Weather Underground Forecast for Wednesday, October 02, 2013.
Unsettled weather will continue to linger in the Pacific Northwest on Wednesday, while the lower Mississippi Valley will likely experience moderate thunderstorms.
A low pressure system continues sliding southward from the Gulf of Alaska and will continue to drive moisture onshore and into the Pacific Northwest. Rain is not expected to be as heavy as the previous few days, but moderate to heavy rainfall may occur along western facing mountain slopes. In addition, temperatures will be low enough for snow accumulation in the Washington Cascades and Northern Rockies. Wet weather will stretch as far east as Montana and Wyoming as a result of this persistent onshore flow. The Southwest and southern Great Basin will stay clear of precipitation on Tuesday, and temperatures should remain well below 100 degrees in the southern California and Arizona deserts.
Rain and thunderstorms will begin to pick up in the central and northern Plains on Tuesday as a cold front boundary propagates eastward over the region. Thunderstorms will likely be strongest in the afternoon as the cold front interacts with a moist, warm air mass moving northward from the Gulf of Mexico.
Along the Gulf Coast, an onshore flow will trigger more thunderstorms in eastern Texas, Louisiana and Mississippi, and flash flooding will be possible in all three states. Spotty thunderstorms will also move through the southern tip of Florida on Wednesday. The remainder of the East Coast will experience dry conditions as a ridge of high pressure will build over the Mid-Atlantic states.
Temperatures in the Lower 48 states Tuesday have ranged from a morning low of 26 degrees at Grand Canyon, Ariz. to a high of 95 degrees at Pecos, Texas