Marine Weather and Tide Forecast for Montross, VA

NEAR TERM /THROUGH TONIGHT/
As of 300 AM EDT Tuesday...

Key Message:

- Warming temperatures and continued dry conditions are expected today.

High pressure is centered just off the VA/NC coast early this morning with calm winds near the coast and 5-10 mph south winds inland. Ridging aloft over the Appalachians will become centered over the local area later today. It is cool with temps in the mid- upper 40s closer to the high and in the lower-mid 50s inland due to the light south breeze. It will be warmer today than it was yesterday with the surface high moving offshore, allowing the low- level flow to increase out of the SSW (with frequent gusts of 20-25 mph likely by midday/aftn). Highs will be in the lower 80s in most areas (locally mid 80s inland), with upper 70s across parts of the eastern shore. While dew pts recover to the upper 40s-lower 50s...afternoon RH values will be 30-35% across much of the area with temps above 80F. Convection develops west of the mountains this afternoon but should weaken as it approaches the local area tonight due to the lower dew pts and resultant lack of instability east of the mountains. Also, a backdoor cold front will begin to approach from the north tonight. The 00z guidance is slightly more aggressive with respect to the southward movement of the front, but the front will likely remain just to our north by sunrise on Wed. Milder tonight with a SSW breeze. Lows only fall into the lower-mid 60s in most areas.

SHORT TERM /WEDNESDAY THROUGH THURSDAY/
As of 300 AM EDT Tuesday...

Key Messages:

- Very warm on Wednesday with mid to upper 80s expected.

- Scattered showers and thunderstorms are expected Wednesday afternoon and evening, with the best chances along and south of I- 64.
Organized severe weather is not expected, but a few stronger storms remain possible with gusty winds as the main threat.

- Showers and storms are possible across mainly N/NW portions of the area Thursday afternoon and evening with continued warm weather.

The ridge aloft becomes suppressed to our SE on Wed/Thu. Meanwhile, the backdoor cold front may cross part of the area (most likely the eastern shore) during the day on Wed. Very warm wx is expected across much of the area with widespread mid to upper 80s in most of our VA/NC zones (w/ upper 70s-lower 80s on the eastern shore). The main forecast challenge on Wed is timing and especially placement of aftn/evening convection. Will have to watch any residual boundaries from dissipating tstms, as these could contribute to convective initiation over the local area Wed aftn. Also, the weak backdoor front could be a focus for scattered convection as well. While the forecast remains uncertain, still feel that the best chc for tstms Wed aftn/evening is along and especially south of I-64. Precip chances are quite low across north/northeast portions of the FA.
With dew pts rising into the lower 60s by the aftn/evening, moderate surface-based instability (1000-1500 J/kg of MLCAPE) will develop.
While organized severe wx is not expected due to weak deep-layer shear, a few storms may produce 45-50 mph gusts which could cause localized tree damage. Mainly dry wx is expected after midnight Wed night with lows in the lower 60s in most areas (mid-upper 50s on the eastern shore with weak onshore flow). The backdoor front quickly retreats northward on Thu as low pressure begins to deepen as it tracks from the Plains to southern Great Lakes. With the retreating front and strong low still well to our NW, the best forcing for ascent will be off to the north/northwest. However, additional isolated to scattered showers and storms will be possible Thu aftn into the evening, mainly across N/NW portions of the FA. Very warm inland w/ highs well into the 80s on Thu. 70s are expected on the eastern shore with the flow remaining onshore for most of the day.

LONG TERM /THURSDAY NIGHT THROUGH MONDAY/
As of 300 AM EDT Tuesday...

Key Messages:

- Highs will be well into the 80s on Friday, with continued shower/storm chances.

- Shower/storm chances continue on Saturday as a cold front crosses the area.

- The forecast for late next weekend into early next week is highly uncertain given varying model solutions with respect to a potential cutoff low.

The above mentioned low pressure system will continue to deepen as it tracks NE through the end of the week, reaching Quebec by Friday night. This feature eventually drags a seasonally strong cold front toward the area, with that cold front expected to cross the area on Saturday. The associated shortwave trough aloft approaches the local area on Friday, before it tracks over the area this weekend. There are significant model and ensemble differences with respect to the evolution of that shortwave. The ECMWF/CMC are forecasting it to become a closed upper low by Sunday and meander over the Mid- Atlantic through at least early next week. Some of the EPS/CMCE members show this as well. On the other hand, the GFS and most of its ensemble members are much more progressive and show the shortwave moving offshore with strong upper ridging building over the area early next week.

Have higher confidence in the forecast for Fri/Sat with very low confidence from Sun-Tue. Very warm once again on Friday with widespread mid 80s inland. Scattered showers and tstms initially develop to our west Friday afternoon (well ahead of the front)
before tracking across the area Friday night into Saturday as the front crosses the area. The highest precip chances are inland on Fri and shift to areas east of I-95 by Saturday aftn as the front crosses the area. A few strong to severe storms are possible Friday aftn/evening into the first part of Friday night, with modest (~30 kt) deep layer shear present along with a decent amount of instability. The main threat will likely be locally damaging winds.
Can't completely rule out a stronger storm or two near the coast on Saturday as well, although highs drop back into the 70s with more cloud cover and precip.

The forecast for late this weekend into early next week depends on the evolution of that shortwave. If it remains progressive like the GFS/GEFS shows, dry and less humid wx prevails Sunday-Tuesday. If a closed low does form, clouds and precip chances will continue through early next week. For now, NBM guidance only has slight chance PoPs near the coast from Sun-Tue AM but the EPS/CMCE ensemble means have areal avg QPFs of ~0.50" from Sun-Tue.

AVIATION /07Z TUESDAY THROUGH SATURDAY/
As of 120 AM EDT Tuesday...

VFR conditions will prevail at all terminals through the 06z/29 TAF period. S winds of 5-10 kt early this morning will become SSW and increase to 10-15 kt (w/ gusts of 20-25 kt) today.
Convection develops well to our west (west of the Appalachians)
this afternoon/evening but weakens tonight before reaching the terminals. Mainly clear skies outside of high clouds/FEW aftn cumulus expected through the period.

Outlook: VFR conditions are expected to prevail through Wednesday morning. A cold front approaches from the north by later Wednesday into Thursday bringing an increased chance of showers and storms. A stronger front crosses the region late Friday into Saturday, bringing a better chance for widespread showers and storms Friday afternoon into Saturday morning.

MARINE
As of 300 AM EDT Tuesday...

Key Messages:

- Small Craft Advisories are in effect for the Chesapeake Bay, coastal waters north of the VA/NC border, and upper rivers from late this afternoon through early Wednesday morning.

- Quieter marine conditions Wednesday and Thursday, outside of scattered afternoon and evening thunderstorms.

- Small Craft Advisories again possible at the end of the week.

Early morning surface analysis depicted high pressure across the local waters with S winds ~10 kt S and 10-15 kt N. High pressure continues to gradually move offshore today, allowing for winds to gradually increase to 10-15 kt with gusts up to 20 kt by early this afternoon, eventually increasing to 15-20 kt with gusts up to 25 kt by late this afternoon into this evening. Winds become SW tonight, increasing briefly to 20-25 kt with gusts up to 30 kt across the N coastal waters. Winds diminish quickly Wed morning as a weak cold front drops S. Wind probs for 18 kt sustained winds increase to 80- 100% across the Ches Bay tonight with wind probs for 25 kt wind gusts across the N coastal waters increasing to 80-100% as well.
Meanwhile, wind probs for 25 kt gusts were much lower across the NC coastal waters (20-40%). Therefore, have opted to keep them out of the SCAs. However, have added the VA coastal waters from Cape Charles Light to the VA/NC border to the SCAs given wind probs of 50- 80% for 25 kt gusts. SCAs are now in effect from 4 PM this evening through 7 AM Wed for the middle and upper Bay, 4 PM this evening through 10 AM Wed for the lower Bay, 6 PM this evening until 4 AM Wed for the coastal waters from the VA/NC border to Cape Charles Light, 6 PM this evening through 7 AM Wed for the coastal waters north of Cape Charles Light, and 10 PM this evening through 7 AM Wed for the upper rivers.

Winds remain light from Wed through Thu outside of convection.
However, scattered afternoon/evening showers and storms are possible both days (lower chance on Thu). An area of low pressure tracks from the Midwest into SE Canada Thu into Fri, with an associated cold front approaching the local waters Fri night. S/SW winds increase to 15-20 kt with gusts up to 25 kt Thu night into early Sat morning in the warm sector of the aforementioned low pressure system. The cold front pushes across the local waters Sat with winds remaining elevated behind the front into Sun. As such, a prolonged period of low-end SCA conditions is possible from Thu night through Sat both ahead of and behind the the cold front.

Waves and seas were ~2 ft early this morning. Waves build to 3-4 ft by tonight with seas building to 4-6 ft across the N coastal waters and 3-4 ft across the S coastal waters. Another period of elevated seas arrives Fri afternoon into Fri night.

AKQ WATCHES/WARNINGS/ADVISORIES
MD...None.
NC...None.
VA...None.
MARINE...Small Craft Advisory from 4 PM this afternoon to 7 AM EDT Wednesday for ANZ630-631.
Small Craft Advisory from 4 PM this afternoon to 10 AM EDT Wednesday for ANZ632-634.
Small Craft Advisory from 10 PM this evening to 7 AM EDT Wednesday for ANZ635>638.
Small Craft Advisory from 6 PM this evening to 7 AM EDT Wednesday for ANZ650-652-654.
Small Craft Advisory from 6 PM this evening to 4 AM EDT Wednesday for ANZ656.