Valid Sunday, December 15, 2013 to Thursday, December 26, 2013
Summary of Forecasts and Hazards
US HAZARDS OUTLOOK
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD
300 PM
EST DECEMBER 12 2013
SYNOPSIS: AT THE START OF THE PERIOD, A
SURFACE LOW IS EXPECTED TO BE DEPARTING COASTAL NEW ENGLAND. HIGH PRESSURE IS
THEN EXPECTED TO BUILD OVER THE CENTRAL AND EASTERN U.S. LATER IN THE PERIOD, A
COLD FRONT IS EXPECTED TO CROSS THE NORTH-CENTRAL U.S. USHERING IN ANOTHER AREA
OF COLD HIGH PRESSURE ACROSS THE NORTHERN ROCKIES, GREAT PLAINS, AND PARTS OF
THE MISSISSIPPI VALLEY AND GREAT LAKES. LOW PRESSURE OVER SOUTHERN ALASKA IS
FORECAST TO WEAKEN AS HIGH PRESSURE BUILDS OVER THE WESTERN AND CENTRAL PARTS
OF THE STATE.
HAZARDS - MUCH BELOW-NORMAL TEMPERATURES FOR
PARTS OF THE NORTHERN GREAT PLAINS, UPPER AND MIDDLE MISSISSIPPI VALLEYS, GREAT
LAKES, AND OHIO VALLEY, SUN-MON, DEC 15-16.
- MUCH BELOW-NORMAL TEMPERATURES FOR PARTS OF NORTHERN NEW ENGLAND, TUE, DEC
17.
- MUCH BELOW-NORMAL TEMPERATURES FOR CENTRAL AND EASTERN INTERIOR ALASKA,
MON-TUE, DEC 16-17.
- MUCH BELOW NORMAL TEMPERATURES SHIFTING SOUTHEAST ACROSS PARTS OF THE
NORTHERN ROCKIES, GREAT PLAINS, MISSISSIPPI VALLEY, AND GREAT LAKES, THU-SUN,
DEC 19-22.
- SEVERE DROUGHT FOR PARTS OF THE MIDWEST, GREAT PLAINS, RIO GRANDE VALLEY,
ROCKIES, SOUTHWEST, GREAT BASIN, CALIFORNIA, AND HAWAII.
DETAILED
SUMMARYFOR SUNDAY DECEMBER 15 - THURSDAY DECEMBER
19: A STORM OFF THE NEW ENGLAND COAST IS EXPECTED TO MOVE AWAY FROM THE
NORTHEAST CONUS. HAZARDOUS WEATHER ASSOCIATED WITH THIS SYSTEM IS EXPECTED TO
DIMINISH BEFORE THE START OF THE PERIOD. IN THE WAKE OF THIS STORM, HIGH
PRESSURE BUILDING OVER THE CENTRAL AND EASTERN CONUS IS EXPECTED TO LEAD TO
MUCH BELOW NORMAL TEMPERATURES FOR PARTS OF THE NORTHERN GREAT PLAINS, UPPER
AND MIDDLE MISSISSIPPI VALLEYS, GREAT LAKES, AND OHIO VALLEY (DEC 15-16), AND
NORTHERN NEW ENGLAND (DEC 17). THE OUTBREAK OF ARCTIC TEMPERATURES WILL BE OF
CONCERN TO AGRICULTURAL INTERESTS ACROSS THE WINTER WHEAT GROWING AREAS OF THE
GREAT PLAINS AND MIDWEST THAT LACK ANY PROTECTIVE SNOW COVER FROM THESE
BITTERLY COLD TEMPERATURES.
ARCTIC HIGH PRESSURE IS EXPECTED TO RESULT IN MUCH-BELOW NORMAL
TEMPERATURES FOR CENTRAL AND SOUTHERN ALASKA ON DEC 16-17. A LOW PRESSURE
SYSTEM IS FORECAST TO BRING WINDY CONDITIONS TO THE ALEUTIANS DURING THE MIDDLE
PART OF NEXT WEEK BUT MODEL GUIDANCE INDICATES THAT A HIGH WINDS HAZARD IS NOT
JUSTIFIED.
ANOTHER AREA OF ARCTIC HIGH PRESSURE IS FORECAST TO MOVE FROM SOUTHWESTERN
CANADA TO THE NORTH-CENTRAL CONUS LEADING TO MUCH BELOW NORMAL TEMPERATURES FOR
PARTS OF THE NORTHERN PLAINS AND UPPER MISSISSIPPI VALLEY DEC 19.
FOR FRIDAY
DECEMBER 20 - THURSDAY DECEMBER 26: THE 0Z GFS AND 0Z ECMWF ENSEMBLE MEANS
FEATURE A BUILDING RIDGE OVER THE NORTHEAST PACIFIC/ALASKA AND AN AMPLIFYING
TROUGH ACROSS THE WESTERN U.S. THIS PREDICTED LONGWAVE PATTERN SIGNALS MORE
ARCTIC AIR SPREADING SOUTH INTO THE NORTH-CENTRAL CONUS EARLY IN WEEK-2. THE 6Z
GFS ENSEMBLE MEAN INDICATES TEMPERATURES AVERAGING MORE THAN 16 DEGREES F
BELOW-NORMAL ACROSS THE NORTHERN GREAT PLAINS AND UPPER MISSISSIPPI VALLEY FROM
DEC 20-22.
ACCORDING TO THE U.S. DROUGHT MONITOR VALID DECEMBER 10 (RELEASED DECEMBER
12),THE SPATIAL COVERAGE OF SEVERE TO EXCEPTIONAL DROUGHT ACROSS THE
CONTINENTAL U.S. REMAINED NEARLY STEADY THE PAST WEEK AT AROUND 16.4 PERCENT.
FORECASTER: RANDY SCHECHTER
$$
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Please consult local NWS Forecast Offices for short range forecasts and region-specific information.
www.nws.noaa.gov 
