Area Forecast Discussion
Issued by NWS State College, PA

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027 FXUS61 KCTP 241832 AFDCTP Area Forecast Discussion National Weather Service State College PA 232 PM EDT FRI JUN 24 2016 .SYNOPSIS... A nearly stationary front will linger just south of the Maryland border today. High pressure will dominate for the weekend before a cold front approaches the area Monday. High pressure should return by midweek. && .NEAR TERM /THROUGH TONIGHT/... Two main clusters of shra at this point and just a few ltg strikes in each of them. The action near the front to our south is well- handled by any model you wish to pick but... The cluster in the central mountains is not captured by the HRRR or RAP at this point - despite existiung in that general area for at least 3 hrs. Gotta go off the (guidance) grid(s) here and allow persistence and conceptual model to work their best. Upper short wave trough is swinging through right now - a little early to catch peak heating to be coincident with the best lift. Lower dewpoints in the north should limit the spread of shra to the north of the current cluster between IPT-UNV. Lowest POPs will be there for the rest of the daylight hours. Higher numbers will follow in the vicinity of those current clusters of convection. Not much cu in the SE yet, but expect some increase there with best heating and higher dewpoints in that area. Will keep POPs on the higher-end of the chance range there. As the upper trough slides eastward in the next few hours, a slight increase in the areal coverage will occur before a commesurate decrease in shra coverage for the remaining few hours before sunset. Most of the convection should be done by sunset. After sundown, a period of clearing is expected, except perhaps right along the southern border. This will allow for rapid cooling without any gradient wind. Patches of fog should start to develop before midnight and may become more widespread later tonight. Low clouds may develop in the SC/SW mountains with the flow in the lower 5 kft from the east providing lift. Mins will range from the L50s N to the L60s SE - almost exactly normal for late June. && .SHORT TERM /SATURDAY/... After any fog burns away, the moisture will lift and could form a scattered cu field along the spine of the mountains. But, the large-scale subsidence and suppression of rising upper heights should keep any cu flat. There is the smallest chance of a sprinkle, but nothing worth putting in the grids. Overall, a wonderful June day with maxes into the 80s and only a very light SE breeze. && .LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/... The large scale pattern will feature a 588+DM ridge on Sunday before an upper trough becomes established from the Great Lakes into the Northeast through the remainder of the period. A frontal boundary/surface trough at the leading edge of the upper trough will press southeastward on Monday followed by the main synoptic cold front on Tuesday. The front becomes stalled along the East Coast back into the TN valley, while high pressure migrates eastward from the Upper Midwest into the North-Central Appalachians Wednesday into Thursday. The models and ensembles are in pretty good agreement with the overall flow pattern through the end of June. There are some minor timing differences concerning the early week FROPAs with larger spread by July 1 concerning a potential wave of low pressure tracking east along the aforementioned stalled frontal zone. Temperatures should peak on Sunday and trend gradually cooler through the middle of next week, as heights remain suppressed. Convective precipitation will focus along the fronts with maximum POPs on Mon-Tue. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... So far, the shra are staying in between the terminals. Two main clusters around MGW/LBE and between UNV-IPT. Cu rather short at this point with heating limited by persistent low-mid cloud cover. Wind light and variable but generally N-E. Upper flow westerly. Enhancement in lift from weak upper trough will pass through this afternoon. This should keep shra going into the very early evening. With less heating than yesterday and lower moisture on the whole, the shra should wind down faster, mainly before 00z. Overnight will hold fog and low clouds in the SW-SC with a light easterly llvl flow and remnant moisture from shra. Will go for a brief period of IFR at most locations as those that do not have the low deck will likely clear out and radiational cooling will allow for fog there as no significant change in dewpoint is expected. The Nrn tier - esp BFD - is the least likely place to have fog due to low dewpoints. Any AM fog should burn away quickly at most sites, with KJST stuck the longest. Moisture lifts to eventually developinto a sct cu field over the spine of the Alleghenies. NW flow and general subsidence should keep the cu very short and no mention of shra necessary. OUTLOOK... Sun...No sig wx expected. Mon...CFROPA. ocnl shra/tsra. Tue...Sct pm tsra impacts poss, mainly east. && .CTP WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Dangelo/La Corte NEAR TERM...Dangelo SHORT TERM...Dangelo LONG TERM...Steinbugl AVIATION...Dangelo

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