ALASKA EXTENDED FORECAST DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 1252 PM EST FRI FEB 14 2014 VALID 12Z TUE FEB 18 2014 - 12Z SAT FEB 22 2014 THE DAY 4-6 MEDIUM RANGE GUIDANCE CONTINUES TO FAVOR A PROMINENT SURFACE RIDGE AT HIGH LATITUDES AND A PROGRESSIVE WESTERLY FLOW ALOFT AT MID LATITUDES--ANCHORED BY A BROAD UPPER-LEVEL LOW/TROUGH OVER ALASKA AND THE NORTHERN GULF. THE PATTERN GRADUALLY AMPLIFIES DOWNSTREAM OVER THE FAR EAST CENTRAL PACIFIC AND ALONG THE WEST COAST OF THE NORTH AMERICAN CONTINENT FOR DAY 7-8. HOWEVER...THE PREVAILING SURFACE RIDGE AND ARCTIC AIR MASS IS EXPECTED TO HOLD FIRM WITH MORE OF A PERSISTENCE TEMPERATURE FORECAST FOR 62N LATITUDE NORTHWARD. THIS PATTERN WILL SHIFT FOCUS FOR INTENSE PACIFIC CYCLONES AWAY FROM GULF OF ALASKA...AND DIRECT THEM AT THE SOUTHERN PANHANDLE...AND POINTS SOUTH...INTO THE PACIFIC NORTHWEST AND SOUTHERN BC. I THINK THE BIGGEST QUESTION MARKS ARE JUST OUTSIDE THE REALM OF THIS FORECAST PERIOD...AND IN THE HIGH ARCTIC REGION OF THE WORLD---NORTHEAST SIBERIA AND THE ARCTIC OCEAN (BERING STRAIT)--WHERE THE MODEL GUIDANCE IS HIGHLY REACTIVE AND VOLATILE. IN THIS FAR EXTENDED RANGE PERIOD...THE RESHUFFLING OF THE ARCTIC AIR MASS AND POLAR JET WILL BE IN TRANSITION OVER NORTHEAST ASIA. CORRESPONDINGLY...TRANSITION SEEMS TO BE OCCURRING OVER ARCTIC CANADA...BUT THERE IS NO AGREEMENT AT DAY8+ TO DAY+11. UNTIL THEN...WILL TAKE MORE OF A PERSISTENCE APPROACH TO THE NORTH PACIFIC WAVE TRAIN AND ALASKAN MEDIUM RANGE FORECASTS...WHERE THE EC MEANS DO REASONABLY WELL. VOJTESAK