912  
FXAK67 PAJK 191433  
AFDAJK  
 
SOUTHEAST ALASKA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE JUNEAU AK  
533 AM AKST TUE NOV 19 2019  
   
SHORT TERM
 
RAIN AND HEAVY RAINS ARE MOVING INTO SOUTHEAST  
ALASKA FROM THE WEST IN A SLOW MOVING SOUTH TO NORTH ORIENTED  
ATMOSPHERIC RIVER. THE SOUTHERN PANHANDLES RAIN IN MORE DELAYED  
AND THEY SHOULDN'T SEE THE LARGER RAIN TOTALS UNTIL WEDNESDAY INTO  
THURSDAY. SPECIAL WEATHER/HYDRO STATEMENTS HAVE BEEN ISSUED FOR  
THE QUANTITY OF RAIN EXPECTED AND POSSIBILITY OF FLOODING ISSUES.  
 
STILL SOME COOLER AIR AT WHITE PASS LEVEL, AND THE WARMER AIR WILL  
NOT SPREAD INTO THAT ARE UNTIL LATER TUESDAY NIGHT SO A WET SNOW  
ABOVE 2500 FEET OR SO IS EXPECTED. WHITE PASS TEMPERATURES ARE  
UPPER 20S ON TUESDAY MORNING. SNOW ACCUMULATIONS LIKELY TO START  
AFTER NOON, WITH THE BETTER SNOW RATES TUESDAY EVENING TO A FEW  
HOURS AFTER MIDNIGHT. AM EXPECTING 4 TO 7 INCHES OF SNOW TO FALL  
THROUGH TUESDAY NIGHT. BREEZY WINDS WITH GUST TO 40 MPH OVER NIGHT  
WOULD BE EXPECTED TO BLOW SNOW AROUND, HOWEVER, WITH THE  
TEMPERATURES WARMING AND EVENTUALLY MIXING RAIN INTO THE SNOW, NOT  
EXPECT BLOWING SNOW OR WHITE OUT CONDITIONS.  
 
A WARM TONGUE OF AIR WITH THE SLOW MOVING FRONT WILL HAVE TEMPS  
IN TO THE MID TO 40S OR NEAR 50 TODAY, AND A COUPLE OF DEGREES  
WARMER FOR WEDNESDAY. SOME OF THESE TEMPERATURE COULD BE BE WITHIN  
REACH OF RECORD WARMTH FOR THE DAY. OVERALL CONFIDENCE OF A WET  
AND WARM NEXT COUPLE OF DAYS IS HIGH. LOCALIZED PONDING OF WATER  
IN LOW LYING AREAS AND RAPID RISES TO STREAMS AND RIVERS WILL  
OCCUR, WE WILL MONITOR THE RIVERS AND STREAMS FOR THREAT OF MINOR  
FLOODING.  
   
LONG TERM
 
THURSDAY OUR FIRST ATMOSPHERIC RIVER OVER THE  
PANHANDLE BEGINS TO PUSH EAST INTO CANADA BEFORE PRIMING SOILS  
ACROSS THE SOUTHERN PANHANDLE FOR SOME FLOODING POTENTIAL LATE IN  
THE WEEK. THERE ARE STILL ISSUES YET TO SOLVE AS THE THE GFS  
HOLDS ON TO A SLIGHTLY SLOWER INITIAL STORM EXIT THURSDAY. BUT AS  
A RESULT, IT ALSO ESCORTS THE LATE WEEK SYSTEM AS MUCH AS 9 HOURS  
BEHIND THE ECMWF AND THE NAM. WHETHER ONE SOLUTION SUGGESTS ONE  
STORM IS EXITING AND ANOTHER MOVES THAT A SECOND IS ENTERING, THE  
MEANING TO MOST SOUTHEAST ALASKANS IS THAT THE WEEK WILL  
DEFINITELY END WITH RAIN AND LOTS OF IT. AND HYDROLOGY AND A  
POSSIBILITY OF SOME FLOODING WILL BE ISSUE ONE FOR THE NEXT  
SEVERAL DAYS AS DETAILS EMERGE. BOTH THE NAEFS AND THE ECMWF  
ENSEMBLE INDICATE PW VALUES OF 3 STANDARD DEVIATIONS HIGHER THAN  
NORMAL DURING THE HEART OF THE WET SEASON TUESDAY THROUGH THURSDAY  
NIGHT. ASIDE FROM THE RAIN, WE DID INCREASE WINDS THROUGH THE  
INNER CHANNELS ON THURSDAY AND THURSDAY NIGHT AS THE RAIN WILL NOT  
ARRIVE WITHOUT WIND.  
 
THE EXTENDED FORECAST DOES POSE MORE CHALLENGES FOR HIGHER  
ELEVATIONS. AFTER THE FIRST STORM EXITS, THE SECOND WILL COME IN  
WITH LOWER SNOW LEVELS ALLOWING THE HEAVIER PRECIPITATION TO FALL  
AS SNOW. THUS THE KLONDIKE HIGHWAY AT WHITE PASS COULD SEE THE  
FIRST SIGNIFICANT SNOWFALL FOR THE REGION LATE THURSDAY INTO EARLY  
FRIDAY. A WINTER STORM WATCH MAY NEED TO BE CONSIDERED AS  
CONFIDENCE RISES.  
 
DETAILS BECOME MURKIER FOR THE WEEKEND, BUT ALL ENSEMBLES COOL  
TEMPERATURES ACROSS SOUTHEAST AND THE GULF IN ONSHORE FLOW, SO  
MUCH SO THAT WE INTRODUCE THE POSSIBILITY OF SOME SNOW MIXING IN  
WITH RAIN SHOWERS OVER THE NORTHERN PANHANDLE EARLY NEXT WEEK. BUT  
AT THIS STAGE, WE DO NOT EXPECT ANY ACCUMULATIONS. ONSHORE FLOW  
OFTEN DISAPPOINTS FOR SNOW LOVERS AS THE BOUNDARY LAYER IS OFTEN  
TOO MOIST FOR SUBSTANTIAL SNOW-MELT COOLING TO OCCUR. THE SOUTHERN  
PANHANDLE WILL CONTINUE TO NEGATE SHORT-TERM IMPACTS OF THE  
MODERATE DROUGHT CURRENTLY IN EFFECT.  
 

 
   
AVIATION
 
PATCHY FOG EARLY THIS MORNING ACROSS THE SOUTHERN  
PANHANDLE, WHERE BREAKS IN THE CLOUDS ALLOWED BETTER RADIATIVE  
COOLING TO REACH SATURATION POINT. NORTHEASTERN GULF COAST HAVE  
LOWER CLOUDS WITH START OF THE RAIN FROM INCOMING FRONTAL BAND AND  
ATMOSPHERIC RIVER. LOCALIZED MARGINAL TO IFR CONDITIONS FROM THE  
LOWER CEILINGS. WINDS ALOFT WILL BE INCREASING THROUGH THE DAY AS  
THE FRONT APPROACHES SO WILL NEED TO WATCH FOR LLWS IN THE  
YAKUTAT AND SITKA AREAS.  
 

 
   
MARINE
 
GALES DEVELOPING OVER THE NORTHERN GULF COASTAL WATERS  
AS THE FRONT MOVES ACROSS THE GULF. SOUTHERLY WINDS IN LYNN CANAL  
INCREASING TO 30 TO 35 KT FOR TUESDAY INTO TUESDAY NIGHT. SEAS OUT  
OVER THE GULF INCREASING ABOVE 15 FEET FOR STRONG SOUTHERLY FLOW  
AND FOLLOWING SEAS/SWELL.  
 

 
   
HYDROLOGY
 
HYDRO OUTLOOK AND SPECIAL WEATHER STATEMENT (SPS)  
OUT FOR THE SE AK AND THE NORTHEAST GULF COAST. TWO ATMOSPHERIC  
RIVERS OVER THE NEXT 2 TO 5 DAYS, THE NORTHEAST GULF COAST  
EXPECTS 5 TO 6 INCHES IN THE YAKUTAT AREA TO WEDNESDAY. THE  
PANHANDLE SHOULD BE SEEING 2 TO 4 INCHES. THIS WILL MEAN HIGH  
RIVER AND LAKE LEVELS THROUGH MID-WEEK. HOWEVER, NO FLOODING IS  
EXPECTED WITH THIS SYSTEM. STRONG WINDS IN AREAS OF STEEP TERRAIN  
MAY POSE A RISK OF MUDSLIDES.  
 

 
   
AJK WATCHES/WARNINGS/ADVISORIES
 
 
PUBLIC...WINTER WEATHER ADVISORY FROM NOON TODAY TO 5 AM AKST WEDNESDAY  
FOR AKZ018.  
STRONG WIND FROM 3 PM AKST THIS AFTERNOON THROUGH LATE TONIGHT  
FOR AKZ018.  
MARINE...GALE WARNING FOR PKZ012-051-052.  
SMALL CRAFT ADVISORY FOR PKZ013-021-022-031-032-034-041>043-053.  
 

 
 

 
 
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