Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 08/25/22

National Weather Service Bismarck ND
918 PM CDT Wed Aug 24 2022 .UPDATE... Issued at 916 PM CDT Wed Aug 24 2022 No changes to the forecast for tonight. Patchy to areas of fog will be the main concern overnight, still favoring the north central into the northern James Valley. UPDATE Issued at 634 PM CDT Wed Aug 24 2022 Will keep a mention of showers southwest mainly for this evening as an area of weak radar returns moves east into the area. Otherwise fairly quiet tonight with patchy to areas of fog developing, with models trying to key in on the north central part of North Dakota where winds will be light and the sky should trend clear. Any lingering clouds will also overall decrease and/or lift with time tonight as an area of surface low pressure builds southward into northeast North Dakota and advects dry air west and south across our area. && .SHORT TERM...(This Evening through Thursday) Issued at 243 PM CDT Wed Aug 24 2022 Afternoon regional radar mosaic remains fairly quiet across western and central North Dakota. A few CAMS still suggest there could be an isolated shower or thunderstorm this afternoon, with the best chances across the south and west. Will hang onto a slight chance pop in those areas where there is the most agreement in the models, though there is still a non-zero chance for a shower or two just about anywhere this afternoon. It should dry out this evening, though if convection in Montana survives long enough to make it into western North Dakota, pops may have to be extended a few hours in the west. Will have to keep an eye out for more fog later tonight with the surface ridge axis across the area. The HRRR and NBM have both been at least hinting at this potential, so have added patchy fog for late tonight into Thursday morning as a start. Something else to watch will be the possibility of a few showers across the southwest part of the state. The low level jet increases late tonight from western South Dakota into southeast Montana, and a few CAMS trigger a few showers in that area late tonight / early Thursday morning. The low level jet weakens Thursday morning, though the west begins to feel the influence of the next H5 wave Thursday afternoon, so will hold pops into the afternoon in that area. .LONG TERM...(Thursday Night through Wednesday) Issued at 243 PM CDT Wed Aug 24 2022 The aforementioned wave continues to work its way across the Northern Plains Thursday night and into the first part of the weekend. In general, global ensemble systems appear to be in fairly good agreement in the larger trough`s passage, but finer details will still need to be narrowed down as those time periods approach. One signal that has emerged already is the potential for a few stronger thunderstorms in the southwest on Friday. CIPS guidance brings in low probabilities to the southwest corner of the state, and that is also in line with the current SPC Day 3 Outlook. The upper trough will continue to influence the area on Saturday, but the stronger / more organized forcing from it should push east of our forecast area. Upper heights then build early next week as the ridge to our west amplifies. We can`t rule out a passing wave during that time, but overall most locations should stay dry. Model spread for Max Temperatures early next week is fairly high, with the GEFS ensembles tilted towards the warmer end, ECMWF the cooler end, and the CMC splitting the difference. In general, the NBM output looks reasonable which is warmer west, a little cooler east, and fairly seasonable overall. && .AVIATION...(For the 00Z TAFS through 00Z Thursday Evening) Issued at 634 PM CDT Wed Aug 24 2022 Ceilings will continue to slowly improve this evening, though some locations will continue to have an MVFR ceiling for another few hours early this evening, mainly for KDIK. Fog is possible again tonight, and we will have to watch trends to see if it will be widespread enough to add back into more TAF locations. Right now KMOT and KDIK have the better probability to see fog and some low stratus late tonight through 14-15Z Thursday. && .BIS WATCHES/WARNINGS/ADVISORIES... None. && $$ UPDATE...NH SHORT TERM...King LONG TERM...King AVIATION...NH
Area Forecast Discussion
National Weather Service Birmingham AL
740 PM CDT Wed Aug 24 2022 .UPDATE... Evening Update and 00Z Aviation. && .SHORT TERM... /Updated at 0659 PM CDT Wed Aug 24 2022/ The latest SPC RAP analysis has the best 925-850mb moisture transport over the southeast counties. There was also some SBCAPE that developed in the far east late this afternoon. A well defined north to south mean moisture gradient still remains over Central Alabama that has persisted several days now. The main upper trough was still back to our west, therefore, this convective activity will continue slowly eastward this evening. Increased pops in the south and east to categorical. Some sporadic rain rates were still over 4 inches per hour, but luckily the areas were moving 35 mph northeast. This has led to radar estimated 1 inch or less the past hour or so. The rain area southeast will keep moving east or slowly dissipate. But there will be an increase in low level winds late tonight along with smaller scale perturbations. So a lull in activity will occur later this evening in most locations and we then see an increase before sunrise. This same general pattern we have experienced the past several days. Thursday, it looks like widespread showers and a few thunderstorms will once again develop will little change in the overall weather pattern. 75 .LONG TERM... /Updated at 0300 PM CDT Wed Aug 24 2022/ The disturbance currently plaguing the region with cloudy conditions and periods of rain showers, will continue to meander over southern Alabama on Friday. Most of the rain should be focused south of I-20 and especially south of I-85, where periods of rain appear likely. As a more organized 500mb trough axis moves through the Appalachians on Saturday, the decaying disturbance and highest rain chances should move farther south. This will mark the return to more typical summertime conditions, with diurnally driven convection expected through Tuesday as a general 500mb weakness persists across the Deep South. 87/Grantham && .AVIATION... 00Z TAF Discussion. Showers and a few thunderstorms were ongoing near MGM/TOI at this writing. This activity will slowly move east and northeast the next several hours. Large scale isentropic lift and moisture convergence remains over Central Alabama like the previous several days. Even though some days did not have restrictions develop overnight, several did. We will lean toward having low ceilings develop at most terminals before 12z. There will also be some patchy fog, most prevalent in conjunction with rain. The main concern will be ceilings. Rain/storms also stay in the forecast in varying degrees most of the 24 hour period. Winds will be light and variable overnight and a southerly component Thursday at 5-6kts. 75 && .FIRE WEATHER... Cloudy and rain conditions should continue to affect much of the area through Friday, especially south of I-20. Minimum RH values will be above 55 percent and 20 foot winds should remain less than 7 kts, mainly from the southeast Thursday and Friday. && .PRELIMINARY POINT TEMPS/POPS... Gadsden 68 85 67 87 69 / 30 70 40 60 20 Anniston 69 83 69 86 70 / 40 70 50 60 20 Birmingham 70 83 70 87 70 / 40 70 50 60 20 Tuscaloosa 70 82 70 86 70 / 50 80 40 60 20 Calera 69 81 70 85 71 / 50 80 50 60 20 Auburn 70 81 69 84 70 / 90 80 50 70 30 Montgomery 71 83 71 87 72 / 90 80 50 70 30 Troy 71 82 70 85 70 / 90 80 50 80 30 && .BMX WATCHES/WARNINGS/ADVISORIES... None. && $$
Area Forecast Discussion...UPDATED
National Weather Service Brownsville TX
645 PM CDT Wed Aug 24 2022 ...New AVIATION... .SHORT TERM... (This evening through Thursday Night) Issued at 246 PM CDT Wed Aug 24 2022 The seabreeze is trying to form and work westward this afternoon. HRRR shows isolated showers and thunderstorms through the evening but left only silent POPs in the forecast for most of the CWA. Otherwise, tonight will be mostly dry with temperatures in the upper 70s with mostly clear skies expected. Tomorrow, a surface trough makes its way towards central Texas and brings us a better chance for rain. The Northern Ranchlands seem to be the most favorable region in regards to POPs. Have a chance of showers and thunderstorms through the evening. PWATs will be over 2 inches up in the northern four counties of our CWA and will also get a boost in energy from the surface trough bringing in an influx of vorticity. High temperatures for tomorrow stay consistent in the upper 90s again. Southeast winds become breezy by the afternoon hours. && .LONG TERM... (Friday night through next Tuesday) Issued at 246 PM CDT Wed Aug 24 2022 A general summer pattern to provide occasional unsettled conditions for Deep South Texas with low to modest rainfall chances and seasonal temperatures. The latest forecast package is an update of the previous forecast showing an inverted trough/ tropical wave approaching Friday with a surge of tropical moisture (pwats 2.25-2.4 in.) as seen total precipitable water vapor loop over the western Caribbean. Consensus pops and overall qpf values remain the highest on this day. Rainfall amounts generally range from 0.25 to 0.50 inches with isolated 1 to 2 inches in stronger showers or thunderstorms. This kind of rainfall can be expected any day anywhere through the long-term. Moisture lingers into the weekend with a subtle weakness aloft which leads to isolated to scattered sea breeze activity each day favoring the coastal areas in the mid to late morning spreading west in the afternoon. Uncertainty among the GFS/EC vs. the NBM consensus plays a factor in pop forecast with the consensus lower both Saturday and Sunday making for a low confidence forecast. for the weekend on what weekend day would be the driest. Another surge of moisture arrives for Monday and Tuesday with little subtle moisture lingering Wednesday. The GFS remains the most energetic with the more distinct inverted trough/tropical wave and vorticity. The ECMWF shows more ridging with just slighlty lower rain chances. None the less forecast trends with isolated to scattered activity through Wednesday with always isolated heavier downpours in the slow moving cells. Temperatures remain seasonal with both the GFS/ECMWF in good agreement with the NBM consensus and previous forecasts. Highs range from near 90 degrees at the coast to lower 100s far west with 75 to 80 degree for overnight lows. Heat indices range from 103 to 108 each afternoon. && .AVIATION... (00Z TAFS) Issued at 632 PM CDT Wed Aug 24 2022 VFR conditions now with moderate southeast winds and scattered high clouds moving in from the north. A dissipating front to the north and an inverted surface trough overhead will keep slight convective chances alive on Thursday, but not enough to include in this TAF set. Lighter southeast winds on Thursday may favor a weak sea breeze. Other than any convection along the front well to the north tomorrow, a few cells could develop over the Gulf. However, VFR conditions should prevail the next 24 hours. && .MARINE... Issued at 246 PM CDT Wed Aug 24 2022 (Tonight through Thursday Night): Favorable marine conditions persist through the Short Term period with seas at 1 to 2 feet and light to moderate southeasterly flow. There is a chance of showers and thunderstorms tomorrow evening due to a surface low pressure system moving through the area. (Friday through Monday):The pressure gradient across the western Gulf of Mexico remains weak to moderate through the weekend and into early next week. Possible periods of fresh breezes Friday afternoon and Monday as two inverted troughs or the northern extent of tropical waves pass into NE Mexico. Generally light to moderate southeast winds and lows seas are expected. Showers and thunderstorms can be expected daily and overnight/early morning with more widespread coverage Friday, Sunday and Sunday night/Monday. && .PRELIMINARY POINT TEMPS/POPS... BROWNSVILLE 97 79 97 79 / 10 0 20 20 HARLINGEN 97 77 96 78 / 10 0 30 20 MCALLEN 100 78 101 78 / 10 0 20 20 RIO GRANDE CITY 102 79 100 78 / 10 10 20 30 SOUTH PADRE ISLAND 89 81 88 80 / 20 0 10 20 BAYVIEW/PORT ISABEL 92 79 93 78 / 10 0 20 20 && .BRO WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...54-BHM LONG TERM....69-Farris AVIATION...54-BHM
Area Forecast Discussion
National Weather Service Cheyenne WY
245 PM MDT Wed Aug 24 2022 .SHORT TERM...(This evening through Thursday) Issued at 241 PM MDT Wed Aug 24 2022 Latest surface analysis shows a low pressure center moving into southern MN with a trailing cold front across northern NE into east- central WY. GOES satellite imagery shows CI mainly over the higher terrain early this afternoon with a few brief storms. Strongest storm so far has developed in the North Laramie Range, but has struggled to maintain itself when detaching from the higher terrain. Storms are expected to continue into early this evening with 1000-1200 J/kg and up to 25 kts of shear per latest RAP guidance along and north of the Pine Ridge. Will need to monitor storms moving out of the Black Hills along with off the southern Big Horns with northwest flow over the area and southeast storm motions. A few strong storms are possible of producing small hail and gusty winds. Hi-res guidance shows most storms in the area dissipating by 9pm, however more storms are expected again Thursday. An upper level shortwave looks to move across central WY. Lee trough looks to develop with a surface low near the CO/NE/WY border with a strong east to west pressure gradient. Synoptically driven scattered showers will develop starting late Thursday morning over Carbon and Albany Counties before intersecting areas of instability around 1000 J/kg in east-central WY. Could see a few strong storms develop mostly along a line from Douglas to Chadron and points north where increased 500mb flow will provide better shear profiles. Additionally, will need to monitor for strong winds across the North Platte River valley in the late afternoon as storms in southeast Wyoming dry out east of the Laramie Range in addition to strong MSLP gradients. A few hi-res models showed wind gusts 40-45 mph near Torrington and Scottsbluff. .LONG TERM...(Friday through Wednesday) Issued at 241 PM MDT Wed Aug 24 2022 An unsettled pattern is expected for the extended forecast with near-daily chances for showers and thunderstorms. Some lingering energy from Thursday`s shortwave will help trigger some convective activity across the CWA. Friday has the potential for marginally severe storms, mainly for our more northern zones. In this area better CAPE (~1000 J/kg), shear (~25 to 30 kts) and dewpoints exist. Model soundings show inverted-V profiles with over 1000 J/kg of DCAPE so a wind threat is possible with any storms that develop. Heavy rain as well as small hail is also possible with these storms. The first half of the weekend looks mostly dry as the shortwave moves off to the east and a trough develops to the west. This will allow a ridge axis to develop over the Rockies on Saturday leading to drier conditions. Cannot rule out a few isolated storms developing over the high terrain, but the plains should remain mostly dry. For Sunday, the GFS and ECMWF are mostly in agreement for some scattered thunderstorms over the high terrain and adjacent plains. Originally, these models had an upper-level trough passing through the CWA on Sunday, but now these models have slowed the progression of it down, thus, decreasing precipitation chances and coverage. By Monday, models still have the upper-level trough/low off to the west in Idaho/Nevada. Again, this looks to limit the coverage and chances of storms to the high terrain and adjacent plains. Tuesday, the upper-level low passes off to the northwest and into Montana. Some scattered storms look possible during the afternoon, but coverage of storms looks better potentially overnight as moist southeasterly flow streams into the CWA. && .AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon) Issued at 1134 AM MDT Wed Aug 24 2022 Biggest aviation concern for the TAF period is the chance for scattered showers and thunderstorms this afternoon and evening. Thunderstorms may contain gusty and erratic winds at times. Conditions will likely stay VFR as thunderstorms will be high based, but cannot rule out brief MVFR conditions if visibility drops in moderate to heavy rain. Southeast Wyoming terminals will mainly be affected this afternoon and evening. Storms develop this evening near western Nebraska terminals. Storm chances will likely wrap up by about 03Z this evening. && .FIRE WEATHER... Issued at 241 PM MDT Wed Aug 24 2022 Elevated fire weather conditions continue this afternoon west of the Laramie Range with RHs dropping into the low 20s and upper teens. Chances for showers and thunderstorms continues along the higher terrain this afternoon extending into lower elevations of Converse and Niobrara Counties through early this evening. Afternoon RHs in the 20s looks to remain through the extended period with Saturday being the driest. Could see near-critical fire weather conditions Saturday afternoon as wind gusts around 30 mph look possible, especially along and west of the Laramie Range. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...None. NE...None. && $$ SHORT TERM...MB LONG TERM...SF AVIATION...SF FIRE WEATHER...MB
Area Forecast Discussion...CORRECTED
National Weather Service Austin/San Antonio TX
659 PM CDT Wed Aug 24 2022 ...New AVIATION... .SHORT TERM... (Tonight through Thursday night) Issued at 145 PM CDT Wed Aug 24 2022 A stalled out frontal boundary remains situated over South-Central Texas, located from Del Rio to San Antonio to Gonzales. Scattered showers and the occasional isolated thunderstorms have developed along this boundary and locally heavy rainfall will once again be possible if one of these manages to park itself over your location for more than 30 minutes. Rainfall rates of 1-2" per hour are possible, given long skinny sounding profiles as well as high PWATs in the 1.9-2.2" range per SPC RAP mesoanalysis. One thing to note: very little in the way of lightning has been observed with storms this morning and early this afternoon. Expect that trend to continue, but if storms manage to light up a bit more, convective rain showers will contain locally heavier rainfall rates. We should carry the rain and isolated thunderstorm chance through sunset before chances decrease overnight, especially east of the Rio Grande Plains. Hi-Res CAMs do indicate a slightly higher chance for heavier rainfall over the Rio Grande and Winter Garden region through tomorrow morning, then spreading north and east through the afternoon. Much-needed rainfall will be taken whenever we can get it and the active pattern is expected to continue into the end of the week. && .LONG TERM... (Friday through Wednesday) Issued at 145 PM CDT Wed Aug 24 2022 A relatively homogeneous long term period is in store with highs in the upper 80s to mid 90s, lows mainly in the 70s, and low-end rain chances mainly in the afternoons most days. Humid conditions will remain in place with dew points likely in the upper 60s to mid 70s even in the afternoons. Coverage of any rains will be isolated at best except the Coastal Plains could see scattered coverage on some days but many if not most locations along and west of I-35 will probably remain dry in the Friday-Tuesday period. Higher uncertainty Tuesday night into Wednesday, but PWATS will be back on the increase with deeper SE flow off the gulf and heights look to be on the decrease, so chances for rain are likely to increase once again. Locally heavy rains will re-enter the realm of possibility next Wednesday through Friday. && .AVIATION... (00Z TAFS) Issued at 635 PM CDT Wed Aug 24 2022 VFR flight conditions to prevail through the period with a mix of mainly broken and overcast mid to high level clouds. Light rain and/or a vicinity shower remains possible over the next hour or two at the KAUS, KSAT, KSSF TAF sites before chances lower to unmentionable levels. A shower chance persists at KDRT through the night with a nearby thunderstorm still possible, especially early. Daytime heating allows for return of scattered convection on Thursday across South-Central Texas. This will result in the return of VCTS for the KDRT, KSAT and KSSF TAFS where the highest chances exist towards the west. Elected to go with VCSH at KAUS during Thursday afternoon with the lowest chances for convection across that area. Winds remain light from out of the north to east-northeast. && .PRELIMINARY POINT TEMPS/POPS... Austin Camp Mabry 75 93 75 95 / 20 30 10 20 Austin Bergstrom Intl Airport 74 92 75 95 / 20 30 10 20 New Braunfels Muni Airport 74 93 74 95 / 30 40 20 20 Burnet Muni Airport 73 91 73 94 / 20 30 10 20 Del Rio Intl Airport 76 90 75 93 / 40 50 30 30 Georgetown Muni Airport 74 92 74 94 / 20 30 10 20 Hondo Muni Airport 75 91 75 93 / 40 40 30 20 San Marcos Muni Airport 74 92 72 95 / 30 40 20 20 La Grange - Fayette Regional 75 92 72 94 / 30 40 20 30 San Antonio Intl Airport 76 91 75 94 / 30 40 20 20 Stinson Muni Airport 76 94 76 94 / 30 40 20 20 && .EWX WATCHES/WARNINGS/ADVISORIES... None. && $$ Short-Term...Morris Long-Term...KCW Aviation...Brady
National Weather Service New Orleans LA
324 PM CDT Wed Aug 24 2022 .SHORT TERM (Tonight through Friday)... A surface low is currently centered near Shreveport with a stalled from extending southwest of there and a warm front/secondary stalled front extending to the east across northern LA and central MS. Abundant moisture and ample instability in place this morning across SELA and S MS set provided the setup to support sustainability for a cluster of showers and storms to pass east across the area. As of 20Z, the eastern edge of the strongest storms are shifting east into AL. There`s still some lingering showers along and north of I-12 and scattered thunderstorms south in the New Orleans Metro. Latest meso data shows local MUCAPE values around 250 J/KG. That means impact from the current activity should be fairly minimal. CAMs suggest convection north of I-10 will completely dissipate this evening with just coastal LA parishes seeing persistent scattered convection. Moving into Thursday, there`s really not much change expected at the surface or aloft. Thus, another round of showers and thunderstorms can be expected. GFS and the HRRR suggest convective initiation starts early (before 15Z) west of I-55, then spreads east throughout the day. Other CAM`s aren`t quite as early with initiation, but still suggest numerous showers and storms again. At the end of the day, near 100% expected, just not nailed down exactly timing. This will be the case for Friday as well. Although the surface low and residual frontal boundary should be gone by then, ample moisture will still be in place. Upper trough just east of the area will keep subsidence limited, thus high POPs continue. MEFFER && .LONG TERM (Saturday through Tuesday)... There really doesn`t seem to be a dominant upper level pattern in place across the CWA with mostly zonal flow during this timeframe as the trough to the east moves further east. Model PW indicates a fairly steady southeasterly flow of 2"+ air. Even though there won`t be a focus for convection, lack of ridging aloft means high daily convective coverage. Therefore, saw no reason to modify NBM`s 70-80 POPs. They may be a little high if the ridge to the west starts to shift east, closer to the CWA. That`s still a week or more out, so holding on to `wet pattern` forecast for now. MEFFER && .AVIATION... Widespread showers and isolated thunderstorms continue to track across the region. Low cloud decks and off/on periods of heavy rain will result in MVFR to LIFR conditions throughout the forecast period. Rain coverage may dwindle during portions of the overnight timeframe, but new develop looks possible early Thursday morning. MEFFER && .Marine... Numerous thunderstorms will continue to form over the nearshore waters over the next several days mainly during the late night into mid morning hours. Broad scale winds and seas will remain in a light southerly flow of 5 to 10 knots and seas of 2 feet or less. The main concern from any thunderstorms will be brief periods of gusty winds up to around gale, frequent lightning, and the potential for a few waterspouts. && .PRELIMINARY POINT TEMPS/POPS... MCB 70 82 70 84 / 80 100 40 90 BTR 74 85 73 87 / 70 100 40 90 ASD 74 85 73 88 / 80 100 60 90 MSY 76 85 75 86 / 70 100 60 90 GPT 74 82 74 86 / 90 100 60 90 PQL 73 82 72 87 / 90 100 60 90 && .LIX WATCHES/WARNINGS/ADVISORIES... LA...Flood Watch until 7 PM CDT this evening for LAZ034>037-039-071. GM...None. MS...Flood Watch until 7 PM CDT this evening for MSZ068>071. GM...None. && $$
Area Forecast Discussion
National Weather Service Nashville TN
743 PM CDT Wed Aug 24 2022 ...New UPDATE... .UPDATE... Issued at 737 PM CDT Wed Aug 24 2022 A few showers are ongoing south of I-40, although the HRRR does show these mostly dissipating as the evening wears on. We may not entirely go PPINE, but very little activity is expected overnight. The 00Z sounding from OHX does show very dry air above ~750 mb, with a pronounced elevated inversion that has us more or less capped off ~700 mb. So we don`t expect any convection to develop this far north at least while the elevated inversion remains as is. The deepest moisture remains to our south this evening, but will creep slowly northward while we also get squeezed by a weak surface boundary and shortwave approaching from the NW. So look for greater rain chances beginning tomorrow. We do still expect some fog development after midnight as dew points start to creep up. No forecast changes are planned at this time. && .SHORT TERM... (This afternoon through Thursday Night) Issued at 239 PM CDT Wed Aug 24 2022 For an August day, this is shaping up to be a nice one. Temperatures are currently around the low to upper 80s, depending on how much cloud cover is overhead. Our southern counties have stayed on the cooler side, along with the higher elevations of the Cumberland Plateau. Heavy rain and storms continue to plague the southern half of Mississippi and are moving into Alabama. That robust activity will stay well south of us, but we will likely see spotty showers and storms develop this afternoon and evening as some of that moisture spreads north. The best chance of isolated showers and storms will be around I-40 and to the south, but a few very isolated cells could wander north of I-40. Dewpoints have been pleasant for most of the day today, but we`re already seeing some 70s dewpoints sneak up from Alabama into our southern most counties. This trend will continue over the next 24 hours. The increasing low level moisture and calm winds will provide conditions conducive to fog from midnight tonight through sunrise tomorrow for most of the area. Precip chances will be a little more widespread tomorrow with scattered storms possible for all of Middle TN. There will be slightly more instability around tomorrow, but no shear, so there could be some gusty winds, but organized severe is unlikely. && .LONG TERM... (Friday through next Wednesday) Issued at 239 PM CDT Wed Aug 24 2022 The remainder of the forecast isn`t a washout, but we`ll be stuck in a pattern with scattered showers and storms possible each day. A passing upper trough on Friday will increase precip coverage in the afternoon, but the trough axis will pass to our east Friday evening. Weak ridging on Saturday may suppress activity to just a few isolated storms in the afternoon, but southerly surface winds and sunshine will allow temperatures to warm into the low 90s that day. Overnight lows will be returning to the 70s as southerly surface flow sticks around through this weekend. A weak upper trough looks to be heading our way as the work week starts next week, but high pressure to our east wins out and that wave appears to fall apart as it reaches our western edge. So we`ll see the moisture linger in our area in the form of humidity and storms, but no real frontal passage looks likely. So no cool wave of relief, but also not much support for organized severe in the extended portion of the forecast. && .AVIATION... (00Z TAFS) Issued at 630 PM CDT Wed Aug 24 2022 Terminals could deal with a period of fog after midnight especially close to dawn. Vis was dropped at all taf sites and was dropped to 1/4 sm in a tempo group at CSV. Models show the potential for sct/bkn MVFR cigs in the morning before cigs increase to VFR for the afternoon. It is possible a terminal is impacted by a shower or storm during the afternoon, but chances are too low to include at this time. && .PRELIMINARY POINT TEMPS/POPS... Nashville 70 88 71 89 / 0 30 20 40 Clarksville 67 87 69 88 / 0 20 10 30 Crossville 65 82 66 81 / 0 40 20 50 Columbia 68 87 69 88 / 10 30 20 30 Cookeville 67 85 68 84 / 0 30 20 40 Jamestown 65 83 66 82 / 0 30 20 50 Lawrenceburg 67 85 69 87 / 10 40 20 40 Murfreesboro 68 88 70 88 / 10 30 20 40 Waverly 69 87 69 89 / 10 20 10 30 && .OHX WATCHES/WARNINGS/ADVISORIES... None. && $$ UPDATE.......Rose SHORT TERM...Whitehead LONG TERM....Whitehead AVIATION.....Reagan
Area Forecast Discussion
National Weather Service Pocatello ID
134 PM MDT Wed Aug 24 2022 .SHORT TERM...Today and Thursday. There is an upper level low over the state of Washington currently with southwest flow aloft over our area. Models show monsoon moisture moving into our area this afternoon in the evening mainly across the Southeast Highlands and the Upper Snake plain this evening. For the Central mountains precipitable water amounts look to be 0.5 to 0.8 supporting a mix of wet and dry thunderstorms. Look for scattered showers and widely scattered thunderstorms for the Central mountains. Small hail and gusty winds up to around 40 to 45 mph are likely. Just north of our area, northern Lemhi County, SPC has this area in a marginal risk for severe thunderstorms supporting moderate hail and gusts of around 50 to 55 mph due to stronger forecasted CAPE and shear amounts. Across our Southeast, precipitable water amounts are 0.80 and rise to near 1 inch overnight. This precipitable water of around 0.8 to 0.9 moves into the Upper Snake Plain after midnight. For the Southeast/Caribou Highlands and Island Park area expect scattered showers and widely scattered thunderstorms. Brief moderate to heavy rainfall is likely in these areas. CAPE and shear support gusty winds of around 40 mph (possible higher) and small (possibly moderate) hail. Outside of the Island Park area, Southeast Highlands, and the Central mountains, look for isolated showers and thunderstorms. Gusty outflow winds are likely, up to around 40 mph. With Southwest flow this afternoon, the Snake plain and ridge tops will see breezy winds with gusts of 25 mph prior to any thunderstorm outflows. Friday the upper level low moves slowly eastward. It pushes most of the monsoon moisture and instability eastward. Models show the best chances of isolated to scattered convection on Thursday afternoon across the Montana Divide region, favoring the Beaverhead, Island Park, Upper Snake Plain and Driggs areas. Temperatures will continue to be in the 70s to 80s in the mountains and 80s to low/mid 90s for lower elevations. Wyatt .LONG TERM...Friday through next Wednesday. Operational models have most of southern Idaho under a zonal flow on Friday with 700mb winds around 20kts across the Snake Plain. This will make things a bit breezier than we have been over the past few days. Models also show some isolated thunderstorms Friday afternoon. As we head into the weekend, an upper low will deepen into the WA/OR coast, but there is some uncertainty on its depth and trajectory. Run-to-run consistency among the models has been poor, but the overall forecast for the weekend is trending cooler and wetter. Looking to the beginning of next week, models are trying to figure out the disposition of the upper low. Previous days` model runs had already been establishing a strong upper ridge by Sunday or Monday. Ridging may now be delayed until about the middle of next week. This means cooler temperatures, particularly Sunday and Monday with a warming trend thereafter. There will still be a potential for isolated afternoon thunderstorms through the extended periods. Hinsberger && .AVIATION...For the 18z Wednesday TAFs. Today look for afternoon and evening showers and thunderstorms due to an upper level over the state of Washington and monsoon moisture coming up from Utah. The best areas of thunderstorms will be the Central mountains, Southeast Highlands, and along the Montana Divide. Expect vicinity showers and thunderstorms for all TAF sites. KPIH and KDIJ have the best chance of showers and thunderstorms on station. The HRRR model shows this the best chance of thunderstorms on station for PIH is from 22z to 01z today. For DIJ, the best chance of thunderstorms on station is from 00z to 03z this evening. Look for gusts up around 35 to 40 mph with thunderstorms outflows. Small hail, lightning, and brief moderate rainfall are likely as well. Wyatt && .FIRE WEATHER...Upper level low pressure continues to spin over eastern Washington with a shortwave lifting northeastward out of NV. Look for widely scattered thunderstorms across southeast Idaho this afternoon through mid-evening. PWATs range from around 0.5 to 0.8" in the Central Mountains to 0.8" to 0.9" over the Southeastern Highlands. PWATs are higher in northern Idaho in proximity of the upper low. SPC has a MRGL risk of severe thunderstorms in the extreme northern tip of zone 475, so outflow winds could be an impact at the Moose Fire. High-res models show convection continuing through 6am tomorrow across the eastern fire zones. The upper low will continue to influence convective activity tomorrow afternoon, with models initiating convection around 3 pm along a line from Mackay to Island Park, and another area over the Caribou Highlands. Friday looks a bit drier with only some isolated convection over the MT and WY borders, but Friday will also be a bit breezier than we`ve been these past few days. Saturday and Sunday look somewhat breezy as well, and much will depend on the trajectory and intensity of the upper low. At this point there is a lot of uncertainty on whether we will see an upper low or an open trough. Humidity will likely bottom out Monday and Tuesday next week as ridging intensifies over the West, though it doesn`t appear winds will be a critical factor. Hinsberger && .PIH WATCHES/WARNINGS/ADVISORIES... None. && $$
Area Forecast Discussion
National Weather Service Phoenix AZ
508 PM MST Wed Aug 24 2022 .UPDATE... Updated Aviation .SYNOPSIS... Today is expected to be another active storm day over central and western Arizona and southeast California with some storms producing strong to severe winds and blowing dust. Heavy rainfall and localized flooding will also be possible across southeast California and western Arizona where Flood Watches are in effect for this afternoon and evening. A gradual downtrend in storm chances will then take place into the weekend with rain chances likely ending altogether by early next week. Slightly below normal temperatures are forecast through the weekend before a warming trend begins Monday. && .DISCUSSION... Another active day is expected as strong to severe thunderstorms, particularly across southeast California and southwest Arizona, are expected through the afternoon/evening hours. Currently, visible satellite imagery and radar show thunderstorms generally confined across the high terrain of the northern Baja Peninsula as well as the interior mountains of interior southeast California. Meanwhile across Arizona, CU development continues to increase with thunderstorms mostly confined to the higher terrain/Mogollon Rim at the moment. HiRes guidance once again favors thunderstorm development across the high terrain north and east of the Phoenix area through the rest of the afternoon. Easterly steering flow will be weaker compared to yesterday but expect it to be enough to push isolated to scattered thunderstorms into parts of the lower deserts. The latest NBM PoPs puts thunderstorm chances around 40% this evening across the lower deserts of south-central Arizona, including the Phoenix metro. Primary concerns with the strongest thunderstorms will be isolated strong to severe thunderstorm wind damage, gusty outflow winds capable of generating some blowing dust, and locally heavy rainfall/flash flooding. These thunderstorms will continue in an unstable environment characterized by MLCAPE values upwards of around 1,000-1,500 J/kg as indicated by SPC mesoanalysis. This morning`s CIN shown on the 24/12Z PHX sounding is expected to mostly erode away through the afternoon according to modeled soundings and RAP data, though some of the more recent model runs keep slightly higher inhibition in place compared to earlier runs, which would potentially impact thunderstorm development. As of now, the latest HREF and HRRR runs show some activity surviving into parts of the Phoenix area. Across southeast California, southwesterly upper level flow associated with an upper level ridge situated to the southeast of the region over northern Mexico is expected to push the thunderstorms currently along the mountains west and southwest of our CWA into parts of the lower elevations of southeast California over the next several hours. These thunderstorms will move into an increasingly moist and unstable environment characterized by MLCAPE values upwards of 2,000-3,000 J/kg and PWAT values around 2" across southeast California and southwest Arizona. Given the better moisture and instability, heavy rainfall leading to flash flooding will be more likely. HREF suggests upwards of a 50% chance of 3 hour rainfall totals exceeding 1" across in some areas. Given the parameters, a Flood Watch is in effect for much of this area through 1 AM MST/PDT Thursday. Strong to severe thunderstorms will be possible, leading to the potential for damaging winds, blowing dust and perhaps some hail, given the instability in place. HREF indicates about a 50-70% of winds exceeding 35 mph and even a 10% chance for gusts to meet severe criteria. DCAPE values upwards of 1,500 J/kg will support this strong to severe wind potential. Some guidance suggest the idea of merging outflows from activity across southeast California and northern Arizona. This would likely result in additional thunderstorm development. Thunderstorms may linger into the overnight hours before winding down thereafter. .PREVIOUS DISCUSSION... Starting Thursday, the H5 high center is forecast to reform south of our area, leading to an eventual shift in our mid level flow out of the west. There will still be abundant moisture for showers and thunderstorms across the area on Thursday, but with less instability and the steering flow turning westerly the coverage of storms is likely to be far less than today. Westerly flow is expected to increase across the area Friday into Saturday as a fairly strong upper level trough is forecast to move across the Pacific Northwest into the Great Basin. Noticeable drying will start to spread over the area from west to east starting Friday leaving little to no storm chances across California and southwest Arizona. Friday and Saturday may shape up to be quite active across the higher terrain of Arizona with adequate moisture remaining in place for showers and storms, while forced ascent increases over the area as the trough approaches. The stronger winds aloft should also lead to increased shear and the potential for stronger/longer lasting storms. This activity is likely to remain north of the Phoenix area, but can`t rule out a few storms clipping the foothills areas just north of Phoenix. Showers and storms will also be fairly likely across Gila County Friday into Saturday with NBM PoPs between 40- 60%. The main threats for these storms are likely to be strong winds and brief heavy rainfall, but any training of storms could lead to localized flooding despite the quicker storm movement. As early as Sunday, but especially by Monday, rain chances will be less than 10% across the lower deserts as the westerly drying continues and PWATs drop below 1.4" to possibly as low as 1". This much drier air should shut down nearly all storm activity across the area, even over higher terrain areas. Model ensembles generally agree this break in monsoon conditions will persist through the first half of next week. After near to below normal temperatures across the area through the upcoming weekend, the drier conditions will bring a warming trend early next week. At this point, NBM guidance shows temperatures reaching normals by Monday and then above normal into the middle part of next week. Seems somewhat likely some of the western deserts will again see highs of around 110 degrees at some point next week. && .AVIATION...Updated 0008Z. South-Central Arizona including KPHX, KIWA, KSDL, and KDVT: Outflow boundaries with abrupt wind shifts will be the primary weather hazard through Thursday morning. Confidence remains good that the current light southerly winds will switch to northeasterly as an outflow from distant t-storms to the north moves into and across the Phoenix area during the 01Z-02Z timeframe. Gusts 20-30kt seem realistic at this point. Chance of TS directly impacting any aerodrome is now down to 20-30%, with enough confidence to only include VCSH mention in the TAFs at this time. Confidence in any SHRA lingering behind the outflow boundary as well as trends in wind directions during the late evening/overnight is fairly low. Enough evidence exists that sfc winds will slosh back to some form a northwesterly direction late this evening/around midnight to include in this TAF package. More typical easterly drainage winds are expected to develop sometime well after midnight/towards morning, then persist thru Thursday afternoon. Chances for t-storms impacting the Phoenix area look to be less on Thursday afternoon/evening (10-20%) as somewhat drier air filters into the region. Thus, have left out any mention of t-storms in the TAFs at this point. Southeast California/Southwest Arizona including KIPL and KBLH: Strong outflow boundaries with abrupt wind shifts along with direct TS impacts will be significant weather hazards for SE CA terminals this evening. Gusty southwesterly winds are expected to continue for the next hour or so as t-storms move across western Imperial County. Once the storms move off to the north, winds are expected to revert back to a southeasterly direction until sometime just after midnight. A period of gusty northeasterly winds are likely later tonight/towards morning as outflows from storms over NW AZ move into SE CA. Winds are then once again expected to revert back to a southeasterly direction during the day on Monday. During the mid/late evening hours, confidence is moderately good storms over Mohave County will surge south towards KBLH with its own round of strong outflow. Strong wind gusts aoa 35kt and brief visibility reductions due to BLDU will be possible with some MVFR/IFR conditions possible. SHRA and variable wind directions may persist well into the overnight hours with winds reverting back to a southerly direction on Thursday. && .FIRE WEATHER... Storm activity will again be fairly widespread today with areas of strong winds, heavy rainfall, and localized flooding all possible, particularly across southeast California and southwest Arizona. A gradual decline in storm chances will take place from west to east beginning Thursday, but the high terrain north and east of Phoenix should remain fairly active into the weekend with good chances for daily thunderstorms through Saturday. Substantial drying will spread across the area starting Sunday, essentially ending rain chances across the lower deserts and then likely even over the Arizona high terrain for early next week. MinRH values will generally remain in a 30-35% range over lower elevations to 40-50% over the higher terrain through Sunday, before lowering starting Monday. Apart from thunderstorms, winds will follow familiar diurnal patterns. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...Flood Watch until 1 AM MST Thursday for AZZ530>533-536. CA...Flood Watch until 1 AM MST Thursday for CAZ560>570. && $$ DISCUSSION...Smith PREVIOUS DISCUSSION...Kuhlman AVIATION...Percha/18 FIRE WEATHER...Kuhlman
Area Forecast Discussion
National Weather Service Blacksburg VA
746 PM EDT Wed Aug 24 2022 .SYNOPSIS... High pressure will remain over the region tonight into Thursday. Low pressure crossing the Upper Mid-West into the Great Lakes is expected to bring increasing chances for showers and storms by the weekend. && .NEAR TERM /THROUGH THURSDAY/... As of 735 PM EDT Wednesday... Isolated to scattered showers in the North Carolina Foothills and Mountains this evening. The quasi-stationary front remains across the Gulf Coast states tonight into Thursday. High pressure will be situated over the central Appalachians. The combination of heating and low level convergence triggered isolated shower or thunderstorm across the higher terrain the southwest mountains. The Namnest and HRRR continue to support the isolated convection. LAPS and MSAS analysis showed a pocket of greater instability along the Blue Ridge in Surry and Wilkes County. This area will gradually stabilize and most of the showers and isolated thunderstorms will dissipate by 11PM. Most areas will remain dry tonight. The 5h trough over the Gulf Coast states deepens tonight, so enough moisture may override the front allow for an small threat of showers overnight along the southern Blue Ridge. Skies will be partly to mostly cloudy tonight. The most cloud cover will be along/south of the VA/NC border. High pressure will exit offshore on Thursday, while a broad upper level trough resides across the East. Scattered showers and storms will develop in the afternoon, especially along the southern Blue Ridge. && .SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY NIGHT/... As of 147 PM EDT Wednesday... Any showers and thunderstorms Thursday afternoon will fade through the evening. Showers will reenter the mountains late Friday afternoon as an upper level trough and a cold front approach the area from the west. The front is expected to stall just west of the south-central Appalachains Thursday evening. After midnight, these two features will track over the area. With a westerly wind already established ahead of this system, only isolated showers are expected overnight. By the time we hit peak heating Saturday, the trough and front should be over the coastal piedmont of VA/NC. There is a chance the models maybe a little too aggressive pushing the front east Saturday. So we will keep a chance for storms over the piedmont Saturday afternoon and evening. Temperatures through the period will run close to normal. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... As of 147 PM EDT Wednesday... An upper level ridge will move across the southeastern and Mid Atlantic states Sunday into Tuesday. Scattered pulse storms are possible each afternoon across the mountains. A cold front is expected to move into the region Thursday and possibly stall over the area into next weekend. This system will bring widespread showers and thunderstorms to the area late this week. With the upper level ridge in the region, temperatures will run 3F-5F warmer than normal. && .AVIATION /00Z THURSDAY THROUGH MONDAY/... As of 745 PM EDT Wednesday... Scattered to isolated MVFR showers and thunderstorms over the North Carolina foothills and along the southern Blue Ridge will dissipate by 03Z/11PM as the atmosphere gradually stabilizes. No rainfall is expected to impact area TAFs. IFR to LIFR fog will form tonight, mainly after 06Z/2AM in the valleys west of the Blue Ridge, including at KLWB and KBCB. The fog is expected to be shallow and will dissipate by 14Z/10AM. Scattered to broken cumulus will develop be afternoon with ceilings from 4-7kft. Scattered showers and thunderstorms with MVFR ceilings and visibility will form in during the afternoon. Coverage will be more extensive than on Wednesday, but probability at any particular airport remained too low to include in the TAFs at this time. KBCB would be the most likely location for a thunderstorm after 18Z/2PM. Average confidence in ceilings,visibilities and wind. .Extended Aviation Discussion... Mainly VFR conditions expected into the weekend. Exceptions will be the normal cycle of late night IFR/LIFR fog in the mountain valleys and scattered mainly afternoon and evening MVFR thunderstorms. Storms chances increase Monday and Tuesday especially in the mountains. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...None. NC...None. WV...None. && $$ SYNOPSIS...PM/WP NEAR TERM...AMS/KK SHORT TERM...RCS LONG TERM...RCS AVIATION...AMS/KK