Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 10/25/21

National Weather Service Albany NY
1037 PM EDT Sun Oct 24 2021 .SYNOPSIS... Rainfall is expected to move in from west to east overnight, tapering to showers from south to north Monday morning. Highs Monday will range from cool across the north to mild across the south on either side of a front under cloudy skies. A stronger system will bring periods of rain, moderate to heavy at times, Monday night into Tuesday night. Dry weather is expected to return for Wednesday and Thursday. && .NEAR TERM /THROUGH MONDAY/... Update...As of 1037 EDT...Clouds continue to thicken and lower from southwest to northeast over the forecast area. The leading edge of the warm advection rainfall has reached the Capital Region and NW CT. We timed the light rain/showers moving into the entire forecast area between 10 pm and midnight. The lower troposphere will gradually saturate prior to midnight. The rainfall will pick up in intensity thereafter, as the isentropic lift increases ahead of the warm front. Low temps will wet bulb into the upper 30s to the northeast to upper 40s to the south. The latest GFS, ECMWF, NAM and HRRR are similar with the placement of the heavier rainfall basically along and in the vicinity of I-90 with a third of an inch to an inch expected with some locally higher amounts over the Berkshires and northern Catskills based on the 00Z NAM. The rain is expected will taper off late Monday morning as ridging briefly builds in. Previous near term... The warm front is forecast to move into local area, however the question how far north will it get. There is high pressure position to our north across eastern Canada and it`s forecast to strengthen. The consensus is the boundary should stall just south of I-90. The thermal gradient across the boundary is impressive and the weather to the north and south of it will be quite different. We are expecting to experience a 20-degree different in temperatures across the local area Monday with highs in the mid 60s in the mid-Hudson Valley with mid/upper 40s across the southern Adirondacks and southern Vermont. && .SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/... The forecast gets complicated as multiple short waves, northern and southern stream energy phase with a coastal low developing off the Southeast Coast by Monday night. The primary, inland, low will weaken as it moves across PA as the coastal low deepens as it moves northeastward up the coast. The coastal low will become the primary low and be drawn back toward the coast Tuesday near the east end of Long Island and Cape Cod. The low is then expected to remain fairly stationary (wobble) Tuesday afternoon and evening with the low expected to begin to move eastward overnight. Rain will once again overspread the area by from the east this time with heavy rainfall expected late Monday night into Tuesday. At this time, expecting 2 to 4 inches across western New England with amounts decreasing as you head westward with 1 to 1 1/2 inches across the western Adirondacks. These amounts could end up be higher especially east of the Hudson River Valley as there is uncertainty in exactly how close to the coast the low ends up. The rain is expected to taper off late Tuesday night. A flood watch may be needed. There are low to moderate probabilities of some forecast points reaching minor flood stage. There is the possibility some points could reach moderate flood stage if the higher QPF is realized. Also can`t rule out some areal or flash flooding. Winds will pick up Tuesday and Tuesday in the north-northeast flow on the back side of the deep low especially across western New England. Gusts up to around 30 mph are expected. Expecting lows in the 40s both Monday and Tuesday nights with highs Tuesday in the 50s below 1500 feet and in the 40s above that. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... Main headlines for the long-term period will continue to focus on the continued active/wet weather pattern. Early to mid week, a second, yet more potent piece of upper energy is expected to detach/separate from the parent anomalous upper trough over the eastern Pacific/Gulf of Alaska (GOA) region. At the surface, a mid- latitude cyclone, associated with the upper level feature mentioned above will track cross-country during the week ahead becoming occluded/negatively tilted in the process. Ultimately, this will be our next rain maker in the Friday-Sunday timeframe. We start off the period on Wednesday-Thursday, when the ALY forecast area will be getting a reprieve, albeit brief, from the wet weather as a narrow surface high pressure moves into the region in the wake of a departing powerhouse low (discussed in the short-term forecast period). With subsidence over the area via the narrow surface high, Wednesday through Thursday will be dry and tranquil with cloud coverage expected to decrease leaving the area with a mix of clouds and sun. High temperatures Wednesday and Thursday will top out in the upper 50s along the river valleys (upper 40s to mid 50s higher elevations). Friday through Sunday, we continue to keep close eye on a mid- latitude cyclone that has the potential to bring another round of widespread, soaking rainfall. This system has the potential to translate to a Nor`easter. According to the latest suite of guidances, rainfall coverage is expected to increase from southwest to northeast Friday afternoon into Saturday. Friday night through Saturday is the time period to when we expect the rainfall to be heaviest at this time. The storm system as mentioned previously is expected to slow as it becomes negatively tilted/occluded. As a result, rain could linger into Sunday before finally moving out Sunday PM into Monday. As far as temperatures, highs are expected to top out in the mid to upper 50s along the river valleys (upper 40s to lower 50s higher elevations). Low temperatures during the extended period will mainly be in the 40s (with some 30s in the higher elevations). Overall, anomalies will run slightly warmer than normal for the period. && .AVIATION /03Z MONDAY THROUGH FRIDAY/... A warm front will bring rainfall into the region tonight through tomorrow morning. The rain will taper to scattered showers and patchy drizzle in the afternoon. A lull in the pcpn is expected into tomorrow night, before rain moves back in late Monday night. VFR conditions will lower to MVFR/IFR levels between 03Z- 06Z/MON with the warm advection rainfall with the rainfall moving into KGFL/KALB/KPOU/KPSF. Cigs will quickly lower in the rainfall, and vsbys should follow. Expect widespread IFR vsbys/cigs to materialize between 06Z-12Z/MON. The flight levels may even lower briefly to LIFR by 12Z/MON. Expect a gradual improvement to low MVFR cigs/vsbys in the late morning into the early afternoon from KPOU northward. KPSF may hang at IFR cigs until 21Z/MON to 00Z/TUE. We expect KPOU/KALB/KGFL to each low MVFR cigs in the 1.0-2.0 kft AGL range between 18Z-21Z/MON. The winds will be light and variable in direction at 5 kts or less overnight. The winds will vary from east/southeast to northeast at 4-8 kts in the late morning into the afternoon. Low- level wind shear will become an issue for KPOU/KPSF 06-14Z /Mon with a south/southeast LLJ around 30-35 kt moving in aloft. Outlook... Monday Night: High Operational Impact. Definite RA...TSRA. Tuesday: High Operational Impact. Definite RA. Tuesday Night: High Operational Impact. Likely SHRA...RA. Wednesday: Low Operational Impact. Slight Chance of SHRA. Wednesday Night: No Operational Impact. NO SIG WX. Thursday: No Operational Impact. NO SIG WX. Thursday Night: Low Operational Impact. NO SIG WX. Friday: Moderate Operational Impact. Chance of SHRA. && .FIRE WEATHER... Periods of rain tonight through Tuesday night will keep fire weather from being a concern. After a brief dry stretch Wednesday and Thursday, additional periods of rain will be likely Friday into next weekend. && .HYDROLOGY... Two periods of rainfall are expected early this week. The first will come tonight into Monday morning resulting in 0.5 to 1 inch of rainfall. Then, a coastal storm will develop with the potential for periods of moderate to heavy rainfall Monday night into Tuesday night. Total rainfall amounts during this second event could range from 1 to 4 inches, heaviest from the Capital District to points south and east. There is still considerable uncertainty in the placement of the low track and axis of maximum rainfall. Latest MMEFS forecasts based on the NAEFS and GEFS still point to low to moderate probabilities of some forecast points reaching minor flood stage. Some spots could reach moderate flood stage if QPF on the higher end of the solution envelope is realized. Some areal or flash flooding cannot be ruled out as well. After a brief period of dry weather Wednesday through Thursday, another system may bring periods of rain Friday into next weekend. For details on specific area rivers and lakes, including observed and forecast river stages and lake elevations, please visit the Advanced Hydrologic Prediction Service /AHPS/ graphs on our website. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. MA...None. VT...None. && $$ SYNOPSIS...Thompson/Wasula NEAR TERM...IAA/Wasula SHORT TERM...IAA LONG TERM...Evbuoma AVIATION...Wasula FIRE WEATHER...Thompson HYDROLOGY...Thompson
Area Forecast Discussion
National Weather Service La Crosse WI
1030 PM CDT Sun Oct 24 2021 .SHORT TERM...(This evening through Monday) Issued at 255 PM CDT Sun Oct 24 2021 Early afternoon water vapor imagery showed a strong shortwave trough across eastern NE/KS with its associated surface cyclone along the MO/KS border. Regional radar mosaics indicated the well- advertised rain shield spreading north into northeast IA/southwest WI. This precip is largely tied to mid-level warm advection and frontogenesis north of the surface warm front. Overall, guidance is in very good agreement with this deformation rain shield continuing to slowly spread north into this evening before pivoting east overnight, exiting southwest WI around sunrise. Little in the way of even elevated instability will reach into the area, so thunder/convective potential remains quite low. The highest rain chances still should hold near and south of the I-90 corridor, in line with placement of the stronger mid-level frontogenesis via the RAP fields. Higher probabilities (>50%) for at least half an inch of rain remain along/south of the MN/IA border with the NBM indicating 60 to 70% probabilities of at least 1 inch of rain across far southwest WI and adjacent portions of IA. Due to plenty of dry air to the north and an easterly track to the trough/deformation band tonight, a sharp cut-off in rain amounts is likely with potential for little rainfall north of the I-90 and I-94 corridors. There also continues to be a signal for strong, gusty winds later this afternoon into tonight as the pressure gradient tightens between high pressure nosing into the Upper Midwest and the surface cyclone passing into central IL. 950-850 mb winds strengthen to around 40 to 50 kts this evening over southwest WI/northeast IA, and it wouldn`t take too much mixing to bring down some of those higher winds. The rain/clouds could limit mixing, but gusts up to around 40 mph are possible this evening for southern areas. High pressure will build over the region on Monday with clearing skies and seasonable highs in the upper 40s to mid 50s. .LONG TERM...(Monday night through Sunday) Issued at 255 PM CDT Sun Oct 24 2021 For the longer term, the attention remains focused on the mid- week system. In the big picture, the models all remain consistent and have fairly similar solutions on how the overall pattern evolves. As the mean long wave trough currently off the West Coast moves across the Rockies, some of the energy from this system will stay to the north and move across southern Canada with another piece of energy in the equatorial side of the long wave trough forming an upper level low over the Lower Plains. The main differences between the models revolves around how quickly this upper level low forms and how much energy will remain in the long wave trough between the upper level low and the energy over southern Canada. The 24.00Z ECMWF and 24.12Z NAM and GEM all form the upper level low Wednesday while the 24.12Z GFS holds off until Thursday and forms the low over the mid-Mississippi River Valley. The ECMWF and GEM are in the camp of having less energy north of the upper level low and actually show a hint of weak ridging from the departing upper level ridge holding over the area while the GFS does not show this ridging being more progressive and later with the formation of the upper level low. No matter when or where the models form the upper level low, they all end up moving it off into the Ohio River Valley by the end of the work week with ridging building back into the Upper Midwest. The main point of contention between the models based on the upper air differences is how fast the rain moves into the local area. With that bit of ridging holding of over the area, the ECMWF and GEM would suggest that the rain would hold off until Wednesday night. The NAM and GFS have more support for the possibility of rain moving in Wednesday with moderate QG convergence in the 1000-700 mb layer, some weak frontogenesis in the 850-700 mb layer and up to 2 ubar/s of upglide on the 295K isentropic surface. There are still a few members of the 24.00Z ECMWF EPS that support the faster solutions so will plan to hold onto at least some rain chances on the leading edge for Wednesday. The rain chances then look to be a good bet for the entire area Wednesday night into Thursday night before pulling out of the region Friday. && .AVIATION...(For the 06Z TAFS through 06Z Monday night) Issued at 1030 PM CDT Sun Oct 24 2021 Cigs: MVFR cigs continue to sit just south of the TAF sites, and most short term models favor keeping them there. Will continue to follow suit. The mid level deck will eventually scattering/clearing out toward 12z Mon. SKC/SCT conditions favored through Tue as the area comes under the influence of a ridge of high pressure. WX/vsby: northern fringe of rain shield (to the south) has not reached KRST/KLSE and doesn`t look like it will anymore - northeast/easterly winds continues to push drier air into the local area while the parent low pressure system tracks east. Winds: tight pressure gradient will keep it blustery/gusty from the northeast overnight, decreasing and becoming more northerly Mon afternoon. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. IA...None. && $$ SHORT TERM...JM LONG TERM...04 AVIATION...Rieck
Area Forecast Discussion
National Weather Service Charleston SC
858 PM EDT Sun Oct 24 2021 .SYNOPSIS... Low pressure will develop off the coast late tonight then push offshore Monday. A cold front will pass through the area Monday night into early Tuesday, followed by high pressure through mid week. A low pressure system is expected to impact the region later in the week. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... The forecast is evolving as expected. The core of the pressure falls offshore are centered just east of Tybee Island. The only major change that was made for the late evening update was to increase pops to 70-80% across the Georgia coastal counties, including the Savannah Metro Area, as high-res guidance along with the 18z HREF continue to increase the pops along the coast overnight. Surface cyclogenesis will rapidly take shape off the Georgia and South Carolina coasts tonight as shortwave energy moving across the Deep South pivots across the Southeast States. 24/23z surface plots already show a coastal trough beginning to sharpen across the coastal waters with east to northeast winds prevailing within 20 NM of the coast and a pronounced veering of winds to the southeast noted at buoy 41004 over the past several hours. Surface pressures are also beginning to show up offshore suggesting the beginning stages of cyclogenesis are likely already underway. The atmospheric column is quite dry early this evening with RAP soundings show a bone dry sub-cloud layer with PWATs averaging less than an inch. A plume of tropical moisture with PWATs 1.50-1.75" will advect north overnight as a southwesterly low-level jet intensifies across Florida and into the South Carolina/Georgia coastal waters. Shower activity is expected to see a steady uptick over the Atlantic overnight as the surface low takes shape within the coastal trough and deep-layered forcing intensifies ahead of the approaching shortwave and left exit region of a subtropical jet streak propagating across the northern Gulf of Mexico. There remains some uncertainty on exactly how far inland the rain shield will penetrate overnight as the surface low deepens offshore. The RAP and H3R are much more bullish in pushing measurable rainfall well inland while the HREF and other CAMs keep rainfall pinned closer to the coast. Given the way the guidance tracks the 850-700 hPa moisture plume, suspect a compromise between the HREF and RAP/H3R is likely the best way to go until trends can be better established overnight. The updated forecast pretty much keeps pops in the 20-30% range well inland pops, but were increased to 70% along the coast through 24/12z. Any meaningful instability will likely remain just offshore, but some data do show some negative lifted indices reaching into the coastal counties after midnight as the low begins to form. A slight chance of tstms was introduced to account for this. QPF will generally average 0.15-0.45 along the coast through daybreak. Lows will range from the lower 60s inland to around 70 at the beaches. && .SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/... A mid and upper level disturbance will be moving through the area at the start of the period. Scattered showers and perhaps numerous showers at the beginning of the period, especially near the coast will quickly shift off to the north and east as the disturbance moves quickly into the western Atlantic and takes a swatch of deep moisture with it. A larger more dominate upper level area of low pressure over the Ohio Valley will then begin to impact the area Monday afternoon and into Monday night and this and an associated cold front approaching the area and then moving into the area could bring mainly a slight chance of showers and perhaps an afternoon or evening thunderstorm. Limited moisture and only modest assent precludes higher rain chances at this time. Drier air moves into the area behind the cold front resulting in the end of the threat for precipitation by first thing Tuesday morning. Highs on Monday should range from the upper 70s at the coast to mainly lower to mid 80s inland. Then as a deep upper level low develops over the western Atlantic, high pressure will build into the area for Tuesday and Wednesday bringing in more seasonable and much drier conditions. Highs will cool into the lower 70s north to the mid to upper 70s south by Wednesday. Lows Tuesday night will range from the upper 40s inland to the upper 50s at the coast Tuesday night. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... A narrow high amplitude upper level ridge over the area at the start of the period will shift east as a deep mid level and initially negatively tilted upper trough and associated surface low moves from the Mississippi River Valley eastward to the East Coast. By the end of the period, it appears the system will be weakening as it moves into the western Atlantic. There is fairy good model agreement on the large scale pattern. It appears that clouds will be increasing and thickening Wednesday night with a threat for showers moving into southeast Georgia counties after midnight, with decent threat for showers across the entire area Thursday and Thursday night, possibly lingering into Friday. There could be a threat for some locally heavy rainfall. A few thunderstorms could be possible in the south and along the coast mainly Thursday and Thursday night. However did not include in the forecast at this time due to uncertainly with regard to the northward movement of the warm front. Afterwards it appears a cool dry weekend is in store for the area. Highs mainly mid to upper 70s Thursday will cool to mainly near 70 by Saturday and Sunday. && .AVIATION /01Z MONDAY THROUGH FRIDAY/... VFR this evening will give way to light rain and lower cigs overnight as low pressure develops offshore. The rain looks to remain fairly light, but could become moderate at times especially along the immediate coast, including KJZI. Vsbys were held at 6 miles in light rain at all sites, but a TEMPO group for 3SM RA BR was introduced at KJZI 10-13z and 4SM at KSAV 06-09z per latest simulated reflectivity output from the H3R. Cigs are expected to drop to MVFR at all three terminals, but will have to watch for possible IFR at KSAV closer to daybreak as rain clears and some lower clouds and possibly some fog tries to push in from the west and southwest. VFR should return to all sites by mid morning. Extended Aviation Outlook: VFR conditions expected to prevail through mid week. Chance for flight restrictions in showers will increase starting on Thursday, possibly lingering into late Friday. && .MARINE... Tonight: High pressure offshore the Mid Atlantic will cause winds to shift out of the southeast late this evening with speeds around 10 knots. Seas will average around 2-3 feet. A disturbance will allow numerous showers and possibly a few thunderstorms to develop just before midnight over the Georgia waters initially, then expanding northward into the South Carolina waters by the early morning hours. Low pressure could develop over the waters by early morning causing winds to weaken slightly and enhancing the coverage of showers. Monday through Friday: Light and variable winds will become southerly across all waters by late Monday with speeds expected to be no greater than 10 knots except in and near any thunderstorms. Winds and seas will increase Monday night into Tuesday and then linger into Tuesday night as a cold front approaches and then passes through the area. It appears that conditions will remain below Small Craft Advisory thresholds during this time period. High pressure will then prevail across the area Wednesday and Wednesday night with winds no higher than about 12 knots and seas 2-4 feet. A low pressure system will then impact the region and this will result in increasing winds and seas Thursday into Friday with a possible threat for Small Craft Advisories for at least portions of the coastal waters during this time period. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. MARINE...None. && $$
Area Forecast Discussion
National Weather Service Goodland KS
1000 PM MDT Sun Oct 24 2021 .UPDATE... Issued at 850 PM MDT Sun Oct 24 2021 Immediate concerns tonight include the Frost Advisory and threat for dense fog. Presently just a few cirrus clouds moving across the area with temperatures in the middle 30s to middle 40s. Winds were generally under 10 mph. A stratus deck currently over northeast and eastern Nebraska is forecast to back in to our northeast zones around 07z, continuing to move west toward the CO/KS border by 12z. The stratus deck is expected to remain along or just inside the CO/KS border through 15z then dissipate quickly from west to east through the rest of the morning. The expected increase in low cloud cover and cirrus moving in from the west may prevent low temperatures from reaching the previous forecast values in the lower to middle 30s which in turn would prevent the development of frost. At this time the western portions of Sherman and Cheyenne counties of Kansas would be void of low cloudiness and have a chance of reaching the middle 30s which may produce some frost. For these reasons I will keep the Frost Advisory going and let the midnight shift take another look. As the stratus moves in from the west visibilities are expected to fall below one mile and very likely closer one quarter mile which would require a Dense Fog Advisory. At this time will be holding off from issuing the advisory and let the midnight shift get some time to look at newer model guidance before making the final decision. && .SHORT TERM...(This evening through Tuesday) Issued at 203 PM MDT Sun Oct 24 2021 RAP analysis indicates a potent low pressure system departing Kansas with high pressure building in over the High Plains. Morning cloud cover dissipated mid morning leading to clear skies and breezy winds, as some winds have gusted as high as 35 mph so far this afternoon. The winds are anticipated to die down around sunset as diurnal heating wanes and the low moves off into Missouri and Illinois. Afternoon high temperatures still appear to be on track in the 60s to perhaps the 70s in spots (especially over Greeley and Wichita counties). Tonight, low clouds and areas of fog are expected to increase from the north along and east of Highway 83 from Oakley to McCook. The fog doesn`t look to be as widespread or dense as last night but a few locales could still get down to around 1 mile in visibility at times. The fog is expected to lift mid morning Monday. The other factor to watch tonight is expected frost development with cooler temperatures. A Frost Advisory has been issued from midnight through 8am MDT for Sherman, Cheyenne (KS) and Yuma counties. The fog/cloud to mainly clear sky gradient looks to lineup across Thomas to Rawlins to Hitchcock counties leading to more expected clearing and winds less than 10 knots will lead to frost development for the advisory counties. Guidance has been a little shaky on how far west the clouds will make it overnight, so if they do end up further east then Hitchcock, Rawlins and Thomas may need to be added to the advisory. Monday, looks to be warmer than today as a SSW wind dominates the area along with clear skies ahead of the next storm system which sends a warm front across the area. Winds will be breezy to gusty as winds may gust up to 30-35 mph through the afternoon as the pressure gradient strengthens. Afternoon highs are currently forecasted in the upper 60s through mid 70s across the area. Monday night, winds stay breezy from the south at 10-20 mph. Overnight low temperatures are forecasted to be warm (for late October standards) as they range from the mid 40s to lower 50s under clear skies. .LONG TERM...(Monday night through Sunday) Issued at 221 PM MDT Sun Oct 24 2021 The focus in the long term revolves around the low pressure system moving east of the Rockies and across the High Plains between Tuesday afternoon and Wednesday afternoon. Concerns include gusty winds south winds along with the dry and warm conditions along the eastern Colorado border ahead of the system Tuesday afternoon and transition to a possibility of severe thunderstorms Tuesday evening and Tuesday night mainly east of a line from McCook, Nebraska to Gove, Kansas. High temperatures will be in the middle 70s to lower 80s ahead of a cold front. RH values along the Colorado border will drop into the upper teens for 2-3 hours with winds gusting around 30 mph. This will produce elevated to near critical fire weather conditions for a few hours Tuesday afternoon. As the cold front moves further east proceeded by the lift ahead of upper trough, storms develop in the warm sector where the instability and moisture is more favorable. Most recent model output suggest the area of severe storms may be east of the forecast area with additional precipitation developing in the wraparound on the back side of the system overnight Tuesday night into early Wednesday morning that moves east of the area by mid day on Wednesday. Gusty northwest surface winds continue on the back side of the system Wednesday and again on Thursday as the low pressure center at the surface sweeps across the southern plains and lifts out across the Mississippi Valley area. Dry and cooler conditions with gradually warming temperatures are expected as the upper ridge expands eastward across the Rockies and High Plains through the end of the week and into the beginning of the weekend. Dont expect any dust concerns with the gusty winds as any precipitation, depending upon how much the area gets, should keep the the soil from blowing around. Late this week, there is a potential for some areas to see near freezing temperatures during the early morning hours. Confidence in any one area needing any kind of frost/freeze statement is low and will have to be reevaluated following the currently issued frost/freeze highlight. && .AVIATION...(For the 06Z TAFS through 06Z Monday night) Issued at 1000 PM MDT Sun Oct 24 2021 KGLD...VFR conditions are expected through 12z then again after 16z. From taf issuance through 12z winds generally from the southeast approaching 11kts. From 13z-15z stratus and fg/br remains on track to back in to the terminal from the northeast producing sub VFR conditions. Winds during this time initially from the southeast around 11kts but picking up with gusts up to 25kts. From 16z through the rest of the period VFR conditions return with southeast winds gusting over 30kts. Wind shear increases after 02z. KMCK...VFR conditions are expected through 08z then again after 17z. From taf issuance through sunrise winds generally very light from the east. From 09z-16z stratus and fg/br remains on track to back into the terminal producing sub VFR conditions. Winds during this time period will be from the southeast under 10kts. After 17z VFR conditions return with southeast winds gusting up to 30kts. From sunset through the rest of the period east-southeast winds remain around 12kts with wind shear increasing. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...Frost Advisory until 8 AM MDT /9 AM CDT/ Monday for KSZ001-013. CO...Frost Advisory until 8 AM MDT Monday for COZ090. NE...NONE. && $$ UPDATE...99 SHORT TERM...TT LONG TERM...LOCKHART AVIATION...99
Area Forecast Discussion
National Weather Service Springfield MO
706 PM CDT Sun Oct 24 2021 ...Mesoscale Discussion... .MESOSCALE DISCUSSION... Issued at 702 PM CDT Sun Oct 24 2021 Surface low pressure continues to track east-northeast across northern Missouri with a cold front extending south from the low across western Missouri. A surface trough/low level convergence zone also extends south from the low across the eastern Ozarks. The warm front associated with this low extends east into central Illinois, thus areas of the Missouri Ozarks east of the cold front are well into the warm sector of this system. Two distinct areas of thunderstorms are ongoing at the 00Z hour. A loose cluster of showers and thunderstorms is located across the eastern Ozarks. We suspect these storms are slightly elevated as cloud base observations across this region have been around 5000 feet agl. Large hail will be the primary threat with this activity. It is possible that a few of these storms could become surface based as they push out of our eastern counties. If this occurs, we may see a brief window of increased tornado potential as low level shear increases owing to a strengthening low level jet. Meanwhile, we expect thunderstorm coverage and organization to increase along the cold front this evening as upper level jet energy digs into the region and the mid levels continue to cool. MLCAPE values of 1200-2000 J/kg will be in place with deep layer shear of 40 to 50 knots. The 00Z KSGF sounding measured MLCAPE values of 1683 J/kg with 0-1 km SRHs now up to 290 m2/s2. With increasing linear forcing and cold pool conglomeration, we think that a broken line of storms will continue to materialize including the potential for QLCS and supercell tornadoes. The last few runs of the HRRR support this well with multiple updraft helicity tracks. The threat for damaging straight-line winds will also increase throughout the evening with QLCS bowing structures. The good news is that the cold front will continue to move east at a good clip with most of this activity out of the eastern Ozarks by 11 PM, thus ending the severe threat. && .SHORT TERM...(This evening through Monday) Issued at 124 PM CDT Sun Oct 24 2021 Main message: Severe storms are likely early in the period with supercell thunderstorms. Tornadoes, damaging wind, large hail will also be possible. Storms will be brief. Sfc low over northeast KS with a trailing cold front over eastern KS will shift east over the next few hours. A weakly capped warm sector ahead of the front has kept convection to a minimum, but have started to see signs of the cap weakening with weak updrafts along the MO/KS line. Cold air aloft/height falls/lift with an upstream low amplitude shortwave over KS will overspread the area further weakening the cap. Moderate MLCAPE values of around 1500 j/kg and deep layer shear of 40-45kts will support organized storms/super cells. Will see convection increase in coverage over the next couple of hours with supercells, and eventually a broken line of storms develop. Prefrontal storms are also possible, with some cams showing some prefrontal convection as well as the cap breaks. All modes of severe weather will be possible. Somewhat veered near surface flow, does not look the best for tornadoes, but flow may back somewhat toward sunset, especially over the eastern cwfa. Will be monitoring the storm environment closely. Storm cell motion will be quite fast given the winds aloft, and some will occur after dark over the eastern cwfa before exiting our eastern counties 10pm-11pm. .LONG TERM...(Tuesday through Sunday) Issued at 124 PM CDT Sun Oct 24 2021 Tuesday-Wednesday: Big storm system off the U.S. west coast will move inland over the next couple of days and out into the Plains Wednesday. Showers and a few thunderstorms will spread east into the region Tuesday night and continue Wednesday. Sfc low track looks to be south of the area over OK/AR with limited instability this far north. While the severe storm risk looks low, will need to watch rainfall amounts with possible heavy rain over the region with the slow moving/high amplitude system. Thursday-Sunday: The slow moving vertically stacked upper system and sfc low will shift east of the area with some clouds/precip lingering into the latter part of the week. Will see a ridge of high pressure move into the region by the weekend. && .AVIATION...(For the 00Z TAFS through 00Z Monday evening) Issued at 613 PM CDT Sun Oct 24 2021 A quick moving cold front was pushing through the area this evening. This front has already pushed through the JLN area and no additional convection is expected there tonight. The thunderstorms will affect the SGF area from 23z through 01z and BBG area from 00z through 02z. Mainly expecting VFR conditions outside of convection and some MVFR to brief IFR within the convection. Later tonight some stratus is expected to move into the area with ceilings in the MVFR category continuing into early Monday morning. Winds will become westerly behind the front and eventually shift to the northwest and north by Monday morning. && .SGF WATCHES/WARNINGS/ADVISORIES... MO...NONE. KS...NONE. && $$ MESOSCALE...Schaumann SHORT TERM...DSA LONG TERM...DSA AVIATION...Lindenberg
Area Forecast Discussion
National Weather Service San Diego CA
838 PM PDT Sun Oct 24 2021 .SYNOPSIS... A cold front moving down the coast tonight will bring rain Monday, mainly in the afternoon and evening. Strong gusty winds will occur Monday in parts of the mountains and deserts. Tuesday will be a dry, cool day, followed by warmer weather and weak offshore flow the second half of this week. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... EVENING UPDATE... Low clouds are developing just off the coast this evening with high clouds continuing to move east across the northern areas. Breezy southwest to west winds are ongoing across the mountains and deserts with gusts mostly below 35 mph. Winds will continue overnight, then strengthen Monday morning. A wind advisory remains in effect for the mountains and deserts except the Coachella Valley Monday morning through early Tuesday morning. The Atmospheric River is still aimed at northern California, soaking the Bay Area into the Sierras with several inches of rain in the past 24 hours. This feature will slowly sag south and lose steam as it moves into So Cal tomorrow. Everything remains on track so no changes were made to the forecast. PREVIOUS DISCUSSION... The elephant in the room is the strong atmospheric river currently moving through northern California. Once it moves into SoCal Monday, it will have weakened, but CW3E maps still indicate IVT values of around or slightly over 500 kg/m/s Monday afternoon over our area based on the ECMWF/GFS/NAM inputs. ECMWF EFI show effectively record values for both QPF and surface winds in central California today though nothing outstanding from LA south. Model time-height cross- sections show most of the moisture at/below 650 MB along with 850 MB winds from the west/southwest of 20-30 knots, so that will be favorable for decent orographic precipitation, though without the instability and dynamics being fairly brief with the cold front, precip amounts will not be too impressive at the coast. ENS/GEFS ensemble members are fairly consistent with each other and run-to- run with mostly around 0.2" at SAN and 0.4" at SNA, though the latest deterministic HRRR is showing a little bit higher values around 0.5" in some coastal locations. Orographic precip will be greatest in the San Bernardino County Mountains as local values could exceed 2", though most mountain locations, especially farther south, will be closer to 1". Given that the nearly- saturated layer only goes up to about 650 mb, it will be difficult for the deserts to get anything substantial, but the high deserts could get up to 0.25" with the lower deserts mostly below 0.1". Timing will mostly be Monday afternoon to early evening, with Orange/San Bernardino Counties coming before San Diego/Riverside Counties. Local wind gust potential of around 55 MPH Monday on the desert mountain slopes which will warrant a wind advisory for then. Regarding snow, the freezing level mostly remains at/above 10000 ft MSL when the moisture is in place, with only a drop below at the end of the storm, so little or no snow will fall on any roadways, even at Onyx Pass. After Monday night, the trough of low pressure associated with the atmospheric river will shift east towards the Rockies while broad zonal high pressure aloft covers much of the eastern Pacific. That high will amplify and move east over the western US Wednesday through Friday. Models are having a tough time past then, with some troughing or possibly a closed low moving by to the north over the weekend. Some offshore flow at the surface will occur as well Wednesay and Thursday, but nothing strong. Daytime highs should increase to above seasonal normals with ENS indicating some 90s in the valleys and especially lower deserts by Thursday, with a slight cooling trend over the weekend. Sunshine should be abundant most of Tuesday through Friday, maybe Saturday. && .AVIATION... 250300Z...Coasts/Valleys/Mountains...Low clouds with bases 1500-2500 ft MSL expected to develop along the coast around 06Z Mon, spreading inland through 12Z Mon. Higher terrain becoming obscured in clouds after 12z Mon. RA expected to start in Orange County around 21Z, with isolated SHRA possible ahead of the main front as early as 17Z Mon. RA will move from northwest to southeast, reaching San Diego County around 00Z Tue. Vis will be reduced to 2-4 SM and cigs may become locally under 1000 ft MSL at times in areas of RA. Dry conditions expected for all areas after 06Z Tue. Bases 3000-5000 ft MSL expected overnight Tue. Strong southerly winds with strong up and downdrafts along with wind shear near mountains and adjacent mountain slopes Monday as winds increase to 20 to 30 knots with gusts approaching 50 knots at times. Gusty southwest winds expected at coastal TAF sites after 21Z Mon. Deserts...SCT-BKN high clouds AOA 20000 ft MSL through 00Z Mon. After 00Z Mon clouds with bases 5000-7000 ft MSL, showers, and deteriorating conditions expected through Tue AM. Gusty north to northwest winds expected after 21Z Mon. Gusts 25-30 kt expected. Strong up and downdrafts near the mountains. && .MARINE... An approaching storm system will bring gusty southwest winds, that will transition to northwest winds after 5 PM Mon. Gusts of 20-25 knots expected in the outer waters and closer to 20 knots across the inner waters Monday afternoon and Tuesday. Combined seas of 6-10 ft expected, highest in the outer waters. Please see the Small Craft Advisory and Coastal Waters Forecast for more information. && .BEACHES... A long period west swell and a long period south swell will result in high surf and a high rip current risk at all beaches Monday through early Wednesday. Surf of 6 to 8 feet is expected, with sets up to 10 feet possible in southern San Diego County. Please see the High Surf Advisory for more information. && .SKYWARN... Skywarn activation will not be needed tonight, but may be requested Monday. && .SGX WATCHES/WARNINGS/ADVISORIES... CA...Wind Advisory from 10 AM Monday to 2 AM PDT Tuesday for Apple and Lucerne Valleys-Riverside County Mountains-San Bernardino County Mountains-San Diego County Deserts-San Diego County Mountains-San Gorgonio Pass Near Banning. High Surf Advisory from 11 AM Monday to 3 AM PDT Wednesday for Orange County Coastal Areas-San Diego County Coastal Areas. PZ...Small Craft Advisory from 11 AM Monday to 5 AM PDT Tuesday for Coastal Waters from San Mateo Point to the Mexican Border and out to 30 nm-Waters from San Mateo point to the Mexican Border Extending 30 to 60 nm out including San Clemente Island. && $$ PUBLIC...SS/Maxwell AVIATION/MARINE/BEACHES...CO
Area Forecast Discussion
National Weather Service Shreveport LA
1016 PM CDT Sun Oct 24 2021 .SHORT TERM... Convection has been slow to develop along the approaching cold front this evening, with the front reaching from near a FSM, to just NW of Hugo, to DAL and just N of CPT line as of 03Z. Instability ahead of the front has begun to wane, with SBCapes of only 500-1000 J/Kg, contributing to the lack of strong updrafts which has limited lightning this far this evening. Instability will remain rather meager as we continue through the overnight hours, with the strongest forcing beneath the shortwave trough expected to remain just NNE of the region over Cntrl/Ern AR. Still can`t rule out an isolated strong storm over Nrn McCurtain County OK during the next hour, and thus will allow the current Tornado Watch #532 to remain in effect until its 04Z expiration, but have taken out severe wording for the Nrn zones overnight, while also lowering pops slightly to mid and high chance for the Nrn zones as well. This convection should gradually diminish late tonight as the best forcing slips ESE into the Mid-South region, with the front reaching the I-20 corridor of E TX/N LA around daybreak Monday. Only very minor adjustments were needed to the forecast min temps, but did delay the onset of the increased cloud cover given the lack of cigs currently over the Wrn half of the region. The front remains progged to drift S into Cntrl LA and Deep E TX Monday afternoon before pulling up stationary, resulting in a gradual clearing of cigs over all but Lower E TX through the day. Did maintain slight chance pops through mid-morning through for portions of Srn AR/Nrn LA along the front, with drier conditions trending during the day as the deeper wedge of drier air advects SSE in wake of the fropa. Zone update already out...but will send another zone update shortly after 04Z with the expiration of the TOR Watch. 15 && .PREV DISCUSSION... /issued 707 PM CDT Sun Oct 24 2021/ .AVIATION... VFR conditions will continue through the evening, although MVFR cigs are expected to develop after 06Z Monday across portions of Deep E TX/N LA, and gradually lower through daybreak ahead of a cold front that will progress SE into the region by/after 06Z. Sct convection has already developed along the front this evening across Ern and SE OK, which will shift ESE into SE OK/adjacent SW AR between 02-06Z. These storms should affect TXK between 05-07Z, and ELD between 07-10Z, producing gusty winds to 30+kts, locally reduced vsbys, and low MVFR cigs, before the convection gradually weakens just prior to daybreak as it enters portions of NCntrl LA. Have held off thunder mention for MLU given the lower confidence in the convection reaching this terminal, but will be monitored for possible amendments overnight. In addition, areas of IFR/LIFR cigs and FG should develop after 08Z across portions of Deep E and SE TX, affecting LFK through 14Z before lifting. The front will reach the I-20 corridor of E TX/N LA between 12-15Z Monday, with cigs scattering out with the passage of the front, as it enters Cntrl LA/Deep E TX by early afternoon before becoming stationary. Thus, any remaining cu field will diminish during the afternoon, although some will linger across portions of Lower E TX and NCntrl LA through the end of the TAF period. S winds 4-8kts this evening will become WSW around 5kts after 06Z. Winds will then become NNE 5-10kts with the fropa after 12Z. /15/ && .PREV DISCUSSION... /issued 410 PM CDT Sun Oct 24 2021/ .UPDATE... Zone update just sent for the issuance of TOR Watch #532 for McCurtain County OK. The latest visible satellite imagery indicates an area of agitated cu developing to our NW over ECntrl and Srn OK, along a cold front steadily progressing E across the state into NW TX. It still will be some time before the narrow line of convection develops and affects McCurtain County, with the latest HRRR depicting this not occurring until around/after 02Z. While not particularly high, enough of a threat warrants a watch as isolated strong to severe convection may affect the NW and Nrn zones late this evening into the early morning hours Monday. Will continue to monitor the evolution and progression of the convection for a possible extention of the watch into SW AR late this evening. 15 && .PRELIMINARY POINT TEMPS/POPS... SHV 69 89 62 85 / 20 10 0 0 MLU 69 89 55 81 / 30 20 0 0 DEQ 58 83 53 79 / 40 10 0 0 TXK 65 85 58 82 / 30 10 0 0 ELD 65 84 52 78 / 50 20 0 0 TYR 67 89 66 87 / 10 10 0 0 GGG 69 89 62 87 / 10 10 0 0 LFK 69 91 67 88 / 10 10 0 0 && .SHV WATCHES/WARNINGS/ADVISORIES... AR...None. LA...None. OK...None. TX...None. && $$ 15