From the National Weather Service:

THE NATIONAL WEATHER SERVICE IN STERLING VIRGINIA HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR… THE DISTRICT OF COLUMBIA… SOUTHERN MONTGOMERY COUNTY IN CENTRAL MARYLAND… NORTHERN CHARLES COUNTY IN SOUTHERN MARYLAND… EASTERN CITY OF FAIRFAX IN NORTHERN VIRGINIA… CITY OF FALLS CHURCH IN NORTHERN VIRGINIA… ARLINGTON COUNTY IN NORTHERN VIRGINIA… CITY OF ALEXANDRIA IN NORTHERN VIRGINIA… EASTERN PRINCE WILLIAM COUNTY IN NORTHERN VIRGINIA… PRINCE GEORGES COUNTY IN CENTRAL MARYLAND… EASTERN FAIRFAX COUNTY IN NORTHERN VIRGINIA…

* UNTIL 1130 PM EDT

* AT 1041 PM EDT… SEVERE THUNDERSTORMS WERE DETECTED ALONG A LINE EXTENDING FROM CHEVY CHASE TO ALEXANDRIA TO WOODBRIDGE… AND WERE MOVING EAST AT 25 MPH. THIS LINE OF STORMS IS CAPABLE OF PRODUCING DAMAGING WINDS IN EXCESS OF 60 MPH.

* LOCATIONS IMPACTED INCLUDE… TAKOMA PARK… NATIONALS PARK… NATIONAL HARBOR… THE DISTRICT… LANGLEY PARK… HYATTSVILLE… FORT WASHINGTON… KENILWORTH…

PRECAUTIONARY/PREPAREDNESS ACTIONS…

THIS IS A DANGEROUS LINE OF STORMS. IF YOU ARE IN ITS PATH… MOVE INDOORS TO A STURDY BUILDING AND STAY AWAY FROM WINDOWS. WHEN IT IS SAFE TO DO SO… REPORT SEVERE WEATHER TO LOCAL LAW ENFORCEMENT OR TO THE NATIONAL WEATHER SERVICE.

The National Weather Service warns that the storms may include heavy rain and hail.

… STRONG THUNDERSTORMS TO AFFECT ARLINGTON… NORTHERN FAUQUIER… SOUTHERN FAUQUIER… PRINCE WILLIAM/MANASSAS/MANASSAS PARK… LOUDOUN AND FAIRFAX COUNTIES…

AT 358 PM EDT… STRONG THUNDERSTORMS WERE LOCATED ALONG A LINE EXTENDING FROM AUBURN TO INDEPENDENT HILL TO MASON NECK… MOVING NORTH AT 20 MPH.

LOCATIONS IMPACTED INCLUDE GREENWICH… FORT BELVOIR… NEW BALTIMORE… NEWINGTON… WEST SPRINGFIELD… GAINESVILLE… FRANCONIA… BROAD RUN… WEST SPRINGFIELD AND MANASSAS PARK.

HEAVY RAIN WITH THESE STORMS WILL REDUCE VISIBILITIES TO BELOW ONE MILE AND MAY CAUSE PONDING OF WATER ON ROADWAYS.

PENNY-SIZE TO NICKEL-SIZE HAIL CAN BE EXPECTED WITH THESE STORMS.

PRIMARY THREATS INCLUDE…
SEVERAL TORNADOES POSSIBLE
SEVERAL DAMAGING WIND GUSTS TO 70 MPH POSSIBLE
A FEW LARGE HAIL EVENTS TO 1 INCH IN DIAMETER POSSIBLE

PRECAUTIONARY/PREPAREDNESS ACTIONS…

REMEMBER…A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR
TORNADOES AND SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH
AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR
THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS
AND POSSIBLE WARNINGS.

Strong storms are expected to blow into the area this afternoon and evening, possibly packing damaging winds and heavy rain. From the earlier NWS Severe Weather Outlook:

.DAY ONE…THIS AFTERNOON AND TONIGHT

THUNDERSTORMS WILL ACCOMPANY A STRONG COLD FRONT THAT WILL MOVE
ACROSS THE AREA LATE THIS AFTERNOON AND EVENING. A FEW STORMS MAY
BE SEVERE WITH LOCALLY DAMAGING WINDS AND HEAVY RAIN.

A GALE WARNING IS IN EFFECT FOR THE MARYLAND CHESAPEAKE BAY AND
TIDAL POTOMAC RIVER FROM 2 PM THIS AFTERNOON UNTIL 10 PM THIS
EVENING. A SMALL CRAFT ADVISORY IS IN EFFECT UNTIL 2 PM. A SMALL
CRAFT ADVISORY WILL LIKELY BE NEEDED AFTER THE GALE WARNING
EXPIRES LATE THIS EVENING AND TONIGHT.

A STRENGTHENING SOUTHERLY FLOW MAY PRODUCE MINOR COASTAL FLOODING
NEAR TIMES OF HIGH TIDE THIS AFTERNOON AND EVENING.

.DAYS TWO THROUGH SEVEN…SATURDAY THROUGH THURSDAY

A SMALL CRAFT ADVISORY WILL LIKELY BE NEEDED FOR THE ENTIRE
MARYLAND PORTION OF THE CHESAPEAKE BAY AND TIDAL POTOMAC RIVER
SATURDAY. A SMALL CRAFT ADVISORY MAY BE NEEDED FOR PORTIONS OF THE
WATERS SATURDAY NIGHT INTO SUNDAY.

Although Arlington Public Schools has not issued any system-wide cancellations, some individual schools have already reported cancellations for evening events in anticipation of the severe weather.

The previous record, of 89 degrees, was set back in 1922. The average high temperature for April 10 is 65 degrees, per the Capital Weather Gang.

The unseasonal spring heat is expected to stick around for at least another day. Tomorrow’s high temperature is predicted to be 81, according to the National Weather Service.

On Friday, rain showers are expected to usher in more April-appropriate temperatures.

As of noon today, the weather station at DCA reported a temperature of 81 degrees. The mercury actually hit 80 yesterday afternoon, as pointed out by ABC 7 meteorologist Alex Liggitt.

The temperature is predicted to keep climbing tomorrow, with Weather.com predicting a high of 90 degrees on Wednesday.

Update at 2:05 p.m. — In another sign of the season, Arlington County paramedics have been dispatched to Arlington National Cemetery for a patient suffering a possible heat stroke. Such calls are common during the summer, but are much less common during early April.

A spring storm system dropped some 1-4 inches of snow on Arlington this morning.

The snowfall made for some pretty scenery but caused a few problems around town.

We asked readers to send their photos of the snow to us via Twitter and Flickr. Check out some of their submissions, and a few photos taken by us, in the gallery above.

(Updated at 9:20 a.m.) Arlington commuters woke up to something of a surprise this morning: accumulated snowfall.

Arlington County says local roads are “slushy,” and its snow removal crews are in the “Phase 2” of snow removal — working to treat heavily-travelled roads.

“Commuters will encounter slushy conditions on area roads,” the county said in an Arlington Alert. “Use caution when approaching intersections and on/off ramps.”

Arlington Public Schools are not impacted by the snowfall; students are currently on spring break. But snow-covered roads perhaps played a factor led in a number of accidents in and around Arlington this morning.

Accidents have been reported on the northbound GW Parkway near Spout Run and Route 123. The second accident involved an overturned car and northbound traffic is reportedly blocked.

Meanwhile, a rollover accident happened earlier at Reagan National Airport.

A vehicle flipped over on the departures roadway, beyond Terminals B and C on the “return to the airport” ramp.

“[The] driver of the vehicle was transported to a local hospital,” said airport spokesman Robert Yingling. “No other occupants [and] no other vehicles [were] involved.”

The vehicle has since been removed and the road reopened.

Although the ground in parts of Arlington has yet to become snow-covered, forecasters say the storm is intensifying and should soon start accumulating here.

The National Weather Service has issued a Winter Storm Warning, upgrading the previous Winter Storm Watch. Forecasters say we’re likely to get 4-8 inches of snow tomorrow (Wednesday).

… WINTER STORM WARNING IN EFFECT FROM MIDNIGHT TONIGHT TO 3 AM EST THURSDAY…

THE NATIONAL WEATHER SERVICE IN BALTIMORE MD/WASHINGTON HAS ISSUED A WINTER STORM WARNING FOR SNOW… WHICH IS IN EFFECT FROM MIDNIGHT TONIGHT TO 3 AM EST THURSDAY. THE WINTER STORM WATCH IS NO LONGER IN EFFECT.

* PRECIPITATION TYPE… SNOW.

* ACCUMULATIONS… 4 TO 8 INCHES WITH THE HIGHER AMOUNTS WEST OF INTERSTATE 95.

* TIMING… RAIN MIXING WITH AND CHANGING TO WET SNOW FROM SOUTHWEST TO NORTHEAST TONIGHT AND WEDNESDAY MORNING. SNOW MAY BE MODERATE TO HEAVY AT TIMES WEDNESDAY. SNOW TAPERS OFF WEDNESDAY NIGHT.

* TEMPERATURES… IN THE MID 30S.

* WINDS… NORTHEAST 15 TO 25 MPH. GUSTS UP TO 35 MPH WEDNESDAY AFTERNOON AND NIGHT.

* IMPACTS… SNOW COVERED ROADS WILL MAKE TRAVEL DIFFICULT. HEAVY WET SNOW AND GUSTY WINDS COULD LEAD TO POWER OUTAGES WEDNESDAY AFTERNOON AND NIGHT.

PRECAUTIONARY/PREPAREDNESS ACTIONS…

A WINTER STORM WARNING FOR HEAVY SNOW MEANS SEVERE WINTER WEATHER CONDITIONS ARE EXPECTED OR OCCURRING. SIGNIFICANT AMOUNTS OF SNOW ARE FORECAST THAT WILL MAKE TRAVEL DANGEROUS. ONLY TRAVEL IN AN EMERGENCY. IF YOU MUST TRAVEL… KEEP AN EXTRA FLASHLIGHT… FOOD… AND WATER IN YOUR VEHICLE IN CASE OF AN EMERGENCY.

Meanwhile, the Metropolitan Washington Airports Authority says travelers should expect delays and cancellations over the next 36 hours or so.

Reagan National and Dulles International Airports are operating normally. An approaching winter storm is affecting flights to and from Chicago today. We anticipate winter weather will affect flight operations here on Wednesday, March 6. Check with directly with your airline to monitor the status of your flight and determine if flight rebooking is necessary.

Our airport snow removal personnel and equipment are prepared for the storm. We will update this page with further information when the winter weather arrives.

Forecasters say chances are increasing that we’ll get a significant late-season snowstorm starting Tuesday night. The storm could dump more than 5 inches of snow, though the precipitation could be mostly rain if the temperature stays too warm.

From the National Weather Service:

…WINTER STORM WATCH REMAINS IN EFFECT FROM TUESDAY EVENING THROUGH WEDNESDAY EVENING…

* PRECIPITATION TYPE…SNOW.

* ACCUMULATIONS…MORE THAN 5 INCHES POSSIBLE…WITH THE POTENTIAL FOR SIGNIFICANT SNOWFALL SOMEWHERE WITHIN THE WATCH AREA.

* TIMING…PRECIPITATION MIXING WITH AND CHANGING TO SNOW TUESDAY NIGHT. SNOW CONTINUING INTO WEDNESDAY EVENING.

* TEMPERATURES…IN THE LOWER AND MID 30S.

* WINDS…NORTHEAST 10 TO 20 MPH WITH GUSTS UP TO 30 MPH.

* IMPACTS…DIFFICULT DRIVING CONDITIONS. HEAVY WET SNOW AND GUSTY WINDS COULD LEAD TO POWER OUTAGES.

PRECAUTIONARY/PREPAREDNESS ACTIONS…

A WINTER STORM WATCH MEANS THERE IS A POTENTIAL FOR SIGNIFICANT SNOW…SLEET…OR ICE ACCUMULATIONS THAT MAY IMPACT TRAVEL. CONTINUE TO MONITOR THE LATEST FORECASTS.

A STRONG LOW PRESSURE SYSTEM IS EXPECTED TO IMPACT THE AREA TUESDAY NIGHT THROUGH WEDNESDAY NIGHT…BRINGING THE POTENTIAL FOR HEAVY WET SNOW…GUSTY WINDS…AND POSSIBLY COASTAL FLOODING. A WINTER
STORM WATCH HAS BEEN POSTED TUESDAY NIGHT THROUGH WEDNESDAY EVENING FOR THE BALTIMORE AND WASHINGTON DC METROPOLITAN AREAS. UNCERTAINTY REMAINS WITH THE TRACK OF THE LOW AND LOCATION OF THE RAIN-SNOW LINE…WHICH ULTIMATELY WILL DETERMINE SNOWFALL TOTALS. PLEASE MONITOR THE LATEST FORECASTS FOR UPDATES.