Area Forecast Discussion
Issued by NWS Binghamton, NY
Issued by NWS Binghamton, NY
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365 FXUS61 KBGM 291953 AFDBGM Area Forecast Discussion National Weather Service Binghamton NY 353 PM EDT Mon Apr 29 2024 .SYNOPSIS... A warm front across the region today will allow for isolated rain showers and thunderstorms across the Twin Tiers this afternoon and evening. The warm front moves north tonight, bringing isolated rain showers to the area. A cold front passage tomorrow brings widespread rain showers and thunderstorms during the afternoon and evening hours. Some of these storms may be severe. && .NEAR TERM /THROUGH TUESDAY/... 330 PM Update... The frontal boundary remains draped across the Southern Tier, with 80s to the south and mid 60s to low 70s to the north. Some isolated showers and storms are expected to develop along and just south of this front boundary where CAPE is climbing above 1000 j/kg. Some patches of 0-6km bulk shear around 20-25kts may allow for these storms to get a little more organized and produce some gusty winds, but severe chances are currently very low. These shower and storm chances are expected to last into the evening hours. Tonight, guidance is showing the warm front pushing north, which should generate some scattered rain showers and isolated thunderstorms across NY, moving from SW to NE. Given the already warm and moist boundary layer, any additional rain will help generate patchy fog, especially in river valleys. Lows tonight will be very warm thanks to the warm front pushing north with mid 50s to low 60s expected. Oneida county should remain in the low 50s as it looks like the warm front will not move through the area. Where rain falls will create cold pools, with temperatures falling into the low 50s. The forecast for Tuesday is complicated with many features in play that will either help or hinder severe thunderstorm development ahead of the approaching cold front. Rain Monday night could create cold pools, where morning temps are several degrees cooler than currently forecasted, causing CIN to be higher than currently modeled. The showers are expected to be scattered so confidence in where this will occur is low. Also, a marine layer is expected to work its way into the Catskills, Poconos and maybe even into areas near I-81 in the Twin Tiers, as some high- res model soundings suggest. This would keep morning temperatures cooler, increasing CIN chances. Model guidance is also putting a lot of mid-level cloud cover over the region during the morning hours, increasing CIN and reducing CAPE in the afternoon. Having said all of that, there does look like a period of clearing occurring across NEPA west of the Poconos, extending up into the Finger Lakes and CNY south of the Mohawk Valley. Current modeled conditions show CAPE values reaching around 1000 j/kg in the afternoon, with 0-6km bulk shear values in the 30-40kt range. If the CIN factors from above can be limited, we could see some discreet supercells form in the early afternoon. Soundings show enough dry air in the mid levels that microbursts will be possible. There are chances for small hail as well over CNY and NEPA, with the better chances for seeing hail approach severe criteria over Luzerne county as 700-500mb lapse rates are approaching 7.5C and we have more CAPE in the hail growth zone. The best chance for severe weather will be during the passage of the cold front where storms shift from discreet to more of a squall line, pushing through during the afternoon and into the evening. Severe parameters are not signaling high chances for a widespread severe weather threat, but isolated pockets along the line will bring gusty winds given the modeled dry air in the mid-levels. Hydrologically, the system is modeled a little more progressive than in previous runs, especially across CNY. PWATs will approach 1.5in along the front, allowing for heavy downpours and isolated flash flooding. NEPA, especially Wyoming, Lackawanna, and Luzerne counties have a greater chance for flash flooding as some CAMs are showing a couple rounds of heavy rain chances within a few hours of each other. The severe threat should end by mid-evening as the tail end of the front should be moving out the NEPA by then. Some rain showers may linger east of I-81 as a few weak shortwaves ripple through the mid-levels. Even with the passage of the cold front, temps are going to remain warm for this time of year, with lows falling into the low to mid 50s across CNY and mid to upper 50s in NEPA. SPC has placed us in General Thunder as of now, given the low confidence in severe weather chances. An upgrade to Marginal will be possible later tonight when hopefully model guidance has more certainty. && .SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/... 350 PM Update... The short term is looking mostly dry and a little cooler compared to the start of the week. Upper level ridging builds in Wednesday with a surface high moving off to the east. Weak cold air advection aloft will cool off 850 mb temperatures a little bit so highs will be 5 to 10 degrees cooler than Tuesday but still above average. Ridging with zonal flow continues Wednesday night into Thursday night with temperatures continuing to remain above average. Forecast soundings show a subsidence inversion present Wednesday into Thursday night so convection is unlikely with the best chance for any showers or thunderstorms being in the Catskills and Poconos where terrain could help break the capping. && .LONG TERM /FRIDAY THROUGH MONDAY/... 350 PM Update... The long term is looking somewhat active with the long wave ridge axis moving east of the region opening up the northeast to more frequent shortwaves with predominantly SW flow. Temperatures are a little more uncertain especially for the weekend as there are quite a few ensemble members that have strong high pressure off of the New England coast with colder onshore flow helping to suppress highs. There is decent amount of spread especially since ensemble members that do not have as strong of high pressure or dont have the marine layer push far enough west keep highs in the low 80s. Precipitation chances were largely kept through the long term especially in the afternoon with day time heating and good low level moisture in place. Also given the set up with high pressure moving off the New England coast this weekend, an approaching front will likely slow down and if that can slow over our region, then greater amounts of rain would be possible. && .AVIATION /20Z MONDAY THROUGH SATURDAY/... A front draped across CNY brings cloudy and MVFR conditons to RME and SYR with the rest of our terminals VFR. Some isolated showers and thunderstorms are expected to develop later this afternoon, which could impact ELM/ITH/BGM/AVP. They will be too scattered to be able to nail down timing of impacts at any particular terminal, but development chances are greatest from mid to late afternoon into the evening hours. If a heavy shower passed overhead, MVFR restrictions will be possible. Another round of isolated rain showers may develop tonight, moving from SW to NE across the area, with ELM/BGM/ITH/SYR/RME having a chance to see some showers in the area. Again, confidence is way too low to forecast restrictions at this time, but if a shower does move overhead, MVFR will be possible. High pressure overhead combined with the aforementioned showers will prime the ground for a chance of patchy fog forming later tonight. ELM has the best chance for IFR restrictions, followed by BGM and AVP as a marine layer will work its way into the region. Signals in guidance are there for IFR conditions, but confidence is not high enough to include it in the TAFs at this time. Outlook... Tuesday Afternoon... Restrictions likely in rain showers and thunderstorms, between 18Z and 00Z Wednesday. Stratus and fog then possible after 00Z Wednesday. Wednesday...Lingering morning clouds and restrictions possible, becoming VFR in the afternoon. Thursday...VFR Likely. Friday..Mainly VFR, but late day showers/t`storms possible. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...None. NY...None. && $$ SYNOPSIS...JTC NEAR TERM...JTC SHORT TERM...AJG LONG TERM...AJG AVIATION...JTC