Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 02/19/18

Area Forecast Discussion
National Weather Service Columbia SC
656 PM EST Sun Feb 18 2018 .SYNOPSIS... A frontal boundary south of the forecast area will lift north as a warm front tonight into Monday morning. Bermuda high pressure will be in control Monday night through Thursday bringing near record high temperatures. Another frontal boundary may affect the area Friday. && .NEAR TERM /THROUGH MONDAY/... High pressure ridging into the Southeastern States from the Mid-Atlantic coast will move further east tonight allowing the low-level winds to turn more easterly promoting increasing moisture across the area. It will also allow the front to the south to begin slowly pushing back north as a warm front through the night. Weak isentropic lift overnight will bring additional cloud cover and isolated showers. However, the highest rain chances will remain further off to the west and north through the night. Will only have a slight chance to possible low chance pops across the western and northern counties late tonight. Fog may become an issue late tonight and towards morning with the warm front moving through, and with the increase in low- level moisture. However, the HRRR and RAP do not show any fog and there is a 30 knot low level jet overnight, so have continued to indicate only patchy fog development. Temperatures will be well above normal overnight due to the front in the area, cloud cover, and mixing. Lows in the lower to middle 50s. && .SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/... Monday and Monday night...frontal boundary will begin Monday just north of the forecast area and slowly move northward away from the area through Monday night. This will result in mostly cloudy skies and patchy fog to start the day with the fog burning off by mid morning. During the afternoon hours high pressure will begin building into the region with the upper level ridge also building over the eastern US. While the southeasterly surface winds and southerly winds aloft will transport moisture into the area the inversion will take time to burn off resulting in stratus clouds persisting into the afternoon hours and little time for diurnal heating to develop cumulus clouds. As such expect mostly cloudy skies through midday becoming partly cloudy during the afternoon. Monday night the moisture will remain through the night and with a developing inversion and light winds aloft expect fog to again develop during the early morning and sunrise hours. Temperatures Monday will range from the upper 60s over the northern and western Midlands to the upper 70s in the southern CSRA...with overnight lows in the middle to upper 50s. Tuesday and Tuesday night...high pressure will continue building into the region with southerly flow from the surface through the mid levels. This will again keep Gulf moisture flowing into the forecast area with the strong inversion taking through the midday hours to again burn off. This will again result in mostly cloudy skies during the morning with decreasing clouds through the afternoon. Tuesday night a short wave will move northward from the Gulf of Mexico through central GA and into Upstate SC. This will keep the short wave just west of the forecast area however there is potential for some showers mainly in the northern CSRA and western Midlands Monday night. Temperatures will be in the mid 70s to around 80 for afternoon highs with low 60s for overnight lows. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... Models continue in good agreement with high pressure off the coast of the Carolinas and an upper level ridge dominating the region. A cold front will move toward the region Wednesday night and Thursday then stall just west of the forecast area as the high pressure and upper level ridge push the system northward. The front will move northward Thursday night through early Saturday with the next front approaching Saturday night and Sunday. Have taken a cautious approach for Saturday night and Sunday as the GFS remains more progressive while the ECMWF again keeps the front just to the northwest of the area. Temperatures through the long term will be well above normal. && .AVIATION /00Z MONDAY THROUGH FRIDAY/... Frontal boundary across central and east Ga will move north into the region overnight. Ceilings are lowering to MVFR in the CSRA and southeast Midlands this evening. The models indicate ceiling will lower overnight to IFR or LIFR conditions late tonight into Monday morning as warm front moves into the area. Highest chance of LIFR appears to be near AGS and OGB. As the front moves possibly to the north of the terminals Monday afternoon, expect ceilings to improve to MVFR and winds to shift to southeast or south 5 to 10 knots. EXTENDED AVIATION OUTLOOK...Chance of showers/restrictions through Wednesday associated with onshore flow, isentropic lift, and then another approaching cold front. && .CAE WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. && $$
Area Forecast Discussion
National Weather Service Dodge City KS
822 PM CST Sun Feb 18 2018 .SYNOPSIS... Issued at 544 PM CST Sun Feb 18 2018 A dry cold front will sag south tonight into Monday, and then stall out over SW Kansas Monday afternoon. A very large temperature difference is expected Monday afternoon, with northern counties below freezing, and areas along the Oklahoma border in the 70s. The cold air will win the battle, with much colder temperatures Tuesday and Wednesday. Expect moderating temperatures Thursday and Friday. Dry weather will continue. && .UPDATE... Issued at 822 PM CST Sun Feb 18 2018 Cold front making excellent progress through NE Colorado, with temperatures crashing quickly behind it (Cheyenne fell from 53 to 26 in one hour). Given the front`s momentum on satellite imagery and these observations, updated Monday`s temperatures by dropping them significantly (especially north of US 50). 00z NAM and latest HRRR runs show the frontal boundary clearing the KS/OK border now by 9 am, and indications are the cold air will win out. Strong cyclogenesis is still expected in SE Colorado Monday afternoon, and the boundary will likely still stall and retreat northward. Some wild temperature differences and temperature swings are likely across the southern counties during the day tomorrow. But north of US 50, it looks like the cold air will reign supreme. UPDATE Issued at 533 PM CST Sun Feb 18 2018 Added areas of smoke to the Barber county vicinity, as smoke plume from fire in NW Oklahoma (Woods county) continues to spread NE. && .SHORT TERM...(This evening through Monday) Issued at 311 PM CST Sun Feb 18 2018 Temperatures are a real challenge in the short term with a sharp baroclinic zone becoming established in western Kansas Monday and uncertainty about how much if any the shallow cold air will mix out during the day Monday. A cold front extended from eastern South Dakota across central Nebraska to eastern Wyoming early this afternoon with pressure rises of two to three millibars in three hours behind the front in South Dakota and northern Nebraska behind an upper level trough that was moving from eastern North Dakota into Manitoba. A deep surface cyclone was centered in southeast Wyoming and northeast Colorado. A sharp pressure gradient across Kansas was producing howling south to southwest winds with frequent gusts to near 50 mph. Relative humidities were below 15% only in west central Kansas, but the dry air should spread farther east by late afternoon. An upper level vorticity maximum evident on satellite imagery off the southwest British Columbia coast will continue to dig into the mean long wave trough position in the western United States, and the upper level flow over the central United States will back tonight and Monday. A weak upper level trough that extended from Wyoming to northeast New Mexico will continue moving northeast tonight, and a weak surface cyclone will ripple along the low level baroclinic zone. The cold front will progress southward into northern Kansas this evening in the wake of the weak cyclone and should reach southern Kansas by morning. Temperatures tonight will be mild for this time of the year with lows in the 40s and lower 50s across southern Kansas in advance of the cold front. Temperatures likely will fall into the upper 20s behind the front in northern Kansas. The models are reasonably consistent in slowing the front to a stop north of the Oklahoma border as cyclogenesis occurs in Colorado as an upper level trough ejects from the long wave position into eastern Colorado by Tuesday morning. Model soundings suggest that stratus will develop north of the front but may erode northward Monday afternoon. It usually is hard to erode cold air once it is in place, but there is good consensus among the model solutions that at least some erosion will occur. The air behind the front is not true arctic air, and there should be quite a bit of sun for some distance on the cold side of the front. There will be a very substantial temperature gradient Monday with temperatures holding in the lower 30s around Interstate 70 and rising into the 70s south of the front. .LONG TERM...(Monday night through Sunday) Issued at 311 PM CST Sun Feb 18 2018 A long wave trough will persist in the western United States with a strong upper level ridge from the Gulf of Mexico across Florida to the western Atlantic Ocean. Minor upper level troughs will move around the mean long wave position and lift out across the central part of the country. Although the potential for beneficial precipitation on southwest Kansas through the end of February is minimal, there will be several opportunities for light precipitation. The upper level trough that will extend from the Dakotas into eastern Colorado Tuesday morning will lift out to the northeast and should extend from James Bay to Minnesota by Wednesday morning. There may be enough isentropic lifting over the front to produce light precipitation in south central Kansas Monday night. The phase of the precipitation is not certain, but most of it should fall before surface temperatures drop below freezing. Cold air will surge southward across the Plains Monday night and Tuesday, and temperatures Tuesday will vary from the 20s in northern Kansas to near 50 along the Oklahoma border. Another minor upper level trough will approach Wednesday, and isentropic lifting over the cold air mass may produce some light precipitation in central and southern Kansas. Temperatures will be below freezing at the surface, and a warm layer aloft will support the possibility of freezing rain or sleet. Yet another upper level trough will approach Thursday and will provide an opportunity for light precipitation. A stronger upper level trough should reach Kansas about Saturday. Warm air advection will occur Friday as a surface cyclone develops in southeast Colorado, and temperatures should be above freezing by the time precipitation develops Friday night and Saturday. However, details in timing of the minor upper level troughs and the thermal structure of the low levels of the atmosphere are uncertain. It still appears likely that the deep upper level low will weaken and retrograde to the Canadian Arctic in early March and that an area of high pressure will spread from northern Europe into eastern Canada. A mean upper level trough is likely to persist in the western United States, so chances for precipitation will continue into early March. && .AVIATION...(For the 00Z TAFS through 00Z Monday evening) Issued at 500 PM CST Sun Feb 18 2018 Very strong SW winds will diminish some around sunset, but remain gusty through the evening hours. The low level jet will reintensify quickly this evening, so maintained a mention of LLWS at all airports through 06z Mon. Starting around 06z Mon, a dry cold front will sag southward across SW Kansas, accompanied by a shift to north winds. Cold front should arrive at HYS by 06z Mon, and DDC/GCK by 09z. The frontal boundary is expected to stall on Monday, and is forecast to remain north of LBL. As such, kept prevailing S/SW winds at LBL through Monday. There is potential for post-frontal stratus behind the boundary, but model agreement on this is poor, resulting in low confidence. NAM forecast soundings are very aggressive with IFR stratus cigs impacting at least DDC/HYS through Monday morning, and this guidance was followed in this TAF issuance. TAF amendments are likely through Monday as this boundary and stratus edge into SW Kansas. && .FIRE WEATHER... Issued at 333 AM CST Sun Feb 18 2018 Strong south to southwest winds will continue this afternoon into the evening. Very dry air in west central Kansas will spread slightly farther to the east, but relative humidities will not fall below 20 percent east of a line from Hays to Liberal. The Red Flag warning will be continued given the extremely dry fuels and high winds even though relative humidity criteria will not be met. Warm temperatures and gusty southwest winds near the Oklahoma border will support active fire behavior Monday, but relative humidities will remain above thresholds for fire weather headlines. && .PRELIMINARY POINT TEMPS/POPS... DDC 44 45 27 36 / 0 0 10 0 GCK 33 40 20 31 / 0 0 10 0 EHA 46 74 28 40 / 0 0 10 0 LBL 49 68 32 43 / 0 0 10 0 HYS 30 34 18 26 / 0 10 20 0 P28 53 66 37 46 / 0 10 30 20 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...Turner SYNOPSIS...Turner SHORT TERM...Ruthi LONG TERM...Ruthi AVIATION...Turner FIRE WEATHER...Ruthi
Area Forecast Discussion...UPDATED
National Weather Service Austin/San Antonio TX
826 PM CST Sun Feb 18 2018 .UPDATE... There is a pulse of energy moving across the northeast part of Mexico this evening. IR satellite images show an increase on cloud top temperatures as the cluster of thunderstorms move over the high Mexican terrain. Both HRRR and the 3km WRF Texas Tech models pick up on this feature and brings it across the Rio Grande Plains including the Del Rio area around 11 PM late this evening through 1 AM Monday. If the cluster of storms holds and move over Del Rio and vicinity, expect heavy rain and thunderstorm wind gusts of 30 mph or so. As the cluster of storms move into the Edwards Plateau, there will be less instability in place and only showers are expected to continue moving into the Hill Country overnight. && .PREV DISCUSSION... /ISSUED 537 PM CST Sun Feb 18 2018/ AVIATION... VFR conditions prevail at all sites but conditions will deteriorate back to IFR/LIFR overnight. In addition, the latest runs of the HRRR and TTU WRF show a complex of showers and thunderstorms developing west of the Rio Grande late this evening and moving east into the CWA around 5-6z. Will watch the trends of this closely and will mention VCSH in the DRT TAF from 5-9z for now and amend as necessary. If this complex were to develop, weakening showers could be possible for the I-35 sites around daybreak. MVFR/VFR conditions will be slow to arrive tomorrow afternoon and will likely only see a few hour reprieve into VFR before IFR conditions return tomorrow evening. Otherwise, southerly flow will be breezy tomorrow around 15 knots. PREV DISCUSSION... /ISSUED 317 PM CST Sun Feb 18 2018/ SHORT TERM (Tonight through Monday Night)... An area of scattered showers and isolated thunderstorms this morning has moved off to the northeast as forecast leaving much of the CWA dry today. There still exists a few weak echoes on radar as of 2PM this afternoon associated with isentropic ascent in the lowest 100 mb. After this moves out late this afternoon and evening, another overnight of low cloud development looks likely. Latest runs of the HRRR also indicate another weak disturbance generating some light shower activity near Del Rio and shifting east overnight. This, plus the potential for some light drizzle, warrants at least slight chance PoPs in the forecast. The maintained isentropic ascent through the day tomorrow will also keep skies cloudy and PoPs non-zero. LONG TERM (Tuesday through Sunday)... Models have continued to show a consistent signal for our first good rainfall event beginning as early as late Monday evening and persisting through at least Wednesday. WPC guidance for QPF continues to highlight an area near TexArKana and by all indications at this point, that still looks very good. The thinking continues that initial convection could begin near Del Rio and west as 925-850mb confluence aligns with the right entrance region of a developing UL jet and quasi-dry line west of Val Verde county. This alone will be enough to likely develop at least elevated showers and storm potential, but the kicker will be instability to allow these to become strong. Looking at forecast soundings from the NAM/GFS for 00Z Tuesday, there is quite a stubborn cap at 850 mb whereas the GFS is uncapped. This will obviously play quite a role in whether hail or wind potential will be associated with the storm development. It will likely also play a role in the evolution of this system throughout the overnight period as these features shift eastward. Currently, the thinking is this cap will indeed hold with the extensive cloud cover likely around due to the persistent isentropic ascent throughout the day Monday. Thus while some storms could produce some small hail, the bigger focus will be as this system progresses eastward and organizes. As these features shift eastward overnight, a quasi-liner system will likely progress across the Plateau towards the I-35 corridor. As this occurs, PWATs will steadily increase to about 1.5+" by mid day Tuesday according to the GFS. The dry line surges eastward in response to a cold front diving south across the Red River Valley. Additionally, another piece of UL energy comes across the Mexican mountains and provides enhanced lifting parallel to the dry line and advancing cold front. The more favorable convergence along the front, additional UL support, and continued strong moisture flux Wednesday morning should re-invigorate the line of rainfall and its at this time that heavy rainfall potential will likely be maximized. QPF values are still generally manageable, with even the highest perturbations staying below 3 inches storm total. Thus, the previous forecast`s mention of 1-2 isolated 3 to 4 inches still looks fair. The variable with the least certainty is instability. There are some indications that as much as 500-1000j/kg of SBCAPE may be present per the KAUS proximity sounding (NAM/GFS). Not sure if this is believable given the presence of shower activity, extensive cloud cover, the potential for outflow should the linear system become more organized, and any other unforeseeable mesoscale features, but IF so, these QPF values would likely need to be raised. For now, there`s just not enough certainty to up the forecast values beyond the previous forecast. After this system moves east and the cold front pushes through, this should at least briefly cease rainfall potential overnight Wednesday night, but overrunning appears agreed upon in the medium range models and thus cloud cover and PoPs quickly return, much like the conditions we have seen over the last several days. && .PRELIMINARY POINT TEMPS/POPS... Austin Camp Mabry 64 74 65 72 59 / 20 20 50 80 90 Austin Bergstrom Intl Airport 63 74 65 73 60 / 20 20 40 80 90 New Braunfels Muni Airport 63 75 65 73 61 / 10 20 40 80 90 Burnet Muni Airport 62 73 64 71 53 / 20 20 70 80 90 Del Rio Intl Airport 64 80 62 79 58 / 40 20 60 20 50 Georgetown Muni Airport 63 74 65 71 55 / 20 20 50 80 90 Hondo Muni Airport 64 80 66 77 61 / 20 20 50 60 80 San Marcos Muni Airport 63 75 65 73 60 / 20 20 40 80 90 La Grange - Fayette Regional 65 75 67 75 64 / 10 20 20 70 80 San Antonio Intl Airport 64 77 66 75 62 / 10 20 40 70 90 Stinson Muni Airport 64 78 66 76 63 / 10 20 40 70 80 && .EWX WATCHES/WARNINGS/ADVISORIES... None. && $$ Mesoscale/Aviation...Hampshire Synoptic/Grids...17 Public Service/Data Collection...33
Area Forecast Discussion
National Weather Service Hastings NE
547 PM CST Sun Feb 18 2018 .SHORT TERM...(This evening through Monday) Issued at 256 PM CST Sun Feb 18 2018 Winds today will decrease late this afternoon and this evening from northwest to southeast. This will occur ahead of a cold front that will move through tonight...shifting winds back to the north. The main concern for the overnight hours is freezing drizzle. As of now, the HRRR/RAP are a good middle ground between the aggressive NAM and the less aggressive GFS. One thing of note is that the ESRL runs of the RAP and HRRR show significantly less precipitation than the operational runs. Nevertheless, the most favored areas for freezing drizzle will be north and east of a line from Ravenna, to Hastings to Superior. Looking closer at HRRR forecast soundings, we could even see some light sleet briefly mix in as temperatures in the lowest 1000` continue to drop. Drizzle is still expected to end 6-9AM as drier air advects in. I don`t plan on making any changes to the winter weather advisory, but the evening and mid shifts will need to keep a close eye on short- term trends. After a cold day on Monday, models indicate another round of wintry mix developing Monday night on an area of lift ahead of a deep trough approaching the area. Based on NAM/GFS, the model blend may be bringing in too much precip too early. Our forecast area will be caught in the middle between frontal precip to our southeast and the better lift across the sandhills. Unsurprisingly, the NAM shows a band of strong 700-500mb frontogenesis developing across the sandhills, and develops a band of heavier snow in that area. What is more interesting is that some of the other mesoscale models (mainly the NCEP WRF-ARW and RGEM) develop this band of snow much closer to, or even in, our forecast area. As a result, the model consensus has increased the snowfall for western parts of the forecast area. .LONG TERM...(Monday night through Sunday) Issued at 256 PM CST Sun Feb 18 2018 Any lingering precipitation should wind down Tuesday morning, and clearing skies may allow wind chills to dip into the -10 to -15 degree range through mid-morning. Tuesday is expected to be the coldest day of the week with high temperatures struggling to reach much higher than the teens for most of the area. Tuesday night will likely also be the coldest night of the week with lows generally ranging from -5 to 5 degrees. Winds won`t be as strong, but we could still see widespread windchill values in the -10 to -20 degree range. Forecast temperatures for the rest of the week have trended downward slightly. Highs are only expected to reach the 20s/30s on Wednesday/Thursday before another system moves through the late Thursday through Friday. There is considerable uncertainty regarding the details of the next system, but it does appear that we will have multiple rounds of precipitation...possibly one late Thursday into early Friday and another Friday night into Saturday. This also appears to be a "warmer" system with high temperatures above freezing each day, so we will likely have multiple precipitation types to contend with as well. && .AVIATION...(For the 00Z KGRI/KEAR TAFS through 00Z Monday) Issued at 534 PM CST Sun Feb 18 2018 A fast approaching cold front will bring a shift in winds over the next hour or two as it rapidly tracks southward across the region. Already have seen this wind shift affect ODX...and expect it to reach both KGRI and KEAR around 19/01Z with gusty northerly winds. While initially conditions will remain VFR...expect MVFR stratus to reach the terminals around midnight...with some very light drizzle possible. Once settling not expect the stratus to go anywhere through the remainder of the period...with winds gust increasing to near 30KTs overnight and then persisting through the mid afternoon hours tomorrow. && .GID WATCHES/WARNINGS/ADVISORIES... NE...Winter Weather Advisory from 3 AM to 9 AM CST Monday for NEZ063- 064-076-077. Winter Weather Advisory from midnight tonight to 9 AM CST Monday for NEZ041-048-049. KS...Red Flag Warning until 7 PM CST this evening for KSZ005-017-018. && $$ SHORT TERM...Mangels LONG TERM...Mangels AVIATION...Rossi
Area Forecast Discussion
National Weather Service Wichita KS
845 PM CST Sun Feb 18 2018 .SYNOPSIS... Issued at 229 PM CST Sun Feb 18 2018 A wave is positioned along the Front Range with the increasing gradient which combined with mixing has brought windy conditions for Kansas. Wind gusts have been from 40 to even 55 mph with the highest gusts in Russell County. Temperatures have climbed into the lower 50s to lower 60s. The Red Flag Warning and Wind Advisory remain in effect until 6PM. && .UPDATE... Issued at 844 PM CST Sun Feb 18 2018 Robust warm advection continues to lead to lots of low level moisture streaming to the north. Latest RAP shows this moisture transport and advection continuing for the late evening hours and overnight. Already seeing increased mid level clouds in response to the advection across wrn OK at this time. As this moisture advection lifts NE overnight, think a few showers will develop for areas east of the KS Turnpike after midnight, as isentropic lift also increases. MUCAPE also increases to around 1000 j/kg which could also lead to a few embedded thunderstorms. Increasing pops for SE KS look on track, with a mention of showers and some isolated thunderstorms. Do not plan on any major changes to the grids/zones at this time. Certainly think that SE KS will see widely scattered showers and a few storms by sunrise Mon morning. Ketcham && .SHORT TERM...(This evening through Wednesday night) Issued at 229 PM CST Sun Feb 18 2018 Forecast challenges and highlights: Precipitation chances for this evening into the first part of the week and high temperatures on Monday as well as Tuesday A trough is moving onshore while a wave along the Front Range is going to have a portion of it head to the northeast. This will create an axis from northeast to southwest. The system is slow moving as much of the trough apparently wants to hang out over the Rockies. As the axis sits in place, there is increasing moisture advecting moving into the Southern Plains. Chances of precipitation may move in beginning tonight with the movement of the wave. Models differ in the extent of the precipitation for tonight into Monday. The highlighted area is still in the southeast corner of the Sunflower State, southern Missouri and eastern Oklahoma. Warm air advection is ramped up for Monday with a piece of cold air advection on the back side of the wave across northwest Kansas into Nebraska. High temperatures for the start of the work week were a challenge as the southeast advance of the cold air could creep into central Kansas. Discrepancies exist in the models with some going much cooler and others keeping the values higher. There will definitely be a cool down, but it is hard to say how much that will be. Chances of precipitation increase for Missouri into eastern Oklahoma with a highlight over southeast Kansas of our county warning area. Thunderstorm activity has a higher likelihood on Monday afternoon and evening. It is possible that there could be an isolated stronger wind gust of 40 to 50 mph or small hail, but heavy rain is more likely. Anticipated precipitation will certainly help the moderate and severe drought conditions for that area. Moisture is certainly going to be welcomed with open arms. Accumulations continue to range from a half of an inch to two inches with the highest values in the southeast corner of the state. Higher amounts are expected in the Ozarks. Across central Kansas, the profile column indicates low level moisture that would suggest freezing drizzle versus freezing rain on Monday night into Tuesday. As the trough finally shifts out of the area, an advance of cold air will occur on Tuesday. On Wednesday morning, the drop in temperatures to the single digits for central Kansas calculate wind chills below zero. Surface high pressure comes in on Wednesday, and high temperatures will only top out in the lower 30s. A mixed type is currently anticipated with the latest blend of the models for Wednesday for the entire area. .LONG TERM...(Thursday through Sunday) Issued at 229 PM CST Sun Feb 18 2018 A weak wave is showing up to move across on Thursday with the more pronounced feature not until Saturday. Chances of precipitation remain in the forecast for most of the extended forecast. The temperatures aloft vary between models and beg the question of the precipitation type. On Thursday night into early Friday morning the focus for a mixed phase of rain and freezing rain is anticipated in central and parts of south central Kansas. It is possible that it could be snow instead of freezing rain, but the potential for warmer air to be in place is what is hinting the liquid variety. Accumulations are not expected at this time. Given the differences in the models and latter part of the forecast, changes will occur. Stay tuned for updates. A gradual warming trend is in store for the end of the week. Weekend temperatures are expected to rise back into the 50s. && .AVIATION...(For the 00Z TAFS through 00Z Monday evening) Issued at 604 PM CST Sun Feb 18 2018 Increasing low level moisture advection will lead to low clouds continuing to increase across south central and southeast KS. Still expect KICT to be on the western edge of MVFR ceilings as they eventually move into southeast KS(KCNU). Should see another round of low level wind shear this evening as low level jet remains rather strong. The low clouds will become more expansive tonight as low level moisture continues to funnel into the region. Currently have high confidence that IFR ceilings will impact areas along and SE of the KS Turnpike tonight into Mon morning. A cold front is still expected to move into central KS on Mon morning, reaching KICT around 18z. This will shift winds around to the north and diminish IFR ceilings. Increasing low level moisture will also lead to the chance of showers and possibly some thunderstorms increasing near the KCNU taf site by around 06z/Mon. So will add this mention to the KCNU taf site. Ketcham && .FIRE WEATHER... Issued at 229 PM CST Sun Feb 18 2018 After the extreme grassland fire danger today, Monday is the only day with very high grassland fire danger indicated for much of the forecast area. The main concern is going to be in the morning for central and south central with the stronger winds. Southeast Kansas will have very high conditions for all of Monday with sustained wind speeds of 20 to 25 mph. There are chances of precipitation for much of the rest of the forecast with the best chances across southeast Kansas on Monday night into Tuesday. Thunderstorms are possible with this activity. && .PRELIMINARY POINT TEMPS/POPS... Wichita-KICT 52 67 41 46 / 10 30 70 60 Hutchinson 50 59 33 38 / 10 20 50 30 Newton 50 61 36 39 / 20 30 70 50 ElDorado 52 66 43 49 / 20 40 80 80 Winfield-KWLD 52 71 52 56 / 20 30 70 80 Russell 32 42 20 28 / 10 10 20 10 Great Bend 39 47 22 31 / 10 10 20 10 Salina 46 47 26 33 / 20 20 50 20 McPherson 48 55 30 36 / 10 20 50 30 Coffeyville 54 71 59 64 / 60 70 80 90 Chanute 52 68 55 61 / 50 60 80 90 Iola 52 66 54 58 / 50 70 80 90 Parsons-KPPF 52 70 58 62 / 60 60 80 90 && .ICT WATCHES/WARNINGS/ADVISORIES... None. && $$ UPDATE...Ketcham SYNOPSIS...VJP SHORT TERM...VJP LONG TERM...VJP AVIATION...Ketcham FIRE WEATHER...VJP
Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
850 PM CST Sun Feb 18 2018 .UPDATE... 850 PM CST GOES-16 differential water vapor RGB this evening shows shortwave trough over the central plains embedded within the broad mid-upper level moisture plume associated with the subtropical jet. The 00z evening upper air analysis showed a significant moisture gradient at 850mb between bone dry air mass sampled at KILX/KDVN and seasonably moist air mass at KSGF/KTOP. Evening RAOBs already were sampling 50 to nearly 60kt southwesterly flow around 850mb with KDVN WSR-88d showing a 10-15kt increase in low level flow in the past 3 hours. This very strong low level jet should transport the more moist air mass upstream rapidly northward tonight above sharp frontal inversion. This supports the high-res model solutions which show convective precip blossoming over eastern IA/western IL later this evening. Anticipating showers and isolated t-storms to quickly develop toward or just after midnight to our west before spreading east across mainly the southern half of our CWA overnight into early Monday morning. At the surface, moderately strong and occasionally gusty southerly winds should result in near steady temps through the night. The higher dewpoints are still well south toward the Missouri Ozarks region, but should begin to surge northward tonight with warm frontogenesis over central IL later tonight. As the low level moisture begins to impinge on the snow covered areas of northern IL and northwest IN believe that dense fog will become an increasing threat, particularly after sunrise Monday morning and lingering into the afternoon north of the northward advancing warm front. As warm front lifts north, look for a quick improvement in visibilities, but there is still some uncertainty how much/if at all, the snow cover will impede the warm front`s northward advance Monday. The NAM gives snow pack apparent super powers and it is likely too cool with temps and slow with the FROPA, with a compromise solution between the NAM and RAP probably most reasonable at this point. Strongly considered issuing a dense fog advisory for tomorrow, but fog can be fickle and have been burnt before with apparent slam dunk fog events, so opted to "message" the dense fog in a graphical nowcast and will let later shift issue the NPW. Flood watch looks on target and no changes made this evening. Updated grids have been saved and will be firing out a new ZFP and LFP shortly. - Izzi && .SHORT TERM... 202 PM CST Through Monday... Temperatures this afternoon will depend on cirrus overhead. Locations that see breaks in the cirrus should see temperatures rise into the 40s. Locations that don`t see breaks will stay in the 30s. Winds will also be strongest where sunshine can get mixing going. The main focus for this period is when rain will start Monday, how far north the warm front will get, and thunder chances. Low pressure will take shape over the High Plains tonight and reach the mid Mississippi Valley mid Monday afternoon. Rainfall will spread south to north. Areas along and south of I-80 should see rain before 6AM. Forecast soundings feature a bit of elevated CAPE and a very stout cap. I think the cap will limit showers from tapping into the CAPE, so I do not have any thunder mentioned prior to 6AM. The GFS and ECMWF lift the warm front north into southern WI, while the NAM stalls the front near I-88. The NAM has a slower progression of rain to the north, but all of the forecast area should see moderate rain showers by Monday afternoon. Embedded thunderstorms are possible, especially in the afternoon as the warm front lifts and the low`s center reaches the region. Severe storms are not expected, but increased rainfall rates could lead to localized flooding especially with the snowpack. Dewpoints will soar into the 50s, and areas of fog are likely late tonight through Monday afternoon, especially if the warm front stalls over northern IL. JEE && .LONG TERM... 202 PM CST Monday night through Sunday... Flooding is the main long term concern. As mentioned in previous discussions, precipitable water (the amount of available moisture in the atmosphere) values, and moisture transport (the movement of moisture into our region) are forecast to reach the maximum values ever reached in the month of February per ILX/DVN sounding climatology. Rivers and small streams will have sharp responses and flood prone areas should be alert in the coming days. A flood watch will be issued for the entire area given some uncertainty in the location of highest impacts, but at this time we are focusing on the Tuesday into early Wednesday time frame. Current forecasts have the Kankakee River at Shelby getting close to major flood stage from the combination of snowmelt (we have 0.85" of liquid here in Romeoville in the snowpack), seasonally frozen ground limiting absorption of moisture, and the heavy rain. While the axis of heavy rain is not always nailed down at this distance and does shift some, the signal is high for a few periods/areas of concern at different times. The issue out of the gate Monday night is the position of the warm front that the global models surge through the area during the day, while the NAM (possibly catching onto the snowpack in place) keeps the front locked across I-80/I-88 and does not lift it through until late Monday night. These uncertainties will affect the position of highest QPF Monday night. In spite of these uncertainties, meteorologically the setup is very favorable for flooding concerns in the region, especially on/near rivers and streams. High pressure will be positioned across the southeast United States, with a digging neutrally tilted upper trough over the western U.S.A. Deep southwest flow ahead of the trough will allow gulf moisture to be advected due north into our region. Sometimes we get robbed of some of this moisture due to convection to our south, but it appears we will not have a problem getting it up here. With a cold front slowing shifting southeastward into the region, the upper level jet will strengthen and enable not only a prolonged period of upper level lift, but will also allow several low pressure waves to ride along the front and keep it stationary. While the initial concern will be over the Rock River Basin area (north central Illinois - I.E. Rockford area, I-88 Northward west of Chicago), the GEFS ensembles gradually shift this axis to Chicago Tuesday and along the Kankakee/Iroquois basins (east central Illinois/Northwest Indiana) later Tuesday and Tuesday night. These subtle shifts of the heaviest axis are helpful to reduce flooding, but am increasingly concerned with the response on Tuesday after snow has melted and then throw a bunch of rain on top that, plus the fact the GEFS ensembles are indicating several 6 hr periods of probabilities of greater than 0.6" of QPF in 6 hours (which is a high number for an ensemble, deterministic models and the real atmosphere can produce much more). Areas across Chicago southeastward appear like they have the highest potential for more prolonged rainfall as the upper jet strengthens, the front stalls some, storm motion values decrease significantly, and precipitable water values increase further Tuesday/Tuesday evening. While the main heavy rain axis will shift southeast of the area Wednesday as high pressure is forecast on all guidance to shift from the upper Midwest into Wisconsin and push the main cold front into Indiana, we remain in strong southwest flow aloft such that there could be some additional rain along and southeast of I-57 into Wednesday, and if the precip gets hung up farther northwest into the colder air, there is lower threat of some wintry precip on the back side both Tuesday night and Weds. Regarding thunderstorms and severe weather potential...Forecast soundings feature very little instability across northeast Illinois and northwest Indiana. The profiles do show deep enough moisture for charge separation, thus chance of thunder (and enhancing rainfall rates) are warranted. Severe weather chances while not zero given the shear profiles, are not very high in this setup. There is a low probability if some surface based cape can be realized ahead of the cold front Tuesday afternoon. Beyond this time, we do still stay in active southwest flow aloft, which will likely bring waves of precip later in the week, but the main frontal boundary appears to remain south of the area which will keep the heavier rain focused across the Ohio and Tennessee River valleys. KMD && .HYDROLOGY... 202 PM CST The combination of snowmelt (we have 0.85" of liquid here in Romeoville in the snowpack), seasonally frozen ground limiting absorption of moisture, and heavy rain, expect sharp rises over area rivers and streams in the next few days. Most areas will see at least an inch of rain, with 2 to 4 inches possible in some locations. Expect several rivers to get into flood, and numerous rivers to get above bankfull. Ice jam breakup may also contribute to flooding in the coming days. While the axis of heavy rain is not always nailed down at this distance and does shift some, the signal is high for flooding concerns. Current forecasts have the Kankakee River at Shelby getting close to major flood stage. KMD && .AVIATION... For the 00Z TAFs... 553 pm...Several forecast concerns this period including cigs/vis Monday...periods of showers Monday...chance of thunderstorms Monday afternoon/evening...low level wind shear this evening and again Monday evening. South/southeast winds will remain gusty this evening into the 20-25kt range. Speeds will slowly diminish overnight as winds turn more southerly. Speeds will diminish further Monday morning as wind directions turn back southeasterly. A warm front will move across the area Monday afternoon...turning winds back to the south/southwest with speeds/gusts increasing. Low level wind shear in the 45-50kt range is expected this evening and then again Monday afternoon into Monday evening and may need to be included for this time period with later forecasts. Much warmer and moist air will spread over the region Monday morning with cigs/vis steadily lowering. While there still remains uncertainty regarding how low visibilities will drop...trends are suggesting vis will lower under 1sm everywhere Monday morning with dense fog possible. Have continued the trend down with tempo 1/2sm with tempo 1/4sm at rfd. Its possible these may become prevailing vis for a time midday. As the warm front lifts north in the afternoon...vis will improve and possibly more so than currently advertised. While some improvement in cigs are possible with the warm front passage...confidence is low regarding cig improvement. Showers are expected to develop south of the terminals early Monday morning and continue through late morning and there could also be some thunderstorms. An isolated shower is possible over the terminals...but confidence is low enough to keep them dry through about sunrise and there could still be some periods without showers Monday morning...though the low cigs/vis may allow drizzle to develop. A steadier rain is expected Monday afternoon into Monday evening which may also aid with improved visibilities. This is also the time period for the best chance of any isolated thunderstorms for the terminals...but confidence is still too low for even prob mention with this forecast. cms && .MARINE... 202 PM CST South winds will still ramp up a bit late this afternoon and evening in the stronger pressure falls ahead of low pressure across the upper Midwest. Some of this may be mitigated by an area of low clouds and fog over the water. The stronger winds are favored over the northern half of the lake, though the nearshore waters will still see some gusts to 25 to 30 kt too. Winds will weaken overnight as the low weakens and moves into Ontario. A cold front trailing from the low will settle half way down the lake by early Monday, before another low pressure wave translates along the boundary from the Central Plains to the south half of the Lake by Monday evening. This will result in northerly winds across northern Lake Michigan north of the front, and south winds to it`s south. Another surface low will ripple along the front along roughly the same track Tuesday, before the front eventually drifts south of the Lake Tuesday night. Northerly winds will affect the entire lake by that time, as strong high pressure builds in from the west. Despite the varying winds, the low pressure systems are not that strong and therefore winds will remain below gale concerns. High pressure will keep concerns low over the lake beyond this time. KMD && .LOT WATCHES/WARNINGS/ADVISORIES... IL...Flood Watch...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-ILZ011- ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-ILZ023- ILZ032-ILZ033-ILZ039...6 PM Monday to 6 AM Wednesday. IN...Flood Watch...INZ001-INZ002-INZ010-INZ011-INZ019...6 PM Monday to 6 AM Wednesday. LM...Small Craft Advisory...nearshore waters until 3 AM Monday. Gale Warning...LMZ777-LMZ779 until midnight Monday. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
National Weather Service Midland/Odessa TX
531 PM CST Sun Feb 18 2018 .DISCUSSION... See aviation discussion below. && .AVIATION... Radar show a few storms passing just s of MAF with SHRA to the sw, we opted to keep TS out of the TAFMAF based on movement. There is the possibility of redevelopment later this evening and again toward morning. Otherwise windy conditions will persist at MAF, FST, HOB until around 06Z, then increase again around 18Z Mon. && .PREV DISCUSSION... /issued 250 PM CST Sun Feb 18 2018/ DISCUSSION... South winds are bringing moisture into West Texas and increasing low level instability. Some evidence of this can be seen west of the Pecos River where heating and orographics are causing a field of cumulus to develop. However there is a cap in place and with no trigger farther east other than weak afternoon heating, it will be difficult for deep convection to form. The HRRR has been showing a lone storm forming near MAF the past few runs so do not anticipate much coverage in the Permian Basin this afternoon. Should anything form, there will be enough potential instability and shear that any storm could become marginally severe so will have to keep an eye on this for the next few hours. This week will be interesting with a quasi-stationary West Coast trough keeping our area under southwesterly upper flow. This pattern normally enhances precip chances though abundant moisture is restricted to the eastern Permian Basin and so will be rain chances this week. A cold front arrives Wednesday which could expand rain chances farther west but otherwise the best rain chances will be in the east. Temperatures will be above normal until the frontal passage on Wednesday, with cooler temps lasting into Thursday before conditions get warmer for the end of the week. Hennig && .PRELIMINARY POINT TEMPS/POPS... Big Spring 59 78 53 73 / 20 0 20 0 Carlsbad 52 78 47 66 / 10 10 0 0 Dryden 58 84 56 83 / 10 10 30 0 Fort Stockton 55 81 50 77 / 20 10 20 0 Guadalupe Pass 47 64 39 55 / 10 10 0 0 Hobbs 47 72 43 65 / 10 0 0 0 Marfa 43 72 37 68 / 10 10 10 0 Midland Intl Airport 55 79 51 72 / 20 0 20 0 Odessa 53 76 51 71 / 20 0 20 0 Wink 49 83 46 72 / 10 10 10 0 && .MAF WATCHES/WARNINGS/ADVISORIES... NM...High Wind Warning from 2 AM to 8 PM MST Monday for Guadalupe Mountains of Eddy County. TX...High Wind Warning from 2 AM to 8 PM MST Monday for Guadalupe Mountains. && $$
...Update to aviation forecast discussion...

.SHORT TERM...(This evening through Monday) Issued at 258 PM CST Sun Feb 18 2018 The strong southerly winds this afternoon will diminish slightly after 00Z as the mixed boundary layer decouples slightly. The wind advisory for the entire CWA will remain in effect through 6 PM. An upper level trough across the northwestern US will dig south- southeast into the southwest US. Strong southwesterly mid-level flow across the central Rockies will cause a lee surface cyclone to deepen across southeast CO. A strong southwesterly low-level jet will advect deeper moisture northeast across the CWA. An EML will overspread the CWA and there may be enough isentropic lift for scattered showers and perhaps an elevated thunderstorms developing. The RAP and ARW show the most MUCAPE across the CWA with 400-800 J/KG while the NAM and GFS show only 100-300 J/KG. Therefore, I cannot rule out an elevated thunderstorm after midnight and through the morning hours of Monday. As the low-level moisture increase through the night there could be some patchy drizzle. However, we may be mixed deep enough with the stronger low-level winds that drizzle may not develop. Monday, Stronger CAA across the central plains will cause a surface cold front to push southeast across the CWA through the day. The front may move just southeast of the CWA before becoming stationary across south central and southeast KS due to a deepening surface low and surface pressure trough from southeast CO, east-southeast across north central OK, then northeast across central MO. Temperatures across north central KS will start out in the 40s and lower 50s in the early morning hours but fall through the 30s into the upper 20s by late Afternoon. As the H5 trough across lifts northeast into the high plains, stronger isentropic lift will develop north of the front where an area light rain will develop. The rain across northeast and north central KS may change over to light freezing rain through the afternoon hours. East central KS will see highs in the lower to mid 60s during the mid morning to early afternoon hours with temperatures falling into the 40s through the late afternoon hours. Temperatures across east central KS will remain warm enough for only rain through the afternoon hours. There is still some question on how far southeast the front will make it during the late afternoon hours. Most of the shorter range models have the front pushing southeast of the CWA and most forecast soundings only show only elevated CAPE above the shallow colder airmass which will advect southeast behind the front. At this time the surface based convection will occur south and southeast of the CWA along the front, where there may be a threat for gusty winds and perhaps large hail with any rotating storms. .LONG TERM...(Monday night through Sunday) Issued at 258 PM CST Sun Feb 18 2018 Tonight and Tuesday, As the H5 trough across the southwestern US lifts northeast into the central plains there will be stronger WAA across eastern OK and southeast KS which will cause the front across southeast KS to lift northwest into the southeast counties of the CWA. The stronger CAA will remain across the western and northern counties of the CWA. Periods of light freezing rain will continue across northeast and most of the western and central counties of the CWA. Temperatures will remain above freezing across much of east central KS through the night. The greatest ice accumulations will occur across the northeast and north central counties, southwest into the central counties of the CWA where 0.1" to 0.2" of ice may accumulate through the overnight hours into the morning hours of Tuesday. However, if the boundary pushes even farther northwest then temperatures may warm closer to or slightly above freezing and ice accumulation may be less than forecasted. A winter weather advisory may be needed for areas northwest of a Nortonville, to St. Marys to Council grove line Monday night through the morning hours of Tuesday. As the upper trough lifts out into the central plains the stronger CAA will push the front and colder air southeast across east central KS after 12Z. The area of rain across east central KS may mix with or change over to freezing rain before ending early Monday afternoon. The 00Z NAM model solution shows a stronger push of colder air across east central KS during the morning hours, which may cause a longer duration of freezing rain through the late morning into the early afternoon hours of Tuesday across east central KS. We`ll have to keep an eye on temperature trends and when the steadier rain shifts southeast of the CWA. If the 00Z NAM solution ends up being more accurate, then there could be up to 0.1" of ice accumulations across east central KS from 15Z through 20Z. However, the NAM QPF looks to be a bit too high given that 850mb winds begin to veer as the H5 trough lifts out into the central plains. Highs on Tuesday will occur in the morning hours across east central with temperatures in the mid 30s to 40s. Temperatures across east central KS will fall through 30s into the upper 20s during the late morning and early afternoon hours, as the surface front pushes southeast across MO. Temperatures across north central and northeast KS will remain steady in the upper 20s to lower 30s. Tuesday night through Sunday, A longer wave length trough will remain across the western US. A shorter-wave length trough will lift northeast across the plains bringing a chance for light rain Thursday afternoon which will chance over to snow or freezing rain, depending on the thermal pattern aloft. A second upper trough will lift out across the plains Friday into Saturday. Temperatures will warm into the 40s and 50s, thus the precip will fall as rain. Though coder air Friday night may change the precip back over to light snow. && .AVIATION...(For the 00Z TAFS through 00Z Monday evening) Issued at 515 PM CST Sun Feb 18 2018 MVFR ceilings are approaching the taf sites currently and should arrive in the next hour or two. Towards sunset there may enough saturation and lift for drizzle as the winds gradually decrease ahead of an approaching front. An isolated shower may develop near TOP/FOE prior to the frontal passage. Some guidance is also suggesting possibly enough instability for thunder showers along the front at TOP/FOE in the late morning and early afternoon. Winds shift to the north behind the front and will not be as gusty. Ceilings will likely drop down to IFR prior to the front then gradual improvement through the day tomorrow. && .FIRE WEATHER... Issued at 258 PM CST Sun Feb 18 2018 Strong southerly winds of 25 to 35 MPH with gusts of 35 to 45 MPH will continue through the remainder of the afternoon hours, and will only diminish slightly after 00Z. Even though RHs have steadily risen above 40 percent through the afternoon hours, the combination of dry fuels and strong southerly winds will cause a very high fire danger the remainder of this afternoon and into the evening hours. Any outdoor burning should be postponed. && .TOP WATCHES/WARNINGS/ADVISORIES... Wind Advisory until 6 PM CST this evening for KSZ008>012-020>024- 026-034>040-054>056-058-059. && $$ SHORT TERM...Gargan LONG TERM...Gargan AVIATION...Sanders FIRE WEATHER...Gargan