Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 09/03/22

Area Forecast Discussion
National Weather Service La Crosse WI
1047 PM CDT Fri Sep 2 2022 .DISCUSSION...(This evening through Friday) Issued at 251 PM CDT Fri Sep 2 2022 Key Messages: - Shower/storms chances continue into tonight - Slightly cooler and mostly quiet weather through the weekend * Scattered shower and storms tonight The shortwave trough currently over Manitoba will continue to shift east into Ontario through the evening. The attending cold front continues to drop south/southeast, with current surface analysis showing the front draped northeast to southwest across MN. Ahead of this front temperatures are in the 80s, with dewpoints across the local area in the 60s and some locations just over 70. CAMs continue to suggest scattered showers and thunderstorms will develop along and ahead of the front where there is more low-level convergence. However, there continues to be some uncertainty in the coverage and location of the development, with the latest runs of the HRRR and RAP consistently showing the least development across central portions of the forecast area. With the increased moisture ahead of the front, models continue to show MLCAPE values nearing 2500 J/kg ahead of the front, but quickly decreasing through the night. Shear still looks to be quite marginal, which would limit severe potential some. Model soundings show an inverted-v profile with DCAPE values nearing 1000 J/kg. So, with any storms that do develop, stronger wind gusts could be possible. Some locally heavy downpours could also be possible, with hail not completely ruled out. The front will continue to push southeast across the forecast area through the night. Model guidance suggests that showers and storms may redevelop into the day on Saturday across portions of our far southwest Wisconsin and northeast Iowa counties. Otherwise high temperatures will be a bit cooler (70s) behind the front on Saturday. * Mostly quiet weather Sunday through much of next week Sunday through a majority of next week is anticipated to have fairly quiet weather conditions with precipitation chances holding off to the south and east of the forecast area. The 02.00z cluster analysis (34%) continues to lean towards high pressure persisting over the western CONUS with a ridge building through southern Hudson Bay area. Although compared to yesterday`s 01.00z run where 32% of the members were favoring that main cluster, the gradient of height anomalies has tightened over the area being between the previously mentioned slanted ridge to the west and eastern trough stretching from the northeast Atlantic Coastal states southwestward into the far southern Great Plains. Will stick with the blended model guidance with keeping preciptiation chances out of the area being more under the ridge. However if the trough retrogrades more than what the main cluster currently suggests, then some low end precipitation chances would be introduced into portions of the area. Afternoon high temperatures will start off on the cooler side in the 70s, but eventually recover from the cold frontal passage bringing upper 70s to mid 80s for the work week. Similarly impacted from the overall synoptic pattern, a more retrograded trough would lead to slightly lower temperatures. && .AVIATION...(For the 06Z TAFS through 06Z Saturday night) Issued at 1046 PM CDT Fri Sep 2 2022 As drier air moves into the region, skies will clear overnight. Winds will shift from the south and southwest to the north. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ DISCUSSION...MEP/EMS AVIATION...Boyne
Area Forecast Discussion
National Weather Service Birmingham AL
727 PM CDT Fri Sep 2 2022 .UPDATE... Evening Update and 00Z Aviation. && .SHORT TERM... /Updated at 0701 PM CDT Fri Sep 02 2022/ The latest RAP analysis has a zone of MLCAPE values around 2000 near the Mississippi state line. Although there is some instability, the overall low level convergence is lacking. This is the easterly boundary that swung across the region yesterday evening. The boundary gradually washes out but a few showers and storms are possible this evening. Another set of boundaries are approaching from the southeast. These appear to be the remnant seabreeze circulations from the Gulf and Atlantic. Held the highest pops southeast and southwest this evening. It appears the main surge from southern Georgia will hang mainly in Georgia, but certainly will monitor for potential impacts near the state line. Otherwise, rain chances held through the overnight hours with lows mainly in the 70s. Low clouds and some patchy fog will develop after midnight and hang around into Saturday morning in several locations. 75 Previous short-term discussion: /Updated at 102 PM CDT Fri Sep 02 2022/ Moisture levels have substantially increased in the low levels over the past 24 hours, with all observation locations across Central Alabama observing 70+ degree dewpoints. The old surface boundary has progressed northwestward and is now stretching roughly from southwest to northeast from near Selma to Cherokee County. That boundary will eventually become diffuse with time, but remain a trigger for isolated to scattered showers and storms through this afternoon. Highest rain chances will remain across the far southeast, where the greatest fetch of tropical moisture will reside. The 12z KBMX sounding profile from this morning still shows a very large amount of dry air aloft which will prevent widespread development across the northern half of the forecast area. With more moisture across the south, we`ll keep an eye on a few storms that could contain some gusty winds with SBCAPE values around 4000 J/kg and DCAPEs over 1000 J/kg. Warmer temps aloft should prevent robust updraft development and we`re not expecting widespread strong storms as a result. This afternoon`s update keeps mention of at least a slight chance of showers through the overnight hours, especially across the north which is closer to the upper level trough that is slowly approaching from the northwest. Showers and storms are expected to increase in coverage on Saturday as the upper trough moves into the region with southerly to southwesterly flow dominating across the atmospheric profile. With tropical moisture and upper level shortwave activity moving through the base of the upper trough, numerous showers and storms can be expected during the day on Saturday. With lots of outdoor activities planned, interests should be prepared for passing showers and storms with brief heavy downpours possible. We`re not expecting all day rains, but folks may have to take shelter at times through the day. Mesoscale boundaries will also dictate where more concentrated showers and storms are able to develop. For now, all areas have been mentioned with likely PoPs and will need to update the forecast through the day tomorrow based on mesoscale trends and movement of boundaries. 56/GDG .LONG TERM... /Updated at 255 PM CDT Fri Sep 02 2022/ No major changes were made to the extended forecast. We remain in a wet pattern with a positive upper trough extending from the Great Lakes into TX over the weekend with SW flow over C AL allowing for waves of shortwave activity with convection enhanced during peak heating. As we move into mid week, troughing looks to build over E Conus centering over MS River Valley with onshore flow into C AL increasing. With increased moisture, this should help to keep our max temperatures a couple of degrees milder. 08 Previous long-term discussion: /Updated at 335 AM CDT Fri Sep 02 2022/ Sunday through Thursday. A positively-tilted upper-level trough is progged to position from the Southern Plains toward the Great Lakes Region this weekend. This will provide a corridor of modest southwesterly flow aloft from the Lower Mississippi Valley into the Mid Appalachians. Tropical moisture will reside across the Deep South as a result of these considerations and a southerly fetch of 925-850 mb flow. With an abundance of moisture, widespread showers and thunderstorms are forecast Sunday afternoon as a shortwave perturbation moves from near LA northeast across Central Alabama. This disturbance should move northeast of the forecast area Monday morning, though scattered to widespread showers and thunderstorms are once again forecast as southwesterly deep-layer flow remains in place with elevated PWs generally 2.0" or above. This could foster some heavy downpours at times, both Sunday and Monday, with GFS/ECMWF forecast soundings depicting saturated profiles and narrow CAPE (MLCAPE <1,000 J/kg). The predictability of the upper- level configuration decreases by Tuesday. Medium range guidance continues to disagree on the evolution of the aforementioned trough, as well as other synoptic features. PoPs were decreased toward the end of the period to account for this uncertainty. However, they remain ~50% as consensus/ensembles suggest a continuation of wet & unsettled weather. 40/Sizemore && .AVIATION... 00Z TAF Discussion. Afternoon convection is already waning. There may be a few showers or storms near MGM/TOI the next few hours, otherwise, held out any mention the remainder of the night. There is a boundary moving up from the south and another stationary boundary near the Mississippi state line that may trigger some activity the next few hours. Will monitor for potential impacts. Low level moisture has increased and there will be lift in these layers. Therefore, anticipate low clouds and patchy fog development tonight. This coverage should be a bit more than last night. Have some mention of IFR ceilings at most locations around 12z, with fog a lesser impact. These ceilings slowly rise through 16z. Winds will be east southeast and light overnight and become southeast around 5 kts on Saturday. Showers and storms will exhibit more coverage by Saturday afternoon than today. Once again, expect terminals to have tempo or prevailing in later issuances. 75 && .FIRE WEATHER... All fire weather elements will remain below critical thresholds over the coming days. Moisture content will be on the increase today, with periods of showers and storms expected through the weekend. The best focus will be in the afternoon into the evening. 20 foot winds should average less than 10 knots. && .PRELIMINARY POINT TEMPS/POPS... Gadsden 71 86 69 83 69 / 20 70 70 90 70 Anniston 72 85 71 83 70 / 20 70 60 80 60 Birmingham 72 87 71 84 71 / 20 70 60 90 60 Tuscaloosa 73 87 72 83 71 / 30 70 60 80 50 Calera 72 86 71 84 71 / 20 70 60 90 60 Auburn 71 84 71 84 71 / 40 60 50 80 50 Montgomery 73 89 73 88 72 / 40 60 40 80 50 Troy 72 88 71 88 72 / 40 60 40 80 40 && .BMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
Area Forecast Discussion
National Weather Service Columbia SC
748 PM EDT Fri Sep 2 2022 .SYNOPSIS... Moisture will spread into the area over the weekend due to a persistent onshore flow. With a weak to moderately unstable air mass, scattered to numerous showers and thunderstorms are expected mainly in the afternoon and early evening the next few days. Temperatures are expected to be near normal. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... Upper level low continues over southern Georgia this evening. The showers earlier this evening have mainly shifted to the west and the surface boundary has become more diffuse. This is in line with the high resolution CAMS. Deep moisture continues along the Savannah river with precipitable water near 2 inches with drier air to the north of CAE where precipitable water falls 1.3 inches in the Pee Dee. The forecast appears on track with a low pop in the CSRA where precipitable water and potential upper level forcing remains. Satellite showing extensive mid and high clouds across the CSRA with higher clouds advancing east from the Upstate. With stratus clouds potentially developing late in the night, expect lows to generally end up in the upper 60s and low 70s across the region. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/... High pressure off the mid Atlantic coast will remain nearly stationary through Sunday with an upper level trough over the MS River Valley. This will keep easterly flow over the region and push Atlantic moisture into the forecast area with pwat values rising to around 2 inches Saturday afternoon. Although the upper trough will remain west of the region and keep upper level divergence out of the area there will be enough instability to trigger afternoon and evening convection. Support for severe weather remains limited however there is potential for locally heavy rainfall. Potential for hydro related issues remains low however a few areas across the southern Midlands and CSRA have received locally heavy rainfall over the past couple days and will be monitored. Sunday will be very similar as the synoptic situation will be very slow to change. This will keep the moist onshore flow in place with pwat values remaining around 2 inches and the upper trough remaining west of the region. Instability will again be weak to moderate however with upper level dynamics again lacking expect another round of mainly diurnal convection. Pops will range from chance in the northern Midlands and Pee Dee to likely in the CSRA. Locally heavy rainfall potential will again be possible and need to be monitored across the southern Midlands and CSRA. Temperatures will be in the mid to upper 80s each day with overnight lows in the upper 60s to low 70s. && .LONG TERM /MONDAY THROUGH FRIDAY/... An amplified upper level pattern combined with a weak Rex block over the mid Atlantic will limit progression of the upper level pattern and keep the synoptic scale pattern relatively unchanged as well. Ensembles remain in good agreement with some progression differences late in the period. This will keep deep moisture across the region through the long term with high chance to likely pops each day. With the chances of rain and expected cloud cover afternoon high temperatures will be in the low to mid 80s which will be slightly to several degrees below normal. && .AVIATION /00Z SATURDAY THROUGH WEDNESDAY/... Low level moisture convergence boundary provided SCT TS/SHRA activity earlier at AGS/DNL. The activity has shifted west of there now. Slightly drier air has mixed in at CAE/CUB with late afternoon dewpoints in the mid to upper 60s. Higher dewpoints at OGB/AGS/DNL, with rain received at AGS/DNL, leading to dewpoints in the lower to mid 70s at those locations. Models are indicating the surface ridge to build down the eastern seaboard a little tonight, with an inverted trough developing near the coast, with light boundary layer winds backing from SE to more of a E to ENE. This appears will keep CAE/CUB in the drier air, so will not indicate restrictions at those sites tonight. Latest HRRR and SREF indicating flight restrictions, mainly in stratus, near AGS/DNL and points westward. Will indicate IFR conditions at AGS/DNL, VFR at CAE/CUB, with OGB somewhere in between. On Saturday, the surface boundary near AGS/DNL appears to become more diffuse and shift to the west some. Nonetheless, moisture is expected to increase from the south and east. Guidance suggests sct diurnal TS/SHRA, more likely to affect OGB/AGS/DNL. So, for now, will indicate VCTS at AGS/DNL/OGB, with VCSH at CAE/CUB, in the afternoon. Later shifts can upgrade TS mention if/when confidence warrants. EXTENDED AVIATION...Chance of mainly afternoon thunderstorms, and late night/early morning fog/stratus. && .CAE WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. && $$
Area Forecast Discussion
National Weather Service Dodge City KS
607 PM CDT Fri Sep 2 2022 ...Updated Aviation Discussion... .SHORT TERM...(This evening through Saturday) Issued at 340 PM CDT Fri Sep 2 2022 The main forecast challenge will be coverage, severity, duration of any thunderstorm activity across west central and southwest Kansas this evening. The next shortwave trough embedded in the northwest flow aloft was moving across eastern Wyoming into adjacent Nebraska Panhandle, which was aiding in larger scale upward vertical motion across western Nebraska. Weak to modest boundary layer convergence across southwest Nebraska led to development of initial showers and thunderstorms in vicinity of McCook. This is pretty close to where the latest several runs of the HRRR model was initiating storms mid afternoon, although the HRRR may be an hour or two too slow with development and southward movement of the initial activity as it moves into northwest KS. As far as severe weather potential goes, there will be enough deep layer shear to support at least loosely organized multicell structures, if not briefly marginal supercell structures like last night`s Dodge City storm. The greatest severe weather risk will be damaging straight line wind in excess of 65 mph with the strongest storm. The next question then becomes how long into the evening any storms last. It will most likely be similar to last night in that once we see loss of direct insolation, activity will wane, but if an organized cold pool can be maintained, then severe/marginally severe wind could be possible through 03Z (10 PM CDT) as far south as Highway 50 corridor. Tonight`s convective activity will most likely be it for rain chances with this system, as the cool surface high pressure ridge continues to expand south late tonight into Saturday. Saturday`s thunderstorm focus will be confined to the Texas Panhandle/West Texas and adjacent western Oklahoma. Saturday afternoon should be fairly pleasant with a sunny sky, light wind, and highs topping out upper 80s to around 90. .LONG TERM...(Saturday night through Friday) Issued at 340 PM CDT Fri Sep 2 2022 Quiet weather is most likely to prevail the duration of the Long Term period. In fact, the latest NBM guidance gives our entire forecast area no mentionable precipitation chances from Saturday through Thursday Night of next week, as the upper level ridge will continue its influence across the West, and any shortwave troughs in the north/northeasterly flow pattern will likely be east of our southwest Kansas forecast area. Peering into the longer range global ensemble information stuff, both the GEFS and the EPS show some weak signal of slightly increased chances for precipitation toward the end of the forecast period (Wed-Thur 7-8 Sep). Otherwise, persistence will be a pretty good forecast method for temperatures with lower-mid 90s each day for highs and lower 60s for lows. && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) Issued at 601 PM CDT Fri Sep 2 2022 As of 23z Friday an area of convection was increasing in coverage where improving 0-1km moisture convergence was occurring across northwest and north central Kansas. RAP was in good agreement with moving this boundary/convection south tonight. These storms will begin to weaken/taper off after sunset as they move south. At this time it appears that Garden City will have the best chance for thunderstorms between 03z and 06z Saturday. Hays also has a chance but storms near the terminal between 04z and 07z Saturday but these appear to be more isolated, if they occur. Southeast winds at around 10 knots will shift to the northwest and increase into the 15 to 25 knot range as outflow from these storms pass the Garden City and Hays areas. The outflow boundary/cold front will cross the remainder of southwest Kansas between 06z and 12z Saturday which will also bring a wind shift in the winds at Dodge City and Liberal. In these areas the southeast winds at 10 knots or less will become northwest at around 15 knots as this cold front passes. && .PRELIMINARY POINT TEMPS/POPS... DDC 65 92 57 90 / 20 10 0 0 GCK 64 93 57 90 / 20 10 0 0 EHA 63 93 59 91 / 20 20 10 0 LBL 63 94 59 91 / 10 10 10 0 HYS 65 90 54 86 / 20 0 0 0 P28 67 95 59 91 / 10 10 10 0 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Umscheid LONG TERM...Umscheid AVIATION...Burgert
Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
1150 PM EDT Fri Sep 2 2022 .AVIATION... While there is some concern that the southeast winds off the warm waters of Lake Erie may allow some fog development into metro Detroit late tonight, the light sfc winds are forecast to veer more toward the south just prior to daybreak. This and the high clouds overhead suggest enough uncertainty in fog potential to leave the mention out of the 06Z metro Detroit TAFs. Se Mi will reside generally in a benign pattern through most of the day Saturday, positioned outside of the influence of an upper low over MO/IL. A cold front will slide south during the afternoon from northern Michigan and into the MBS region late Saturday afternoon. This front will support a chance of showers and thunderstorms late Sat afternoon and MBs and into the evening at FNT. While the surface front is forecast to advance into metro Detroit Sat night, the drop in instability will limit the convective potential farther south. DTW THRESHOLD PROBABILITIES... * Low for ceilings at or below 5kft on Saturday afternoon and evening. Moderate Saturday night. && .PREV DISCUSSION... Issued at 358 PM EDT Fri Sep 2 2022 DISCUSSION... A standard uptick in warm and humid air is in progress over the central Great Lakes today as south wind gradually increases between New England high pressure and the next upper Midwest cold front. Inbound surface Td in the mid and upper 60s has been adequate for a moderate cumulus response over interior sections of southern Lower MI while radar trends showed an isolated/short-lived return as of mid afternoon. This reflects weakening of an already fragile cap under a hint of 500mb ridge and surface high pressure that barely reaches back into SE MI. RAP and hi-res model output are about split on the cap holding vs isolated convective development with mid afternoon observations suggesting a lean toward isolated showers as the mid MS valley 500mb trough drifts closer this evening. Any showers fade with the loss of daytime heating while a generous complement of high clouds holds with mild temperatures into Saturday morning. The bulk of Saturday is dry and at least partly sunny before the Midwest cold front becomes the subject of conditions in SE MI for the remainder of the holiday weekend. It settles eastward into central Lower MI late in the day while becoming further removed from the northern stream upper level flow and somewhat aligned with the Ohio valley trough. Despite the unfavorable positioning, there is a notable convective response across the range of model solutions affecting the Saginaw valley and Thumb with coverage likely getting a boost from the higher terrain of northern Lower MI and as afternoon high temperatures approach the 90 degree mark. The general thunder SPC outlook appears on target in an otherwise soft lapse rate and low shear environment. High pressure strengthens impressively across northern Ontario and Quebec Saturday night downstream of the pronounced northern stream upper level ridge. The surface pressure rise combines with a nocturnal release off Lake Huron to propel the cold front through SE MI Saturday night into Sunday morning before stalling just south of the Ohio border. This appears primarily due to continued influence of the southern stream trough that is also stalled across the Ohio and mid MS valleys. Elevated portions of the frontal slope are shown extending well north over the south half of Lower MI which keeps a chance of showers in the forecast for Sunday into Sunday night mainly along and south of the I-69 corridor. After that, there is some spread among the deterministic model solutions on positioning of the southern stream 500mb trough and therefore also the surface front. A slight trend toward a farther east position is noted in the ECMWF and GFS runs which matches up Ok with NBM POPs more confined to the Ohio/Canadian borders through Labor Day. The mid week period is setting up dry with temperatures around normal for early September. This is subject to extended range models holding a forecast of the upper level ridge folding over the Great Lakes from both the northern stream and the 4 corners area. The Ohio valley trough clings to life while being nudged farther south toward the Gulf coast toward late next week. MARINE... Southerly winds 10 to 20 knots this afternoon ahead of a cold front pushing into the Western Great Lakes, with modest decreasing winds speeds tonight. This front looks to drop south through Lake Huron on Saturday, leading to a wind shift. Scattered showers and thunderstorms are likely to develop during the afternoon. Strong high pressure will then build over Eastern Canada through Sunday, and this will lead to prolong moderate northeast winds, gusting 20 to 25 knots. This will cause a build up of waves over southern Lake Huron basin, reaching and exceeding 4 feet, and small craft advisories have been issued Saturday evening through Sunday evening. It is possible the advisory will be extended as northeast winds continue into Monday, but the strength of the winds are a bit in question and are forecasted to reach at or below 15 knots by Tuesday. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...None. Lake Huron...Small Craft Advisory from 7 PM Saturday to 10 PM EDT Sunday for LHZ421-422-441>443. Lake St Clair...None. Michigan waters of Lake Erie...None. && $$ AVIATION.....SC DISCUSSION...BT MARINE.......SF You can obtain your latest National Weather Service forecasts online at
Area Forecast Discussion
National Weather Service Goodland KS
538 PM MDT Fri Sep 2 2022 .SHORT TERM...(This evening through Saturday night) Issued at 130 PM MDT Fri Sep 2 2022 Overview: Modest NW flow aloft (~300 mb).. on the eastern periphery of an upper level ridge (presently centered over the Intermountain West).. will prevail through tonight. In the lower- levels, a cold front -- presently extending southwestward from Lake Superior to far northeast Nebraska -- will progress southeastward into WI/IA and northern MO late this aft/eve and overnight. The far western fringe of the frontal zone/thermal gradient (in western Nebraska) should move little /remain near- stationary/.. and the SFC-H85 pattern over the Tri-State area (GLD CWA) will likely remain ill-defined. The aforementioned ridge aloft (over the Intermountain West) will amplify and extend eastward over the Rockies on Sat. Today-Tonight: Challenging convective forecast. Forcing will be confined to [potential] small amplitude waves (250-300 mb level) in modest NNW-NW flow aloft and [perhaps] outflow emanating from nearby and/or upstream convection in Nebraska. A west-east oriented low- level moisture/instability axis is present over the region.. with MLCAPE ranging from ~250 J/kg in eastern CO to 1000-1500 J/kg invof Hwy 283 (Norton/Hill City). Since 00Z.. the HRRR has steadily trended toward decreased convective development/coverage/intensity in southwest NE and northwest KS this aft/eve. Given that convection allowing guidance tends to be less reliable in weak forcing regimes.. whether or not this trend is reasonable remains uncertain. With northerly steering flow.. diurnal development along the CO Front Range should largely be relegated along/west of a line from Limon-Akron. Steep (8-9 C/km) mid-level lapse rates and strong (1200-1500 J/kg) DCAPE will foster a potential for brief/localized severe downbursts with any updraft capable of producing lightning. Severe hail cannot be ruled out -- mainly in northeast portions of the area where ~30 kt effective deep layer shear overlaps greater low-level moisture/ instability -- and organized updrafts are [relatively] more likely (21-02Z time frame). Sat-Sat night: With upper level flow further weakening (i.e. a reduced potential for small amplitude waves progressing over the area).. expect dry conditions. Guidance suggests that cooler temperatures (upper 80s) will prevail on Sat.. perhaps depending on the degree/extent of convective airmass modification upstream of the area this evening. .LONG TERM...(Sunday through Friday) Issued at 104 PM MDT Fri Sep 2 2022 The long term period looks to remain relatively uneventful with above normal temperatures and dry conditions. Upper level pattern remains stagnate with high pressure over the west which will slowly traverse east throughout the week. Potential may exist for some rogue diurnally driven showers and storms to develop Sunday and Monday, but confidence is very low in this occurring. Elevated fire weather conditions may be possible Monday and Tuesday afternoons as RH values are currently forecasted in the mid to upper teens west of Highway 25. The "breeziest" day appears to be Monday thus far with sustained winds of 10-15 knots during the afternoon, winds Tuesday currently appear to be around 10 knots. Temperatures each day will be in the upper 80s to mid/upper 90s with the currently warmest day appearing to be Wednesday where some locales may be able to reach the triple digits. Some cooler weather may be in store during the latter portion of the extended due to an approaching cold front. Mex guidance indicates temperatures in the mid 80s, whereas the GFS has the front up across the northern Plains still on Friday, then there is the ECMWF which keeps the high pressure over the western CONUS in place. It appears that not all guidance is on board with timing and evolution of the front, but there does appear to be potential for more normal temperatures and our next chance of precipitation into next weekend. && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) Issued at 520 PM MDT Fri Sep 2 2022 KGLD expects to see VFR conditions throughout the 00Z TAF period beginning with easterly winds around 8 kts with thunderstorms in the vicinity of the terminal. At 03Z, KGLD winds become variable around 6 kts when the thunderstorm threat ends before becoming east-northeasterly around 9 kts at 10Z. By 19Z, KGLD sees winds become easterly once again around 11 kts. KMCK also sees VFR conditions during the 00Z TAF period starting with northeasterly winds around 8 kts that become variable around 5 kts at 01Z. By 06Z, KMCK winds return to northeasterly around 8 kts and then increase to around 11 kts at 18Z. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...VINCENT LONG TERM...Trigg AVIATION...076
...Updated Aviation Forecast Discussion...

.DISCUSSION... Issued at 246 PM CDT Fri Sep 2 2022 .Forecast Summary: - Isolated strong to severe storms remain possible late this afternoon through evening. - Cooler this weekend, then turning warm again next week. .Late this afternoon and tonight: Early afternoon mesoanalysis places a surface cool front from northwest IA through northeast NE into central NE. That boundary will continue south through the remainder of our area this afternoon and evening. Isolated to widely scattered convection has persisted this morning ahead of the front, and is likely rooted in the midlevels atop an elevated-mixed-layer. Additional, surface- based thunderstorm development remains possible along the front from late afternoon through the evening hours. The 12z CAMs and the last several runs of the HRRR indicate varying degrees of storm coverage and intensity along the front. The FV3 and NSSL-ARW are the most aggressive solutions, whereas the HRRR shows little in the way of thunderstorm development. A possible explanation for the model variance is the weak forcing for ascent attending the surface front. 2 pm (19z) SPC mesoanalysis data indicate a moderately unstable air mass ahead of the front with a gradually weakening cap. Continued heating ahead of the front should support further weakening of the cap with isolated, surface-based storm development becoming more probable by late afternoon or early evening. The current vertical wind profile derived from the KOAX radar data is exhibiting pronounced veering with height through the lowest 3 km with 35-40 kt of deep-layer shear. When combined with the moderately unstable, steep-lapse-rate environment, the setup is supportive of organized multicell and/or supercell structures. So, there is a conditional threat for hail up to quarters or ping-pong-ball size and/or wind gusts of 55-65 mph, mainly in the 6 pm to 9 pm timeframe. Any storms that develop should either dissipate or exit our area by midnight. .This weekend: Midlevel ridging will build across the northern Plains into the upper-MS Valley with downstream troughing from the Great Lakes into southern Plains. In the low levels, we will remain within influence of surface ridging, which will maintain a cooler Canadian air mass across the region with highs in the upper 70s to lower 80s. .Next week: The 12z EPS, GEFS, and CMCE mean 500-mb height anomalies indicate elongated ridging from the Great Basin through the Great Lakes through the middle of next week. Thereafter, the western component of the ridge will begin to weaken in response to an evolving trough over the Pacific Northwest. In regard to sensible weather, that upper-air pattern is conducive for above-normal daytime temperatures with low rain chances. && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) Issued at 537 PM CDT Fri Sep 2 2022 VFR conditions through the period. Winds are northerly at KOFK, and will become that way at KLNK/KOMA by 06-08z. Looking more likely that storms may not develop tonight, so continued to keep the forecast at KLNK/KOMA dry. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...None. IA...None. && $$ DISCUSSION...Mead AVIATION...DeWald
Area Forecast Discussion
National Weather Service Norman OK
1041 PM CDT Fri Sep 2 2022 ...New AVIATION... .SHORT TERM... (This evening through Saturday) Issued at 248 PM CDT Fri Sep 2 2022 After a very active week, the weather pattern today is a bit more benign this afternoon. The MCV/trough interaction that has dominated our weather pattern for days has shifted eastward for the time being. In its wake, a remnant frontal boundary remains across north central Oklahoma with a confluence zone noted across our southeastern CWA from Ardmore to Ada. Plenty of instability remains across the area, with HRRR forecasts of up to 3,000 J/kg of MLCAPE. However, the deep tropical moisture has abated somewhat, and without high mid-tropospheric relative humidity convective towers that attempt to develop into full-fledged thunderstorms will be entraining less-favorable air. The anticipation is that this will reduce the amount of randomly scattered convection across the area, with storms mainly focusing along and southeast of the confluence zone in our southeastern CWA. These storms may contain strong gusty winds, as the drier mid-level air will encourage DCAPE of up to 1,400 J/kg. Flooding may also be an isolated concern, although the reduction in moisture and modest northerly flow through much of the troposphere should mitigate that. Any convection in that region should diminish rapidly with the loss of daytime heating tonight. There is a chance for storms to approach the northern CWA from Kansas late overnight. A few 0Z HREF members showed this outcome occurring, but none of the 12Z members did. Thus, left PoPs below anything mentionable in the area. Low temperatures were bumped up slightly with high surface dewpoints, similar to the pattern last night. By tomorrow, a belt of stronger northerly 500 mb flow will approach the area from the north. Most models depict an embedded shortwave trough within this flow pattern. This pattern will push a cold front southward into northern Oklahoma. The two features seem primed to initiate convection by mid-to-late-afternoon. Strong daytime heating will lead to deeper, more well-mixed boundary layers than we have seen recently, with MLCAPE reaching about 1,500 J/kg. Every 12Z HREF member depicts robust, scattered to widespread convection across the CWA. The rub is that they all depict that convection in slightly different locations - the HRRR and ARW depict convection along the cold front in northern Oklahoma, while the NAM 3km, NSSL, and FV3 all depict convection near and south of the Red River at the same time. Have opted to introduce 25-35 PoPs area-wide with the highest values covering the northern Oklahoma cold front region and the the western north Texas counties. MEISTER && .LONG TERM... (Saturday night through next Thursday) Issued at 248 PM CDT Fri Sep 2 2022 The cold front will push further south Saturday night, bringing drier air in particular to northwest Oklahoma. This should act to limit rain chances in the medium-term to southeastern Oklahoma, where the front will have the most difficult time penetrating. A weak cyclogenesis event across north Texas Sunday into Monday will help to stall the front in that region. Thus, the best chances of showers and storms through Labor Day will be south and east of I-44. NBM is also quite a bit warmer with high temperatures this weekend into next week. Opted to knock a couple of degrees off of the highs for the next few days, as high rainfall totals should favor latent heat fluxes during the afternoon. Let NBM high temperatures stand toward the end of the forecast period, as soils should begin to dry back out if we have several days of sunshine in a row. MEISTER && .AVIATION... (06Z TAFS) Issued at 1034 PM CDT Fri Sep 2 2022 A few high clouds will move into northern OK overnight, as storms across far SW KS continue to dissipate. Some patchy BR is still expected early in the morning but for now have only mentioned VFR visbys. It will be difficult to determine where/if they drop to or below MVFR. Another round of thunderstorms is expected tomorrow, likely somewhere from northern to central OK from 21-03Z. PROB30 groups have been included for several of the terminals. && .PRELIMINARY POINT TEMPS/POPS... Oklahoma City OK 70 91 67 90 / 20 30 20 10 Hobart OK 71 94 67 92 / 20 40 20 10 Wichita Falls TX 72 92 70 92 / 20 40 20 10 Gage OK 66 92 62 90 / 10 40 20 0 Ponca City OK 67 93 64 90 / 10 40 20 0 Durant OK 71 91 71 92 / 30 20 20 20 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...None. TX...None. && $$ SHORT TERM...04 LONG TERM....04 AVIATION...03
Area Forecast Discussion
National Weather Service Pocatello ID
140 PM MDT Fri Sep 2 2022 .SHORT TERM...Tonight through Saturday night. Ridge of high pressure remains centered over the central Great Basin this afternoon. A low pressure system is working up the western side of the ridge and will pass through Washington into the Idaho Panhandle on Saturday. The ridge is simply too strong and the airmass over central and east Idaho too dry to support any rain chances. However, we will see some wind gusts of 20 to 25 mph Saturday afternoon. Winds look slightly stronger, closer to the low, across the central mountains where a red flag warning is in effect. Temperatures for Saturday look very hot and record-breaking. Highs will be in the upper 90s to near 100 across much of the Snake Plain and Magic Valley. There is approximately a 50% chance of any given location in the Snake Plain or Magic Valley seeing 100 degree on Saturday. Smoke and haze primarily from the central Idaho fires will persist across central and east Idaho into Saturday with the HRRR smoke indicating that visibilities along the I-15 corridor may reduce to 5 miles or less during the overnight hours tonight. However, once the winds kick in Saturday afternoon that should lift much of the smoke into Montana. Although some smoke/haze will linger across the upper Snake Plain and central mountains into Saturday night. Valle .LONG TERM...Saturday through Thursday. Models continue to show ridge holding strong through Wednesday with NBM probabilities supporting a greater than 50% chance of high temperatures of 95 or more across the Snake Plain and eastern Great Basin. For this reason, have decided to extend the heat advisory through Tuesday to fully cover the Labor Day weekend. Around 80% of model clusters now support the ridge breaking down late week. About half of the members support a deep low moving through the Pac NW (similar to the 12z operational ECMWF) while 30% favor a shallow trough solution (similar to the 12z operational GFS). So there`s a lot of uncertainty as to how much cooler we will be for late week and whether or not we see precipitation. The potential for some form of wind event certainly exists as the ECMWF Extreme Forecast Index (EFI) is highlighting central and east Idaho Wednesday into Thursday. Valle && .AVIATION...High pressure will give way to a trough passing through western Montana, but with little effect for the five airdromes, except for the return of high elev clouds to KBYI and KSUN at the very end of the TAF period. Wind should increase during Sat afternoon, just beyond the current TAF period. Until the trough gets close, the wind will continue light. The stagnant air will make smoke and haze an issue, especially during overnight periods when the air is its most stable. However, no fire is near enough to any airport to do more than bring marginal VFR at its worst. Most affected appears to be KSUN, which is closest to the active wildfires. Messick && .FIRE WEATHER...Low pressure crossing through western Montana will do little to bring significant moisture to central and eastern Idaho, perhaps some high-level cloudiness. But it will bring some gusty wind. This will combine with the extreme high temperatures and extreme low humidity to create Red Flag conditions in some of the fire weather zones. On Sat, it will be the central Idaho mountains, with gusts to 40 mph in some areas. The hardest hit should be Zone 476, and pretty much everywhere, while Zone 422 and 475 will see a good percentage of the area affected. On Sunday, the strong winds shift southward, where the Wood River valley, eastern Magic Valley and the Snake River plain are at risk for reaching critical fire weather conditions. Right now, the wind just barely qualifies for the gust threshold, but there are good portions of the eastern part of 425, the southern portion of 422, and the western portion of 410 that should reach their respective criteria for wind and humidity. The wind subsides for Mon while conditions stay hot and dry. The strongest feature of the week should arrive Wed night: a dry cold front that should bring moderate to strong wind, and for Thu a cool down. Messick && .PIH WATCHES/WARNINGS/ADVISORIES... Heat Advisory until midnight MDT Tuesday night for IDZ051>059- 075. Fire Weather Watch from Sunday afternoon through Sunday evening for IDZ410-422-425. Red Flag Warning from 3 PM to 9 PM MDT Saturday for IDZ475-476. Red Flag Warning from noon to 9 PM MDT Saturday for IDZ422. && $$