060  
FXAK69 PAFG 172240  
AFDAFG  
 
NORTHERN ALASKA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE FAIRBANKS AK  
240 PM AKDT SUN JUN 17 2018  
   
DISCUSSION
 
 
MOIST PATTERN CONTINUES OVER NORTHERN ALASKA WITH FOCUS ON  
RAINFALL AMOUNTS OVER THE WESTERN INTERIOR, BROOKS RANGE AND  
STRONG WINDS THROUGH THE ALASKA RANGE.  
 
ALOFT AT 500 MB, A DEEP LONGWAVE TROUGH OVER THE EASTERN BERING  
SEA AND WESTERN ALASKA AND RIDGING OVER THE YUKON AND EASTERN  
ALASKA WILL CONTINUE INTO THE LATE NEXT WEEK. A STRONG UPPER  
LEVEL LOW OVER BRISTOL BAY WILL SLOWLY WEAKEN IN PLACE THROUGH THE  
WEEK AS THE RIDGE OVER THE YUKON BUILDS NORTH AND WEST OVER THE  
EASTERN INTERIOR THROUGH THE WEEK. AN UPPER LEVEL LOW NEAR 80N AND  
165W WILL MOVE EAST TO BE LOCATED ALONG 75N AND 140W TUESDAY AND  
WEDNESDAY.  
 
A STALLED TROUGH AT 700 MB ALONG A A YK DELTA TO ATIGUN PASS LINE  
WILL BE THE FOCAL POINT FOR PERIODS OF RAIN AND NUMEROUS SHOWERS  
WITH WETTING RAINS EXPECTED OVER MUCH OF THE AREA. RAINFALL  
TOTALS ALONG THE TROUGH ARE EXPECTED TO RANGE FROM ONE QUARTER TO  
ONE HALF INCH WITH THE HEAVIEST TOTALS IN THE BROOKS RANGE THROUGH  
TUESDAY MORNING. ISOLATED THUNDERSTORMS ARE POSSIBLE THIS EVENING  
FROM GALENA TO BETTLES TO FORT YUKON. CONVECTION IS EXPECTED TO  
BE MINIMAL MONDAY AFTERNOON AND EVENING OVER THE INTERIOR.  
 
ON THE SURFACE A 993 LOW OVER THE NORTHERN PACIFIC WITH A SURGE OF  
MOISTURE FROM THE SUB-TROPICS WILL PLOW NORTHWARD INTO BRISTOL  
BAY AND WILL BRING ANOTHER ROUND OF HEAVY RAIN TO THE ALASKA RANGE  
AND WILL PRODUCE STRONG WINDS THROUGH AND NEAR THE ALASKA RANGE  
PASSES. RAINFALL TOTALS IN THE ONE HALF TO ONE AND A HALF INCHES  
RANGE ARE EXPECTED THROUGH TUESDAY MORNING ALONG THE SOUTHERN  
SLOPES OF THE ALASKA RANGE.  
 
STRONG GAP WINDS WILL CONTINUE AND STRENGTHEN TONIGHT AND TOMORROW  
THROUGH THE PASSES AND ALONG THE NORTH SLOPES OF THE ALASKA RANGE  
AS WINDS ALOFT PRODUCE A MODERATE STRENGTH MOUNTAIN WAVE. A WIND  
ADVISORY CONTINUES FOR THESE AREAS THROUGH TUESDAY MORNING. THE  
STRONGEST WINDS ARE EXPECTED LATE MONDAY AFTERNOON AND EVENING  
AND MAY APPROACH WARNING LEVEL MONDAY EVENING AND WILL NEED TO BE  
MONITORED.  
 
THE 12Z MODEL SUITE INITIALIZED WELL AGAINST THE 12Z SURFACE  
ANALYSIS AND VERIFIED WELL AGAINST THE 18Z SURFACE ANALYSIS.  
MODEL SPREAD REMAINS MINIMAL IN THE SHORT RANGE AND IS REASONABLE  
IN THE BOTH THE MID RANGE AND EXTENDED RANGE.  
 
COASTAL HAZARD POTENTIAL DAYS 3 AND 4...NONE.  
 

 
   
FIRE WEATHER
 
 
FIRE WEATHER CONDITIONS WILL BE MINIMAL ACROSS THE MAJORITY OF THE  
STATE WITH MOST AREAS EXPECTING THE POTENTIAL FOR WETTING RAIN  
RETAINING HIGH RH OVER THE WESTERN INTERIOR AND WEST COAST. VERY  
LITTLE IS EXPECTED IN THE WAY OF CONVECTION THIS EVENING OVER THE  
CENTRAL AND EASTERN INTERIOR, WITH ONLY A SMALL CHANCE FOR  
ISOLATED EMBEDDED THUNDERSTORMS NEAR THE FRONT FROM GALENA TO  
BETTLES TO FORT YUKON. CHINOOK CONDITIONS AND A STRENGTHENING  
RIDGE WILL SUPPORT RH VALUES DOWN TO THE AROUND 30 PERCENT WHERE  
WINDS ARE LIGHT. STRONG WINDS THROUGH ALASKA RANGE PASSES WILL NOT  
BE CO-LOCATED WITH SUFFICIENTLY LOW RH.  
 

 
   
HYDROLOGY
 
 
ADDITIONAL RAINFALL OF BETWEEN ONE QUARTER AND ONE HALF INCH IS  
EXPECTED ALONG THE FRONTAL BAND STRETCHING FROM THE LOWER YK  
DELTA TO AMBLER TO THE NORTHEAST BROOKS RANGE WITH THE HEAVIEST  
TOTALS IN THE BROOKS RANGE. SIMILAR RAINFALL TOTAL HAVE BEEN  
OBSERVED OVER THE SAME AREAS OVER THE LAST 24 HOURS. 24 HOUR  
RAINFALL TOTALS ARE EXPECTED TO BE IN THE ONE HALF INCH TO ONE AND  
HALF INCH RANGE OVER THE SOUTHERN SLOPES OF THE ALASKA RANGE WITH  
PERSISTENT AND DEEP SOUTHERLY FLOW.  
 

 
   
AFG WATCHES/WARNINGS/ADVISORIES
 
 
WIND ADVISORY FOR AKZ223-AKZ226.  
 
SMALL CRAFT ADVISORY FOR PKZ210.  

 
 

 
 
CCC JUN 18  
 
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