Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 04/15/22


Area Forecast Discussion
National Weather Service Binghamton NY
930 PM EDT Thu Apr 14 2022 .SYNOPSIS... A cold front will push into New England this evening, taking scattered showers and thunderstorms with it. High pressure will build in overnight, with drier weather on Friday, but gusty winds are also expected. Another cold front will bring additional showers and cooler temperatures this weekend. && .NEAR TERM /THROUGH FRIDAY/... 915 PM Update... This update involved quite a few minor adjustments for a little bit of everything. There are some lingering showers moving through the Poconos and Catskills, so a slight chance remains for mainly those areas until the top of the hour. Otherwise, skies continue to clear behind these lingering showers. Fog has developed at Rome where it is one of just a few locations where the obs indicated the dew point depression is in the single digits. So patchy fog was added in Oneida County for the next couple of hours. Then dew points up there should drop and conditions will then be too dry for fog to remain. As mentioned in the last update, the dew points were a struggle. The NBM was lower than what was previously forecasted and model guidance was indicating lower dew points overnight as well. For this update, the NBM, Conshort, and HRRR was used for the hourly dew points through the overnight hours. This blend better matched recent observations. The forecasted hourly temperatures were actually doing fairly well, so only minor adjustments were needed. 600 PM Update... The thunderstorms are out of our region and there is no longer a severe threat. However, there are some scattered showers passing through. Because of a trailing line of light showers/drizzle, PoPs were expanded westward slightly. Though with how dry areas have become after the frontal passage, anything from the trailing line may struggle to reach the ground. Showers should be completely out of the region within the next few hours. Since we are not seeing any lightning with anything that is over the region, chances for thunderstorms were removed. Skies are clearing behind the showers. This will allow some to have a view of the sunset this evening. The hourly sky forecast was updated based on satellite and updated guidance. Blending in some of the NAM Nest and NBM with the previous forecast does speed up the clearing this evening. By midnight, the region is expected to be under mostly clear skies. The hourly winds were touched up over the next few hours. Conditions will remain gusty until an inversion develops close to the surface, cutting off any mixing from above. As mentioned, behind the clouds and rain showers, conditions are becoming quite dry with dew points quickly dropping. This may need to be the focus for the update. 338 PM Update... Showers that developed ahead of the front appear to have limited instability over most of the CWA, though there`s still a narrow window where a stronger thunderstorm could affect Pike or Sullivan County before 5 PM. Otherwise, expect the front will pass though most areas with some brief gusts of 30 to 40 mph, and scattered post-frontal showers will linger a couple hours behind the frontal passage. Most areas west of I-81 will see some sunshine before sunset. High pressure will build across the Carolinas overnight, with a sharp ridge axis extending north into the Mid-Atlantic states. Meanwhile, a slow moving upper low will remain over northwestern Ontario. We`ll see a return to west-southwest winds on Friday, with temperatures recovering back into the lower to middle-60s, warmest over the Finger Lakes region. Deep mixing will allow for some gusty winds again, peaking around 35 to 40 mph in places during the afternoon. Another disturbance associated with the big upper low will move into the Lower Great Lakes later Friday, with a few showers possible in the afternoon north of the Thruway. A stalled out cold front will slowly sag southward through Friday night, with rain showers expanding south as the front drifts south. Precip should stay north of the Twin Tiers through Midnight Friday Night (Sat AM), but will work into PA before dawn. 145 PM Update... Cold front currently extends from just east of Rome to near Marathon and Towanda, and is quickly pushing to the east. Wind gusts of 35 to 45 mph have been occurring with the frontal passage. RAP analysis shows SBCAPE vales of around 500 J/Kg just ahead of the front, but this is likely erroneous with the model not accounting for the spotty showers and slightly cooler temperatures that have cropped up out ahead of the front. As time goes on, it`s looking more like the thunderstorm chances will be limited to the far eastern 2-4 counties of the CWA, with gusty showers elsewhere. && .SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/... 245 pm Update... Another upper level trough moves through our area this period. A slow moving northeast to southwest cold front moves southeast Saturday with up to half an inch of rain. The front will be a sharp boundary for 2 air masses. Highs Saturday from the upper 40s north to low 60s far south. Temperatures fall in the afternoon. It is cold enough for precipitation to change to snow Saturday night. By that time showers will be light with a short wave and weak front moving through. Higher terrain could get a dusting of snow. Some lake enhancement with 850 mb temperatures dropping to -8C. Mixed showers continue into Sunday before ending late in the day as the trough moves through New England. Low temperatures in the upper 20s and lower 30s. Sunday will be the coldest of the next week with high temperatures in the 40s. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... 245 PM update... Little change. A cool unsettled pattern with an upper level trough on Tuesday and another on Thursday. Briefs breaks of dry weather. Discussion below covers the complexities of next week`s weather well. 330 AM Update... The long term is looking cooler than average and fairly active. Weak ridging builds in Sunday night into Monday with a break in precipitation as well as some moderating temperatures. Monday night into Tuesday is looking a little more interesting. Ensemble mean flow at 250 mb shows a trough over the Great Lakes with a strong jet max advecting in. This supports the chance of a stronger surface low during the Monday night into Tuesday timeframe. WPC clusters show good agreement on low 500 mb anomalies associated with a deeper trough over the Great Lakes region. The location of the surface low is uncertain with two low pressure systems forming, one inland and one a coastal low. If the inland low becomes the dominant low then rain will be likely area wide. The coastal solution could pull enough cold air into the region as it deepens to give higher elevations a shot at some accumulating snow. Even if this solution occurs, there is differences in the timing of the snowfall. In order to get accumulations of more than an inch or 2 the snow would need to fall at night and at a fairly good pace to overcome the melting from the warm soil temperatures. There is higher confidence in mid week as the low moves into the Canadian maritimes and deepens with NW flow. Another system could move in mid to late next week though the complexity of the pattern only a slight chance of precip was added Wednesday into Thursday. && .AVIATION /01Z FRIDAY THROUGH TUESDAY/... High pressure building in from the west along with a very dry air mass will keep weather conditions quiet through the next 24 hours. Skies will be mostly clear tonight before high clouds approach from the west late Friday morning and then thicken in the afternoon as a weak front slowly slides in from the west. Winds will remain light less than 7 kt tonight out of the southwest and then increase after 13Z Friday with gusts 15 to 20 kt. Should see a period between 16-23Z where gusts 20 to 30 kt are possible. Winds subside and shift to the northwest across the northern terminals before 00Z Saturday. Outlook... Friday Night through Saturday Night...Showers possible with associated restrictions. Sunday...Mostly VFR, though some lake effect rain and snow showers with associated restrictions possible over Central NY. Monday...Mainly VFR. Monday Night through Tuesday...Showers possible with associated restrictions return. && .FIRE WEATHER... Despite scattered showers today, high pressure building in overnight bring in much lower dewpoints to the area. Southwest winds will redevelop tomorrow as the surface ridge axis shifts east of the area, and with a fairly tight pressure gradient, a few gusts could top 35 to 40 mph, especially in favored downslope locations. Temperatures will warm back up to the 60s in most areas, with middle-60s in downslope areas around the Finger Lakes. With the drier airmass, very fine fuels will dry out rather quickly despite the rain. Minimum RH values in the afternoon range from 28 to 35 percent in the Mohawk Valley, and around 25 percent across the Finger Lakes, Twin Tiers, and most of northeast PA. This will result in enhanced fire weather conditions. No red flag warnings are in effect at this time, but will be reassessed based on fuel conditions. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...None. NY...None. && $$ SYNOPSIS...MPH NEAR TERM...BTL/MPH SHORT TERM...TAC LONG TERM...AJG/TAC AVIATION...BJT/MPH FIRE WEATHER...
Area Forecast Discussion
National Weather Service Peachtree City GA
807 PM EDT Thu Apr 14 2022 .UPDATE... Chances for showers, and especially thunderstorms, is looking increasingly unlikely in east-central Georgia, so PoPs have been lowered and thunder has been pulled from the forecast entirely for the remainder of the day. Otherwise, the short term forecast remains mostly on track this evening. Updated for the 00Z Aviation Discussion. && .PREV DISCUSSION... /Issued 347 PM EDT Thu Apr 14 2022/ SHORT TERM /Rest of today through Friday Night/... Chances for any regeneration of convective triggering in the south and east look to be lowering as persistent cloud coverage/solar sheltering appears to have limited destabilization needed for any storms. CAM solutions overall have little to no development as well this afternoon into evening but will hold onto some pops as we cannot rule out some isolated showers or thunderstorms though general to weak intensity. SPC has also removed the Day 1 Marginal out of the area and the RAP progged SBCAPE looks quite meager in the next several hours. Otherwise the focus shifts to how low some dewpts and resultant RH values get Friday afternoon into evening and any fire danger concerns. Went with a NBM/MAV/MET blend which looked like a decent compromise to go a bit lower than just the NBM but not too low, given how we should switch over to an east/SE fetch and the Nam thermal profile looks dry near the top of the boundary layer but not as dry as seen in previous dry dewpt "bust" days where we get much lower than forecast. For now it looks borderline in parts of the north so will let evening or overnight updates assess with possible new or consistent guidance. Friday night/Saturday morning looks to have an upper disturbance and phased enhanced moisture field traversing the near zonal flow aloft approaching from the TN Valley. This should bring the next increased chance of precip. There is question as to how much or if any CAPE is accompanying this feature but for now have slight thunder mention. Temps tonight a bit below climo norms given post frontal regime and lessening cloud cover/moisture. Generally looking at 40s in the north and 50s south. We should warm up to above normal Friday afternoon with many areas in the mid 70s to low 80s, then above normal lows Friday night given aforementioned zonal flow and increased moisture/precip chances. Baker LONG TERM /Saturday through Thursday/... With mostly zonal flow in the mid-levels and the remnants of the front starting a slow crawl northward, the passage of a few shortwave disturbances aloft will lead to a summerlike pattern with chances for rain daily through the weekend. Even with the passage of several days on the long term desk and numerous model runs, there remains a great deal of uncertainty in potential for lingering weekend thunderstorms. Coverage of instability will depend greatly on where the frontal boundary drifts to, and there is much disagreement among global models. The Euro continues to take the more bullish route, keeping an unstable airmass in place (500-1000 J/kg of SBCAPE) across much of the area south of I-20 through Sunday and even into Monday, while the GFS keeps regions of instability rather sparse north of the Georgia/Florida border after sundown and lower in magnitude as a whole. It seems likely that portions of the CWA will hear a rumble of thunder or have the potential for the isolated strong storm form through the start of the week, so have opted to carry a slight chance to chance of thunderstorms through Sunday. To start off the work week, a stout upper trough across the northern Plains and associated broad frontal boundary dig to the south and east. Models prog. a leading shortwave disturbance to drift across the Florida panhandle around the same time the front enters the southeastern CONUS, resulting in a broad shield of precipitation ahead of the frontal convection. As has been the theme for the long term, there is significant divergence in terms of atmospheric moisture between global models. The secondary lobe of low pressure the develops in the Euro solution suggests the potential for isolated severe concerns and higher QPF, whereas the GFS solution has patchier/lower coverage and lacks the reinforcing low at the surface. Will need to keep an eye on this going forward, especially after taking into consideration weekend precip totals for antecedent conditions for flooding concerns. Have kept chance to low-end likely PoPs for Monday to account for dissenting model opinions. Beyond that, ridging begins to build in once again aloft and at the surface to dry things back out through the end of the extended. 96 && .AVIATION... 00Z Update... VFR conditions are expected through the period, as ceilings have moved south and east away from all TAF sites. Lower ceilings and precipitation chances are expected to return just beyond the TAF period. Winds will start the evening at NW at 7-12 kts, diminishing to 3-5 kts and shifting to NE by 09Z early Friday morning. Winds will increase to 10-12 kts by mid-morning, with gusts up to 22 kts during the afternoon hours. Meanwhile, winds will shift to E by 13Z and SE by 17-18Z. //ATL Confidence...00Z Update... High confidence on all elements. King && .PRELIMINARY POINT TEMPS/POPS... Athens 48 76 54 74 / 0 0 30 50 Atlanta 49 76 58 74 / 0 0 40 50 Blairsville 41 70 49 69 / 0 0 60 40 Cartersville 43 77 56 74 / 0 0 50 40 Columbus 50 81 60 79 / 0 0 30 50 Gainesville 48 73 54 72 / 0 0 50 40 Macon 50 80 57 80 / 5 0 20 50 Rome 45 78 56 75 / 0 0 60 50 Peachtree City 47 78 57 76 / 0 0 40 50 Vidalia 57 79 59 82 / 20 5 10 50 && .FFC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Baker LONG TERM....96 AVIATION...King
Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
953 PM CDT Thu Apr 14 2022 .UPDATE... Issued at 950 PM CDT Thu Apr 14 2022 After a VERY windy day, winds have eased considerably since sunset with speeds across the area much nicer in the 10 to 15 mph range. A narrow axis of mid-level clouds is beginning to shift east into areas south of I-80. Thanks to very dry air at the surface this is currently only in the form of virga. This will likely serve as the focus for our precipitation potential early Friday morning into the daytime hours. Confidence in precipitation trends over the next 24 hours remains on the lower side, however, with a fair amount of variability in when we saturate enough for precipitation to reach the surface as well as how quickly the precipitation eventually exits the area. Did make some minor edits to the precip forecast for late tonight through tomorrow morning to nudge up chances along and between the I-80/88 corridors. Model soundings would support snow mixing in within any band of rain where rates are high enough for sufficient wet-bulb cooling for snowflakes to reach the ground. So I wouldn`t be surprised of a narrow axis (favoring areas mainly north of I-80 and west of the metro) that could see minor slushy accumulations if we can get a persistent band of precipitation to develop. The RAP and HRRR have precipitation expand in coverage along and southeast of I-55 Friday late afternoon into the evening. For now have made no changes to that period given a fair amount of model guidance still moving the precip out of the area more quickly. Petr && .SHORT TERM... Issued at 222 PM CDT Thu Apr 14 2022 Through Friday... Forecast concerns include high winds through sunset this evening and then a chance for mixed rain/snow or a period of snow early Friday morning. Wind gusts continue to slowly increase early this afternoon with many locations gusting into the mid/upper 40kt range. So far UGN has seen the highest gust, to 55kt. These high winds will continue through sunset and then quickly diminish through the early/mid evening hours. There will likely still be some gusts overnight but its possible gusts will diminish for much of the area overnight. Gusts will increase again on Friday, possibly back into the 30 mph range. There remains quite a bit of uncertainty for precipitation chances late tonight into Friday. The global guidance is more aggressive with a band of light rain either mixed with light snow or possibly turning to light snow across the center part of the cwa overnight. The high res guidance does not develop much of anything, perhaps some sprinkles/flurries. Its difficult to move away from chance pops and made no significant changes to this time period, along with no changes to light qpf. If this precip materializes, that likely means that its intensity will be heavy enough to cool the column sufficiently to produce a period of light snow. And if that happened, some minor snow accumulation on grassy surfaces is possible. But overall confidence is low. Midday then looks mainly dry with additional light rain chances in the afternoon and mainly along and south of I-80 as a cold front begins to move across the area. cms && .LONG TERM... Issued at 246 PM CDT Thu Apr 14 2022 Friday night through Thursday... Relatively quieter weather Friday night into next week, with only a couple of chances of precipitation as weak waves/fronts move through our area. Temperatures will be below normal through the weekend and into next week, with a warming trend expected around the middle of next week. In the wake of Friday`s cold front, colder air will filter in Friday overnight, leading to lows in the mid to lower 30s, with locations further away from Michigan falling to, or even below freezing Saturday morning. High pressure will ridge in from the west, keeping our winds out of the northwest and dropping the 925 mb temperatures to near -5 degrees C. Even with mostly clear skies, high temperatures will remain below the norm of around 60 F for mid April, climbing only into the mid to upper 40s. Little will change Saturday overnight, with continued mostly clear skies allowing our lows to drop even colder, with most locations falling down to or below freezing again Sunday morning, while highs will again be in the mid to upper 40s Sunday. Our first wave/front is forecast to arrive sometime Sunday afternoon to overnight, with cloud cover increasing with this system. Models are not in agreement as to the exact timing of this system, but a chance for some precipitation to occur Sunday night exists. With temperatures still on the cold side, some of this precipitation may fall in the form of rain/snow mix, especially Monday morning during our coolest temperatures. Presently no accumulation is expected as cloud cover should keep surface temperatures above freezing Monday morning. With this reinforcing shot of cold air, highs on Monday are expected to remain below the seasonal normals, reaching into the upper 40s to near 50. Winds will be gusty from the northwest Monday afternoon. Temperatures will remain cool on Tuesday, with lows again near to below freezing and highs around 50. The next weather system is expected on Wednesday, with winds becoming southerly ahead of this system, allowing temperatures to warm up a bit, with lows Wednesday morning expected to stay above freezing, while highs will climb into the mid to upper 50s. Similar to the Sunday system, models are not in great agreement on timing and location of the front, but there will be a chance for some precipitation Wednesday. And although we warm up a bit, temperatures will still be cool enough to once again possibly have some snow mixed in with the rain, but again no accumulations are expected. The cooler air with the Wednesday system does not stay in place for long, with temperatures expected to be more seasonal on Thursday. BKL && .AVIATION... For the 00Z TAFs... Forecast points of interest for ORD and MDW through Friday are: * Gusty west-southwest winds easing fairly quickly between sunset and 03Z * Likelihood of light rain within the pre-dawn through morning period during Friday, with the chance for some snow to mix in or even briefly go to all snow between 11Z and 15Z West-southwest winds have begun to abate and that rate of diminishing should increase after sunset with the loss of mixing. Prior to sundown at 0030Z, sporadic gusts to or exceeding 40 kts will be seen across the area. An upper level weather disturbance will scoot across the area during the pre-dawn hours on Friday into the morning. While the atmosphere is dry ahead of this, the forcing for ascent will result in deepening saturation. Trends in guidance indicate that this should be enough for periodic light precipitation within that time. The envelope of model solutions tend to support the Chicago area airports being in this light precipitation axis, with Rockford potentially just beyond the northern periphery. With this precipitation occurring at the coolest time of day and the atmosphere fairly cool to begin with, some snow could mix in as temperatures fall to their web bulb values. Cannot rule out the precipitation just going to only snow for a 1-3 hour period, and that would overlap the morning rush. At present though, this is still more of an outlier solution. If that were to happen, it would be unlikely snow would stick on most paved surfaces. For the remainder of Friday after the light rain ends by 16Z-17Z, southwest winds will be breezy but far less than today. MTF && .LOT WATCHES/WARNINGS/ADVISORIES... IL...None. IN...None. LM...Small Craft Advisory...nearshore waters until 5 PM Friday. && $$ Visit us at weather.gov/chicago Follow us on Facebook, Twitter, and YouTube at: www.facebook.com/NWSChicago www.twitter.com/NWSChicago www.youtube.com/NWSChicago
Area Forecast Discussion
National Weather Service Springfield MO
600 PM CDT Thu Apr 14 2022 Key Messages: 1. Elevated fire conditions continue this afternoon with gusty winds and a dry airmass. 2. Rain chances about every other day (Friday/Sunday/Tuesday Night into Wednesday). 3. Below normal temperatures likely through early next week. 4. Warming trend by the middle of next week. .SHORT TERM...(This evening through Friday Night) Issued at 251 PM CDT Thu Apr 14 2022 Gusty southwest winds and relative humidity values in the 25-35% range will allow for areas of locally elevated fire weather conditions to continue this afternoon into early evening, primarily in locations that have not seen much rainfall in the last couple of weeks. As a ridge of surface high pressure slides south and eastward of the Missouri Ozarks, winds will shift back out of the south later this evening. Sounding profiles show mid- level saturation and cloud cover increasing overnight keeping overnight lows in the mid to upper 40s. A few locations in the eastern Ozarks could drop into the low 40s tonight. Afternoon temperatures Friday look to rise into the low 60s across Central MO and the upper 60s to low 70s over southwestern MO and the MO/AR border. A few shortwave impulses look to traverse through the overall zonal flow aloft Friday. With moisture increasing throughout the day Friday, there should be enough synoptic-scale ascent for some scattered shower activity and isolated thunderstorms through the day tomorrow. A boundary looks to push into the southern portions of the CWA Friday evening into Friday night. On the warm side of that boundary, an axis of moderate instability looks to sprawl across eastern Oklahoma and the Ozarks region. The greatest instability looks to reside along and just south of the MO/AR border where the HRRR and RAP both hint at an environment with 1000-1500 J/kg of MLCAPE. 12Z high- resolution guidance continues to pick up on a few isolated stronger storms, possibly severe due to sufficient deep layer shear, around the MO/AR border late Friday evening into early Friday night. Storms may take on a more elevated nature due to some capping below 850mb. However, with steep 700-500mb lapse rates and strong 0-6km shear, isolated large hail and damaging wind gusts will be a possibility. .LONG TERM...(Saturday through Thursday) Issued at 251 PM CDT Thu Apr 14 2022 Northerly winds will be present Saturday as high pressure filters in from the north behind that frontal boundary that pushes through the area Friday night. A quick moving upper-level ridge will also pass over the area Saturday with afternoon temperatures only rising into the upper 50s and mid 60s with those breezy northerly winds. Another round of rain chances is expected on Sunday as models agree upon a shortwave trough pushing into the region leading to a cool and rainy Easter Sunday. The SGF CWA will most likely still be north of that boundary, therefore very little instability will allow for mostly rain showers on Sunday with some possible embedded thunder. There is quite a bit of spread in the NBM guidance for high temperatures on Sunday, likely to due with uncertainties in the coverage of showers during the day. 25th %tile lies near 50 degrees while the 75th %tile sits near 60 degrees in the Springfield area for Sunday afternoon. The middle of the road 50th %tile brings the Springfield metro into the mid 50s on Sunday. As high pressure builds in and that system moves out Sunday night, skies may clear some and frost potential may arise Sunday night into Monday morning. Monday and Tuesday both look cool and dry with afternoon temperatures rising into the mid 50s and mid 60s both days. Frost potential may return again Monday night into Tuesday morning. WPC Cluster Analysis shows decent agreement between ensemble members of another shortwave trough pushing into the area late Tuesday night into Wednesday bringing widespread rain chances to southeastern Kansas and the Missouri Ozarks during that time frame. A gradual warming trend under a broad ridging pattern looks more likely the second half of next work week. The CPC highlights this warming trend well with above average temperatures currently in the 8-14 Day Outlook. GEFS and ECMWF ensembles anomalies also support this warming trend the second half of next week. && .AVIATION...(For the 00Z TAFS through 00Z Friday evening) Issued at 557 PM CDT Thu Apr 14 2022 Low level wind shear is expected late tonight into Friday morning as a low level jet develops over the area. Shear of 40 to 50 kts will be possible. Gusty winds will develop on Friday by mid morning. Eventually a front will begin to push south through the area with scattered showers developing by late in the afternoon and continuing into the evening. Expecting VFR conditions through much of the period, with a chance of some MVFR within any showers that develop. && .SGF WATCHES/WARNINGS/ADVISORIES... MO...NONE. KS...NONE. && $$ SHORT TERM...Langfeld LONG TERM...Langfeld AVIATION...Lindenberg
Area Forecast Discussion
National Weather Service Sacramento CA
325 PM PDT Thu Apr 14 2022 .SYNOPSIS... Cool weather continues with unsettled weather bringing periods of rain and mountain snow into the weekend. Warmer with dry weather expected Sunday. An unsettled weather pattern returns next week with the potential for more rain and mountain snow. && .DISCUSSION... We are going to remain in an active and unsettle weather pattern the next few days with periods of rain and mountain snow. A short wave trough pushing into far southern OR is showing up nicely on water vapor. This trough is pushing a cold front into NorCal stretching from the Lassen Park area southwest through the Ukiah area. We are seeing light Valley showers ahead of this front with widespread rain and snow over the higher elevations. PWATs ahead of the front are 0.50 to 0.90" and we are seeing hourly rain rates generally 0.10 to 0.35" over the higher elevations and less than 0.05" in the lower elevations. Expect these rain rates to continue for the next few hours but things will start to let up quickly after 8 pm this evening. Snow levels are generally around 5000-5500 feet and we should see them come up about 500 feet this evening. Mountain snow will continue to bring mountains travel issues into the evening. The HREF and other CAM models such as the HRRR are building in instability over the northern Sacramento Valley and Shasta County. Currently Meso-analysis is starting to show 100 mb of MUCAPE over this region and CAPE has been slow to build in due to cloud cover and this should limit the thunderstorm threat but there is about a 15% chance or so to see a few thunderstorms. CAPE in the area looks to linger into the later evening but we should see the thunderstorm threat end by midnight. Soundings do show some low level veering but 0-1 km shear is pretty low and that should limit any funnel potential with small hail and gusty winds the main threat with any thunderstorms. PWATs even behind the front are quiet high, ~0.50" but somewhat fast storm motion should limit heavy rain but brief downpours can be expected. Things will dry out overnight and we will see a mainly dry start to Friday. The dry conditions will be short lived though as another short wave trough digs over the Pacific and moves over NorCal Friday night into Saturday. This will be a quick moving system but is able to pick up decent amount of moisture again with PWATs 0.50-0.90". With the further south track of this trough we will see higher snow levels in the 5500-6000 foot range over the Sierra and 4500-5500 feet over the Coastal Range and Shasta County Mountains. With the trough axis moving just to our south the highest QPF can be expected from about I-80 north. QPF totals are looking to be 0.90-2.25" over the mountains with locally higher amounts over the Lassen Park area. Valley totals 0.15-0.75" and 0.75-1-75" in the foothills. Snow totals are looking to be 6-12" above 5500 feet with locally higher amounts over Lessen Park. We do see some CAPE build in Saturday afternoon mainly over the northern Sierra Foothills and the Sierra north of I-80. Forcing will be rather weak by the afternoon and the thunderstorm threat is looking low but not zero. An isolated cell or two will be possible. The environment on Saturday will be very similar to today and similar threats can be expected with any thunderstorms that end up developing. Our active and unsettle weather will take a break on Easter Sunday as weak ridging builds in and we will see temperatures warm to near average. -CJM && .EXTENDED DISCUSSION (Monday THROUGH Thursday)... Unsettle weather is going to return for the extended forecast as we will see a few troughs push over the region. The first one will dig out of the Gulf of Alaska later Monday into Tuesday. There is some spread in the ensembles mainly with how deep the trough digs but also some with timing. The northern mountains will see the best chances for showers. Wednesday should start out dry but another trough will bring rain and snow chances but uncertainty is quite high with this trough in the ensembles. Highs will generally be near seasonal averages. -CJM && .AVIATION... Widespread MVFR with local IFR/LIFR conditions over Norcal thru 06z tonight as Pacific storm system moves inland. Chance of thunderstorms over the northern Sacramento Valley continues through 04z, along with gusty southerly winds to 30 kts through 00Z. Sierra terrain obscured AOA 4000 feet. && .STO WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory until 11 PM PDT this evening for West Slope Northern Sierra Nevada-Western Plumas County/Lassen Park. && $$