Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 10/27/22

Area Forecast Discussion...UPDATED
National Weather Service Cheyenne WY
814 PM MDT Wed Oct 26 2022 .UPDATE... Issued at 759 PM MDT Wed Oct 26 2022 Updated forecast for tonight and Thursday morning to increase POP and QPF across mainly the I-80 corridor from Elk Mountain to Cheyenne. Models and this afternoon`s ensembles are trending a little more aggressive on the potential for some light snowfall tonight across southeast Wyoming. 700mb low pressure feature is expected to develop along the Front Range late tonight and drift slowly southeast...which should result in some additional convergence along the Front Range and adjacent plains. In addition, A few hours of WAA aloft around the 650 to 700mb layer should result in enough moisture advection to increase snowfall probabilities along the I-80 corridor after midnight. HRRR guidance agrees with this outcome between 06z and 18z Thursday, and has verified well so far today with the activity further west. Would not be surprised to see 1-2 inches of snow accumulation by 9 am Thursday for Laramie, Arlington, the I-80 Summit, and near Cheyenne based on current trends. Increased snow totals tonight/early Thursday, but not nearly as high as the ensemble guidance suggests yet due to limited confidence with virga and how much dry air remains in the residual boundary layer. Updates have been sent. && .SHORT TERM...(This evening through Friday night) Issued at 215 PM MDT Wed Oct 26 2022 A low was located over central ID with a trough axis trailing south into NV. The bulk of the energy and QG lift was located over southern ID and northern NV/UT with convective activity increasing and even a couple lightning strikes. Well ahead of this feature, light showers were developing across southern WY. Rain and snow showers will continue to increase in coverage from west to east through the rest of the afternoon. There will be periods of moderate snowfall for the Snowy and Sierra Madre mountains this afternoon and evening, with 2 to 4 inches expected, with heavier snow falling south of the WY/CO border along the track of the mid level low. The showers will taper off from NW to SE Thursday morning, with skies clearing. It will continue cooler than normal with 700mb temperatures from -4C to -8C. Clear skies and lighter winds Thursday night will result in low temperatures in the upper teens to upper 20s. The warming trend commences Friday as 700mb temperatures rise to 2C to 6C in the afternoon. Expect high temperatures in the mid 50s to mid 60s along and east of I-25, with 40s to lower 50s west. Lows Friday night will be milder with lower 20s to mid 30s. .LONG TERM...(Saturday through Wednesday) Issued at 215 PM MDT Wed Oct 26 2022 Fairly quiet weather over the weekend will likely turn more active for the latter part of the long term forecast period next week. The main concerns are the potential for strong winds on Monday and the next possible precipitation event on Wednesday. Uncertainty remains quite high for both of these. The synoptic pattern over the weekend will be largely under a zonal flow regime. A cutoff low, which will be spawned by the system moving through our area today, will be sitting over the southern plains, while a few weak shortwaves will perturb the flow slightly over the western US. An elongated area of 500-mb vorticity is expected to pass through on Saturday, which will likely increase mid to high level cloud cover. 700-mb temperatures will hover around 0C, leading towards near normal temperatures. Another shortwave right on the tail of this pushes through early Sunday and may knock another degree or two C off the 700-mb temps, so expecting slightly cooler temperatures Sunday afternoon. This period looks dry with limited lift, so precipitation is unlikely. A strong jet stream slamming into British Columbia over the weekend will start to sag southward on Monday, bringing the temperature gradient and storm track closer to our area. A week surface low spinning up over the Canadian prairie at the nose of the jet aloft will lead to falling MSLP over the high plains and increase the cross-barrier MSLP gradient, though this isn`t too impressive now based on current forecasts. Similarly, jet shifting southward will increase height gradients to near typical high wind thresholds. The GFS shows 700-mb winds around 40-45 knots on Monday, pointing to a the possibility for a strong wind event for the wind prone areas. Will need to watch this period to see how this unfolds, but it looks marginal for reaching high wind criteria. For Tuesday, the zonal flow starts to transition more towards western troughing as a longer wave digs southward. Models show the flow aloft turning southwesterly with good warm-air advection and downsloping leading to climbing 700-mb temperatures to around +2 to +4C. Ensemble spread is fairly tight through about Tuesday. Little variability between member forecast temperatures projects higher confidence in the general temperature forecast, but this changes dramatically on Wednesday. For example, the GEFS 10th to 90th percentile 700-mb temperature spread at 00z Wednesday is about 3C, but this increases to about 12C by 00z Thursday. This indicates a major drop in forecast confidence. The deterministic GFS shows a deep and impressively strong upper level trough digging into the Great Basin, leading towards lee-cyclogenesis over the high plains. This specific solution ejects the trough quickly, keeping much of the precip along and west of the Laramie range, but still would bring some light QPF to the east. The deterministic ECMWF is vastly different, showing a shallow, progressive trough sliding through around this time. This keeps most of the precip to our north, but does allow some light QPF west of the Laramie range. Most of the ensemble members are somewhere in between these two extremes. For now, keeping the official forecast near the NBM 50th percentile for temperatures, with PoPs for most of the area, but highest west of the Laramie range. && .AVIATION...(For the 00Z TAFS through Thursday evening) Issued at 535 PM MDT Wed Oct 26 2022 A potent upper level trough will dig southeast across western and southern Wyoming tonight and will result in cloudy skies and an increasing threat for locally heavy snow showers until midnight (06z). Snowfall will then increase in coverage after 06z with light to moderate snow possible along the I-80 corridor terminals. Snowfall may linger through 15z early Thursday morning before skies gradually clear from west to east. HAZARDS/WEATHER TRENDS: Will continue with prevailing VFR conditions tonight for all terminals. However, scattered to numerous snow showers this evening through 05z will result in brief IFR conditions in VIS below 1 mile and CIGS around 500 feet for mainly KLAR and KRWL. Snow will become lighter after 06z but should become more widespread further east, impacting KCYS and possibly KSNY with periods of IFR conditions through 15z Thursday. Kept VCSH in the TAFs for now but will likely update later with increasing confidence. && .FIRE WEATHER... Issued at 215 PM MDT Wed Oct 26 2022 A upper level disturbance will move east across Colorado tonight and Thursday morning. Rain and snow showers will develop this afternoon and become all snow tonight before tapering off Thursday morning. Snow accumulations of 2 to 4 inches are likely through tonight over higher elevations west of the Laramie Range. Temperatures will remain cool Thursday, followed by a warming trend Friday through early next week. Afternoon relative humidities of 30 to 40 percent Thursday will lower to 15 to 25 percent Friday and Saturday. Gusty winds at that time will elevate fire weather concerns along and east of the Laramie Range. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...None. NE...None. && $$ UPDATE...TJT SHORT TERM...MAJ LONG TERM...MN AVIATION...TJT FIRE WEATHER...MAJ
Area Forecast Discussion
National Weather Service Grand Forks ND
611 PM CDT Wed Oct 26 2022 .UPDATE... Issued at 610 PM CDT Wed Oct 26 2022 A tranquil evening is expected across the FA, with light winds and only a small amount of cloud cover. These clouds will continue to increase late tonight into Thursday, but mainly south of a line from Valley City to Bemidji. Made some minor sky cover adjustments, otherwise the forecast is in good shape. && .SHORT TERM...(This evening through Thursday night) Issued at 300 PM CDT Wed Oct 26 2022 Forecast challenges will be if we get any precip in our southern counties tonight, along with temperatures throughout the period. Water vapor shows split flow aloft with the cut off upper low spinning over the Intermountain West. This cut off will stay well to our south tonight and tomorrow morning, but a weak lead/northern branch shortwave will be moving through SD/Nebraska area. This weak system could bring a few light rain showers to our southern counties, with the formally drier HRRR run now showing some decent returns into west central MN. Any amounts reaching the ground will be very light, and with all rain expected impacts will be negligible. Further north, skies will have less cloud cover tonight and southwest winds could bring some patchy fog from northwestern and north central ND into our area. SREF probabilities have around 40 percent chance of less than a mile visibility for our northwestern counties, so will continue to keep a patchy fog mention going. South to southwesterly surface winds providing warm air advection and good mixing should help boost temperatures into the mid 50s tomorrow, with some slightly cooler temps in west central MN where clouds will hang on longer. Southwesterly surface winds will continue into Thursday night and should help keep temps above freezing even with decreasing clouds. .LONG TERM...(Friday through Wednesday) Issued at 300 PM CDT Wed Oct 26 2022 Overview... The long term period looks to remain on the quiet side, with precipitation chances increasing toward late next week. Otherwise, seasonably mild weather is expected to persist from the weekend into early next week as well. Discussion... The upper level flow pattern looks to be unwavering through the weekend with split flow over the CONUS resulting in generally zonal flow over the northern Plains. A transient period of upper level ridging is expected on Friday ahead of this as a trough closes off over the southern CONUS. This will result in what looks to be the warmest day of the extended period on Friday, with widespread highs in the upper 50s to low 60s. The weekend will then feature a continuation of quiet weather as zonal flow sets up aloft. This flow pattern looks to persist into early next week. High temperatures look to fall a few degrees from Fridays high temperatures, but are still expected to remain well above normal for this time of year, generally in the 50s, with a few low 60s possible across the southern FA. Tuesday is when global consensus begins to introduce a shift in the upper level pattern. As large scale troughing builds in over the western CONUS, southwesterly flow aloft is expected to set up over the northern Plains. Despite this, quiet weather is anticipated on Tuesday, with high temperatures once again firmly in the 50s. Beyond Tuesday, there are signals within ensemble guidance indicating that the longwave trough building in over the western CONUS will eventually travel eastward. Ensemble cluster analysis is largely in good agreement on the progression of this feature, with some discrepancies on exact location and timing. There are still a lot of questions surrounding the progression of the wave, however, as well as any precipitation potential, timing, and location at this time. While far from a guarantee, given prominent signals within ensemble guidance, it would be remiss to not at least mention the possibility for increasingly active weather toward the middle/end of next week. && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 610 PM CDT Wed Oct 26 2022 No big impacts are expected for this TAF period. South winds will pick up Thursday morning, and be fairly breezy through the afternoon. Some BKN040-060 ceilings look to affect KFAR and KBJI late Thursday morning and afternoon. There may also be a few light showers around, but overall confidence in that is pretty low, so did not mention any at this time. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...None. MN...None. && $$ UPDATE...Godon SHORT TERM...JR LONG TERM...Rick AVIATION...Godon
Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
924 PM CDT Wed Oct 26 2022 .UPDATE... Issued at 924 PM CDT Wed Oct 26 2022 The forecast is in good shape with few changes needed this evening. A recent hand analysis of the surface pressure, dew point, and wind fields reveals an expansive 1020mb surface high pressure system sliding across the Mississippi River Valley into Wisconsin. Meanwhile, composite RGB GOES-16 imagery depicts an eastward-moving cirrus shield associated with a weakening upper-level wave approaching western Illinois within quasi-zonal flow aloft. With the resident dry airmass in place (characterized by surface dew points in the lower 30s and mean 850-500 RH in the neighborhood of 5%), temperatures will continue to drop steadily over the next few hours before upper-level clouds "dampen" the party and slow the fall. Overnight lows still look good to hit the low to mid 30s, save for the core of Chicago where the urban heat island will hold temperatures in the lower 40s. Fog development overnight will be contingent on any holes in the clouds that develop or westward erosion of the upper-level clouds toward sunset (as hinted within recent HREF guidance). For now, we will hold off on any formal fog mention in the gridded database in favor of watching trends. Updated products have been sent. Borchardt/KK && .SHORT TERM... Issued at 220 PM CDT Wed Oct 26 2022 Through Thursday night... The forest in the short term remains relatively quiet thanks to a large area of surface high pressure that will drive most of our weather for the next couple of days. A tight pressure gradient ahead of the high pressure center has resulted in some breezy conditions this afternoon. This will only last into this evening before the pressure gradient weakens and we stop mixing into the enhanced flow aloft for the night. Mostly clear conditions will hold on through the night causing temperatures to cool to near or just above freezing for most by early Thursday morning with the help of some very light winds overnight. The clear skies and light winds are also expected to result in some areas of fog overnight. Guidance insists that the fog shouldn`t be widespread, yet models are having a hard time agreeing on where to place the most favorable areas for fog to develop. However, the RAP has liked the Illinois River valley all day long and the HRRR is trending toward the same idea. Heading into Thursday, we should begin the day with lots of blue sky. However, after the center of high pressure moves to our east Thursday morning, the return flow will introduce some mostly cloudy conditions for the latter half of the day. Despite the clouds, no rain is expected through the day on Thursday. Temperatures will be similar to today with highs in the mid-50`s. The added cloud cover is one factor that will keep temperatures a bit warmer Thursday night than tonight. Lows early Friday are forecast in the middle and upper 30`s. Doom && .LONG TERM... Issued at 220 PM CDT Wed Oct 26 2022 Friday through Wednesday... There are no noteworthy weather impact concerns through mid next week. A rather tranquil pattern is in store, with seasonably mild daytime temperatures. Friday and Saturday will be quiet under the influence of surface high pressure centered over the eastern Great Lakes and Northeast. Forecast highs are in the upper 50s-low 60s Friday, followed by seasonably chilly mid-upper 30s lows Friday night outside of Chicago (40-45 in/near the city). Modest warm advection aloft amidst rising heights will support highs reaching pleasant low-mid 60s on Saturday (except slightly cooler IL shore) for a nice start to Halloween weekend. The main feature of interest for sensible weather effects is a mid-upper short-wave tracking from the northern Rockies to New Mexico by later Thursday. This short-wave will become a closed low cut off from the primary upper jet displaced well to the north, resulting in it meandering eastward across Texas Friday into Saturday. It will then become an open wave as it lifts north from the lower and mid MS Valley to the Great Lakes Sunday into Monday. The weakening nature of large scale forcing should tend to result in a more disjointed precip shield with northward extent, and relatively higher shower coverage Sunday PM for the southeast half or so of the CWA, where chance PoPs appear reasonable. Mostly cloudy skies will keep temps a bit cooler, in the upper 50s-lower 60s. Another weaker short-wave lifting northeastward across the region may keep the spotty shower threat into Monday/Halloween for the southeast half or third of the CWA, mainly in the morning. With the exception of slower guidance, current signs point toward favorable trick or treating conditions for most of it not the entire area, with highs in the upper 50s-lower 60s and temps by 7PM in the lower-mid 50s. In the wake of the weak systems Sunday- Monday, prevailing south-southwesterly flow and warm advection will yield highs in the mid-upper 60s Tuesday-Wednesday along with above normal overnight lows. Some precip chances may return just beyond day 7 from troughiness in the west. Castro && .AVIATION... For the 00Z TAFs... There are currently no significant aviation weather concerns over the TAF period. Light northwesterly winds will trend essentially light and variable this evening and overnight, and may occasionally acquire a NE direction at the Chicago-area terminals. Winds will likely remain under 7 kts. There is a small potential for some patchy BR development overnight, mainly in the vicinity of river valleys. The main limiting factor tonight appears to be from an incoming area of mid and high-level cloud cover which will thicken up through the late evening hours. As a result, have left BR out of all the TAF sites, but will keep an eye on GYY and DPA, however. Eventually, winds will come around of the east or east-southeast through Thursday morning where they will remain through the rest of the TAF periods. Carlaw && .LOT WATCHES/WARNINGS/ADVISORIES... IL...None. IN...None. LM...None. && $$ Visit us at Follow us on Facebook, Twitter, and YouTube at:
Area Forecast Discussion
National Weather Service Lubbock TX
641 PM CDT Wed Oct 26 2022 ...New AVIATION... .SHORT TERM... (This evening through Thursday) Issued at 217 PM CDT Wed Oct 26 2022 A surface low over southeastern Colorado will keep winds mostly out of a southerly direction this evening and much of the night. The surface low will migrate southward across northeastern New Mexico into the far northwestern Texas Panhandle/western Oklahoma Panhandle by mid morning in response to what will be an approaching upper low. The upper shortwave that will eventually become the upper low is currently over Idaho and is expected to push southeastward towards Colorado/Wyoming and become a closed low by 12Z tomorrow. The low will then deepen slightly as it reaches Farmington, New Mexico by 18Z. Models have a general consensus of having the low over Cline`s Corner by 00Z tomorrow evening. The speed and location of the low will be one factor in helping or hindering the possibility for convection along the dryline before 00Z tomorrow evening. Currently models are relatively dry before 00Z with the exception of higher res models such as the 12Z HRRR and 00Z NSSL FV3. The HRRR mostly keeps precip in the form of virga showers pre-00Z with convection developing along the dryline east of the Caprock at 00Z. The FV3 is the most bullish in terms of afternoon precip with virga showers developing by 18Z behind the dryline with coverage increasing just before 00Z as the cold front moves into the region. A mention of slight chance of showers and thunderstorms has been introduced across much of the FA for late tomorrow afternoon as enough mid/upper level lift should be present for the development of at least virga showers with a rumble or two of thunder. The overall main threat from any storm that does develop will be wind gusts up to 60 mph. && .LONG TERM... (Thursday night through next Tuesday) Issued at 217 PM CDT Wed Oct 26 2022 Isolated to scattered showers and thunderstorms ongoing to begin Thursday evening should quickly expand in coverage as the upper low over central New Mexico moves southeastward toward Hobbs by midnight. Increasing vertical motion and cooling mid level temperatures eroding lingering convective cap will see an expansion of storms along the dryline across the eastern third of the forecast area as well as increasing high-based and elevated convection in the dry air west of the dryline and north of a southward-moving cold front. There remains a narrow window for marginally severe thunderstorms along the dryline early in the evening with progged surface-based CAPE of 1250-1750 J/kg across the Rolling Plains at 00Z. Precipitation in the form of rain will wrap-around the low as continues its march to the east-southeast late Thursday night through Friday with likely to categorical PoPs justified between midnight and noon before slowly tapering off Friday afternoon to early evening. The post-storm period from Saturday through the end of the forecast period will see slowly moderating temperatures as heights and thicknesses increase slowly underneath a continuation of generally cyclonic mid to upper level flow. && .AVIATION... (00Z TAFS) Issued at 636 PM CDT Wed Oct 26 2022 VFR conditions will continue through the majority of this TAF period. Winds roughly 800 ft AGL will increase overnight leading to LLWS at all three TAF sites tonight through Thursday morning. Tomorrow afternoon, southwesterly surface winds will become breezy and towards the end of the TAF period showers and thunderstorms should be developing. However, confidence on a direct impact to a TAF site remains too low at this time to include a mention in the TAF but KCDS and KPVW will be the most likely sites to see any activity. && .LUB WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...51 LONG TERM....07 AVIATION...58
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
648 PM CDT Wed Oct 26 2022 .DISCUSSION...(This evening through Wednesday) Issued at 229 PM CDT Wed Oct 26 2022 Key Messages: - Chance for showers in western Minnesota tomorrow morning, weakening by the middle of the day. Cloudy for much of the area tomorrow. - Quiet and dry weather return after Thursday and continue through the weekend, with above normal temperatures through at least the middle of next week. Tonight and Thursday... Now that a few of the CAMs have begun to resolve the precipitation potential for western Minnesota tomorrow, the signal for rainfall is a bit stronger than 24 hours ago. The HRRR has a decent amount of scattered showers making it as far east as the western Twin Cities Metro around sunrise tomorrow, with stronger showers mainly confined to southwestern Minnesota. These showers will form along the nose of a weak low level jet, with low to mid level moisture and WAA resulting in the showers. As we head into daylight, this jet will weaken and cut off both the lift and moisture, thus the showers should dissipate fairly quickly once we reach the middle of the day and afternoon. For those that do not see rain, we will end up being cloudier than it has been over the past few days and cloudier than it will be as we head into the weekend, with clearing gradually through late Thursday into Friday. Friday through Wednesday... Upper level flow returns to primarily zonal over our coverage area, with a cut off system remaining far to our south and primarily affecting the southernmost states. This likely will keep any further precipitation chances through the period to a minimum, with weak surface high pressure lingering in the northern plains as we remain moisture starved. Temperatures under this scheme will remain above normal in the mid 50s to low 60s for highs compared to normals around 50 this late in October. It is looking to be a great day for Halloween on Monday, with high temperatures in the upper 50s to mid 60s under mostly sunny skies which will linger into the evening. Our nights will continue remain above freezing, dropping into the upper 30s to low 40s. Precipitation chances will remain absent with a lack of both forcing and moisture, however this could change as we head towards the end of next week. A few long-range models and ensembles are beginning to show potential for a pattern shift, with a more active upper level pattern aiding in guiding a more dynamic surface regime to the area. This is still in the 200-240 hour time frame and thus heavily subject to change. && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 619 PM CDT Wed Oct 26 2022 Light rain in Nebraska will continue to move northeast this evening, bring light rain to western MN Thursday morning. Expect some wet surfaces in RWF and AXN and possibly STC into early Thursday afternoon, when this rain is expected to dry up with the forcing. Despite the rain, expect VFR cigs to remain, with cig heights ranging from as low as 5k feet in western MN, up to around 15k feet in western WI. For winds, as the high continues to slide into MI, we`ll continue to see southeast winds become established overnight, that will become southerly on Thursday, with speeds slowly bumping up toward 10 kts. KMSP...A few sprinkles can`t be ruled out Thursday morning, but the chances aren`t high enough to include in the TAF. Otherwise, confidence is once again in the TAF this period. /OUTLOOK FOR KMSP/ FRI...VFR. Wind SW 10-15 kts. SAT...VFR. Wind SW 5-10 kts. SUN...VFR. Wind W 5-10 kts. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...None. WI...None. && $$ DISCUSSION...TDH AVIATION...MPG
Area Forecast Discussion
National Weather Service Pocatello ID
201 PM MDT Wed Oct 26 2022 .SHORT TERM...Today through Thursday. The cold front is just about all the way through the eastern highlands this afternoon and cooler air is moving in now along with our gusty winds. The band of precip with the front was our main push of snow with this system, but snow showers will still continue on and off through the afternoon and evening, especially up on the mountains. The NAM and HRRR and both picking up on a convergence band of snow developing between Arco and Idaho Falls around 3-4PM and moving southeast before fizzling out around 10PM. The biggest impact from this would be reduced visibility for anyone traveling on I-15 between 6-9PM. At the same time, the wind will be starting to back off which will decrease snow squall potential. With this quick burst of snow, up to about an inch is possible. The WSUP NBM 4.1 is showing a 60-70 percent chance of over a tenth of an inch of snow between Pocatello and Idaho Falls by midnight. However, it only shows about a 5 percent chance of at least an inch. Precipitation looks to wrap up by midnight across the entire area and the highest snow totals by the end of this event are still expected to be up in the mountains. Event totals in the Sawtooths will be up to about 7 inches of snow, 4-6 inches in the Bear River Range, 3-6 inches in the Big Holes, and about 2-4 inches for the rest of our mountains. The wind will still be blowing into the evening, too, with sustained winds between 20-30mph and gusts between 35-45mph. The strongest gusts will be in the South Hills and up through the Arco Desert and Snake Plain. Winds begin to back off around 8-9PM. Thanks to lighter winds overnight and moisture from today, patchy valley fog is expected to develop after midnight and continue through 8AM. Overall, Thursday will be a much quieter weather day in comparison as ridging builds back in to the area. Some afternoon sunshine will help warm most of the area back into the low to mid 40s, which is still well below average for this time of the year. AMM .LONG TERM...Friday through Wednesday. Upper ridge remains in place Friday, then starts to flatten Saturday with passage of dry shortwave feature. Temperatures cool slightly in association with this feature. Models continue to trend slower with onset of precipitation associated with approaching Pacific trough. Ensemble clusters for Sunday favor generally a flat flow across the entirety of the Pacific northwest and northern Rockies. NBM introduces weak precipitation chances across portions of the central mountains Sunday night, spreading the moisture across the rest of East Idaho on Monday through the base of shallow active trough sliding inland along the Canada border. Flow remains nearly zonal and unsettled behind this feature and ahead of next incoming Pacific trough. Only edits to the extended period were to nudge winds higher for Monday- Wednesday in response to guidance trends. DMH && .AVIATION...Cold front with attendant precipitation band has pushed almost completely through East Idaho early this afternoon, with showers developing in wrap-around air mass. Ceilings remain generally VFR/MVFR outside of the precipitation but IFR/LFR within the band and stronger showers. Winds remain gusty especially in clear pockets where deepest mixing can be realized. Showers and gusty winds continue into early evening, then second consolidated band of showers works out of central mountains through the Snake Plain for another round of snow. For the remainder of the night into early Thursday, expect gradual clearing with weakening winds. Skies should improve back to VFR most areas, though lower elevation areas could see stratus/fog development with IFR conditions. KDIJ would be the most likely location for this to occur overnight. DMH && .PIH WATCHES/WARNINGS/ADVISORIES... None. && $$
Area Forecast Discussion
National Weather Service Raleigh NC
1043 PM EDT Wed Oct 26 2022 .SYNOPSIS... A weak cold front will move across the Carolinas tonight. High pressure will extend into the region on Thursday and persist into Saturday. The next storm system may bring unsettled weather to the area later Sunday into Monday. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... As of 1040 PM Wednesday... Just issued a DFA for portions of the northeast Piedmont and Coastal Plain of central NC through 6 AM, as more obs are reporting a quarter mile or less. Still think the threat for dense fog will only be for a couple of hours for most locations, but could lingering across portions of the coastal plain if the front hangs up. Previous discussion... As of 1015 PM Wednesday A weak band of showers associated with a cold front moving through central NC this evening has shifted to the east of the area. However, the main cold front and CAA continues to slowly move through/filter into the area this evening, with the main front as of 10 PM located across the northwest Piedmont and is denoted by a northwesterly wind shift and dewpoints falling into the 40s. With clearing skies and calm winds ahead of the front, we are seeing some fog develop in advance of the front, especially across the northeast Piedmont and Coastal Plain including some patchy dense fog. Will need to monitor obs for a possible short lived DFA. Expect visbys should improve within the next few hours for most locations (by 06Z). However, the latest few runs of the HRRR show the potential for the front to hang up across our far east, with a lingering threat for fog until around 12Z when a push of drier air from the north will send the front to the south of the area. Low temps are expected to range from the upper 40s northwest to the mid 50s southeast. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/... As of 245 PM Wednesday... Central NC will be situated between a split flow regime with the polar jet situated over the Northeast into the Great Lakes region, while the subtropical jet weakly ridges into the lower MS Valley and extending southeast into FL. Farther west, a phasing between the two jets will be underway as a deep positively tilted trough dives into the Four Corners region by Thursday morning. As subtropical riding builds into the Southeast, immediately downstream of the amplifying trough, a 70-100kt jet streak will move into Lower MS Valley extending into the TN/OH Valley and direct upper level moisture into southern Mid-Atlantic Thursday night into early Friday morning. At the surface, the cold front should be pushed through central NC by Thursday morning with much drier air in place (15 degrees lower) as strong high pressure will begin to build into the Great Lakes region and strengthen through the day, as it migrates eastward over the Northeast by Friday morning and nose down through the southern Mid- Atlantic into the Southeast. Skies should be partly cloudy to mostly clear (from SE to NW) during the morning hours with fair weather cumulus developing under very dry/stable thermodynamic profiles above 850mb during the afternoon hours. Cool northerly winds will usher in near normal temperatures ranging from mid 60s to low 70s for highs and falling into the 40s Thursday night into early Friday morning. && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... As of 245 PM Wednesday... Focus shifts to the west as a closed low develops over the southern Plains by Friday morning. Ensemble guidance continues to show a clear split in solutions between the EPS and the GEFS/CMCE. The latter shows a quicker eastward progression by Sunday evening while the former favors a slower solution as the closed low briefly becomes detached from the northern stream flow. How far this system can migrate east by Sunday night before being picked up by the next shortwave will have implications on timing/longevity of potential precipitation this weekend into early next week. Given the nature of the pattern and potential cutoff nature of the southern stream low, will opt with the slower Euro and its ensemble members for late this weekend into early next week. This solution results in a surface low in the vicinity of Arkansas Sunday morning that will lift to the northeast and into Great Lakes region by Monday morning. Strengthening flow and WAA at 850mb will be directed over the western Piedmont Sunday into Monday morning with likely a lull Monday afternoon then increasing again as a cold/occluded front pushes moisture eastward Monday night into Tuesday morning. Unfortunately, this timing will likely coincide with trick-or-treating activities, but confidence on this solution is medium/low given timing differences with upper level pattern as noted above. As for temperatures in the extended, high pressure wedging down the southern Appalachians will set up a CAD regime and will favor below normal highs through Sunday warming up to 5 degrees above normal by early next week. Lows should favor above normal conditions through early next week (up to 10-15 degrees above normal by Monday). && .AVIATION /00Z THURSDAY THROUGH MONDAY/... As of 800 PM Wednesday... 24-hour TAF period: A cold front will continue to move across central NC this evening and reach the coast late tonight. Persistent low level moisture is present ahead of the front resulting in lingering patches of mainly VFR stratus and stratocumulus clouds. In addition, some areas of MVFR fog will continue to develop across the northern Piedmont and northern Coastal Plain for a brief period this evening into the early overnight potentially impacting the KRWI terminal and possibly KRDU with a brief period of fog. As drier air moves into the region behind the front, expect the fog to dissipate and any lower stratus to lift a bit. Mainly VFR conditions are expected on Thursday with SCT to occasionally BKN stratocumulus clouds with bases of 3-5kft. Light west to northwest winds this evening will become northerly overnight at 5 to 10kts and then north to northeasterly at 7 to 12kts on Thursday. Outlook: High pressure will extend into the region on Thursday and persist into the first part of the weekend. Generally fair weather is expected through Saturday although the moist northeast flow could result in some CIG restrictions across the east on Friday and especially Saturday. A storm system will approach and move across the area Sunday into Monday resulting a chance of adverse aviation conditions in clouds and showers. -Blaes && .RAH WATCHES/WARNINGS/ADVISORIES... Dense Fog Advisory until 6 AM EDT Thursday for NCZ007>011-024>028- 040>043-076>078. && $$ SYNOPSIS...BSD/Blaes NEAR TERM...BSD SHORT TERM...AS LONG TERM...AS AVIATION...Blaes