500 millibar height/Precip map valid at midnight Friday night (06z Sat) Jan 16, 2010

Image from 00z GFS model run from National Weather Service/Nashville/AWIPS

Major pattern change underway across North America

Heavy rain along Gulf Coast Friday and Saturday

Rain in Mid State Saturday Night and Sunday

Bobby Boyd

Meteorologist

National Weather Service

Nashville, Tennessee

A major pattern change is underway across North America similar to 1989-90 with impressive wave train across the Pacific. The first in a series of upper level systems will move into California today and then down across Arizona on Thursday and into south Texas by Friday. Once system moves into south Texas heavy rains are expected to develolp along the southeast Texas coast on Friday and then across southern Louisana and into the panhandle of Florida by Saturday. Middle Tennessee will be on the northern fringes of this system as it moves northeast and phases with the low over Kansas (see map above) this weekend. The heaviest rain should be south of the Tennessee Valley. Temperatures are expected to be too warm for any frozen precipitation in Middle Tennessee but rain will be likely Saturday night and Sunday.

Posted 1/13/2010/0300 cst

Expires 1/14/2010/0300 cst