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

Area Forecast Discussion
National Weather Service Burlington VT
1034 PM EDT Sat May 21 2022 .SYNOPSIS... Warm and muggy conditions will exist tonight and into Sunday before a cold front sweeps through Sunday afternoon accompanied by a line of showers and thunderstorms, some of which have the potential to be strong to severe. Cooler and less humid conditions are expected for Monday and Tuesday, followed by daily chances for showers through the end of the work week. && .NEAR TERM /THROUGH SUNDAY NIGHT/... As of 1034 PM EDT Saturday...Warming cloud tops associated with convection across western New York will continue to lift northeast tonight and we should see some showers and isolated storms overnight, especially across northern New York and northwest Vermont. Made some minor adjustments to the forecast to account for this scenario. Rest of forecast remains unchanged. Previous Discussion... It`s taken all day but the cap has finally broken across the entire region with RAP analyzed 3000-4000 J/kg of CAPE. While we`re not lacking in instability, we are lacking in any deep layer shear and a clear forcing mechanism. Upstream though, storms have begun to fire along a lake breeze off Lake Ontario and with the mid/upper level flow southwesterly we will see some of this activity shift into the forecast area this afternoon and evening before diminishing after sunset. With impressive progged DCAPE values up to 1400 J/kg the main convective threat will be damaging winds especially given reports from a convective complex moving through the Ottawa Valley which produced gusts up to 70 mph. Can`t rule out some large hail either or some rotating supercells as storm relative helicity of 100- 150 m2/s2 should exist. After sunset activity should quickly quiet down with a generally quiet but muggy and warm night on tap. Residual showers from upstream convection may shift briefly across portions of the St. Lawrence Valley around midnight with some light shower, but elsewhere should trend mainly dry with lows only in the mid 60s to around 70. We`ll be looking for a repeat of severe potential again tomorrow as a potent cold front will work through the region. Given the overnight moisture in place it won`t take much to generate SBCAPEs upwards of 2000 J/kg ahead of the boundary mainly from the Adirondacks eastward, and with better deep layer shear in the vicinity we expect more widespread showers and thunderstorms to develop from noon onward. Once again, the primary threat would be damaging winds and large hail, and while brief heavy rainfall will be possible storm motions of 30-40kts should preclude any flash flooding threat. After sunset, the convective show should quickly come to an end with the loss of surface heating/instability with showers lingering through midnight before the aforementioned cold front sweeps through ad high pressure builds in behind in. After 2 warm and muggy nights, Sunday night will be nice a cool with lows ranging from the mid 40s to mid 50s. && .SHORT TERM /MONDAY/... As of 346 PM EDT Saturday...A cool forecast for Monday. Following the strong frontal boundary to pass through Sunday, our temperatures will be below normal, with a steady north wind. Highs range in the 60s across the North Country. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... As of 1029 PM EDT Saturday... Overnight Monday night there will be light winds, clear skies, and a surface 1030mb high pressure should promote efficient radiational cooling. Lows fall into the 40s in the valleys, with mid to upper 30s across the Northeast Kingdom and Adirondacks, which are approaching their median frost date, and frost advisories may be needed. Conditions will then remain dry through Wednesday evening as strong deep layer ridging keeps moisture well to our west. A surface low is expected to develop as an upper trough moves east of the Rockies and tracks towards the Great Lakes. By Wednesday night, that system`s warm front will lift northwards with rain propagating east parallel to the front as moisture ridges the crest of the upper ridge. The center of a 500 hPa high will shift northwards and intensify a bit, which may push the bulk of that precipitation north of the area, which is in line with the GFS. A weaker 500 hPa high would bring moderate, perhaps heavy, rain across our area, as the ECMWF depicts. Given it`s about 5 days out, will remain close to blended data, but probabilistic guidance hints a bit more centered over our area. A negatively tilted shortwave follows right on the heels of that system, with a surface low developing along the frontal boundary of the system ahead of it that then ejects northeastwards. This sends another wave of high theta-E air Thursday night into Friday morning, but precipitation seems scattered in nature at this time. This leaves plenty of clouds lying around Friday afternoon, but development of a modest cold front should provide a focus for convection and additional chances for moderate to heavy rain. Beyond Friday, trends in the data support a return to drier weather and temperatures right around seasonal normals. && .AVIATION /03Z SUNDAY THROUGH THURSDAY/... Through 00Z Monday...Threat for strong to severe storms has come to an end this evening. There are some showers and isolated storms moving northeast into far western New York this evening. This activity may move into the area producing showers that could result in brief MVFR ceilings and visibilities between 03z and 12z. VFR conditions will exist between 12z and 18z and then the potential for showers and thunderstorms will increase as a cold front moves across northern New York. After 18z strong to severe storms will be possible from the northern Adirondacks eastward across Vermont with hail, strong winds, lightning, and heavy downpours with any of these storms. This will likely create IFR and LIFR conditions for brief periods. Winds will be 10 knots or less, but then pick up out of the south and southwest with gusts to 20 knots after 18z. Outlook... Sunday Night: VFR. Chance SHRA. Monday: VFR. NO SIG WX. Monday Night: VFR. NO SIG WX. Tuesday: VFR. NO SIG WX. Tuesday Night: VFR. NO SIG WX. Wednesday: VFR. Chance SHRA. Wednesday Night: Mainly VFR, with local MVFR possible. Chance SHRA. Thursday: Mainly MVFR, with local VFR possible. Likely SHRA. && .CLIMATE... Near record highs are possible today, May 21 and Sunday, May 22 as we are anticipating temperatures to reach well into the upper 80s and lower 90s. Here are the current daily record temperatures. Date KBTV KMPV K1V4 KMSS KPBG KSLK 05-21 92|1911 89|2021 89|2021 89|1975 92|1975 94|1911 05-22 93|1977 90|1994 84|9999 89|1977 92|1977 91|1911 && .BTV WATCHES/WARNINGS/ADVISORIES... VT...None. NY...None. && $$ SYNOPSIS...Lahiff NEAR TERM...Evenson/Lahiff SHORT TERM...Haynes LONG TERM...Evenson/Haynes AVIATION...Evenson CLIMATE...WFO BTV
Area Forecast Discussion
National Weather Service Cleveland OH
1015 PM EDT Sat May 21 2022 .SYNOPSIS... A cold front moves west to east across the region tonight. High pressure builds eastward across the Great Lakes region tomorrow night through Tuesday. A warm front extending from low pressure over the mid-Mississippi Valley will move northward across the area Wednesday. && .NEAR TERM /THROUGH SUNDAY NIGHT/... Low pressure over NW OH still needs to move eastward near the south shore of the lake through the overnight hours. As this low moves eastward it will pull a cold front with it. Still enough upper level jet energy to provide some lift along the front but the region has little in the way of instability remaining. However we do think there is enough moisture and lift to at least generate some isolated/scattered showers, maybe a few thunderstorms after midnight, then continuing through Sunday morning. Best chances through sunrise look to be west of I-71. As we heat things up ahead of the cold front on Sunday there could be a few thunderstorms along the cold front as it moves into western PA. Previous Discussion... The environment is primed for severe thunderstorms this afternoon, with RAP mesoanalysis suggesting SBCAPE as high as 4000 J/kg, with projections building it up to 4500 J/kg. Combined with effective bulk shear 30-40 kts and we have a favorable environment for severe convection. Damaging wind gusts are likely to be the prime culprit this afternoon and evening with max theta-e difference of up to 30 C, DCAPE up to 1200 J/kg and low level lapse rates of 7-8 C/km all contributing to a favorable environment for damaging winds. However, large hail will also be possible with moderate mid-level lapse rates of 6.5-7 and hail growth zone (-10 to -30 C) CAPE of up to 1000 J/kg. While not especially favorable, an isolated tornado can not be ruled out with modest 0-1 km shear of around 10-15 kts, effective SRH around 50, and LCL heights around 1000m. Flash flooding is also pose a risk with a very moist environment in place, especially if convection initiates off a WSW-ENE boundary. The cold front finally pushes east of the area tomorrow morning and precipitation will gradually taper off during the morning and early afternoon Sunday from west to east. Cooler air will spread into the area tonight with considerably colder temperatures compared to this morning`s lows. Also, notably cooler temperatures expected for Sunday. As we remain in the warm sector today, temperatures will take a stab at hitting the 90 degree mark. However, with advancing clouds, temperatures should hold below the 90 degree level across much of the area. && .SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... High pressure over the Great Lakes will foster dry weather through the majority of the short term period. However, lingering cold air advection will provide below normal temperatures Monday, with highs in the low to mid 60s anticipated. By Tuesday, a building ridge across the southeastern US will allow temps to increase and highs will recover to the low to mid 70s. Overnight lows will be in the 40s to low 50s each night. Pops begin to increase Tuesday night as low pressure developing over the Mississippi Valley lifts a warm front northeast towards the local area. The best chance of scattered showers will be confined to the western half of the forecast area. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... An unsettled weather pattern is expected mid to late week as a deepening upper-level trough and surface low inch eastward across the region and several shortwaves move across the local area. This will result in several waves of precipitation, including potential for thunderstorms during peak heating hours. As of now, the highest pops are Wednesday and Thursday, with slightly lower chances heading towards the end of the week due to divergence in model guidance. A cold front will likely move across the area Friday, allowing pops to decrease Friday night into Saturday. However, scattered showers may persist through the first half of the weekend as a reinforcing cold front moves across the lower Great Lakes. Wednesday and Thursday will most likely be the warmest days of the week with highs in the mid to upper 70s. Temps will be slightly cooler in the upper 60s Friday and upper 60s to low 70s Saturday. Overnight lows will be in the upper 50s to low 60s Wednesday and Thursday night and expect cooler lows in the low 50s Friday night. && .AVIATION /00Z Sunday THROUGH Thursday/... Strongest thunderstorms moving across western PA. MVFR/IFR conditions with the strongest convection. Gusts may reach 45 knots. Otherwise light rain continues in the wake of the stronger convection. Low pressure tracks near the south shore of Lake Erie through 06Z eventually pulling the cold front eastward across northern OH into NW PA in the morning. may be some MVFR ceilings in the wake of the front into Sunday afternoon. Winds variable with the convective outflows and the area of low pressure moving eastward near the south shore of the lake. Winds eventually shift to the west and northwest in the wake of the cold front. Winds may reach 10 to 15 knots for a few hours with gusts around 20 knots. Winds decrease through the afternoon. Outlook...Non-VFR possible Tuesday night through Thursday with showers and afternoon thunderstorms. && .MARINE... Thunderstorms will impact the lake this afternoon into early this evening and any thunderstorms that move over the lake may produce hail and strong winds. Outside of thunderstorms, expect variable winds 6 to 12 knots this afternoon before becoming southwesterly this evening. Winds shift to the northwest and increase to 15 to 20 knots Sunday morning and a short-fused Small Craft Advisory may be needed before winds and waves decrease Sunday afternoon. Onshore flow continues through the first half of next week and although winds will remain below 20 knots, persistent onshore flow may keep waves elevated in nearshore zones. Will continue to monitor wind and wave forecast trends for any Small Craft Advisory conditions through the weekend. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...None. PA...None. MARINE...None. && $$ SYNOPSIS...MM/Saunders NEAR TERM...MM/Saunders SHORT TERM...Maines LONG TERM...Maines AVIATION...MM MARINE...Maines
Area Forecast Discussion
National Weather Service El Paso TX/Santa Teresa NM
902 PM MDT Sat May 21 2022 ...UPDATE FOR WIND ADVISORY... .UPDATE... Models are trending stronger with the winds expected behind the cold front tonight. Forecast soundings from multiple models show mountain level winds of 30-35 knots across Southern Dona Ana and Otero Counties and our Texas zones. The NAM NEST and HRRR wind/wind gust parameters are showing 30G45kt for the usual windy spots in these areas. Winds will pick up west to east with the front passage, so the strongest winds are likely to occur between 3AM and 7AM for El Paso before diminishing. && 34 .PREV DISCUSSION...535 PM MDT Sat May 21 2022... ...00Z AVIATION UPDATE... .AVIATION...Skies are expected to remain mainly SKC through the period. Winds will continue from the west and west-southwest before diminishing some after sunset. A cold front will begin to affect the region between 6z and 9z, which will abruptly shift winds from the east and southeast of 10 to 15 knots with gusts of 20 to 25 knots. Smoke has remained north of TCS, but drainage flow may allow smoke to move into/over TCS between sunset and the front`s arrival. Left mention of smoke in TAFs, but occurrence is uncertain. && .PREV DISCUSSION...246 PM MDT Sat May 21 2022... .SYNOPSIS... A cold front will bring cooler weather on Sunday along with a slight chance of thunderstorms for Hudspeth County into Monday. Continued dry and warm weather is expected Monday into next week. Breezy west winds early this week, then again next weekend. && .DISCUSSION... .SHORT TERM...Tonight into Sunday... Aloft, west flow will remain along with the approach of a subtle system into Sunday afternoon. The story will be a frontal boundary approaching from the east tonight, however. Frontal boundary will move into the Borderland this evening and tonight, across the far east after sunset, then the RGV around Midnight, and farther west by the morning hours. Easterly winds will be gusty (values up to 40 mph possible) across west slopes of terrain (Huecos and Franklins especially), and breezy across most other locations within the vicinity of the International Border. Winds will be northeast and a bit breezy at T-or-C for a few hrs Sunday morning as the front drains from the north. Overnight low temps will be about 5, maybe locally up to 10 degrees cooler than they were Saturday morning for the Rio Grande on eastward. Values will be mainly in the 50s. Stiff southeast winds are expected to continue on Sunday, with more south to southwest in the vicinity of the Continental Divide. As a result, in addition to scattered cloud cover, temps will be pleasant, with values in the low to mid 80s across the lowlands and 60s in the highest elevations. No precipitation is expected during the period. However, by Sunday evening, dewpoint temps will be in the mid 40s with increasing instability and an approaching little perturbation aloft. See details below in the long term discussion. && .LONG TERM... Decent moisture leftover behind Sunday`s cold front will allow for some of our region`s first rain chances in quite some time Sunday night into Monday morning, with the best moisture and near neutral stability indices existing east of the Rio Grande. Scattered showers and thunderstorms will be possible over Hudspeth County and the far eastern fringes of the CWA, generally east of the US-54 corridor. Rain chances still don`t look good for El Paso or Las Cruces as moisture is quickly pushed back eastward and out of the area by midday Monday. A few additional showers will be possible over the Sacramento Mountains Monday evening, with no significant precipitation (spatially or quantitatively) expected. Northwest flow aloft on the front end of a Pacific high will drive a continued breezy, dry, and mild weather pattern through Tuesday. Temperatures will quickly return back to seasonal normals Monday/Tuesday as moisture is scoured out under breezy west winds. Afternoon wind speeds look breezy (15 to 20 mph) but nothing we haven`t already seen consistently this spring. Disturbance aloft crosses the Southern Rockies to our north again Wednesday morning, inducing a surface high along the western Plains and thus another cold front down the TX panhandle and eastern NM. Ensemble solutions disagree on the western extend of this boundary, with consensus generally seeping into the Rio Grande valley by Thursday morning. The disruption of lee low formation will allow winds to be much lighter these days, but no major adjustment to the current weather pattern is expected with this weak intrusion. Precipitation chances will continue to be slim to none and Wednesday`s temperatures will remain near normal for late May. High pressure aloft will progress over northern Mexico by Thursday, suggesting a warming trend which is confirmed by latest MOS guidance. Lowland highs will quickly return to the upper 90`s/near 100 Thursday into next weekend along with the return of breezy westerlies Friday/Saturday. Fairly significant diversions in ensemble solutions 7 days out, with several GFS members suggesting high pressure directly overhead and the deterministic ECMWF moving a strong trough across the Western U.S. at the same time. Leaned this forecast toward the more seasonal GFS solution with dry, warm weather prevailing into June. && .FIRE WEATHER... A cold front will move into the region tonight, with an east to southeast wind shift along with increased moisture. As a result, overnight recoveries will be much more friendly east of the Rio Grande (50 to 80%). On Sunday, southeast winds will remain most areas, the exception being in the vicinity of the Continental Divide where south to southwest winds will prevail. Much cooler temperatures are expected east of the Continental Divide, with values 5 to 15 degrees below average, in addition to richer moisture. Consequently, min RH will be in the 20 to 30% across Fire Zones 055, 056, and 113. A few showers and thunderstorms will be possible east of the Rio Grande as well Sunday night into Monday, mainly across Hudspeth county. By early next week, energy across the Rockies will produce breezy winds across the Borderland Monday and Tuesday, values 15 to 25 mph, with critical humidity most locations. The potential exists for local Red Flag conditions with near normal temperatures both days. By the end of the week, a ridge of high pressure will move overhead with warming temperatures and potentially mild breezes. Expect a mix of Poor to Fair ventilation east and Good to Excellent out west on Sunday, then excellent early next week. && && && .PRELIMINARY POINT TEMPS/POPS... El Paso 56 82 61 92 / 0 0 20 0 Sierra Blanca 51 75 57 83 / 0 0 40 20 Las Cruces 54 83 56 91 / 0 0 0 0 Alamogordo 51 83 55 88 / 0 0 10 0 Cloudcroft 35 63 43 65 / 0 0 20 20 Truth or Consequences 54 82 58 89 / 0 0 0 0 Silver City 53 79 54 80 / 0 0 0 0 Deming 50 84 52 90 / 0 0 0 0 Lordsburg 53 88 52 88 / 0 0 0 0 West El Paso Metro 56 82 61 91 / 0 0 10 0 Dell City 50 75 52 88 / 0 0 30 20 Fort Hancock 53 83 58 91 / 0 0 30 20 Loma Linda 51 75 55 83 / 0 0 20 0 Fabens 54 83 60 92 / 0 0 20 0 Santa Teresa 54 81 56 89 / 0 0 10 0 White Sands HQ 56 80 61 89 / 0 0 10 0 Jornada Range 48 81 55 88 / 0 0 0 0 Hatch 50 84 55 90 / 0 0 0 0 Columbus 56 85 56 91 / 0 0 0 0 Orogrande 50 79 57 89 / 0 0 10 0 Mayhill 36 70 45 78 / 0 0 20 20 Mescalero 37 73 45 75 / 0 0 20 20 Timberon 41 69 47 74 / 0 0 20 20 Winston 39 80 45 84 / 0 0 0 0 Hillsboro 51 81 54 86 / 0 0 0 0 Spaceport 48 82 54 88 / 0 0 0 0 Lake Roberts 45 79 46 82 / 0 0 0 0 Hurley 47 82 48 85 / 0 0 0 0 Cliff 44 88 40 90 / 0 0 0 0 Mule Creek 38 82 50 83 / 0 0 0 0 Faywood 51 80 51 84 / 0 0 0 0 Animas 51 88 50 89 / 0 0 0 0 Hachita 51 85 51 88 / 0 0 0 0 Antelope Wells 51 87 53 88 / 0 0 0 0 Cloverdale 52 83 53 83 / 0 0 0 0 && .EPZ WATCHES/WARNINGS/ADVISORIES... NM...Wind Advisory from midnight tonight to 8 AM MDT Sunday for NMZ411-417. TX...Wind Advisory from midnight tonight to 8 AM MDT Sunday for TXZ418-420>424. && $$ 99/99/99
Area Forecast Discussion
National Weather Service Houston/Galveston TX
636 PM CDT Sat May 21 2022 .AVIATION... MVFR ceilings are spreading inland early this evening, and expect this trend to continue as the evening progresses. Eyes then turn to the central TX area SHRA/TSRA complex that has developed along the cold front. Have the front and its convection moving into SE TX later this evening and on through the overnight hours. Very different timing/strength/coverage scenarios are being displayed by the most recent models, so confidence on how this will all unfold remains low at this time. It is possible that convection could accelerate overnight as it moves through our area resulting in a shorter time period of TSRA risk. Timing differences could also mess with when MVFR and possible IFR ceilings develop behind the front and how long they persist along with where/when any development happens on Sunday. We`ll see how this all evolves and unfolds. Periods of SHRA/TSRA similar to tonight`s event can be expected into the middle of the upcoming week. 42 && .PREV DISCUSSION... /ISSUED 338 PM CDT Sat May 21 2022/ SHORT TERM [Through Sunday Night]... Beginning to see some convective initiation to our nw in advance of a frontal boundary. Expect shra/tstm coverage to fill in along the front as it approaches northern parts of the CWA in the late evening hours and eventually toward the coast around sunrise. Not much in the way of shear, but there will be a threat of some isolated severe storms with wind/hail the primary threat. At this time, locations generally north of a Brenham-Trinity line will see the better chances for any severe wx. Further south, capping should mostly hold into the evening, then we`ll lose daytime heating and some would anticipate that overall intensity should begin to wane. That said, things could eventually be run on the mesoscale. For example, a cold pool developing behind the precip slightly speeding the boundary up, etc, etc. Several of the 12z HREF members showed something like this being a possibility later tonight...with a cold pool/meso-high developing across extreme east Tx and northern La and a healthy line of precip trekking southward along the Sabine then eventually southwest toward the metro area and upper Tx coastal waters in the 2-8am timeframe. Latest HRRR runs have trended a bit different. Tx Tech WRF, on the other hand, has been consistent showing little in the way of meaningful precip across southern parts of the region until maybe Sunday afternoon where the front stalls near the coast. So...a lot of writing to say that overall fcst confidence in regards to how things exactly evolve late tonight isn`t exactly very high. With a lack of upper support for a continued swd push, expect the front/wind shift to eventually stall somewhere near the coast. Coastal areas might just see winds back to a e/ne direction in association with some weak coastal troughing. Regardless of the finer details, we`ll welcome the increased cloud cover Sunday, chances of scattered precip, and a lower daytime temps. Surface high pressure slides off to the east and the front/boundary should begin lifting back north late Sunday night & Monday. Deeper plume of moisture will follow so rain chances continue into next week... 47 LONG TERM [Monday Through Saturday]... An active weather pattern is expected to continue through mid week. First, the weekend cold front that is to stall over the Gulf coastal waters will move northward, back inland as a warm front during the day Monday while a few weak shortwaves rounding the base of an upper level trough situated over the Great and Southern Plains, move overhead. Though there is a slight chance some capping may be present on Monday, it does not seem strong enough to be able to suppress our chances of rain at the moment, especially along the northern and western sectors of Southeast TX where the greatest instability and moisture lies. Tuesday into Wednesday, a series of stronger upper level shortwaves will move over TX as the upper level trough progresses eastward over Central/North Central CONUS. A cold front will make its way into Southeast TX sometime Wednesday afternoon/evening. Persistent onshore flow will give us plenty of moisture to play with (PWs of 1.5 to 1.9 inches) and with sufficient instability in place, showers and thunderstorms are most likely going to develop ahead and along the front. The front is expected to move into the Gulf waters Wednesday night, bringing northerly winds and slightly cooler/drier airmass across the region. High pressure will build across Southeast TX on Thursday, inhibiting rain chances and resulting in light variable winds through Friday morning. Winds will turn southeasterly Friday night into Saturday and gradually increase low level moisture. As for temperatures, Monday`s highs will be mostly in the mid to upper 80s and cool down into the low to mid 80s on Tuesday. The highs on Wednesday are forecast to increase back into the upper 80s (mainly along the central and southern portions) but will ultimately depend on the timing of the front. If it arrives sooner than what is currently forecasted, then those locations will experience highs closer to the low to mid 80s. With the intrusion on drier/cooler air in the wake of the front, highs on Thursday will likely be in the low to mid 80s (slightly higher along the southern counties and coasts) and the lows will drop into the low to mid 60s Thursday night. Expect a gradual warming trend thereafter, as onshore flow returns. 24 MARINE... Small Craft Advisory has been extended through 5 PM this afternoon across Coastal waters from Freeport to Matagorda Ship Channel TX out 20 NM and Waters from Freeport to Matagorda Ship Channel TX from 20 to 60 NM due to elevated seas. Conditions will improve this evening into the overnight hours, however, hi-res models are indicating another round of strong showers and thunderstorms just ahead and along a cold front Sunday morning. These storms may be accompanied by strong gusty winds with speeds up to gale force possible and could result in higher seas as well. The front is expected to stall along the coastal Gulf waters Sunday, continuing the chance for showers and thunderstorms throughout the day. Expect east northeast winds Sunday. Light to moderate onshore flow will return Monday as the front moves back inland. A series of upper level disturbances will move overhead through mid week, resulting in periods of showers and thunderstorms across the bays and Gulf waters. The next cold front is progged to move into the coastal waters sometime late Wednesday night or Thursday morning. Expect north northeasterly winds in the wake of the front. For the beachgoers, high risk of strong rip currents will continue throughout the weekend for the Gulf facing beaches. It is recommended to practice beach safety and swim near a lifeguard. 24 && .PRELIMINARY POINT TEMPS/POPS... College Station (CLL) 65 82 69 85 71 / 70 50 10 50 60 Houston (IAH) 73 85 72 86 73 / 70 60 30 40 50 Galveston (GLS) 78 86 78 87 79 / 60 70 30 30 40 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...High Rip Current Risk through Sunday evening for the following zones: Bolivar Peninsula...Brazoria Islands...Galveston Island...Matagorda Islands. GM...NONE. && $$
Area Forecast Discussion
National Weather Service Huntsville AL
845 PM CDT Sat May 21 2022 ...New NEAR TERM... .NEAR TERM... (Tonight) Issued at 844 PM CDT Sat May 21 2022 Isolated to scattered showers/storms currently across the Tennessee Valley this evening. These showers/storms developed earlier this afternoon in the hot, humid, and unstable atmosphere. These showers/storms were initiated along outflow and differential heating boundaries. With the large instability in place, a few of these storms became marginally severe earlier this evening. These storms are having a more difficult time developing over the last hour or so with the loss of daytime heating and expect this will continue to be the trend over the next couple of hours. The focus then shifts to the MCS approaching from the northwest. This line of showers/storms has developed ahead of an approaching cold front. Portions of the line are currently warned as it approaches Memphis, TN. The last few scans indicate a shift southward in the motion of the MCS. The MCS looks to try to stay in the area of higher instability. Still not certain how intense the MCS will be as it moves into NW AL. So far, not seeing much warming at all in the cloud tops. However, the latest HRRR has the activity falling apart as soon as it enter NW AL. Would expect a weakening trend with the loss of daytime heating but so far things are holding somewhat steady state. For now, have the line entering NW AL around 05z and fading quickly as it moves across the area. && .SHORT TERM...(Sunday through Tuesday night) Issued at 242 PM CDT Sat May 21 2022 Present indications are that the decaying MCS discussed in the near term section will continue to translate southeastward between 12-18Z Sunday, with abundant cloud cover and lingering light rain in the wake of this system expected to limit instability. Nonetheless, virtually all model guidance suggests that widespread convection will redevelop once again by early afternoon, as a slow-moving cold front drops southeastward into the region. There is still a good deal of uncertainty regarding how far south the cold front will penetrate into the region, but our best guess is that is will remain nearly stationary and bisect the forecast area from Sunday night through Monday morning. It still appears as if a stronger mid-level disturbance in the southern stream will begin to lift northeastward from the southern LA vicinity on Sunday evening, providing weak but sufficient synoptic scale ascent for the development of widespread showers and thunderstorms on both sides of the front. Weak shear and only meager instability suggest that the main impact from this activity will be locally heavy rainfall, especially as convection to the north of the boundary will be slightly elevated. Although the location and orientation of the front will likely not change, this precipitation regime should spread slowly eastward on Monday afternoon/evening as the mid-level wave lifts northeastward and away from the region. The stalled boundary will begin to return northward as a warm front on Tuesday morning, as an amplifying shortwave trough digs east-southeastward across the central Rockies and adjacent High Plains. This will place the local area within the warm/moist sector of the trough`s developing surface cyclone, with an increasing coverage of showers and thunderstorms expected both periods. Highs through the short term will be in the u70s-l80s, with lows in the l-m 60s. && .LONG TERM...(Wednesday through Friday) Issued at 242 PM CDT Sat May 21 2022 The central High Plains shortwave trough discussed above will continue to deepen as it tracks eastward across the Great Plains during the mid-week period, perhaps evolving into a partially closed low as it reaches eastern MO/western IL by 00Z Friday. Given the dynamic nature of this system, flow throughout the lower troposphere will strengthen considerably to levels more typical of an early Spring system rather than one in late May. With this in mind, deep- layer shear will quickly become favorable for organized/severe convection during the day on Wednesday, when several clusters of thunderstorms will begin to spread northeastward in rapidly strengthening warm advection ahead of this system. This regime will persist on Wednesday night and Thursday, and with the low-level jet expected to reach the 40-50 knot range atop a very moist boundary layer with dewpoints in the m-u 60s, all severe hazards including tornadoes will be possible. At this point, it appears as if some form of a QLCS preceding the cyclone`s cold front will end both the risk for severe weather and thunderstorms as it crosses the region Thursday afternoon. A drier and cooler airmass will spread into the region in the wake of this system for the end of the work week. && .AVIATION... (00Z TAFS) Issued at 631 PM CDT Sat May 21 2022 VFR conditions currently across the terminals. There are a few isolated storms across the area this afternoon/evening but they are outside of the 10 mile radius of the airports. For now, think they will stay far enough away from the airports to not include VCTS over the next couple of hours. Will monitor radar trends and make amendments as necessary. Another area of showers/storms will approach from the northwest later this evening around 04z. These showers/storms should be weakening as they move through but did include VCTS at both terminals overnight. This precipitation will come to an end after midnight. However, another round of showers/storms is forecast after 15z. Additionally, MVFR ceilings are forecast late in the TAF cycle. && .HUN WATCHES/WARNINGS/ADVISORIES... AL...None. TN...None. && $$ NEAR TERM...MA SHORT TERM....70 LONG TERM....70 AVIATION...MA
Area Forecast Discussion
National Weather Service Indianapolis IN
1159 PM EDT Sat May 21 2022 ...Updated Aviation Discussion... .Forecast Update... Issued at 1037 PM EDT Sat May 21 2022 Severe weather has come to an end over the area. With the low currently passing overhead, light precipitation and a few rumbles of thunder are making its way across central Indiana. Behind this rain, cooler air will settle in with Sunday morning lows expected in the 50s. The rain should end and exit off to the east by sunrise. Updated the forecast to match current conditions, including upping PoPs over the SW portion of the area where there is a swath of more widespread rain. Across the southern edge of the forecast area is where lightning will be most likely, but should remain sporadic overnight. && .Short Term...(This evening through Sunday night) Issued at 305 PM EDT Sat May 21 2022 - Showers and Thunderstorms this afternoon and tonight. - Dry weather returns Sunday and Sunday Night Surface analysis early this afternoon shows the frontal boundary near HUF to north of IND and NW of Anderson and Muncie. Clouds dissipating from the departing MCS were beginning to allow for some heating in the warm sector south of the front where temps have risen to the lower 80s. Recent radar trends show the approaching MCS convection continuing to make progress east toward the forecast area...but weakening upon approach. New convection is breaking out in the warm sector across SE Indiana and KY. This afternoon... HRRR suggests the MCS crossing Indiana will be continue to make progress to the northeast...but radar trends continue to suggest weakening upon approach. This will be due to limited instability across Indiana north of the frontal boundary and also due to a worked over air mass due to earlier clouds and rain. Better conditions for storms will be found across the southern parts of the forecast area where CAPE is most favorable and where heating has had a chance to occur today. Tonight... After this afternoons weather system the surface frontal boundary should be pushed to far southern parts of the forecast area...again limiting the source for additional instability overnight. Models shows southwest flow in place aloft tonight with a short wave within the flow passing well north of Indiana...across WI and the Great Lakes. HRRR suggests another wave pushing across Indiana late this evening and overnight...but confidence is low with that feature as given the previous two waves...instability should be limited and the surface boundary should be well to the south across southern Central Indiana. Thus not all of our features are lining up well and models seem to be having issues handling these multiple rounds of convection. Forecast soundings show deep saturation as the storms pass this afternoon...but fail to show deep saturation for the rest of the night. Thus will use high pops late this afternoon...and per the HRRR trend toward a few dry hours this evening before increasing pops late this evening and early overnight as the final wave appears to pass. Although will trend pops a bit lower than the NBM as confidence is a bit low on whether this second wave of showers and storms will come to fruition on the cold side of the boundary. Sunday... Models suggest southwest flow remains in place aloft with little in the way of upper support available. The remains of the frontal boundary are expected to be well south of Central Indiana...elongated across Kentucky. Forecast soundings suggest subsidence within the column with some lower level moisture trapped beneath an inversion. This appears representative of cold air advection stratocu in the wake of the departed front. As the day progresses...strong high pressure over the plains is suggested to continue to make progress into the Ohio valley...drying out the forecast soundings and pushing the lingering frontal boundary farther south and away from Indiana. Thus after some morning cloudiness (mainly across southern Central Indiana) skies should become partly cloudy to mostly sunny. Given our northerly winds highs in the middle to upper 60s appear on the mark. Sunday Night... Little change is expected within the upper flow on Sunday night as southwest flow remains along with little in the way of upper support. Large high pressure over WI and IA will maintain its influence across Indiana...with subsidence and cool northerly flow in place across Indiana. Thus will trend toward a dry forecast under mostly clear skies and lows in the middle 40s. && .Long Term...(Monday through Saturday) Issued at 305 PM EDT Sat May 21 2022 Monday-Tuesday... Drier and cooler conditions expected as a surface high pressure builds across the great lakes region. The surface high will likely produce northerly flow early Monday, and veering to predominantly easterly Monday afternoon. This will allow for lower dewpoints and cooler temperatures. Cloud cover will begin to increase during the day Tuesday as a Surface low begins to approach the region with slight POPs for Tuesday afternoon. Temperatures will be slightly below average to near average for this time of year. Tuesday night-Friday Several damp days are possible as a deep broad trough slowly approaches the region with Central Indiana remaining in the warm moist sector for multiple days. Southerly flow will return early Wednesday morning. This will allow for moisture to be advected into the region with dewpoints increasing into the 60s. Likely POPs are in place across the CWA from Tuesday night through early Friday. precipitable water values, usually within the upper portions of a 1.00-1.80 inch range will bring the potential for locally moderate- heavy rainfall. Embedded thunderstorms would be mainly widely scattered and diurnally-driven, per generally modest shear and considerable cloudiness limiting daytime heating on both Wednesday/Thursday. High temperatures will be slightly below to near average for this time of year due to cloud cover and rainfall. Lows will be above average as persistent moisture will keep temperatures mild overnight. Friday night-Saturday The broad upper trough will finally progress eastward and push the greater axis of gulf moisture into Ohio. This will allow for an upper ridge to build across the region. Drier conditions expected due to synoptic subsidence. Northwest flow will keep temperatures below average towards the end of the long term period. && .Aviation...(06Z TAF Issuance) Issued at 1159 PM EDT Sat May 21 2022 IMPACTS: * Additional showers and scattered convection will continue tonight. * Predominantly MVFR through the night, then VFR on Sunday. DISCUSSION: Additional showers will work across central Indiana tonight. Can`t rule out a few rumbles of thunder but not enough to include in the TAFs tonight. Rain diminishes late tonight with dry conditions expected on Sunday. MVFR conditions will become widespread at the beginning of the period and will continue through the night. There may be pockets of IFR. Improvement to VFR will occur on Sunday. && .IND WATCHES/WARNINGS/ADVISORIES... None. && $$ Update...KH Short Term...Puma Long Term...Melo Aviation...KH
Area Forecast Discussion
National Weather Service New Orleans LA
907 PM CDT Sat May 21 2022 .EVENING UPDATE... Have updated most grids to handle short term trends, as outflow from thunderstorms has pushed most precipitation to the north and west of the least for now. The 00z LIX sounding was a post-storm environment with much of the column between 950 and 500 mb comparatively dry. Precipitable water value at that point was 1.3 inches. This compares to 1.8 inches at Lake Charles and 1.5 at Jackson. Water vapor imagery shows convection firing from Arkansas southwestward into Texas, as well as over the Gulf of Mexico to the south of Louisiana. Latest HRRR run indicates at least some threat of convection from either or both areas approaching our CWA prior to sunrise, so we can`t go with a totally dry forecast. Don`t see temperatures falling much, if any, from where they are at, and if onshore winds return, temperatures could even rise a few degrees before sunrise. 35 && .PREV DISCUSSION... /issued 408 PM CDT Sat May 21 2022/ SYNOPSIS... Upper ridging centered over Florida this afternoon with a shortwave moving northward on the west side of it. Thunderstorms over the Gulf of Mexico associated with this shortwave are producing outflow that is generally moving westward with gusts to around 40 mph. The next shortwave in the southwesterly flow is currently moving across Colorado and New Mexico. Areas that have received precipitation this afternoon have fallen into the upper 70s, while dry areas are generally in the lower 90s. SHORT TERM (through Monday night)... A weak upper low is expected to try to develop over the Gulf over the next 24 hours or so, and then lift northeastward Monday and Monday night. The airmass is continuing to moisten up with precipitable water values around 1.5 inches today, which will increase to near 2 inches tomorrow and tomorrow night before retreating to 1.5 inches Monday and Monday night after the passage of the shortwave. Potential for severe weather and excessive rainfall will continue during the afternoon hours on Sunday as the airmass will remain unstable. As the upper low lifts northeastward tomorrow night, it may provide a focus for excessive rainfall, especially on the Mississippi coast, as heavy rainfall tends to focus near the center nocturnally. Threat will likely diminish for a period Monday afternoon and evening behind the low, but not enough for a dry forecast. Generally kept near the NBM numbers with the exception of overnight tonight, as NBM has been too cool on lows the last couple nights, bumped up a couple degrees, and that might not be enough. 35 LONG TERM (Tuesday and beyond)... Southwesterly upper flow expected to continue through at least Thursday. With differences in timing of individual shortwaves, didn`t veer very far from NBM PoPs, as there aren`t large scale differences. Convective threats should mainly focus on the daytime hours, particularly in the afternoons. Precipitable water values crash below 1 inch on Friday, so that should end the precipitation threat. Temperatures generally in good agreement, so NBM numbers aren`t likely to provide a significant target of opportunity. 35 AVIATION (valid through 00z Monday)... Main concern over the next few hours will be TSRA, which should gradually dissipate with loss of surface heating. Gusts to 35 to 40 knots possible with the strongest storms. MVFR to IFR visibilities will be brief. Beyond midnight, likely to see some MVFR ceilings develop as moisture gets trapped under the inversion again. As heating commences on Sunday, redevelopment of SHRA/TSRA is expected at most terminals with the same limitations as today. MARINE... Will extend the Small Craft Exercise Caution headlines overnight, although some portions of the waters are likely to fall below those levels at least briefly. Headlines may need extended tomorrow, but more significant marine threat over the next several days will be thunderstorms producing gusty winds. 35 && .PRELIMINARY POINT TEMPS/POPS... MCB 69 85 66 83 / 30 90 60 60 BTR 71 85 68 84 / 60 90 60 60 ASD 71 86 67 86 / 40 90 70 70 MSY 75 85 72 84 / 50 90 70 70 GPT 73 86 70 83 / 50 90 80 70 PQL 71 86 69 82 / 40 80 80 70 && .LIX WATCHES/WARNINGS/ADVISORIES... LA...None. GM...None. MS...None. GM...None. && $$
Area Forecast Discussion
National Weather Service Louisville KY
903 PM EDT Sat May 21 2022 .Mesoscale Update... Issued at 901 PM EDT Sat May 21 2022 Latest convective and environmental trends suggest our severe weather threat is extremely low given increasing low-level CIN with the nocturnal inversion beginning to setting in. As such, the severe thunderstorm watch has been allowed to expire at 9PM EDT/8PM CDT. An additional line of showers and storms are ongoing across southern Illinois through Arkansas, but these should weaken as they approach our region later tonight given how `worked over` the atmosphere is from our previous storms. The latest CAMs also suggest that this will be the case. Issued at 650 PM EDT Sat May 21 2022 After coordination SPC we will expand in area and in time WW254 to cover the remainder of our SE CWA and delay expiration until 900 PM EDT. Have gone ahead and removed another row of north-central KY counties where the threat of severe has ended. Highest threat of severe weather will generally be along and south of a line from Russellville northeast to Richmond. The most unstable air and uncontaminated atmosphere is roughly south of the Cumberland Parkway. Large MCS with expanding cold pool should push a squall line through northern TN and far southern KY this evening. Updated products are in production and will be available shortly. Issued at 610 PM EDT Sat May 21 2022 Did another quick update to remove some our KY counties bordering the River from the WW254. Also did an expansion of WW254 to the south and east for the next hour until the original expiration of 21/23Z. Outflow boundary continues to surge out ahead of ongoing convection across east-central KY. Atmospheric is a little worked over up in this area (between Lexington/Louisville) from where previous convection fired earlier this afternoon. Storms in this area are under severe limits producing mainly heavy rainfall, wind gusts of 30-35 mph and quite a bit of lightning. Stronger instability continues to reside off to the south, mainly south of the WK/BG Parkways where the atmosphere has been relatively undisturbed. Mesoanalysis suggests around 2000 J/kg of MLCAPE along with 0-3km lapse rates of nearly 8C/km ahead of eastward moving complex. Overall threat continues to look mainly a damaging wind event as cold pool gradually expands eastward. Depending on convective trends additional EXA/EXT to WW254 may be required within the next hour. Will coordinate those issues with SPC in a bit. Issued at 531 PM EDT Sat May 21 2022 Did a quick update to clear our southern Indiana counties out of WW254. Updated grids and text products have been produced and sent. Currently we`re tracking a line of convection pushing east- southeastward across central Kentucky. Line that moved into the region became outflow dominant with gusts of 35-40 mph with the actual outflow. Resultant convection that fired behind the outflow was strong/severe as storms pulsed up and collapsed resulting in damaging winds across our southern Indiana counties and into portions of the metro Louisville area. The outflow boundary currently extends from near Frankfort southwest to just south of Elizabethtown and then back toward Greenville, KY. We expect this outflow to continue to push southeastward with additional convection firing up behind it. The convection behind the outflow is just below severe levels with mainly wind gusts of 40- 50 mph, heavy rainfall, marble sized hail, and frequent lightning. The strongest cells were located across our southwestern sections. The strongest storm at this time is across Muhlenberg county with another strong storm near Rough River Lake on the border of Grayson/Breckinridge. These storms will move east-northeast over the next 1-2 hours. To the south of the outflow boundary, the atmosphere has continued to warm. Temperatures from the KY Mesonet were in the lower 80s with dewpoints in the upper 60s. This results in MLCAPE values of 2500-3000 J/kg with DCAPE values between 1200-1300 J/kg. Storms ahead of the outflow boundary may continue to pulse up and down with damaging winds, marble sized hail, possibly up to nickels/dimes, and frequent lightning. We`ll continue to watch convective trends and if convection starts to uptick further an EXA to WW254 or possibly a new watch issuance may be required across portions of our southern/southeast sections. && .Short Term...(This evening through Sunday) Issued at 315 PM EDT Sat May 21 2022 Afternoon satellite imagery shows partly sunny skies across the region. Two clusters of convection were being tracked. The first is moving eastward across the Bluegrass region with a second line coming in from the west. In areas not affected by storms as of yet, temperatures were in the upper 80s. However, in rain cooled spots, temperatures ranged from the upper 60s to the lower 70s. In the near term, we`ll be watching these two areas of convection closely. The first one moving eastward through the Bluegrass is within a plume of instability where MLCAPE values of 2500-3000 J/kg were found. Bulk shear values were less than 25 knots here. Model proximity soundings show good instability here with DCAPE values over 1000 J/kg. Based on CAPE/shear profiles, pulse type severe storms will be possible with this activity. Damaging winds and hail up to the size of quarters will be possible. Slightly higher values of shear were analyzed north of the I-64 corridor, so in the next 1- 2 hours, the corridor of highest severe weather will be across portions of Scott/Harrison/Woodford/Fayette/Bourbon/Clark/Nicholas counties. Further south along the southern edge of the Bluegrass convection, storms have generally remained linear and weaker due to the bulk shear being less as one heads down toward Somerset. Nonetheless, a period of showers/storms can be expected for those areas out in the I-75 corridor. Further out to the west, ongoing line of storms has crossed into southwest Indiana and western Kentucky. KVWX radar shows healthy convection moving through Evansville with outflow racing ahead of the storms. Bulk shear across western KY is not all that strong with values in the 0-6km layer of 20 knots or less per the KPAH VAD profiles. Shear values are little stronger to the north from the KVWX VAD profile where 20-25 knots of shear was noted. As the outflow races ahead of the line, we`re likely to see further convective development as it moves through southern Indiana and extreme northern KY. The atmosphere out ahead of it has been baking for a while with KY Mesonet readings in the mid 80s with dewpoints in the upper 60s/lower 70s resulting in MLCAPE values of around 3000 J/kg. Proximity soundings from the HRRR from Owensboro east to Fort Knox show a well mixed lower PBL with DCAPE values of 1000-1100 J/kg. The outflow should knock parcels upward and allow further convection to develop rather quickly. Again shear values south of the river drop off decently, so the main threats with this line as it moves through our western areas will be damaging winds (45-65 mph), frequent lightning, and perhaps a few instances of large hail (marbles to quarters) in the strongest cores. The western line of convection should continue to head eastward late this afternoon and this evening across Kentucky posing a risk of damaging winds and scattered hail reports. We`ll probably see some downstream watches come out as the line moves on through. However, convective intensity should wane due to the loss of heating later this evening. Wind shear values remain weak across our area as the higher shear values will be found to our southwest across AR. Nonetheless with the frontal boundary out to the west, some additional elevated convection may be possible overnight. So, we`ll continue with high PoPs. Cooler air will filter into the region behind the front late tonight. Lows will range from the lower 50s over SW IN with lower-mid 60s over much of KY east of I-65. For Sunday, the cold front will continue to move eastward through the region. Best chances of rain on Sunday looks to be mainly east of I-65. Instability and shear profiles look rather weak, so widespread shower activity with perhaps a few embedded storms out near the I-75 corridor will be possible. Highs will range from the upper 60s west of I-65 to the lower 70s east of I-65. .Long Term...(Sunday night through Saturday) Issued at 320 PM EDT Sat May 21 2022 Sunday night, surface high pressure with anticyclonic northerly winds will limit temperatures to the 50s under mostly cloudy skies. Suppressed temperatures will remain with highs in the low to mid 70s on Monday before southern flow returns on Tuesday, lifting temperatures to either side of 80. Tuesday, precipitation chances will return to the CWA. Near the southern tip of the axis of a large upper trough covering the US, a surface low will begin strengthening over TX as it moves towards WI through Wednesday. Extending east of the low, a warm front using Gulf of Mexico moisture will work its way north increasing precipitation chances from the south into the Lower Ohio Valley during the day Tuesday, and with the system over MO Tuesday night, shower and t-storm chances will increase and remain until the cold front trailing the system passes from west to east Wednesday afternoon and evening. Precipitation behind the front could remain through Thursday. The GFS and Euro differ on placement of the best forcing which plays with the timing of precipitation. The Euro is slower with heavier precipitation going through the Ohio Valley on Thursday. The GFS keeps heavier rain on Thursday afternoon farther south in the southern states. Beginning on Friday heading into the weekend, upper riding will follow the upper trough out of our region. This along with surface high pressure will help bring sunnier skies and drier conditions. Temperatures will continue in that upper 70s and 80s range. && .Aviation...(00Z TAF Issuance) Issued at 704 PM EDT Sat May 21 2022 IMPACTS: - Showers and thunderstorms this evening - Low cigs Sunday morning DISCUSSION: Band of convection stretching from KBWG northeast to KLEX will continue to slowly push off to the east-southeast over the next few hours. Convection should diminish in intensity with the loss of heating this evening. Some additional convection out across SE MO will continue to push east, but this activity should diminish to just showers later this evening as it moves across the area. Surface cold front will push through the region late tonight and cross the I- 65 after sunrise Sunday. We expect cigs to lower overnight with cigs dropping to FL012-FL015 by Sunday morning. CONFIDENCE: Medium on all elements. && .LMK WATCHES/WARNINGS/ADVISORIES... IN...None. KY...None. && $$ Mesoscale...MJ/DM Short Term...MJ Long Term....KDW Aviation.....MJ
Area Forecast Discussion...Updated Aviation
National Weather Service Saint Louis MO
1051 PM CDT Sat May 21 2022 .SHORT TERM... (Through Late Sunday Night) Issued at 247 PM CDT Sat May 21 2022 Key Messages: 1. Showers and thunderstorms will continue this afternoon and evening. While unlikely, I can`t rule out a thunderstorm becoming strong enough to produce quarter sized hail this afternoon. 2. Locally heavy rain associated with individual thunderstorms, and minor flooding continues to be a threat, particularly across areas that have already seen heavy rainfall today. 3. Temperatures will cool drastically behind the front. Showers and elevated thunderstorms will continue this afternoon and into the evening along the 850mb baroclinic zone, behind the surface cold front that now lies from KHRO to KCGI and KCUL. MUCAPE values are weak across the region in the post-frontal environment, but the best instability is across central Missouri where the RAP analysis shows MUCAPE peaking near 1000 J/kg. Effective bulk shear between 40-50 kts should be enough to organize the elevated thunderstorms over central Missouri, and the 7.5 degree/km lapse rates make hail the primary threat with any storms that become strong. Instability is our limiting factor with these thunderstorms, and confidence is low that any storm will become strong enough to produce quarter sized hail. By the evening instability and the threat for strong thunderstorms is expected to be very weak as the 850mb front continues to slide southeastward. Localized heavy rainfall and localized flooding associated with these thunderstorms is a greater threat. The axis of heaviest rainfall from this morning has fallen along a line from Springfield, MO through St. Louis, MO, into Springfield, IL. About an inch of precipitation, with locally higher amounts, has fallen across this area. The showers and thunderstorms that are forming and increasing in coverage this afternoon are following a similar path and pose a localized flooding risk, particularly in low lying and poor drainage areas. The continued retreat of the cold front and advance of a surface high into the region will help shunt lingering precipitation out of the area by tonight, ending the hail and localized flooding threats. Cold air advection will continue in the low-levels behind the front, pulling the 850mb temperatures into the single digits aloft by Sunday, translating to below normal temperatures at the surface. Temperatures overnight will cool into the 40s to mid 50s, near to up to -15 degrees below normal for this time of year. Despite the clearing sky on Sunday under the influence of the surface high, sustained cold air advection and cool 850mb temperatures will keep temperatures stunted. High temperatures in the mid 60s will make Sunday feel more like mid-April than mid-May. MRM .LONG TERM... (Monday through Next Saturday) Issued at 247 PM CDT Sat May 21 2022 A longwave mid-level trough will continue to deepen across the western half of the CONUS during the first half of the work week, amplifying southwesterly mid-level flow over the mid-Mississippi Valley. At the surface the high pressure will continue to shift eastward across the region Monday, keeping the forecast area precipitation free for another day in advance of our next low system. By Monday evening a shortwave will travel up the mid- level southwesterly flow into the mid-Mississippi Valley, mirrored at the surface by the northeastward movement a surface low. The warm front associated with this low is expected to lift northward through the forecast area Monday night into Tuesday morning. Light precipitation is possible with isentropic lift over the warm front as moisture surges back into the area south of the front, but confidence is not high that widespread showers and thunderstorm will be able to form. The next best chance for showers and thunderstorms will be Tuesday through Thursday as the surface low, and perhaps a second surface low, move through the region in step with the northeastward movement of the mid-level shortwave. The NAEFS continues to indicate PWAT values near the 90th climatological percentile in association with this event, however the NBM viewer isn`t currently indicating that significant rainfall will be an issue. Severe weather conditions continue to be more favorable to the south of our area, however I can`t rule out that threat moving north in the intervening days. Guidance differs in how quickly the mid-level trough will push through the mid-Mississippi Valley. About 40% of the WPC Cluster members favor a more progressive trough, pushing east out of the region Thursday into Friday. Confidence is high that by Friday the trough will be retreating from the area, with 80% of members indicating the trough will moving into the Ohio River Valley. Rising heights associated with the exit of the trough axis will continue into the weekend as a ridge builds into the area. Temperatures will be absolutely wonderful during the work week. Cooler 850mb air will keep temperatures near to slightly below normal with highs generally in the 70s. Periods of showers and heavy cloud cover could stunt temperatures mid-week. By the weekend the rising heights aloft and southwesterly low-level flow will help warm temperatures to near normal. MRM && .AVIATION... (For the 06z TAFs through 06z Sunday Night) Issued at 1048 PM CDT Sat May 21 2022 The last of the light showers or drizzle are in the process of moving out of the St. Louis terminals and expect any lingering MVFR ceilings will be out of these terminals by 06Z. With drier air moving into the area, have gone dry and VFR conditions with this set of TAFs. Winds will be out of the north at 12 knots or less. Britt && .LSX WATCHES/WARNINGS/ADVISORIES... MO...None. IL...None. && $$ WFO LSX
Area Forecast Discussion
National Weather Service Newport/Morehead City NC
1014 PM EDT Sat May 21 2022 .SYNOPSIS... Ridging aloft continues through the weekend. A cold front will move into the area Monday bringing unsettled weather. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... As of 1010 PM Sat...Partly cloudy conditions prevail late this evening with all convective activity well north into Virginia. Focus for overnight convection now shifts offshore where considerable instability still lingers. A weak signal remains for some overnight activity to potentially drift across the southern coast this evening, but an ongoing convective complex off the coast of far southern SC may interfere with moisture transport and prevent any development - the 00Z HRRR appears to be catching onto this idea. Current PoPs are reasonable and left them alone for this update. Prev disc...Little change in the pattern tonight with high pressure centered offshore. Any sct storms across the coastal plain will dissipate this evening with loss of sfc heating, but weak shortwave energy will be present acrs the region through tonight, so cannot rule out a widely sct shower or even a storm, but only a 20 pop in the fcst to account for this as most places remain dry. Guidance is also suggesting that we could see stratus development along the coast overnight once again. Swly flow will keeps temps very warm with lows no lower than 70. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/... As of 330 PM Sat...Aforementioned weak shortwave energy will be prevalent in the morning, so a sct shower or storm is possible early in the day, esp srn half of the FA. Diurnal heating and strengthening onshore flow will transition any convection chances inland during the afternoon. Have lowered pops a bit, with around 30% fcst, as best forcing is still going to be west of the Coastal Plains tomorrow. Highs a touch lower, though still quite humid. Expect readings in the low 90s interior to 80s coast. && .LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/... As of 3 AM Sat...Unsettled weather expected through the period with more seasonable temperatures. Front will push through the area Monday then linger just off the coast through mid week, with a stronger front expected to impact the area late week and early next weekend. Monday through Saturday...Still looks unsettled through much of the period. Front is progged to push into the area Monday with low pressure developing inland along it. Most guidance now pushes the front all the way through the area, then stalling offshore through Wednesday. This would keep the area on the cool side of the boundary with moist low level NE-E flow. Best precip chances still look like Monday afternoon and Monday night with potential for locally heavy rain. Precip becomes more scattered Tue through Thu, maybe even more isolated at times, likely enhanced during diurnal peak heating. Cloud cover, precip and NE-E flow will keep temps near or below normal with highs in the 70s/80s. Boundary will likely lift back north as a warm front late Wed and Wed night while complex low pressure strengthens over the Mid-West lifting towards the Great Lakes. The cold front associated with this system is currently progged to push through the eastern NC late week/early next weekend. 00z GFS and EC are in pretty good agreement with fropa this far out in time. Capped pops at high chance late week for now. && .AVIATION /02Z SUNDAY THROUGH THURSDAY/... SHORT TERM /through Sunday/... As of 735 PM Sat...High confidence in VFR conditions through the period for TAF terminals. Shower and storm threat has largely ended and an overcast evening courtesy of mid and high level clouds is forecast with steady southwesterly flow, precluding a fog threat. Low-level stratus could form again for south coastal terminals (MRH, NJM, etc.) like last night resulting in localized LIFR conditions overnight. LONG TERM /Sunday night through Wednesday/... As of 3 AM Sat...Scattered showers and thunderstorms may bring brief periods of sub-VFR conditions Sunday night. A front will push into the area Monday, likely stalling through mid week. This will bring increasing chances for scattered to numerous showers and thunderstorms along with potential for periods of sub-VFR. Guidance shows cigs lowering to MVFR, possibly IFR Monday behind the front and persisting through at least Monday night. && .MARINE... SHORT TERM /Through Sunday/... As of 330 PM Saturday...High pressure remains centered offshore bringing SW winds across the waters through the short term. Typical thermal gradient will strengthen winds late afternoon to early evening, and a few gusts to 25 kt are possible, before gradient relaxes later tonight to Sunday morning with 10-15 kt. Afternoon thermal gradient returns again for Sunday afternoon with an inc to 15-20 kt once again. Seas will remain on the lower side, generally 2-4 ft with a 5 second wind chop. LONG TERM /Sunday night through Wednesday/... As of 3 AM Sat...Moderate SSW winds 10-20 kt continue Sun, strongest during the late afternoon and evening hours with potential for a few gusts to 25 kt, with seas generally 2-4 ft. Front will push into the waters Monday, then likely stall across the waters through mid week. NE winds 10-20 kt expected behind the front, though placement of boundary will make the wind forecast challenging. Stronger NE winds 15-25 kt may develop Tue and Tue night with waves developing along the front. Which would allow seas to build to 3-5 ft across the northern and central waters, possibly up to 6 ft. A period of SCA conditions will be possible, with best chances across the northern waters/sounds and central waters early to mid next week. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...None. MARINE...None. && $$ SYNOPSIS...MHX NEAR TERM...TL/MS SHORT TERM...TL LONG TERM...CQD/SGK AVIATION...CQD/MS MARINE...CQD/TL
Area Forecast Discussion
National Weather Service Nashville TN
954 PM CDT Sat May 21 2022 .UPDATE... FOR EVENING DISCUSSION. && .DISCUSSION... Updated suite of forecast products per current regional weather trends per radar, satellite, and surface observation analysis. 22/00Z HRRR model run initialized best and has the most realistic evolution of weather pattern development across mid state region remainder of evening through overnight hours compared to other CAMs. Best potential for some strong thunderstorm activity approaching 22/03Z(10 PM CDT Tonight) remains generally confined to southwestern portions of mid state region. Overall trend of weakening convection strength should continue, including line of showers and thunderstorms approaching TN River Valley region in western TN approaching 22/03Z(10 PM CDT Tonight), that will shortly move into western portions of our area, as remainder of evening into overnight hours progress. Certainly can not rule out a strong thunderstorm here or there, but again, overall trend of convection strength will be a weakening one. Tweaked hourly gridded temperature, dewpoint, and wind speed/direction grids blending them with associated previously forecasted late evening/early overnight hourly gridded values. Current regional temperature trends generally in line with forecasted lows across mid state region. Will be issuing an update to the suite of forecast products shortly after top of hour as the severe thunderstorm watch for the four northwestern counties of mid state region will be allowed to expire. Remainder of forecast continues to be on track. && .AVIATION... 00Z TAF DISCUSSION. Scattered TSRA will impact the terminals (except CSV) this evening. There will be a break after 02Z, then more scattered showers and storms will move in after 04Z. A cold front will pass through the area around 12Z for most sites. The front will bring NNW winds. Scattered showers and a few thunderstorms will follow the front throughout Sunday with mainly MVFR cigs area wide. && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ DISCUSSION......JB Wright AVIATION........13
Area Forecast Discussion
National Weather Service Springfield MO
625 PM CDT Sat May 21 2022 Key Messages: 1. Showers and storms likely through this evening. Few severe storms possible along with minor flooding. 2. Cool and dry conditions Sunday. 3. More showers and storms are expected at times late Monday through mid week, with widespread excessive rainfall possible. 4. Below average temps likely this week. .SHORT TERM...(This evening through Sunday) Issued at 200 PM CDT Sat May 21 2022 A surface cold front was located southeast of Springfield early this afternoon, generally near West Plains. The front has slowed down as low pressure was moving through northern Arkansas. Temperatures northwest of the front were in the lower to middle 50s, with lower to middle 70s occuring along and southeast of the front. Showers and thunderstorms were beginning to increase in coverage as lift associated with the right entrance region of a strong upper level jet was placed near the area. Latest RAP data indicates about 1000-2000j/kg of elevated MU CAPE and 20-30kts of effective bulk shear. Therefore some storms could remain organized this afternoon behind the front with some small hail as mid level lapse rates remain steep. Areas ahead of the front across south central Missouri are more unstable and could pose a threat for a severe storm or two. A moist airmass remains over the area with PW values well above average, around 1.7 in. Minor flooding occurred this morning and with additional pockets of heavy rainfall developing, additional areas of minor flooding will remain possible. The front and associated precip will clear the area completely overnight, however high clouds will remain. A drier and colder airmass will build in with temps dropping into the lower to middle 40s by early Sunday morning. HREF guidance shows that high clouds should begin to move out during the afternoon, however northerly winds and slight cold air advection will only lead to highs in the middle 60s, which is about 10-15deg below average. .LONG TERM...(Sunday Night through Saturday) Issued at 200 PM CDT Sat May 21 2022 Showers and thunderstorms will develop in Oklahoma and southern Kansas late Sunday night into early Monday morning as a low level jet begins to strengthen ahead of the next storm system. This activity could drift into western Missouri during the day Monday. Highest chances for rain Monday look to be west of Highway 65. Clouds and precip will likely keep temps in the middle to upper 60s. Another shortwave will move up from the southwest during the day Tuesday. Ensemble clusters all show precip with this system therefore precip chances remain quite high. Good moisture fetch from the Gulf will be present with this system and will need to monitor for flooding potential. Currently the NBM has high probs for a widespread 0.5 to 1 inch of rainfall with this round. Uncertainty increases on Wednesday and Thursday as the next upper trough pushes into the area. It is possible that the heaviest qpf axis shifts south of the area and this trend will be monitored. Well below average temps are likely through mid week. Conditions look to dry out for the end of the week as a mid level ridge begins to develop. This should allow for temps to climb closer to average. && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) Issued at 623 PM CDT Sat May 21 2022 Main convection has shifted well east of the terminals early this evening. A few showers lingering behind the front, but those have decreased significantly over the past few hours. Have thrown in VCSH for SGF/BBG for a couple/few hours this evening. IFR ceilings should lift into MVFR this evening and eventually VFR later in the evening and overnight. && .SGF WATCHES/WARNINGS/ADVISORIES... MO...NONE. KS...NONE. && $$ SHORT TERM...Burchfield LONG TERM...Burchfield AVIATION...Lindenberg