Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 06/27/22


Area Forecast Discussion
National Weather Service Cleveland OH
943 PM EDT Sun Jun 26 2022 .SYNOPSIS... A cold front located from Toronto to Akron to Columbus will continue to move eastward through midnight. High pressure then builds into the region from the Central Plains Monday into Tuesday. A cold front moves to near the north shore of Lake Erie on Wednesday as it weakens. && .NEAR TERM /THROUGH MONDAY NIGHT/... A cold front located from Toronto to Akron to Columbus will continue to move eastward through midnight. A couple showers were located along it but should only cause brief heavy rainfall. After midnight all showers should be east of the CWA with dry conditions expected. Previous Discussion... The cold front is now oriented along a SE Michigan, NW Ohio, SE Indiana line. Increased low-level convergence ahead of this boundary combined with upper divergence and mid-level height falls on the southern flank of a shortwave trough swinging into the central Great Lakes is initiating widely scattered showers and thunderstorms over north central and NE Ohio. The airmass is only weakly to moderately unstable, but uncapped, allowing the convection to develop. The latest RAP analysis depicts SBCAPE of 1500-2500 J/Kg over east central Ohio where there have been more breaks in the overcast, but MLCAPE values remain poor at only 500-1000 J/Kg. This is due to both today`s cloud cover and flat mid-level lapse rates only averaging 5.5 C/Km since we do not have an EML in place and mid-levels are quite warm. This meager instability combined with only weak deep layer shear of 20-25 knots will not support much in the way of organized convection or large storm coverage, so expect the convection to remain scattered and only loosely organized at best as it propagates east the rest of the afternoon. The latest SWODY1 keeps a marginal risk for isolated downbursts over far eastern Ohio and western PA, and this remains reasonable since we cannot entirely rule out something localized. Additionally, we will continue to monitor for locally heavy rainfall/localized flash flooding since PWATs are running 1.9 to 2.1 inches, freezing levels are high with deep warm cloud layers, and there is a fairly skinny CAPE profile with 850-300 mb mean flow only supporting storm motions of 20-25 knots. The cold front will be positioned along the OH/PA border by about 01Z with any lingering showers and thunderstorms exiting quickly east. As the mid/upper trough axis swings farther into the central and eastern Great Lakes tonight and early Monday while deepening a bit more, much cooler and drier air will quickly advect into the region. This will be aided by a strong 1026 mb surface high over the Midwest tonight building east into the Great Lakes Monday and becoming centered over the Ohio Valley by Monday night. The end result of all of this is skies clearing from west to east tonight and mostly clear conditions continuing Monday and Monday night with pleasantly cool, below normal, temperatures. Highs Monday will average mid/upper 70s areawide with low 70s in NW PA. Lows tonight will cool into the mid/upper 50s except low 60s near the lakeshore where onshore flow off of the 70 degree lake water will keep conditions milder. Lows Monday night will dip into the low/mid 50s areawide due to clear skies and light winds beneath the surface high. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... High pressure will be the primary driver of weather throughout the short term period, keeping conditions across the area dry. On Wednesday, an upper level trough will dip across the Great Lakes region as a low pressure system moves east in Canada. This will result in a cold front approach the area, however with the strong high still in place, all showers associated with this system should remain north of the area. Winds with a northerly component will persist on Tuesday, allowing highs to reach into the upper 70s to low 80s. On Wednesday however, winds will shift to southwesterly on the back side of the surface high and usher in much warmer temperatures with highs on Wednesday reaching into the mid to upper 80s. Overnight lows will follow a similar pattern, dropping into the mid to upper 50s on Tuesday night and then into the low to mid 60s on Wednesday night. && .LONG TERM /THURSDAY THROUGH SUNDAY/... As high pressure lingers of the area on Thursday into the first half of Friday, temperatures are expected to continue to rise, reaching into the low to mid 90s on Thursday and Friday. On Friday afternoon, a cold front associated with a low pressure over Quebec will begin to move east across the area, which will mark the next chance of appreciable rainfall across the area. The front will be slow to meander through the area, keeping the chance of showers and thunderstorms in the forecast through Saturday afternoon. Diurnal instability trends will need to be monitored as any enhanced instability will live increase the strength of any storms that develop along and ahead of the front. However, if this front speeds up at all, highs on Friday may be a bit cooler than currently forecast, which may limit some instability, and vice versa. Once the front passes, temperatures will cool a bit and conditions will dry out for the last half of the weekend. && .AVIATION /00Z Monday THROUGH Friday/... We will watch the eastward progression of a cold front that was located from central Lake Erie to near Elyria to Mount Gilead as of 2345Z. There could be a couple showers along this boundary but dont think they will amount to much since we are losing heating with the setting sun. This front should be east of the CWA by midnight taking all the rain eastward with it. Maybe some patchy MVFR ceilings near the showers. Otherwise we should be VFR through the TAF period. However we will need to monitor for some patchy fog where it did rain this afternoon/evening. Nights are short right now so any fog that can develop should be brief but could drop visibilities to MVFR levels around sunrise, especially near KCAK and KYNG. Winds become west to northwest for all locations in the wake of the front. Speeds generally 8 to 14 knots. A little stronger near the lakeshore with gusts to around 20 knots. All locations may gusts to around 20 knots through Monday morning. Outlook...Non-VFR in scattered thunderstorms Friday. && .MARINE... As a cold front moves east across the lake this afternoon/early evening, winds behind the boundary will become northwesterly and increase to 15-25 knots, allowing waves to build for much of the nearshore waters to 3-5 feet. As a result, a Small Craft Advisory has been issued for all near shore zones beginning this evening and continuing into tomorrow. In conjunction, this will also create a high of rip currents, making swimming conditions hazardous. A Beach Hazards Statement has been issued for this. Scattered showers and thunderstorms are possible through this evening, particularly for the central and eastern basins. On Monday, high pressure will begin to build over the area, with winds initially remaining out of the northwest at 15-20 knots, but gradually weakening throughout the day. By Monday night, winds will become light and variable, returning Lake Erie to calm marine conditions. As high pressure shifts east on Tuesday into Wednesday, winds will shift to southwesterly at 10-15 knots on the back end of the high. These conditions are expected to persist into Friday, before another cold front moves across the area at the beginning of the weekend, marking another shift in winds. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...Beach Hazards Statement through Monday morning for OHZ007. Beach Hazards Statement through Monday afternoon for OHZ009. Beach Hazards Statement through Monday evening for OHZ010>012. Beach Hazards Statement through Monday evening for OHZ089. PA...Beach Hazards Statement through Monday evening for PAZ001. MARINE...Small Craft Advisory until 11 AM EDT Monday for LEZ142-143. Small Craft Advisory until 2 PM EDT Monday for LEZ144. Small Craft Advisory until 8 PM EDT Monday for LEZ145>147. Small Craft Advisory until 8 PM EDT Monday for LEZ148-149. && $$ SYNOPSIS...Garuckas/MM NEAR TERM...Garuckas/MM SHORT TERM...Campbell LONG TERM...Campbell AVIATION...MM MARINE...Campbell
AREA FORECAST DISCUSSION
National Weather Service Morristown TN
1057 PM EDT Sun Jun 26 2022 .UPDATE... EVENING UPDATE. && .DISCUSSION... The convective activity associated with a surface boundary has began to decrease in coverage and intensity with the loss of daytime heating tonight. Most recent SPC mesoanalysis data suggest surface based CAPE has fallen to around 500-1000 J/kg. As upper level support remains situated well to the north, the marginal risk has been removed. This evening update focused primarily on adjustments to PoPs based on recent trends. Some additional activity will continue overnight as the front meanders E/SE and be primarily isolated and spotty in nature but could become more scattered in the morning hours as suggested by some CAMs. Recent observations suggest very little lightning is present across the area so also updated the wording from chance to only slight chance thunder... which may even be a little generous. Otherwise, the forecast remains pretty well on track. Updated zones and HWO have been sent. KRS && .AVIATION... 00Z TAF DISCUSSION. Numerous showers and storms on going across eastern Tennessee associated with an approaching cold front. The best chances for showers and thunderstorms to impact terminals will continue through roughly 5Z. It remains possible that any stronger shower/storm could result in some reduced flight conditions, however, not expecting predominant MVFR conditions until earlier Monday morning. TRI/TYS remain the main focus for MVFR cigs but CHA may see a brief period as well. Some guidance shows additional showers moving through NE TN and SW VA Monday morning which has been included with a prob30 at TRI. This could also result in some fog. Northerly winds upwards of 10 kts tomorrow afternoon as cigs return to VFR. KRS && .PREV DISCUSSION... /ISSUED 334 PM EDT Sun Jun 26 2022/ SHORT TERM (This Evening through Monday)... Key Messages: 1. Isolated strong to possibly severe storms through this evening. Main concerns are localized flash flooding and strong/gusty winds of 40-50 mph. 2. Frontal boundary moves across the area Monday morning with cooler air spreading into the region. Discussion: Meso analysis shows a quasi-stationary outflow boundary from the morning convection between GKT and MOR northward. Fairly unstable air mass along and west and south of this boundary with MLCAPES of 1500-2200 with very moist air with PWS approaching 2 inches. DCAPES limited between 500 and 600. Shear is essentially no existant making storm mode more pulse celluar to multi-cell in nature. Message remains that the main concern with these storms are localized flash flooding due to the slow movement of the storms and strong/gusty winds of 40-50 mph due to precipitation loading enhancing downdrafts. These winds can produce isolated downed trees and power lines. Similar to yesterdays storms but more coverage. Latest HREF and HRRR models show widespread shower and thunderstorm activity over much of the area through this evening producing some much needed rainfall. This activity is associated with an approaching frontal boundary with weak 850mb southerly flow/transport winds. Upper level forcing is quite weak with best dynamics well north of the area thus convection will weaken significantly by around sunset. For late Tonight, frontal boundary will move into the Plateau counties. Plenty of moisture and weakening instability can be expected overnight ahead of this boundary. Isolated to scattered showers and possibly a thunderstorm is expected. For Monday, frontal boundary moves across the area during the morning. Greatest coverage of shower and storm redevelopment will be generally east of interstate 40/75 corridor. Frontal boundary will exit the far east Tennessee Mountains and southwest North Carolina by mid to late afternoon ending chances of convection. Drier air will advect into the western and northern sections of the southwest Virginia and east Tennessee during the afternoon with sunshine returing in the afternoon. More pleasant temperatures and humidity levels are expected late in the day. LONG TERM (Monday Night through Sunday)... Key Messages: 1. Below normal temperatures and stable conditions Tuesday with a cold front south of the area. 2. A warming trend through the rest of the work week, with rain chances increasing late in the week. Discussion: Front will continue to slowly move southeastward across the southeast US. Front may remain close enough to the southern Appalachian Mountains Tuesday into Wednesday that we get some precipitation with an inverted trough over the area. Best chances will be along the mountains and across southeast TN. Have kept PoP chances low as it looks like any activity that does occur would be isolated in nature. There will be cooler and more seasonable temperatures for the first half of the work week under the more stable air mass. Temperatures will begin to warm up during the middle of the week, and we`ll be flirting with 90`s Thursday through the rest of the weekend. With the low level moisture remaining in place with the surface high off the Atlantic coast can`t completely eliminate some isolated diurnal convection developing, but widespread rain is not forecast through Thursday. Better chances for convection will come as we near the weekend time frame with increased moisture flow ahead of an approaching front. Have undercut PoP guidance for this weekend, as it seems there`s some discrepancies with the strength and timing of the low pressure system, and associated frontal boundary as it moves across the eastern portion of North America. && .PRELIMINARY POINT TEMPS/POPS... Chattanooga Airport, TN 72 86 66 84 68 / 50 40 10 20 10 Knoxville McGhee Tyson Airport, TN 71 83 63 84 67 / 80 50 10 20 10 Oak Ridge, TN 70 84 62 84 65 / 80 30 0 10 10 Tri Cities Airport, TN 67 81 55 83 61 / 60 50 0 10 10 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$
Area Forecast Discussion
National Weather Service Pueblo CO
320 PM MDT Sun Jun 26 2022 .SHORT TERM...(This evening through Monday) Issued at 312 PM MDT Sun Jun 26 2022 Key messages: 1) Low chance for flash flooding over the Chalk Cliffs and the Decker and Hayden Pass burn scars this evening. 2) Isolated to scattered showers and thunderstorms tomorrow afternoon over the mountains and the Pikes Peak region. Currently: Main focus of the stratiform precipitation regime is focused over the southern San Luis Valley and extending over eastern Las Animas County. Low stratus, drizzle, and light rain have been observed over the northern I-25 corridor, as well. Some convective showers are being observed over the Continental Divide extending over northern Park County, which will eventually propagate over the Pikes Peak region. Tonight and Tomorrow: A weak wave, which has initiated convection to the west, will continue to propagate to the east-southeast, increasing shower and thunderstorm potential over the Pike Peak region and Fremont County. Recent sky cover clearing over northwestern Teller County and Park County have allowed CAPE values to increase to greater than 500 J/kg. While not the highest impact, there is the potential for locally heavy rainfall rates and cloud to ground lightning strikes. Burn scar flash flooding will be possible as the showers and thunderstorms propagate to the southeast, with the main scars at risk being the Decker, Hayden Pass, and Junkins burn scar. The Chalk Cliffs in Chaffee County are also at risk. However, the risk still seems low across all those aforementioned areas. Southeasterly winds will keep the adjacent plains socked under overcast cloud cover and the eastern mountains, whereas mid-level moisture will keep broken to overcast clouds across the rest of the region. The cloud cover will keep the low temperatures tonight right around average for this time of year, even though we have this cold air mass. Lingering showers will continue over the far southeastern plains throughout the overnight in response to a continuous stream of PVA and WAA. Less precipitation coverage is expected tomorrow, with scattered showers over the mountains and over the Pikes Peak Region. With that being said, there is a low end shot at burn scar flash flooding if one of those scattered thunderstorms develop over one of them. CAPE values range from 500 to 1000 J/kg over the mountain. 0-6km bulk shear values are close to 40kts in response to this NW flow regime. So overall thoughts with this pattern and environment... isolated showers and thunderstorms are expected, if one of those thunderstorms develops over the better shear over El Paso County a stronger storm is possible. Main hazards will be locally heavy rainfall, small hail, and wind gusts up to 45 mph. Warmer temperatures are expected tomorrow with 80s returning to the plains and the upper Arkansas River Valley, and the 70s over the rest of the mountain valleys. .LONG TERM...(Monday night through Sunday) Issued at 312 PM MDT Sun Jun 26 2022 Key messages: 1) Isolated PM thunderstorms are going to be possible over the mountains, with a very slight chance over the adjacent plains/I-25 corridor on Tuesday. 2) Better chance of widely scattered PM thunderstorms over the mountains and an increasing chance over the plains on Wednesday. Most areas will see a chance of PM storms from Thursday through Sunday. 3) Temperatures are going to gradually warm and be back to the seasonal average by Wednesday. Then a slight cooling trend on Friday through Saturday after passage of a cool front Thursday afternoon. Detailed discussion: Monday night through Wednesday... Any remaining showers and/or thunderstorms over the mountains will continue to diminish going into the late evening hours on Monday. The HRRR is showing some stronger convection still being possible over the southern Sangre de Cristo Mountains at around 9 PM where CAPE and instability is greater. This CAM also shows there being a storm moving out over the northern I-25 corridor that continues to weaken as instability decreases over the plains. The NAM 4km Nest has a discrete cell over the San Juans at around the same time. It appears that will all of the models that any convection should cease by midnight. Winds will become light and variable across most areas of the CWA. Temperatures will continue to cool under mostly clear skies by early Tuesday morning down into the 50s over the plains, to the 30s and 40s for high country. The monsoonal moisture plume will shift slightly back towards the west a little more as ridging subsequently builds back in over the region on Tuesday. Mid level flow will be primarily south- southeasterly and weak, so thunderstorm activity will primarily be confined to the mountainous regions with only some storms potentially moving off over the adjacent plains and over the Palmer Divide area. With the weak mid level flow, there is the possibility that some thunderstorms that develop over the mountains could remain stationary and the outcome could be possible flash flooding, especially over the burn scars. Southeasterly winds will also remain in place over the plains and help to draw up warmer temperatures, with max temperatures being much warmer and closer to the seasonal average for this time of year. Wednesday through Thursday... On Wednesday, the ridge will begin to flatten and troughing upstream will allow for the mid and upper level winds to become a little more southwesterly at the 700mb level and westerly at the 500mb level. Given this, along with a higher content of the monsoonal moisture plume remaining in place, PM storms will have a better chance of moving off the mountains and over the plains, especially along the I- 25 corridor. This will also be the case on Thursday, with even more of a west-northwesterly mid level wind flow as weak longwave troughing to the north sends a minor 500mb perturbation over the region. This will also send a cool front through the area by later in the afternoon or early evening on Thursday, although timing is not completely certain at this point as models vary. If the front moves through a little sooner than what the ensembles reflect at this time (of around 3 PM over the northern portions of the CWA and 5 PM over southern portions), then this could keep max temperatures from getting to be quite as warm as what is currently displayed on the plains. Otherwise, max temperatures will be even warmer on Wednesday and Thursday with the downsloping southwesterly winds ahead of the trough, heating up the valleys and the plains at or slightly above the seasonal average. Friday through Sunday... Ensembles and deterministic models have been fairly consistent with the longwave trough propagating to the northeast and then ridging occuring behind it over the Great Basin on Saturday that will move over the region on Sunday. There will also be a weak upper level low over southern California which will help draw up some more moisture from the south and enhance the mid level monsoonal moisture plume. This will allow for further destabilization in the mid levels, allowing for an uptick in thunderstorm development later in the afternoon and evening over most areas for all three days. With the 700-500mb level winds remaining out of the west-northwest, this will help to push off any convection over the mountains into the plains by later in the evening. Behind the frontal passage on Thursday afternoon, cooler air advection will result in a cooling trend on Friday and Saturday, with the coolest day being Saturday where temperatures will be anywhere from 5 to 10 degrees below the seasonal average. Temperatures will begin to warm back up by Sunday as the ridge moves over and southerly to southwesterly surface winds increase over the CWA. -Stewey && .AVIATION...(For the 00Z TAFS through 00Z Monday evening) Issued at 312 PM MDT Sun Jun 26 2022 KALS: Showers and thunderstorms are expected over KALS this evening with MVFR and IFR conditions possible. Vicinity showers will last through around 9z this morning. Low clouds will keep MVFR conditions possible, through late morning before clouds mix out. Thunderstorms are expected to develop over the mountains tomorrow afternoon, but are not expected to make it over the terminal. VFR conditions will be the prevailing flight category after the low clouds dissipate. KCOS: Low clouds and drizzle continue over KCOS, however visible satellite is showing some clearing around the Pikes Peak region. This will break from the drizzle and lower visibility. However, low clouds will remain an issue throughout the evening an overnight. By late morning clouds will mix out and the prevailing flight category will be VFR. Some isolated thunderstorms are possible tomorrow afternoon, if a thunderstorm develops overhead, MVFR conditions are possible as well as gusty and erratic winds. KPUB: Low clouds remain over KPUB and those low clouds will likely be an issue through the overnight. The ceilings will be straddling the VFR and MVFR threshold, unfortunately. After the clouds mix out in the morning, VFR conditions are expected throughout the rest of the forecast period. A gusty outflow wind is possible tomorrow afternoon, but conditions will remain dry. && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...SKELLY LONG TERM...STEWARD AVIATION...SKELLY