Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 11/09/23


Area Forecast Discussion
National Weather Service Jacksonville FL
817 PM EST Wed Nov 8 2023 ...New UPDATE... .UPDATE... Issued at 815 PM EST Wed Nov 8 2023 For the latest NE FL and SE GA Daily Key Messages please visit: https://www.weather.gov/media/jax/briefings/nws-jax-briefing.pdf High pressure was analyzed around 1019 mb over northeast FL with light to calm winds over the forecast area. This high will not move much into Thursday morning. Only a few high clouds over the area at this time, but will increase a bit into Thursday. Guidance shows potential for patchy to areas of fog, which appears reasonable based on the fact that dewpoints have increased several degrees compared to 24 hrs ago, mainly over northeast FL. The higher threat for some stratus and fog, using HRRR and HREF progs, looks to be near the far western areas so have bumped up fog coverage for the Suwannee Valley area early Thursday morning. The forecast remains on track with little overall change with a slight decrease in the min temps based on the past couple of days. For the marine forecast, little change with just a slight decrease in winds and seas tonight. && .NEAR TERM... (Through Tonight) Issued at 223 PM EST Wed Nov 8 2023 For the latest NE FL and SE GA Daily Key Messages please visit: https://www.weather.gov/media/jax/briefings/nws-jax-briefing.pdf Surface high pressure over the area will slowly shift into the Western Atlantic with ridge axis just south of the NE FL/SE GA region Tonight. Sunny skies still on track this afternoon along with above normal temperatures into the lower to middle 80s inland, while weak east coast sea breeze development will hold Atlantic beach highs in the upper 70s as it pushes slowly inland later today. A few high clouds push in aloft from the West- Southwest tonight but still overall Mostly Clear conditions as initial high clouds should be fairly thin and not much impact expected to overnight lows which will continue below NBM guidance by 2-4 degrees with Min Temps around 50F over inland areas and generally in the mid/upper 50s along the Atlantic Coast. Models have continued to struggle with late night fog formation this week, with very little fog this morning (likely due to the lack of recent rainfall), but the transition to a light Southwest steering flow tonight in the boundary layer should add enough low level moisture to produce more patchy/areas of fog towards Thursday morning, mainly across NE FL with some locally dense fog possible around sunrise. && .SHORT TERM... (Thursday through Saturday night) Issued at 223 PM EST Wed Nov 8 2023 High pressure will be centered to the east Thursday. The front will move further away to the east Thursday night, as a cold front approaches from the northwest. Patchy fog will be possible Thursday night, but widespread is not expected due to forecast cloud coverage. This front will slowly slide south into the area Friday into Friday night. Moisture is limited with the front itself, so not much precipitation, if any, is expected. The boundary will stall just to the south Saturday into Saturday night, as an inverted trough develops over the coastal waters. The combination of the proximity of the front, and the added convergence from the trough will increase chances for showers. Temperatures will remain above normal through Friday night. With the boundary near area Saturday, temperatures across SE GA will fall below normal, whereas above normal readings will continue for NE FL. Temperatures will generally be above normal Saturday night. && .LONG TERM... (Sunday through next Wednesday) Issued at 223 PM EST Wed Nov 8 2023 High pressure will build from the north on Sunday, helping to push the front a little further to the south. However, the inverted trough will continue to linger near the coast, keeping chances for showers in the forecast. The high is expected to push the front further to the south Monday into Monday night, with a period of dry weather expected. A surge of winds down the coastal waters will accompany the building high, with gusty winds along the coast early next week. Long range models diverge in the Tuesday into Wednesday time frame, with GFS building the high south across the area, and the ECMWF lifting a low across the Gulf, which pushes rain back across the area. The GFS has been most consistent with this later period, so will trend toward this drier solution, but confidence in the precip forecast in this later portion of period is not high. Temperatures will trend below normal this period. && .AVIATION... (00Z TAFS) Issued at 635 PM EST Wed Nov 8 2023 For late tonight patchy fog is the main aviation concern and is forecast with some MVFR vsby possible for JAX, GNV, and CRG, with more confidence in fog down to LIFR for VQQ. Fog should dissipate by 12z-13z. Mostly clear skies otherwise, except for some cirrus at times through Thursday. A bit more cumulus clouds near 5 kft expected on Thursday, mainly over northeast FL. Light/variable to calm winds tonight, become light southwest to west by 15z Thursday. A sea breeze expected for to push through SSI, CRG, and SGJ for Thursday afternoon. && .MARINE... Issued at 223 PM EST Wed Nov 8 2023 High pressure will be centered to the east through Thursday night. A cold front will slowly move south into area and stall Friday into Friday night. This front will stall just to the south over the weekend, as an inverted trough develops over the waters. High pressure will build south toward the area early next week, which will push this front further south. A surge of winds will move down the coastal waters, as the high builds in, with Small Craft Advisory conditions beginning Saturday afternoon, and continuing next week. Rip Currents: SE GA Low Today, Moderate Thursday NE FL Moderate through Thursday && .PRELIMINARY POINT TEMPS/POPS... AMG 50 82 56 83 / 0 0 0 0 SSI 57 80 62 80 / 0 0 0 0 JAX 52 83 59 83 / 0 0 0 0 SGJ 58 82 62 82 / 0 0 0 0 GNV 52 84 59 85 / 0 0 0 0 OCF 55 84 61 85 / 0 0 0 0 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...None. GA...None. AM...None. && $$
Area Forecast Discussion
National Weather Service New Orleans LA
531 PM CST Wed Nov 8 2023 ...New AVIATION... .SHORT TERM... (This evening through Thursday night) Issued at 234 PM CST Wed Nov 8 2023 Key Messages: 1. Dense fog is likely to develop again across portions of southeast LA and southern MS on Thursday morning. Smoke from the wildfire in New Orleans East could reduce visibility to less than 100 feet across small portions of east Orleans and St. Tammany parish during morning commute hours. 2. Dense fog potential is much more uncertain on Friday morning as increasing cloud cover and precipitation ahead of the cold front could make it more difficult for smoke to get trapped and for dense fog to form. Surface high pressure remains centered off to the east allowing for gradual moisture return with dew point temperatures now in the 60s almost areawide. A broad surface trough of low pressure moving through the midwest has slightly tightened the pressure gradient prompting daytime wind speeds to increase to 10-15 mph but should decrease as the trough quickly departs and the gradient weakens tonight. Despite the morning fog and upper-level cirrus, temps have reached the low to mid 80s with exception to coastal areas. The upper-level cirrus driven by the weak shortwave trough axis centered currently near Sabine Pass will continue eastward tonight bringing in drier mid-level air overnight that will increase clearing overhead at least for the northern half of the CWA where more efficient radiational cooling could occur as winds decrease. This coupled with moisture advection will aid in development of dense fog tonight across parts of southeast LA and southern MS, much like this morning. Latest RAP model soundings for Thursday morning show a similar strong temperature inversion near the surface which will result in trapping of wildfire smoke near New Orleans East in addition to moisture which will make super fog a threat yet again for the stretch of I-10 between I-510 and Irish Bayou. The plume direction in the overnight hours will be slightly more northerly toward the Twin Span bridge but as the sun comes up winds will quickly become more easterly pushing the dense smoke plume over Lake Pontchartrain and potentially create visibility hazards on the Causeway bridge like we observed this morning. After sunrise, areas of dense fog will dissipate with the only remaining concern coming from the smoke plume over the lake as it will take slightly longer to mix that out. Upper-level cloud coverage will gradually increase through the day on Thursday as the prevailing southwest flow and mid-level troughing over northern Mexico and SW CONUS encroaches. The surface front surging through the plains will put on the brakes as it approaches the area given mid-level southwest flow will continue to favor an onshore regime that will put up some resistance to the frontal boundary. Regardless, increasing surface convergence and gradually falling heights will induce increasing lower clouds and showers beginning on Thursday night and continuing into Friday. With the complexity of cloud coverage and showers impeding radiational influences, any fog development on Friday will have to come from almost a purely advective regime which is indicated by the deeper layer moisture and warm air advection profile present in RAP forecast soundings for Friday morning. With less cooling ongoing at the surface overnight, the steep inversion observed through midweek will be less pronounced which could keep the wildfire smoke from being trapped as much near the surface. However, strong uncertainty still exists regarding these finer details at this range. Patchy dense fog is plausible especially in areas that stay clearer on the MS coast, but elsewhere is very low confidence and low probability currently which is portrayed by the less than 10% ensemble probs for dense fog on Friday morning. && .LONG TERM... (Friday through Tuesday night) Issued at 234 PM CST Wed Nov 8 2023 By Friday morning, a cold front should be moving into the northwestern portion of the local area. Still looks like upper level winds will be mostly parallel to the surface boundary, so it is expected to be moving slowly and should stall out somewhere around the coast as it loses its push from the upper shortwave. Above the surface, the 850mb front lags behind and winds continue to keep a southerly component to them through Saturday. With the front stalled near the coast, these more onshore winds above the surface will ride up and over the front and should provide enough isentropic lift to result in at least isolated to scattered showers continuing through Saturday. Whether this activity continues into Sunday will depend on when and if the 850mb front slides south of the coast. Guidance remains split on when/if that will happen, so have stuck pretty close to the NBM which favors slightly higher POPs through Sunday. Despite the slightly higher POPs lingering through the weekend, overall still not expecting a ton of rainfall, with the axes of heaviest rain currently expected to be west and south of the local forecast area closer to the surface boundary and a developing low over the western Gulf. Through Sunday, the forecast calls for generally one half inch to one inch of rain. While this is obviously better than nothing, it won`t do much with respect to the ongoing drought. By Monday a weak surface low is expected to begin developing over the western Gulf on the tail end of the stalled boundary. This low will then move east/northeastward to another fast moving upper shortwave moving through the middle Mississippi Valley with stronger high pressure building in behind it. The local weather will greatly depend on exactly where this low moves. If it stays over the Gulf we may see some overrunning precipitation with cooler temperatures. If it moves farther north over land areas, there could be more rain and warmer temperatures. Given a bifurcation in the ensemble member solutions, will still pretty close to the NBM for the time being, knowing that the forecast will likely need to be adjusted in one direction or the other over the coming days. && .AVIATION... (00Z TAFS) Issued at 523 PM CST Wed Nov 8 2023 VFR conditions are expected during the day, but another round of early morning to mid morning fog concerns is in the forecast again. Fog which could be very dense at times could bring terminals down to the IFR/LIFR range especially around 8z to 14z. Terminals downwind nearby of any current wildfires (e.g. ASD) could also see further localized reductions of visibility due to smoke. Once the fog starts to dissipate mid to late morning, conditions should improve and no ceiling/vis concerns are expected for the rest of the forecast period. -BL && .MARINE... Issued at 234 PM CST Wed Nov 8 2023 Onshore flow will remain as the surface high sits off to the east of the coastal waters. Dense fog and smoke is expected to impact portions of eastern and northern Lake Pontchartrain due to the smoke plume associated with the New Orleans East wildfire which could quickly reduce visibility to less than 1 NM. Perhaps a small threat of thunderstorms over the open waters Friday into the weekend. Don`t anticipate any winds greater than 15 knots until perhaps Saturday into Monday. && .PRELIMINARY POINT TEMPS/POPS... MCB 58 81 61 70 / 0 0 50 60 BTR 61 84 65 79 / 0 0 40 50 ASD 58 80 63 79 / 0 0 40 50 MSY 64 80 68 79 / 0 0 50 40 GPT 61 78 64 76 / 0 0 40 50 PQL 56 81 61 79 / 0 0 20 50 && .LIX WATCHES/WARNINGS/ADVISORIES... LA...Dense Fog Advisory from 1 AM to 10 AM CST Thursday for LAZ034>037-039-046>048-056>060-065-071-076-078>086. GM...Dense Fog Advisory from 3 AM to 10 AM CST Thursday for GMZ530. MS...Dense Fog Advisory from 1 AM to 10 AM CST Thursday for MSZ068>071-077-083>088. GM...&& $$ SHORT TERM...TJS LONG TERM....DM AVIATION...BL MARINE...TJS
Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
613 PM CST Wed Nov 8 2023 .SHORT TERM... Issued at 225 PM CST Wed Nov 8 2023 Through Thursday night... Key forecast concerns... * Showers and perhaps an isolated storm this afternoon through mid- evening * Increasing winds tonight into Thursday with 30 to 40 mph gusts possible Thursday afternoon A surface low continues to advance across central Illinois this afternoon with a warm front extending east-northeastward along the I- 80 corridor. The current orientation of the front has developed a north-south temperature gradient across the area with low to mid-50s north of the front while areas to south sit in the low to mid-70s. Showers have started to develop across northwestern Illinois along the 850 mb front with additional showers expected to develop along the warm front as the surface low moves further into our area. While most of the precipitation will occur in the form of light to moderate showers, RAP mesoanalysis is showing around 250 to 300 J/kg of MUCAPE over northern Illinois which may allow a couple of embedded thunderstorms to take shape through early evening as well. As the low moves into Indiana this evening, the warm front is expected to get shoved back southward by the 850 mb front which will gradually taper showers from northwest to southeast through the mid to late evening hours (~10 PM to midnight CST). Winds will begin to increase in the wake of the cold front as the pressure gradient rapidly tightens (6 to 8 mb pressure rise per 6 hr) overnight into Thursday morning. While gusts overnight may be somewhat tempered over land due to the lack of mixing, they are expected to increase Thursday morning as mixing increases. The westerly gusts are forecast to reach into the 30 to 35 mph range during the afternoon with the possibly for higher gusts near 40 mph if deeper mixing is achieved. However, the pressure gradient is expected to weaken late Thursday afternoon which will allow winds and gusts to gradually subside Thursday evening. Otherwise, seasonable temperatures and clear skies can be expected for Thursday and Thursday night. High temperatures are forecast to be in the low to mid-50s with overnight lows in the low to mid-30s heading into Friday morning. Yack && .LONG TERM... Issued at 225 PM CST Wed Nov 8 2023 Friday through Wednesday... A rather quiet period of weather is in store late this week through next week as loosely zonal Pacific flow across the northern CONUS transitions into an expansive ridge across the central CONUS by early next week. +2SD 500 hPa heights and 850 hPa temps running 10C degrees or more above normal across the north- central CONUS will support dry and unseasonably conditions for the western Great Lakes region next week. Other than a rather small chance of a few WAA-forced high-based showers brushing our area to the north late Saturday night into Monday, no precip is expected through the forecast period. Kluber && .AVIATION... For the 00Z TAFs... Key messages: * Showers through early evening * Trending lower cigs with periods of IFR and some LIFR with and behind the showers * Winds out of the northwest will turn more westerly, then increase overnight with stronger gusts expected by Thursday afternoon, potentially around 30 knots Thunderstorm coverage is on the decrease and even the line of showers west of the terminals at 00z TAF issuance time is not really holding together too well. Opted to remove mention of VCTS, but did lower CIGs in the TEMPO group based on upstream trends of LIFR in the 300-500 ft range. The back edge of this lower coverage seems to be somewhere around the IA/IL border, so we may end up needing to amend to keep more than two hrs of these lower conditions. Quieter conditions are expected through the remainder of the fcst period, though west winds do pick up by late morning through mid afternoon tomorrow, possibly gusting to around 30 knots at times. Lenning && .LOT WATCHES/WARNINGS/ADVISORIES... IL...None. IN...None. LM...Small Craft Advisory...Winthrop Harbor to Gary IN until 11 AM Thursday. Gale Watch...LMZ740-LMZ741-LMZ742-LMZ743...11 AM Thursday to 6 PM Thursday. Small Craft Advisory...Gary to Michigan City IN until 6 PM Thursday. && $$ Visit us at weather.gov/chicago Follow us on Facebook, Twitter, and YouTube at: www.facebook.com/NWSChicago www.twitter.com/NWSChicago www.youtube.com/NWSChicago
Area Forecast Discussion
National Weather Service Shreveport LA
923 PM CST Wed Nov 8 2023 ...New UPDATE... .UPDATE... Issued at 916 PM CST Wed Nov 8 2023 Cold front as of 03z was located near a Gainesville, TX to Fort Smith, AR line and continues to make very slow progress south and east this evening. Latest 12z NAM as well as HRRR output takes the front south and east towards the I-30 Corridor of NE TX into SW AR by 12z Thu which looks very similar to where the current forecast has the front in the morning. Slight chance to low end chance pops are currently forecast along and ahead of the boundary after midnight towards sunrise in the morning which looks good as well. Latest IR Imagery showing mid level cloud cover streaming north and east out of Central TX and into NE TX with stratocumulus deck beginning to pool just ahead of the cold frontal boundary across the Middle Red River Valley of NE TX, SE OK and SW AR. Concerning temperatures, forecast lows are very close to current observations in a few locations late this evening but with the rapid return of cloud cover witnessed on IR Imagery, the fall in temperature should flatten out in the warm sector ahead of the frontal boundary through sunrise in the morning. Therefore...no changes are necessary this evening. 13 && .SHORT TERM... (This evening through Thursday Night) Issued at 232 PM CST Wed Nov 8 2023 The low stratus from this morning has finally starting to lift across the region. This has played a major role in today`s temps as locations underneath the low clouds have mostly remained in the 70s today, while the remainder of the region has climbed into the 80s. In fact, some areas across NE & Central Louisiana have climbed into the upper 80s, which is around record high territory. If not for the cloud cover, we would probably see more records across the region. Above normal temperatures will remain overnight, as lows will only fall into the 60s areawide. However, a big change is coming to the region starting Thursday morning. An upper trough and associated cold front will move through the region on Thursday, bringing widespread rain chances. Can`t rule out 1 to 2 inches across areas north of a line from Lufkin Texas to Shreveport to El Dorado AR. Behind the front, much cooler temperatures will push into the region along with continued widespread rain chances. Overnight temps Thurs night/Fri morning will range from the upper 40s north of I-20, to lower to mid 50s across the remainder of the region. /20/ && .LONG TERM... (Friday through next Tuesday) Issued at 232 PM CST Wed Nov 8 2023 Unsettled weather is anticipated to remain for most of the long- term, as our region comes under the influence of two distinct systems. The first is the cold front that we`ve been mentioning the last few days. This cold front will bring some much needed rainfall to the region, as well as much colder temperatures into the weekend. There is still some uncertainty in just how much rain we`ll see across the region, with current thinking still mostly between 1-2 inches area-wide. Some locations could see locally heavier rainfall, resulting in isolated 3 inches. Unfortunately, it looks like these areas will remain to the north of where we really need the rain. In turn, look for drought conditions to go relatively "unbusted" where it`s most needed. Temperatures should remain seasonal behind the cold front, before SW flow returns to the region by Sunday. This will allow temperatures to rebound into the upper-60s, and rain chances to return to the forecast. This SW flow will be associated with a closed low pressure moving to the east towards the middle of the week. If this low pulls north, we could be looking another another healthy round of rain towards the middle of next workweek. However, that solution still has plenty of time between then and now, with plenty of uncertainty in between. /44/ && .AVIATION... (00Z TAFS) Issued at 502 PM CST Wed Nov 8 2023 VFR conditions currently prevailing across our airspace but that will be changing later tonight and through the day Thursday with the arrival of a cold front. The frontal boundary will be near or south of an ELD/TXK/TYR line by 09/18z and near a MLU/SHV/GGG line by 09/21z and through all but the LFK terminal by 10/00z according to latest progs. Possibility of MVFR ceilings will exist in advance of the boundary with ceilings quickly deteriorating to IFR and perhaps LIFR in the wake of the boundary with prevailing showers. Also, look for MVFR VSBYS with those prevailing showers as well along with a wind shift to the NNE near 10kts or less with the frontal passage. 13 && .PRELIMINARY POINT TEMPS/POPS... SHV 67 75 52 59 / 10 80 100 80 MLU 64 77 52 60 / 10 70 90 80 DEQ 58 64 46 61 / 30 90 90 40 TXK 63 67 47 57 / 20 100 100 60 ELD 63 70 46 56 / 20 100 100 80 TYR 67 72 52 59 / 10 90 100 60 GGG 66 74 51 59 / 10 90 100 70 LFK 66 80 56 62 / 10 40 90 90 && .SHV WATCHES/WARNINGS/ADVISORIES... AR...None. LA...None. OK...None. TX...None. && $$ SHORT TERM...20 LONG TERM....44 AVIATION...13