Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 03/11/23

Area Forecast Discussion
National Weather Service Quad Cities IA IL
556 PM CST Fri Mar 10 2023 ...00z AVIATION UPDATE... .SYNOPSIS... Issued at 202 PM CST Fri Mar 10 2023 Latest water vapor loops show upper low responsible for our precipitation yesterday, rotating across eastern MI and Lake Erie. While some subsidence allowed for a few breaks in the clouds this morning for a few hours evident on visible satellite, cyclonic flow aloft has brought more broken/overcast skies to the CWA late morning. As a result, temperatures have struggled to climb much today, especially over new snowpack. Readings at 2pm, were in the lower to middle 30s. && .SHORT TERM...(This evening through Saturday night) Issued at 202 PM CST Fri Mar 10 2023 Key Messages: 1. Dry conditions with cloudy skies this evening and tonight. 2. Storm system still on track to bring a chance of accumulating snow north of I-80 Saturday afternoon through Saturday night. There still remains quite a bit of uncertainty regarding impacts with this storm. This Evening-Tonight...cloudy skies and a weak convergent signal will foster a chance of scattered flurries this evening, mainly in IL. Otherwise, light winds under 5 kts will be seen with temperatures dropping into the mid to upper 20s. If any breaks in the clouds can develop, than these readings may be a little too high. Saturday-Saturday night...details below. Synoptic setup...a strong upper low currently over the Pacific Northwest on water vapor, will track east over the Rockies into northern Montana and North Dakota. A sub-1000mb surface low will develop with this wave. In addition, a weaker upper level wave will track over the Colorado Rockies and induce a weak surface low into the Plains. Broad upper ridging and an increasing pressure gradient will occur ahead of these features over the local area, with breezy southeast winds developing in the late morning/early afternoon hours with winds between 10-20 mph. Clouds will also increase from west to east through the day, Precipitation type...latest model solutions and thermal profiles have delayed the onset of precip with this storm into our area and now expecting the bulk of this event to fall during the evening and overnight hours Saturday night. Surface temps will be similar to the last winter storm with readings in the low to mid 30s initially, but then slowly falling throughout the night. Max wet bulb aloft from the RAP quickly falls below 0C along and north of I-80 after 23z, with surface wet bulbs quickly following suit. Expect all snow north of I-80, with a rain-snow mix south of I-80 at onset quickly transitioning to snow a few hours later as the column fully saturates. There is some concern that the rain-snow line may be a little further south as noted by the 12z HREF and could see a quicker transition to snow everywhere. Timing and Amounts...while this system still has some disagreement within the 12z deterministic and ensemble runs even this late in the game, precipitation will start across central IA and track east through the evening and overnight hours Saturday. Model QPF consenus has 0.2"-0.3" of liquid for this event. A heavy wet snow is once again anticipated with low SLRs (8:1-11:1) resulting in a 1-3 inch snowfall, where snow is the main ptype. This is currently forecast along and north of I-80 and accumulate primarily on elevated and grassy surfaces. Locations south of the interstate will see less than an inch and more of a rain-snow mix. Taking a look at forecast soundings, the DGZ is not as deep as the previous winter event yesterday leading to a lower confidence forecast in snow amounts and impacts. WPC snowfall has also come in lower than their 00z run last night. However, the 12z GFS and NAM solutions are outliers with respect to the GEFS/ECS ensemble and NBM probabilistic output at the moment with much higher amounts further south. Something will have to keep an eye on for any forecast adjustments and any potential headline decisions. Precipitation will quickly come to an end around sunrise Sunday. Overnight lows will be in the upper 20s to lower 30s. .LONG TERM...(Sunday through Friday) Issued at 202 PM CST Fri Mar 10 2023 [Key Messages] 1) Quiet conditions favored through mid-week with below normal temperatures favored. 2) Warm-up late week with chances of rain returning ahead of a cold front. [Discussion] Storm will exit the area early Sunday with surface high pressure and ridging aloft following right on its heel. This will promote a dry, albeit cool, start to the week. Look for highs Sunday through Tuesday to be in the 30s for most (near to low 40s in northeast MO and west central IL) with lows dropping into teens (mainly Monday night) and 20s. Milder air will return to the area by Wednesday with strengthening southerly flow and increasing heights aloft. Blended guidance favors much of the area south of Interstate 80 seeing highs well into the 50s. This will change with the arrival of a cold front Thursday, which will bring in another cool down and chances for precipitation. At this time, temperatures and forecast soundings primarily favor rain. Dry and cool weather is favored for next weekend with high pressure building back across the region. && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) Issued at 552 PM CST Fri Mar 10 2023 MVFR cloud decks will continue to stream acrs the area tonight into Saturday morning, with northwesterly to north sfc winds veering around to the east into the early morning hours. MVFR to VFR clouds continue for much of Sat as the sfc winds become east- southeast and increase to 10-15 KTs. An incoming precip shield of snow or rain-snow mix ahead of the next incoming weather system will make it acrs or in the VCNTY of most of the TAF sites from west-to-east by late Sat afternoon with a trend back to lower MVFR decks and VSBYs. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && $$ SYNOPSIS...Gross SHORT TERM...Gross LONG TERM...Speck AVIATION...12
National Weather Service Hastings NE
539 PM CST Fri Mar 10 2023 ...Aviation Update... .UPDATE... Issued at 523 PM CST Fri Mar 10 2023 Added some patchy fog to the forecast after midnight tonight per the HRRR and somewhat favorable southeasterly surface winds. While overall cloud cover and strength of winds will likely keep visibilities higher than what the HRRR is suggesting, felt it was worth a mention given the set-up...with some patchy fog expected (with 1-3 miles of visibility) peaking in coverage just after daybreak. && .DISCUSSION...(This evening through Friday) Issued at 346 PM CST Fri Mar 10 2023 Key Messages: * Freezing drizzle, drizzle, and light snow expected across portions of the area tonight into Saturday morning with light rain possible Saturday morning into Saturday afternoon. * Winter Weather Advisory in effect tonight into Saturday morning for northern portions of the area. * Warmer temperatures expected Tuesday and Wednesday. * Colder temperatures along with precipitation expected on Thursday. Mostly cloudy to cloudy skies for most of today have lead to temperatures being cooler than previously expected so have cooled high temperatures for today by a few degrees. An upper level trough currently over the northwestern part of the country will move eastward over the Northern Plains tonight into Saturday morning. This will increase upper lift over south central and central Nebraska and north central Kansas. Southeasterly winds will also advect in low-level moisture. Expect low temperatures tonight to range from the upper 20s across central Nebraska to the mid 30s across north central Kansas. Precipitation will likely start out in the form of freezing drizzle around 3 am across central Nebraska with drizzle expanding across the rest of the area by 6 am. Light snow will also be possible late tonight into Saturday morning for areas generally along and north of I-80. Light ice accumulation will be possible across this same area. Little to no snow accumulation is expected. Forecast soundings across central Nebraska indicate freezing drizzle will be possible from around 3 am to 11 am so a Winter Weather Advisory has been issued for that time. Drizzle is possible across areas that will be above freezing. There is some uncertainty in regards to precip type due to temperatures hovering around the freezing mark for areas south of the advisory. Light rain is expected later on Saturday as temperatures climb above freezing. Have cooled temperatures slightly below the NBM for tomorrow due to the presence of clouds and precipitation. The previously mentioned upper trough will move eastward towards the East Coast next week. High temperatures Sunday and Monday will be in the 30s and 40s with winds generally out of the north. Winds will increase out of the south on Tuesday with a surface trough developing in the lee of the Rocky Mountains. This will contribute to temperatures warming up into the 50s and 60s on Tuesday. Temperatures will warm up even further on Wednesday with highs in the 60s and 70s expected. The warmup will come to an end on Thursday as another cold front arrives and another upper trough passes over the Northern Plains and Upper Midwest. This upper trough will connect with another upper trough over the Four Corners region. This will result in an increase in upper lift over Nebraska and Kansas which will allow for another chance of precipitation. Some of this precipitation may be of a frozen variety depending on temperatures. High temperatures on Thursday are expected to cool into the 40s and 50s. && .AVIATION...(For the 00Z KGRI/KEAR TAFS through 00Z Sunday) Issued at 523 PM CST Fri Mar 10 2023 Lots of cloud cover continues across the region this afternoon and MVFR CIGS expected to persist into the overnight hours. Moisture should increase from the south around midnight, resulting in CIGS lowering to IFR levels along with some BR and the chance for -DZ through the mid-morning hours. CIGS should improve just before midday Saturday, with a return to mostly sunny skies late in the period as model time heights are showing a sharp cut off in cloud cover by late afternoon behind this next frontal boundary. && .GID WATCHES/WARNINGS/ADVISORIES... NE...Winter Weather Advisory from 3 AM to 11 AM CST Saturday for NEZ039>041-046>049. KS...NONE. && $$ UPDATE...Rossi DISCUSSION...Schuldt AVIATION...Rossi
Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
949 PM EST Fri Mar 10 2023 .SYNOPSIS... Dry and cool high pressure will build into the region from the northwest tonight and Saturday. A stronger low pressure system will approach the region from the west Saturday night and move through Sunday into Sunday night, bringing moisture back into the area for the latter half of the weekend. Colder air will arrive from the northwest on Monday and persist through the middle of the week. && .NEAR TERM /THROUGH SATURDAY/... As of 945 PM Friday: Main change this update was adding the potential for light snow showers and flurries across the northern NC mtns overnight. Have been seeing cloud tops along the NC/TN border gradually cool the last several hours. Cloud top temps look to range from -9C to -11C across the northern NC mtns this evening. With the potential for some light wrap around moisture from the departing sfc low, could see some light snow flurries and showers develop. No snow accums are expected at this time. The other change needed was regarding some tweaks to temps and dewpoints to better match the latest obs. Did a 50/50 blend of the CONSShort and the HRRR temps and dewpoints to better match obs for the next couple of hours. Otherwise, sfc high pressure will build into the region tonight with a narrow gradient situated across the higher elevations. This will lead to stronger winds and gusts this evening into tonight. Gusts around 40 kts are possible, especially across elevations above 3500 ft. Thus, the Wind Advisory remains in effect through 10 AM Saturday. As for temperatures, CAA behind the FROPA will lead to lows tonight near or below freezing across the NC mountains. The Piedmont should remain well above freezing, but still remain colder than the above normal temps the area has felt the past few weeks. Saturday looks to be dry and cool, with winds gradually tapering off into the afternoon hours. Meanwhile, upper ridging will start to propagate across the area on Saturday and continue to keep high pressure the dominate air mass through the forecast period. Highs on Saturday will be around 2-5 degrees below climo across the CWA. Upper level moisture will start to trickle into the western Carolinas ahead of the next approaching system, but this will mainly lead to increased cloud cover throughout the day. As for fire weather concerns, RH values look to dip down into the upper 20s to lower 30s Saturday afternoon. However, given the recent rainfall increasing fuel moisture, and wind gusts decreasing through the afternoon hours, the overall increased fire danger potential looks to remain low. && .SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/... As of 130 PM EST Friday: Deep layer ridge axis will slide across the CFWA Saturday night, while height falls accompanying broad upper troughiness will push in from the west. Moisture advection from the Gulf and associated forcing will traverse into the Southeast by daybreak Sunday, leading to elevated PoPs in the forecast for all of the western Carolinas and northeast Georgia Saturday night through much of the daytime period on Sunday. Weak in-situ damming will keep conditions cold and should be cold enough to support the development of snow/sleet around daybreak Sunday along the northern Blue Ridge Escarpment. Profiles favor a transition to freezing rain later Sunday morning once warmer air entrains the mid-levels with increasing west-southwesterly flow. Expect this event to be self-limiting and should transition back to rain at some point during peak heating Sunday afternoon, but there should be a long enough period of time with wintry p-types that a Winter Weather Advisory will likely be issued for the northern Mountains and Blue Ridge Escarpment. The area will experience a "Miller-B" system as a surface low lifts into the OH Valley and Lower Great Lakes and a secondary low races across the Southeast Sunday. With cold and dry low-levels present at the onset of precip Sunday morning, wouldn`t be surprised for wet-bulb processes to be cold enough to support wintry p-types across some locations in the mountains and even breaking containment into portions of the I-40 corridor in the NC Piedmont for a brief period of time Sunday morning, before transitioning to all rain. The cold air won`t be well established, so this shouldn`t have much of an impact in the alluded area, except potentially on social media. Temperatures on Sunday will be 10-15 degrees below normal for most locations. The system pushes offshore Sunday night as broad upper troughiness remains in place across the eastern CONUS. Outside of a few northwest flow snow showers along the NC/TN border Sunday night, deep CAA will filter into the region and settle over the region through the end of the period. Temperatures will be near-normal Sunday night and Monday, but great radiational cooling conditions Monday night will allow temperatures to fall 5-10 degrees below normal. Current forecast has the Monday night low dropping to the freezing mark at GSP. This would be the first overnight low to hit the freezing mark since February 18th. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... As of 230 PM EST Friday: Stout CAA and continental high pressure will remain in control during the early part of next week. With heights remaining relatively low, expect for only a gradual modification in the airmass during the medium range. Mostly dry conditions should prevail during the forecast period. Model guidance are in decent agreement 7 days out with a longwave upper trough and attendant frontal system moving in from the west. Otherwise, temperatures will be near-normal until the middle part of the week, when heights rises in response to an upper ridge allows most locations to reach above normal temperatures through the end of the extended. && .AVIATION /03Z SATURDAY THROUGH WEDNESDAY/... At KCLT and elsewhere: VFR and dry through the 00Z TAF fcst period thanks to high pressure building in behind a departing cold front. Winds have already turned NW at KAVL and should turn NW east of the mtns within the next hour or two. Low-end gusty NW winds are expected across the terminals this evening into late tonight, with gusts at KAVL expected to continue through early Saturday afternoon. These gusty winds should limit fog development overnight. Upper- level shortwaves will track overhead this evening into tonight increasing upper-level cloud cover to SCT to BKN. Should see cloud cover scatter out a few hours prior to daybreak. Could not rule out a few intermittent low-end wind gusts east of the mtns Saturday morning into Saturday afternoon. Cloud cover will gradually increase throughout Saturday as moisture increases ahead of a low pressure system approaching out of the west. Winds will be light and vrb at KAND early Saturday morning through the end of the fcst period. Winds elsewhere should remain NW on Saturday before turning NE Saturday evening. Outlook: A low pressure system brings precip and associated restrictions back Sunday into Sunday night before drier conditions return early next week as high pressure builds into the region. && .GSP WATCHES/WARNINGS/ADVISORIES... GA...None. NC...Wind Advisory above 3500 feet until 10 AM EST Saturday for NCZ033-049-050. SC...None. && $$ SYNOPSIS...PM NEAR TERM...AR/CP SHORT TERM...CAC LONG TERM...CAC AVIATION...AR
Area Forecast Discussion
National Weather Service Las Vegas NV
157 PM PST Fri Mar 10 2023 .SYNOPSIS...Rain and high elevation snow will continue in the Sierra Nevada and Owens Valley today, with light scattered rain showers spreading eastward across the Mojave Desert this afternoon. Gusty southwest winds will continue through the evening. Conditions will improve through the weekend with clear skies and above average temperatures. Next week, another atmospheric river will return precipitation chances to the region. && .SHORT TERM...Today and Saturday. Southeastern California continues to experience light to moderate rainfall this afternoon thanks to an atmospheric river aimed at the coast. Warm wind coupled with rain-on-snow will accelerate snow melt in the Sierra Nevada, where extremely above-average snowpack exists. In this morning`s AFD update, we mentioned a couple of ways the forecast was slightly off track. (1) Snow levels started off lower than expected, with Mammoth Yosemite Airport (around 7100 feet) consistently observing snow. An observer located in Aspendell around 8500 feet has noted wet snow with about a 2:1 ratio all morning. In the forecast update, went with 5th percentile snow levels to better align with observations. (2) More moisture spilled over the Sierra Nevada into the Owens Valley than anticipated. As of 1:45pm PST, Bishop Airport has received 1.89 inches of rain since the start of the event, allowing it to break daily rainfall records for the site. As such, with the forecast update, increased QPF a bit for the Owens Valley this afternoon. The bulk of the precipitation has occurred, but can expect another 0.10 to 0.30 inches in Bishop with higher amounts in southern Inyo County where the highest radar reflectivity returns of the day are ongoing. Widespread flooding has been observed in the Owens Valley, with US-395 closed from Bishop south to the Inyo / Kern County line. Areal Flood Warnings exist along this route where 2 to 3 feet of water and debris have been reported on side roads. The Flood Watch remains in effect for the eastern Sierra Slopes and the Owens Valley through 4am PST Sunday. Though precipitation will largely cease past the Sierra this evening, flooding will continue to be a concern over the next 24-36 hours as run off and snow melt inundates washes. In addition to flood concerns, the Winter Storm Warning for the Sierra Nevada and Winter Weather Advisory for the White Mountains continue through 4am PST Sunday due to persistent snow accumulations above 7000 feet. Through the afternoon and evening, moisture will spread eastward across the forecast area, increasing PoPs over the southern Great Basin and Mojave Desert. Valley rainfall totals will remain less than a tenth of an inch, but higher elevations can see upward of a half inch. The exceptions are the panhandle of Lincoln County where the HRRR continues to highlight a robust band of precipitation setting up late this afternoon and the Spring Mountains, where upslope dynamics could produce 1-2 inches of rainfall this afternoon. There is some question in precipitation type on the Spring Mountains due to the uncertainty in snow levels, but largely expecting rain below 8000 feet. Skies will clear west-to-east tonight and Saturday, allowing afternoon temperatures to warm to above-average across the region. .LONG TERM...Sunday through Thursday. Sunday and Monday look like a break in the atmospheric river action, with zonal flow transitioning to flat ridging and limiting precip chances to the Sierra and the northern fringes of the CWA, with minimal to no impact expected. Expect locally gusty westerly winds in the favored terrain areas such as Barstow and the Sierra, but not looking like advisory level at this time. The next AR is still targeting our area Tuesday and Wednesday. On the positive side, snow levels look a bit lower, hovering around 8000 feet during the heaviest precipitation, and dropping to 5000 to 6000 feet on the back side of the storm. Another round of very heavy precip is likely for the Sierra, with liquid equivalent totals of about six inches at the crest. Snow ratios around 12:1 would suggest about six feet of snow at the crest, with a bit less at the resort level. Barring a significant change in either storm track or snow levels, Winter Storm Warnings will be needed. Low pressure passing by to the north on Wednesday (a bit slower than in previous model runs) should generate enough forcing for some light precip in the deserts. There is quite a bit of model spread for Thursday, with solutions ranging from ridging overhead in the wake of the storm to low pressure lingering overhead for one more day. Regardless, impactful weather looks unlikely. Of note, Monday and Tuesday could be the warmest days since about November 1st for much of the Mojave Desert. This will promote more mountain snow melt, possibly keeping creeks and rivers swollen. && .AVIATION...For Harry Reid...South to southwest winds with occasional gusts to around 25-30 kts will continue through the afternoon and early evening before diminishing to around 10-20 kts. There is some indication during the overnight and early Saturday morning period that winds could decrease even more than forecast and be under 10 kts. If this occurs, the likely timeframe would be between between 08z and 15z. Southwest winds are forecast to increase once again after 17z Saturday with speeds between 10-15 kts and gusts to around 25 kts. There may be a few showers around into this evening, but the majority will remain over the higher terrain. CIGS are expected to be around 6k feet with gradual improvement this evening and overnight. For the rest of southern Nevada, northwest Arizona and southeast California...Significant precipitation will continue through the afternoon across Inyo County with the KBIH seeing low CIGS and occasional mod-heavy precipitation. Rain chances will diminish this evening across Inyo County, but lower CIGS are expected to remain overnight into Saturday along with isolated showers. Elsewhere, look for CIGs generally around 6k feet or lower with widespread mountain obscurations. Some improvement overnight, but still remaining at 8k feet or lower. South to southwest winds 10-20 kts with gusts to around 30-40 kts over most areas into this evening with winds diminishing somewhat this evening. && .SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report any significant weather or impacts according to standard operating procedures. && $$ SHORT TERM...Varian LONG TERM...Morgan AVIATION...Gorelow For more forecast information...see us on our webpage: or follow us on Facebook and Twitter