Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 02/21/19

Area Forecast Discussion
National Weather Service Grand Forks ND
751 PM CST Wed Feb 20 2019 .UPDATE... Issued at 751 PM CST Wed Feb 20 2019 Made adjustments to overnight temps as lingering low clouds will limit radiation cooling, and near term guidance (reflecting current trends) now show more locations holding in the teens through Thu morning. Light snow continues across much of our area, with small pockets or narrow bands of moderate snow. Have held off on any changes to current Winter Weather Advisory based on these trends (still set to expire at 06Z). UPDATE Issued at 554 PM CST Wed Feb 20 2019 Lobes of maximum divergence aloft showing weakening trends on latest RAP analysis, however radar/satellite/obs indicate several moderate band of snow still orientated west to east over our CWA. Still expect a weakening trend for central and northern parts of our CWA this evening, with potential for lingering light snow (or flurries) overnight. Trends have improved enough with main areas of snow far enough north to allow southern part of advisory to expire on time at 6PM, and will continue to hold onto the rest of the advisory for the evening period. && .SHORT TERM...(This evening through Thursday) Issued at 321 PM CST Wed Feb 20 2019 Upper level trough was located over northwest IA with a trough extending into ND. Southern end of trough will shear off toward the Great Lakes tonight while northern end will also shear off but will occur through Thu afternoon. Most of the snow will fall this afternoon and will taper off tonight. Low to mid level low pressure system will bring moisture into the area for tonight. Weak east-west 700 theta-e ridge over the area will shift into the northern valley and stall on Thu. Will keep winter weather advisory going for this evening. .LONG TERM...(Thursday night through Wednesday) Issued at 321 PM CST Wed Feb 20 2019 Thursday night into Friday morning the next system within this more active pattern lifts from southwest to northeast at 500mb. Broad scale lift with q vector divergence above low and mid level warm advection will bring widespread snowfall to the southern and eastern areas Friday afternoon. Will continue to watch the western edge as the 12Z EC remains a bit more west with its QPF compared to the GFS/NAM ensembles. As the system approaches adjustments to its coverage will be refined and much like todays system may end up affecting more of the valley than currently forecast. Potential banding from frontogenetical forcing still possible, though currently appears transient at best, could add to the totals though placement remains in question. Additionally model soundings suggest ice aloft decreases with saturated lower layer creating a freezing drizzle signature for the southern valley and lakes area of west central MN possible Saturday morning. Arctic front set to push through the region Saturday night into Sunday morning with falling temps and strong winds creating some patchy blowing snow in open country. How severely reduced visibilities will be will yet need to be refined. Nonetheless the arctic airmass will bring a return of single digit highs to the region for Monday and Tuesday with lows in the teens to 20 below. Will keep the light snow chances for Tuesday as a models bring a weak disturbance into the northern plains. && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 534 PM CST Wed Feb 20 2019 Main part of system is transitioning east, however light snow with IFR/LIFR vis and CIGS 1200-3000 FT AGL continue across eastern ND and northwest MN. A gradual improving trend south to north is expected regarding VIS as snow continues to decrease in intensity/coverage, however low CIGS are expected to continue through the TAF period becoming IFR by midday Thursday. Winds will tend to be light and variable through the TAF period or eventually prevailing from the west-northwest around 5kt later Thursday as low pressure transitions east and gradient remains weak. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...Winter Weather Advisory until midnight CST tonight for NDZ027>030-038-039. MN...Winter Weather Advisory until midnight CST tonight for MNZ001>003-007>009-013>017-022>024-027-028-032. && $$ UPDATE...DJR SHORT TERM...JH LONG TERM...JK AVIATION...DJR
Area Forecast Discussion
National Weather Service Goodland KS
726 PM MST Wed Feb 20 2019 .UPDATE... Issued at 721 PM MST Wed Feb 20 2019 Forecast remained generally on track as far as T, Td, Wind and Sky grids were concerned with minor tweaks by way of raising temperatures by several degrees to reflect incoming cloud cover and come into better agreement with most recent model runs. Areas of freezing fog were added to the extreme southwestern region along and south of a line from SW Yuma County to Burlington, Wallace, and Selkirk Kansas. Visibilities may drop below one half mile in these areas of freezing fog. The GFS, NAM and the RAP were all in agreement highlighting these areas for freezing fog development. && .SHORT TERM...(This evening through Thursday) Issued at 222 PM MST Wed Feb 20 2019 Continuing to warm up today with highs in the mid 30s and lows overnight in the low to mid teens. Winds will be south around 10 mph with winds increasing to 10 to 15 mph to the south. Closed low over the Great Basin will help in generating moderate southwesterly flow aloft over our CWA. Along this flow we see a shortwave ahead of the next system pushing across the Tri-State area Thursday afternoon/ Thursday evening bringing in freezing drizzle. Models are hanging onto some dryer air aloft, which will inhibit snow development until overnight Friday, in the long term forecast period. Temps will linger in the low 30s to upper 30s throughout the day Thursday, so we will see a transition from freezing drizzle to drizzle and back to freezing drizzle by Thursday night. There is a potential for fog / freezing fog development throughout the evening Thursday and Thursday night with low level moisture increasing from upslope flow from our southeast. .LONG TERM...(Friday through Wednesday) Issued at 100 PM MST Wed Feb 20 2019 Generally speaking, the long term period will continue to see below normal temperatures and above normal precipitation. Most of the precipitation will occur early in the period with the potential for a significant winter storm Friday night and Saturday. There will be another chance for light snow on Monday but it will be far less impactful. Will start off Friday morning with the potential for freezing drizzle and freezing fog across northern and eastern parts of the area. Shallow low level moisture return and weak upslope flow ahead of the approaching system will result in light QPF, only a few hundredths at worst, but with temperatures well below freezing it will have an impact on travel. By mid day Friday, temperatures should get above freezing and improve the situation. Stronger system will begin to impact the area Friday night. Models in fairly good agreement lending some more confidence to the forecast. Shortwave trough will eject out of the Four Corners with a closed upper low tracking from southwest Kansas to southeast Nebraska Friday night and Saturday. This is a good track to bring moderate to heavy snow and very windy conditions to the Tri State area. There is the potential for widespread snow amounts in the 3 to 6 inch range with locally heavier amounts up to 10 inches possible. In addition to the snow, as the surface low deepens expecting very strong northwest winds to accompany the snow. It looks like a classic set up for a blizzard in the central High Plains. Will not hoist a watch at this time only because it is still beyond the typical watch time frame, but will ramp up wording elsewhere. Winter storm should wind down Saturday afternoon and evening, with perhaps some patchy blowing snow on the backside through about midnight. Remainder of the long term period will be relatively quiet, if cold, with only the low chances for light snow on Monday with a weak shortwave in the zonal flow aloft. Less than an inch is expected at this time. Really see no chance for temperatures returning to normal until late next week when the western ridge finally starts to build across the Rockies. && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 432 PM MST Wed Feb 20 2019 The forecast has been kept as VFR at both terminals throughout the forecast period although there indicates some potential for sub- VFR ceilings advecting in between 12Z-15Z with the southeasterly wind flow. There may even be intermittent periods of slightly reduced visibility from mist in association with the low-level moisture present during hours of radiational cooling. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ UPDATE...SANDERSON SHORT TERM...EV LONG TERM...024 AVIATION...SANDERSON
Area Forecast Discussion
National Weather Service Blacksburg VA
1058 PM EST Wed Feb 20 2019 .SYNOPSIS... A cold front will slowly move across the area overnight into tomorrow finally allowing the surface wedge of cooler air to erode by midday Thursday. Following the frontal passage tomorrow, high pressure will build south over the area into Thursday night. Rain returns by Friday and will remain in the area until the next frontal passage on Sunday. && .NEAR TERM /THROUGH THURSDAY/... As of 830 PM EST Wednesday... Have just about run the full suite of weather this evening with a bubble high over ice/snow holding the wedge in place resulting in more freezing rain. This while elevated instability per warmth aloft seen on evening soundings helped convection to the west make it into southwest sections. In addition, the heavier rainfall from earlier combined with where temps have warmed in the far west to combine with snow melt to result in flooding/mudslides, and bankfull streams over the far west. However it appears that the final slug of at least patchy rain will be crossing back through the Blue Ridge over the next couples of hours likely resulting in at least added patchy freezing rain. Temps have jumped up in spots but given the true surface warm front to the south, and the cold front will west of the mountains, values have tended to topple back toward freezing espcly eastern slopes and points north. Thus will keep the winter storm warning and updated winter weather advisory going for now. Appears since most readings are just around freezing that added icing will be light espcly since falling from such a warm layer aloft, but still enough to cause problems with trees given the wet ground and elevated surfaces such as bridges and overpasses. Otherwise just some added tweaks to pops and to keep ice accumulation going longer this evening. Still expecting temps to slowly rise per the latest HRRR but given the stubborn wedge, it may be morning before spots from BCB/ROA to LYH and points north trend upward. Update as of 655 PM EST Wednesday... With heavier precip exiting the southern end of the warning area, that was set to expire at 7 pm, and temps slowly edging up, decided to replace that area with an advisory to cover added spotty freezing rain and residual impacts until midnight. The remainder of the warning that runs until midnight remains in place espcly given colder temps and the current band of precip crossing the north. Otherwise bumped up pops and added more thunder over the southwest this evening. Models continue to struggle with the exodus of the wedge despite prelim values off the evening sounding showing temps in the warm nose better than +10 deg/C this evening. No added changes for now. Previous discussion as of 300 PM EST Wednesday... A cold front will approach the area overnight, increasing mixing and eroding the wedge from west to east. The wedge will erode over the mountains by midnight, but hang over the foothills and piedmont counties through the early morning hours Thursday. While the wedge is over an area, temperatures will remain in the lower 30s. Once the wedge erodes, temperatures will warm to near 40F. Areas outside of the wedge (Richlands and Chilhowie) have warmed into the 40s this afternoon and may only drop a few degrees tonight. With temperatures warming, precipitation overnight will turn to or stay a cold rain. Rain will persist over the area tonight as a slow moving cold front tracks over the region. If rain does stop, even briefly, areas of fog and/or drizzle will take its place. The cold front is expected to be near the Blue Ridge by 12Z/7AM, moving over the foothills around noon, then exiting the piedmont during the afternoon. Rain should end within an hour or two following the front. Rainfall amounts overnight will range from a quarter to half of an inch. Some concerns for flooding across SE WV as 1-2 inches of rain has fallen today. Most of this water is being held by snowpack and could be released with convective showers currently across Tennessee and eastern Kentucky move over the area the evening. Temperatures will warm into the 50s across the mountains to 60F east of the Blue Ridge Thursday. A lingering wedge and rain may remain over NC tomorrow. If this is the case, north-northwest NC foothill and piedmont counties may only warm into the low to mid 50s. && .SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY NIGHT/... As of 400 PM EST Wednesday... Surface front which moves through the area Thursday will stall just south of the region Thursday night as large area of High pressure over the Bahamas and eastern Gulf of Mexico impedes its progress to the south. This front will return as a warm Front Friday into Saturday in response to backing flow ahead of a vigorous upper level trough which is progged to move through out of the Rockies Friday and into the Upper Mid-West Saturday. Warm southerly flow will bring a conveyor belt of moisture northward from the Gulf of Mexico with widespread precipitation breaking out along and north of the warm front, and extending west into the developing cyclone that will develop in advance of the upper level trough. Any brief drying Thursday night will be short-lived with clouds and an opportunity for more rain returning to the forecast area Friday and Saturday. Temperatures during this period are expected to be above freezing. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... As of 400 PM EST Wednesday... A strong storm system is forecast to move through the Great Lakes and into Ontario Sunday with a cold front trailing south into the Appalachians. This front is forecast to cross the mountains early Sunday, then east and off the Coast by Sunday night, bringing an end to the rain. This will bring a surge of strong post frontal winds that will linger into Monday before diminishing. The airmass ahead of the front is a brief spike in temperature is anticipated Sunday, before we spiral back down Sunday night and Monday as colder air advects across the region. Temperatures by Monday will return closer to the mid/late February normals. High pressure will allow for a few days of drying before precipitation chances increase again for mid-week. && .AVIATION /04Z THURSDAY THROUGH MONDAY/... As of 1058 PM EST Wednesday... Poor flying conditions to continue into the overnight with mostly IFR cigs east and MVFR mountains as the low level wedge of cool air weakens. However cant totally rule out a period of VFR around KBLF where warmer air will mix out the low cloud canopy sooner. Thus keeping the going trends going with cigs mainly below 1K feet into later tonight, but perhaps rising to MVFR within spotty rain into the early morning hours. Rainfall should gradually taper off but will see areas of MVFR vsby as fog settles in espcly where mixing is less overnight. Late tonight, winds will gradually shift southwesterly as a warm front lifts northward from the Carolinas, allowing warm air aloft to finally reach down to the surface. The warm front will be followed closely by a trailing cold front that will enter from the west toward daybreak Thursday, shifting winds from the west- northwest. It is this downslope flow that will result in rapidly improving ceilings/visibilities beginning just after 12Z/7AM Thursday. Extended Aviation Discussion... A frontal boundary will meander around the region into the start of the weekend, along with several areas of low pressure moving along this boundary. This will keep the potential for rain and sub-VFR conditions across the area through Sunday. Should finally see improving conditions behind a passing cold front Sunday night with VFR returning to start next week. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...Winter Weather Advisory until midnight EST tonight for VAZ014- 017-018-022-032-033. Winter Storm Warning until midnight EST tonight for VAZ019-020- 023-024-034-035-045>047. NC...None. WV...Winter Weather Advisory until midnight EST tonight for WVZ044. Winter Storm Warning until midnight EST tonight for WVZ507-508. && $$ SYNOPSIS...JH/RCS NEAR TERM...JH/RCS SHORT TERM...PM LONG TERM...PM AVIATION...JH/RCS