Glen Arm, MD

2:34 PM EDT on August 18, 2017 (GMT -0400)
Glen Arm | | Change Station

Elev 430 ft 39.45 °N, 76.52 °W | Updated 15 seconds ago

Partly Cloudy
Partly Cloudy
87.4 °F
Feels Like 100 °F
Wind Variable Wind from SE
Gusts 2.5 mph

High -- | Low -- °F
--% Chance of Precip.
High -- | Low -- °F
Precip. -- in
Pressure 29.84 in
Visibility 10.0 miles
Clouds Scattered Clouds 3000 ft
Scattered Clouds 8000 ft
Scattered Clouds 20000 ft
Heat Index 100 °F
Dew Point 78 °F
Humidity 73%
Rainfall 0.00 in
Snow Depth Not available.
6:21 AM 7:57 PM
Waning Crescent, 12% visible
METAR KMTN 181745Z 14011KT 10SM SCT030 SCT080 SCT200 30/27 A2984
Pressure 29.84 in
Visibility 10.0 miles
Clouds Scattered Clouds 3000 ft
Scattered Clouds 8000 ft
Scattered Clouds 20000 ft
Heat Index 100 °F
Dew Point 78 °F
Humidity 73%
Rainfall 0.00 in
Snow Depth Not available.
6:21 AM 7:57 PM
Waning Crescent, 12% visible
METAR KMTN 181745Z 14011KT 10SM SCT030 SCT080 SCT200 30/27 A2984

Get Your Daily Forecast Email!

Thanks for signing up!

Be on the lookout for a verification email in your inbox.

You'll start receiving severe weather alerts in your inbox..


10-Day Weather Forecast



Aug. 18, 2017 Rise Set
Actual Time
Civil Twilight
Nautical Twilight
Astronomical Twilight
Length of Visible Light
Length of Day
Tomorrow will be .
, % of the Moon is Illuminated

Today's Extremes

State Highs State Lows



Category 6

Welcome to Category 6. This is the collective home for Weather Underground's featured writeups by Dr. Jeff Masters (right), Bob Henson (left), Chris Burt, and other regular contributors.


Air Quality

  Air Quality AQ Index Pollutant
Not available.

Snow Depth

Station Depth Elevation

Earthquake Activity

City Distance Mag. Time & Date
Minimum magnitude displayed is 2.5.

Coastal Water Temperatures

Place Temperature


Nearby Weather Stations

Station Location Temp. Windchill Dew Point Humidity Wind Precip. Elev Updated Type

Watches & Warnings

Severe Thunderstorm Watch
Issued: 2:27 PM EDT Aug. 18, 2017 – National Weather Service

The National Weather Service has issued Severe Thunderstorm Watch
455 in effect until 9 PM EDT this evening for the following areas

The District of Columbia

In Maryland this watch includes 13 counties

In central Maryland

Anne Arundel Howard Montgomery
Prince Georges

In north central Maryland

Carroll Frederick Washington

In northern Maryland

Baltimore Baltimore City Harford

In southern Maryland

Calvert Charles St. Marys

In Virginia this watch includes 20 counties

In central Virginia

City of Fredericksburg Greene
King George Orange Spotsylvania

In northern Virginia

Arlington city of Alexandria City of Fairfax
City of Falls Church City of Manassas
City of Manassas Park Culpeper
Fairfax Fauquier Loudoun
Prince William Stafford

In northwest Virginia

Clarke Madison Rappahannock

In West Virginia this watch includes 2 counties

In Panhandle West Virginia

Berkeley Jefferson

This includes the cities of Aberdeen, Alexandria, Annapolis,
Arlington, Arnold, Aspen Hill, ballenger creek, Baltimore,
Bel Air, Berryville, Bethesda, Bowie, California, Camp Springs,
Catonsville, Chantilly, Charles Town, Chesapeake Beach, Clinton,
College Park, Columbia, Culpeper, Dahlgren, Dundalk, Dunkirk,
Edgewood, Eldersburg, Ellicott City, Essex, Fairfax,
Falls church, Fallston, Falmouth, Frederick, Fredericksburg,
Gaithersburg, Germantown, Glen Burnie, Gordonsville, Greenbelt,
Hagerstown, Havre de Grace, Herndon, Huntingtown, Joppatowne,
Laurel, Leesburg, Lexington Park, Lusby, Madison, Manassas,
Manassas Park, Martinsburg, McLean, North Beach, Odenton, Orange,
Parkville, Pikesville, Potomac, Prince Frederick, Randallstown,
Reston, Rockville, Severn, Severna Park, Shepherdstown,
Silver Spring, South Gate, Spotsylvania courthouse, St. Charles,
Stanardsville, Sterling, Suitland-Silver Hill, Towson, Waldorf,
Warrenton, Washington, Washington, Westminster, and Woodbridge.

Flash Flood Watch
Issued: 12:35 PM EDT Aug. 18, 2017 – National Weather Service

... Flash Flood Watch in effect through late tonight...

The National Weather Service in Sterling Virginia has issued a

* Flash Flood Watch for portions of Maryland, the District of
Columbia, and Virginia, including the following areas, in
Maryland, Anne Arundel, Calvert, Carroll, central and
southeast Howard, central and southeast Montgomery, Charles,
Frederick MD, northern Baltimore, northwest Harford, northwest
Howard, northwest Montgomery, Prince Georges, southeast
Harford, southern Baltimore, and St. Marys. The District of
Columbia. In Virginia, Arlington/Falls Church/Alexandria,
Culpeper, eastern Loudoun, Fairfax, King George, Madison,
northern Fauquier, Orange, Prince William/Manassas/Manassas
Park, Rappahannock, southern Fauquier, Spotsylvania, Stafford,
and western Loudoun.

* Through late tonight

* thunderstorms with heavy rainfall are expected across the region
this afternoon and evening. The potential for training
thunderstorms exists, which could result in several inches of
rain in one to two hours. Soils are already very moist, meaning
most of this rain would rapidly run off.

* Runoff from excessive rainfall may cause rapid rises of water
in low-lying and poor drainage areas as well as streams and
creeks, resulting in flash flooding. Urban areas will be most

Precautionary/preparedness actions...

A Flash Flood Watch means that conditions may develop that lead
to flash flooding. Flash flooding is a very dangerous situation.

You should monitor later forecasts and be prepared to take action
should flash flood warnings be issued.


Heat Advisory
Issued: 11:15 AM EDT Aug. 18, 2017 – National Weather Service

... Heat advisory remains in effect until 8 PM EDT this evening...

* heat index values... around 105 degrees due to temperatures in
the lower 90s and dewpoints in the mid to upper 70s.

* Impacts... the heat and humidity may cause heat stress during
outdoor exertion or extended exposure.

Precautionary/preparedness actions...

A heat advisory means that a period of high temperatures is
expected. The combination of high temperatures and high humidity
will create a situation in which heat illnesses are possible.

Take extra precautions if you work or spend time outside. When
possible, reschedule strenuous activities to early morning or
evening. Know the signs and symptoms of heat exhaustion and heat
stroke. Wear light weight and loose fitting clothing when
possible and drink plenty of water.

To reduce risk during outdoor work, the occupational safety and
health administration recommends scheduling frequent rest breaks
in shaded or air conditioned environments. Anyone overcome by
heat should be moved to a cool and shaded location. Heat stroke
is an emergency - call 911.