Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 11/27/20

Area Forecast Discussion
National Weather Service Fort Worth TX
628 PM CST Thu Nov 26 2020 ...New Short Term, Aviation... .SHORT TERM... /NEW/ /Tonight through Friday Night/ A cold front continues to sweep south through the Plains this evening and will likely advance south of the Red River by midnight. Initially, the front will slide through without much in the way of precipitation across North Texas. Winds will turn to the north and there will be an increase in cloud cover. As the front approaches Central Texas, however, low level moisture coupled with increasing large scale ascent will result in the development of precipitation (showers and storms). Pockets of fog---some dense---will be possible near and just behind the front as low level moisture convergence occurs. The most probable area for fog will be across East Texas and the Brazos Valley. Instability will steadily increase with MUCAPE values approaching 800-1000 J/kg. With mid-level flow increasing, a sufficient combo of shear and instability may exist to facilitate strong to marginally severe storms. At present time, the primary concern would be hail, though this threat looks greatest farther south into the Texas Coastal Plain and Hill Country. We`ll continue to monitor trends, however, as latest HRRR suggests that a few strong to near severe storms could be possible near and south of the I-14/US HWY 79 corridor in our forecast area. As 925-850mb WAA increases across Central TX and the Big Country, I anticipate additional showers and storms will develop later in the day. I`ve nudged PoPs upward some from the previous forecast given the strong large scale ascent. Decent surface pressure rises upstream will also drive a breezy north wind and speeds will range between 10 and 20 mph. It`ll also be cooler Friday with highs in the 50s and 60s. Bain && .LONG TERM... /Issued 134 PM CST Thu Nov 26 2020/ /Friday night through next Thursday/ The cold front will be well to our south near the TX SE Coast, but the breezy north winds are expected to continue Friday night into Saturday. Rain chances will also increase, especially across the Central TX zones, where better moisture and ascent is forecast. Overnight lows Friday night will be a few degrees cooler than tonight`s temps. The upper closed-low upstream of the cold front will slowly move across the southern plains over the weekend. Plenty of isentropic lift and rich moisture ahead of this system will bring widespread rain chances through at least Sunday morning. Rainfall rates will remain on the light side, but we can`t rule out some brief periods of moderate/heavy rain. Most of the enhanced rainfall and convection will remain across the Gulf Coast. Rainfall totals for our area are expected to remain between half an inch to around 1.5 inches through this period. Saturday`s temps will stay on the cool/chilly side due to the rain, breezy north winds, and cloudy skies. We`re looking at highs ranging from the mid 40s (western counties) to mid 50s (eastern counties). Both medium and long-range models are pretty consistent on showing the upper level low moving to our east on Sunday. Behind that, another surge cold cold advection will travel southward as we head into next week, keeping the steady north winds and well below normal temps. Many locations will see light freezes Monday morning, with a few spots across the northwest reaching the upper 20s. The coldest night still appears to be Monday night into Tuesday morning, where widespread freeze is in the forecast. Temperatures will range from the upper 20s to lower 30s. If the forecast verifies, we are looking at the first freeze of the season for DFW Airport, and the third freeze for Waco. Most of our area will remain in this cool/chilly and dry weather pattern through mid-week before we see the next system. At this time it looks like rain chances will return to North and Central TX next Thursday and Friday with the approach of another cold front. Sanchez && .AVIATION... /NEW/ /00 UTC TAF Cycle/ Concerns---FROPA and ceiling trends. VFR will prevail over the next 4-6 hours across area aerodromes before stratus invades. At North Texas TAFs, post-frontal MVFR stratus is anticipated everywhere in the 08-12 UTC time frame. The exception will be AFW where dry air will maintain VFR. The window for MVFR (cigs around 1200 feet) looks to be on the order of 2-4 hours elsewhere, with DAL likely experiencing the longest breadth of cigs near 1200 feet. In addition to MVFR cigs, northerly winds will increase to around 12-15 knots. Some gusts to near 20 knots are possible. The potential for SHRA or TSRA looks limited, but will need to be monitored for the 30 hour D/FW TAF in future forecasts. At Central TX, MVFR stratus will develop in the southerly flow regime. As the cold front slides southward, it`ll interact with greater moisture for a longer duration stratus event. Lift will also result in pockets of SHRA with embedded TSRA. The best instability will reside south and east of ACT and I`ll omit TSRA from the TAF at this time. Northerly breezes around 15 knots are also expected here. Bain && .PRELIMINARY POINT TEMPS/POPS... Dallas-Ft. Worth 51 59 46 49 41 / 5 10 20 60 70 Waco 54 62 50 52 41 / 10 50 50 80 60 Paris 50 59 43 51 41 / 5 5 5 30 80 Denton 45 60 42 48 37 / 0 5 20 60 60 McKinney 49 59 44 50 40 / 5 5 10 50 70 Dallas 52 61 48 50 42 / 5 10 20 60 70 Terrell 55 61 47 50 41 / 10 10 20 50 70 Corsicana 58 64 52 54 44 / 20 40 40 70 70 Temple 56 62 49 52 39 / 20 70 60 80 50 Mineral Wells 45 59 42 47 37 / 0 10 30 80 50 && .FWD WATCHES/WARNINGS/ADVISORIES... None. && $$
Area Forecast Discussion
National Weather Service Lincoln IL
930 PM CST Thu Nov 26 2020 .SYNOPSIS... Issued at 233 PM CST Thu Nov 26 2020 Dry weather and seasonable temperatures will dominate central and southeast Illinois into this Thanksgiving weekend. Lows overnight will be in the 30s. Highs Friday will be in the mid to upper 40s in central IL and lower 50s in southeast IL. && .UPDATE... Issued at 922 PM CST Thu Nov 26 2020 Updated the forecast for some adjustments in sky cover and cooler lows west of I-57 where low clouds cleared, allowing quicker temp drop. Low clouds with bases of 1.5-2.5k ft were east of I-57 at mid evening and slowly eroding eastward. Thin cirrus clouds covered rest of central and western IL, with another batch of low clouds over much of WI, central IA and se MN. These clouds were behind a cold front that was over se WI to near the IA/IL border. Temps have cooled to mid to upper 30s west of I-57 where low clouds have clearing with Galesburg and Macomb at 34F and Jacksonville down to 33F. Latest CAMs bring cold front southeast toward the IL river by sunrise Fri, and near I-57 by noon Friday. Models show some increase in low clouds overnight in central IL ahead of approaching cold front with fairly light south to sw flow. Also the 00Z ILX sounding shows a strong inversion from 1.8-3k ft which could trap low level moisture and HRRR, RAP and GFS lamp data showing patchy fog developing overnight east of the IL river, and mainly west of I-57. Will need to watch for this possible fog development overnight into early Fri morning as temps already close to dewpoints. Lows tonight in the low to mid 30s west of I-57 and upper 30s to near 40F from I-57 east, mildest readings near the Wabash river where low clouds likely remain thru the night and into Fri morning. && .SHORT TERM...(This evening through Friday) ISSUED AT 233 PM CST Thu Nov 26 2020 18z surface map indicated a weak cool front from northeast into central IA, while 1020 mb high pressure was centered over the lower Mississippi Valley. Resulting southwest low level flow was working to erode the low level cloud deck, and had advanced east of the IL River by 2 pm. Expect clearing to continue through much of the central CWA into this evening, then cloud cover should redevelop ahead of the advancing cold front. These clouds should persist well into Friday morning, then begin to decrease from the west towards midday. Due to the rather persistent cloud cover, low diurnal temperature ranges will be observed with lows in the mid/upper 30s tonight, and highs in the upper 40s Friday. .LONG TERM...(Friday night through Thursday) ISSUED AT 233 PM CST Thu Nov 26 2020 Cool and quiet weather will be seen Saturday as 1025 mb high pressure builds across central and southern IL. The pattern begins to turn more active Sunday, when a northern stream wave pushes a dry cold front into the area. Meanwhile a southern stream disturbance will move into the lower Mississippi Valley. 12z guidance still shows varying solutions on how quickly the waves will phase, but the overall deterministic and ensemble solutions favor this process occurring from the Ohio Valley towards the Appalachians. This would bring higher impact winter weather to Indiana and points east/northeast Sunday night through Monday. NBM guidance brings chances for light rain into the southeast third of the CWA Sunday evening, changing to snow after midnight as the column cools below freezing behind the front. Any minor accumulations would diminish on Monday east of I-57. Still plenty of time for changes in the track of this system, as the northern stream energy is still off the Pacific coast. Higher confidence that a period of below normal temperatures will impact the area Monday through Wednesday while low pressure occludes over the eastern Great Lakes. This should result in highs in the 30s with breezy northwest winds. && .AVIATION...(For the 00Z TAFS through 00Z Friday evening) Issued at 559 PM CST Thu Nov 26 2020 Stratus/stratocumulus clouds with MVFR ceilings 1.5-2k ft affecting DEC and CMI early this evening while low clouds have scattered out at SPI and BMI and clear of low clouds at PIA with some passing cirrus clouds. DEC on western edge of low clouds may see these clouds scatter out to for a time next few hours. But broken to overcast MVFR clouds likely to return to central IL during late evening/early overnight. Some models like HRRR even show more fog developing after 08Z/2 am overnight and for now added MVFR vsbys from 09-15Z. A cold front over se parts of WI/IA into nw MO to push se toward IL river/PIA by 12Z/6 am Fri and to DEC and CMI by late Fri morning and should pass thru dry. MVFR clouds to scattered out behind the cold front by Fri afternoon. South to SW winds 5-10 kts early this evening to weaken to around 5 kts next few hours. Winds switch NW with passage of cold front during Fri morning at 5-10 kts. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...07 SYNOPSIS...25/07 SHORT TERM...25 LONG TERM...25 AVIATION...07
Area Forecast Discussion
National Weather Service Jacksonville FL
927 PM EST Thu Nov 26 2020 ...DENSE FOG LATE TONIGHT AND EARLY FRIDAY MORNING IN THE SUWANNEE VALLEY AND INLAND SOUTHEAST GA... .UPDATE... Evening surface analysis depicts a weakening cold front stretching from the Mid-Atlantic coast southwestward across the southern Appalachians and through the Deep South to the Louisiana and Texas Gulf coast region. zonal flow prevails as a strengthening subtropical branch of the jet stream is nosing into our region from the northern Gulf coast. Meanwhile, a potent shortwave trough was diving southeastward from the Canadian prairies through the Dakotas and troughing was cutting off from the main flow over the Desert Southwest. Latest GOES-East derived Total Precipitable Water imagery indicates that deeper moisture is gradually advecting into our region from the west ahead of the decelerating frontal boundary, with PWATS of 1.3-1.5 inches in place across our area and values in excess of 1.5 inches noted over the western FL panhandle. Scattered convection that developed along a prefrontal trough ahead of the upstream cold front this afternoon over the Suwannee Valley and along the Altamaha/Ocmulgee Rivers has since dissipated, with debris cloudiness thinning out along the I-10 corridor and coastal southeast GA. Meanwhile, GOES-East nighttime infrared imagery already shows an expanding area of low stratus cloudiness to the west of the Suwannee River in north FL and west of I-75 in south GA. Temperatures and dewpoints at 02Z were only slowly falling through the 60s across our region. Support aloft for the frontal boundary to our northwest has weakened, while shortwave energy embedded within the strengthening subtropical branch of the jet stream was developing scattered convection along the boundary over the lower Mississippi Valley. Debris cloudiness from this convection will migrate across our skies after midnight, which may impact the extent of dense fog formation for locations south of I-10 late tonight. Short-term, high resolution guidance such as the last several HRRR runs as well as the 15Z SREF suggests that low stratus ceilings will advect eastward into the northern Suwannee Valley and inland southeast GA after midnight and will expand eastward towards coastal southeast GA and along the I-10 corridor during the predawn and early morning hours. Low stratus and fog may arrive at or just after sunrise in metro Jacksonville and along the southeast GA coast, with lower confidence in fog reaching southern portions of the St. Johns River basin and coastal northeast FL. Shortwave energy migrating into the FL panhandle from the west late tonight could also spark a few showers towards sunrise just ahead of the front near the Altamaha/Ocmulgee Rivers. Lows tonight will only fall to the 60-65 degree range as surface winds decouple around midnight. Troughing aloft digging southeastward from the Upper Midwest and the western Great Lakes region on Friday will nudge the frontal boundary southward towards the Altamaha and Ocmulgee Rivers by sunset on Friday. Widely scattered showers and possibly a few thunderstorms will be possible on Friday afternoon ahead of this front, mainly for inland locations north of I-10. Increasing multi-layered cloudiness should keep highs in the upper 70s for most of southeast GA, with lower 80s elsewhere, except mid 80s for north central FL. An afternoon sea breeze will move slowly inland from coastal locations, with isolated convection also possible along this boundary during the mid to late afternoon hours. && .MARINE... A weakening cold front will move slowly southeastward on Friday and will cross our coastal waters early on Saturday. High pressure will briefly build over the Ohio Valley in the wake of this front on Saturday night and will then progress eastward, moving off the Mid-Atlantic coast by Sunday afternoon as low pressure rapidly strengthens over the lower Mississippi Valley and begins to accelerate northeastward. A brief period of onshore winds are expected in the wake of the weak frontal passage on Saturday night and Sunday. Showers and thunderstorms will then increase on Sunday afternoon as the front returns northward. Low pressure will continue to deepen as it traverses the Appalachians on Sunday night and Monday morning, driving a strong cold front across our waters by midday on Monday. A few strong thunderstorms will be possible on Sunday night and early Monday ahead of this front, with Small Craft Advisory Conditions developing offshore. Strong low pressure will then remain nearly stationary over the Great Lakes region through midweek, with breezy offshore flow continuing over our waters and elevated seas prevailing offshore. Rip Currents: A lingering long period easterly ocean swell will likely keep a low-end moderate risk at the northeast FL beaches on Friday. && .PREV DISCUSSION [708 PM EST]... .NEAR TERM [Through Tonight]... A broken pre-frontal squall line of showers and isolated thunderstorms is moving eastward into inland southeast Georgia and Suwannee Valley this afternoon into evening. A few stronger storms will be possible given elevated shear and marginal diurnal instability as a nose of upper 60s dew pts edges inland across the Suwannee River Valley from the GOMEX this afternoon. Potential strong storm hazards today include small hail with below climo 500 mb temps of -13 to -14 degC under 45-50 kts within the hail growth zone. There could also be some gusty winds from stronger downdrafts with 40-50 mph at the surface and 0-6 km shear near 40 kts (38 kts TAE and 43 kts JAX 12z RAOBs). Low level subsidence will keep mostly dry conditions over northeast Florida. With the loss of diurnal instability, showers will come to an end later tonight. Widespread patchy fog will be possible tonight into the early morning hours with the increase of low level moisture. Locally dense fog will also be possible. Lows tonight will be above normal in the 60s. .SHORT TERM [Friday Through Saturday Night]... A weak cold front will stall over southern Georgia on Friday and drift southward into north Florida on Saturday. Embedded weak impulses will move through zonal flow aloft contributing to the development of scattered showers and isolated storms mainly north of the I-10 corridor. Temperatures will remain above average with temperatures closer to average on Saturday. .LONG TERM [Sunday Through Thursday]... On Sunday, an upper low over the TX/OK border will move eastward as a surface low deepens over the lower Mississippi valley. The lows will lift northeastward toward the southern Appalachians by Monday morning. This will cause the frontal boundary over north Florida to lift northward as a warm front on Sunday. Widespread rainfall with embedded thunderstorms will affect the area with isolated strong storms possible. A strong cold front will then move through the region Monday morning bringing a much colder and drier airmass for early next week. Temperatures will drop below normal and could bring our first freeze of the season. Lows will drop into the 30s Monday night and Tuesday night. Widespread freezing temperatures will be possible across southeast Georgia Tuesday night. Brisk winds will likely produce windchill temperatures in the upper 20s and 30s. .AVIATION... [Through 00Z Saturday] VFR conditions will prevail through at least 05Z. Low stratus and fog will overspread the Suwannee Valley and inland portions of southeast GA after 06Z, with LIFR ceilings of 200-400 feet reaching GNV towards 09Z and VQQ towards 10Z. These low stratus ceilings and fog should then reach JAX and CRG between 11Z-12Z. Confidence was too low to include the coastal terminals of SSI and SGJ in the LIFR ceilings at this time, but there may be a period of low stratus at these terminals after 12Z through around 15Z. VFR conditions should then prevail at the regional terminals by 16Z. Southerly surface winds sustained around 5 knots this evening will become calm towards midnight, followed by southwesterly surface winds of 5-10 knots beginning around 15Z. The Atlantic sea breeze boundary will then develop at the Atlantic coast, crossing the coastal terminals by 18Z and then the Duval County terminals by 21Z. Surface winds will shift to east- southeasterly around 10 knots following the passage of this boundary. && .PRELIMINARY POINT TEMPS/POPS... AMG 63 77 61 71 56 / 30 30 50 60 10 SSI 65 77 64 70 61 / 10 30 40 50 10 JAX 62 80 63 73 61 / 10 30 40 60 10 SGJ 65 81 65 74 64 / 0 20 20 40 20 GNV 61 82 63 76 60 / 10 20 20 50 10 OCF 62 83 62 78 63 / 0 20 10 30 10 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...None. GA...None. AM...None. &&
National Weather Service Jackson KY
1055 PM EST Thu Nov 26 2020 .UPDATE... Issued at 1055 PM EST THU NOV 26 2020 The stratus deck has been building south some over the past several hours now. It does appear that portions of the Cumberland Valley and far southeast could remain mostly clear through the night. Therefore, you can see some fog in the river valleys and this is well placed in the grids. Hourly temperatures have been complicated since this stratus has been tougher to predict where it will develop or track. The Cumberland Valley and east have seen shaper temperature drops and adjusted for this in the hourly grids, but will likely have to be refined given the complicated cloud cover forecast. Also updated the sky grids to once again match the latest trends and favored the HRRR in terms of guidance. UPDATE Issued at 658 PM EST THU NOV 26 2020 We are seeing a deck of stratus this evening mainly north of the Mountain Parkway and it has been pulling back northwest. However, another wave will ride east and pull the stratus back across the remainder of the area later tonight. The valleys have seen a little quicker drop offs in the east and across the Cumberland Valley and adjusted the temperatures to better capture this. Otherwise main adjustments were to the sky grids to better reflect the current obs and trends. && .SHORT TERM...(This evening through Friday night) Issued at 345 PM EST THU NOV 26 2020 As of mid afternoon, an upper level ridge was centered in the vicinity of the Bahamas, an upper level low was moving through the northeast Conus, while an upper level trough extended from the Hudson Bay region to the southwest Conus. This pattern leaves the lower OH Valley in generally southwest flow aloft between he ridge to the southeast and the trough to the northwest and west. A weak shortwave moving through the OH Valley is moving east of East KY at this time, while a more substantial shortwave was upstream over the southern Plains and an upper level low was currently over the southwest Conus but should not affect the weather in the OH Valley until the end of the weekend. At the surface, a ridge of high pressure extended from TN Valley into the OH Valley, while a cold front was upstream of the area extending from the Hudson Bay area to the Plains. Meanwhile, clearing has worked into the southeastern half of the region and continues to work to the northwest. This evening and tonight, low level moisture trapped below a subsidence inversion as weak mid level ridging builds across the area is expected to persist in the 925 mb to 850 mb layer tonight and into the day on Friday, despite sfc high pressure building into the area. This low level moisture is finally expected to thin as Friday progresses as the upstream cold front and associated shortwave trough begin to approach from the west and northwest. However, mid level moisture will arrive within a few hours of the low level moisture thinning with the cold front moving across the area from late Friday into Friday night preceding a mid level trough. As for sensible weather in the near term, plenty of clouds should be experienced across much of the area during the entire near term period. Clearing of low clouds should continue moving a bit further northwest this evening, but guidance suggests this stratocu and stratus should spread back to the southeast later this evening and overnight. Some of the south or southwestern sections may remain clear for several hours and with light winds some valley fog may develop there in locations such as the Cumberland River valley. The low clouds, however, should finally thin out on Friday morning to Friday afternoon, before clouds arrive ahead of the front and mid level arrive. Temperatures during the near term period are expected to average above normal for both highs on Friday as well as lows tonight and Friday night with cloud cover anticipated. .LONG TERM...(Saturday through Thursday) Issued at 356 PM EST THU NOV 26 2020 The beginning of the extended consists of a fairly benign forecast. We start by seeing heights rise with the exit of an upper level trough, while sitting on the backside of its associated surface front. High pressure builds in from the west behind this front through the day, keeping things dry as skies begin to clear. Temperatures take a dip for Saturday, but it`s not overly significant. Moving into the beginning of the workweek is where more of the impactful weather takes place. Guidance has come to more of an agreement over this system`s progression. A closed upper level low over the southwestern US moves east over the weekend, before gradually phasing with a trough moving through the northern stream. This supports the formation of a surface low along the western Gulf coast on Sunday. This low moves northeast through the Tennessee Valley and up the Appalachians on Monday, strengthening significantly as it does so. Eventually this low stalls above the Ohio Valley near the Great Lakes Tuesday. In terms of sensible impacts, this system starts by bringing us rain late Sunday through the first part of Monday. However, temperatures take a drop as cold air moves in, allowing for a transition to snow Monday night. Snow continues through Tuesday as moisture wraps around the system, potentially impacting evening and morning commutes. Confidence is growing for this to be the first accumulating snow of the season, however, it is still too early to nail down any specific accumulation amounts. Transitioning into the latter half of the workweek, PoPs are on the decrease as the low pressure system begins to weaken, filling in as it moves away to the northeast. && .AVIATION...(For the 00Z TAFS through 00Z Friday evening) ISSUED AT 639 PM EST THU NOV 26 2020 The latest trends in the satellite data and obs shows the primary area of stratus pushing back north and west this evening. This is allowing for most sites to clear outside of JKL/SYM who remain in MVFR to start the period. There is a weaker shortwave aloft that should pull this deck back east later tonight and this will affect all the TAF sites once again bringing MVFR CIGs. The clearing through the evening could allow for a little fog to develop in the Cumberland Valley later tonight and this could affect SME/LOZ, but this will be dependent on the progression the stratus deck through the night. Finally by morning we will see improvements to any VIS restrictions, and a return to VFR across the board by Friday afternoon. The winds will remain light and variable through the period. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...DJ SHORT TERM...JP LONG TERM...HAS AVIATION...DJ
Area Forecast Discussion
National Weather Service Pueblo CO
310 PM MST Thu Nov 26 2020 .SHORT TERM...(This evening through Friday) Issued at 247 PM MST Thu Nov 26 2020 Current water vapor imagery and upper air analysis is indicating moderate southwesterly flow aloft across the region, as a broad upper trough is shearing apart across the Intermountain West at this time. Water vapor imagery is indicating the main portion of the trough translating across the Northern Rockies with shear axis into northwestern Colorado at this time, as secondary energy digging down the backside of the system is developing a mid level circulation across the southern Great Basin at this time. IR satellite and regional radars indicating cloud top cooling with scattered echoes along the shear axis stretching from east central Utah, through northwestern Colorado and into northeastern Wyoming, with mainly clear skies across southeast Colorado at this time. Latest models remain in good agreement of the main trough continuing to translate east into the Upper Midwest tonight, as secondary energy cuts off an upper low across southern Arizona by 12Z Friday. This will allow for weak uvv to slowly shift south and east across the central Rockies through the evening as the shear axis dissipates through the overnight hours. Models indicating the best lift and moisture to remain across the northern and central mountains through the late afternoon and evening, with the HRRR the most aggressive at spreading light qpf south across the Pikes Peak region and into the southeast mountains after midnight, as north to northeast upslope flow develops behind the passing system`s weak cold front. At any rate, current forecast keeps isolated to scattered pops across central mtns tonight, with isolated pops spreading south and west across the higher terrain through the evening into early Friday morning. Lack of available moisture remains a limiting factor for snowfall, with accumulations of a few inches possible across the higher terrain of the ContDvd, and mainly flurries if anything over and near the eastern mts. For tomorrow, the southern Arizona upper low is forecast to start to lift out across the southern Rockies, with some differences in the track, though most keep it too far south to bring widespread precipitation to the area. Best chances of generally light snowfall will be across the eastern San Juan mountains Friday morning, with pops spreading east into the southern Sangre de Cristo mountains through the day as southerly flow aloft becomes more east to southeast Friday afternoon. Otherwise, dry conditions are expected across the area with temperatures near to slightly cooler than today`s readings. .LONG TERM...(Friday night through Thursday) Issued at 247 PM MST Thu Nov 26 2020 Better agreement among the models through Monday before large discrepancies arise for next week. Ensemble spreads continue to be large, and operational solutions all over the place with little run to run consistency. This continue to lead to very low forecast confidence for next week. Friday night and Saturday...a slow moving upper level low will be tracking eastward across the Desert Southwest into the Texas Panhandle. The GFS and ECMWF remain in agreement with the storm track, while the NAM continues to be the northerly outlier. Expecting light snow over the San Juan Mountains and southern Sangre de Cristo range Friday night into Saturday morning. Not anticipating much in the way of accumulations, with 1 to 3 inches possible through Saturday morning. Continued with low pops along the New Mexico border for Saturday morning based on the NAM, but wouldn`t be surprised if everything remains to the south of the Plains. If precipitation does fall on the Plains along the New Mexico border, it will be in the form of rainfall, as afternoon high temperatures are expected to be in the 50s. Saturday night into Monday...a secondary trough will pass into the northern Plains Saturday night sending a cold front south across the Plains. This will bring about a 10 degree cool down for Sunday. This frontal boundary will come through dry, with the main issue being gusty north winds across the Plains throughout Sunday. Expected continued dry conditions to continue on Monday under broad northwesterly flow aloft. Temperatures will rebound back into the 50s across the region. Tuesday through Thursday...very low confidence in the forecast evolution during this period. The GFS pattern evolution seems a bit far fetched, developing an upper low over Colorado and wobbling it around the Intermountain West through the end of the week. The ECMWF is a bit more feasible, dropping an upper level low out of the Northern Rockies, but then has no idea where it wants to take it. The ECMWF would bring chances for rain and snow to the area Tuesday into Wednesday. But given the uncertainty and large ensemble spreads, confidence in any solution is very low at this point. For now, just have low chances for precipitation over the Mountains through the middle of next week, which will likely need to be either raised or removed if we can gain any run to run model consistency. Mozley && .AVIATION...(For the 00Z TAFS through 00Z Friday evening) Issued at 247 PM MST Thu Nov 26 2020 VFR conditions expected at COS, PUB and ALS over the next 24 hours, as an upper level disturbance translates across the Rockies. This system will bring increasing clouds to the area tonight. Isolated to scattered snow showers are expected across the northern and central mts this afternoon and evening, with a few showers possibly moving into the Pikes Peak region later this evening. && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...MW LONG TERM...MOZLEY AVIATION...MW
Area Forecast Discussion
National Weather Service Tulsa OK
915 PM CST Thu Nov 26 2020 .DISCUSSION... Weak cold front has pushed into wrn Osage/Pawnee/Creek Counties at this time, and will continue to move through much of our CWA overnight. Increasing low level moisture/isentropic upglide will result in low clouds overspreading southeastern Oklahoma and west central Arkansas tonight. Latest HRRR and RAP as well as 00z NAM suggest some light rain is possible in that area overnight, as isentropic upglide in 290k through 300k surfaces increases with condensation pressure deficits decreasing to only 10mb. In addition, seven of twenty 18z GEFS members produce measurable precip sern OK tonight. Will introduce slight chance pops/light qpf 06-12z, with lift expected to shift south and east of our CWA after 12z. Remainder of forecast elements trending well. Happy Thanksgiving y`all! && .TSA WATCHES/WARNINGS/ADVISORIES... OK...None. AR...None. && $$ SHORT TERM...69