Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 12/01/22

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
518 PM CST Wed Nov 30 2022 .UPDATE... Issued at 517 PM CST Wed Nov 30 2022 The forecast remains on track this evening. No major changes are planned. && .SHORT TERM...(This Evening through Thursday Night) Issued at 223 PM CST Wed Nov 30 2022 As of 21Z, the CWA is seeing a mostly sunny sky with temperatures in the teens and 20s. Breezy northwesterly winds continue impacting the eastern half of the CWA with a steady decrease across the western half. The winds should become light and variable later this evening before shifting to the southeast overnight. Models continue showing a strong LLJ developing especially over the eastern half of the CWA after 6Z. Wind gusts may exceed 45 mph at times over the higher terrain areas of the Sisseton Hills. The increasing winds should cause temperatures to become steady or slowly rise after midnight. High temperatures on Thursday are somewhat challenging. Depending of deterministic model used, 925 mb temps may warm into the single digits above zero C, or as the NAM indicates, around 0C. The NAM, as well as the 12 and 18Z HRRR show a fairly good inversion over the eastern half of the CWA, keeping temperatures on the cooler side of NBM guidance. With some snow cover south of the CWA, along the potential for snow melt and southerly winds, the added moisture in the boundary layer may limit heating on Thursday. Also, the lack of southwesterly or westerly winds at the surface is a limiting factor as well. With warm temps at 850 mb, along with a southwesterly wind component at 850 mb and the lack of snow cover over the CWA, will continue with warmer temperatures over much of the CWA. Did go with NBM 50th over the eastern half of the CWA due to poor mixing winds. An approaching area of low pressure and associated frontal boundaries will keep the environment well mixed Thursday night, keeping temperatures in the teens and 20s. .LONG TERM...(Friday through Wednesday) Issued at 223 PM CST Wed Nov 30 2022 The biggest weather concerns between Friday and next Wednesday is over what portion of the CWA will a light accumulation of snow occur on Friday while strong northwest winds increase, along with how cold it could be Monday through Wednesday of next week. When the period opens, deterministic and ensemble camps of models all showcase a low pressure system churning across the northern plains states. Rather strong low level (700hpa and below) fronto- forcing potential seen in the models, associated with the cold fropa progged to occur on Friday, but synoptic scale lift still only seems to be topping out around 10 microbars. The latest trend seems to be pushing the potential for measurable snow further north into North Dakota (NBM/EC Ensemble Mean probability of an inch or more of snow). That said, there is still the potential for some of the northern tier counties of the CWA to pick up a light accumulation (generally an inch or less) of snow between 9AM CST and 9PM CST on Friday. Regarding the cold fropa, once the wind shifts to the northwest on/along the Prairie Coteau and starts increasing in speed/gustiness, there could be the potential for a little bit of additional terrain-forced light snow enhancement (perhaps upwards of 2 inches?) there on the Coteau Friday afternoon/evening. Wind speeds/gusts could be tickling advisory strength by late Friday afternoon and on into the overnight hours. Running things through the blowing snow model for Friday/Friday night only yields "patchy blowing snow" mention for now. Generally speaking, once this Friday system clears the region Friday night, the CWA will be influenced for much of the forecast period by northwest flow. The northern branch of a developing split flow regime will dictate if and when smaller transient areas of low pressure will dive south-southeastward over the Dakotas, influencing the region`s sensible weather conditions. Right now, PoPs in the extended (beyond Friday) are non-measurable (less than 15%), but would not be shocked if between Saturday and Wednesday, the CWA sees a couple quick shots of heavy flurries or light (accumulating?) snow. More than that, deterministic and ensemble output today supports the idea that after a potential brief temperature recovery back to near normal by the end of the weekend, another strong arctic cold frontal passage will sweep through the CWA early next week, setting the stage for more much below normal temperature conditions. && .AVIATION...(For the 00Z TAFS through 00Z Thursday Evening) Issued at 517 PM CST Wed Nov 30 2022 Terminals KABR,KATY,KPIR,KMBG VFR conditions are expected through the next 24 hours. South to southeast winds will increase tonight. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...None. MN...None. && $$ UPDATE...Wise SHORT TERM...SD LONG TERM...Dorn AVIATION...Wise
Area Forecast Discussion
National Weather Service Charleston SC
857 PM EST Wed Nov 30 2022 .SYNOPSIS... High pressure will build in across the region through Friday. A front will then shift into the area Saturday and Saturday night, and could linger in the vicinity into early next week. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... No major changes were made for the late evening update. Satellite, surface observations and RAP instability analysis at showed the cold front was located roughly along a Moncks Corner-Walterboro-Denmark-Claxton-Baxley line at 01/0145z. A little fog has developed just ahead of the front, but it will not last too long as surface winds will pick up quickly with FROPA. The boundary is showing a classic bending pattern in the lee of the Southern Appalachians, typical when fronts interacts with the higher terrain of the Black Mountains of southwestern North Carolina, including Mount Mitchell. The deepest moisture has pushed offshore and with it any risk for measurable rainfall. The front will clear the coast roughly in the 10-11 PM timeframe with drier and cooler conditions advecting in behind it. Once the front pushes through, expect rapid clearing to occur with clear skies prevailing overnight. Lows will range from the mid- upper 30s well inland to the upper 40s/near 50 at the beaches. Lake Winds: Winds on Lake Moultrie are expected to surge a bit overnight as low-level cold air advection interacts with water temperatures near 60. Winds in the mixed layer look to fall just short of Lake Wind Advisory criteria, but a solid 15-20 kt along with waves 1-2 ft are expected. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/... Thursday and Thursday night: High pressure will continue building into the region Thursday, becoming centered near the Virginia Tidewater region Thursday night. The airmass will be very dry, with precipitable water values of a quarter of an inch or less through the day. The main story will be the significantly cooler temperatures. Highs are forecast to only reach the mid to upper 50s, with some low 60s possible along and south of I-16. Such temperatures would be on the order of 10 degrees below normal for early December. Also, northeast winds will be elevated due to the tight pressure gradient, making it feel even cooler. Overnight, lows will be chilly with low to mid 30s across the far inland counties, ranging to the low to mid 40s along the coast. Friday through Saturday: The center of the high will shift out over the northwest Atlantic as a subtle coastal trough sits just offshore. As the high moves away, the low-level flow pattern will be easterly and southeasterly through Friday night, then southerly ahead of an approaching front on Saturday. Friday is currently expected to be dry, though with the coastal trough nearby we can`t completely rule out some weak shower activity along the coast. For Saturday, it appears that nearly all of the precipitation will remain upstream along the front and any that approaches from the northwest late in the day will be on a distinct diminishing trend. Temperatures will moderate significantly through the period with highs increasing well into the 60s Friday and then back into the 70s Saturday. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... The front will drift into the area Saturday night and become oriented west to east. How far south across the area the front pushes is in question and then it appears as though it will linger int he vicinity into early next week before lifting back northward as a front. This injects some uncertainty into the forecast regarding rain chances because depending on the position of the front, the axis of rainfall could shift significantly north or south. For now it looks like the best chance of rain will come Sunday night into Monday before the front starts lifting northward taking with it the best forcing for precip. For now this is where we have the best rain chances, though they are held in the 20-30 percent range. As the positioning of the front and its movement come more into focus, rain chances could end up being higher with better confidence in the timing. Otherwise, temperatures will generally be above normal, especially once the front lifts north of the area. && .AVIATION /02Z THURSDAY THROUGH MONDAY/... KCHS/KJZI/KSAV: VFR. The cold front will push through the terminals roughly 02-03z with a wind shift to the northwest and eventually north. Extended Aviation Outlook: Mostly VFR. && .MARINE... Tonight: Northwest then north winds will pick up quickly behind the cold front has it pushes across the waters over the next few hours. Winds will peak 20-25 kt with gusts to 30 kt all coastal legs with 15-20 kt in the Charleston Harbor. Frequent gusts will will be very close to advisory levels for a few hours overnight, so a Small Craft Advisory has been posed for the Charleston Harbor until 4 AM. Seas will build 4-6 ft nearshore waters and 5-7 ft over the Georgia offshore water where Small Craft Advisories remain posted. Thursday through Monday: Thursday will begin with a solid northeast surge underway as high pressure build into the region. Small Craft Advisories are already in effect for all waters outside of Charleston Harbor, and we should see a solid 20-25 knots of wind with gusts to 30 kt. Seas will increase to 4-6 feet across the nearshore waters and 6-7 feet for the outer waters. One thing to watch will be winds in Charleston Harbor, especially Thursday morning. Wind gusts will be near 25 knots for several hours and a Small Craft Advisory could be needed. Conditions will gradually improve through Thursday night as winds and seas diminish. Winds will then turn more southerly and then southwesterly into the weekend before a front drifts in from the north late in the weekend. Overall, once the advisory conditions come to an end Thursday and Thursday night, winds and seas should remain well below advisory thresholds into early next week. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. MARINE...Small Craft Advisory until 4 AM EST Thursday for AMZ330. Small Craft Advisory from midnight tonight to 4 PM EST Thursday for AMZ350-352. Small Craft Advisory from midnight tonight to 7 PM EST Thursday for AMZ354. Small Craft Advisory from midnight tonight to 1 PM EST Friday for AMZ374. && $$
Area Forecast Discussion
National Weather Service Goodland KS
411 PM MST Wed Nov 30 2022 .SHORT TERM...(This evening through Thursday) Issued at 143 PM MST Wed Nov 30 2022 This evening through the overnight hours a weak disturbance aloft is expected to travel across the Rockies and over the area, strengthening the lee trough along the Front Range. This and a tightening pressure gradient will bring an increase in sky cover and winds during the overnight hours. The winds are expected to be out of the southeast to south at 10-25 mph and gusts up to 40 mph through sunrise tomorrow. The strongest winds are anticipated to be along and south of I-70. Temperatures tonight will be in the upper teens to mid 20s with wind chills in the upper single digits to upper teens. On Thursday another upper disturbance will sit over the area while the lee trough broadens across the Plains ahead of Friday`s strong cold front. Temperatures warm up nicely tomorrow with highs in the mid 50s to lower 60s. Thursday, southerly to southwesterly winds are expected to be around 10-20 mph with gusts up of 25-30 mph possible. Overnight lows will be in the mid 20s to upper 30s tomorrow night. .LONG TERM...(Friday through Wednesday) Issued at 250 PM MST Wed Nov 30 2022 Strong gusty winds on Friday will cause concern for increased fire weather and blowing dust threats. Model guidance for Friday is beginning to align, although there is still a decent amount of variance. The GFS and NAM are both suggesting that the surface low pressure system and associated cold front will move across the Goodland CWA earlier than previously expected. The cold front will cross the Tri-State area from the northwest to the southeast, and is expected to enter Yuma county in Colorado during the late morning hours. The FROPA will quickly cross the CWA and is expected to be clear of the area by the evening. With the earlier passage of the cold front, temperatures will top out in the 50s and 60s, and minimum RH values will be at least in the upper teens. This will help decrease the fire weather risk. However, continuing dry conditions have provided ample fuels to burn and winds will work to increase the fire weather threat. Sustained winds of 20 to 30 kts and gusts up to 44 kts are expected throughout the CWA. Strong winds are expected before and after the cold front, and the wind shift it will cause. If any fires were to start, the wind could quickly spread them and the change in wind directions (from the southwest becoming northwestern) with the FROPA could make firefighting operations challenging. Blowing dust is also a concern on Friday. The GFS and RAP are showing 0-2 km lapse rates over 9 C/km, 2-2.5 km lapse rates of 3-6 C/km, and 0.5-1 km winds over 40 kts around 18-21Z on Friday. These conditions paired with strong winds at the surface could produce blowing dust. There is a concern that the FROPA could create a wall of dust, but at this time confidence is not high that this will occur. If the cold front were to move through the area later in the day, temperatures could climb into the 60s and 70s which would lower RH values into the mid teens. If this were to happen, the risk for fire weather danger would increase substantially. Another implication of the later timing of the FROPA would be a lower chance of a wall of dust, but areas of patchy blowing dust would be more likely. After the cold front has passed, Friday night will cool into the low to mid teens and wind chills will drop into the lower and middle single digits by Saturday morning. Saturday through Monday, a warming trend will be the big news due to a high pressure system moving over the southern portion of the CWA. Monday`s temperatures will max out in the upper 40s and mid 50s, a 5 to 10 degree difference from Saturday`s high temperatures. Overnight low temperatures will be in the lower to mid 20s for these nights. Monday afternoon will see a weak cold front pass through the area and cause the winds to come from the north again, cooling the Tri- State area into the mid and upper teens for Tuesday and Wednesday morning. This will also cap Tuesday`s high temperatures in the lower to mid 40s. Thankfully, this shift should be short lived and Wednesday will warm back up into the mid 40s, about normal for this time of year. && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 410 PM MST Wed Nov 30 2022 Only aviation concern will be LLWS tonight at both KGLD and KMCK as a southwesterly nocturnal low level jet develops. Otherwise, VFR expected to prevail at both terminals. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...KMK LONG TERM...CA AVIATION...024
Area Forecast Discussion
National Weather Service Pocatello ID
239 PM MST Wed Nov 30 2022 .SHORT TERM (Tonight - Friday AM)... A period of active winter weather is underway across eastern Idaho this afternoon and this will continue for the next 48 hours or so. A strong area of low pressure off of British Columbia and its associated moisture will overspread the region over the next few days bringing widespread snow and gusty winds. Starting with the snow, the next few days will bring FEET of snow to the Wood River Valley north to Stanley and north of Ashton through Island Park with up to around 2 feet of snow in the valleys and amounts up to 4 feet of snow in the mountains. Highest totals will be across southern upslope favored areas of the Sawtooths, Western Smokys, and Centennials. Totals across the eastern and southeastern Highlands won`t be nearly as high but still likely to reach around a foot, or a bit more. Winter storm warnings continue for these areas and we`re expecting SIGNIFICANT impacts in these areas not only from snow, but gusty winds creating widespread blowing/drifting snow making travel extremely difficult in these areas. Elsewhere, Winter Weather Advisories are now in effect for the rest of the area, including into the Snake Plain and eastern Magic Valley. In those areas, accumulations are a bit more difficult to forecast as southerly winds will likely allow for temps to warm above freezing for a brief period, perhaps allowing for a rain/snow mix during the afternoon hours. That being said, hi-res model soundings show this layer as being very shallow or non-existent (depending on your model of choice) so that complicates matters a bit. Nevertheless, by late evening as the front moves through, confidence is high that precip will be all snow at this point and it will likely come down quite quickly with the front. In addition to this, winds will be a concern as the snow is falling creating some very difficult driving conditions around much of the area and this will likely be during the evening commute. For these reasons feel an advisory is the best course of action for this event although totals will be on the low side especially as you head into the eastern Magic Valley. Totals will be higher however as you head towards AF and Pocatello and especially from Blackfoot north on I-15. Totals across the Upper Snake Plain, mainly from Rexburg into St. Anthony could flirt with Winter Storm Warning criteria so an upgrade in this zone could be needed on subsequent forecasts although Idaho Falls likely falls in the 4-6" range for this event. In short, things are still a bit in flux in spots but outside of the Snake Plain and Magic Valley, there`s good confidence in meeting advisory criteria. Briefly discussed the wind concern already but late Thursday and into Friday appears to be the time of biggest concern with winds. Current wind forecast relies heavily on the NBM 90th percentile and NBM 4.1 which has winds gusting in the 25-35 mph range for much of the region with higher gusts expected in the higher terrain and in the more wind-prone locations like near Yale and Idahome. Bottom line is this, expect a prolonged period of high-impact winter weather across the region but the most significant impacts will be focused across the Central Mountains and eastern Highlands. Even if the current snow forecasts in the Snake Plain don`t quite materialize as they`re currently forecast, winds will still create winter weather impacts with the snow that does fall and the snow that is currently on the ground across the region. McKaughan .LONG TERM (Friday through next Wednesday)... This week`s weather system will come to an end on Friday, but we`ll be dealing with some lingering snow east of Interstate 15 through Friday afternoon. We`ll also be dealing with some gusty winds throughout the day Friday in a post-cold frontal regime. Weather will settle down Friday night with models depicting a transient ridge shift through the area on Saturday. Deterministic models indicate an upper low developing off the OR/CA coast Saturday, pushing onshore on Sunday. As the low moves inland, moisture will advect into Idaho from the south. Ensemble clusters are still showing some uncertainty on when the upper low will fill and eject eastward, a factor that will ultimately drive QPF for the region. The 00Z EFI continues to maintain a relatively low- impact weather system with no extreme snowfall, but anomalously cooler temperatures. Quieter weather is indicated by most models by Tuesday afternoon, but the region will remain at the backside of a broad upper trough through Wednesday. Hinsberger && .AVIATION... Moisture continues to stream across southeast Idaho with snow ongoing as SUN and DIJ. SUN remains below airfield minimums to start off the TAF period, but NBM and HRRR guidance shows improvements there by mid afternoon. DIJ has seen some bouts of IFR visibility this morning, and NBM shows this to continue for a couple more hours, but the terminal was VFR at TAF issuance. IDA may see some periods of IFR visibility this afternoon with a band of snow moving through, but PIH, IDA, and BYI should have a dry, downslope wind through tonight. Conditions will again deteriorate tonight as another batch of moisture is transported into the region mostly impacting SUN and DIJ. Hinsberger && .PIH WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory from 5 AM Thursday to 11 AM MST Friday for IDZ051-052-068-070. Winter Weather Advisory from 5 AM Thursday to 5 PM MST Friday for IDZ053>059-061-062. Winter Storm Warning from 5 AM Thursday to 5 PM MST Friday for IDZ060-063>065. Winter Storm Warning until 5 PM MST Friday for IDZ066. Winter Storm Warning until 11 AM MST Friday for IDZ067-069. Winter Storm Warning until 5 AM MST Friday for IDZ071>075. && $$