Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 07/30/22

Area Forecast Discussion
National Weather Service Boston/Norton MA
951 PM EDT Fri Jul 29 2022 .SYNOPSIS... Weak low pressure tracks south of New England, resulting in periods of light rain overnight, with steadiest rain over RI and southeast MA. Not a drought buster, but beneficial rains. Then dry weather this weekend with warm days, cool nights and comfortable humidity. Very warm to hot temperatures with increasing humidity levels anticipated for the upcoming workweek, with the most oppressive days looking to be Thursday and Friday. Showers and thunderstorms are possible on Tuesday, but significant rains are not anticipated and dry weather should prevail much of the workweek. && .NEAR TERM /UNTIL 5 AM SATURDAY MORNING/... 10 PM Update: Forecast dilemma remains unchanged, will short wave trough over Lake Erie this evening have sufficient amplitude to back the mid level flow to capture deep layer moisture over VA/MD northward into SNE? 18z guidance continues the theme from the 12z CAMs on a period of steadier rains after midnight across RI and southeast MA. This is response to a strengthening 850 mb SW jet over the ocean south of New England, with max moisture and thermal advection into RI and southeast MA, especially the Cape and Islands. Previous forecast captures this well, thus no major changes with this update. Earlier discussion below. ================================================================ Following trends, the 18z guidance and HRRR runs, adjusted PoP/Wx/QPF for anticipated rains overnight tonight. Changes essentially focus less QPF north and west of I-95, with similar or slightly more towards central/southern RI, South Coast, Cape and Islands. Axis of surface wind convergence and CAPEs on the order of 1000 J/kg appear the culprits in developing a cluster of scattered convection across the Berkshires into western Hampshire and Franklin Counties (with additional development in east-central NY). Suspect these are probably high-based and while a brief downpour looks possible given radar trends, with 25-30 degree dewpoint spreads it certainly could make it tough to generate much rain. The dry profiles look to exist thru still a decent depth of the lower atmosphere across all of SNE. While radar is indicating showers mainly near or south of Route 6 from Hartford to west of Providence, falling from lower to mid-based clouds. None of these showers appear to be reaching the ground but expect that to change moving toward late evening/midnight with mainly light rains within a few miles north of I-84 northeastward to the North Shore. For these locations in interior CT and MA though, duration of rain looks fairly short and I`ve reduced rain totals for these areas to a few hundredths to a tenth of an inch. Rain looks to become steadier across southeast New England and particularly central/southern RI, South Coastal towns and the Cape and Islands overnight as convectively enhanced surface wave low passes over the 40/70 benchmark. Though rain should predominate, some limited instability (LIs 0 to -1) in fcst soundings across southeast New England could result in some thunder and in-cloud lightning flashes as low approaches. Rain then diminishes by the pre-dawn/early Sat AM hrs. Made a little bit of an increase in QPF towards a half to two-thirds of an inch, with 2 inch PWAT values contrasting with a rather progressive system. No changes to lows which look on track attm. && .SHORT TERM /5 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/... Highlights... * Warm and less humid for Saturday under mostly sunny skies. Saturday: Surface low departs the near shore waters of southeastern Massachusetts during the early morning hours. An isolated shower or two isn`t out of the question along with areas of patchy fog through mid Saturday morning. High pressure builds in from the west and provides all of us a wonderful day under mostly clear skies. As we are located on the eastern edge of the area of high pressure the flow is out of the northwest and this ushers in a drier air mass with dew points in the mid 50s. Winds are northwest 8 to 12 knots. Afternoon temperatures are seasonable in the middle and upper 80s. Saturday night: Quiet night with clear skies and light winds. Should expect good radiational cooling with many locations outside of the urban centers falling into the mid 50s, great night for sleeping with the windows open. The urban centers will retain some heat, resulting in lows 63 to 65 degrees. && .LONG TERM /SUNDAY THROUGH FRIDAY/... Highlights: * Warm, dry and tranquil weather Sunday with still comfortable humidity levels. * Very warm to hot weather with increasing humidity levels for most of the upcoming workweek, potentially to oppressive levels mid to late in the week. * Best chance for showers and storms is with a cold front Tuesday, though significant rain is not expected. Details: Sunday: Tranquil and dry weather prevails as surface ridge remains in place with shortwave ridge aloft. Good weather for outdoor plans Sunday, and while it will be a touch more humid than Sat, still fairly comfortable with dewpoints in the upper 50s to lower 60s and highs in the mid 80s to perhaps a spot 90F reading away from the coast (mid 70s to low 80s for the coasts). Low-amplitude shortwave trough induces weak height falls and spreads increased cloudiness late-day Sunday into overnight, but the cloud cover looks to be of the mid to high variety and not likely to produce rains. Decreasing clouds second half of the night but dewpoints rise into the mid to upper 60s. Fairly mild lows in the mid 60s to near 70. Monday: High pressure offshore brings SW flow to SNE. Very warm, humid but also with some modest southwest breezes. Possible sea-breezes near the coast as synoptic gradient at the moment looks on the weaker side. Highs in the upper 80s to low 90s inland, lower 80s coastal locales. Mostly clear to partly cloudy skies for the evening with muggy lows mid-upper 60s to lower 70s. Tuesday: Tuesday still looks to feature the best chance for showers and possible storms as a cool front moves eastward through New England. Despite this, differences in deterministic and ensemble QPF both placement and amounts are apparent as well as some minor variance in frontal timing (at the moment, a frontal passage around the afternoon to mid evening hours are favored but 12z ECMWF is a few hours slower). Any rains will help and precipitable water values are around 1.8 to 2 inches, but front seems too progressive to bring significant wetting rains. Clearing by evening with highs in the upper 80s to lower 90s inland, lower to mid 80s coastal areas. Lows upper 60s to lower to mid 70s. Wednesday through Late Week: Ensemble means still indicate even warmer to hot weather and more humid conditions are in store for Southern New England. While deterministic global guidance is a few degrees higher, there are strong probabilities for 850 mb temps at or greater than 20C. Latest guidance indicates Thursday projects as the hottest and most humid of the stretch; however Friday may also feature mid/upper 90s highs as prior guidance has backed off on the timing of a sagging cold front toward the weekend. Potential exists for heat headlines for at least a part of this period but exact heat indices are still unclear. && .AVIATION /02Z SATURDAY THROUGH WEDNESDAY/... Forecaster Confidence Levels: Low - less than 30 percent. Medium - 30 to 60 percent. High - greater than 60 percent. 02z TAF Update: no change from previous forecast thinking. Best chance for a period of steady rains with MVFR conditions after midnight over RI and southeast MA, then exiting 09z-12z. Earlier discussion below. ================================================================= Tonight: High confidence in trends, moderate on timing. VFR initially begins to deteriorate approx. 03-05z as rain expands NE. Rain however looks light enough for airports north and west of I-95 that prevailing VFR looks more likely with mainly dry runways. Best chance at MVFR/brief IFR ceilings/vsby for PVD, Cape Cod and Islands after 06z. Rain begins to taper off in the 08-12z timeframe. SW winds 6-10 kt ease a bit thru midnight then to trend NW/N. Saturday...High confidence. VFR. NW winds 8-12 kt. Saturday Night...High confidence. VFR. NW winds 5-8 kt. KBOS...High confidence in TAF. KBDL...High confidence in TAF. Outlook /Sunday through Wednesday/... Sunday through Sunday Night: VFR. Monday: Mainly VFR, with local MVFR possible. Breezy. Monday Night: Mainly VFR, with local MVFR possible. Slight chance SHRA. Tuesday: Mainly VFR, with areas MVFR possible. Slight chance SHRA, isolated TSRA. Tuesday Night through Wednesday: VFR. && .MARINE... Forecaster Confidence Levels: Low - less than 30 percent. Medium - 30 to 60 percent. High - greater than 60 percent. Winds and seas expected to remain below SCA thresholds through Sunday. Rain showers move in this evening and exit on Saturday morning. Can`t rule out a few thunderstorms for the waters south of Block Island to Nantucket. Outlook /Sunday through Wednesday/... Sunday through Sunday Night: Winds less than 25 kt. Monday through Monday Night: Winds less than 25 kt. Slight chance of rain showers. Tuesday: Winds less than 25 kt. Slight chance of rain showers, isolated thunderstorms. Tuesday Night through Wednesday: Winds less than 25 kt. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...None. && $$ SYNOPSIS...Loconto/Gaucher NEAR TERM...Nocera/Loconto/Gaucher SHORT TERM...Gaucher LONG TERM...Loconto AVIATION...Nocera/Loconto/Gaucher MARINE...Loconto/Gaucher
Area Forecast Discussion...UPDATED
National Weather Service Corpus Christi TX
632 PM CDT Fri Jul 29 2022 .AVIATION...00Z TAFs Isolated showers will affect the COT area for the next hour with gusty winds and near MVFR vsbys possible with the stronger showers. Convection is expected to diminish by 02Z. Gusty southeast winds will linger through the evening hours over the Brush Country, then become light over inland areas overnight. Patchy fog/MVFR vsbys could occur over the inland coastal plains and brief MVFR ceilings may develop over the Brush Country around daybreak. But chances are remote and did not include in TAFs. Models depict air mass will become drier on Saturday and the mid level ridge to the north builds southward into the region. Do not expect isolated convection with the sea breeze on Saturday. VFR conditions with winds becoming gusty over the coastal plains in the afternoon with the sea breeze. && .PREV DISCUSSION... /Issued 330 PM CDT Fri Jul 29 2022/ SHORT TERM (Tonight through Saturday Night)... Hot and humid summer time conditions continue into the weekend. Broad mid level high pressure draped generally from TX to the FL coast, will build slightly southwest across S TX tonight through Saturday. This will bring drier mid level air across the area leading to highs on Saturday being a degree or two warmer and lows Saturday night a couple of degrees cooler. Low level moisture will remain sufficient for the humidity to remain elevated through the short term. The humidity combined with the hot temperatures Saturday afternoon will result in heat indices of 105 to 109. A few locations could briefly reach 110. The drier airmass will lower the PWATs down to around 1.5 inches on Saturday which is near normal for this time of year. Despite the limited moisture and the high building across the area, most models show isolated convection over the coastal waters Saturday with the HRRR and RAP showing the isolated convection moving inland with the sea breeze Saturday afternoon. Went with a 20 PoP across the Victoria Crossroads where the moisture will be slightly deeper and went with silent 5-10 PoPs across the remainder of the CWA for any possible rogue showers. There is a small window Saturday afternoon/evening across the Brush Country/Rio Grande Plains when winds increase and just before the humidity also increases, where elevated fire weather conditions will be possible. LONG TERM (Sunday through Friday)... Concur with the deterministic GFS/ECMWF that an upper level inverted trough of low pressure, and associated copious moisture, will move westward across the region and contribute to at least isolated convection Sunday/Monday. Expect the best chance for convection activity over the CWA to occur Monday afternoon owing to the combination of sea breeze convergence, moisture, and forcing associated with the upper trough. The trough will move west of the CWA and the upper ridge will begin to build Tuesday. Nevertheless, additional isolated convection anticipated for Tuesday owing to lingering moisture. Drying/subsidence should preclude convection during the remainder of the period. Maximum Heat Index values 105- 109F Sunday/Monday. A slight increase in maximum temperatures beginning Tuesday (owing to lower PWAT values/less moisture in the vertical column) will combine with continued near surface moisture to generate greater Heat Index values. Heat Advisory conditions may occur Tuesday-Thursday over a significant portion of the CWA. Greater wind speed magnitudes beginning Tuesday (owing to slightly greater temperatures resulting in a greater MSLP gradient) may combine with low minimum relative humidity values to generate Elevated fire weather conditions over the Country/Rio Grande Plains Tuesday-Friday. MARINE... A moderate onshore flow can be expected through this evening. The flow will then become weak to moderate by Saturday morning and will continue through Saturday night. Can not rule out an isolated shower or two early Saturday morning. Isolated to scattered showers and thunderstorms are possible by Saturday night. The combination of an upper inverted trough/associated copious moisture, will contribute to at least isolated convection Sunday/Monday. Addition isolated convection early Tuesday owing to lingering moisture. Anticipate moderate onshore flow during the period. Brief Small Craft Advisory conditions may occur, especially Tuesday/Wednesday. && .PRELIMINARY POINT TEMPS/POPS... Corpus Christi 78 96 77 93 77 / 10 10 10 10 10 Victoria 76 98 76 96 76 / 10 20 0 10 10 Laredo 78 106 77 102 77 / 10 0 0 10 0 Alice 75 102 74 99 74 / 0 10 10 10 10 Rockport 83 94 82 94 81 / 10 10 10 10 10 Cotulla 79 107 77 105 77 / 10 10 0 10 0 Kingsville 79 101 76 95 76 / 0 10 10 10 10 Navy Corpus 83 96 82 90 81 / 10 10 10 20 20 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...None. GM...None. && $$ TMT/89...AVIATION
Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
814 PM EDT Fri Jul 29 2022 .SYNOPSIS... A weak surface front will settle southward from Kentucky and the Virginias into the western Carolinas late today and stall across the region over the weekend. Abundant moisture will remain in place across the area through the weekend and into early next week. The front should dissipate by Tuesday, with high pressure over the western Atlantic taking control for the rest of the week. && .NEAR TERM /THROUGH SATURDAY/... As of 810 pm EDT: Convection has mostly dissipated across the western Carolinas and NE GA this evening. The weak frontal boundary to our west has lead to showers and thunderstorm development across eastern TN. This activity looks to weaken as it tracks eastward into the western NC mtns. Have maintained chance PoPs along the NC/TN border overnight to account for this activity. Went ahead and decreased PoPs east of the mountains this evening into late tonight. Otherwise, satellite imagery and RAP 500 mb heights continues to show broad cyclonic flow in place over the eastern CONUS. Meanwhile, the a weak cold front remains over over eastern KY and western WV this evening. This boundary is expected to make steady progress southward into the western Carolinas late this evening into the overnight hours. Deeper moisture moving in with the frontal zone could permit isolated to scattered showers to persist into the overnight hours. Mins will run 5 or more degrees above climo, and mountain valley fog/low stratus will be possible again if the debris clouds thin sufficiently. Precipitable water values will rise further during the day on Saturday and the lingering boundary in the region should permit coverage to be a bit higher during peak heating. That may be especially true if the low-level flow acquires more of a S to SE component as suggested in some models. Additional vorticity lobes in the cyclonic flow aloft could yield a bit better upper support as well. The hydro problem potential will rise with PWAT values nearing 2 inches and efficient rainfall likely in the warm cloud processes. Still, no one area appears to have a high enough risk of flooding to warrant any Flood Watches at this point. The severe threat could be a bit less with more cloudiness and warm and moist profiles, but isolated severe will remain possible in any areas receiving better heating. Maxes should be near climatological values most areas on Saturday afternoon. && .SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/... As of 100 PM EDT Friday: Stalled frontal boundary will set up shop from west to east across the CFWA Saturday night through much of the day on Sunday. The better upper forcing should overlap the boundary by the beginning of the short-term. With stout PWAT values in place (2.00"+), deep warm cloud layer, skinny (-ish) CAPE, and very weak MBE velocities, expect for convection that develops along or in the vicinity of the boundary to potentially train. This will uptick the overall flash flood threat, especially in areas that have received appreciable rainfall the previous few days leading up to the weekend. Numerous to widespread showers and thunderstorms will be in store through the early part of next week in this setup. With an enhancement of convective coverage during peak heating due to the frontal boundary and upper divergence under weak confluent flow, precipitation coverage should be able to thrive in this setup and linger into the overnight hours Saturday and Sunday. Thus, nocturnal chance to likely PoPs will remain in the forecast. Few shortwaves will pass to the north during this time, but a stronger shortwave trough will round out from the mid-MS Valley Sunday through the OH Valley Sunday night and help reactivate the frontal boundary into a warm front, which should help lift it north of the CFWA by Monday. Placed under a warm sector regime and factoring in the loss of upper forcing and surface convergence, expect for more typical diurnally driven convection by peak heating Monday. Temperatures will be near normal through the period due to extensive cloud cover and higher than normal PoPs. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... As of 230 PM EDT Friday: Lingering upper troughiness will remain in place across the area through the early part of next week, which should continue to allow for above normal PoPs and near normal temperatures. The synoptic pattern will begin to shift as the upper ridge over the western Atlantic retrogrades over the southeastern CONUS behind the departing upper trough to the north. Typical mid-Summer pattern should settle over the region by the middle part of next week with diurnally driven convection and slightly above normal temperatures. Localized pulse severe storms and flash flooding will still impact the region, but these threats will be much lower compared to the short-term forecast. && .AVIATION /00Z SATURDAY THROUGH WEDNESDAY/... At KCLT and elsewhere: SHRA and TSRA have mostly dissipated across the western Carolinas this evening. Have a scattered convection tracking across eastern TN that is associated with a weak frontal boundary. This activity should weaken as it tracks into the western NC mtns. Added VCSH at KAVL to account for this activity. Mountain valley fog and low stratus are expected again overnight into daybreak Saturday. Low stratus and fog are possible east of the mountains for areas that saw heavy rainfall earlier today. However, confidence was too low to mention in the 00Z TAF forecast period. Winds will be light and variable overnight into early Saturday morning. The weak frontal boundary will continue pushing east across the western Carolinas overnight into Saturday morning before stalling across the SE CWA. This FROPA will allow for scattered SHRA and TSRA chances to return Saturday afternoon and evening, so have PROB30s at all TAF sites. Expect lighter wind speeds on Saturday compared to the last few days. Outlook: Diurnal scattered to numerous showers and thunderstorms are expected this weekend and into early next week. Fog and low stratus may develop each morning in the mtn valleys and where appreciable rain has fallen the previous evening. && .GSP WATCHES/WARNINGS/ADVISORIES... GA...None. NC...None. SC...None. && $$ SYNOPSIS...CAC/HG NEAR TERM...AP/HG SHORT TERM...CAC LONG TERM...CAC AVIATION...AP
Area Forecast Discussion
National Weather Service New York NY
1200 AM EDT Sat Jul 30 2022 .SYNOPSIS... A cold front, with a wave of low, tracks through the region overnight. A weak surface trough passes through on Saturday while high pressure begins to build in from the Midwest. The high moves overhead on Sunday and slides offshore by midweek. A few weak frontal systems will impact the region late Monday through Tuesday, followed by building high pressure toward the end of the week. A cold front approaches on Friday. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... Made minor updates to the forecast for the overnight, removing the chance of thunder over the ocean waters. Aloft, an upper- level low within a 500-mb trough is located over southeast Canada, with a relatively potent jet rounding the base of the low. A weak area of low pressure develops along the approaching front and tracks just south of the region tonight into early Saturday morning. With the trough to our west, and the area falling under the RR quadrant of a potent 140 kt jet streak over northern New England, clouds and rain with the wave should extend farther north through the area. The wet weather comes to an end from west to east after 06z, with everyone dry by 12z at the latest. Patchy fog may develop in spots close to daybreak. Storm total rainfall is expected to be around a quarter of an inch for much of the region, though higher amounts are likely where the corridor of heaviest rain falls. Temperatures overnight range from the mid 60s to low 70s. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/... The upper level trough axis remains over the area early in the day, with heights beginning to rise as the trough lifts north and east. Cyclonic flow associated with the trough may allow for a few mid- level clouds to develop in the afternoon, though skies should be predominantly sunny through the day. Temperatures remain warm behind the frontal passage, with most areas topping out in the mid-to-upper 80s. Drier air advects in, however, with a northwest flow setting up as surface high pressure begins to build in from the Midwest. Forecast dew pts fall into the 50s, helping make it feel more comfortable outside. Ideal radiational cooling conditions set up Saturday night, with light winds and clear skies. Leaned toward the cooler MOS guidance for lows. Cooler spots in the interior and LI Pine Barrens likely bottom out in the upper 50s, with mid 60s to low 70s elsewhere. && .LONG TERM /SUNDAY THROUGH FRIDAY/... Ensembles depict zonal flow followed by an amplifying longwave ridge over the northeast through much of the period, with building heights aloft from midweek through the end of next week. The area will likely experience another round of excessive heat next week as a result. In terms of sensible weather, high pressure remains overhead on Sunday giving way to a warm front that will approach from the south as its parent surface low heads through upstate NY on Monday. Shower chances will increase on Monday afternoon as the front approaches, but at this point, precip looks to be light with very limited instability. By Tuesday, the area becomes warm sectored as southerly flow increases, and have added thunder chances for the afternoon as instability increases (500-1000J/kg per GFS soundings.) ahead of a weak cold front and prefrontal trough. Precip chances ramp down the frontal system moves offshore by Tuesday night. CSU ML severe forecasts showing the 5-15% chance for severe across much of the eastern seaboard for Tuesday. High pressure then follows for Wednesday and moves offshore by the end of the week. This will allow deep southwest flow to begin bringing in a more warm and humid airmass for Wednesday. 850mb temperatures begin to rise to the low 20s into Friday, as dewpoints are progged to reach the low 70s. Have adjusted high temperatures up toward the NBM 50th percentile, which is above the NBM deterministic MaxTs. The 50th percentile MaxT from NBM performed quite well during the previous heat event across the local area. Heat indices are expected in the upper 90s to low 100s for much of the area on Thursday, and possibly into Friday. A cold front approaches for Friday, and depending on the timing, Friday may be a few degrees warmer than Thursday should the front sweep through late in the day. && .AVIATION /04Z SATURDAY THROUGH WEDNESDAY/... A frontal wave passes to the south and east overnight, dragging a cold front through the area. High pressure will then build in slowly from the west on Saturday. Mainly VFR overnight, but occasionally MVFR in some heavier showers. Much of the showers will be east of the area by daybreak with the possible exception of the terminals east of NYC. Few-Sct Cu around 5-7kft Saturday afternoon. W/SW winds become light and variable over the next few hours as low pressure approaches from the SW and a cold front approaches from the NW. Winds shift to the N-NW late at less than 10 kt, then become NW 10-15kt on Saturday, with occasional higher gusts in the afternoon, gradually backing to the west. ...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty... Timing of showers this evening (00z to 07z) may be off by an hour or two. .OUTLOOK FOR 00Z SUNDAY THROUGH WEDNESDAY... .Saturday Night through Sunday...VFR. .Monday and Tuesday...Mainly VFR. Slight chance of a shower or thunderstorm, mainly in the afternoon and evening. .Wednesday...VFR. Detailed information, including hourly TAF wind component forecasts, can be found at: https:/ && .MARINE... Adjusted winds, gusts, and ocean seas for current conditions and trends through the overnight. Also, removed the thunderstorms over the ocean waters as any convective activity will remain well to the south. Winds and seas should remain below SCA levels on all waters into early next week. && .HYDROLOGY... No hydrologic impacts are expected through late next week. && .TIDES/COASTAL FLOODING... There is moderate rip current risk on both Saturday and Sunday from a combination of 2-3 ft S wind waves and 2-3 ft SE swells. The rip risk may lessen by Sunday afternoon. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...None. && $$ SYNOPSIS...DBR/DR NEAR TERM...DBR/DR/MET SHORT TERM...DR LONG TERM...DBR AVIATION...DW MARINE...DBR/DR/MET HYDROLOGY...DBR/DR TIDES/COASTAL FLOODING...
Area Forecast Discussion
National Weather Service Pueblo CO
352 PM MDT Fri Jul 29 2022 .SHORT TERM...(This evening through Saturday) Issued at 232 PM MDT Fri Jul 29 2022 Key Messages: 1) Scattered to numerous showers and thunderstorms through the evening with best coverage across the Southern Tier. 2) Warmer tomorrow with best coverage of afternoon storms over and near the higher terrain. Current water vapor imagery and upper air analysis is indicating modest westerly flow aloft across the region, with satellite data indicating PWATS running 120 to 150 percent of normal across the Central Rockies. Water vapor imagery is also indicating one embedded short wave translating through the Northern Rockies, with another embedded wave translating across northern New Mexico. SPC meso- analysis has MUCape of 1000-2000 j/kg across the higher terrain, greatest across the Northern mountains, with MUCape of 500-1000 j/kg across the southeast plains. Models continue to indicate flow aloft becoming more north to northwest through the day tomorrow, though remaining weak, as the northern Rockies wave continues to translate south and east into the High Plains and upper level ridging continues to build into the Great Basin. For the rest of tonight, should see showers and storms continuing to develop and move east southeast across the region, with the best coverage of storms remaining across the southern tier and out across the far southeast plains. These storms could continue into the late evening and into the overnight hours, especially across the far southeast plains, as the northern New Mexico wave continues to translate east overnight. Cloud cover and low lapse rates across the region has limited storm strength today, especially across the southern tier, however, with more solar heating, storms across the northern and central mts and moving into the Teller County have been more feisty, with very heavy rainfall being observed with these stronger storms. At any rate, the latest runs (19Z and 20Z) of HRRR indicates these stronger storms will diminish in strength as they continue to move southeast across the adjacent plains. Further east, with storms continuing to develop across the far southeast plains, will keep the Flood Watch out for Bent, Prowers and Baca Counties, where saturated soils could lead to flash flooding. With the ample moisture in place and weak upslope flow across the plains, will see some clouds persisting across the area into the overnight hours, with stratus possible again along the lower eastern slopes. On Saturday, should see clearing skies through the early morning, with showers and storms developing over and near the higher terrain once again through the late morning and afternoon. Best coverage of storms shifts slightly west across the ContDvd, with all storms being slow moving and capable of producing heavy rainfall, leading to another day of possible flash flooding. However, with no evident short wave to help trigger storms, there is no clear cut place for any flash flood highlights at this time. Further east across the plains, models indicate low level moisture in place, leading to Sbcape of 1000-1500 j/kg into the afternoon. However, model soundings indicating a healthy cap in place. Temperatures do warm back into the 80s across the plains, with 60s and 70s across the higher terrain. .LONG TERM...(Saturday night through Friday) Issued at 232 PM MDT Fri Jul 29 2022 Key messages: 1) Warmer and generally drier weather for the week. .Sunday through Tuesday...Upper ridge over the Pacific Northwest continues to drift to the east southeast passing over Colorado on Monday. Middle and upper level monsoon moisture will continue moving through the ridge for diurnal convection over and near the mountains. The best chances for thunderstorms will mostly be over the eastern San Juan Mountains. Precipitable waters over the mountains remain roughly 0.5 to 0.75 inches, which can result in storms producing locally heavy downpours. Models and ensembles have precipitation chances decrease towards the east with residual moisture remaining on the plains. Suspect that storms which move off of the mountains and into the I25 corridor and eastern plains will become higher based with less rainfall and gusty winds. Hot weather returns to the plains with highs in the 90s to around 100. .Wednesday through Friday...Ensemble means have the upper ridge drift to the east with increase southerly flow aloft, which would increase the mid and upper level monsoon moisture over the region. Models hint at a weak front passing over the plains on Wednesday. The upslope behind this front could briefly increase low level moisture on the plains. NBM PoPs increase over the mountains and nearby plains with the increase in moisture. The latest GFS and EC show a fairly sharp trough passing across the northern Rockies, which could enhance convection. Latest EPS and GEFS show hints of this feature, but it is not a sharp as in the operational models. Ensembles suggest there is much variability in the strength and timing of this trough. Hot weather continues on the plains with highs generally in the 90s. --PGW-- && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) Issued at 232 PM MDT Fri Jul 29 2022 Moist upslope flow and monsoonal moisture in place across the region will keep mainly VFR cloud cover in place at COS and PUB through the evening, as storms develop across the higher terrain and try to move east into a more stable environment across the adjacent plains. Storms will still be possible at terminals from the late afternoon and evening hours, with MFVR and brief IFR conditions possible with heavy rainfall and gusty outflow winds the main threats, if storms can develop/move over the terminals. Convection wanes through the evening, and with the ample moisture in place, could see MVFR stratus develop once again at the terminals overnight. VFR conditions are expected through the rest of the period, with storms remaining over and near the higher terrain. At ALS, scattered showers and storms expected at the terminals through the afternoon and evening hours, bringing occasional mvfr and patchy ifr conditions. Showers could linger into the late evening hours, with MVFR stratus likely developing once again at the terminal overnight. VFR conditions are expected across through the rest of the period, with more isolated storms possible Saturday afternoon. && .PUB WATCHES/WARNINGS/ADVISORIES... Flood Watch until 10 PM MDT this evening for COZ094-097>099. && $$ SHORT TERM...MW LONG TERM...PGW AVIATION...MW
Area Forecast Discussion
National Weather Service Blacksburg VA
944 PM EDT Fri Jul 29 2022 .SYNOPSIS... A frontal boundary will slide south into the Carolinas Saturday, then lift back north as a warm front Sunday into early next week. This will keep our area in an unsettled weather pattern. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... As of 940 PM EDT Friday... ...Warm and muggy night... Convection is waning and having a hard time arriving along the cold front. Have cancelled the Flood Watch a little early. It will be a warm and muggy night with some fog around where we can get some clearing. It will take all night for the front to move through, and until tomorrow when some drier air finally arrives. As of 650 AM EDT Friday... Remainder of Severe Watch cancelled, Flood Watch still in effect... Weak storms are continuing to move east out of the area. Still some convection south of Danville into parts of northern NC, but besides heavy rainfall and lightning the storms are not a threat. To the west, have kept the Flood Watch up as a cold front nears locations which have seen 1-4+" in the last 48 hours, mainly along the WV/VA border and a county or so south. Showers and storms currently forming in central WV will try and reach the Flood Watch area, but many CAMs show them diminishing as they run into the terrain and also a more stable and cooler air mass. This will also coincide with the loss of heating. However, the threat of training cells increases as the boundary nears, and it would not take much to cause flooding problems. So will keep a close eye on this. Expect fog to form overnight into the early morning hours with dry air lagging behind the actual FROPA. As of 515 PM EDT Friday... Trimming back Severe Watch... Convection has been having trouble becoming severe or even strong, even in areas that saw plenty of sun today. The best instability is to our south while the better speed shear at 500mb and 300mb is to our north. Westerly winds at the surface are also not helping the situation as a surface trough shifts into eastern VA. Have dropped part of the watch that we do not expect to see redevelopment in, but we may be dropping the remainder of the Severe Watch and perhaps the Flood Watch in the next 1-3 hours. Dropping the Flood Watch will depend on what develops along a cold front which is still to our northwest. As of 130 PM EDT Friday... Currently watching the progression of a cold front to the west, slowly drifting southeast through this evening. Ahead of this front, have seen quite a bit of clearing and in response to this, strong destabilization is occuring across much of Virginia and North Carolina. Expecting wider coverage of storms within the next hour or two as better forcing works eastward, with activity beginning over the mountains and then eventually spreading east into the Piedmont of Virginia and North Carolina. Storm mode will likely be multicell/line segments with damaging winds being the main threat. Flooding remains a threat this afternoon and evening as well owing to a very saturated airmass in place. RAP analysis has PWAT values of around 2 inches across the area which will result in very efficient, heavy rainfall rates. The biggest concern for flooding will be for southeast West Virginia and southwest Virginia where saturation has occured from multiple days of rainfall through the week. Due to low flash flood guidance and the potential for very heavy rainfall rates impacting these areas again today it will not take much rainfall to cause flooding issues, so opted for a Flood Watch until 10 PM EDT for southeast WV and far southwest Virginia. Front will progress through the area tonight and rain should eventually taper off with the exception being some lingering showers for the far western mountains. The front eventually stalls over the Carolinas and most rainfall on Saturday will be confined along and south of the NC/VA border. Temperatures this afternoon will feature 90s across the eastern areas, with 70s and 80s elsewhere. Guidance has been running a bit low on temperatures so have bumped up highs slightly this afternoon. Temperatures on Saturday will be several degrees cooler, featuring highs in the 70s and 80s across the entire area. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/... As of 200 PM EDT Friday... Lifting front Sunday returns rain... A front will sag southward late Saturday, pushing the currently stalled front also south of its position. This will help keep any rain chances near or south of the VA/NC border Saturday night. Into Sunday and part of Monday, the front will slowly lift northward, transiting the CWA at a leisurely pace, but again returning heavy showers and storms to the forecast area. Of particular concern are the regions of far southwest VA, particularly Tazewell and Smyth counties, and southeast WV, where almost daily rain has saturated the ground for the past week. Flash flood guidance values will be exceptionally low, so it won`t take much rain to tip the scales and create flooding issues in these areas. When considering the high rain rates expected with these showers, a close eye will be kept on hydrology concerns Sunday and Monday. Since we will be on the cool side of a frontal boundary and sitting under clouds and rain showers, temperatures have been held on the cool side, with highs only in the 70s and low 80s for this forecast period. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... As of 310 AM EDT Friday... Warming Temps And Diurnal Rain Chances...L After the front exits to our north Monday, we will return to a more typical diurnal summer pattern as a subtropical ridge edges north and into the Mid-Atlantic. Some chance PoPs will fit in each afternoon as heating destabilizes the atmosphere. Model guidance doesn`t exhibit a consistent time frame for the next organized system or front to pass through next week. Temperatures will be around normal for early August in the extended time frame. && .AVIATION /02Z SATURDAY THROUGH WEDNESDAY/... As of 635 PM EDT Friday... Showers and storms are diminishing and moving southeast away from KDAN and KLYH. A cold front will move through tonight, and may still bring a few SHRA/TSRA to KBLF and perhaps KLWB through 02Z. Thereafter the rain threat should drop everywhere. Cigs and vsbys will drop to sub-VFR tonight as drier air takes its time filtering in. Fog may become more an issue at LWB/BCB/LYH once we begin to clear. Fog burns off an hour or two after sunrise and most locations should go back to VFR with perhaps some lingering mixed MVFR conditions in the mountains. Forecast confidence is average. .Extended Aviation Discussion... The front will meander and linger through Saturday with highest chances for storms in the afternoon hours Saturday south of the VA/NC border. The abundant moisture and daily precipitation will result in areas of dense late night/early morning fog/low clouds with MVFR or lower conditions. The front to our south lifts back north as warm front Sunday into early next week, keeping the rain threat around with sub- VFR likely at times. Fog also possible in the late night/early morning time frame. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...None. NC...None. WV...None. && $$ SYNOPSIS...BMG NEAR TERM...BMG/SH SHORT TERM...VFJ LONG TERM...VFJ AVIATION...BMG/WP