Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 02/10/19


Area Forecast Discussion
National Weather Service Green Bay WI
532 PM CST Sat Feb 9 2019 Updated aviation portion for 00Z TAF issuance .SHORT TERM...Tonight and Sunday Issued at 242 PM CST Sat Feb 9 2019 The latest RAP analysis and satellite/radar imagery show a 1045mb high pressure system centered across the Great Lakes early this afternoon. Mid and high clouds are increasing from the west ahead of a weak shortwave and associated warm advection occurring over the northern Plains. A more potent shortwave is moving east over southern California, which will be the system to impact the region on Sunday. Snow accumulations and potential impacts are the main forecast concerns in this period. Tonight...The shortwave currently over the northern Plains will shear apart as it moves across the northern Great Lakes. It will bring a chance of light snow with it, but models project the snowfall should remain north of the U.P. border. Otherwise, the jet stream will continue to push mid and high clouds overhead. Clouds should become thicker through the night, but with high pressure and light winds across the region, any clearing would promote tanking temps. Dropped temps slightly at the cold spots over north-central WI. Lows ranging from 5 below across the north to the upper single digits over east-central WI. Sunday...The potent desert SW shortwave trough will move northeast across the central Plains and into Wisconsin, and shear apart slightly in the process. As the shortwave draws closer, isentropic ascent and mid-level fgen will increase across the state. Some of the higher resolution models indicate a band of snow will develop and push east across central to northeast WI during the morning before expanding rapidly across the area around midday. It appears the strongest forcing will reside downstate during the afternoon. But widespread qpf amounts of 0.1-0.2 inches appear likely over central to east-central WI in the afternoon. With high snow to liquid ratios, accumulations of 3-4 inches appear possible south of a Tomahawk to Sister Bay line. Locally higher amounts are possible near the Lake Michigan shoreline, where light onshore flow will occur for much of the event. With coordination from surrounding offices, will issue a winter weather advisory starting in the 12-15z period. Highs warming into the mid-teens to mid 20s. .LONG TERM...Sunday Night Through Saturday Issued at 242 PM CST Sat Feb 9 2019 Very active pattern setting up for next week with several bouts of winter weather to deal with. Temperatures will fluctuate from a few degrees below/above normal as each system passes through the Great Lakes. Light snow will be ongoing/ending Sunday evening as the weak shortwave shears out and exits the area. Additional accumulations should be pretty minor (up to around 1" for most spots). Could see the snow linger a little longer and have some higher totals near Lake Michigan, especially the farther north you go, due to lake effect/enhancement as 850 mb temp hover between -11C and -15C. One thing to keep an eye on will be the mid-level drying that takes place Sunday night into Monday morning. Looks like eastern WI will lose ice crystals generation so a transition to freezing drizzle is possible. Question will be whether the depth of moisture will be sufficient to have drizzle occur or it will just be dry. Monday looks dry for most of the area, but some lingering drizzle or flurries are possible, mainly across eastern WI, with a little moisture aid from Lake Michigan. With all the lingering moisture below 850 mb, it will be a challenge to see much sunshine. High temps look to be mainly in the 20s. Attention then turns to the next storm which will bring another round of wintry weather to the area Monday night into Tuesday night and early Wednesday morning. This system is still being handled differently by the models, especially the Canadian which is weaker and farther south. GFS/ECMWF still show a healthier/ wrapped up system, bringing significant impacts to the area with accumulating snow (6+ for many spots), along with blowing and drifting snow. The amount of blowing snow will hinge on just how wrapped up the system gets. Will lean the forecast to the heavier amounts with an advisory/warning type event looking very likely. There could be a little freezing drizzle at the onset of the storm Monday evening, but saturation occurs quickly and a change over to snow will happen quickly. As the system exits, the snow will wrap up late Tuesday night into early Wednesday morning. Snow will linger the longest across north central WI where lake effect snow showers will continue into Wednesday. As winds veer Wednesday afternoon and evening, the lake effect will shut off and dry weather is expected across the area Wednesday night. The quiet weather will be short- lived as the next winter system arrives on Thursday. Models have shifted a little south with this storm, so the area might miss out of the brunt of this system, but there is plenty of time for this system to change its track. && .AVIATION...for 00Z TAF Issuance Issued at 532 PM CST Sat Feb 9 2019 Good flying weather expected tonight with middle and high clouds and light surface winds. Snow still looks set to arrive Sunday morning and then linger through late afternoon or early evening. A few inches of snow are possible, which will lead to lower ceilings and visibilities, likely in the MVFR to IFR range. && .GRB WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory from 9 AM Sunday to midnight CST Sunday night for WIZ019>022-031-037>040-045-048>050-073-074. Winter Weather Advisory from 6 AM to 9 PM CST Sunday for WIZ018- 030-035-036. && $$ SHORT TERM.....MPC LONG TERM......Bersch AVIATION.......Cooley
Area Forecast Discussion
National Weather Service Marquette MI
616 PM EST Sat Feb 9 2019 .SHORT TERM...(This evening through Sunday) Issued at 359 PM EST SAT FEB 9 2019 WV imagery and RAP analysis indicated confluent zonal mid/upper level flow between a deep mid level trough over northeast Canada and a ridge over the se CONUS. At the surface, calm or light westerly winds prevailed as a 1044 mb ridge builds into the area. A weak shortwave trough into nrn MN supported mainly mid and high clouds along with a few flurries. Tonight, the weak shortwave will streak across the northern Great Lakes. There may be some light snow or flurries ove mainly the west and north if the low-level dry air can be overcome. The shrtwv may also support an increase in light west flow LES. However, inversion heights only to around 3k ft and substantial ice cover should limit any amounts to under an inch. Sunday, the models were in better agreement in bringing snow northward supported by 280k-290k isentropic lift. However, the associated 850-600 mb fgen circulation will maintain dry low level north to northeast flow that will result in a sharp northern boundary to the pcpn. So, likely POPs were mentioned south with chance north due to uncertainty with the nrn extent of the snow. 1-3 inch amounts may be possible toward MNM with around an inch or less closer to US-2, and less than an inch over the north. .LONG TERM...(Sunday night through Saturday) Issued at 354 PM EST SAT FEB 9 2019 With fairly benign weather otherwise, attention is on a potential storm system late Mon night through Tue. GFS/ECMWF/NAM agree fairly well on the system, and have been pretty consistent run to run, with showing a shortwave moving through the region along with the associated surface low moving through Lower MI. The ECMWF is about 6 hours slower than the GFS and NAM, but otherwise agrees well. This resulting in snow moving in from the S late Tue night and mostly moving out by 06Z Wed, with only lake effect snow continuing after that. Gusty NE winds will lead to lake/upslope enhancement over the N-central and also blowing snow in areas near Lake Superior exposed to E and NE winds. The central and eastern U.P. are expected to see the most snow, with potential for around 6" total. NW and W Upper MI should be closer to 3-6". Much of that snow falls in a roughly 8 hour period Tue, potentially falling heavily at times. Will be watching things closely as we continue to refine the forecast with future model runs. Also, could see some light flurries or freezing drizzle over the S-central for a few hours preceding the synoptic snow, but do not expect many impacts from that at this time. There is potential for another storm system late in the week, but confidence is very low given significant model disagreement. && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) Issued at 616 PM EST SAT FEB 9 2019 VFR conditions are expected to prevail until Sun afternoon for IWD when a weak system comes in and brings in some IFR/MVFR conditions. At KCMX, VFR conditions will last through this evening. Otherwise, MVFR cigs will likely prevail with -shsn/flurries at times under continued westerly winds off Lake Superior. At KSAW, VFR conditions will set back in this evening and last into Sun afternoon before MVFR conditions move in with the next weather system. && .MARINE...(For the 4 PM Lake Superior forecast issuance) Issued at 359 PM EST SAT FEB 9 2019 A low pres system lifting from the southern Plains to the Great Lakes region next week may bring a period of e to ne winds of 30 to 35 knots on Tue. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... None. Lake Superior... Heavy Freezing Spray Warning until 7 PM EST this evening for LSZ249>251-266-267. Heavy Freezing Spray Warning until 1 AM EST /midnight CST/ Monday for LSZ162-240>244-263-264. Lake Michigan... None. && $$ SHORT TERM...JLB LONG TERM...Titus AVIATION...07 MARINE...JLB
Area Forecast Discussion
National Weather Service Omaha/Valley NE
933 PM CST Sat Feb 9 2019 .UPDATE... Issued at 930 PM CST Sat Feb 9 2019 There is a large variation in model output in regards to precip amounts overnight through Sunday morning. The NAM12 is the most bullish with amounts 06z to 12z across eastern NE and southwest IA (it has the highest values). It is much higher than any other recent model output, including the SREF, HRRR and RAP13. The 00z GFS is drier between Lincoln and Omaha than the NAM, putting its heaviest QPF overnight in western IA. Will stay pretty close to the previous forecast with minor adjustments. 00z upper air maps indicated 12 hour height falls of 50-70 meters at 500 mb back over the Four Corners region and a 300 mb jet streak of around 130 kts. This will help generate a short period of strong lift later tonight. UPDATE Issued at 520 PM CST Sat Feb 9 2019 Expect potential snow amounts of about 1 to 3 inches for much of the forecast area for tonight, highest amounts north and northeast of Omaha. Amounts around an inch or less expected in the far western and southern parts of the forecast area. For Monday and Monday night, amounts could be up to 3 or 4 inches with the highest amounts, at this time, expected in western IA and the northern parts of northeast NE. && .SHORT TERM...(Tonight through Tuesday) Issued at 300 PM CST Sat Feb 9 2019 Accumulating snow will be possible tonight through Sunday morning. All this in part to a minor shortwave trof ejecting out of the four- corners region and lifting toward the Dakotas. Expect snow to develop around midnight as ascent/mid layer ageostrophic forcing within area of stout 290-300k isentropic upglide. Short term models are in decent agreement moist dendritic omega will be most prevalent over the IA CWA. Sunday night a more complicated precip scenario setting up with a mix of liquid/freezing/frozen across eastern NE and southwest IA through late Monday night. Once again moist dendritic omega will be most prevalent over the IA CWA. .LONG TERM...(Tuesday night through Saturday) Issued at 300 PM CST Sat Feb 9 2019 Pacific NW wave drops into the central Rockies Thursday afternoon and strengthens as it pushes into the central Plains Thursday evening. ECM and CMC prefer a more southern track through OK. Meanwhile the GFS shows the system crossing across KS. At any rate, increasing DPVA induces surface cyclogenesis along the CO/KS border with precipitation forming just north of the deepening system. As the surface low lifts across the mid MS valley region, precipitation is progged to expand mainly across the eastern portion of the CWA Thursday afternoon into early Friday morning. Cold conditions over most of the CWA Wednesday and Thursday with well below normal highs generally in the low/mid 20s north of I-80, and mid 30s/low 40s south of I-80. On Friday and Saturday, entire CWA cold with highs only in the mid teens/low 20s. && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) Issued at 520 PM CST Sat Feb 9 2019 Expect deteriorating conditions for tonight, especially after midnight. Conditions should drop to IFR with both ceilings and visibilities with light snow. Expect conditions to improve a bit at least for visibilities as snow ends late morning or early afternoon. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...None. IA...None. && $$ UPDATE...Miller SHORT TERM...DEE LONG TERM...DEE AVIATION...Miller
Area Forecast Discussion
National Weather Service Tucson AZ
858 PM MST Sat Feb 9 2019 .SYNOPSIS...A few sprinkles are possible for southeastern Arizona tonight. Isolated showers are expected on Sunday mainly south and east of Tucson, and mainly northeast of Tucson on Monday. Otherwise, dry conditions through Wednesday. There will then be a chance of valley rain and mountain next Wednesday night through Friday, as a stronger storm system moves through the region. Expect cooler temperatures Sunday into Monday. Warmer temperatures return by the middle of next week. && .DISCUSSION...Cloudy skies across southeast Arizona this evening under southwesterly flow aloft. 00Z KTWC sounding shows the story very well with plenty of moisture above about 600 mb with a very dry sub-cloud layer and a 0.30 inch PWAT. Clouds are expected to persist overnight and given the widespread virga currently showing up on the KEMX radar, we can`t rule out a few sprinkles as well, especially in the higher terrain. A quick look at the 00Z NAM and latest HRRR continue to show the potential for some light showers Sunday across portions of Cochise County. This is handled well in the ongoing forecast. Only minor tweaks for the overnight period to account for current trends. Otherwise, the forecast was left as is. && .AVIATION...Valid through 11/06Z. SCT-BKN clouds above 12k-14k ft AGL with another layer of BKN-OVC clouds AOA 20k ft AGL through the evening. Overnight through Sunday cigs lower to 10k-14k ft AGL at KOLS and KDUG and remain AOA 20k ft AGL at KTUS. Winds will be gusty this afternoon out of the southwest at 10-15 kts with gusts up to 25 kts. This evening and Sunday night winds drop below 8 kts then become gusty out of the southwest again Sunday afternoon. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...Slight chance of sprinkles this afternoon then a slight chance for showers mainly in Cochise County Sunday. Monday morning into the afternoon precip chances move to the White Mountains. After a brief lull, a more expansive weather system brings a chance of widespread showers later on Wednesday continuing into early Friday morning. 20-ft winds breezy this afternoon and on Sunday out of the southwest reaching 10-20 mph. These breezes return by midweek with the arrival of the next weather system. && .PREV DISCUSSION...Only made minor tweaks for this afternoon and evening. Expanded the slight chance of sprinkles west into Tucson Metro and then gradually drying out through the late afternoon and into the evening. Enough afternoon mixing has allowed surface winds to increase, thus causing dew points to crash as dry air mixes to the surface. This was most recently seen across the western portions of the Tucson Metro as winds picked up, dew points dropped by 20 degrees. This should help curb any moisture making it to the ground, outside of the highest peaks. Winds are finally increasing across the Tucson Metro, with wind gusts 10-20 mph and 20-30 mph across the west side of town. Winds have also been breezy across the White Mtns and from Nogales east to Sierra Vista, where gusts have been in the 20-35 mph range. Winds are expected to diminish after sunset. No major changes were noted with the new 12Z guidance for Sunday and Monday. Best chance of showers for Sunday remain across the eastern sections of Santa Cruz County and most of Cochise County. A stronger shortwave will pass through the area Monday, bringing continued cool temperatures and a renewed threat for isolated showers across Graham and Greenlee Counties. Elsewhere will remain dry. The dry weather will continue into Tuesday and at least the daytime on Wednesday. The biggest changes in the extended range were to increase POPs modestly from late Wednesday into Friday morning as a much stronger storm system moves across the region. Forecast guidance continues to suggest a wet system, with a good soaking rain and high elevation mountain snow. Beyond Friday morning, greater uncertainty remains with the forecast. There could be another storm system moving across the region, however the details will need to be ironed out as we progress into next week. && .TWC WATCHES/WARNINGS/ADVISORIES...None. && $$ Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson