Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 10/02/19

Area Forecast Discussion
National Weather Service Amarillo TX
638 PM CDT Tue Oct 1 2019 .AVIATION...00Z TAFs... Moist airmass with scattered showers and a couple thunderstorms will continue to play havoc on aviation conditions, primarily in the form of MVFR ceilings at all site sometime during the next 24 hours. DHT and GUY should only be dealing with restrictions for the first few hours of the period before the mid levels dry out as the moist axis shifts east. AMA, while initially VFR, is expected to return to MVFR as stratus and perhaps another round of showers expands northward overnight. Low probability of thunder at each site precluded mentions in this TAF issuance, save for later this evening as a storm currently between PVW and CVN skirts just to the east of AMA. Ferguson && .PREV DISCUSSION... /Issued 336 PM CDT Tue Oct 1 2019/ SHORT TERM...Tonight and Tomorrow... Current observations show the cold front stalled across southeastern Colorado and northwestern Kansas. Meanwhile, rain showers cover the a majority of the Panhandles. Moisture continues to be pumped into the West Texas as the upper level low over Idaho/Montana and high pressure over the southeast CONUS puts the area under southwest flow aloft. However, mid-level satellite analysis and RAP 500mb heights reveals dry air wrapping clockwise around the upper level high and pushing west across Texas. All the while, dry air associated with the trough axis pushes east causing the two dry air masses to begin pinching off the moisture source. High res models indicate the showers will become less widespread through the afternoon hours, with the chance for a few isolated stronger showers during the afternoon and early evening. These isolated showers may continue on through the early morning hours Wednesday across southeast Texas with the current forecast keeping a 30 to 40 PoP to account for any straggling moisture. The stalled cold front will finally begin its push south across the Oklahoma Panhandle Wednesday; however, models are showing this progression to be later in the evening. This is where the forecast for precipitation gets a bit tricky and depends on the remnants of any outflow boundaries from today`s showers and the timing/strength of the frontal passage. Overall, the instability along the front will play an important role in any additional showers across the Texas and Oklahoma Panhandles Wednesday evening. Sounding analysis shows the front to the be shallow and weak with little instability. The current forecast leaves a 30 PoP in for the southeast Panhandles to include for the slight chance of storms along the cold front and any lingering boundary from today and tonight. Temperatures are going to struggle to reach the low 70s for a high today across the western Panhandles due to lack of solar heating from low clouds along with on and off rain showers cooling the air. Areas that have had a chance to see the sun a bit today with little to no rain have chances to see the mid to upper 80s. Low temperatures tonight will drop into the upper 50s and lower 60s across a majority of the western Panhandles. Temperatures Wednesday will slightly recover to normal and slightly above normal in the upper 70s to mid 80s with mostly cloudy skies persisting through the day. Rutt LONG TERM...Tomorrow Night through Monday... Long term forecast begins with upper ridge centered over TN, an upper trough swinging eastward over the northern Plains, with a second trough working into the Pacific NW. As the lead trough heads over Ontario, cold front looks to push through the Plains and through the Panhandles, with the latest GFS largely coming around to the more aggressive solution seen in the last couple runs of the EC/CMC/NAM. While 700mb moisture will be less notable than earlier in the week, still a decent amount of moisture progged to be available below this level, so showers and a few rumbles of thunder are likely along the front as it pushes south during the day Thursday. Additional showers and a few storms will also be possible Thursday night as southwesterly flow aloft continues with the attendant possibility of disturbances in this flow generating upglide over the post-frontal cold dome. Considering the rainfall earlier in the week combined with progged PWAT values around 1.5 inches, flooding may be a concern once again Thursday and Thursday night. As for other sensible weather, Thursday should be cool thanks to the early frontal passage and expected mostly cloudy conditions. Tricky forecast for Friday as cross barrier flow looks to induce lee surface troughing across E CO, leading to south-southwesterly winds across the Panhandles by the afternoon. While operational guidance and most GEFS members depict this occurring, still quite a bit of moisture lingering in the mid-levels, so do not think airmass will rapidly recover due to continued cloud cover. Still, downsloping should allow us to get back into the 70s. Finally, cannot rule out some additional showers and thunderstorms Friday as southwesterly flow aloft - combined with the aforementioned moisture - continues over the CWA. Southeastern CONUS ridge breaks down Saturday, allowing a transition to zonal flow aloft. GFS/EC/CMC in general agreement that the trough that worked into the Pacific at the start of the long term forecast will be moving downstream over the northern Plains at this time as well. Behind this feature, cool air mass is progged to advect southward on the eastern side of the Rockies, with most guidance depicting this reaching the forecast area by Saturday afternoon. With the later arrival of the cold front and less cloud cover compared to Thursday, will not go all out on a cooler solution for now, but this may be a period to watch in future updates. Quick moving longwave trough swings over the central Plains into toward the Ohio Valley Sunday into Monday, leading to another cold frontal passage. While latest trends suggest frontal passage will occur Sunday, timing differences between guidance become an issue by this time period, so did not jump on either Sunday or Monday for cooler temperatures with the update. Progged 850mb moisture ahead of the front may lead to showers and storms as the feature moves south. Ferguson AVIATION...18Z TAFs... MVFR to VFR conditions are expected at all three TAF sites as lingering showers continue across the Panhandles through around 21z. A few isolated strong showers may occur between 21z and 01z at all three sites. KGUY/KDHT will begin to dry out after 01z with VFR conditions through the remainder of the period. However, KAMA will see the chance for storms through the overnight hours until the end of the TAF period. MVFR conditions are possible with these storms, otherwise VFR conditions are expected. Winds will be out of the south southwest at 10 to 15 knots with gusts up to 20 knots possible through 18z tomorrow. KGUY will begin to see the winds become westerly near 18z as a cold front approaches the Oklahoma Panhandle. Rutt && .AMA Watches/Warnings/Advisories... TX...Flood Watch through Wednesday morning for the following zones: Carson...Deaf Smith...Hansford...Hutchinson...Lipscomb... Moore...Ochiltree...Oldham...Palo Duro Canyon...Potter... Randall...Roberts...Sherman. OK...Flood Watch through Wednesday morning for the following zones: Beaver...Texas. && $$ 77/21
Area Forecast Discussion
National Weather Service Buffalo NY
1104 PM EDT Tue Oct 1 2019 .SYNOPSIS... Expect an unsettled weather pattern to continue into the remainder of the work week as a slow moving frontal boundary sags south across our region later tonight and Wednesday...then remains in our vicinity through Thursday. This feature will act as the focus for several rounds of showers and some embedded thunderstorms... while also ushering in progressively cooler air. By Friday daytime highs will only be in the lower to mid 50s...with the first frost or freeze of the season then becoming possible across interior sections Friday night. && .NEAR TERM /THROUGH WEDNESDAY/... Regional radar shows initial round of thunderstorms that produced some wind damage earlier this evening in Niagara county have exited into eastern NY. A few other showers are streaming into southwest NY, but otherwise there is a break in most showers until you reach central lower Michigan. Though cannot rule out a few showers or thunderstorms into the early overnight hours, as is occurring over western NY, looks like most of the more organized showers and thunderstorms will not arrive back over western NY until after 3-5 AM. Showers and thunderstorms upstream are on perifery of upper level ridge and driven by stronger disturbance riding the ridge. Activity is in swath of 1.8-2.0 inch pwats and on edge of higher MUCAPES. 0-1km shear in this area is also 20-30 kts suggesting low- level cold pools can effectively be balanced and activity could persist through the night as it moves toward western NY. Latest HRRR seems to be latched onto this idea very well and followed it heavily for this update. Kept pops lower into the early overnight hours, then ramped up pops to categorical late tonight. As we saw earlier tonight, gusty winds could again be a hazard late tonight through daybreak Wednesday. And with the abnormally high PWATS and higher freezing levels toward 14kft, heavy rain is a concern. Will have to watch if training storms develop as upper level flow becomes parallel with sfc front settling across NY by Wednesday morning. Kept gusty wind and heavy rain mention in grids with expected evolution of convection late tonight into mid morning on Wednesday. Risk for stronger storms and should then fade by later Wednesday morning as the front becomes increasingly anabatic in nature and we become embedded more deeply within the cooler airmass to its north...and accordingly see available instability diminish. As mentioned previously...the bulk of the more widespread showers and embedded thunder will occur from late tonight through the first half of Wednesday...before slowly diminishing from north to south Wednesday afternoon and evening as the frontal boundary makes further southward headway across Pennsylvania. With the 12z model guidance continuing the trend of previous runs of a somewhat faster/ further southward progression of the front during Wednesday...have sped up the timing of the improving trend a little more from continuity... with the rain completely coming to an end across the North Country... and diminishing to some scattered showers across the Niagara Frontier and much of the Finger Lakes during the afternoon. This said...low clouds will still hang tough across all areas south of Lake Ontario right through Wednesday given the cool/moist northeasterly upslope flow regime to the north of the front...with only the North Country seeing some partial sunshine develop during the afternoon. With respect to temperatures...the gradual southward progression of the frontal zone will induce a notable north-south gradient in temperatures both tonight and Wednesday. Lows tonight will range from the mid 50s across the North Country to the mid 60s across the Southern Tier...with the ongoing steady cool air advection regime and widespread cloud cover on Wednesday then keeping highs from rising more than a couple degrees above these values. In fact... its actually more likely that most locations will just continue to see slowly falling temperatures through the bulk of Wednesday... with readings dropping into the 50s in most places (and perhaps even to the upper 40s across interior portions of the North Country) by early Wednesday evening. && .SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/... By Wednesday evening the frontal zone will be into Pennsylvania, with the best chance for showers across the Southern Tier which will be closest to this boundary. Clouds will hold tough south of Lake Ontario due to a northeasterly upslope flow. Meanwhile, high pressure will ridge southward into the North Country where a partial clearing is expected. Temperatures will be much cooler Wednesday night, but clouds and a moderate northeasterly flow will limit radiational cooling with low temperatures mainly in the 40s. The exception is across somewhat sheltered interior portions of Lewis and Jefferson counties where some frost is possible. Thursday and Thursday night a sharp mid level trough will move from the upper Great Lakes to southern Quebec. The forcing ahead of this wave will allow a wave of low pressure to develop along the stalled frontal zone to our south. This surface low will then move across New York State late Thursday afternoon and evening. Model guidance has been in poor agreement concerning the strength of this surface low, which lowers forecast confidence for this time period. Showers are likely move across the region during this period, with these more numerous Thursday afternoon and evening. A few thunderstorms are possible across the Western Southern Tier. These depend on the track of the low and if it is able to break into the warm sector ahead of the cold front. Either way, a cool northwesterly flow will develop across the region Thursday night. Consensus 850mb temperatures will drop to near zero Celsius by daybreak Friday and this will support lots of lake effect clouds and some lake enhanced rain showers Thursday night and into Friday morning. Even after the showers end, expect Friday will be a mostly cloudy day. As a result, the forecast holds in cloud cover longer during the day Friday, and hedges cooler than consensus guidance. The coldest air of the young autumn season will be upon us Friday night. Though temperatures begin to warm some aloft, a broad surface high will track to right over the region by Saturday morning. This will create excellent radiational cooling conditions, with clear skies and light winds allowing for temperatures to drop into the mid to upper 30s on the lake plains and upper 20s to lower 30s across the interior Southern Tier and east of Lake Ontario. Widespread frost or freeze conditions are becoming more likely for Friday night for a good portion of our area away from the Lakes. && .LONG TERM /SATURDAY THROUGH TUESDAY/... It will be a crisp start to this period with post sunrise temperatures Saturday morning around freezing to the upper 30s. Surface high pressure will be nearby to our east and this feature will allow for ample sunshine to support a nice rebound in temperatures Saturday afternoon...into the upper 50s to around 60F. Sunday through Tuesday look to be wet as a large scale trough sets up over our region. There are model differences, with the ECMWF actually forming a cut off low within the base of this trough by next Tuesday, while the GFS moves the upper level large scale features along. The slower ECMWF will allow for rain chances into Tuesday, whereas the faster GFS brings high pressure and drier air into our region for the last day of this period. Will continue with rain shower chances through this period as a surface baroclinic boundary wavers across the region. Gulf of Mexico moisture will enhance the low level moisture along this frontal boundary such that moderate to heavy rainfall is possible along the slow moving front. Temperatures Sunday and into early Monday will side towards above normal...while later Monday and Tuesday behind this surface frontal boundary temperatures will drop back close to normal. && .AVIATION /03Z WEDNESDAY THROUGH SUNDAY/... The frontal boundary to the north will slowly press southward across our region through the balance of tonight and Wednesday morning. This will bring widespread showers and scattered embedded thunderstorms, mainly after midnight. As we saw Tue evening, some of the storms could produce locally heavy rainfall and gusty winds. The resultant increase in low level moisture (both from the precip and a developing cool northeasterly upslope flow behind the front) will result in flight conditions lowering to the LIFR to lower-end MVFR ranges overnight and Wednesday morning. Wednesday afternoon the front will make further southward progress across Pennsylvania...and this will allow the showers to come to an end across the North Country...and become more scattered across the remainder of the area north of the Southern Tier. This said... a continued cool northeasterly upslope flow will keep widespread lower clouds and associated LIFR to MVFR flight conditions in place across most areas south of Lake Ontario...with only portions of the North Country possibly seeing some improvement to VFR. Outlook... Wednesday night and Thursday...Areas of IFR/MVFR with numerous to widespread showers at times. Friday...Mainly VFR with a chance of showers. Saturday...VFR. Sunday...Mainly VFR with a chance of showers. && .MARINE... Through Wednesday a slow moving cold front will slowly sag southward across the Lower Great Lakes. This could bring a few more thunderstorms with locally gusty winds and higher waves... but more importantly will induce a wind shift to the northeast... with a moderately brisk flow developing across Lake Ontario very late tonight and Wednesday. This will bring advisory conditions to Lake Ontario during the day Wednesday. Looking a bit further out in time...even stronger northeasterlies should then produce solid advisory-level conditions across the western two thirds of Lake Ontario Wednesday night and Thursday. Meanwhile on Lake Erie...a period of marginally advisory-worthy conditions will be possible in tandem with a period of increased northeasterly flow late Wednesday and Wednesday night. && .CLIMATE... A more summerlike day today yielded record highs at ROC (88F breaks previous record of 86F set in 1877) and ART (83F breaks previous record of 80F set in 2002). BUF fell short of record high as that site saw a high of 81F (Record high is 83F set in 1898). && .BUF WATCHES/WARNINGS/ADVISORIES... NY...None. MARINE...Small Craft Advisory from 8 AM Wednesday to noon EDT Thursday for LOZ043-044. Small Craft Advisory from noon Wednesday to 6 PM EDT Thursday for LOZ042. && $$ SYNOPSIS...JLA/JJR NEAR TERM...Hitchcock/JLA/JM/JJR SHORT TERM...Apffel/Hitchcock LONG TERM...Thomas AVIATION...JLA/JJR MARINE...JLA/JM/JJR CLIMATE...JLA