Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 06/01/23


Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
905 PM CDT Wed May 31 2023 .UPDATE... Issued at 856 PM CDT Wed May 31 2023 CWA is free is precipitation currently, and based on recent runs of the HRRR and other CAMs, been cutting back on PoPs through the rest of the night. Several boundaries floating around the region from earlier convection, some of which are visible on radar. Surface obs also continue to indicate the presence of the main boundary draped across the region. Not much to hang your hat on for overnight shower/storm chances and will likely have to wait until tomorrow afternoon for any noteworthy redevelopment. Only minor modifications to other weather elements for the overnight hours. && .SHORT TERM...(This Evening through Thursday Night) Issued at 230 PM CDT Wed May 31 2023 Our unsettled weather pattern and warmer than average temperatures continue through the short term. Deterministic and ensembles agree on a ridging pattern across the central and eastern CONUS with a trough in the western CONUS and mid level low centered over CA/AZ this evening. This will continue to provide southwest flow at 500mb with wind speeds at 15kts at most. This pattern continues through Thursday with winds at this level turning more southerly Thursday afternoon then southeasterly by Friday morning (15-25kts) as the low moves northeast. Several shortwave pulses will push from the southwest towards the northeast then wrap back west around the low as it moves northeast, mainly over central and western SD through Friday. This whole pattern really only shifts slightly east over the next few days. Models do show an increase in wind speed overnight at 850mb (LLJ) across our central and western CWA with speeds up to 25 kts per NAM/GFS. EC has some higher speeds (up to 32 kts). At the surface, a trough sets up over the CWA this evening and tonight with winds out of the south/southeast and more east/southeast Thursday and increasing Thursday afternoon and again Friday mainly across central and western SD. As of 200 PM, Satellite/RAP model continues to show the vort max/MCV hybrid pushing into ND. Ongoing showers and thunderstorms continue to push northeast and are weakening. Earlier, we had some modest CAPE, steep low level LR, and the slightest low level curvature on the hodograph over eastern/northeastern SD/western MN per Rap model where some of these storms had some very weak rotation to them, especially early on in the storm`s life. We did have a warning on one of the cells for quarter size hail and 60 mph winds. No organized severe weather occurred as overall bulk wind shear remained low. Models have really backed off on the chances of pops for late this afternoon and evening behind this line of storms. So went with more of a broad brush slight chance wording. This may even need to be taken out if nothing forms. Same story again for Thursday with similar ingredients in the atmosphere and synoptic setup, more spotty chances of showers and thunderstorms expected. Again, no organized severe weather expected but some could pulse high enough to produce some small hail and gusty winds. .LONG TERM...(Friday through Wednesday) Issued at 230 PM CDT Wed May 31 2023 In the out periods, the biggest forecast challenges will focus on thunderstorm chances and temperatures. This CWA will be influenced heavily by high pressure in the mid/upper levels of the atmosphere. An overall/over-arching upper level ridge in place over the eastern two-thirds of North America will support the retrogression of an area of upper level high pressure, currently over the east CONUS coastline, westward into the country`s mid-section up into southern Canada throughout the period. Ensemble-based PoPs are rather generous through the period, given the lack of an adequate forcing/lift signal on any given day. Similar to the past couple of weeks, precipitation chances are either a result of previous convection-leftover OFB-forcing, nocturnal low-level jet-forcing, or convection that rolls down out of the higher terrain of the central/northern high plains. Ensemble-based probabilities of temperatures reaching or exceeding 90 degrees are still targeting portions of the southwestern and eastern forecast zones several days in the extended, as well. && .AVIATION...(For the 00Z TAFS through 00Z Thursday Evening) Issued at 638 PM CDT Wed May 31 2023 Terminals KABR,KATY,KPIR,KMBG VFR conditions are forecast through the TAF period. Just a very slight chance for a stray -TSRA/SHRA this evening/overnight. Will await Thursday afternoon before any more potential meaningful coverage of -TSRA/TSRA that deserves a VC mention in the TAFs. Like the past few days, hard to pinpoint exact locations as coverage will be scattered, but if something were to move over a terminal, potential exists for MVFR VSBY in heavier downpours. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...None. MN...None. && $$ UPDATE...TMT SHORT TERM...MMM LONG TERM...Dorn AVIATION...TMT
Area Forecast Discussion
National Weather Service Amarillo TX
702 PM CDT Wed May 31 2023 ...New AVIATION... .MESOSCALE UPDATE FOR HAIL, WIND, AND FLASH FLOODING THREAT FOR THIS AFTERNOON THROUGH THURSDAY MORNING... Issued at 216 PM CDT Wed May 31 2023 * Synoptic Overview: The latest H500 RAP analysis shows a upper level low pressure system continues to remain nearly stationary near the southern tip of Nevada early this afternoon. This feature will continue to drift very slowly towards the east through early tomorrow morning. Out ahead of this feature, shortwaves embedded in the upper level flow will propagate across the Southern High Plains beginning later today and will continue through early Thursday morning. The PVA associated with these waves will generate numerous rounds of precipitation of the next 18 hours or so. Southerly winds in the low to mid levels will allow a decent axis of positive theta-e to move across eastern NM and West Texas this afternoon through the overnight hours tonight which will aid in generating a few rounds of thunderstorms. * Mesoscale: As of 18z, showers and thunderstorms continue to move east and northeast across eastern New Mexico. Across the southwestern and south central TX Panhandle, visible satellite imagery shows some attempts at a cumulus field trying to develop over this area. The first run (17z) of the Warn on Forecast (WoFS) suggests that these showers and storms will move across the northwestern TX Panhandle later on this afternoon, leaving the southwest and central portion of the CWA in the clear from this initial activity. A few isolated thunderstorms may develop across these areas later on this afternoon in an environment that will be primed for storms to become strong to severe. MUCAPE values could be approaching 2500 to 2750 J/kg and bulk shear values of 20 to 25 kts could lead to a few strong to severe isolated supercells. The next upper level wave will be approaching the High Plains by early this evening and a line of storms will begin to move across the Panhandles. Before this line approaches, if any storms are able to remain discrete out ahead of the line, a marginal tornado threat may be possible as low level shear begins to increase in response to stronger H850 winds moving over the area. The main threats with the aforementioned line of storms will be strong wind gusts up to 75 mph and torrential rainfall. Cannot rule out a quick tornado spin-up along this line as the low level shear increases. Forecast PWAT values continue to remain around the climatological max for late May/early June and forecast soundings continue to depict a very moist profile this evening through early tomorrow morning. Multiple rounds of showers and thunderstorms are possible through tomorrow morning, which is leading to a high concern for flash flooding, especially if storms train over the same areas. * Threats: The primary hazards with the storms today will be large hail, damaging wind gusts, and flash flooding. The large hail threat will be the highest with any discrete supercells during the mid to late afternoon across the central and west where hail up to golf ball size will be possible should any storms develop out ahead of the main line. Damaging wind gusts up to 75 mph are possible as a line of thunderstorms moves across the Texas and Oklahoma Panhandles this evening. The tornado threat is low, but cannot rule out one or two especially if any supercells can remain discrete enough closer to sunset once the stronger low level winds begin to ramp up. The main hazard with the showers and storms will be the flash flood threat. This is due to already very saturated soils and the ongoing flood concerns of lakes, rivers, and streams. Very heavy rainfall is possible with rain rates up to 2 to 4 inches per hour with the strongest storms. * Timing & Location: Multiple rounds of showers and thunderstorms are expected starting in the middle of the afternoon through early Thursday morning. A few discrete thunderstorms may form across the western and central Panhandles during the middle to late afternoon today. A line of showers and storms is expected to move across the Panhandles this evening. Some of these storms could be strong to severe. Overnight tonight through early Thursday morning, multiple rounds of showers and storms are possible across the entire area. The severe threat will decrease after midnight, but a few strong to severe storms will remain possible. Muscha && .SHORT TERM ... (This evening through Thursday night) Issued at 216 PM CDT Wed May 31 2023 Synopsis: A few rounds of thunderstorms are expected starting this afternoon and potentially lasting into Thursday morning. Some storms may be severe mainly before midnight, with large hail and damaging winds being the main threat. The bigger concern tonight will be potential for flooding and flash flooding, and this threat will extend into tomorrow. Another round of severe storms is possible tomorrow, but there is a chance that the area becomes worked over and possibly socked in with clouds which would limit that threat. More details for today`s severe/flood threat will be laid out in the mesoscale discussion. Details on tomorrow`s threat can be found below. Details: Showers and storms may be ongoing Thursday morning as shortwaves continue to eject out ahead of an H5 low near the Four Corners. This low will weaken some but the center won`t move much through the day leading to continued moist return flow and broad lift in proximity to a left jet exit region. If the area can destabilize going into the afternoon (which most of the ensembles believe will occur), then thunderstorms may develop once again mainly favoring the southern TX Panhandle. The exact location of storm initiation will depend on the position of a left over outflow boundary and dryline. If storms do develop, some increased flow in the mid and upper levels will support effective shear in the 30 to 40 knot range which would support supercell development with a risk for large hail and damaging winds (low tornado chance due to lacking low level shear, but not out of question). Shortwave passage in the evening (along with increased low level jet) may upscale growth into QLCS structure across the east, but at this time it does`t look like storms will be ongoing all night as the area goes into a brief period of subsidence behind the impulse. Ward && .LONG TERM ... (Friday through next Tuesday) Issued at 216 PM CDT Wed May 31 2023 Synopsis: Bottom line is the pattern doesn`t change much as the blocking pattern keeps reloading H5-H25 low pressure over portions of the Desert Southwest. This keep a subtropical jet going over the southern plains and almost daily shortwave disturbances with ample moisture (PWATs remain above normal). Thus, daily thunderstorm chances can be expected and this will include at least some risk for severe storms and especially flooding as the area lakes, creeks, and rivers continue to rise. Friday will see a fairly significant shortwave that could result in another round of widespread heavy rain. Ward && .AVIATION... (00Z TAFS) Issued at 656 PM CDT Wed May 31 2023 For the 00Z TAFs, periods of showers and thunderstorms are expected at the terminal sites tonight through Thursday morning as an upper level storm system impacts the area. These individual waves of showers and storms will be hard to time for the TAF sites, as will any vsby and cig issues. Therefore, this is a low confidence forecast with amendments possible as the evening unfolds. 02 && .PRELIMINARY POINT TEMPS/POPS... Amarillo TX 59 74 58 77 / 100 70 40 60 Beaver OK 60 80 59 81 / 50 60 30 60 Boise City OK 55 73 53 78 / 60 60 20 30 Borger TX 61 78 60 81 / 90 60 40 50 Boys Ranch TX 58 75 58 78 / 100 70 30 50 Canyon TX 58 75 57 77 / 100 70 40 70 Clarendon TX 60 77 59 78 / 90 60 40 70 Dalhart TX 55 72 54 76 / 90 60 30 40 Guymon OK 58 76 56 79 / 80 50 30 40 Hereford TX 58 76 57 76 / 90 70 30 60 Lipscomb TX 61 80 59 80 / 60 50 40 60 Pampa TX 59 76 58 78 / 90 60 40 60 Shamrock TX 62 80 60 80 / 80 50 50 70 Wellington TX 64 82 61 81 / 70 50 40 70 && .AMA WATCHES/WARNINGS/ADVISORIES... TX...Flood Watch through Thursday morning for TXZ001>003-006>008- 011>013-016>018-317. OK...Flood Watch through Thursday morning for OKZ001-002. && $$ SHORT TERM...05 LONG TERM....07 AVIATION...02
Area Forecast Discussion
National Weather Service La Crosse WI
1100 PM CDT Wed May 31 2023 .DISCUSSION...(This evening through Wednesday) Issued at 150 PM CDT Wed May 31 2023 Key Messages: - Low risk for showers and storms this afternoon and tonight (10-20%) across southeast Minnesota and northeast Iowa. - Scattered storm risk for Thursday, with lessening confidence for Friday and the weekend. - Unseasonably warm stretch of weather persists through the weekend with the hope for a cooler stretch of weather fading for early next week. Rainfall Hopes for the Next Week... An MCV developed in conjunction with a complex of storms that worked out of northern Iowa this morning, tracking across the western forecast area and bringing light to moderate rainfall to locations from Saint Ansgar to Lake City. The residual cold pool trailing this MCV may be the focus for renewed convective development, though the rapid air mass recovery observed in its wake does not bode well for new convection later today and have capped the precipitation grids at 20 percent. A weak convergence zone over southern and central Wisconsin will also be the focus for showers and thunderstorms this afternoon, but the overall coverage looks sparse and likely just east of the forecast area. As with the last few days, the lack of deep shear and minimal steering flow will result in disorganized, pulse convective structures that will pose little more than a lightning and gusty wind threat. The slower storm motions will result in decent rainfall rates for those areas that find themselves under a stronger updraft, but such updrafts will be hard to come by this afternoon and tonight. Moving into Thursday, a weak upper level perturbation works through the longwave ridging and may provide enough support to kick start scattered showers and storms at peak heating. The HRRR and other members of the 31.12Z HREF do depict this scenario and have pushed PoPs up into the 30-50 percent range during the afternoon. The lack of a forcing mechanism and dry boundary layer will act to limit the overall coverage of the storms. The upper ridge strengthens during the day on Friday with the center of the ridge axis centered through Minnesota. It is interesting (bizarre?) to note the large PoP values from the global deterministic/ensemble members despite the unfavorable synoptic pattern. Have manually lowered PoPs by 20-30 percent over the NBM and as the CAMs are assimilated over the next 24-36 hours, it is likely--given the wet bias of the global models--that these PoPs will fall further. Heading into the weekend, confidence in the precipitation forecast degrades further as differences arise in the longwave pattern, mostly pertaining to whether any shortwaves work down the east flank of the ridge. Have maintained the low (20-30 percent) NBM PoPs for this time range, though we should stay primarily dry into next week with just a few, low probability shots of rain. The Heat Continues... The overall temperature/dewpoint forecast changes little through the weekend given the weak flow pattern and minimal changes to the lower tropospheric air mass. The dry soils have allowed temperatures to overachieve the NBM guidance and have pushed values slightly above the deterministic progs in favored regions. Ensembles are tightly clustered around the mid-80s to low 90s through the weekend before a vort lobe drives down the east flank of the upper level ridge early next week. This trough ushers a polar airmass southward with dew points possibly falling into the 30s and 40s again by midweek. The strength of this continental polar airmass and position of the central CONUS ridge remain a source of variability in the forecast and recent ensemble trends have been shifting this push of cooler air further east, lessening the impacts and keeping highs at or above average for this time of year over the region. We still reside on the periphery of this pattern shift, so the forecast can still change over the coming days. && .AVIATION...(For the 06Z TAFS through 06Z Thursday night) Issued at 1055 PM CDT Wed May 31 2023 Increasing moisture transport and theta-e advection into the area this evening led to some isolated showers in the area. Some hint that an MCV over MO will lift north across Iowa into the forecast area. With a moist and unstable airmass in place, we`ll continue to see isolated to scattered showers and thunderstorms increase for Thursday. For now included variable mid and high level clouds and a prob30 for tsra at KLSE Thursday afternoon and early evening. Will need to monitor in the short term for adding any additional shra/tsra. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ DISCUSSION...Skow AVIATION...Zapotocny
Area Forecast Discussion
National Weather Service Binghamton NY
943 PM EDT Wed May 31 2023 .SYNOPSIS... High pressure will remain over the region with dry and warm conditions through the end of the week. A backdoor cold front will increase chances for rain and bring cooler temperatures across the area on Saturday into Sunday. && .NEAR TERM /THROUGH THURSDAY NIGHT/... 930 PM Update... Evening temps remain right on track with widespread mid 60s to low 70s across the area. Ran the latest HRRR smoke guidance and updated the forecast with the new output. Looks like the best chance for patchy smoke making it to the ground will be across NEPA and far southern Catskills with haze move into the eastern Southern Tier and Catskills. The rest of the forecast remains on track. 630 PM Update... Some fair weather cumulus clouds that developed this afternoon over the Finger Lakes are beginning to dissipate as afternoon heating subsides. Currently, temps in the low to mid 80s are hanging on across the region. Dry air will allow for temps to quickly cool over the next few hours as the sun begins to set. For example, Syracuse, currently at 87, is expected to be at 74 by 9pm. Across the region, upper 60s to mid 70s are expected by 9pm. The forecast for tomorrow remains on track from the afternoon package. Some slight adjustments were made based on new model guidance, but mid to upper 80s expected across the CWA with river valleys in the low 90s.Clear, dry and warm this evening with 145 PM Update... High pressure remains parked over the region, with dry conditions and warm temperatures continuing. Although temperatures will reach into the mid to upper 80s on Thursday, humidity will remain low with dew point temperatures in the 40s to low 50s. Smoke, produced from a wildland fire in Nova Scotia, may push into NE PA and the Southern Tier late tonight and early Thursday morning as onshore southeasterly flow develops. Although, patchy smoke and haze will likely be observed, we are not expecting a reduction to visibility at this time. Low level flow will start to turn out of the north by tomorrow afternoon and this should push any smoke back out of the region. && .SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... Another day of summerlike warmth and relatively low humidity is in store Friday as high temperatures climb into upper 80s and low 90s, then some changes are on the way that will lead to an increase in clouds and even the chance for a little wet weather. The upper-level ridge that has been in place the past several days will retrograde back to the west Friday and a weak shortwave will drop in from the north during the afternoon and evening. This will produce some scattered clouds and there can be a spotty shower or two, perhaps even a thunderstorm, into early Friday night. The best chance for anything stray will be over eastern parts of the CWA. Later Friday night into Saturday, a backdoor cold front will slide south over the area and an upper- level trough will move south out of eastern Canada as well. A couple of showers will be around Saturday as the front moves through and perhaps even a thunderstorm, but given the dry air the boundary is moving into, PoPs look to remain pretty low. With the frontal passage, high temperatures Saturday will be mainly in the 70s. Most of the spotty shower activity is expected to taper off Saturday evening. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... Unlike Tuesday afternoon when there was pretty decent agreement in guidance for Sunday through the first half of next week, the same cannot be said this afternoon. A cutoff low is expected to form from the trough dropping southward from Canada, but there`s differences in the timing of its formation and placement. The GFS is much quicker with the low forming Saturday night over the northeast and hovering over the area Sunday. The 00z run even had the low retrograding westward toward the Ohio Valley. This would lead to some clouds and perhaps a couple of showers Sunday, and the shower chance would carry over into Monday and Tuesday as well. The Euro has this low forming Sunday well off to the east near Cape Cod and is dry across the CWA to end the weekend. It also has a couple of weak shortwaves dropping south Monday into Tuesday with a persistent northerly flow, but little if any moisture looks to be around. The Canadian forms the low Saturday night but it`s similar in placement to the Euro, but rotates in another vort. max from the north Monday and Tuesday that could spark a shower. Regardless of the uncertainty and the potential for more clouds to be around, there`s not a great chance of seeing much in terms of any rainfall with none of these features emerging from a decent moisture source. Ensembles show fairly low heights in place through midweek over the Northeast, supporting seasonable temperatures in the 70s for most into at least early next week. && .AVIATION /02Z THURSDAY THROUGH MONDAY/... High pressure over the region will continue to bring IFR conditions and light/variable winds through the forecast period. Outlook... Thursday afternoon through Friday...Mainly VFR. Saturday through Sunday...Mostly VFR, but some brief restrictions will be possible from showers. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...None. NY...None. && $$ SYNOPSIS...MPK NEAR TERM...JTC/MPK SHORT TERM...DK/MPK LONG TERM...DK/MPK AVIATION...MPK/MPH
Area Forecast Discussion
National Weather Service Birmingham AL
742 PM CDT Wed May 31 2023 ...New SHORT TERM, AVIATION... .SHORT TERM... (Tonight through Thursday) Issued at 722 PM CDT WED MAY 31 2023 The latest RAP analysis has a large moisture gradient over the southeastern counties near Troy and Eufaula. Previous convection has allowed a nice outflow boundary to develop and was near Montgomery to Phenix City. The global models indicate some good omega near this gradient and slowly moves east to west. These features were on the far north side of low in the northern Gulf of Mexico. Most of the activity was showers as the lightning activity has waned over the past hour. Expect the overall coverage to eventually lessen in the south, but did have to increase pops for the early evening hours south. Mean relative humidity remains high overnight especially south and will monitor if these showers do indeed all go away. 75 Previous short-term discussion: (This afternoon through Thursday) Issued at 1159 AM CDT WED MAY 31 2023 High pressure extends southwest along the Mid-Atlantic coast and through the Appalachians which is resulting in easterly flow across Central Alabama. To our south, a mid-level low is developing over the Central Gulf of Mexico while a Rex Block pattern remains in place along the East Coast which is resulting in moist onshore flow along Georgia and Florida. These features will allow for a slight increase in moisture across Central Alabama over the next couple of days which will support routine afternoon chances for isolated to scattered showers and thunderstorms. Dry mid-level air is likely to remain over the area, especially as 500mb winds become northerly tomorrow afternoon in response to a breakdown of the Rex Block. This should help to limit thunderstorm intensity and overall coverage of rain as mid-level lapse rates are poor, and really the overall moisture profile is still of low quality. There will be mostly sunny to partly cloudy skies, but cloud cover may increase at times due to the trough circulating over the Gulf of Mexico. Nonetheless, expect warm daytime temperatures with highs in the 80s and mild conditions overnight with lows in the 60s. 86/Martin && .LONG TERM... (Thursday night through Tuesday) Issued at 256 PM CDT WED MAY 31 2023 No major changes were made to the extended forecast. We have slid into a typical summertime diurnal pattern with isolated heat induced afternoon and evening convection possible almost every day in the extended. Although we will continue to monitor the tropical feature over the Gulf of Mexico, the latest guidance suggests that the most impactful weather is expected over the Florida Peninsula as it drifts in that direction. 08 Previous long-term discussion: (Thursday night through Tuesday) Issued at 254 AM CDT WED MAY 31 2023 Rain chances from Thursday into Friday look to be largely dependent on the evolution of the tropical disturbance in the Gulf. Indications are that while the system should ultimately move to the east, there could be a couple outer bands that try to push into southern areas of Central Alabama. Most of this activity will remain along/just north of the coast, however. Otherwise, nearly every afternoon looks to have at least a slight chance of isolated to scattered showers and thunderstorms. Will be watching the evolution of an upper low over the northeast states this weekend. The GFS retrogrades the feature back to the southwest, over the Ohio Valley, by Tuesday, while other models take it out to sea from New England. As such, the GFS has considerably cooler afternoon temps on Tuesday vs. the ECMWF. Model blends capture this nicely, and the forecast splits the difference here for the upper 80s on Tuesday. These temps are characteristic of the entire period, which will see highs each day from the mid to upper 80s to occasionally low 90s. 12 && .AVIATION... (00Z TAFS) Issued at 722 PM CDT WED MAY 31 2023 Low pressure over the northern Gulf of Mexico will keep and easterly flow over Central Alabama this period. There are some showers and a few thunderstorms near a moisture gradient over southern Alabama. Have some mention of convection in for MGM/TOI a few hours this evening before moving out/dissipating. A brief wind gust is possible along with brief vis reduction, but most ceilings will stay VFR. The remainder of the overnight hours will see VFR ceilings slowly decreasing. Although model output is not indicating it too much, believe some MVFR ceilings will show up around sunrise. These clouds will lift with daytime heating and only last a few hours in restrictions. There will be some drier air entering the picture on Thursday. Therefore, all areas will not experience convection. But the exact location will play a role in where pops are highest. At this time, have PROB30 mention south and west. Winds remain easterly 5-10kts. 75 && .FIRE WEATHER... Typical diurnal summertime activity is expected through the forecast with mainly isolated showers and thunderstorms possible each afternoon. Minimum relative humidity percentages should continue to decrease a little each day through the next week, but we should not reach critical values. 20ft winds should remain from the east to northeast through the weekend and generally less than 12 mph. && .PRELIMINARY POINT TEMPS/POPS... Gadsden 62 84 62 88 / 10 20 20 20 Anniston 64 84 64 87 / 10 20 20 20 Birmingham 65 87 66 89 / 20 30 20 20 Tuscaloosa 65 87 66 89 / 20 30 20 20 Calera 65 85 66 88 / 20 20 20 20 Auburn 65 83 65 85 / 20 20 20 20 Montgomery 66 86 66 88 / 50 20 20 20 Troy 65 85 66 88 / 50 30 20 20 && .BMX WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...75 LONG TERM....08 AVIATION...75
Area Forecast Discussion
National Weather Service Burlington VT
1018 PM EDT Wed May 31 2023 .SYNOPSIS... Smoky conditions will be possible again tonight across the Champlain Valley as smoke from Nova Scotia wildfires moves back into our region. Otherwise, dry weather is expected through Thursday before a backdoor cold front will bring some showers and thunderstorms late Friday into Saturday. In the meantime, much above normal temperatures are expected through the week with the warmest temperatures expected on Thursday when highs are expected to climb near or above 90 degrees. && .NEAR TERM /THROUGH THURSDAY NIGHT/... As of 1015 PM EDT Wednesday...No changes were needed with this update. As expected, temperatures have cooled since sunset, and now are generally in the 60s to around 70. Given trends from last night, lows in the 50s to around 60 still seem reasonable. The latest HRRR and RAP guidance continues to indicate the potential for near-surface smoke late tonight/early Thursday morning; otherwise, clear skies and light winds will prevail tonight. Previous discussion...Temperatures will be mild again tonight with lows reaching only the mid-50s to lower 60s F, staying especially warm in the Champlain Valley due to light southerly surface winds, and 925mb temps could be as high as 21-23 C during the coolest portion of the night. Outside of conditions near 10 degrees above average, some of the smoke from Nova Scotia wildfires is anticipated to return to the Champlain and lower Connecticut River valleys tonight, trapped under an inversion in the atmosphere. It should be fairly similar to last night/this morning, where people may be able to smell the smoke and see the smoke close to the surface, but it wouldn`t cause widespread visibility issues. For air quality information, see the EPA`s air quality index site. Mild temperatures tonight will help spring temperatures higher than we`ve seen so far this year, likely breaking records across the forecast area. Highs will be in the upper 80s and lower 90s F as 925mb temps soar into the 24-26 C range as high pressure to our west advects in hot air from the north/west, a notably unusual place to advect in hot air. We continue to expect relative humidity to be low, perhaps in the 20-30% range for most, allowing for a dry heat. Fortunately for fire weather though, northwesterly winds will be below concerning thresholds. Regardless of dry heat vs. humid heat, temperatures of this magnitude can be dangerous for those working or playing outside and in the sun, and proper precautions are needed. Thursday night could be even milder than tonight as all that heat during the day struggles to leave the earth and atmosphere, especially with potential clouds ahead of our next backdoor cold front, discussed further below, and moisture increases. Lows in the upper 50s to low and even mid-60s are expected with calm or light winds. Some slight chances start arriving in the Northeast Kingdom late Thursday night/early Friday morning, but anything of note will be in the short term period below. && .SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/... As of 342 PM EDT Wednesday...Friday will be the last of the hot days before temperatures noticeably cool down Saturday after a frontal passage. Ahead of the front on Friday, we`ll see some subtle cold air advection and an increase in humidity and cloud cover. The slightly cooler air mass along with scattered clouds will prevent temperatures from climbing quite as high on Friday as what we`ll have seen on Thursday, though hot conditions are still expected with high temperatures in the mid to upper 80s. A few of the hotter locations in the Champlain Valley and Connecticut River Valley may again reach into the low 90s. The bigger difference on Friday will be the noticeable increase in humidity/mugginess with dewpoints forecast to climb into the low 60s. Overall will feel quite muggy, especially after the recent drier air mass that has been in place. With the high temperatures and increasing humidity, also expecting increasing instability over the area that will support the development of some afternoon showers/thunderstorms. Best chances for these showers/storms will be over the higher terrain of the northern Adirondacks and Greens. 0- 6 km shear values are quite low during the day on Friday, so any thunderstorms are not expected to be severe. For Friday night, we`ll see a backdoor cold front drop southward though the area. Some scattered showers/thunderstorms will continue into the night as the boundary moves through and just enough MUCAPE will be present to keep thunderstorms in the forecast through the night. Any thunderstorms that continue into the overnight hours should be elevated above a low-level inversion, so again no severe threat. The better cold air advection won`t occur until Saturday, so overnight lows Friday night will still be seasonably warm in the 50s. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... As of 342 PM EDT Wednesday...Widespread showers and thunderstorms will come to an end Saturday morning as the back door cold front pushes south of our area. Throughout the day Saturday, a shortwave in the upper-levels will close off over our forecast area, becoming an upper-low that will gradually drop southward through the weekend. Under the upper-low, expect cloudy and much cooler conditions with weekend highs only in the 60s to around 70. Lows will be in the 40s to around 50. As mid- level lapse rates steepen with the upper-low moving overhead, expected some isolated to scattered instability- driven showers during the day on Saturday. The precipitation forecast from Sunday onward is a little less clear given the uncertainty in timing of the departure of the upper low, and potential phasing of the low with additional shortwaves dropping down from the north. However, the development of an omega block over the United States will keep troughing in some form anchored over our area, which will result in continued cooler and unsettled weather going into next week. && .AVIATION /02Z THURSDAY THROUGH MONDAY/... Through 00Z Friday...VFR conditions to prevail at all sites through the TAF period, with KSLK the lone exception. Much like last night, brief MVFR/IFR will be possible at KSLK in patchy fog 08z-11z. Otherwise, SKC expected through the period. Some surface smoke could also travel up the Champlain Valley again tonight, but it is not expected to impact the TAF sites or reduce visibility. Winds will be light/near calm overnight, then picking up out of the north/northwest around 5 kt after 13z Thursday. Outlook... Thursday Night: VFR. NO SIG WX. Friday: VFR. Chance SHRA, Chance TSRA. Friday Night: MVFR/IFR conditions possible. Chance SHRA, Chance TSRA. Saturday: Mainly VFR, with areas MVFR possible. Chance SHRA. Saturday Night: Mainly VFR, with local MVFR possible. Slight chance SHRA. Sunday: VFR. Slight chance SHRA. Sunday Night: VFR. Slight chance SHRA. Monday: VFR. Chance SHRA. && .CLIMATE... New daily records may be set at most if not all climate sites below over the next few days: Max Temp Records Date KBTV KMPV K1V4 KMSS KPBG KSLK 05-31 91|2013 87|2013 89|2013 90|1999 92|2013 87|2013 06-01 90|2013 88|2013 90|2013 87|2018 90|2013 87|1920 06-02 89|1970 84|2013 88|2013 87|1996 87|1990 90|1919 && .BTV WATCHES/WARNINGS/ADVISORIES... VT...None. NY...None. && $$ SYNOPSIS...Storm NEAR TERM...Hastings/Storm SHORT TERM...Duell LONG TERM...Duell AVIATION...Hastings CLIMATE...Kutikoff
Area Forecast Discussion
National Weather Service Dodge City KS
1045 PM CDT Wed May 31 2023 ...Updated Aviation... .SHORT TERM...(This evening through Thursday night) Issued at 120 PM CDT Wed May 31 2023 Main focus over the next 36 hours will be chances for strong to severe thunderstorms tonight. Subtle upper waves embedded in a weak flow will move out of New Mexico into the West Central High Plains this afternoon. A more significant upper level system that will be associated with the left exit region of an 250mb upper level still if forecast to approach southwest Kansas by early evening. Although any of the subtle upper waves during the day may trigger some afternoon thunderstorms before 21z today...the main focus for possible strong to severe thunderstorms from near 00z Thursday through midnight and will be associated with the upper wave and left exit region of the upper level jet early this evening. For the afternoon thunderstorms the RAP was forecasting 20-25 knots 0-6km shear with 10-20knots 700-500mb flow and dcape 1000 or less. SPC mesoanalysis at 18z has cin eroding quickly with cu already starting to develop near this boundary/instability axis. As a result do expect some isolated to widely scattered afternoon convection and a few of these storms may also be capable of producing isolated wind gusts in excess of 50 mph, lightning and heavy rainfall. After 21z today the focus will shift to extreme southwest Kansas where the better upper level dynamics from the left exit region of a 250mb jet, a surface boundary and low level moisture return will be located late today/early evening. These thunderstorms that do develop in this area late today and early tonight will have a better chance to become strong or severe given that these storms will be moving into an area of more unstable air with little to no cap. Large low level lapse rates, weak flow aloft and high preciptable water values. This would support wind gusts up to 60 mph along with heavy rainfall and isolated hail will be possible from the strongest storms. The opportunity for precipitation persists on Thursday, driven by the progression of the next upper-level trough within the southwesterly flow, originating from New Mexico and advancing into the West Central High Plains. Throughout the day, showers and thunderstorms are projected to propagate across southwest Kansas as this subsequent upper wave nears from the southwest. The primary hazards associated with these storms will be lightning and intermittent episodes of moderate to heavy rainfall. .LONG TERM...(Friday through Wednesday) Issued at 120 PM CDT Wed May 31 2023 Key Message in the later periods will be the potential for heavy rainfall and possible water related issues Friday through Sunday. From Friday through the upcoming weekend, an upper level deformation zone will gradually move into and establish itself across southwest Kansas. This movement coincides with a 500mb high shifting from the Western Great Lakes Region into the Plains. This deformation zone will serve as the focal point for ongoing precipitation chances from Friday through early next week given the presence of a moist environment and the intermittent influence of multiple weak waves within this flow, which will enhance lift in the region periodically. In addition to the daily precipitation potential...water issues may end up being the main concern from Friday through Sunday. This concern is supported by the agreement among the ECMWF and GEFS ensembles regarding the general location and duration of the deformation zone which is where ongoing rainfall will likely occur, the majority of QPF clusters from 00z Sunday through 00z Monday highlighting the same locations over multiple days, as well as the agreement on past 24-hour trends indicated by the ECMWF Extreme Forecast Index and Shift or Tails and above normal precipitable water values . All this is increasing confidence for the risk of the possibility of localized flash flooding. Individuals with weekend plans should be prepared for the possibility of widespread rainfall, which may lead to some water related issues in certain areas. && .AVIATION...(For the 06Z TAFS through 06Z Thursday night) Issued at 1045 PM CDT Wed May 31 2023 Radar imagery at 0340z indicated numerous showers and thunderstorms from EHA to LBL, and across the Texas panhandle, all lifting slowly northward. Some of this activity will impact the LBL terminal over the next few hours and included a convective TEMPO group to cover. To varying degrees, models forecast rain showers and embedded thunder to move northeast across SW KS through 12z Thu. Included VCTS/CB/VCSH wording only, with very low confidence on impacts on any specific airport. Outside of any convection, VFR will continue to prevail through this TAF, with mid level cloud decks prevailing. Light winds will continue through 15z Thu, again outside of convective outflows. After 15z Thu, south winds will increase at all airports, gusting 25-28 kts. Scattered convection is expected to redevelop after 18z Thu, but only included a VCTS/CB mention for now. && .PRELIMINARY POINT TEMPS/POPS... DDC 60 76 59 79 / 30 40 40 50 GCK 58 77 58 78 / 30 40 60 40 EHA 57 73 57 79 / 60 50 50 30 LBL 58 76 58 80 / 30 50 60 40 HYS 62 78 60 82 / 30 40 50 70 P28 65 78 62 81 / 30 40 30 60 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Burgert LONG TERM...Burgert AVIATION...Turner
AREA FORECAST DISCUSSION
National Weather Service Hastings NE
647 PM CDT Wed May 31 2023 ...Aviation Update... .DISCUSSION...(This evening through Wednesday) Issued at 301 PM CDT Wed May 31 2023 Key Messages: * Chances for isolated/scattered storms will continue into this evening/tonight across the area...and while some storms could be on the strong side with gusty wind/small hail/heavy rain, the overall threat for severe weather is low. * Off-and-on thunderstorm chances remain in the forecast through the weekend and into early next week...with the best overall chances looking to be Thursday-Saturday. Could be drier Sunday- Wednesday, but plenty of uncertainties remain. * Not looking at any notable swings in high temperatures, remaining mainly in the 80s through the forecast...but changes in precipitation chances could affect those highs. Currently through tonight... Upper air and satellite data continue to show a fairly light flow pattern in place across the region today...flow is generally southerly, with areas of low pressure over the Desert SW, Gulf Coast region and northeastern CONUS. Overall it`s been a dry day, though some isolated activity has developed in the last hour or so, just barely clipping far eastern portions of the CWA. Any upper forcing is subtle at best, but looking at SPC Meso page it`s an area with little/no CIN and in axis of higher instability (~2000 j/kg MLCAPE). Can`t rule out some additional activity late this afternoon, but along with forcing being weak, mid-level lapse rates aren`t great and deeper layer shear is on the low side...so while a few storms could be on the stronger side at times, overall threat for severe storms remains low. Additional thunderstorm activity has developed off to our west over the High Plains, driven by shortwave upper level forcing, sfc troughing and peak heating. For the most part, models are not showing great chances of a notable amount of that activity making it this far east overnight...with our chances looking to be more scattered in nature and aided by the LLJ. Kept PoPs on the lower side, in the 20-40 percent range...they`re likely too broad in nature, but with plenty of difference in models, hard to completely rule out any particular areas. Similar to this afternoon and evening, elements needed for a more organized severe weather threat are lacking...but some gusty winds/small hail/heavy rain will remain a possibility. Thursday into early next week... As far as preciptiation chances go, unfortunately, it`s a pretty low confidence forecast for mid-week on into the start of next week, with plenty of differences continuing between models. Looking at Thursday through Saturday, NBM continues with CWA-wide PoPs through each day, but it`s not looking to be a 3-day washout...just enough uncertainties/spread in model solutions to be able to focus in on any one particular area/time frame to rule out chances. Driving those daily PoPs is the continued Rockies/western CONUS broader troughing, and any shortwave disturbances that get ejected out ahead. For the most part models have favored the mid-late afternoon and evening/overnight for the main chances for storms, but there is even some uncertainty with that for tomorrow/Thursday, some models show the better chances being morning through mid-afternoon and then a lull...others have chances never totally gone through the afternoon. It`s a frustrating pattern for sure. As far as severe weather goes, models still showing a generally modest CAPE/lower shear environment...and the CWA remains outside of the Days 1-3 SPC risk areas. Some stronger storms will certainly be possible, but some things are lacking for a more organized/widespread severe weather threat. Models hint at the chance for a drier period late in the weekend- early next week with the potential for higher pressure/blocking pattern to develop over the central CONUS...but like any day prior, lot of uncertainty in the forecast. Looking at temperatures, the overall trend of highs being above normal for this time of year looks to continue...with no notable swings either way expected. Normal highs for this time of year are in the upper 70s to low 80s...and in general highs look to be the low-mid 80s. However, with the uncertainties in precipitation chances, that spills over into and lowers confidence in high temperatures. && .AVIATION...(For the 00Z KGRI/KEAR TAFS through 00Z Friday) Issued at 645 PM CDT Wed May 31 2023 Generally a low confidence forecast in terms of potential for convection tonight into Thu. Kept the VCTS that was already in there after midnight, though latest HRRR trends have been for less convection overnight. There`s enough convective activity W/SW of the area that outflow and/or MCVs could kick E and keep chcs going in presence of elevated instability. Otherwise, expect SCT CU around 7K ft for a few more hrs, then SCT-BKN mid to high cld blow off from convection off to the W. Thu looks like another day with a mix of CU and high clds. A couple models hint at low stratus Thu AM, but given other uncertainties have left it out attm. Wind will be SE to S 5-10kt tonight, then incr to 10-15kt, gusting up to 25kt for daytime hrs Thu. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ DISCUSSION...ADP AVIATION...Thies
Area Forecast Discussion
National Weather Service Grand Junction CO
546 PM MDT Wed May 31 2023 .SHORT TERM...(Tonight through Thursday night) Issued at 300 PM MDT Wed May 31 2023 Showers and thunderstorms have fired this afternoon with plenty of coverage seen across the CWA. As expected, those drier subcloud layers have allowed some gusty outflow winds to materialize. A stronger cell near Durango caused a 50 mph gust at the airport but, by and large, most gusts have been spread between 35 to 45 mph. CAM guidance has picked up on the location and intensity of this convection fairly well and they show convection continuing through the early evening hours before subsiding. Of note, the NAMNEST is picking up on another line of showers moving from the Four Corners up into the Grand Valley around midnight while the HRRR does show some activity in the same area but nowhere near as robust. Might see a few showers, a rumble of thunder or two, or maybe just some clouds...it`s that kind of environment. Thursday, look for more of the same as the low pressure will be over the Four Corners region. The added lift from the low will work on the available moisture and increased instability will further aid in convective development. Those areas not seeing convection will see plenty of cloud cover and thus, lower high temperatures. This trend will continue into the weekend. .LONG TERM...(Friday through Wednesday) Issued at 300 PM MDT Wed May 31 2023 Very little change noted from previous model runs with regards to the long term period. The closed low will open up as it moves across the CWA and eventually stalls on top of Colorado. Plenty of moisture and instability will allow showers and thunderstorms to form each afternoon and evening heading into the weekend. As previously mentioned, this area of low pressure will basically dissolve in place as a retrograding downstream high pressure cell creates a strong omega block over central NOAM by early next week. This extremely amplified pattern persists into the middle of next week and is so anomalous that the models are struggling to find agreement in many areas. The basic flavor of the forecast remains daily afternoon showers and thunderstorms becoming fairly widespread through the weekend with lingering isolated convection during the overnight hours. Monday onwards, there will be no focus, per se, for convection aside from lingering moisture and daytime heating. Even so, it will be enough for convection to fire though coverage should lessen some from what was seen over the weekend. As we`ve said for the last several days, the finer details are still just not there but there is high confidence in widespread showers and storms. As one would expect, high temps will run below normal thanks to increased cloud cover and the precip. Sure doesn`t seem like June... && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 541 PM MDT Wed May 31 2023 Scattered showers and thunderstorms will continue to fire along the terrain of western Colorado and eastern Utah this evening. Some of these showers will be capable of producing strong outflow gusts and brief IFR visibilities with rainshowers. Convection will tamp down after sunset and mostly quiet conditions will prevail from midnight into the morning hours across the region. Shower activity will develop again Thursday morning and continue through the afternoon over the region. Showers and storms will develop on the terrain again and drift out over the valleys, bringing strong outflows, brief torrential rain, lightning, and small hail. && .HYDROLOGY... Issued at 300 PM MDT Wed May 31 2023 No major changes in terms of hydrologic conditions today. Warm temperatures the last several days have helped accelerate snowmelt across high elevations, and narrowed the extent of snow left over mid-elevation zones. In general, the season`s daily peak in flow typically coincide when these two elevation zones dwindle in unison. However, the oscillating temperatures this spring have mitigated the rate of snowmelt across the board, so far this year. As a result, the originally expected peaks are trending down. Instead, prolong periods of high water and fast flow have been observed and are expected to continue across much of the West Slope. Weather shifts in the coming days, towards a cooler and wetter than normal pattern. In terms of temperature, the rate of snowmelt will slow, decreasing the risk of a high spike along rivers and streams. On top of that, cooler mountain peaks (mainly above 10,500 ft) could accumulate several new inches of snow in this moist regime, which would just add to the delayed mountain season. In contrast, precipitation in the form of rain (heavy rain) falling on snow would enhance snowmelt processes. So in summary, the variance in the weather over a given basin in the coming days translates to a level of uncertainty in river forecasts, as spring runoff is highly dependent on spring weather. In general, though, forecast hydrographs are trending down through the weekend, which would reflect a cool regime and reduced snowmelt. Though, the caveat, convective processes may not be captured. Training storms focused over one basin could lead to instantaneous spikes in flow, or end becoming the daily peak we`ve been anticipating. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...None. UT...None. && $$ SHORT TERM...TGR LONG TERM...TGJT AVIATION...LTB HYDROLOGY...ERW
Area Forecast Discussion
National Weather Service Grand Rapids MI
721 PM EDT Wed May 31 2023 LATEST UPDATE... Aviation .SHORT TERM...(This evening through Thursday night) Issued at 328 PM EDT Wed May 31 2023 Visible satellite imagery shows an extensive cumulus field over much of Lower MI, with pockets of more vigorous cumulus congestus over the northern half of Lower MI, where recent reflectivity returns and lightning strikes are noted. RAP mesoanalysis depicts a plume of drier air at 850 mb encroaching on Lower MI from the east, along the southern edge of the high over eastern Ontario. The entrainment of this drier air into the boundary layer is likely contributing to lower surface dewpoints over parts of southeast Lower MI, with a corresponding NW-SE gradient of surface-based instability across the Lower Peninsula. Away from this dry air, RAP guidance suggests that appreciable surface-based instability is present over the northern half of the forecast area, with MLCAPE of 1000-1500 J/kg. This instability likely extends to areas slightly west of the advancing lake-breeze boundary, where onshore low-level trajectories have undergone sufficient warming. Another area of surface-based instability is present over northern IN, with MLCAPE of around 500 J/kg. Through this evening, CAM guidance suggests that isolated to widely scattered showers/t-storms are most favored north of a line from roughly Fremont to Clare, with additional convective initiation likely to be aided by low-level convergence along the lake-breeze boundary. Convective organization will be constrained by weak 0-6 km bulk shear (10 kts or less). However, inverted-V thermodynamic profiles beneath the CCL will contribute to sizable DCAPE (800-1200 J/kg) through early evening. In this environment, locally gusty outflow winds are possible with isolated/pulse storms that develop. Storms through this evening will tend to drift slowly northward, approximately with the 0-6 km mean flow. A broadly similar environment will remain in place on Thu. However, the eastward extent of instability across the forecast area is questionable (e.g., in 15z RAP guidance), likely owing to the continued influx of dry air near 850 mb. Slight chance PoPs will be carried across the western half of the forecast area, as supported by HREF probs. .LONG TERM...(Friday through Wednesday) Issued at 328 PM EDT Wed May 31 2023 Friday still appears to be the warmest day in this stretch with H8 temps near 20C underneath the upper high and would not be surprised to see a few highs up around 95. Convective threat/coverage expected to be very limited or non-existent Friday due to drier air mass and presence of greater CIN related to the warmer temps aloft. Retrograding upper high and development/evolution of an east coast longwave trough should lead to gradually cooler air filtering in from the northeast-- especially Sunday through Tuesday-- although ensemble temp spread increases in these periods. Low level northeast flow will deliver lower sfc dew points to the area once again for the first half of next week, with 40s likely and 30s even possible. Will need to monitor wind speeds as critical fire weather parameters could be reached. The lower dew points will obviously keep rain chances quite low (less than 20 pct), so the dry conditions will only worsen. && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 721 PM EDT Wed May 31 2023 VFR conditions will continue through Thursday evening. Only scattered afternoon cumulus with bases AOB 7000 KFT AGL are expected on Thursday. && .MARINE... Issued at 328 PM EDT Wed May 31 2023 Winds in the nearshore waters will continue to be driven primarily by the diurnal land-breeze / lake-breeze circulation. Through Thu afternoon, guidance suggests that these winds will likely remain rather light. On Fri and Sat, models suggest that a broad surface ridge will become established west of the region. This synoptic- scale regime should favor a somewhat stronger lake-breeze circulation on Fri and Sat afternoons, yielding N or NNW winds in the nearshore zones. Given the possibility of stronger winds and greater fetch, conditions may necessitate a SCA and Beach Hazards Statement (high swim risk) as early as Fri afternoon, with a somewhat greater chance of hazardous winds/waves on Sat afternoon. Aside from these wind/wave considerations, isolated t-storms are expected to continue forming inland this afternoon/evening, and again on Thu afternoon. T-storms through this evening will drift northward, with a small chance of storms reaching the nearshore waters from Holland south. T-storms on Thu afternoon will move slowly northwestward, with a small chance of storms across most nearshore zones. && .CLIMATE... Issued at 342 AM EDT Wed May 31 2023 Record High Temps GRR MKG LAN AZO BTL BIV Wed 5/31 95-1934 88-2016 96-1895 93-1911 94-1919 92-1934 Thu 6/1 102-1934 88-2014 97-1934 102-1934 100-1934 100-1934 Fri 6/2 95-1934 87-1963 93-1919 102-1934 97-1934 95-1934 Record Warm Lows GRR MKG LAN AZO BTL BIV Wed 5/31 73-1937 70-1970 73-2022 71-2022 71-2022 73-1937 Thu 6/1 74-1934 66-1970 68-1970 71-1895 71-1895 75-1934 Fri 6/2 69-2014 66-1949 69-2014 76-1934 72-1934 70-2014 && .GRR WATCHES/WARNINGS/ADVISORIES... MI...None. LM...None. && $$ SHORT TERM...Kenyon LONG TERM...Meade AVIATION...Ostuno CLIMATE...NJJ MARINE...Kenyon
Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
1001 PM EDT Wed May 31 2023 .SYNOPSIS... Weak high pressure remains over the area through Friday. A weak cold front drops south across the area Saturday. High pressure returns for early next week. Another cold front will arrive from the north by the middle of next week. && .NEAR TERM /THROUGH THURSDAY/... As of 950 pm EDT Wednesday: Isolated late evening showers continue mainly in upslope-enhancement and convergence regions along the eastern slopes of the mountains, and also east of the I-77 corridor where modest Atlantic moisture has wrapped west from the offshore low center. Anticipate the eastern showers battling with some degree of drying on northeast flow overnight to generally dissipate with time. Mountain coverage should gradually become sparser as well with the loss of daytime instability and weakening flow. The area should be mostly free of light rain showers after midnight. The combination of patchy high clouds, lingering stratocumulus in various layers, and spotty lower stratus on the northeast flow should keep partly cloudy conditions north to mostly cloudy skies south across the region overnight. The clouds and dewpoints mostly in the lower 60s will keep minimum temperatures from falling much below current values. Still anticipate low cloud and fog development in the mountain valleys where boundary layer moisture persists, but with most guidance not depicting much dense fog. Northeasterly 850 mb flow will alternately bring morning drying on Thursday followed by a brief uptick in Atlantic moisture during the afternoon. Instability continues to look quite limited in all but the far western mountains and this should confine isolated to scattered weak convective coverage primarily to the mountains. Cannot rule out a few rogue showers making a run westward into the Piedmont in a few bands of arriving Atlantic moisture, but with any showers encountering drier profiles and dewpoints near the I-77 corridor. With less in the way of morning stratus, temperatures should rebound closer to climatology for the first of June. && .SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/... As of 158 PM EDT Wednesday: Generally shallow instability in the mountains, and nonexistent instability elsewhere, will give way to quiet conditions going into Friday night. The pattern at this point will remain dominated by a broad surface high over the upper Mid- Atlantic, which will maintain easterly flow and at least some moisture flux into the area through Friday evening. This will result in cloudy, though generally dry, conditions across the area on Friday, beneath weak forcing aloft. Apart from a few pop-up thunderstorms over the mountains, there`s generally little to talk about. Temperatures will be around normal. By Friday night, as a surface low drifts up the Atlantic coast, flow over the Carolinas will take on an increasingly northerly component...which will cut off the better moisture. Thus, despite some measure of clearing, instability actually looks more anemic (if that`s even possible) on Saturday and virtually no thunder chances will be carried into the new forecast package. Temperatures will continue to rise, reaching solidly-above-normal values by Saturday afternoon. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... As of 215 PM EDT Wednesday: Oh what a challenge it has been to gain steady insight into the synoptic pattern for the end of the weekend and next week. As noted by the previous forecaster, the pattern does look to become more amplified by Sunday, but it remains unclear exactly how that will play out since each guidance source is off in its own little world. The CMC and ECWMF are in decent enough agreement through Sunday night, depicting a fleshed-out upper low off the New England coastline...which remains too far north and east of the forecast area to promote much moisture or synoptic forcing in the Carolinas. This would promote some isolated to widely scattered low-end diurnally-forced convection...but little else. And granted, the 06z and 12z GFS cycles are showing this as well...it`s just that where the other guidance keeps this feature to our northeast, the GFS (and the majority of its ensembles, for what that`s worth) depict some retrograde motion of the low, westward into the Ohio Valley through Monday. Were this scenario to play out, it`d pretty strongly enhance the dynamical forcing over the Carolinas by by Monday afternoon, and more active weather could be in order. I like to imagine the GFS as similar to an 80s-style action movie villain: sitting in its dark lair laughing, its intentions unclear and yet definitively at odds with everyone else. In the case of 80s movies, of course, this typically resulted in various popcorn-worthy action sequences...while in the case of the GFS, the "villainous" solution would just result in far better convective potential than what the rest of the guidance favors. Regardless of which solution plays out for Monday...most of the guidance depicts some flavor of shortwave rotating across the Mid- Atlantic on Wednesday, though impacts will hinge on timing and intensity of this feature, which at this point is about as clear as mud. Temperatures will fall a little below normal for Monday (maybe a lot below normal if the GFS`s deep-upper-low solution pans out) before rebounding to at least a category above normal by Wednesday. && .AVIATION /02Z THURSDAY THROUGH MONDAY/... At KCLT and elsewhere: Varying VFR bases are evident this evening, with areas of high clouds, lingering high-based stratocumulus, and persistent patches of lower VFR cumulus showing up on satellite imagery and in observations. Low-level northeast flow could bring in some patchy MVFR-level clouds from an Atlantic moisture source, but even the most aggressive RAP has backed off on this for the overnight hours, with other solutions tending toward drier 950 to 850 mb flow. Will keep VFR conditions through the night across the foothills and Piedmont, but feature some SCT020 to hint at lower bases. Restrictions could be a bit more widespread in the mountain valleys and around KAVL overnight where the boundary layer moisture has been most persistent. Will feature a window of IFR conditions around daybreak at KAVL. VFR stratocumulus or cumulus bases will then return with heating on Thursday. SHRA/TSRA chances will be best in the mountains, but generally stay modest around KAVL. Expect NE winds through the period except for southeast flow at times at KAVL. Low end gusts will be possible throughout with mixing Thursday afternoon. Outlook: Isolated SHRA/TSRA and associated restrictions appear possible in and near the Appalachians again on Friday afternoon. Shower chances may rise modestly over the weekend as a backdoor cold front settles south through the region. The easterly flow regime should get reinforced over the latter half of the weekend and linger into early next week. && .GSP WATCHES/WARNINGS/ADVISORIES... GA...None. NC...None. SC...None. && $$ SYNOPSIS...DEO NEAR TERM...HG SHORT TERM...MPR LONG TERM...MPR AVIATION...HG
Area Forecast Discussion...Updated Aviation
National Weather Service Saint Louis MO
610 PM CDT Wed May 31 2023 .SHORT TERM... (Through Late Thursday Night) Issued at 224 PM CDT Wed May 31 2023 Above normal temperatures and precipitation chances will be the main focus through Friday. The broad area of showers and thunderstorms over western Missouri and eastern Kansas has since collapsed. Visible satellite shows variable cloud cover surrounding a remnant MCV pushing from eastern Kansas into western portions of Missouri. Ahead of the MCV is an elongated area of surface to mid-level convergence that has supported showers and a few thunderstorms over central Missouri. Latest guidance tracks the MCV more north than east late this afternoon into this evening, also aiding to shunt the convergent feature into northeast Missouri by sunset. Surface dewpoints in the 60s, MLCAPE values in the 1,000-1,500 J/kg range and mid-level lapse rates of 6.5-7C will be plenty of support showers and thunderstorms as lift is provided by the MCV moving north-northeast into Iowa through late this evening. Shear has been a big limiting factor with 10-15 knots depicted in RAP soundings through the depth of the modeled environment. While nothing is expected to be well-organized, PWATs around 1.5-1.7 inches will make efficient rain producers with localized heavy rainfall possible with the best potential over central and northeast Missouri through about 02z this evening. PoPs have been trimmed (15-20 percent) over eastern sections of the CWA with little more than near-1,000 J/kg MLCAPE values and 60 degree dewpoints supporting isolated activity. The envelope of lower dewpoints (50s) that essentially separate the western and eastern sections of the CWA today will give way to an expanding field of moisture with dewpoints rising into the 60s across the entire forecast area. Though the potential for showers and thunderstorms broadens in area, the chances themselves are not impressive. Limitations are similar to today with weak shear and the absence of an organized system nor convergent feature. That said, any development could result in localized heavy downpours and outflow boundaries that lead to downstream, sporadic convection, mainly through the diurnal peak. Friday once looked to be the day for broader convection. However, latest indications show a quicker influence from easterly flow around the strengthening ridge to the north. NBM probabilities (40- 60 percent) are likely too high and may trend downward in time if latest guidance is any indication of trends to come. This is especially true at the eastern fringes of the potential (east of the Mississippi River). Nighttime periods will likely see lulls between diurnally driven daytime convection. Temperatures will largely be uniform in nature with 80s covering the entire CWA and a few 90s in relatively warmer locations. The one caveat will be localized rain-cooled due to afternoon convection. Outside of that, temperatures will run approximately 10 degrees above normal. Maples .LONG TERM... (Friday through Next Wednesday) Issued at 224 PM CDT Wed May 31 2023 The potential for showers and thunderstorms will wane this weekend as upper level ridging retrogrades through the Upper Midwest and stations itself over south central Canada. This ridge is expected to be anomalously strong, with both the NAEFS and ECMWF ensembles showing 500 mb heights above the climatological maxmimum near the peak of the ridge. As the ridge climbs northwest, an upper level low will be retrograding to the southwest through southeast Canada and New England. This will force deep dry air into the region over the weekend, cutting off our chances at rainfall. A backdoor front will pass through the Mid-Mississippi Valley Saturday morning in response to the change in pattern. East- northeasterly winds will follow, accompanied by the aforementioned dry air. Temperatures will remain above average, with Saturday actually forecast to be the warmest day of the next seven. Clear skies and dry low levels will result in efficient mixing, allowing 18 to 20C 850 mb temperatures to reach the surface. This is expected to translate to highs Saturday afternoon in the mid-90s. These temperatures are encroaching upon record territory, with KUIN currently the closest climate site to reaching or exceeding their previous record of 92 degrees set in 2011. KSTL (96/2011) comes within a degree as well, but KCOU will likely remain just out of reach (97/1911). The upper level low in the eastern CONUS will meander around that region of the country before deepening and expanding early next week. This will place the Mid-Mississippi Valley in northwest flow aloft on the backside of the trough, an area not conducive for beneficial rainfall. Ensemble guidance supports this, with over half of the members of the ECMWF, CMC, and GEFS combined showing no rainfall, and the majority of the rest showing less than 0.5 inches through next week. Although the next week looks dry, the Climate Prediction Center outlook for June 7th through June 13th shows some optimism with precipitation probabilities leaning above normal for the southern CWA. The seasonal (June-July-August) precipitation outlook also highlights our CWA with above average probabilities. Hopefully this means the rest of the spring and summer won`t be as dry as the beginning. Jaja && .AVIATION... (For the 00z TAFs through 00z Thursday Evening) Issued at 608 PM CDT Wed May 31 2023 Isolated showers and weak thunderstorms should slowly wane and dissipate through late this evening. Current activity is east of central Missouri sites and west of KUIN and metro St. Louis so no terminal is likely to be impacted by this activity. Dry/VFR conditions forecast overnight tonight into early Thursday with light southeasterly winds. Coverage of showers and weak thunderstorms may be a bit higher and more expansive tomorrow, but confidence is low overall in terms of where activity may be more focused than others. Given that, went with a VCSH group for now beginning in the mid/late afternoon. Gosselin && .LSX WATCHES/WARNINGS/ADVISORIES... MO...None. IL...None. && $$ WFO LSX
Area Forecast Discussion
National Weather Service Marquette MI
1138 PM EDT Wed May 31 2023 .SHORT TERM...(This afternoon through Tonight) Issued at 235 PM EDT WED MAY 31 2023 Today has been another very warm day in the Upper Peninsula, we hit 90 degrees breaking the record high temp of 88 degrees previously set in 1988 here at the WFO! RAP analysis shows high pressure over New England with a sfc low and mid level trough over northwestern Ontario. This sets up southerly flow near the surface and aloft that continues to bring highs this afternoon well into the 80s with some seeing low 90s. Dew point temps have been slightly higher than yesterday, however the elevated fire potential remains through the afternoon with the warm temps, winds gusting up to 15 mph, and the RHs settling into the Upper 20s/low 30s before dew point temps can recover this evening. Bufkit soundings indicate no real layers of moisture, but the CAMS still are indicating some spotty shower development over the west half of the CWA. CAPE has already reached into the 500-1000 J/kg range and the model soundings yield some values late afternoon/evening into the 1000-1500 J/kg range. Radar/satellite imagery already show some cumulus development, which will continue mainly over the central UP, but I am fairly confident that the dry air will win against any potential shower development preventing anything from reaching the ground until this evening or tonight (if at all in this forecast period). This synoptic pattern will continue through tonight continuing the mostly dry weather outside some possible showers over the far west. With a similar pattern to last night, I kept low temps in the 50s with warmer temps, possibly in the low 60s, along the lakeshore areas. Mostly dry weather will continue outside some slight potential for showers over the very far west tonight; most likely any precip chances will stay out over the far west end of Lake Superior. .LONG TERM...(Thursday through Wednesday) Issued at 436 PM EDT WED MAY 31 2023 Above normal temperatures and below normal precipitation are expected to continue over the next week. There are near-daily chances of rain across portions of the west half, but any rainfall that occurs is expected to be localized in nature. The Keweenaw from Houghton northward and counties east of Marquette/Dickinson are most likely to stay completely dry. At the synoptic scale, a 500mb ridge centered over the lower Great Lakes Thursday morning retrogrades westward to southern Manitoba by Friday night where it reaches peak amplitude Sunday evening. This ridge gradually decays next week as troughing along the Atlantic Coast amplifies resulting in increasing northerly flow aloft across the UP. Low level flow backs from warm/moist southerlies on Thursday to southeasterly flow Friday then drier easterly flow behind a weak cool front on Saturday. A more pronounced cool front moves through late Sunday with a longer-lasting period of dry northeasterly flow early next week. The warmest temperatures are expected downwind of the prevailing wind direction each day with another warm day along the Lake Superior on Thursday, converging lake breezes Friday and Saturday, then another day near 90F across the interior west on Sunday. Assuming the cold front comes to pass, Monday and Tuesday look 5-10F cooler with mid 70s to low 80s areawide, coolest near Lake Superior. Regarding precipitation chances, recent HREF guidance has persistently highlighted the area between Ironwood and L`Anse tomorrow aftn/evening. Confidence is high (>70%) that a few storms will initiate there, but spotty coverage caused me to cap PoPs around 50%. CAMs highlight MLCAPE values approaching 1500 J/kg with bulk shear values near or below 20 knots suggesting a pulse storm mode. There were a few reports of pea-dime-nickel size hail to our south today in a similar environment and I wouldn`t be surprised to see that threat materializes again with the strongest storms tomorrow. The threat should be brief/localized before the storms rain themselves out, but additional activity may pop up along a southeastward propagating outflow boundary before instability diminishes in the evening. Friday also has a relatively high probability of isolated afternoon/evening thunderstorms. The upper level ridge axis moves overhead during the day resulting in a noticeable wind shift across the lake. This should allow for a more robust afternoon lake breeze and global models suggests MLCAPE values could approach 2000 J/kg along the boundary, but bulk shear values are even lower (AoB 10 kts) suggesting a lower threat for small hail. Saturday is probably the best chance for the eastern UP to get any rainfall with light easterly flow resulting in converging lake breezes, but shear remains AoB 10 kts. An upper level vort max associated with a frontal boundary pushing northeast to southwest across the area could locally enhance precip too. Much drier air moves in behind the front for Sunday allowing precip chances to return to zero, but light winds preclude a more substantial fire wx threat. && .AVIATION...(For the 06Z TAFS through 06Z Thursday night) Issued at 1137 PM EDT WED MAY 31 2023 VFR will continue with mid-level ridging holding strong over Upper Michigan. Winds will be light and generally southerly, except at CMX where there is an easterly component. Chances will be better later today for pop-up showers and thunderstorms, but confidence is too low at this point in regard to location and timing to insert mention at any one TAF site. && .MARINE...(For the 4 PM Lake Superior forecast issuance) Issued at 436 PM EDT WED MAY 31 2023 With mid-level ridging over the region for a majority of the forecast period, expecting winds of 20kts or lower across the lake through the weekend. Thunderstorms are possible each day through at least Saturday, mainly across the western half of Lake Superior. Very stable conditions over the lake and the lack up any low level jet features to force elevated storms suggests any activity should be confined to the ports and nearshores. Severe storms are not expected, but a few storms capable of small hail are possible during the afternoons and evenings. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... None. Lake Superior... None. Lake Michigan... None. && $$ SHORT TERM...Jablonski LONG TERM...EK AVIATION...TDUD MARINE...EK
Area Forecast Discussion
National Weather Service New York NY
1135 PM EDT Wed May 31 2023 .SYNOPSIS... High pressure will remain in control but will be slightly weakening across the local area Thursday night into early Friday. A backdoor cold front is expected Friday night/Saturday morning with low-pressure building through the weekend. A coastal low will impact us Monday-Tuesday. Another cold front is expected Tuesday into Wednesday. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... Forecast remains on track with only minor adjustments to temperature and dew points to reflect the most recent observations and trends. Mostly clear sky conditions initially along with decreasing winds has allowed for radiational cooling. With light onshore flow along the coast, expecting for the development of low clouds and fog. Some of the fog could become dense, especially further east. Forecast lows range from upper 40s to upper 50s using a blend of the NBM and its 50th percentile. This is relatively warmer for the coastal areas due to the abundance of low clouds and fog as well as light onshore flow. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/... For Thursday, the morning low clouds and fog will get scoured out with diurnal heating and vertical mixing in the boundary layer. The fog and low clouds shift south of Long Island and dissipate, with a mostly sunny day expected. Winds are pretty light but increase in the afternoon with sea breeze development. Used a combination of MAV MOS, MET MOS, NBM and consensus of raw data for forecast highs Thursday ranging from low 70s across SE CT and Eastern LI to upper 80s within parts of NE NJ and Lower Hudson Valley. This combo keeps cooler temperatures along the coast compared to MOS and NBM. For Thursday night, similar fog and low cloud development forecast to redevelop along the coast with slight increase in dewpoints. Otherwise, mostly clear sky conditions farther north and west across the interior. Lows forecast from lower 50s to lower 60s. Regarding the patchy smoke, HRRR forecasts this to move back southeast but at gradually lowering concentrations as it gets more dispersed. && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... Stuck fairly close to the NBM through the long term period. Pretty much every day has a chance of rain in the forecast. Ridging aloft from the west begins to breakdown on Friday as a trough drops south from Canada to New England. 850 mb temps warm into the 16-18C range with surface temps likely reaching the upper- 80s to lower-90s inland with mid/low-80s for coastal areas. A backdoor cold front is also expected overnight Friday into Saturday morning. The prefrontal trough will bring PVA and instability leading to scattered showers and thunderstorms. SBCAPE values are 1000-1500 J/kg from the GFS, but looking higher on the NAM at 2000- 2800 J/kg. Some of the stronger instability occurs inland where there is also a chance for some possible small hail give colder air aloft as seen on model soundings. After the backdoor front passes overnight, we should maintain north or easterly flow through the weekend with gusting winds 20-25 kts and maintain it through Monday. High will be much cooler Saturday thanks to the front, with highs in eastern areas in the mid-60s with western areas in the low-70s. The trough building in New England cuts off at upper-levels and slowly retrogrades south and west over the weekend. The cyclonic flow from this low could lead to daily shower chances. The lower heights will prevent us from warming up much through the weekend. A coastal low riding up the coast will bring more showers for Monday and Tuesday, also allowing temperatures back into the mid-70s. FROPA may occur sometime on Tuesday or Wednesday but models do not have a consensus on timing with this. && .AVIATION /04Z THURSDAY THROUGH MONDAY/... High pressure remains in the vicinity of terminals throughout the TAF period. VFR gives way gradually to low stratus/fog from east to west, bringing IFR to LIFR conditions. Highest probability of IFR and LIFR is for NYC terminals on east. City terminals more likely to experience IFR and LIFR conditions after 6z. Winds go light and variable overnight and will remain light to calm into early Thu morning. The winds will be mainly SE to S during the day Thu at 5 to 10 kt. Smoke from Canadian wildfires could limit visibilities slightly, to around 6SM at times Thu. Confidence remains low so kept haze and smoke out of TAFs for the time being. ...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty... Timing of onset of IFR and LIFR cigs overnight may be off by up to 2 hours, along with questions as to how far west it gets. Low stratus and fog may only impact KEWR/KTEB for only an hour or two into early Thu am. There remains some uncertainty with how much surface restrictions to sky/vsby there will be with the haze and smoke on Thursday. For now keeping haze and smoke out of TAFs, but amendments may be needed on Thu. OUTLOOK FOR 0Z FRIDAY THROUGH MONDAY... Thursday night: Mainly VFR, but chance of IFR or lower with stratus, with best chance for eastern most terminals. Friday: Mainly VFR. Low chance of showers/thunderstorms and MVFR, mainly at night. Saturday: MVFR possible with a chance of showers throughout the day. NE-E winds near 10-15kt with gusts near 20-25kt, highest at the coastal terminals. Sunday: Becoming VFR. Monday: VFR to start, then MVFR possible in afternoon showers. Detailed information, including hourly TAF wind component forecasts, can be found at: https:/www.weather.gov/zny/n90 && .MARINE... With a relatively weak pressure gradient remaining across the local waters, conditions for winds and seas will remain below SCA thresholds through Thursday night. Sub-SCA winds and waves expected Friday. SCA conditions expected on all waters on Saturday with gusts upwards of 30 kt. SCA conditions then persist mainly on the ocean waters Sunday through Monday with gusts of 25-30 kts, waves 5-7 feet. && .HYDROLOGY... No hydrologic impacts expected through early next week. && .TIDES/COASTAL FLOODING... A moderate rip current risk is expected Thursday and Friday. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...None. && $$ SYNOPSIS...BR NEAR TERM...JM/MW SHORT TERM...JM LONG TERM...BR AVIATION...JE MARINE...JM/BR HYDROLOGY...JM/BR TIDES/COASTAL FLOODING...
Area Forecast Discussion
National Weather Service Pendleton OR
434 PM PDT Wed May 31 2023 Updated Aviation Discussion .AVIATION...00Z TAFs...VFR conditions over the next 24 hours. Gusty winds remain through 04-08Z all sites. Overnight winds should then become light and generally 10kts or less. Breezy winds then possible again tomorrow though not as strong as today, generally less than 25kts. Skies clear or some CIGs at FEW 20k feet or higher possible. Goatley/87 && .PREV DISCUSSION... /issued 254 PM PDT Wed May 31 2023/ SHORT TERM...Rest of Today through Friday night...Satellite imagery reveals a sharp gradient in moisture across the forecast area as a shortwave trough approaches. Dry and mostly clear conditions are present west of the Blue Mountains while isolated convection continues across eastern Grant, Union, and Wallowa counties where just enough instability, moisture, and forcing is present to support showers. Farther east into Idaho and southeast Oregon where the environment is more moisture rich, scattered convection is occurring ahead of a shortwave trough. Most of the convection across our forecast area has been shallow with the highest echo tops in the vicinity of 20-25 kft and only isolated lightning strikes picked up by lightning networks. Convection is forecast to diminish this evening with mostly dry conditions then forecast overnight. Winds through the Columbia River Gorge and Kittitas Valley have flirted with advisory criteria much of the morning and afternoon, and sustained winds at DLS and ELN are now just above criteria (30 mph). Observed pressure differences of roughly 5 mb between DLS and PDX and 8 mb between ELN and SEA have been slightly stronger than forecast by guidance and are supporting windy conditions. Pressure gradients and 850 mb winds are forecast to peak over the next few hours, and the vorticity maximum associated with the incoming shortwave will cross over the region this evening so confidence of a few hours this afternoon and evening where advisory criteria are reached or exceeded at DLS and ELN is high enough to issue a short-duration Wind Advisory for the Kittitas Valley and eastern Columbia River Gorge. Winds are then forecast to slacken below advisory levels overnight and into Thursday morning. Hot on the heels of the first shortwave, a second compact, albeit weak, vorticity maximum is forecast to slide into the Pacific Northwest on Thursday. Moisture and instability is lacking so chances for thunderstorms are very low (<10%), but the HRRR remains consistent in placing a few showers across the southeast part of our forecast area over the higher terrain of Grant County. 12Z HREF and NBM probabilities for precipitation do not support putting a "slight chance" mention for showers in the forecast so have omitted due to low confidence. Friday, heights rise across the forecast area with a warming trend and mostly dry conditions across the forecast area. Plunkett/86 LONG TERM...Saturday through Wednesday...Good consensus amongst ensemble guidance that sensible weather concerns through the extended period will revolve around increasing afternoon temperatures each day and potential convective activity during the midweek. Overall, ensemble members in good agreement in the region being under the influence of an upper level ridge centered over the Plains through at least Wednesday next week. The increasing high pressure over the region will result in temperatures increasing several degrees day to day, with moderate confidence (50%) of Wednesday being the warmest day in the period. Though at the end of the period, low percentages of the GFS(10%), the ECMWF(22%) and Canadian(20%) ensemble members indicate a ~20% chance of exceeding 100 degrees in the Tri-Cities area on Wednesday afternoon. While a warm-up is expected, confidence is very low (15%) on detailed temperatures. The other feature to direct our attention to will be a weak upper low developing off the CA coast, and moving inland over the Desert Southwest Monday into Wednesday. Ensemble guidance is in fairly high agreement in this feature developing, with all ensemble cluster solutions showing this feature, with very minimal differences in strength, timing, and position. As a result, ensembles indicate increasing PWATS from the south and east as the low pushes inland. This, in tandem with increasing surface based instability, will result in at least isolated thunderstorms developing in the afternoon Tuesday and Wednesday over the mountainous terrain in northeast OR, though confidence in intensity and coverage is low(30%). Otherwise, under the influence of the upper ridge, there is moderate confidence (40-60%) in dry conditions prevailing across the forecast area with light diurnally driven winds each day. Lawhorn/82 && .PRELIMINARY POINT TEMPS/POPS... PDT 42 73 45 79 / 0 0 0 0 ALW 47 77 51 83 / 0 0 0 0 PSC 49 80 51 85 / 0 0 0 0 YKM 43 78 47 83 / 0 0 0 0 HRI 47 78 49 84 / 0 0 0 0 ELN 44 76 48 81 / 0 0 0 0 RDM 36 71 40 77 / 0 0 0 0 LGD 41 72 46 75 / 0 0 0 0 GCD 39 73 43 76 / 0 0 0 0 DLS 46 77 48 81 / 0 0 0 0 && .PDT WATCHES/WARNINGS/ADVISORIES... OR...Wind Advisory until 11 PM PDT this evening for ORZ041. WA...Wind Advisory until 11 PM PDT this evening for WAZ024-026. && $$ SHORT TERM...86 LONG TERM....82 AVIATION...87
Area Forecast Discussion
National Weather Service Shreveport LA
1001 PM CDT Wed May 31 2023 ...New UPDATE... .UPDATE... Issued at 915 PM CDT Wed May 31 2023 As of 945 PM CDT, temperatures have fallen into the mid-70s with some lingering high clouds in an otherwise mostly clear sky. Surface winds remain light and easterly with dew points expected in the lower 60s. This makes for another fairly average night conditions-wise temperature minimums in the upper 60s as a result. Fog also remains possible overnight in Deep East Texas. With weather and observed trends continuing as anticipated, forecast grid adjustments were not necessary at this time. /16/ && .SHORT TERM... (This evening through Thursday Night) Issued at 255 PM CDT Wed May 31 2023 Nice field of cumulus clouds over most of our four state area. Towering earlier in NE TX, but just some left over outflow boundaries now and one lonely cell near Longview. Most of the convection is now firing south of our area in the Jasper and Derider vicinities. HRRR is not excited about anything different happening through the remainder of the afternoon. The weaking and elongating shear axis can be seen well on the water vapor imagery right over Toledo Bend country for the most part. Otherwise, a couple of sites have reached 92 along I-49. Most sites are nearing 90 at this time. Winds are all over the place, but seemingly NE- SE less than 10 mph or lots of calm obs. So, "Play it again Sam" seems to be on course for another 24 hrs, just slightly warmer along a south of I-20 and in the nights to come. Highs again tomorrow will be around 90 degrees, just slightly above late May averages. Lows are gaining traction back towards that mark. /24/ && .LONG TERM... (Friday through next Tuesday) Issued at 255 PM CDT Wed May 31 2023 With the Ern Gulf upper low progged to drift ESE through the Ern Gulf Friday, the residual weakness aloft extending NW from this low across N LA/Srn AR is expected to erode as ridging aloft expands NE across E TX/Wrn LA, with increased subsidence resulting in hot, humid, and mostly dry conditions areawide. In fact, max temps will reach or exceed 90 degrees across the region, with a few mid 90s not out of the question especially across portions of N LA. However, this will be short-lived as a spoke of energy developing along and ahead of troughing aloft over the Rockies begins to shift E along the Red River Valley of NW TX/Srn OK. Remnants from this shortwave should begin to erode the ridging in place Friday night/Saturday morning, and interact with strong diurnal heating during the day Saturday to enhance scattered convection development across much of the region during the afternoon. Have maintained likely pops NW of I-30 Saturday afternoon, with mid and high chance pops elsewhere as overall shear will remain quite weak, and the convection very outflow dominant. Did maintain slight chance pops Saturday evening over much of the area to account for any residual convection, although this should quickly diminish with the loss of heating/instability. Another piece of energy aloft remains progged to traverse the region during the day Sunday, and again will interact with diurnal heating to enhance scattered convection once again, where mid and high chance pops were maintained over much of the area. Isolated convection may again lingering during the evening mainly over E TX/Wrn and Cntrl LA, with the lingering weakness aloft expected to gradually sink SSW into Cntrl/SE TX and Srn LA. The GFS is the outlier in trying to mix much drier air SW into the Mid-South and Lower MS Valley while eventually backdooring into the region Monday, which seems too aggressive given the fact that the deeper troughing aloft will remain well to the E from the OH/TN Vallies E to along the Ern Seaboard. While the NBM does suggest that some drier air may try and backdoor SW into the region Monday, the lingering weakness aloft may still help focus isolated to widely scattered convection during the afternoon especially over E TX/Wrn and Cntrl LA, before diminishing by sunset. Hot and mostly dry conditions will persist through the remainder of the long term, although the slightly drier air backdooring in may take a bit of the edge off of heat indices, especially as ridging aloft building over the Plains begins to expand SSE into the region. /15/ && .AVIATION... (00Z TAFS) Issued at 701 PM CDT Wed May 31 2023 For the 01/00Z TAF update, VFR conditions are expected through the period with the main exception being with FG possible in KLFK by 01/10-14Z. Otherwise, light winds will remain from the east at 5-10 mph. /16/ && .PRELIMINARY POINT TEMPS/POPS... SHV 68 90 71 92 / 0 10 0 10 MLU 66 90 69 92 / 0 10 0 0 DEQ 62 89 66 90 / 0 10 0 10 TXK 65 90 69 93 / 0 10 10 10 ELD 63 88 67 90 / 10 10 0 10 TYR 68 89 69 90 / 0 10 0 10 GGG 68 89 68 91 / 0 10 0 10 LFK 67 90 68 91 / 0 10 0 0 && .SHV WATCHES/WARNINGS/ADVISORIES... AR...None. LA...None. OK...None. TX...None. && $$ SHORT TERM...16 LONG TERM....15 AVIATION...16
Area Forecast Discussion
National Weather Service Las Vegas NV
855 PM PDT Wed May 31 2023 .SYNOPSIS... An area of low pressure will move east and into Mohave County this afternoon and will bring isolated to scattered rain showers, and a slight chance of thunderstorms, particularly over the higher elevations today. No impactful rainfall amounts are expected, but these storms will be capable of producing lightning, small hail, and wind gusts around 30 mph. Chances for showers persist over the southern Sierra and central Nevada on Thursday and Friday with similar thunderstorms risks expected each day. Dry and warmer weather is forecast for the weekend. && .UPDATE...Current satellite imagery shows the upper-level cut-off low spinning over western Arizona. This system was responsible for the isolated showers and thunderstorms across portions of the area today. These showers and thunderstorms have largely dissipated with the loss of daytime heating to fuel convection. Another round of isolated showers and thunderstorms will be possible tomorrow afternoon, but will be mainly limited to the Sierra and Southern Great Basin. Temperatures will continue to remain a few degrees below normal through the end of the work week, but will return to normal in time for the weekend. && .SHORT TERM...Today through Friday. We had some showers/thunderstorms develop around daybreak in eastern San Bernardino County but they continue to diminish. The center of the upper low is currently in far southeastern California and will be slowly working its way into western Arizona during the afternoon hours. Moisture and instability are quite limited and with the low moving away dynamics will be marginal as well. However, isolated to scattered showers and thunderstorms are expected to develop, particularly over the higher elevations and beneath the colder air aloft (Mohave County). The latest couple of HRRR runs and the HREF actually diminish the SBCAPE during the afternoon but 100-300 J/kg will still be available. Lightning, small hail due to cold temperatures aloft, and sudden gusty winds will be possible with any storms today. Today`s high temperature should remain in the 80s in Las Vegas which is well below normal. However, we had a high of only 68 degrees on this date in 1991. The upper level system will continue to slowly move east Thursday and Friday. As it pulls away, precipitation chances should diminish each day. On Thursday, the focus will be across the Southern Great Basin where continued troughing will sit and instability will develop in the afternoon. The latest HREF is indicating at >50% probability of these storms to produce wind gusts greater than 30 mph across Esmeralda, central Nye and northern Lincoln Counties. By Friday, precipitation chance shift into central Nye through Lincoln County and favoring northern Lincoln County. Temperatures will slowly trend higher and should be close to the seasonal normals by Friday. .LONG TERM...Saturday through Wednesday. Weak ridging will be in place over the weekend across the southern Great Basin and Mojave Desert. The ensembles are in good agreement that the next upper level low will form off of the southern California coast on Sunday afternoon. However, mostly sunny skies and dry conditions will be the rule for the weekend other than some increase in southwest winds across the Mojave Desert on Sunday. The upper low will move onshore during the day on Monday and both the GEFS and EPS ensemble means have the upper low located over southeast California in a nearly identical position to the current upper low (just slightly weaker). The exact impacts from the upper low are little murkier but the ensembles support some increase in shower and thunderstorm activity at least over the higher terrain each afternoon Monday through Wednesday. Temperatures will once again trend lower starting on Monday under the influence of the upper low and return to below normal levels on Tuesday and Wednesday. && .AVIATION...For Harry Reid...Scattered thunderstorms are expected to develop near the terminal later this afternoon, mainly to the south and southeast. As a result, there is the potential for outflow winds with gusts as high as 30kts to affect the field, generally after 22Z. Until then, winds less than 10kts with easterly components can be expected. Once thunderstorm activity ends early this evening expect southerly winds that will become light and variable overnight. Additional thunderstorms are possible tomorrow, although coverage should be less, limiting the threat of outflow winds. For the rest of southern Nevada, northwest Arizona and southeast California...Overall, south to southwest winds are expected at area terminals today into Thursday. Scattered areas of convection are still expected to develop this afternoon across the area, and any of these storms will be capable of producing gusty outflow winds, along with lower ceilings and obscured terrain. Storms should dissipate after sunset allowing winds to return to normal diurnal patterns. Additional convective activity is again possible on Thursday, although the coverage should be less. && .SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report any significant weather or impacts according to standard operating procedures. && $$ UPDATE...Stessman SHORT TERM...Czyzyk LONG TERM...Czyzyk AVIATION...Planz For more forecast information...see us on our webpage: https://weather.gov/lasvegas or follow us on Facebook and Twitter