Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 03/07/20

Area Forecast Discussion
National Weather Service Dodge City KS
704 PM CST Fri Mar 6 2020 ...Evening Updated to issue Fire Watch east and south of Dodge City... .UPDATE... Issued at 702 PM CST Fri Mar 6 2020 NAM, GFS, and HRRR BUFR soundings were all in decent agreement late today with a low level jet of around 50 knots developing overnight. These strong winds will mix down to the surface by late Saturday morning and then continue through late day. Sustained winds during the afternoon are expected to range from 25 to near 35 mph with gusts of 45 mph being possible at time. In addition to these strong winds the afternoon dew points may also end up being lower than previously thought given the depth of the mixed layer and forecast moisture profiles in this mixed layer. Have therefore lowered the surface dew points during the day on Saturday and as a result am noticing that the afternoon relative humidity values are now expected to range from the teens to around 20 percent. These strong winds and lower humidity values will contribute to ongoing drying fuels. The potential exists for fires to escape control more easily and containment is difficult. Conditions in some locations will come very close to Red Flag conditions, mainly east of a Liberal to Dodge City to near Hays line. As a result will be issuing a Fire Weather Watch for locations east of a Liberal to Dodge City to near Hays line. && .SHORT TERM...(This evening through Saturday) Issued at 223 PM CST Fri Mar 6 2020 A broad ridge of high pressure in the mid-upper troposphere overspread much of the western and central CONUS today. Meanwhile, a deep trough encompassed the eastern CONUS with a significant storm developing off the Mid-Atlantic Coast. A surface ridge of high pressure was centered from Iowa south into Texas. A new leeside trough was developing fairly quickly as the upper level flow pattern was starting to increase and become increasingly southwesterly component across the Central and Northern Rockies. The main sensible weather element of interest through this period will be the strong winds. A strong south-southwest wind was already underway along and west of the U283 corridor with a number of observations showing 25 to 30 mph sustained wind, especially across far southwest Kansas. As the leeside trough continues to develop and increase its influence on the pressure gradient, the strong south-southwest winds will continue to expand its areal extent. Tonight`s winds will be in the 15 to 25 mph range pretty much everywhere across western Kansas without any break. These strong winds through the night will keep temperatures up in the 40s. Saturday will be the windiest days coming up, with all areas expected to experience 25 to 35 mph sustained winds. Some gusts in the 40 to 45 mph range will also occur, especially in the afternoon. We updated the temperature forecast for Saturday adding more (warmer) HRRR weight over the NBM starting point. .LONG TERM...(Saturday night through Friday) Issued at 223 PM CST Fri Mar 6 2020 A fast-moving southern stream storm will be pushing northeast out of New Mexico and across Kansas late Sunday/early Monday. Low level moisture will increase quite a bit over what have been seeing lately, as dewpoints increase to the mid to upper 40s. These dewpoints will be enough to result in just enough MUCAPE to support inclusion of thunder in the Wx grids (Slight Chance). Overall, the forecast has not changed much with respect to POP and QPF, although some of the latest runs of the GFS and ECMWF support a little more precipitation now, perhaps up to one-quarter inch in some areas along/east of U283. The cold air advection behind the Sunday Night storm system will be brief and largely inconsequential. The highs Monday will be 5 to 10 degrees cooler across the whole region. The Another storm will be digging down south off the California coast, which will cut off from the northern branch. This is starting to look like a more impressive system for the southern and central Great Plains with perhaps widespread substantial rainfall toward the end of next week. So much can and will change with respect to this storm around March 12-14, including how much cold air may be involved north of the front (wherever it may be positioned once the California low comes out). && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) Issued at 514 PM CST Fri Mar 6 2020 Gusty south southwest winds at around 20 knots at 23z Friday will decrease some after sunset as the boundary layer winds decouples this evening. Breezy conditions however can still be expected overnight with a south wind at 15 to 20 knots. HRRR, NAM and even the GFS BUFR soundings indicating wind speeds in the 1500 to 2000 ft AGL will increase to 45 to around 50 knots by 06z Saturday and then continue through early Saturday morning. As a result have included a low level wind shear group at GCK, DDC, HYS, and LBL overnight. These winds in the 1500 to 2000 ft AGL level will then mix down to the surface by 15z Saturday which will result in gusty south southwest winds increasing to around 25 knots. Only High level clouds (greater than 15000ft AGL) can be expected over the next 24 hours. && .FIRE WEATHER... Issued at 223 PM CST Fri Mar 6 2020 Elevated to Near-critical fire weather conditions were occurring across southwest and west central Kansas west of U283 where sustained winds were in the 20 to 30 mph range. There is just enough moisture with dewpoints in the upper 20s to lower 30s to prevent the relative humidity from reaching the critical 15-percent. There will likely be a few hours later in the afternoon/early evening when the RH will be around 20 percent or so. Regardless, very aggressive fire behavior can be expected along and west of U283. Saturday will be windier everywhere with sustained winds of 25 to 35 mph. Again, the afternoon relative humidity is not expected to fall much below 25- percent as dewpoint temperatures are expected to remain mostly in the lower 30s. Given how strong the winds will be, Near-critical fire weather behavior can be expected on Saturday. && .PRELIMINARY POINT TEMPS/POPS... DDC 42 71 45 70 / 0 0 0 10 GCK 42 71 44 73 / 0 0 0 10 EHA 42 73 45 72 / 0 0 0 10 LBL 40 71 43 70 / 0 0 0 10 HYS 42 73 45 72 / 0 0 0 0 P28 37 70 42 67 / 0 0 0 10 && .DDC WATCHES/WARNINGS/ADVISORIES... Fire Weather Watch Saturday afternoon for KSZ046-065-066-078>081- 086>090. && $$ UPDATE...Burgert SHORT TERM...Umscheid LONG TERM...Umscheid AVIATION...Burgert FIRE WEATHER...Umscheid
Area Forecast Discussion
National Weather Service North Platte NE
604 PM CST Fri Mar 6 2020 .SHORT TERM...(This evening through Saturday night) Issued at 301 PM CST Fri Mar 6 2020 The guidance blend plus bias correction was the basis for the temperature forecast tonight through Saturday night. The models continue to show h850mb temperatures rising to around 15C and h700mb of 0C to 5C. This should support highs in the upper 60s to upper 70s throughout wrn and ncntl Nebraska Saturday. Nearly full sun is expected but some patches of cirrus will move through at times. These high clouds are associated with an upper low affecting the swrn U.S. and are not expected to affect the heating cycle across Nebraska. The guidance blend plus bias correction keeps overnight lows in the upper 20s and 30s tonight with 30s and 40s Saturday night. The RAP and NAM models shows a 40kt low level jet developing both nights and this should disrupt the radiational cooling process. The thermal ridge moves overhead Saturday night and this will contribute to the lows which will be close to record warm in some areas. .LONG TERM...(Sunday through Friday) Issued at 301 PM CST Fri Mar 6 2020 The models have collectively slowed the progress of the cold front approaching nrn Nebraska Sunday afternoon. Several models hold the front north of Nebraska until 21z. The temperature forecast Sunday has warmed a few degrees and now features highs mostly in the upper 60s to mid 70s. The models show high clouds during the day and this will have a modest affect the heating cycle. Rain chances continue Sunday night and Monday and the models are showing signs of modest amplification of a wave moving off the the Colorado Rockies. The models are tracking the disturbance east northeast through Nebraska and this would favor wrn and ncntl Nebraska for the best rain chances vs earlier model runs which favored KS. The rain forecast Tuesday and Thursday now indicates chances of showers and the GFS ensemble is perking up on rainfall amounts with each of these disturbances. && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) Issued at 604 PM CST Fri Mar 6 2020 The main aviation concern heading into the next day will be the gusty winds across the eastern Panhandle and northern Nebraska. KVTN will continue to experience gusty winds up to 25 knots through early evening. Gusty winds return on Saturday afternoon at KVTN with gusts again up to 25 knots. VFR conditions are expected at KLBF through Saturday afternoon. && .FIRE WEATHER... Issued at 301 PM CST Fri Mar 6 2020 A blend of the guidance suggests temperatures in the upper 70s and wind speeds of 15 to 25 mph across northwest Nebraska Saturday afternoon. The dew point and humidity forecast using the HRRR, RAP and short term model blend produces humidity values near or below 15 percent. All of this, assuming the forecast is not too aggressive, warrants a Red Flag Warning across parts of western Nebraska Saturday. && .LBF WATCHES/WARNINGS/ADVISORIES... Red Flag Warning until 7 PM MST Saturday for NEZ204. Red Flag Warning from noon to 8 PM CST Saturday for NEZ206-208. && $$ SHORT TERM...CDC LONG TERM...CDC AVIATION...Kulik FIRE WEATHER...CDC
Area Forecast Discussion
National Weather Service Pocatello ID
242 PM MST Fri Mar 6 2020 .SHORT TERM...Today through Sunday night...Current satellite imagery shows our area in southerly flow with the high pressure ridge axis well east of our area. There is an approaching Pacific trough that is currently coming on shore off the Washington and Oregon coasts. Models continue to show this system move over our area tomorrow afternoon into early Sunday morning. Still expecting much warmer than normal temperatures this afternoon through Saturday afternoon.The NOHRSC modeled snow melt has 0.50 to 1.00 inch (with localized amounts in our southeast areas up to around 1.5 inches) of snow melt today through Saturday with the warm temperatures ahead of this system as well as rain on snow for mainly the Upper Snake Plain between Blackfoot and Idaho Falls extending south and east across the Southeastern Highlands, especially the Franklin/Oneida region. Models are indicating around 0.05 to 0.25 inch of rain to fall on the snow areas mentioned above. This snow melt/rain on snow will likely cause minor ponding of water. Idaho Falls and Malad are the two bigger cities in these areas that will likely see some ponding of water. The cold front that is currently off the Washington and Oregon coasts moves through Saturday into Sunday morning from west to east bringing valley rain and mountain snow. Expect snow levels around 5500 feet rising to 6500 to 7000 feet. Snow amounts look to be around 4 to 8 inches for the northern Central mountains above 7000 to 7500 feet where a winter weather advisory remains in place above 7500 feet. Galena Pass will be the main travel way that will have impacts. Look for 2 to 5 inches for the Eastern Highlands above 6000 to 6500 feet and the Southeastern Highlands above 6500 to 7000 feet. Winds will be breezy, especially for our Southeast areas on Saturday afternoon into the evening. Sunday morning the snow lingers along our eastern areas with colder/drier air moving into the Central mountains. By late Sunday models are showing precipitation to redevelop mainly for our southeast area with snow levels around 5000 to 5500 feet which could add additional rain on snow below these levels. Wyatt .LONG TERM...MONDAY THROUGH NEXT FRIDAY... In the wake of our weekend shortwave trough/storm system, the parent high pressure center is forecast to track east across Canada, with an attendant second, more pronounced shortwave trough loading up along the Pacific coast. Models continue to show decent agreement on the approaching lift generating another round of precip starting late Mon AM, focused across the srn/ern highlands and Bear Lake (although light showers will be possible anywhere). Meanwhile, a fairly intense low pressure center will be approaching the CA coast, and strong SW flow may pick up additional moisture from this low and feed it NE ahead of the shortwave trough. There remain some slight timing differences between the GFS/ECMWF/Canadian on when the trough axis/associated cool front will cross SE Idaho, but the general window is between about sunrise and sunset Tues, with precip ending. More seasonal temps for this time of year will again support a mix of rain/snow depending on elevation, with snow levels running about 5,000 to 6,000 feet during the day and close to valley floors at night. We used a WPC/NBM blend for QPF, which still doesn`t look terribly concerning for snowfall, generally a dusting to an inch below about 6,000 feet and 1 to 5 inches above with a pretty decent terrain-based gradient, again mostly across the srn/ern highlands. This forecast is running near or slightly above the NBM 50th percentile, which increases our confidence that overall impacts are looking limited from this system. (Even the NBM 90th percentile is only painting some advisory-level snowfall in this zone.) GFS/EC ensembles are running hot for the Teton Valley, suggesting 4 inches or more of snow, but this seems potentially overdone, especially if temps are warm enough for any rain to mix in Mon (it will be borderline). Overall, plan on some potentially slick travel south/east of the Snake Plain Mon afternoon into Tues, especially over mntn passes, with little to no impact elsewhere. Winds do not appear to be a concern at this time. From Wed onward, the main story will be the closed low shifting east into the 4-corners region. At this time, all models keep this storm south of our forecast area with little to no impact for ID, but we will continue to monitor trends for any shifts in the track. Temps mid-late week are forecast to run near to slightly above normal, generally topping out in the 40s to low 50s. Model agreement breaks down by next weekend, but in general it appears another low pressure system or trough may drop into the northern Rockies with another round of precip. - KSmith && .AVIATION...High pressure remains firmly in control of our weather today across the region with VFR cigs/vsbys, but wind has been the big story. NAM time-height plots and NAM/NAMNest/RAP BUFKIT soundings all show a strong SW flow reaching 20-30 knots as you ascend toward 2,000 feet (weaker in the Central Mntns), with PIREPs even suggesting 10+ knots of gain in just the lowest 500 feet. At KPIH, strong southerly downsloping (well overperforming MOS guidance but captured by the HRRR) has mixed the stronger winds down to the surface and reduced shear (and increased runway crosswinds), but with a rather weak northerly wind field at KIDA and no expectation of SW winds reaching the terminal or much of a diurnal increase, we are likely close to or meeting LLWS criteria, and we have amended to add this to the TAF throughout the day. Winds just off the surface may strengthen even further tonight, possibly reaching 30-40 knots by 1,500 to 2,000 feet, just in time for sfc winds to decouple. Thus, we carry LLWS at KPIH, KIDA, and KDIJ throughout the night into Sat. The magnitude of the shear looks a little weaker at KBYI, so we left LLWS out of their TAF for now as our confidence is lower, but we will need to continue to reevaluate this in future TAFs. LLWS concerns will likely remain right through the end of the 18z TAF period or just beyond. The HRRR supports the strong S 22G32kt downslope and crosswind concern continuing through 02z this eve at KPIH before rapidly decreasing, and this matches well with when their winds have tended to drop off previous evenings. Our weekend storm will arrive from NW to SE over the course of the day Sat, and we have KSUN dropping to MVFR cigs by 17z with RASN. Onset of the greatest impacts is just beyond the TAF period for the rest of the major terminals, but in general, expect a trend toward MVFR cigs and increasing precip over the course of Sat afternoon/Sat night, with possibly IFR vsbys at KDIJ during periods of snowfall. - KSmith && .PIH WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory from 5 AM to 11 PM MST Saturday for IDZ072>074. && $$
...Update to aviation forecast discussion...

.SHORT TERM...(This evening through Saturday) Issued at 350 PM CST Fri Mar 6 2020 South to southwest winds increase for tomorrow with temperatures still running about 15 degrees above normal. A meridional surface high pressure cell axis shifted east of the forecast area this afternoon, with south to southeasterly winds slowly increasing on its backside. By 3pm, winds at Concordia had already risen to 15 to 20 kts with the increasing pressure gradient upstream. This area of pressure falls shifts eastward tonight, with winds at higher elevations staying mixed just mixed enough to keep speeds from dropping overnight. Despite a small degree of lower-level theta-e advection taking place overnight on this return flow, strong daytime mixing should quickly result in dewpoints falling into the mid-20s and high temperatures pushing the 70 degree mark. South to southwest surface winds rapidly strengthen at the onset of daytime mixing, with gusts over 35 kts possible at times. At this point, did not go with a wind advisory for Saturday, but conditions will be very close and will need reassessing tonight. The only fly in the ointment to the forecast is a a band of high clouds trailing the H500-300 ridge axis, which may temper mixing slightly. The 18Z HRRR, however, still shows very deep mixing akin to today and given the recent verification success of the HRRR in this pattern, did trend dewpoints towards this solution. Extreme fire weather conditions are likely on Saturday--please see the fire weather section for more information. .LONG TERM...(Saturday night through Friday) Issued at 350 PM CST Fri Mar 6 2020 A more active weather pattern sets in for next week with multiple chances of precipitation through the rest of the forecast period. The broad upper level ridge shifts east of the forecast area by Saturday evening ahead of a longwave trough digging into the western CONUS. Southwesterly flow becomes established Sunday morning behind the aforementioned shortwave embedded near the crest of the longwave ridge. Lower tropospheric theta-e advection increases Saturday night into Sunday on an H850 40-50 kt jet, setting the stage for a warm day on Sunday, though dewpoints will be 20 degrees higher than Saturday. Lee cyclogenesis results in a low pulling off the Front Range Sunday evening with broad isentropic upglide ahead of the system possibly resulting in rain for Sunday night. As the low shifts eastward, it will drag a weak surface cold front through during the morning on Monday. NAM/GFS forecast sounding lapse rates are rather shallow for thunder potential, but did still keep some mention of thunder in the forecast at times with the passage of this system. There is some uncertainty with the timing of the wave based on the various medium range solutions, but there should be a period of drier weather on Tuesday before a northern stream wave drops southward midweek. No real appreciable airmass changes are forecast for the week, resulting in highs in the upper 50s/60s and lows in the 40s. Both the 12Z EC and GFS do depict a much more potent system for late in the week, but confidence in its track, evolution, and impacts are low at the present time. && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) Issued at 536 PM CST Fri Mar 6 2020 VFR conditions will continue with only some areas of thin cirrus throughout the forecast. The only minor changes were to winds and wind shear with notable wind conditions developing by 08Z and persisting well beyond this forecast. && .FIRE WEATHER... Issued at 350 PM CST Fri Mar 6 2020 South to southwest winds increase Saturday morning to between 20 and 30 mph with gusts to 40 mph by midday. Transport winds will push 35 to 40 mph and mixing heights rise to over 4 kft, promoting excellent ventilation rates. Daytime humidity values are forecast to fall to around 20 percent, though there is slight degree of uncertainty in these values due to an increase in high cloud cover during the day that may temper daytime mixing. There is also a chance that humidity values fall even lower if temperatures are warmer or dewpoints lower than forecast as a few model solutions are depicting. A very high to extreme fire danger will be present during the afternoon hours. A fire weather watch has been issued for Saturday afternoon for these conditions. && .TOP WATCHES/WARNINGS/ADVISORIES... Fire Weather Watch Saturday afternoon for KSZ008>012-020>024-026- 034>040-054>056-058-059. && $$ SHORT TERM...Skow LONG TERM...Skow AVIATION...65 FIRE WEATHER...Skow