Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 05/16/22

National Weather Service Wakefield VA
916 PM EDT Sun May 15 2022 .SYNOPSIS... A lee trough lingers in the western Piedmont bringing the chance for late afternoon and evening showers and thunderstorms to the local area. A few strong to severe storms are possible Monday afternoon through Monday evening ahead of and along a cold front moving through. High pressure settles in from the north through midweek. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... As of 915 PM EDT Sunday... Early evening analysis continues to show a weak leeside trough to the W-NW of the local area. Regional radar mosaic showing ongoing, loosely organized convection over SE MD and the VA northern neck. SBCAPE ~1000-1500 J/kg and PW of ~1.33 along with relatively weak lift and effective shear (~20kt) have made for a predominately sub-svr threat with slow moving showers and storms. Showers and embedded T-storms will continue for the next hour or two before diminishing further, remaining mainly dry for the overnight hours. Given the slow storm motion, locally heavy rainfall remains the primary concern, with isolated 1"+ rates possible. Isolated to widely scattered showers overnight, mainly along the trough/theta-e ridge from AVC to RIC to XSA. Overnight lows mainly in the 60s under a partly to mostly cloudy sky. && .SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY NIGHT/... As of 350 PM EDT Sunday... A weak prefrontal trough moves through Mon morning which may allow for isolated to scattered showers to form in the Piedmont. The HRRR is the most aggressive, with less support from other CAMs. As such, have kept slight chance PoPs for now. A cold front moves through the area Monday afternoon/evening associated with a rapidly deepening area of low pressure that develops across far W PA, moving NE into upstate New York late in the day. SBCAPE increases Monday afternoon to ~1500-2500 J/kg. 0-6 km shear increases to 35-45 kt by late in the day with storms developing ahead and along the cold front and moving ESE through the afternoon into the evening. Given modest instability and relatively strong shear, expect scattered strong to severe storms along the front overspreading most of the CWA from late afternoon into the evening. Damaging winds are the most likely threat given the linear storm mode, although occasional large hail will be possible in any semi-discrete storms that may form. Cannot completely rule out an isolated tornado, however, SSW/SW surface winds and 0-1 srh generally <100 m2/s2 will limit this threat, especially if enough mixing occurs that LCLs increase above 1000m. Timing is still low confidence as some CAMs have early afternoon prefrontal storms as well as several hours of difference between when the main cold front storms move through. SPC has most of the are under a slight risk for severe weather with an enhanced risk across far northern portions of the FA. Convection moves offshore Mon evening. Highs in the mid to upper 80s Monday with lows in the lower 50s NW to lower 60s SE Monday night. High pressure begins to build in Tuesday into Wed with a reinforcing cold front moving through Tues night/Wed. Mostly sunny and dry both days with highs in the lower 80s (upper 70s along the coast) Tues and mid 80s SW to mid 70s NE Wed. A shortwave moves through the area Wed evening into early Thurs which will allow for scattered showers/storms Wed night. && .LONG TERM /THURSDAY THROUGH SUNDAY/... As of 350 PM EDT Sunday... A warm front lifts north Thurs with a shortwave passing north of the FA Thurs night. Showers/storms are possible Thurs with highs in the upper 80s SW to the upper 70s NE. The SE ridge builds in Fri through the weekend with much warmer temps expected, especially Fri and Sat with highs in the lower to mid 90s. Cannot rule out isolated, diurnally-driven storms Sat afternoon/early evening. A cold front moves through Sun with scattered showers/storms possible. Highs Sun in the upper 80s S to the lower 80s N. Lows in the lower to mid 60s Thurs night, upper 60s to around 70F Fri night, lower 60s NW to upper 60s SE Sat night, and upper 50s NW to mid 60s SE Sun night. && .AVIATION /01Z MONDAY THROUGH FRIDAY/... As of 800 PM EDT Sunday... Predominately VFR conditions across area terminals this evening. Exception is between KWAL and KOXB in low clouds and fog. Expect these low clouds will persist for much of the evening into the late night, with some clearing possible after 08-10z. Lowering CIGs also eventually reach the SBY terminal late tonight into Monday morning, again with some improvement after 08-10z Mon morning. Showers continue mainly north of the RIC/SBY terminals this evening, tapering off and moving north of the area after midnight. While a few isolated to widely sct showers could reach the RIC terminal, expect CIGs likely remain VFR for RIC and all other terminals except SBY in BR. A few showers will be possible after sunrise Mon morning, but confidence is areal coverage is quite low and will not include in the TAF right now. Winds remain light overnight (<5 kt) and become SW 10-15 kt by late Mon morning. Outlook: More widespread showers and embedded thunderstorms (potentially with strong winds) are possible later Mon afternoon into Mon evening ahead of and along a passing cold front. SW winds will be 10-15kt with gusts to 20 kt on Monday. Flight restrictions will be possible with any storms. Drying conditions Mon night, with VFR conditions returning late Mon night through midweek. && .MARINE... As of 330 PM EDT Sunday... After seeing improvement in the FG off portions of the ern shore roughly an hr least patchy FG has returned according to beach web cams. So...have added the FG back into the forecast for the ocean waters generally N of Parramore Isl VA for this evening. Previous discussion: The persistent FG over the local waters (esp off Ocean City MD to WAL) appears to have largely dissipated (finally) early this afternoon. Will likely cancel the Dense FG advisory shortly. headlines anticipated the next few days. SSE winds generally AOB 10 kt become SSW overnight...increasing to about 10-15 kt. Waves remaining 1-2 ft (less than a foot on most of the rivers) and seas 2-3 ft. SSW winds avg 10-20 kt Mon ahead of a cold front approaching from the W. That front (w/ ISOLD-SCT tstms) crosses the local waters late Mon evening...w/ winds shifting to WNW post frontal (into Tue morning). Winds briefly become light SSE Tue afternoon ahead of a (weak) reinforcing cold front moving through Tue night which will turn winds to the NNW with a surge of only around 10-15 kt. High pressure settles in by Wed w/ winds becoming SSE by late Wed/Wed night. Seas generally 2-4 ft...waves 1-3 ft Mon-Wed. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...None. NC...None. VA...None. MARINE...None. && $$ SYNOPSIS...RMM NEAR TERM...MAM/RMM SHORT TERM...RMM LONG TERM...RMM AVIATION...MAM/RMM MARINE...ALB/ESS
National Weather Service Albany NY
1050 PM EDT Sun May 15 2022 .SYNOPSIS... A warm and humid air mass will continue over eastern New York and western New England tomorrow. Isolated showers and thunderstorms will diminish overnight. On Monday, a strong cold front will bring strong to severe thunderstorms during the afternoon and evening hours. Cooler and less humid conditions are forecast Tuesday through Thursday behind the cold front. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... .Update as of 1045 pm EDT...A weak low pressure system and its sfc trough continues to move east of eastern NY across New England. Some showers are exiting NW CT. Weak short-wave ridging will build in ahead of the strong cold front and pre-frontal sfc trough overnight. A weakening cluster of showers and thunderstorms continues to move across southern Washington Co. into southern VT. An SPS was issued for the heavy rainfall, but it continues to weaken. PWAT was 1.31" on 00Z KALY sounding. Lots of low-level moisture in place. The winds are going light to calm and the skies should become partly cloudy to mostly clear in some spots allowing patchy to areas of radiational fog to form which could become locally dense and low stratus in the valleys with recent wet ground. Lows will range from the 50s to lower 60s across the region. Previous near term... Sfc trough is moving east of the Hudson River Valley with broken line of showers and thunderstorms over the southeast Catskills, mid Hudson Valley, and NW CT. This should clear over the next hour or two. Numerous SPS statement issued for wind gusts 35-45 mph and the heavy rainfall. Rainfall rates an inch an hour have been reported and we continue to have an FLS for southern Ulster Co. where multiple rounds of showers and thunderstorms have hit that area. MLCAPE values are still around 500 J/kg over the areas south of the Capital Region according to the RAP. We kept the highest PoPs there, and left some chance PoPs to the north near the Lake George Saratoga Region where an outflow boundary allowed new storms to form. The main threat has been locally heavy rainfall with the SPC RAP mesoanalysis indicating PWATS of 1.2-1.4". Slow movement of the thunderstorms has allowed for the localized 1-2+ inch amounts. We diminished the PoPs across the region shortly before midnight with the loss of the diurnal heating and some clearing patchy to areas of fog may form. && .SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/... Enhanced Risk for severe thunderstorms for eastern NY, and Slight Risk for western New England on Monday... Slight Risk for excessive rainfall for parts of the southern Adirondacks on Monday... Monday looks to be mild early with morning fog gradually dissipating, but looks to become convectively active, as a potent shortwave becomes negatively tilted, with a strong cold front approaching during the peak heating hours. Latest HREFs suggest MUCAPES increase to 1000-1500 J/kg by afternoon, with 0-6 km shear increasing to 30-40 KT. The combination of favorable instability and strong upper level dynamics will provide an environment capable of producing strong to severe thunderstorms Monday afternoon and early evening, with the greatest threat being damaging straight-line wind gusts associated with a potential QLCS (quasi-linear convective system) and/or smaller bowing line segments. However, a discrete thunderstorm cell or two may develop just ahead of a main line. Large scale spin shown in the models imply that a mesoscale convective vortex (MCV) may develop which could enhance shear and helicity. The enhanced risk for severe by SPC on Monday looks warranted. CAMs exhibit some uncertainty on exact timing of thunderstorms, with main consensus being between 3-9 PM from west to east across the region. PWATs ahead of the cold front on Monday rise to between 1 and 1.5 inches. Showers and storms will have the potential to produce heavy rain. The entire ALY forecast area is a marginal risk for excessive rainfall with parts of the southern Adirondacks in a slight risk for excessive rainfall. Movement of storms monday looks fairly fast but any areas that get hit by multiple storms would be at most risk. Max temps ahead of any showers/thunderstorms could reach into the upper 70s to lower 80s in valley areas, and lower/mid 70s for higher terrain. Showers/thunderstorms will linger into Monday evening for areas east of the Hudson River. Then, breezy/windy and much cooler and less humid. Some wind gusts of up to 40 mph could occur Monday night in the wake of the cold front. Lows by daybreak Tuesday in the low 40s to low 50s. Tuesday looks to be partly to mostly cloudy with a northwesterly cold advection flow. It will remain breezy, with west/northwest winds gusting up to 30-40 mph at times. Some upslope showers will be possible across the southern Adirondacks and other higher terrain. Some model guidance suggests that a secondary cold front may cross the area later in the day. This front may trigger showers over other areas. Highs mainly in the lower/mid 60s for valleys, and 50s across higher terrain areas, although portions of the mid Hudson Valley could approach 70 where more sunshine is expected, along with downsloping west to northwest winds off the Catskills allowing for additional warming. Lingering showers for northern areas Tuesday evening, otherwise becoming clear to partly cloudy. It will be breezy and cold for May, with lows in the 30s for the southern Adirondacks and higher terrain of southern VT and 40s elsewhere. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... Zonal flow will be in place for Wednesday and Thursday as high pressure glides overhead. We should have mainly dry conditions these days. A weak disturbance looks to pass to the south of our area on Thursday with the majority of guidance keeping any activity to our south (the GFS being the outlier in the latest runs). We will continue to run with a drier forecast. Highs Wednesday will be in the upper 50s to around 60 with mid-60s to mid-70s Thursday. Friday into the weekend will feature a warming trend as upper-level ridging builds into the region. Highs will trend into the 70s and 80s. A warm front looks to lift northward across our area Friday with possibly some showers and a few thunderstorms before a cold front looks to push across Saturday with more widespread showers and thunderstorms. There is some model differences with the timing of this event with most models on a more progressive track (and cold frontal passage Saturday). The GFS is the outlier once again on this being the slowest and almost a day behind. Will run with the NBM for this period which favors more of the non-GFS solutions. Certainly there will be updates to the forecast as the event nears. If the front passes Sunday, cooler and less humid conditions will return. && .AVIATION /03Z MONDAY THROUGH FRIDAY/... One surface trough has moved through eastern NY and western New England tonight. Another prefrontal trough and a cold fornt with a strong wave of low pressure will bring showers and strong thunderstorms to the region tomorrow afternoon into the early evening. Conditions are generally VFR after the showers and thunderstorms that went through KGFL/KALB/KPSF this afternoon. The last of the thunderstorms continues to move through KPOU and IFR vsbys and MVFR cigs will likely linger until 01Z/MON. We did include a TEMPO at KALB for an hour, but the convection continues to diminish. Mid and high clouds will persist early this evening but then clearing is expected with the winds going light to calm and recent wet ground anticipating mist/fog and low stratus to form. Have brought IFR/LIFR conditions with mist/fog at KGFL by 06Z/MON, KALB/KPOU at 09Z/MON, at KPSF about 08Z/MON. The best chance of LIFR/VLIFR cigs will likely be at KGFL/KPSF/KPOU between 08Z-13Z/MON. The mist/fog and lower stratus will burn off between 12Z- 15Z/MON. VFR conditions will return with a few cumulus and sct- bkn high clouds. Isolated showers/thunderstorms may fire initially ahead of the prefrontal disturbance 16Z-19Z/MON. Expect a line of strong to potentially severe thunderstorms between 19Z/MON-00Z/TUE. Later TAF issuances can refine the thunderstorm window. We used PROB30 groups for all the TAF sites with IFR vsbys/MVFR cigs and possibly wind gusts to 35 kts (could be greater) from the west with the frontal passage. The winds will south/southeast at 7 kts or less early tonight and then will become light to calm shortly before midnight. Expect south to southeast winds 5-10 kts in the late morning into early to mid pm before the strong cold front and wave arrives with the showers and thunderstorms. Outlook... Monday Night: High Operational Impact. Breezy. Likely SHRA...TSRA. Tuesday: Low Operational Impact. Breezy. Slight Chance of SHRA. Tuesday Night: Low Operational Impact. Breezy. NO SIG WX. Wednesday: No Operational Impact. NO SIG WX. Wednesday Night: No Operational Impact. NO SIG WX. Thursday: No Operational Impact. NO SIG WX. Thursday Night: Low Operational Impact. NO SIG WX. Friday: Low Operational Impact. Slight Chance of SHRA. && .FIRE WEATHER... A warm and humid air mass will lead to scattered showers and thunderstorms today into this evening. On Monday, a strong cold front will bring strong to severe thunderstorms during the afternoon and evening hours. Cooler and less humid conditions are forecast Tuesday through Thursday behind the cold front. RH values will recover to 90-100 percent tonight with areas of dew formation likely. RH values will fall into the 50-60% range Monday afternoon ahead of showers and thunderstorms. RH recovers to 70-90% again by Tuesday morning. Winds will become light and variable tonight. Winds will then become south to southwest and increase to 10-20 mph by Monday afternoon. Westerly winds of 10 to 20 mph with gusts to 40 mph are expected on Monday night. Winds will be stronger, and variable in direction in and near any thunderstorms. && .HYDROLOGY... Showers and thunderstorms are forecast this afternoon and evening, and again Monday afternoon and evening. Any thunderstorms will be capable of producing heavy downpours. Given relatively dry soil conditions and low streamflows, no flooding is expected on larger rivers and streams in the Albany HSA through Monday. However, localized ponding of water in urban or poor drainage areas is possible from any heavy downpours that occur. For details on specific area rivers and lakes, including observed and forecast river stages and lake elevations, please visit the Advanced Hydrologic Prediction Service /AHPS/ graphs on our website. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. MA...None. VT...None. && $$ SYNOPSIS...SND/Wasula NEAR TERM...SND/Wasula SHORT TERM...SND LONG TERM...Rathbun AVIATION...Wasula FIRE WEATHER...SND HYDROLOGY...Evbuoma/KL
Area Forecast Discussion
National Weather Service Cleveland OH
938 PM EDT Sun May 15 2022 .SYNOPSIS... A strong upper trough will cross the Great Lakes tonight dragging a cold front across the area. A secondary cold front will move through late Monday followed by high pressure Monday night and Tuesday. Low pressure moving through the Midwest Wednesday and Thursday will pull a warm front into the region. && .NEAR TERM /THROUGH MONDAY NIGHT/... The main change to the forecast at this time is that thunder coverage across the region seems to be decreasing and with cooling temperatures, expect this trend to continue outside of stronger convection in southern Indiana and points south. With that, have opted to low thunder chances to just a slight chance after midnight. Also modified sky cover and temperatures a bit to match current trends, but everything seems on track with rain filling in across the area tonight into Monday. Previous Discussion... Well, another summer-like day continues across NE Ohio and NW PA! For the 6th consecutive day, the high temperature at Cleveland Hopkins Airport (KCLE) has surpassed 80 F. Average temps in the low 80s do not occur until mid July, so we have easily been running 10- 15 degrees above normal for the past week. This string of summer weather will, however, come to an end tonight. Signs of the pattern change can already be seen across the Upper Midwest this afternoon where current visible satellite and water vapor loops show a deepening mid/upper trough. A shortwave rounding the base of the trough, which is currently generating an MCS over the Mid Mississippi Valley, will help the trough to deepen and become negatively tilted as it swings through the Great Lakes and Ohio Valley tonight with the left exit of an 80-100 knot H3 jet streak strengthening a surface wave on the trailing cold front. This deepening surface low will pass through the lower Ohio Valley late tonight lifting through Pennsylvania on Monday, with the cold front crossing our region early Monday morning. The stronger upper forcing mentioned above will support a solid line of showers and embedded thunderstorms moving through the region from west to east tonight into Monday morning as the low-level jet and resultant moisture advection increase in response to the left exit region of the aforementioned jet. However, a few factors will significantly limit the potential for severe convection. First, the overnight timing of the frontal passage will limit instability with the latest RAP guidance suggesting both SBCAPE and MLCAPE rapidly falling to a couple hundred joules after sunset. Second, the low- level jet is now progged to be weaker, generally under 30 knots, further limiting the advection of higher CAPE and theta e. This will all result in the line of convection rapidly weakening with eastward extent across our CWA, but pockets of thunder will still make it into NE Ohio and NW PA by late tonight driven by 25-30 knots of effective bulk shear. Expect showers/storms to reach NW Ohio around 00-02Z, north central Ohio 05-08Z, and NE Ohio and NW PA about 08- 11Z, so brought likely to categorical PoPs across the area. Since the storms will be weakening and PWATs are at seasonable levels (1 to 1.2 inches), rainfall amounts will remain in-check with generally a few tenths to 0.50 inches in most areas. With all of this in mind, cannot totally rule out an isolated severe storm with gusty winds and hail, but the main area for that to occur would be in NW Ohio mid to late evening, so a SWODY1 marginal risk remains. Showers will continue over NE Ohio and NW PA Monday morning into early afternoon due to wrap around moisture beneath the mid/upper trough and associated deformation, so kept higher PoPs in those areas through early afternoon. Drier air quickly working into the area Monday afternoon will allow most areas to dry out, but the one fly in the ointment is a secondary cold front progged to drop into the region Monday evening as the mid/upper trough axis swings into the eastern Great Lakes. Skies clearing out nicely Monday afternoon will build a couple hundred joules of SBCAPE beneath the steeper lapse rates associated with the cold pool aloft, and CAMS are suggesting a broken line of showers and thunderstorms crossing Lake Erie during the late afternoon and evening with this front. For this reason, increased PoPs to chance in most of north central and NE Ohio/NW PA Monday afternoon and evening, but most areas will stay dry. Strong 1020 mb surface high pressure building into the western Great Lakes Monday night will support dry and clear conditions. Highs Monday will be much cooler with generally upper 60s to low 70s and a few mid 60s in NW PA. Lows Monday night will drop into the low 50s with mid/upper 40s in NW PA. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... The Great Lakes region will be in a much cooler northwest flow aloft. Our 850 mb temperatures will bottom out to around 2C to 4C by midday Tuesday. At the surface, high pressure will be centered over the Great Lakes by Tuesday afternoon with a brisk northwest to westerly wind 10 to 15 mph. Afternoon temps may not climb out of the upper 50s closer to northwest Pennsylvania. Elsewhere, we expect lower to middle 60s across much of northeast Ohio and upper 60s to around 70 for northwest Ohio by Tuesday afternoon. The center of the high pressure will be moving over the area Tuesday night with light winds and cooler overnight lows. Temperatures in upper 30s and some patchy frost could be possible in the higher terrain of NW PA by early Wednesday morning. Most locations in northern Ohio will be in the middle to upper 40s for late Tuesday night into early Wednesday morning. The overall mid and upper level flow will become zonal from west to east by Wednesday. The next mid level disturbance will be riding through the flow late on Wednesday into Wednesday night. We will have clouds increasing with scattered rain shower chances on Wednesday and Wednesday night. && .LONG TERM /THURSDAY THROUGH SUNDAY/... A warm front starts to advance northward from near the Ohio River towards our area by Thursday. We will continue to have considerable cloudiness and the risk for a few scattered showers on Thursday north of the warm front. Temperatures will start to rise on back into the middle 70s to lower 80s with the approaching warm front and slight riding develops in the upper levels. We will have to watch for possibly another mid level disturbance Thursday evening riding through the westerly and overtop of the developing upper level ridge. This disturbance will be interacting with the warm frontal boundary moving northward across the southern Great Lakes region Thursday night with showers and possible thunderstorms as well. By Friday, A sharp upper level trough will develop across the northern and central CONUS with an upper level ridge near the East Coast. We will a deep southerly flow of warmth and low level moisture in between the high and low pressure systems on Friday with high temperatures easily reaching up into the middle to upper 80s areawide. There could be a few spots that top 90 degrees over northwest Ohio by Friday afternoon. It will be noticeably more humid with dewpoints climbing into the middle and upper 60s. We will be watching the timing and overall placement of a cold front sliding through the Midwest and Great Lakes region on Friday. Right now, the model guidance has the frontal passage through our region late Friday night or early Saturday with showers and thunderstorms. If the timing of the front passage aligns with better thermodynamics, we might have to watch for the potential for organized or stronger convection. A broad upper level trough moves into the Great Lakes region next weekend with much cooler weather with a mix of sun and clouds. && .AVIATION /00Z Monday THROUGH Friday/... Convection has finally made it into Northwest Ohio but is deteriorating as it pushes east into the KTOL airspace. Some TS could make it into KTOL and KFDY over the next several hours but trends are weakening and have just some MVFR conditions and 25 kt winds with any TS that hits the terminals. Further east, the confidence in any TS making it to a terminal is decreasing with how poorly storms are doing in Indiana. Have gone ahead and removed VCTS from the remaining 5 terminals and with showers expected to fill in across the area overnight have pushed some of the low VFR and MVFR mention in the TAFs to highlight what the rain will likely bring across the area. Rain and low ceilings will clear from west to east during the day on Monday. There is some potential for rain redevelopment on late in the afternoon on Monday, but it is too conditional to mention in the TAFs. Outlook...Non-VFR possible in rain late Wednesday through Friday morning. && .MARINE... Light winds and waves are expected on the lake this evening and tonight. We will see a weak front move across the lake on Monday followed by another front late Monday night. During the time period of late Monday into Tuesday, we could be closer to Small Craft Advisory conditions with west to northwest winds increasing to 15 to 20 knots behind the cold fronts. High pressure moves across the lake Tuesday night with light winds and waves. A series of weak low pressure systems will move across the lake starting Wednesday through Thursday with winds shifting around and variable around 10 to 15 knots. A modest southerly flow of winds develop over the lake starting Thursday night through Friday evening ahead of a cold front. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...None. PA...None. MARINE...None. && $$ SYNOPSIS...Garuckas NEAR TERM...Garuckas/Sefcovic SHORT TERM...Griffin LONG TERM...Griffin AVIATION...Sefcovic MARINE...Griffin
Area Forecast Discussion
National Weather Service Indianapolis IN
1122 PM EDT Sun May 15 2022 ...Updated Aviation Discussion... .Forecast Update... Issued at 950 PM EDT Sun May 15 2022 Convectively reinforced cold front is on its way out of the area at this time, with an area of showers and isolated thunderstorms still to work its way through central Indiana late this evening into the early overnight associated with the main upper wave. Have made adjustments to the pops as a result, ending them a bit earlier per latest CAM guidance, and reduced thunder coverage to isolated overnight per ongoing trends. Remainder of forecast looks to be in good shape. && .Short Term...(This evening through Monday night) Issued at 218 PM EDT Sun May 15 2022 - Strong to Severe Storms possible this evening and overnight Surface analysis early this afternoon shows a weak trough of low pressure in place from MI...across IL to SW MO. Convection was present over MO with this feature. GOES16 shows high cloud/convective debris over IL advancing east toward Indiana. Winds were light and mainly westerly across the forecast as high pressure was found over the southeastern states. Dew Points have fallen to the mid 50s as some dry air aloft has been mixing down. Tonight... Convective temperatures are expected to be reached this afternoon...leading to CU developing and perhaps and isolated shra/tsra as CAPE values linger around 1000 J/KG. Thus will continue with increasing pops late this afternoon and early evening. A short wave aloft over the plains is depicted by the models is responsible for the previously mentioned weak surface trough and associated convection. This feature is expected to push toward Indiana tonight and cross the state overnight. With favorable moisture in place...showers and thunderstorm development is expected late this evening as the wave passes. Forecast soundings show a saturated column by 03Z...and HRRR depicts showers and storms pushing through Indiana during the late evening. With a loss of instability will be gone...but an isolated evening severe thunderstorm cannot be ruled out. Will use high pops this evening as these forcing features pass. Subsidence and drying is shown in the column by 09Z...thus will trend toward dry forecast late overnight after the wave is expected to pass to the east. Regarding eclipse viewing...clouds from convection and the passing wave will make it difficult to nearly impossible to view the lunar eclipse tonight. Perhaps Indiana will have better luck on November 8 2022. Monday and Monday Night... Models continue to depict a quick NW flow aloft across Indiana on Monday. A strong ridge aloft will be found across the Rockies...allowing for NW flow along with subsidence across the plains spilling into the Ohio Valley. Forecast soundings on Monday show a dry column but convective temps may be reached in the afternoon with some sct flat topped CU due to an inversion aloft. Thus will trend toward a mostly sunny day and mostly clear night. && .Long Term...(Tuesday through Sunday) Issued at 218 PM EDT Sun May 15 2022 The synoptic pattern on Tuesday will feature a digging but progressive trough across Quebec into the northeast states, and an eastward progressing but deamplifying upper level ridge across the west and central part of the country. Mean northwesterly flow over Indiana will result, but trend zonal. This will hold temperatures near or just below mid-May climatology through Wednesday. Within the increasingly zonal/quasi-zonal flow pattern, a few midlevel perturbations will move through the area. Perturbation #1 arrives late Tuesday night, inducing modest warm/moist advection and some light to moderate precipitation especially just to our north. The greater QPF signal in the models appears to be tied to upscale growth and MCS evolution from Plains convection that reaches our area early Wednesday. Spatiotemporal details with these type of events are notoriously difficult at this time range, given several smaller scale difficult to resolve influencing factors. One possible scenario may be a tendency for the MCS to build southward on preferential flank of cold pool where it interacts with modest low level jet. In this scenario, precipitation would mostly move southwest of our area. Ensemble members seem evenly split with a more northward or southward track. Perturbation #2 will arrive late Wednesday and would be more productive at convective generation if antecedent convection hasn`t overturned the environment. In this conditional scenario, instability and shear would be sufficient for organized strong/severe thunderstorms. Perturbation #3 should arrive late Thursday, although at this time range GEFS/EPS ensemble members are more chaotic so there are varying QPF footprints and magnitude. Instability and shear will again be sufficient for strong to severe thunderstorms, if they occur in our area. A deeper closed low is shown in most medium range models over the northern Plains or northern Rockies, though individual ensembles and deterministic are quite out of phase by this time range. Most show an intense enough mid-latitude system with established warm conveyor belt, anomalous moisture, and forcing for significant convective development along the trailing cold front. This could occur in our area anytime from late Friday afternoon to Saturday afternoon, given the current spread in the models. In either case, we will see around 10 degree positive 2m temperature anomalies preceding the system, and only modest cold advection in its wake next weekend given consensus on a northeastward track, despite timing and amplitude differences. If models trend more closed and northwestward with the track, impactful/widespread convection would be less likely at this latitude and this far east. We will refine as model spread lessens over the next few days. && .Aviation...(06Z TAF Issuance) Issued at 1122 PM EDT Sun May 15 2022 IMPACTS: * Scattered showers and a few thunderstorms early in the period. * Potential for some fog or low stratus depending on degree of clearing. * A few wind gusts overnight, with more developing Monday afternoon. DISCUSSION: An upper level disturbance will work through the area tonight, producing showers and a few thunderstorms. Depending on the degree of clearing with high pressure working in behind this activity, some fog or low stratus may develop late tonight into daybreak Monday. Uncertainty remains a bit high here. Will take the outlying sites down to MVFR and include a BCFG mention. A few wind gusts to around 18-20KT will be possible at times at HUF/IND due to what appears to be wake effects of the earlier convection. Gusty winds will redevelop tomorrow afternoon with gusts around 20KT at times out of the northwest. && .IND WATCHES/WARNINGS/ADVISORIES...None. && $$ Update...Nield Short Term...Puma Long Term...BRB Aviation...Nield
Area Forecast Discussion
National Weather Service New Orleans LA
701 PM CDT Sun May 15 2022 .AVIATION...00Z TAF Package...Most terminals are and will likely remain in VFR but if a storm moves over you can expected all forms of impact; lowered vsbys, low cigs, gusty winds, and perhpas even hail. Outside of storms the terminals will remain fine. Convection will be isolated this evening but watching closely to see if the storms well to our north make it down here around 6/7z. /CAB/ && .PREV DISCUSSION... /issued 333 PM CDT Sun May 15 2022/ SHORT TERM (Tonight through Tuesday)... Troughiness extending from the NE Conus hangs into the NE Gulf with an weak upper level low with ridging from the SW Conus trying to nudge into the region from the west. Environment unstable enough for isolated to scattered showers and thunderstorms to develop through the overnight hours...likely with less than 30 percent coverage of the area and mainly east of I-55 where it will be a bit more away from the influence of the nudging ridge. MCS developed over the plains today and will drop south towards LA...though may stay west of the area according to HRRR runs and weaken as it does. Will go with that...but this must be watched in case it ends up slightly further west. Don`t think it is any severe threat for the region..but could bring rainfall that is currently not forecasted early tomorrow morning if that should occur. Ridhing nudges further east into the area and the upper level low moves into FL by afternoon Monday...maybe an isolated T-storm in the late afternoon and evening with peak heating. Ridge moves into the area by early Tuesday. Above average temps will continue through the period...with normal highs around 85 this part of May. -ABS LONG TERM (Wednesday through Sunday)... Ridging looks to be set in place Wednesday and Thursday above average temps and dry mostly sunny days for the region. Friday a large syatem moves from the Rockies into the far Northern Plains and flattens the ridging across the region...surface high siting off FL will start to push deeper moisture back into the area as a cold front tries to push into LA but stalls by Saturday allowing for better chances of showers and thunderstorms as we start the weekend. The front fizzles north of the area...but could be enough for continued showers and thunderstorms Sunday. Above normal temps are likely through the period...though a bit cooler over the weekend is possible due to the clouds and rainfall. -ABS PREV DISCUSSION... /issued 1225 PM CDT Sun May 15 2022/ AVIATION (18z TAFS)... VFR conditions across the region with light winds. Seabreeze/lake breeze will affect winds through the afternoon as it pushes inland across the coastal sites. VCTS has been added especially along the MS Gulf Coast as the seabreeze boundary may help focus TS development later today. Will continue to watch for development and if coverage looks more widespread than anticpated may need to consider addition of VCTS or TSRA at MSY/BTR/NEW. Soon after sunset chances for TS should be low, and VFR will dominate with light west or NW winds. Don`t think fog will be much of an issue with some CI blow off from storms up stream...will have to watch that MCS complex as it may reach here early morning/daybreak and TAFs currently do not show such a scenario. -ABS MARINE... A few scattered storms this afternoon but other than that just a potential for isolated, mainly nocturnal, thunderstorms, no major impacts are expected over marine areas during the forecast period. 35/ABS && .PRELIMINARY POINT TEMPS/POPS... MCB 67 91 67 92 / 0 20 20 10 BTR 68 92 69 92 / 0 20 20 10 ASD 68 93 68 93 / 10 20 20 10 MSY 72 91 73 91 / 10 10 10 10 GPT 70 91 70 91 / 10 30 20 10 PQL 67 91 67 92 / 10 30 20 10 && .LIX WATCHES/WARNINGS/ADVISORIES... LA...None. GM...None. MS...None. GM...None. && $$
Area Forecast Discussion
National Weather Service Louisville KY
857 PM EDT Sun May 15 2022 .Forecast Update... Issued at 850 PM EDT Sun May 15 2022 Cold front is now draped roughly along the I-70 corridor. Most of our upstream convection has been lost to a split, as part of the line has taken the plunge into Tennessee while the line with any remaining interest is along the cold front, with a few strong cells between Vincennes and Jasper. These storms are moving into an increasingly hostile environment as they try to push east, but we could see thunderstorms brushing our northernmost counties over the next couple hrs. Small hail and sub-severe gusts are not out of the question, but the already low-end SVR threat continues to diminish. Hi-res models still want to light up the cold front as it pushes SE into central Kentucky after midnight. Showers and storms are a decent bet, but by that time any instability is elevated and wind profiles are unimpressive, so not expecting any real organization. The overall forecast isn`t changing much, but the messaging will be toned down in the next hr or two. Issued at 705 PM EDT Sun May 15 2022 A couple of lines of strong convection off to our west, one arcing from west-central Indiana into southern Illinois, and the other from far western Kentucky into eastern Arkansas. Neither is organizing very well, and the northern line is north of I-64 and moving ENE, while storm motion on the southern line is to the ESE. Our air mass remains quite warm and moist, with modest instability, but it`s also a less favorable environment than what the storms are working with right now, and it won`t improve as the sun goes down. The developing split between those two lines also does not favor severe weather chances in our County Warning Area, but our risk remains non-zero. Some of the hi-res models do still favor redevelopment toward midnight as the cold front pushes into southern Indiana and central Kentucky, but at that point most of the instability is likely to be elevated and would mainly support some sub-severe gusts and marginal hailers. Bottom line, there is a low-end SVR threat west of I-65 through this evening, and that could be further skewed toward the Hoosier National Forest, and toward the KY/TN border. && .Short Term...(This evening through Monday) Issued at 252 PM EDT Sun May 15 2022 ...Chance of Strong to Severe Storms This Evening... A 5H speed max will be diving into a shortwave trough as it approaches from the west this evening, weakening overnight but bringing a chance of showers/storms. Showers and thunderstorms have been ongoing ahead of this feature all day over portions of Kansas and Missouri, with new development occurring south of the original convection into Arkansas. Though 850mb winds will increase slightly over the Ohio and Tennessee Valleys tonight, the main low level jetting and best theta-e ridging will remain well to our southwest over the Red River Valley feeding those storms moving through the Ozarks. Another potential trigger for storms will be a possible MCV moving from mid-Missouri into Illinois. Showers and storms ahead of this feature so far today over eastern Missouri have been struggling, but some intensification will be possible as they proceed into a corridor of greater instability extending from southeast Missouri into central Illinois. As evening falls, instability will decrease. So, for severe storm chances in southern Indiana and central Kentucky, it may end up being a race to see if the storms to our west can make it this far east before the atmosphere begins to stabilize (relatively speaking...some instability will remain to support a degree of thunder into the overnight hours). It continues to look like the best chance of severe weather will be early-mid evening west of Interstate 65. It`s worth noting, though, that if an organized cold pool can get established behind the Missouri/Illinois storms and the MCV helps to push things along, storms could arrive earlier with a greater threat of severe, and possibly a farther east severe threat as well. Will have to monitor upstream radars to keep an eye on how the MO/IL convection evolves. There`s very little environmental wind available, but if a bowing line of storms can get going, as is suggested by the RAP and 12km NAM, then there would be a more enhanced wind threat. Wet bulb zero heights and deep layer shear support the idea of hail, but decreasing instability and the HREF showing weakening updraft strength as we move past sunset suggest that it may be difficult to get severe sized hail. As we go through the late night/pre-dawn hours other potential triggers for showers and storms will include a cold front moving through the region and any leftover outflow boundaries from evening storms. This late night convection may be slightly elevated, further reducing severe chances. Overall confidence in how tonight plays out is slightly lower than normal, given the many factors involved. The biggest question marks are when exactly storms will arrive or develop, and how much support will be available for them when they do. Tomorrow any lingering clouds and showers in the morning will quickly leave the region as the cold front way to sunshine in the afternoon and a light west breeze. Highs will generally be in the mid-upper 70s, though urban cores may touch 80. .Long Term...(Monday night through Sunday) Issued at 255 PM EDT Sun May 15 2022 Monday Night - Tuesday... At the start of the extended period, expect to find an upper-level trough over the eastern CONUS with ridging over the central CONUS, placing the OH Valley in NWly flow aloft. As the upper trough lifts northeast along the East Coast, expect the upper pattern to flatten out with quasi-zonal flow overhead by midweek. At the surface, high pressure will slowly drift across the area before exiting to the east Wednesday. Overall expect dry weather and clear skies Monday Night through Tuesday with seasonable low temperatures in the 50s and slightly above normal high temperatures in the upper 70s to lower 80s. Wednesday - Thursday... By Wednesday, southerly flow will begin to take hold in the lower levels with a 30-40 kt SWly LLJ advecting warm and moist air into the region and dewpoints climbing into the lower 60s. A stalled out frontal boundary is expected to be in our vicinity, draped across the OH Valley. As a series of compact shortwaves ripple through the zonal flow aloft overtop this surface boundary, expect increasing chances of showers and storms across the area Wednesday and Thursday. In general, the highest precip chances are expected to be over southern IN and northern KY closer to the boundary. Surface temps will rise noticeably into Thursday with highs running about 10 degrees above climatological normals in the mid to upper 80s. Friday - The Weekend.. The upper level pattern will then become increasingly amplified as we move into the end of the week and the weekend as shortwave energy moving around a closed low digs through the northern and central Plains and progresses eastward, sending a cold front through the region to end the period. Mostly dry weather is expected for Friday as heights briefly rise ahead of the approaching system, with high temperatures pushing even warmer into the upper 80s to around 90 degrees. Chances for showers and storms then increase Saturday ahead of and along the cold front. Temperatures should moderate back towards normal in the wake of the front with mostly dry weather then for Sunday as high pressure builds in once again. && .Aviation...(00Z TAF Issuance) Issued at 730 PM EDT Sun May 15 2022 Deteriorating flight cats are expected through this TAF period as a cold front brings showers and storms to the region. Confidence going into tonight remains low given the overall coverage of storms to be rather uncertain. Storms currently to our west will be weakening this evening, but we may see storms redevelop along the cold front later tonight. While severe threat appears low for late tonight, any stronger storm we get on top of an airfield will result in a brief period of gusty winds, reduced vis, and low ceilings. After showers and storms chances diminish tonight, low ceilings associated with the passing cold front will be primarily along and east of I-65, resulting in MVFR and possibly even a short time of below fuel alternate (below 2000 ft), especially at LEX and BWG. Conditions will improve after sunrise tomorrow, with VFR making a return to all terminals by the late morning hours. && .LMK WATCHES/WARNINGS/ADVISORIES... IN...None. KY...None. && $$ Update...RAS Short Term...13 Long Term...JML Aviation...CJP
Area Forecast Discussion
National Weather Service Melbourne FL
1040 PM EDT Sun May 15 2022 .UPDATE... ...High Astronomical Tides Expected to Cause Minor Inundation Near Inlets, Including the Intracoastal Waterway... Scattered to numerous showers and lightning storms formed along the east coast sea breeze this afternoon and evening as it pushed inland. The west coast and east coast sea breeze collision occurred near Lake and Sumter counties late this afternoon and early evening, with additional storms forming along the collision and then pushing back eastward into east central FL with the west coast sea breeze. Scattered showers and storms are ongoing along the interior. Storm motion is east to northeast around 15 mph. Main storm impacts with any storms this evening will be frequent cloud to ground lightning, gusty winds up to 50 mph, hail, and heavy rainfall. Temperatures this afternoon were warm, but about normal for this time of year, with temperatures in the upper 80s to low 90s. Shower and storm activity is expected to linger this evening, with cell motion moving eastward, towards the coast through the late evening hours, with storms pushing offshore after midnight. Highest PoPs 30-40 percent will be along a line extending from Melbourne to Lake Kissimmee northward before midnight, when activity transitions to the Atlantic waters. Partly to mostly cloudy skies expected through late tonight, which could potentially limit viewing opportunities for tonight`s lunar eclipse, especially north of Melbourne. Light and variable winds tonight and into the morning hours as the pressure gradient remains weak over the local area. HRRR and LAMP guidance is coming into better agreement about fog potential for the early morning hours from Orlando to Titusville northward and into northern Lake county. Current temperatures are in the low to mid 70s with dew points in the low 70s. Overnight lows will be right around average for this time of year, with lows in the mid to upper 60s. Forecast remains mostly on track with only minor changes to the precip chances through tomorrow, as well as including the potential for patchy ground fog from Titusville to Orlando northward and into northern Lake county starting at 10Z and going until 13Z. && .AVIATION... Brief MVFR CIGs/VIS this evening from convection. Storms ongoing across interior, with cell motion toward the east. HRRR and LAMP guidance is coming into better agreement about fog late tonight and into early morning. Thus, have included TEMPO groups for 3SM BR BKN009 for LEE, MCO, SFB, DAB. Light and variable winds through tonight and into the morning hours before winds become southwest around 5-10 KT by late morning/early afternoon. Scattered showers and lightning storms in the afternoon, mainly across the far interior and across the Treasure Coast. Included VCTS for MCO starting 21Z. General VFR conditions expected through the TAF period outside of convection and possible fog/mist. && .MARINE... Current buoy 41009 observations show seas are 4 ft with SE winds around 12 KT. Scattered showers and storms are expected over the Atlantic waters tonight as activity over land moves offshore into the local waters. General cell movement is towards the east. Southerly winds around 10 KT overnight and into the morning before becoming 10-15 KT in the afternoon. The east coast sea breeze is expected to form in the afternoon, but is expected to remain pinned to the coast as southwest winds dominate overnight land. Isolated showers and lightning storms will be possible tomorrow afternoon, mainly in the nearshore waters. Seas will be 2-4ft. ...(Previous Discussion).... Water levels will run a little over 2 feet above normal near high tide starting this evening and will continue through Tuesday evening. This may cause minor inundation of low lying properties near inlets, nearby areas along the Intracoastal Waterway, and adjacent canals. Some docks may briefly get overtopped by water. Fortunately, this did not coincide with the coastal low last week! Here are the evening high tide cycles for the next 2 days: Monday May 16th......901PM-934PM *Peak High Tides Tuesday May 17th.....953PM-1025PM && .HYDROLOGY... (Previous Discussion) The Saint Johns River at Astor will remain around Action Stage of 2.0 feet through early this week, and then is forecast to gradually decrease below Action Stage from mid- late week. && .PRELIMINARY POINT TEMPS/POPS... DAB 68 89 68 91 / 20 20 0 20 MCO 69 93 69 95 / 40 30 0 20 MLB 68 89 69 89 / 20 20 0 20 VRB 67 89 66 89 / 20 20 0 10 LEE 69 91 69 92 / 40 20 0 20 SFB 68 92 69 94 / 40 30 0 20 ORL 71 93 71 95 / 40 30 0 20 FPR 67 89 66 89 / 20 20 10 20 && .MLB WATCHES/WARNINGS/ADVISORIES... FL...Coastal Flood Advisory until midnight EDT Tuesday night for Coastal Indian River-Coastal Martin-Coastal Saint Lucie- Coastal Volusia-Mainland Northern Brevard-Mainland Southern Brevard-Northern Brevard Barrier Islands-Southern Brevard Barrier Islands. AM...None. && $$ Watson/Pendergrast
National Weather Service Morristown TN
1025 PM EDT Sun May 15 2022 .UPDATE... EVENING UPDATE. && .DISCUSSION... Not much change is needed to the forecast this evening. The convection to our west has dissipated quickly, but we should see increasing activity over KY over the next few hours as the upper jet streak noses into the OH Valley on the back side of a negatively-tilted trough, which will increase upper divergence and vort advection over our eastern KY and our northern sections. Will continue with likely PoPs for SW VA and the TN/VA border counties from 12-16Z. There is soem tall, skinny CAPE in the forecast soundings at TRI, and some speed shear, which may lead to a marginal threat of damaging winds and hail. DGS && .AVIATION... 00Z TAF DISCUSSION. VFR conditions will prevail through tonight, with gradually increasing high clouds as storms currently over West TN make their way east. The best chance of TSRA will be in NE TN/SW VA, so TRI will have a TEMPO for MVFR conditions from 11-15Z. Same for TYS, although confidence is lower there. With lower chances at CHA, a PROB30 for MVFR conditions and SHRA will be included there. A cold front passing through the area around midday will shift winds to W and increase to 10-15 kt in the afternoon. DGS && .PREV DISCUSSION... /ISSUED 327 PM EDT Sun May 15 2022/ SHORT TERM...(Tonight through Monday)... Key Messages: 1. Isolated to scattered showers and storms continue until this evening across the Appalachians. 2. A broken line of showers and storms move across our area tomorrow morning just ahead of a cold front. A few strong storms are possible, no severe weather expected. Discussion: Isolated to scattered showers and storms continue until this evening across the Appalachians and will then dissipate with loss of heating. Quiet conditions are expected overnight. Then, a broken line of showers and storms will move across the area tomorrow morning. This activity occurs just ahead of a cold front that is associated with a shortwave moving though the Ohio River Valley. Showers and storms will arrive between 5 to 7 AM EDT along the plateau and exit northeast TN between 11 AM 1 PM EDT. CAMs really vary on the coverage of the activity. HRRR is the least excited and shows very little activity while the NAM nest is the most aggressive which shows a broken line of showers and storms moving across the entire CWA. Even if the NAM nest is correct though, storms aren`t expected to be severe due to limited instability. NAM soundings show roughly 500 J/kg MLCAPE during this time but there is however moderate shear in place. Because of this, a few strong storms are possible but no severe weather is expected. For POP coverage, going with a blend of the HRRR and NAM Nest due to little confidence on which model will be right. Low confidence is attributed to how poorly the CAMs have recently performed. Redevelopment of isolated showers and possible storms are possible along the cold around by 1 PM EDT across the east TN valley. These showers and storms should exit to our east by 4 PM to 5 PM EDT. A few light showers may linger across the east TN mountains through early evening. SR LONG TERM...(Monday Night through Sunday)... Key Messages: 1. Return of scattered showers and storms for mainly Wednesday afternoon and Thursday, especially northern sections of Tennessee and southwest Virginia. 2. Building heat is expected for the latter half of the week into next weekend. Heat Safety precautions, especially child heat safety will be the main message. 3. Very warm and muggy for next weekend. Scattered storms anticipated. Some strong to severe storms possible. Discussion: For Monday night through Tuesday night, surface ridging and drier air advects into the southern Appalachians with the frontal boundary pulled well south of the Tennessee valley. Dry and seasonal conditions anticipated. For Wednesday and Thursday, the frontal boundary to our south will lift north as a warm front. A series of short-waves with associated jet will move across the Ohio valley and northern sections of the Tennessee valley. Areas of showers and thunderstorms will move the region, mainly along and north of interstate 40. Model soundings show increasing instability with MLCAPES of 1500-2000. Much more supportive mid-level lapse rates of 7-7.5 degree C with some mid- level dry air. There is a good deal uncertainty of how much of the convection will stay north of the area but latest GEFS and ECMWF ensemble show fairly high probabilities of rainfall over the northern third of Tennessee and southwest Virginia. Will need to watch for the potential of severe storms for late Wednesday and maybe again over southwest Virginia for Thursday. Main concern will be large hail and damaging winds. For Friday, upper and surface ridging builds across the southeast United States with increasing heights and 850mb temperatures. First heat wave possible. GEFS mean temperature anomalies show fairly high values over the southern Appalachians. PWs are quite low (below 1 inch) for Friday. For Saturday and Sunday, upper ridge is flattened some as a wave moves across the Ohio/Tennessee valleys. Models show a frontal boundary approaching the area mainly for Sunday. Good deal of disagreement between the deterministic models on how fast frontal boundary moves south across the area. The ECMWF is the slowest. Overall, increasing chances of showers and storms. Continued very warm temperatures and muggy. Depending on evolution of convection so of these storms could be strong to severe. DH && .PRELIMINARY POINT TEMPS/POPS... Chattanooga Airport, TN 64 83 59 85 60 / 10 20 0 0 0 Knoxville McGhee Tyson Airport, TN 63 79 56 82 57 / 30 40 0 0 0 Oak Ridge, TN 62 79 55 83 57 / 40 50 0 0 0 Tri Cities Airport, TN 59 76 51 79 51 / 40 70 0 0 0 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$
Area Forecast Discussion
National Weather Service Nashville TN
710 PM CDT Sun May 15 2022 .UPDATE... FOR EVENING DISCUSSION. && .DISCUSSION... A few isolated storms have formed this evening in Middle TN, but for the most part we`re focused on the activity moving through west Tennessee. Storms maintained their strength as they crossed the Mississippi River, but seem to be exhibiting a weakening trend over the last hour, with the strongest storms along the Tennessee and Mississippi state line. The expectation is for storm strength to continue to dwindle as they move east of the Tennessee River. MLCAPE, which is highest west of I-65, should rapidly decline between now and 9PM. Another quick wave of storms is possible across our northern and northeastern counties later tonight and early Monday morning. Some elevated instability will likely still exist, even at that late hour, which could allow for some strong storms with that second wave. Mid level lapse rates will be around 6 to 7 degrees as well, so some small hail isn`t out of the question. Tweaked hourly pops with this update, but most of the forecast remains the same. && .AVIATION... 00Z TAF DISCUSSION. BNA/MQY/CKV/CSV...A line of strong to severe storms is currently marching across West Tennessee, but all indications are that this line will weaken considerably once it enters Middle Tennessee. The HRRR shows the strongest echoes remaining south of I-40, which means that our terminals ought to be spared any evening convection. A cold front will sweep through Middle Tennessee toward morning, with a few hours of MVFR ceilings and some vicinity showers to show for it. && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ DISCUSSION......11 AVIATION........08
Area Forecast Discussion
National Weather Service Pendleton OR
824 PM PDT Sun May 15 2022 .EVENING UPDATE... The upper-level shortwave trough responsible for initiating the earlier convection has moved out of the region and as a result showers and T-storms have come to an end across the CWA this evening excluding far south-southeast Union and Wallowa county. Expect drier and much calmer conditions to prevail the rest of the overnight hours although upslope showers remain possible near the crests of the Cascades. Some of the high resolution guidance like the HREF depicts a chance for a lingering pop-up shower or two overnight near the crests of the Blues and eastern Wallowa County as well, but QPF values appear low(a few hundredths of an inch) especially in comparison to the earlier activity. Guidance continues to keep any shower activity limited to the crests of the Cascades and eastern Wallowa county on Monday under zonal flow aloft then dry all areas on Tuesday. Its worth noting winds may be breezy Monday afternoon into the evening for spots like the Kittitas Valley and eastern Columbia Gorge; gusts up to 30-38mph. Our next chance for active conditions and precipitation arrives with a fast moving trough of low pressure during the day Wednesday. 99 && PREV DISCUSSION... /issued 138 PM PDT Sun May 15 2022/ SHORT TERM...Sunday through Tuesday...Shortwave trough lifting up through the Olympic Peninsula will drive our weather concerns today, as this system will bring a round of convective showers across the Cascades, as well as the potential for strong to severe thunderstorms across the eastern half of the forecast area. SPC continues to show a slight risk of severe storms for an area stretching from the southern Blues of Oregon up through extreme SE Washington. Not much change in forecast messaging over the last couple days, as CAMs continue to show some isolated storms popping up around 2-3pm this afternoon, before larger storms flare up around 4-5pm around the northern Blues, spreading ENE toward Wallowa County. Hi-res guidance showing MUCAPEs in excess of 1000 J/kg, with amounts closer to 2000 J/kg in the latest HRRR run and 18z NAM. With dewpoints in the upper 40s/low 50s in the area, combined with PWs around 1.00- 1.25 inches and mid-level lapse rates around 6.5-7 C/km, the instability and moisture is certainly there, along with synoptic- level SW flow assisting in lift, to trigger storms across the eastern mountains. Shear profile looks to be just enough to at least mention the threat of isolated tornadoes, with sfc-1km SRHs around 100 m2/s2 and Effective Bulk Wind Difference around 40-50 kts, but will primarily be concerned with the potential for large hail given instability and lift. Damaging winds also a concern for any severe thunderstorm cell. Was concerned about the role of cloud cover this morning in the ability to build instability before the onset of convection, but have seen some robust warming already, with temps climbing well into the 70s, with almost 80 here at the office. Bulk of threat looks to occur between 2pm to 8pm, before CAMs carry any remaining storms east and north out of our area and towards the Idaho Panhandle. Monday and Tuesday look quiet as more zonal flow aloft prevails, with near normal high temps around upper 60s/low 70s for our lower elevation zones and valleys. Could see some locally breezy conditions in the Gorge and Kittitas Valley Monday afternoon in the wake of Sunday`s passing system, otherwise only marginal chance of upslope showers exists for our high mountain zones through Tuesday night. Evans/74 LONG TERM...Wednesday into the Weekend...Expectations for the medium to long range period of changed little over the last 24 hours as model ensembles continue to point to another storm system affecting the region mid to late week. Ensemble solutions have come into better alignment with this feature, with most members pointing to a more fast moving open wave structure dropping southeastward and closing off over the Northern/Central Rockies into the weekend. For Wednesday and Thursday, ensemble solutions have come into better agreement with a broad fast moving trough dropping southeastward into the Inland Northwest. This is clearly evident when assessing a cluster of ensemble output, whereby most solutions have converged on something similar. Initially, this will bring rain and mountain snow chances to the Washington Cascades, with precipitation spreading south and east late Wednesday into Thursday. Given a more west or northwest orientation of the flow, solutions have trended back a bit on low elevation precipitation somewhat, and it may wind up being a bit drier in these areas than previously forecast. However, there does appear to be high confidence in rather wet conditions for the higher terrain, especially the Washington Cascades, where ECMWF Extreme Forecast Index (EFI) values of 0.7 to 0.85 are noted both for rain and high elevation snow. Some precipitation will also likely fall over the mountains of northeast Oregon and southeast Washington, but the signal is a bit weaker than it was this time yesterday. In addition to precipitation, a fast moving front looks to bring breezy to windy conditions. EFI values for wind speeds and gusts are on the order of 0.8 to 0.9 for the Wednesday afternoon and Wednesday night period, suggesting an unusually windy period. Typically, we may be concerned with blowing dust with such winds, and there certainly may be some, but recent rains will likely have a dampening effect on potential for significant blowing dust. As snow levels fall, expect some snow accumulations above 4000 feet, with the greater totals generally confined to the Cascades owing to the more west/northwest flow in these areas. Some light accumulations could occur across the Blues and Wallowas as well. From late Thursday night into Friday, activity is expected to shift eastward rather quickly, with cooler and dry conditions overspreading the region. Depending on cloud cover and winds, rather chilly temperatures may return on Friday morning with frost and/or a light freeze for some low elevations. This appears most probable in the higher elevation valleys and across central Oregon. While this may not typically be much to highlight, considering how late in the growing season we are getting, it may be worth keeping an eye on to protect any sensitive plants from damage. As we head into the weekend, ensembles are in general agreement in building an upper ridge over the eastern Pacific Ocean. There remain some differences, however, on exact placement of the ridge and its intensity. However, there does appear to be good confidence in a drier weekend at least. Though, at this time, ensembles are pointing to below normal temperatures given the potential for continue northwesterly flow. Austin/79 && .AVIATION... 00Z TAFS... Latest radar shoed an area of SHRA and a few embedded strong TSRA near PDT. These showers and TSRA are moving northeast and will likely impact ALW in the next couple of hours. Gusts to 30 kts are possible at PDT and ALW as these SHRA and TSRA move through. Some local MVFR is possible, but it will be short-lived. All other sites are expected to remain dry. Once this activity moves through, expect dry and calm conditions fro the remainder of the TAF period, though there could be some gusty winds Monday afternoon in the 15 to 20 kt range in most areas and up to 25 kts at DLS.77 && .PRELIMINARY POINT TEMPS/POPS... PDT 51 67 41 68 / 40 10 0 0 ALW 54 70 44 70 / 50 10 0 0 PSC 54 74 46 73 / 10 0 0 0 YKM 44 70 38 71 / 10 0 0 0 HRI 52 72 44 72 / 20 0 0 0 ELN 45 64 39 67 / 10 10 0 0 RDM 41 66 34 71 / 0 0 0 0 LGD 48 63 37 67 / 60 10 0 0 GCD 47 67 39 71 / 10 0 0 0 DLS 53 68 44 71 / 10 10 0 0 && .PDT WATCHES/WARNINGS/ADVISORIES... OR...None. WA...None. && $$ UPDATE...99 SHORT TERM...74 LONG TERM....79 AVIATION...77