Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 03/26/19

Area Forecast Discussion
National Weather Service Bismarck ND
939 PM CDT Mon Mar 25 2019 .UPDATE... Issued at 928 PM CDT Mon Mar 25 2019 The main forecast concern continues to be fog potential. Latest RAP forecast soundings continue to indicate a better potential for stratus than fog. Mesoscale models continue to indicate the potential for low visibilities. Currently, Hettinger is the only station in the area with a reduction in visibility and they are 4 miles. See no need to deviate from current forecast with areas of fog, mainly after midnight and no need for a dense fog advisory at this time. We did bump up sky cover in the far west this evening, and decreased clouds a bit after midnight. If sky clears in the far west late tonight we could see some radiational fog but with increasing southwest winds just above the surface, think this potential is also minimal. UPDATE Issued at 533 PM CDT Mon Mar 25 2019 There may be a sprinkle or flurry over the far southwest late this afternoon, otherwise precipitation chances have ended. The main issue tonight for the southwest will be fog development. Mesoscale models are hitting this area pretty hard for fog potential late this evening through tomorrow morning. BUFKIT soundings do suggest more potential for stratus than fog, but for now will monitor. Otherwise just populated latest sensible weather elements and blended to early evening values. Updated text products will be out shortly. && .SHORT TERM...(This evening through Tuesday) Issued at 235 PM CDT Mon Mar 25 2019 A weak shortwave embedded in the upper ridge to our west continues to slide southeast across our far southwest where a slight chance of drizzle, freezing drizzle, or light rain/snow remains over the next couple of hours. Expect more fog to develop overnight across roughly the western third of the state. As the ridge axis begins to move into the state, light southerly flow and abundant moisture at the surface will promote the potential for another Dense Fog Advisory but will defer to the evening shift as trends and guidance should come together a bit better as we reach sunset regarding exact placement. Fog may very well stick around until lunch time before lifting. Clouds should gradually begin to clear across the west through the afternoon. With the ridge axis pushing over the area Tuesday, most of the forecast area will see much warmer temperatures. Western locations will climb to well above average with widespread highs in the 60s and possibly the lower 70s. The one detail that could put a wrench in the high temperature forecast would be cloud cover. We should see enough clearing in the west to reach these temperatures in the northwest but fog has been stubborn to lift over the southwest the past few days and that will have quite a bit of impact regarding temperature potential if it sticks around again. .LONG TERM...(Tuesday night through Monday) Issued at 235 PM CDT Mon Mar 25 2019 Although the ridge starts to flatten Wednesday as a trough swings through the northern stream, mild temperatures will continue. A secondary trough slides in from the west late Wednesday into Thursday, bringing rain or snow chances to the southwest, along with cooler temperatures. Temperatures remain near normal to end the work week going into the weekend. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 928 PM CDT Mon Mar 25 2019 Mainly VFR conditions to begin the 00Z TAF forecast period this evening. The exception is KDIK where areas of fog and stratus are likely to remain through the night, before lifting during the morning on Tuesday. Elsewhere, VFR ceilings this evening will become MVFR late tonight into early Tuesday morning as a weak frontal boundary moves from western into central North Dakota. Winds will remain generally southerly around 5-10kts through the forecast period. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...TWH SHORT TERM...ZH LONG TERM...ZH AVIATION...TWH
Area Forecast Discussion
National Weather Service Blacksburg VA
1056 PM EDT Mon Mar 25 2019 .SYNOPSIS... A cold front will slide to the southeast of the region this evening and then offshore overnight. Drier but cooler weather returns for mid-week as high pressure builds back across the area from the north Tuesday into Wednesday. The high exits offshore later in the week resulting in much warmer temperatures heading into Friday and Saturday. && .NEAR TERM /THROUGH TUESDAY/... As of 1050 PM EDT Monday... Main concern this hour is areas of dense fog developing along and west of the Blue Ridge, especially through the New River Valley and along/west of I-77. Feel this may continue for several hours until drier air advects southwest from northern VA overnight, mainly after 09Z in the west. Thus, issued an SPS to cover the situation. The main area of rain has moved off to the east and may linger a while along our southeastern border, but for the most part is expected to remain south/east of our CWA. Another area of rain associated with the upper trough lingers in the western areas and this should progress toward the New River Valley over the next few hours, then dissipate as the drier air works southeast into this region before daybreak. The New River Valley will likely also see drizzle linger the longest as it becomes a convergence zone between the moist air across the southwest and the drier air approaching from the northeast, at least until around daybreak. Temperatures and dewpoints were pretty well on track, so most adjustments were to shaping the pops better to match the most recent obs and latest runs of the HRRR/NAMNest. One other note, is that northeast winds will become a bit strong and gusty across the eastern areas later tonight, but should remain below wind advisory criteria. As of 630 PM EDT Monday... No major changes are in the plans for the forecast update early this evening. Precipitation is concentrated the greatest across the southern and eastern sections of the forecast area, nearest the departing front. The area near and north of Interstate-64 is experiencing either an end to the rain there, or at the most, has some remaining sprinkles. Light precipitation is still expected to redevelop across this area as we progress into tonight with northeast winds pushing lingering low level moisture upslope into the mountains. The thunder threat has shifted east of the area, so have removed any additional mention from the forecast. Have tweaked hourly temperatures and dew points to better match the current conditions and the expected trends through the evening hours. As of 222 PM EDT Monday... Initial band of showers continues to work east across the region this afternoon and should spill to the southeast of the area this evening. Still some potential for an isolated storm far southeast ahead of the trailing strong upstream shortwave and where seeing faint instability, but iffy at this point. Otherwise will continue with high pops from northwest to southeast through sunset espcly given possible added upstream showers with the main wave aloft to the west. However still appears overall low QPF of around a quarter inch or so. Once the surface wave/front sag to the southeast early this evening will see an influx of increasing low level northeast flow that will progress from northeast to southwest tonight. Models suggest that a convergence zone may develop along the southern Blue Ridge as the upper wave passes while an inverted surface trough develops. This scenario remains uncertain espcly given decreasing depth to the moisture but appears enough to warrant a continuation of higher pops mountains through at least midnight before gradual drying from the north/east wins out. Since similar to the HRRR and FV3, bumped up pops a bit more through the evening west where may change to flurries or spotty light snow before ending late. Think enough drying to preclude much in the way of pops needed northeast, but still cloudy and turning chilly with lows 30s/40s except for a few 20s far north. Upper trough to remain over the region Tuesday as surface low pressure moves east and strong high pressure to the north wedges in east of the mountains. Guidance showing a pronounced shot of drying heading in from the northeast during the day on northerly winds, with only the far southwest perhaps still stuck under some cloud cover during the afternoon before clearing. Otherwise looking at increasing sunshine from northeast to southwest into the afternoon under rapidly decreasing moisture within the column. However will remain cool under the 850 mb cold pool that will result in a rather deep north/northeast trajectory that should hold temps below guidance (mainly 50s) despite the developing sunny skies. && .SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/... As of 230 PM EDT Monday... High pressure center over New York Tuesday night will slide east into Thursday night. Low temperatures Tuesday night will range from the mid 20s in the mountains to the lower 30s in the piedmont under mostly clear skies. As high pressure slides off the Mid-Atlantic region Wednesday, return flow will set the stage for a warming trend across the region. With a dry airmass and good mixing, low afternoon relative humidities are expected Wednesday afternoon with values into the 20 to 25 percent range, with light east to northeast surface winds. The light winds should help alleviate any significant fire weather concerns. Under full sunshine with strong subsidence, high temperatures Wednesday will warm into the mid 40s in the mountains to the mid 50s in the piedmont. Mostly clear skies continue Wednesday night with low temperatures generally in the lower to mid 30s. Warming trend continues on Thursday, high temperatures will climb in the lower to mid 60s with lows mainly in the 40s. Forecast confidence is overall high for this period. && .LONG TERM /FRIDAY THROUGH MONDAY/... As of 230 PM EDT Monday... The surface high pressure will push further offshore Friday allowing deepening warm advection to develop ahead of another cold front which arrives over the weekend. The combination of sunshine under strong ridging/warming aloft per 850 mb temperatures climbing to +10 deg/C or higher should result in above normal temperatures from Friday onward. A weak vort max rotating around the upper ridge may create an isolated shower in northern Greenbrier Friday afternoon. A stronger shortwave and richer moisture ahead of the main cold front may create scattered showers mainly mountains Saturday into Saturday night and elsewhere on Sunday. The models have different solutions with some more progressive and consolidated evolution compared slower and wetter. Decided to utilize WPCGuide with a more progressive system for weekend into early next week. Highs on Friday and Saturday will be from mid 60s to the lower 70s. Low temperatures Friday and Saturday night will be generally in the 40s. High temperatures Sunday will vary from the lower 50s in the mountains to the upper 60s in the piedmont. Cooler temperatures are expected MOnday with highs from around 50 in the west to the lower 60s in the east. && .AVIATION /03Z TUESDAY THROUGH SATURDAY/... As of 715 PM EDT Monday... The main area of precipitation associated with the passing front is now focused across the southeastern sections of the forecast area. And end of precipitation, or at most some lingering sprinkles, was noted across the northern sections around the I-64 corridor and points north. The main area of rain will continue to exit the region to the southeast. However, northeast low level flow will help keep moisture to banked up against the mountains, through most of the night. This will keep, or return, light precipitation to mainly western areas along with keeping sub-VFR conditions in this area. Eventually, the drier air will win out, allowing for a trend to VFR conditions starting mainly after daybreak Tuesday morning in the north once the nocturnal inversion breaks. Lingering low cigs/vsbys will improve from north to south Tuesday morning with most locations bouncing back into VFR under drier north/northeast flow Tuesday afternoon. Confidence in the above aviation forecast is moderate on average. While the general trend is expected to be on target, the specifics reflected in the the individual TAFs as to which which terminals have a better potential to be IFR vs MVFR is more challenging. EXTENDED AVIATION DISCUSSION... VFR under strong high pressure should prevail Tuesday night through Friday with northerly winds gradually becoming southwest by the end of the week. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...None. NC...None. WV...None. && $$ SYNOPSIS...JH NEAR TERM...DS/JH/RAB SHORT TERM...KK LONG TERM...KK AVIATION...DS/JH/PM