Flood Watch 4, NWS Anchorage, AK

169 
WGAK68 PAFC 261958
FFAAFC

FLOOD WATCH
NATIONAL WEATHER SERVICE ANCHORAGE AK
1158 AM AKDT THU JUN 26 2014

AKZ145-262100-
/O.CAN.PAFC.FA.A.0004.000000T0000Z-140628T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SUSITNA VALLEY-
INCLUDING THE CITIES OF...TALKEETNA...WILLOW...CANTWELL
1158 AM AKDT THU JUN 26 2014

...FLOOD WATCH IS CANCELLED FOR THE UPPER SUSITNA VALLEY AND
TALKEETNA MOUNTAINS...

THE FLOOD WATCH FOR A PORTION OF AK HAS BEEN CANCELLED. A FLOOD
ADVISORY IS NOW IN EFFECT FOR RIVERS AND CREEKS IN THE SUSITNA
VALLEY.

$$

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
501 AM AKDT WED JUN 25 2014

.ANALYSIS AND UPPER LEVELS...
THE LOW OVER THE GULF THAT HAS BEEN A PERMANENT FEATURE ON THE
WEATHER MAP SINCE THE WEEKEND IS BEGINNING TO MAKE ITS SLOW
DEPARTURE TOWARDS THE NORTHEASTERN GULF COAST. TO THE NORTH OF
THE GULF LOW...AND IMPRESSIVE LOOKING BROAD SCALE EASTERLY WAVE IS
COVERING THE EASTERN MAINLAND WITH EXTENSIVE CLOUDS AND WIDESPREAD
WETTING RAINS. JUST AHEAD OF THIS WAVE...SHOWERS ARE BEGINNING TO
MAKE THEIR WAY INTO INTERIOR SOUTHCENTRAL...WHICH WILL BECOME
STRATIFORM LATER THIS MORNING AS THE WAVE APPROACHES. ANOTHER
PACIFIC LOW CONTINUES TO PROGRESS THROUGH THE EASTERN ALEUTIANS
AND ALASKA PENINSULA...BRINGING WITH IT RAIN AND GUSTY
SOUTHEASTERLY WINDS. THE PERSISTENT STRATUS AND FOG OVER BRISTOL
BAY AND THE EASTERN BERING IS BEGINNING TO BREAK UP AND MOVE TO
THE NORTHWEST IN ADVANCE OF THE APPROACHING PACIFIC LOW. FURTHER
INTO THE NORTHERN BERING...THE RIDGE CONTINUES TO HOLD OVER THE
NORTHERN BERING AND INTO THE SOUTHWEST MAINLAND...BRINGING PARTLY
CLOUDY SKIES OVER THE LAND WITH WIDESPREAD STRATUS OVER MUCH OF
THE WATERS. THIS RIDGE WILL SLOWLY SPREAD INTO THE WESTERN BERING
BEHIND THE PACIFIC LOW TODAY...AND CONTINUE THROUGH THE WORK WEEK.

&&

.MODEL DISCUSSION...
THE MODELS CONTINUE TO BE IN DECENT AGREEMENT WITH GENERAL TIMING
OF THE EASTERLY WAVE MOVING INTO SOUTHCENTRAL THIS MORNING. JUST
SOME MINOR DISCREPANCIES REMAIN WITH THE TIMING OF INDIVIDUAL
SHORTWAVES...AND THEREFORE WHEN HEAVIER BANDS OF STRATIFORM RAIN
WILL ARRIVE. DIFFERENCES THEN INCREASE ON THURSDAY REGARDING HOW
LONG THE STEADY RAIN WILL CONTINUE. THE GFS/GEM AND TO SOME
EXTENT THE NAM ARE IN THE BEST AGREEMENT BY BRINGING MOST OF THE
STEADY RAIN WEST OF SOUTHCENTRAL BY MID THURSDAY MORNING. AT THIS
POINT IS WHEN THE MODELS BEGIN TO DIVERGE SIGNIFICANTLY WITH THE
UPPER LOW TRACK...RESULTING IN WIDELY DIFFERENT RAINFALL FORECASTS
FOR FRIDAY. THE EC/GEM CONTINUE TO KEEP A BULK OF THE
PRECIPITATION TO THE NORTH OF THE AOR BY FRIDAY...WHICH IS CLOSEST
TO THE CURRENT FORECAST AND PREFERRED FOR THE MORNING PACKAGE. THE
NAM/GFS ON THE OTHER HAND REMAIN MUCH MORE AGGRESSIVE WITH
BREAKING DOWN RIDGING OVER THE SOUTHWEST MAINLAND AND BRINGING
SOAKING RAINS INTO INTERIOR SOUTHWEST BY LATE THURSDAY.

&&

.SHORT TERM FORECAST...

SOUTHCENTRAL ALASKA...WIDESPREAD SHOWERS OVER SOUTHCENTRAL WILL
QUICKLY BECOME SOAKING STRATIFORM RAIN THIS MORNING AS THE
EASTERLY WAVE CURRENTLY OVER THE COPPER RIVER BASIN MOVES INTO THE
AREA. THIS RAIN WILL THEN CONTINUE THROUGH LATE TONIGHT.
AFTERWARDS...AS IS DISCUSSED IN THE MODEL DISCUSSION ABOVE...THERE
CONTINUED TO BE LOW CONFIDENCE ON HOW LONG THE WIDESPREAD RAIN
WILL LAST INTO THURSDAY FOR SOUTHCENTRAL. THERE IS GOOD AGREEMENT
THAT RAINFALL OVER THE COPPER RIVER BASIN WILL BEGIN TO DIMINISH
ON THURSDAY...AND CONDITIONS WILL IMPROVE FROM EAST TO WEST
DURING THE DAY. EXACTLY WHEN AND WHERE THIS IMPROVEMENT OCCURS STILL
REMAINS FAIRLY UNCERTAIN...AND WILL TAKE FURTHER MODEL RUNS TO
FIND OUT. FURTHER TO THE SOUTH...THE SOUTHERN KENAI PENINSULA WILL
LIKELY STAY MOSTLY CLOUDY WITH JUST SOME PASSING SHOWERS
THROUGHOUT THE EVENT...AS A MAJORITY OF THE RAIN WILL OCCUR OVER
THE NORTHERN PENINSULA. EVEN FURTHER TO THE SOUTH...KODIAK ISLAND
WILL CONTINUE TO HAVE SOME OF THE QUIETEST WEATHER IN THE ENTIRE
REGION THROUGH LATE IN THE WEEK AS THEY WILL REMAIN WELL SOUTH OF
THE EASTERLY WAVE...AND WILL ONLY RECEIVE A GLANCING BLOW FROM THE
APPROACHING PACIFIC SYSTEM. STRATUS CLOUDS WILL MOVE ONTO THE
ISLAND THIS MORNING AS THE FLOW BECOMES ONSHORE...BUT OTHERWISE
THE ISLAND SHOULD STAY DRY OTHER THAN A FEW PASSING LIGHT RAIN
SHOWERS.

SOUTHWEST ALASKA...CONVECTIVE SHOWERS AND A SLIGHT CHANCE OF
THUNDERSTORMS WILL BE THE FOCUS FOR MUCH OF THE SOUTHWEST
MAINLAND THIS AFTERNOON AND EVENING AS THE THERMAL TROUGH WILL BE
FURTHER INVIGORATED BY A GLANCING BLOW FROM THE EASTERLY WAVE THIS
AFTERNOON. THERE IS A CHANCE THAT SOME ISOLATED DRY THUNDERSTORMS
WILL FORM OVER THE KUSKOKWIM VALLEY THIS AFTERNOON DUE DRY
NORTHERLY FLOW A THE LOW LEVELS. THESE ARE HOWEVER NOT EXPECTED AT
THIS TIME TO BE WIDESPREAD ENOUGH TO WARRANT A RED FLAG WARNING.
SHOWERS AND ISOLATED THUNDERSTORMS WILL MOSTLY FORM ALONG THE
KUSKOKWIM MOUNTAINS AND HIGHER ELEVATIONS IN NORTHERN BRISTOL
BAY...THEN TAKE A SOUTHERLY TRACK AS THEY DISSIPATE INTO THE
VALLEYS. AS IS MENTIONED IN THE ABOVE MODEL DISCUSSION...FORECAST
CONFIDENCE QUICKLY DIMINISHES ON THURSDAY AND FRIDAY DUE TO UNCERTAINTY
IN THE TRACK OF THE UPPER LEVEL LOW OVER THE INTERIOR AND
RESULTING RAIN. RAIN LOOKS TO BE THE MOST LIKELY IN THE EASTERN
KUSKOKWIM VALLEY AND NORTHEASTERN BRISTOL BAY...AS WELL AS ALONG
THE ALASKA RANGE. THERE IS ALSO A GOOD CHANCE THAT WHEREVER THE
RAIN SETS UP...THERE WILL MOST LIKELY BE WIDESPREAD SOAKING
RAINS...SIMILAR TO THAT EXPERIENCED IN THIS SAME AREA ON SATURDAY.

BERING SEA/ALEUTIANS...THE PACIFIC LOW WILL CONTINUE TO BRING RAIN
AND GUSTY WINDS FROM DUTCH HARBOR TO THE ALASKA PENINSULA TODAY.
RAIN OVER THE ALASKA PENINSULA WILL THEN BEGIN TO DIMINISH EARLY
THIS EVENING...WHILE THE EASTERN ALEUTIANS WILL REMAIN WET BUT
WITH LIGHT WINDS THROUGH THURSDAY AS A WEAK SURFACE TROUGH SETS UP
TO THE NORTH. BY THURSDAY AFTERNOON...FOG AND STRATUS WILL QUICKLY
REDEVELOP THROUGHOUT THE REGION AS RIDGING BUILDS IN FROM THE
WESTERN BERING. THIS WILL THEN REMAIN IN PLACE INTO THIS WEEKEND.

&&

.LONG TERM FORECAST...
STARTING LATE THIS WEEK...THERE IS INCREASING AGREEMENT THAT THE
PERSISTENT RIDGING OVER THE BERING SEA WILL BREAK DOWN LATE THIS
WEEKEND...ALLOWING FOR A SERIES OF UPPER LEVEL TROUGHS TO DIVE
SOUTHWARD FROM SIBERIA TOWARDS SOUTHERN ALASKA. THESE SYSTEMS WILL
BRING DOWN INCREASING CLOUDS AND COOLER TEMPERATURES...ESPECIALLY
TO WESTERN ALASKA EARLY NEXT WEEK. IT REMAINS TO BE SEEN HOW THIS
WILL IMPACT THE EASTERN MAINLAND AND SOUTHCENTRAL...AS THERE IS
ALSO INCREASING AGREEMENT THAT RIDGING OVER THE YUKON TERRITORY
WILL NOSE INTO THE EASTERN INTERIOR...AND POTENTIALLY TO THE SOUTH
OF THE ALASKA RANGE. IF THIS RIDGING IS ALLOWED TO DEVELOP SOUTH
OF THE ALASKA RANGE (AS THE GFS IS TRENDING TOWARDS) TEMPERATURES
AROUND SOUTHCENTRAL WOULD RISE TO ABOVE NORMAL BY EARLY NEXT
WEEK...WITH RAINFALL LIMITED TO CONVECTIVE SHOWERS RESULTING FROM
THE THERMAL TROUGH. IF IT SETS UP FURTHER NORTH (AS THE LATEST EC
IS DEPICTING) THEN THE FORECAST WILL BE GENERALLY
COOLER...CLOUDIER...WITH A GREATER CHANCE OF RAIN FOR SOUTHERN
ALASKA EARLY NEXT WEEK.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...GALE 132 150 155.
MARINE...NONE.
FIRE WEATHER...NONE.

&&

DEK JUN 14