Marine Weather and Tide Forecast for Whitehaven, MD

KEY MESSAGES
1) Warmer and more humid Wednesday with scattered showers/storms possible.

2) Hot and humid Thursday-Friday, along with the chance for isolated to scattered showers and storms.

3) A cold front crosses the area early Saturday, bringing drier, and somewhat cooler temperatures to the region.

DISCUSSION
As of 400 PM EDT Tuesday...

KEY MESSAGE 1...Warmer and more humid Wednesday with scattered showers/storms possible.

Surface high pressure has drifted offshore this aftn, with a lot of high clouds moving over an upper ridge axis along the east coast. Temps are mostly in the low-mid 80s well inland, with 70s near the coast. Dew pts remain in the 50s, with a few lower 60s into the piedmont and across NE NC. Partly cloudy this evening, with increasing (and lowering) clouds overnight from W to E.
Some of the CAMS show spotty showers between 06-12Z across mainly N/NW portions of the FA as low-mid level southerly flow increases, along with significantly higher dew pts. Have PoPs to 30-40% NW of RIC prior to 12Z, but elsewhere, expect only a minimal chance for measurable rain. Warmer with lows in the mid 60s to lower 70s. On Wed, the northern 1/2 of the area remains in a Marginal SVR risk as the mid level flow modestly increases (greatest to the north). A lot of clouds and a few showers are expected through the AM hours, with some potential for some clearing into the aftn. The aftn/evening scenario is a bit uncertain, but if enough clearing develops, ML CAPE values would rise to ~1000 J/KG, and would help support the Marginal threat.
Otherwise, highs will rise in to the mid to upper 80s, with dew pts in the upper 60s to lower 70s, a significant change from today's dry airmass.

KEY MESSAGE 2...Hot and humid Thursday-Friday, along with the chance for isolated to scattered showers and storms.

Surface high pressure anchors offshore as an upper ridge builds across the Southeast Thu-Fri. The upper ridge will be centered south of the local area with stronger flow aloft impinging on the Mid-Atlantic, allowing for the potential for upper level disturbances to traverse the region and spark mainly diurnal chances for showers and storms.

The upper ridge amplifies to our south Thursday and Friday with modestly rising heights aloft. High temperatures likely rise into the mid and upper 90s each afternoon but cloud cover and continued chances for showers and storms lend some lingering uncertainty to the temperature forecast. Low level moisture is also expected to tick up late this week which will result in the potential for heat index values to rise mainly into the 100- 105 range Thursday and Friday, depending on coverage and timing of any convection or thicker cloud cover. Heat Advisories may be needed for at least some of the region. At this time, Friday has a slightly better chance for seeing dew pts mix down into the 60s across inland areas. An additional Marginal Risk for SVR is in effect for most of the CWA Thursday.

KEY MESSAGE 3...A cold front crosses the area early Saturday, bringing drier, and somewhat cooler temperatures to the region.

Latest guidance continues to depict the upper level ridge breaking down Friday night into the weekend as a strong upper trough/low gradually drifts E-SE from northern Ontario towards the St Lawrence Valley. While the airmass in the wake of the front will remain warm, the wind shift to N-NE should lead to significantly cooler conditions saturday at the coast, along with lower dew pts area-wide. ECMWF ensemble and GEFS show the PWAT anomalies dropping to below 100% or normal before a modest return flow starts late Sunday into Monday ahead of another front. Will still have a low chc for showers/storms, mainly SE, for Saturday, and 15-30% PoPs Sunday. High temps Sat will stay in the low 90s inland, with mid-upper 80s near the coast, along with lower humidity.

AVIATION /00Z WEDNESDAY THROUGH SUNDAY/
As of 730 PM EDT Tuesday...

VFR conditions continue to be favored tonight, though BKN-OVC high clouds will persist. Closer to 12z, some potential exists for lowering CIGs as a batch of showers move in from the W.
Model guidance varies with the placement of these lower clouds (and showers), but episodic MVFR is possible in the Piedmont and potentially near RIC in the 12-16z timeframe. Morning showers would generally be favored at RIC and SBY before a lull arrives in the afternoon. Otherwise, mainly VFR is expected tomorrow afternoon and evening, though another round of showers, with a better chance of storms, is possible in the late afternoon and evening. Have introduced PROB30 groups at SBY, RIC, and PHF for locally reduced VSBY, generally after 21z. Winds average 5-10 kt out of the S/SSE tonight, shifting to the SW with gusts to ~20 kt tomorrow afternoon.

Outlook...Mainly VFR conditions Thu-Fri, but with a chc of mainly diurnal showers/tstms. A few stronger storms are also possible. A weakening cold front slowly approaches from the NW Friday and Saturday with a chc of mainly diurnal showers/tstms continuing SE (with lower coverage to the N for the weekend).

MARINE
As of 330 PM EDT Tuesday...

Key Messages:

- Small Craft Advisories have been issued for the coastal waters north of Cape Charles Light for Wednesday night as elevated southerly flow increases.

- A period of elevated southerly flow is possible this evening into Wednesday morning in the Chesapeake Bay, but will likely remain below SCA conditions.

High pressure that was overhead the area this morning has shifting offshore with mostly southerly flow today. Winds are currently 10-15 kt and will increase slightly overnight to ~15 kt with gusts up to 20 kt. Have decided against issuing a SCA for the Ches. Bay tonight as local wind probs for 18 kt sustained winds have decreased to 30- 40% and southerly flow tends to under-perform. Southerly winds will prevail Wednesday at 10-15 kt in the Ches. Bay and increase throughout the day for the coastal waters to 15-20 kt with gusts to 25 kt by the evening. Local wind probs for gusts to 25 kt are around 50-60% for the northern coastal waters. Seas will additionally build to 4-5 ft for the coastal waters north of Cape Charles Light Wednesday evening into overnight. Although on the more marginal side, SCAs have been issued with this package for the northern coastal waters. Behind the elevated winds, benign marine conditions (outside of any convection) will return Thursday and last through the weekend.

There is a moderate risk of rip currents today across all area beaches. Wednesday, there is a moderate risk of rip currents at the northern beaches and a low risk at the southern beaches.

CLIMATE
Record High Temperatures:

- Date: Thu 6/11 Fri 6/12

- ORF: 98 (1911) 99 (1986)
- RIC: 97 (1984) 100 (1914)
- SBY: 96 (1914) 98 (1914)
- ECG: 99 (1947) 97 (1947)

Record High Min Temperatures:

- Date: Thu 6/11 Fri 6/12

- ORF: 75 (2020) 76 (2016)
- RIC: 75 (1914) 74 (1986)
- SBY: 73 (2013) 75 (1947)
- ECG: 75 (2020) 76 (2016)

AKQ WATCHES/WARNINGS/ADVISORIES
MD...None.
NC...None.
VA...None.
MARINE...Small Craft Advisory from 7 PM Wednesday to 4 AM EDT Thursday for ANZ650-652-654.