Rio Grande Valley:
Today was a very nice day, weather wise, in the Valley. Highs reached 70 degrees at Brownsville and 69 at the McAllen International Airport. Winds were out of the north between 10 and 15 mph. High pressure is going to keep the forecast relatively the same the next few days with sunny to mostly sunny skies.
(12/19): Sunday, look forward to sunny skies with temperatures in the lower 70s throughout the Valley. Winds will be out of the south southeast at 5-10 mph. Sunday night will be mostly clear with lows in the mid 50s in most areas. Winds will be calm, with the chance of some patchy fog after midnight.
(12/20): Monday will be warmer, with highs in the upper 70s or lower 80s. Skies will be mostly clear with winds out of the south and gusty at times. Gust could hit 20 mph or greater. Monday night the winds should calm to 10-15 mph with lows in the lower 60s.
(12/21): Tuesday looks to be generally the same as Monday. Mostly sunny skies, with highs in the lower 80s. Winds should be out of the south southeast at 10 mph. Tuesday night will be partly cloudy with lows in the mid 60s.
Rest of the Nation:
High pressure dominates the central portions of the United States, thus resulting in subsiding air aloft. With sinking air, it is difficult to create precipitation and clouds. The western half of the United States is a much different story.
As talked about in the previous day, there is a low pressure in the Pacific northwest, just off the coast of Washington/Oregon. The counter clockwise flow around the low is generating lots of snow and rain in California. Winter Storm Warnings and Flood Warnings have been issued out for much of California and will not be cancelled for a good amount of time. The low in the Pacific northwest is forecasted to not move much over the next few days. As a result of this low, snow, rain and clouds are also being generated as far inland as Montana and Colorado.
A low off the coast of North Carolina/South Carolina is bring rain for the two states. This low is moving north west and might evolve into a nor’easter for the northeastern portion of the United States. More on this later.