From the ABC 7 Weather team

Another Blast of Gusty Winds For DC Weather Monday

November 16, 2013 - 05:21 PM
Text size Decrease Increase

The weather coming up Monday morning looks almost like a carbon-copy of what the DC area had at the very beginning of the month; gusty winds.

The weather pattern across the U.S. has been very progressive this month; multiple cold fronts have crossed the country, with warm air in advance in colder winds in their wake.

The next front is organizing in the Northwest and poised to roll through just in time for the morning commute Monday. The upper-level energy from this weather system will push into the Plains Sunday and then lift into the eastern Great Lakes Monday. Ahead of it, there is significant potential for severe storms in the Midwest and Ohio Valley. The Government’s Storm Prediction highlights a moderate potential for damaging thunderstorm wind gusts in the bull's eye seen on the map below.

convective_outlook

The jet stream, or zone of upper-level winds, this time of the year favors strong winds because temperature contrasts in northern and southern latitudes increases, allowing for a faster flow of air and more atmospheric mixing (cold air sinking and warm air rising).

This front will draw upon the fast jet stream winds to produce rain and wind. Looking closer at the data from Reagan National Airport, notice on the image below how winds not far from the surface (5,000 feet) are 57 knots, which translates to about 65 mph. This image shows the atmosphere profile (vertical cross section) of the winds, temperature and dew point in Washington early Monday morning just before the front is slated to move through.

DCA_profile

The cold front will likely cross just as the morning commute is in full swing. Notice the light blue or pink line highlighted in the image below. This shows a sharp pressure rise immediately in the front’s wake. A combination of high winds aloft and a sharp pressure rise will contribute to gusty winds along the leading edge of the front in the showers that move through.

DCA_pressure_rise

While all of the high winds aloft will not translate to the surface, at least half of this momentum will transfer to the ground in the heavier showers. Gusts will likely reach 35 mph in Washington. Closer to the best upper-level support with the front in the western suburbs and where there are elevations closer to that critical 5,000 foot level, gusts of 40-50 mph are likely. Due to these factors, Wind Advisories will likely be issued along and west of the Blue Ridge ahead of the front on Sunday.

lwx_area

If you recall, on November 1, a line of thunderstorms trucked through the Ohio Valley and became a north to south line of showers by the time it reached I-81 and then drove east through the morning. Wind gusts were 35-45 mph and sporadic damage was noted, mainly tree branches down, in Frederick and Carroll County.

Be prepared for a potentially longer than normal commute Monday due to the brief intense rain and gusty winds and it may be wise to set an alternative alarm in case the power briefly goes out in your location overnight Sunday. Stay with ABC7 for the latest forecast and the latest wind-related advisories that could be issued for parts of the region.

The air behind the front initially won’t be very chilly. As a matter of fact, the breezy northwest winds in the front’s wake will downslope, warm off the Blue Ridge (when air compresses it warms up) and overcome the bit of cooling to the post-frontal air, allowing temperatures to actually recover close to 70 degrees in downtown Washington Monday afternoon.

 

Read More:
comments powered by Disqus