####018011325#### FXUS62 KRAH 190606 AFDRAH Area Forecast Discussion National Weather Service Raleigh NC 205 AM EDT Fri Apr 19 2024 .SYNOPSIS... A weak backdoor front will drop into the area from the north tonight, then lift back north as a warm front Friday afternoon. A cold front will cross the region late Friday night into early Saturday, and then settle just to our south late Saturday. A wave of low pressure will track along the front Sunday into Monday, bringing unsettled weather. && .NEAR TERM /THROUGH TONIGHT/... As of 850 PM Thursday... No major changed to the forecast with this evenings update. Skies are mostly clear but coverage will increase late tonight early tomorrow morning ahead of the next disturbance. Low temperatures tonight will be in the low to mid 50s north and upper 50s to low 60s south. As of 200 PM Thursday...Afternoon surface analysis reveals a weak surface trough extending down over the Coastal Plain of NC. This is associated with an area of low pressure off Delmarva. A stationary front was also present across the lower OH valley, while a cold front and surface low pressure was centered over OK/KS/MO/IA. Lastly, high pressure existed off ME. Temperatures will continue warm some additional 3-5 degrees before sunset. With time, high pressure off the NE US will build south and west overnight, bringing a backdoor cold front through at least eastern sections of central NC and the coastal Plain. At the same time, the front over the Mississippi Valley is forecast to reach the TN valley as the surface low reaches the Great Lakes. The backdoor front is expected to produce some shallow and scattered low clouds along and immediately behind the boundary, centered around Fri morning, with the highest chances along the northern Coastal Plain. Winds should shift around to be from the ENE, with some brief gusts to 15 kt. Aloft, ridging over the area will transition to some shortwave energy over the Mississippi Valley tracking into western portions of NC/SC tied to the Midwest cold front. Models show mid and high clouds tied to this but also some convection that is forecast to reach eastern TN and western NC by sunrise. Instability in our neck of the woods is rather limited, if not non-existent. However, enough isentropic ascent appears favorable for a few spotty light showers around midday Fri morning across the western Piedmont. Overnight lows could range to around 50 in the far NE behind the backdoor front, to the mid upper 50s across the west with greater cloud cover. && .SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... As of 315 PM Thursday... Friday and Friday night: The stalled front draped across SC-NC state line to start the day will lift back north as a warm front during the day, ahead of a cold front and developing weak surface low that will traverse eastward across the mountains and into the western Piedmont during the late afternoon and evening. A band of pre-frontal showers, which seems to be closely associated with a sheared vorticity axis moving through the area, could produce isolated to widely showers by mid morning and into the early/mid afternoon period. Additional convection is likely during the late afternoon and into the evening and early overnight hours with the arrival of the cold front and sfc wave into central NC. Amidst west- northwest flow, which typically is not a favorable environment for convection, isolated to widely scattered showers and storms are possible. Model spread is higher than normal wrt to PoPs and coverage. Thus, forecast confidence is below average. The severe threat remains conditional. If a severe threat is realized, it will be with the late day convection as moderate instability develops and spreads into the western and central Piedmont. With this afternoon's update, the Storm Prediction Center has expanded the Marginal/Level 1 severe threat a little further north and east to now include most of central NC. However, the greatest severe threat appears to be across the western/SW Piedmont. Damaging wind gusts and hail are the primary threat. The chance for showers and storms will move east through the evening and into the overnight hours, with the bulk of the convection expected to either have dissipated or moved out of the area around midnight. Highs ranging from mid/upper 70s north to mid 80s south. Lows Friday night will depend on the exact timing of the cold front through the area, which could be slower than forecast. Lows in the mid 50s north to lower 60s south. Saturday: The surface cold front and the associated weak instability will sag slowly south and out of the area through midday. Some lingering showers are possible across the far eastern zones during the mid to late morning. Otherwise it should be mostly dry with cloud cover decreasing through the afternoon with a west-northwest downslope component noted across the area, which will delay the arrival of appreciably cooler air into the area until Saturday night. Highs ranging from lower/mid 70s north to near 80 south. Saturday night: The aforementioned cold front will continue to shift slowly south through SC and into GA as high pressure builds east into NC. Meanwhile, a low-amplitude shortwave over the Southern Plains will eject eject in advance of a more vigorous shortwave trough diving SEwd into the Central Plains. A ribbon of shortwave impulses will begin to interact with the front to our south and will result in the onset of isentropic lift and moisture advection into the area after midnight. Clouds will fill back in Saturday night, with stratiform rain spreading in/developing, mainly across southern portions of the area during the predawn hours. Significantly cooler with lows ranging from mid/upper 40s north to lower/mid 50s south. && .LONG TERM /SUNDAY THROUGH THURSDAY/... As of 400 PM Thursday... A shortwave trough and associated surface low will move NE along a cold front from the Gulf Coast to off the NC coast on Sunday and Sunday night. Southwesterly flow aloft will increase moisture advection into central NC during this period, with PW values increasing to around 1-1.5 inches. Deterministic models and ensembles are in good agreement for a period of widespread light to moderate rain across much of the area on Sunday afternoon and evening, when POPs are likely outside of the far north. Overall forecast amounts both among the models and from WPC have decreased somewhat from yesterday, with expected totals ranging from a tenth of an inch or less across our far northern counties to half to three quarters of an inch in the southern Coastal Plain. With the front likely well to our south by this point, we will be on the cool and stable side which will preclude any chance of storms and would result in just stratiform rain. It will also keep rain rates from getting too heavy, so not concerned about a flash flooding threat and WPC removed our area from the marginal risk of excessive rain. Leaned toward the cooler guidance for temperatures on Sunday given potential for some CAD. Highs in the upper-50s will be possible in some spots, with lower-to-mid-60s elsewhere. The raw NAM and GFS actually depict some highs in the lower-50s, and the forecast may need to be trended down further in the coming days if this continues. Widespread rain will end on Sunday night and Monday morning from west to east as the low moves away. A more potent shortwave will move across the region on Monday afternoon and evening, but the GFS is much stronger with it and brings additional light rain, while the ECMWF keeps the rain to our south. The GFS appears to be an outlier as only a small minority of its ensembles have precipitation, and nearly all the ECMWF ensembles are dry. Also PW values drop significantly by this point. So continue to only have slight chance POPs at this time. Regardless it will be quite cool once again, with forecast highs in the lower-to-mid-60s, and if the raw GFS verifies there may be additional CAD with some highs in the 50s. Tuesday will finally turn mostly sunny and dry as surface high pressure builds in, with highs increasing back to near normal (in the lower-to-mid-70s). Tuesday morning looks chilly with decent radiational cooling, with lows in the lower-to-mid-40s and possibly some upper-30s. Yet another cold front will approach on Wednesday, as southwesterly flow ahead of it warms temperatures into the mid- 70s to lower-80s. It may be accompanied by isolated showers and storms, but most ensembles are dry and the best upper forcing again goes to our north, so only have slight chance POPs at this time. Thursday will turn cooler again as Canadian high pressure builds down from the north. && .AVIATION /06Z FRIDAY THROUGH WEDNESDAY/... As of 205 AM Friday... INT/GSO: VFR conditions are likely to hold through the next 24 hours at INT/GSO, with clouds thickening early this morning and remaining largely broken through this evening, but with VFR bases. Isolated showers are possible from late morning through mid afternoon (15z- 20z) at INT/GSO, followed by a potential for isolated storms into early evening (20z-02z) as a cold front approaches. Shower/storm chances will end by mid evening, as the front pushes to the E. Surface winds will be light, under 10 kts, starting from the NE before shifting to SE, then SW, then NW after nightfall behind the front. RDU/RWI/FAY: These sites will see a high chance of IFR to low-end MVFR stratus early this morning, especially RWI which will see these low cigs as a prevailing condition from 07z to 14z. RDU/FAY will see a shorter duration of possible IFR/low-MVFR cigs, mainly 10z to 14z. Otherwise, VFR conditions are expected, but with thickening clouds this morning. Isolated showers are possible starting in the mid afternoon (mostly after 18z), with a few thunderstorms possible from late afternoon through late evening (mainly 21z to 03z), ending thereafter. Surface winds will be light and variable, under 10 kts. Looking beyond 06z Sat, sub-VFR conditions are possible across the NE and E late night through Sat morning, mainly affecting RWI/FAY, but chances are not as high as this morning. After mostly dry weather Sat (except a slight rain chance at FAY) as the front settles just to our S, a wave of low pressure tracking along the front will bring a high chance of sub-VFR conditions and rain from Sun afternoon through early Mon. Rain chances may linger esp at FAY Mon night, but otherwise VFR conditions are expected Mon through Tue. Showers/storms are possible Wed associated with an approaching cold front. -GIH && .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Hartfield NEAR TERM...CA/Kren SHORT TERM...CBL LONG TERM...Danco AVIATION...Hartfield ####018005896#### FXUS62 KFFC 190608 AFDFFC Area Forecast Discussion National Weather Service Peachtree City GA 208 AM EDT Fri Apr 19 2024 ...New 06Z Aviation Discussion... .SHORT TERM... (This afternoon through Friday) Issued at 238 PM EDT Thu Apr 18 2024 Low confidence pop forecast for overnight and into tomorrow. Challenging forecast for tonight into tomorrow. The models, including the hi-res, continue to struggle with the convection near the ARKLAMISS. The hi-res models do weaken any convection as it nears the AL/GA state line late this afternoon into the evening hours. Do think some weakening will occur due to loss of heating, but coverage of storms may be a bit more than the models are progging. There will be enough surface instability around through the early evening for isolated/scattered thunder and the lapse rates remain pretty steep. Luckily shear remains pretty low. Strong storms are possible with an isolated severe storm not out of the question, mainly near the central AL/GA border. Strong storms will be capable of producing gusty winds and hail. A break in storms is likely well into the overnight hours. The models are progging a second round of storms (MCS) potentially moving in from the NW towards 12Z. There has been some run to run consistency within the HRRR, but the hi-res models remain all over the place with the evolution of this system. With such uncertainty with this system, will refrain from using likely pops and stick to scattered at this time. However, if models come into better agreement, pops will have to be adjusted upwards. A third round of storms is possible again tomorrow as a front sags south across northern portions of the state. Convective initiation will be highly dependent upon any morning convection that moves through. If there is good coverage of storms with the early morning MCS, then initiation may be later in the day. If the early morning MCS falls apart near the border, then convective initiation/coverage should be greater tomorrow afternoon. With all of this said, the models struggle with these types of systems...especially the timing. However, if/when convection fires, it will definitely have the potential to be strong or severe, especially tomorrow afternoon. CAPE values should be around 1500 J/kg with steep lapse rates. Shear remains low, but frontal forcing will be another player. Damaging wind gusts and large hail would be the primary severe thunderstorm hazards. NListemaa && .LONG TERM... (Saturday morning through next Wednesday) Issued at 238 PM EDT Thu Apr 18 2024 The long-term period picks up on Saturday with 25% to 40% PoPs in the afternoon and evening, generally along and south of I-20. The SREF is progging SBCAPE of 800-1200 J/kg across said area, which indicates the potential for isolated to scattered showers and thunderstorms. The greatest surface-to-500-mb bulk shear will be much farther north, so the setup will not be conducive for organized convection. That said, a few strong to severe storms posing a hail threat and downburst threat cannot be ruled out. A southern-stream shortwave trough passage on Sunday will increase the surface- to-500-mb bulk shear to 40-50 kts, and while the SREF is progging less instability on Sunday, thinking is that the shortwave will provide enough lift to warrant a 60% to 80% chance for showers with a 15% to 25% chance for thunderstorms. Again, widespread severe weather is not expected, but a strong to severe storm or two are possible. Continuing to message a QPF of ~0.50" to 0.80" with this weekend rainfall. On Monday, the shortwave and larger-scale, synoptic trough axis will shift east of the forecast area, pushing a cold front through. Much drier air will overspread the forecast area as high pressure settles across a portion of the eastern CONUS. The airmass associated with the high pressure will be noticeably cooler starting on Sunday and continuing into early next week with lows in the 40s and 50s, and highs in the 60s and 70s. Martin && .AVIATION... (06Z TAFS) Issued at 156 AM EDT Fri Apr 19 2024 VFR conditions continue with mid and upper level clouds blanketing the area. However, shower activity is presently developing across N AL, with some embedded in-cloud lightning starting to show up. This activity is presently tracking almost due E. Have included a tempo shower at RYY from 10-13Z with VCSH at other Atlanta metro terminals except ATL. May need to expand tempo group into the remainder of the metro area depending on progression of this activity. More tstm activity is forecast to sag into N GA this afternoon. As indicated by previous shifts, models are performing poorly, so confidence in timing and areal extent of tstms is fairly low. //ATL Confidence...06Z Update... High for all elements over the next several hours, medium for timing and S extent of early morning convection, low-medium for timing and extent of afternoon thunderstorms. SEC && .PRELIMINARY POINT TEMPS/POPS... Athens 63 83 55 65 / 30 30 30 80 Atlanta 62 79 56 62 / 30 30 40 80 Blairsville 55 73 48 57 / 30 20 40 80 Cartersville 58 76 50 60 / 30 20 30 80 Columbus 67 86 60 70 / 20 40 30 80 Gainesville 62 80 55 62 / 30 20 30 80 Macon 66 86 60 71 / 20 40 30 80 Rome 58 75 50 60 / 30 20 40 70 Peachtree City 62 81 54 64 / 30 30 40 80 Vidalia 69 89 65 79 / 20 40 30 70 && .FFC WATCHES/WARNINGS/ADVISORIES...None. $$ SHORT TERM...NListemaa LONG TERM....Martin AVIATION...SEC ####018009823#### FXUS61 KBGM 190609 AFDBGM Area Forecast Discussion National Weather Service Binghamton NY 209 AM EDT Fri Apr 19 2024 .SYNOPSIS... Drier yet cloudy this morning before another cold front ushers in scattered showers this afternoon and evening. We turn breezy and cooler for the weekend with some rain or even snow showers possible Saturday afternoon and evening. A dry stretch of weather is finally expected Sunday through Tuesday seasonable temperatures. && .NEAR TERM /THROUGH TODAY/... Only minor changes with the mid evening update. Previous below. Early this evening we are watching some drizzle move through the region. So expanded the coverage of drizzle with this update. A general dreary night is still expected. Previous discussion below. Heading into tonight, any partial clearing early on will quickly fade behind cloudy skies as Canadian high pressure continues to build into northern New England. Despite the increased low-level moisture, guidance maintains a mainly dry forecast tonight as our washed-out warm front lifts eastward and upper level ridging and mid-level dry air build into further into the Northeast. However, some pockets of drizzle may linger, especially in NE PA and the Catskills, at least through Midnight as low-level southeast flow upslopes the terrain. Otherwise, we will not see a large diurnal change tonight given clouds. Overnight temperatures only cooling into the mid to upper 30s in the Catskills, Mohawk Valley and NE PA with low to mid 40s in the Southern Tier, Fingers Lakes, and towards Syracuse. Cloudy skies continue tomorrow with temperatures turning milder in comparison to today with much of the region warming into the 50s to low 60s as shortwave ridging continues overhead. Upstream we have a closed upper level low positioned north of the Great Lakes with its associated occluded sfc low near the Hudson Bay. An attendant cold front will be tracking eastward from the Ohio Valley into the Northeast. A few weak shortwave embedded in the southwest flow aloft look to allow a secondary sfc low to develop along the thermal/moisture gradient as the front reaches west/central NY. Overall moisture is not very impressive but with the secondary sfc low will likely provide additional forcing for showers to continue and spread into the Twin Tiers, the Finger Lakes eastwards towards the Catskills, NE PA, and the Mohawk Valley. Best chance for showers looks to be tomorrow afternoon into tomorrow evening and have maintained widespread chance POPs with even likely POPs west of I-81 by 18 - 21 UTC. Overall QPF is light with around a tenth expected. Higher amounts ranging 0.25 - 0.40 inches expected in Oneida County where some lake enhanced moisture can contribute to increased QPF. The boundary looks to weaken as it reaches the Catskills Fri night with the thermal and moisture gradient becoming less defined. The boundary may slow down overnight so have maintained slight chance and low end chance POPs east of the Susquehanna River into the southeast Catskills. Otherwise, clearing should ensue behind the front as westerly flow ushers in a drier air mass. Overnight lows turn cooler dropping into the mid to upper 30s with low 40s in valley areas thanks to some radiational cooling. Winds become a bit elevated behind the front becoming sustained 5 - 12kts overnight. && .SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/... Expect a chilly weekend as our large scale upper level closed low tracks towards the Hudson Bay with associated secondary shortwaves dig into the Northeast. For Saturday, weak high pressure in the morning will exit to the east as a secondary cold front will be on the approach for the afternoon thanks to a more potent shortwave trough tracking through Ontario into the Northeast. There is some mid-level moisture with the front and combined with additional lake moisture, a few afternoon rain showers are possible and we maintained slight chance POPS to low end chance POPs. We placed the highest POPs near and north of the NY Thruway into the southern Tug Hill and for the northern Fingers Lakes given closer proximity to Lake Ontario. Best chance for showers will be in the afternoon as the front pushes through the region from northwest to southeast. After temperatures rise into the upper 40s to low-mid 50s by early to mid-afternoon, west to northwest winds turn gusty in the wake of the front reaching up to 20-25kts with temperatures cooling into the 40s by sunset. Deterministic guidance is not too enthused with QPF generally under a tenth of inch given the incoming front should just generate isolated to scattered showers with some locally higher amounts from lake enhancements possible. The 500hPa cool pool associated with the incoming shortwave is rather impressive nearing -25C to -30C so would not be surprised if some sleet or graupel is mixed in the rain showers, especially late afternoon as temperatures cool into the 40s. Clearing skies continues Saturday night with westerly winds staying a bit breezy overnight as large scale highs pressure centered in the Central Plains will builds eastward. It will be a chilly night with temperatures cooling into the low to mid 30s thanks to some radiational cooling. We close out the weekend with high pressure maintaining mainly sunny skies and seasonably cool temperatures for Sunday as northwest flow continues aloft. High temperatures will stay cool given ongoing cold air advection only warming into the low to mid 50s...cooler in the upper 40s in the Catskills. Westerly winds will stay breezy as yet another shortwave and reinforcing cold front track through Ontario into northern New England. The winds will make it feel a bit cooler despite the sunshine as deep boundary layer mixing support gusts up to 20-25kts once again. Winds gradually weaken overnight but stay a bit elevated. Overnight lows drop into the low to mid 30s under clear skies. Leaned on the cooler end of guidance for Sunday night lows given the more favorable raditional cooling conditions. && .LONG TERM /MONDAY THROUGH THURSDAY/... Sunshine and pleasant spring temperatures are in store for Monday as large scale high pressure stays in control. West to northwest winds remain a bit breezy for the first half of the day but trend downwards during the afternoon as high pressure shifts into New England. As some weak return southwest flow ensues, high temperatures should trend warmer compared to the previous few days with highs reaching into the mid to upper 50s with even low 60s in NE PA and valley areas within the Twin Tiers. Pleasant and even milder weather ensues for Tuesday as southwest return flow ushers in an even milder air mass with temperatures trending into the upper 50s with more of the region reaching into the low to even mid-60s. Another cold front looks to impact the region Tuesday night into Wednesday with chances for rain returning. Still uncertainty on the exact timing of the front and moisture fields but maintained widespread chance and even likely POPs given good run to run consistency on this system occurring and decent moisture fields and thermal gradient along the boundary. The parent shortwave is rather potent and guidance shows it taking on a negative tilt as it tracks into Ontartio but there remains discrepancies on its exact track. Despite the strong forcing, this system looks fast moving and progressive so any hydro issues appear unlikely. Drier and cooler conditions return for Thursday. && .AVIATION /06Z FRIDAY THROUGH TUESDAY/... 2 AM Update MVFR Fuel Alternate CIGs at AVP and RME are expected to persist for the rest of the overnight and most of the morning hours. Meanwhile, ELM and ITH are IFR and are forecast to remain so through around daybreak. SYR and BGM are LIFR, with SYR expected to jump up to just IFR in the next 1-2 hours, and remain there until around daybreak (10z). BGM will slowly improve out of LIFR, to IFR by mid-morning (14z) then fuel alt, and just MVFR CIGs for the early afternoon. The same gradual trend for improvement will occur at the rest of our taf sites as well, with most back to MVFR or low VFR by 16-18z this afternoon. SYR looks to reach VFR for a time late morning and early afternoon, before the next front moves in bringing renewed restrictions. Conditions fall back to MVFR Fuel Alt areawide after about 21-22z today...then even back to IFR at BGM and AVP expected this evening. There will be occasional periods of light rain or showers in this timeframe over the region. Drier air begins working in from the west, with fast rising CIGs at the tail end of this TAF period; ELM, ITH, SYR and perhaps RME rise to VFR by 04-06z Saturday...reaching BGM and AVP by 06-09z early Saturday morning. Southeast winds increase today, between 8-15 kts with occasional gusts around 20-25 kts this afternoon. Winds shift southwest, then westerly behind the front this evening...while also decreasing back down around 10 kts. Outlook... Saturday...Mainly VFR expected. Occasional MVFR CIGs/VSBYs possible for CNY terminals in the afternoon with sct'd showers. Sunday...VFR expected. Monday...VFR expected. Tuesday...VFR expected. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...None. NY...None. && $$ SYNOPSIS...MJM/TAC NEAR TERM...MWG SHORT TERM...JTC LONG TERM...JTC AVIATION...ES/MJM