Marine Weather and Tide Forecast for Williamsport, MD

KEY MESSAGES
- A retreating front could bring a wintry mix of precipitation Monday night into Tuesday.

- A warming trend will develop mid-week into next weekend.

DISCUSSION

KEY MESSAGE 1...A retreating front could bring a wintry mix of precipitation Monday night into Tuesday.

KEY MESSAGE 1 DESCRIPTION...

Strong high pressure will build north of the area Monday, eventually wedging southward along the eastern side of the Appalachians. Northerly low level flow will bring cold and dry advection. The forecast continues to trend dry through Monday evening.

Overruning precipitaiton is expected to develop after 06Z Tue, earlier in some models, and overrun shallow cold air near the surface. Light to moderate mixed precip is expected late Monday night into Tue morning. Since the source of cold air will be retreating to the east rather quickly, the duration of wintry precip looks to remain relatively short with minimal impacts of ice, except perhaps at elevated surfaces like trees and power lines. Continued warm air advection Tue will result in temperatures rising above freezing with precip turning into all rain by Tue afternoon. Our latest ice totals only show amounts in the winter weather advisory criteria.

KEY MESSAGE 2...A warming trend will develop mid-week into next weekend.

KEY MESSAGE 2 DESCRIPTION...

As we move into the middle of next week, a substantial pattern shift will take place across the entire CONUS. Upper-level ridging, which had been over the west coast, will shift to the east coast. Ensemble guidance for 500mb heights are in the 1.5 to 2 sigma range towards the end of next week into next weekend. This should yield temperatures that are well above average for this time of year. The presence of a lingering warm front nearby could lend some uncertainty with just how warm we get, but assuming it does clear to our north, temperatures well into the 70s are certainly in play by Thursday. Saturday could be the warmest day of the period, with highs perhaps nearing 80. However, if the front does not clear to our north, but rather lingers nearby, daily showers and cooler temperatures can be expected for portions of the region. This would be most likely along the MD/PA border, and less likely over central VA into southern MD. Still too early to be sure what will happen, but a majority of model guidance favors the warmer solutions at this time.

AVIATION /18Z SATURDAY THROUGH THURSDAY/

A dry cdfnt will cross the terminals Sunday morning with shifting winds and bringing MVFR cigs. Winds will pick from the north and gusts to around 20 kt.

MVFR to IFR conditions with potential for a wintry mix into Tuesday morning. Any precipitation should be rain by Tuesday afternoon. MVFR conditions could linger at MRB and BWI and MTN if areas of rain occur along a front through Wednesday. VFR conditions expected Wednesday and Wednesday night. Winds south to southwest 5 to 10 knots Tuesday and Tuesday night. Winds shifting northwest to northeast then southeast 5 knots Wednesday into Wednesday night.

MARINE

SCAs have been issued for Sunday afternoon into Sunday night for northerly channeling behind a dry cold front. SCAs likely need to be extended into Monday.

No marine hazards Tuesday. Small Craft Advisories are possible Tuesday night. No marine hazards Wednesday and Wednesday night.
Winds south to southwest around 10 knots Tuesday and Tuesday night.
Winds becoming variable and 5 to 10 knots Wednesday and Wednesday night.



LWX WATCHES/WARNINGS/ADVISORIES
DC...None.
MD...Small Craft Advisory from 1 PM to 6 PM EST Sunday for MDZ008.
VA...None.
WV...None.
MARINE...Small Craft Advisory from 1 PM to 6 PM EST Sunday for ANZ530- 531-535-536-538-539-542.
Small Craft Advisory from 1 PM Sunday to 6 AM EST Monday for ANZ532>534-537-540-541-543.