Marine Weather Net

Tidal Potomac from Indian Head to Cobb Island MD Marine Forecast









The Marine Weather Forecast In Detail:
ANZ536 Forecast Issued: 436 AM EDT Sun May 26 2019

Rest Of The Overnight...Sw Winds 5 Kt. Waves Less Than 1 Ft. A Slight Chance Of Showers And Tstms. Patchy Fog. Vsby 1 To 3 Nm.
Today...W Winds 5 Kt. Waves Less Than 1 Ft. A Chance Of Showers And Tstms.
Tonight...Nw Winds 5 Kt. Waves Less Than 1 Ft. A Chance Of Showers And Tstms.
Mon...Nw Winds 5 Kt. Waves Less Than 1 Ft. A Chance Of Showers And Tstms.
Mon Night...S Winds Around 5 Kt. Waves 1 Ft. A Chance Of Showers.
Tue...Sw Winds 5 To 10 Kt. Waves 1 Ft. A Chance Of Showers.
Tue Night...Sw Winds Around 5 Kt. Waves 1 Ft.
Wed...Sw Winds 5 To 10 Kt. Waves 1 Ft.
Thu...W Winds 5 To 10 Kt. Waves 1 Ft. A Chance Of Showers. A Chance Of Tstms. Winds And Waves Higher And Visibilities Lower In And Near Tstms.
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Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
409am EDT Sunday May 26 2019

Synopsis: A weak cold front will approach from the north today, stalling across the region on Monday before lifting northward again Tuesday. Bermuda high pressure sets up toward the middle portion of the week, resulting in hot and humid conditions over much of the eastern United States.

Near Term - Through Monday
Latest analysis places the warm front stuck over the region, but it should rapidly proceed northeastward once the sun comes up, so expect the entire forecast area to be deep into the warm sector. Patchy fog remains a concern in areas which saw rain last night, but it should dissipate fairly quickly after the sun rises. The bulk of the morning and midday, therefore, should see partly sunny skies and rapidly rising temperatures as warm advection aloft allows surface readings to approach 90. With the moist southerly flow, dew points will also approach 70. This combination should help result in significant CAPE by afternoon, perhaps 2000+ J/kg. Shear is decent, but most of it is more elevated than in recent days, with low-level shear pretty modest by comparison, generally around 20 knots 0-3km. This is due to the surface flow becoming more westerly. Heigheights will be falling this afternoon ahead of an approaching shortwave, but the core will linger further west, perhaps not catching up with the best instability. Thus, expect decent storm coverage overall, with damaging winds and hail being the main threat, with a lesser tornado threat than what we've seen in recent days. The westerly flow gives me pause regarding coverage, as historically its not favorable due to the downslope component, so kept POPs relatively low with most places just reaching the likely range.

Tonight, weak boundary slips back south, likely helped along by cooling from the convection itself. After a relative min after sunset, the approaching mid-level trough may cause a reinvigoration of storms, or at least, rain, as we head later into the night, and this could in fact linger into the morning on Memorial Day. After the shortwave passes, coverage should diminish, and with lingering clouds expected much of the day, temperatures will be cooler (80s) and afternoon convection should be limited.

Short Term - Monday Night Through Tuesday Night
The weak boundary starts heading back north Monday night and progresses back north of most of the region on Tuesday. Before that happens, however, another shortwave crosses the region, with a round of late night/early morning showers and t-storms possible. Time of day suggests there won't be a lot of severe threat with this round, but will need to watch heavy rain potential. After the front moves north, temps should rise back close to 90 later in the day Tuesday, with plenty of humidity. This will result in another surge in instability, with CAPE again possibly exceeding 2000 J/kg. This could also be accompanied by significant shear, particularly low level shear, with 0-3km readings possibly reaching 40 knots. This means we will have yet another day with severe weather potential, and unlike today, the tornado threat will be back, along with damaging winds and hail. As the sun sets, CAPE should rapidly decline, so we should turn out dry late Tuesday night, but remain muggy and mild

Long Term - Wednesday Through Saturday
The middle and end of next week will feature above normal temperatures and multiple opportunities for scattered showers/thunderstorms.

For Wednesday, the main weather feature will be a large upper level ridge over the southeastern US, with our highest heigheights of the period overhead. This will lead to mainly dry and hot conditions, with highs likely reaching the 90s pretty much area- wide.

A frontal system will approach the region Thursday/Thursday night, leading to another increased chance of showers/thunderstorms. Temperatures will still be very warm to hot out ahead of the front, and will have upper 80s to low 90s in the forecast.

The front will push south/eastward Friday as the upper ridge over the southeastern US flattens, and high pressure builds towards the region. However, recent trends in guidance indicate that the front may not quite clear the area Friday and Saturday, leading to continued opportunities for scattered showers/thunderstorms. Temperatures will be cooler, but still likely remain above normal, with highs in the low 80s.

Marine Discussion
Southerly channeling should diminish this morning, with SCA conditions ending over all waters. Light winds likely to prevail through the following few days as a weak front meanders across the region. Main concern will be potential Special Marine Warnings due to thunderstorms with highest odds today and again on Tuesday.

Small Craft Advisory conditions become possible out of the southwest Wednesday and Thursday as winds increase out ahead of an approaching front

Tides / Coastal Flooding
Anomalies are spiking as southerly flow has brought more water northward up the bay. Further changes are uncertain as winds are expected to shift to a more westerly direction later today, but right now it appears that anomalies are high enough to cause minor flooding around high tide later today at least across Baltimore and Anne Arundel counties in MD and in DC. Will need to watch water levels closely over the next few hours in case further forecast adjustments and advisories are necessary. Anomalies should decline as winds become more northerly tonight behind a cold front

NOAA Baltimore MD/Washington DC Office: Watches - Warnings - Advisories
DC...Coastal Flood Advisory from noon today to 4pm EDT this afternoon for DCZ001. MD...Coastal Flood Advisory from 8am this morning to 4pm EDT this afternoon for MDZ011.
Coastal Flood Advisory from 7am this morning to 5pm EDT this afternoon for MDZ014. VA...None. WV...None.
Small Craft Advisory until 6am EDT early this morning for ANZ533-537-541.
Small Craft Advisory until noon EDT today for ANZ534-543

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