Marine Weather and Tide Forecast for Ashton-Sandy Spring, MD

KEY MESSAGES
- 1) Freeze Warnings are in effect in the Alleghenies, Blue Ridge, and central Shenandoah Valley. Frost Advisories are in effect from central Maryland into parts of central Virginia tonight and early Sunday.

- 2) A strong cold front brings widespread showers and thunderstorms midweek, followed by cooler temperatures.

DISCUSSION
KEY MESSAGE 1...Freeze Warnings are in effect in the Alleghenies, Blue Ridge, and central Shenandoah Valley. Frost Advisories are in effect from central Maryland into parts of central Virginia tonight and early Sunday.

Freeze Warnings extend from western Maryland, into parts of northeastern West Virginia, as well as the central Shenandoah Valley until 9AM this morning. Frost Advisories extend from central Maryland, the eastern West Virginia Panhandle, and along the eastern slopes of the Blue Ridge into the Virginia Piedmont. As cloud cover dissipates this morning, temperatures drop into the upper 20s to low 30s across the higher elevations and valleys along and west of the Blue Ridge.
Temperatures are already in the low 30s within the Freeze Warning and are expected to cool further this morning.

As high pressure shifts offshore today, temperatures through early next week. While overnight temperatures tonight will be warmer, dew points below freezing will yield possible frost for those along the highest elevations in the Alleghenies.
Elsewhere, low temperatures tonight will be in the 40s for most.

KEY MESSAGE 2...A strong cold front brings widespread showers and thunderstorms midweek, followed by cooler temperatures.

A shortwave trough passing through to the north could bring a few residual showers to the area on Tuesday, primarily north of the I-66 corridor. Meanwhile, a deep upper level trough centered over the Great Lakes on Wednesday will bring significantly more widespread chances for showers and thunderstorms to impact the region as it moves through the area between Wednesday and Thursday. As of right now, early QPF estimates are forecasting 1.00-1.25 inches of rain in the area by Friday, which would be extremely beneficial given widespread drought concerns that have impacted the region for some time now. As for the severe potential, NCAR's Medium-Range AI NWP Convective Hazards Forecast still has our area under a 5%-15% chance for severe potential during this time, but it has much higher severe chances centered around where its forecasted low is to the south. Should this center low trend northward, we could see a much greater potential for thunderstorms and severe convection in our area.

Once this frontal boundary passes through, temperatures cool a bit towards the end of the week, with temperatures in the 50s and 60s again on Friday.

AVIATION /06Z SUNDAY THROUGH THURSDAY/
VFR conditions are expected through Monday as high pressure builds over the terminals. Northwest winds gust 15 to 25 knots this afternoon before diminishing overnight. On Monday, southwest winds remain light blowing 5 to 10 knots.

Periodic sub-VFR conditions are possible at KMRB on Tuesday with scattered showers possible. Widespread showers and thunderstorms on Wednesday could bring periods of sub-VFR conditions across terminals. Winds remain southerly during this time, with gusts reaching 20-30 knots starting Tuesday evening and going into Wednesday afternoon.

MARINE
Small Craft Advisories remain in effect through this afternoon as northwest winds gust up to 25 knots. Winds quickly diminish this evening with winds remaining light overnight. On Monday, winds shift to southwesterly, remaining below SCA criteria through the day.

SCA conditions remain likely through at least midweek, with 15 knot winds potentially increasing to 25 knots by Wednesday morning; gusts up to 30 knots will be a possibility across the bay on Wednesday. Winds continue to flow southerly during this period.

TIDES/COASTAL FLOODING
Tidal anomalies rise tonight into Monday morning, with sensitive tidal locations(Annapolis) nearing minor flood level during the high tide cycle Monday morning.

LWX WATCHES/WARNINGS/ADVISORIES
DC...None.
MD...Small Craft Advisory until 6 PM EDT this evening for MDZ008.
Frost Advisory until 9 AM EDT this morning for MDZ003>006-507.
Freeze Warning until 9 AM EDT this morning for MDZ501-502-509- 510.
VA...Frost Advisory until 9 AM EDT this morning for VAZ028>031- 036>040-050-051-501-505.
Freeze Warning until 9 AM EDT this morning for VAZ025>027-503- 504-507-508.
WV...Frost Advisory until 9 AM EDT this morning for WVZ051>053.
Freeze Warning until 9 AM EDT this morning for WVZ050-055- 501>506.
MARINE...Small Craft Advisory until 6 PM EDT this evening for ANZ530>534-537-539>541-543.
Small Craft Advisory from 8 AM this morning to 6 PM EDT this evening for ANZ535-536-538-542.