Valid Sunday, May 05, 2013 to Thursday, May 16, 2013
Summary of Forecasts and Hazards
US HAZARDS OUTLOOK
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD
300 PM
EDT MAY 02 2013
SYNOPSIS: EARLY IN THE PERIOD, SURFACE LOW
PRESSURE IS FORECAST OVER THE TENNESSEE VALLEY. THIS AREA OF LOW PRESSURE IS
EXPECTED TO MOVE SLOWLY EASTWARD TO THE MID-ATLANTIC COAST. COLD SURFACE HIGH
PRESSURE IS FORECAST OVER THE CENTRAL PART OF THE NATION. OFFSHORE FLOW IS
ANTICIPATED FOR THE WESTERN U.S. AS AN AREA OF UPPER-LEVEL HIGH PRESSURE
DEVELOPS OVER THE PACIFIC NORTHWEST AND SURFACE AND UPPER-LEVEL LOW PRESSURE
REMAINS NEAR THE COAST OF CALIFORNIA. WEAK SURFACE LOW PRESSURE FORECAST OVER
SOUTHERN ALASKA IS EXPECTED TO REMAIN NEARLY STATIONARY AND DISSIPATE AS ARCTIC
HIGH PRESSURE DOMINATES MUCH OF THE REST OF THE STATE. LATER IN THE PERIOD,
SURFACE LOW PRESSURE EXPECTED ALONG THE MID-ATLANTIC COAST IS ANTICIPATED TO
DRIFT NORTHWARD AND DISSIPATE. ANOTHER AREA OF LOW PRESSURE IS FORECAST TO
DEVELOP OVER THE SOUTHERN PLAINS AND MOVE TO THE MISSISSIPPI VALLEY WHILE HIGH
PRESSURE DOMINATES MOST OF THE EASTERN U.S., THE NORTHERN PLAINS, AND ROCKIES.
HAZARDS - HEAVY RAIN FOR PARTS OF THE OHIO AND TENNESSEE
VALLEYS, SOUTHERN APPALACHIANS, AND MID-ATLANTIC, SUN-MON, MAY 5-6.
- MUCH ABOVE NORMAL TEMPERATURES FOR WASHINGTON, OREGON, NORTHERN PORTIONS
OF CALIFORNIA, NORTHWESTERN IDAHO, AND WESTERN MONTANA, SUN-THU, MAY 5-9.
- MUCH BELOW NORMAL TEMPERATURES FOR PARTS OF THE CENTRAL AND SOUTHERN
PLAINS, PARTS OF THE LOWER AND MIDDLE MISSISSIPPI VALLEY, THE TENNESSEE
VALLEY, AND SOUTHEAST, SUN-MON, MAY 5-6.
- MUCH BELOW NORMAL TEMPERATURES FOR MUCH OF CENTRAL AND EASTERN ALASKA,
SUN-THU, MAY 5-9.
- RIVER FLOODING POSSIBLE OR OCCURRING FOR PARTS OF THE MISSISSIPPI VALLEY,
OHIO VALLEY, MIDWEST, GREAT LAKES, AND NORTHERN GREAT PLAINS.
- RIVER FLOODING POSSIBLE FOR CENTRAL AND EASTERN ALASKA.
- SEVERE DROUGHT FOR PARTS OF NORTHERN FLORIDA, UPPER MISSISSIPPI VALLEY,
GREAT PLAINS, RIO GRANDE VALLEY, ROCKIES, SOUTHWEST, GREAT BASIN, AND HAWAII.
DETAILED SUMMARYFOR SUNDAY MAY 05 -
THURSDAY MAY 09: WIDESPREAD MAJOR FLOODING CONTINUES ACROSS THE MIDDLE
MISSISSIPPI VALLEY, OHIO VALLEY, MIDWEST, NORTHERN PLAINS, AND GREAT LAKES. LOW
PRESSURE OVER THE TENNESSEE VALLEY IS EXPECTED TO BRING HEAVY RAIN TO PARTS OF
THE OHIO AND TENNESSEE VALLEYS, SOUTHERN APPALACHIANS, AND MID-ATLANTIC,
SUN-MON, MAY 5-6.
LATER IN THE PERIOD, LOW PRESSURE IS FORECAST TO MOVE FROM THE SOUTHERN
PLAINS TO THE MISSISSIPPI VALLEY. THIS IS EXPECTED TO BRING HEAVY RAIN TO THE
CENTRAL CONUS WHICH COULD EXACERBATE AND EXPAND THE AREAS OF FLOODING.
SIGNIFICANT MODEL UNCERTAINTY PRECLUDES THE SPECIFICATION OF A HAZARD AREA AT
THE CURRENT TIME.
HIGH PRESSURE IS FORECAST TO BUILD OVER THE CENTRAL CONUS LEADING TO MUCH
BELOW NORMAL TEMPERATURES FOR PARTS OF THE CENTRAL AND SOUTHERN PLAINS, PARTS
OF THE LOWER AND MIDDLE MISSISSIPPI VALLEY, THE TENNESSEE VALLEY, AND
SOUTHEAST, SUN-MON, MAY 5-6.
OFFSHORE SURFACE FLOW AND A STRONG UPPER-LEVEL RIDGE FORECAST OVER THE
NORTHWESTERN CONUS IS EXPECTED TO LEAD TO MUCH ABOVE NORMAL TEMPERATURES FOR
WASHINGTON, OREGON, NORTHERN PORTIONS OF CALIFORNIA, NORTHWESTERN IDAHO, AND
WESTERN MONTANA, SUN-THU, MAY 5-9. GUSTY WINDS ARE ANTICIPATED FOR PARTS OF
SOUTHWEST OREGON AND NORTHERN CALIFORNIA SUN MAY 5, BUT SUSTAINED WIND SPEEDS
ARE NOT CURRENTLY EXPECTED TO REACH HAZARDOUS CRITERIA.
LOW PRESSURE IS FORECAST NEAR THE CALIFORNIA COAST WHICH IS EXPECTED TO
BRING SOME PRECIPITATION TO CALIFORNIA, THE CENTRAL GREAT BASIN, AND SOUTHWEST.
WHILE THIS IS SOMEWHAT UNUSUAL FOR THIS TIME OF YEAR, PRECIPITATION AMOUNTS ARE
NOT CURRENTLY EXPECTED TO REACH HAZARDOUS CRITERIA.
A WEAK AREA OF LOW PRESSURE IS ANTICIPATED OVER SOUTHERN ALASKA. COLD HIGH
PRESSURE IS EXPECTED TO DOMINATE MOST OF THE REST OF THE STATE WHICH IS
EXPECTED TO BRING MUCH BELOW NORMAL TEMPERATURES TO MUCH OF CENTRAL AND EASTERN
ALASKA, SUN-THU, MAY 5-9.
FOR FRIDAY MAY 10 - THURSDAY MAY
16: DUE TO SIGNIFICANT MODEL UNCERTAINTY, NO SPECIFIC HAZARDS, EXCEPT FOR
POSSIBLE FLOODING AND SEVERE DROUGHT, CAN BE IDENTIFIED ACROSS THE LOWER 48
STATES. RIVER FLOODING IS EXPECTED TO CONTINUE ALONG THE RED RIVER OF THE NORTH
DURING WEEK-2. RIVER FLOODING IS EXPECTED TO BEGIN ACROSS PARTS OF CENTRAL AND
EASTERN ALASKA DURING EARLY MAY.
ACCORDING TO THE U.S. DROUGHT MONITOR VALID APRIL 30, SEVERE (D2) TO
EXCEPTIONAL (D4) DROUGHT COVERAGE ACROSS THE CONTINENTAL U.S. INCREASED
SLIGHTLY TO 33 PERCENT, MOSTLY RELATED TO DROUGHT INTENSIFICATION ACROSS TEXAS.
FORECASTER: RANDY SCHECHTER
$$
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