Marine Weather and Tide Forecast for Betterton, MD

NEAR TERM /THROUGH TONIGHT/
As of 9:00AM, the cold front has continued to progress south and east, now approaching the coast of Delaware and New Jersey. Basis current trends, the front should move fully offshore within the next couple of hours.

The front is relatively weak in terms of cold air advection.
Dry air advection however, will likely lead to dewpoints dropping into the 20s and 30s (see the Fire Weather section below for more fire weather details). In portions of Delmarva and SE NJ which will be the latest to see the front could get into the 80s before the front arrives.

High pressure builds in for tonight leading to dry conditions.
Expecting light onshore flow along the coast, but with dry air in place, marine fog is unlikely to develop. Clear skies expected with lows falling into the 40s/50s.

SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/
Very warm and more humid Friday as a warm front lifts to the north.

Low pressure will advance from the Midwest into the Great Lakes region and then on through Ontario towards Quebec. This will pull a warm front across our area Thursday night with much warmer and more humid conditions for Friday as the flow becomes southwesterly. High temperatures Friday are forecast to be in the 80s, except cooler along the coast and in the higher elevations of the southern Pocono region. As isentropic lift increases with the incoming warm front Thursday night into early Friday, some showers should occur (a few thunderstorms cannot be ruled out). The uptick in the moisture advection will result in more clouds Thursday night and to start Friday, and this could be in the form of stratus as dew points increase quite a bit by daybreak Friday.

Some showers and thunderstorms should develop across parts of the region or move in from the west ahead of a cold front Friday afternoon. Some showers and a few thunderstorm may continue Friday night as the cold front gets closer. The development of convection however could be delayed Friday as the parent upper-level trough may hang back well to our west, unless some development can become focused along a possible lee-side trough. The severe thunderstorm potential looks to be limited at this time as instability may be on the weaker side and stronger forcing potentially remains farther to our west. Something to monitor though as some model forecast soundings Friday afternoon show steepening low-level lapse rates which could result in some convectively induced strong wind gusts pending some stronger convection can develop.

LONG TERM /SATURDAY THROUGH TUESDAY/
Summary...Warm especially to start, however potentially becoming more unsettled depending on the development and location of a closed low through early next week.

Synoptic Overview...An upper-level trough is forecast to arrive in the East during Saturday and Sunday. Whether this becomes closed off through early next week varies among the model guidance, with some guidance not even developing a closed low. The evolution of this will greatly affect our sensible weather. At the surface, low pressure along a cold front slides through our area Saturday followed by high pressure building across the Great Lakes and Ohio Valley. This high should then shift to northern New England with time. A secondary upper-level trough may arrive keeping surface low pressure near or just off the Mid-Atlantic coast. Depending on if and where a closed low becomes centered, the development of a conduit of moisture from the southeast could evolve over or near our area.

For Saturday and Sunday...A cold front crosses our area Saturday as a sharpening upper-level trough arrives and this should support low pressure along the front. This could slow the front down and keep things unsettled with more showers lasting most of Saturday. Deep southwesterly flow ahead of the upper-level trough should result in warm temperatures, although not as warm as Friday. High temperatures are forecast to be in the mid to upper 70s for much of the region.
The upper-level trough looks to remain in place for much of Sunday with cyclonic flow across our area. Some additional shortwave energy rounding the base of the trough may result in some showers, especially with colder air aloft. This will also result in temperatures Sunday being closer to average.

For Monday and Tuesday...The evolution of the upper air pattern as we go through this time frame especially is highly uncertain. This is due to a couple of features at play that may or may not result in a slow moving closed low to traverse the East. The model guidance including ensemble members vary quite a bit of how the upper-level flow evolves with time. There is the potential that a closed low develops somewhere in the East, and if this does occur then where it becomes centered will determine our sensible weather. Some guidance/ensembles keep the trough progressive and therefore lift it northward while some others hang back energy and it becomes a closed low. Given some of the signals in the guidance, a more unsettled pattern is possible however how much so is uncertain. A closed low centered near the Kentucky and surface high pressure centered to our northeast could potentially bring quite a bit of moisture into our area, however this is only one possible outcome and the guidance offers many others. Given so much uncertainty, opted to go with the NBM (National Blend of Models) which favors low chance PoPS (around 30 percent) at this time.

AVIATION /13Z WEDNESDAY THROUGH SUNDAY/
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY and surrounding areas.

Today...VFR. Winds starting light out of the southwest, becoming northwest 10-15 kts. High confidence.

Tonight...Prevailing VFR conditions. Winds should generally favor the NNE direction with speeds less than 5 kt, but direction could be variable at times. High confidence.

Outlook...

Thursday...VFR during the day, then sub-VFR conditions may develop due to low clouds and some showers.

Friday and Saturday...Sub-VFR conditions at times with some showers and thunderstorms.

Sunday...Conditions should be mostly VFR.

MARINE
Winds and seas are expected to stay below Small Craft Advisory conditions through tonight.

Outlook...

Thursday...The conditions are anticipated to be below Small Craft Advisory criteria.

Friday...Small Craft Advisory conditions probable.

Saturday and Sunday...Small Craft Advisory conditions may linger to start Saturday, otherwise the conditions are anticipated to be below Small Craft Advisory criteria.

FIRE WEATHER
There is an elevated risk for fire spread, particularly in New Jersey, Pennsylvania, and Delaware today where a Special Weather Statement has been issued through 8 PM.

Minimum relative humidity will range from around 15-30%. For northern Delmarva which will be the last to see the dry air filter in, the relative humidity values are expected to be 20-35%.
Northwesterly winds around 10-15 mph with gusts up to 25 mph possible. For Delmarva and far southeastern New Jersey, winds will start westerly, before shifting to northwesterly by mid-day.

For Thursday, minimum relative humidity will range from around 25- 40%. Winds should be lighter, and mostly out of the southeast, around 10 mph with gusts up to 20 mph possible.

PHI WATCHES/WARNINGS/ADVISORIES
PA...None.
NJ...None.
DE...None.
MD...None.
MARINE...None.