Small Craft Advisory 117, NWS Anchorage, AK

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
542 AM AKST FRI FEB 6 2015

.ANALYSIS AND UPPER LEVELS...
WITH HIGH PRESSURE OVER THE NORTHERN BERING AND A LOW OVER THE
EASTERN GULF A TIGHT GRADIENT SITS OVER MAINLAND ALASKA. THIS
GRADIENT IS CAUSING STRONG NORTHERLY FLOW THROUGHOUT THE WHOLE
COLUMN THAT IS BRINGING COLD AND DRY AIR TO THE SOUTHCENTRAL AND
SOUTHWEST. THE GRADIENT AT THE SURFACE IS ALSO TIGHT WHICH IS
FORCING STRONGER WINDS THROUGH MANY NORTH-SOUTH ORIENTED GAPS.
THIS IS AIDED BY THE UPPER LEVEL NORTHERLY FLOW AND THE COLD AIR
MOVING IN.

&&

.MODEL DISCUSSION...
MODELS IN THE SHORT AND MID TERMS ARE IN GOOD AGREEMENT. THERE ARE
SOME MINOR DISCREPANCIES IN EXACT LOW PLACEMENT WITH THE LOW
MOVING THROUGH THE GULF AND THE LOW SOUTH OF THE ALEUTIANS BUT
IMPACTS FROM THESE DIFFERENCES WILL BE SMALL.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (DAYS 1 AND 2)...
THE TIGHT PRESSURE GRADIENT OVER THE SOUTHCENTRAL WILL LAST INTO
THE WEEKEND WHICH MEANS STRONGER WINDS WILL ALSO REMAIN INTO THE
WEEKEND. HOWEVER...ONCE A SHORT WAVE MOVES THROUGH THE AREA FROM
THE NORTH ON FRIDAY NIGHT THE WIND FLOW WILL START TO DIMINISH.
AT THE SAME TIME THE LOW OVER THE EASTERN GULF WILL TRACK WEST AND
AS IT DOES THE UPPER LEVEL CORE OF STRONGER WINDS WILL MOVE OFF
TO THE WEST. BUT WITH THE LOW STILL IN THE GULF THE SURFACE
PRESSURE GRADIENT WILL REMAIN KEEPING GAP WINDS THROUGH MUCH OF
THE WEEKEND EVEN WHILE THE OVERALL WINDS DIMINISH.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (DAYS 1 AND 2)...
A COLD ARCTIC AIR MASS WILL BE ON THE MOVE TODAY SPREADING FROM
THE KUSKOKWIM VALLEY TOWARD THE SOUTHWESTERN COAST. TEMPERATURES
ARE EXPECTED TO START DROPPING THROUGH THE AFTERNOON ACROSS THE
VALLEY AND THEN ACROSS THE REST OF THE SOUTHWEST OVERNIGHT. GUSTY
WINDS ACROSS THE KUSKOKWIM DELTA WILL TAPER DOWN SLIGHTLY TODAY
AND THEN INCREASE AGAIN TONIGHT. THE KUSKOKWIM VALLEY AND BRISTOL
BAY WILL SEE WINDS INCREASE EARLY SATURDAY MORNING AS THE PRESSURE
GRADIENT TIGHTENS ACROSS THE SOUTHWEST. THE COMBINATION OF COLDER
TEMPERATURES AND GUSTY WINDS WARRANTED WIND CHILL ADVISORIES TO BE
ISSUED WITH THE MORNING PACKAGE FOR THESE TWO ZONES. THE GUSTY
WINDS ACROSS THE ALASKA PENINSULA ARE EXPECTED TO INCREASE THIS
AFTERNOON...ESPECIALLY THROUGH CHANNELED TERRAIN AND THEN CONTINUE
THROUGH LATE SATURDAY NIGHT.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (DAYS 1 AND 2)...
GUSTY GALE WINDS WILL DOMINATE THE EASTERN AND NORTHERN BERING
THROUGH THE FIRST HALF OF THE WEEKEND AS THE PRESSURE GRADIENT
TIGHTENS ACROSS THE BERING. LIGHT RAIN AND SNOW WILL MAINLY BE
CONFINED ALONG A WEAK BOUNDARY ALONG THE ALEUTIAN CHAIN.
HOWEVER...A LOW IN THE GULF OF ALASKA WILL BRING AN INCREASE OF
PRECIPITATION TO THE ALASKA PENINSULA LATE SATURDAY.

&&

.LONG TERM FORECAST (DAYS 3 THROUGH 7)...
GUSTY OUTFLOW WINDS WILL PERSIST THROUGH THE WEEKEND AS LOW
PRESSURE OVER THE GULF AND ARCTIC AIR OVER THE INTERIOR HELP TO
MAINTAIN A STRONG PRESSURE GRADIENT ALONG THE COAST. HOWEVER...
WINDS WILL GENERALLY BE TRENDING DOWNWARD BY SUNDAY INTO MONDAY AS
UPPER LEVEL SUPPORT WEAKENS. BLOWING SNOW COULD BE A CONCERN FOR
KODIAK ISLAND AS THE LOW SPREADS PRECIPITATION BACK INTO THE GULF
AND GUSTY NORTHERLY WINDS REMAIN IN PLACE AT THE SURFACE.

AS WE MOVE FURTHER INTO NEXT WEEK A PATTERN SHIFT IS LOOKING
LIKELY. MONDAY AND TUESDAY A STRONG UPPER LEVEL RIDGE WILL BUILD
OVER THE WEST COAST OF CANADA AND ACROSS SOUTHEAST ALASKA. THIS
WILL TURN THE PREVAILING FLOW MORE SOUTHERLY AND BRING A
WARMER...MORE MOIST AIR MASS ACROSS THE GULF AND INTO SOUTHCENTRAL
ALASKA MID TO LATE WEEK IN THE FORM OF A SERIES OF FRONTAL
SYSTEMS. INITIALLY THESE FRONTS WILL BATTLE THE OFFSHORE FLOW AND
ENTRENCHED COLD AIR MASS BUT EVENTUALLY IT IS LOOKING LIKE THE
WARMER SOUTHERLY FLOW WILL WIN OUT AND MIXED PRECIPITATION TYPES
WILL BECOME AN ISSUE AGAIN TOWARDS THE END OF THE WEEK.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...HIGH WIND WARNING 111 131
		 WIND CHILL ADVISORY 141 152 155 161
MARINE...GALE WARNING 121 126 127 128 130 131 132 136 137 138 139
					  140 141 150 155 160 165 179 180 181 185
		 HEAVY FRZ SPRAY 121 125 126 127 128 129 130 138 139 140
						 141 150 165 179 180 185
FIRE WEATHER...NONE

&&

SYNOPSIS AND MODEL DISCUSSION...DK
SOUTHCENTRAL ALASKA...DK
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...KH
LONG TERM...CB/JR

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE ANCHORAGE AK
119 PM AKST FRI FEB 06 2015

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

1200 PM     NON-TSTM WND GST ANCHORAGE               61.22N 149.87W
02/06/2015  M48 MPH                             AK   ASOS

1200 PM     NON-TSTM WND GST 4 SW ANCHORAGE          61.18N 149.96W
02/06/2015  M52 MPH                             AK   ASOS

            LAKE HOOD

1200 PM     NON-TSTM WND GST ELMENDORF AIR FORCE BAS 61.25N 149.80W
02/06/2015  M53 MPH                             AK   ASOS

1200 PM     NON-TSTM WND GST 1 NNW ANCHORAGE         61.23N 149.88W
02/06/2015  M49 MPH                             AK   CO-OP OBSERVER

1200 PM     NON-TSTM WND GST 1 ENE ANCHORAGE         61.22N 149.83W
02/06/2015  M35 MPH                             AK   ASOS

            MERRILL FIELD

1200 PM     NON-TSTM WND GST WASILLA                 61.58N 149.46W
02/06/2015  M54 MPH                             AK   AWOS

1200 PM     NON-TSTM WND GST 6 WSW PALMER            61.56N 149.26W
02/06/2015  M68 MPH                             AK   DEPT OF HIGHWAYS

            GLENN-PARKS HWY INTERCHANGE

1200 PM     NON-TSTM WND GST E WASILLA               61.58N 149.45W
02/06/2015  M56 MPH                             AK   CO-OP OBSERVER

            WASILLA FIRE STATION

1200 PM     NON-TSTM WND GST PALMER                  61.60N 149.11W
02/06/2015  M75 MPH                             AK   ASOS

1200 PM     NON-TSTM WND GST TALKEETNA               62.34N 150.09W
02/06/2015  M30 MPH                             AK   ASOS

1200 PM     NON-TSTM WND GST SUTTON                  61.72N 148.88W
02/06/2015  M47 MPH                             AK   CO-OP OBSERVER

1200 PM     NON-TSTM WND GST THOMPSON PASS           61.14N 145.75W
02/06/2015  M96 MPH                             AK   CO-OP OBSERVER

1200 PM     NON-TSTM WND GST 3 NNW VALDEZ            61.12N 146.35W
02/06/2015  M96 MPH                             AK   CO-OP OBSERVER

1200 PM     NON-TSTM WND GST VALDEZ                  61.08N 146.30W
02/06/2015  M92 MPH                             AK   AWOS

&&
ALL REPORTS THROUGH 1200 NOON FRIDAY

KUTZ