Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 09/01/19

Area Forecast Discussion...Updated
National Weather Service Billings MT
848 PM MDT Sat Aug 31 2019 .UPDATE... Upper ridge over the southern Rockies was keeping southern Montana and northern Wyoming dry. No updates. TWH && .SHORT TERM...valid for Sun and Mon... Water vapor imagery showed moisture moving ESE along the Canadian border. Observations showed this moisture was a mix of mid and high clouds. Visible satellite imagery showed stratus E of the Dakotas` border. This stratus and fog was over SE MT earlier today. There was some question of the stratus and fog returning to the SE late tonight. Latest HRRR and other models keep stratus mostly out of the area through the night so just went with a few clouds over the far SE. Ensembles were in good agreement in building a strong ridge over the area through Sunday. Sunday will be hot and dry with temps in the low 90s in many areas and RH`s from the teens W to the low 30s E. Winds will not be overly strong. Models hinted at possible QPF in the SE Sun. evening due to an inverted trough and low-level jet. NBM supported this with a slight chance over KBHK so included it in the forecast. Looking at GFS soundings, which have been reliable with their RH`s/Td`s, noted that RH recoveries will not be very good central and W Sun. night. In addition, RH`s looked very low in these areas on Monday, with a cold frontal passage from the N expected in the afternoon. Mixing on Mon. will be up to 550 mb in KLVM, and 600 mb in KBIL and KSHR. This will promote hot, dry and windy conditions, with windy conditions persisting into Mon. evening behind the front. Given the above, went below the NBM for RH`s and above it for winds. Used a GFS/ADJMAV model blend. An upper trough moves in Monday into Monday night. Noted that ensembles showed a little uncertainty in the timing/placement of the trough. There was decent Integrated Water Vapor transport in the trough area, so there will be moisture, with a chance of thunderstorms across the area Mon. evening, decreasing overnight. Noted a lot of shear Mon. night, but not much CAPE. Area was outlooked for only General Thunderstorms. Temps on Monday will reach the upper 80s to low 90s with RH`s in the teens central and W, and in the 20s to low 30s E. If fuels were drier, would be considering a RFW for portions of the area, but for now, will continue the headlines in the Fire Weather Forecast. Arthur .LONG TERM...valid for Tue...Wed...Thu...Fri...Sat... Tuesday will be dry and cooler behind the cold front that will move through Monday. Highs will temporarily drop into the 70s, but by Wednesday highs will be back into the mid to upper 80s. By Friday another wave will move up into the area. As it does, PoPs will be increase with some afternoon thunderstorms possible and temperatures will cool back into the upper 70s to lower 80s. Showers and afternoon thunderstorms will continue into the weekend with highs in the 70s. Reimer && .AVIATION... VFR conditions expected over the next 24 hours. Reimer && .PRELIMINARY POINT TEMP/POPS... Sun Mon Tue Wed Thu Fri Sat ----------------------------------------------------------- BIL 059/093 062/092 054/077 052/089 057/088 059/080 054/077 00/U 01/U 41/U 10/U 11/U 22/T 33/T LVM 051/091 053/088 046/079 046/088 051/086 052/079 048/076 00/U 01/N 31/U 10/U 12/T 44/T 53/T HDN 056/092 060/090 052/075 050/087 055/088 056/079 052/076 00/U 00/U 41/U 10/U 00/U 22/T 32/T MLS 058/090 062/087 053/072 049/084 055/086 055/076 051/073 00/U 10/U 30/U 10/U 10/U 12/T 32/T 4BQ 057/091 061/090 052/072 048/084 054/086 055/077 051/073 00/U 00/U 31/U 10/U 00/U 22/T 42/T BHK 054/087 058/087 051/069 046/081 052/083 051/073 047/069 00/U 21/B 30/B 01/U 10/U 12/T 32/T SHR 054/092 058/092 052/075 048/086 053/087 054/079 051/076 00/U 00/U 31/U 11/U 11/U 33/T 44/T && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...None. WY...None. && $$
Area Forecast Discussion
National Weather Service Quad Cities IA IL
643 PM CDT Sat Aug 31 2019 ...AVIATION UPDATE... .SYNOPSIS... Issued at 248 PM CDT Sat Aug 31 2019 It`s been a fairly pleasant day across much of the region as we close out Meteorological Summer. As of 2 pm, temperatures ranged from 66 in Macomb, to 74 the Quad Cities. Skies featured increasing cloud cover. Across northern Iowa to southwest Wisconsin, scattered sprinkles and rain showers were falling as a result of an upper level shortwave passing over southern Minnesota and northern Iowa. Thankfully, as our extra balloons for Hurricane Dorian support have shown, there is plentiful dry air in the low and mid levels of the atmosphere over our neck of the woods, keeping coverage from isolated to near nil. && .SHORT TERM...(This Evening through Sunday) ISSUED AT 248 PM CDT Sat Aug 31 2019 Main short term concerns are chances of precipitation for the rest of the day and tonight. All global models are in agreement of the aforementioned shortwave passing across the region later this evening and tonight. This, combined with increasing theta-e advection from southerly return flow, should help generate lift and saturate the dry low levels to gradually increase rain shower chances as we head through the late evening into tonight. Think some CAMs like the HRRR are a bit overdone on precip as they initialized much warmer air and higher dewpoints than observed, even with clouds being overhead much of the day. In addition, there isn`t much instability to work with due to poor low to mid level lapse rates, so chances of thunderstorms are low. Still expecting some scattered showers and have handled this with high end chance of POPs for now in the grids. Patchy fog will also be possible with the increasing moisture at the surface. Locations that do see rain may have amounts of a few hundreths to a tenth of an inch, which will be a nice little welcome relief for those in the moderate drought area. Expecting lows to be a little warmer than last night with increased cloud cover and dewpoints, and currently advertise upper 50s along Highway 20, to low to mid 60s to the south. Leftover rain showers, clouds and areas of fog will decrease in coverage from west to east late Sunday morning, with subsidence from high pressure allowing clouds to break by the afternoon and evening. Lowered temperatures a little bit from previous forecasts due to expected prolonged cloud cover, and now advertise highs in the upper 70s to near 80. Regardless, we will be right around normal as we kick off Meteorological Fall. .LONG TERM...(Sunday Night through Saturday) ISSUED AT 248 PM CDT Sat Aug 31 2019 Summer-like heat and humidity now looks likely to a make a brief come back for the start of the work week, followed by a return to below normal temperatures and dry conditions. Tuesday`s highs could push 90 in some locations with dewpoints possibly back in the 70s. Sunday night through Monday: Passing high pressure will be followed by a south to southwesterly low level return flow warm, leading to lows in the 60s, then highs in the lower to mid 80s. A strong upper level trough moving across Canada and associated surface low passing from the Dakotas to Great Lakes will draw much warmer 850 mb temperatures northeastward out of the western U.S. ridge into the local area for late Monday into Tuesday. A wedge of 850 mb temperatures progged as high as 20 to 22 degrees C would support high in the upper 80s to around 90 from I-80 southward, while the north may at least reach the mid 80s on Tuesday. Brisk southwest winds at the surface should draw in dewpoints in the upper 60s if not lower 70s, for a July-like feel. Will have low chance pops across the north from Monday night through Tuesday morning, where there is a low confidence potential for convection along the edge of the stronger thetae advection focused further north and west. SPC has a marginal threat for severe storms north of highway 20 for Monday night, but the main severe weather potential looks to be further north, where there will be greater shear and better low level convergence. A better potential for widespread showers and thunderstorms will arrive with the cold frontal passage in the afternoon or early evening hours Tuesday. Surface high pressure and a northwest flow aloft follow for Wednesday through Friday, bringing back similar conditions as the past several days with highs in the 70s and low in 50s, and perhaps even a few upper 40s in the northeast Wednesday morning. Saturday, there is good model consensus depicting the next cold front advancing through the area and the next chance for showers and thunderstorms, which are kept at slight chances for now. && .AVIATION...(For the 00Z TAFS through 00Z Sunday Evening) ISSUED AT 639 PM CDT Sat Aug 31 2019 The combination of a weak upper level trough and northward progression of a warm front will generate light rain or sprinkles this evening, but conditions generally should remain VFR. However later tonight, weak flow and abundant moisture will support development of fog and low clouds. MVFR conditions should prevail, but the risk of IFR ceilings will exist mainly from around the Quad Cities south and east. By mid-day ceilings and visibilities across the area should improve to VFR. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && $$ SYNOPSIS...Speck SHORT TERM...Speck LONG TERM...Sheets AVIATION...Wolf
Area Forecast Discussion
National Weather Service Hastings NE
651 PM CDT Sat Aug 31 2019 .SHORT TERM...(This evening through Sunday Night) Issued at 224 PM CDT Sat Aug 31 2019 A shortwave and the associated thunderstorms have largely passed to the southeast of the area as of early afternoon. The HRRR still shows a few showers developing over the north which would likely be diurnally-driven. I kept some low-end PoPs in to account for this, but I think that any impacts will be minimal. Tonight, low clouds will move back in. The HREF and SREF still hint at some fog developing in the area, so I maintained a mention of patchy fog. Due to the cloud cover, I do not think that it will be widespread or dense, though. Sunday will be notably warmer than today as skies slowly clear out. Highs are expected to return to the 80s for the entire area. This warmup will occur as ridging expands over the Rockies. Despite the rising heights aloft, a subtle perturbation is forecast to move into northern and central Nebraska late Sunday night, possibly allowing for a few thunderstorms. With 25-35 kts of effective shear, an isolated strong storm is possible if these storms develop. .LONG TERM...(Monday through Saturday) Issued at 224 PM CDT Sat Aug 31 2019 The main story of the upcoming week is that it will be mostly dry. Many locations have had excessive rain over the past couple weeks, so a dry forecast should be a welcome sight for most. Labor Day should be the warmest day of the week with highs in the upper 80s and 90s. A fairly strong front is expected to move through the area on Tuesday. This will lead to a cooldown and strong northerly winds. Gusts to 30 MPH are likely. A few showers and storms could also develop along this front Tuesday night, mainly over southern portions of the forecast area. High pressure moves into the area on Wednesday, leading to a pretty cool and fall-like day. Highs are only forecast to reach the low 70s for most of the area. Overnight lows are expected to be in the 50s, and could even dip into the 40s in some areas. Slightly warmer weather then returns for Thursday and Friday, and the weather should remain quiet in the local area. Another front then moves through the area Friday night into Saturday, bringing a chance for rain and thunderstorms to the area. Deterministic models disagree on the strength and exact timing of this feature though. && .AVIATION...(For the 00Z KGRI/KEAR TAFS through 00Z Sunday) Issued at 649 PM CDT Sat Aug 31 2019 VFR conditions are expected this evening, but we could see the cloud deck lower as we near dawn with indications that we could see at least a few hours of MVFR if not IFR conditions around sunrise or just after sunrise. Ceilings should lift and clouds scatter out by late Sunday morning. && .GID WATCHES/WARNINGS/ADVISORIES... NE...None. KS...None. && $$ SHORT TERM...Mangels LONG TERM...Mangels AVIATION...Wesely
Area Forecast Discussion
National Weather Service Goodland KS
523 PM MDT Sat Aug 31 2019 .SHORT TERM...(Today through Sunday night) Issued at 145 PM MDT Sat Aug 31 2019 Overview: Modest NW flow aloft will prevail over the Tri-State area, on the NE-ENE periphery of an upper level ridge centered over the Desert Southwest/4-Corners. Today-Tonight: An impressive MCV spawned by widespread convection early this morning continues to track southeast toward Wichita early this afternoon. Subsidence in the wake of this feature will gradually fade as it gains distance and progresses into southeast KS this afternoon. However, 18Z SPC mesoanalysis data (H7-H4 DPVA, in particular) suggests that subsidence may persist in assoc/w another cyclonic feature -- subtle and difficult to pinpoint in WV imagery, as it may be -- as it progresses southeast through northwest and north-central KS during the early-mid afternoon. Aside from differential heating along the slopes of the Colorado Front Range, little if any forcing can be discerned over the region today. Although steep mid-level lapse rates and residual low-level moisture (H85 dwpts ~16C) will likely support moderate diurnal destabilization (1500-2000 J/kg MLCAPE) by peak heating, lingering convective inhibition (50-150 J/kg CINH), lingering subsidence, and scarce/anemic forcing are expected to preclude convective development over the Tri-State area. With steering flow from the NW at 15 knots, it`s conceivable that isolated Front Range convection could propagate downstream into eastern CO (i.e. Cheyenne county) this evening, though simulated reflectivity forecasts from recent runs of the HRRR suggest activity will initiate along/south of Colorado Springs -- and that downstream propagation would be confined to southeast Colorado. Sun-Sun night: With little change in the synoptic pattern, expect conditions similar to (albeit several degrees warmer than) today. Anemic forcing is anticipated to preclude convective development over the Tri-State area -- and simulated reflectivity forecasts via the HRRR and NAM NEST suggest little if any upstream development will occur in CO/WY/NE during the late aft/eve. With this in mind, will continue to indicate a dry forecast. It should be noted -- particularly in NW flow aloft -- that thermodynamic/ kinematic profiles will remain conditionally supportive of organized severe convection. .LONG TERM...(Monday through Saturday) Issued at 105 PM MDT Sat Aug 31 2019 For the extended period the National Blended Model (NBM) is showing a dry pattern for the work week, with the exception of Tuesday, for the local area. Followed by another round of showers/thunderstorms activity next weekend. For the most part the models do agree with the NBM; however, Tuesday could end up being dry as well. The models show an upper- level ridge being the main influence for the region for the extended. On Tuesday they have a long wave trough moving over the northern High Plains with an associated surface front. The tail end of this front should pass through the local area and cool us off during midweek. The question remains if it will produce any precip with it. A couple more model runs are needed to know for sure. For next weekend it looks like another longwave will follow suit. Unlike the passing trough/front on Tuesday, the NBM is more aggressive with this one. However, the models are not in agreement at all this far out. So staying with the MBM at this time. At this time, Monday will see highs reach the upper 90s before dropping into the middle 70s to lower 80s by midweek, after the front passes through. Follow by a climb into the middle 80s by Friday. Overnight lows will start out in the lower to upper 60s on Monday and Tuesday night then drop into the middle 50s for the rest of the period. && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) Issued at 518 PM MDT Sat Aug 31 2019 VFR to IFR conditions forecast for the TAFs. Low ceilings will move in around 6z for both sites as low clouds move up from the south. The low ceilings will linger until mid to late morning then shift east of the TAF sites. The lowest ceilings will occur by 12z. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...VINCENT LONG TERM...BW AVIATION...JTL
Area Forecast Discussion
National Weather Service Wichita KS
657 PM CDT Sat Aug 31 2019 .SHORT TERM...(This evening through Tuesday night) Issued at 324 PM CDT Sat Aug 31 2019 Morning remnant convection over south central KS continues to wane as the afternoon progresses, as low level moisture transport is lost. Latest satellite and 88d mosaic shows a very pronounced meso vort center (MCV) west of Kingman is currently making its way SE and will probably trekking into nrn OK for the late afternoon hours. Lots of available instability for this MCV to work with, as most of south central KS got worked over by last nights complex of storms. So think the MCV will continue to drift southeast, possibly leading to renewed surface based convection as it moves into southern OK early this evening. Easterly low level flow will lead to dry and somewhat pleasant evening for most of the area, with any lingering sprinkles ending by late this afternoon. Latest RAP shows low level moisture transport again to trys to increase across the panhandle of OK into SW KS late evening, with some scattered nocturnal convection expected to develop over wrn and NW KS. Think Latest hi-res model solutions are not very bullish on renewed convection even coming close to the forecast area, keeping any overnight convection well to the west of the area, as it treks south where instability axis will be located. Ridging over the rockies looks to shift further east for Sun and then into Mon and early Tue. This will lead to warmer temps aloft moving into the area with dry and breezy southwest downslope flow, leading to max temps warming back towards seasonal normals. Ketcham .LONG TERM...(Wednesday through Saturday) Issued at 324 PM CDT Sat Aug 31 2019 Both the GFS and ECMWF continue to advertise that a cold front will ooze into the area for Tue afternoon, and make its way across the forecast area by Tue night. Not alot of moisture for this front to work with as it moves south, with both the GFS and ECMWF showing the chance for some post frontal showers for Tue evening/night across portions of central KS. Expect cooler temps for Wed/Thu, for central KS on the north side of the front. A short warming trend will continue for Fri. Model consensus supports increasing storm chances and cooler weather once again by next weekend, as another cold frontal zone oozes south across the region. Ketcham && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) Issued at 645 PM CDT Sat Aug 31 2019 A relatively moist pbl persists across the area and with a light moist easterly upslope flow progged across the area tonight we expect to see some pockets of MVFR & IFR cigs and perhaps lowered visibilities across much of the area. Some low and mid clouds remain across the area early this evening as the MCV drifts eastward across the area but with some breaks in the clouds and increasing radiational cooling, more widespread MVFR & IFR will likely develop across much of the area after 08-10Z and lingering into the morning hours on Sunday. && .PRELIMINARY POINT TEMPS/POPS... Wichita-KICT 65 87 69 90 / 10 10 0 0 Hutchinson 64 86 69 90 / 10 10 0 0 Newton 64 85 69 90 / 10 10 0 0 ElDorado 64 85 69 90 / 10 10 0 0 Winfield-KWLD 64 86 69 90 / 10 10 0 0 Russell 64 87 69 94 / 10 10 0 0 Great Bend 64 87 69 92 / 10 10 0 0 Salina 65 86 70 92 / 10 10 0 0 McPherson 64 84 68 90 / 10 10 0 0 Coffeyville 65 86 69 90 / 20 10 0 0 Chanute 63 85 69 89 / 20 10 0 0 Iola 63 85 69 89 / 20 10 0 0 Parsons-KPPF 64 85 69 89 / 20 10 0 0 && .ICT WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...BDK LONG TERM...BDK AVIATION...MWM
Area Forecast Discussion
National Weather Service Lincoln IL
913 PM CDT Sat Aug 31 2019 .SYNOPSIS... Issued at 300 PM CDT Sat Aug 31 2019 Scattered showers or sprinkles will affect mainly the northern half of central Illinois tonight, primarily north of I-72. Skies will remain cloudy, as low temperatures drop into the lower to middle 60s. Patchy fog will be possible later tonight. While an isolated thunderstorm can not be ruled out this evening, no severe storms are expected. Shower chances will linger on Sunday, mainly east of I-55, as high temperatures climb into the upper 70s to lower 80s. && .SHORT TERM...(This evening through Sunday) ISSUED AT 300 PM CDT Sat Aug 31 2019 The warm front positioned south of central Illinois is making very slow progress back to the north, which was previously advertised in the high res guidance. It has instead remained nearly stationary along I-64. North of the front, scattered showers or sprinkles have bubbled up from time to time, with no concentrated focus for precip evident in the satellite or radar images. Have therefore covered the evening portion of the forecast with a broad brush of slight chance PoPs for showers. An isolated thunderstorm could develop late this afternoon and early this evening, but instability has not increased under the veil of clouds across the area. So any storms would be short lived. After midnight tonight, an upper level trough will progress into Illinois, bringing a wave of positive vorticity advection, and forcing for precip. The affects of the that trough and shortwave will continue Sunday morning, and linger east of I-55 in the afternoon. The precipitation should remain scattered in general, with rainfall amounts remaining less than a quarter inch from tonight through Sunday afternoon. Despite the cloud cover, high temps are still expected to rise into the upper 70s to lower 80s. .LONG TERM...(Sunday night through Saturday) ISSUED AT 300 PM CDT Sat Aug 31 2019 Dry conditions are expected to begin Sunday night, and continue into Tuesday as high pressure settles in across the area. Upper level ridging will support a noticeable warm-up Labor Day into Tuesday. Highs on Monday should reach to near or just above normal in the mid 80s, with Tuesdays highs potentially reach the upper 80s to around 90. Humidity levels will become uncomfortable as well, especially on Tuesday, as southerly winds boost surface dewpoints into the lower 70s. Heat index readings on Tuesday afternoon will climb toward the middle to upper 90s in some locations. A cold frontal passage late Tuesday afternoon and evening will bring an airmass change, along with some scattered showers and storms, primarily Tuesday evening. The precip chances will be more confined to the NE half of central Illinois, generally NE of Peoria to Lincoln to Mattoon. The front will be relatively moisture starved, so rainfall production will be on the light side from any showers that do develop. Cooler and drier air will settle into the area for Wednesday and Thursday, as high temps return back down into the 70s. Thursday looks to be the cooler of the two days with most areas topping out in the mid 70s. Rain looks to hold off the rest of the week through Saturday, with the storm track remaining north of our area. A slight warmup on Friday toward 80 will be short-lived, as highs Saturday pull back into the low to mid 70s. && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) Issued at 913 PM CDT Sat Aug 31 2019 Very light precip is moving across the CWA this evening and will continue to do so during the overnight hours as well. Will keep pops low given how light it is. Based on HRRR hires model, could be most light precip from late tonight through early tomorrow morning. Looks like all precip will be showers or sprinkles and not expecting any storms. Will be making these adjustments and sending new forecast shortly. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...Shimon SHORT TERM...Shimon LONG TERM...Shimon AVIATION...Auten
National Weather Service Jackson KY
1104 PM EDT Sat Aug 31 2019 .UPDATE... Issued at 1105 PM EDT SAT AUG 31 2019 It`s been an interesting evening watching some strong storms develop to our east and to our west, but not impacting our CWA. The one just to the west of our northern counties was quite impressive, producing golf ball sized hail in Harrison county before finally dissipating as it neared our Bath county border. One small shower developed over Harlan County in the last hour, a bit unexpected, but has since dissipated as it moves NW. Made several adjustments since the previous update, first to reduce pops to isolated across the remainder of the CWA for the rest of the evening based on the current radar trends, and then to increase the pops in the SE where the Harlan County shower developed. Also have tweaked the temps and winds a bit to make sure they line up with the latest observations. All updates have been published and sent to NDFD/web. New zones and HWO have been sent out to remove evening and storm wording. UPDATE Issued at 737 PM EDT SAT AUG 31 2019 Forecast was in pretty good shape. So far we haven`t had any storms pop up across our CWA, though there is some storms around us, and a couple that may still make their way into our northern CWA from the west. Since Chance pops were currently forecast for the northern CWA, went ahead and reduced those to isolated with the lack of ongoing convection. Blended into the chance pops in place in the northeast, though if the radar trends continue, will likely drop these to isolated as well. Otherwise, main updates were to adjust the near term temp, dew point, and wind forecasts to make sure they were on track with the current observations. All updates have been published and sent to NDFD/web. && .SHORT TERM...(This evening through Sunday night) Issued at 435 PM EDT SAT AUG 31 2019 A weak mid level shortwave is moving across the Lower OH Valley at this time in westerly flow aloft. Mid and upper level ridging is centered near Bermuda and extends into the southeast Conus with another center of ridging near the Four Corners region. The axis of weak troughing extends south through the MS Valley. Another shortwave trough is upstream and moving through the Central Plains. A quasi stationary and weakening sfc boundary that is located in the vicinity of the Mountain Parkway and is expected to remain in nearly the same location and dissipate through the period. Cumulus has developed across the region, but the most agitated cumulus is over Central KY with recent development of a shower northwest of LEX. MLCAPE is analyzed in the 500 to 1500 J/KG range from Hal Rogers/KY 80 corridor north. 1000 to 1500 J/KG MLCAPE is analyzed from along Mtn Parkway corridor and north. Mid level lapse rates are on the meager side, though low level lapse rates are currently steep in the 8C to 9C range. DCAPE is currently analyzed in the 1000 to 1500 J/KG range. Bulk shear is on the order of 25 to 30KT. Gusty to possibly damaging winds will be the primary threat from any thunderstorms. As the weak shortwave moves east, some additional development should occur in the vicinity of the boundary. Convective allowing models such as the HRRR support this with development near or just north of the Mtn Parkway corridor in the instability axis. With the loss of daytime heating, the chances for convection will diminish within 1 to 2 hours past sunset. With low and mid level clouds diminishing overnight and weak pressure gradient across the region, valley fog should develop. Sunday into Sunday night, another shortwave trough axis should approach the are on Sunday while the weakening boundary remains across the area. Some isolated to possibly scattered convection should develop during peaking heating, mainly in the northern portions of the area. Otherwise, temperatures will again be warm and above normal. Warm and despite rainfall during the past week, the recent dryness over the past four weeks and relatively low soil moistures highs should again be warmer than MOS guidance guidance and NBM highs appear generally on target with some minor adjustments in a couple of spots. Any convection should diminish by a couple of hours past sunset on Sunday night with lows averaging in the mid 60s. .LONG TERM...(Monday through Saturday) Issued at 419 PM EDT SAT AUG 31 2019 The extended portion of the forecast begins on Monday with a strong ridge in place over the western CONUS. Also, at the beginning of the extended, a decent shortwave trough will cross the OH Valley. This trough will dig south enough to bring a cold front across Kentucky. Closer to the surface, model soundings for Monday afternoon and evening show weak capping and instability around 2500 J/KG. Thus have put some slight chance pops in for Monday afternoon and into the evening. With pops in the previous forecast and the operational models continuing to show QPF over the area, will decide to keep the pops in the forecast despite the dry forecast from the NBM. According to the trends in the model soundings, the main threat for Monday evening will likely be some strong wind gusts. After the first wave ejects east, a second strong shortwave crosses the crest of the ridge over the western CONUS and into the northern Plains. Shortwave ridging behind the previous wave will keep dry conditions over eastern Kentucky for Tuesday. The second mentioned shortwave will track into the the Great Lakes for Wednesday and will bring a second cold front into the region. Once again, with the ridge out west rebound in strength, the trough will dig south into the OH Valley again bringing a cold front through the area again. MU CAPE values for this event will range into the 2000 to 2500 J/KG range with once again, weak capping to the north. The initial forecast from the NBM came in with some slight to low chance pops so will keep this forecast in place for Wednesday afternoon. Temperatures through these first 3 days of the extended will be in the middle to upper 80s. Did lower highs for Tuesday and Wednesday as the EC and GFS MOS were at least 2 degrees below the NBM solution. Strong surface high pressure will settle into the area behind the previous front with dry weather expected through the rest of the extended. Highs for Thursday and Friday will be significantly cooler with upper 70s to around 80 expected. Some locations to the north may actually be cooler. && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) ISSUED AT 743 PM EDT SAT AUG 31 2019 A quasi stationary boundary located in the vicinity of the Mtn Parkway should be a focus for isolated storm potential through about 2Z this evening. Based on current radar trends, while there are no storms currently in the VC of the TAF sites, there are some across the northern Bluegrass moving eastward. Kept VCTS at KSJS since they will have the best likelihood of seeing these or any other developing storms over the next couple of hours. Otherwise, remaining TAF sites should not be affected. Outside of brief MVFR or IFR in any thunderstorms, VFR should prevail through the period. However, some river valley fog is again be expected between about 6Z and 13Z. Winds will be light and variable outside of any thunderstorms. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JMW SHORT TERM...JP LONG TERM...DJS AVIATION...JMW
Area Forecast Discussion
National Weather Service Blacksburg VA
1008 PM EDT Sat Aug 31 2019 .SYNOPSIS... Mostly dry weather and seasonal temperatures are expected for the majority of the Appalachians and central mid Atlantic region through early next week as high pressure remains over the area. However, it remains to be seen if Hurricane Dorian will track far enough westward to have any effects on our weather later next week. && .NEAR TERM /THROUGH SUNDAY/... As of 1000 PM EDT Saturday... WSR-88D radars showed cluster of showers and thunderstorms over the Greenbrier Valley and Alleghany Highlands. Overall trends was for slow weakening and a gradual north-northeast drift. A bulk of the Hi-Res, ConsShort, SREF, and HRRR diminish the areal coverage of the precipitation enough after 06Z/2AM to remove any remaining probability of precipitation after that time. Only minor changes to minimum temperatures based on current temperature trends and the latest LAV/MAV guidance. High pressure wedging down from New England will continue to push the frontal boundary through the region. This will generate some low clouds and fog late tonight into early Sunday morning. Anticipate Sunday will remain dry for the vast majority of the area with maybe an isolated shower well north if Interstate 64. Expect lows tonight a few ticks warmer than last night with low/mid 60s east of the Blue Ridge and generally mid 50s/lower 60s to the west. Highs in the wedge on Sunday will be cooler as well with middle 80s east to mid 70s/near 80 west. && .SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/... As of 300 PM EDT Saturday... No significant weather hazards expected for our forecast area during the short term. A weak upper level trough over the region Monday is forecast to lift northeast and off the New England Coast, subsidence increasing Tuesday in advance of the tropical cyclone to our southeast. There is a slight chance for a shower/thundershower over the mountains Monday, associated with the trough, but increasing subsidence should put a lid on things by Tuesday with little or no rain anticipated. Temperatures Monday are expected to reflect the seasonal norm with Highs ranging from the 70s mountains to mid 80s piedmont, and Lows in the 50s mountains to the mid 60s piedmont. Tuesday is expected to be a few degrees warmer...more sun and subsidence contributing to the warming. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... As of 315 PM EDT Saturday... Upper ridging over the southern Rockies and into the southern Plains, and western Atlantic Ocean, will help to funnel Hurricane Dorian northward near/along the Atlantic coast Wed-Fri. As troughing in the northern stream swings through the Great Lakes Wednesday, it will begin to tug Dorian northeastward near/along the Carolina coast as additional height falls push through Ontario by Friday. This suggests the overall impact to our forecast area from Dorian will be limited, with the end result favoring a dry forecast as opposed to a tropical deluge. That said, will continue to entertain at least a chance for some rain associated with Dorian in our far eastern CWA (east of Highway 29) to account for potential changes in the forecast track. In addition, the trough which is expected to move across the Great Lakes Wednesday, will also provide as a lifting mechanism for showers, so the shower threat may not be just limited to the eastern CWA, and will entertain at least low chance pops areawide for Thursday to account for both systems (the trough and the Hurricane). After Thursday, think the trough will move to the coast and limit the westward influence from the tropics, confining the rain threat mainly to the Tidewater region. The warmest temperatures are expected Wednesday, ahead of the trough and within the subsidence region in advance of Dorian. Temperatures are expected to top out in the 80s mountains to near 90 in the piedmont. The trough should introduce a relatively cooler/drier airmass for the end of the week, highs/lows retreating to the seasonal norm, or even a few degrees below that pending cloud cover. && .AVIATION /02Z SUNDAY THROUGH THURSDAY/... As of 743 PM EDT Saturday... VFR conditions will prevail at the taf site this evening into tonight with isolated sub-VFR conditions in showers and thunderstorms for next couple of hours. The best low level convergence is location north of Interstate 64. Convection will dissipate this evening with loss of heating. The front will push southward overnight as high pressure wedges down from New England. This will bring a surge of low level moisture into the region on easterly flow and generate some stratus/fog toward daybreak. The models are showing the richest moisture in the northwestern portions of the forecast area. Anticipate a slow improvement in flight conditions by late morning/early afternoon Sunday. VFR conditions will return to all taf sites Sunday afternoon. Winds will generally be light with no significant impact to aircraft operations expected. Medium conditions in ceilings, visibilities and winds during the taf period. .Extended Aviation Discussion... Generally VFR conditions are expected through much of next week, outside any late night fog and isolated showers. Dorian appears to be staying away from us in the near future, but forecasts could change. Aviation interests should monitor conditions along the southeast through next week. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...None. NC...None. WV...None. && $$ SYNOPSIS...MBS/WP NEAR TERM...AMS/MBS SHORT TERM...PM LONG TERM...PM AVIATION...KK/MBS