Storm stalking: Hurricane winds

Jessica Williams, flight director of the NOAA Winter Storms Reconnaisance, and a native of Willow Grove, Pa, goes over the weather charts while flying over the jets stream at 43000 feet over the North Pacific on Thursday afternoon, March 11, 2010. (Laurence Kesterson / Staff Photographer)

The reconnaissance jet just passed over a jet-stream wind of 161 m.p.h., equivalent to a Category 5 hurricane, and then some.

The plane is making a loop through the upper-air low pressure system that is giving a kick to an impressive storm affecting an area from southern Alaska all the way to central California.

The plane is now on the western side of the storm center, and the winds, which were from the southwest, have backed around and now are  from the west-northwest.

It storm is generating hurricane-force winds even at the surface near Vancouver. The winds at the surface below the aircraft are whipping up  white caps on the Pacific, big enough to be visible from 45,000 feet.

Ultimately, it is not at all clear what the future of this system will mean for Philadelphia, but the flight meteorologist, Willow Grove's  own Jessica Williams, says more heavy precipitation is possible early next week from some remnant of this feature.

As the plane makes a loop through the system, Charles Lynch, the crew engineer, is about to send out the 11th probe of the mission, with five more to go.

One big advantage these "data bombs" have over satellites is that the  latter have a hard time seeing through cloud cover, which, of course,  is standard fare in storms.

Weather balloons that profile the atmosphere are sent up every 12 hours. However, that data is lacking over lesser-developed countries  and the oceans. Since weather moves west to east, the North Pacific is a crucial area for the United States.

Saturation bombing of the data-poor North Pacific would be  prohibitively expensive, so the National Oceanic and Atmospheric Administration, which runs the Gulfstream program, has to pick its spots.

It looks for places where trouble is brewing, and where the computer  models have wide disagreements on exactly what is unfolding there.

Today's trouble spot encompasses a tear-drop shaped area, about 1,600 miles long, from north of Honolulu to a latitude just north of Philadelphia's.

Typically, the jet flies missions every few days, but this is the second consecutive day that it has come out to look at this feature.  Yesterday, it dropped probes to the north and west of today's reconnaissance area, and today it shifted the focus east with the storm.

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