Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 06/04/19

Area Forecast Discussion
National Weather Service Amarillo TX
702 PM CDT Mon Jun 3 2019 .AVIATION... 00z TAF Cycle: Watching scattered thunderstorms entering the western Oklahoma Panhandle with one or two isolated storms in the western Texas Panhandle. Added a tempo group for KGUY for this TS activity as confidence is on the high side that storms will impact that terminal. TS mention was left out at KDHT and KAMA, as confidence is too low to include at this time, but amendments may be needed. Any storms could produce gusty downburst winds, heavy rain and some hail resulting in brief periods of MVFR vsbys. Storm activity is expected to shift east of the terminals by 09z. VFR conditions should prevail for most of the period. Another round of storms could move into the area towards the end of this TAF period, so included POP30 groups to account for this potential. Ward && .PREV DISCUSSION... /Issued 309 PM CDT Mon Jun 3 2019/ SHORT TERM...This Afternoon through Tonight... Upper level analysis reveals broad cyclonic flow across the Desert Southwest with slow moving upper low over souther CA. The main 500mb jet streak remains over western NM with very minor perturbations ejecting into central and eastern NM. These perturbations are almost impossible to detect via water vapor imagery. Raw models do indicate a few vorticity maxima advancing east, but this may just be convective feedback. For storms to survive as they move into the Panhandles, some kind of lift associated with a shortwave will be needed. Storms are forming near Ruidoso and Angel Fire, where terrain induced moisture convergence is being enhanced. As these storms move east, they will move closer to the ridge axis situated across the southern Plains. This setup has not changed much from the last two days, however there are some indications of slight height rises, and without better lift associated with a better shortwave, storms may struggle a bit more as they move into the Panhandles. This is especially true given the recent model trends suggesting a drier PBL, and more pronounced EML with MLCIN values of 50 to 100 J/kg which certainly won`t help storms as they move into the Panhandles. That being said, CAMs and and the latest model runs still try to bring convection across the area from NM, and the latest HRRR now is developing storms around 06z in the western zones. Confidence in anything more than isolated to perhaps scattered activity is not high. Slightly better surface dew points do exist across the central and eastern Oklahoma Panhandle and northeastern Texas Panhandle, so the cap issues may not be as bad there. Instability is higher based today, with an axis of MLCAPE around 2000 J/kg extending from northeast NM across our northwest zones. Shear is not as strong today given weaker winds aloft and overall less turning in the cloud bearing layer. Effective shear may approach 30 knots this evening as the low level jet ramps up along with some backing of the surface winds. DCAPE is quite large today given more inverted-V type soundings, with 1400-1500 J/kg showing up on the current SPC mesoanalysis page. Moreover, some multicell storms will be possible (there is enough anvil layer winds to get some tilt to the updraft). Large hail and dry microburst winds will be the main concern with the stronger storms into the evening, but this threat should be isolate. Perhaps a higher concern is the localized flooding potential. Even through the precipitable water values aren`t as high as yesterday, and are now well below the 90th percentile, storms do not have a lot of steering flow resulting in slower storm motions. Soil conditions are quite saturated over a good portion of the Panhandles, so storms will have the potential to produce some flash flooding in a relatively short period of time. Ward LONG TERM...Tuesday through Monday... No major changes have been made to the forecast. Models and ensembles still in good agreement regarding evolution of closed mid-level low taking aim at the Texas and Oklahoma Panhandles. Some slightly slower movement has been noted, but the story remains the same. Low-level moisture will continue to be sustained for the next several days. Moderately high values of CAPE are expected through Thursday, but shear is not expected to be high. Thus, widespread severe thunderstorms are not anticipated. Thunderstorms are forecast, with Wednesday through Thursday offering the best time frame for widespread precipitation. Closed low expected to cross Panhandles Wednesday night and Thursday. Heavy rains are likely to occur, which could lead to flooding issues, mainly Wednesday through Thursday. Rain and thunderstorms may linger Thursday night across eastern sections as low departs. Dry weather expected Friday through Saturday as brief ridging develops in the wake of the departing low. Poor agreement between models regarding surface features in later periods, but low-level moisture and instability expected to increase Saturday night, with eventual passage of a cold front by Sunday night, followed by moist upslope flow on Monday. Blended pops for thunderstorm chances have been utilized for Saturday night through Monday. Cockrell && .AMA Watches/Warnings/Advisories... TX...None. OK...None. && $$ 7/2
Area Forecast Discussion
National Weather Service Des Moines IA
640 PM CDT Mon Jun 3 2019 .DISCUSSION.../Tonight through Monday/ Issued at 332 PM CDT Mon Jun 3 2019 Tonight into Tuesday...weak area of theta-e advection continues to provide enough lift for showers and a few isolated thunderstorms to dribble eastward this afternoon. The slow movement east and with the large surface high pressure over the Great Lakes providing plenty of dry air to contend with should limit the extent in the east-southeast of the shower activity this afternoon/early evening. Another batch of weak mid-level theta-e advection pushes across the state late tonight into early Tuesday morning and looks to provide enough forcing to spawn showers and a few thunderstorms over the north. The NAM and ARW/NMM suggest redevelopment b/t 03z-06z Tuesday along the Highway 30 to Highway 20 corridors. Even the latest ESRL HRRR shows hints of rain in this location tonight. Have a brief dry period this evening before the rain starts up again by the aforementioned period. This shower/storm activity will be over by 12z with some lingering showers across the northeast. Tuesday afternoon and evening remain troublesome as instability increases dramatically. Surface based CAPE ranges from 3000-4000 J/kg by 00z Wednesday but the deep layer shear ranges from 25 to maybe 40 knots across the forecast area Tuesday afternoon. Low level shear is even weaker and it is difficult to pinpoint any sort of forcing mechanism to initiate storms tomorrow afternoon/evening. Still, with the amount instability present and any outflow boundary hanging around to potentially cause storms to develop, kept with chance pops past 21z Tuesday across the forecast area. Severe weather potential looks to be elevated hail threat as well as damaging winds threat due to the DCAPE of 500-1000 J/kg. Wednesday through Monday...Large upper level ridge covers much of the central CONUS mid to late week with a cutoff low trickling out of the southern Rockies Wednesday and then meandering over the central to southern Plains into the weekend. The cutoff low finally moves into the mid-Mississippi River Valley by Saturday. Thus, from Wednesday night through Saturday, southern Iowa has the potential see rain and a few storms as the upper low brings several waves of weak theta-e advection and vorticity into this location. With the large surface high pressure remaining planted across the Great Lakes, it will be difficult to get any rain north of Interstate 80 until the early part of the weekend when the surface high begins to breakdown. Thus, trended drier across the central to northern sections of the forecast area during the extended forecast period. && .AVIATION.../For the 00Z TAFS through 00Z Tuesday evening/ Issued at 640 PM CDT Mon Jun 3 2019 Showers passing through central Iowa from highway20 to the MO border will bring brief MVFR conditions mainly with respect to ceilings. Cannot rule out a brief rumble of thunder either but any thunder will be insignificant. Several disturbances will pass across Iowa overnight and Tuesday, each will bring with it a chance for shra/tsra but timing location confidence is low so I only have vcsh in the forecast. The reason for the low confidence is that instability is strong but shear is fairly weak so convection is conditional. MVFR cigs will be more prevalent in the morning (12Z - 16Z)but overall VFR conditions expected. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ DISCUSSION...Podrazik AVIATION...FAB
Area Forecast Discussion
National Weather Service Green Bay WI
1034 PM CDT Mon Jun 3 2019 Updated aviation portion for 06Z TAF issuance .SHORT TERM...Tonight and Tuesday Issued at 238 PM CDT Mon Jun 3 2019 The latest RAP analysis and satellite/radar imagery show surface high pressure stretching from northern Ontario, across the western Great Lakes, to the Ohio Valley early this afternoon. A band of mid-level clouds above 8 kft continues to hold back temps after a chilly start to the day. Readings remain in the upper 50s over north-central WI to the mid 60s over the Fox Valley. The cloud cover will continue to slowly move to the east, which may allow a couple hours of rapidly warming temps over north-central and central WI later this afternoon. Looking upstream, a warm front remains positioned across the Plains with a cluster of showers/storms near the Nebraska-Iowa state line. As this warm front moves towards the area on Tuesday, forecast concerns mainly revolve around thunderstorm potential and any threat of severe weather. Tonight...The clouds will continue to lift off to the northeast, and exit northeast late in the evening. After a period of mostly clear conditions, clouds will return from the southwest ahead of the northeast advancing warm front. Although instability never reaches this far north, there is a small chance of a shower reaching central WI after 09z. High pressure will continue to move away from the region, and the tightening pressure gradient should keep a steady south or southwest wind. Temps should therefore be significantly warmer than last night and range from the upper 40s over far NE WI to the mid 50s over central WI. Tuesday...Southwest winds will continue to lead to warmer and more humid air invading the region. With increasing elevated moisture transport and some indications of a weak shortwave impulse, the greatest threat of showers will likely occur over central and east-central WI in the morning. Instability does not increase until afternoon from the west, but the warm front is only forecast to reach the Mississippi Valley by 7 pm, which is still relatively far west of the area. In a weak warm advection regime ahead of the boundary though, perhaps this will be enough to kick off an isolated storm. Most likely, however, the afternoon will be dry for most places, while thunderstorm chances increase in the evening. Mostly cloudy skies will hold back temps some, but thinking mid to upper 70s for highs. .LONG TERM...Tuesday Night Through Monday Issued at 238 PM CDT Mon Jun 3 2019 Low amplitude WNW mid level flow is expected to prevail across the region through much of this week before a closed circulation in the southern Plains moves toward the Great Lakes late in the week. There is a chance for showers and tstorms Tuesday night associated with mid level short-wave trof and surface low/cold front. Timing of the cold front across forecast area (late Tue night) should preclude widespread tstorm activity in this part of the state. SPC Day 2 looks reasonable, with best chance for strong storms over western part of Wisconsin. Typical early June temps expected much of the week. Cooler temps expected as upper low and associated clouds/rain moves into the region later in the weekend. Forecast temps a blend of best performing bias-corrected models. && .AVIATION...for 06Z TAF Issuance Issued at 1030 PM CDT Mon Jun 3 2019 VFR conditions will continue overnight into Tuesday morning. A few sprinkles are possible along the Michigan border overnight. On Tuesday, models indicating low level moisture, combined with daytime heating will CIGS to drop into the MVFR category. Some discrepancy in the bufkit soundings and the latest MET/MAV guidance if the low clouds will be in the MVFR or VFR category. Leaned toward the lower cloud heights based on the bufkit soundings. The chances of showers and thunderstorms will be on the increase late Tuesday afternoon and especially Tuesday evening. CIGS are likely to drop into the IFR category Tuesday evening across portions of central and north-central Wisconsin. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM.....MPC LONG TERM......JKL AVIATION.......Eckberg