Marine Weather and Tide Forecast for Millersville, PA

NEAR TERM /THROUGH TONIGHT/
GOES afternoon imagery shows considerable cloudiness covering the northern 2/3 of central PA as northwest flow regime weakens and drier air and some sunshine reaches into the southern 1/3 of central PA. Imagery also showers a northern stream 500mb trough dropping from the northern GLAKS towards the St. Lawrence Valley. REgional radar mosaic shows a light shield of flurries and snow showers extending from Lake Ontario across the northern portion of Lake Erie and into the Fingerlakes Region. Model consensus continues to show WAA snow showers staying mainly to the north of the PA/NY border through this evening, but areas north of Route 6 may be brushed by flurries or snow showers through late tonight.

Breezy conditions are expected to increase overnight with the passage of sfc trough. Hires ensemble data shows a non diurnal temperature trend in play with 12hr min temps (in the mid 20s to low 30s) likely reached shortly after 00Z followed by a neutral to slowly rising curve through daybreak Sunday.

SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/
Zonal flow aloft will deliver much milder conditions by Sunday afternoon despite continuing cloudiness. The warmup will last from Sunday afternoon through Tuesday, with max temps projected to rebound 5-10F vs. Saturday and climb into the 40-50F range (give or take a few degrees either side) by Monday.

Strong WAA continues Sunday night downstream of lead southern stream shortwave reaching the middle OH/TN Valley by 12Z Monday. Models trending faster than previous runs with the arrival of precip late Sunday night, bringing the potential onset prior to 12Z Monday especially across the western part of the forecast area. This increases the risk of a wintry mix or freezing rain on the front end of precip shield and some areas could see AM Monday commute impacts. There is very high confidence in measurable precip covering all of central PA in the 12-18Z window.

The anticipated timing and evolution of precip pattern favors undercutting NBM highs for Monday with a very tight (<=3F)
max/min temp spread -- thanks to saturated low level moisture profiles and continued WAA via southerly flow.

LONG TERM /TUESDAY THROUGH SATURDAY/
EPS/GEFS still tracks a cold front across Central PA Tuesday night, which is likely to be preceded by scattered rain showers.
Temperatures could potentially spike well into the 50s ahead of this front Tuesday afternoon if the region breaks into the warm sector ahead of the approaching front. It's looking increasingly likely that a changeover to snow before ending occurs on the backside of this system as the cold air catches up to the stalled baroclinic zone on Wednesday. A trend toward drier and colder conditions is then expected behind the front. However, an upstream mid level trough and potential secondary cold front will keep the chance of a few rain showers in the forecast Wednesday. A seasonably cold northwest flow is likely to result in scattered lake effect snow showers over the W Mtns by Thursday, followed by drier and a glancing shot of colder air to end the week and start next weekend.

AVIATION /20Z SATURDAY THROUGH THURSDAY/
Current satellite view shows lower clouds still holding on tough across central and northeast PA. MVFR to VFR conditions will continue into the evening in these locations. Clearing has made its way to locations along and to the south of a YNG-JST-HAR- PTW line or genrally Low Enroute V12.

Expect conditions to improve to good VFR in all locations as the evening moves along. High clouds from an approaching weak weather system will keep and BKN-OVC FL150-200 overnight.

A core of strong westerly winds aloft will overspread the entire region overnight with LLWS a possibility at most locations. Wind speeds around 2,000 AGL will generally be around 50KTS.

The above mentioned low pressure passing north of the region could potentially spread a bit of light snow into extreme Northern PA (KBFD) by Sun AM. However, odds favor it will not make it south of the NY border.

Outlook...

Sun...Low cigs possible NW Mtns.

Mon...Rain/low cigs likely.

Tue...Low cigs possible, mainly N Mtns.

Wed...Rain/low cigs possible. Possibly turning to snow over the Central Mtns.

CTP WATCHES/WARNINGS/ADVISORIES
None.