Small Craft Advisory 163, NWS Anchorage, AK

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
200 PM AKST SAT FEB 22 2014

.ANALYSIS AND UPPER LEVELS...
THE OVERALL WEATHER PATTERN HAS STABILIZED AND FEATURES A DEEP
LONGWAVE TROUGH OVER THE BERING SEA. MEANWHILE...HIGH PRESSURE HAS
DEVELOPED OVER THE INTERIOR WITH A RIDGE AXIS CURRENTLY LOCATED NEAR
ANCHORAGE. THERE IS A 963 MB LOW OVER THE NORTHWEST BERING SEA...WITH
AN ASSOCIATED FRONT THAT EXTENDS FROM EASTERN RUSSIA ALL THE WAY BACK
DOWN THE ALASKAN WEST COAST WITH A SUBTROPICAL MOISTURE PLUME ALL THE
WAY DOWN TO 30N. WARM AIR HAS SURGED ACROSS THE SOUTHWEST
MAINLAND...CHANGING PRECIPITATION OVER TO RAIN AT MOST LOCATIONS. A
SIGNIFICANT SHORTWAVE IS MOVING NORTHWARD ALONG A NEARLY STATIONARY
FRONTAL BOUNDARY...WITH AN ASSOCIATED 989 MB SURFACE LOW APPROACHING
THE ALASKA PENINSULA FROM THE SOUTH. THIS LOW WILL BRING ANOTHER
ROUND OF HEAVY PRECIPITATION TO KODIAK ISLAND AND THE SOUTHWEST AK
COASTLINE THIS EVENING.

.MODEL DISCUSSION...
THE MODELS ARE IN ABOVE AVERAGE AGREEMENT THROUGH 84 HOURS ON THE
MOVEMENT OF MAJOR FEATURES. THERE ARE SOME MINOR DIFFERENCES MAINLY
TOWARD THE END OF THE SHORT TERM IN REGARDS TO SEVERAL FAIRLY WEAK
LOWS LANGUISHING SOUTH OF THE ALEUTIANS IN THE BASE OF THE LONGWAVE
TROUGH. THE NAM IS A SLIGHT OUTLIER...AND WITH STRONGLY MERIDIONAL
FLOW AM NOT SURPRISED TO SEE THE NON-GLOBAL MODELS STRUGGLING A BIT.
THUS FOR THE ALEUTIAN REGION WILL OPT TO MAKE RELATIVELY MINOR
UPDATES TO THE FORECAST WITH THE ECMWF/GFS GLOBAL MODELS THIS
AFTERNOON. ACROSS THE EASTERN DOMAIN...LARGER DIFFERENCES DO NOT
MANIFEST UNTIL ANOTHER SIGNIFICANT LOW APPROACHES FROM THE SOUTH
TUESDAY AFTERNOON. THE ECMWF IS FASTER BRINGING PRECIPITATION BACK
INTO THE
GULF THAN THE AMERICAN MODELS...AND IS TRENDING SLOWER WITH THE 12Z
ECMWF RUN. THUS WILL OPT FOR THE SLOWER GFS-BASED SOLUTION FOR THIS
FEATURE.

.SHORT TERM FORECAST...
SOUTHCENTRAL...HIGH PRESSURE OVER THE INTERIOR WILL GRADUALLY
DECREASE CLOUD COVER OVER THE AREA FOR THE NEXT FEW DAYS. WITH
INCREASING AMOUNTS OF SUNSHINE WILL ALSO COME STEADILY WARMING
TEMPERATURES...WITH MANY AREAS ABOVE FREEZING BY THE START OF THE
WEEK. THE DRAMATIC EXCEPTION TO THIS SCENARIO WILL BE KODIAK
ISLAND...WHERE A STATIONARY FRONTAL BOUNDARY WILL BRING NUMEROUS
PERIODS OF MODERATE TO HEAVY RAIN (MIXED AT TIMES WITH WET SNOW) OVER
THE NEXT SEVERAL DAYS.

SOUTHWEST MAINLAND...THE AFOREMENTIONED WAVE RIDING UP THE FRONT WILL
INCREASE THE ALREADY-STRONG WINDS ACROSS BRISTOL BAY AND THE DELTA
COAST THIS EVENING AS ANOTHER ROUND OF HEAVY PRECIPITATION RETURNS TO
THE AREA. WITH AN ACCOMPANYING SECONDARY SURGE OF WARM AIR...MOST
LOCATIONS SHOULD SAFELY REMAIN ALL RAIN. WINDS ACROSS THE POPULATED
AREAS OF THE BRISTOL BAY ZONE SHOULD REMAIN JUST BELOW WARNING
LEVEL...AS RENEWED WARM ADVECTION STEEPENS LOW-LEVEL TEMPERATURES
INVERSIONS AND HELPS TO KEEP THE CORE OF STRONGEST WINDS ALOFT. BY
SUNDAY MORNING THE STEADY PRECIPITATION WILL END FROM SOUTH TO NORTH
AS
WINDS ALSO GRADUALLY SUBSIDE.

BERING SEA AND ALEUTIANS...THE ALASKA PENINSULA AND FAR EASTERN
ALEUTIANS WILL FEEL THE IMPACT OF THE STALLED FRONTAL ZONE TONIGHT
WITH HEAVY RAINFALL ESPECIALLY OVER THE PACIFIC SIDE. THE REST OF THE
BERING WILL SEE CONTINUED SHOWERY CONDITIONS WITH COLD AIR SLOWLY
SPREADING EASTWARD ACROSS THE REGION THROUGH MONDAY.

.LONG TERM FORECAST...
ABOVE-NORMAL TEMPERATURES WILL CONTINUE THROUGH THE UPCOMING WEEK
ACROSS THE SOUTHWEST MAINLAND...WITH SOUTHCENTRAL ALASKA GETTING IN
ON A MORE SUBSTANTIAL WARMUP BY MIDWEEK AS MANY TEMPERATURES CLIMB
TOWARD 40. MOST PRECIPITATION WILL REMAIN OVER KODIAK AND THE
SOUTHWEST COAST...ALTHOUGH LONG RANGE MODELS ARE NOW BEGINNING TO
SUGGEST THAT RAIN AND SNOW MAY SPREAD INTO THE NORTHERN GULF AND
POTENTIALLY INLAND BY THE MIDDLE OF THE WEEK.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE
MARINE...STORM 130 131 150 160 180
         GALE 120 132 136 137 138 150 165 178 180 185
         HEAVY FREEZING SPRAY WARNING 127
FIRE WEATHER...NONE

AMD FEB 14

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE ANCHORAGE AK
235 AM AKST SUN FEB 23 2014

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0124 AM     NON-TSTM WND GST 1 E KOLIGANEK           59.73N 157.26W
02/23/2014  M75 MPH                             AK   AWOS

&&

DSTRICKL