Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 02/20/21

Area Forecast Discussion
National Weather Service Amarillo TX
554 PM CST Fri Feb 19 2021 .AVIATION... 00z TAF Issuance...VFR conditions are expected for both DHT/GUY. AMA has a chance for some fog later tonight into tomorrow morning with MVFR conditions. There is a chance AMA may dip down to IFR/LIFR with some areas of dense fog for several hours between 06z and 15z. South southwest winds will prevail through the period at all three sites. Winds will become breezy at DHT/GUY through the afternoon and evening hours tomorrow with wind speeds around 10 to 15 knots and gusts up to 25 knots possible. && .PREV DISCUSSION... /Issued 140 PM CST Fri Feb 19 2021/ SHORT TERM...Tonight through Tomorrow Night... Under a cloud free sky and lee side troughing, we are finally seeing temps rise above freezing this afternoon. Satellite reveals that there is still quite a bit of area across the Panhandles under snow cover. The sun will help melt some of this. However, the southeast TX Panhandle is still expected to still have snow cover overnight. With light winds and a slight upslope flow, the southeast is the most likely to have some freezing fog overnight. Visibility may get below a mile at times. The NAM suggests that more of the area may see this fog potential, but hi-res models like the HRRR are not as keen on this. Will need to monitor the trends this evening closely. Saturday will see the upper level flow turn zonal ahead of the next system. The trough is set to come onshore across southern Oregon/northern California and dive across the desert southwest by Saturday night. The surface low that forms with this system will move east across southern KS/OK Panhandle and bring the next cold front to the area starting early Sunday morning. Beat LONG TERM...SUnday through Thursday... H500 northwesterly flow will start for the long term forecast period becoming westerly by the middle of next week. From Sunday through Tuesday, the main H250 jet displaced to the north in the central Plains along with westerly and southwesterly surface flow, temperatures will begin to warm up the Panhandles with dry conditions expected. Highs on Sunday will start below average with highs in the 40s (lower 40s along the eastern corridor of I-40 in the TX Panhandle with residual snow cover). Going into Monday and Tuesday, high temperatures will rise into the mid/upper 50s and then mid to upper 60s respectively. Tuesday will likely be the warmest day of the up and coming week ahead of our front dropping temperatures and our next chance of precipitation. As the main large scale H500 ridge shifts west for the western CONUS coast further into the Atlantic, the western CONUS domain will have an enhanced sinusoidal flow which will help to steer disturbances into the southwestern CONUS. As a result, latest 19/12Z model and numerical data shows a H500 trough moving ESE into the Panhandles in the wake of a surface cold front late Wednesday night into Thursday morning. Going with the latest NBM guidance, light snow will be possible for the northwestern Panhandles but could extend further southeast if system moves slower and the positive tilted trough moves further southeast. Latest GFS shows a progressive trough moving southeast and out of the area by Thursday evening. NBM/ECMWF shows the main H500 trough enhancing surface cyclogenesis in south Texas near a stalled frontal boundary which could bring an additional round of precipitation for the eastern Panhandles on the western periphery of the second surge of moisture transport. Precipitation type at the beginning and the end may be a rain/snow mix but most of the event should be in the form of snow as temperatures behind the passing cold front Wednesday night will be below freezing for all locations in the Panhandles. too early at this time to determine QPF amounts but check back for updates. Not the most favorable temperatures outlook given our record breaking col temperatures this week but high temperatures will drop into the mid 40s to lower 50s by Wednesday and mid 30s to lower 40s by Thursday. Meccariello && .AMA Watches/Warnings/Advisories... TX...None. OK...None. && $$ 23/11
Area Forecast Discussion
National Weather Service Bismarck ND
949 PM CST Fri Feb 19 2021 .UPDATE... Issued at 940 PM CST Fri Feb 19 2021 For the late evening update we eliminated any pops after 06 UTC. We have yet to see anything other than some mid-level clouds as the warm front moved through western ND and now is traversing central ND. Could maybe see a flurry or two along the Highway 83 corridor through midnight. For lows tonight, we dropped temperatures in the east and raised temperatures in the west by a few degrees. Currently Zero at Rolla, and they could drop a couple more degrees before slowly rising through the rest of the night. Temperatures in the west behind the warm fron have been slow to fall this evening. It`s still in the mid 20s out west, but with a few hours of clear skies (more clouds move in late) and a dry atmosphere, hate to raise them too much. Updated text products will be sent shortly. UPDATE Issued at 534 PM CST Fri Feb 19 2021 A warm front is currently pushing into western North Dakota. Latest satellite and radar analysis, with observational data and webcams depict mainly mid level clouds from around 7-10kft with no precipitation notes as of yet. Comparing latest guidance with previous forecast, we decided to slow down the progression of small pops across western into central ND, and for now kept them as slight chance. Time lagged HRRR seemed to have a good handle on latest cloud cover so used this as the bulk of guidance for clouds tonight. Forecast soundings do show a little shallow low level moisture late tonight into Saturday, but not really confident about low clouds at this time. && .SHORT TERM...(This evening through Saturday night) Issued at 231 PM CST Fri Feb 19 2021 A chance of light snow is in the forecast tonight with warmer temperatures on Saturday. A north-south oriented warm front was across eastern Montana and approaching the western North Dakota border this afternoon. This front is expected to push across the state tonight with the arrival of a weak mid- level shortwave trough. Increasing clouds and a chance of light snow (with possibly rain mixed in initially) will accompany this front. Upstream observations in Montana indicate only light precipitation so far with liquid totals of a trace to several hundredths of an inch. The ceiling for precipitation should be similar in west/central North Dakota, especially with an antecedent mid-level dry layer to work through. 12Z HREF was leaned on for precip timing as well as longevity, as the CAMs that do carry snow through the forecast area wane intensity in the eastern portions of the state. Saturday, a broad trough begins to dig through the Four Corners region, with mostly zonal flow across the Northern Plains. A 700mb wave crosses South Dakota through Kansas, but should stay far enough south to keep precipitation out of the state through Saturday night. 12Z guidance is somewhat inconsistent in the deepening of this wave early Sunday morning, with a few solutions wrapping QPF into the southern James River Valley of North Dakota. A slight chance of snow was introduced but notable accumulations are not expected at this time. .LONG TERM...(Sunday through Friday) Issued at 231 PM CST Fri Feb 19 2021 Gradually warmer temperatures are expected through the early portion of next week. The warmest temperatures are expected to be Monday as well as potentially windy conditions. Broad ridging in the upper levels begins to take over Sunday into early next week with warmer temperatures expected, especially Monday. Strong unidirectional flow in the upper through lower levels is also expected as an upper level jet noses into the region. The overlap of 40-50kt 850mb winds and deeper boundary layer mixing looks to be west and south central, well signaled by GFS/EC ensemble wind gust potential. Thus we will introduce the potential for a Wind Advisory in the HWO for these areas. Given adequate mixing, there is a strong chance for highs to reach 50 generally near and west of the Missouri River with 40s elsewhere. If cloud cover behaves, NBM and MEX/ECM are in good agreement of the high end potential of upper 50s in these historically warmer locations. The latter half of next week will be characterized by a cool down, though with still near or above average temperatures. 12Z guidance is consistent in running weak, embedded waves through the region with any precipitation being light. Thus the blended guidance produces a mostly dry forecast for now. There is some agreement of a chance of snow or rain on Tuesday as the next front pushes through. && .AVIATION...(For the 06Z TAFS through 06Z Saturday night) Issued at 940 PM CST Fri Feb 19 2021 VFR conditions expected through much, if not all, of the 06Z TAF period. A weak warm front and associated cloud cover is currently working its way into the central portion of the state and will continue moving east this evening and overnight. There is a slight chance this cloud cover may produce MVFR ceilings along with some flurries at times across the south, but confidence is not high enough to include MVFR ceilings or VCSH in the TAFS at this time due to an abundance of dry air above the surface. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...TWH SHORT TERM...AE LONG TERM...AE AVIATION...TWH
Area Forecast Discussion
National Weather Service Dodge City KS
521 PM CST Fri Feb 19 2021 ...Updated Aviation Discussion... .SHORT TERM...(This evening through Saturday) Issued at 255 PM CST Fri Feb 19 2021 What a difference a couple of days make! Temperatures have actually over-achieved a bit across southwest Kansas, thanks to the ever- growing hole in the snowpack centered right over our forecast area. The temperature peaked at 45 degrees officially here at Dodge City, which is a wonderful rebound from the morning low of 9. The warming trend will carry right into tomorrow with warmer than previously forecast highs...well into the lower 50s for most. The next storm system will be approaching late tomorrow and tomorrow night, and as it does so, stratus clouds will build back in, and low level warm advection will increase east of the developing low. The increased low level warm/moist advection will most likely manifest as a growing area of freezing drizzle late in the night after temperatures drop back down into the lower 30s or even upper 20s. This could cause some problems for those that may be out and about late Saturday Night, particularly for areas north and east of Dodge City. This is something we will have to continue to monitor closely. The heavier, accumulating precipitation with this storm system is still expected to be well east-northeast of our forecast area. .LONG TERM...(Saturday night through Friday) Issued at 255 PM CST Fri Feb 19 2021 Behind the weekend storm system on Sunday, winds will pick up out of the north at 20 to 35 mph. Strongest of the winds are expected to be during the first half of the day when the pressure rises behind the front are greatest. The cold advection will be masked by downslope warming some, so the drop in temperatures Sunday will not be all that great over what we will see Saturday afternoon. Thereafter, Monday and especially Tuesday still appears to be very mild with highs around 60 Monday with mid to perhaps even upper 60s now possible Tuesday afternoon. This warmth will only last two days, though, as another frontal system impacts the Central Plains region mid-week, potentially marking the beginning of a more unsettled pattern with the mean upper level trough axis out west of us. && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) Issued at 504 PM CST Fri Feb 19 2021 Southerly winds will become more southwesterly after midnight with a period of light and variable winds being possible around daybreak. Latest HRRR BUFR soundings appears to have backed off on the near surface moisture return given the gradually veering of the surface winds. Still with light and variable winds around daybreak the potential still exists for some patchy freezing fog being possible with visibilities falling as low as one mile at times between 10z and 14z Saturday. The light winds early Saturday morning will back to the southeast and increase to around 20 knots after 18z Saturday as surface pressures begin to fall across eastern Colorado. && .PRELIMINARY POINT TEMPS/POPS... DDC 20 53 27 47 / 0 0 10 0 GCK 17 52 25 45 / 0 0 0 0 EHA 20 53 27 45 / 0 0 0 0 LBL 16 51 25 47 / 0 0 0 0 HYS 17 52 24 45 / 0 0 30 0 P28 16 41 27 48 / 0 0 20 0 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Umscheid LONG TERM...Umscheid AVIATION...Burgert
National Weather Service Hastings NE
713 PM CST Fri Feb 19 2021 ...Aviation Update... .DISCUSSION...(This evening through Friday) Issued at 230 PM CST Fri Feb 19 2021 Variably cloudy skies are being observed across the region this afternoon and are expected to continue into the evening and overnight hours. So far...this cloud cover has had minimal impact on temperatures...which are struggling to get out of the mid-20s in snow covered area...while they have warmed into the mid 30s across our KS counties...which have comparatively little snow cover remaining. With some melting of snow today due to the breaks in the cloud cover and increasing sun angle...available moisture in the low levels should be sufficient for the formation of fog this evening and overnight. SREF probs are pretty high in confidence for fog formation...and the last few runs of the HRRR are giving us dense fog upped the areal coverage of fog in the forecast along with introduced some lower visibilities into the actual wording of the forecast. That said...if trends continue...would not be surprised if a dense fog advisory eventually becomes necessary late this evening or overnight for more widespread visibilities near or below 1/4 SM. Depending on if/when/how quickly the fog burns off on Saturday...temperatures might be a bit too optimistic...but either way there will likely be a significant temperature gradient from the snow free areas across north central Kansas to snow covered areas just a bit further north. Tomorrow night...expect the next upper level disturbance moving out of the Rockies to spread some light precip across the local area...likely beginning as freezing drizzle near and southeast of the Tri-cities before transitioning to all snow by Sunday morning. With a good signature for freezing drizzle in both soundings and in precip fields from the NAM...the likelihood of some light icing is looking pretty good by Sunday morning...although overall accumulations of ice should be in the few hundredths of an inch of precipitation range. Thereafter... some very light snow accumulation is possible mainly through the first half of Monday...but the main impact of this system does not appear to the be the snow itself...rather the tightening pressure gradient associated with the deepening surface low...which could result in wind gusts near 40 mph during the daytime hours on Sunday. While this will not be one of the strongest wind producers we have seen this winter...winds will likely be strong enough to pick up some of the un-crusted snowpack we have across the region...resulting in possibly some blowing and drifting snow (from previous storms) Sunday. While blowing snow does not have a mention in the official forecast just yet...decided to add some wording for its potential to the HWO this afternoon. Thereafter...dry weather should prevail as the upper level flow turns more westerly and milder weather returns to the local least to start the week...before a dry cold front arrives mid-week dropping temperatures back down below climo. && .AVIATION...(For the 00Z KGRI/KEAR TAFS through 00Z Sunday) Issued at 713 PM CST Fri Feb 19 2021 General overview: Although confidence is fairly high that the first 3-6 hours and final 3-6 hours of the period will feature prevailing VFR conditions, the middle 12-18 hours centered on late tonight- Saturday morning brings a decent chance of sub-VFR visibility (and probably ceiling as well), as at least light fog is good bet, and dense fog a possibility but not overly-high confidence at this time. As for winds, no big issues here, as speeds throughout the period will only average 5-10KT at most, with direction overnight into Saturday morning fairly variable, and a more consistent southeast direction established by later Saturday afternoon. Additional ceiling/visibility details: As mentioned, confidence in just how "bad" fog and resultant visibility/low ceiling overnight into Saturday morning is not the greatest, especially given that some models/guidance tend to be over-aggressive with the severity of overnight fog development prior to the occurrence of more widespread above-freezing daytime temperatures/significant snow-melt (neither of which occurred at KGRI/KEAR today). As a compromise between the most optimistic/pessimistic fog solutions (but leaning toward the pessimistic), have opted to go as low as IFR/LIFR during mainly the 09-17Z time frame, but did not have the confidence to go full- blown VLIFR in long-lasting dense fog. No matter how bad fog gets during the period, confidence is at least medium-high in a return to VFR visibility by around 17Z as fog lifts/dissipates. The bottom line: Stay tuned for potentially notable changes regarding expected visibility/ceiling in later TAFs/amendments. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ DISCUSSION...Rossi AVIATION...Pfannkuch
Area Forecast Discussion
National Weather Service Goodland KS
355 PM MST Fri Feb 19 2021 .SHORT TERM...(This evening through Monday) Issued at 230 PM MST Fri Feb 19 2021 Patchy freezing fog will be a concern once again tonight along the Republican River valley in southwest Nebraska and into Decatur, Norton, Graham and Sheridan counties in northwest Kansas. These areas did not warm up much today and dew point depressions remain relatively low. HRRR suggesting fog may be dense at times. Elsewhere, light westerly winds and larger dew point depressions should keep fog from developing, though cannot completely rule it out in low lying areas. Low temperatures will be in the teens, possibly single digits in low lying areas such as the Republican. Moderating temperature trend will continue on Saturday as upper ridge axis moves across the area combined with breezy south winds at the surface. Expecting highs generally in the upper 40s, a bit cooler around McCook which may only reach the lower 40s. Next system will move into the central Rockies Saturday afternoon and across the area Saturday night. Expecting light snow north of Interstate 70, less than one inch, with perhaps mixed precipitation after midnight in eastern areas where moisture/cold air will be shallow. Best chance of accumulating ice, a hundredth or two, will be from McCook to Hoxie and Hill City. In addition to the precipitation, breezy to windy northwest winds will accompany the associated surface cold front. Strongest winds will be in western areas near the Colorado border after midnight, with gusts up to 40 mph possible. The system will quickly exit the area early Sunday morning with skies becoming mostly sunny by the afternoon. Breezy to windy northwest winds will continue, gradually diminishing by the afternoon. High temperatures will be in the upper 30s to lower 40s and lows Sunday night in the teens and 20s. Upper ridge will begin to build over the region on Monday resulting in sunny skies and much milder temperatures. We are expecting highs in the 50s across the entire area with breezy west winds. Lows Monday night will be in the 20s. .LONG TERM...(Tuesday through Friday) Issued at 102 PM MST Fri Feb 19 2021 The main points of interest for the extended period include warmer weather for the start of the forecast period with a chance of precipitation towards the middle of the work week. Tuesday into Wednesday, northwesterly flow will back into more westerly flow in advance of an approaching trough. Some disagreements in timing of the trough exists within guidance as the GFS is the faster solution. A cold front is forecasted to enter Yuma County during the late afternoon on Tuesday, the GFS also has some precipitation forming late Tuesday night, whereas the ECMWF is roughly 12 hours later with with the precipitation chances. Currently the best area for precipitation to occur is along and west of the Kansas/Colorado border, with the possibility of flurries along and east of Highway 25 on Wednesday. Highs on Tuesday are currently forecast to be in the upper 50s to low 60 across the entire Tri-State area. The timing of the cold front will need to be watched as if it moves through earlier then our forecasted temperatures might be to high. Highs for Wednesday will be noticeably cooler in the 30s to 40s and overnight lows falling into the teens to 20s. For Wednesday night through the remainder of the forecast period, guidance does not agree well as mentioned before as the GFS is faster with the passage of the trough. The GFS ensembles brings in weak ridging during the day Thursday. The ECMWF and Canadian model hints at the potential for some snow showers on Thursday night, but my confidence at this point is not high enough to introduce into the forecast. High temperatures on Thursday will be similar to Wednesday with upper 30s to low 40s expected, before a slight warm up for Friday as highs reach the 40s. && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) Issued at 353 PM MST Fri Feb 19 2021 At KMCK...freezing fog expected to develop once again in the Republican River valley tonight, including near KMCK. Visibility may drop to IFR towards early Saturday morning before improving by mid Saturday morning to VFR. At KGLD...VFR expected to prevail through the TAF period. Surface winds will increase from the south by Saturday afternoon, with gusts to 25kts possible. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...024 LONG TERM...TT AVIATION...024
Area Forecast Discussion...UPDATED
National Weather Service Gray ME
907 PM EST Fri Feb 19 2021 .SYNOPSIS... Low pressure passing south of New England will bring light snow through late tonight. An upper trough swinging through Saturday will bring scattered snow showers to the mountains. High pressure builds in Sunday followed by a quick hitting system Monday and Monday night. A weak system will cross south of the region Wednesday night and early Thursday. Temperatures will be on the rise through the middle of the week with above normal temperatures expected for much of next week. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... Update...Heaviest band of snow is beginning to slide E of the forecast area. Snowfall intensity is coming down evidenced by rapidly improving visibility across the region. Scattered snow showers are already popping up in the axis of the upper trof...and I expect this activity to continue most of the night despite steady precip moving out to sea. Previous discussion... Impacts...Light snowfall continues through this evening, gradually coming to an end late this evening. There is a chance for higher snowfall rates and totals over the I-95 corridor in York County and the Seacoast of NH, and while this would pose some threat for accumulating snow on roadways and reductions in visibility, this would occur primarily after the evening commute. Weak low pressure continues to pass well to the southeast of Cape Cod today as light snow continues over all but the northernmost zones of the CWA. The trend throughout the day has been for visibility to fluctuate with the intensity of the snow, but all of the automated sites have stayed above 3/4 to 1 mile and amounts have generally been rather light so far. However, this afternoon through this evening does look like a period where we may see some significant accumulation before things wind down later this evening, at least for some locations. High-res guidance continues to indicate some enhancement in rates and totals for the I-95 corridor from Portland south through the Seacoast of NH, though the mechanism for getting there appears to differ. The HRRR shows what appears to be a mesoscale/ocean effect band moving onshore after 00Z that provides a quick burst of an inch or so for those areas...while the NAM shows a more broad enhancement through much of southern NH with similar amounts but from now through this evening. Decided to incorporate both of these scenarios into the QPF and snow amounts, and some locations along the coast between Portland the Mass. border could get around 3 inches total while amounts elsewhere in southern NH and York County should be closer to 1-2 inches. Certainly some bust potential, particularly with that HRRR scenario...but thought it best to include it now to be removed later if it never materializes since the evening commute could be affected. Area webcams indicate that major highways look to be in good shape at the moment, but heavier snowfall rates could lead to issues for the evening commute, particularly with cooling pavement temperatures; if conditions warrant, could issue an SPS to cover this. Most locations outside of those discussed above are looking at another half inch before things finally wind down later this evening. Light snow will continue through the overnight hours before finally coming to an end early Saturday morning with most locations picking up another tenth or two. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/... Impacts...Minimal. Snow showers will be possible in the mountains on Saturday. As low pressure pulls away on Saturday, northwest flow develops in its wake. A mid-upper trough also swings through the region, and between it and the northwesterly upslope component, expecting at least a few snow showers in the mountains with very light accumulations. Clouds will linger, keeping skies mostly cloudy, and the northwest winds will be steady throughout the day. High temperatures will rise into the mid to upper 30s in the mountains and the lower to mid 30s elsewhere. High pressure begins to build into New England Saturday night, putting an end to any lingering snow showers in the mountains and allowing skies to clear for most of the CWA. Blended in some of the cooler guidance for lows Saturday night, yielding lows ranging from the positive single digits north to the mid to upper teens south. && .LONG TERM /SUNDAY THROUGH FRIDAY/... High pressure will build towards New England from the west on Sunday. It will be mainly clear with temperatures slightly below normal for this time of the year in the mid 20s north to the lower 30s in the south. Downslope northwesterly winds will aid the drying and sunshine over southern locations. The narrow ridge of high pressure will crest over the forecast area during the evening hours. With light winds and clear skies, temperatures will quickly fall after sunset due to radiational cooling. Temperatures may level off late at night with clouds increasing after midnight. Nevertheless, temperatures will easily fall into the single numbers in the north to the lower teens across portions of the coastline. Have forecasted min temperatures slightly below most model guidance. This cold air will likely play a role in the ptype across interior locations as we start out a new work week. The 12Z operational and ensemble solutions continue to have subtle but important differences in the development and track of low pressure late in the day Monday and Monday night. The Euro and Canadian indicate the development of the surface low slightly further offshore than other model solutions. The Euro ensemble mean tracks the surface feature through the Gulf of Maine Monday night. This track, or a track near a coastal front seems reasonable given the cold place likely to be in place in Maine and New Hampshire. Despite the cold air in place enough warm air both at the surface and aloft may make it into coastal areas to allow for a changeover to rain after a period of snow. This changeover has been supported by the Euro ensemble mean low level temperatures as well as NBM ptype probabilities. There is also the possibility of a narrow ribbon of freezing rain during this event. However, confidence levels remain low for this possibility and any changeover would be brief. The system will be a quick mover so snow amounts should not be overly high as QPF remains moderate at best. A gusty westerly flow develops thereafter through the midweek period. Despite some initial cold air advection on Tuesday, temperatures will be above normal for much of the week. Temperatures in the 40s are possible Tuesday through Thursday. During this period, a weak system may pass south of our region Wednesday night or early Thursday. Early indications continue to indicate a weak and fast moving system. && .AVIATION /02Z SATURDAY THROUGH WEDNESDAY/... Short Term...Light snow continues through late this evening or early tonight for most terminals. HIE is the only site not currently snowing, but it looks like some is on the way. WIdespread IFR conditions will gradually improve to MVFR and perhaps VFR by Saturday morning. Northwest winds increase Saturday morning. Long Term...VFR expected Saturday night through Monday morning. MVFR to IFR conditions expected in snow and rain Monday afternoon and evening. Improvement to VFR possible late Mon night. && .MARINE... Short Term...SCA remains in effect for the outer waters as winds and seas finally begin to reach criteria this afternoon. Light snow over the waters should be winding down this evening into tonight, followed by increasing northwest winds Saturday morning and afternoon. Those northwest winds could lead to some light freezing spray Saturday night. Long Term...A northwesterly gradient will continue to support gusty winds on Sunday. Winds will pick up out of the southwest on Monday into Monday evening ahead of a fast moving system bringing building seas to the region which will continue on Tuesday into Wednesday. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...None. NH...None. MARINE...Small Craft Advisory until 7 PM EST Saturday for ANZ150-152- 154. && $$ NEAR TERM...Legro
Area Forecast Discussion
National Weather Service Lincoln IL
902 PM CST Fri Feb 19 2021 .SYNOPSIS... Issued at 328 PM CST Fri Feb 19 2021 Clouds will increase into this evening, as scattered snow showers develop across areas north of a line from Rushville to Danville. However, any snow accumulations that do develop will remain around a dusting to less than a half inch. Lows tonight will remain cold, in the single digits above zero. Patchy fog could develop into Saturday morning, with partly cloudy skies and warmer temperatures Saturday afternoon. && .UPDATE... Issued at 902 PM CST Fri Feb 19 2021 A warm front just south of the forecast area and warm advection above the surface is resulting in a few very light precipitation reports north of I-74, and models suggest this zone should gradually shift eastward through the night. Only low chance values for measurable precipitation are in the forecast along and north of I-74, and this looks good. Otherwise, have added some additional cloud cover late this evening in west central IL based on satellite trends, and added a few degrees to low temperatures due to cloud cover and recent observations above forecast. Exception is southeast IL, where little change was made from single digit forecast lows. && .SHORT TERM...(This evening through Saturday) ISSUED AT 328 PM CST Fri Feb 19 2021 An upper level shortwave evident on satellite loops in west- central Illinois will progress across the northern portions of our forecast areas tonight. Clouds will increase as forcing for precipitation increases under positive DPVA. Periods of light snow or flurries are expected, but confidence in the amount of measurable snow is still low. Upstream obs have been void of snow under the radar returns. The 18z NAM3K still indicates a narrow swath of 0.5" snow north of Peoria to Bloomington, while the latest HRRR barely indicates small areas of 0.1". Due to marginal confidence, have kept PoPs in the 20-40 pct range this evening into the overnight. Southerly winds overnight combined with some cloud cover will help prevent the bitterly cold sunrise temps of this morning. However, we will still remain well below normal, with lows in the single digits above zero and wind chills in the single digits below zero. Saturday may start out with patchy fog or freezing fog again, due to sunrise producing some light melting on Friday. Impacts from that should remain low. The rest of the day will see decreasing clouds from south to north, helping to push high temps toward the freezing mark for areas south of Springfield to Effingham. .LONG TERM...(Saturday night through Friday) ISSUED AT 328 PM CST Fri Feb 19 2021 While the extended forecast will be dominated by the warming trend, we still have one wintry precip event to close out the weekend. Sunday morning will feature the development of a warm frontal circulation across our CWA, as low pressure advances from near Colorado Saturday evening toward Illinois on Sunday. The low track is still projected to be across the northern portions of Illinois, with the warm frontal boundary located roughly along or north of I-74 as the low reaches Illinois. Boundary layer should occur by afternoon, with snow the primary precip type initially for areas north of I-72, and a mix of rain and snow south of there. A steady surge of warm air during the day will transition the precip type toward rain as far north as I-74. However, plenty of snow on the ground will delay the surface temp warm-up above freezing on Sunday. That could set the stage for the rain drops to reach the ground while surface temps remain at or below freezing in some areas. As a result, a period of freezing rain can not be ruled out. However, there should not be significant icing from freezing rain due to eventual warming above freezing in our entire CWA Sunday afternoon. Snow amounts remain a tough call, but if the snow lingers longer north of I-74 Sunday afternoon, we could see snow accum climb up to 1-2", mainly from Galesburg to Lacon to El Paso. At this point, we have a half inch of snow as far south as Peoria to Bloomington to Champaign, but that snow could get rained on as the warm front briefly surges northward later Sunday afternoon. Once the low passes across northern IL, somewhat colder and dryer air will filter into Illinois. Any lingering precip after midnight Sunday night could change back to snow before ending, but current thoughts are precip will end before a deep enough layer of cold air advances into eastern IL. Beyond that system, the pronounced warming will develop, under the zonal flow aloft. Pacific origin air will advance into IL, helping to push high temps into the 40s across the board on Tuesday and Wednesday. The remaining snowpack will keep Monday`s highs a bit colder than guidance, but very little snow is expected to be remaining for the Wednesday warm-up. A weak cold frontal passage Wed night will trim 6-8 degrees off of high temps for Thursday and Friday, as Pacific Northwest high pressure shifts east across the Plains into Illinois. Highs will generally settle out in the mid 30s north of Peoria to the low 40s south of I-70. && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) Issued at 547 PM CST Fri Feb 19 2021 Areas of MVFR cigs and light snow expected to develop this evening for mainly around KPIA-KBMI-KCMI. Snow expected to end by 08Z- 10Z. Cigs expected to lift and dissipate somewhat by 17Z, becoming VFR, however some re- development of cloud cover could develop in the afternoon, resulting in occasional MVFR cigs. Winds W 5-10 kts becoming light and variable overnight. SE winds 5-10 kts expected to develop by 17Z. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...37 SYNOPSIS...Shimon SHORT TERM...Shimon LONG TERM...Shimon AVIATION...37
Area Forecast Discussion
National Weather Service Memphis TN
923 PM CST Fri Feb 19 2021 .UPDATE... Temperatures are beginning to plummet across the area due to mostly clear skies, calm winds, and lingering snow pack on the ground. Will update to make some adjustments to temperatures. The other thing that we will continue to watch is for the possible development of freezing fog. The HRRR has been showing development of fog across the Mississippi Delta on every run for the last 24 hours. If that occurs it may keep lows from dropping as much depending on how dense the fog gets. KRM && .DISCUSSION... /issued 242 PM CST Fri Feb 19 2021/ Skies remain sunny across the Mid-South this afternoon with temperatures ranging from the mid 20s to upper 30s. High pressure extends from the Texas northeastward into the Mid-South at this time. The surface high will slide slowly east tonight. With snow remaining on the ground temperatures will be quite cold tonight with lows Saturday morning mainly between 10 and 15 degrees. A couple of locations may see wind chill values approach 0 but most areas will be readings in the single digits. Some freezing fog may also develop late tonight and could become widespread overnight. Saturday will be sunny as the surface high starts to move east of the Mid-South. Winds will shift to the south on Saturday allowing for milder air to move into the region. Temperatures will be warmer with highs in the lower 30s to mid 40s. Dry weather will continue into Saturday night as milder air continues to move into the region. Temperatures will milder Saturday night with lows Sunday morning in the low to mid 20s. Some freezing fog may develop again Saturday night. On Sunday, a cold front will move across the southern plains and into Arkansas. Scattered showers are expected to develop ahead of the front and some of the activity may move into northwest sections of the Mid-South in the afternoon. Temperatures will be warmer with highs in the lower 40s to mid 50s. The cold front will move through the region Sunday night with more rain expected to move through the Mid-South. As the front moves east of the region on Monday, precipitation will be ending in the morning with a mix of wintry precipitation possible before moving out. High pressure will move back into the region by Monday night bringing a period of dry weather for Monday night through Wednesday. Temperatures will be cooler Monday but warm back up for Tuesday and Wednesday. Another cold front will move through the region for Wednesday night and Thursday bringing more rain to the Mid-South. This front will stall out across southern Mississippi so more precipitation, some of it possibly wintry, is expected for Thursday night and next Friday. ARS && .AVIATION... VFR conds will continue into the evening. The main forecast concern is whether freezing fog will develop as advertised by the HRRR/HREF. There has been some melting and as result some additional moisture lying around. However this will quickly refreeze as temps fall. Seems like the excess moisture in the boundary layer will deposit on the ground and surfaces as frost vs forming freezing fog. Also the HRRR has some odd surface temp data by 06z with temps falling below zero across parts of the Delta which is highly unlikely. This is the area where the freezing fog is first predicted to develop by the HRRR. Attm will hedge with a 3SM BR tempo 1SM BR at KMEM, KJBR and KMKL. Forecast confidence is low from 20/06z - 20/15z. Winds will be light overnight becoming light south on Saturday. SJM && && .MEG WATCHES/WARNINGS/ADVISORIES... AR...None. MO...None. MS...None. TN...None. && $$