Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 05/10/19

Area Forecast Discussion
National Weather Service Austin/San Antonio TX
948 PM CDT Thu May 9 2019 .UPDATE... Rain chances and amounts are dropped significantly north of Hwy 90 and West of I-35. Strong north winds from a cold front will scour out large amounts of low level moisture which will force the overrunning lifting processes to be elevated. Southeast of I-35 locally heavy rainfall and severe weather will remain possible through midnight, but pockets of heavy rain could still occur over the far southeast counties after midnight. CAMS models show minimal activity across the area between 06Z and 10z with redevelopment from the next wave of instability advancing north over the frontal inversion closer to daybreak. This downward trend change for the overnight period is only a minor and temporary deviation off the continued messaging of daily 1-3 inch pockets of heavy rain and isolated pockets of 5 inch totals through Friday night. && .PREV DISCUSSION... /ISSUED 708 PM CDT Thu May 9 2019/ UPDATE... We have updated to include the remainder of the eastern/southeastern CWA in the Severe Thunderstorm Watch through 11 PM. HRRR shows expanding line of storms through this region through the evening. Mesoscale analysis reveals pockets of 4000-5000 J/kg SBCAPE through this region coinciding with 40-50kts of deep layer shear. A threat for very large hail exists over the next hour or two across southern and eastern areas of the CWA transitioning to damaging straight-line wind threat. An isolated tornado can`t be ruled out. Southern and eastern areas of the CWA will also be under the threat for locally heavy rainfall through the evening hours. 1-3 inches of rainfall is possible with isolated pockets up to 5 inches (see WPC latest Mesoscale Precip Discussion) AVIATION... SHRAs and TSTMS ongoing this evening across South Central Texas. Threat for strong to severe storms will primarily will be east and south of the TAF terminals. Threat of SHRAs and TSTMs should exit east of the region around 04Z-07Z. Gusty N to NE winds will develop at AUS/SAT/SSF through the evening and overnight hours, as pressure rises increase behind the cold front. Gusts over 25 kts possible. In addition, MVFR ceilings will develop 03Z-09Z areawide, possibly IFR at SAT/SSF/AUS overnight. PREV DISCUSSION... /ISSUED 332 PM CDT Thu May 9 2019/ SHORT TERM (Tonight through Saturday)... Scattered showers and thunderstorms have developed across the western parts of the CWA over the past couple of hours. A pre-frontal boundary just before the cold front has provided the initial lift for the convection. At the same time, a weak upper level disturbance is expected to push into South-Central Texas from the west. Latest high-res guidance continues to show these two features working together with the bulk of the stronger thunderstorms remaining near the boundary. The front is expected to continue to push south through the region this afternoon and evening. By 7 PM, the front is expected to be near our southern border with WFO CRP. The atmosphere is quite unstable, with SBCAPEs near 5000 J/kg. This in combination with 0-6km shear values near 40-50 knots will provide the ingredients necessary for some of the storms to be quite robust with very large hail being the main threat. A dry layer at 700 mb could inhibit storms a bit, but with the instability amounts these should be able to be overcome. A Severe Thunderstorm Watch has been issued for locations generally south and east of a Fredericksburg to San Marcos to Gonzales line to cover the initial threat through 04z. Another watch may need to be issued at a later time for downstream depending on how things evolve tonight. As the front makes it near the southern boundary of the CWA late this afternoon and evening, storms could increase in coverage with the arrival of the best forcing. There are some indications in the latest high-res models that this activity will eventually congeal into an MCS tracking east into the Houston area overnight. If this does occur, mesoscale subsidence on the backside of the complex should limit rain chances after 06-09z tonight and into tomorrow morning. The cold front is expected to push well into South Texas by tomorrow morning. Additional activity is expected to move in from the southwest by tomorrow afternoon as some weak lift above the frontal layer moves into the area. This precip is shown best by some of the CAMs, while the GFS is much drier. One last wave of rainfall is expected Friday night into Saturday ending from west to east by Saturday afternoon. The activity Friday through Saturday is not expected to be severe, but the threat of locally heavy rainfall will continue. The Flash Flood Watch will continue for areas east of a Fredericksburg to Hondo to Pleasanton line through 00z Sunday. While the bulk of the heavy rainfall will fall across the Coastal Plains, a conditional threat of flash flooding remains for the Hill Country and Austin metro areas within the Flash Flood Watch. As what was seen yesterday, a quick inch of rainfall will cause additional flooding concerns. In addition to the rainfall tomorrow, temperatures will be well below normal behind the front. Highs tomorrow will be in the low 60s to near 70 degrees. Austin Bergstrom should break a daily record low maximum temperature. The current record is 75 degrees, and the current forecast high is 66. The other 3 climate sites should not break any records. LONG TERM (Saturday Night through Thursday)... Will show no PoPs Saturday night as activity should be east of the area. Mother`s Day should be mostly dry as well. The GFS is showing some precip with an approaching trough through Monday, but the Euro remains dry. Will show slight chance PoPs for the beginning of the long-term forecast to cover this threat. Slightly higher PoPs are in the forecast through the mid-week period as models have slightly better consistency on the placement of the trough axis. Temperatures in the extended will moderate but will be cooler than normal. && .PRELIMINARY POINT TEMPS/POPS... Austin Camp Mabry 56 66 60 74 60 / 60 60 80 70 10 Austin Bergstrom Intl Airport 57 66 60 75 60 / 70 60 80 70 10 New Braunfels Muni Airport 58 67 59 76 60 / 70 70 80 70 10 Burnet Muni Airport 53 63 57 72 58 / 40 60 80 60 10 Del Rio Intl Airport 59 67 59 79 61 / 40 60 70 20 10 Georgetown Muni Airport 54 63 59 73 59 / 40 50 80 70 10 Hondo Muni Airport 59 68 59 77 60 / 50 70 70 50 10 San Marcos Muni Airport 56 65 59 74 60 / 70 70 80 70 10 La Grange - Fayette Regional 60 70 64 78 63 / 80 70 80 90 10 San Antonio Intl Airport 58 68 61 78 61 / 70 70 80 70 10 Stinson Muni Airport 60 70 62 78 63 / 70 70 80 70 10 && .EWX WATCHES/WARNINGS/ADVISORIES... Flash Flood Watch through Saturday evening for Atascosa-Bandera- Bastrop-Bexar-Blanco-Burnet-Caldwell-Comal-De Witt-Fayette- Gillespie-Gonzales-Guadalupe-Hays-Karnes-Kendall-Kerr-Lavaca-Lee- Llano-Medina-Travis-Williamson-Wilson. && $$ Aviation...Oaks Short-Term/Long-Term...Oaks Public Service/Data Collection...EWilliams Social media/Coordination...Runyen Radar...CP/BW
Area Forecast Discussion
National Weather Service Hastings NE
657 PM CDT Thu May 9 2019 .SHORT TERM...(This evening through Friday) Issued at 322 PM CDT Thu May 9 2019 Showers appear to be under-producing today so far today, with radar returns struggling to make it into southern parts of our forecast area. Short term models have backed off on this as well, therefore I believe that most of the area will just see spotty sprinkles through the rest of the afternoon. Tonight, attention shifts to the potential for freezing temperatures. High pressure moving in will make winds light and variable and should also clear out skies this evening. The complicating factor will be high clouds moving back in with an approaching upper level jet streak. It may end up being a situation where temperatures plummet quickly after sunset, then level off as high clouds move in. As a result, I am a little concerned that some locations may remain warmer than forecasted...especially when looking at temperature forecasts from the HRRR and RAP that are notably warmer. Nevertheless, I continue to think that the current warning/advisory cover the threat well. Winds will remain light on Friday as the surface high slowly shifts off to the east, but we will likely see continued high cloud cover into the afternoon which will limit our temperatures getting any higher than the low 60s. Friday night will be warmer than tonight, but its still possible that we see some patchy frost in northwestern portions of the forecast area. .LONG TERM...(Friday night through Thursday) Issued at 322 PM CDT Thu May 9 2019 A cold front moves through the area on Saturday. This will likely bring some scattered showers to the area during the afternoon and evening, and models even show some very modest instability. As such, I added a slight chance for thunderstorms, but it shouldn`t be anything more than an isolated rumble or two. Once again Saturday night we will have to watch for some patchy frost in northwestern areas, but most of the area will only drop into the low 40s. A warming trend begins on Sunday as highs are forecasted to reach the mid 60s to near 70 degrees. This trend will continue Monday and Tuesday as the upper level ridge moves in from the west. Highs are actually forecast to reach the 80 degree mark on Tuesday. The area should remain dry Sunday and Monday, but there should be at least some chance for rain and thunderstorms Tuesday into Wednesday. The timing and positioning of the cutoff low exiting the southwest are significantly different between the GFS and Euro, and as a result our blends probably don`t reflect the overall precipitation chances very well. Beyond that, the pattern appears to become a little more active as we move into the latter half of next week. && .AVIATION...(For the 00Z KGRI/KEAR TAFS through 00Z Friday) Issued at 649 PM CDT Thu May 9 2019 The wind will quickly die off this evening and become calm to light and variable after midnight. Clouds will also thin out tonight and VFR conditions are expected to continue throughout the forecast period. We could see a heat of the day scattered deck of clouds on Friday but should be above 4000 ft agl. && .CLIMATE... Issued at 337 PM CDT Thu May 9 2019 ...First time in 6 years that 4-CONSECUTIVE MAY DAYS have failed to reach 60 degrees in the Tri-Cities... - Today (Thursday) marks the 4th-consecutive day with high temperatures falling short of 60 degrees at all 3 official Tri Cities airport stations (Grand Island/Hastings/Kearney). While this sort of thing happens occasionally in May, it is not very common. - The last time all three Tri Cities stations went 4 CONSECUTIVE MAY days without reaching 60 degrees was six years ago from May 1-4, 2013. - Based on our latest forecast, this streak is expected to end Friday (albeit barely), as highs are forecasted to reach the low 60s. - The record streaks for consecutive May days without reaching 60 in the Tri Cities all occurred back in 1935, and are as follows: Grand Island: 8 days...May 13-20, 1935 Hastings: 8 days...May 13-20, 1935 Kearney: 9 days...May 12-20, 1935 && .GID WATCHES/WARNINGS/ADVISORIES... NE...Frost Advisory from 1 AM to 10 AM CDT Friday for NEZ041-048-049- 062>064-074>077-084>087. Freeze Warning from 1 AM to 10 AM CDT Friday for NEZ039-040-046- 047-060-061-072-073-082-083. KS...Frost Advisory from 1 AM to 10 AM CDT Friday for KSZ005>007- 017>019. && $$ SHORT TERM...Mangels LONG TERM...Mangels AVIATION...Wesely CLIMATE...Pfannkuch
Area Forecast Discussion...UPDATED
National Weather Service Jackson MS
903 PM CDT Thu May 9 2019 .UPDATE... Updated for evening discussion. && .DISCUSSION... The region remains in a relative lull in activity this evening, with remaining light showers along the I-59 corridor on a continued decreasing trend. The storms from earlier today have temporarily stabilized the atmosphere across the area, and there has been a decrease in deep layer moisture over much of the area. However, overnight a disturbance currently instigating convection along the TX coast will track northeastward. The low level jet will increase, helping to spread deeper moisture right back into our area by tomorrow morning. The next round of rain and storms, associated with the aforementioned disturbance, looks to arrive early Friday morning, spreading across the area through the day. The latest HRRR runs suggest this system may be weakening as it arrives but a remnant MCV could help kick off new development during the afternoon hours. The forecast has been updated to refine POPs/wx timing, showing lower rain chances this evening areawide, with increasing rain chances across the southwest overnight into early tomorrow morning. /DL/ Prior discussion below: Tonight through Saturday... It has been a rather busy day as a line of storms moved through the region and is now located across the Gulf Coast. This line brought some wind damage to the region but it also brought heavy rain and plenty of flooding. This is just the first round of storms to move through the region, with plenty more to come over the next several days. The actual cold front is still to the northwest and will progress into the region this evening and tonight and stall across the area. There should be a lull in the rain activity overnight. However, model guidance is in decent agreement that a disturbance will move northeast into the region tomorrow. This will bring another round of showers and storms to the region through the day tomorrow. Some of these storms could be knocking on our doorstep in the southwest as early as daybreak or a little thereafter and continue through the afternoon into the evening. SPC has highlighted the southeast part of the forecast area in a marginal risk for severe storms tomorrow. Given somewhat steep lapse rates and vertical totals around 26-27C, and sufficient deep layer shear across the region, I cannot rule out a few severe storms during the morning into the afternoon. I do not anticipate it being a setup like today was across the area. Will mention this in the HWO and graphics for tomorrow. Given another wave moving through on Saturday, there likely will need to be another outlook for severe storms(at this point marginal risk) for the area, but will leave out of the HWO/graphics for now and focus one day at a time, given uncertainty in how convection evolves each day and what residual boundaries may develop and linger. Of greater concern will be the continued risk for heavy rain and flash flooding across the region. With copious amounts of rain that fell today, the entire area is primed for more flooding with just about any rain that falls over the next few days. With continued southwest flow aloft and ample moisture in place, heavy rain and more flooding will likely occur. That being said, we have gone ahead and expanded the Flash Flood Watch to include the entire forecast area through Saturday night. It may need to be expanded in time later, but will let future shifts make that assessment. We have also included the entire area in an elevated flood risk in the HWO/graphics. An additional two to five inches of rain will be possible, with locally higher amounts as well. /28/ Saturday night into next week... A pattern change will finally begin to bring some relief to our region beginning Saturday night as a deep closed low approaches the Great Lakes and helps to finally push a front through our region on Sunday. The front will begin to slowly push into the region on early SUnday morning, a little later than previously expected. Showers and storms will continue along and ahead of the front resulting in at least a threat of flash flooding remaining into Sunday. There are still uncertainties at this point in severe weather becoming a threat through the day. Rain and storms will begin to taper off from west to east by Sunday afternoon as drier air begins to filter into the region. NW flow aloft and high pressure near the surface will help to keep the region clear and temperatures below normal through the early week period. Rain chances will return to the region by mid week as a few upper level disturbances embedded within the persistent upper NW flow pattern could result in showers in the northern portions of the region while a few weak disturbances embedded within the southern stream could result in showers/storms in the southern portions of the region. && .AVIATION... 00Z TAF discussion: The latest round of SHRA/TSRA continues to exit the area, with only lingering -RA across parts of south MS. Considerable low stratus exists across the area, with conditions ranging from MVFR to LIFR. Ceilings are expected to deteriorate overnight with some reductions in visibility possible as well. Conditions will be slow to improve through the morning and afternoon hours. Another round of SHRA/TSRA will move into the area Friday morning, continuing eastward through the day. With that, temporary ceiling/visibility reductions are possible in TSRA/+RA. /DL/ && .PRELIMINARY POINT TEMPS/POPS... Jackson 65 77 66 78 / 46 93 67 94 Meridian 64 78 67 80 / 20 92 60 94 Vicksburg 67 75 66 76 / 62 93 70 93 Hattiesburg 66 80 69 81 / 38 93 49 93 Natchez 66 77 67 78 / 80 93 67 94 Greenville 65 72 64 73 / 32 76 68 94 Greenwood 66 73 64 75 / 25 80 71 94 && .JAN WATCHES/WARNINGS/ADVISORIES... MS...Flash Flood Watch through Saturday evening for MSZ018-019- 025>066-072>074. LA...Flash Flood Watch through Saturday evening for LAZ007>009-015- 016-023>026. AR...Flash Flood Watch through Saturday evening for ARZ074-075. && $$ DL/28/JPM3
Area Forecast Discussion
National Weather Service Key West FL
1014 PM EDT Thu May 9 2019 .DISCUSSION... Area radars show a cluster of showers and thunderstorms moving south from the Gulf waters off Mainland Monroe toward the Lower and Middle Keys, with scattered showers and isolated thunderstorms also present over the Atlantic waters east of Miami-Dade County and the far Upper Keys. A few showers moved over parts of North Key Largo earlier, otherwise dry conditions have prevailed over the Keys island chain so far this evening. Skies have become partly to mostly cloudy, as high cloudiness emanating from the convection to our north spreads southward. Temperatures are dropping into the lower 80s, and winds on land are from the east at 10 to 15 mph. Surface analysis depicts a large high pressure area centered east of New England and sprawling southward along the eastern seaboard and over the western Atlantic. The Keys lie along the southwestern edge of this high, driving gentle easterly breezes over our area. Aloft, a weak mid/upper level trough is dropping southeastward across the Florida peninsula. The 00Z Key West sounding shows a moderately moist and conditionally unstable airmass in place, with PW of 1.65 inches and no significant inversions. GOES derived TPW imagery shows similar estimated PW values surrounding the Keys. The overnight forecast remains tricky. While little rainfall has occurred over the Keys so far this evening, increasing northerly flow aloft appears to now be pushing the convective cluster to our north down toward the Lower and Middle Keys, where it could interact with pre-existing boundaries, or other shower activity riding in from the Straits on easterly low level flow. The airmass in place certainly will support convection, and is only lacking a trigger, which could be provided by boundary interaction as noted above. In addition, the Upper Keys may also be impacted later tonight by convection moving WSW from the Atlantic waters east of Miami. The latest HRRR does show increasing rainfall coverage around and over the Keys late tonight. Have maintained 50 percent rain chances throughout the Keys for the overnight period. Otherwise, mostly cloudy skies will prevail, with low temperatures varying from the mid 70s to around 80, depending on if a particular location receives rainfall or not. && .MARINE... Evening marine observations show winds backing to E or even ENE with speeds mostly in the 10 to 15 knot range. Expect little change overnight, although locally stronger and shifting winds will be possible with any thunderstorms. No significant changes are planned for the late evening forecast issuance. && .AVIATION... The cluster of showers and storms pushing south toward the Lower and Middle Keys may bring MVFR or even brief IFR impacts along with gusty and shifting winds to the EYW and MTH terminals from 03Z through 06Z, and have included VCSH and TEMPO groups in both TAFs for that time period. Shower/storm chances should decrease by Friday morning, and currently expect VFR conditions to prevail during the day. Surface winds will remain generally from the east around 10 knots, outside of any convective influences. && .KEY WATCHES/WARNINGS/ADVISORIES... FL...None. GM...None. && $$ Public/Marine/Fire...Jacobson Aviation/Nowcasts....Jacobson Data Collection......DR Visit us on the web at Follow us on Facebook and Twitter at:
Area Forecast Discussion
National Weather Service Medford OR
856 PM PDT Thu May 9 2019 .DISCUSSION...The forecast is relatively straight-forward in the short term. A strong ridge centered offshore will build inland into Saturday. Wind speeds will not be as strong on Friday, and will continue a weakening trend into Saturday. But, it will remain unusually warm and dry. There was an update sent earlier this evening to enhance the cloud cover this evening to overcast at the coast south of Cape Blanco. Also, late this evening, the RAP and NAM models support a forecast of low level northeast winds pushing the stratus away from the shoreline with a gradual diminishing through Friday. The thermal trough that was at the coast today will push inland on Friday. This will result in a warming trend inland and slightly warmer at Brooking on Friday while the remainder of the coast will have weak winds and the beginning of a cooling trend. By Sunday, the ridge will be flattened/weakened by a trough moving into Canada while another trough will be moving into the Gulf of Alaska before deepening over the eastern Pacific. As such, Sunday will be a transition day with a modest increase in cloud cover and relative humidity, with slight cooling west of the Cascades. Monday`s weather will resemble that of Sunday while the broad trough approaches and brings afternoon winds from very slightly weaker to very slightly stronger than normal. Model differences are important beyond Monday, but there is confidence in a transition to a seasonable, active, occasionally wet pattern. The first point in question is whether the first wet front approaching from the west will bring rain to any part of our area before the end of Tuesday afternoon. The highest probability is for rain to reach the coast early Tuesday evening. The next question regards whether precipitation during next week will be very light, light, or moderate in any given area during any given period. As the time draws nearer, clarity in the appropriate answers is likely. This return to more typical spring weather is likely to persist in the day 8 to day 14 time frame. && .AVIATION...For the 10/00Z TAFS...Along the coast south of Cape Blanco and the adjacent coastal waters...Widespread IFR cigs/vsbys in low clouds and fog with higher terrain obscured will move offshore during the day Friday, then return Friday night. Over the remainder of the area...VFR conditions will prevail through Friday night. && .MARINE...Updated 800 PM PDT Thursday 9 May 2019...The thermal trough has weakened and winds and seas are now subsiding. Small craft advisory conditions will persist into Friday morning due to residual wind waves and fresh swell. A southerly wind surge is bringing low clouds and fog to areas south of Cape Blanco that will persist into Friday morning at the least. Relatively calm winds and seas will persist Friday afternoon through Monday. A weak front will arrive Tuesday night. Small craft advisory conditions are not expected at this time. && .PREV DISCUSSION... /Issued 211 PM PDT Thu May 9 2019/ DISCUSSION...Current observations are showing mainly clear skies with some cumulus moving westward across portions of northern California and east of the Cascades in southern Oregon. These winds from the east are responsible for the very dry conditions as well as warm temperatures ongoing, especially at places like North Bend. In stark contrast, the marine layer continues to be difficult to forecast as a small eddy (circulation) is off the coast of Humboldt County. This has kept fog and low stratus across the southern Oregon coast of Brookings to Gold Beach. Meanwhile, the easterly winds at Red Mound (1753 feet) have been gusting to 25 mph and bringing temperatures into the 80s as of 11 AM. These east winds have remained aloft and have not mixed into the boundary layer. This is why Brookings has only reached the upper 50s and North Bend is already reaching the mid 80s. The thermal trough will move inland overnight into tomorrow, and the coast could reach warm temperatures yet again, and they should peak in the morning. This is dependent on the east winds keeping overnight temperatures from dipping back to normal. Then, winds turn to be westerly, and the marine influences will cool things out. Meanwhile, temperatures on Friday are expected to really soar, especially in the valleys west of the Cascades. Additionally, expect the coastally trapped wind reversal to surge up the Oregon coast on Friday and begin to wash out on Saturday as the marine layer returns Saturday afternoon. Temperatures remain pretty warm on Saturday but will slowly begin a cooling trend on Sunday. Models are conflicted with possible precipitation on Sunday in the form of Thunderstorms in the area. The ECMWF is showing completely dry conditions, while the GFS and GEFS ensemble are showing some convective potential in southern Siskiyou County. This could be convective feedback (or it could be legitimate and I could be wrong), and would make sense that it would make its way into the blend of models. Have used the blend of models, but have toned down the probabilities of precipitation on Sunday. Should any precipitation actually form, expect an isolated thunderstorm to occur with it. Monday returns to mainly dry conditions, and cooler. Then the pattern begins to shift for midweek and a low pressure system with cold front approaches the Pacific Northwest. Models are confident in the cool down of high temperatures, and the standard differences in precipitation are occurring (the GFS being more progressive and stronger with more precipitation as opposed to the ECMWF which is weaker and somewhat drier, but still with some precipitation). Have gone with the blend of models ensemble at this point as this system will need to be monitored in the coming days. -Schaaf FIRE WEATHER...Updated 200 PM PDT Thursday 9 May 2019...Gusty east to northeast winds and very low humidities will produce critical to near-critical fire weather conditions across the area this afternoon and evening. A Red Flag Warning remains in effect for the foothills of eastern Douglas County and for a significant portion of northern and central Klamath County. Conditions will improve slightly overnight, but east winds will continue and overnight to early morning recoveries will trend moderate to poor, especially over high terrain along and west of the Cascades. The thermal trough will continue its slow slide inland Friday and Saturday, producing the warmest temperatures of the week over all but the very-near coastal areas. Humidities are expected to be very similar to today, but winds will be significantly weaker. While this should keep the region free of any Red Flag conditions, many areas could still get very close with the typical afternoon breezes. Also worth noting will be the increased instability Friday afternoon, mainly west of the Cascades and down along the coast, where Haines values of 5 to 6 are expected. These conditions could promote plume dominated growth over any new or existing fires. After another hot and dry day Saturday, conditions should begin to improve Sunday into early next week, with cooling temperatures, gradually rising humidities, and improving recoveries. There will be a slight chance for showers and isolated thunderstorms over southern Siskiyou and modoc counties Sunday afternoon, and across portions of northern California and south central Oregon Monday afternoon. It is looking increasingly likely that widespread rain may enter the area by midweek, although the timing and amount of rain remains uncertain. -BPN && .MFR WATCHES/WARNINGS/ADVISORIES... OR...None. CA...None. Pacific Coastal Waters...Small Craft Advisory until 5 AM PDT Friday for PZZ350-356-370-376. $$ DW/JRS
Area Forecast Discussion
National Weather Service Sacramento CA
326 PM PDT Thu May 9 2019 .SYNOPSIS... Showers and thunderstorms are possible today over the northern Sierra, potentially spreading into the northern San Joaquin Valley this evening. Chances of showers and thunderstorms continue into the weekend, mainly south of I-80. A pattern change is currently projected for the middle of next week bringing cooler, potentially wetter weather across Northern California. && .DISCUSSION... Delta flow earlier brought a thick band of low stratus clouds to the Sacramento region northward toward Oroville and Chico. Gradually increased mixing from the early May solar angle allowed this band of clouds to burn off leading to mostly sunny skies across the Valley. Further east across the Sierra, diurnal heating in conjunction with forcing from the retrograding upper low has sparked a few thunderstorms over Tuolumne County. At this point they appear to be locked to the terrain with heavy rainfall and lightning noted in the MRMS data. Farther north, any capping issues have eroded given the expansion of radar echoes stretching from Highway 50 southward along the western slopes of the Sierra. The latest RAP objective analysis shows MUCAPE values in excess of 1000 J/kg over the Sierra (mainly south of I-80) with more capping issues toward the foothills and Valley floor. Thus, anticipate any storms moving off the terrain to initially struggle to sustain their updraft given downstream convective inhibition. However, will maintain the threat for showers and thunderstorms across the northern San Joaquin Valley through the evening hours as high-resolution guidance has shown. The other aspect of this "Inside Slider" is the modest wind field on its western periphery. Maximum wind gusts thus far have been around 30 mph observed at the Redding Municipal Airport (KRDD). A Wind Advisory remains in effect for the northern Sacramento Valley through 9 PM with north-northeasterly gusts possibly up to 35 mph in some locations. Closer to the Delta, Mesowest observational data has shown sustained southwesterly winds around 20 to 25 mph with slightly higher gusts. Winds should maintain a decent strength into the evening hours with occasional gusty northerly flow continuing into early Friday afternoon. Looking to Friday and into the weekend, much of the region will dry out as the parent upper low continues its southward push into the coastal waters of southern California by Friday afternoon. With an upper ridge building to the north over the Pacific Northwest, a rex block configuration sets up for the weekend. Net mid/upper-level easterly flow will maintain daily shower and thunderstorms chances for the Sierra. Coverage may be widely scattered at times given the lack of meaningful perturbations in the flow aloft. Regarding winds, it appears the Delta breeze kicks up again over the weekend which would influence cloud cover forecasts in its vicinity. Otherwise, the region can expect a warm weekend with Valley highs in the low/mid 80s with perhaps near 90 degrees around Redding and Red Bluff. ~BRO && .EXTENDED DISCUSSION (Monday THROUGH Thursday) Ensemble solutions continue to support a shift in the synoptic pattern along the West Coast. As the ridge/trough couplet will have advanced into the Rockies by Monday, a broad longwave trough centered between 150W-135W longitude should have an opportunity to impact the state by mid-week onward. While the week begins dry accompanied by slightly above average temperatures, conditions will change during the middle to latter portion of next week. This would favor increased cloud cover, decreasing temperatures, and chances for showers and thunderstorms. Given deterministic solutions continue to waver, ensembles will remain the best path to follow. By next Thursday (May 16), the mean upper trough axis is forecast to settle just offshore with the 12Z GEFS/ECMWF ensemble means in near spatial agreement. Looking farther ahead, the central/eastern Pacific flow becomes quasi-zonal which could keep conditions wet somewhere along the West Coast into further forecast periods. The Climate Prediction Center highlights above average precipitation during the May 15-23 timeframe. ~BRO && .AVIATION... Mainly VFR conditions next 24 hours except local MVFR conditions possible in showers or thunderstorms for areas south of I-80 through 03z Friday, and again over higher terrain south of I-80 after 21z Friday. Northerly wind gusts 20-30 kts northern terminals through 03z Friday; increasing again after 14z Friday. && .STO WATCHES/WARNINGS/ADVISORIES... Wind Advisory until 9 PM PDT this evening for Northern Sacramento Valley. && $$