Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 07/17/24


Area Forecast Discussion
National Weather Service La Crosse WI
1103 PM CDT Tue Jul 16 2024 .KEY MESSAGES... - Pleasant weather ahead! A cooler, less humid, and drier forecast through the rest of the week. && .DISCUSSION... Issued at 211 PM CDT Tue Jul 16 2024 A fairly nice start to the day with observations as of 2 PM showing temperatures in the upper 70s to lower 80s and dewpoints in the upper 50s to lower 60s. A bit of relief after a hot, humid, and quite busy weather weekend. Satellite imagery and RAP progs show an upper level trough which is forecast to move down across the Great Lakes into Wednesday, with a wave currently moving across the region. Hi-res models still produce some light echoes across the area, with current radar starting to show some development in the north. Have maintained low chances (15-25%) for some sprinkles/showers this afternoon and early evening with weak CAPE values looking to keep thunder chances lower as well. Otherwise, any showers that do develop should diminish with the loss of daytime heating. An amplified upper level pattern will remain as a strong ridge holds across the western U.S. and a trough over the east-central U.S. through the week. At the surface Canadian high pressure looks to dominate over the region bringing cooler conditions and less humid air. Low spread between the 25th and 75th percentiles of ensemble/blended model guidance supports near to below normal temperatures with highs in the 70s to near 80 Wednesday through Friday. A slight upward trend in temperatures is indicated for the weekend into early next week, though highs are still forecast to only top out in the mid 70s to low 80s. There remains low signal among ensemble model solutions for any impactful precipitation through much of the week, so have maintained a mainly dry forecast. Some low rain chances return to the forecast for the weekend, but confidence is low with the given pattern and low predictability of any waves. && .AVIATION /06Z TAFS THROUGH 06Z THURSDAY/... Issued at 1103 PM CDT Tue Jul 16 2024 VFR conditions are expected through the rest of the TAF period with scattered low to mid-level clouds. As we head into the afternoon, winds will increase to around 10 kts remaining generally north to northwesterly. Cannot completely rule out some valley fog at KLSE early this morning with decoupling winds, however with winds just off the deck to around 15 kts in the 16.21z RAP this appears very unlikely (5-10% chance). && .ARX WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. IA...None. && $$ DISCUSSION...EMS AVIATION...Naylor
Area Forecast Discussion
National Weather Service Cheyenne WY
548 PM MDT Tue Jul 16 2024 .KEY MESSAGES... - Widely scattered storms possible this afternoon. Increasing moisture Wednesday will support strong to possibly severe thunderstorms Wednesday afternoon. Daily chances for precipitation continue through the rest of the week. - Warm mid-week before cooling trend begins for the weekend. && .SHORT TERM /THROUGH THURSDAY NIGHT/... Issued at 230 PM MDT Tue Jul 16 2024 Latest radar scans showing isolated thunderstorms over the CWA at 2 PM this afternoon. Cells are moving from north to south in northwest flow. Latest RAP mesoanalysis showing around 500 J/KG surface based CAPE. Cells don`t appear to have much vertical growth . Still considerable lightning being observed with these isolated storms...so we will continue to monitor. Current PWATs over southeast Wyoming are quite dry...GFS showing .6 to .8 inches over southeast Wyoming and .9 inches over the Panhandle. Latest HRRR/RAP simulated radar shows convection decreasing significantly after 01Z or so. SBCAPE does not increase significantly through the late afternoon...so severe storms are not a concern for the rest of the day. Better chances Wednesday as low level winds shift easterly this evening and draw low level moisture north from western Kansas. Later shifts will need to be on the lookout for low stratus in the Panhandle Wednesday morning for aviation forecasts. PWATS increase to 1.27 inches in the Panhandle Wednesday afternoon to near .9 inches here at Cheyenne. NAM/SREF/GFS showing pretty widespread QPF over areas east of the Laramie Range Wednesday afternoon. The outlier is the ECMWF that keeps the more widespread QPF south in Boulder`s CWA. Afternoon MUCAPE in the Panhandle up near 1500 J/KG. So could see a few severe storms out that way. Look for another round of showers and storms Thursday as low level moisture remains in place through the day. Though less than what we see Wednesday. && .LONG TERM /FRIDAY THROUGH TUESDAY/... Issued at 335 AM MDT Tue Jul 16 2024 Upper-level ridging will develop once again over the western CONUS Thursday through most of the long term forecast. This ridge is progged to bring warmer temperatures to southeast Wyoming and western Nebraska once again, but should be cooler than this previous weekend. 700mb temperatures will only increase to the 15C mark under the ridge on Thursday leading to surface temperatures in the mid-80s to mid-90s. This ridge will remain overhead for Friday as well, with a 500mb high centered over the Four Corners region and advecting in monsoonal moisture. Precipitable water will surge well over an inch for portions of the Panhandle with closer to an inch over southeast Wyoming. With several vorticity maxima traversing through the ridge, precipitation looks likely both Thursday and Friday evening, with Friday having the better chance for wider-spread precipitation. As a result of the additional precipitation and cloud cover expected for Friday, temperatures will be cooler in the low-80s to low-90s across the region. Saturday and Sunday both look cooler as the upper-level ridge retrogrades slightly back to the west and colder air floods down from Canada. Northerly to northwesterly flow aloft will remain for both days, leading to the potential for precipitation chances in the afternoons. A large fetch of northerly winds will be present from southern Canada to northern Arizona, further promoting the cooler temperatures. Temperatures on Saturday are expected to be in the low- to upper-80s, with upper-70s to mid-80s expected Sunday. Kept PoPs fairly low for these two days, between 20 and 30%, as afternoon showers and storms will be difficult to track down at this time. The cooler temperatures look to remain through the early week as the strong northerly flow aloft remains. && .AVIATION /00Z TAFS THROUGH 00Z THURSDAY/... Issued at 544 PM MDT Tue Jul 16 2024 A few showers and thunderstorms mainly over Wyoming are ongoing at this time, but convection is dissipating elsewhere. While there is a slight chance for a second round to develop around KCYS, KBFF, and KSNY this evening, the probability is too low to add to the TAF. There is also a slight chance for MVFR to IFR CIGs moving into KAIA or KSNY around sunrise Wednesday, but confidence is low at this time. Look for a nice morning Wednesday, but scattered to numerous showers and thunderstorms will begin developing by early afternoon. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...None. NE...None. && $$ SHORT TERM...GCC LONG TERM...AM AVIATION...MN
Area Forecast Discussion
National Weather Service Goodland KS
455 PM MDT Tue Jul 16 2024 .KEY MESSAGES... - Severe chances during the late afternoon to overnight hours with wind the primary hazard, but also a few instances of marginally severe hail and flash flooding possible. - Strong to severe storms are possible Wednesday into Friday as well. - Temperatures closer to normal beginning tomorrow and continuing through the weekend. && .SHORT TERM /THROUGH FRIDAY NIGHT/... Issued at 219 PM MDT Tue Jul 16 2024 Across the region this afternoon, skies are a mostly sunny to sunny mix, with a light/variable wind regime due to high pressure still influencing the area. Temperatures are ranging mainly in the lower to mid 90s. The main wx concerns for the short term period will focus on storm chances later this afternoon into this evening. And again Wednesday through Friday. With an elevated ridge over the western portion of the country, several shortwaves are set to move along the eastern periphery of the ridge and into the CWA. Today`s round of potential storms will be aided by a stalled boundary that is currently draped along the Oklahoma panhandle into eastern Colorado. The latest HRRR and NamNest are showing storms cropping up by 22z-00z. Model track focuses on the area south of I-70. The NamNest does continue to lean on some areas north of I-70 still seeing 20-40% chances for rw/trw. SPC currently has a Marginal Risk for severe over a good portion of the CWA, with a Slight Risk still south of Highway 40 into Greeley and Wichita counties. Inverted-v soundings still show wind as main threat, but initial storms could give a brief hail threat as well. WPC has an Excessive Rainfall outlook for locales along/south of I- 70. Slow movement of some of these cells, combined with PW values of 1.1 to 1.4 inches could give some locally heavy rainfall. Some areas south of I-70 into Logan county did receive around 2.00" with storms last night, so can`t rule out some isolated flooding issues if training occurs as with last night. The bulk of storms should stay south of the Interstate, but can`t rule out lingering precip overnight north into Wednesday morning over the eastern CWA. Going into Wednesday, surface ridge north shifts east of the CWA, with a lee-side trough setting up over the eastern Rockies. Aloft, the upper ridge remains in place with yet another shortwave working off the Rockies into the CWA. Latest guidance starts things west around 18z and pushes a bit eastward to at least Highway 25 at best as blocking effects prevent any further eastward push into the afternoon and evening. Late evening though, the ridge gives way east allowing for any remaining rw/trw to drift east towards 12z Thursday. SPC does show a Marginal Risk for severe wx for locales along/west of Highway 25. Instability warrants mention of high wind threat once again, although hail could be initially as storms form in Colorado. WPC has a Marginal Risk for excessive rainfall in Colorado as here lies the best chance for persistent heavy rainfall due to the slow moving storms expected. On Thursday, chances for storms through the first half of the day with the western CWA seeing best chances(20-30%) for storms. The shortwave expected for Thursday is a bit weaker than Wednesday and coming from the north due to amplification of the ridge into the Rockies. Guidance carries 20 pops going into the evening hours before things taper by 06z Friday. There is a Marginal Risk for severe for Thursday afternoon and evening in the northwest, but storms set to weaken as the evening progresses with a wind threat once again. Going into Friday, a brief reprieve over the area as high pressure sets up east of the CWA, with a strong lee-side trough over the eastern slopes of the Rockies. Another shortwave(500-700mb) dives southeast Friday afternoon into the evening for another round of storms, with better areal coverage due to ample low level moisture inflow/instability. 40-60% chance for storms is in place Friday evening as the system pushes through. Looking for wind/hail threats as well as potential for heavy rainfall again due to high PW values around 1.2" to 1.6". For temps, highs in the short term period will see an increasing trend with midweek numbers ranging in the lower to mid 80s. On Thursday, warmer with mid to upper 80s expected, and for Friday, lower to mid 90s. Overnight lows will range widely from the upper 50s into the mid 60s. Warmest night will occur Thursday night where all areas will be in the 60s. && .LONG TERM /SATURDAY THROUGH TUESDAY/... Issued at 135 PM MDT Tue Jul 16 2024 Looking at the latest runs of the GFS and ECMWF, both models do carry an amplified 500 mb ridge over the western portion of the country. A trough swings through the northern/central Plains during this time. Models do differ as to the system forming a meandering cutoff low or staying as a trough. From previous runs it does look like consensus for a cutoff low forming in the 500/700 mb range, meandering slowly over the central Plains. At the surface, a front will settle south of the CWA going into Saturday, as a strong ridge works into the northern Plains. The placement of the ridge will play a key role in amount/chances(20- 40%) for rw/trw potential each day. Areal coverage spans the CWA but does trend westward due to the surface ridge building south into the CWA by the beginning of next week. The result of this will have storms chances peaking late in the weekend into next Monday, before shifting towards the west. The caveat for the extended forecast will be the potential for heavy rainfall. PW values will range from 1-1.5" w/ best numbers in the east as surface winds shift easterly late in the period. For temps, looking for highs to start off the upcoming weekend to range in the mid to upper 80s on Saturday, giving way to slightly cooler numbers on Sunday with upper 70s to mid 80s expected. Going into next week, conditions begin an upward trend with mainly lower 80s Monday, mid to upper 80s for Tuesday. Overnight lows will range mainly in the mid to upper 50s this weekend. A few spots east of Highway 83 will reach the 60F mark. Next week, a similar setup to this weekend with mid and upper 50s Monday night, then a range from west to east Tuesday night from the upper 50s to lower 60s. Warmest along/east of Highway 25. && .AVIATION /00Z TAFS THROUGH 00Z FRIDAY/... Issued at 455 PM MDT Tue Jul 16 2024 KGLD...VFR conditions are expected through the period. A northeasterly wind around 10kts at taf issuance will veer to the southeast then south at similar speeds overnight. On Wednesday, light and variable winds in the morning become easterly at speeds up to 10kts or so with perhaps a few higher gusts. Presently, convection well west of the area is forecast to move to the southeast and should remain out of the area. There could be outflow wind gusts to 30kts or so in the 02z timeframe. KMCK...VFR conditions are expected through the period. Winds will generally be from the east around 10kts through the period. Will keep shower/thunderstorm mention out of the forecast at this time. Will be watching for the potential for storms to impact the terminal from the northwest in the 02z-06z timeframe. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...None. CO...None. NE...None. && $$ SHORT TERM...JN LONG TERM...JN AVIATION...99
Area Forecast Discussion
National Weather Service Gray ME
946 PM EDT Tue Jul 16 2024 .SYNOPSIS... Heat and humidity build continue through Wednesday as high pressure strengthens off the Eastern Seaboard, with chances for scattered afternoon or evening showers and thunderstorms each day. A cold front moves through late Wednesday through Thursday, bringing drier and somewhat cooler conditions for the end of the week and going into the weekend with high pressure building in from the west. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... 945 PM Update...The line of severe thunderstorms that brought damaging winds across southern NH into SW Maine has now weakened below severe thresholds as it encounters stable air across western Maine. The Severe Thunderstorm Watch has now been canceled. Have mainly fine tuned PoPs and removed enhanced wording for thunderstorms with this update. Showers with embedded thunder will continue to push east into central Maine while precipitation has mostly ended across southern NH. 615 PM Update...A Severe Thunderstorm Watch has been issued for much of New Hampshire into York and Cumberland Counties in Maine. A well developed QLCS is crossing into southern VT and is progged to reach the Lower CT Valley around 7 PM. This line of strong storms has history of producing wind gusts in excess of 70 mph. Latest guidance from the HRRR and WoFS suggest this QLCS will maintain its strength as it crosses Cheshire and Sullivan Counties and will start to weaken as it crosses NH into SW Maine while still posing a damaging wind threat into SW Maine. In addition to damaging winds, 0-3 km shear orthogonal to the bowing segment will bring the threat of a QLCS spin up. This line of storms will reach the ME/NH border around 9 PM and will move offshore around 10 PM. Previously... For tonight, early focus is on developing MCS over central NY this afternoon, which should strengthen as it moves east, and move into central/southern NH around 23Z . The timing of this system is better for severe than last night, but also, it looks to be organized than last nights system with CAMs developing a cold pool behind the convective line and possibly a rear inflow jet. It will likely peak over S VT but the system should continue to blow itself out as it crosses NH, so some damaging winds will be possible, and the SPC slight risk area seems like a reasonable approximation of where the threat is the greatest. The system should be off shore of ME by 02Z and I dont see any sever threat beyond this time as well, but a cluster of thunderstorms will likely continue to move across the N zones through about midnight. Patchy fog likely develops behind this line overnight, with lows once again in the mid to upper 60s in the N and around 70 in the S. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY/... The subsidence and associated sfc high behind this system will allow for a sunny start a a quick warm up Wed morning, and I think convection in advance of the front will hold off until around 18Z. This will allow for another hot and humid with heat advisories issued over the same areas Tuesday except for Cheshire county. Showers and Thunderstorms will be more widespread in the afternoon and evening, and could see isolated severe storms, with the best chance in southern NH again. Highs reach into low to mid 90s in the S, with heat index in the mid to upper 90s. The convection should help knock back the temps in the mid to late afternoon, and therefore the advisory is only until 22Z. Likely wont get to see too much effect from the cold front Wed night as the front slows around or just S of the CWA and the threat of showers storms will linger, especially in srn NH and near the coast through the night, as will the higher dew points and fog. So lows will rage from the low 60s in the mtns to near 70 again in the S. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... A weak cold front will be in the process of crossing through the area early Thursday with a continued chance of showers and maybe a storm or two, mainly in the morning. After that, drier air behind the front will make for mostly to partly sunny skies going into the afternoon. There may be a couple of additional afternoon showers, but the drier air/increasing subsidence aloft will keep coverage low, and for this reason I have also removed any mention of thunder during the afternoon hours. More importantly it won`t be quite as hot with highs staying in the 80s south of the mountains, and dewpoints will also be lower and in the upper 50s to lower 60s. More comfortable lows are on the way for Thursday night thanks to the drier air, mostly clear skies, and light winds. Most should see lows in the 50s with upper 40s even possible across the northern valleys. A period of pretty quiet weather is expected from Friday through the weekend with high pressure largely in control along with a dry airmass. There will be a chance of showers late Saturday as a weak cold front crosses through, but this looks mainly confined to northern areas, and moisture does not look particularly favorable with this system at the moment. While temperatures will be "cooler" than what we have been experiencing lately, highs in the 80s are still forecast each day, possibly close to 90 degrees for southern areas on Saturday ahead of the frontal boundary. The silver lining is that dewpoints will be lower to make the warm temps more manageable, and temperatures will be able to cool off more at night. We`ll probably have some valley fog at night/early morning, too. Mostly dry conditions look to start out Monday of next week, but after that global models are in pretty decent agreement showing a broad low pressure approaching the OH Valley/Great Lakes region. Out ahead of this system, moisture will be on the upswing, and a warm front lifting northward toward New England will increase chances for precipitation toward the end of the forecast period (late Tuesday or even slightly beyond into Wednesday). This is supported by the GFS/ECMWF ensembles, and the NBM showing increasing PoPs on Tuesday looks good. && .AVIATION /02Z WEDNESDAY THROUGH SUNDAY/... Short Term...Expect a line of potential severe storms to move through srn NH this evening, affect KMHT/KCON/KLEB, with heavy rains, frequent lightning and potential W wind gusts to 50 kts in the 23-01Z period. It is less likely to reach KPSM or KPWM, but could still see heavy rain and frequent lightning here. Otherwise patch fog could develop after midnight, especially where it rained. However VFR returns by 12Z Wed, and should VFR into the mid afternoon before another round of showers and storms crosses the area through the evening. Fog and low cigs will be widespread Wed night with a period of IFR-LIFR possible at any terminals. Long Term...Thursday may continue to see some degree of flight restrictions in the morning with low ceilings a few showers and storms, but conditions will improve to VFR by the afternoon. Mainly VFR Friday through the weekend with the exception of nighttime/early morning valley fog. A weak front approaching from the north late Saturday could bring a few showers to northern areas, but this would be primarily for HIE. && .MARINE... Short Term...SW flow persists tonight into Wed evening, and could see gusts in the 20-25 kt range, but should stay below SCA for the most part. Winds will shift to W and diminish Wed night. Long Term...SCA conditions are not expected. A weak cold front crosses the waters on Thursday, switching winds to NW to N later in the day into Thursday night, but these will become onshore by Friday afternoon as the seabreeze develops. Another weak front crosses late Saturday and could result in another brief wind shift to the NW. High pressure then settles over the waters Sunday into Monday before low pressure brings increasing precip chances by Tuesday. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...Heat Advisory from noon to 6 PM EDT Wednesday for MEZ012- 018>024-033. NH...Heat Advisory from noon to 6 PM EDT Wednesday for NHZ004-006- 008>010-012>015. MARINE...None. && $$ SYNOPSIS... NEAR TERM...Cempa/Schroeter SHORT TERM...Cempa LONG TERM...Combs AVIATION... MARINE...
Area Forecast Discussion
National Weather Service Louisville KY
956 PM EDT Tue Jul 16 2024 .KEY MESSAGES... * Thunderstorms redeveloping overnight could cause locally gusty winds and heavy rainfall. * Cooler temps in the 80s for Thursday into the end of the week. * Storm chances return early next week. && .UPDATE... Issued at 956 PM EDT Tue Jul 16 2024 Tricky forecast overnight with MCS and associated MCV coming out of the Ozarks. For now we are left high and dry in the Ohio Valley, with low confidence in the placement of any convection overnight. Satellite imagery, sfc observations, and SPC mesoanalysis suggest the most favorable areas for storms overnight will be roughly along the Western Kentucky and Bluegrass Parkways. This is farther south than previously advertised, and gets into areas with rainfall deficits so far this summer rather than surpluses. Additionally, the hi-res models suggest a more progressive look, resulting in precip totals of less than 1 inch for most. That being said, we do expect thunderstorms to fire around midnight or just after, mainly moving across central Kentucky. Locally heavy rainfall and minor flooding are still possible, but impacts should be brief and limited. Therefore the Flood Watch will be cancelled. && .SHORT TERM /THROUGH WEDNESDAY/... Issued at 301 PM EDT Tue Jul 16 2024 Plenty of convective cloud debris has hung around today, from both the morning line of showers and storms, as well as from the stationary cluster of convection over Illinois today. This cloud cover has help limit our sfc heating, with most obs in the upper 80s so far this morning. Less cloud cover over the Bluegrass has allowed that area to warm into the 90s. Besides the Bluegrass region, heat indices have not reached the triple digits, so the Heat Advisory will be let go with this forecast package. It`ll still be very warm and muggy this afternoon, specailly in the Bluegrass. For the rest of this afternoon, a few isolated pop-up showers or storms will be possible in an unstable airmass. The latest HRRR was suggesting a few isolated cells over in the Bluegrass later this afternoon, which is the area with the best heating today, so it seems possible. Otherwise, the higher precip chances will come tonight. ===== Tonight ===== A very slow moving frontal boundary will still be extending from central Missouri to central Indiana tonight, but a very muggy airmass ahead (south) of the front will support shower and storm development overnight. While run-to-run consistency has been a struggle, there is good agreement on our area having very high PWATs, with over a 60-70% probability of exceeding 2 inches. While QPF has come down slightly in today`s runs, the environment overnight will be favorable for heavy rainfall, along with some possible training as showers and storms line up and move parallel to the frontal boundary to our north. The flood watch will remain as is for now, especially given the concern for any nighttime flooding from heavy rainers. As for the storm potential, most model soundings depict elevated instability, with stable air in the lowest levels. Not too concerned for severe risk tonight, but perhaps we could have a few gusty winds with any stronger core that develops and results in a water-logged downburst. The main timing for overnight activity will be after midnight and before 12z tomorrow. ===== Wednesday ===== We`ll remain in the same type of airmass tomorrow, as the front will still be to our north. PWATs will remain quite high, with another round of isolated to scattered showers and storms for the day as we become unstable in the afternoon. While we`ll have plenty of instability for storms to work with, we will be lacking shear, leaving most storms to be messy and unorganized. Soundings show a bit more saturation in the columns, resulting in lower DCAPE values. Will mostly expect garden variety storms tomorrow, but a few strong storms could pack a punch of wind. Otherwise, overall severe threat is low for tomorrow. Eventually the front will begin to make its way through our area late in the day, but it will only make it to around the Ohio River towards the end of the short term period. && .LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/... Issued at 301 PM EDT Tue Jul 16 2024 By Wednesday night, the cold front should begin entering the Commonwealth, draped roughly parallel along the OH River, as isolated to scattered showers and thunderstorms out ahead of the front begin to wane across the CWA with the setting sun. Cold front is progged to be exiting our area by sunrise Thursday morning, allowing for surface high pressure to build in across the region. This will bring some relief to the recent sultry conditions, as afternoon max temperatures reach into the low 80s Thursday while increasing a couple degrees each day into the weekend. Drier air will also result in surface dew points falling into the low 60s, which is quite comfortable for July standards. The aforementioned cold front stalls over the northern Gulf States before beginning to waver back northward. Our area appears to remain on the cooler side of this boundary through the weekend but close enough to warrant slight chance mention of showers and possible thunderstorms, mainly for areas south of the Parkways. Chances of showers and thunderstorms increase going into the beginning of next week as the OH Valley resides between synoptic scale features: one being the cut-off low over the Central Plains, next is the Bermuda high over the Atlantic, and last is our position south of the wavering boundary. This set up will allow for rich moist air advection along return flow and a destabilized environment. && .AVIATION /00Z TAFS THROUGH 06Z FRIDAY/... Issued at 756 PM EDT Tue Jul 16 2024 VFR evening with W to SW winds diminishing after sunset. Main challenge is timing and placement of storms developing overnight. Look for convection to impact BWG beginning around 05Z, and pushing east into LEX and RGA around 07Z. Will handle those with TEMPO groups. Less confident in SDF as the focus is mainly south, but will straddle daybreak with a PROB30 for storms. Heaviest part of the storms will likely drop vis into IFR, but that will be brief so will just go with low-end MVFR. Low ceilings will linger well into Wednesday morning, perhaps with some light precipitation, but expect the atmosphere to recover around midday. Cigs should lift back to VFR, but the muggy air mass and lingering boundaries will support enough of a storm chance to warrant a PROB30 for TS/CB after 18Z. Winds generally due west around 10 kt. && .LMK WATCHES/WARNINGS/ADVISORIES... KY...None. IN...None. && $$ UPDATE...RAS SHORT TERM...CJP LONG TERM...CRG AVIATION...RAS
Area Forecast Discussion...UPDATED
National Weather Service Little Rock AR
610 PM CDT Tue Jul 16 2024 ...New AVIATION... .SHORT TERM... (This evening through Thursday) Issued at 240 PM CDT Tue Jul 16 2024 The overall synoptic pattern had Arkansas was on the eastern edge of an upper ridge this morning. The ridge is retrograding and amplifying over the western US, which will result in a trof taking its place over the midsection of the country. Ultimately Arkansas will end up under a NW-W flow aloft. A cold front will be moving out of the Plains and making its way into Arkansas tomorrow. The front will take its time and may not make it out of the forecast area until late tomorrow night into the early hours of Thursday morning. Thunderstorm chances will increase across the state tomorrow, reaching the highest POPs tomorrow night. The only lingering question is what the rain chances will look like overnight into early tomorrow morning. NAM is rather aggressive at developing showers and thunderstorms along outflow coming out of MO/OK later this evening, and the HRRR follows suit, albeit with the convection further north and with somewhat less coverage. With that in mind, I have introduced some lower grade POPs further south toward central AR by morning...faster than the NBM brings anything into the area. Last but not least, afternoon heat index values across the southern counties tomorrow will top 105...so I went ahead and issued a heat advisory for those areas. && .LONG TERM... (Thursday Night through next Tuesday) Issued at 240 PM CDT Tue Jul 16 2024 Guidance remains in relatively good agreement this afternoon and any changes to the extended period will be relatively minor. Confidence remains on the higher side that temperatures will actually average below seasonal average with at least some chances of precipitation, especially in the latter part of the period. Period starts with a highly amplified pattern in place that is highlighted by upper ridging over the western CONUS and subsequent downstream troughing stretching from the western gulf coast NE to the eastern Great Lakes. Surface boundary forecast to be located over northern Louisiana with ongoing chances of scattered showers and thunderstorms over the south through Friday. Additional precip amounts will be minimal with just a few hundredths of an inch possible. Front will remain quasi-stationary over northern Louisiana before starting to retreat back to the north and stalling out over south Arkansas Sunday. Most of the state, with the exception of the far south, will be dry on Saturday before widespread precipitation chances return on Sunday. Precipitation amounts are not expected to be very high but some areas could pick upwards of a half an inch. A slightly cooler but noticeably drier airmass will overspread the region behind the front with both high and low temperatures below average. Moisture levels will begin to increase as the boundary moves north but temperatures should stay below average with increased cloud cover and precipitation chances in place. && .AVIATION... (00Z TAFS) Issued at 609 PM CDT Tue Jul 16 2024 Chances for convection increase late this afternoon and through the evening hrs across NRN sections...then gradually shifting south during the overnight/morning hrs for the central to SRN terminals. By Wed afternoon...expect a break in precip...but additional convection may redevelop during the heat of the afternoon. && .PRELIMINARY POINT TEMPS/POPS... Batesville AR 73 87 68 84 / 70 80 60 30 Camden AR 76 96 70 86 / 10 30 60 70 Harrison AR 69 84 65 82 / 80 80 30 10 Hot Springs AR 74 94 70 85 / 30 50 70 60 Little Rock AR 75 91 72 84 / 40 50 70 50 Monticello AR 78 96 72 86 / 0 40 60 70 Mount Ida AR 73 93 68 84 / 30 50 70 50 Mountain Home AR 71 84 67 84 / 80 80 40 10 Newport AR 73 88 70 83 / 60 70 60 30 Pine Bluff AR 76 94 71 83 / 10 40 70 60 Russellville AR 73 90 70 85 / 60 60 70 40 Searcy AR 73 88 70 83 / 60 70 70 40 Stuttgart AR 74 90 73 82 / 20 40 70 50 && .LZK WATCHES/WARNINGS/ADVISORIES... Heat Advisory until 8 PM CDT this evening for ARZ004-052-053-056- 057-062>069-103-112-113-123-137-140-141-203-212-213-221>223-237- 240-241-313-340-341. Excessive Heat Warning until 8 PM CDT this evening for ARZ005>008-014>017-024-025-031>034-039-042>047-054-055-121-122- 130-138-230-238. Heat Advisory from 11 AM to 8 PM CDT Wednesday for ARZ052-053- 062>069. && $$ SHORT TERM...53 LONG TERM....56 AVIATION...62
Area Forecast Discussion
National Weather Service Morristown TN
1022 PM EDT Tue Jul 16 2024 ...New UPDATE... .UPDATE... Issued at 1022 PM EDT Tue Jul 16 2024 Overall, the forecast is holding up well. The main change was lowering the surface temperatures for tonight. This is due to the widespread cloud cover across much of the region. This alongside some scattered showers definitely inhibited the heating late this evening. We can also expect some higher cloud coverage tonight into tomorrow morning as indicated by satellite imagery. Chances of precipitation rise throughout the morning, however the highest chances are in the northern areas of our region and along the mountains. Patchy fog is also possible, mainly in areas that saw rain today. && .SHORT TERM... (This evening through Wednesday night) Issued at 229 PM EDT Tue Jul 16 2024 Key Messages: 1. Isolated to scattered showers and thunderstorms this evening, tonight, and Wednesday. 2. Increasing humidity will result in heat index values near or over 100F. Discussion: To say that the short term forecast is uncertain would be an understatement. There are many complicating factors to consider. First, an upper-level jet will strengthen overnight with a jet streak of over 100 kt. A strong shortwave will amplify troughing across the Upper Mississippi Valley and Great Lakes, too. This will enhance ascent across the Great Lakes and Ohio Valley with increasing SW/WSW 850 mb winds in response. At the surface, there is a defined outflow boundary near the Interstate 40 corridor from early morning convection across western KY. Ongoing convection along the deformation axis and higher terrain of the plateau will also result in localized outflow boundaries that will linger across the area overnight. As WSW/SW 850 mb winds increase late tonight, this will increase localized convergence along these boundaries with the potential for isolated to scattered convection during the overnight and early Wednesday morning time-frame. Confidence in timing and location is very uncertain because of these mesoscale boundaries. Shortwave vort maxima will lower heights across the region on Wednesday with the potential for increasing coverage of isolated to scattered showers and thunderstorms. A surface cold front will shift southeast late in the day through Wednesday night with the potential for scattered showers and thunderstorms along this boundary. RAP forecast soundings are indicating MLCAPE of 2000 to 3000 J/Kg across the area on Wednesday with DCAPE of 800 to 1000 J/Kg. PW values will also increase late Wednesday ahead of the front near 2.0 inches. This will produce a low severe risk with localized strong wind gusts in addition to frequent lightning and heavy rain rates. While not everyone will see abundant rain, this is expected to be the most widespread convection across the area in weeks. && .LONG TERM... (Thursday through next Tuesday) Issued at 229 PM EDT Tue Jul 16 2024 Key Messages: 1. A frontal passage will keep widespread showers and storms across the area through Thursday. 2. A break from the heat is expected behind the front, with slightly below normal temperatures Thursday through Tuesday. Good chances for rainfall will return late Friday into Saturday and again Sunday through Tuesday Discussion: At the beginning of the extended forecast A cold front will be over or near the forecast area ahead of a large upper trough moving south from the northeast states. The big forecast question for the beginning of the extended forecast is how far south does the frontal boundary move Thursday. If it is still in the vicinity expect another day of widespread showers and storms. However, if it pushes too far south then the bulk of the precip will be to the south and we will be much drier. NBM POPs suggest the front is still in the vicinity Thursday so will continue with that trend. Storm total QPF ending Thursday has most locations around 1 to 1.5 inches of much needed rainfall. After Thursday the front will have shifted south but shortwave energy moving through the upper flow and south to southeast flow off the Gulf of Mexico will keep a chance of showers and storms in the afternoon and evening Friday...higher near the mountains. Models want to bring a surface low along the front into Alabama later Friday and lift it northward Saturday. As the front lifts back north through and over the forecast area and eventually remain stationary Saturday, rain chances increase. The moist flow will keep diurnal afternoon and evening showers and storms across the region through Sunday. Rain chances will be highest in the eastern mountains and lowest northern plateau and Virginia through Sunday. Highs Thursday through Sunday will be a few degrees below normal and mainly in the lower 80s northeast to mid and upper 80s central and southwest. For Monday and Tuesday the frontal boundary lifts farther north into the Ohio Valley Monday and Tuesday as the Bermuda high stays strong along the southeast coast. There still should be elevated precipitation chances due to higher than normal moisture values across the area. The position of the High pressure area helps Gulf moisture stream into the southeastern U.S. The convection will be driven by daytime heating. Temperatures the last two days of the extended forecast will be slightly below normal during this time. High temps will generally be in the mid 80s to upper 80s. && .AVIATION... (00Z TAFS) Issued at 718 PM EDT Tue Jul 16 2024 Currently, there are showers and storms west of TYS and TRI. It is unclear if they will hold together and/or make it to the terminals overnight. The current indications are for them to fall apart with little impact. Based on this trend, VFR is expected to prevail with fog development mainly being in places that saw rain measurable rain today. Shortly after sunrise, there are indications for additional shower development around TRI that could create MVFR conditions, but confidence is limited. Through the afternoon, southwesterly winds are expected with some higher gusts at TYS and TRI. Late in the afternoon, scattered storms are likely to approach the terminals, but timing is uncertain. && .PRELIMINARY POINT TEMPS/POPS... Chattanooga Airport, TN 73 94 73 89 / 20 80 70 80 Knoxville McGhee Tyson Airport, TN 73 91 71 85 / 50 80 80 80 Oak Ridge, TN 71 91 71 84 / 20 80 80 70 Tri Cities Airport, TN 69 89 69 80 / 60 90 80 70 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$ SHORT TERM...BW/HD LONG TERM....TD AVIATION...BW/HD
Area Forecast Discussion
National Weather Service Pocatello ID
219 PM MDT Tue Jul 16 2024 .SHORT TERM...Today through Wednesday Night. The heat is back on today and tomorrow as highs continue to slowly rise. Many will go from the upper 80s to low and mid 90s this afternoon to more widespread low to mid 90s on Wednesday afternoon. Even though high pressure is generally in control, it has slipped just far enough to our southeast and will be flattened just a bit more by a shortwave trough moving into the PNW tomorrow. This will allow some monsoonal moisture to creep into our area. The best chance, about a 10 to 20 percent chance, for that today will be along the Wyoming state line. Wind gusts today are expected to be "typical" afternoon gusts around 15 to 20 mph through the eastern Magic Valley and Snake Plain. Gusts associated with any convection we can get going would be closer to the 30 to 40 mph range. As for continued haze across the area and any smoke impacts, the HRRR is showing reduced visibility tonight down to about 3 to 7 miles through parts of the Wood River valley, eastern Magic Valley, and lower Snake Plain from the Bench Lake fire. The NAM and NBM don`t seem to be picking up on this at all, but the HRRR generally does a bit of a better job in this aspect. So, we will see how that pans out overnight to get a better feel for model verification (and a reality check on my own bias). The potential for isolated afternoon convection continues on Wednesday for parts of the Eastern Highlands, but also for portions of the Magic Valley, South Hills, and Central Mountains. These will likely be dry storms again, as monsoonal moisture is quite limited, but convective-related wind gusts will be in the 35 to 45 mph for many. This may push closer to 50 to 55 mph in parts of the Magic Valley and South Hills. AMM .LONG TERM...Thursday through Tuesday. The long term pattern remains relatively unchanged. Ensemble clusters maintain ridge of high pressure over the Great Basin throughout. Weak moisture rotating around the ridge may provide for isolated mainly higher elevation thunderstorms each day. Forecast temperatures remain stable, still hot but generally below our recent excessive heat event. There may be a few zones that flirt with Heat Advisory conditions, but relatively cool low temperatures below 65 degrees MOST areas will mitigate some of the potential. DMH && .AVIATION...There is still a minor potential for convection, with the main threat until about 02Z for KDIJ, and even less so for KIDA. Outflow potential to about 30kts. That said, not sure there is enough confidence to include VCTS at either location. Some of the high res model solutions also depict weak overnight convection. Again, not enough confidence to include any mention at this time. The main overarching concern will be smoke impacts. Satellite imagery shows widespread swath of smoke/haze from upstream wildfires. HRRR Smoke has been persistent and robust with smoke influence impacting KSUN overnight under downslope northerly flow regime. Have brought KSUN down to at least MVFR VSBY overnight, with expectations for occasional IFR. KBYI also likely to see occasional obscuration overnight, but kept VSBY at VFR. KPIH and KIDA will also have potential, but expectations remain VFR at this time. DMH && .FIRE WEATHER...Temperatures will continue to slowly climb through the rest of the week and at least a 10 to 20 percent chance of afternoon convection will persist. These chances will be mostly confined to parts of the Eastern Highlands along the Wyoming border. These storms are expected to be dry storms with the potential for convective wind gusts of 30 to 40 mph. By Wednesday afternoon, parts of the Magic Valley, South Hills, and Central Mountains will join in on the isolated convection. These will likely be dry storms once again, though wind gusts with these will range from 35 to 45 mph with the potential for strong gusts of 50 to 55 mph in the Magic Valley and South Hills. The SPC and GACC have also highlighted portions of fire weather zones 422, 425, 427, 475, and 476 tomorrow for the isolated dry thunderstorm chances mentioned above. In the second half of the week, we will keep around the chance for isolated convection each afternoon. Otherwise, synoptic wind gusts will be in the 15 to 20 mph range each day with min RHs ranging from mid teens to mid 20s. AMM && .PIH WATCHES/WARNINGS/ADVISORIES... None. && $$
Area Forecast Discussion
National Weather Service Tucson AZ
255 PM MST Tue Jul 16 2024 .SYNOPSIS...Temperatures slightly above normal through the rest of this week, with typical mid July moisture levels across the region. This will result in the daily chances for showers and thunderstorms. The main threats will continue to be strong gusty outflow winds and heavy rainfall leading to localized flash flooding. && .DISCUSSION...We started this morning with some weak showers/ thunderstorms across Southeast Arizona, and we will likely finish the day with more established stronger storms. The storm activity we saw this morning was associated with a mid-level MCV that tracked across southern Pima county and eventually moved into NW Sonora Mexico. Typically in the wake of these types of features, we see a subsidence field that hinders storm development. In this case though, it is far enough away where it shouldn`t have too much impact on Southeast Arizona this afternoon. There are three things that are around to help thunderstorm activity/development today. The overall pattern is defined by a mid-upper high centered over central New Mexico with the flow around this feature resulting in a weak diffluent area across Southeast Arizona. A trough moving into the Pacific Northwest will force this high to align more into a NW-SE orientation, resulting in an area of weak stretching deformation assisting with the overall lift. The third thing of note today is a weak vort max in northern Chihuahua Mexico that will continue to rotate around the base of the upper high and push into the far SE corner of the state this evening. So, with this in mind...our thinking is that we will see thunderstorms develop NE of Tucson this afternoon (which we are already watching develop via radar). The latest 16/20Z HRRR has these storms moving off the higher terrain into the Upper Gila River valley between 4-6 pm. I would expect these storms to produce a strong outflow as it moves off the terrain, potentially impacting Safford. Otherwise, thunderstorms east and southeast of Tucson will be pulse-type and/or delayed until the late afternoon and evening as we start to see the impact of the approaching vort max. I have confidence in the University of Arizona 16/12Z WRF-RR run since it has been resolving the timing/location of convection very well the past few days. This run delays the majority of the activity well into the evening hours. Tucson will likely stay on the northern periphery of the majority of storm activity, just clipping the Tucson Metro Area late (between 8-10 pm MST) this evening. Drier air in the mid-levels of the storm residing in NM and will push west and entrain into the thunderstorms along the Arizona/New Mexico border. The 16/12Z HREF is suggesting a 50-70 percent likelihood of wind gusts in excess of 30+ kts from storms east of Tucson today. It should be noted that 16/00Z HREF run had a 10 percent chance of wind gusts in excess of 50 kts but has backed off on this run. The 16/12Z HREF is also pinpointing the heaviest rainfall to occur S and SE of Tucson in Cochise and Santa Cruz counties this afternoon/evening with a 10-30 percent chance of 3-hr rainfall amounts in excess of 1 inch, and even a 10 percent chance of rainfall in excess of 3 inches along the International Border. In general, the main threat from storms today will be strong and gusty thunderstorm outflows, but heavy rainfall is also in the mix...especially S and SE of Tucson in Cochise and Santa Cruz county where there is a better mix of moisture and will be impacted by the weak vort max later this evening. Otherwise, we will see a continued chance of mainly afternoon and evening thunderstorms persist into early next week. The upper high center will slowly drift into NW Arizona by late this week, then near southern Nevada by the weekend. This puts us in into a more favorable pattern for strong storms as the flow will move off the Mogollon Rim/higher terrain into SE AZ. However, resolving which day that will be more active at this juncture is difficult. && .AVIATION...Valid through 18/00Z. SCT-BKN clouds at 8k-12k ft AGL thru 17/05Z and again aft 17/18Z, with diminishing cloud cover between 17/05Z and 17/18Z. SCT TSRA/SHRA thru 17/05Z, mainly east through south of KTUS and in the White Mountains. SCT TSRA/SHRA developing again aft 17/19Z. MVFR conditions in TSRA, with mountain obscurations, vsby reductions and wind gusts to 40+ knots. Outside of TSRA, SFC wind at most locations 12 knots or less favoring a WLY/NWLY direction during the afternoon and early evening hours and variable in direction at other times. The exception will be in the upper Gila River valley near KSAD where WLY/NWLY SFC wind will be 16-22 kts with gusts to 32 kts thru 17/04Z. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...Deeper moisture remains across southeast Arizona, with typical mid July moisture levels expected through at least the upcoming weekend. This will result in the daily cycle of mainly afternoon and evening showers and thunderstorms. The main threats will be strong, gusty and erratic outflow winds and heavy rainfall leading to localized flash flooding. Minimum relative humidity values will be 20-30 percent in most lower elevation locations and 25-40 percent in mountain areas. Away from thunderstorms, 20-foot winds will generally be 15 mph or less, with afternoon/early evening gusts to 20-25 mph and light winds overnight. Wind direction during the afternoon will primarily be west to northwest into the weekend. The exception will be in the upper Gila River valley around Safford, where afternoon/early evening winds will be west-northwest around 20 mph and gusts to 30-35 mph through this evening. && .TWC WATCHES/WARNINGS/ADVISORIES...None. && $$ Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson