Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 03/02/20

Area Forecast Discussion...UPDATED
National Weather Service Albuquerque NM
450 PM MST Sun Mar 1 2020 .AVIATION... 00Z TAF CYCLE Gusty and erratic winds with virga over northern and western NM will diminish thru 03Z. This activity will move east to northeast around 25 kt. A weak back door cold front will shift into northeast NM late tonight with an area of MVFR low cigs developing southward toward I-40 thru sunrise. Winds will veer around to the south and southwest by early afternoon across the eastern plains with clearing skies aft 19Z. The next weather system will edge closer to NM from SoCal thru Monday afternoon with mid level clouds developing once again across the western half of the state aft 20Z. Guyer && .PREV DISCUSSION...306 PM MST Sun Mar 1 2020... .SYNOPSIS... High temperatures will cool on Monday and there will be a chance of rain showers, thunderstorms, and high terrain snow showers over western areas. An upper level low pressure system will pass just south of NM Tuesday through Wednesday morning with wetting precipitation and continued cooling mainly south of I-40. The southeast plains could accumulate up to 1.5 inches of rain, while a few to several inches of snow will be possible in the south central mountains including Ruidoso. Dry weather, warming temperatures, and light winds are expected Wednesday and Thursday, but a back door cold front should result in some cooling in many areas on Friday. && .DISCUSSION... SHORT TERM...(TONIGHT THROUGH MONDAY NIGHT)... Mid-level moisture has intruded into western NM this afternoon, with 20-35F dewpoint depressions at the sfc underlying it allowing for virga to develop. This will expand into the RGV from Socorro to ABQ to Santa Fe and will produce erratic gusty winds this afternoon. There is some convective activity apparent on the GOES-16 Day-Cloud- Phase hinting at mixed phase clouds along the continental divide, and there could be a stray dry lightning strike as a result. The virga, along with westerly gusts of 25-40mph mainly through eastern NM will taper off by or just after sunset as the atmosphere decouples. As the virga wanes, wintry weather begins to eek into far northern NM over the Tusas Mountains tonight. A backdoor frontal boundary will bring a northerly wind shift into northeastern NM tonight. Chances for precipitation will remain fairly low, however the HREF and RAP have been showing another round of virga Monday afternoon. Under an area of diffluence aloft, there is enough CAPE with -2 to - 4 LI to warrant mention of a chance of thunder Monday afternoon through western NM. Overall, precipitation accumulations will be quite paltry with little chance for wetting precipitation. Better chances for precipitation lay over southeastern NM in the Long Term Tuesday as this Pacific storm tracks south of NM. 24 LONG TERM...(TUESDAY THROUGH SUNDAY)... An upper level low pressure system tracking southward along the CA coast will pass eastward over northern Mexico Tuesday through Tuesday night, then exit gradually eastward across south TX on Wednesday. The coverage and intensity of precipitation will increase over southern areas (along and south of I-40) Tuesday and Tuesday night, then some lingering precip is expected along and east of the south central mountains into Wednesday. There may also be some thunderstorms over southern areas on Tuesday. Rain and liquid equivalent precipitation amounts should should range from a tenth of an inch over southwest areas to around 1.5 inches over the southeast plains. The south central mountains will be favored for snow accumulation, where a few inches are expected below 7500 feet, and as much as 10 inches will be possible above 7500 feet. Depending on how much cold air arrives with a gusty back door cold front on Tuesday, the Ruidoso area could get more than a few inches of snow. We will be watching this possibility closely with each new model run. In the wake of the upper low, a low amplitude ridge of high pressure will cross the southwest US Wednesday night through at least Friday morning with drier and warmer weather. Models are diverging on the depth and timing of an upper level trough expected to migrate inland from the west coast Friday. If the latest operational GFS run is right precip could begin spreading over western areas as early as Friday, but the NBM ensemble delays spreading precipitation over western areas until Saturday night and Sunday. Models are in better agreement on the arrival of a back door cold front early Friday with a brief downtick in high temperatures that day. Overall the late weekend trough looks fairly warm with lowland rain showers, perhaps some thunderstorms, and only high terrain snow on Sunday. 44 && .FIRE WEATHER... The main fire weather concerns may very likely be today with elevated conditions across eastern NM given warm, dry, and breezy westerlies this afternoon. Even western NM is seeing a good amount of virga which will produce some erratic gusty winds this afternoon. Conditions calm after sunset as the atmosphere decouples. Some non- wetting precipitation is set to enter into western NM Monday, shifting toward southern NM Monday night. There will likely be another round of virga over western NM Monday afternoon producing erratic gusty winds with a small chance for a stray lightning strike. The best chances for wetting precipitation will be Tuesday over southern and southeastern NM as a Pacific storm system tracks south of the state. Any significant snow accumulations will be relegated to the high terrain, focusing over the Tusas and Sacramento Mountains. Conditions clear out and warm up starting Wednesday through the rest of the work week. A weak backdoor front looks to swing into eastern NM Thu, but have little effect on temperatures. Ventilation for the most part will remain good to very good. MinRH will be low but above critical each day with good to excellent recoveries. Transport winds notably shift out of the south Friday as a ridge begins to exit to the east. 24 && .ABQ WATCHES/WARNINGS/ADVISORIES... None. && $$
Area Forecast Discussion
National Weather Service Bismarck ND
844 PM CST Sun Mar 1 2020 .UPDATE... Issued at 843 PM CST Sun Mar 1 2020 Latest fog/stratus imagery loop and surface observations shows stratus has eroded for most of the west, and not pushing into central North Dakota. Followed the GFSLamp guidance which has done a better job in holding onto the stratus verses the HRRR or RAP13. Should see the stratus continue to dissipate from west to east and clear the James River Valley by around 06z Monday. High clouds now over western Saskatchewan associated with warm air advection will overspread western and northcentral ND between 09z- 12z Monday, and south central and the James River Valley 12z- 18z Monday. This is out ahead of our next shortwave trough aloft and surface cold front which slide into central ND Monday afternoon. Minor changes in this update included holding back more clouds central this evening, and slowing down the decrease in winds across the James River Valley for a couple more hours. UPDATE Issued at 615 PM CST Sun Mar 1 2020 Winds have fallen below sustained and gust wind advisory criteria, thus have allowed the wind advisory to expire at 6 PM CST Sunday. Over the next few of hours, expect the stratus to gradually lift and dissipate as a shortwave ridge approaches and surface high pressure nudges into western North Dakota from Montana. Expecting a quiet night ahead with a clearing sky and decreasing winds this evening. Otherwise, have issued a flood warning for the Cannonball River at Breien as the river level is just below minor flood stage, and is forecast to rise above Minor Flood Stage this evening. This is expected to be a short duration flood event with the river level most likely falling below minor flood stage Tuesday afternoon. && .SHORT TERM...(This evening through Monday) Issued at 322 PM CST Sun Mar 1 2020 Concerns in the short term are the gusty winds for the remainder of this afternoon and some light rain, and gusty winds Monday. Current winds are diminishing slowly after this mornings high winds of 60 to 65 mph moved though with the pressure rise. The winds will diminish rapidly by evening. Until then we will keep the wind advisory going. Otherwise we expect to see some clearing skies tonight, followed by increasing clouds and Monday as a fast shortwave trough follows and quickly moves through. At this time we do not think winds will be nearly a strong as today, but gusty winds of 25 to 35 mph appear likely Monday afternoon. We expect a few rain showers/snow showers with this feature. .LONG TERM...(Monday night through Sunday) Issued at 322 PM CST Sun Mar 1 2020 The extended period will feature a progressive flow through Thursday followed by a ridge that should bring mild and dry weather for Friday and Saturday. On Tuesday, a strong h300 jet of 135 kts across Montana into southwest North Dakota should support some light precipitation across the left front quad, and the ECMWF/GFS support this. This will end up being some light rain. Wednesday will see another shortwave trough move through. The GFS is by far the strongest model with a closed low in Saskatchewan, but the NAM/ECMWF and SREF remain an open wave. So will follow the blend which brings a chance for rain and a bit of snow Wednesday across the north. Otherwise the remainder of the extended looks mild for Friday and Saturday, then a chance for rain and snow Sunday. && .AVIATION...(For the 00Z TAFS through 00Z Monday evening) Issued at 615 PM CST Sun Mar 1 2020 MVFR cigs begin this taf period at all terminals, however expecting a return to VFR status by 03z Monday. Gusty northwest winds to 30kt will also decrease to less than 10kt by 03z Monday for all terminals except KMOT and KJMS. Wind shear is expected at all terminals except KJMS between 10z and and 18z Monday. See each terminal for specific times. Otherwise, another cold frontal passage is expected after 18z Monday, with westerly winds increasing and gusting to 35kt. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...KS SHORT TERM...WAA LONG TERM...WAA AVIATION...KS
Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
657 PM EST Sun Mar 1 2020 .AVIATION... VFR conditions are in place across Southeast Michigan early this evening as deep column ridge works across the area. Models show warm air advection increasing significantly now moving forward. Strong, unwavering consensus that low level thetae between 2.0 and 5.0 kft agl will move into Southeast Michigan after 04Z this evening. Problem is that one has to go back portions of southern Illinois/MO to get close to some MVFR cigs. Will steady the course and keep previous timing of MVFR/moisture as model data shows favorable trajectory to low level jet to maximize moisture advection during the late evening. Pretty pessimistic on fog tonight given very high sfc T-Td spreads and the look of RAP soundings. Nevertheless did keep a light hz mention. Combination of strong low level theta e advection with cold temperatures aloft will lead to very steep lapse rates above 500mb late tonight/before daybreak. Liked the signal out of the HREF probs for a VCTS mention with showers in the 08-11Z timeframe for the southern taf sites. The shower activity could also yield some temporary IFR conditions. West flow develops post cold front Monday morning. Lack of any true cold air advection will mute the wind response Monday. For DTW...Prevailing rain showers with VCTS between 08-11Z. Some of the showers may lead to temporary IFR conditions. Rain clears out with some modest low level/boundary layer cloud early in the day. No significant wind expected. DTW THRESHOLD PROBABILITIES... * High for ceilings at or below 5000 feet tonight. * High for precip type being rain. && .PREV DISCUSSION... Issued at 357 PM EST Sun Mar 1 2020 DISCUSSION... South wind gusting around 25 mph is proving to be the main driver of the afternoon temperature response in spite of snow cover and with modest contribution from sun filtered through high clouds much of the day. The result is stage 1 of the warming trend consisting of lower to mid 40s temperatures with a few upper 30s still in the shandow of Lake Erie and Huron. These readings with dewpoint only in the teens and 20s is no doubt sublimating some snow cover. NOHRSC maps already indicate minimal depth in the Saginaw valley while a 2 to 4 inch cover generally extends over the rest of SE Michigan into northern Indiana and Ohio. This is enough to hang around a while tonight in stage 2 of the warming trend that consists of a notable increase in surface dewpoint and boundary layer moisture. Upstream observations this afternoon indicate lower to mid 50s temperatures up to Chicago, Muncie, and Dayton. Readings in the mid 60s accompanied by lower to mid 40s dewpoint reach the Missouri/Illinois border as of mid afternoon. These readings support expectations of a rising temperature and dewpoint trend across Lower Michigan after a muted evening drop tonight. Readings could even push the 50 degree mark by sunrise Monday. The low level moisture transport also coincides with the onset of rain showers that develop late tonight and last through Monday morning. The activity is supported along and ahead of a weak and slow-moving cold front that is positioned roughly from Port Huron to South Bend at sunrise. Model solutions in today`s forecast cycle look nearly identical to previous runs regarding larger scale forcing mainly associated with a weak coupled upper jet structure inducing a surge of fgen in the frontal zone surface to 850 mb. This is more capable of increased shower intensity and near categorical coverage south of the I-69 corridor. A rumble of thunder is also possible near the Ohio border. The northern stream jet max exits into Quebec and carries the front south and east of the Michigan border by Monday afternoon. It is followed by short wave subsidence and dry weather with surface high pressure lasting through Monday night. A minor intrusion of colder air is then quickly scoured out as renewed southwest flow develops during Tuesday. Morning lows in the mid to upper 20s rebound back into the mid 40s following the passage of a dry but mostly cloudy trough/warm front. Westerly low level flow develops Tuesday night and Wednesday on the south flank of low pressure moving through northern Ontario. Low level thermal fields and partial thickness indicate minimal temperature advection during this time which allows generally above normal conditions to hold through mid week. Precipitation prospects are dependent on low predictability of a very small scale upper level impulse that would bring some light rain during Wednesday afternoon. Extended range models then bring a stronger low into central Canada by Thursday that has potential to pull another round of warm air into Lower Michigan on strong SW flow followed by a longer period of colder NW flow by Friday. Assuming projections hold on the highly amplified and relatively progressive large scale pattern, guidance temperatures are then barely down to normal Friday into Saturday before yet another big warming trend is shown to finish next weekend. MARINE... A fresh to strong south to southeast breeze continues across the waters this afternoon into the early evening, limited to below 30 kt by a stable lower atmosphere. Winds will veer to the southwest tonight as low pressure tracks north of Lake Superior. A cold front then moves through Monday morning, shifting winds to the west but without an increase in speed. Winds then remain near or below 10 kt through the remainder of Monday into Tuesday morning as high pressure builds in, with the exception being northern Lake Huron where the gradient will stay a bit stronger, with winds on the order of 15 to 20 kt there. This high will be short-lived as another weak low moves across Ontario Tuesday night and brings another weak cold front through. The rest of the week follows a similar pattern of alternating high and low pressure advancing through the region with the better chance for more impactful marine weather holding off until Friday. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. Lake Huron...NONE. Lake St Clair...NONE. Michigan waters of Lake Erie...NONE. && $$ AVIATION.....CB DISCUSSION...BT MARINE.......TF You can obtain your latest National Weather Service forecasts online at
Area Forecast Discussion
National Weather Service Grand Rapids MI
1037 PM EST Sun Mar 1 2020 LATEST UPDATE... Update/Marine .SYNOPSIS... Issued at 329 PM EST Sun Mar 1 2020 - An isolated thunderstorm possible near I-94 tonight - Low clouds and fog tonight - Possible showers Tue PM - Another chance for showers/snow shower Thu night into Friday && .UPDATE... Issued at 1037 PM EST Sun Mar 1 2020 Updated the forecast to remove the mention of thunder in the far southern forecast area. Instability looks to be pretty meager with the latest NAM showing 850mb LIs only slightly negative. Deep layer CAPE is only on the order of a few hundred joules. Just do not feel this amount of instability is worthy of a mention of thunder in the forecast. Latest model runs have even tapered back on the amount of precipitation overall along the I-94 corridor. Some light fog is possible tonight along and south of I-96, but not expecting this to be too impactful as visibilities are not really expected to go below 1-2 miles. && .DISCUSSION...(This evening through next Sunday) Issued at 329 PM EST Sun Mar 1 2020 -- An isolated thunderstorm possible near I-94 tonight -- Isolated thunderstorms with locally heavy rainfall (over a 1/2 inch in one hour) are more than possible near and south of I-94 tonight. The SPC SREF 3 hour calibrated thunderstorm forecast has a 5 pct chance of thunderstorms in the 10 pm to 1 am time frame. As it turns out there is a southern stream shortwave that is being ejected northeast from the southern plains into northern Ohio Valley and possibly as far north as the southern Great Lakes. The 1000/805 moisture transport vectors on the RAP model are aimed at I-94 this evening. This is similar to what the ECMWF shows too. The HRRR has area of more than .5 inches of 3 hour rainfall near and south of I-94. Given surface dew point are in the 45 to 50 degree range as close as western Illinois, and precipitable water values reach near .75 inches this evening, this would make some sense. In fact the RAP model, for nearly every run of it since at least 10z has nearly 800 j/kg of MU cape over western Van Buren county in the 9 pm to 1 am time frame. There is a 40 knot low level jet helping the cause. The NAM is not as strong on this but given the continuity of HRRR, RAP and ECMWF and some support from the GFS, I am thinking showers are likely near and south of I-94. North of I-94 to much mid level dry air comes in so I do not think the storms/heavy rain will get north of I-96 tonight. -- Low clouds and fog tonight -- With all of that moisture being brought north by the frontal system tonight, and given the snow cover will not be totally gone in the I-69 area, it makes sense to believe some fog and low clouds should be expected over the area where snow still remains. Other locations with no snow on the ground will just see low clouds with drizzle not out of the question. -- Possible showers Tue PM -- A stronger northern stream system comes through the area Tuesday and with it comes a chance for showers in the afternoon and possibly evening. The GFS and ECMWF have deeper moisture with this system farther south than does the NAM, given the strength of this system, I am thing we will see some showers with this. More than likely it will be rain showers as temperatures will likely be in the lower 40s in the afternoon Tuesday. Once the front comes through though we get 850 temperatures falling near -8c and there is some clouds up to 5000 ft in depth, so there could be some flurries Wednesday morning. -- Another chance for showers/snow shower Thu night into Friday -- Overall we still have a progressive upper air pattern with Pacific shortwaves moving across the CONUS about every 48 hours or so. The next system impacts this area Thursday into Friday. This looks to have more impacts on us and more than likely will bring showers to the entire area ahead of the storm and we get into the deep cold air aloft behind the system early Friday so I would think some snow showers are possible. This is a progressive pattern so it will warm up again over the weekend and another storm with possible impact is possible by the middle of next week. && .AVIATION...(For the 00Z TAFS through 00Z Monday evening) Issued at 724 PM EST Sun Mar 1 2020 The main forecast concern the next 24 hours will be some lower clouds and precipitation that will move into Southern Lower Michigan tonight. MVFR ceilings are forecast to develop just after midnight along I-94 and lower to IFR around 200am. This will coincide with some precipitation that will be moving through. Visibilities will likely dip to IFR levels as well in some fog and rain. The I-96 TAF sites will largely be spared, but some MVFR conditions are expected for a time after 100am. The rain should remain off to the south however towards I-94. The low clouds will move out to the east through the course of Monday morning. By noon, VFR conditions should prevail. In regard to wind a cold front will pass through the area tonight. South winds will turn to the west tonight and the northwest on Monday. There may be a few hours of low level wind shear this evening where 2000ft winds are southwest around 45 knots through 03z. && .MARINE... Issued at 1037 PM EST Sun Mar 1 2020 We will let the Small Craft Advisory expire at the top of the hour. Latest model runs of the WaveWatch3 and the GLERL model both show wave dropping below 4 feet. Winds have fallen to below 15 knots at Big Sable Point. Winds and waves should stay below SCA criteria through Monday night. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...None. LM...Small Craft Advisory until 11 PM EST this evening for LMZ844>849. && $$ UPDATE...Duke SYNOPSIS...WDM DISCUSSION...WDM AVIATION...Duke MARINE...Duke
Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
848 PM CST Sun Mar 1 2020 .UPDATE... 846 PM CST Main update this evening was to tighten up the PoP gradient on the northwestern flanks and to generally reduce thunder chances to a narrower corridor across our far southeastern counties overnight. Mid-evening moisture channel imagery reveals our initiating shortwave in question translating fairly swiftly across central Missouri. Based on its current more easterly translation component, it appears most of the large-scale DCVA-induced forcing for ascent will remain confined mainly to our far south and eastern counties overnight. Noting developing elevated showers off to our southwest at the edge of the main mid-level moisture plume, and this spotty activity should continue to develop northeastward through the evening hours, although this may initially struggle as it moves into a drier airmass. At the surface, a cold front is just about to move through the Rockford area and will continue to push through the forecast area overnight. This intrusion of cooler/drier air will set a northwestern terminus to any potential shower or embedded thunderstorm activity that will be continually marching southeastward with time. Surface observations show the 50 degree isodrosotherm is still well off to our south, closer to the I-64 corridor across southern Illinois, which is notably farther south than midday model guidance (RAP/HRRR) would have suggested. Recent VAPOR AMDAR soundings out of Midway reveal that things are pretty parched through the low and mid-levels, and even ILX`s evening RAOB sampled plentiful lingering dry air below 600 mb. So, while mid- level lapse rates are more than supportive of thunderstorm development, pretty marginal moisture and thermodynamic profiles look to chew into this potential a good deal tonight. With this in mind, have confined the thunder mention for the rest of the overnight to areas south of a Pontiac to Valparaiso line and also trimmed PoPs in the vicinity of I-55 as the incoming front looks to scour moisture out before the main slug of mid- level moisture arrives. Should still see some pretty good shower coverage east of I-57 tonight before everything shifts east of our area by daybreak on Monday. Updated products have been sent. Carlaw && .SHORT TERM... 135 PM CST Through Monday night... A significant but somewhat short lived air mass change continues this afternoon as dewpoints climb into upper 30s and the 40s are knocking on the door. Several features of note on water vapor pictures, a strong jet core across the southern tier of states, with a few smaller scale disturbances in mostly westerly flow aloft to our south, maybe a slightly more distinguishable wave moving into MO early this afternoon. Morning soundings out of Little Rock, AR and Springfield, MO depict the airmass that will advect toward the area ahead of an approaching cold front this evening. A noted but modest increase in PWATs up to 0.55" but with impressive lapse rates in excess of 8 deg/km around the 700-500 mb layer, and quite the elevated mixed layer a bit further upstream at Fort Worth, TX and PWATs in excess of 0.75". RAP modeled soundings are a tad moist at this point. The driver for the cold is a more significant upper low across the northern international border region. This will drive through the upper Great Lakes tonight and push the cold front into the area this evening and through the area by Monday morning. This aforementioned features will lead to an expansion of showers and thunderstorm across the mid Mississippi valley late this afternoon. The cold front will provide for a sharp cut off in the precip axis which still roughly aligns with the I-55 corridor. The better moisture will certainly shift into the Ohio Valley thus some mixed signals on the strength of the precip and instability this far north, but enough moisture will advect to our area to support a period of some decent showers. Cannot argue against the chance of a few thunderstorms given the impressive lapse rates upstream, and narrow ribbon of moisture ahead of the front, with a little better signal south of I-80 across east central IL and into central IN. Main time window is 9PM CST until about 2-3AM CST. The cold front will quickly move through overnight ending precip chances. Northwest flow will maintain a cold advection regime on Monday, with highs back more in the department of normal or slightly above under mixed sun and clouds. Noted the previous AFD mention of lake breeze potential which should form. Current 12z runs depict 925-950 mb flow would be strong enough to keep it at bay for most of the day before the flow weakens at a diurnally unfavored time for a lake breeze to move inland too much, but this will be more of a mesoscale feature to see how the hi-res models resolve tomorrow. High pressure will shift through the lower Great Lakes region Monday night supporting cool temperatures and fog would be possible in some areas, with some hints that this may be favored across the recently rained areas of EC IL and NW IN, though there is enough low level flow to suggest it would shallow. KMD && .LONG TERM... 125 PM CST Tuesday through Sunday... A split flow regime will remain in place mid week with a strong jet across the Ohio Valley ahead of a southwest trough and the northern stream pushing out of the Canadian northwest/Rockies. The southern jet should keep the better moisture south of the Great Lakes with our weather potentially more influenced by the northern stream. The surface low associated with the shortwave trough in the northern stream will pass well north of our area, which should keep precip limited with the first wave Tuesday morning, but a weak cold front will nevertheless slide through Tuesday night accompanied by a sharper upper trough. After a day of mixing and the cut-off low preventing any northward transport of meaningful moisture, The front will likely come through dry. Wednesday will be breezy with northwest winds in the wake of the cold front and with the front of Pacific origin we will likely only see a smaller dip in temperatures, though it may feel cooler with the northwest breezes. Winds will quickly become southwesterly again by Thursday in advance of the next shortwave trough, which will help boost temperatures toward the upper 50s. The second cold more potent front of the week will sweep through Thursday evening. Model guidance does paint some light QPF with this stronger front, though moisture is still limited and this front may yet still some through dry in with the cut-off low still meandering along the Gulf hogging moisture. A pocket of colder air will be found behind the front this time around, Friday will end up the coolest day this week with highs in the 40s, still near or maybe a tad above normal, though it will be breezy again to make it feel cooler, especially lakeside. There are some lakeshore flooding concerns in Northwest and portions of Cook County given the gusty winds behind this stronger front. The weekend will begin dry and mild as upstream ridging and deep south-southwest flow returns (some cooling IL lakeside due to some SE component possible), but there are some inconsistencies in model guidance as to if the ridge will hold precip off through the whole weekend, but conditions will remain on the mild side. KMD && .AVIATION... For the 00Z TAFs... A cold front will shift southeast across the area late this evening into the early overnight hours. Observational data and model guidance has suggested a southward trend with associated SHRA and embedded TS that is expected to develop along the front late this evening. While ORD/DPA/RFD were already expected to remain dry, the southward shift will likely keep MDW dry as well and push the TS chance south of GYY. However, an isolated light shower cannot be ruled out for MDW around midnight, while scattered showers are expected around the same time for GYY. The southward trend in precip has also resulted in a trend to higher ceilings for all Chicago metro sites, with VFR ceilings now expected at all sites but GYY through the period. SW winds around 10 knots ahead of the front will become NW 10-15 knots, with some gusts nearing 20 knots possible at times on Monday. Kluber && .LOT WATCHES/WARNINGS/ADVISORIES... IL...None. IN...None. LM...None. && $$ Visit us at Follow us on Facebook, Twitter, and YouTube at:
Area Forecast Discussion
National Weather Service Pueblo CO
331 PM MST Sun Mar 1 2020 .SHORT TERM...(This evening through Monday) Issued at 331 PM MST Sun Mar 1 2020 Main forecast concerns/challenges are with the expected winter weather this evening into Monday morning, with periods of heavy snow likely causing hazardous travel during the overnight hours and Monday morning commute. In the near term, outside of the higher elevations, mainly dry conditions still in place across much of the area. Radar imagery depicting some light returns over southeast Colorado, however, this is currently stemming from mid/high clouds with no precip likely making it to the surface. Do expect that to change over the next several hours though as large scale ascent further increases. Previous wintry precip trends with model guidance has continued with today`s guidance, with snow increasing across the higher elevations late this afternoon and a rain snow mix likely developing over adjacent locations. Still anticipate mid/upper level flow to increase while several short wave troughs noted on latest satellite imagery traverse this flow. Meanwhile, surface front in place across Colorado surges southward this evening, with northerly winds and gusts strengthening into the night. Should then see precip really develop and spill into Teller and El Paso counties by early to mid evening. A rain snow mix may initially occur, but think stronger CAA post FROPA and increasing forcing will quickly cool the column, with thermal profiles then likely supporting all snow by mid evening. Previous concerns of a window of more focused and heavy snow remain and have even increased, especially along the I-25 corridor from mid evening to early Monday morning. Not only is upslope flow focused in this location that would bring bands of snow across the Palmer divide, but most guidance indicating a fairly long window of more focused isentropic ascent in this location. This would support additional banded heavy snow. Additionally, the anticipated CAA will likely help keep already steep low and mid level lapse rates in place, per latest RAP analysis. This would all then produce a period of stronger snow development into early Monday morning. While current forecast snow amounts of 3-5 inches are expected across northern El Paso county, do think locations across southern El Paso county back southwest to around Canon City could see these amounts. Also, the banded nature of this snow will likely produce highly variable amounts, and even locally higher amounts. So will continue to closely monitor trends and latest guidance, to hopefully pin point where exactly this may occur later tonight. So, with the expected heavy snow and high snowfall rates, snow covered and slippery roads, and significantly reduced vis all producing hazardous driving conditions overnight tonight and for the Monday morning commute, felt an Advisory was warranted. Did even add parts of Fremont county as this looks to be in this favored location. Pueblo county will need to be monitored for possible inclusion in this Advisory, as they will be right on the line of this potential heavier snow. At this time, most of this looks to stay just to the northwest and west, however, it`s still possible for a heavy band to develop overhead. Another aspect to monitor for Pueblo will be with the rain snow mix and then transition to all snow tonight. A mix of rain and snow before cooling conditions tonight, may support more icy road conditions. Confidence is not high on this potential though at this time. Expect snow to likely continue across the higher elevations Monday morning, but likely come to an end over the plains. Did add a small window of patchy freezing drizzle/rain to the forecast for a time Monday morning though. Guidance showing rather moist lower levels lingering Monday morning, and with some light upslope flow still in place, do think it`s a possibility. .LONG TERM...(Monday night through Sunday) Issued at 331 PM MST Sun Mar 1 2020 Monday Night and Tuesday: As advertised in previous forecasts, the upper level low pressure center will propagate west to east over Mexico and through Texas. No major impacts are expected due to how far south the low pressure system is. Very pleasant weather is expected Monday night and Tuesday. There isn`t much expected for cloud cover, the winds will be relatively lights, and the temperatures will be right around average for this time of year. Enjoy! Wednesday through Sunday: A warming trend will begin as an upper level ridge develops over southern Colorado, with the warmest day expected to be Saturday and temperatures expected to be around 10 to 20 degrees F above average. Each day will have critical or near critical fire weather conditions over the plains. Wednesday, Friday, and Saturday seem to be the days with better fire weather conditions as they are associated with the best downslope flow off of the eastern mountains. Otherwise, dry conditions are expected through Saturday morning. Long term models are resolving the next low pressure system impacting southern Colorado by Saturday morning. There is still a lot of uncertainty with timing, but the impact are expected to bring snow only over the mountains. && .AVIATION...(For the 00Z TAFS through 00Z Monday evening) Issued at 331 PM MST Sun Mar 1 2020 KALS: VFR conditions are expected for KALS throughout the forecast period, but there will be vicinity rain and snow showers during the overnight. If a rain or snow shower develops over the forecast point, MVFR to IFR conditions are possible. Otherwise, morning and day are expected to be VFR. KCOS and KPUB: A cold front is expected to develop over KCOS and KPUB this evening which will bring snow, heavy at times to both locations. Expect conditions ranging from MVFR to LIFR during the overnight and morning. Low level saturation and weak upslope event will keep fog over KCOS and KPUB through the morning, so MVFR to IFR conditions are expected. During the late morning to early afternoon, fog is expected to mix out and VFR conditions will return. && .PUB WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory until 7 AM MST Monday for COZ077-081>085. && $$ SHORT TERM...RODRIGUEZ LONG TERM...SKELLY AVIATION...SKELLY
Area Forecast Discussion
National Weather Service Springfield MO
532 PM CST Sun Mar 1 2020 .SHORT TERM...(This evening through Tonight) It felt like a spring day over extreme southeast Kansas and the Missouri Ozarks. Breezy south winds brought in a Gulf airmass, which will set the stage for showers and thunderstorms this evening and through the overnight hours. A few of these storms could become strong to severe, with large hail up to the size of quarters being the primary risk. There will also be a very limited risk for a damaging wind gust or two. Deep layer shear will be the limiting factor, as 0-6km values only range from 20 to 30 knots. Models have increased CAPE progs ranging from 1000 to 1500. There will also be a flash flood risk along a narrow corridor. This corridor will likely stretch roughly from Columbus Kansas to Springfield, and then east along the Highway 60 corridor. The HRRR and RAP have consistent signals with each other, and have consistently showed this potential each hourly run today. This zone is correlated with an 850mb jetlet that triggers convection around the Joplin/Columbus Kansas area around 9 or 10pm this evening. Showers and thunderstorms will likely shift south and east of the CWA by early Monday morning. A Flash Flood Watch for tonight is being considered for a narrow corridor from Columbus Kansas eastward along the Highway 60 corridor. .LONG TERM...(Monday through Sunday) Northwest flow will push the frontal boundary into Arkansas by early Monday, setting the stage for several days of dry and mild weather. The Ozarks will remain under the influence of northern stream energy as the southern belt churns across the deep south within the split flow regime and tropical atmospheric river. Locations across the I-20 and I-40 corridors will rob any low level moisture return to the Ozarks as widespread convection occurs in this area through Thursday morning. Another shot of continental air will spread across the region early Friday morning. This front will be rain free given the dry air in place. A large upper ridge of high pressure builds across the nations midsection for next weekend. This feature will help boost temperatures back into the 60s, and possibly the 70s by Sunday afternoon. No rainfall is expected through Saturday night. A precipitation signal then occur by late Sunday which could feature some heavy rain given the upper pattern and stationary southwest to northeast baroclinic zone. && .AVIATION...(For the 00Z TAFS through 00Z Monday evening) Issued at 529 PM CST Sun Mar 1 2020 A weak cold front will move south through the region this evening into the overnight hours. Scattered showers and a few storms are expected to develop along the front. Due to limited coverage confidence was too low to include a mention of thunder at this time in the TAFs, did include a TEMPO group for showers in the TAFs as coverage in showers should be greater than thunderstorms. If the TAF sites are affected by thunder it will be in the same time range as they would be affected by showers. Will amend the TAFs as needed this evening if confidence in a TAF site being affect by a thunderstorm increases. Ceilings will lower into the MVFR range and possibly the IFR range behind the front. Winds will also switch to the north after the frontal passage. && .SGF WATCHES/WARNINGS/ADVISORIES... MO...NONE. KS...NONE. && $$ SHORT TERM...Cramer LONG TERM...Cramer AVIATION...Wise