Valid Monday, February 13, 2012 to Friday, February 24, 2012

Summary of Forecasts and Hazards

US HAZARDS OUTLOOK
NWS CLIMATE PREDICTION CENTER CAMP SPRINGS MD
300 PM EST FEBRUARY 10 2012

SYNOPSIS: CANADIAN HIGH PRESSURE IS FORECAST EARLY IN THE PERIOD TO BRING SOME OF THE COLDEST AIR OF THE WINTER TO PARTS OF THE EASTERN SEABOARD ALLOWING FOR SNOW NEAR THE GREAT LAKES. AS THE HIGH MOVES EASTWARDS, RETURN FLOW OFF THE GULF OF MEXICO FAVORS ABOVE NORMAL TEMPERATURES AND ABOVE AVERAGE PRECIPITATION FOR PARTS OF THE SOUTHEAST.

HAZARDS

• HEAVY LAKE-EFFECT SNOW ON FEBRUARY 13.
• HEAVY RAIN FOR PARTS OF EASTERN TEXAS AND NORTHWESTERN LOUISIANA ON FEBRUARY 13.
• SEVERE DROUGHT FOR PARTS OF THE CENTRAL AND SOUTHERN GREAT PLAINS, SOUTHWEST,
• SOUTHEAST, WESTERN CORN BELT, NORTHEAST MINNESOTA, AND HAWAII.
• FLOODING FOR WEST-CENTRAL LOUISIANA.

DETAILED SUMMARY

FOR MONDAY FEBRUARY 13 - FRIDAY FEBRUARY 17: A STRONG PRESSURE GRADIENT ALONG THE NORTHERN PERIPHERY OF SURFACE HIGH PRESSURE CENTERED IN THE OHIO VALLEY IS EXPECTED TO LEAD TO HEAVY LAKE-EFFECT SNOW IN LOCATIONS DIRECTLY EAST OF A LAKE. BECAUSE THE LAKE TEMPERATURES ARE RELATIVELY WARM, LAPSE RATES SHOULD BE LARGE, POSSIBLY LEADING TO CONVECTIVE SNOW RATES OF AT LEAST 1-2 INCHES AN HOUR.

IN ADDITION, THE STRONG, DRY WINDS MOVING OVER DRY SOILS IN THE SOUTHEAST COULD LEAD TO RED FLAG WARNINGS AND ENHANCE THE RISK OF WILDFIRES. HOWEVER, BECAUSE OF THE COOL TEMPERATURES ALSO EXPECTED, NO HAZARDS ARE DENOTED AT THIS TIME.

AS THE HIGH PRESSURE CENTER MOVES OFF THE EAST COAST, RETURN FLOW OFF THE GULF OF MEXICO IS EXPECTED TO WARM TEMPERATURES AND BRING THE CHANCE OF RAIN FOR THE MISSISSIPPI VALLEY AS A SERIES OF STORMS MOVES INTO THE SOUTHERN TIER OF STATES. THE FIRST STORM IS FORECAST TO MOVE THROUGH AT THE BEGINNING OF THIS PERIOD BRINGING AT LEAST ONE INCH OF RAIN IN LESS THAN 24 HOURS TO PARTS OF EASTERN TEXAS AND NORTHWESTERN LOUISIANA. A HAZARD HAS BEEN PLACED ON THE MAP DUE TO THE HIGH RAINFALL RATE COUPLED WITH THE FACT THAT SOILS IN THIS PART OF THE COUNTRY ARE VERY MOIST DUE TO RECENT RAINS AND SIGNIFICANT RIVER FLOODING ALREADY EXISTS.

TOWARDS THE END OF THIS PERIOD, AN AMPLIFIED UPPER-LEVEL TROUGH IS FORECAST TO DIG DOWN INTO BAJA CALIFORNIA. AS IT EJECTS EASTWARDS, SURFACE CYCLOGENESIS IS EXPECTED, BRINGING RAIN TO A WIDE SWATH OF TEXAS AND THE LOWER MISSISSIPPI VALLEY. THERE IS SOME MODEL DISAGREEMENT AS TO THE EXACT TRACK AND INTENSITY OF THIS STORM AND CONSEQUENTLY HOW MUCH RAIN WILL FALL. BECAUSE OF THIS UNCERTAINTY, NO HAZARDS ARE PLACED ON THE MAP AT THIS TIME.

FLOODING ALONG THE CALCASIEU RIVER IN WEST CENTRAL LOUISIANA IS EXPECTED TO CONTINUE THROUGH AT LEAST THE BEGINNING OF THIS PERIOD DUE TO RAINFALL OF AT LEAST 5 INCHES OVER THE LAST TWO WEEKS.

FOR SATURDAY FEBRUARY 18 - FRIDAY FEBRUARY 24: THE FORECAST MEAN UPPER-LEVEL HEIGHT PATTERN DURING THIS PERIOD SHOWS A RIDGE OFF THE WEST COAST AND A TROUGH OVER THE EASTERN THIRD OF THE COUNTRY. THIS PATTERN FAVORS HIGH PRESSURE CENTERS MOVING INTO THE MOUNTAINOUS WEST, ALLOWING FOR OFFSHORE FLOW ALONG THE CALIFORNIA COAST. THIS WILL INCREASE THE CHANCES FOR HIGH WINDS AND AN ENHANCED WILDFIRE RISK DURING THIS PERIOD. AT THIS TIME, THERE IS TOO MUCH UNCERTAINTY AS TO THE EXACT TIMING AND STRENGTH OF ANY POTENTIAL WIND EVENT, THUS NO HAZARDS ARE DENOTED ON THE MAP. IN ADDITION, THIS PATTERN WOULD MEAN THAT NORTHERLY FLOW WILL EXIST OVER THE WESTERN THIRD OF THE CONUS, FAVORING BELOW NORMAL TEMPERATURES AND BELOW MEDIAN PRECIPITATION TO LOCATIONS WEST OF THE ROCKIES. FLOW WILL THEN SHIFT TO SOUTHWESTERLY AROUND THE EASTERN TROUGH, FAVORING ABOVE NORMAL TEMPERATURES AND ABOVE MEDIAN PRECIPITATION FOR MOST PLACES EAST OF THE ROCKIES.

SEVERE DROUGHT IS EXPECTED TO CONTINUE OR PARTS OF THE CENTRAL AND SOUTHERN
GREAT PLAINS, SOUTHWEST, SOUTHEAST, WESTERN CORN BELT, NORTHEAST MINNESOTA, AND
HAWAII.

FORECASTER: KENNETH PELMAN

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