####018007634#### FXUS61 KOKX 040231 AFDOKX Area Forecast Discussion National Weather Service New York NY 1031 PM EDT Fri May 3 2024 .SYNOPSIS... High pressure along the New England coast and into our area will remain nearly stationary into Saturday. A cold front then slowly approaches from the west on Sunday and moves across the area Sunday night into Monday. The boundary likely stalls to our south Monday afternoon through Tuesday before returning as a warm front Wednesday. A series of frontal waves may impact the area to end the week. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... Forecast remains on track this evening with only minor adjustments to account for the latest observations. A high amplitude upper ridge over the eastern third of the country will be slow to translate east through the first half this weekend. This will keep surface high pressure ridging down along the New England coast and into our area. Expect a light easterly flow to continue with varying amounts of cloud cover. Satellite imagery shows a fair amount of high clouds moving through the upper ridge axis. This could impact temperatures somewhat depending on the opacity. Lows will generally be in the mid to upper 40s, but around 50 for the NYC metro. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY/... Not much change during this time as the forecast area will remain under an easterly flow at 10 mph or less. Varying amounts of high clouds will filter through the upper ridge over the area on Saturday, which works to the east Saturday night. Clouds will lower and thicken Saturday night with some fog possible toward daybreak Sunday. Warm advection rain on the backside of the ridge, ahead of an approaching warm front, continues to trend slower. Chances of rain Saturday night remain low and mainly after midnight. Temperatures during this time will at or just below normal. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... *Key Points* *An approaching front will bring rain Sunday into Sunday night, which ends early Monday morning. Rainfall amounts average one quarter to one half inch. *The front stalls to our south early next week with limited chances for showers through Tuesday. *Unsettled conditions are likely Wednesday through next Friday, although not a wash out. Several frontal waves are possible, which may bring periods of showers, but timing is uncertain. *Below normal temperatures Sunday should trend back above normal next week. Timing of the potential precip could impact temperatures late in the week. A shortwave associated with a larger upper low over Central Canada will try to break down the highly amplified ridging over the east coast to start the long term. The guidance has continued to show a slower trend to this process with the associated frontal system not moving through the area until Sunday night or early Monday. Rain associated with the front should start in the morning west of the NYC metro and then slowly spread eastward through the afternoon. This continues to look like mainly an overrunning rainfall with little to no elevated instability. Average amounts range from around one quarter to one half inch. The shortwave axis will push offshore later Monday with the front stalled to our south and west. Another highly amplified ridge builds across the Great Lakes in response to a large upper low over the Northern Plains and Northern Rockies. There are conflicting signals in the guidance for whether or not energy will traverse underneath the ridge towards the area Monday night. This potential energy would interact with the stalled front to bring another chance of rain. However, some of the global guidance weakens the energy with the height field becoming suppressed over New England in response to an upper low over the Maritimes. A weak high pressure should build towards New England which should keep any precip, if it were to develop, mainly near the coast closer to the stalled front. Have used the NBM for PoPs with just a low chance near the coast Monday night. A piece of the ridge builds overhead on Tuesday, so this should end up being a mainly dry day. The next forecast challenge will be for Wednesday through the end of the week. The stationary front to our south and west should begin lifting back north as a warm front on Wednesday. The parent low will be associated with the upper low over the Northern Rockies and Northern Plains, but there may be a few waves along the warm front. One of these may be enough to initiate some convection Wednesday afternoon or evening. The upper low then slowly moves east towards the Great Lakes to end the week. Several frontal waves may move across or just south the area keeping conditions unsettled. Timing of these waves is highly uncertain given a late Day 5 through Day 7 forecast, so have capped PoPs off at high chance for now. Sunday will be cool with rain and temperatures in the middle to upper 50s. Conditions should begin rising back above normal next week with temperatures in the 70s most afternoons away from the immediate coastline. Have followed the NBM deterministic, but it should be noted that there is a fair amount of spread in the guidance, especially later in the week due to the potential precip. && .AVIATION /03Z SATURDAY THROUGH WEDNESDAY/... High pressure remains along the New England coast and into our area through Saturday. VFR to start. Cigs may fall once again into late tonight into Saturday morning with potential stratus development, though confidence is too low to prevail at this time. Left a TEMPO group for this possibility generally from 06/08Z-10/12Z Saturday. An E/SE flow with speeds around 10 kt or less will shift to the E overnight for the city terminals, and become light and variable for the outlying terminals. SE winds on Saturday with speeds at or below 10 kt. ...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty... There is uncertainty with the development of MVFR or lower clouds tonight. Best timing for this is between 06Z-10Z. OUTLOOK FOR 00Z SUNDAY THROUGH WEDNESDAY... Saturday Night: MVFR to IFR. Increasing chance of showers overnight. Sunday...Likely showers, with MVFR or lower conditions. ESE winds G15-20kt. Monday...VFR. Tuesday... Mainly VFR. Chance of MVFR showers. Wednesday...MVFR or lower with a chance of showers. Detailed information, including hourly TAF wind component forecasts, can be found at: https:/www.weather.gov/zny/n90 && .MARINE... Sub-SCA conditions are forecast to start the weekend with high pressure along the New England coast maintaining an easterly flow across the waters. Winds will generally be around 10 kt. Winds and seas should remain below SCA criteria Sunday the middle of next week with a weak pressure gradient in place. There may be an increase in winds closer to 20 kt and seas building to around 4 ft, but conditions are expected to remain below SCA levels. && .HYDROLOGY... There are currently no hydrologic concerns through next week. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...None. && $$ SYNOPSIS...DS/DW NEAR TERM...DW/MW SHORT TERM...DW LONG TERM...DS AVIATION...MW MARINE...DS/DW HYDROLOGY...DS/DW ####018005030#### FXUS64 KLIX 040233 AFDLIX Area Forecast Discussion National Weather Service New Orleans LA 933 PM CDT Fri May 3 2024 ...New UPDATE... .UPDATE... Issued at 928 PM CDT Fri May 3 2024 Overall, forecast is in decent shape, although may push an update just to remove evening low end PoPs from northwest corner of the CWA. Will also update hourly temperature/dew point grids to reflect current trends, but not adjusting overnight lows at this time. There is at least a small threat of fog over southwest Mississippi overnight for a few hours, but we've already got a mention of fog there. Not enough confidence to justify an advisory at this time. && .SHORT TERM... (This evening through Sunday) Issued at 347 PM CDT Fri May 3 2024 An MCS that developed near the southeast Texas/southwest Louisiana border last night is now almost completely east of the CWA. After peaking in intensity nearly 12 hours ago, it's steadily weakened and is barely discernable on radar. Even with an embedded MCV, still seen on radar in southwest Mississippi, there's no appreciable winds associated with it. The remainder of the afternoon and evening may still have intermittent rain in the early portions of this period. KLCH radar shows continued thunderstorms along a residual outflow boundary along the coastline. Latest trends as well as CAMs suggest that convection will remain along the coast with just a few showers possibly reaching western portions of SELA before all dissipating around sunset. For Saturday, the CWA remains in a region between ridging to the southwest and trough to the northwest. There's some hints on the 500mb maps that indicate a weak shortwave will pass across the area. Not sure how much that matter with mid 80s to 90 degrees at the surface, still cool aloft, and ample moisture at the surface. This setup is pretty textbook early summertime pattern with the potential for afternoon thunderstorms. Although not outlooked by SPC, marginally severe storms with hail and gusty winds will be possible. Coverage will be limited, however, so may only see a couple to few storms with any appreciable intensity. Sunday will be nearly a complete repeat of Saturday with yet another shortwave passing SW to NE across the lower MS Valley and possibly aiding in the development of afternoon storms. Looking at same area of impact...SW MS and adjacent LA parishes. Probably won't see much, if any, convection south of I-12. && .LONG TERM... (Monday through Thursday night) Issued at 347 PM CDT Fri May 3 2024 The upper level flow pattern along the Gulf Coast will be somewhat zonal but with a slight northern expansion of the ridge centered south of the local area. This will provide subsidence to stunt convection as well as moderate already above normal temps. Guidance spread is surprisingly minimal mid week when forecast temps are in the lower to mid 90s. No, not earth shattering warm, but that's at or above records for this time of year. Heat Risk will likely be elevated for sensitive groups. && .AVIATION... (00Z TAFS) Issued at 626 PM CDT Fri May 3 2024 All terminals currentlyy VFR, although a few are reporting scattered clouds around FL020-025. Later in the night, expect MVFR ceilings to become fairly common, but the only terminal I currently have forecast to experience IFR or lower conditions would be KMCB (LIFR) for a few hours around sunrise. Cumulus redevelopment expected around 14-15z Saturday, with MVFR ceilings possible. there's at least some threat of convective development across northwest sections by the afternoon hours. Will carry VCTS at KMCB/KBTR/KHDC from about 19z Saturday until sunset. Can't rule out remaining terminals seeing at least isolated convection Saturday afternoon, but probabilities too low to mention in the forecast at this time. && .MARINE... Issued at 347 PM CDT Fri May 3 2024 MCS feature mentioned in previous forecast passed right along the Louisiana and Mississippi coastlines. It steadily decayed throughout the day which limited its ability to produce winds over 30kts. Residual westerly winds from this MCS are collapsing and gradient onshore flow will resume. Surface ridge centered east of the region and extending across the Gulf of Mexico will maintain southeasterly winds around 10 to 15kts throughout the week. && .PRELIMINARY POINT TEMPS/POPS... MCB 63 85 64 83 / 10 30 10 40 BTR 68 89 69 87 / 10 20 0 40 ASD 68 87 69 86 / 10 20 0 20 MSY 71 87 72 86 / 10 10 0 20 GPT 69 84 69 84 / 10 10 0 10 PQL 67 87 67 87 / 10 10 0 10 && .LIX WATCHES/WARNINGS/ADVISORIES... LA...None. GM...None. MS...None. GM...None. && $$ SHORT TERM...ME LONG TERM....ME AVIATION/UPDATE...RW MARINE...ME ####018005239#### FXUS65 KTFX 040234 AFDTFX Area Forecast Discussion National Weather Service Great Falls MT 834 PM MDT Fri May 3 2024 .SYNOPSIS... Lingering showers and snow showers will be around through the early evening ahead of a mild and dry Saturday. Precipitation chances will return Sunday into much of next week, with potential for an impactful spring system over the middle of next week. && .UPDATE... Surface high pressure is dominant across the state this evening. Rain showers have dwindled down as skies continue to clear. No major changes were made to the update as dry weather stays overnight. Patchy fog will be limited due to drier air at the surface. -Wilson && .AVIATION... 600 PM MDT Fri May 3 2024 (04/00Z TAF Period) More stable air is moving into the CWA this evening, as a cold pocket of colder air is moving away to our east. This will result in cloud cover becoming more scattered this evening, along with any remaining light rain/snow showers diminishing. Generally expect a quite day on Saturday, with VFR conditions prevailing. Brusda Refer to weather.gov/zlc for more detailed regional aviation weather and hazard information. && .PREV DISCUSSION... /ISSUED 600 PM MDT Fri May 3 2024/ Through Saturday...Transient shortwave ridging is beginning to build in across the Northern Rockies between one upper disturbance exiting eastward across Southern Canada and another approaching the Pacific NW. Lingering northwesterly flow aloft will combine with daytime heating to result in rain and snow showers the remainder of this afternoon and early evening, primarily across the plains. Clearing skies and light winds tonight will allow for patchy fog formation into Saturday morning, but is not expected to pose many impacts at this time. Saturday looks to be a pleasant day as the aforementioned ridge moves overhead, with the only potential blemish being breezy easterly to southeasterly winds across the plains in the afternoon. Daytime highs look to rise to near to a touch above average in most areas. -AM Saturday night into next week...Deep southerly flow aloft develops over Southwest MT Saturday night ahead of a closed low moving onto the Pacific NW coast. This system will trek eastward into S ID on Sunday, placing the Northern Rockies on the ascent side of the system for northward expansion of shower and isolated thunderstorm activity, though temperatures will remain near average for one more day. H700 flow slows down by Sunday afternoon and MU CAPE looks to be around 100 to 300 J/kg (highest southwest MT), so not expecting anything beyond general thunderstorm risks at this time. Ensembles remain in decent agreement with the aforementioned closed low swinging NE into E MT and slowing down some Monday through early Thursday. Although, there are differences on the precise path of the low, most favor cool, wet, and windy periods during this timeframe. According to the NAEFS Standardized Anomaly, H700 temperatures are forecast to be around -8C for much of this event, which would support mountain accumulating snow, but mostly rain at lower elevations. Current probabilistic forecasts for rainfall highlight the eastern portions of North-central MT with the highest chances (50 to 70%) for 1 inch of rainfall during the 72 hr period ending next Thursday at 6 am, with nearly all locations in the CWA standing at least a 50% for a quarter inch of rainfall for the same time period. The one drier exception looks to be southwestern valleys from Dillon to the Three Forks area. As mentioned earlier, thermodynamic profiles should confine accumulating snow to mountain areas, with the Little Belts and the Madison/Gallatin ranges seeing 60% + chances for 8 inches of snow or more Monday through Thursday, with most of it falling Tuesday night into Wednesday. H700 flow on the backside of this low will be at or above the 30 to 40 kt range for an extended period, resulting in gusty to at times strong northwesterly surface winds. While all days Monday through Wednesday look to be on the windier side, Tuesday is being singled out by the EC Extreme Forecast Index and NBM probabilistic forecasts as the windiest day overall, with many locations seeing 70% + chances for wind gusts above 40 mph. Drier and milder conditions move in for Thursday and Friday of next week, though around 50% of the ensembles support weaker troughing remaining in place for non-zero chances for precipitation and near average temperatures heading into next weekend. - RCG && .PRELIMINARY POINT TEMPS/POPS... GTF 29 64 42 63 / 0 0 10 40 CTB 28 60 37 59 / 0 0 10 30 HLN 32 69 44 69 / 0 0 10 60 BZN 27 67 42 65 / 0 0 10 70 WYS 21 60 36 52 / 0 0 30 90 DLN 30 66 43 60 / 0 10 40 70 HVR 27 64 39 71 / 0 0 0 20 LWT 25 59 36 65 / 10 0 10 30 && .TFX WATCHES/WARNINGS/ADVISORIES... None. && $$ http://www.weather.gov/greatfalls