####018007114#### FXUS63 KLSX 031950 AFDLSX Area Forecast Discussion National Weather Service Saint Louis MO 250 PM CDT Fri May 3 2024 .KEY MESSAGES... - Isolated strong to severe thunderstorms are possible from 2pm to 7pm Saturday. Hazards include up to 60 mph winds and up to quarter sized hail. - Confidence is increasing in a multi-day severe event taking place in the central U.S early to mid-next week. However, there is still uncertainty regarding details like timing, exact location, and how one day's thunderstorms will impact the next day's severe potential. && .SHORT TERM... (Through Late Saturday Night) Issued at 249 PM CDT Fri May 3 2024 Thursday night/Friday's cold front will continue to slowly buckle northward through the bi-state tonight as a quasi-stationary boundary. Meanwhile, a mid-level shortwave and surface cold front will push east through the Plains, arriving in Mid-Missouri early Saturday afternoon. This system will push the boundary to the northeast and leave us within its warm sector. Because of this, temperatures Saturday will be much warmer than they were today, reaching the mid-70s to mid-80s. Moisture will also pool into the area, mostly along and just ahead of the incoming cold front. Instability will be maximized here with SBCAPE values of 1500-2000 J/kg. Deep layer shear will be lacking, though, ranging from 20-30 kts. Modest CAPE and bulk shear values are expected to result in a severe weather threat much like yesterday - disorganized clusters of outflow dominant cells. Although we're confident in thunderstorm development, strong to severe thunderstorms are expected to be isolated in nature due to them being outflow dominant and likely quick to intensify and even quicker to die. The greatest potential for severe weather will be between 2pm and 7pm as the front is passing through the CWA. In any thunderstorms that become severe, damaging winds of up to 60 mph and up to quarter sized hail are possible. We're confident in the end time of the severe potential, as the front will be close to exiting to the southeast, and that coincides with the downfall of daytime instability. With the lack of appreciable shear, diminishment in instability will be detrimental to the life of any thunderstorm. Saturday night will be relatively chilly for portions of the areas surface high pressure passes to our north. Areas in northeast Missouri and west-central Illinois are forecast to fall into the upper 40s. To the south, further from the influence of the high and under more dense cloud cover, low temperatures may not fall under 60 degrees. Jaja && .LONG TERM... (Sunday through Next Friday) Issued at 249 PM CDT Fri May 3 2024 Sunday will be a relatively quiet opening to the week, almost literally the calm before the storm as we face a potential multi-day severe event between Monday and Wednesday. Despite the relative quiet, wet weather is expected beginning Sunday afternoon and continuing into overnight. This is due to a shortwave passing through the Mid-Mississippi Valley from the southwest and driving a weak surface low through our CWA. This surface low will cause Saturday's remnant cold/stationary front to buckle back north as a warm front with showers with embedded thunderstorms along it and within the system's warm sector. Severe weather is not expected, even earlier in the afternoon, due to weak lift, weak moisture convergence along the front, mid-level subsidence, and minimal instability (<250 J/kg MUCAPE). High temperatures Sunday will be near normal, landing in the 70s areawide. Monday kicks off the potential for multiple days of severe weather extending from the central and southern Plains into the southwestern Great Lakes and western Ohio Valley. A deep mid-level closed low will be responsible for this as it ejects northeast into the Plains on Monday. At the surface, two low pressure systems will develop lee of the Rockies, advecting warm air and moisture into the region ahead of a dryline and developing cold front. The dryline will act as a trigger for convective initiation in the Plains on Monday. On Tuesday, the system as a whole will be further east, and a shortwave and vorticity lobe will swing through our region. The cold front will be further east as well, shifting the severe threat into our area. Guidance across the board is in consensus that instability, deep layer shear, moisture, and synoptic level dynamics will all be favorable for severe weather on Tuesday and again on Wednesday as the cold front continues its eastward advancement. With the environment that may be in place, no hazard can be discounted at this point. Of course, this multi-day event begins four days out from now, so there's uncertainty to discuss. Firstly, although WPC cluster analysis shows consistency amidst guidance in the mid-level trough/closed low early next week (positioning, strength, size), there are differences in the phasing that impact the mid-level flow and thus impact the timing of the overall system. For a multi-day system like this, a faster or slower passage of the system could increase or decrease our potential for severe and/or lengthen or shorten our window for it. A faster frontal passage may shift Wednesday's severe threat further east and out of our CWA, whereas a slower frontal passage may extend our severe threat into Thursday. There's also the question of how/if severe weather to our west impacts our severe weather threat for the following day (Monday into Tuesday and Tuesday into Wednesday). Overnight low-level jets may cause ongoing convection to continue into the next morning, potentially dampening the potential for severe that day. The opposite scenario is also equally as likely - thunderstorms dying in the evening could lay down outflow boundaries and open up the potential for rapid destabilization the next day, increasing our chances for severe. All of this to say despite the very favorable synoptic set-up for severe, there's still plenty of variability that could sway our severe potential and its timing. Jaja && .AVIATION... (For the 18z TAFs through 18z Saturday Afternoon) Issued at 1204 PM CDT Fri May 3 2024 IFR/MVFR ceilings have been slow to scatter this morning. Observations have shown very gradual improvement, but restricted flight conditions will likely last into early afternoon. Otherwise, winds will veer to southeasterly overnight and to southwesterly by 18z Saturday. By this time, a cold front will be approaching the forecast area, introducing the chance of showers and thunderstorms and a wind shift to northwesterly to all terminals Saturday afternoon into evening. Jaja && .LSX WATCHES/WARNINGS/ADVISORIES... MO...None. IL...None. && $$ WFO LSX ####018005136#### FXUS63 KOAX 031951 AFDOAX Area Forecast Discussion National Weather Service Omaha/Valley NE 251 PM CDT Fri May 3 2024 .KEY MESSAGES... - Thunderstorms are expected this evening into the overnight hours with a 5 to 10% chance of damaging hail and wind. - There is a chance of severe thunderstorms (15 to 30 percent chance) Monday afternoon and evening. - Additional chances for showers and storms possible through the end of the week, but no organized threat for severe storms. && .DISCUSSION... Issued at 251 PM CDT Fri May 3 2024 This afternoon - Saturday: There are still some high clouds around the area this afternoon, causing some echos to show up on radar, but we're not seeing anything reach the ground. Winds are out of the southeast and temperatures are in the upper 60s to around 70 here around 2 PM, and should rise into the low 70s for highs this afternoon. We're watching a cold front associated with a low pressure system out over the Nebraska Panhandle this afternoon which will move through overnight tonight. This will bring a line of showers and thunderstorms through around 10 PM to 6 AM. We are under a marginal risk for severe weather from the Storm Prediction Center. The environment out ahead of the cold front does have up to 500 J/kg of MUCAPE indicating enough instability for thunderstorms, and combined with 50-60 kt of 0-6 km Bulk Shear indicates a threat of up to quarter-size hail and damaging winds. This line should move through fairly quickly, but we could see up to an inch or more of rain in places. Once the main line moves through, expect a post-frontal rain shield to trail the main line, tapering off an hour or two later. Low clouds will hang around through the morning on Saturday, with the sun coming out Saturday afternoon. Temperatures will be a bit cooler with highs only in the low-to-mid 60s with breezy winds out of the north gusting to 25 mph in the morning, dropping off during the afternoon. Sunday-Monday: Another upper-level trough will start to dig into the Four- Corners region on Sunday, approaching our area. Sunday should be a fairly nice day with light winds in the morning becoming southeasterly and starting to increase during the afternoon ahead of the approaching system. Temperatures will stay on the cooler side with highs in the mid-to-upper 60s. We'll see the surface low start to develop on the lee side of the Rockies Sunday evening with a surge of moisture lifting north out of the Gulf of Mexico associated with the Low-Level Jet across central and eastern Nebraska. We probably won't see precipitation start Sunday night, but we'll see increasing clouds with chances for rain starting Monday morning. We'll want to watch Monday evening for potential severe weather as the main upper-level wave pushes the dry-line across our area. This is our best opportunity for severe weather, with large hail, damaging winds, and tornadoes all possible. There is some possibility that stronger storms developing to our south cut off a lot of our moisture which could limit our severe potential, as the greater severe weather threat does appear to be to our south. We do still want to monitor this time frame, though. Storms do appear likely to be out of our area by Tuesday morning. Tuesday-Thursday: No other notable severe weather risks to mention through the rest of the forecast. We do see a shortwave move through Tuesday night that could bring another round of more modest storms through Tuesday night into early Wednesday. Through the end of the week we see a broad trough set up across much of the central CONUS with a fairly baroclinic pattern that could bring additional low chances for showers and storms, but no organized threat for severe weather. High temperatures stay in the 60s and 70s and lows in the 40s and 50s. && .AVIATION /18Z TAFS THROUGH 18Z SATURDAY/... Issued at 1207 PM CDT Fri May 3 2024 VFR conditions this afternoon with some high clouds over northeastern Nebraska and winds out of the southeast. We'll see a line of thunderstorms move across eastern Nebraska overnight tonight along a cold front with winds shifting to northwesterly behind the line of storms. I have given a good estimate of timing for storm arrivals at each of the terminals but this timing may need to be adjusted as we see the complex develop this evening and we get a better idea of timing. Models are fairly confident in MVFR cigs developing behind the line of storms with a shield of light rain. Cigs could lower as low as 700 feet, but more confident in MVFR cigs at this time. Will see how models trend ahead of the next TAF package to see if we need to change post-frontal cigs to IFR (20 percent chance at this time). Expect low cigs to break out by Saturday afternoon. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...None. IA...None. && $$ DISCUSSION...McCoy AVIATION...McCoy ####018004994#### FXUS64 KEWX 031951 AFDEWX Area Forecast Discussion National Weather Service Austin/San Antonio TX 251 PM CDT Fri May 3 2024 ...New SHORT TERM, LONG TERM... .SHORT TERM... (Tonight through Saturday night) Issued at 215 PM CDT Fri May 3 2024 Convection has begun northeast of Midland along the dryline and over the mountains east of the Big Bend. This region will be active this evening and some of these storms could move toward the east into our CWA. There is a Tornado Watch in effect north of our CWA. We have chances for showers and thunderstorms this evening, mainly across the northern counties. There is a chance that some storms could be strong to severe with very large hail the primary threat and damaging wind gusts and tornadoes also possible. Convection should dissipate after midnight. Saturday will be mainly dry. Winds will shift toward the east early and then back southeast during the afternoon. This should result in less cloud cover leading to warmer temperatures over most of the CWA. A cold front will drop through north TX during the day. Convection will initiate along this front and move southward toward our area. Chances for showers and thunderstorms will increase through the afternoon becoming likely in the evening. SPC has our CWA north and west of the Coastal Plains in the Marginal Risk area for this time. All severe threats are possible. At this time the best timing for storms is late evening to early overnight. && .LONG TERM... (Sunday through Friday) Issued at 215 PM CDT Fri May 3 2024 Rain chances may be ongoing over South Central Texas Sunday morning and continue through the afternoon hours associated with a departing shortwave trough. Models hint that a complex of thunderstorms will move through part of the area Saturday night into Sunday morning, with some lingering unorganized showers and thunderstorms remaining into the afternoon. With increasing destabilization through the day, there could be an isolated threat for a severe storm or two over the area Sunday afternoon but confidence is too low for any specifics at this point. PoPs should taper off Sunday evening with drier conditions returning to the forecast the rest of the week. That said, moisture in the low to mid levels lingers on Monday and a few showers would not be out of the question over the Hill Country or portions of the I-35 corridor. Zonal flow returns over the area on Tuesday, with upper flow becoming southwesterly mid to late week as troughing develops over the northern Plains. At the surface, South Central Texas will heat up Tuesday trough Thursday with the hottest temperatures expected along the Rio Grande. In the west, triple digit heat seems likely while the rest of the area stays in the upper 80s and 90s. Elevated humidity continues east of the dryline mid to late week which could push some locations over the I-35 corridor and Coastal Plains into triple digit heat indices. A slight cool down along and low end precipitation chances return Friday. && .AVIATION... (18Z TAFS) Issued at 1224 PM CDT Fri May 3 2024 It's a bad flying day in Austin and San Antonio. IFR/LIFR conditions are still hanging around. It doesn't look like there will be a lot of improvement this afternoon. Ceilings should get to MVFR this afternoon and maybe briefly to VFR at AUS. Ceilings should lower again starting this evening dropping to IFR for the late evening and overnight. There is a small chance for showers and thunderstorms this evening with better chances at AUS, but too low to include in the TAF. Ceilings should finally get back to VFR Saturday afternoon. At DRT clouds have scattered out and they will be VFR through the afternoon and early evening. There is a chance for showers and thunderstorms this afternoon and evening with the better chances during the evening. MVFR ceilings will develop during the evening and to IFR overnight. && .PRELIMINARY POINT TEMPS/POPS... Austin Camp Mabry 71 85 69 82 / 20 20 70 60 Austin Bergstrom Intl Airport 69 85 68 82 / 20 10 60 60 New Braunfels Muni Airport 71 88 71 84 / 20 10 60 50 Burnet Muni Airport 69 82 67 80 / 30 30 70 60 Del Rio Intl Airport 74 91 72 87 / 30 30 70 50 Georgetown Muni Airport 69 83 67 80 / 30 30 70 60 Hondo Muni Airport 70 88 69 83 / 30 20 70 60 San Marcos Muni Airport 70 86 69 83 / 20 10 60 60 La Grange - Fayette Regional 72 85 72 82 / 20 10 40 50 San Antonio Intl Airport 71 86 71 83 / 20 10 60 50 Stinson Muni Airport 72 89 72 85 / 20 10 60 60 && .EWX WATCHES/WARNINGS/ADVISORIES... None. && $$ Short-Term...05 Long-Term...27 Aviation...05 ####018007138#### FXUS62 KTAE 031951 AFDTAE Area Forecast Discussion National Weather Service Tallahassee FL 351 PM EDT Fri May 3 2024 ...New NEAR TERM, SHORT TERM, LONG TERM, FIRE WEATHER, HYDROLOGY... .NEAR TERM... (Through Saturday) Issued at 248 PM EDT Fri May 3 2024 Vapor imagery this afternoon depicts a storm system attendant to its shortwave trough traversing eastward across the Lower MS Valley with a downstream ridge axis bisecting the Coastal Carolinas down to the FL Peninsula. These features are making for warm/moist conditions with a mix of cloudiness, and isolated showers & thunderstorms today. The latter is seabreeze driven, initially focused mostly along the Eastern FL Big Bend before drifting towards the I-75 corridor into the early evening hrs. Additional cell development is possible from remnant outflow boundaries during that time. Lingering showers are possible tonight from the west as the aforementioned shortwave pivots NE through the Wiregrass. A muggy airmass will make for an unseasonably warm overnight/early-morning period with widespread forecast lows in the upper 60s, or about 10- 12 degrees above normal! Patchy fog is also forecast to develop in the pre-dawn hrs from Southern AL/Emerald Coast, then spreading to the FL Big Bend into parts of South-Central GA. Dissipation should occur within a couple hrs after sunrise. For tomorrow, expect greater coverage of showers and thunderstorms thanks to some upper-level support provided by the lifting shortwave, afternoon seabreeze, and sufficient daytime instability amidst a moist airmass. These parameters should support deep convection capable of strong/gusty winds, frequent lightning, and locally heavy downpours. The latter could produce localized high rain amounts exceeding 1 inch. Minimal vertical wind shear precludes severe weather concerns, but several strong storms (perhaps isolated "pulse" severe) are likely. The best chances are along the interstate corridors, followed by a northward drift past the FL state line. Aside from storm activity, temperatures peak in the mid/upper 80s. && .SHORT TERM... (Saturday night through Sunday night) Issued at 248 PM EDT Fri May 3 2024 Another shortwave will move across the mid-South Sunday into Sunday evening, which will bring another enhancement to our chances for showers and storms Sunday afternoon. The highest rain chances will be across southwest GA and the eastern FL Big Bend. Some mid-level dry air as well as inverted-V profiles on forecast soundings may lead to some gusty wind potential Sunday afternoon. Otherwise, it will continue to be warm and humid with highs in the upper 80s and lows in the mid to upper 60s. && .LONG TERM... (Monday through Thursday) Issued at 248 PM EDT Fri May 3 2024 One more shortwave traverses the Tennessee and Ohio Valleys Monday afternoon, which provides another boost to our rain chances. However, forecast soundings don't appear as conducive for gusty winds given less mid-level dry air and more moisture near the surface. Highs Monday will be in the upper 80s with lows in the mid to upper 60s. Beyond Monday, strong ridging takes hold of the area, shutting off the rain and bringing increasing heat through the middle to latter part of the week. Ensemble guidance indicates that we may see 500 mb heights near 589-590 dam, which is close to record heights for this time of year based on SPC's sounding climatology. Similarly, 850 mb temperatures will be in the 18-22C range, which is also near record levels for this time of year. All that to say, it's going to be hot. Highs will climb in to the lower to middle 90s, and with dew points near 70, heat index values could approach 100 in some areas. Lows will also climb into the upper 60s to lower 70s. && .AVIATION... (18Z TAFS) Issued at 141 PM EDT Fri May 3 2024 Mainly VFR conds away from t-storms with a south to SW wind and mix of upper/lower clouds. Isolated convection is expected to focus mainly around the interstate corridors this aftn. Highest confidence in being impacted by thunder is VLD where an evening tempo group was introduced amidst prevailing VCTS. Lingering showers appear likely tonight, then MVFR cigs/vsbys aim to develop in the pre-dawn hrs at ECP/TLH. Better convective coverage is fcst tmrw just after the end of this TAF cycle. && .MARINE... Issued at 351 AM EDT Fri May 3 2024 High pressure in the Atlantic will lead to tranquil boating conditions through the period. Light winds, generally out of the south-southeast, are expected with seas around 1 to 3 feet into the weekend. There is a slight chance of showers and thunderstorms Saturday and Sunday. && .FIRE WEATHER... Issued at 248 PM EDT Fri May 3 2024 Afternoon and early evening thunderstorms capable of gusty/erratic winds and lightning will be the main fire concerns the next 3 days. For tomorrow, convection aims to focus along the interstate corridors after seabreeze initiation on the Big Bend side, then drifting north past the FL state line. Convective potential is expected to be greater compared to today. Wetting rains are also possible. Additional rounds of diurnal showers/thunderstorms are forecast Sunday-Monday, albeit lesser coverage, but targeting roughly the same locations as Saturday. Otherwise, look for hot daytime conditions with highs in the upper 80s away from the immediate coast, southerly winds, and a daily afternoon seabreeze. High dispersions are forecast over parts of SE AL/FL Panhandle Monday afternoon. && .HYDROLOGY... Issued at 248 PM EDT Fri May 3 2024 Abundant moisture will be in place with a decent coverage of showers and storms this weekend. While widespread totals of 0.5 to 1 inch, localized totals if storms are slow moving could reach 2 to 3 inches in a short period of time. This could result in some nuisance flooding of poor drainage or urban areas. Otherwise, no additional flood concerns are expected. && .SPOTTER INFORMATION STATEMENT... Spotter activation is not requested. However, spotters are always encouraged to safely report significant weather conditions when they occur by calling the office or tweeting us @NWSTallahassee. && .PRELIMINARY POINT TEMPS/POPS... Tallahassee 69 86 67 88 / 10 60 20 40 Panama City 69 83 67 85 / 10 20 0 10 Dothan 68 89 65 88 / 20 40 10 40 Albany 69 87 67 88 / 30 70 30 50 Valdosta 68 86 67 88 / 40 70 30 60 Cross City 66 87 66 88 / 10 50 20 50 Apalachicola 69 80 69 82 / 10 10 0 10 && .TAE WATCHES/WARNINGS/ADVISORIES... FL...None. GA...None. AL...None. GM...None. && $$ NEAR TERM...IG3 SHORT TERM...Young LONG TERM....Young AVIATION...IG3 MARINE...Reese FIRE WEATHER...IG3 HYDROLOGY...Young ####018005368#### FXUS61 KALY 031952 AFDALY AREA FORECAST DISCUSSION National Weather Service Albany NY 352 PM EDT Fri May 3 2024 .SYNOPSIS... High pressure will provide continued dry conditions through tonight. The high will only move slightly east off the coast through Saturday, with a frontal system slowly approaching from the west. Clouds will increase on Saturday, with chances for showers developing west of the Hudson Valley. Showers will become more likely by Sunday as the system tracks east across the area with cool temperatures. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... Just some areas of thin high clouds across NY State into western New England. Low level ridging in eastern New England slowly building offshore as upper ridging over our region providing some larger scale subsidence. Light southeast to south low level flow could support development of some low clouds tonight, especially in the mid Hudson Valley, NW CT and southern Berkshires, but low levels have been drying and inversions are being mixed out, so low clouds may be more sparse than last night. Clouds associated with the slowly approaching frontal system in the Great Lakes and OH Valley will stay mainly to the west overnight. Light winds and just thin high clouds will allow for some radiational cooling. Lows by daybreak Saturday in the 40s to around 50. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/... The axis of deeper moisture associated with the upper energy and associated warm and cold front will slowly approach through the day Saturday. Sources of guidance/ensembles suggest the leading edge of the deeper cloud cover and any rain is timed for very late Saturday afternoon and night. This suggests more periods of high clouds through the day with steady light south to southeast winds and highs in the 60s to around 70. Showers move into our region from southwest to northeast through the night Saturday night and by daybreak Sunday many areas will see showers. Depending on the timing, the onset of showers in the Capital Region and points north and east may be after daybreak Sunday. Then, clouds and showers across the entire region Sunday, limiting warming. There could be a rumble of thunder but chances are low with a lack of instability. Highs mainly in the 50s Sunday. Rain moves out Sunday night and there cold be a lingering early morning shower Monday. Then, weak cold advection begins with the exit of the upper system and cold front Monday. Highs Monday in the 70s with 60s higher terrain. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... Dry weather continues Tuesday with highs in the 70s. Increasing clouds through the day, with around 70 higher terrain and near 80 mid Hudson Valley and NW CT. By Wednesday through the rest of next week, split upper flow with northern stream upper energy slowly dropping out of Canada and a closed upper low slowly approaching from the northern and central plains. Confluent upper flow and associated moisture advection and low level jet forcing will result in showers and a possible rumble of thunder Tuesday night through Friday. There will be some periods of dry weather but there is a lot of spread in sources of guidance as to the timing of embedded smaller upper impulses and associated focused moisture, low level forcing and areas of showers. Still, the general upper pattern should support unsettled weather. So, again, indicating chances for showers Tuesday night through Friday. The threat for severe weather and/or heavy rain looks limited due to the relatively weak upper dynamics and weak low level forcing. Highs Wednesday in the 70s with 60s higher terrain. Highs Thursday in the 60s to around 70. Highs Friday in the 60s with near 70 mid Hudson Valley and NW CT and some 50s southern Adirondacks. && .AVIATION /20Z FRIDAY THROUGH WEDNESDAY/... VFR conditions prevail at all TAF sites through 06 UTC with light and variable winds. Southeasterly winds will develop after 06 UTC and some low stratus may redevelop but confidence is lower compared to previous nights. We only included TEMPO groups at PSF where confidence was a bit higher. Any early stratus burns off by 12-14 UTC, VFR conditions return with mid and higher level clouds spilling over the terminals ahead of our next approaching disturbance. Light and variable winds become southeasterly by or shortly after 06 UTC sustained around 5kts. South-southeasterly winds continue through the end of the TAF period becoming sustained around 5kts. Outlook... Saturday Night: Moderate Operational Impact. Likely SHRA. Sunday: High Operational Impact. Definite SHRA. Sunday Night: High Operational Impact. Likely SHRA. Monday: No Operational Impact. NO SIG WX. Monday Night: No Operational Impact. NO SIG WX. Tuesday: No Operational Impact. NO SIG WX. Tuesday Night: Moderate Operational Impact. Chance of SHRA. Wednesday: High Operational Impact. Likely SHRA...TSRA. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. MA...None. VT...None. && $$ SYNOPSIS...NAS NEAR TERM...NAS SHORT TERM...NAS LONG TERM...NAS AVIATION...Speciale ####018007514#### FXUS63 KGLD 031954 AFDGLD Area Forecast Discussion National Weather Service Goodland KS 154 PM MDT Fri May 3 2024 .KEY MESSAGES... - Thunderstorms will develop along a cold front surging southeastward through the area late this afternoon and evening. Damaging winds and instances of large hail appear to be the primary hazards. Isolated supercells capable of producing all hazards may develop in advance of the front, south of Highway 40 in CO/KS, between 4-8 pm MDT. - Fire weather concerns return Monday through Thursday for most of the Tri-State area, but favor along and south of I-70. - Thunderstorms, a few of which may become strong to possibly severe, will be possible Monday afternoon/evening. && .SHORT TERM /THROUGH MONDAY NIGHT/... Issued at 130 PM MDT Fri May 3 2024 Not much has changed from previous thinking with two areas of concern for the remainder of the afternoon and this evening. Convective initiation has occurred in eastern Colorado near Las Animas. HRRR shows this activity expanding into northeast Colorado south of I-70 and northwest Kansas over the next few hours. Latest analysis and forecast of SBCAPE shows 1500-2000 j/kg available along with effective bulk shear values of 40-50 kts. Those parameters should be sufficient for a few severe thunderstorms capable of producing large hail, damaging winds and perhaps a tornado with any discrete supercell. Further north, initiation has also occurred along the cold front in the Nebraska panhandle. As the cold front surges south this evening, convection will increase rapidly into a line capable of producing damaging wind gusts. Given the same parameters above, a few embedded cells in the line will also be capable of producing large hail and a brief tornado. The front will exit the area by around 06z ending the severe threat, though a few showers and storms may linger past 06z in southern and eastern areas. Mean precipitation amounts for the event range from around a tenth to a quarter of an inch in Colorado, a quarter to a half inch west of Highway 83, and around a half inch east of Highway 83. The higher percentiles show locally up to 1 inch possible in just about the entire area, with up to about 1.5 inches in northeast corner (McCook, Oberlin, Norton) and southern areas (Tribune, Leoti). Winds will gradually diminish overnight with low temperatures ranging from the lower 30s in Colorado to the lower 40s in north central Kansas. Saturday will be mostly sunny and breezy with just a hint of shortwave ridging aloft ahead of weak shortwave in southeast Colorado. High temperatures will be in the lower 60s. Saturday night now looks dry with the shortwave staying south of the area. There will be some increase in clouds with low temperatures in the lower 40s. Models do hint at fog developing in western portions of the area late Saturday night into Sunday morning (along the Kansas and Colorado border area and westward). Southwest flow aloft continues on Sunday with embedded weak waves which may result in a few isolated showers and thunderstorms by Sunday afternoon. There is a very narrow corridor of weak instability forecast along the Kansas and Colorado border area with a 100-200 j/kg currently indicated. So, not expecting any severe storms should any develop. High temperatures will be in the upper 60s to lower 70s. Shower and thunderstorm chances increase going into Sunday night with height falls ahead of the approaching trough and nocturnal low level jet. MUCAPE increases overnight to 1500-2000 j/kg with shear values of 40-50kts. So may see elevated thunderstorms late with a risk for hail, but confidence is low at this time range. Low temperatures will be in the 50s. Main trough axis ejects out of the Rockies and across the plains with a negative tilt on Monday. Surface low will deepen in the Nebraska panhandle with the dry line trailing south into the forecast area. The dry line will be the focus for convective initiation in the afternoon and the models indicating the dry line will likely be in eastern areas at least for a few hours before moving east. Timing of initiation will be critical, but if it happens before the dry line moves out may see a short window for severe storms along/east of Highway 83. Instability and shear will be more than adequate for a risk of large hail, damaging winds and tornadoes. West of the dry line may see few wraparound high based showers, but no severe threat. However, afternoon relative humidity values will be dropping to near critical or critical values and wind speeds also appear to meet critical thresholds for fire weather concerns. Precipitation should be east of the area Monday night. High temperatures will range from the upper 60s in Colorado to the upper 70s in north central Kansas and lows Monday night in the upper 30s to lower 40s. && .LONG TERM /TUESDAY THROUGH FRIDAY/... Issued at 153 PM MDT Fri May 3 2024 Tuesday, an upper trough will be in place over the High Plains and Central High Plains. Models continue to show variations in the placement of a low pressure system ranging from Nebraska to the Dakotas. Kept winds where they are for now due to continued uncertainty on the location of the low, but wouldn't be surprised if later model runs start to bring up wind potential a bit. Zonal flow will be in place over northwestern Kansas and eastern Colorado through the day. Expected highs will range from the upper 60s in portions of Yuma and Kit Carson counties to the mid to upper 70s south of I-70. Wednesday, a disturbance will move across the Dakotas and Nebraska. We are currently forecast to stay dry through the daytime hours. Some cooler air will move in, with highs ranging from the mid to upper 60s in eastern Colorado to the upper 60s to low 70s in Kansas and Nebraska. Heading into the evening and overnight hours, there will be a 10-20% chance of a few showers and thunderstorms, mainly for areas along and west of the Colorado state line. Thursday, the disturbance will continue to move to the east, with low end chances (10-30%) of shower and thunderstorm activity. For the time being, areas west of a line from McCook to Tribune stand the best chance of receiving precipitation with this system. Expected temperatures will be in the 60s for highs and the 30s and 40s for lows. && .AVIATION /18Z TAFS THROUGH 18Z SATURDAY/... Issued at 1118 AM MDT Fri May 3 2024 VFR expected to prevail at both KGLD and KMCK through this afternoon. Isolated storms may develop in northwest Kansas late this afternoon, but probability of directly impacting the terminal is low. Tonight, a strong cold front will move through both terminals between 02-04z. The front will be accompanied by thunderstorms and strong surface winds shifting to the north. Some visibility restrictions due to blowing dust will be possible along and immediately behind the front. Storms will continue south during the late evening with surface winds gradually diminishing through the overnight. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...None. CO...None. NE...None. && $$ SHORT TERM...024 LONG TERM...Wekesser AVIATION...024