UPDATE: District of Columbia Under Flood Warning

MAP from the NWS shows the area in bright green under a Flood Warning Tuesday.

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WASHINGTON, DC -- The National Weather Service has upgraded its previous Flood Watch to a Flood Warning for the District of Columbia, in effect until 2 p.m. Tuesday.

Here’s the announcement:

PRECAUTIONARY/PREPAREDNESS ACTIONS... A FLOOD WARNING MEANS THAT FLOODING IS IMMINENT OR HAS BEEN REPORTED. STREAM RISES WILL BE SLOW AND FLASH FLOODING IS NOT EXPECTED.

HOWEVER...ALL INTERESTED PARTIES SHOULD TAKE NECESSARY PRECAUTIONS IMMEDIATELY. EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE PONDING OF WATER IN URBAN AREAS...HIGHWAYS...STREETS AND UNDERPASSES AS WELL AS OTHER POOR DRAINAGE AREAS AND LOW LYING SPOTS. DO NOT ATTEMPT TO TRAVEL ACROSS FLOODED ROADS. FIND ALTERNATE ROUTES. IT TAKES ONLY A FEW INCHES OF SWIFTLY FLOWING WATER TO CARRY VEHICLES AWAY.

Through Tuesday evening, a low pressure system will move across the region. This will result in rain, which will be heavy at times during the first half of the day. Rainfall totals across the watch area are expected to range between 1 to 1.5 inches.

This heavy rainfall, coupled with snow melt will lead to the potential of small streams and tributaries in the watch area to overflow their banks.

Urban areas prone to poor drainage will be susceptible to flooding, according to the NWS. The time of the greatest threat of flooding will be from Tuesday afternoon through Tuesday evening, according to the weather service.

Precautionary actions

A Flood Watch means there is a potential for flooding, based on current forecasts. You should monitor later forecasts and be alert for possible flood warnings. Those living in areas prone to flooding should be prepared to take action should flooding develop, the NWS warns.

Patch will update this story Tuesday if new information becomes available.