Marine Weather and Tide Forecast for Butler, MD

NEAR TERM /THROUGH THURSDAY/
Low pressure in the Ohio Valley gradually weakens while a new surface low develops off the Mid-Atlantic coast by late today. These will result in periods of rain and much cooler air through Thursday.

An extensive upper-level trough will evolve into the East today and tonight, then this shifts eastward through Thursday. Additional energy diving into this trough will result in cyclogenesis near the lower Mid-Atlantic coast by later today. The initial low in the upper Ohio Valley to the eastern Great Lakes looks to remain as it becomes embedded beneath a closed low or the trough axis itself. As we go through today, some initial warm air advection aloft will drive forcing for ascent across our area. This will result in an expanding shield of rain through early/mid afternoon, although there looks to be some breaks in the rain by later this afternoon especially across the southern areas as the initial organized forcing shifts northward. During these breaks though, some drizzle will be quite possible as the model forecast soundings overall show a period of mid to upper level drying while the low levels remain moist. This may also result in a more showery pattern evolving across Delmarva especially this afternoon. Also, the leading edge of the rain today looks to battle some lingering dry mid level air and therefore it should be rather light or even sprinkles to start and also may take longer to reach our far northern zones.

As the new surface low consolidates and moves north to off the New Jersey coast later tonight, the forcing for ascent should increase for a time again and this may be tied to a zone of enhanced frontogenetic forcing to the north and west of the surface low.
Depending on the strength and placement of this, a zone of heavier rain is certainly possible. This should also result in an increase in the rain from west to east across much of the area this evening.
An easterly low-level jet migrates northward across our area, especially tonight into Thursday morning, which could add to the ascent across parts of the region. Some of the rain will be heavier at times, which is when some localized urban flooding cannot be ruled out. Total rainfall amounts are forecast to be 1.0-1.5 inches across the region through the day Thursday. Some elevated instability could occur for a time especially this evening mostly south and east of Philadelphia, although it is less certain if it would be enough to result in some lightning/thunder.

Onshore flow will increase as the surface low develops to our south today, however this looks to peak later this afternoon and tonight from south to north. Therefore, easterly wind gusts in the 25-35 mph range are forecast with the strongest gusts closer to the coast.
Once the surface low shifts north and northeastward during Thursday, the surface winds will shift out of the north and northwest and may diminish some. Any rain Thursday should become more showery across the area.

Given the rain/showers, low cloud cover and onshore flow, temperatures will be held way down today with a little recovery Thursday with the lessening precipitation and the flow backing to the north and northwest. The warmer temperatures should be most improved Thursday across Delmarva into southern New Jersey where less precipitation should occur and perhaps some breaks in the overcast occurs.

SHORT TERM /THURSDAY NIGHT THROUGH FRIDAY/
The secondary low will be over New England Thursday night, continuing to lift to the northeast towards the Gulf of Maine on Friday. The primary low will lowly pass north of the region from the eastern Great Lakes, through northern New York State, eventually merging with the secondary low somewhere over Maine on Friday. Several shortwaves will continue to pass through the local region, so showers will continue to pass through from time to time, but those showers will not be widespread as they will be Wednesday night and Thursday, and additional QPF Thursday night and Friday will generally around 1/10 inch or so.

LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/
The upper level low will be over the Canadian Maritimes over the weekend, and shortwaves passing through the region may keep unsettled weather through Sunday. Slight chance to chance PoPs are possible mainly for northern zones on Saturday, and then slight chance PoPs are possible for Sunday. QPF will be minimal, and the weekend will certainly not be a washout. Temperatures will be below normal this weekend, but temperatures will be creeping up somewhat from what they will be late this week.
Highs will mostly be in the 60s on Saturday, and then in the 60s to low 70s on Sunday.

The upper low departs by Monday and weak surface high pressure noses in from the west. Low pressure organizing and developing over the Gulf Coast states will lift north and east and looks to pas south of the region. Uncertain as to how far north this system will be able to track. For now, will follow NBM PoPs and will carry slight chance- chance PoPs on Monday and chance PoPs on Tuesday, but there may end up being a tight north-south gradient depending on the strength and placement of the aforementioned high. Highs creep back up into the low 70s early in the new week.

AVIATION /07Z WEDNESDAY THROUGH SUNDAY/
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY and surrounding areas.

Today...VFR ceilings lower to MVFR and IFR along with periods of rain developing this morning, the continuing this afternoon.
Visibility restrictions will occur due to the rain, especially during periods of some heavier rain. Southeast to east winds becoming east-northeast 5-10 knots, then increasing to 10-15 knots with gusts 20-30 knots this afternoon. The strongest winds should be closer to the coast. Low confidence regarding the timing details.

Tonight...Mainly IFR ceilings, MVFR visibilities, with periods of rain or some showers. A couple of thunderstorms possible in the evening mainly south and east of KPHL. East to east-northeast winds 10-15 knots with gusts 20-25 knots, diminishing to 10 knots or less overnight. Moderate confidence overall.

Thursday...IFR, possibly LIFR, conditions along with periods of rain tapering to some showers. An afternoon thunderstorm possible mainly east and south of KPHL. Northeast winds 10-15 knots, becoming north to northwest. Low confidence.

Outlook...

Thursday night...Ceilings improve to MVFR, then possibly VFR late. Some showers around.

Friday through Saturday...Brief sub-VFR conditions possible in some showers.

Sunday...VFR overall.

MARINE
A Small Craft Advisory is in effect today, tonight and part of Thursday. Onshore winds will increase as a coastal storm develops today with winds peaking late this afternoon and especially tonight from south to north. While some gusts to near gale-force will be possible tonight across mainly the northern New Jersey Atlantic coastal waters, confidence is low and therefore will maintain a strong Small Craft Advisory. Seas will also build to and above 5 feet. The conditions will gradually improve Thursday as the winds turn more from the north and northwest as low pressure shifts north and then northeast.

Outlook...

Thursday night...Conditions continue to improve.

Friday through Sunday...Sub-SCA conditions.

Rip Currents...

For today, east winds will increase to 15-25 mph with a 5-6 second period and breaking waves of 2-3 feet. A MODERATE risk for the development of dangerous rip currents is in place for all beaches, however a HIGH risk may be warranted pending further conditions.

For Thursday, gusty northeast winds 25-30 mph for Ocean and Monmouth County. Winds will be more west-northwest for Atlantic, Cape May, and Sussex counties 20-25 mph. Seas will be 3 to 5 feet north with 2 to 4 feet south with a swell of 5 to 6 feet with a 8 second period. A HIGH risk was issued for Ocean and Monmouth County and a MODERATE risk was issued for the rest of the coast.

For specific beach forecasts, visit weather.gov/beach/phi

PHI WATCHES/WARNINGS/ADVISORIES
PA...None.
NJ...None.
DE...None.
MD...None.
MARINE...Small Craft Advisory from 10 AM this morning to 6 AM EDT Thursday for ANZ430-431.
Small Craft Advisory from 10 AM this morning to noon EDT Thursday for ANZ450>455.