Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 03/23/17

Area Forecast Discussion
National Weather Service La Crosse WI
1029 PM CDT Wed Mar 22 2017 .SHORT TERM...(This evening through Thursday) Issued at 345 PM CDT Wed Mar 22 2017 At 3 PM, a 1037 mb surface high was centered over central Lake Michigan. East and southeast winds on the back side of this high continues to bring very dry air into the Upper Mississippi River Valley. Dew points ranged from 5 to 15F. Temperatures ranged from 30 to 35F north of Interstate 94 and 35 to 41F across the remainder of the area. Meanwhile further west, weak to moderate 800 to 600 mb frontogenesis was producing some a light wintry mix of precipitation from southwest Minnesota southeast into central Iowa. The 22.12z models continue to show that an elevated warm front will move east across southeast Minnesota and northeast Iowa late tonight and Thursday morning and across western Wisconsin on Thursday afternoon. The HRRR continues to show that maybe some elevated showers may develop across western Wisconsin overnight ahead of this warm front. However with the low levels (sub-cloud layer) remaining very dry, this precipitation may not make it to the ground. As a result, kept the forecast dry for the overnight. During the day Thursday, BUFKIT soundings show that the air mass will gradually saturate as moisture surges ahead of an approaching front from the northwest. This will result in the development of rain across the region. The highest chances will be during the afternoon. With very dry air still advecting into the area during the morning, there may be the potential for a light wintry mix at the onset. However this looks to be brief and should not cause any impacts. .LONG TERM...(Thursday night through Wednesday) Issued at 345 PM CDT Wed Mar 22 2017 From Thursday night into Sunday, a slow moving upper level low will move from the Southern Plains into the Ohio River Valley. A deformation band of rain on the north side of this low will slowly move south across the forecast area. This deformation band will be mainly along and north of Interstate 90 from Thursday night into Friday night, and along and south of Interstate 90 from Friday night into Sunday. It continues to look like the much of the instability will remain south of the forecast area. As a result, kept the mention of thunder out of the forecasts. Rainfall amounts from this system will likely range from 1 to 1.5 inches. With this rain spread out of over a long-period of time, only anticipating in bank rises on area rivers. With the potential that the southern part of the forecast area could enter the warm sector of this system on Friday, the temperatures forecast is rather tricky. The ECMWF ensemble is showing standard deviations of 4 to 6. For the time being, just staying close to the ensemble mean. However with that said there could be potential for a large bust in the temperature forecast for areas along and south of Interstate 90. && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 1029 PM CDT Wed Mar 22 2017 Mid clouds continue to thicken and gradually lower through sunrise, with VFR conditions transitioning to MVFR through the afternoon and early evening hours, north of a warm front lifting into Iowa. Ahead of that front, a smattering of showers and perhaps even a few thunderstorms is expected, though with plenty of questions regarding coverage, a "vicinity" mention remains warranted. Winds will remain from the southeast the next 24 hours, becoming gusty at both LSE and RST with some gusts to around 25 knots at times from late morning onward. Even with those gusts, low level wind shear is expected to develop at RST after 00Z. && .HYDROLOGY...(Thursday night through Wednesday) Issued at 345 PM CDT Wed Mar 22 2017 It continue to look like the area will be in a prolong wet period from Thursday night into Sunday as a thin ribbon of Gulf of Mexico moisture is brought northward into the region. Precipitable water values continue to be 2 to 3 standard deviations above normal. Rainfall totals will likely be in the 1 to 1.5 inch range. However with this rain spread out of over a long-period of time, only anticipating in bank rises on area rivers. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. IA...None. && $$ SHORT TERM...Boyne LONG TERM...Boyne AVIATION...Lawrence HYDROLOGY...Boyne
Area Forecast Discussion
National Weather Service Bismarck ND
926 PM CDT Wed Mar 22 2017 .UPDATE... Issued at 921 PM CDT Wed Mar 22 2017 As the warm front has moved east this evening the lower clouds have pretty much cleared out of the James River Valley. Scattered high thin clouds remain over the west and central. Warm advection should limit temperatures from falling much tonight east. Current forecast looks good with increasing clouds far west and a slight chance of rain by morning southwest. UPDATE Issued at 636 PM CDT Wed Mar 22 2017 This Wednesday evening a warm frontal boundary had progressed through central North Dakota resulting in decreasing clouds across the northwest. Temperatures had warmed into the middle 50s late this afternoon over much of west central and southwest North Dakota. Meanwhile stratus cloud cover and cool temperatures in the lower 30s remained in place across the James River valley. Mainly scattered to broken high clouds covered the central and west. Gusty southerly winds should extend into the evening hours across the James River valley otherwise the winds will diminish west and central. Updated the sky cover to account for less cloud cover northwest otherwise forecast trending ok. && .SHORT TERM...(This evening through Thursday) Issued at 309 PM CDT Wed Mar 22 2017 Precipitation chances late tonight through Thursday highlight the short term forecast. The 12 UTC global suites and the 19 UTC RAP are in agreement on a shortwave ejecting out of the southwest CONUS deep trough to propagate into the Northern Plains late tonight through Thursday. Overall forcing is aided by jet coupling between a jet streak across northeast Montana into southern Canada, and the jet across Colorado and New Mexico in to the southern portions of the Northern Plains. Did significantly reduce the mention of freezing rain for Thursday morning from the previous forecast as the 12 UTC NAM/GFS bufr soundings depict rather dry air in the 800-700mb layer Thursday morning that will limit significantly how much liquid precipitation may be able to reach the ground in a narrow temporal window with favorable surface temperatures for freezing rain. .LONG TERM...(Thursday night through Wednesday) Issued at 309 PM CDT Wed Mar 22 2017 Above normal temperatures highlight the extended forecast. The 12 UTC global models are in agreement on split flow across the Northern Plains Friday and Saturday transitioning to quasi-zonal Sunday into Monday before an upper level ridge potentially builds across the region by Tuesday. This overall favors above normal temperatures with highs in the 40s and 50s and sporadic, weak precipitation events. && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 636 PM CDT Wed Mar 22 2017 At 6 PM CDT a warm front extended across central North Dakota. Mainly scattered to broken high clouds were found from KISN-KDIK- KBIS-KMOT with ceilings around 5 thousand agl at KJMS. For tonight VFR is expected. On Thursday low pressure will spread increasing rain chances across southern North Dakota. A brief period of freezing rain is possible after sunrise along and north of KBIS- KJMS route. At this time not enough confidence to add FZRA to the KBIS-KJMS TAFS. MVFR possible at KJMS after 20z. && .HYDROLOGY... Issued at 309 PM CDT Wed Mar 22 2017 In response to increased releases from Alameda Reservoir, Lake Darling will increase its releases to 1000 CFS by Thursday, with the potential for further increases next week. This will cause the Souris River downstream of Lake Darling near Foxholm to rise but remain just below flood stage. As this pulse of water travels further downstream where greater ice cover remains on the Souris River, ice break up will have to be closely monitored. Furthermore, snowmelt will be on the increase with a sustained period of above normal temperatures late this week and through next week. While soil moisture was high across the Souris Basin going into the winter, early snow insulated the ground, preventing much frost from forming. Thus, some uncertainty remains as to how much melt from the snowpack will infiltrate into the ground versus runoff and reach the river, streams and coulees. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...WAA AVIATION...WAA
Area Forecast Discussion
National Weather Service Las Vegas NV
308 PM PDT Wed Mar 22 2017 .SYNOPSIS...A Pacific system will bring a chance of showers and thunderstorms to portions of the area through this evening with showers persisting overnight into Thursday morning over Lincoln, Clark and Mohave counties. Otherwise, expect breezy winds and seasonal temperatures through Thursday. A second system will move into the area late Friday into Saturday bringing another round of showers to portions of the area. && .SHORT TERM...through Saturday night. A low pressure system will move across the southern Great Basin and Mojave Desert tonight and then into Utah and Arizona Thursday. This will bring plenty of cloud cover and an increasing chance of showers tonight which will linger across portions of the area on Thursday. The latest HRRR has been nudging a line of showers it had forecast earlier over the Spring Mountains further east and now has the line mostly east of Las Vegas...focused primarily on the Lake Mead NRA, southeastern Lincoln and northern Mohave counties. There is also a second area of shower activity forecast along the front as it moves south and east through the southern Great Basin tonight into early Thursday. Counties potentially impacted include portions of Inyo, Esmeralda, Nye, Lincoln, Clark and Mohave. The HRRR forecast lines up fairly nicely with the 18z NAM12 in where showers are expected to develop and move. Thunderstorms will be possible through this evening but should tail off behind the front. Eastern Lincoln and Mohave counties will be the focus areas for showers and thunderstorms Thursday afternoon as moisture wraps around the back side of the low. Gusty winds...southwest to west ahead of the front and northwest behind...will affect the area through Thursday as well. Shortwave ridging and area wide dry conditions are expected Thursday night and Friday as a ridge axis shifts across the region. A second trough will bring another round of showers beginning in the Sierra Friday evening and spreading south and east through Saturday. In addition, local breezy conditions will be possible. Showers end overnight Saturday as the system moves east of the area. Expect seasonal temperatures through Saturday. .LONG TERM...Sunday through Tuesday. Model agreement is pretty good through Sunday, but quickly deteriorates thereafter, so confidence beyond Sunday is low. Solid model to model and run to run consistency on ridging for Friday points to a dry day with temperatures rising back to a few degrees above normal. Next storm passing through Saturday looks like a quick hitter, with precip chances mainly from Las Vegas north and breezy to windy conditions over the deserts. The next storm should be approaching the West Coast Sunday afternoon, but as was the case yesterday, the models disagree on whether this storm will be another quick moving weak trough or will deepen and slow down as it moves inland. By Monday night, model solutions range from shortwave ridging over our area to a cold closed low overhead. Chose to make no changes for Monday and Tuesday due to a lack of confidence in any one pattern evolution. && .AVIATION...For McCarran...Gusty southwest winds this evening turning more westerly later tonight as a front approaches from the north. The winds are expected to turn to the northwest with the best timing between 14Z and 16Z Thursday morning. Winds should then stay primarily out of the northwest through the day Thursday. There remains a small chance of rain showers later this afternoon near the airport with an initial round of showers forecast to pass just east of the airport between 5 and 7 pm. Probably a better chance of showers actually impacting the airport complex will be after 5 am Thursday morning and continuing through the late morning. Dry conditions are expected in the afternoon. For the rest of southern Nevada, northwest Arizona and southeast California...Showers and thunderstorms are possible through this evening becoming mainly showers overnight into Thursday morning. A few storms may redevelop Thursday afternoon over eastern Lincoln and Mohave counties. Southwest winds gusting 25-35 knots will persist ahead of front moving south and east through the area tonight. Winds will turn to the northwest behind the front and be locally breezy. && .SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report any significant weather or impacts according to standard operating procedures. && $$ Short Term/Aviation...Salmen Long Term...Morgan For more forecast information...see us on our webpage: or follow us on Facebook and Twitter