####018007692#### FXUS61 KGYX 031342 AFDGYX Area Forecast Discussion National Weather Service Gray ME 942 AM EDT Fri May 3 2024 .SYNOPSIS... High pressure near the coast will provide a drier and quieter couple of days between today and Saturday, however, it will also contribute to a growing onshore flow this weekend. Thickening clouds, cooler temperatures and rain showers are expected by Sunday... with clearing likely not coming until Monday. Warmer and sunnier conditions are expected Monday and Tuesday, then more unsettled weather returns around the middle of next week. && .NEAR TERM /UNTIL 7 PM THIS EVENING/... 945 AM Update... Minor changes to reflect latest observational trends. Partly sunny skies will persist through the day with warmer high temperatures than yesterday. Previously... Impacts: *No significant weather impacts expected 1030 AM UPDATE...Breaks in the clouds are making for a sunny morning in many places. Fog is still present in many of the valleys, but that is expected to dissipate over the next couple of hours. This update was the usual refreshing of near term temperature, dewpoint, and sky trends with observations. Previous Discussion... Clouds continue to roll over the ridge this morning, however a clear slot did develop overnight allowing fog to form and some areas to quickly drop a few degrees. Now, as the mid- level cloud deck fills back in, fog is dissipating and temperatures are plateauing. As the ridge moves overhead and surface high pressure builds in today, skies will gradually clear and with BUFKIT soundings showing a return to good mixing, high temperatures should climb into the 60s areawide. The only exception would be the coast where the seabreeze will keep temperatures in the 50s. && .SHORT TERM /7 PM THIS EVENING THROUGH 6 PM SATURDAY/... Impacts: * No significant weather impacts expected Skies will remain partly cloudy overnight which will keep us from having a widespread radiational cooling night, but with continued light winds there is opportunity for patchy dense fog and some quick temperature drops in areas that can find some clear skies. Generally low temperatures look to be in the low to mid 40s across the area with some upper 30s north of the mountains. The 500mb ridge axis inches ever closer, but models suggest the offshore upper low keeps the pattern pretty blocked up for Saturday. Expect clouds to increase through the day as we see warm moist advection from the southwest. BUFKIT profiles suggest another well mixed day so the clouds shouldn't keep us from once again climbing into the 60s across most of the area, with the coast once again topping out in the 50s due to the seabreeze. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... An upper level ridge this weekend is replaced by an upper level trough to start next week, with rainy and cool weather eventually yielding to a drier, warmer couple of days to start the upcoming work week. Another frontal system approaches with increasing rain chances around the middle or latter part of next week. All in all neither of these systems look to be particularly impactful in terms of a significant hydrological or convective threat, and overall this will be a stretch of typical Spring weather with an active but ultimately benign pattern. Starting Saturday night... high pressure along the eastern periphery of Maritime Canada and a cold front approaching from the Great Lakes continue to produce onshore flow into New England. Clouds will fill in through the low and mid-levels especially south and east of the mountains into Sunday, with potential for fog and perhaps some patchy drizzle development during the morning as an upper level ridge rolls overhead. Shower chances meanwhile will increase from the west through the day Sunday amid pressure and height falls... culminating in a likely period of rain as a pre-frontal trough crosses Sunday afternoon and/or evening. Although the cold front itself won't cross until Monday, the moisture axis will be attached to the pre-frontal feature... with generally 0.2-0.4" of rainfall. Temperatures meanwhile won't warm too much on Sunday thanks to warm advection atop the cool marine layer, with highs generally in the 50s... coolest in the 40s along the coast. In terms of sensible weather conditions, a question will be the progression of the cold front itself as its passage will bring fresh westerly flow. There will be a gap between the bulk of the rain/deep moisture exiting late Sunday and the low-level humidity being flushed out with the cold front on Monday. Thus, would expect the overnight to remain a bit damp with fog and drizzle potential. Current model consensus mixes this out through the mid- or late- morning hours, with a mix of sun and clouds and far warmer temperatures on Monday. Highs are forecast to be in the 60s and 70s, coolest in the north where upsloping clouds and a few showers are expected to remain. Light winds and the warm temperatures should allow a sea breeze to develop. Upper level low pressure settles across Maritime Canada and a ridge axis nudges east toward New England. Resultant northwest flow reinforces the drier airmass with what looks to be a great day on Tuesday... featuring temperatures again warming into the 60s and 70s, light flow, an afternoon seabreeze, and what will likely be partly or mostly sunny skies. Forecasting the upper air pattern becomes a bit fuzzy toward the middle of next week with an increasingly blocked pattern and a general trend toward more zonal flow over the Northeast with the jet nearby or overhead. This introduces the potential for shortwaves moving through the jet to bring showers across the area... and indeed have PoP and cooler temperatures on the increase again toward the middle of the week. && .AVIATION /14Z FRIDAY THROUGH TUESDAY/... Short Term...A mixed bag of LIFR/IFR/MVFR ceilings early this morning will gradually improve to VFR as the day goes on. We will most likely return to areas of LIFR in fog tonight, but quickly improve back to VFR Saturday. Winds will be light and variable across the area. Long Term...Periods of IFR are likely Sat night through Mon morning with light SE flow turning N thru Sun, then SW or W Mon. Prolonged and more significant restrictions are most likely along the coast with low CIGs and some lowered VSBY... with all terminals expected to have at least a few hours of restrictions with -RA crossing the area on Sunday. Conditions trend back to VFR Mon, except potentially MVFR CIGs in the north... then all VFR on Tue. && .MARINE... Short Term...Conditions hazardous to small craft are not expected. High pressure building over the waters will keep winds light and variable through tonight, with an afternoon seabreeze developing. For Saturday, winds will be blowing onshore at around 8-10 kts. Long Term...SE flow across the waters Sat night increases to around 10-15 kts sustained by late Sun...with potential for fog and rain thru Mon morning. A front crossing the waters brings clearer conditions late Mon into Tue, with light winds generally out of the west (NW or SW) into midweek. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...None. NH...None. MARINE...None. && $$ NEAR TERM...Tubbs SHORT TERM...Baron LONG TERM...Casey ####018008727#### FXUS61 KPBZ 031345 AFDPBZ Area Forecast Discussion National Weather Service Pittsburgh PA 945 AM EDT Fri May 3 2024 .SYNOPSIS... Dry and unseasonably warm weather precedes increasing precipitation chances Friday afternoon and continuing through the weekend. Cooler, but still above average, temperatures prevail Saturday and Sunday with warm and unsettled weather continuing into next week. && .NEAR TERM /THROUGH TONIGHT/... KEY MESSAGES: - Showers and thunderstorms Friday afternoon and evening. - Temperatures well above average approaching a few records. ------------------------------------------------------------------- Did another minor refresh to the grids for today. Do think that the thickening cirrus will mute the temperature rise slightly today, and have 84-87 degrees as a top-end range for much of the area. Although a shower or two may creep into the ZZV area this morning, the bulk of the shower/thunderstorm activity is still projected to kick off during the mid to late afternoon hours. .. Previous Update .. High pressure will retreat off to the east as a disturbance approaches from the west. Cirrus coverage will thicken and lower through the morning with increasing upper level moisture. Forecast soundings suggest another day similar to Thursday with a quickly breaking nocturnal inversion and a dry boundary layer allowing for mixing up to nearly 700 mb. The 850 mb ridge will gradually shift to the east and allow for warm advection in southwesterly flow to bring layer temperatures up to 15-16C across the area by afternoon, suggesting that high temperature will achieve the mid to upper 80s despite the cirrus. A couple sites have the potential to approach record highs (see climate section). Some lingering uncertainty in ensemble cloud coverage with suggestions for periods of scattering as cirrus push to the east lends potential for additional insolation to push temperatures up even a degree or two higher than currently forecast. This also could aid in a bit more destabilization ahead of showers and thunderstorms expected to develop by afternoon. Indications are that showers and storms pop after 17z despite copious low level dry air (LCLs 6-8kft) as convective temperatures are met and a shortwave moves through, though weak net height rises through the day are expected. Mean hi res ensemble CAPE has increased in the latest run with 600-900 J/kg; conditional on potential scattering of clouds, the 75th percentile is up to 1400 J/kg. Most guidance suggests that warm mid-levels will suppress updrafts with an equilibrium level below about 500mb. Latest CAMs suggest that the best shot for deeper convection may be across eastern Ohio where slightly less warmth and moisture in the mid-levels may allow for greater vertical growth. Even if the higher end of the instability spectrum is achieved, weak cloud bearing layer flow will present a moderate CAPE/low shear environment likely more favorable of gusty wind with brief heavy downpours. PWATs will be pushing 1.5" and upwind propagation vectors around 10 knots despite practically no low level jet suggest this potential. HREF probs for >0.5"/hr rates reach up to around 60% by evening. As a result, the Weather Prediction Center has our area in a Marginal Risk (1/5) for excessive rainfall on Friday. Record low max temperatures may be broken Friday night with persistent cloud cover not allowing for radiative cooling. Convection is favored to wane as instability is lost and the upper wave departs. Nonetheless, scattered showers will continue overnight. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... KEY MESSAGES: - Unsettled pattern remains with rain chances continuing through Sunday. Thunder possible on Sunday. - Temperatures drop, but still remain above normal. ------------------------------------------------------------------- Come Saturday, there is some suggestion the trough progression will come to a halt and allow rain to persist ahead of it being reinforced by approaching low pressure and additional shortwave support arriving from the south. The positioning of the trough will have a great influence on the weekend weather. No significant changes to the forecast for Saturday as instability looks limited to the western side of the stalled boundary/trough with a 50-60% of >500 J/kg while elsewhere plenty of low to mid level warm air will cap the environment. Total rainfall Saturday is favored in the half to three quarters of an inch range. There is good agreement the trough finally pulls through by Sunday. An area of maximized precipitation ahead of or just along the trough axis is favored, as is a greater chance for more instability to work with. Ensemble probability for CAPE >500 J/kg reaches 70-80% Sunday, but with a good amount of clouds around and a low probability of any scattering. Still, with a bit better dynamics in play and marginal instability, a few thunderstorms accompanying the trough appear possible. Most likely total precipitation amounts Friday night - Sunday night sit around 1.0-1.3", but the 90th percentile exceeds 2" primarily across the WV panhandle and western PA resultant of some convective enhancement along the aforementioned trough. This does not raise any flooding concerns for now, but may warrant watching if the higher end becomes more likely. Thick cloud coverage through the weekend will hold temperatures in check, but still above average, in the 70s. && .LONG TERM /MONDAY THROUGH THURSDAY/... KEY MESSAGES: - Rain chances continue into early next week but more uncertainty lends lower confidence. - Temperatures favored to remain above normal. ------------------------------------------------------------------- After a brief lull in the precip late Sunday night into early Monday morning as flat upper ridging slides through and surface high pressure meanders on by, rain chances again increase. Seeing some better ensemble agreement for Monday with shortwave low pressure approaching from the southwest but weakening as the responsible upper wave flattens out. High pressure to the north should keep the highest precipitation chances south of I-70. Much more ensemble spread comes into play after Monday primarily with the progression of the upper pattern as ridging tries to develop but a deep upper low across the Dakotas throws shortwave energy to the east and tries to break the ridge down. A warm front likely lifts through sometime Tuesday into Wednesday increasing rain chances again, but with uncertainty in the strength and positioning of the ridge, timing and precipitation amounts remain low confidence at this time. && .AVIATION /14Z FRIDAY THROUGH TUESDAY/... VFR conditions through most of the day, with high clouds increasing this morning and mid clouds this afternoon. Scattered showers and thunderstorms are expected to develop late this afternoon and evening. Expect locally lower ceilings and visibilities, lightning, and possibly some gusty winds to accompany any stronger storms. The probability that a storm will hit any particular port is low at this time so will use prob30 to cover the convection threat. Activity should dissipate with the loss of sunlight. Lower clouds are possible late tonight. .Outlook... Restriction potential continue through Saturday, then again early next week as multiple disturbances cross the region. && .CLIMATE... Some record highs may be approached on Friday as well as record lows on Saturday. (* denotes current forecast temperature exceeds value) 5/3 Record High Year Pittsburgh 95 1887 Wheeling 90 1942 Morgantown 88 1965, 2012 New Philadelphia 89 2012 Zanesville 91 1938 Dubois 84 2012 5/4 Record Low Year Pittsburgh 65 1938 Wheeling 63 1931, 1939, 1941 Morgantown 63 2021 New Philadelphia 60* 2012 Zanesville 65 1902 Dubois N/A N/A && .PBZ WATCHES/WARNINGS/ADVISORIES... PA...None. OH...None. WV...None. && $$ SYNOPSIS...MLB NEAR TERM...MLB/CL SHORT TERM...MLB/Milcarek LONG TERM...MLB AVIATION...22/Milcarek CLIMATE...MLB