Area Forecast Discussion
Issued by NWS State College, PA

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000 FXUS61 KCTP 211426 AFDCTP Area Forecast Discussion National Weather Service State College PA 1026 AM EDT SUN AUG 21 2016 .SYNOPSIS...
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A cold front will push through the region this afternoon, followed by a cooler airmass with much lower humidity. It will be very comfortable for much of the upcoming week. The next significant chance for rain won`t arrive late Thursday or Friday.
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&& .NEAR TERM /UNTIL 6 PM THIS EVENING/...
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Widespread showers (some containing brief heavy rain) are lifting northeast across the region late this morning. So far, widespread thick cloud cover has negated the development of cape. That should be the case for the western half of the CWA, where we expect the surface cfrontal passage to push through during the early afternoon hours. Across the east...will have to keep a sharp eye out for any appreciable breaks in the cloud cover...since moderately strong and veering low-mid level hodograph will help to create pockets of EHI in the 1.5-2.5 m2/s2 range (esp from the KSEG vcnty south and southeast during the mid-late afternoon hours. LCLs will stay low across the eastern half of the CWA as a warm front lift slowly north ahead of the cfront and helps to focus the enhanced llvl helicity. Temps across the Lower Susq Valley are already approaching 80F...and the latest SPC mesoanalysis A rather broad area of 70+ dewpoints is noted across roughly the southern two-thirds of our CWA with Tds in the upper 60s across the ncent mtns. The associated 2 inch PWAT axis will help to create an environment conducive to ocnl heavy showers and perhaps some low-topped tsra with total rainfall amts of 0.75 to 1.5 inches by this evening. Made very few changes to the timing of shra/tsra and kept mention of gusty winds for the eastern third/half of the area for this afternoon. MRGL risk for SVR continues for the eastern half of PA. The second half of the day should be fair in the wrn mtns as the dry air comes in behind the cfront.
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&& .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
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Storms/showers should be off to the east of the area around sunset. But the final push of drier air may not occur until 03z in the east. Thus, just a few shra are possible this evening. The cool air drops 8H temps down to +8-10C by midnight in the NW and over most of the area by morning. This cold air advection and cyclonic flow behind the system tonight and early on Monday could generate some lake effect showers - as the lake-8H temp diff will be 25 to 30 degs F. The subsidence and dry air will win out in short order. Clearing will complete on Monday - but the morning could be mostly cloudy in the NW third/half. Mins tonight will drop into the l-m50s in the NWrn mtns, so a little fog could form in the valleys, but the low clouds expected could keep the fog from occurring, and may also keep the temps up a little higher than currently fcst. Maxes on Monday will get near 80F in the SE, but may not get out of the 60s in the higher elevations of the west.
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&& .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... Cooler, drier air will advect into the region bringing a long period of precipitation-free weather through most of next week. The next period of active weather will come as an upper level trough moves into the region Thursday night into Friday. A front with +1 to 2 STD/anomalous PWATS progress through Friday. That should correspond with a passing but possibly weakening/shearing cold front. Dry air under high pressure is expected for next weekend. && .AVIATION /14Z SUNDAY THROUGH THURSDAY/...
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A moist southerly flow preceding a strong cold front will be accompanied by numerous mdt to briefly heavy showers with mainly MVFR cigs (ocnly dipping into the IFR category). Improving conds are expected over the western half of the state this aftn as a drier westerly flow arrives behind the cold front. Over the eastern half of the state, MVFR reductions in showers could persist through the late afternoon until passage of front. Also, a few stronger tstorms could form (near and just in advance of the on the front in a region of stronger southerly llvl flow within the 1-3 kft agl layer), and possibly affect KIPT, KMDT and KLNS during the afternoon. There is high confidence of VFR conds over most of Central Pa this evening, with the exception of KBFD, where a second batch of MVFR strato cu clouds and -shra could arrive with passage of upper level trough. Outlook... Mon...No sig wx expected. Tue-Wed...Patchy AM fog possible. Thu...Isold pm tsra impacts possible w mtns.
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&& .EQUIPMENT... The KCCX radar has been activated in order to monitor the potentially dangerous weather expected today. Radome painting is not yet complete. Therefore, the radar will likely be taken off line during the benign weather stretch in the first part of this week to allow the work to be completed. && .CTP WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Dangelo/Lambert NEAR TERM...Lambert SHORT TERM...Lambert/Dangelo LONG TERM...Dangelo/Lambert AVIATION...Lambert/Gartner EQUIPMENT...Lambert/Dangelo

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