National Weather Service United States Department of Commerce

Heavy Rainfall Threat for Portions of Mid-Atlantic and Northeast; Heat Linger for Southeast and Expands for the West

Moisture and nearby frontal boundary will focus more showers and thunderstorms for portions of the Mid-Atlantic and Northeast today. Rainfall could be locally heavy resulting instances of flash flooding. Meanwhile, the heat lingers for areas of the Southeast and expands across the Western U.S. the next several days. Between these areas, severe thunderstorms possible for the Plains and Midwest. Read More >

Wind-Wave Correlations for Wave Forecasting

WFO Baltimore-Washington forecasts significant wave heights in the local Coastal Waters Forecast (CWF) product. Significant wave heights are the average heights (trough to crest) of the one-third highest waves. For simplicity, significant wave heights are termed waves in the WFO Baltimore-Washington CWF.

For wave forecast guidance over the Maryland portion of the Chesapeake Bay and Tidal Potomac River, WFO Baltimore-Washington uses the NWPS model. Where the NWPS domain is incomplete and beyond the NWPS time period (102 hours), wind-wave correlations are used for wave forecasts.  Those correlations are outlined below.

Generally, for wind speeds of 5 kt, waves will read "less than 1 ft." For other wind speeds, the correlations below are utilized for each marine zone. Remember that forecasts of wave heights do not include effects of wind direction relative to tidal currents. Expect higher waves when winds are blowing against tidal flow.

 

Click for the latest Coastal Waters Forecast (CWF)

 


 

POTOMAC RIVER - KEY BRIDGE TO INDIAN HEAD


[Key Bridge to Indian Head]
 
  W NW N NE E SE S SW
10 KT <1 <1 <1 <1 <1 <1 <1 <1
15 KT 1 1 1 1 1 1 1 1
20 KT 1 1 2 1 1 1 2 1
25 KT 2 2 2 2 2 2 2 2
30 KT 2 2 3 2 2 2 3 2
35 KT 2 3 3 3 2 3 3 3
40 KT 3 3 4 3 3 3 4 3
45 KT 3 4 4 4 3 4 4 4
50 KT 3 4 4 4 3 4 4 4


 

POTOMAC RIVER - INDIAN HEAD TO COBB ISLAND


[Indian Head to Cobb Island]
 
  W NW N NE E SE S SW
10 KT <1 1 <1 <1 <1 1 <1 <1
15 KT 1 1 1 1 1 1 1 1
20 KT 2 2 2 2 2 2 2 2
25 KT 2 3 2 2 2 3 2 2
30 KT 2 3 2 2 2 3 2 2
35 KT 3 3 3 3 3 3 3 3
40 KT 3 4 3 3 3 4 3 3
45 KT 3 4 4 4 3 4 4 4
50 KT 4 5 4 4 4 5 4 4


 

POTOMAC RIVER - COBB ISLAND TO SMITH POINT


[Indian Head to Cobb Island]
 
  W NW N NE E SE S SW
10 KT 1 1 < 1 < 1 1 1 < 1 < 1
15 KT 2 2 1 1 2 2 1 1
20 KT 2 3 2 1 2 3 2 1
25 KT 3 4 2 2 3 4 2 3
30 KT 3 5 3 2 3 5 3 2
35 KT 4 5 3 3 4 5 3 3
40 KT 4 6 4 3 4 6 4 3
45 KT 5 6 4 4 5 6 4 4
50 KT 5 6 4 4 5 6 4 4


 

CHESAPEAKE BAY - NORTH OF POOLES ISLAND


[Chesapeake Bay N of Pooles Island]
 
  W NW N NE E SE S SW
10 KT 1 1 1 1 1 1 1 1
15 KT 1 1 1 2 1 1 1 2
20 KT 2 2 2 2 2 2 2 2
25 KT 2 2 2 3 2 2 2 3
30 KT 3 3 3 4 3 3 3 4
35 KT 3 3 3 4 3 3 3 4
40 KT 4 4 4 5 4 4 4 5
45 KT 4 4 4 5 4 4 4 5
50 KT 5 5 5 6 5 5 5 6


 

CHESAPEAKE BAY - POOLES ISLAND TO SANDY POINT


[Chesapeake Bay - Pooles Island to Sandy Point]
 
  W NW N NE E SE S SW
10 KT 1 1 1 1 1 1 1 1
15 KT 1 2 2 2 1 2 2 2
20 KT 2 3 3 3 2 3 3 3
25 KT 2 3 4 3 2 3 4 3
30 KT 3 4 5 4 3 4 5 4
35 KT 3 4 5 4 3 4 5 4
40 KT 4 5 6 5 4 5 6 5
45 KT 4 5 6 5 4 5 6 5
50 KT 5 6 7 6 5 6 7 8


 

CHESAPEAKE BAY - SANDY POINT TO NORTH BEACH


[Chesapeake Bay - Sandy Point to North Beach]
 
  W NW N NE E SE S SW
10 KT 1 1 1 1 1 1 1 1
15 KT 1 1 2 1 1 1 2 1
20 KT 2 2 3 2 2 2 3 2
25 KT 2 3 4 3 2 3 4 3
30 KT 3 4 5 4 3 4 5 4
35 KT 3 4 5 4 3 4 5 4
40 KT 4 5 6 5 4 5 6 5
45 KT 4 5 6 5 4 5 6 5
50 KT 5 6 7 6 5 6 7 6


 

CHESAPEAKE BAY - NORTH BEACH TO DRUM POINT


[Chesapeake Bay - North Beach to Drum Point]
 
  W NW N NE E SE S SW
10 KT 1 1 1-2 1-2 1 1 1-2 1-2
15 KT 2 2 3 3 2 2 3 3
20 KT 2 2 4 3 2 2 4 3
25 KT 2 3 5 4 2 3 5 4
30 KT 3 4 6 5 3 4 6 5
35 KT 3 4 6 5 3 4 6 5
40 KT 4 5 7 6 4 5 7 6
45 KT 4 5 7 6 4 5 7 6
50 KT 5 6 7 6 5 6 7 6


 

CHESAPEAKE BAY - DRUM POINT TO SMITH POINT


[Chesapeake Bay - Drum Point to Smith Point]
 
  W NW N NE E SE S SW
10 KT 1 1-2 2 1-2 1 1-2 2 1-2
15 KT 2 2 3 2 2 2 3 2
20 KT 3 3 4 3 3 3 4 3
25 KT 4 4 5 4 4 4 5 4
30 KT 4 4 6 5 4 5 6 5
35 KT 5 5 7 6 5 6 7 6
40 KT 5 5 7 6 5 6 7 6
45 KT 6 6 8 7 6 7 8 7
50 KT 6 6 8 7 6 7 8 7