Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 04/03/23


Area Forecast Discussion
National Weather Service Columbia SC
739 PM EDT Sun Apr 2 2023 .SYNOPSIS... High pressure and drier air will remain over the region tonight with an upper level disturbance moving into the region Monday morning with chances of showers and a few thunderstorms. Temperatures will warm to well above normal for the middle of the week with another front moving into the area late this week with unsettled conditions for Thursday into the weekend. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... Surface high pressure will move offshore tonight with weak southerly flow leading to increasing moisture. However, it will take considerable time to moisten the atmosphere making measurable rainfall unlikely. Models indicate PWAT values by daybreak Monday will likely be near or under 0.75 inches. An upper level shortwave will work to increase cloud cover early Monday morning but no rain is expected. Lows tonight will be in the upper 40s to low 50s. && .SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/... A weak mid level shortwave embedded within broad zonal flow will steadily cut across the southern CONUS late Sunday into Monday morning. The dynamic lift from this impulse will help drive some showers and possibly thunderstorms across our area throughout much of Monday. However, instability remains fairly limited aloft, and at the surface, thanks to lingering dry air from Saturday-Sunday`s cold front; dry air towards the surface across GA and SC will generally help scattered out and weaken any convection that does roll eastward into the CWA. That being said, PoP`s increase to around 40-50% throughout the day before tapering off in the evening; total QPF amounts between 0.1-0.3" expected. HREF members are all in fairly good agreement over this solution, with some additional deep convection progged in the hi-res to our southwest, robbing some further moisture from reaching us. High temps Monday should reach into the low 70`s despite cloud cover and some precip, but with the cloud cover, overnight lows into Tuesday should stay fairly warm, in the upper 50`s. Ridging quickly builds in for Tuesday as the shortwave quickly exits east. Height rises thanks to strengthening low level warm advection will steadily build throughout Tuesday as a deep trough digs in the Central CONUS. Temps will climb into the low- mid 80`s as southwest surface develop. Precip chances remain low thanks to the rising heights and general subsidence throughout mid and upper levels. Warm advection along with some returning low level moisture may pop a few showers particular across eastern GA, but again probabilities remain below 15%. Low temps will remain well above average heading to Wednesday, falling into the mid 60`s. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... Deep ridging is expected dominate the early parts of the long term forecast, for Wednesday and Thursday. Strong warm advection below 500mb will continue to force rising heights across the entire region and consequently temps will surge to near record highs. GEFS and NBM solutions are quite consistent with this pattern, showing a tight window of high temps right around 90F. NAEFS does a nice show depicting this anomalously warm pattern with near or at record high heights and temps over our area. A distinct pattern shift is becoming more likely by late week as a front is progged to stall somewhere across the Southeast as a strong high pressure center digs to our north. So confidence is rapidly increasing in much cooler weather along with high precip chances starting Friday through Sunday as that front stalls over the area. && .AVIATION /23Z SUNDAY THROUGH FRIDAY/... VFR conditions expected overnight with mid and high clouds increase toward daybreak. Low level moisture will increase after 09z. The NBM and HRRR suggest some patchy fog may develop near the Savannah river but confidence not high at this time with a relatively dry air mass in place. A warm front will be approaching from GA late Monday. Moisture will be increasing and expect ceilings to lower through the day. Showers will be possible in the afternoon. But higher probabilities for restrictions appears west of the area. Winds will be light and variable becoming southeast 5 to 10 knots Monday. EXTENDED AVIATION OUTLOOK...Low confidence in ceiling restrictions continuing into Monday night as a weak disturbance crosses the region. Restrictions possible Thursday afternoon through Friday as a frontal boundary stalls across the region with chances of showers and thunderstorms. && .CAE WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. && $$
AREA FORECAST DISCUSSION
National Weather Service Kansas City/Pleasant Hill MO
639 PM CDT Sun Apr 2 2023 .Discussion... Issued at 307 PM CDT SUN APR 2 2023 Key Messages: - Isolated to Scattered Thunder/Showers Tonight - Scattered Thunderstorms Monday Afternoon - Windy Tuesday; Favorable Severe Thunderstorm Environment Discussion: The mid and upper-level flow is generally zonal across most of the CONUS but there are couple of H5 short-wave troughs that are moving through the flow. One of these short-waves is moving through the Southern Plains of Texas. While the forcing with this short-wave remains well south of the area, this will aid in pumping some moisture northward into forecast area later this evening. The short- wave for us to keep a closer eye on is currently moving across the northern Plains, and is dragging a weak surface cyclone along the U.S./Canada border. For the early part of the evening, the last of the surface high pressure pushing off to the east will keep the area dry. The pressure gradient should weaken as that high is pushed eastward, thus the gusty winds from this afternoon will not last into the evening. As the northern short-wave moves eastward, a thermal boundary drops southward toward the area. The 850mb-700mb thermal gradient will move ahead of the surface boundary and arrive in northern Missouri by late evening. Convergence ahead of this boundary will provide enough lift for isolated to scattered shower activity. With the clear skies this afternoon and stronger insolation, would expect MUCAPE around 1000 J/kg to support a few rumbles of thunder. This evening, the wind shear will not be overly strong, thus would not anticipate late evening activity to greatly organize. The better shear holds off until Monday morning/afternoon. But for tonight, the CAMs indicate initialization shortly after 00z. Given the dry boundary layer, and that it may take time for the moisture from the south to arrive, thinking that 00z may be a tad early for shower activity. Certainly could see increasing cumulus clouds before sunset, as this trend is currently visible in northeast Oklahoma and moving northeastward. QPF will be light with any shower activity tonight with the overall dry conditions that this morning started off with. Monday late morning and into the afternoon, strong PV anomaly comes ashore, developing a trough that will be digging toward the Rockies. A 100+ kt jet streak develops with trough, and promotes strong CVA across the Intermountain West into the Front Range. The preceding WAA into the Front Range with increasing dCVA will kick off surface cyclogenesis in the Front Range, and out ahead of it strong response in southerly low-level flow from the Central Plains to the Middle Mississippi River Valley. This stalls the boundary somewhere across the forecast area. In the past 24 hours, model guidance has allowed for faster intensification of the surface cyclone, which stalls the boundary further north (just north of Hwy 36). However, there are few ensemble members that still keep the boundary further south. This will make for a difficult temperature forecast across the area, as temperatures north of the boundary will be in the mid to upper 50s and south of the boundary upper 60s to lower 70s. Where exactly the boundary stalls out at could make difference of 15 to 20 degrees in Monday`s high temperature. For areas south of the boundary, the southerly flow will result in strong WAA, and expecting isentropic ascent across most of the forecast area to provide showers. Moisture transport should increase through the day, but likely have several breaks that should allow for areas of diabatic heating. Therefore, Monday morning into late afternoon could also see scattered thunderstorms to develop. There is potential for some amount of organization, especially closer to the thermal boundary where convergence will be better and may have slightly enhanced wind shear. Since 17z, the HRRR has been developing more robust thunderstorms right along the boundary, as this is also closer to the H5 jetstreak that will help to provide shear. The 12z NSSL WRF and Hires-FV3 developed weaker activity on the south (warm) side of the boundary, but does not appear to be as intense as the activity closer to the boundary. The simulated storms in on the warm side also have considerably weaker deep layer shear. For most of Monday late morning and early afternoon, the boundary layer should be relatively stable, therefore most activity will remain elevated. Stronger updrafts may be able to produce up to quarter size hail. This threat is highlighted in the SPC Day 2 Marginal Risk Convective Outlook. By Monday night, as the trough out west comes to the end of digging, subtle H5 height rises may occur very late in the evening. This could provide subsidence that helps to clear some of the cloud cover that develops with isentropic ascent. This largely depends on the degree of moisture transport that occurs south of the thermal boundary. Attention turns to Tuesday as the deep H5 trough begins to lift out of the desert southwest with the 100+ kt jet rounding east of the trough axis. This develops a negative tilt throughout Tuesday morning, while dCVA and WAA remained phase ahead of the axis and allow the surface cyclone to continue to deepen. This strengthens southerly flow across the area. First off, this will result in another windy day. The gradient winds alone will begin to push advisory criteria, and if clouds clear late Monday Night, mixing during the early morning may help bring wind gusts to near 40 kts. This may also lead to elevated fire weather threat. Secondly, this robust synoptic setup is expected to result in a favorable severe thunderstorm environment. Ensemble probabilities for at least 1000 J/kg MUCAPE are above 90 percent. This will be a rather robust warm sector, as temperatures are progged to reach the lower 80s with dewpoints eventually climbing the into the lower 60s. Throughout the day, the thermal boundary that stalled on Monday is pushed northward into Iowa. As the surface cyclone deepens, surface troughing extends across the Plains to east of the Mississippi River Valley. Most deterministic solutions continue to depict rapid pressure falls especially in the vicinity of the warm front. As the nose of the H5 100+ kt jet streak approaches, deep layer shear drastically increases, and will likely see bulk shear values in the 0-6km layer exceed 60 kts. For the most part, there is strong consensus among model guidance with the track of the surface cyclone. There are still differences in the strength of the surface cyclone, but only about 4-6 mb. These differences likely will not make a big difference in the impacts expected from this system. The main question is how long does it take for shower and thunderstorm activity to start. As was the case with this past Friday`s event, there will likely be a pseudo dryline that comes through prior to the main cold front, dropping dewpoints but keeping temperatures in the upper 70s to lower 80s. Isentropic ascent may continue, and could foster some shower development Tuesday morning. Currently, synoptic scale models are not overly excited with producing rain Tuesday morning for our forecast area. Most of the QPF comes after 18z, essentially waiting for peak heating. Analysis of GFS model soundings does show a strong EML advecting in from 775mb and upward with the southwesterly mid-level flow ahead of the main trough, and provides a stronger a cap across a large portion of the warm sector that is ahead of the pseudo dryline. The convergence along the surface cyclone and cold front will likely be needed to lift parcels past this cap. Given the strong dynamics of this system though, would not be surprised if a weak vorticity max ejects from the main PV anomaly, and provides some forcing for elevated storms early Tuesday afternoon. However, the main show and severe weather threat will need to wait for surface based convection. Once the cap erodes, the warm sector throughout much of the lower Missouri River Valley will have mid-level lapse rates between 7.5 to 8.5 C/km, with nearly dry adiabatic boundary layers. With respect to wind shear, current model hodographs are showing strong cyclonic shear in the lowest 0- 1km in areas near the center of the surface cyclone, mainly where the surface winds are backed to the southeast. There are few points that also show a veer-back profile in the vicinity of the warm front and surface cyclone center. Right now, this is favored north of Hwy 36 from NE Kansas into southern Iowa (essentially the northern enhanced risk in the SPC Day 3 outlook). This would be the favored area for discrete supercell storm mode, with areas further south looking at more linear storm along the cold front. A secondary area south of Interstate 44 associated with a secondary vort max could also favor this, but this is not currently depicted in our forecast area. If the environment remains favorable for a discrete storm mode Tuesday afternoon into early evening, supercells will be capable of all threats. Areas along the cold front with the linear storm mode would mainly be damaging winds, but will need to monitor surges and inflections and how it orients with the 0-3km shear vector, as the bulk shear values in this layer will exceed 40 kts later in the evening as the LLJ kicks in. If the warm front does not surge as quickly, or the H5 short-wave closes off sooner and lifts differently then currently progged, this will likely change where favorable low-level cyclonic shear sets up, and could change the area of the discrete storm threat. The 00z CAMs this evening may provide us some of the first hints on this potential. The CAMs this evening will also provide the opportunity to dive into smaller scale details, storm motion, storm inflow, etc. Confidence is medium-high in the occurrence of strong to severe storms across the area, medium confidence in the specific threats and low-medium in timing. Severe storms could start early afternoon, and it is possible a severe threat continues into the late evening. Expect neutral conditions through the middle of the weak with respect to the zonal mid-level pattern. Deterministic solutions continue to depict a troughing pattern in the far west, that could eventually lead to more precipitation activity toward the end of week. Wednesday afternoon main remain windy on the backside of the convection, especially as eastern Kansas and most of Missouri remain on the backside of cyclonic flow. && .Aviation...(For the 00Z TAFS through 00Z Monday Evening) Issued at 632 PM CDT SUN APR 2 2023 Watching a cumulus field to the southwest of the metro that may lead to a few showers and thunderstorms through the evening hours. The storms may impact IXD, but coverage should be fairly spotty with better chances farther east so have not included at this time. Front across the area is expected to stall across the area overnight into Monday. Expect stratus to develop along and north of the boundary, with the potential for drizzle and an isolated storm or two. && .EAX WATCHES/WARNINGS/ADVISORIES... KS...NONE. MO...NONE. && $$ Discussion...Krull Aviation...BT
Area Forecast Discussion
National Weather Service Midland/Odessa TX
633 PM CDT Sun Apr 2 2023 ...New AVIATION... .SHORT TERM... (This afternoon through Monday night) Issued at 113 PM CDT Sun Apr 2 2023 * WINDY TO VERY WINDY CONDITIONS AND CRITICAL TO EXTREME FIRE WEATHER EXPECTED MONDAY. A low-amplitude shortwave is currently moving overhead per latest water vapor imagery and RAP 500 hpa analysis, and has served to shunt the dryline and any available moisture to the east of the region, paving the way for a warm, dry, and breezy afternoon. Westerly winds have picked up across the area, with associated downslope warming beneath a low-level thermal ridge resulting in noticeably warmer temperatures this afternoon in the upper 70s and 80s for most. Tonight looks to be the last "quiet" period in the forecast for at least a couple of days, as wind gusts diminish and lows drop into the middle 40s to middle 50s for most. By Monday morning, flow aloft will transition to southwesterly as a potent mid-level trough digs southward over the West Coast and into the Great Basin. Ahead of this feature, a lee surface trough will develop and aid in increasing westerly surface winds and associated warming coincident in the amplification of the low-level thermal ridge. Highs Monday afternoon will soar well above normal into the middle 80s and lower 90s for most, with upper 70s in the higher terrain and lower 100s through portions of the Rio Grande Valley. As the jet associated with the approaching trough begins to nose into the region, guidance indicates the development of a mountain wave signature over the Guadalupe and Delaware Mountains, marking the beginning of a prolonged significant high wind event. Thus, a High Wind Warning will go into effect at Noon CDT/11 AM MDT with gusts to 75 mph possible there, with a Wind Advisory across the adjacent plains as well as in the Davis and Chinati Mountains, where winds are expected to start gusting to 50-55 mph Monday afternoon. Windy to very windy conditions will persist thereafter, with the High Wind Warning remaining in effect through late Tuesday night, and the Advisory in effect until Tuesday morning. Of note, is that with the loss of mixing after sunset Monday evening, winds will diminish for all but the Guadalupe and Delaware Mountains. However, the aforementioned trough will translate eastward across the Four Corners Region, and as it approaches the region late Monday night into early Tuesday morning, winds will quickly increase once again, first across western areas. Thus, despite the all-too-brief respite from the stronger winds, the Advisory will remain in effect through the night. Given the continued hot, dry, and windy pattern, elevated fire weather conditions today will give way to widespread critical and extreme fire weather conditions on Monday. A Red Flag Warning is in effect beginning Monday late morning for Southeast New Mexico and areas south to the Marfa Plateau and Brewster County, as well as across the northern tier of the Permian Basin. Unfortunately, as conditions will remain dry overnight and winds elevated Monday night, little reprieve is expected, with the Red Flag Warning remaining in effect for the duration. Additional details can be found in the Fire Weather Discussion below. && .LONG TERM... (Tuesday through Saturday) Issued at 113 PM CDT Sun Apr 2 2023 * HIGH WINDS WITH EXTREME TO HISTORICAL FIRE WEATHER TUESDAY. An upper trough over the PacNW approaches the region Tuesday, tightening the gradient with a 700mb 75kt jet max over SE New Mexico. Sunny skies with ample mixing means high winds are expected to develop nearly area-wide by late Tuesday morning. A High Wind Warning is currently in effect for the Guadalupe and Delaware Mountains and most other counties are currently in a High Wind Watch through Tuesday evening. Wind speeds are expected to be 40-50 mph with gusts up to 65 mph in the plains and Permian Basin and gusts up to 100 mph in the higher terrain. These will be extremely hazardous winds, making it difficult to control vehicles and blowing away unsecured objects. Given the intensity of the winds, blowing dust is expected for most of Tuesday which could drastically reduce visibility. These extremely strong winds, along with humidity falling to as low as 3%, have created extreme to historical fire weather concerns and a long fuse Red Flag Warning is in effect...see Fire Weather Discussion below for more information. Thickness falls and a Pac front moves through later in the afternoon Tuesday. In response, temperatures Tuesday look to be 10-15 degrees cooler than Monday, although still above normal in the 70s across the west, 80s in the Permian Basin, and 90s along the Rio Grande. As the aforementioned trough lifts northward into the Great Lakes Tuesday night/Wednesday morning, winds will decrease with the exception of Guadalupe and Delaware Mountains where high winds will continue into early Wednesday morning. By sunrise, winds shift more northwesterly with a backdoor cold front bringing another push of colder air. Surface high pressure sets up and Wednesday will be the first below-normal day we`ve had in over a week as highs struggle to break above the 60s. Temperatures are expected to remain below normal in the 60s and 70s through Easter Sunday. Models have pulled back a bit on the precipitation chances in the Thursday-Friday time range as expected, given that the better moisture will be southeast of us and will struggle to reach our region post-front. The better precipitation chances have been pushed back to the late Friday-Saturday time frame when an upper low approaches from the west-southwest, bringing us better moisture. This far out models aren`t aligned with the track of this system so at this time, the likelihood of this precipitation coming to fruition is low. -Zuber && .AVIATION... (00Z TAFS) Issued at 630 PM CDT Sun Apr 2 2023 VFR will continue through the forecast period. Wind speeds will continue to diminish through sunset, becoming less than 10 kts overnight. Winds will increase out of the WSW again late tomorrow morning at most terminals with highest gusts expected at CNM. && .FIRE WEATHER... Issued at 113 PM CDT Sun Apr 2 2023 * CRITICAL TO EXTREME FIRE WEATHER MONDAY. * EXTREME TO HISTORICAL FIRE WEATHER TUESDAY. Near critical to critical fire weather today, so a Fire Danger Statement has been issued for this afternoon area-wide. This is mainly due to an increase in 20ft winds, especially across the higher terrain, and humidity falling to 6% or less everywhere. RFTIs are highest in the mountains (values of 5-7) where 20ft winds are 25+ mph. ERCs remain in the 70th-90th percentiles but will continue to dry over the next several days as humidity remains critically low. Overnight recovery will be very poor, with many spots across the west and south not getting above 15%. On Monday, winds switch out of the southwest in response to lee troughing over the Rockies, and humidity will fall to the lowest levels of the week...as low as 3%. 20ft winds increase Monday as well to 30+ mph across the west with higher in the mountains. High clouds may increase from the southeast which will likely hinder some fire weather concerns down along the lower Trans Pecos. Areas further north and west, however, will have RFTI values of 7-8 due to the strong winds and critical humidity. Fuels will be critically dry for the aforementioned locations as well, leading to critical to extreme fire weather conditions Monday. This is a particularly dangerous fire weather pattern with extremely critical fire weather conditions expected for an extended period with little to no improvement overnight, as overnight recovery looks to max out around 15%. Because of this, a prolonged Red Flag Warning has been issued stretching all the way from Monday morning through Tuesday late evening. Tuesday will be even worse with extreme to historical fire weather conditions expected. Winds will be ramping up dramatically with high winds expected across much of the CWA, not just the mountains. A High Wind Watch has been issued for nearly the entire CWA for Tuesday while the Guadalupe and Delaware Mountains are in a High Wind Warning. The mountains may see 20ft winds of 60-70 mph with the Permian Basin, Trans Pecos, and areas further south seeing 20ft winds of 35-55 mph. Clouds clear and RFTI values will be 8-9 everywhere, with humidity falling to as low as 4%. Fuels will be critically dry by Tuesday due to the low humidity the previous days and ERC values will have reached the 90th-96th percentile for parts of the Basin. Again, this day will see some of the worst fire weather conditions this area has experienced in quite some time. Extreme precaution needs to be taken on Tuesday to prevent devastating and deadly wildfires as these conditions will be ideal for fire spread. Any fires that develop will rapidly grow and may become difficult to impossible to control given the expected winds. The Red Flag Warning remains in effect through late Tuesday evening. Winds should decrease by early Wednesday morning as the upper trough responsible for our high winds moves north. Humidity will still be critically low Wednesday but with winds significantly lighter, fire weather concerns are lower. Concerns drop further Thursday and Friday as better moisture moves in, including the potential for some showers and thunderstorms late Thursday through Saturday across the eastern regions. Humidity recovery will be good to very good by Thursday night with below normal temperatures Wednesday through Sunday. -Zuber && .PRELIMINARY POINT TEMPS/POPS... Big Spring 50 91 55 85 / 0 0 0 0 Carlsbad 48 86 55 73 / 0 0 0 0 Dryden 53 97 65 93 / 0 0 0 0 Fort Stockton 55 92 59 87 / 0 0 0 0 Guadalupe Pass 50 78 48 65 / 0 0 0 0 Hobbs 47 84 51 74 / 0 0 0 0 Marfa 39 82 43 78 / 0 0 0 0 Midland Intl Airport 51 90 55 83 / 0 0 0 0 Odessa 52 90 56 82 / 0 0 0 0 Wink 47 92 50 81 / 0 0 0 0 && .MAF WATCHES/WARNINGS/ADVISORIES... TX...Red Flag Warning from 11 AM CDT /10 AM MDT/ Monday to 11 PM CDT /10 PM MDT/ Tuesday for Andrews-Borden-Central Brewster County-Chinati Mountains-Davis Mountains-Davis Mountains Foothills-Dawson-Eastern Culberson County-Ector-Gaines- Glasscock-Guadalupe Mountains Above 7000 Feet-Guadalupe and Delaware Mountains-Howard-Loving-Marfa Plateau-Martin- Midland-Mitchell-Reeves County Plains-Scurry-Van Horn and Highway 54 Corridor-Winkler. High Wind Warning from noon CDT /11 AM MDT/ Monday to 3 AM CDT /2 AM MDT/ Wednesday for Guadalupe Mountains Above 7000 Feet-Guadalupe and Delaware Mountains. Wind Advisory from noon Monday to 9 AM CDT Tuesday for Chinati Mountains-Davis Mountains-Eastern Culberson County-Van Horn and Highway 54 Corridor. High Wind Watch from Tuesday morning through Tuesday evening for Andrews-Borden-Central Brewster County-Chinati Mountains- Chisos Basin-Davis Mountains-Davis Mountains Foothills- Dawson-Eastern Culberson County-Ector-Gaines-Howard-Loving- Lower Brewster County-Marfa Plateau-Martin-Midland-Mitchell- Pecos-Presidio Valley-Reeves County Plains-Scurry-Van Horn and Highway 54 Corridor-Ward-Winkler. Red Flag Warning from 9 AM to 11 PM CDT Tuesday for Chisos Basin- Crane-Lower Brewster County-Pecos-Presidio Valley-Reagan- Terrell-Upton-Ward. NM...Red Flag Warning from 10 AM Monday to 10 PM MDT Tuesday for Chaves Plains-Eddy Plains-Lea-Sacramento Foothills and Guadalupe Mountains. High Wind Warning from 11 AM Monday to 2 AM MDT Wednesday for Guadalupe Mountains of Eddy County. Wind Advisory from 11 AM Monday to 8 AM MDT Tuesday for Central Lea County-Eddy County Plains-Northern Lea County. High Wind Watch from Tuesday morning through Tuesday evening for Central Lea County-Eddy County Plains-Northern Lea County- Southern Lea County. && $$ SHORT TERM...24 LONG TERM....72 AVIATION...24
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
1049 PM CDT Sun Apr 2 2023 .DISCUSSION...(This evening through Sunday) Issued at 330 PM CDT Sun Apr 2 2023 KEY MESSAGES: - Major winter storm will impact the Upper Midwest Tuesday through Wednesday. A plethora of hazards are expected across the area, including heavy snowfall, strong winds, and scattered thunderstorms. The storm track will greatly influence what areas receive the different weather elements. - A major warming trend is looking increasingly likely next weekend with some 60s possible across southern and eastern Minnesota into Wisconsin. It`s the first 50 degree day for some today, regardless of recent snow. Temperatures have exceeded expectations, which could be a sign of things to come, especially next weekend when the snowpack may have taken a big hit by then. More on that later. A cold front is passing through and temperatures have started to drop behind it as winds shift west northwest and the thermal ridge is pushed east. The airmass incoming is not particularly cold and temperatures will be just a bit below normal for Monday. Attention then turns to the large winter to impact much of the U.S. Monday night into Wednesday. Model consistency remains pretty good, but some deterministic members (NAM and CMC) have shifted east a bit. Despite this, temperatures aloft remain quite warm even with those models and a wintry mix or rain is still likely to spread across the whole area. Probabilities for all snow even across western MN have decreased and the bullseye for significant snow is centered across the eastern Dakotas and northern MN. With the track of the low being overhead, even small shifts to the east or west could mean big changes to the forecast. Generally, the low will track from Colorado to MN by Tuesday night. An arc of precipitation will develop over the central and northern Plains late Monday night and overspread the area Tuesday. Thermal profiles suggest a wintry mix at the onset in most locations. As the low tracks into MN, winds will shift southeasterly to the east of the track and turn any wintry mix to rain. Steep mid level lapse rates and a prominent, moist inversion around 750 mb could lead to robust elevated instability by Tuesday evening. Elevated supercells with large hail will be a threat. Continued with relatively high thunderstorm chances Tuesday afternoon and evening ahead of the system. Winds will also be quite strong as the sub-990mb low tracks through. CAA will be sufficiently strong that low level lapse rates will be steep, so confidence in 40+ kt wind gusts remains high. Wrap around snow showers and strong winds should impact the whole region Wednesday with the potential for light accumulations. Left the Winter Storm Watch mostly intact, aside from dropping Meeker Co and reducing some of the blizzard verbiage with more of a mix expected. A small shift to the east could mean larger snow totals and greater impacts again. Will await further trends before completely buying into one solution of the other at this range. High pressure will then slide east across the area late week and southwesterly flow should bring a robust warming trend by next weekend. How warm it gets will depend on the snowpack situation, but the incoming airmass appears capable of bringing 60s for highs across southern/eastern MN and WI Saturday-Sunday with 70s just to the south. There will be a cold front approaching late weekend, so lower confidence for Sunday. && .AVIATION...(For the 06Z TAFS through 06Z Monday night) Issued at 1037 PM CDT Sun Apr 2 2023 VFR conditions are expected the rest of tonight. The issues this period revolve around how much progress the stratus currently in NoDak will be able to make into the dry air currently over central MN. The HRRR continues to struggle to bring this clouds into central MN, even to AXN. Haven`t seen enough changes with the guidance from the 00z TAFs to change what we were going with, so kept MVFR cigs in at AXN and out at STC, but really could have gone either way at both of those locations. As for when the "crud" finally arrives, the RAP/HRRR keep pushing that out a little and it looks like it will be pretty close to 12z Tuesday before conditions really start to tank. KMSP...Debated bringing MVFR cigs in at 10z Tuesday morning, but with the HRRR trending later with arrival of the lower cigs, kept MSP VFR until we get a better handle on when MVFR or lower cigs will move in. /OUTLOOK FOR KMSP/ Tue...MVFR-IFR with SHRA. Wind ENE 15-20G30 kts. Wed...MVFR. Chc IFR with -SHSN. Wind W 20-30G35-40 kts. Thu...VFR. Wind W 10-15G25 kts. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...Winter Storm Watch from Tuesday morning through late Wednesday night for Benton-Chippewa-Douglas-Kandiyohi-Lac Qui Parle- Mille Lacs-Morrison-Pope-Stearns-Stevens-Swift-Todd-Yellow Medicine. WI...None. && $$ DISCUSSION...Borghoff AVIATION...MPG
Area Forecast Discussion
National Weather Service Tallahassee FL
942 PM EDT Sun Apr 2 2023 ...SEVERE WEATHER WITH HEAVY RAINFALL POSSIBLE ON MONDAY ALONG AND NORTH OF I-10... ...New UPDATE... .UPDATE... Issued at 941 PM EDT Sun Apr 2 2023 No significant changes to the previous forecast appear necessary. Areas of fog are possible later tonight across portions of the Florida big bend and panhandle, especially near the coast. Otherwise, the forecast for Monday still looks potentially stormy. && .NEAR TERM... (Through Monday) Issued at 308 PM EDT Sun Apr 2 2023 A weakening mid-level shortwave vorticity maxima is forecast to push through the lower Tennessee river valley and into the Carolinas throughout the day tomorrow. This morning`s CAM guidance has this mid- level feature supporting the initiation and maintenance of a MCS later this evening across the Arklatex region. This MCS is forecast to progress east into Mississippi and eventually western Alabama by Monday morning as the aforementioned mid-level shortwave vorticity maxima starts to become more elongated and weakens in the westerlies. At this time, there is much uncertainty in the forecast regarding the path this MCS takes throughout the day on Monday; however, the greatest chances for showers and thunderstorms to develop look to be across SE Alabama and SW Georgia. As the mid- level vorticity maxima weakens, the MCS could become more self- sufficient and mesoscale processes may take over. This could be in the form of the MCS becoming more cold-pool dominant through the afternoon. If this occurs, the MCS may take a slight southeastward jog, and could end up along the Florida/Georgia border by the evening hours. The HRRR which typically does well, has forecast this situation in its latest model runs; however, most CAM and global guidance keeps a majority of the convection north across SE Alabama and SW and South- Central Georgia. This provides some uncertainty with tomorrow`s forecast, and the overall track of the MCS through the afternoon and evening. With MLCAPE values surging into the 1000- 1500 J/Kg through the afternoon across the area tomorrow, combined with roughly 60 knots of deep layer shear through the SFC-6km layer, the environment is extremely favorable for the MCS to be maintained through the afternoon and evening hours. At this time, SPC has outlined a Marginal Risk (level 1 of 5) for all of our SE Alabama, SW Georgia, and northern rows of Florida counties across our area. Given the environment above, isolated damaging wind gusts and large hail are the main threats expected with these storms tomorrow; however, an isolated tornado or two can`t be ruled out as surface winds are forecast to be backed out of the southeast tomorrow. Overall, temperatures will be warm, with highs climbing into the low to mid 80s across Florida, and upper 70s across SE Alabama and SW Georgia. && .SHORT TERM... (Monday night through Tuesday night) Issued at 308 PM EDT Sun Apr 2 2023 Upper level ridging will begin developing over the region, expanding from the Bay of Campeche in the Gulf of Mexico. Through the day, the ridge will be traversing northeast towards the Atlantic as an upper level low will be approaching the midwest states. The high pressure will keep rain chances for Tuesday at or near zero. Temperatures will start in mid-upper 60s Tuesday morning and will warm to the mid to upper 80s in the afternoon, with low 80s along the immediate coastline. && .LONG TERM... (Wednesday through Saturday) Issued at 308 PM EDT Sun Apr 2 2023 The upper level ridging will hold its pattern across the Gulf of Mexico over the FL Peninsula towards the Atlantic Ocean through Thursday. A cold front approaching from the northwest will create a tight gradient, which will increase the winds on Wednesday to be breezy with gusts around 15-20 mph. On Thursday, the ridge will begin to flatten, with a cold front bringing in a chance for showers and thunderstorms for our Alabama and Georgia counties by Friday into Saturday. It looks like the front will stall along the FL border, which could keep PoPs elevated along and north of I-10 in the forecast past the Long term period as the troughing pattern remains over the region through the weekend. PoPs for the Long Term range from 30%-50% during the afternoon from Thursday through Saturday with the highest chances north of I-10. Temperatures during this period will be very warm in the upper 80s, reaching towards 90 degrees Wednesday through Friday. Overnight lows will be in the upper 60s. Temperatures will be "cooler" on Saturday as the front begins to move in with Highs in the low to mid-upper 70s for regions north of I-10, and upper 70s/low 80s south of I-10. && .AVIATION... (00Z TAFS) Issued at 746 PM EDT Sun Apr 2 2023 Increasing moisture overnight is expected to lead to areas of fog and low ceilings around TLH and ECP late tonight with LIFR conditions. Fog and low ceilings are expected to lift during the mid- morning hours. By late morning into the afternoon, a round of strong to potentially severe thunderstorms is expected to affect DHN and ABY. && .MARINE... Issued at 308 PM EDT Sun Apr 2 2023 A cold front has moved into the northeast Gulf this morning and will further dissipate this afternoon. A surface high pressure center will then move from near the Outer Banks this evening to north of Bermuda on Monday, where it will remain anchored through Thursday. This will support gentle to moderate southeast breezes over the waters starting this evening. Wave heights are also expected to increase to 3-4 feet by Wednesday before the surface High pressure will bridge in from the north on Thursday night; bringing a turn to northeast and east breezes. && .FIRE WEATHER... Issued at 308 PM EDT Sun Apr 2 2023 Monday will feature higher dispersions and winds, with the highest dispersion levels focused along the I-75 corridor. Minimum relative humidity levels will also increase, due to southerly flow returning to our area ahead of the next potential rainmaker for the second half of Monday. Lightning activity levels will be highest in northern counties in SE Alabama and SW Georgia. While rain chances decrease, similar conditions will persist for Tuesday, with decently high dispersions and minimum relative humidity sitting at roughly 45- 60% across much of the region. && .HYDROLOGY... Issued at 308 PM EDT Sun Apr 2 2023 The Flood Warning for the Flint River - Newton (SR 37) was cancelled this morning as the latest forecast shows a crest just below minor flood stage. Given the cresting from its Albany counterpart, there is confidence in this forecast trend continuing. As for Flint River - Bainbridge (US 27), flooding remains a possibility by midday Tuesday, but the forecast level is right at the threshold 25 ft and just beyond the 48-hr warning window for this cycle. On the Apalachicola, releases at Woodruff Dam have been coming down since Saturday morning, and they may soon fall below 47 kcfs. Once that happens, it could take an additional couple of days to see the river level at Blountstown fall below minor flood. A cluster of thunderstorms is likely to move across or north of our Alabama and Georgia counties on Monday. The 12z HREF shows the neighborhood probabilities of exceeding flash flood guidance around 10-30 percent, with the higher probabilities from Eufaula Alabama to Leesburg Georgia. This same area has about a 10 percent chance of exceeding 3 inches of rain. Depending on how the cluster of thunderstorms tracks and evolves, a flash flood threat could develop anywhere near and north of the Florida state line, and west of the I- 75 corridor on Monday. The QPF total is about 1-3 inches for Monday into Tuesday with the highest amounts located in the previously mentioned regions. More rain is in store later in the week, approaching the weekend but, there are no flooding concerns with this system at the moment. && .SPOTTER INFORMATION STATEMENT... Spotter activation is not requested. However, spotters are always encouraged to safely report significant weather conditions when they occur (while following all local, state, and CDC guidelines) by calling the office or tweeting us @NWSTallahassee. && .PRELIMINARY POINT TEMPS/POPS... Tallahassee 83 61 84 67 / 0 0 30 0 Panama City 77 65 78 69 / 0 10 30 0 Dothan 74 58 79 67 / 0 10 60 0 Albany 74 58 80 64 / 0 0 60 10 Valdosta 78 59 85 64 / 0 0 20 0 Cross City 85 59 86 63 / 0 0 0 0 Apalachicola 75 66 76 69 / 0 0 10 0 && .TAE WATCHES/WARNINGS/ADVISORIES... FL...None. GA...None. AL...None. GM...None. && $$ UPDATE...DVD NEAR TERM...Bunker SHORT TERM...Montgomery LONG TERM....Montgomery AVIATION...DVD MARINE...Montgomery FIRE WEATHER...EAO HYDROLOGY...Montgomery