Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 07/27/22

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
851 PM CDT Tue Jul 26 2022 .UPDATE... Issued at 849 PM CDT Tue Jul 26 2022 The sfc front has exited the region this evening, thus the main chances for rain have shift east/south of the CWA. The rest of the night looks pretty much dry. That said the HRRR does try to bring in isold showers late, but am not sure it`s worth the mention in the forecast, so far now will keep it dry. Temperatures look fine. && .SHORT TERM...(This Evening through Wednesday Night) Issued at 258 PM CDT Tue Jul 26 2022 The forecast challenge is lingering precipitation chances tonight/Wednesday along with temperatures. At 2 PM CDT, skies are partly cloudy and winds have switched around to the northwest behind a cold front that is almost through the CWA. Winds out ahead of the front are out of the southwest. Temperatures have been warming through the 70s and 80s this afternoon. The earlier showers/weak thunderstorms ended a couple hours ago. However, beginning to see the cold front up in North Dakota and Minnesota become active here this afternoon. There are even a couple of showers developing on the boundary over this CWA over/near the Clark/Day/Codington counties border area. The general consensus is enough instability/shear exists over this frontal boundary to support some isolated/widely scattered multi- cellular convection this afternoon into early this evening mainly east of a line from Lake City to Tulare. Not really expecting any severe weather out of this afternoon`s convection. Perhaps some small hail and localized heavy downpours will be the biggest threats with most of the convection. Once the boundary clears the eastern edge of the CWA, precipitation chances take a break. There is some question as to whether or not a couple of shortwaves embedded within northwest flow cloud bring some small/localized rain shower chances to the CWA later tonight and then again on Wednesday. Overall, the region is being influenced at the surface/in-the-low- levels by high pressure working down out of Canada tonight through Wednesday night. Leaning moreso toward a dry forecast for now in the short term, with room to introduce some small pops as needed. Temperatures are going to be dropping into the 50s overnight tonight, and again Wednesday night. Actually, it would not be a surprise if a few localities across north central South Dakota dip down into the upper 40s for low temperatures Wednesday night. The low level neutral air or cold air advection pattern will help keep the lid on temperatures Wednesday, with highs likely only topping out in the 70s, with some low 80s possible down over southwest and south central South Dakota. .LONG TERM...(Thursday through Tuesday) Issued at 258 PM CDT Tue Jul 26 2022 Surface high pressure will be parked over the area Thursday and looks to stick around through the day Friday. This will bring dry conditions and coolish temperatures in the 70s and low 80s. Low temperatures Friday morning under the high could still potentially drop into the upper 40s under the right radiational cooling conditions. Current forecast lows are in the low 50s to right around 50 for most areas, but NBM10 still showing some upper 40s, so not totally out of the question given the right conditions. It`s not until Friday night when the surface high moves away and warm/hot air begins moving back into the region for the weekend, with highs rising back into the 80s and 90s. Dewpoints likely getting back into the 60s as well, mainly east of the Missouri. Not overly oppressive, but still a noticeable uptick in the muggy conditions nonetheless. As for precipitation, things look mostly dry throughout the period. About the only time there looks to be a chance for precip would be Saturday night into Sunday, as shortwave energy and a surface trough move through the area. That said, an ensemble approach to POPs would suggest keeping chances fairly low at this time. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday Evening) Issued at 608 PM CDT Tue Jul 26 2022 Terminals KABR,KATY,KPIR,KMBG VFR skies/vsbys are expected through tonight regionwide. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...None. MN...None. && $$ UPDATE...TDK SHORT TERM...Dorn LONG TERM...TMT AVIATION...TDK
Area Forecast Discussion
National Weather Service Duluth MN
648 PM CDT Tue Jul 26 2022 .DISCUSSION...(This evening through Monday) Issued at 311 PM CDT Tue Jul 26 2022 Summary: A cool week ahead with several cold fronts bringing showers and thunderstorms for the first half of the week. Dry at the end of the week, but heating up for the weekend. A cold front is moving through the Northland today. A few of the cells that it has generated up on the Iron Range have produced copious amounts of rainfall (in excess of 3”). CAPE has been underplayed from prior model guidance – the latest RAP analysis has around 1500 to 2000 J/kg of MUCAPE with higher values near Brainerd where surface dewpoints are in the mid 60s. PWATs near 1.5” will support healthy rainfall totals with whatever convection continues with the cold front this evening. After the cold front passes, it appears fog may be a threat overnight as saturated soils with clearing skies should generate a good environment for fog. Winds will be light, but not calm so that could be a limiting factor with mixing still occurring albeit weak/light. A weaker cold front will cross Wednesday for more shower activity, but most of that should be north of Highway 2. High pressure builds for the latter half of the week giving quiet weather. Friday and Saturday should be dry and a little warmer after what should be a cool week. An upper trough approaches for Sunday bringing back a chance for showers and storms. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 649 PM CDT Tue Jul 26 2022 A cold front is passing through this evening with showers and thunderstorms associated with it. The rain has passed through HIB/INL and will pass through DLH/BRD in the next hour or two. HYR will see shower and storm chances starting in a couple hours. A wind switch to northwesterly will follow the frontal passage. Winds will become lighter tonight, and with the clearing skies and high moisture content at ground level due to today`s rainfall, there is a chance for some fog to develop. Fog is not a guarantee at all terminals, and visibilities will likely fluctuate a bit if fog does form. This is mainly because winds are not likely to become completely calm, and there may be enough mixing in place to prevent dense fog except for short durations. The only exception may be at HYR where the timing of the frontal passage and rain may be just right for winds to become very light behind the cold front for a period later tonight, allowing a greater probability of some dense fog. An approaching upper level trough may allow for some scattered redevelopment of showers later tonight, mainly at INL/HIB. VFR conditions are expected for most of tomorrow morning, but scattered showers and storms are likely to develop during the afternoon with upper level waves and another cold front passing through. && .MARINE... Issued at 311 PM CDT Tue Jul 26 2022 Sub-SCA conditions out on the lake for the next 48 hours, but gusts will flirt with 20 knots this afternoon as a cold front crosses bringing non-severe thunderstorms with it. Fog is expected to develop overnight into Wednesday. && .PRELIMINARY POINT TEMPS/POPS... DLH 56 76 55 70 / 50 30 20 50 INL 51 71 52 65 / 30 80 60 60 BRD 56 76 54 70 / 30 20 10 20 HYR 56 77 52 70 / 70 20 10 40 ASX 58 79 56 73 / 70 20 20 40 && .DLH WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. LS...None. && $$ DISCUSSION...Wolfe AVIATION...JDS MARINE...Wolfe
Area Forecast Discussion
National Weather Service Houston/Galveston TX
644 PM CDT Tue Jul 26 2022 .AVIATION [00Z TAF Issuance]... While activity along the sea breeze has dissipated, there does ap- pear to be additional development approaching from the E/NE. But, the loss of daytime heating should help to keep things quiet into the evening/overnight hours. Brief patchy low clouds/fog is going to be possible at some inland terminals around sunrise once again. Rain chances could be enhanced a bit more tomorrow as a series of weak shortwaves approach and move across from the east. Kept with the mention of VCTS for most sites tomorrow afternoon. 41 && .PREV DISCUSSION /Issued 334 PM CDT Tue Jul 26 2022/... SHORT TERM [Tonight Through Wednesday Night]... Afternoon showers and thunderstorms are a little more active this afternoon due to increased low level moisture. Temperatures outside of rain-cooled air remain relatively unchanged with inland areas reaching the upper 90s to low 100s this afternoon and coastal areas reaching the mid 90s. Overnight lows will only cool down to the upper 70s to low 80s. Tomorrow`s weather pattern will be fairly similar again, except an easterly moving mid-level shortwave will undercut the ridge overhead. This combined with continued low level moisture advection will enhance rain chances tomorrow. Should the shortwave arrive early (like the 18Z HRRR is suggesting) then, we can expect more coastal showers in the morning that will push inland throughout the day, before dissipating by the late afternoon as the environment gets mixed over. However, other hi-res models are hinting at the shortwave arriving later and coinciding with peak daytime heating. If that`s the case, we can expect enhanced sea breeze and bay breeze convection in the afternoon and dissipating after sunset with the loss of daytime heating. Long story short, rain chances will range from 30-40% tomorrow compared to the 20% today. Regarding tomorrow`s temperatures, 850mb temperatures cool a degree or two and this combined with some increased cloud cover will help cool surface temperatures a few degrees. Despite this, we can still expect inland areas to reach the upper 90s to low 100s while coastal areas will reach the low to mid 90s. Overnight lows on Wednesday will cool to the upper 70s to low 80s again. Lenninger LONG TERM [Thursday Through Tuesday]... The persistent mid/upper level ridge will continue to bring above normal temperatures to the area at the end of the week, over the weekend and on into the start of next week. Our area will occasionally reside on the southern fringes of the ridge which will allow for the possible of weaknesses (inverted troughs) to move across the area and bring us a chance of showers and thunderstorms (20%-30% range). At this time, it looks like Thursday (and maybe Friday?) might end up being our best chance of seeing these storms through the period. The big weather issue will still be the heat with highs in the upper 90s thru lower 100s inland and in the lower to mid 90s near and along the coast. Heat index values look to continue to peak just below Heat Advisory levels almost every day. Have included a Climate section below with some updated information on the July heat. 42 .CLIMATE... Here is an update on hot July has been. For July 1-25... -College Station ...Average high is 103.4 degrees (8.3 degrees above normal) (warmest July on record is 101.1 in 1917) ...Average low is 78.5 (3.7 degrees above normal) (warmest July on record is 77.5 in 2009) ...Average temp is 91.0 (6.1 degrees above normal) (warmest July on record is 89.1 in 2009) -Houston ...Average high is 98.9 degrees (4.6 degrees above normal) (warmest July on record is 99.4 in 1980) ...Average low is 77.8 (2.2 degrees above normal) (warmest July on record is 78.3 in 1963) ...Average temp is 88.3 (3.3 degrees above normal) (warmest July on record is 87.5 in 1980) -Houston Hobby ...Average high is 97.8 degrees (5.1 degrees above normal) (warmest July on record is 96.6 in 1998) ...Average low is 78.8 (2.3 degrees above normal) (warmest July on record is 78.8 in 2020) ...Average temp is 88.3 (3.7 degrees above normal) (warmest July on record is 86.8 in 2016) -Galveston ...Average high is 92.8 degrees (1.6 degrees above normal) (warmest July on record is 94.7 in 1875) ...Average low is 83.8 (4.2 degrees above normal) (warmest July on record is 82.2 in 1993) ...Average temp is 88.3 (2.9 degrees above normal) (warmest July on record is 87.4 in 1875) Galveston`s low temperature this morning was 86 degrees. If the temperature does not fall below 86 before the end of the day, this will tie their all-time record high minimum temperature for July that was set earlier this month four other times (19th, 20th, 23rd and 24th). Their all-time record high minimum temperature for the entire year is 87 degrees, and it was set four consecutive days in a row (8/31/2020 thru 9/3/2020). If Galveston`s low temperature today does not fall below 85 degrees, this will be the 8th consecutive day that their low temperature has been at or above 85 degrees and will be a brand new record (current record of seven consecutive days has happened four times, including this month between the 4th and the 10th and also the current streak between the 19th and the 25th). -Palacios ...Average high is 93.1 degrees (1.5 degrees above normal) (warmest July on record is 93.6 in 1954) ...Average low is 83.0 (4.0 degrees above normal) (warmest July on record is 81.3 in 2009) ...Average temp is 88.1 (2.8 degrees above normal) (warmest July on record is 87.0 in 2019) College Station records date back to 1889 Houston records date back to 1889. Houston Hobby records date back to 1931. Galveston records date back to 1874. Palacios records date back to 1943 42 && .PRELIMINARY POINT TEMPS/POPS... College Station (CLL) 78 101 78 102 78 / 10 20 10 10 0 Houston (IAH) 78 98 78 98 79 / 20 40 20 30 0 Galveston (GLS) 85 94 85 93 86 / 30 30 20 20 20 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...None. GM...None. && $$
Area Forecast Discussion UPDATED
National Weather Service Hanford CA
435 PM PDT Tue Jul 26 2022 ...Update to Air Qaulity Issues Section... .SYNOPSIS... Triple digit heat in the valley and Sierra foothills with showers and thunderstorms over the Sierra will continue for the 7-day period. Smoke from the Oak Fire will reduce air quality throughout the region. && .DISCUSSION... Area of subtropical moisture spread across parts of the nrn cwfa and provided some light showers across Merced county early this morning. isolated showers and thunderstorms are expected above 7000 feet today and mainly confined to the crest. Radar is picking up some of the showers attm. Temperatures have been steady over the past few days as triple digits continue over the SJV and the Kern county desert regions. Winds have been light and mainly terrain driven, except gusty and erratic near heavier showers and thunderstorms. Ensemble guidance is indicating that we will still remain at or just above triple digit values through the forecast period. The hottest day appears to be on Friday where there is a 58 percent chance of getting over 105 at Fresno. Subtropical moisture will shift eastward as high pressure builds over the PACNW through Wednesday and remain nearly stationary through the weekend. Temperatures will max out on Friday as the high will be centered over NORCAL. Strong offshore flow will shut down any convection across the Sierra by the end of the week and into this weekend. As mentioned earlier, the hottest day appear to be Friday attm. Smoke from area fires will play a role in parts of the SJV as a more easterly component will start to bring more smoke into the SJV than we have seen so far. HRRR surface smoke model is spreading smoke into the SJV and mainly along the eastern side and Sierra foothills over the next few days. && .AVIATION... MVFR or lower visibilities are likely in Mariposa and Madera Counties due to heavy smoke and haze from the Oak Fire. Otherwise, VFR conditions will prevail across the remainder of Central California for at least the next 24 hours. && .AIR QUALITY ISSUES... On Wednesday July 27 2022... Unhealthy for Sensitive Groups in Fresno... Kern... Madera... Merced and Tulare Counties... and Sequoia National Park and Forest. && .CERTAINTY... The level of certainty for days 1 and 2 is medium. The level of certainty for days 3 through 7 is medium. Certainty levels include low...medium...and high. Please visit for additional information an/or to provide feedback. && .HNX WATCHES/WARNINGS/ADVISORIES... None. && $$ public/aviation/fire weather....JDB pio/idss/social media...........CM
Area Forecast Discussion
National Weather Service Northern Indiana
744 PM EDT Tue Jul 26 2022 .SYNOPSIS... Issued at 345 PM EDT Tue Jul 26 2022 Skies will remain mostly cloudy overnight with lows in the lower to middle 60s. An increase in moisture late tonight and into Wednesday brings a chance of showers and perhaps a few thunderstorms Wednesday with highs near 80. A low chance of rain lingers into Thursday. Less humid air then filters into the region Friday into the weekend. && .SHORT TERM...(This Evening through Wednesday) Issued at 345 PM EDT Tue Jul 26 2022 Broad/shallow North American trough through base of two Canadian cyclones and elongated anticyclone stretching from northeast Texas to Bermuda high. As Manitoba low dives southeast into Ontario an attendant front over the Upper Midwest will slide eastward through the Upper Great Lakes/CWA early Wednesday afternoon. Meanwhile, monsoonal moisture tap into the Intermountain Region being routed by deep westerly confluent flow through Central Plains-Lower Ohio Valley-Carolinas noted per water vapor imagery. This moisture conveyor accentuating surface/low level thermal gradient stalled along Kansas/Oklahoma border into Tennessee. Moist (14-16 g/kg 1000- 850 mb mixing ratios) ascent into cool side of frontal zone responsible for heavy/regenerative convection from northern Missouri into Lower Ohio Valley overnight into this afternoon. Record rainfall rates/amounts have led to ongoing historic flood event in Saint Louis metro area today. For tonight, concern is how far north does northern edge of rain showers lifts late tonight into Wednesday morning. Embedded shortwaves within deep westerly flow will buckle/back upstream low level /925-850 mb/ flow and afford moisture transport north of I-70 early tonight, but then veer back more westerly by daybreak. Richer moisture will have showers likely reaching into far southern CWA late with notably sharp northern edge/trailing chances. Next concern is how much destabilization can be realized prior to northern stream frontal passage Wednesday. Convection failure more probable given paltry mid level lapse rates and thick cloud cover debris, with pattern recognition pointing to hindered surface insolation. Increasing low level convergence and moderate /30-35 knots/ deep layer shear in place does provide a conditional/low thunderstorm chance midday/afternoon Wednesday with perhaps some gusty winds should pockets of MLCAPE 1500 to 2000 J/kg per the aggressive HRRR be realized. && .LONG TERM...(Wednesday Night through Tuesday) Issued at 345 PM EDT Tue Jul 26 2022 Secondary northern stream shortwave trough rotates through Thursday with relatively low chances for convection. Strong surface ridge follows as mid level trough ejects through southeast Canada. Notably less humid airmass with surface dewpoints into the middle/upper 50s Friday into the first part of the weekend. Gradual moisture return as high slides to eastern seaboard, combined with a minor shortwave digging southeast through the Upper Mississippi Valley, brings chances for showers and a slight chance of thunderstorms early next week. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday Evening) Issued at 743 PM EDT Tue Jul 26 2022 Continued with similar forecast, though have concerns with respect to how expansive morning IFR stratus is across far northern Indiana Wednesday morning, especially at KSBN. Moisture tansport from the Middle Ohio Valley west into the Ozarks will shift northward overnight as 925-850 mb flow within belt of moisture backs southwesterly and increases to 40 knots through far southeast Illinois/southwest Indiana. Cooling boundary layer and ascent should allow for saturation/stratus development by daybreak. Northern extent of IFR ceilings remains the queestion with the highest low level theta-e air only reaches to about KLAF- KFWA line by 12 UTC then is shunted eastward. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...NONE. && $$ SYNOPSIS...Murphy SHORT TERM...Murphy LONG TERM...Murphy AVIATION...Murphy Visit us at Follow us on Facebook...Twitter...and YouTube at:
Area Forecast Discussion
National Weather Service North Platte NE
638 PM CDT Tue Jul 26 2022 .SHORT TERM...(This evening through Wednesday night) Issued at 132 PM CDT Tue Jul 26 2022 A large upper level area of low pressure will remain located near Hudson Bay through Wednesday. Meanwhile upper level ridging has expanded northward across the Pacific west coast states. Between the two features moderately strong west-northwest flow aloft is in place across our region. At the surface a weak cold front is sagging southward through the area. The front by early this evening should extend from northeast CO through central into northeast NE. Most CAM guidance develops scattered convection late this afternoon near the front, but this is mostly just south and east of our counties of western and north central Nebraska. There has been a signal the past several runs of the HRRR that a few storms could develop in the moist post frontal upslope environment across the western Sandhills. If these were to form then a small cluster could move southeast across central into southwest NE early this evening. Clearing is taking place across the area late this morning, and will allow for some instability to develop this afternoon. Shear is such that storm organization could occur with a few briefly severe cores possible. A small disturbance embedded within the flow aloft may bring another cluster of showers/thunder to the area late tonight into Wednesday morning. Moisture will certainly not be lacking, with east to southeast low-level flow north of the weak cold front continuing to advect Gulf moisture northwest into the area. PWATS will average around 1.25" so spotty heavy rain is possible. Unclear has to how much clearing will occur during the day Wednesday. Several CAMs linger mid-level showery activity through much of the day. Does appear that at least some clearing will take place farther to the west across the Panhandle into northern CO. This is where the better instability would develop, and most models suggest a cluster of storms should materialize and track southeast toward/through southwest NE and northwest KS Thursday night. .LONG TERM...(Thursday through Tuesday) Issued at 132 PM CDT Tue Jul 26 2022 The upper low near Hudson Bay will shift eastward by the weekend. Meanwhile the upper ridge across the western CONUS will begin to build farther to the east across the Rockies. A weak nearly stationary front will remain draped across the High Plains from western KS into the NE Panhandle. Several rounds of showers/thunder are expected across this area into the weekend. Unfortunately the main focus for precipitation looks to remain mostly south and southwest of our area. The exception will be across southwest nearer the front and stands the better chance of seeing at least some rainfall. The heat will gradually build back into the area as the upper level high builds toward the Central Plains next week. Highs by Monday and Tuesday will be back into the 90s to lower 100s. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 638 PM CDT Tue Jul 26 2022 A weak frontal boundary near I-80 this evening will drop south and be the focus for isolated TSRA across swrn Nebraska until 02z. Additional scattered TSRA are expected from 06z tonight through 21z Wednesday afternoon. These storms will begin across northwest Nebraska and spread southeast throughout the night and during the day Wednesday. Otherwise, VFR is generally expected throughout wrn and ncntl Nebraska. The chance of MVFR or lower ceilings is about 20 percent along and south of Interstate 80. && .LBF WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...Taylor LONG TERM...Taylor AVIATION...CDC
Area Forecast Discussion
National Weather Service Phoenix AZ
526 PM MST Tue Jul 26 2022 .UPDATE...Updated 00Z Aviation Discussion. && .SYNOPSIS... With plentiful moisture over the Southwest, widely scattered showers and storms are forecast to continue over the next several days. Heavy rainfall and briefly gusty winds will accompany the stronger showers and storms that develop through the work week. Areas that see repeated rounds of heavy rain will be monitored for flash flooding. However, the nature of the activity will keep some areas from seeing significant rainfall, and many hours will be spent rain- free. Due to thicker clouds and rain in the vicinity, high temperatures will remain at or below normal, but it will also be rather muggy. && .DISCUSSION... Current satellite/radar imagery continues to show scattered showers and a few t-storms continuing across south-central/SW AZ at this hour. The most active area this afternoon appears to be over Pinal/eastern Maricopa/southern Gila County, which missed out on late last night/early this morning`s rainfall, which saw some areas of western Maricopa County measure as much as 2 inches of rain. The MCV that triggered last night`s rainfall has stalled over south- central AZ. This feature will provide the lift to trigger more showers/t-storms through this evening. Current ACARS soundings are showing a very wet atmosphere today, with PWATS all the way into the 2.10-2.20 inch range, which is a near-record levels for this time of year. The worked-over nature of the atmosphere over western Maricopa/eastern La Paz/Yuma Counties will likely continue to inhibit convective active over these regions thru the evening hours, but areas across eastern Maricopa/Pinal/southern Gila Counties look like they will have more activity, with the latest SPC showing an axis of 1000-1500 J/Kg of CAPE extending across those regions. Storm motion will be quite slow. with mid-level winds remaining quite light. Combined with high rainfall rates (1-2 inches/hour), localized flash flooding with be the main issue. As far as the forecast for tonight thru Thursday is concerned, latest high-res HRRR and HREF models are suggesting a bit of a break late this evening, then an increase in convective activity over SW and the western portion of South-Central AZ as another MCV possibly rotates southwestward from NW AZ into that region. Again, the main impacts will likely be locally heavy rain/flooding as well. The activity appears it will shift to the higher terrain north and east of Phoenix by Wednesday afternoon as the flow aloft becomes light easterly, importing a bit drier air into the region ahead of another weak disturbance that will be moving into SE AZ. Another round of nocturnal convection appears possible late Wednesday night over the western lower deserts as the airmass remains very moist (PWAT`s aoa 1.70 inch) with yet another disturbance dropping southern into the region. Given the continuing threats for convection/very moist airmass, decided to extend the FLood Watch until 12Z Thursday for most of our CWA east the the Colorado River. WPC continues to highlight much of AZ in a slight risk for excessive rainfall through Wednesday. Peering out into the extended forecast period, there is not a lot of change to speak of. The upper ridge axis will continue to extend from GA - TX - UT, allowing occasional weak disturbances a path into the Sonoran Desert while no mechanisms will be in place to scour out our antecedent monsoon moisture. This will keep 20-40% storm chances over Central Arizona and even higher coverage over the higher terrain at least into the upcoming weekend, and likely even longer. This enhancement of the monsoon pattern will continue to give us a break from the intense heat. Lower deserts will see high temperatures ranging from 98-105 the next several days, hottest the farther west you go into SW AZ/SE CA where less clouds/rain are forecast. Muggy to occasionally humid conditions will also prevail. && .AVIATION...Updated 0026Z. South-Central Arizona including KPHX, KIWA, KSDL, and KDVT: Showers and storms this afternoon have developed mostly around the metro area so far, however at anytime outflows from the surrounding convection, most favorably from the north to northwest, could generate new showers and storms. Thus, have maintained VCSH through this evening. The environment will remain favorable for isolated to scattered convection through Wednesday morning. Although confidence in hi-res models is low, majority of members support most of the overnight convection focusing more through western Maricopa, perhaps just outside the metro. Primary threats will be heavy rain, occasional lighting, and brief gusty winds with magnitudes most likely less than 30 kts. Wind directions will be driven by vicinity showers and any distant outflows, but diurnal trends will continue to favor a west through the day and east overnight. Cloud bases as low as 4-5 kft will be possible through tonight, but CIGs will mostly be aoa 7-8 kft. Southeast California/Southwest Arizona including KIPL and KBLH: Persistent southeast to south winds are expected. At KBLH, there is a somewhat higher chance of storms late this afternoon through early Wednesday morning, though probabilities and confidence remain low. Skies will be a bit clearer at KIPL with showers and storms not expected into the Valley. && .FIRE WEATHER... MinRH values will feature a gradient from 20-30% near and west of the CO River to 35-45% near Phoenix and points eastward. Overnight recovery will remain good. Heavy rain potential will be best through tonight and a Flood Watch is in effect for districts east of the Lower Colorado River Valley (except southern Yuma County). From mid-week onward, the highest rain and storm chances will become relegated to the higher elevations with 20-40% chances into the eastern lower deserts (lower out west). Apart from thunderstorm outflows, winds will favor familiar warm season patterns. High temperatures will be below normal through at least Wednesday over south- central AZ (less so further west) followed by gradual warming (little change further west). && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...Flood Watch through late Wednesday night for AZZ533-534-537>563. Flood Watch through late tonight for AZZ531. CA...None. && $$ DISCUSSION...Percha/Heil AVIATION...Benedict/Feldkircher FIRE WEATHER...Heil/AJ
Area Forecast Discussion
National Weather Service Reno NV
1233 PM PDT Tue Jul 26 2022 .SYNOPSIS... Near record daytime highs along with warm overnight low temperatures will lead to high risk of heat health impacts for much of the region Thursday through Saturday. Smoke and haze from the Oak Fire will continue to impact parts of the Sierra and western Nevada. Isolated thunderstorms are expected in the Sierra today, possibly spreading through out the region by the weekend. && .SHORT TERM... Widespread haze continues to impact much of the Sierra and western Nevada with slightly degraded (moderate) air quality. Light northwest flow aloft and increasing low level mixing should slowly improve conditions through the day today for most areas east of the Sierra Crest. For tomorrow, HRRR smoke forecast show westerly flow returning and potentially pushing smoke and haze into the Mammoth Lakes area. Thunderstorm chances continue today, mainly in the Sierra, from northern Mono County to around South Lake Tahoe. An upper wave that moved through that area this morning is bringing increased midlevel moisture and cloud cover along with light virga showers. Upper level instability is weak and increased cloud cover today may inhibit surface heating enough to hamper convection a bit. That being said, the area with the greatest potential for thunderstorms this afternoon is where some of the higher threat burn scars remain, including the Tamarack and Caldor, where even brief heavy rain raises concern for flash flooding and debris flows. Thunderstorm chances retreat on Wednesday back to Mono/Mineral Counties. Otherwise, temperatures remain around the triple digit mark in the low valleys with generally light winds as our typical afternoon zephyr winds remain subdued. -Zach .LONG TERM...Thursday onward... Greatest concern is the heat risk Thursday through Saturday. Current forecast is for near if not record highs, with little relief overnight as low temperatures hover within a few degrees of record warmth as well. The EFI (Extreme Forecast Index) and SOT (Shift of Tails) from the EC clearly is picking up on this signal, with the NBM indicating a 90%+ chance to reach record highs in several locations. We went ahead and issued a heat advisory for all zones, except the Sierra, Thursday through Saturday. Don`t get us wrong, it will be quite warm in the mountains as well, but there will be more efficient cooling at night, limiting the heat risk. Try to limit strenuous activity midday and be sure to stay hydrated. Check in on individuals who are more heat sensitive such as young children or the elderly, and don`t forget about pets either. With the area of high pressure centered almost directly over the Sierra/western Nevada, winds will be fairly light outside of any possible thunderstorm development. Speaking of, the subsidence aloft under the high may help to squelch widespread thunderstorm chances as it tends to cap things off. However, considering the remnant elevated PWATs and very warm temperatures, we could still easily pop isolated thunderstorms for the end of the week into the weekend, mainly in Mono/Mineral Counties. A trough moving into the Pacific Northwest Sunday into Monday will push the high pressure center back over the four corners region. This will bring a surge of moisture and an increased risk for thunderstorms Sunday-Monday, with heavy rain a possible concern as about 1/2-2/3 of ensemble members are pushing PWATs over 0.7", and some are nearing the 1" mark. Could the prolonged dry streak at KRNO (currently at 77 days, and tied for 15th longest streak since 1893) finally end? Sunday and Monday look like our greatest hope. The one wildcard is there are times we have "too much moisture" and cloud over too early in the day, limiting stronger thunderstorm potential. We`ll continue to monitor. Storm chances decrease in coverage once again by the middle of next week as drier southwest flow returns to the region. This would also drop temperatures back closer to normal, which is still warm given the time of year, but would be a relief after the triple digit heat. -Dawn && .AVIATION... A weak wave brought virga and spotty light showers to the region this morning, which is limiting thunderstorm development to a degree this afternoon. Per the latest high resolution guidance, isolated thunderstorms are still expected along the Sierra from KMMH-KTRK from 21z-03z, with a 40% chance for a storm to impact terminals directly in this area. Into western Nevada, there is a 20% chance for terminal sites near and south of US-50 with a 10% chance north of there. Smoke from the Oak Fire near Yosemite will continue to be a concern, but the general lighter flow will keep the worse impacts away from the eastern Sierra and western Nevada. We`ll mainly see haze with some slantwise visibility reductions possible. Fire activity and suppression efforts will determine smoke impacts as we go through the week. An incoming heat wave will bring density altitude concerns Thursday through Saturday. It may also limit thunderstorm chances, however isolated storms remain possible, with a 10% chance to impact terminal sites, mainly in Mono/Mineral Counties. Greater storm chances exist Sunday-Monday across the entire region. Otherwise, winds will be fairly light surface and aloft outside of any possible thunderstorm development. -Dawn && .REV Watches/Warnings/Advisories... NV...Heat Advisory from 11 AM Thursday to 10 PM PDT Saturday NVZ001-003>005. CA...Heat Advisory from 11 AM Thursday to 10 PM PDT Saturday CAZ070-071. && $$ For more information from the National Weather Service visit...