567
FXAK68 PAFC 190035
AFDAFC
SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
435 PM AKDT SAT JUL 18 2026
SHORT TERM FORECAST SOUTHCENTRAL ALASKA (DAYS 1 THROUGH 3)
WITH THE DISSIPATION OF TODAY'S ROUND OF SHOWERS THIS AFTERNOON,
EXPECT A BRIEF BREAK IN THE RAIN AHEAD OF A MORE SIGNIFICANT
RAINFALL EVENT TO AFFECT SOUTHCENTRAL THROUGH THE REMAINDER OF THE
WEEKEND. THE FORECAST REMAINS ON TRACK, WITH A DEEP AND AMPLIFIED
UPPER LOW SET TO BRING AN ATMOSPHERIC RIVER TO PORTIONS OF
SOUTHCENTRAL OVER THE WEEKEND AND INTO NEXT WEEK. AHEAD OF THE
SYSTEM, THE COASTAL RIDGE WILL CONTINUE TO BUILD THROUGH THIS
EVENING LEADING TO INCREASING GAP WINDS. THE WINDS WILL BE SIMILAR
(THOUGH SLIGHTLY WEAKER) TO THE WIND EVENT EARLIER THIS WEEK.
TONIGHT THE MAIN PLUME OF MOISTURE WILL ARRIVE WITH DEEP SOUTH-
SOUTHEAST FLOW ALOFT. WITH THIS FLOW DIRECTION, AND A FEW EMBEDDED
SHORTWAVES, THE EASTERN KENAI PENINSULA AND WESTERN SUSITNA
VALLEY WILL BE FAVORED FOR MODERATE TO HEAVY RAINFALL. SEWARD WILL
LIKELY RECEIVE THE MOST, WITH 4 TO 6 INCHES OF RAIN EXPECTED
THROUGH MONDAY EVENING. ANCHORAGE WILL HAVE SOME DOWNSLOPING, BUT
PERTURBATIONS MOVING THROUGH THE SOUTHERLY FLOW MAY BRING PERIODS
OF LIGHT RAIN, ESPECIALLY IN THIS MOIST ENVIRONMENT. RIDGING
FARTHER TO THE EAST WILL HELP TO KEEP THE COPPER VALLEY DRY WITH
WARMER TEMPERATURES.
BY TUESDAY THE UPPER TROUGH WILL TAKE ON A NEGATIVE TILT AND
BEGIN TO MOVE EAST, SPREADING MOISTURE TO THE REST OF SOUTHCENTRAL
ON TUESDAY. LOOKING AHEAD, MORE OF THE SAME. RAIN.
SHORT TERM FORECAST SOUTHWEST ALASKA (DAYS 1 THROUGH 3)
THE LOW IN BRISTOL BAY WILL CONTINUE TO BRING ONSHORE FLOW AND
RAIN SHOWERS TO THE MAINLAND AND AK PEN INTO SUNDAY EVENING AS IT
SLOWLY MOVES ONSHORE THIS WEEKEND. ALSO, PERSISTENT NORTHERLY FLOW
IN THE CENTRAL ALEUTIANS AND NORTHWEST FLOW IN THE WESTERN
ALEUTIANS RESULTS IN CONTINUED WIND GUSTS RANGING FROM 35 TO 45
MPH THROUGH THE WEEKEND.
AS THE LOW MOVES ONSHORE AND A BERING STRAIT LOW FORMS MONDAY, A
MORE PRONOUNCED TROUGH PATTERN BEGINS TO FORM IN THE BERING SEA.
THIS BRINGS MULTIPLE WAVES OF MOISTURE THROUGH BERING SEA /
BRISTOL BAY. THE FIRST OF THESE WAVES SLIDES A WEAK LOW
SOUTHEASTWARD FROM RUSSIA MONDAY MORNING REACHING JUST NORTH OF
THE PRIBILOF ISLANDS BY MONDAY AFTERNOON. IT BRINGS A RESURGENCE
OF PRECIPITATION AND WINDS TO THE CENTRAL ALEUTIANS AND PRIBILOF
ISLANDS BY THIS TIME. THE FRONT THEN REACHES THE MAINLAND COAST
MONDAY EVENING WITH RAIN AND ONSHORE S/SE WINDS. THIS COINCIDES
WITH LOW TIDE. THE TROUGH WILL ALSO BRING CONTINUED WAVES OF
MOISTURE THROUGH THE WESTERN ALEUTIANS RESULTING IN CONTINUED
SHOWERS THROUGH MID-WEEK.
-JOHNSTON
.LONG TERM FORECAST (DAYS 4 THROUGH 7: WEDNESDAY THROUGH
SATURDAY)...
FORECAST MODELS ARE SHOWING SIGNS THAT PERSISTENT TROUGHING OVER
THE BERING MAY FINALLY BREAK DOWN OVER THE LATTER HALF OF NEXT
WEEK. SOUTHWESTERLY FLOW, STILL IN PLACE ON WEDNESDAY, BEGINS TO
WEAKEN AND SHIFT EASTWARD AS A RIDGE OF HIGH PRESSURE NUDGES INTO
THE BERING FROM THE WEST. THIS COULD SPELL A TEMPORARY REPRIEVE
FROM OUR WET PATTERN ACROSS MUCH OF ALASKA BY THE END OF THE LONG
TERM FORECAST ON SATURDAY. BEFORE THE WEEKEND ARRIVES, HOWEVER,
EXPECT ABOVE NORMAL PRECIPITATION CHANCES TO CONTINUE AS MULTIPLE
WAVES OF LOW PRESSURE TRACK THROUGH SOUTHERN ALASKA FROM THE
BERING.
-BL
AVIATION
PANC...WIDESPREAD RAIN SHOWERS ARE EXPECTED. THERE COULD BE A
BRIEF PERIOD OF DECREASED SHOWER ACTIVITY THIS AFTERNOON AND
EVENING WHEN GUSTY SOUTHEASTERLY WINDS FROM TURNAGAIN ARM MOVE
ACROSS THE AIRPORT. VFR TO MVFR CEILINGS ARE EXPECTED WITH
RAINFALL. BY 08Z, NORTHERLY FLOW WILL BEND TURNAGAIN ARM WINDS
DOWN-INLET. AT THAT TIME, LOW-LEVEL WIND SHEAR APPEARS MORE
PROBABLE AS SOUTHEAST WINDS CONTINUE ACROSS THE CHUGACH MOUNTAINS,
WHILE SURFACE WINDS OVER THE AIRPORT BECOME LIGHT AND NORTHERLY.
THIS COULD LAST THROUGH AT LEAST SUNDAY AFTERNOON.
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