Small Craft Advisory 411, NWS Anchorage, AK

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
146 PM AKDT FRI MAY 23 2014

.ANALYSIS AND UPPER LEVELS... A BROAD AREA OF LOW PRESSURE WAS
EVIDENT OVER THE WESTERN AND NORTHERN GULF AS WELL AS COOK INLET.
A BROAD AND DENSE AREA OF SMOKE FROM FIRES ON THE WESTERN KENAI
REDUCED VISIBILITIES ACROSS THE CENTRAL AND SW KENAI PEN
OVERNIGHT THROUGH EARLY THIS AFTERNOON.

OUT WEST...
STABLE CONDITIONS UNDER A BROAD HIGH PRESSURE SYSTEM OVER THE
BERING SEA BROUGHT WIDESPREAD STRATUS AND FOG TO MUCH OF THE AREA
TO AS FAR EAST AS THE DELTA COAST. NORTHERLY FLOW JUST TO THE
EAST CONTINUED FAIR SKIES FROM THE KUSKOKWIM VALLEY SOUTH TO OVER
MUCH OF BRISTOL BAY. A THIN BAND OF LOW CLOUDS AND FOG WAS
EVIDENT OVER THE BERING SEA SIDE OF THE AK PEN AS FAR EAST AS PORT
HEIDEN.

A SHORT WAVE OVER EASTERN RUSSIA MOVES RAPIDLY EAST ACROSS THE
CENTRAL INTERIOR SAT NIGHT AND SUN. THE BERING SEA RIDGE WEAKENS
AND SHIFTS TO THE GULF BY MON AS A SERIES OF WAVES MOVE EAST AS
THE LONG WAVE BROADENS OVER THE BERING SEA/ALEUTIANS.

&&

.MODEL DISCUSSION...
MODELS ARE IN GENERAL AGREEMENT ACROSS SOUTHCENTRAL AND THE GULF
THROUGH THE SHORT TERM. OUT WEST...MODELS DIVERGE SIGNIFICANTLY ON
SUN AND MON AS THE BERING SEA RIDGE BREAKS DOWN. THE ECMWF AND GEM
GLOBAL APPEAR TO THE THE BEST CHOICE.

&&

.SHORT TERM FORECAST...

SOUTHCENTRAL ALASKA...
PRESSURE GRADIENTS WILL INCREASE ACROSS SOUTHCENTRAL SAT AND
CONTINUE INTO SUN AS HIGH PRESSURE BUILDS ALONG THE NORTH GULF
COAST AND PRESSURES FALL OVER THE INTERIOR WITH A STRENGTHENING
THERMAL TROUGH. GAP FLOWS AND ENHANCED SEA BREEZES WILL BE THE
GENERAL RULE ACROSS MUCH OF THE AREA UNDER GENERALLY FAIR SKIES.
HOWEVER...THE ONSET OF THE SOUTHERLY FLOW ACROSS COOK INLET WILL
SPREAD SMOKE FROM FIRES OVER THE WESTERN KENAI NORTH AND IMPACT
THE MATANUSKA/SUSITNA VALLEYS AND ANCHORAGE BOWL. THE SHORT WAVE
MOVING ACROSS THE MAINLAND WILL BRING A CHANCE OF SHOWERS TO THE
COPPER RIVER BASIN AND SUSITNA VALLEY SAT NIGHT AND SUN.

SOUTHWEST ALASKA... THE HIGH PRESSURE RIDGE WILL CONTINUE TO
PRODUCE STABLE CONDITIONS WITH OFFSHORE WINDS THROUGH SATURDAY
MORNING. THE WINDS WILL SHIFT TO ONSHORE AS THE HIGH PRESSURE
MOVES EASTWARD BY SATURDAY AFTERNOON. THE ONSHORE FLOW WILL
INCREASE THE POSSIBILITY OF STRATUS AND FOG BEING ADVECTED INLAND.
RAIN ASSOCIATED WITH A FRONTAL SYSTEM MOVING ACROSS ALEUTIANS WILL
START TO ENCROACH ON SW ALASKA AND BRING INCREASING CHANCES OF
RAIN TO THE COAST MON.

BERING SEA/ALEUTIANS...
THE HIGH PRESSURE WILL COVER THE MAJORITY OF THE BERING SEA AND
THE ALEUTIAN ISLANDS. RESULTING IN WIDESPREAD STRATUS AND FOG
UNDER THE INVERSION ASSOCIATED WITH THE HIGH PRESSURE THROUGH THE
WEEKEND. THE WESTERN ALEUTIANS WILL HAVE A FRONTAL SYSTEM
APPROACHING BY SATURDAY AFTERNOON BRINGING RAIN WITH GUSTY WINDS.

LONG TERM FORECAST...
THE SHIFT OF THE UPPER RIDGE TO THE EAST AND THE BROADENING TROUGH
OVER THE BERING SEA WILL BRING MOIST SW FLOW ACROSS MUCH OF THE
MAINLAND NEXT WEEK AND INCREASED CLOUD COVER AND CHANCES OF RAIN.

AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...NONE.
FIRE WEATHER...RED FLAG WARNING...121 145.

RMC MAY 14