlikely at any TAF. Extended Discussion... This entire system should move east and off the coast by Wednesday. In general, first half of the week looks unsettled with a high likelihood for sub VFR conditions followed by slow improvement to VFR by Wednesday or Thursday pending just how fast the boundary pushes to the south by midweek. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...None. NC...None. WV...None. && $$ SYNOPSIS...KK NEAR TERM...AL/KK SHORT TERM...WP LONG TERM...WP AVIATION...AL/KK
Area Forecast Discussion
National Weather Service Shreveport LA
936 PM CST Mon Nov 6 2017 .UPDATE... The cold front has pushed a bit farther southeastward than initially forecasted, as it was located along a Hope AR to near Vivian LA to north of Jacksonville TX line. The HRRR seems to have an excellent handle on the cold frontal propagation and as such, should reach Shreveport shortly before midnight tonight. Have therefore adjusted the forecast to reflect this trend. Furthermore, temperatures have fallen a bit faster post-frontal across southeast OK and extreme northeast TX and southwest AR thus, lowering the min temperatures several more degrees seems justified /lower 50s northwest to middle to upper 60s south/. Also tweaked the dewpoint temperatures and relative humidity values as a result of the faster frontal propagation. Computer models continue to hint at the potential for post-frontal light precip so have held onto slight chance POPs mainly near and north of the Interstate-20 corridor tonight. Had to insert light patchy fog across southwest AR as a few 03Z metars are reporting this occurrence, and also added a fog mention across deep east TX and central LA overnight given low temperature-dewpoint spreads /and several computer models hinting at this plausibility/. && .PREV DISCUSSION... /issued 554 PM CST Mon Nov 6 2017/ AVIATION... For the 07/00z TAFs, ceilings are expected to gradually deteriorate into the MVFR range areawide by 07/06z. Flight conditions will likely continue to fall into the IFR range at most sites through the overnight hours. Some patchy drizzle is also possible before sunrise. MVFR/IFR ceilings will persist for the remainder of the period. Scattered showers are expected to develop by late morning as a cold front begins to slowly move across the area. CN PREV DISCUSSION... /issued 222 PM CST Mon Nov 6 2017/ DISCUSSION... Another very warm November day across the entire Four State Region today with Shreveport having already eclipsed yet another record high with us sitting at 87 degrees as of this writing. Mid 80s are common across all areas along and south of the I-20 Corridor this afternoon with temperatures north of the corridor near 80 to the middle 70s across the Middle Red River Valley of Southeast Oklahoma. This should be the last day of threatened record high temps as a slow moving, yet potent, cold front will be working its way into our region overnight from the north and west. This front has finally begun moving very slowly south and east this afternoon and as of 20z was located near a Mena, Ar. Idabel, Ok. Mineola, Tx. line. Given the shallow nature of the cooler post frontal airmass, the front has had a difficult time clearing the Ouachitas which is often the case with these airmasses but the airmass should win out overnight. The front should be near a Palestine, Tx. Shreveport, La. to El Dorado, Ar. line by 12z Tue and through all but our extreme southeast zones by 00z Wed. Cannot rule out some spotty showers along the southeastward moving frontal boundary overnight but the models have been overdoing our rain chances last night and today so have lowered overnight pops to slight chance variety across our northwest half late. Obviously a big spread in overnight min temps tonight as well with lower 50s possible across Northern McCurtain County to near 70 across our southern most zones. Kept some post frontal light rain chances going during the day Tuesday across most of the region but the cooler temperatures will filter into the region behind the cold front as we await the big weather maker in the form of a shortwave trough moving into the Southern Plains late Tue Night. Isentropic lift over top a much cooler boundary layer Tue Night appears to be much weaker than what the models showed this time yesterday so have shaved pops slightly for Tue Night but regardless of when the precip begins, Wed looks very wet as PVA will be very strong with the above mentioned trough as it moves into the Mid Red River Valley. Could easily see rainfall amounts of 1-3 inches when it`s all said and done with the rain pulling out of our region late Wed Night/very early Thu morning. Cannot rule out some elevated embedded thunder with this widespread rainfall event but no severe weather is expected Northwest flow aloft follows the trough for the end of the work week but ridging quickly moves east of our region Fri Night with another much weaker trough moving across the plains and another cold front swinging through our region late in the day Saturday or Sat Night. Not much moisture return with this trough but the models continue to spit out some moisture along the above mentioned frontal boundary so kept this kind of wording for the weekend as well. Prelims to follow...13. && .PRELIMINARY POINT TEMPS/POPS... SHV 65 75 55 55 / 20 30 50 80 MLU 67 77 56 56 / 10 30 50 80 DEQ 54 60 50 50 / 20 30 50 80 TXK 59 63 51 51 / 20 30 50 80 ELD 63 67 51 51 / 20 30 50 80 TYR 61 69 50 50 / 20 30 50 80 GGG 63 72 53 53 / 20 30 50 80 LFK 68 80 57 57 / 10 10 50 80 && .SHV WATCHES/WARNINGS/ADVISORIES... AR...None. LA...None. OK...None. TX...None. && $$ 29/09/13
...Update to aviation forecast discussion...

.SHORT TERM...(This evening through Tuesday) Issued at 401 PM CST Mon Nov 6 2017 The coverage and timing the front edge of the current stratus deck, along with whether it will generate any drizzle tonight, is the primary challenge for the tonight and tomorrow forecast period. Broad zonal upper level flow was present across the central U.S. this afternoon with a coupled jet streak feature noted over the area- -bringing light snow to the Siouxland. At the surface, a large high pressure ridge extended across the Northern Plains and was exerting its influence across northeast Kansas in the form of a modest northeasterly wind. This wind and associated weak near-surface CAA kept temperatures 10-20 degrees below average for this time of year despite ample sunshine over much of the area. However, flow at 925- 850mb had backed to the S/SE, allowing a higher theta-e plume/low stratus clouds to begin working northwestward back across southern portions of the forecast area. The leading edge of the stratus was along a line from Newton to Lawrence at 21Z. Leaned heavily on the NAM/RAP/HRRR for timing of this stratus deck...which resulted in pushing the edge of the stratus further westward with this update. Expect that the stratus will reach Topeka around 00Z--with the edge of the clouds remaining just to the north and west of the city. Low clouds look to linger through the overnight areas east of the Flint Hills with moisture confined to 850mb and below. RAP BUFR soundings depict enough lift within this layer to possibly generate light drizzle--primarily along and southeast of I-35--though there is a chance that Topeka and Lawrence will see some drizzle. Continued CAA ahead of the advancing high pressure cell resulted in lowering max temps for tomorrow a few degrees from the going forecast. Also kept overcast skies for a longer period in the east per recent short-term guidance solutions. .LONG TERM...(Tuesday night through Monday) Issued at 401 PM CST Mon Nov 6 2017 Elongated upper trough axis over the CO Rockies gradually drops southeast towards the southern plains Tuesday evening through Thursday. Much of the available qpf resides south and west of the CWA as the weak frontal boundary passes through dry on Thursday. Upper riding is temporary through Friday before the next progressive shortwave trough impacts the Midwest late Friday evening into Saturday. Extended guidance is more on track with the GFS, ECMWF, and Canadian models than previous runs with the qpf amounts increasing across the eastern half of the CWA. Precip type remains as rain with the lack of a colder airmass behind the boundary. Temperatures improve throughout the week into the lower to middle 50s from Friday onward. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 451 PM CST Mon Nov 6 2017 Forecast for lower cigs to move into TOP/FOE only adjusted a few hours, as still anticipate stratus to advect in this evening. Clouds remain through the overnight, should lift to MVFR then VFR through the day Tuesday. May see drizzle near TOP/FOE but chances too low to include this far out. && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Skow LONG TERM...Prieto AVIATION...67