Marine Weather and Tide Forecast for Fort Washington, MD

KEY MESSAGES
- 1) A strong cold front brings gusty winds & potential for severe thunderstorms on Friday.

- 2) Below average temperatures Sunday through Wednesday.
Possible frost and freezing temperatures in the Appalachians early Sunday. Dry each period.

DISCUSSION
KEY MESSAGE 1...A strong cold front brings gusty winds & potential for severe thunderstorms on Friday.

As a passing cold front sags to the south, scattered showers will continue to move through the region throughout this afternoon and into tonight. Instability remains limited, limiting thunderstorm coverage overall as this front gradually slides south of the area overnight.

By tomorrow, a brief period of warm temperatures and sunny conditions returns as southwest winds gradually increase throughout the day. Meanwhile, a deep digging trough forming over the Midwest will quickly traverse the Ohio River Valley before tracking towards the East Coast, forming a line of thunderstorms that will move through in the afternoon & evening timeframe. Combined with warmer temperatures (with highs in the 80s by Friday afternoon) and low-end instability, some of these thunderstorms could become severe as the associated cold front tracks through the region. Due to conditions remaining relatively dry (ensemble guidance indicates PWATs ranging from 1.2-1.4 inches), the primary hazard will likely be gusty to damaging winds as DCAPE ranges in the low-1000s and shear remains elevated. SPC has included the metro regions in a Slight risk for severe weather impacts during this time period. While damaging wind gusts are going to be the primary threat, a quick QLCS tornado spin- up is certainly possible.

This line of thunderstorms pushes east of the area by late Friday night, but the trough will lag behind this line of thunderstorms and traverse the area throughout the day Saturday. Thus, additional rain showers remain possible into the weekend as this trough finally pushes through. While winds likely remain elevated through this period, with peak gusts over the mountains approaching 30-40 MPH, most areas likely stay below wind advisory criteria. Conditions begin to clear by Sunday, with much colder temperatures settling in in the wake of the front. Highs on Saturday only reach the mid-50s as the trough moves through, with continued cooler temperatures anticipated through the start of next week.

KEY MESSAGE 2...Below average temperatures Sunday through Wednesday. Possible frost and freezing temperatures in the Appalachians early Sunday.
Dry each period.

A sharp transition to cold weather is expected behind a strong cold front this weekend. This dry airmass in combination with clearing skies and weakening winds creates an ideal environment for efficient radiational cooling conditions throughout the area.
Overnight temperatures could drop to near or below freezing west of the Blue Ridge on Saturday and Sunday night. Most areas across our region have opportunities for frost to form, particularly west of I-95.

High pressure will build across the region Sunday through Wednesday.
Light and variable winds in the mountains of the Appalachians could result in areas of frost and near freezing temperatures Sunday morning. Elsewhere and otherwise, dry conditions Sunday through Wednesday in part to the area of high pressure. Temperatures will modify some toward late Tuesday into Wednesday.

AVIATION /19Z THURSDAY THROUGH TUESDAY/

Terminals will continue to see gradually lowering CIGs today as a stalling cold front produces scattered showers throughout the afternoon & evening. Periods of IFR are likely this evening into tonight, with CIGs gradually improving by Friday morning. Some patchy fog could linger in the early morning after showers transition east, with VFR conditions returning soon afterwards.

A second cold front bringing scattered showers and thunderstorms will bring back sub-VFR conditions beginning Friday afternoon and into the evening. Some of these storms could become severe, producing gusty to damaging winds. Low clouds from this line of thunderstorms could linger into Saturday morning, with conditions returning to VFR after sunrise Saturday.

Easterly winds shift southerly by Friday morning, with wind gusts up to 20-25 knots possible ahead of the cold front. Winds shift northwesterly by Saturday morning in the wake of the front, with gusts staying elevated throughout the day Saturday before diminishing overnight.

VFR conditions Sunday through Monday night. Winds north 5 to 15 knots Sunday, becoming light and variable Sunday night through Monday night.



MARINE

Winds have fallen below SCA criteria as of this afternoon. Easterly winds shift southerly overnight, staying below SCA thresholds until Friday morning. Winds could gust up to 20-25 knots Friday afternoon, with locally higher gusts possible throughout the afternoon & evening as scattered thunderstorms move through the region. Winds shift northwesterly early Saturday morning in the wake of the cold front, potentially reaching gale conditions later that day. A Gale Watch has been issued for the lower portions of the Bay until Sunday morning as this front pushes through.

Winds will diminish Sunday afternoon through Monday night. Winds northeast 15 to 20 knots gusts 25 to 30 knots Sunday morning. Winds quickly diminishing 10 to 15 knots Sunday afternoon through Monday night and becoming light and variable.

LWX WATCHES/WARNINGS/ADVISORIES
DC...None.
MD...Small Craft Advisory from 9 AM Friday to 6 AM EDT Saturday for MDZ008.
VA...None.
WV...None.
MARINE...Small Craft Advisory from 9 AM Friday to 6 AM EDT Saturday for ANZ530>543.
Gale Watch from Saturday morning through late Saturday night for ANZ532>534-537-543.