Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 12/19/16

Area Forecast Discussion
National Weather Service Melbourne FL
909 PM EST Sun Dec 18 2016 .DISCUSSION... .UPDATE... Scattered showers a few lightning storms moved NE from Osceola county toward Orlando and nrn Brevard and Srn Volusia county into late evening. Latest HRRR indicates convection should continue to move NE through midnight and then start to dissipate. Will continue some low convective chances thru midnight and then expect fog and stratus to develop into the late night hours mainly across nrn and interior sections with light southerly low level flow ahead of a slow moving front across the FL panhandle. There could be some locally dense fog in spots across the nrn interior late tonight though around sunrise. Lows will be mild from 65-70. && .MARINE... Update...Little change to current CWF with southerly winds decreasing to around 10 knots overnight. Seas 3-4 ft near shore up to 4-5 ft well offshore. No headlines needed. Tonight-Monday.. Winds/seas over the marine area will continue to decline as gradient ascd with high pressure well east of the state shunts farther Ewd over the open Atlc. Sly winds of 10 to 15 kts this evening will reduce to around 10 kts by early Mon. Winds Aob 10 kts are expected Mon with an onshore breeze developing along the immediate coast. && .CLIMATE... Daytona Beach has set a new daily record high of 86 degrees, breaking the old record of 84 in 1961. If everything holds for the rest of the day today, all four climate sites will at least tie daily record warm minimums. The current low is 68 for Daytona Beach which would tie the current record set in 1961. Orlando International Airport only dropped to 67 this morning which would tie its record also set in 1961. Melbourne would set a new daily record warm minimum of 69 degrees breaking the current record of 68 set in 1961. Vero Beach is on pace to tie its daily record warm low of 71 set in 2006. Local warm temperature records Today-Monday: LOC DATE HI-MAX HI-MIN DAB 18-Dec 85 2017 68 1961 MCO 18-Dec 90 1961 67 1961 MLB 18-Dec 88 1961 68 1961 VRB 18-Dec 86 1961 71 2006 DAB 19-Dec 87 1990 67 1931 MCO 19-Dec 88 1922 68 1961 MLB 19-Dec 84 1990 68 1961 VRB 19-Dec 85 1990 70 2006 && .MLB WATCHES/WARNINGS/ADVISORIES... FL...None. AM...None. && $$ Volkmer/Sedlock
Area Forecast Discussion
National Weather Service Blacksburg VA
925 PM EST Sun Dec 18 2016 .SYNOPSIS... A cold front will continue to push east of the region overnight into early Monday allowing a large area of high pressure to slide in from the west through the middle of the week. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... As of 855 PM EST Sunday... Cold front is now south and east of the area with the evening RNK sounding showing quite a bit of dry air in the mid levels mainly between 500-800 mb attm. Expect this to continue to advect east overnight but likely wont be able to push the deeper moisture out of the far southeast as yet another wave ripples up the boundary per latest water vapor loop. In fact the latest HRRR and 00z Nam bubble light rain back into southeast sections after midnight so plan to leave in some low pops there overnight. However appears deeper cold advection wont be able to catch up with much of the moisture, but could be close for spotty freezing rain/drizzle pending how far north the precip returns and how close to freezing surface temps get. Since quite uncertain with both will leave out any icing mention for now. Otherwise expect mainly cloudy skies overnight with perhaps some breaks east of the upslope western zones later and across the northeast where drier air may undercut by morning. Also appears moisture will remain too shallow for western snow showers overnight but cant rule out some spotty freezing drizzle across the ridgetops within the low clouds. Gusty northerly flow at times should diminish some overnight but still much colder with lows looking on track with 20s west to low/mid 30s east. Previous discussion as of 235 PM EST Sunday... At 245 pm, the surface front was moving off the Blue Ridge and over the foothills counties of Virginia. Since the front has moved east of the mountains and into relatively more stable air from recent cold air damming yesterday, the overall coverage of showers has become disorganized. However, a narrow line of organized convection is forming along the front as it tracks across the Carolinas. With the front and associated convection tracking to the coast and cooler drier air filters in overnight, rain/snow chance will be on a sharp decline starting this evening. The last area that will see rain this evening will be across Southside VA and northern Carolina piedmont. Bufkit forecast soundings displaying cold air will arrive first in the low levels. Since some warm air exist aloft and cold northwest flow increases this afternoon and evening, some light snow may fall and/or freezing drizzle since the layer is shallow. Any accumulations will remain light with no headlines need. Temperatures tonight will range from the 20s across the northern and western CWA to the lower 30s across the southeast. Where skies completely clear, there will be an opportunity to dip into the teens...these sort of temperatures favoring the WV/VA Highlands. && .SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY NIGHT/... As of 236 pm EST Sunday... Upper trough slow to move across the area and will hang frontal boundary aloft across the eastern Carolinas. Some overrunning may spread into southside VA/Caswell County early Monday before further upstream trough strengthens and kicks this system east. Staying chilly Monday with highs in the 30s most locations, with a northerly wind, mainly under 10 mph. Should see clearing skies with high pressure building in for Tuesday into Wednesday. Zonal flow will keep temps within a few degrees of seasonal norms by midweek. Until then light surface winds and clearing skies should allow temps to drop into the 20s Monday night with some teens in the valleys. Tuesday sees the wind flow turn more south but expect still cool day with highs in the 40s. By Wednesday highs will range from the mid to upper 40s west to lower to mid 50s east as high pressure stays centered over the southern Appalachians and Carolinas. Some models showing precip arriving ahead of next front Thursday morning but think drier air in place will keep main threat after 7am Thursday so keeping it dry Wed night with increasing clouds, and lows in the 30s, though temps may rise toward dawn. && .LONG TERM /THURSDAY THROUGH SUNDAY/... As of 100 pm EST Sunday... Really only one system to deal with showers this period as models are in enough agreement for sfc front to push east across us Thursday. Appears fast enough flow aloft and speed of front will limit amounts but will see best threat of showers during the day. Question of ptype should be answered as looks like enough warm advection ahead of this system to have all precip as rain. Colder air and gusty northwest winds will arrive Thursday night with some upslope component keeping the threat of rain to snow showers around but will see low chance pops. Friday-Saturday will be seasonably cool with highs in the upper 30s to lower 40s west to mid 40s to near 50 east. Lows Friday morning are expected to range from the mid 20s in the higher elevations to lower to mid 30s east, then as high pressure works east the low level flow appears to turn around to the southeast causing similar temps area wide as mixing starts to bring warmer air into the west late. Lows will generally be in the upper 20s to lower 30s, though some lower to mid 20s possible across the deeper valleys. As we head toward Sunday the flow aloft steadily increases from the west southwest while at the surface, high pressure moves from the Ohio Valley to the northeast U.S. A strong frontal system works across the Central Plains toward the Mississippi Valley. Will start to see clouds increase Saturday night and especially Sunday. Question will be in how fast the low levels moisten up. A blend of the extended models leads to slight chance of rain Sunday along the Blue Ridge and southeast. Look for warmer temperatures but not too much above normal Sunday with cold air wedge a possibility. Highs will mainly run in the upper 40s to lower 50s. && .AVIATION /02Z MONDAY THROUGH FRIDAY/... As of 605 PM EST Sunday... Cold front exiting to the east this evening will take the remainder of the residual light precip out of the area overnight. However may still see some upslope driven spotty snow showers or patchy freezing drizzle around KBLF/KLWB through about midnight before moisture becomes quite shallow. However dense freezing fog along with mountain obscurations may linger overnight in these areas where will maintain MVFR to IFR into early Monday. Otherwise looking at a period of mainly VFR to the east of the mountains this evening with MVFR along the Blue Ridge and points west. Bufkit soundings then show some added lowering of cigs elsewhere espcly southern/western sections after midnight as another weak wave slides up the front to the southeast. This may be overdone but given consensus with support from the HREF kept the trend of keeping MVFR cigs at KBCB and perhaps including at KROA overnight, with mainly low end VFR cloud bases across eastern sites. Northerly winds will remain gusty at 15-25 kts this evening before diminishing to around 10 kts overnight. Guidance suggests that low level moisture will be slow to vacate the western sites Monday while clearing in the east as a brief wedge of dry air sinks in east of the Blue Ridge. Just how long to keep sub-VFR cigs espcly KROA westward a bit uncertain as most solutions hold low clouds in until around midday before scattering out under a mid/high canopy. Thus plan to show improvement across the mountains after midday with all locations becoming VFR early to mid afternoon under a drier north/northeast trajectory at 5-15 kts. Should then see mainly VFR Monday night as high pressure slides closer and low level moisture becomes more limited. Extended aviation discussion... Weather conditions are expected to remain VFR for Tuesday into Wednesday under high pressure. Next potential for sub- VFR is Thursday associated with another cold front that will move from west to east across the region. Precipitation associated with this front is expected to be rain with perhaps a period of snow showers and gusty northwest winds across the mountains Thursday evening. Expect a return to overall VFR under diminishing winds on Friday with high pressure building overhead. && .EQUIPMENT... The NOAA Weather Radio in Ashe county at Mt Jefferson remains off the air tonight possibly due to phone line issues. Technicians have been notified but the time that restoration will occur is unknown at this time. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...None. NC...None. WV...None. && $$ SYNOPSIS...JH NEAR TERM...JH/RCS SHORT TERM...WP LONG TERM...WP AVIATION...JH/RCS EQUIPMENT...JH