Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 05/02/20

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
621 PM CDT Fri May 1 2020 .UPDATE... Issued at 620 PM CDT Fri May 1 2020 Forecast is on track this evening. No major changes are planned. && .SHORT TERM...(This Evening through Saturday Night) Issued at 247 PM CDT Fri May 1 2020 Forecast challenges revolve around fire weather concerns on Saturday. Currently, breezy to windy northwest winds have overtaken pretty much the entire CWA now, behind a cold front that has passed over into MN. Under a mostly sunny sky, temperatures have warmed into the 70s and 80s everywhere except portions of north central South Dakota where the cold front had moved through earlier this morning. There, temperatures have only been able to muster 60s to around 70 degrees for many locations. There`s also been more low level/boundary layer moisture around today, so that has helped to offset the warmer temperatures, keeping afternoon relative humidities generally between 30 and 55 percent. Between now and late Saturday night, the only place currently holding any precipitation potential is the far southwestern forecast zones later tonight into Saturday morning, where a little bit of light showery potential will exist when the next area of low pressure lifts out across the central plains. Mainly, the concern heading into Saturday is how dry the airmass will be that advects into the CWA tonight into Saturday behind the cold front that has moved through the forecast area today. RAP model boundary layer RH/mixing tool rh values suggest a good portion of the CWA could be dealing with RH values Saturday afternoon less than 30 percent (some areas close to 20 percent). BUFKIT suggests there could be some gusts of 20 to 25 mph Saturday afternoon, mainly along/north of a line from Britton to Clear Lake. Coordination resulted in a Fire Weather Watch for Big Stone and Traverse Counties in Minnesota for Saturday afternoon. Overall, Red Flag conditions at this point do not appear to be a slam dunk for any fire weather zones on Saturday. But, if conditions like that could materialize, the highest confidence/greatest potential for it right now is across the far northeast tip of South Dakota over into west central MN. Temperatures over the next 36 to 48 hours will remain, generally, near to above normal. But, the cooling trend will become more noticeable by late Saturday night heading into the second half of the weekend, due to a "back-door" cold front progged to push south and east into the CWA Saturday evening/night. Shallow cold airmass temps from the surface to 925hpa suggests temperature recovery into the 70s may be tough to come by for a few days after Saturday. .LONG TERM...(Sunday through Friday) Issued at 247 PM CDT Fri May 1 2020 The pattern starts with a ridge overhead Sunday, with high pressure centered in Canada with a surface ridge extending down along the Red River Valley, and low pressure in Montana. Dry initially, southerly flow becomes more pronounced into the evening, with a plume of "moisture" moving up into the Dakotas. Dewpoints reach near 50 at the surface with NAM profiles suggesting this moisture is mixed through the boundary layer by the time it arrives. MUCAPE will peak between 500-1500 j/kg, with that maximum along a north south front that moves across the CWA Monday. Environmental winds below 400mb are 30kts or less, which will limit the severe weather threat. The GFS has a much stronger low compared to other deterministic members at this point. There is evidence for a wave following mid-week as an upper low develops over eastern North America, but deterministic guidance is somewhat divergent on handling these weak features. As for temperatures, will stay continued seasonal with a partial cool down early Sunday for the northeast CWA with a backdoor front. && .AVIATION...(For the 00Z TAFS through 00Z Saturday Evening) Issued at 620 PM CDT Fri May 1 2020 VFR conditions are expected through the period with breezy northwest winds. ***Construction to improve the taxiway for runway 13 at the KPIR terminal may cause an occasional temporary visibility reduction due to blowing dust (bldu), mainly during daytime hours UFN. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...None. MN...Fire Weather Watch from Saturday afternoon through Saturday evening for MNZ039-046. && $$ UPDATE...Wise SHORT TERM...Dorn LONG TERM...Connelly AVIATION...Wise
Area Forecast Discussion
National Weather Service Bismarck ND
936 PM CDT Fri May 1 2020 .UPDATE... Issued at 922 PM CDT Fri May 1 2020 Skies are clearing in broad subsidence as seen on the water vapor loops this evening. Current surface features have high pressure across Montana sliding southeast tonight. Winds are diminishing as the surface becomes decoupled from the boundary layer winds. Current forecast looks good for tonight. Friday looks like a near critical fire weather day across central and northwest North Dakota. New evening runs of the HRRR model have dewpoints into the lower to middle 20s. However, the stronger surface winds will be across the north central, not where the lowest afternoon Relative Humidity is forecast, which is more southwest. So agree in holding off on any fire weather watches or warnings at this time for Saturday afternoon. UPDATE Issued at 633 PM CDT Fri May 1 2020 Latest sounding data taken at 6 pm CDT shows a well mixed atmosphere up through nearly 10k ft MSL at Bismarck. The Mid level water vapor channel shows the strongest subsidence lies across southwest North Dakota spreading northeast into south central North Dakota. The main feature in the short term will continue to be gusty winds to 30 mph for a short period early this evening. By mid evening the winds will generally be less than 15 mph. Skies will clear as the area of weak subsiding air spreads across the region tonight. Current forecast looks ok. && .SHORT TERM...(This evening through Saturday) Issued at 204 PM CDT Fri May 1 2020 Latest suite of satellite imagery shows a departing shortwave trough sliding through southern Manitoba this afternoon with weaker shortwaves trailing back into northeast Montana and western North Dakota. Isolated scattered showers still possible through this afternoon, but most areas will be dry and windy. Expect a clearing sky tonight followed by a plethora of sunshine Saturday. Lows tonight will be in the upper 30s west to mid 40s south central. Highs Saturday will be in the upper 60s to lower 70s. Northwest winds 15 to 25 mph along and east of the Missouri River early in the afternoon will weaken through the afternoon. .LONG TERM...(Saturday night through Friday) Issued at 204 PM CDT Fri May 1 2020 A backdoor cold front grazes the James River Valley Saturday night into early Sunday morning. Nothing significant with this feature. Mid-upper level ridge will be moving overhead Saturday night into Sunday morning, keeping conditions dry. However, a shortwave trough in southwest flow aloft will impinge into western North Dakota Sunday afternoon resulting in showers thunderstorms. The GFS shows a narrow ribbon of most unstable cape around 1000 J/kg, deep layer shear of 35kt- 40kt, and favorable lapse rates in the far southwest Sunday afternoon. Will continue to monitor these trends for any changes and possible severe threat during late Sunday afternoon southwest. Otherwise, an area of primarily showers migrate across western and central North Dakota Sunday night into early Monday morning. A stronger upper low and associated shortwave trough both advertised differently in the GFS/ECMWF deterministic solutions. The ECMWF essentially is dry, while the GFS advertises one to two inches of rainfall across southern North Dakota. The GFSEnsembles are much lower, averaging around a quarter of one inch. WPC qpf has backed off from eight tenths over Bismarck now down to about a third of an inch. This is more in line with the GFSEnsemebles but still higher than the deterministic ECMWF. Much uncertainty continues on precipitation amounts at this time. Once this system departs, northwest upper flow will become dominate with a couple of strong shortwaves and much cooler air for the rest of the week. Temperatures will be below normal, as depicted on the CIPS Analog. The first push of precipitation and cooler air arrives Thursday. Another push is slated for the weekend. && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) Issued at 633 PM CDT Fri May 1 2020 VFR expected at all TAF locations. Surface high pressure across Montana will move east tonight and Saturday. Initial gusty northwest winds will diminish this evening. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...WAA SHORT TERM...KS LONG TERM...KS AVIATION...WAA
National Weather Service Hastings NE
624 PM CDT Fri May 1 2020 .SHORT TERM...(This evening through Saturday) Issued at 210 PM CDT Fri May 1 2020 A weak front...more like a winds shift is moving across the forecast area today. As of 2pm it is through the Tri-cities and is on its way southeast. Skies are clear and insolation is plentiful. Mixing behind the front and plentiful insolation have helped temps soar into the 80s for most locations by 2pm. Highs in the mid- upper 80s looks to be on track...maybe a 90 degree may peek its head in, but don`t expect it to be widespread at this time. A very weak wave is expected to move across the High Plains and with plentiful insolation some thunderstorms are expected to develop across Colorado, Wyoming and the NE Panhandle. However, as the sunsets, this weak disturbance will struggle to provide much in the way downstream. Expect much of the activity to diminish before it reaches the GID forecast area, but have kept a small chance for areas to the west and north. Now the 12 NAM and NAMnest disagree and do pull quite a bit of QPF over south central Nebraska. But throughout the morning, the high-res HRRR runs, do not support this happening. Overnight, the main area of concern looks to remain north of the forecast area. Instability will be greatest to the not expect much for thunder, and no strong to severe storms tonight. If you get rain...count yourself among the lucky...most will likely remain dry. Saturday will be cooler than today, as cloud cover will persist across portions of the area. One question if this activity tonight remains as far to the north as it seems...will the whole area be socked in. Think there could be breaks tomorrow, which could help temperatures increase a bit beyond currently forecasted. Winds will be north to northeasterly and breezier than today. Highs ranging from the mid 60s to the upper 70s are possible...and of course an increase of sunshine may increase these. .LONG TERM...(Saturday night through Friday) Issued at 210 PM CDT Fri May 1 2020 An active pattern through the extended forecast. The cold front that moved through today will continue to slide southward through Kansas. This will keep the focus of the majority of precipitation to our south. While model blends include pops for the whole area Saturday night into Sunday....feel it`ll likely be dry for most with the better chances across KS. A disturbance will move across the Northern Plains and may develop precip Sunday night into Monday and right now that looks like the best shot in the first few days of the forecast. Temps for the weekend look to be in the 70s for most of the area...a pleasant spring weekend. Another...stronger disturbance will in behind the first one Monday morning and bring another decent chance for precipitation...there are some discrepancies on timing of this wave, with the EC being faster than the GFS/NAM. Behind this wave...mid-week surface high pressure will build in. Yet another disturbance moves in for the end of the work-week and will bring another chance for precip. With discrepancies earlier in the week...won`t worry to much about this period now. Overall temps are expected in the 70s through the workweek with lows in the 40s. && .AVIATION...(For the 00Z KGRI/KEAR TAFS through 00Z Sunday) Issued at 616 PM CDT Fri May 1 2020 Anticipate VFR conditions through the forecast period. A mid level disturbance to the west has triggered a few tstms that have moved into the Neb panhandle and northeast CO. There is a slight chance these could hold together and move into the terminal areas after midnight but at the moment chances look to be twenty percent or less so will leave out mention for now. Winds expected to remain northerly overnight and could be on the gusty side Sat morning. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ SHORT TERM...Billings Wright LONG TERM...Billings Wright AVIATION...Ewald
Area Forecast Discussion
National Weather Service New York NY
1149 PM EDT Fri May 1 2020 .SYNOPSIS... A surface trough continues to shift east of the region tonight. High pressure then builds in Saturday. A series of fronts then cross the area Saturday night through Monday. High pressure builds in for Tuesday, but weakens at night into Wednesday morning as low pressure passes to the south. High pressure rebuilds thereafter through Friday. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... Upper level trough and surface trough move east of the region overnight. Along the trough axis, some upper level forcing as evident from model forecast fields of mid level positive vorticity advection. NAM12 and HRRR both still indicate some possible shower development along part of the axis, mainly for Long Island and Southern Connecticut. While trends earlier this evening decreased with shower coverage, did not remove it from forecast altogether with isolated to widely scattered rain showers, again mainly for Long Island and Southern Connecticut. Otherwise, made minor adjustments with hourly temperatures, dewpoints, winds, as well as cloud coverage to better match observed trends. Expecting some gusts to occur overnight up to near 20-25 mph. Along with some broken cloud coverage heading into the overnight, this will mitigate radiational cooling. Winds shifts out of the northwest behind the trough and much drier air works its way into the forecast area. Dew points fall 10 degrees overnight into the 40s. This coupled with clearing skies will cause ambient temperatures to settle around 45-50 degrees prior to sunrise. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/... With the trough well off to the east by Saturday morning mid level heights begin to build and the resulting subsidence clears out skies setting up a pleasant day. Model soundings have the 925 mb temperature around 11-12C near 700-800m. Meaning once mixing begins in the late morning and early afternoon, we could see temperatures in the upper 60s and low 70s. This would be our first chance to reach 70 degrees in over a month. Conditions change towards the evening. Once the surface ridge axis makes its way across southern New York, winds shift out of the south allowing for moisture to return to the region. Precipitable water values jump from 0.50 inches to 1.00 inches after midnight. Priming our area for showers. The main forcing mechanism will be from a weak elongated cold from extending from a broad low pressure system in southwestern Quebec. This low travels rapidly east aided by a 110 kt upper level jet located over the Great Lakes. As such scattered showers will likely be quick moving only permitting 0.10- 0.20 inches of accumulation at the most. Temperatures overnight Saturday night into Sunday should be mild remaining in the low 50s. && .LONG TERM /SUNDAY THROUGH FRIDAY/... A chance of showers lingers during Sunday morning as an occluded or weak cold front exits to the south and east. This will lead to partial clearing and dry conditions in the afternoon. Westerly winds through the boundary layer should allow mixing up to 850mb where temps are forecast to be 9-10C. Not confident to go with "full sun" potential highs, but mid to upper 70s seem reasonable for parts of the city and NE NJ. The rest of the forecast area likely ends up mostly 70-75, but WSW winds over/near the Twin Forks and SE CT should hold temps in the 60s. The SE progression of the frontal boundary to our south will be fairly slow, and some models indicate an increase of moisture convergence along this boundary Sunday night. This will bring a chance of rain Sunday night, with the higher chances being over southern portions of the forecast area. A cold front drops south through the region most likely during the morning on Monday, followed by cyclonic flow aloft as shortwave energy sharpens a longwave trough over the Northeast. Moisture is fairly limited throughout the day, but cannot rule out a shower at any point through the day with these features. High temperatures will return to near normal. High pressure builds back in for Tuesday with a dry day and highs around 5 degrees below normal. Models are then split regarding the position of low pressure emerging off the East Coast Tuesday night into Wednesday morning. Will introduce a slight chance of rain for the time being for Tuesday night and Wednesday. High pressure then builds for Thursday and lasts at least into part of Friday with highs generally in the 60s. && .AVIATION /04Z SATURDAY THROUGH WEDNESDAY/... Low pressure moves east of the region tonight with high pressure to follow through Saturday. VFR conditions expected through the TAF period. Only exceptions would be a low chance for MVFR for KISP, KBDR and KGON before 08Z as well as a low chance for MVFR late in TAF period with showers ahead of next low pressure system. Winds will become more NW and increase a few kts late tonight to a 10-12 kt range. Some gusts to near 17-20 kt are forecast into the overnight. These winds continue into Saturday and increase slightly in the afternoon. Gusts will develop as well Saturday, reaching near 20 kt. Winds expected to back to more W-SW for coastal locations during the afternoon. .OUTLOOK FOR 00Z SUNDAY THROUGH WEDNESDAY... .Saturday night...Chance of showers with MVFR possible late. Gusts subside early. .Sunday...Chance of showers with MVFR possible early for Long Island/Southern CT, otherwise VFR. .Sunday night...Chance of showers with MVFR possible, mainly NYC metros/Long Island. .Monday through Wednesday...Mainly VFR. NW winds G15-20kt Monday. && .MARINE... Northwest winds 10-15 kts with gusts up to 20kts are expected to maintain their speeds overnight. Seas should remain elevated around 7 to 10 feet overnight and 6 to 8 ft most of Saturday on the ocean. As such the SCA remains in effect through Saturday on the ocean. By Saturday night, seas begin to diminish below SCA criteria and winds 10-15kts become more southwesterly. SW winds on Sunday diminish in the afternoon, then veer NW behind a cold front on Monday and increase. Winds and seas through this period are expected to prevail below advisory criteria. High pressure builds in on Tuesday with a storm passing well south of the waters Tuesday night into Wednesday morning. The storm will shift winds from NW to ENE, but at this point the storm still looks far enough south to prevent winds and seas from increasing to advisory criteria. && .HYDROLOGY... No hydrologic impacts are expected through the forecast period. && .EQUIPMENT... NYC NOAA Weather Radio Station KWO35 (162.55 MHz) is undergoing its final stages of testing, and is operating at full power. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...Small Craft Advisory until 6 PM EDT Saturday for ANZ350-353- 355. && $$ SYNOPSIS...JC/DJ NEAR TERM...JC/DJ/JM SHORT TERM...DJ LONG TERM...JC AVIATION...JM MARINE...JC/DJ/JM HYDROLOGY...JC/DJ EQUIPMENT...
Area Forecast Discussion
National Weather Service Blacksburg VA
754 PM EDT Fri May 1 2020 .SYNOPSIS... Clouds and scattered showers will gradually decrease as high pressure builds over the region Saturday and brings a trend for warmer temperatures this weekend. A cold front will then bring a chance for showers and thunderstorms back to the forecast later on Sunday, followed by cooler and unsettled conditions through the middle of next week. && .NEAR TERM /THROUGH SATURDAY/... As of 754 PM EDT Friday... The upper trough will move east tonight allowing ridging to build in from the west. High pressure will build across the Southeast tonight into Saturday. The HRRR and NAMnest showed showers tapering off tonight as the upper low pulls off to the east and instability wanes with loss of solar heating. Made some minor adjustments to temperatures for tonight utilizing the latest surface obs, their trends, and blended in the NBM. Low temperatures tonight will vary from the mid 30s in the mountains to the mid 40s in the piedmont. As of 200 PM EDT Friday... Satellite and radar show considerable cloudiness west of the Blue Ridge with scattered showers. Even had some reports of wet snowflakes down to the lower elevations. Conditions a bit better east of the Ridge still looking partly sunny at best with some isolated showers. Expect scattered/widely scattered showers will persist for the rest of the afternoon and some isolated thunder can not be ruled out especially across the piedmont. Showers will then diminish this evening as the upper low pulls off to the east and instability wanes with loss of heating, through some upslope showers will linger for a bit in the mountains. Winds will also remain blustery before lessening this evening. Anticipate a chilly night but believe there will be enough wind to mix the air to avoid frost/freeze issues. High pressure builds over the Appalachians and central mid Atlantic region Saturday with quiet and warmer conditions to start the weekend. Temperatures tonight will generally be in the lower 40s east of the Ridge, mid/upper 30s to the west. Highs on Saturday will be in the low/mid 70s east, upper 60s/near 70 west. && .SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/... As of 200 PM EDT Friday... Approaching low pressure from our NW Saturday night will start to increase moisture aloft, brining clouds in starting off for our WV counties. As this low/front approaches, high pressure to our south shifts off the coast/moves further south. This makes way for the front to arrive late Sunday into Sunday night. While timing of it is not agreed on, all guidance does agree that this line starts to dry up as it pushes through the region, meaning the west will receive the greatest rainfall (~.5"). Overall, there looks like there should certainly be some thunderstorms mixed in with this front with ~500J/KG of CAPE and modest shear. However, it looks like the two players will be out of phase with shear decreasing when instability increases. Because of this, no foreseeable severe risk, just general thunderstorms. After the front passes, it stalls to our south, so cloud coverage is still questionable for MOnday. With this update I am going with the optimistic side and mostly clearing everyone out for a majority of Monday, but its possible for clouds to hang out both on the southern side and along the western slopes. Temperature wise Monday, we do cool off slightly from the front...but not by much since it will barely have just made it south of us. A new system approaches from our west Tuesday, looking to first bring a warm front into the region early in the day. This will bring our first round of rain for the day. Our second round will come later in the day when the associated cold front arrives. This is another scenario where overall, it looks like we should just get some thunderstorms out of the system. Likewise, the front looks to become more anemic as the low shifts northward, meaning decreased rainfall for the east. && .LONG TERM /TUESDAY THROUGH FRIDAY/... As of 200 PM EDT Friday... Thanks to Tuesday`s system, cooler weather arrives for the remainder of the forecast. 50-70 will be the highs and lows will be mid 30s to mid 40s after Tuesday night. That said, with the growing season started in the west now, frost/freeze headlines look possible at this point for Wednesday and Thursday AM. Current temperature look warm enough at the moment that most upslope showers that develop Thursday on the backside of Tuesday`s system will be rain showers, but a few high elevations could maybe get a few flakes, similar to what we are seeing today. Another system is poised to arrive mid to late day Friday, bringing a new round of rain, but not before helping try to usher in a warmer airmass ahead of it. && .AVIATION /00Z SATURDAY THROUGH WEDNESDAY/... As of 739 PM EDT Friday... Expect VFR conditions to dominate east of the Blue Ridge while MVFR holds tough to the west with IFR for the higher elevations into KBLF. Scattered showers or pocket of drizzle will linger into this evening, then gradually taper off tonight into Saturday morning. Conditions will become VFR at all sites Saturday morning and continuing into Saturday afternoon. Gusty winds this evening will subside with loss of heating tonight. Generally light winds overnight, though still some gusts may linger on the hilltops. Medium confidence in ceilings,visibilities and winds during the taf period. Extended Aviation Discussion... An upper disturbance across the midwest will race eastward and push a west-east oriented frontal boundary into the TN Valley and Mid-Atlantic region Sunday. There are considerable differences with respect to how far south the front will travel before stalling in the zonal flow aloft. GFS stalls the front across the region Sunday-Monday awaiting another disturbance by Tuesday. Meanwhile, the ECMWF pushes it further south into the Carolinas before it stalls. This leaves us with an unsettled pattern. Temperatures and dewpoints rise enough to result in a rather unstable air mass in place by Sunday afternoon. CAPES could be near 1000 J/KG and scattered thunderstorms Sunday afternoon seem like a good possibility given either the GFS or ECMWF scenario at that point. Expect VFR conditions much of Sunday in the east to MVFR in the west, but greater likelihood of convection and sub- VFR conditions throughout the area Sunday afternoon. Wind does not appear to be an issue through the period with no major low/high pressure areas expected to impact the area. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...None. NC...None. WV...None. && $$ SYNOPSIS...MBS NEAR TERM...KK/MBS SHORT TERM...RR LONG TERM...RR AVIATION...KK/MBS