The NWS is in the process of changing over the forecast system to a new method, known as API (Application Programming Interface). In the mean time both are available and sometimes the new one (API) comes up with errors. So this is a side-by-side comparison of the two methods.

https://www.halethorpeweather.com/advforecast2-V4.04.php?inc=y&z=0 output

https://www.halethorpeweather.com/advforecast2-V5.09.php?inc=y&z=0 output

National Weather Service Forecast for: Halethorpe MD
Issued by: National Weather Service Baltimore, MD/Washington, D.C.
Updated: 5:43 am EST Jan 18, 2019

Halethorpe, MD
 
Today

Today: A slight chance of snow before 7am.  Patchy fog before 10am.  Otherwise, cloudy, then gradually becoming mostly sunny, with a high near 44. Light and variable wind becoming west 5 to 7 mph in the morning.  Chance of precipitation is 20%.
Slight Chance
Snow and
Patchy Fog
then Mostly
Sunny
Tonight

Tonight: Partly cloudy, with a low around 30. North wind 3 to 6 mph.
Partly Cloudy


Saturday

Saturday: Snow, freezing rain, and sleet likely between 10am and 4pm, then rain.  High near 36. Light northeast wind becoming east 6 to 11 mph in the morning.  Chance of precipitation is 80%. Little or no ice accumulation expected.  New snow and sleet accumulation of less than a half inch possible.
Slight Chance
Wintry Mix
then Wintry
Mix
Saturday
Night
Saturday Night: Rain.  Low around 32. East wind 6 to 9 mph becoming southwest after midnight.  Chance of precipitation is 100%. New precipitation amounts between 1 and 2 inches possible.
Rain


Sunday

Sunday: Rain showers likely, possibly mixing with snow after 10am, then gradually ending.  Mostly cloudy, with a high near 37. Breezy, with a northwest wind 6 to 11 mph increasing to 15 to 20 mph in the afternoon. Winds could gust as high as 34 mph.  Chance of precipitation is 60%.
Rain/Snow
Likely and
Breezy

Sunday
Night
Sunday Night: Partly cloudy, with a low around 9.
Partly Cloudy


M.L.King
Day
M.L.King Day: Sunny, with a high near 20.
Sunny


Monday
Night
Monday Night: Mostly clear, with a low around 12.
Mostly Clear


Tuesday

Tuesday: Mostly sunny, with a high near 33.
Mostly Sunny


Hi 44 °F Lo 30 °F Hi 36 °F Lo 32 °F Hi 37 °F Lo 9 °F Hi 20 °F Lo 12 °F Hi 33 °F

 

Today
 
A slight chance of snow before 7am. Patchy fog before 10am. Otherwise, cloudy, then gradually becoming mostly sunny, with a high near 44. Light and variable wind becoming west 5 to 7 mph in the morning. Chance of precipitation is 20%.
Tonight
 
Partly cloudy, with a low around 30. North wind 3 to 6 mph.
Saturday
 
Snow, freezing rain, and sleet likely between 10am and 4pm, then rain. High near 36. Light northeast wind becoming east 6 to 11 mph in the morning. Chance of precipitation is 80%. Little or no ice accumulation expected. New snow and sleet accumulation of less than a half inch possible.
Saturday Night
 
Rain. Low around 32. East wind 6 to 9 mph becoming southwest after midnight. Chance of precipitation is 100%. New precipitation amounts between 1 and 2 inches possible.
Sunday
 
Rain showers likely, possibly mixing with snow after 10am, then gradually ending. Mostly cloudy, with a high near 37. Breezy, with a northwest wind 6 to 11 mph increasing to 15 to 20 mph in the afternoon. Winds could gust as high as 34 mph. Chance of precipitation is 60%.
Sunday Night
 
Partly cloudy, with a low around 9.
M.L.King Day
 
Sunny, with a high near 20.
Monday Night
 
Mostly clear, with a low around 12.
Tuesday
 
Mostly sunny, with a high near 33.
Tuesday Night
 
A chance of rain and snow. Mostly cloudy, with a low around 29. Chance of precipitation is 30%.
Wednesday
 
Rain likely. Cloudy, with a high near 49. Chance of precipitation is 60%.
Wednesday Night
 
Rain and snow likely. Cloudy, with a low around 35. Chance of precipitation is 70%.
Thursday
 
A chance of rain and snow. Mostly cloudy, with a high near 39. Chance of precipitation is 50%.

 

Forecast from NOAA-NWS for Halethorpe MD.

National Weather Service Forecast for: Arbutus, MD
Issued by: National Weather Service Baltimore/Washington
Updated: Fri, 18-Jan-2019 3:31am EST

Halethorpe, MD
 
Today

Today: Patchy Fog then Partly Sunny
Patchy Fog then Partly Sunny
Saturday

Saturday: Light Snow Likely
Light Snow Likely
Sunday

Sunday: Chance Rain And Snow Showers
Chance Rain And Snow Showers
M.L. King
Jr. Day
M.L. King Jr. Day: Sunny
Sunny
Tuesday

Tuesday: Mostly Sunny
Mostly Sunny
Wednesday

Wednesday: Rain And Snow Likely
Rain And Snow Likely
Thursday

Thursday: Rain And Snow Likely
Rain And Snow Likely
 
Hi 44 °F Hi 36 °F Hi 37 °F Hi 20 °F Hi 33 °F Hi 49 °F Hi 39 °F  
 
Tonight

Tonight: Partly Cloudy
Partly Cloudy
Saturday
Night
Saturday Night: Light Rain
Light Rain
Sunday
Night
Sunday Night: Partly Cloudy
Partly Cloudy
Monday
Night
Monday Night: Mostly Clear
Mostly Clear
Tuesday
Night
Tuesday Night: Chance Rain And Snow
Chance Rain And Snow
Wednesday
Night
Wednesday Night: Rain And Snow Likely
Rain And Snow Likely
Thursday
Night
Thursday Night: Chance Rain And Snow then Slight Chance Snow Showers
Chance Rain And Snow then Slight Chance Snow Showers
 
Lo 30 °F Lo 32 °F Lo 9 °F Lo 12 °F Lo 29 °F Lo 35 °F Lo 24 °F  

 

Today
 
Patchy fog and a slight chance of snow before 10am. Partly sunny, with a high near 44. Southwest wind 3 to 7 mph. Chance of precipitation is 20%. New snow accumulation of less than one inch possible.
Tonight
 
Partly cloudy, with a low around 30. Northwest wind around 6 mph.
Saturday
 
Snow likely and sleet likely and freezing rain likely between 10am and 4pm, then rain. Mostly cloudy, with a high near 36. East wind 3 to 12 mph. Chance of precipitation is 80%. New snow accumulation of less than half an inch possible. Little or no ice accumulation expected.
Saturday Night
 
Rain. Cloudy, with a low around 32. Southeast wind 6 to 10 mph. Chance of precipitation is 100%. New rainfall amounts between 1 and 2 inches possible.
Sunday
 
Rain before 10am, then a chance of rain and snow showers between 10am and 4pm. Mostly cloudy, with a high near 37. Northwest wind 6 to 20 mph, with gusts as high as 35 mph. Chance of precipitation is 90%.
Sunday Night
 
Partly cloudy, with a low around 9.
M.L. King Jr. Day
 
Sunny, with a high near 20.
Monday Night
 
Mostly clear, with a low around 12.
Tuesday
 
Mostly sunny, with a high near 33.
Tuesday Night
 
A chance of rain and snow after 7pm. Mostly cloudy, with a low around 29. Chance of precipitation is 30%.
Wednesday
 
Rain and snow likely. Mostly cloudy, with a high near 49. Chance of precipitation is 60%.
Wednesday Night
 
Rain likely before 7pm, then rain and snow likely. Cloudy, with a low around 35. Chance of precipitation is 70%.
Thursday
 
Rain and snow likely. Mostly cloudy, with a high near 39. Chance of precipitation is 70%.
Thursday Night
 
A chance of rain and snow before 7pm, then a slight chance of snow showers. Mostly cloudy, with a low around 24. Chance of precipitation is 50%.

 

Forecast from NOAA-NWS for Arbutus, MD.