753  
FXUS21 KWNC 032000  
PMDTHR  
US HAZARDS OUTLOOK  
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD  
300 PM EDT NOVEMBER 03 2017  
 
SYNOPSIS: ON NOVEMBER 6, A FRONTAL SYSTEM IS PREDICTED TO STRETCH ACROSS THE  
ENTIRE CONTIGUOUS UNITED STATES, FROM NEW ENGLAND TO CALIFORNIA. TWO DAYS  
LATER, THIS FRONTAL BOUNDARY IS FORECAST TO BE ROUGHLY ORIENTED IN AN EAST-WEST  
DIRECTION, FROM THE CAROLINAS TO SOUTHERN ARIZONA, WITH COAST-TO-COAST SURFACE  
HIGH PRESSURE NORTH OF THE BOUNDARY. AT THE SAME TIME, A PACIFIC STORM SYSTEM  
IS ANTICIPATED TO APPROACH THE PACIFIC NORTHWEST COAST AND GRADUALLY WEAKEN AS  
IT MOVES INLAND. DURING WEEK 2, FAST WESTERLY FLOW ALOFT IS PREDICTED ACROSS  
THE CONUS. IN ALASKA, MOST OF THE OUTLOOK PERIOD IS FORECAST TO BE DOMINATED BY  
STRONG NORTHERLY FLOW ALOFT AND MINIMAL STORM ACTIVITY, EXCEPT FOR PERSISTENT  
SURFACE LOW PRESSURE IN THE VICINITY OF THE PANHANDLE.  
 
HAZARDS  
 
HEAVY RAIN NEAR THE CONFLUENCE AREA OF KENTUCKY, VIRGINIA, AND WEST VIRGINIA,  
MON-TUE, NOV 6-7.  
 
HEAVY RAIN NEAR AND ALONG THE NORTHERN HALF OF THE PACIFIC COAST, WED-THU, NOV  
8-9.  
 
HEAVY SNOW OVER THE CASCADES AND SIERRAS, WED-THU, NOV 8-9.  
 
MUCH BELOW-NORMAL TEMPERATURES FROM EASTERN WASHINGTON STATE TO MINNESOTA,  
MON-TUE, NOV 6-7.  
 
FLOODING OCCURRING OR IMMINENT ACROSS PART OF CENTRAL FLORIDA.  
 
SLIGHT RISK OF MUCH BELOW-NORMAL TEMPERATURES IN NEW ENGLAND ON SAT, NOV 11.  
 
SLIGHT RISK OF MUCH BELOW-NORMAL TEMPERATURES NEAR THE CANADIAN BORDER FROM  
WASHINGTON STATE TO MINNESOTA, SAT-WED, NOV 11-15.  
 
SEVERE DROUGHT ACROSS THE NORTHERN PLAINS, THE NORTHERN ROCKIES, PARTS OF  
ARIZONA AND TEXAS, AND HAWAII.  
 
DETAILED SUMMARY  
 
FOR MONDAY NOVEMBER 06 - FRIDAY NOVEMBER 10: A FRONTAL SYSTEM APPROACHING THE  
EASTERN SEABOARD IS EXPECTED TO BRING AN AREA OF HEAVY RAIN (1-2 INCHES) TO THE  
REGION WHERE KENTUCKY, WEST VIRGINIA, AND VIRGINIA MEET, ON NOV 6-7.  
 
ANOMALOUSLY COLD AIR FROM CANADA IS ANTICIPATED TO MOVE ACROSS THE NORTHERN  
TIER OF STATES FROM EASTERN WASHINGTON TO NORTHWESTERN MINNESOTA ON NOV 6-7, IN  
THE WAKE OF THE PREVIOUSLY MENTIONED FRONTAL SYSTEM. MINIMUM TEMPERATURES ARE  
FORECAST TO RANGE BETWEEN 12-20 DEGREES F BELOW NORMAL.  
 
ON NOV 8-9, A CYCLONIC SYSTEM OVER THE EASTERN GULF OF ALASKA IS EXPECTED TO  
MOVE INTO THE PACIFIC NORTHWEST, BRINGING HEAVY RAIN (2-5 INCHES) TO THE  
COASTAL AREAS OF WASHINGTON, OREGON, AND NORTHWESTERN CALIFORNIA, AND HEAVY  
SNOW (6 INCHES OR MORE IN A 24-HOUR PERIOD) TO THE CASCADES AND SIERRAS.  
 
PROLONGED FLOODING CONTINUES ALONG THE ST. JOHNS RIVER IN CENTRAL FLORIDA.  
 
NEAR THE END OF THE 3-7 DAY PERIOD, THE 0Z ECMWF AGAIN PREDICTS THE POSSIBILITY  
OF A SIGNIFICANT WINTER STORM ACROSS NEW ENGLAND, BUT THE FORECAST TRACK TAKES  
THE LOW PRESSURE CENTER WELL EAST OF THE 40N/70W BENCHMARK, WHICH SUGGESTS  
LITTLE IF ANY PRECIPITATION WILL REACH NEW ENGLAND. THE GFS CONTINUES TO  
FORECAST A FAST-MOVING OPEN WAVE WHICH SLIDES ACROSS THE MID-ATLANTIC AND  
RAPIDLY OUT TO SEA. AT THIS TIME, IT IS THOUGHT THAT IF ANY WINTER STORM DOES  
DEVELOP, IT WILL BE WELL OFF THE EAST COAST AND A HAZARD ONLY FOR SHIPPING IN  
THE WESTERN ATLANTIC.  
 
HIGH PRESSURE PREDICTED ACROSS THE YUKON IS PREDICTED TO LEAD TO EASTERLY WINDS  
THROUGH THE MOUNTAIN PASSES OF THE ALASKA PANHANDLE ON NOV 7. DUE TO THE  
RELATIVELY LOCALIZED NATURE OF ANY WIND THREAT, NO HAZARD WAS PLACED ON THE MAP  
TODAY.  
 
FOR SATURDAY NOVEMBER 11 - FRIDAY NOVEMBER 17: DURING WEEK-2, ANOMALOUS 500-HPA  
TROUGHING IS FORECAST ONLY OVER THE PACIFIC NORTHWEST, WITH NEAR TO  
ABOVE-NORMAL 500-HPA HEIGHTS OVER THE REMAINDER OF THE CONUS. THE ONLY HAZARDS  
INDICATED DURING THE WEEK-2 PERIOD INCLUDE PERSISTENT, LONG-TERM DROUGHT  
PRIMARILY OVER THE NORTHERN PLAINS, AND A SLIGHT RISK OF MUCH BELOW-NORMAL  
TEMPERATURES DURING NOV 11-15 FROM NORTHERN WASHINGTON STATE EASTWARD ACROSS  
THE NORTHERN TIER OF STATES TO LAKE SUPERIOR. THERE IS ALSO A SLIGHT RISK OF  
MUCH BELOW-NORMAL TEMPERATURES (A QUICK COLD SHOT) ACROSS NEW ENGLAND AND  
ADJACENT PARTS OF NEW YORK ON NOV 11. THE TIMING OF THIS QUICK COLD SHOT IS  
UNCERTAIN, AND COULD EASILY BE A DAY EARLIER. THE SLIGHT RISK AREAS DENOTE  
WHERE THE GEFS PROBABILISTIC EXTREMES TOOL INDICATES AT LEAST A 20% CHANCE OF  
MINIMUM TEMPERATURES BEING BELOW THE 15TH CLIMATOLOGICAL PERCENTILE.  
 
THE U.S. DROUGHT MONITOR, VALID ON OCTOBER 31, INDICATES THAT SEVERE TO  
EXCEPTIONAL (D2-D4) DROUGHT COVERS 2.67 PERCENT OF THE CONTINENTAL U.S., WHICH  
IS A SLIGHT INCREASE FROM 2.58 PERCENT LAST WEEK. THE WORST CONDITIONS CONTINUE  
TO BE OVER THE NORTHERN GREAT PLAINS REGION. THE MOST SIGNIFICANT IMPROVEMENTS  
MADE TO THE DROUGHT DEPICTION THIS WEEK WERE OVER THE NORTHEAST, WHERE MUCH OF  
THE REGION RECEIVED MORE THAN 4 INCHES OF RAIN DURING THE PAST WEEK.  
 
FORECASTER: ANTHONY ARTUSA  
 

 
 
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