textproduct: State College

WHAT HAS CHANGED

* Keeping an eye on rain amounts/intensity in the SW

KEY MESSAGES

1) Numerous showers ahead of a cold front will die off as we lose the heating of the sun.

2) An unsettled but not particularly wet period is expected mid to late week.

DISCUSSION

KEY MESSAGE 1: Numerous showers ahead of a cold front will die off as we lose the heating of the sun.

The cold front is advancing through northern PA showing up as thin line of shallow convectionm at 3 PM. The air behind the front is not all that dry, but enough of a change should take place that those in nrn PA should notice tonight and Tuesday. The immediate showers and a couple of thunderstorms out ahead of the front in the 68-71F dewpoint airmass seem to be moving along consistently/quickly. But, some training is starting to occur. We'll have to keep an eye on the radar and radar/gauge estimates to exceed FFG. But, thus far, the heaviest rates do not get to that level of worry. Not thinking of a flood watch at this point with the threat sub-concerning. The stronger forcing will linger over the NE counties early this evening, but most of this convection will die off around sunset.

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KEY MESSAGE 2: An unsettled but not particularly wet period is expected mid to late week.

After a dry 36 hrs tonight thru Wed AM, a short wave trough rotating around the base of the deep upper low over Hudson & James Bays. It will be the next help to lift and destabilize the air over PA. Expect some showers to impinge upon Warren Co in the aftn on Wed and spread along the NY border. Some of them could advance another county to the south before daylight wanes and they die off. Precip chcs Wed night and Thurs AM now look a little lower than previous forecasts. But, isolated showers are still possible then. Heights do dip for real on Thursday/night and will probably develop a weak low pressure system to our south. That low will push east to the sea Friday. Some light to moderate rain should overrun the boundary to our south and make the southern half of the CWA wet - but not too wet - on Thurs night and early Friday. Model agreement lowers for the weekend, clouding the crystal ball. PoPs end up at 40-50% Sat and Sun without confidence in the forecast being either wet or dry.

AVIATION /18Z MONDAY THROUGH SATURDAY/

Scattered showers are moving across PA as of 18Z this afternoon. As these move southeast, the sites most likely to see effects from this activity are JST, AOO, and IPT. Thunder is likely to accompany the strongest cores, but will remain spotty, said cores have IFR visibility potential. The scattered nature of these storms means exact impacts to sites such as UNV, MDT, and LNS are more uncertain this afternoon with confidence < 30% of impacts to any one site. Regardless, these sites may need to be watched for a quick amendment if they cross paths with a stronger core of precipitation. VFR otherwise into the night.

As a cold front sweeps through the state, drying air will shunt precipitation off to the south overnight and into Tuesday. Lingering moisture and clearing skies are likely to lead to visibility restrictions and low cloud ceilings across most sites overnight and into early Tuesday morning. MDT and LNS look to be the least impacted from these restrictions, although some visibility drops are possible and may depend on how much rain falls this afternoon. Once this activity burns away with the sun rising, a dry, less cloudy postfrontal environment follows with VFR categories.

Outlook...

Wed... VFR conditions with restrictions from afternoon SHRA/TSRA possible in the northwest

Thu... Afternoon SHRA/TSRA with brief restrictions possible. Otherwise, VFR conditions.

Fri...Chance of SHRA across the south, restrictions possible, otherwise dry.

Sat...Chance of SHRA statewide, restrictions possible

CTP WATCHES/WARNINGS/ADVISORIES

None.