Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 01/23/22

Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
902 PM EST Sat Jan 22 2022 .UPDATE... Sufficient magnitude to low level drying in the wake of the first in a trio of clipper systems will effectively offer a window of benign conditions as support wanes for snow shower production overnight. Forecast through 09z will continue to call for the occasional flurry, but rapid loss of even a stratocu field off lake Michigan indicative of the increasingly unfavorable enviroment for greater downstream moisture flux. Attention Sunday morning tied to the next clipper on pace to pivot across the Ohio valley. Meaningful large scale ascent marking the inbound height falls still expected to sweep across southeast Michigan 09z-15z. Given the synoptic improvement in moisture quality, this should prove sufficient for a widespread, light accumulating snowfall for areas mainly south of the I-69 corridor. A more localized axis of deeper ascent appears to manifest within the I-94 corridor and Ohio border region, as a noted uptick in mid level deformation engages a southward advancing frontal boundary. Some iterations of the HRRR and RAP offer an elevated response within this corridor, suggesting there remains some forecast sensitivity to the possibility of a smaller scale, moderately intense fgen band. A general 1 to 2 inch accumulation remains highlighted within this corridor, highest amounts toward the Ohio state line. Elsewhere, accums below an inch on target. && .PREV DISCUSSION... Issued at 632 PM EST Sat Jan 22 2022 AVIATION... Lingering window through roughly 02z for light lake effect snow showers to transit the southeast Michigan airspace. Intervals of MVFR conditions will exist during this time. Upstream trends lend confidence in some improvement in cloud bases toward prevailing lower VFR for a period overnight /03z-09z/, with a slightly drier low level environment also supporting a decrease snow shower/flurry coverage. A modestly gusty west-southwest wind this evening, gradually veering with time from PTK northward overnight as a weak boundary eases across the area. Moisture increases during the mid- late morning hours north of a low pressure system tracking through the Ohio valley. This will result in a period of widespread, light accumulating snow in IFR conditions across the Detroit/PTK airspace. This moisture glances across FNT/MBS, affording a shorter window of light snow in MVFR conditions. Improving conditions from north to south by early afternoon under drier northerly flow. This will ease ceiling heights back into lower VFR, with a general reduction in overall coverage of stratus more likely toward evening. For DTW...Very light snow showers or flurries will persist this evening /through 02z/, before a brief window of dry conditions emerge overnight. Upstream trends suggest activity will remain limited in intensity. A light accumulating snowfall arrives for the mid-late morning period Sunday /09z-15z/. Potential for accumulation of around an inch during this time. DTW THRESHOLD PROBABILITIES... * High in ceilings aob 5000 feet through Monday morning. Medium Monday afternoon. * High for precipitation falling as all snow through the TAF period. PREV DISCUSSION... Issued at 401 PM EST Sat Jan 22 2022 DISCUSSION... Reflectivity data from 1830-2030Z depicts more transient coverage of lake-supported snow with diminishing rates (sans Tri-Cities). These lingering snow showers will persist into the late evening hours as the trailing edge of the PV anomaly lifts northeast and the corridor of lower isentropic lift is shunted into southern Ontario. Sub-H7 winds then veer WNW stripping away some moisture from the residual stratus layer before midnight solidifying a brief break in precip. Given persistent mixing potential tapping into +35 knot 900 mb winds, also nudged gusts up to 25 knots through 00Z this evening. Dry mid levels will be shortlived as a second embedded shortwave trough noses in late tonight, reintroducing middle troposphere moisture advection. Marked ThetaE convergence after 06Z reinvigorates the west to east expansion of the mid-cloud layer. This provides some insulating potential for the southern half of the forecast area where temperatures should settle in the upper teens to low 20s. Meanwhile, H8 temps nearing -20C spill south across the Tri- Cities/Thumb, and coupled with a longer window of partial clearing, overnight lows approach single digit readings north of I-69 by daybreak. The embedded inbound progressive shortwave and associated surface low will focus further south than today`s disturbance resulting in minor accumulations along and south of the I-96 corridor where the baroclinic zone is sharpest. Model trends suggest a Sunday morning timeframe for the bulk of snowfall, although more limited in spatial extent. Got more aggressive with PoPs and accumulations for the southern four counties with between 0.5-1.0 inches by midday (isolated 1.5 inches). Just a dusting to a coating north of I-69 of dry snow where FGEN contribution is absent. After a two week lull in +1 inch snow events (nearly three weeks for DTW), a system with appreciable snowfall is set to arrive Monday morning. Low amplitude troughing within the polar jet will support a sharpening and strengthening jet streak with the core brushing the MI/OH state-line. Supporting top-down moisture surge complimented by strong ThetaE advection within the H8-H7 layer ramps up after 06Z Monday, although the highest specific humidity air holds further south. Forecast soundings remain cold, so no question that p-type will continue as snow throughout the event. Currently looking at SLRs near 15:1, but if the 5-10 kft layer comes in a bit colder, the depth of the DGZ would expand substantially, increasing the potential for higher mean SLR and increased snowfall. 18Z model suite has fallen into better agreement regarding the peak of the event which now appears centered around the evening commute with snowfall rates near a half inch per hour. The most likely outcome for snow totals still holds in the 2-4 inch range by Tuesday morning. Locally higher amounts near 5 inches cannot be ruled out, especially south of I-94. Will hold off on a Winter Weather Advisory at this time given the onset is still some 40 hours away and the duration for the forecast event totals is marginal, particularly for areas along and north of I-69. Colder and drier conditions expected for the mid-week timeframe in the wake of Monday`s system. Surface high pressure from the northern Plains builds southeast to 1037 mb over eastern Iowa by Wednesday. There are some hints of isentropic ascent within a canopy of low stratus supported by anticyclonic advection of lake moisture as the thermal trough makes its coldest approach. QPF would be low and coverage isolated-scattered, but far enough out that kept NBM PoPs at this time. Highs will be stuck in the teens Tuesday and Wednesday with the cold Canadian airmass, but aforementioned clouds should prevent a collapse in overnight lows. GFS/ECMWF are out of phase Wednesday night, onward, but perturbed height field will provide additional opportunities for precip into the end of the week with a recovery in thermal profiles by Thursday. MARINE... Southwest winds will be on the decrease into this evening cold front passes over the central Great Lakes late this afternoon and evening. The Gale Warning was allowed to expire, but there remains a chance that an occasional gust to gales may occur through this evening. Post frontal winds will shift to the west with gusts remaining above 20 knots through most of tonight across Lake Huron. A weak high pressure moving across southern Ontario will shift winds more northwesterly for Sunday morning with winds at this point 20 knots or below. The next inbound low pressure system will quickly shift winds back to the west Sunday evening and eventually towards the southwest for Monday. Winds will become elevated again late Monday into Tuesday morning as northwesterly winds bring a reinforcing shot of arctic air pushes into the region. Forecasts gusts from the northwest are to around 25 knots. Arctic high pressure will bring lighter winds Tuesday afternoon into Wednesday. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. Lake Huron...NONE. Lake St Clair...NONE. Michigan waters of Lake Erie...NONE. && $$ UPDATE.......MR AVIATION.....MR DISCUSSION...KK MARINE.......AA You can obtain your latest National Weather Service forecasts online at
Area Forecast Discussion
National Weather Service Quad Cities IA IL
848 PM CST Sat Jan 22 2022 .UPDATE... Issued at 843 PM CST Sat Jan 22 2022 Radar suggests an uptick in snow intensity west and north of the area. This looks to be tied to the largscale ascent moving into the area. RAP omega in the DGZ suggests that we may see less of a sharp gradient on the southern end of this system. The HRRR still thinks its going to be much further north, however the more convective like returns on the back end of the system suggests that current forecast is on track, if not a little more snow on the southern end. Generally the 1-3 looks good across the southern part of the advisory. We will need to watch what happens as the rain on the backend transitions into cooler air. Potential exists for increasing the totals on the southern end of the adv. Regardless, little changes to overall messaging and impacts associated with this clipper, just fine tuning of amounts. && .SYNOPSIS... Issued at 124 PM CST Sat Jan 22 2022 At 200 PM, a shortwave/Alberta Clipper was evident on water vapor imagery over southeastern South Dakota with clouds spreading into north central Iowa. A weak frontal boundary was sliding across eastern Iowa into northwest Illinois. Temperatures ranged from the upper teens to lower 30s across the area. Cedar Rapids was the cool spot at 17 degrees while keokuk was the warm spot at 34 degrees. There were gusty westerly winds across the area with speeds of 10 to 20 knots. && .SHORT TERM...(This Evening through Sunday) ISSUED AT 124 PM CST Sat Jan 22 2022 Key Messages: 1. There are no adjustments to the Winter Weather Advisory for tonight. 2. The area of accumulating snowfall has shifted northward slightly with this issuance. 3 to 5 inches of snow is possible north and east of a Manchester Iowa to Sterling Illinois line with 1 to 3 inches possible across the remainder of the advisory. There is going to be a sharp cutoff in accumulating snow south of the advisory area. 3. Patchy drifting snow is possible overnight with winds of 10 to 20 knots especially in open areas. Models continua to trend more northerly with this wave and faster with the bulk of the snow falling between 00 to 12 UTC Sunday. The main forecast concerns were snowfall amounts. Models are in very good agreement on the overall forecast over the next 24 hours. The track of the Alberta Clipper tonight has trended northward by a few miles. This currently brings the surface low from Sioux Falls late this afternoon to the Quad Cities at 06 UTC to central Illinois by 12 UTC Sunday. A band of FGEN forcing will overspread northern Iowa into southern Wisconsin this evening and overnight focusing the best lifting and moisture along the Highway 20 corridor. Soundings will slowly saturate after 00 UTC as moisture spreads into the area ahead of the wave with precipitation beginning after between 00 to 03 UTC northwest of a Cedar Rapids to Dubuque line then spreading southward through 06 UTC. Model soundings show good saturation through the dendritic growth zone as the wave moves across the area. Models hold temperatures in the teens through the event resulting in a snow to liquid ration of roughly 15 or 20 to 1 with the highest SLRs east of a Manchester to Sterling line. This results in a 3 to 5 inches of snow across this area along with 1 to 3 inches possible east of a Cedar Rapids to the Quad Cities to Princeton Illinois line with a quick drop off in snow totals south and west of this line. Additionally, expect winds of 10 to 20 knots between 12 to 18 UTC Sunday that may result in some drifting of snow through the morning north of Interstate 80. The low temperatures for Sunday morning will occurring in the 7 t0 9 AM range as temperatues quickly drop as the clipper exits to the east and strong cold advection spreads across the area. High pressure will quickly build into the area for the day on Sunday allowing clouds to quickly clear with sunshine expected across the area through the afternoon. High temperatures on Sunday will range from the lower teens along the Highway 20 corridor to the lower 20s south of a Fairfield to Galesburg line. .LONG TERM...(Sunday Night through Saturday) ISSUED AT 124 PM CST Sat Jan 22 2022 Key messages: 1. Clipper system to bring another chance of light snow Sunday night/Monday mainly across northeast IA through northern IL. Snow amounts between a dusting and 2 inches is forecast. 2. Dry conditions and below normal temperatures are expected for much of the work week, with wind chills approaching advisory levels (below -20 degrees) Tuesday night and Wednesday night. Sunday night-Monday...the last in a line of clippers will track through the CWA bringing another chance of light snow. Most of the 12z model runs and their ensemble members keep the best lift/forcing and higher snow chances across northeast IA into northern IL. With that being said, there has been a slight increase in QPF with this system and now has 0.05-0.20" forecast through Monday 18z. The higher QPF amounts are now seen across northern IL in Jo Daviess, Stephenson, and Carroll counties and points east, which will be closer to the low pressure track. Can`t rule out some light snow along the cold front across our far southern areas as the 12z NAM suggests and after coordination with neighbors, have added slight/chance PoPs for this possibility. Snowfall amounts between 1- 2 inches is possible along and north of a line from Independence IA, to Clinton, to Princeton IL. Snow totals from a dusting up to an inch will be possible south of that line. This new snow should fall prior to the morning commute on Monday for all areas except northwest IL, where the greatest impacts of snow covered roads and sidewalks are expected. Snow will end by late morning in all areas. Breezy northwest winds are forecast Monday afternoon and may keep temperatures from rising too much throughout the day. Highs should occur in the morning or early afternoon with readings in the mid/upper 30s south of I-80, to the upper 20s/low 30s north. Monday night-Wednesday...large 1037mb surface high will build into the Midwest bringing dry conditions and below normal temperatures. 850mb temps will drop into the -15 to -17C range keeping highs in the single digits over fresh snow cover and the lower teens elsewhere. The coldest night will be Tuesday night, with the surface high overhead. Lowered min temps some Tuesday night from the NBM as temperatures will quickly drop into the single digits and teens below zero by Wednesday morning. These readings will not be too far off from record lows for CID/DBQ. Even with a light wind Monday night and Tuesday nights, wind chills will drop into the -10 to -30 degree range and wind chill headlines will likely be needed. Wednesday night-Saturday...return flow develops Wednesday night ahead of another cold front to move through Thursday. Moisture along the front will be quite limited and just an increase in clouds is expected at this time. The rest of the period will bring near to slightly above normal temperatures and dry conditions with northwest flow aloft. && .AVIATION...(For the 00Z TAFS through 00Z Sunday Evening) ISSUED AT 608 PM CST Sat Jan 22 2022 VFR conditions will come to an end as snow and lower clouds move into the area in the next few hours. DBQ has the potential for LIFR vsbys as potentially heavy snow moves in. Winds could be gusty after the snow and may lead to some blsn. Otherwise, expect improvement to VFR later in the period. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...Winter Weather Advisory until 6 AM CST Sunday for Cedar-Clinton- Dubuque-Jackson-Jones-Scott. Winter Weather Advisory until 4 AM CST Sunday for Benton- Buchanan-Delaware-Linn. IL...Winter Weather Advisory until 6 AM CST Sunday for Bureau-Carroll- Henry IL-Jo Daviess-Putnam-Rock Island-Stephenson-Whiteside. MO...NONE. && $$ UPDATE...Gibbs SYNOPSIS...Cousins SHORT TERM...Cousins LONG TERM...Gross AVIATION...Gibbs
Area Forecast Discussion
National Weather Service Jacksonville FL
914 PM EST Sat Jan 22 2022 ...INLAND FREEZE TONIGHT... .UPDATE... Latest satellite imagery shows widespread low clouds continuing with ceilings mainly in the 500-1000 ft range. The guidance has been too quick to let up on the clouds and the imagery and guidance suggested to keep more of the area in the clouds overnight. This will have affects on the eventual low temps with some uncertainty on the min temps mostly over the srn zones where the clouds will likely linger the longest, and some of the guidance has hinted at low temps slightly warmer than prior forecast. The 00Z JAX sounding shows warming in the lowest layers but cold advection just above the cloud deck, indicating a a pattern of erosion of the low clouds at least around the JAX metro area. For the update, mainly just refreshed the temps and increase the sky cover rest of tonight. Otherwise, the freeze warning remains up but may not be as cold in some areas due to the lingering clouds. Of note too for today, we have broken the record low maximum temperatures at the following local climate sites: Alma, Craig Airport, Jacksonville Intl Airport, and Gainesville. .MARINE... Current forecast was on track with little change. SCA remain intact for most of the area waters. && .PREV DISCUSSION [659 PM EST]... .NEAR TERM [Through Tonight]... Observed temperatures this afternoon/evening are trending colder than the forecast temperatures due to a persistent deck of low stratus over the entire area, and we could set records for coldest maximum temperatures for this day (see climate section). Overcast skies are expected to continue through this evening for most of the area, then cloudiness will begin to decrease from north to south throughout the night. Northerly winds will become calm over SE GA and the Suwannee Valley tonight, which will allow surface low temperatures to drop into the upper 20s. Areas generally from Amelia Island to Gainesville will also see cold low temperatures in the lower 30s. A Freeze Warning has been issued for areas where lows will be at or below freezing tonight, and widespread frost will be possible in this area as well. Cloud cover will linger longer and winds won`t be as calm over N central FL and along the NE FL coast, so low temperatures will be slightly warmer in the middle 30s. Patchy frost will be possible in N central FL and in rural areas of coastal counties in NE FL, but winds and cloud cover are expected to prevent frost from becoming widespread. .SHORT TERM [Sunday Through Monday Night]... High pressure will be centered to our west on Sunday with the ridge axis extending over the area, then the high is expected to shift directly over the area on Monday. West-northwesterly winds will prevail on Sunday, then winds will become calm across the entire area on Monday. Dry weather is expected both days with clear skies Sunday and mostly clear skies on Monday. Temperatures on Sunday will be warmer than they were today during the day, but clear skies and calming winds will lead to another cold night. Sunday high temperatures will be in the 50s area- wide, and Sunday low temperatures will be in the upper 20s to lower 30s inland and middle 30s at the coasts. A Freeze Watch has been issued for late Sunday night into Monday morning for all of SE GA and inland NE FL where lows are expected to be at or below freezing. Widespread inland frost is expected as well. Temperatures will increase on Monday with highs in the upper 50s to lower 60s and lows in the upper 30s to lower 40s. .LONG TERM [Tuesday Through Saturday]... An upper level cutoff low moving over the southern US is expected to spawn a surface low over the northern Gulf of Mexico that will track across the Florida peninsula on Tuesday. Scattered showers are expected to start over our western zones during the early morning hours on Tuesday, and showers are expected to become widespread in the afternoon. The low will exit into the Atlantic Tuesday night, and showers will come to an end by Wednesday morning. High pressure will build to the northwest on Wednesday, then to the north and northeast on Thursday. Coastal troughing is expected to develop Thursday into Friday that could produce coastal showers. Next weekend, an upper level shortwave trough is expected to dive south towards the Southeast US and could bring another low pressure system across the area. However, there is quite a bit uncertainty in the forecast this far out due to large difference in model solutions. The GFS brings a low across the area with widespread showers, but the ECMWF only brings a few showers to our area and spawns the low off the Mid-Atlantic coast. .AVIATION... [Through 00Z Monday] At 00Z, IFR ceilings continues at all sites except for SSI where it went to MVFR a few hours ago. LIFR ceilings are stubborn to improve at SGJ which is not addressed in most of model guidance. The LIFR/IFR conditions for the northeast FL TAFs look to, more or less, continue through the night though some temporary improvements are possible later tonight for JAX and CRG but it appears that ceilings could lower again toward the 07Z-10Z time frame. We can`t rule out a short window of LIFR ceilings for GNV later tonight based on NBM guidance. We should still see gradual improvement Sunday morning but have pushed back the MVFR and VFR a bit later based on HRRR and NAM guidance and VFR conditions expected to develop at TAF sites in the 15Z-18Z Sunday time frame. North-northwest winds decrease tonight through Sunday morning, with winds turning more northwest to west at 5-10 kt Sunday afternoon. .MARINE... High pressure will be to the west through Sunday, then shift over the area on Monday. Winds and seas will remain elevated through Sunday, but conditions will relax on Monday. Small Craft Advisories are in effect through Sunday. A low pressure system is expected to form over the northern Gulf of Mexico and move across the local waters late on Tuesday. The low will exit to the northeast on Wednesday, then high pressure will build to the north and northeast on Thursday. Rip Currents: High risk today at NE FL beaches, moderate risk today at SE GA beaches. Moderate risk at all area beaches Sunday. .FIRE WEATHER... High pressure to the west-northwest will gradually shift over the area through Monday with dry weather expected Sunday and Monday. Northerly winds tonight will shift to westerly Sunday. Light transport winds will result in lower daytime dispersions for NE FL on Sunday, values will be in the 20-30 range with lower dispersions closer to the Gulf coast. Transport winds will become weak on Monday, resulting in low daytime dispersions below 20 for most of NE FL. Significant fog not expected. Cold temperatures expected tonight and Sunday night, freeze and frost conditions expected for most of the area. && .PRELIMINARY POINT TEMPS/POPS... AMG 27 54 30 58 38 / 0 0 0 0 20 SSI 32 53 35 58 43 / 0 0 0 0 20 JAX 31 55 32 60 41 / 0 0 0 0 20 SGJ 36 56 35 60 44 / 0 0 0 0 20 GNV 32 56 30 61 39 / 0 0 0 0 20 OCF 35 58 30 63 40 / 0 0 0 0 20 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...Freeze Watch from late Sunday night through Monday morning for Baker-Bradford-Central Marion-Eastern Alachua-Eastern Clay- Eastern Marion-Eastern Putnam-Gilchrist-Hamilton-Inland Nassau-Northern Columbia-Southern Columbia-Suwannee-Trout River-Union-Western Alachua-Western Clay-Western Duval- Western Marion-Western Putnam. Freeze Warning from 1 AM to 9 AM EST Sunday for Baker-Bradford- Coastal Nassau-Eastern Alachua-Eastern Clay-Gilchrist- Hamilton-Inland Nassau-Northern Columbia-Southern Columbia- Suwannee-Trout River-Union-Western Alachua-Western Clay- Western Duval-Western Putnam. GA...Freeze Watch from late Sunday night through Monday morning for Appling-Atkinson-Bacon-Brantley-Clinch-Coastal Camden- Coastal Glynn-Coffee-Echols-Inland Camden-Inland Glynn-Jeff Davis-Northeastern Charlton-Northern Ware-Pierce-Southern Ware-Wayne-Western Charlton. Freeze Warning from 1 AM to 9 AM EST Sunday for Appling-Atkinson- Bacon-Brantley-Clinch-Coastal Camden-Coastal Glynn-Coffee- Echols-Inland Camden-Inland Glynn-Jeff Davis-Northeastern Charlton-Northern Ware-Pierce-Southern Ware-Wayne-Western Charlton. AM...Small Craft Advisory until 7 PM EST Sunday for Waters from Fernandina Beach to St. Augustine FL from 20 to 60 NM- Waters from St. Augustine to Flagler Beach FL from 20 to 60 NM. Small Craft Advisory until 9 AM EST Sunday for Coastal waters from Fernandina Beach to St. Augustine FL out 20 NM-Coastal waters from St. Augustine to Flagler Beach FL out 20 NM- Waters from Altamaha Sound GA to Fernandina Beach FL from 20 to 60 NM. &&
National Weather Service Jackson KY
928 PM EST Sat Jan 22 2022 .UPDATE... Issued at 925 PM EST SAT JAN 22 2022 Only minor updates to the near term forecast. A weak impulse moving through the area this evening is resulting in a thin band a lower stratus crossing the area from NW to SE. Also made minor tweaks to temps based on current trends. Otherwise, forecast remains on track. Updates sent to NDFD and web servers. && .SHORT TERM...(This evening through Sunday night) Issued at 332 PM EST SAT JAN 22 2022 It has been a fair but chilly afternoon with 20z temperatures running in the upper 20s and low 30s. Have tweaked grids slightly as forecast temperatures were running a few degrees behind. Looking regionally, surface high pressure is in control across the Southern Plains and Lower Mississippi Valley this afternoon. To our north, an upper level longwave trough is placed across Eastern Canada, supporting a surface low just north of the Great Lakes. A cold front will run just east of Montreal, bending back across the state and through Southern Missouri near 12z Sunday, breaking back north in the form of a warm front tomorrow afternoon. An approaching cold front will then take shape across the Upper Mississippi Valley, sliding east into the evening and bringing a slight opportunity for PoPs. This quick moving clipper is expected to pass through to our north, doing just that, clipping portions of Eastern Kentucky. With very low QPF associated and fairly dry mid levels initially, anticipate little in the way of precipitation for all but our far northern counties and the high terrain late Sunday evening. Hi- Res guidance, namely the HRRR and Nest are a bit more aggressive, suggesting both PoPs making it a bit further south and higher QPF, but am not so inclined to agree given ensemble runs, sounding profiles, and other Hi-Res members. With that said, will see the increase of cloud cover across the CWA into Sunday morning and through the day, with flurries during the morning and sprinkles in the afternoon possible for mainly the northern half of the CWA. Additionally, a SW to NE oriented LLJ will cross the CWA during the morning to mid afternoon. 850mb winds are between 35-45 kts and any momentum transfer down to the surface could produce gusts up to 20- 25 mph. Dry conditions then return for the start of the new work week. Sensible weather through the short will be fairly quiet. Flurries in our farthest north counties are possible into the morning tomorrow, eventually changing over to isolated to scattered rain showers. With some upslope flow taking place into the evening and overnight tomorrow, could see lingering stratus and the opportunity for light snow showers/flurries in the high terrain bordering Virginia. Temperature-wise, another chilly night is on tap with valleys bottoming out in the mid teens and ridges in the upper teens to low 20s. Temperatures will continue rebounding for the end of the weekend topping out in the upper 30s (in the north) and mid 40s (in the south). With a bit more cloud coverage overnight Sunday, ridge/valley splits won`t be as pronounced, ranging from the mid teens for the Bluegrass and lower 20s in the southeast. .LONG TERM...(Monday through Saturday) Issued at 251 PM EST SAT JAN 22 2022 Monday starts quiet but transitions to a potentially active period late Monday night into Tuesday. There`s a lot of variability on the events for Tuesday and none of the models are lining up to present any sort of consensus or clear-cut solution. With that being said, currently leaning for a middle ground approach which is the NBM solution as the NAM is too aggressive and the GFS/ECMWF is not aggressive enough. Nonetheless, if any precipitation occurs it`ll be light snow showers or light rain/snow showers with little to no accumulations except or higher elevations in relationship to upslope snow showers in the eastern mountains. Moderately weak ridging/zonal flow builds in behind Tuesday`s event keeping slightly below average temperatures overhead through the remainder of the week. Downstream attention turns toward the end of the period as somewhat decent model consensus exists for an end of the week winter system bringing widespread PoP to the Ohio Valley. && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) ISSUED AT 610 PM EST SAT JAN 22 2022 VFR to start the 00Z TAF period. SCT to BKN ceilings around 4k ft will pass across SYM early in the period, otherwise mainly FEW high clouds across eastern KY this evening. Winds will be light and variable tonight and overnight, then become SW 5-10 kts with gusts of 15-20 kts during the day on Sunday, becoming westerly towards the end of the period. Some MVFR ceilings will drop down ahead of a cold front late Sunday afternoon into early evening, most likely to impact SYM during this TAF cycle. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...CMF SHORT TERM...BB LONG TERM...VORST AVIATION...CMF
Area Forecast Discussion
National Weather Service Pendleton OR
749 PM PST Sat Jan 22 2022 .UPDATE...Fog and stratus clouds are blanketing portions of the Lower Columbia Basin, Blue Mtn Foothills, and the eastern Columbia River Gorge this evening with dense fog along the Blue Mtn Foothills. Current Freezing Fog Advisories for the Basin and Foothills look good, and there are no plans to extend to other forecast zones at this time. The southern end of the Yakima Valley has the best potential for dense fog where dewpoint spreads are currently around 2-3 degrees, but the north end of the valley has about an 8 degree spread at this time. The HRRR has been quite impressive this evening showing the fog making its way into Prosser and Sunnyside which the night fog on GOES-17 is showing. High pressure aloft with the center of the upper level ridge off the coast will remain stationary through Sunday afternoon. Strong low and mid level inversions have developed, and surrounding RAOB sites at BOI, MFR, SLE and OTX show the top of the mid level inversion around 12K-15K feet. A strong stable air mass along with weak winds aloft have created poor ventilation and limited mixing. There will be some improvement in the mixing Sunday night when a shortwave trough moves south from Canada and across the PacNW. There is very little impact on the forecast area except to bring gusty winds in the Grande Ronde Valley where gusts 30-40 mph are expected south of La Grande. Pressure gradients will tighten and thermal gradients from the colder Baker Valley to the Grande Ronde Valley will be fairly significant. Otherwise, the fog and stratus may lift some in and around the Columbia Basin. Wister/85 && .PREV DISCUSSION... /issued 221 PM PST Sat Jan 22 2022/ SHORT TERM...Tonight through Tuesday...Strong high pressure aloft just off the coast will remain in place for the next few days. There is one shortwave trough that will drop sewd across the region on the eastern periphery of the high Sunday night and Monday. The main weather concern through the short term is the potential for freezing fog and low clouds. Have just issued a freezing fog advisory for the Columbia Basin and the northern foothills of Oregon and SE Washington through 1 pm Sunday. The fog is hanging around this afternoon longer than earlier anticipated and think once the sun sets it will only expand and visibilities will deteriorate. The HRRR visibility forecast shows rather low visibilities overnight into Sunday morning. Other areas of concern are the Yakima and Kittitas Valleys but will let subsequent shifts monitor visibility trends since confidence is not sufficient to issue fog highlights at this time. On Sunday the pressure gradient in the southern Grande Ronde Valley tightens a bit and this will lead to at least breezy winds in Ladd and Pyles Canyons. Latest pressure difference forecast between Ontario and Meacham from the NAM is 7.7 mb Sunday evening which is weaker than previous model runs so confidence that wind highlights will be needed is low. At least patchy fog and low stratus will continue into Tuesday which will keep the lower elevations cold compared to the mountains where temperatures will be above normal. 78 LONG TERM...Tuesday Night through Saturday...Models continue to show general agreement in having a ridge off the west coast though they have differences about passing weak shortwaves that become more pronounced by Friday. Ensemble analysis shows the deterministic runs are well positioned towards the average of their ensembles but the model ensembles are clearly in different camps which affects overall confidence later in the week. A quiet period with low clouds and fog is expected in the Columbia Basin and adjacent lower valleys through Friday with mostly clear skies elsewhere. Conditions in the Columbia Basin are expected to improve on Friday though confidence in this isn`t high. Tuesday night the ridge axis will be offshore but the GFS has a moderately strong wave moving over the ridge while the Canadian has a weaker wave. The ECMWF has a barely perceptible wave. Even the GFS wave will do little more than provide a brief mixing out of the Columbia Basin low clouds and fog. Thursday and Thursday night models have the ridge axis overhead, so am expecting the low clouds and fog to persist with mostly clear skies elsewhere. Friday and Friday Night, the ECMWF brings a trough through the area while the Canadian brings a weaker trough through about 6-12 hours later. The GFS shows a weak wave riding over the ridge mainly into British Columbia. Have leaned towards the ECMWF and Canadian with a chance of snow in the Cascades Friday through Saturday with a slight chance of snow in the eastern Oregon mountains on Saturday. At this point, mountain snow amounts look to be light and generally less than an inch. Temperatures under the fog and low clouds will be in the lower to mid 30s while elsewhere temperatures will be in the 40s to lower 50s. Winds will be light aside from some 10 to 20 mph winds in the Grande Ronde Valley on Wednesday and again on Friday and Saturday. 83 AVIATION...00Z TAFs...High pressure will provide generally clear skies over much of the area for the next 24 hours aside from some high cirrus. However, low clouds and fog have developed today in the Columbia Basin and with high pressure remaining in place, am expecting the low clouds and fog to increase in intensity and coverage. ALW is expected to remain at LIFR CIGs and visibility for the next 24 hours with brief MVFR conditions for a few hours around 00Z. PSC will likely also see LIFR conditions return after 05Z as will PDT and DLS after 09Z. YKM will have low stratus and MVFR/IFR CIGs and visibilities are expected there. DLS, YKM, PDT and perhaps PSC will see some improvement after 18Z-21Z tomorrow afternoon. RDM and BDN are expected to remain at VFR for the next 24 hours. Winds will remain under 10 KTS for the next 24 hours. 83 && .PRELIMINARY POINT TEMPS/POPS... PDT 26 30 25 32 / 0 0 0 0 ALW 28 34 27 33 / 0 0 0 0 PSC 27 34 26 36 / 0 0 0 0 YKM 21 37 24 39 / 0 0 0 0 HRI 26 34 27 37 / 0 0 0 0 ELN 22 36 23 41 / 0 0 0 0 RDM 27 53 27 56 / 0 0 0 0 LGD 23 41 24 42 / 0 0 0 0 GCD 26 49 29 48 / 0 0 0 0 DLS 30 40 29 42 / 0 0 0 0 && .PDT WATCHES/WARNINGS/ADVISORIES... OR...Freezing Fog Advisory until 1 PM PST Sunday for ORZ044-507. WA...Freezing Fog Advisory until 1 PM PST Sunday for WAZ028-029. && $$ UPDATE...85 SHORT TERM...78 LONG TERM....83 AVIATION...83
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