Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 07/17/20

Area Forecast Discussion
National Weather Service Amarillo TX
624 PM CDT Thu Jul 16 2020 .AVIATION... VFR conditions are expected throughout the 00Z TAF period. Winds will be out of the south and southwest at 10-15 kts with some gusts near 20 kts at times, especially past 18Z Friday. Some mid to high clouds at times, but fair weather conditions are expected. && .PREV DISCUSSION... /Issued 304 PM CDT Thu Jul 16 2020/ SHORT TERM...Tonight through Friday Night... Looking at satellite, we can detect the mid-level shortwave across CO and NM that is firing off storms. With surface flow from the southeast and mid-level steering flow from the west, storms are moving northeasterly across New Mexico. Short range and hi-res models are not certain if these storms will move close enough to cross over the forecast area. The NAM and the HRRR want to bring storms across Cimarron County between 6 PM and midnight but other models keep it just out of our area. The HRRR presents meager instability of only around 600 J/kg of ML CAPE but the NAM wants to throw over 2000 J/kg at it. The discrepancy continues in available DCAPE, but they do agree that there will be minimal shear, so most likely we will only see general thunderstorms if they do cross our area, but can`t rule out the possibility of a storm becoming more intense and having some large hail and damaging winds. Temps will soar back to close to or over 100 degrees tomorrow as surface and low level winds become more southwesterly and bring more WAA to the area with heating from downsloping. We will likely need a Heat Advisory for Palo Duro Canyon as temps are expected to reach 107. Another shortwave is expected to create storms in NM tomorrow afternoon which may affect the northwest portions of the area. Forecast soundings are not that excited for instability in the area tomorrow so if we do see storms, they are expected to stay below severe limits. Beat LONG TERM...Saturday through Wednesday... An upper level high pressure system stretches across the entire southern CONUS with heights around 591mb to 594mb. The elongated high will begin to split Saturday and the western portion will center over the Four Corners Region with northwest flow aloft for the forecast area. At 850mb, winds are expected to be from the south southwest through the extended period as several disturbance form off the Rockies. Every night from Saturday through Wednesday, there is a low level jet present at 850mb with 25 to 35 knot winds. Thunderstorms are possible every evening through the extended across the northwest half of the combined Panhandles. Storms are likely to fire off the higher terrain and along trough axes associated with the lee side lows forming off the Rockies. Severe weather cannot be ruled out at this time, especially in the far northwest Panhandles where the environment is slight more unstable with higher MLCAPE values paired with meager effective shear. Sunday and Monday evening have a greater potential for strong to severe thunderstorms across the northwest half of the Panhandles with a decent 700mb theta-e axis setting up both days. Hot temperatures will continue through the extended period with the hottest day being Saturday as highs will reach the upper 90s to 108. The remaining days will be in the 90s to around 104. Low temperatures will be in the upper 60s to 70s through the extended. Rutt && .AMA Watches/Warnings/Advisories... TX...None. OK...None. && $$ 29/88
Area Forecast Discussion
National Weather Service Dodge City KS
707 PM CDT Thu Jul 16 2020 ...Update for Convective Activity... .UPDATE... Issued at 652 PM CDT Thu Jul 16 2020 Convective activity in eastern CO has struggled to mature over the last several hours with the exception of one cluster of sub-severe thunderstorms that has formed in far southeast CO/northeast NM. This cluster is expected to continue moving northeast and enter the western KS counties in the next 1-2 hours. Most CAMs kill this convection shortly after it enters KS, but some indicate potential for a weak cluster/MCS to propagate ENE just N of U.S. Highway 50 in the 03-09Z time frame. Given modest low level and deep layer shear, severe weather is not expected. However, MLCAPE of 1000-2000 J/Kg could support small hail and locally heavy rainfall. Gusty winds are possible as well owing to pressure perturbations within the outflow. && .SHORT TERM...(This evening through Friday) Issued at 312 PM CDT Thu Jul 16 2020 The mid level temperatures are not as capped as recent days, +12C at 700 mb this on the Dodge City sounding. There is still very noticeable variability in the CAMs output. In particular the the NMM drives the late afternoon isolated eastern Colorado activity northeast into west central Kansas counties ( Syracuse-Scott City to Hays by midnight). By contrast the other HiRES model core clear, as well as the HRRR clearly struggles with convective initiation altogether n Kansas and allows the Co afternoon convection to decay before it reaches our area of concern. The moist dew points will keep temperatures mild overnight. Even to coolest solutions keep the higher elevation far western counties no cooler than the upper 60s overnight. .LONG TERM...(Friday night through Thursday) Issued at 312 PM CDT Thu Jul 16 2020 The atmosphere should still be conditionally unstable on Friday. However as the day goes foreword, a dryline will develop out of the southwest, dropping surface dew points into the 40s in the west, relegating 60s dew points to the easternmost counties. Of the most aggressive recent solutions in terms of convective development , the NMM develops a cluster of storms in the evening, hinting at the area of best boundary layer theta-e convergence. That might be a isolated occurrence in the mid evening as there is not forcing or reason for storms to be sustained. Saturday looks hot and dry and potential breezy. The ECMWF shows a synoptic scale mid level trough dropping southeast over the northern Rockies Sunday as the northern Plains airmass is shifted farther south, setting up a zone of moisture pooling and upslope flow from the mid Mississippi valley into the central High Plains. This will bring the return of chances for convection from Sunday night through early Tuesday, as well as a slight break in the hot temperatures. && .AVIATION...(For the 00Z TAFS through 00Z Friday evening) Issued at 522 PM CDT Thu Jul 16 2020 Partly cloudy skies and light winds will bring VFR flying conditions this TAF period for all terminals. There is a slight chance of thunderstorms this evening and overnight, especially at GCK and HYS in the 06-11Z time frame. However, confidence that thunderstorms will impact any terminal is low, so I have neglected to include any VCTS. && .PRELIMINARY POINT TEMPS/POPS... DDC 70 101 76 103 / 10 0 10 0 GCK 70 101 72 102 / 20 0 10 10 EHA 68 99 71 100 / 20 10 20 0 LBL 70 103 74 103 / 0 0 10 0 HYS 70 98 75 100 / 20 0 10 0 P28 73 102 77 103 / 10 0 0 0 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...Springer SHORT TERM...Russell LONG TERM...Russell AVIATION...Springer
Area Forecast Discussion
National Weather Service Wichita KS
617 PM CDT Thu Jul 16 2020 .SHORT TERM...(This evening through Sunday night) Issued at 258 PM CDT Thu Jul 16 2020 The remnants of the the SE KS storm complex are making progress into SW MO at this time. The Meso Induced Vort center (MCV) associated with this system lags a little behind the main rain shield, over SE KS. Most locations of southern and southeast KS look to be "worked over" from the earlier convection, and current RAP instability progs show this with an instability minimum over SE KS at this time. So even with the MCV still over SE KS, think any renewed convective chances will probably end up being over extreme SE KS, SW MO and NE OK. Plan on leaving a small pop in SE KS for any lingering showers, but think this chance will end late this afternoon or early this evening. For the rest of the night, moisture transport will again increase across wrn KS late tonight, with showers and storms developing over the high plains, and eventually shifting over portions of central KS late tonight through early on Fri. This warm advection could also lead to additional elevated showers and storms developing across central KS and possibly SE KS with most of this activity moving northeast of the area by early Fri. Hot and breezy conditions will be the story for the daytime hours on Fri and Sat, as the zonal flow leads to warm southwesterly flow across the plains. The good downslope flow will lead to max temps flirting with the century mark for both Fri and Sat. Surface dewpoints still in the lower 70s across the eastern half of KS will lead to heat index values of climbing to 103 to 106. So with collaboration with offices to the east have decided to go with a heat advisory for areas along and east of Interstate 135 for Fri through Sat. Sat looks like the most sultry day of the weekend with the highest combination of max temps and 72-75 degree dewpoints. Could see some high plains storm chances move across Neb late Sat night, possibly clipping portions of central KS. So will leave a small pop in for this chance. Highs plains storm chances look to increase by the end of the weekend as low level moisture returns. Some of this activity will propagate back into portions of central KS for Sun night through Mon. Ketcham .LONG TERM...(Monday through Thursday) Issued at 258 PM CDT Thu Jul 16 2020 Both the GFS and ECMWF suggest an unsettled weather pattern will settle over the area for Mon night through Wed, as a weak frontal boundary is expected to sag across the forecast area for the middle of the week. Ketcham && .AVIATION...(For the 00Z TAFS through 00Z Friday evening) Issued at 615 PM CDT Thu Jul 16 2020 VFR conditions are forecast at all sites throughout the period. Chances for convection appear to considerably lower than the past few days. While not zero, there is still a small but too low to mention chance per NAM/RAP at KRSL/KGBD and less likely chance at KHUT/KSLN for remnants of High Plains convection from about 12-15 UTC. Otherwise increasing surface pressure gradient suggest gusty winds developing at most sites by afternoon. -Howerton && .PRELIMINARY POINT TEMPS/POPS... Wichita-KICT 75 99 78 101 / 10 0 0 0 Hutchinson 72 97 76 100 / 10 0 0 0 Newton 72 97 76 100 / 10 0 10 0 ElDorado 72 96 75 98 / 10 0 0 0 Winfield-KWLD 73 99 76 99 / 10 0 0 0 Russell 71 97 75 101 / 20 0 10 10 Great Bend 71 98 75 101 / 20 0 10 0 Salina 72 97 78 102 / 10 10 10 0 McPherson 72 96 76 100 / 10 0 10 0 Coffeyville 74 96 76 95 / 20 0 0 0 Chanute 73 96 76 96 / 20 10 0 0 Iola 72 96 76 97 / 20 10 0 0 Parsons-KPPF 74 95 76 96 / 20 10 0 0 && .ICT WATCHES/WARNINGS/ADVISORIES... Heat Advisory from noon Friday to 8 PM CDT Saturday for KSZ049- 051>053-068>072-083-092>096-098>100. && $$ SHORT TERM...Ketcham LONG TERM...Ketcham AVIATION...PJH
Area Forecast Discussion...UPDATED
National Weather Service Memphis TN
953 PM CDT Thu Jul 16 2020 .UPDATE... Showers and thunderstorms ended over the Midsouth earlier this evening. CAM output is mixed for tonight with respect to additional storm chances. GOES water vapor imagery suggests a possible weak MCV from earlier storms over the Midsouth. This feature alone likely wouldn`t be sufficient for additional storms in the absence of heating, and weak overall shear. Overnight forecast reflects a more conservative HRRR depiction. Where storms don`t form and veil of cirrus thins, patchy fog could develop. PWB && .PREV DISCUSSION... /issued 706 PM CDT Thu Jul 16 2020/ UPDATE... See the 00Z aviation discussion below. PREV DISCUSSION... /issued 209 PM CDT Thu Jul 16 2020/ SHORT TERM (Tonight through Friday)... Indeed storms proximal to the surface boundary are ongoing and expected into the evening hours. Localized heavy rainfall and a gusty wind are the main byproducts. The heat index values above 105 are not quite as widespread as thought going into today. The convection has had impact and dew points are a bit lower as well in a number of spots. The advisory will expire at 7 am LT. Speaking of heat advisory, have considered the possibility of issuing for Friday, however will hold off for now as forecast readings are largely just below 105. Thus, will allow later shifts to better pinpoint areas and assess confidence in making criteria. Additionally, thunderstorms again will threaten on Friday with a diurnal flavor. This may too have an impact on our heat index topping out above 105. Belles LONG TERM...(Friday night through Thursday)... The upper ridge is boss across the region this forecast period. Hot and humid with diurnal convection is generally our lot in life for the next week. There are some exceptions as a weak trough slips by the from late Tuesday into early Thursday. This may increase the coverage of the convection for our area and potentially knock back temps a shade. Belles && .AVIATION... 00Z TAFS Diminishing showers and clearing skies can be expected overnight. Winds will remain less than 5 kts and from the south at all sites. There is some concern that fog may form at MKL or JBR, but confidence is too low to add to the TAF at this time. Scattered storm coverage is expected again on Friday, warranting a VCTS at MEM, MKL, and JBR by late morning. Activity should diminish again near sundown. AC3 && .MEG WATCHES/WARNINGS/ADVISORIES... AR...None. MO...None. MS...None. TN...None. && $$
Area Forecast Discussion
National Weather Service Phoenix AZ
432 PM MST Thu Jul 16 2020 .UPDATE...Updated Aviation Discussion. && .SYNOPSIS... Above normal temperatures are forecast at least through the weekend with daily lower desert highs around 110 degrees. Day to day thunderstorm chances will continue across the eastern Arizona high terrain through the weekend before a likely increase in moisture by the middle of next week spreads the thunderstorm chances westward into the lower deserts. As rain chances increase next week, temperatures are forecast to eventually drop back to around normal levels. $$ DISCUSSION... Early afternoon radar showed another round of scattered rain showers and embedded thunderstorms from E central AZ to and along the Mogollon rim associated with a small UL vort max, with more isolated thunderstorms across SE AZ. Some mostly light to moderate showers were also across NE Maricopa and S. Gila Cty around the Bush fire burn scar. This activity was moving north along the favored moisture and instability axis on the E AZ western flank of the UL high still centered over TX. The 12Z Phx sounding had moistened up to 1.27" PW and a mean W near 9 gm/kg with an even mixture of SE to SW flow aloft. Upper air analysis confirms the southerly component flow aloft through H5. While struggling a bit, the HREF CAMs remain in good agreement on keeping this afternoon`s and evening`s storm activity confined to scattered to isolated activity SE-E and NE AZ more isolated activity S of the Phoenix area, very much like most of yesterday`s activity. For tomorrow`s storms some members including the HRRR are suggesting the coverage spreading slightly farther west with some convection possible in SW Maricopa and/or Pinal county with a chance of some isolated storms cropping up briefly in the Phx valley during the evening hours Friday night. However chances in the Valley still remain low and less than 10 percent. This evening there is again a slight chance of gusty storm outflow winds and blowing dust with this afternoon`s and evening`s storms to the E and SE, although similar to yesterday the activity it is generally expected to be too distant to impact the Phoenix metro, with Pinal cty being only slightly favored for blowing dust. For tomorrow afternoon and evening there are more bullish signals for a wider and more pronounced outflow, originating in stronger convection around the Pima-MX border, that may have the potential to reach as far as the S Phx Valley area. Areas E and SE of Phoenix and the Mogollon rim will continue to be the favored location for isolated storm development for the weekend and next week with only minor day to day variation in the storm paths expected. Although some models show part of the ridge shifting over the Desert Southwest, it remains favorably positioned to continue developing the moist easterly and southeasterly flow and UL inverted trough tracks along it`s southern flank with a series of them peeling north into the region. However it`s not until the middle of next week that an increase in moisture, along with instability and shear begin to slowly improve chances for storms after a possible drying trend for the first half of next week. Although uncertainty remains on how robust the storm activity will actually be closer to Phoenix. Temperature will remain above normal in the 108-111 degree range for Phoenix and 109-114 degrees out west. A cooling trend starting Tuesday will bring temperatures back down to near or slightly below normal by Wednesday and Thursday next week. && .AVIATION...Updated at 2332Z. South-Central Arizona including KPHX, KIWA, KSDL, and KDVT: There are no major aviation concerns through at least Fri morning as winds will follow typical diurnal trends at all the TAF sites. Expect some afternoon breezes, but nothing out of the ordinary. Thunderstorms are expected to remain east and southeast away from the terminal areas. Although a remote threat of outflows from distant storms during the evening and early night hours does still exist, leaving any kind of wind shift out of the TAFs until later this evening. Clouds will generally remain AOA 10k feet through the TAF period with an increase in mid-level clouds late this evening.As far as Fri is concerned, expecting a bit earlier-then-normal shift to westerly winds around midday. Although there looks to be a better chance for outflows from distant thunderstorms on Fri evening, confidence is too low to include a wind shift in the TAFs at this time. Southeast California/Southwest Arizona including KIPL and KBLH: There are no major aviation concerns as winds will follow typical diurnal trends. Expect some afternoon breezes, but nothing out of the ordinary. && .FIRE WEATHER... Saturday through Wednesday: Modest moisture levels through the weekend will provide at least a slight chance for showers/thunderstorms mainly over the higher terrain north and east of Phoenix. Higher moisture levels into next week will expand storm chances into the AZ lower deserts by Tuesday or Wednesday. Outflow winds, even from distant storms, will be a concern most days across eastern and possibly south- central Arizona. Daytime RH values will be in the 10-20% range through Monday, increasing to 15-25% starting Tuesday. Overnight recoveries rise into the 30-50% range each day. Outside of any thunderstorms, winds will follow diurnal/terrain driven trends with typical afternoon breeziness. && .SPOTTER INFORMATION STATEMENT... Spotters should follow standard reporting procedures. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...None. CA...None. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...None. CA...None. && $$ DISCUSSION...Sawtelle AVIATION...Percha/Benedict/AD FIRE WEATHER...Sawtelle/Kuhlman
Area Forecast Discussion
National Weather Service Pueblo CO
342 PM MDT Thu Jul 16 2020 .SHORT TERM...(This evening through Friday) Issued at 340 PM MDT Thu Jul 16 2020 Main forecast concerns/challenges this period will remain with shower and thunderstorm chances through this evening, and once again on Friday. An isolated strong to severe storm will remain possible through early this evening. In the near term, scattered showers and storms continue to develop across parts of southern CO. While development continues across the higher terrain, focus has shifted a little to the east along parts of the I-25 corridor. In these locations, have noted slightly higher focus, with these storms developing along two separate moisture convergence axes. Per latest RAP analysis, these are located from Fremont county northeast to Teller and El Paso counties, and from around Pueblo southeast to Springfield. These locations will have the highest potential to see the highest coverage of storms for the remainder of the afternoon into the early evening, along with an isolated strong to severe storm. Despite forcing remaining limited, instability remains on the higher side this afternoon with very steep lapse rates in place, that once again will support an isolated strong/severe storm capable of hails to the size of quarters and wind gusts to around 60 mph. Don`t think the flash flooding threat is high for most areas given the limited coverage, however, slow storm movement with brief heavy downpours could support localized minor flooding concerns. Most thunderstorm development is focusing to the east of the burn scars and think the flash flooding risk for area burn scars has lowered. However, can`t rule out an isolated storm to move across the burn scars and will continue to closely monitor. Should see any stronger development end by mid evening, but think some isolated showers and storms will persist slightly longer this evening. Additional showers and thunderstorms will again be possible Friday afternoon, though focus looks to be over the mountains. Can`t rule out an isolated storm spilling into parts of the I-25 corridor though, but any severe threat looks low at this time. .LONG TERM...(Friday night through Thursday) Issued at 340 PM MDT Thu Jul 16 2020 Friday Night and Saturday: Ongoing convection will continue into Friday evening. The forecast seems to be on track from yesterday with convection primarily staying over the mountains, the Raton Mesa, and the Palmer Divide. Some of the storms may develop over Baca County, as well. The environment isn`t the greatest, the best instability will be over the mountains, so the flash flooding risk will continue over the burn scars during the evening. Over the plains, CAPE values will be under 1000 J/kg and deep shear values will be less than 25 kts, meaning storms that form over Baca County will be weak and unorganized. All thunderstorm chances will dissipate shortly after midnight. Saturday will be similar to Friday, except there will be less shear in the atmosphere due to weak winds aloft and weak surface winds, therefore weak thunderstorms are expected to develop over the mountains once again. There is a flash flood risk over the burn scars as thunderstorms develop during the afternoon. With the limited convection and general southwesterly flow over the region, temperatures will be hot over the entire region. Widespread +100F over the plains, mid to upper 80s over the mountain valleys and Teller County, and the mid 70s over Lake County. Sunday: A frontal passage is expected on Sunday, but the timing and intensity is still uncertain. Via deterministic models, the GFS is flip-flopping between a strong frontal passage and a weak frontal passage being stalled over the eastern plains and eventually being overcome with westerly winds off of the mountains. Whereas the NAM has a strong frontal passage, but the model run stops before the potential impacts. Soundings reveal a pretty dry low-level, so even if the front does pass over the region, it`ll be hard for precipitation to fall. The main forecast impact of how strong the front is will be wind speeds and temperatures. Monday through Thursday: The rest of the forecast will depend on the frontal intensity, but the forecast is that Monday will be a post-frontal scenario. Southeasterly winds will develop over the plains, sparking thunderstorms over the mountains that may spread east over the plains. Low CAPE values are expected so the storms will be weak. The rest of the weak looks awfully wavy, with shortwaves propagating over Colorado each day. Each day also looks to bring scattered showers and thunderstorms over the mountains and the lower elevations. The daily thunderstorms will help keep the temperatures down as well. && .AVIATION...(For the 00Z TAFS through 00Z Friday evening) Issued at 340 PM MDT Thu Jul 16 2020 Main forecast concerns continue to be with thunderstorms through this evening across all of the TAF sites. Latest radar imagery is showing an increasing coverage of showers and storms near all of the sites, and think it`s possible for a storm to move overhead over the next couple of hours. COS and ALS still have the highest potential, but think there might be a slightly higher chance for PUB and will continue to monitor trends. Thunderstorm potential lowers by mid evening, but think there will be some scattered showers lingering across the area later into the evening. Impacts should be low though. VFR and dry conditions tonight into Friday morning, with shower and thunderstorm development once again possible Friday afternoon. Focus should remain away from the sites, but will need to monitor for the potential of an isolated storm or two. && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...RODRIGUEZ LONG TERM...SKELLY AVIATION...RODRIGUEZ
Area Forecast Discussion
National Weather Service Blacksburg VA
929 PM EDT Thu Jul 16 2020 .SYNOPSIS... High pressure over the east coast and a frontal system across the midwest will keep our area in a southerly flow through Friday. The front enters the area late Friday and then moves north as a warm front Saturday. && .NEAR TERM /THROUGH FRIDAY/... As of 930 PM EDT Thursday... Ongoing isolated pulse/multicell thunderstorms will continue for a couple more hours, bringing localized gusty winds and very heavy rainfall. Small hail is also possible with the strongest storms. Adjusted POPs overnight, with highest POPs corresponding to the ongoing activity along and just west of the Blue Ridge. Gradually reducing the chance by morning. Areas east of the Blue Ridge dry after midnight. Highest CAPE values remain pooled up along and west of the Blue Ridge, with latest RAP analysis indicating some areas in excess of 2500 j/kg. This should be enough to keep shower/thunderstorm activity going for the next couple of hours. NAM Nest and most recent HRRR also agree that isolated thunderstorms will continue. Also bumped up low temperatures a degree or two overnight. Tropical/humid airmass will keep temperatures very mild overnight, with lows in the upper 60s and lower 70s. As of 130 PM EDT Thursday... Widely scattered showers have been developing since mid-morning mainly along and east of the Blue Ridge. Nothing very strong or slow-moving to present water problems yet. Fairly high instability along with high PWATS of 1.6 to 1.7 inches per mesoanalysis suggest some heavy rainers possible but severe potential limited, although a marginal pulse severe not out of the question. Activity should follow a diurnal trend with weakening after sunset. Plenty of clouds and high humidity will make for a warm overnight with mid- to upper 60s even in the mountains and low 70s east. Slow-moving boundary approaches tomorrow with better chances for showers and storms. Very high PWATS approaching 2 inches again indicate decent chances for pockets of heavy rainfall and WPC has most of the area under Marginal Risk for excessive rainfall. Which would be be highly beneficial in most cases (see Hydro section below). Warm and muggy as usual. && .SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/... As of 145 PM EDT Thursday... A front from Friday stalls over the area overnight. Despite it being over the region, POPs will decrease overnight with the loss of heating. However, this front will serve as a lifting mechanism Saturday to help re-ignite showers and thunderstorms during the day. The greatest concentration/chances will depend on where exactly the front stalls, which looks to be near the VA/NC boarder at the moment. By Sunday, this stalled front will shift slightly further south with forcing from a new upper level disturbance that will be passing to our north. This will bring yet another weak front Sunday afternoon, sparking the greatest POPs along the west. Sunday`s front will stall over the region for Monday, creating a somewhat similar repeat in forecast from Saturday, though POPs look more likely to be widespread. The reason for thoughts on more widespread POPs will be the ample heating Monday with guidance suggesting that it will be the warmest day of the forecast. Temps through the period remain above average, with Monday looking like the warmest day of the forecast with areas east of the mountains topping in the mid to upper 90s. && .LONG TERM /MONDAY THROUGH THURSDAY/... As of 145 PM EDT Thursday... Zonal flow will dominate the forecast through the period while numerous upper level disturbances to our far north move through. These disturbances will help drive numerous shortwaves into the Mid- Atlantic. These shortwaves in turn will help drive ample chances for afternoon showers and thunderstorms during the afternoons each day. Temperatures will continue to remain above normal through the period. && .AVIATION /02Z FRIDAY THROUGH TUESDAY/... As of 730 PM EDT Thursday... Highly variable environment in terms of CIGS with scattered showers and thunderstorms tonight and also again on Friday. Most of the activity this evening will be confined to west of the Blue Ridge. Brief reduction in VSBY where showers/thunderstorms occur, but overall mainly VFR conditions will prevail during the TAF period. The exception to the VFR conditions will be for LWB before sunrise Friday. Fog could briefly drop LWB into IFR, however, confidence in this occurring is low. Extended Aviation Discussion... Overall mainly VFR weather to continue through the weekend. We will have uptick in storms by Saturday through Monday, so periods of sub-VFR are possible in storms, and potential for late night/early morning fog at LWB/BCB will increase. && .HYDROLOGY... As of 130 PM EDT Thursday... As we reach the mid-point of July, climatologically the wettest month of the year, the rainfall numbers are impressively unimpressive and quite the turnaround from April through June. Here are the July 1-15 rainfall totals (inches) and ranking from four of the five `official` climate sites: Bluefield `T` - driest (since 1909) Roanoke 0.19 - 3rd driest (since 1912) Lynchburg 0.34 - 10th driest (since 1893) Blacksburg 0.70 - 17th driest (since 1893) Danville has been wetter, having received several downpours. But the bulk of the CWA has been quite dry for 3+ weeks, really since around June 18th. Impacts are mainly in terms of rapidly drying surface soils, browning lawns and parched gardens. But another week of dry weather may be enough to tip the area into recognition from the U.S. Drought Monitor. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...None. NC...None. WV...None. && $$ SYNOPSIS...WP NEAR TERM...BMG/PC SHORT TERM...RR LONG TERM...RR AVIATION...BMG/PC HYDROLOGY...PC
Area Forecast Discussion
National Weather Service Tucson AZ
345 PM MST Thu Jul 16 2020 .SYNOPSIS...Scattered mainly afternoon and evening thunderstorms into next week. Expect locally heavy rainfall, gusty outflows and patchy blowing dust at times. Daytime temperatures generally a few degrees above normal into early next week. && .DISCUSSION...Scattered showers and thunderstorms were occurring as of this writing mainly across Cochise County, eastern Pima County and Santa Cruz County. These showers and thunderstorms were mostly stationary, or moving to north around 5 mph. Several outflow boundaries were also apparent via radar imagery, with the most notable outflow from near KEMX radar southward to near Lochiel. Several HRRR solutions and the 16/12Z Univ of AZ WRF-GFS suggest that showers/tstms will continue into early this evening, then gradually dissipate after sunset. The bulk of showers/tstms should end by midnight. However, have maintained isolated showers/tstms late tonight mainly east to south of Tucson. Regarding the potential for blowing dust of significance, have trended toward the U of A WRF- GFS 10m wind depiction. As such, have favored an area along Interstate 10 near the Willcox Playa eastward to the New Mexico state line for patchy blowing dust until around 8 pm MST this evening. There is the potential for some blowing dust northwest of Tucson and along the I-10 corridor. However, have opted to remove the inherited depiction of patchy blowing dust given fairly low high-resolution model wind speeds this evening. For the period Friday through around Tuesday, the 16/12Z GFS/GEFS and ECMWF/ECENS have a general theme of suggesting that scattered showers and thunderstorms will occur mainly during the afternoon and evening hours, and favor locales NE-SE-SW of Tucson. However, the entire forecast area has at least a 10 percent chance of showers/tstms during almost any forecast period. Starting around Wednesday and continuing into Thursday (last day of this forecast package, and perhaps even beyond Thursday), the global models continue to suggest a potentially pronounced increase in daily coverage and rainfall amounts from showers and thunderstorms. The potential increased coverage and rainfall amounts appear to be in response to the models depicting a deeper southeasterly flow regime across the area. High temperatures will generally be a few degrees above normal into early next week, then highs moderating a few degrees later next week. && .AVIATION...Valid through 18/00Z. FEW-SCT clouds 10-15k ft MSL and SCT-BKN clouds above 20k ft MSL through much of the period. Isolated to scattered TSRA/SHRA this afternoon and evening near all terminals. Expect similar TSRA activity Friday afternoon. Gusty outflow winds around 40 kts and brief MVFR conditions may occur near the stronger TSRA. Outside of gusty outflows, SFC winds will be WLY/SWLY 8-12 kts this afternoon. Windspeeds diminish late this evening into Friday morning becoming variable at less than 10 kts. Wind increase again out of the NW Friday afternoon. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...Expect isolated to scattered showers and thunderstorms each afternoon/evening through the forecast period for most of southeast Arizona. Daytime relative humidities will be 15-30 percent into early next week with generally good overnight recoveries. Additional moisture may arrive by the middle of next week resulting in higher humidity levels. 20-ft winds generally follow diurnal patterns at less than 15 mph with some afternoon gustiness, although any thunderstorms will be capable of producing gusts of 45 mph or higher. && .TWC WATCHES/WARNINGS/ADVISORIES...None. && $$ DISCUSSION...Francis AVIATION...Hardin FIRE WEATHER...Hardin Visit us on Facebook...Twitter...YouTube...and at
Area Forecast Discussion
National Weather Service Las Vegas NV
543 PM PDT Thu Jul 16 2020 .SYNOPSIS...Hot and dry weather will continue through early next week with generally light winds. Monsoonal moisture may begin to creep back into the region by the middle or end of next week, with an uptick in cloud cover and thunderstorm activity possible. && .AFTERNOON UPDATE... With convection evident in northern Mohave County and on the crest of the Sierra, made some modifications to the PoP/Wx/QPF grids for those respective areas. Convection over northern Mohave hasn`t been overly impressive as individual cells, but have been redeveloping updrafts in the same general area north of Mount Trumbull. Additionally, GOES-W trends show additional updraft formation farther south along the Sierra crest. Keeping a close eye on any new fire starts due to isolated CG lightning strikes but so far, no evidence of this yet within the VEF CWA. HRRR trends have just about all of this activity over with by 03Z thus trended as such in the hourly PoP grids. .SHORT TERM...through Sunday. Fairly benign conditions expected through the weekend with a weak low pressure trough off the SoCal coast while the subtropical ridge remains anchored across the Southern Plains region. The end result for us will be continued hot temperatures with southerly breezes, while conditions remain rather dry as the monsoon flow remains focused to our east. The only exception to the dryness may be across the Sierra where daily thunderstorm chances remain in the forecast thanks to intense surface heating and the associated instability, as well as a slightly diffluent flow ahead of the upper low offshore. Isolated storms will also be possible across far eastern Mohave county closer to the deeper monsoonal moisture, mainly on Saturday and Sunday. .LONG TERM...Monday through Thursday. Changes will begin to take hold in the longer term period as the first notable monsoon push into the region continues to be advertised for arrival sometime next week. However, forecast trends keep nudging the arrival of this moisture later and later. Part of the reason for the delayed timing is due to uncertainty in the depth and location of a weak trough over central California. If the trough remains a bit stronger, it could keep a drier westerly component in place and delay the moisture arrival till very late in the week. Alternatively, a weaker trough or one lingering further offshore would allow an earlier moisture return. Ensemble guidance lends some credence to a deeper trough, though still attempts to bring in some monsoonal moisture Wednesday onward, mainly along and east of I-15. In addition, this pattern could result in a little added dynamic support for convective activity late in the week. For now, given the uncertainties, PoPs are limited to Northwest Arizona, but chances may get nudged westward with time owing to model trends. && .AVIATION...For McCarran...Light southeasterly winds will continue through the remainder of the morning and into the early afternoon. Southerly winds will increase by mid-afternoon with gusts 15-20 kts possible. These winds will become more southwesterly and the gusts will fall off after sunset, becoming light and variable overnight. A similar situation expected Friday, with light southeasterly winds prevailing through the morning and early afternoon, followed by southerly gusts mid-afternoon through sunset. No operationally significant cloud cover expected through the TAF period. For the rest of southern Nevada, northwest Arizona and southeast California...Light winds expected to continue for the remainder of the morning and into the early morning hours before gusty southerly winds 15-20 kts build in mid-morning. After sunset, these gusts will fall off, becoming light and variable for most overnight, though southerly winds around 10 kts will sustain through the overnight hours for the Colorado River Valley TAF sites. KDAG will sustain a westerly direction 10-15 kts through the TAF period. A similar story expected Friday as well. No operationally significant cloud cover expected through the TAF period. && .SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report any significant weather or impacts according to standard operating procedures. && $$ UPDATE...TB3 DISCUSSION...Outler AVIATION...Varian For more forecast information...see us on our webpage: or follow us on Facebook and Twitter