Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 05/14/24


Area Forecast Discussion
National Weather Service La Crosse WI
1036 PM CDT Mon May 13 2024 .KEY MESSAGES... - Smoke from Canadian wildfires continue to impact the local area with hazy conditions/milky skies tonight. - Rain chances linger far south tonight and Tuesday, much drier air to move in from the north. - Rain chances favorable, but still light (50-70% chance of 0.10+) Wednesday night into Thursday with the weekend still unsettled for now. && .DISCUSSION... Issued at 224 PM CDT Mon May 13 2024 Overview: Water vapor satellite imagery, 500mb heights, and lightning showed a closed low over the Mid-Missouri River Valley with another area of closed low pressure over Hudson Bay. Lightning was noted over parts of IA/MO into IL, with clusters of storms farther south across TX/LA/MS/AL. The first surface front was over parts of northern IL with a reinforcing push/wind shift moving through as the wave to the northeast pushes through with dewpoints in the 30s pushing south and dewpoints in the 50s to around 60 lingering across parts of eastern Iowa and southern Wisconsin. Smoke Tonight - Rain chances tonight/Tuesday: Visible satellite imagery from 13Z this morning showed an expanse of smoke across the local area, however by 15Z, local visibilities had improved some. Hazy conditions with some visibility reductions will be possible into the overnight hours. The latest RAP Near- Surface Smoke forecast shows a north to south push of improving conditions. By 06Z, parts of northeast Iowa and the PDC area could see some reduced visibilities. Some low values of particulates will linger area-wide 14.09-16.00Z Tuesday. Air quality alert for parts of MN/WI/IA remain in effect this evening. The trough over the Upper Mississippi Valley phases with the mid- tropospheric low over the Mid-Missouri River Valley, but then closes off again off over IL shifting east through the day Tuesday. Showers and a few storms will continue to graze parts of the southern forecast area today, then a few showers will persist until the storm system shifts east into Tuesday. The general consensus with the hi-res models is for the bulk of the activity to remain southeast of the forecast area Tuesday. The 13.12Z HREF was a bit farther south with the precipitation compared to the 13.00Z run. The RAP is a little more aggressive farther north. For now will hold on to some pops in the south and monitor push of drier air and northward extent in the short term. Temperatures Tuesday and Wednesday should be seasonable in the 60s to lower 70s. Rain chances mid to late week: The trough over the Pacific Northwest is forecast through the Plains Tuesday night toward the Upper Mississippi Valley Wednesday night. The low level jet increases and 850mb moisture pools ahead of the cold front from MN/wrn IA/ern KS Wed. Moisture transport increases locally Wednesday night into Thursday. Deepest moisture and stronger moisture transport vectors remain to the south across parts of MO/IL. There appears to be enough vorticity/warm air advection and limited instability (500J/kg) with the front for scattered showers and a few storms. 0-6km is generally limited...20-30kts, however there is a period of time Wednesday night with higher shear values north of I94, however instability is quite low then. Will maintain likely shower/storm chances Wednesday night into Thursday. Forecast soundings hint that a few showers could re-develop Friday/Friday night in the northwest flow aloft. For the weekend, we are still unsure of if the pattern will be more zonal locally or have a trough coming through. Due to this uncertainty of dry vs. a trough and timing differences, we do have rain chances in for the weekend, but this will be refined as we hone in on the synoptic patern. The NAEFS/EFI remain on the lackluster side. Weekend temperatures appear to be seasonably warm in the 70s. && .AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/... Issued at 1037 PM CDT Mon May 13 2024 VFR conditions are expected through the TAF period with some high cirrus and some smoke aloft. Any remaining surface smoke will move out of the region early in the TAF period with increasing easterly surface winds into the morning and afternoon hours to around 10 kts. A disturbance passing to our south may bring in a shower or two into portions of northeast Iowa and southwestern Wisconsin overnight and into the morning hours on Tuesday however both TAF sites are expected remain dry. Winds will begin to diminish during the evening on Tuesday to around 5 kts as diurnal mixing begins to wane. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. IA...None. && $$ DISCUSSION...Zapotocny AVIATION...Naylor
Area Forecast Discussion
National Weather Service Denver/Boulder CO
808 PM MDT Mon May 13 2024 .KEY MESSAGES... - Scattered showers and isolated thunderstorms over the mountains and foothills with isolated showers and storms over the nearby plains. - Scattered afternoon/evening showers and thunderstorms Tuesday. - Front brings cooler and wetter weather on Wednesday. Light snow for elevations mainly above 10,000 feet. - Warmer and generally drier starting Thursday, with lesser but at least isolated daily afternoon showers/thunderstorm coverage, highest for the mountains. && .UPDATE... Issued at 802 PM MDT Mon May 13 2024 A few showers are still lingering across the high country and eastern plains, but it`s generally a quiet evening. Showers should diminish through the rest of the evening although a snow shower or two will remain possible overnight across some of the northern mountains. No significant changes to the previous forecast were made as it was in good shape. && .SHORT TERM /Through Tuesday/... Issued at 217 PM MDT Mon May 13 2024 Radar showing scattered showers over the mountains and foothills. Best instability resides over the higher terrain with ML CAPE to around 500 J/kg, so still expect isolated storms to form. Instability decreases eastward onto the plains. Weak ridging will move across Colorado this evening and tonight. Expect this to keep convection weak and isolated to scattered. The stronger storms will be capable of produce small hail (pea sized), wind gusts to 40 mph, and brief heavy rain. Convection dies off early to mid evening with the loss of daytime heating stabilizing the airmass. For Tuesday, westerly flow aloft will prevail behind the exiting ridge and in advance of a wave dropping southeast across Wyoming. This wave should help produce at least scattered convection (more than today). Instability will slightly increase with ML CAPE up to 700 J/kg. Still expect storms to stay sub severe, with brief heavy rain and small hail under the stronger storms. Wind gusts may be slightly stronger, up to 50 mph. Airmass warms a little more with some locations topping 80F degrees over northeast Colorado. && .LONG TERM /Tuesday night through Monday/... Issued at 217 PM MDT Mon May 13 2024 Tuesday evening into Wednesday, an upper level trough approaches from the west with weak QG lift ahead it. An associated cold front moves across the region, likely early Wednesday morning (midnight- 6am). North to northeasterly flow persists during the day Wednesday post-front. The upslope component will provide an addition source of moisture, especially in the favored areas such as the Palmer Divide, Front Range, and adjacent plains. This will bring a cooler and more unsettled day. In the cooler post-frontal airmass, high temperatures likely stay in the 60s across the plains, considerably cooler than Tuesday`s highs. Sounding profiles and instability fields show marginal instability Wednesday afternoon (MLCAPE < 500 J/kg). Within the weak upslope environment, this could support convective showers and embedded storms. With respect to amounts, ensemble means show a range of 0.20" to 0.60". There is notable small variations happening from run to run and the GFS is appearing to be the wetter suite of solutions. The higher amounts will likely be focused in those upslope favored areas (Front Range, Palmer Divide, south foothills, Denver metro). The cooler air stays north with the trough, but it be should enough to bring snow levels down to 10,000 during the day and around 9500 overnight. As a result, snow showers are possible for the higher mountains/mountain passes. Ensembles show light accumulations, so at this point not major impacts are anticipated. On Thursday, the upper trough exits to the east putting northeast Colorado under northwesterly flow aloft. Subsident flow should keep dry out much of the region from Wednesday. Model cross sections show some residual moisture in the high country with marginal instability building in the afternoon to support scattered showers/storms. Given the limited instability/moisture, coverage/chances will be less (< 25%) and mainly over the higher terrain. Temperatures recover from Wednesday with highs pushing back into the upper 60s/low 70s for the lower elevations and 40s/50s for the high country. Friday into the weekend, expect weak ridging to zonal flow in the upper level pattern. 700mb temperatures warm a degree or two each day, supporting a gradual warming trend. Highs in the upper 70s to low 80s Fri/Sat. Daily heating/instability should support scattered afternoon showers and thunderstorms in the mountains with a low chance for a few to stray onto the adjacent plains. Friday through the weekend will be drier across the plains with relative humidity values dropping into the 20 percent range in the afternoons. && .AVIATION /00Z TAFS through 00Z Tuesday/... Issued at 533 PM MDT Mon May 13 2024 Generally VFR through the TAF period. In the near term, main concern is an outflow boundary draped fro GXY to just east of DEN which is slowly drifting west. Speeds on either side of this boundary aren`t terribly strong, but if any showers/TS form in the next hour or two it would likely be on this boundary. The HRRR does hint at another round or two of organized showers later this evening but confidence in that is fairly low. Drainage flow is expected overnight tonight, followed by a turn to the northwest by tomorrow afternoon. Additional widely scattered storms are possible tomorrow afternoon. Model consensus supports this being isolated enough to not include a PROB30/TEMPO at this point. && .BOU WATCHES/WARNINGS/ADVISORIES... None. && $$ UPDATE...Hiris SHORT TERM...Meier LONG TERM...Mensch AVIATION...Hiris
Area Forecast Discussion
National Weather Service Burlington VT
1029 PM EDT Mon May 13 2024 .SYNOPSIS... An unsettled weather pattern will continue over the next couple of days with several rounds of showers, with numerous showers and some embedded thunderstorms expected tomorrow. Seasonable high temperatures and mild overnight lows are expected for much of the upcoming week. && .NEAR TERM /THROUGH WEDNESDAY/... As of 1030 PM EDT Monday...Forecast remains in good shape so only made minor tweaks to bring it up to date with current obs. Warm front is lifting northward across NY state this evening, helping to fuel a few showers with a few cloud flashes and even a solitary lightning strike across far western St Lawrence county. But lightning activity is not expected to make too much eastward progression, as the embedded shortwave energy will be steered northeastward roughly parallel to the St Lawrence River valley. RAP mesoanalysis shows height rises associated with a H5 ridge east of the Adirondacks into Vermont. One favorable parameter is the 2-6 km AGL lapse rates, which are in the 6.5 to 7C/km range. But the expectation is that outside of northern NY which has the best chance of hearing a few rumbles of thunder, our Vermont zones should primarily see rain showers with the isolated brief downpour. Temperatures will be slow to fall overnight thanks to strong warm advection and southerly flow. PREVIOUS DISCUSSION...Light showers across the region have brought little to no measurable precipitation this afternoon, with only a few hundreths at most so far. As we head into the evening, a frontal boundary will become stalled near the International Border, with increased chances for showers and some possible rumbles of thunder across northern New York overnight due to increased elevated instability and stronger forcing. Overnight lows will be on the mild side tonight, in the 50s, although spots east of the Greens will drop into the upper 40s. Model soundings for tomorrow show tall and skinny CAPE profiles, supporting the idea of some heavy downpours and embedded thunderstorms tomorrow afternoon, with PWAT values in excess of an inch. Current QPF amounts range from a few tenths to near an inch, with localized higher amounts expected in any thunderstorms. The latest CAM guidance suggests CAPE values between 500 to 1200 J/kg across southern portions of the forecast area tomorrow, with temperatures warming into the 70s. Meanwhile closer to the International Border, temperatures will only warm into the upper 60s. There is still a little uncertainty regarding the instability across the region tomorrow afternoon as lingering cloud cover will limit surface heating. There is the potential for training storm motions with any developing convection, which will need to be monitored given the potential for heavier downpours. While widespread severe is not currently anticipated, NCAR is showing a non-zero threat for some severe weather and there will likely be plenty of activity to monitor tomorrow afternoon. Shower activity will dwindle heading into the evening with the lack of diurnal heating, with overnight lows expected to be quite mild for this time of year. && .SHORT TERM /WEDNESDAY NIGHT/... As of 402 PM EDT Monday...ANother round of showers is expected for much of Wednesday as a cut off low becomes stuck over the Mid- Atlantic region. This slow moving low pressure system is expected to drape a warm frontal boundary across our forecast area which should allow for shower activity to increase throughout the day on Wednesday given modest heating under cloudy skies. Thermal profiles have varied from run to run but it seems we will be looking at closer to moist adiabatic lapse rates which in this case likely won`t favor thunderstorms. Could a rumble of thunder occur? Possibly, but most likely we should just see scattered to numerous showers on Wednesday. The main focus on rainfall accumulations will be across southern Vermont where we could see a quarter to maybe a third of an inch of rain but lesser amounts as you get closer to the International Border. Shower activity is expected to wane as we head into Wednesday evening with the loss of daytime heating but a few showers will likely continue through the overnight period. && .LONG TERM /THURSDAY THROUGH SUNDAY/... As of 402 PM EDT Monday...Thursday had been looking drier for a while but the latest guidance suggests it may not be as dry as we had been thinking. The stall frontal boundary mentioned in the above section will remain over the area on Thursday. We better heating due to slightly less cloud cover, a resurgence of shower activity is expected during the afternoon hours. It won`t be as widespread as Wednesday but isolated to scattered showers could drop some light rain throughout the day with thunderstorm potential again looking rather meager. Friday, on the other hand, has trended a little drier as the 12Z guidance is showing building 500 mb heights in response to a deepening trough over the central US. Increasing subsidence is expected to keep shower activity largely at bay although a few diurnal showers cannot be ruled out. Rain chances will increase throughout the day on Saturday as the aforementioned trough slides eastward and we see a series of frontal boundaries move through the region. With good fetch of Gulf of Mexico moisture, we could see some heavy rain showers this weekend but the details will be ironed out over the next several days. Those with outdoor weekend plans are encourages to keep a close eye on the forecast. This period of unsettled weather is likely to continue well into next week with a series of disturbances likely to pass near the northeastern US. The good news is that we aren`t expecting any significant rainfall so flooding doesn`t look to be a concern moving forward. && .AVIATION /02Z TUESDAY THROUGH SATURDAY/... Through 00Z Wednesday...Mainly VFR conditions are expected for the next few hours. Winds throughout the period will range between southeast to southwest between 5 and 10 knots through the period, with a few gusts 15 to 18 knots at KBTV. Some showers are already present over northern New York and did produce some lightning, but have been decaying. The stronger convection is north of Lake Ontario, and that will shift into the region alongside the warm front about 02z to 03z. Showers will be likely across the region between 03z and 10z as it lifts north and then stalls near the international border. In heavier elements, 3-6SM visibility and ceilings 2000-3000 ft agl will be possible. Thunderstorm activity should decay moving east, and so KSLK is the only to have a TEMPO for TSRA between about 03z and 05z, but could be possible further east if it holds together. Patches of low level wind shear will develop behind the warm front from about 04z to 10z for 35 to 40 knot southwest winds at 2000 ft agl. Some partial clearing and lifting ceilings follow the warm front 10z-12z, but where warm front stalls is not entirely certain. So outside of KMPV and KRUT, the forecast maintains VCSH for several terminals. Additional showers and thunderstorms will develop about 18z. A weak trough will shift south, with convection near the trough and lifting north-northeast towards the trough axis until is passes south sometime near or after 00z Wednesday. It`s too far out now, but some thunderstorms could be strong, and there will be potential for ceiling and visibility reductions between 18z beyond 00z Wednesday. Outlook... Tuesday Night: Mainly VFR, with local MVFR possible. Chance SHRA. Wednesday: Mainly MVFR, with local VFR possible. Likely SHRA. Wednesday Night: Mainly VFR, with areas MVFR possible. Chance SHRA. Thursday: Mainly VFR, with local MVFR possible. Chance SHRA. Thursday Night: Mainly VFR, with local MVFR possible. NO SIG WX. Friday: VFR. Chance SHRA. Friday Night: VFR. Chance SHRA. Saturday: Mainly MVFR, with local IFR possible. Chance SHRA. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...None. NY...None. && $$ SYNOPSIS...Kremer NEAR TERM...Chai/Kremer SHORT TERM...Clay LONG TERM...Clay AVIATION...Haynes
previous forecast discussion mentioned, instability and shear will
be very marginal, with effective shear values progged around 20
knots or less, with HREF surface based CAPE up to 1000 J/kg this afternoon. Given this parameter space, severe storms aren`t expected. However, with Pwat values hovering around 1.2 to 1.4, which is near or above the 90th percentile off the SPC sounding climatology, periods of heavier rainfall are expected. A deformation zone appears to develop north of the cut-off low, and pivot across our southern forecast area. Slow moving or repeated rounds of showers and storms would allow rainfall to accumulate rapidly, so we will continue to watch for flooding issues. WPC continues to paint a Slight risk of flash flooding for areas along and south of Interstate 80. In total, between 1 to 2 inches of rainfall remains possible for areas along and south of I-80, with gradually lighter amounts farther north. HREF localized probability-matched mean indicates some isolated areas could see between 2 to 3+ inches of rainfall, given the higher Pwat values. As we go into Tuesday, the deformation band is expected to weaken with time, but it won`t move a whole lot, so showers will continue to linger across our southern forecast area. Eventually, the upper low will move off to the east by late in the day Tuesday, which will bring any lingering showers to an end and lead to decreasing cloud cover from the northwest. One other thing to watch for, especially in the afternoon hours Tuesday, is the potential for some Canadian wildfire smoke to filter in from the north. Air Quality Alerts have been issued for areas of northern Iowa into Minnesota and Wisconsin. The HRRR Smoke model shows a smoke plume dissipating as it filters into our region, but the impacts from this smoke are expected to be little, if any, at this time. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... Issued at 221 PM CDT Mon May 13 2024 The long-term period starts off with dry conditions for Tuesday night through Wednesday, thanks to an area of high pressure nosing into the region from Ontario Canada. Temperatures will be seasonal for this time frame, with lows Tuesday night in the middle to upper 40s, and highs Wednesday in the lower to middle 70s. The next chances of widespread showers and storms returns for Thursday as an upper-level trough translates eastward across the central Intermountain West region. A southern stream mid-level impulse is progged to lift northward towards our region, and bring widespread chances (40 to 70% from the NBM) of rainfall. Pwat values of around 1 to 1.3 inches are progged off the deterministic GFS and NAM guidance, so another round of decent rainfall is possible Thursday, although NBM probabilities of total rainfall of a quarter inch or greater is between 40 to 60 percent, so not a strong signal either way. At this time, the threat for any strong to severe storms Thursday remains low, given meager values of effective shear and instability. The upper-level pattern continues to be active into the end of the week, with additional upper-level troughs traversing the northern CONUS, but confidence in the timing of these troughs for our area remains uncertain due to differences in the guidance. && .AVIATION /00Z TAFS THROUGH 00Z TUESDAY/... Issued at 618 PM CDT Mon May 13 2024 VFR conditions will quickly transition to MVFR and IFR through the evening and night. Widespread showers and thunderstorms are being seen throughout, which are actively lowering cigs and vis throughout, continuing through the night. Currently, cigs are forecast to drop into the 1000-3000 ft range before 06z, with cigs dropping below 1000 ft after. These conditions will persist through the night, as the low pressure slowly moves through the area. The lowest cigs will be seen in heavier showers and storms, which may drops cigs to 500 ft or less briefly. Confidence is low on this though. Vis will also be a concern, but mainly in the heavier showers/storms. These conditions will prevail through 12z, waning away around 18z and beyond. Although, the low cigs will remain through much of the TAF period. Main hazards with these storms will be lightning and non-severe wind gusts, with small hail being secondary. Surface winds are currently variable, but will mostly be out of the east-northeast through the night and into tomorrow. The winds will be relatively light through the night, increasing after 12z, with gusts upwards to 20 KTs possible tomorrow. && .HYDROLOGY... Issued at 221 PM CDT Mon May 13 2024 New forecasts by the North Central River Forecast Center this evening showed little to no change for the Wapsipinicon River near DeWitt. The river should reach flood stage before 7am tomorrow morning and slowly rise to 11.4 feet over the next 3 days. Depending on where additional rain falls this afternoon into this evening, more rises may be possible. However, at this time the highest totals are expected south of the Wapsi basin. The Flood Warning was continued with this forecast issuance. The forecasts for the Cedar and Iowa Rivers have come in lower this morning. The Cedar River near Conesville forecast was kept just at flood stage for now due to the incoming QPF uncertainty. For this reason, have kept the Flood Watch going there. Flood Watches have been issued for the Mississippi River at Gladstone and Burlington due to routed flow as well as rainfall amounts forecast through Tuesday. Taking a deeper dive into the QPF, widespread rainfall in the 0.5" to 1.5" range is expected in the next 24 hours, with some localized higher amounts. The 12z HREF probability-matched mean QPF values through Tuesday morning are painting a swath of rainfall in excess of one inch, with some isolated amounts over two inches slightly northward closer to the downstream portions of the Iowa, Cedar, and Mississippi River basins. This QPF placement and how much runoff occurs will be very important to whether additional rises are seen and if warnings will be needed. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...None. IL...None. MO...None. && $$ SHORT TERM...Schultz LONG TERM...Schultz AVIATION...Gunkel HYDROLOGY...Cousins
Area Forecast Discussion
National Weather Service Austin/San Antonio TX
653 PM CDT Mon May 13 2024 ...New UPDATE, AVIATION... .UPDATE... Issued at 653 PM CDT Mon May 13 2024 Isolated showers and thunderstorms have re-developed early this evening across Kerr and northern Medina counties, along a weak surface front and close to where where recent HRRR runs were indicating. A few WoFS members are showing isolated convective development along this boundary over the Hill Country over the next hour. The HRRR and WoFS dissipate activity after sunset. && .SHORT TERM... (Tonight through Tuesday night) Issued at 207 PM CDT Mon May 13 2024 The ongoing cluster of storms across the CWA, associated with a mid- level shortwave, will continue to push east through the afternoon. The current storm mode now favors more of a wind threat compared to hail, though severe hail will still be possible, especially with the more discrete updrafts. While more uncertain, there remains potential for additional development along the surface front/boundary currently extending from just south of Del Rio northeastward through the northern Hill Country. This boundary is unlikely to move much farther to the S/E this afternoon, but will serve as a weak lifting mechanism. This is evident already between Val Verde and Kerr County where there have been attempts at convection on satellite imagery and radar. Where exactly any new development forms later this afternoon and evening, if any, is the the big question, though the HRRR seems to favor the Hill Country into northern portions of the I-35 corridor. Working against this however would be the widespread cloud cover in place and rain cooled air. Regardless, if any storms do form, the severe threat will remain with the CAPE and shear in place. As far as the plan for the Severe Thunderstorm Watch, it can likely be dropped once the cluster of storms pushes east as any additional activity should be isolated. However, this is not set in stone and will continue to be re- evaluated through the afternoon. Otherwise, dry conditions are expected overnight and through the end of the short term period. Some models are indicating potential for patchy ground fog forming early tomorrow morning, which makes sense given the rainfall today and light surface winds in place. Any fog/low clouds should quickly burn off after sunrise, with mostly sunny skies expected for the remainder of the day and temperatures warming into the upper 80s to upper 90s. && .LONG TERM... (Wednesday through Monday) Issued at 207 PM CDT Mon May 13 2024 A west coast trough is still expected to arrive later in the work week, though timing may be slightly delayed from forecasts issued over the weekend. The best rain chances from this system are now expected mainly on Thursday and possibly lingering through the day on Friday. Due to the changes in model guidance and the the potential for widespread rainfall across the southern Plains, the extent of the severe weather threat remains unclear. However, given the time of year, at least an isolated severe threat seems plausible as we get closer in time in addition to the potential for locally heavy rainfall. We will then trend drier and warmer over the weekend and into the beginning of next week with temperatures likely becoming several degrees above normal. Just beyond the end of the long term, deterministic guidance shows another trough moving into the Plains, but with a more northerly trajectory compared to the system late this week. && .AVIATION... (00Z TAFS) Issued at 643 PM CDT Mon May 13 2024 VFR conditions will prevail across most of south central Texas tonight and Tuesday. The only exception will be in any isolated SHRA/TSRA activity through sunset along a weak cold front across the Hill Country as well as 09Z-14Z across portions of the Hill Country and east of the I-35 corridor where patchy BR and low stratus produce IFR to MVFR conditions. && .PRELIMINARY POINT TEMPS/POPS... Austin Camp Mabry 64 92 66 91 / 20 0 0 0 Austin Bergstrom Intl Airport 62 90 64 90 / 20 0 0 0 New Braunfels Muni Airport 63 92 64 92 / 20 0 0 0 Burnet Muni Airport 62 88 66 90 / 20 0 0 0 Del Rio Intl Airport 68 100 72 98 / 0 0 0 10 Georgetown Muni Airport 62 88 65 89 / 20 0 0 0 Hondo Muni Airport 62 93 65 92 / 10 0 0 0 San Marcos Muni Airport 62 90 64 91 / 20 0 0 0 La Grange - Fayette Regional 64 88 65 90 / 20 0 0 0 San Antonio Intl Airport 64 92 66 91 / 10 0 0 0 Stinson Muni Airport 64 93 66 93 / 10 0 0 0 && .EWX WATCHES/WARNINGS/ADVISORIES... None. && $$ Short-Term...Gale Long-Term...Gale Aviation...76
Area Forecast Discussion
National Weather Service Hastings NE
633 PM CDT Mon May 13 2024 .KEY MESSAGES... - Showers and thunderstorms will be possible Tuesday afternoon through Wednesday night. Severe thunderstorms are generally not expected. - Temperatures will be pleasant through Thursday with highs in the 70s. Temperatures will be warmer Friday through the weekend with highs in the 70s and 80s, with highs Saturday potentially approaching 90 degrees across most of the area. - Off and on chances for thunderstorms exist across the area through the period, with the best chances for this occurring (beyond Wednesday) being over the weekend. && .DISCUSSION... Issued at 200 PM CDT Mon May 13 2024 An area of low pressure exists along the KS/MO border this afternoon. A few showers and isolated thunderstorms rotating around the low continue to impact mainly southeast portions of the forecast area, but these will depart as the low continues east into Missouri this afternoon and evening. Tonight and Tuesday... High pressure will briefly move over the area, even as a front begins to move into the northern and central Plains. Overnight lows tonight will be in the 40s. This evening and overnight, with light winds across the area, RAP and HRRR model guidance is showing a little bit of smoke from Canadian wildfires moving down into Nebraska...while most of this will remain over northeastern portions of the state, some of this may drift over northern and far eastern portions of our forecast area. This probably will not impact the surface too much, but you may notice some haze in those areas Tuesday. With winds becoming south to southeast Tuesday and a ridge in place, trended high temperatures toward the higher side of forecast guidance...especially west of Highway 281 where southerly winds of 15 mph or greater are favored. With that, high temperatures are forecast to range from the upper 70s to the low 80s. Tuesday night through Wednesday night... Showers and thunderstorms are expected to return to the forecast area late Tuesday afternoon through Wednesday night. Although overall any thunderstorms are not expected to be severe, with increasing deep layer shear and marginal instability going into Tuesday evening, cannot rule out an isolated strong to severe thunderstorm early on in this event (late Tuesday afternoon into Tuesday evening)...so while there is a low chance of this occurring, we could see a sneaky storm with some hail to nearly quarter sized west of Highway 281 right along the frontal boundary...but anything approaching severe should be limited to just that. As far as rainfall amounts, even with pretty high PoPs (50-70%), QPF values remain low, around 0.25" or less in most places. Thereafter... A weak broad upper trough will be present over the central Plains Thursday and Friday, bringing low chances (< 20%) of showers and storms to the area. High temperatures will be in the 70s Thursday and in the 80s Friday. We have slightly better chances of storms in the forecast (20-35%) this weekend, but deterministic and ensemble models diverge a good bit this far out. Ensembles seem to have a better handle on temperatures Saturday, with two-thirds of the ENS and GEFS ensemble members settling on highs in the 80s across the area. && .AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/... Issued at 630 PM CDT Mon May 13 2024 VFR conditions are expected for the next 24 hours. Winds will be out of the northeast to northwest through 12z then switch to the east to southeast around 15z. && .GID WATCHES/WARNINGS/ADVISORIES... NE...None. KS...None. && $$ DISCUSSION...Hickford AVIATION...Schuldt
Area Forecast Discussion
National Weather Service Goodland KS
536 PM MDT Mon May 13 2024 .KEY MESSAGES... - Smoke from Canada may impact the Tri-State area through Tuesday. Those with respiratory concerns are encouraged to keep a watchful eye on air quality levels. - Summer-like temperatures are expected Tuesday, with widespread 80s expected. - Periodic chances for showers and thunderstorms are expected Tuesday/Wednesday and again Saturday/Sunday. && .SHORT TERM /THROUGH TUESDAY NIGHT/... Issued at 247 PM MDT Mon May 13 2024 For the rest of this afternoon, an upper trough will continue to move to the east, with the western part of the Tri-State area coming under northerly flow. Expected afternoon high temperatures will be primarily in the 70s. Visible satellite imagery shows a few cumulus clouds moving across the region. There is a small, non-zero chance of an isolated shower or thunderstorm popping up this afternoon in the eastern part of the area. Northerly winds have been transporting smoke from fires in Canada into the region. Those with respiratory concerns will want to be mindful of conditions over the next day and a half as the HRRR shows the potential of smoke staying in the region. Tuesday, northwesterly to westerly flow will be set up over the region. Expected high temperatures will be reminiscent of early summer, reaching the low to mid-80s across most areas. At least for the morning hours, dry conditions are expected. There will also be a chance of some smoke from Canada impacting the area. Heading into the afternoon, an upper trough drops south into northern Utah and Colorado. There will be a chance for showers and thunderstorms beginning in the afternoon. At this point in time, severe weather is not anticipated. Tuesday evening, a cold front is expected to move into the region. This will bring in some cooler air to the region. This should also help clear out some of the smoke. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... Issued at 247 PM MDT Mon May 13 2024 An upper trough will move across the region on Wednesday, bringing additional chances for showers and thunderstorms. There is a possibility that any thunderstorms that develop will produce heavy rain, which may result in some localized water issues. Thursday, the trough will exit the region, and the area will come under northwest flow on Friday. Expected high temperatures will be in the 70s Thursday. Expect a warm up on Friday with the northwest flow in place, ahead of our next system. High temperatures Friday will be in the 80s. A few low 90s will be possible for an area along and east of a line from McCook to Colby to Tribune. Periodic showers and storms will be possible over the weekend. && .AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/... Issued at 535 PM MDT Mon May 13 2024 Aside from a potential for sub-VFR conditions associated with scattered showers/storms Tuesday afternoon and evening (~22-03Z).. VFR conditions are anticipated to prevail through the TAF period. Guidance suggests a relatively greater potential for convection at the GLD terminal (compared to MCK), though.. confidence in convective coverage and location is below average. N to NNE winds at 10-15 knots will weaken and become variable overnight. Winds will shift to the S and increase to 10-15 knots late Tuesday morning. At GLD, south winds may weaken and become variable during the afternoon. At MCK, a southerly breeze may persist through the afternoon. Gusty/erratic winds can be expected in vicinity of any showers/storms. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...None. CO...None. NE...None. && $$ SHORT TERM...Wekesser LONG TERM...Wekesser AVIATION...Vincent
Area Forecast Discussion...Updated
National Weather Service Lincoln IL
745 PM CDT Mon May 13 2024 .KEY MESSAGES... - Showers and storms are expected (70-90% chance) through Tuesday afternoon. Expect generally 0.50 to 1 inch with 10-30% chance of over 1.5 inches. - Another system will bring rain to the area Thursday into Friday, with generally another 0.25 to 0.75 inches of rain. && .UPDATE... Issued at 745 PM CDT Mon May 13 2024 Majority of the showers/storms are currently northeast of a Galesburg-Olney line. There was a noticeable uptick in lightning activity in the 5-6 pm time frame, though this has been waning some over the last half hour as we get closer to sunset. The focus the remainder of the evening will continue to shift northward, north of a weak boundary that is currently extending from near Rushville to Danville. High-res models show some decrease in showers over most areas after midnight, before the next surge begins to lift in toward sunrise. Evening forecast updates mainly concentrated on rain chances into Tuesday. Geelhart && .DISCUSSION... Issued at 324 PM CDT Mon May 13 2024 The expected upper level low is currently in eastern KS according the latest analysis...but continues to push eastward towards IL. We`ve seen some showers and weak thunderstorms across central IL this afternoon and expect coverage to increase through late afternoon and into the early evening hours. Deep shear remains weak at <20 kts with MLCAPE of 500-1000 J/kg. The latest RAP model has a pocket or two of MLCAPE around 1000 J/kg this afternoon from 4-7 PM when storms will likely be the strongest. A few near-severe storms will be possible with hail close to 1" and/or wind gusts nearing 60 mph, but generally, severe storms are unlikely this afternoon/evening. Showers and perhaps some thunderstorms will be possible through the night as a mid level vort lobe rotates northward around the approaching system. Another lobe rotates north- northwestward tomorrow morning with the low moving from eastern MO into southern IL during the day Tuesday. Expect showers and embedded thunderstorms to continue Tuesday, with the strongest storms south of I-72. With MUCAPE generally around 500 J/kg up to 1000 J/kg and deep share around 20-30 kts, severe potential is limited once again tomorrow. Rainfall will likely be in the 0.5 to 1" range across much of the area, with a 10-30% chance of over 1.5" for the Mon-Tue total. The area sees weak ridging on Wednesday, providing a break from precipitation. However, rain chances return on Thursday and into Friday as the next upper wave moves through the region. Not too excited about severe weather chances with this second system at this time since the NBM has CAPEs at 500 J/kg or less along with 25 kts of deep shear. However, the latest ECMWF is showing some higher CAPEs for Friday, so will need to watch how this one evolves. Generally expecting around 0.5" of rain with this system. Weak ridging in NW flow aloft is expected for Saturday with an upper wave passing to the north on Sunday. We`ll see a surge of warm air ahead of the associated surface low pressure system, bringing highs into the 80s for the weekend. More shower and thunderstorm activity is possible by Sunday with the frontal system and upper support. We`re still too far out to speculate on severe potential with this one. Knutsvig && .AVIATION... (For the 00z TAFs through 00z Tuesday Evening) Issued at 620 PM CDT Mon May 13 2024 Scattered thunderstorms continue across a large part of central Illinois early this evening, and are expected to continue through about 02-03Z. Some brief MVFR/IFR visibility drops will accompany the heavier showers, but a more widespread ceiling lowering is expected late evening. By 08-09Z, probabilities of ceilings below 1,000 feet are around 60-80%, with any significant improvements holding off until after midday. With the storm system slowly advancing across the area Tuesday, widespread showers will return before midday. Isolated lightning cannot be ruled out throughout the afternoon, but chances are too low to include a mention at this point. Geelhart && .ILX WATCHES/WARNINGS/ADVISORIES... None. && $$
AREA FORECAST DISCUSSION...UPDATED
National Weather Service Jackson KY
1141 PM EDT Mon May 13 2024 .KEY MESSAGES... - Dry weather holds into the afternoon, before an approaching system from the Plains brings more unsettled conditions. - Shower and thunderstorm chances will be around through Wednesday with a lull on Thursday then renewed chances to close out the week. - Near, to a little above, normal temperatures are expected through the work week. && .UPDATE... Issued at 1141 PM EDT MON MAY 13 2024 A passing mid-level short wave is kicking off some shower activity across portions of the forecast area. The more notable light measurable precipitation has occurred across our southwest, where lower dew point depressions were in place initially. As the showers travel east and northeast, relatively drier low level air has eroded some of this activity, as seen on radar trends. Have freshened up the PoPs through the night, accounting for this current uptick, and then allowing for some diminishment behind the departing wave overnight. This will be followed by yet another increase towards dawn, as the next short wave approaches, affecting locations more so in the east. Instability has also been lacking across the area, and given the meager MU CAPE forecast for the rest of the night, have removed thunder from the forecast. Lows will range from the upper 50s southwest, to the lower 60s northeast. Updates have been sent. UPDATE Issued at 726 PM EDT MON MAY 13 2024 The NBM, and the current forecast, still depict high-end chance to categorical PoPs (50 to 90) developing by mid-evening with the increase in southerly low-level winds after dark. However, given how dry it looks and given eastern Kentucky lies on the cool side of the upper-level jet stream, am inclined to think those PoPs are overdone. If showers do not begin to develop shortly after dark, will lower PoPs accordingly. Main change with the early evening update is to lower temperatures in the south where cloud cover has kept temperatures in the lower 60s late this afternoon into early evening. Otherwise, just blended in the near-term forecast with current observations. && .SHORT TERM...(This evening through Tuesday night) Issued at 337 PM EDT MON MAY 13 2024 The afternoon surface analysis shows high pressure is still out to the east along the North Carolina coast line. Meanwhile, low pressure is developing across Missouri along with a cold front. This is providing south and southeast flow at the surface, which has led to mostly downslope flow. This has kept it dry this afternoon and will continue to be the case until we can moisten up in the low levels later this afternoon and evening. In the mid- and upper levels an upper low will push toward the Ohio Valley tonight. The CAMs and ensembles like the HREF have been in decent agreement with bringing a line of showers and possibly a thunderstorm across the area later this evening into the overnight hours. This could be in response to a slight increase in the low level jet noted in some of the ensembles. Given this opted to stay closer to the NBM PPI for PoPs this evening and into tonight, as it seemed to have this handled fairly well. Tuesday, this upper low meanders eastward toward the Ohio Valley. This coupled with and area of low pressure and some upper level divergence will give way to another shot (70-90 percent) of showers and thunderstorms through the day. However, there will be a lull in activity early in the day. Some of the data suggests there would be just enough instability (MUCAPE around 1000-2000 J/kg) and shear (effective shear of 30-40 knots) to help organize some of this convection. The HRRR and other CAMs want to bring an line of convection through the area tomorrow afternoon around 17Z and progresses across the area through the remainder of the afternoon into the evening. Right now, it looks like a marginal set up for severe weather, but strong storm or two can`t be completely ruled out. The primary risk would be small to perhaps marginally severe hail. SPC did push the marginal risk into a very small portion of the Cumberland Valley. Tuesday night, the shower and thunderstorm chances roll on given upper low is still meandering east. However, its a little more uncertain how convection will evolve through the evening given the line that is expected to move through in the afternoon and early evening. For now will keep highest PoPs in the evening time and lessen some through the night. .LONG TERM...(Wednesday through Monday) Issued at 400 PM EDT MON MAY 13 2024 Still looking at an active weather pattern in the extended, as a series of low pressure systems are forecast to move across the eastern half of the CONUS. The models were in pretty agreement with the overall large scale pattern aloft and systems evolution. The ECMWF was a bit wetter at times than the GFS, but overall the models had similar solutions. Used the GFS Ensembles for overall pattern details and locations and evolution of lows and highs. Precipitation details were derived from combination of the GFS and ECMWF models. The pattern will begin with a weak trough of low pressure, both aloft and at the surface, moving through the Ohio and Tennessee Valleys Wednesday and Wednesday night, and eventually out to sea off the southeast CONUS Atlantic coast by Thursday afternoon. In the meantime, we should see a weak northern stream trough moving quickly across the Canadian border region and across the Great Lakes to end the week. Another more pronounced trough aloft is forecast to be making its way through the southern stream and through the southern Plains and Gulf to end the week and on into the weekend. These two troughs are forecast to phase on Friday, and will bring rounds of rain to eastern Kentucky Friday through Sunday. The initial trough will bring widespread showers and storms to the area Wednesday and Wednesday night, with some precip lingering behind the trough as it departs late Thursday. Another system will be right on the heels of the first, and will bring another batch of showers and storms to our area Thursday night through Saturday, as it slowly moves through the region. The highest rain chances during the second system passage will be Friday, as a cold front pushes through. This batch of rain should taper off late Friday night and Saturday, with a few showers and storms lingering behind the departed front. The details for the end of the extended are a bit murkier, due to model uncertainty, but it appears that we will see scattered showers and storms moving through the area again Sunday through Monday, perhaps triggered by the passage of either a northern or southern stream low, or from the phasing of each. Due to this, precip chances for Sunday through Monday were kept fairly low, 20 to 40 percent to be exact, for now. The best times for showers and storms will be during the afternoon and evening hours, when peak heating and instability will be maximized. There will be, however, enough instability left over to allow for some night time thunderstorms as well through out the extended period. Aside from Wednesday, when highs are expected to be slightly below normal, we should see above average temperatures, both day and night, through most of the period. Daytime highs will average from the upper 70s to lower 80s, and night time lows the upper 50s to lower 60s. Persistent southerly and southwesterly flow will keep a steady flux of warm, moist air feeding into the area and should help keep temperatures up in spite of the expected clouds and rain. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) ISSUED AT 808 PM EDT MON MAY 13 2024 Conditions will remain mainly VFR through 06z, besides some passing light shower activity, that made lead to some temporary MVFR visibilities. Ceilings will lower to low-end VFR or MVFR between 06 and 15z, with locations along and west of a line from KSYM to KLOZ likely seeing the lower heights. Light passing showers will continue to threaten at times tonight into early Tuesday morning, but these look to be more scattered in nature. The better coverage of showers and/or thunderstorms looks to hold off for most locations until late Tuesday morning and especially the afternoon, when a more defined upper level disturbance rotates in from the west. South to southeast winds of 5 to 10 kts will diminish this evening and overnight, before backing to the south to south southwest and increasing once again to 5 to 10 kts by mid to late morning Tuesday. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...GEOGERIAN SHORT TERM...DJ LONG TERM...AR AVIATION...GEOGERIAN
Area Forecast Discussion...UPDATED
National Weather Service Memphis TN
951 PM CDT Mon May 13 2024 ...New UPDATE... .UPDATE... Issued at 950 PM CDT Mon May 13 2024 Current forecast remains on track. Thunderstorms continued to develop over the MS River delta of eastern AR at midevening. These storms were likely becoming rooted in an elevated layer as they lifted north from Arklamiss. HRRR sounding for Clarksdale, MS at 03Z depicted a shallow nocturnal inversion, with nearly 1000 J/kg of mixed layer CAPE above 800mb. Below this layer, down to the inversion, lapse rates are depicted as moist adiabatic. For updrafts surviving this marginally stable low layer, relatively steep midlevel lapse rates will support marginally severe hail. Increasing deep layer bulk shear is expected under the right entrance region of a 250mb speed max. This may aid storm organization and persistence potential into the early overnight hours. PWB && .SYNOPSIS... Issued at 248 PM CDT Mon May 13 2024 Unsettled weather will continue through Tuesday as an upper level disturbance and cold front slowly progress across the region. A few strong storms are possible late tonight and again in the afternoon hours on Tuesday. Dry conditions will return on Wednesday as we are in between weather systems. Showers and thunderstorms will return Thursday and persist through early Saturday. A mostly dry weekend with near normal temperatures is expected. && .DISCUSSION... (This evening through next Sunday) Issued at 248 PM CDT Mon May 13 2024 A cool and cloudy afternoon across the Mid-South. Heavy cloud cover has persisted this afternoon beneath southwest flow aloft. The latest KNQA radar sweep reveals just a few light showers, mainly over portions of northwest Tennessee. The latest GOES east Water Vapor Imagery shows a robust MCS across the Florida Panhandle, with another MCS over southeast Texas. A compact upper low was also analyzed near the Missouri and Kansas border. Mainly dry conditions will persist through early evening across the entire Mid-South. Thereafter, a shortwave will eject from the base of upper low and nearly phase with a southern stream wave coming out of the ArkLaTex. As it does, two areas of scattered showers and thunderstorms will develop this evening. A few of the storms could be strong to severe, as up to 1000 J/kg of MLCAPE and up to 50 knots of deep layer shear will be on hand. The main threats with any strong storms will be hail and gusty winds, as mid level lapse rates will approach 7.5 C/km and DCAPE values will be nearing 800 J/kg. The threat of strong storms should end as storms approach the Tennessee River before sunrise Tuesday morning. The upper low and associated surface low will push slowly through the Mid-South late tomorrow morning through tomorrow evening. Instability will be maximized ahead of the front or for areas east of the Mississippi River, where up to 1500 J/kg of MLCAPE will be available. Strong storms could form along the cold front by early afternoon and produce hail and gusty winds. Storms will likely push east of the Tennessee River before midnight. Dry conditions will return on Wednesday and persist into much of Thursday as shortwave ridging builds in overhead. The weather will become unsettled once again late Thursday, as several shortwaves translate through southwest flow aloft. A marginal threat of strong storms will likely exist during this period as 1000 J/kg of SBCAPE will be available and up to 30 knots of shear. Mainly dry conditions are expected this weekend as we remain under a weak ridge. Did carry a 20 to 30 PoP each day, as some diurnal showers and thunderstorms may bubble up. A weak and mostly dry cold front looks to move through the Lower Mississippi Valley late Sunday into Monday as a large trough digs across the Ohio Valley. AC3 && .AVIATION... (00Z TAFS) Issued at 627 PM CDT Mon May 13 2024 A couple of shortwave troughs rotating around an upper-level low centered near west central Missouri will be the focus for showers and elevated TS later this evening and overnight. This is generally in line with the latest high-res, TCF, and GLAMP guidance. Ceilings were adjusted for the start of the 00Z TAF period as latest guidance including HREF Grand Ensemble data holds off IFR ceilings until mostly during the overnight period. An improvement to MVFR conditions anticipated Tuesday morning, then VFR conditions by Tuesday afternoon. && .MEG WATCHES/WARNINGS/ADVISORIES... AR...None. MO...None. MS...None. TN...None. && $$ PUBLIC FORECAST...AC3 AVIATION...CJC
Area Forecast Discussion
National Weather Service Morristown TN
1125 PM EDT Mon May 13 2024 ...New UPDATE... .UPDATE... Issued at 1119 PM EDT Mon May 13 2024 Forecast is on track tonight, with no significant changes made to the current forecast. Looking ahead to tomorrow, the overall expectation is the same. Couple rounds of showers and thunderstorms expected, with the stronger thunderstorms bordering severe arriving in the late afternoon in a broken set of clusters of cells. Stronger to severe activity will most likely be south of Interstate 40. && .SHORT TERM... (This evening through Tuesday) Issued at 215 PM EDT Mon May 13 2024 Key Messages: 1. Wind Advisory for the far east Tennessee Mountains and Foothills. Gust up to 45 mph possible. 2. Strong to possibly severe storms late Tuesday afternoon and evening for the Plateau and southeast Tennessee. Marginal severe hail up to 1 inch and strong gusty winds to 50 mph are possible. Low-end threat of tornadoes across southeast Tennessee late in the day. Discussion: Through the rest of the afternoon into the evening, weak isentropic lift will produce scattered showers with light rain or sprinkles. Besides the potential of light rain, main concern will be windy conditions across the far east Tennessee Mountains and Foothills. Camp Creek currently reporting gusts to around 35 mph but speeds have decreased at Cove Mountains. The low-level jet is forecast by HREF to increase this evening and expect the greatest potential of strong winds between 01-06Z. The boundary layer jet will enhance the potential for scattered showers this evening/early morning especially over southwest Virginia and northeast Tennessee. For Tuesday, upper forcing from the left exit region of the jet moving into the northern Gulf Coast states and continued isentropic lift will pull warm/moist air into the region. The model soundings show more elevated instability as the warm front remains south of the area until late. Exact timing of a band of scattered showers and storms remains uncertain but do expect an area of convection during the day moving northeast. By late afternoon, another area of convection will form over middle Tennessee moving the Plateau and southeast Tennessee. This second area of showers and storms will be more surface based with MLCAPES up to 1500-1800. Shear will be strong enough to support organized multi-cluster storms with effective shear of 35 m2/s2. Mid-level lapse rates are near 6.5 which also supports decent hail growth resident time. Overall, marginal severe hail and damaging winds are the main threat. The HREF is showing some 2-5km updraft helicity tracks across southeast Tennessee with latest HRRR depicting 0-1km shear of 15-20kts. There is a low-end probability of tornado development across these areas late in the day. && .LONG TERM... (Tuesday night through next Monday) Issued at 215 PM EDT Mon May 13 2024 Key Messages: 1. Showers and thunderstorms continue through Wednesday. 2. A short break is expected, before another round of storms begins heading into the weekend. Discussion: Tuesday evening/night should be the time-frame when we see the boundary associated with this early week system move thorugh the area providing a decent environment for thunderstorms. Forecast soundings show there could be areas of over 500 J/kg of available CAPE and some moderate (albeit mostly unidirectional) shear in the mid and deep layers. This atmosphere should be conducive to seeing more widespread thunderstorms and maybe even some strong to severe thunderstorms. In the strongest storms we could possibly see near severe level winds and marginally severe hail... But the primary threat for the day continues to be the chances for isolated flooding under heavy thunderstorms. With the weak and nearly unidirectional shear the threat for tornadoes looks very low at this time. We should get a break for much of the night and into early Wednesday morning before the base of the trough/low moves overhead later in the day leading to another (but hopefully more tame) round of showers and thunderstorms. Much of Wednesday night and Thursday should be dry as we sit between systems and we should see temperatures climb back up to near or above normal as we head towards the weekend. By Friday we`ll see increasing precipitation chances as another system looks to move out of the southern plains towards the Ohio/Tennessee Valleys through the weekend. There is high confidence in showers and thunderstorms across the southeast Friday/Saturday, but lower confidence on the timing and strength of the storms. Some models are showing more vigorous thunderstorm activity to our south near the Gulf Coast which typically inhibits convection in the southern Appalachian. But if the boundary and storms develop further to the north we`ll likely see more widespread thunderstorms in our region. && .AVIATION... (00Z TAFS) Issued at 736 PM EDT Mon May 13 2024 Expecting CIGs to deteriorate to IFR at CHA tonight, with a return to VFR by the late afternoon. Given a minor wind event in the mountains, TYS and TRI should be more resistant to low ceilings. Two rounds of rain are probable tomorrow, first crossing from SW to NE in the late morning to early afternoon, second a set of afternoon TS in the late afternoon to the end of the period. Any TS will potentially have brief reductions in VIS and gusty winds. && .PRELIMINARY POINT TEMPS/POPS... Chattanooga Airport, TN 63 76 63 78 / 50 90 70 60 Knoxville McGhee Tyson Airport, TN 60 76 61 74 / 50 80 90 90 Oak Ridge, TN 60 75 61 74 / 40 80 90 90 Tri Cities Airport, TN 58 76 58 71 / 60 60 80 100 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...Wind Advisory until 4 AM EDT Tuesday for Blount Smoky Mountains- Cocke Smoky Mountains-Sevier Smoky Mountains-Southeast Carter-Southeast Greene-Southeast Monroe-Unicoi. VA...NONE. && $$ SHORT TERM...Wellington AVIATION...Wellington
Area Forecast Discussion
National Weather Service Paducah KY
142 PM CDT Mon May 13 2024 .KEY MESSAGES... - Shower and thunderstorm chances will peak later tonight into Tuesday. A stronger storm cannot be ruled out, but the risk remains very marginal. - While rain chances on Wednesday will be much lower, another risk for showers and thunderstorms returns Thursday afternoon into Friday. Rain chances may linger through Sunday, but the weekend overall does not appear to be a washout. - Temperatures will be near normal through the middle of the week before gradually rising above normal late week into the weekend. && .DISCUSSION... Issued at 140 PM CDT Mon May 13 2024 The synoptic setup this week is quite unsettled as a 500 mb shortwave trough and low ejects across the Plains today, providing forcing for ascent. Scattered showers and a few isolated thunderstorms will be possible through this evening, with the better risk for convection arriving late tonight into early Tuesday morning. The RAP shows about 600-850 J/kg of 0-1km MLCAPE with pockets of bulk shear upwards 30-35 kts and 700-500 mb lapse rates around 6.5 C/km, keeping the severe risk very marginal mainly across southeast Missouri. Although the 0-1km MLCAPE will be upwards of 1000-1500 J/kg Tuesday afternoon when another uptick in pcpn is progged, the shear will be decreasing. Overall, the setup is very marginal, but a stronger storm cannot be ruled out, with the risk shifting east into western Kentucky on Tuesday. QPF generally remains between a half to one inch for most of the FA, with locally higher amounts possible. By Wednesday, the FA will still be under the influence of cyclonic flow on the backside of the aformentioned 500 mb low as recent runs of the GEFS/EPS and deterministic ECMWF are more pessimistic. Meanwhile, the 12z GFS/NAM remain more progressive keeping most of the FA dry. Given that the overall trend favors a slower departure, NBMs 20-40% PoPs seem reasonable for Wednesday, especially across southwest Indiana and western Kentucky where the risk of seeing pcpn will be the greatest. Locations near and west of the Mississippi not only likely remain dry, but can also expect breaks of sun as a weak ridge axis aloft eventually moves over the entire FA Wednesday night. While Thursday looks to start off dry, southern stream energy will eventually eject NE towards the FA bringing the risk for more showers and thunderstorms Thursday afternoon into Friday. Uncertainty then increases over the weekend as model ensembles are not in agreement on if the southern stream energy gets held back with NBM chance PoPs progged for both days. Despite the lower forecast confidence, the entire weekend does not appear to be a washout. It is also possible most of the weekend remains dry if the 12z ECMWF/CMC were to be correct while the GFS lingers pcpn into Saturday. Temperatures will be near normal Tuesday and Wednesday with maxTs in the mid to upper 70s and minTs in the upper 50s to lower 60s. Daytime temps gradually warmer into the low 80s Thursday and Friday before eventually rising into the mid 80s over the weekend with nighttime temps in the low to mid 60s. && .AVIATION /18Z TAFS THROUGH 18Z TUESDAY/... Issued at 1213 PM CDT Mon May 13 2024 The main concern is MVFR/IFR cigs building in from the west through this evening as a disturbance approaches. A few scattered showers will also be possible, perhaps a rumble of thunder. A greater risk for showers and storms arrive during the overnight when TSRA cannot be ruled out, especially at KCGI/KPAH. Brief MVFR vsbys are also possible early Tuesday morning as low cigs prevail across the entire region. Light S-SE winds between 5-11 kts are expected. && .PAH WATCHES/WARNINGS/ADVISORIES... IL...None. MO...None. IN...None. KY...None. && $$ DISCUSSION...DW AVIATION...DW
Area Forecast Discussion
National Weather Service Salt Lake City UT
353 PM MDT Mon May 13 2024 .SYNOPSIS...A weak storm system will graze northern Utah through this evening before another system moves through the area Tuesday into Wednesday, bringing less warm and more unsettled conditions. High pressure will return late in the week with a renewed warming and drying trend. && .SHORT TERM (Through 12Z/6AM Wednesday)...Early Monday afternoon, a shortwave trough was rotating eastward through southwest Idaho. Increased moisture, lift and kinematics associated with this feature will move across northern Utah and SW Wyoming this evening. The combination of 500-750J/kg of SBCAPE (per HREF ensemble mean), deep-layer shear in the 25-30kt range, just enough moisture (PWATs in the 0.5" to 0.6" range) and ascent from the shortwave will be enough to encourage isolated to scattered showers and storms, with a few stronger storms across northern Utah and SW Wyoming through this evening. Main hazards will be gusty microburst/outflow winds, lightning and sub-severe hail up to 3/4" of an inch. Latest HREF wind probabilities peg a 70% contour for gusts up to 39 mph across northern Utah, with a 10% probability contour for gusts up to 58 mph centered over extreme NW Utah. There is a region of higher wind probabilities over the Dugway area as well, a region that is no stranger to convectively-induced wind gusts. Farther south, isolated showers are attempting to initiate over high terrain areas of southern Utah, but with much lower lift, instability and shear here, activity will tend to diminish as it moves off the terrain. Thanks to the large-scale ascent courtesy of the shortwave, additional shower and thunderstorm development will persist through the evening across northern Utah and SW Wyoming, with activity winding down quickly after midnight. A weak cold front associated with this lead shortwave will stall over central Utah tonight. A trailing shortwave will pivot across eastern Idaho and northeastern Utah by Tuesday afternoon, reinvigorating shower and thunderstorm activity. While convective initiation can`t be ruled out across terrain features across the area, initiation will tend to be tied to the near stationary frontal boundary across central Utah. Moisture, lift, instability and shear parameters look similar for tomorrow when compared to day, with the most robust ingredients centered over central Utah. Gusty outflow winds and sub-severe hail will be the main threats. With weak westerly flow parallel to the nearly stationary frontal boundary, there as a low-end risk for flash flooding should any stronger cells tend to train across vulnerable locations. 1-hr ensemble max QPF values do reach into the 0.50"-1.00" range, suggestive that cells that verify on the high end of the distribution could indeed present a low-end flash flood risk. Finally, the HRRR smoke does indicate a low concentration of near-surface smoke that is shown advecting across the area in the post-frontal airmass across northern and central Utah on Tuesday. This smoke appears to be originating from a wildfire in Oregon. Check Utah DEQ for air quality forecasts. .LONG TERM (After 12Z/6AM Wednesday)...Long term forecast period begins within cooler deep north to northwesterly flow as a weak grazing shortwave departs eastward. Some semblance of an associated diffuse frontal boundary may remain draped across the south and eastern portions of Utah, but expect this feature to largely be washed out and only serve as maybe a very slight enhancement to lower level convergence. In general, area will remain unsettled enough to see some isolated to scattered afternoon convection fire off of Utah`s high terrain (as well as likely SW Wyoming) and subsequently gradually drift south to southeastward downwind. Subcloud layers will be fairly dry, so could see some moderate downburst winds from any convection that matures sufficiently. Additionally, given fairly weak storm motion, could at least see some potential for convection to drift over more sensitive and fast responding drainages/washes, and will need to keep an eye on flood threat accordingly. That said, given dry subcloud layers (though PWATs near normal) and limited coverage, thinking the threat overall is on the lower end. Aside from the precipitation potential, weak post frontal environment will result in slightly cooler afternoon temperatures than the prior day, though still near to slightly above normal. Additionally, HRRR Near-Surface Smoke Density product suggests maybe some lingering light smoke/haze associated with the ongoing Little Yamsay fire in Oregon, though that will also be dependent on ongoing containment efforts. Guidance for Thursday still shows good agreement in ridging nosing in from the west, with continued ridging into Friday now also supported by the majority of deterministic and ensemble sources. In addition to increased dry and stable conditions, this ridge will help initiate a warmup, with forecast highs along the Wasatch Front by Friday in the low to mid 80s, and for Lower Washington County in the mid 90s. While highly unlikely, NBM probabilities do show a 4% chance of KSLC hitting 90F for the first time this year. For those not ready to hear it, the good news at least is that the average first date of 90F or higher for KSLC is not until June 8th, so we probably have a little more time to enjoy Spring. Unfortunately, suite of ensemble guidance continues to diverge on the pattern evolution moving into the weekend, primarily in regard to the position/strength of the ridge as a modestly strong mid/upper jet and impulse approaches through the PacNW. An additional muddying factor is a more southern stream cutoff low approaching the mid/lower California coast, and if/how/when this may interact with the northern stream. A stronger ridge solution would yield continued warm/dry conditions, where a trough would bring about cooler and more unsettled conditions depending on the strength. For Saturday, ensembles sit with roughly 55% of members supporting continued ridging, and 45% supporting at least some sort of weak troughing. Sunday stands closer to a 50%/50% split between trough/ridge, with 20% of overall solutions showing some phasing between southern cutoff and northern trough, which would be the coolest/wettest of plausible solutions. Monday offers little in the way of extra confidence. Opted to keep NBM values with this forecast package, which include isolated to scattered showers/thunderstorms and seasonably mild conditions, but worth mentioning the spread between 25th/75th percentile for highs remains around 10F or so. Overall, will likely see exact numbers for temps/PoPs fluctuate a decent bit until guidance hopefully begins to trend towards a solution. && .AVIATION...KSLC...Showers and thunderstorms, mainly to the northwest, will diminish by around 06Z. Sprinkles or light rain showers are likely, but outflow winds from 00-03Z could enhance prevailing northwest winds. Clouds will diminish as showers and thunderstorms taper off. Winds will transition to southeast around 06Z. .REST OF UTAH AND SOUTHWEST WYOMING...Scattered showers and thunderstorms for southwest Wyoming and northern Utah will diminish by around 06Z. Gusty, erratic outflow winds are likely near showers and thunderstorms. Those will diminish from 03-06Z. Showers will be isolated further south with less outflow wind compared to the north. Showers will diminish through the evening. && .FIRE WEATHER...A weak cold front will move through northern Utah this evening, bringing isolated showers and thunderstorms. The weak cold front will move southward across central Utah on Tuesday, and finally to southern Utah by Wednesday. Isolated to scattered showers and storms will accompany the front each day, favoring central and southern Utah by Tuesday and Wednesday. Isolated areas will see wetting rains, but most areas are not expected to see wetting rains with this activity. Warmer, drier conditions will build across the state for Thursday and Friday, with increasingly poor overnight recovery across southern Utah, especially for lower elevation areas. Another weak system is forecast to graze northern Utah this weekend, bringing some gusty westerly winds, especially as one approaches the Idaho border. && .SLC WATCHES/WARNINGS/ADVISORIES... UT...None. WY...None. && $$ ADeSmet/Warthen/Wilson For more information from NOAA`s National Weather Service visit... http://weather.gov/saltlakecity