Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 04/11/22


Area Forecast Discussion
National Weather Service Boise ID
940 PM MDT Sun Apr 10 2022 .DISCUSSION...Regional weather radar imagery showing precipitation associated with a cold Pacific low is advancing inland this evening. No update to the forecast for this evening as models remain consistent in timing and amounts of snow across the region for tonight into Monday. There has been a shift in the high resolution models to bring the accompanying cold front through the region slightly earlier Monday afternoon. Otherwise the formation of a stronger line of showers and possible thunderstorms remains unchanged as the front crosses through southwest Idaho. Areas from Glenns Ferry to Twin Falls-Jerome-Rogerson will see the strongest winds (gusts up to 60 mph) and chance for significantly reduced visibility in brief heavy snow with the frontal passage Monday afternoon. && .AVIATION...Scattered rain and snow showers across the area will bring periods of MVFR conditions this evening. Snow will increase across eastern Oregon and far southern Idaho after 06z Monday and spread through the rest of the area after 12z. Snow will bring local IFR conditions and mountain obscuration. Snow will mix with rain in the lowest valleys by late Monday morning. A cold front will arrive Monday afternoon across Idaho, accompanied by brief heavy snow with LIFR conditions and wind gusts of 35-50 kt. Thunderstorms are also possible along the front. Surface winds: Becoming S to SE 5-15 kt, with gusts to 30 kt after 12z. Winds becoming W-NW 15-25 kt with gusts to 35 kt behind the cold front on Monday. Winds aloft at 10kft MSL: West to southwest 35 to 50 kt. && .PREV DISCUSSION... SHORT TERM...Tonight through Tuesday night...Snow and rain showers continue in southwest Idaho and nearby Malheur County but models expect them to end late this afternoon. An atmospheric river has set up in the north Pacific along 45N and will be drawn into our CWA late tonight through Monday as an upper trough in the Gulf of Alaska digs southeastward, and right into our area Monday. Models begin heavier pcpn in eastern Oregon after midnight tonight and western Idaho by sunrise. HRRR and NAMNest bring it into Idaho a little earlier than other models, but by mid-morning all areas will be receiving snow, with rain only below 3000 feet. Snowfall will be significant in the mountains, especially north of the Snake Basin, with accumulations 6 to 12 inches. Lower elevations will have 3 to 6 inches, and even the Snake Basin should get 1-2 inches, except less than a half inch in the lower Treasure Valley. Some shadowing of pcpn is expected in the Treasure Valley in the morning while southeast winds are blowing. But around midday or early afternoon hi-res models carry a strong cold front eastward across western Idaho and into south- central Idaho later in the afternoon. The front will be strong enough for brief heavy rain and snow showers and a slight chance of thunderstorms with strong winds and hail. After that, showers will decrease and the air mass will become much drier and colder, allowing the snow level to drop to lowest valley floors Monday night. Another disturbance in the flow aloft will set off more snow showers Monday night and Tuesday morning, decreasing later Tuesday and Tuesday night. Tuesday will also become quite windy, especially in the Snake Basin, where gusts to 40 mph will be likely. High temperatures will be cold enough to set records for Monday and Tuesday, and low temps Tuesday night will be winter- like: 5 above to 20 in the mountains and 20 to 25 in the lower valleys. LONG TERM...Wednesday through Sunday...Large scale upper level trough will remain over much of the Conus through the period for cold conditions with periods of precipitation. Mountain snowfall will be present, with morning snow across valley locations. On Thursday, another more significant push of moisture associated with a warm-frontal passage will produce another round of significant mountain snow and a mix of rain/snow in the valley. Moisture and related showers will continue into Friday as the area of low pressure moves into the Northern Plains. Another trough will impact the forecast area through the weekend, with another round of showers possible. Ensemble forecast have trended for drier conditions with the trough passage. Temperatures will remain well below normal through the period with highs about 10-15 degrees below normal. && .BOI WATCHES/WARNINGS/ADVISORIES... ID...Winter Weather Advisory from 6 AM Monday to noon MDT Wednesday IDZ011-013-015-028>030. OR...Winter Weather Advisory until 6 PM MDT /5 PM PDT/ Tuesday ORZ061>063. && $$ www.weather.gov/Boise www.facebook.com/NWSBoise www.twitter.com/NWSBoise DISCUSSION...DG AVIATION.....ST PREV SHORT TERM...LC PREV LONG TERM....JDS
Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
1159 PM EDT Sun Apr 10 2022 .AVIATION... Southeast Michigan is currently under the influence of high amplitude midlevel ridging and strong absolute anticyclonic vorticity advection. Efficient meridional southerly flow after 06Z will result in a rather abrupt moistening the latter half of the night. Warm advection showers are likely for a short period between 08-12Z this morning. The potential for an isolated rumble of thunder appears to low to include in the tafs. Warm advection pattern will support MVFR cigs this morning becoming VFR mid cloud by midday. A wave of low pressure will then bring the potential for a 3hr period of shower activity at the Detroit terminals after 20Z Monday. Prevailing VFR is expected Monday evening. .DTW THRESHOLD PROBABILITIES... * Low for ceiling 5000 ft or less through this evening. High Monday morning. && .PREV DISCUSSION... Issued at 305 PM EDT Sun Apr 10 2022 DISCUSSION... Fairly compact/strong 6 HR height fall center (-100 M) to track through Minnesota tonight and into western Lake Superior by Monday morning. Main wave of isentropic ascent/moisture advection over southeast Michigan arriving 6-10Z tonight, as 60 Knot low level jet works through the area, pushing PW Values to around 1 inch and showalter index lowering to around -2 C with steep mid level lapse rates as dry slot impinges on the area Monday morning. MUcapes briefly reach aoa 500 J/KG per NAM/RAP bufkit soundings, but sliver thin below 12000 ft. Northern areas/Tri-Cities region still looks to have the best chances for showers and possible thunderstorm, as subtle shortwave looks to be embedded in the strong southwest flow and tracks close to Saginaw Bay. Based on the preponderance of the hires solutions (ARW/FV3) and local probabilistic guidance, went with scattered-numerous pops for showers late tonight, highest in Tri-Cities region. From a southeast part of the CWA prospective, rain chances are higher late Monday afternoon with left over low level baroclinic zone in place and getting into right entrance forcing of the departing jet moving through Ontario. RAP showing a well defined surface trough/convergence in the surface pressure field tracking through in the afternoon. Being on the western fringe of the departing moisture/850-700 MB Theta-E ridge axis does add to the doubt in the response however. Powerful storm system coming ashore of the Pacific Northwest tonight and then tracking through the southern Rockies tomorrow. Strong high pressure off the southeast Coast will lead to tight pressure gradient over the Gulf of Mexico, leading to a tremendous surge of moisture through the day, with record/near record moisture (0 C dew pt at 700 MB/12 C at 85O MB) for early April standards reaching southern Lower Michigan Tuesday night. The warm front should have no problem becoming active with sufficient instability, as Euro indicates 1000-850 MB capes in excess of 500 J/kg with K indices into the lower 30s. Although, should be be noted the Euro solution is one of the deeper solutions. Negative tilted trough axis lifting into Great Lakes region Wednesday night assuring another round of rain and possible thunderstorms, with activity in the warm sector during Wednesday being the more uncertain part of the forecast. None-the-less, it appears a shortwave will be ingested out ahead of the front, likely resulting in shower/possible thunderstorm activity in the afternoon. Sub 980 MB low in the vicinity of western Lake Superior will promote strong wind fields/cold advection on Thursday before quickly filling and tracking along/north of the northern Great Lakes as we end the work week. With 50 knots of wind advertised at 850 MB level, gusts of 40+ mph appear likely on Thursday, with still potentially 40 knots at 850 MB level on Friday to work with as we reside a bit deeper in the cold air, but looks to be a sharp south to north temperature gradient over Great Lakes region which is reflected in the max temp forecast (over 10 degrees difference from southern Michigan border to the northern reaches of the CWA). MARINE... Weak high pressure will drift eastward from the central Great Lakes through tonight as low pressure deepening in the north central Plains continues lifting northeastward towards Lake Superior into Monday. Marine conditions will begin to deteriorate late tonight and into Monday as southeasterly winds increase with the resulting tightening pressure gradient from the deepening low. Gusts will approach 25 knots at times along with 3-5 foot waves for the Lake Huron nearshore waters from Port Austin to Port Sanilac where a Small Craft Advisory is in effect for Monday. Gusts over the northern open Lake Huron waters will also approach 25-30 knots at times as well, but enough stability near the surface will limit gusts to 30 knots. Rain showers will also become more prevalent ahead of the system`s cold frontal passage, especially late in the day across the southern half of the local waters. Variable and light flow then prevails Tuesday as weak high pressure quickly moves through before southeast flow strengthens yet again as strong low pressure once again develops in the central Plains. Renewed small craft concerns will again be possible during the midweek period for portions of the Lake Huron nearshore waters. HYDROLOGY... Scattered to numerous showers tracking through late tonight, but basin average rainfall under a quarter of an inch. Another round of showers developing Monday afternoon, mainly east of U.S 23. Once again, basin average rainfall a quarter of an inch or less before activity exits east Monday evening. Strong warm front will bring showers and possible thunderstorms Tuesday evening and Tuesday night. Average rainfall of a quarter to half an inch expected, especially north of M-59, where up to one inch is not out of the question due to longer duration expected. Multiple round of showers and possible thunderstorms are then expected Wednesday and Wednesday night, with timing and intensity of the rainfall still in question. None-the-less, total rainfall of half an inch to one inch appears reasonable. Flooding is not anticipated at this time based on those amounts, but river rises and ponding of water in low lying areas is expected. There is potential for && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. Lake Huron...Small Craft Advisory from 4 AM to 4 PM EDT Monday for LHZ421- 441>443. Lake St Clair...NONE. Michigan waters of Lake Erie...NONE. && $$ AVIATION.....99 DISCUSSION...SF MARINE.......IRL HYDROLOGY....SF You can obtain your latest National Weather Service forecasts online at www.weather.gov/detroit.
Area Forecast Discussion
National Weather Service Austin/San Antonio TX
818 PM CDT Sun Apr 10 2022 .UPDATE... Winds have fallen below Wind Advisory and Red Flag Warning Criteria. As a result, have let those expire. Gusty winds will continue for another few hours east of the dryline as it retreats to the west. Isolated showers and thunderstorms will continue for another couple of hours or so out west until the airmass stabilizes and capping inversion strengthens. However, there is a possibility that they may become strong or severe. Of note, a severe storm near Los Angeles, east of Cotulla may move into our area and we are monitoring that storm. && .DISCUSSION... For Monday, have maintained the ongoing rain free forecast due to the strong capping inversion seen on forecast soundings. However, similar to this evening, the dryline may provide the forcing to break this cap. Should this happen, then CAPEs of 2,000 to 3,000 J/kg and steep mid level lapse rates of 8 to 9 C/km indicate a potential for strong to severe storms with very large hail the main threat. && .AVIATION... (11/00Z TAFs) At the I-35 sites, SCT-BKN VFR clouds lower to MVFR CIGs later this evening as south-southeasterly winds of 15 to 25 KTs with gusts to 30 KTs decrease to 10 to 15 KTs. CIGs lift and mix to SCT-BKN VFR around midday on Monday with south-southeasterly winds around 10 KTs. MVFR CIGs return Monday evening. At KDRT, VFR clouds with SHRA in the VCNTY early this evening, then a brief period of MVFR CIGs early in the morning. A rapid return to VFR skies is expected as winds shift to northwesterly at 7 to 12 KTs in the wake of the dryline passage. && .PREV DISCUSSION... /ISSUED 224 PM CDT Sun Apr 10 2022/ SHORT TERM (Today through Monday Night)... Seeing some changes in the low-levels noted on satellite this afternoon, as low-clouds continue across the Coastal Plains and east of the I35. This is a sign of increasing low-level moisture for the eastern areas as continued deep southerly flow prevails over that region. Across the west, dry air remains in place and some breezy southwesterly flow will likely lead to near critical to critical fire weather conditions for Val Verde County this afternoon. Latest aircraft soundings at AUS and SAT both show a very large CAP above the moist boundary layer. This should limit any surface based convection today, but some recent runs of the HRRR show some elevated showers associated with some mid-level moisture in the western CWA. Will continue to hold onto the mention of PoPs with a 10 PoP through 3z to account for this and the small chance an isolated storm is able to break through the cap. For tonight, low clouds are likely for the eastern 2/3rds of the area with the increase in moisture continuing. Lows will therefore be warmer, in the lower to upper 60s across the region. Model soundings are continuing to show a stout cap in place across the area Monday afternoon. Not expecting to see much in the way of convective development once again tomorrow. However, if anything does initiate, steep mid-level lapse rates would support the threat of large hail and damaging winds. The fire weather threat tomorrow will be anchored by continued very dry humidity values in the west. However, winds in this same area tomorrow will be in the 7-12 mph range and not expecting any need for fire weather headlines. Highs tomorrow will be in the middle 80s in the east and into the upper 90s in the west. More low clouds are expected Monday night with lows in the middle 60s to near 70 degrees. LONG TERM (Tuesday through Saturday night)... On Tuesday, warm, moist air will be in place with dew points in the 60s to near 70. While cloud cover will likely remain over our far eastern counties much of the day, sunshine in the afternoon will allow temperatures to rise to near 100 over our southwestern areas. A trough axis over the western CONUS will be in the process of taking on a more negative tilt as it pushes towards the high Plains during the day. While it`s primary mid-level lift will remain well to our north during the afternoon and evening, a subtropical jet to it`s south looks to potentially set up with it`s left exit region near south-central Texas. In addition a shortwave embedded within the WSW flow aloft should bring at least modest PVA to the area late in the day, and a dryline will mix east towards US-281. West of it, elevated to near-critical fire weather conditions are expected. East, thermodynamic profiles could support a potential for severe storms over the east half of our region, but the question becomes: Will there be enough low to mid-level mixing and lift to overcome the cap? There is a dichotomy in the available model guidance with the answer to this question, with the NAM holding onto and even strengthening the capping inversion in the afternoon while the GFS depicts it eroding. If storms are able to develop (~30% chance at this time) the potential would be there for large to very large hail (primary risk) , damaging winds, and a low chance for a tornado. However, the opposite solution would mean another day with no rain and a continued worsening of drought conditions across the Hill Country. For the time being, this morning`s SPC outlook is still valid, with a Marginal Risk of severe storms remains in place east of Kerrville to Castroville to Charlotte, with a Slight Risk for areas northeast of Llano to San Marcos to La Grange. A secondary shower and storm chance may arrive overnight into Wednesday morning ahead of this systems cold front. Although this wouldn`t be the primary severe threat, there would still be a chance for some stronger storms with this round. It`ll move out quickly by midday, with brisk, dry NW flow behind it. Red flag warnings will be needed for much if not all of the area as RH will fall into the single digits across the west half of the region and teens to low 20s east. Winds will be weakest over the Coastal Plains but still in the 10-15 mph range in the afternoon. Zonal flow returns aloft on Thursday, and sfc winds will gradually return to the E and then SE through the day. Temperatures will be near to slightly above normal still behind the front Wednesday through Friday. Continued elevated to near critical fire weather conditions are expected, but moisture will begin to return overnight into Friday. Could be a low chance for some precip on Friday, but forecast confidence decreases significantly at that time. We do anticipate a return to well-above normal temperatures on Saturday. && .PRELIMINARY POINT TEMPS/POPS... Austin Camp Mabry 67 87 69 86 69 / 10 - 10 30 30 Austin Bergstrom Intl Airport 67 87 68 86 69 / 10 10 10 30 30 New Braunfels Muni Airport 66 89 68 88 69 / 10 - 10 30 30 Burnet Muni Airport 66 91 67 88 66 / 10 - 10 30 20 Del Rio Intl Airport 67 98 70 100 65 / 10 0 - 10 0 Georgetown Muni Airport 67 88 68 87 69 / 10 - 10 30 30 Hondo Muni Airport 65 94 67 97 67 / 10 0 10 20 - San Marcos Muni Airport 66 88 68 87 68 / 10 - 10 30 30 La Grange - Fayette Regional 68 85 70 84 70 / 10 10 10 30 30 San Antonio Intl Airport 67 90 69 89 69 / 10 - 10 20 20 Stinson Muni Airport 68 93 70 93 70 / 10 - 10 20 20 && .EWX WATCHES/WARNINGS/ADVISORIES... None. && $$ Short-Term/Aviation...04 Long-Term...05 Decision Support...Morris
Area Forecast Discussion
National Weather Service Grand Rapids MI
802 PM EDT Sun Apr 10 2022 LATEST UPDATE... Update/Aviation .UPDATE... Issued at 801 PM EDT Sun Apr 10 2022 Basically the on-going forecast is very much on track. At 730 there is still no showers associated with the cold front headed our way. All of the latest runs of HRRR, RAP models and the 18z run of the NAM, ECWMF and GFS all show showers developing in the 9 pm and midnight time frame over eastern WI into central IL. This is in response to quickly strengthening Low Level jet. At 10 pm there is 40 knot jet core southwest of Chicago. By midnight it is forecast to be 60 knot jet core near where the south buoy would be if it were deployed. That puts southwest lower Michigan in the speed convergence area of that jet core (actually this does not happen all the much, typically we are the speed divergence area of the low level jet). This will mean the storms will strengthen as they move across Lake Michigan into Southwest Lower Michigan. Helping the cause for these storms is MU capes between 500 and 1000 j/kg. In fact the HREF has a 60 pct chance of thunderstorms in the I-69 area between midnight and 4 am. This is likely to be a scattered line of storms as it moves on shore but will become more of broken to solid line of convection as it passes east of US-131. The area that at this point had the greatest risk of rainfall is actually north of I-96 but that is due to dynamical forcing from the mid-level shortwave. The storms will be elevated so I do not expect and severe storms from this as there is a nearly 3000 ft deep stable layer near the ground. Also the cape at mid-levels is narrow so I do not expect any significant hail. && .DISCUSSION...(This evening through next Sunday) Issued at 211 PM EDT Sun Apr 10 2022 - Scattered storms tonight Models are in general agreement in showing a 50 knot 850 mb jet forming over the Central Plains this evening...then building into Southern Lower MI overnight. A plume of higher PWAT values from the Gulf...up over an inch...is drawn into the CWA then. Elevated instability advects into the CWA as a result with the SPC HREF mean MU CAPE values topping 500 J/kg roughly 06z to 10z tonight. At the same time a strengthening upper level jet moves in from the west leading to upper level divergence. Given the combination of moisture...lift and instability tonight...we will maintain the forecast for showers and thunderstorms. We will feature a slight increase in the POPs as most of the ensemble members of the various models are showing some light qpf. - Potential for strong storms Tuesday night into Wednesday Evening A surface low becomes centered over the Upper MS Valley Tuesday night with a warm front extending eastward into Lower MI. With a large 850 mb jet developing out ahead of the low in the warm sector...abundant Gulf moisture gets drawn into the system. PWAT values make a run at 1.25 inches along the warm front here in MI. Aloft the upper level jet takes on an anticyclonic shape with the low level jet underneath. This is a common setup for numerous showers and thunderstorms...with an elevated risk for a period of heavier rain. How much rain we end up with will depend partly on where this warm front sets up. There is some potential for the main area of rain to end up just north of the CWA Tuesday night. We will still feature high POPs then to account for the warm frontal passage Tuesday night. There is an increasing potential for some severe weather on Wednesday with the mid afternoon to evening hours looking like the main period of concern. Aloft a strengthening upper level wave is shown to lift up through the Western Great Lake Region with abundant upper level divergence during this period as it takes on a negative tilt. A strengthening low level jet forms upstream in the Middle MS Valley and moves into the CWA with the region fully in the warm sector during this window. Forecast hodographs yield abundant helicity and low lcl`s. Ensemble guidance for surface based CAPE values shows uncertainty as far as how much instability we will generate...which could be a limiting factor. However enough dynamics and lift will be present to make the most of what instability we can generate. The cold front pushes through from west to east in the late afternoon and evening hours...which will likely the be main trigger for the strongest convection. - Impactful winds possible Thursday As the surface low winds up in Southern Ontario...a tight pressure gradient sets up here in MI on Thursday. Deep mixing associated with cold air advection develops during the day. The mixing height is shown to reach into the 40 knot range of winds here in Grand Rapids from the GFS. The 12z High Res Euro shows 50 knot 850 mb winds and stronger cold air advection the...which would also support a potential for impactful surface winds. As a result...an increased potential for winds to exceed 40 knots exists then. This would be enough to warrant a wind advisory. && .AVIATION...(For the 00Z TAFS through 00Z Monday evening) Issued at 801 PM EDT Sun Apr 10 2022 Really for the most part expect VFR conditions for the next 24 hours. However there will be 45 to 50 knots of Low Level Shear tonight as there is 50 to 60 knots of wind from the southwest between 2000 ft and 7000 ft agl through the night. Once the cold front comes through and the sun can heat the air enough to cause mixing winds will be gusty from the west - southwest. There will also be a developing line of scattered showers developing west of CHI-MKE prior to 05z. As that line crosses Lake Michigan and moves into Southwest Lower Michigan in the 06z to 09z time frame thunderstorms are expected to develop. This line of showers and storms should be east of Lansing by 09z or so. Cigs and vsby should mostly be VFR but in the heavier storms do expect some MVFR or even IFR in the storm cores. Once the front clears the area around 12z, skies will clear below 10000 ft. However a mid-level shortwave trailing the front will cause and area of rain to develop in the cold air north of that cold front. The real question is how far north will that rain area get into Michigan. I have VCSH for the TAF south of I-96 in the afternoon but I put rain in JXN TAF late in the day. It should stay VFR even so. && .MARINE... Issued at 211 PM EDT Sun Apr 10 2022 We will maintain the small craft advisory for later this afternoon into tonight. The low level wind fields will be strengthening as low level jet moves in. Based on mixing heights and forecast winds at those levels...surface gusts over 25 knots look likely. There could even be a few gale gusts. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...None. LM...Small Craft Advisory until 6 PM EDT Monday for LMZ844>849. && $$ UPDATE...WDM DISCUSSION...MJS AVIATION...WDM MARINE...MJS
Area Forecast Discussion
National Weather Service Gray ME
1042 PM EDT Sun Apr 10 2022 .SYNOPSIS... Showers this afternoon will gradually give way to clearing tonight and a sunny day to start the work week. Monday will be warm and dry, though a seabreeze in the afternoon may knock temperatures back near the coast late in the day. A warm front moving through the region Monday night will lead to showers but also some pleasant weather Tuesday afternoon and again Wednesday. A more organized system makes an approach to New England by late week. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... 1045 PM Update... No significant changes for the near term portion of the forecast. Scattered upslope snow showers will continue under a northwesterly flow. Most of the cloudiness will continue to be over northern areas which is supported by the latest HREF solution. Winds will continue to gradually ease with time during the overnight hours. Minor adjustments were made to temperatures, dew points and cloud cover. Prev Update... Winds will continue to ease late this evening across the forecast area despite a northwesterly gradient over the region. Nevertheless, the breeze will keep the region relatively well mixed, allowing for overnight lows to fall into a tight range, mainly from the upper 20s north to the mid 30s in the south. Most of the cloud cover will continue to be over the upslope regions of the mountains through the night. This is where there will be scattered snow showers and possibly light accumulations over the higher terrain. These overnight snow showers are supported by the latest HRRR and the 3 km NAM solutions. Prev Disc... Scattered showers, mainly across NH, will begin to taper into the evening w/ loss of daytime heating. A light breeze will also continue overnight as temperatures again fall into the lower 30s. The broad trough/upper low that had been parked over the Maritimes late this week will finally move east, freeing northern New England from its unsettled influence. There will be one last push of NW winds tonight in the low levels, and with cold air here, mixing and breeze will continue. HREF guidance from this morning and last evening echo continuing cloud cover for much of the western mountains and valleys through late tonight/ early Mon morning, with most other locations becoming clear with drier air. Temps should fall back into the lower 30s with the clear skies and mixing just undulating more cool air to the sfc without decoupling/inverting. While some icy patches developed on elevated surfaces last night w/ recent rain and falling temps, believe that threat will be lower tonight. The exception may be south/central NH where passing showers today could have wet some surfaces. && .SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/... Ridging pushes east into New England Monday. This will bring dry and sunny conditions for the forecast area. Will need to monitor fire weather conditions, noted in section below. Monday will begin a stretch of warm days set for this week. With widespread clear skies expected by daybreak, a full sun start to the day will surely help areas warm quick towards 60 for much of the coastal plain and interior. Even some of the mountain valleys will climb into the upper 50s with just the higher summits cooler. NW winds continue as the ridge presses the pressure grad against exiting low. Slackening winds in the column will mean less breezy conditions to mix down, but will also mean the possible formation of a sea breeze along the coast later. This may spoil 60s along the immediate coast come early afternoon, but the sun will feel warm nonetheless. The ridge crests Monday night with increasing cloudiness ahead of precip advancing w/ weak triple point low. Temps should remain warmer than Sunday night, both with SW flow and the increasing cloud cover capping some of the warm air left over from daytime. There will be the chance of some snow mixing in north of the mountains, however after the warm day, little to no accumulation is expected. && .LONG TERM /TUESDAY THROUGH SUNDAY/... Overview: Ridge trof ridge pattern continues in the extended...with a broad trof settling over the region by the weekend. While there may be some cool temps sprinkled in...overall they should average above normal for the period. Impacts: No significant weather related impacts are anticipated through the end of the week. Wed may see another deep mixing day with RH values dropping near to below 30 percent...but winds will remain lighter. Forecast Details: Either a rapid progression of warm/cold front combo or an occlusion moves thru on Tue. After a quick round of showers there should be relatively fast clearing from west to east thru the day. That will delay mixing to start...but by afternoon we should be mixing to near H8 and there will be pleasant temps across the area. Given the rain and delayed mixing the RH values will remain mostly above 40 percent for the forecast area. High pressure and clear skies Wed will allow for much faster mixing despite some return flow and moistening occurring. Dewpoints may actually be cooler in the mid morning time frame before deeper moisture starts to work in aloft. Mixing down from the top of the boundary layer keeps dewpoints mainly in the 30s during the afternoon...but with warmer temps that means RH values between 25 and 30 percent for a large part of the forecast area. Once again winds will be fairly well behaved and remain at or below 10 kt...preventing more widespread critical fire weather concerns. Weak S/WV trof still there in the guidance Wed night...topping the ridge and sending a backdoor cold front thru at least part of the forecast area. There will be showery weather along the warm frontal boundary as it lifts thru the region. The best chance to salvage a decent day will be the CT River Valley and the Monadnocks where some brief clearing may occur before the cold front arrives. Timing on that cold front will be sometime in the late afternoon or evening Thu. Because of the backdoor front remaining fairly stationary...the warm sector will be quite narrow in our forecast area...but a marginally unstable air mass is still possible. Around 500 J/kg CAPE is forecast across parts of southern NH into the Lakes Region...and adjacent southwestern ME. I have thunder in the forecast for these regions...but will need a little more consensus before getting more detailed than scattered to isolated storms. Fri looks to be another pleasant day before a rather flat trof settles into the region for the weekend. Showers look more likely Sun than Sat...so I have higher PoP on the latter half of the weekend. && .AVIATION /03Z MONDAY THROUGH FRIDAY/... Short Term...VFR tonight. -SHRA will taper across NH and parts of ME this afternoon, leading to clear skies through Monday. A sea breeze may cause a wind shift at RKD, PWM, or PSM Mon afternoon. Clouds will thicken and lower Monday night ahead of more -SHRA. Long Term...Mostly VFR conditions expected thru Wed night. Some local MVFR or lower conditions are possible in SHRA Tue morning before clearing out quickly in the afternoon. Backdoor cold front and prolonged onshore flow Wed night thru Thu will likely lead to widespread MVFR or lower conditions north of the boundary. The threat of marine fog/stratus will increase late Thu before the cold front crosses the region. Some local IFR conditions are possible in SHRA/TSRA Thu as well. && .MARINE... Short Term...SCA conditions this evening and overnight as NW winds increase ahead of arriving high pressure Monday. Conditions improve, with below SCA conditions expected Monday into Monday night. Long Term...Winds and seas are forecast to remain below SCA conditions thru the extended. If they are to occur the best chance for SCA conditions will likely be with the cold frontal passage Thu night as seas increase on southerly flow. && .FIRE WEATHER... Despite a few damp days across the CWA, some variables will approach critical fire weather conditions Monday. A dry air mass will move in overnight, with relative humidity values falling into the 20 to 25 percent range across much of central and southern NH during the afternoon. Low RH values 25 to 30 percent will also be possible across the ME interior/foothills. Going against these dry air conditions will be lighter winds and the recent wetting rains from showers Saturday and for some locations Sunday. Additionally, a sea breeze may develop along the coast with locally breezier conditions amid a wind shift, but also higher humidity air. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...None. NH...None. MARINE...Small Craft Advisory until 9 AM EDT Monday for ANZ150>154. && $$ NEAR/SHORT TERM...Cannon LONG TERM...Legro
Area Forecast Discussion
National Weather Service Indianapolis IN
1135 PM EDT Sun Apr 10 2022 ...Updated Aviation Discussion... .Forecast Update... Issued at 945 PM EDT Sun Apr 10 2022 Surface analysis this evening shows deep low pressure in place over MN with a cold front extending south through eastern IA and NE MO to SE KS and OK. A moderate pressure gradient was in place across Central Indiana ahead of the low pressure system. Central Indiana remained within the warm sector with southeast surface winds and ongoing warm air advection. GOES16 shows mid and high clouds across Central Indiana as well as across the region. The nearest convection and precipitation was found over Central TX and western MN. Dew points remained quite dry...within the mid 30s. Overnight the low to the north is expected to push northeast and continue to slowly drag the associated cold front east toward Indiana. Minimal forcing is expected overnight...however a moderate LLJ with wind speeds of 40-50 knts is expected to persist overnight. HRRR tries to suggest some sct shra development overnight...but other than the LLJ forcing...little in the way of overall dynamics are present. Only high clouds are found across the region and dew points as stated remain quite dry. Thus confidence for rain developing overnight has diminished. Have trended pops toward a dry forecast until about 4AM...and then slowly beginning ramping toward low chance pops by morning as the cold front to our west will be much closer to arriving. Given our good mixing...high cloud and warm air advection...temperatures are not expected to fall much. Only trended lows toward the mid 50s. && .Short Term...(This evening through Monday night) Issued at 210 PM EDT Sun Apr 10 2022 * Significant warm-up underway * Rain returns tomorrow and we continue to refined timing and amounts * Thunderstorms are possible Monday; a few strong to severe storms possible in southern Indiana In the near term, we`ve made minor adjustments upward to temperatures based on observational trends. Also, mixing and momentum transfer has caused wind gusts to around 30 mph, especially across western Indiana. In water vapor channel imagery, a shortwave trough is clearly evident emerging from the Rockies onto the northern Plains. This is inducing strong meridional low-level flow and warm/moist advection in the Plains, which will nudge northeastward into our area later tonight. A surge of deeper moisture is already seen in advected layer precipitatable water in Texas, and models show a deep moisture connection for our area emanating from low- latitudes. Showers and isolated thunderstorms will begin to increase in coverage across Illinois tonight and could move into portions of central Indiana after midnight. Anomalous precipitable water values and modest isentropic ascent within the warm advection regime will lead to fairly widespread coverage of showers and isolated thunderstorms tomorrow, until the front sent south by the aforementioned shortwave trough pushes through most of the area by tomorrow night. Later in the day there is some signal for deeper more intense convection to our southwest to move into portions of southern Indiana, perhaps as far north as Vincennes and Bedford. A low probability of marginally severe thunderstorms exists from those locations southward. Hail up to quarter size and wind gusts to 60 mph would be the threats in a reasonable worst case scenario. Limiting factors include (1) elevated parcels and modest effective shear from the warm nose (parcel origin) upward, (2) uncertainty on position of the front and potential for elevated fast-moving cells to organize further south, closer to the Ohio River, displacing the threat south of our forecast area. The front and precipitation near it should shift into southern Indiana overnight, with limited coverage across our forecast area. && .Long Term...(Tuesday through Sunday) Issued at 210 PM EDT Sun Apr 10 2022 * Continued warm with a conditional low risk of storms Tuesday * Strong/severe storms possible Wednesday; damaging winds and heavy rainfall are the primary concern * Modest cool down to near normal late week A strong mid-latitude system will move through mid-week bringing some concern for strong to severe storms and heavy rainfall. Above normal temperatures will precede this system, with only a modest cool down in its wake. Details are found below. Tuesday: There is a conditional risk for thunderstorms on Tuesday, and this potential will mainly depend on the position of the warm front. Isentropic ascent north of the front may drive elevated convection. South of the front, differential advection pattern is seen in model soundings with residual capping elevated mixed layer atop a relatively cool/moist PBL. With large scale ascent remaining to the west and lack of focus for convective initiation, much of the anomalously warm/moist open warm sector may fail to see deep convection and the light QPF signal in models is probably tied to a shallow convective process. With regards to warm front timing, models have converged on a solution of returning it northward through the morning hours from its quasi-stalled position Monday night to our south. We have over- achieved with temperatures with previous warm advection regimes so far this season, but this time may be different given the potential for substantial PBL moisture/saturation limiting the diabatic contribution and depth of mixing somewhat. Thus, we`re reluctant to deviate from blended model guidance for temperatures Tuesday at this time. Still pleasantly warm though. Wednesday: A compact southern stream shortwave trough will move quickly into the area providing a brief period of ascent and deep saturation sometime Wednesday. This will likely be during the morning, but model timing differences still exist. This will be accomplanied by a wave of precipitation. Moist adiabatic profiles and poor midlevel lapse rates should limit thunder potential with this round. There may be a break in precipitation post-lead wave and before the deep mid-latitude system`s trailing front passes. Medium range deterministic and ensemble guidance has generally converged on similar timing with deep cyclone and its attendant frontal convective band that will move into our area sometime late Wednesday or Wednesday night. We will highlight this time range with the highest precipitation probabilities accordingly. Strong kinematic fields, anomalous moisture, and instability (albeit minimal) will be enough for some strong to severe storm concern. Most likely in the form of linear connection within a strongly forced regime. The primary threat would be damaging winds. Colorado State University machine learning severe probabilities do extend into the area, and there is a CIPS analog signal, too. The flooding threat appears to present but low given the progressive nature of the frontal precipitation band. Certainly, there is enough deep saturation to increase precipitation efficiency for a short period of heavy rainfall rates though. Rainfall amounts may be enough to see at least a minor uptick in river levels into late week, however. Thursday and Friday: Pivoting PV lobe, deeper saturation and precipitation will shift east by Thursday. The track of the deepening mid-latitude system over southern Canada supports only modest cold advection, lowering our temperatures only to near or just below normal values. Next weekend: Chaos grows in the medium-range ensemble spaghetti plots into next weekend. The general pattern should feature low-latitude ridging/positive height anomalies and high-latitude broad troughing/negative height anomalies, with fast quasi-zonal flow at jet level in between. We will still carry low probabilities in precipitation given some signal in the models for a PV lobe rotating around filling Canadian deep low interacting with a perturbation in the westerlies. This would be a conditional and complicated enough interaction that probabilities were kept broad in time range and low, for now. Temperatures during this period should stay close to climatology, or perhaps just below. && .Aviation...(06Z TAF Issuance) Issued at 1135 PM EDT Sun Apr 10 2022 IMPACTS: - VFR the rest of the of the overnight. - Non-convective low level wind shear possible overnight - CIGs deteriorating to MVFR 12z-15z Monday morning - SHRA/isolated TSRA coverage slowly increasing Monday. DISCUSSION: GOES16 shows high cloud over IL and Indiana pushing east within the warm sector ahead of a cold front. VFR conditions were found across the region as Central Indiana. A moderate LLJ is expected overnight as 850 winds appear near 40-50knts. Again have included a LLWS mention for this feature. A few echos within the LLJ have appeared over Central IL but these appear to be short lived as a less favorable air mass is in place across Central Indiana with dew points in the mid 30s. Little eastward propagation is expected and any coverage will be minimal. As the surface low pushes northeast overnight...a cold front is expected to nudge toward Indiana. Time heights and forecast soundings show saturation arriving within the lower levels amid warm air advection...mainly late tonight. Thus have trended toward MVFR Cigs arriving late overnight and on Monday. As the associated cold front passes across Indiana on Monday... showers and a cold front are expected to push across the state...with more favorable forcing in place. HRRR shows sct showers lingering across Central Indiana and time heights show good lift and saturation through the day. Thus trended toward prevailing -shra for much of the afternoon. Timing on any TSRA is uncertain at this point but lapse rates within forecast soundings suggest a rumble of thunder cannot be ruled out. Brief IFR conditions will be possible with any brief TSRA that does occur. && .IND WATCHES/WARNINGS/ADVISORIES... None. && $$ Update...Puma Short Term...BRB Long Term...BRB Aviation...Puma
Area Forecast Discussion
National Weather Service Memphis TN
912 PM CDT Sun Apr 10 2022 .UPDATE... Windy conditions continue along and west of the Mississippi River at this hour. A few locations are still gusting to 30 knots with sustained winds near 20 knots. The wind advisory was extended to account for these gradient winds and may be cancelled early if conditions diminish. The latest surface analysis places a 995mb low near MSP with a cold front extending south through Waterloo, Iowa, southeast back into Kansas City, Missouri, and back into Stillwater, Oklahoma. Ahead of the front, a few showers have begun to form near the ArkLaTex along an upper level leading shortwave. This shower activity will move into the Mid-South overnight with a few rumbles of thunder possible as mid level lapse rates steepen to around 7.5 C/km. No severe weather is anticipated. Shower and storm activity is expected to blossom by late morning tomorrow with a few strong storms possible along the Kentucky and Tennessee state lines. The current forecast is on track with major changes needed at this time. AC3 && .PREV DISCUSSION... /issued 641 PM CDT Sun Apr 10 2022/ UPDATE... See the 00z aviation discussion. && .PREV DISCUSSION... /issued 302 PM CDT Sun Apr 10 2022/ DISCUSSION... Warm and windy conditions are occurring across the Mid-South this afternoon. Winds are currently 20-25 mph with gusts up to 35-40 mph. The strong winds have helped temperatures climb into the upper 70s to lower 80s. The winds are slowly bringing an increase in moisture but there is a lag across much of North Mississippi and portions of West Tennessee where Red Flag conditions are being met due to the winds and low relative humidity values at or below 25 percent. Expect the winds to begin to diminish around sunset which will also alleviate the fire weather concerns. Meanwhile, an active weather pattern is expected across the Mid-South this week. Several round of possible severe weather could occur as warm temperatures and an unstable airmass remain over the region. Warm air advection showers and thunderstorms will begin occurring during the overnight hours tonight into Monday morning. This activity should dissipate by midday Monday. The first round of severe weather is then expected to occur late Monday afternoon into Monday evening. The ongoing southerly flow will bring lower 60s dew points into the area by Monday afternoon. Most of the CAM models are showing a frontal boundary dipping south into Northern Arkansas stretching northeastward to the Ohio River Monday night where showers and thunderstorms will develop along and ahead of the front and drift southward toward the I-40 corridor by midnight. In addition, the HRRR continues to show some supercells out ahead of the front developing across Central Arkansas during the late afternoon hours. If this occurs these would move into Eastern Arkansas during the early evening hours. Damaging winds, large hail, and tornadoes will be possible with any severe storms. Expect the severe threat to diminish by midnight due to the loss of daytime heating. The front will lift back north as a warm front Tuesday morning. Expect much of Tuesday to be dry with the exception of a few isolated warm air advection showers. Temperatures should climb into the upper 70s to lower 80s for highs. This will produce a warm, moist, and unstable air mass across the Mid-South just in time for the next round of severe weather which is expected Tuesday evening into the overnight hours on Wednesday. Models are showing thunderstorms developing across Southern Arkansas as a shortwave trough moves into the region. The convection will then lift northeastward into the Midsouth and eventually into the Ohio Valley by Wednesday morning. All modes of severe weather will be possible with this round as well as Heavy rain which could lead to flash flooding. Questions still remain about round 3 of severe weather which is expected to occur late Wednesday afternoon into Wednesday Night. It will depend on if there is any lingering morning convection and how quickly it clears? If the convection hangs on too long then the atmosphere may not have time to recover in time for the next round of severe weather. However, if the atmosphere can indeed recover then there will be possibility of severe weather as a potent negatively upper trof will be moving through the Upper Midwest as the associated trailing cold front moves into the Mid- South late Wednesday afternoon into Wednesday Night. Supercell development out ahead of the front in addition to a QLCS along the front will be possible with the front as dewpoints climb into the mid to upper 60s ahead of the approaching front. CAPE values will likely be around 1500 J/KG and will be combined with 0-1 km SRH of greater than 300 M2/S2. Thus if this airmass is in place then tornadoes, damaging wind and large hail will be possible with any severe storms. Flash flooding may also occur especially in locations that receive heavy rain Tuesday Night into Wednesday. High pressure will build into the region for Thursday. However, the tranquil weather will be short-lived as another low pressure system is then expected to affect the Mid-South next weekend. Chances for showers and thunderstorms will occur during this time period. However, there is a lot of model disagreement in how the system will exactly evolve. Stay tuned. KRM && .AVIATION... /00z TAFs/ Strong southerly winds will prevail through the overnight period with gusts to 30 kts at JBR/MEM. Only a few high clouds are expected this evening, but lower clouds will begin to move into the area after 06z with a few warm advection showers developing between 08-12z. Areas of MVFR ceilings around 2500 ft AGL are expected Monday morning across much of the Mid-South with additional showers, and a few thunderstorms, developing through early afternoon. We should see a bit of a convective lull by mid- afternoon with improving sky conditions along/south of I-40. However, lower ceilings are expected to hang on at JBR with IFR conditions anticipated after 18z. Southerly winds will increase again Monday, though not as strong as today. We`ll see compression impacts from low-level wind shear (SSW wind at 2 kft AGL near 45 kts) tonight and likely again tomorrow night. MJ && .MEG WATCHES/WARNINGS/ADVISORIES... AR...Wind Advisory until midnight CDT tonight for Clay-Craighead- Crittenden-Cross-Greene-Lee AR-Mississippi-Phillips- Poinsett-St. Francis. MO...Wind Advisory until midnight CDT tonight for Dunklin-Pemiscot. MS...Wind Advisory until midnight CDT tonight for Coahoma-DeSoto- Panola-Quitman-Tallahatchie-Tate-Tunica. TN...Wind Advisory until midnight CDT tonight for Dyer-Lake- Lauderdale-Obion-Shelby-Tipton. && $$
Area Forecast Discussion
National Weather Service San Francisco Bay Area
623 PM PDT Sun Apr 10 2022 .SYNOPSIS...Breezy to gusty winds are likely through this afternoon and again on Monday, especially near the coast and in the hills/ridges. A frontal boundary will bring widespread, albeit light, rainfall to the region on Monday along with cooler temperatures. Cool and unsettled weather continues through late week with additional rainfall possible. && .DISCUSSION...as of 01:46 PM PDT Sunday...High clouds continue to move over the region this afternoon ahead of an approaching mid/upper level low pressure center along the British Columbia coast. Meanwhile, temperatures have warmed into the upper 50s near the coast to lower 70s inland as anticipated with a few degrees of additional warming possible. Winds across the interior continue to diminish as well and have turned onshore near the coast. Thus, look for breezy and gusty northwesterly winds along the coast and in the hills/ridges this afternoon. Wind gusts generally will range between 30 to 40 mph with isolated locations peaking around 45 mph. All attention turns to the aforementioned mid/upper level system which will drop southward through the night and push a frontal boundary across the Bay Area on Monday. This will result in light rain developing over the North Bay around sunrise before spreading inland and southward through the morning. By late morning and into the early afternoon, this boundary will impact the Central Coast while conditions begin to dry out to the north. Rainfall amounts generally will remain light with most urban areas picking up < 0.10" with isolated amounts upwards of 0.20". Meanwhile, the coastal ranges look to receive around 0.25" with the latest HRRR and other short-range, high-resolution models indicating the potential for upwards of 0.50" the typically wetter spots. Breezy winds will also develop in wake of the passing frontal boundary during the daylight hours with winds gradually diminishing by Monday night. The cloud cover, precipitation and cold air advection aloft will hold daytime temperatures in the 50s for much of the region on Monday as well. Cool and unsettled weather conditions then are likely to persist through the remainder of the upcoming week as a broad mid/upper level trough lingers over the West. Additional weather systems are likely to drop southward into the Pacific Northwest and northern California by late week. These systems are likely to bring additional rainfall to the region, yet details remain difficult to nail down at this point. The greatest probability of additional rainfall and greatest rainfall amounts will be over the North Bay with diminishing chances as you head south across the Central Coast. Overall though, rainfall amounts do not look to be substantial. Stay tuned... && .AVIATION...as of 6:23 PM PDT Sunday...For the 00Z TAFs. VFR through the evening then quickly lowering ceilings and visibilities /MVFR-IFR/ north to south tonight and early Monday morning with showers, possibly moderate to heavy, with a fast moving cold front Monday morning. Strong and gusty northwest winds this evening with high pressure quickly moving across the cwa preceding Monday`s cold front and reinforcement of cold air. Decent surface pressure falls with Monday`s cold front along with the meso-scale models showing a surface low center developing over the Sacramento Valley; forecast precipitable water (pw) values quickly approaching 0.80" to 0.90" Monday morning prior to cold frontal passage, that`s high end pw for a cold front, model qpf may be under-forecast especially if dynamics spin up a little stronger than forecast. Rapidly deteoriating conditions late tonight and Monday morning, then strong cold air advection primarily driving strong and gusty west to northwest winds Monday. Winds likely easing Monday night and Tuesday morning with clearing, returning air mass stability favoring surface wind decoupling. Freezing levels lowering to 2-3 thousand feet AGL across our cwa per upper air forecast soundings Monday afternoon and evening. Vicinity of KSFO...Northwest wind peak gust so far 50 knots (58 mph) at 4:53 pm, 5 minute observations still showing gusts to 35 to 42 knots. On the ocean side of the peninsula, strong and gusty winds are lifting sea spray into the air, resulting in hazy conditions along the coast and periodically lowering surface visibility to MVFR /3-5 miles/ in haze at KHAF Airport. Strong winds are also transporting hazy/haze conditions to SFO Airport. Ceiling rapidly developing late tonight and Monday morning with showers, possibly moderate to heavy, with cold frontal passage Monday morning. MVFR forecast Monday morning with cold front, conditions could lower to IFR in heavier showers; may adjust the taf to reflect this by 06z taf issuance. Post cold frontal winds ramping up again Monday, statistical guidance shows at least similarly strong winds Monday as compared to today`s winds. Showers diminishing by late Monday morning and afternoon, VFR forecast though hazy conditions may still continue with wind driven sea spray lofted into the air and advected toward SFO Airport in the afternoon and evening. West to northwest winds diminishing Monday night and Tuesday morning. KSFO Bridge Approach...Similar to KSFO. Monterey Bay...Gusty winds around here as well, KMRY Airport peak gust so far 32 knots (37 mph) at 4:45 pm. Gusty northwest winds across the Monterey Bay is lifting sea spray into the air (the vsby is reduced somewhat by a hazy view outside our office windows) and transported to KMRY, the ceilometer is incorrectly indicating OVC ceiling. The current air mass and northwest upsloping winds is furthering cooling which may eventually yield a BKN-OVC ceiling this evening which the HREF output shows beginning possibly as soon as 04z this evening. Will closely monitor conditions and amend as necessary for possible IFR ceiling(s) developing this evening. && .MARINE...as of 5:02 PM PDT Sunday...The sea state remains wind driven as strong northerly winds with gale force gusts prevail. Large, very steep wind driven combined seas are possible of 09 to 13 feet at 09 to 11 seconds. Smaller craft vessels are advised to avoid venturing out in these rough conditions. A lull in the winds is forecast for Sunday night into Monday, before intensifying again Monday night. Slight chance for light rain over the waters early Monday morning as a weak front passes southward. Gradual weakening is forecast Tuesday through the end of the week. && .MTR WATCHES/WARNINGS/ADVISORIES... .Tngt...GLW...Pt Reyes to Pigeon Pt 0-10 nm until 3 AM GLW...Pigeon Pt to Pt Pinos 0-10 nm until 3 AM GLW...Pigeon Pt to Pt Piedras Blancas 10-60 nm until 3 AM SCA...Pt Arena to Pigeon Pt 10-60 nm GLW...Pt Pinos to Pt Piedras Blancas 0-10 nm GLW...Pt Arena to Pt Reyes 0-10 nm until 9 PM SCA...SF Bay until 3 AM SCA...Mry Bay until 3 AM && $$ PUBLIC FORECAST: RGass AVIATION: Canepa MARINE: DK Visit us at www.weather.gov/sanfrancisco Follow us on Facebook, Twitter, and YouTube at: www.facebook.com/nwsbayarea www.twitter.com/nwsbayarea www.youtube.com/nwsbayarea
Area Forecast Discussion
National Weather Service Nashville TN
835 PM CDT Sun Apr 10 2022 .UPDATE... FOR EVENING DISCUSSION. && .DISCUSSION... Hourly forecast grids are holding up well so far, but have trimmed the overnight POP`s across our western zones. HRRR shows very few cells developing in Middle Tennessee until after 12Z. Evening sounding from OHX shows a largely dry atmosphere still in place. Surface dew point spread is still 32F at 01Z, so it will take some additional moisture advection to get us to a point for precipitation to be able to reach the ground. && .AVIATION... 00Z TAF DISCUSSION. BNA/MQY/CKV/CSV...Surface winds have increased considerably from the south now that high pressure has shifted to our east. A cold front that is currently developing to our west will continue to gather moisture before entering the mid state tomorrow night. In the near term, expect LLWS to develop later this evening as near- surface winds continue to pick up steam. Expect showers to develop overnight and tomorrow as the front edges closer. && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ DISCUSSION......08 AVIATION........08
Area Forecast Discussion
National Weather Service Tulsa OK
952 PM CDT Sun Apr 10 2022 ...New SHORT TERM... .SHORT TERM... (The rest of tonight) Issued at 952 PM CDT Sun Apr 10 2022 At mid evening...a cold front stretched from northern Missouri to far southeast Kansas into northeast Oklahoma...near a Bartlesville to Pawnee line... and then extended southwest to a surface low in southwest Oklahoma. North of this boundary...dewpoints were in the upper 30s to mid 40s in far northeast Oklahoma. While along and southeast of the front...upper 50s to around 60 deg dewpoints were common across the rest of eastern Oklahoma and northwest Arkansas. A mid level impulse marked by increasing mid level moisture/cloud cover was pushing eastward from western Oklahoma this evening. The interaction of this feature with lift along the slowly moving cold front will aid in the anticipated storm initiation across northern/northeast Oklahoma over the next hour or so. Overnight tonight...thunderstorm development is expected near and to the north of the surface frontal boundary in northeast Oklahoma...and then spreading into east central Oklahoma and northwest Arkansas overnight tonight into Monday morning. At the onset of development...surface based CAPE of 1000j/kg and greater combined with steep mid-level lapse rates and 500-mb temperatures around -18C will increase severe potentials with large hail and damaging wind being the primary threats. If any storm can be more discrete along the boundary and take advantage of forecast 2-300 m2/s2 effective storm relative helicity and pooling 60 deg dewpoints...an isolated tornado may be possible. This looks to be a short window as storms are forecast to become increasingly elevated behind the front overnight tonight. The greater severe potential is expected across northeast Oklahoma into far northwest Arkansas through tonight...with overall severe potentials weakening late tonight into Monday morning. The cold front and or surface outflow boundary is forecast to push into east central Oklahoma and far northwest Arkansas by 12z Monday. Northerly winds will help temps behind the front to fall into the 50s...while southerly winds keep temps in the 60s ahead of the boundary tonight. For the evening update...have adjusted pops/wx based on the mentioned above and latest trends. Also added minor adjustments to hourly temp/dewpoint trends based on latest obs and forecast movement of the boundary. The rest of the forecast seems to be handling well at this time. && .LONG TERM... (Tomorrow through Sunday) Issued at 240 PM CDT Sun Apr 10 2022 The boundary will work its way down into southeast OK and western AR on Monday. The extended hours of the latest HRRR and the 12Z HREF suggest some potential for storms along/east of the front by Monday afternoon/evening. Slowly rising mid level heights suggest no upper support and thus coverage should remain fairly isolated. Strong instability suggests severe storms possible with hail/winds main threat. Shower and storm chances will increase Tuesday afternoon and evening across the ArkLaTex and neighboring portions of SE OK and WC AR in association with a subtropical wave. As previous shift mentioned, some subsidence in the wake of this wave makes dryline development farther to the west more uncertain. If a storm goes, storms would have higher-end severe weather potential. Warm advection showers and storms may increase in coverage late Tuesday night in advance of the ejection of a strong upper level storm system into the Plains with some severe potential. A cold front will march east across the region Wednesday, earlier rather than later. Severe storm potential will be greatest over far eastern OK into western AR ahead of the front during the midday and early afternoon hours before the threat moves quickly east of the region. Shower and storm chances will increase by the Easter weekend, first in on Friday with a weak wave, and then by Sunday in association with a stronger cold front. Cooler weather is expected as we head into the following week with the possibility of more frost/freeze headlines at some point. && .AVIATION... (00Z TAFS) Issued at 641 PM CDT Sun Apr 10 2022 Cold front, currently located near a KOKC/KBVO line will continue to push slowly southeast overnight. As mid level speed max approaches from the west, strong storms will likely develop in the KBVO area, near frontal boundary, by late evening. Lingering areas of rain with embedded thunderstorms will likely persist, north of the front, across NE OK, through the overnight hours. Otherwise, lower IFR/MVFR ceilings will likely develop along/south of the front, continuing for much of the day with scattered showers and maybe an isolated thunderstorm or two across NW AR. && .PRELIMINARY POINT TEMPS/POPS... TUL 55 70 57 84 / 70 20 10 10 FSM 61 76 62 81 / 40 60 30 20 MLC 62 78 62 81 / 20 30 10 20 BVO 51 69 51 84 / 90 20 10 10 FYV 56 70 57 79 / 80 80 30 20 BYV 57 67 56 78 / 80 80 30 10 MKO 59 72 58 81 / 60 60 10 10 MIO 52 66 52 81 / 90 60 10 10 F10 59 73 58 83 / 60 30 10 10 HHW 64 83 66 81 / 10 20 20 30 && .TSA WATCHES/WARNINGS/ADVISORIES... OK...None. AR...None. && $$ SHORT TERM...20 LONG TERM....30 AVIATION...12