Valid Monday, March 10, 2014 to Friday, March 21, 2014

Summary of Forecasts and Hazards

US HAZARDS OUTLOOK
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD
300 PM EST MARCH 07 2014

SYNOPSIS: A FAIRLY QUIET, MILD WEATHER PATTERN EARLY IN THE PERIOD IS EXPECTED TO GIVE WAY TO A MORE ACTIVE PATTERN LATER IN WEEK-1. A LATE-SEASON WINTER STORM IS POSSIBLE FOR PARTS OF THE NORTHEASTERN U.S. DURING THE MIDDLE OF NEXT WEEK. ACTIVE WEATHER IS LIKELY FOR MUCH OF ALASKA DURING WEEK-1, WHILE RIDGING IS FORECAST TO DEVELOP LATE IN THE PERIOD ACROSS THE STATE.

HAZARDS

• HEAVY PRECIPITATION FOR PARTS OF THE SOUTH COAST OF ALASKA, TUE-WED, MAR 11-14.
• HEAVY SNOW SPREADING EASTWARD ACROSS PARTS OF THE MIDWEST AND NORTHEAST, TUE-THU, MAR 11-13.
• HIGH WINDS FOR PARTS OF THE CENTRAL AND SOUTHERN PLAINS, TUE, MAR 11.
• HIGH WINDS EXTENDING FROM THE SOUTHERN GREAT LAKES TO THE MIDDLE MISSISSIPPI VALLEY AND SOUTHERN PLAINS, WED, MAR 12.
• MUCH BELOW-NORMAL TEMPERATURES FOR PARTS OF THE NORTHEAST, GREAT LAKES, AND UPPER MIDWEST, WED-SAT, MAR 12-15.
• SEVERE DROUGHT FOR PARTS OF IOWA, WESTERN GULF COAST, GREAT PLAINS, ROCKIES, SOUTHWEST, PACIFIC NORTHWEST, GREAT BASIN, CALIFORNIA, AND HAWAII.

DETAILED SUMMARY

FOR MONDAY MARCH 10 - FRIDAY MARCH 14: A SPLIT-FLOW PATTERN IS FORECAST ACROSS THE CONUS AT THE BEGINNING OF THE PERIOD, TRANSITIONING TO MORE AMPLIFIED FLOW LATER. THE RESULT IS FAST-MOVING SHORTWAVES MOVING ACROSS THE NORTHERN TIER, WITH SLOWER-MOVING CUT OFF LOWS ACROSS THE SOUTH. THIS PATTERN IS EXPECTED TO BE QUITE WARM FOR MUCH OF THE NATION, WITH TEMPERATURES MON-TUE RANGING FROM 10-25 DEGREES ABOVE NORMAL AT THE PEAK OF THE WARM-UP FROM THE CENTRAL PLAINS TO THE SOUTHEST/MID-ATLANTIC. THE NORTHERN STREAM IS EXPECTED TO AMPLIFY DURING THE MIDDLE OF NEXT WEEK, ALLOWING COLDER AIR TO SURGE SOUTHWARD ONCE AGAIN BEHIND SURFACE LOW PRESSURE SYSTEM. ANOTHER ROUND OF ARCTIC AIR IS THEREFORE EXPECTED TO IMPACT THE NORTHEAST, GREAT LAKES, AND MIDWEST LATER IN THE PERIOD, LINGERING INTO WEEK-2 IN THE NORTHEAST.

A LARGE DEGREE OF UNCERTAINTY EXISTS WITH RESPECT THE DETAILS CONCERNING THE SURFACE CYCLONE DURING THE MIDDLE OF NEXT WEEK. THE 00Z ECMWF FAVORED A MORE AMPLIFIED SOLUTION, WHILE THE 12Z GFS AND CANADIAN DETERMINISTIC RUNS FAVOR A MORE PROGRESSIVE SOLUTION AND LESS INTERACTION WITH THE SOUTHERN STREAM SYSTEM. THE ENSEMBLE MEANS, INCLUDING THE 12Z GEFS MEAN, ARE IN FAIRLY GOOD AGREEMENT WITH RESPECT TO THE TRACK OF THE SURFACE LOW. THEREFORE, CONFIDENCE IS HIGH ENOUGH TO WARRANT A HEAVY SNOW HAZARD EXTENDING FROM THE SOUTHERN GREAT LAKES TO THE INTERIOR NORTHEAST.

ALSO ASSOCIATED WITH THIS STORM SYSTEM, HIGH WINDS ARE EXPECTED FOR PARTS OF THE SOUTHERN AND CENTRAL PLAINS TUESDAY, SHIFTING EASTWARD TO INCLUDE MUCH OF THE GREAT LAKES AND MISSISSIPPI VALLEY ON WEDNESDAY. HIGH WINDS, LOW RH, AND FAIRLY WARM TEMPERATURES LEAD TO ENHANCED RISK OF FIRE WEATHER ACROSS PARTS OF NEW MEXICO AND WEST TEXAS ON TUESDAY.

MULTIPLE LOW-PRESSURE SYSTEMS ARE EXPECTED TO IMPACT PARTS OF ALASKA THROUGHOUT THE PERIOD, WITH THE MOST HAZARDOUS PERIOD OCCURRING TUESDAY THROUGH FRIDAY.

FOR SATURDAY MARCH 15 - FRIDAY MARCH 21: THE ENSEMBLE MEAN FORECASTS FOR WEEK-2 HAVE SHOWN ENHANCED RUN-TO-RUN VARIABILITY AND DECREASED AMPLITUDE OVER THE PAST DAY, SUGGESTING AN INCREASE IN UNCERTAINTY HEADING PAST THE MIDDLE OF THE MONTH. GENERALLY, TROUGHING IS FAVORED IN THE NORTHEAST WITH RIDGING ACROSS PARTS OF THE WEST. HOWEVER, THE STRONGEST ANOMALY APPEARS TO BE A RIDGE FORECAST TO MOVE NORTHWESTWARD TOWARD ALASKA DURING THE PERIOD, INTRODUCING UNCERTAINTY WITH RESPECT TO DOWNSTREAM WAVELENGTH/AMPLIFICATION. THAT SAID, MUCH BELOW-NORMAL TEMPERATURES ARE EXPECTED EARLY NEXT WEEKEND ACROSS PARTS OF THE NORTHEAST, WHERE LOW TEMPERATURES OVER SNOW COVER COULD RANGE FROM 12-20 DEGREES BELOW NORMAL.

PARTS OF SOUTHERN ALASKA MAY BE IMPACTED BY AN ADDITIONAL LOW-PRESSURE SYSTEM EARLY IN THE PERIOD. ENSEMBLE GUIDANCE SUGGESTS THAT RIDGING MAY BUILD INTO ALASKA THROUGHOUT THE PERIOD, ENDING A VERY ACTIVE PERIOD ACROSS MUCH OF THE STATE.

FORECASTER: STEPHEN BAXTER

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