ALASKA EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
205 PM EDT TUE JUN 18 2013

VALID 12Z SAT JUN 22 2013 - 12Z WED JUN 26 2013

...LARGER SCALE PATTERN OVERVIEW AND SENSIBLE WEATHER HIGHLIGHTS...

THE AMPLIFIED AND ANOMALOUS ALASKAN MEDIUM RANGE LARGER SCALE FLOW
PATTERN SHOULD PROVE SLOW TO GRADUALLY TRANSITION AND REMAINS
HIGHLIGHTED BY HOT SUMMER RIDGING CENTERED OVER THE ALASKAN
INTERIOR AS AMPLE ALEUTIAN/SRN BERING SEA CENTERED LOW/TROUGH
ENERGIES AND DEEP WEATHER/QPF FOCUS UNDERNEATH TRANSFER STEADILY
OUT INTO THE NERN PACIFIC/GULF OF ALASKA WITH INCREASING URGENCY
OVER TIME AND EVENTUALLY MORE TOWARD SERN AK.

...GUIDANCE AND UNCERTAINTY ASSESSMENT...

WPC ALASKAN SURFACE FRONTS/PRESSURES AND 500 MB PROGS ALONG WITH
ASSOCIATED 5 KM SENSIBLE WEATHER GRIDS HAVE ALL BEEN PRIMARILY
DERIVED FROM COMPATABLE GUIDANCE FROM A BLEND OF THE LATEST
GFS/ECMWF AND GFS/NAEFS/ECMWF ENSEMBLE MEANS.  MODEL AND ENSEMBLE
FORECAST SPREAD AND UNCERTAINTY IS REDUCED SINCE YESTERDAY AND
THIS COMPOSITE BLEND OFFERS GOOD WPC CONTINUITY.  MANUAL WPC
FORECASTER ADJUSTMENTS WERE APPLIED TO MAINTAIN SLIGHTLY MORE
ORGANIZED SURFACE LOW ORGANIZATION AND WEATHER/QPF FOCUS THAN
EXPLICITLY DEPICTED BY THE BLEND CONSIDERING GOOD DYNAMIC SUPPORT
ALOFT COMMON TO MUCH GUIDANCE.

SCHICHTEL