US HAZARDS ASSESSMENT
NWS CLIMATE PREDICTION CENTER CAMP SPRINGS MD
300
PM EDT MAY 08 2008
SYNOPSIS: THIS ASSESSMENT PERIOD WILL HAVE AN
ACTIVE WEATHER PATTERN. A SURFACE LOW PRESSURE SYSTEM WILL DEVELOP OVER THE
MIDDLE AND LOWER MISSISSIPPI VALLEY BRINGING RAIN TO MOST OF THE EASTERN HALF
OF THE CONUS AS IT MOVES EASTWARD ACROSS THE CONUS. THERE IS A RELATIVELY BROAD
AREA OF POSSIBLE SEVERE THUNDERSTORMS ACROSS PARTS OF THE SOUTHEAST AND MIDDLE
ATLANTIC AS THIS LOW PRESSURE SYSTEM PASSES THROUGH THIS AREA. AS THIS STORM
SYSTEM DEEPENS AND REACHES THE MIDDLE ATLANTIC AND NORTHEASTERN COAST, THESE
REGIONS MAY EXPERIENCE HIGH WINDS WHICH COULD CAUSE TIDAL SURGES, COASTAL
FLOODING, AND BEACH EROSION. ANOTHER SURFACE LOW PRESSURE SYSTEM MAY DEVELOP
OVER THE CENTRAL PLAINS EARLY NEXT WEEK WHICH COULD PRODUCE MORE RAIN FOR THE
EASTERN TWO THIRDS OF THE CONUS.
HAZARDS - SEVERE
THUNDERSTORMS FROM THE TENNESSEE VALLEY EASTWARD INTO THE CAROLINAS AND
SOUTHERN VIRGINIA ON SUNDAY MAY 11.
- HEAVY RAIN OVER PARTS OF THE TENNESSEE VALLEY, OHIO VALLEY, MIDDLE
ATLANTIC, SOUTHEAST, AND NORTHEAST MAY 11-MAY 12.
- HIGH WINDS OVER THE MIDDLE ATLANTIC AND NORTHEAST COAST MAY 12-MAY 13.
- ONGOING LOCALIZED RIVER FLOODING OVER THE MIDDLE AND LOWER MISSISSIPPI
VALLEY.
- SEVERE DROUGHT PERSISTS IN PARTS OF THE PLAINS, WESTERN US, WITH SOME
RELIEF POSSIBLE IN THE SOUTHEAST.
- ELEVATED WILDFIRE RISK MAY 12 AND MAY 13 ACROSS PARTS OF THE SOUTHWEST AND
THE SOUTHERN PLAINS.
DETAILED SUMMARYFOR SUNDAY MAY 11 - TUESDAY MAY 13: A SURFACE LOW PRESSURE
SYSTEM WILL MOVE ACROSS THE OHIO VALLEY EARLY IN THIS PERIOD. A NEGATIVELY
TILTED UPPER LEVEL SHORTWAVE, COMBINED WITH SUFFICIENT MOISTURE INFLOW AND
INSTABILITY WILL PROVIDE CONDITIONS FOR POSSIBLE SEVERE THUNDERSTORMS ACROSS
THE TENNESSEE VALLEY EASTWARD INTO THE CAROLINAS AND SOUTHERN VIRGINIA ON
SUNDAY MAY 11. AS THE STORM SYSTEM MIGRATES INTO THE NORTHEAST, PARTS OF THE
TENNESSEE VALLEY, OHIO VALLEY, MIDDLE ATLANTIC, SOUTHEAST, AND NORTHEAST COULD
RECEIVE HEAVY RAIN MAY 11-MAY 12. AS THE LOW DEEPENS AND MOVES ONTO THE
NORTHEAST/MID-ATLANTIC COAST, COASTAL REGIONS IN THOSE AREAS COULD EXPERIENCE
HIGH WINDS. THESE HIGH WINDS AND STRONG LOW PRESSURE CAN LEAD TO TIDAL SURGES,
COASTAL FLOODING, AND BEACH EROSION. RAIN PRODUCED FROM THIS SURFACE LOW
PRESSURE SYSTEM WILL ALSO CONTINUE LOCALIZED RIVER FLOODING OVER PORTIONS OF
THE MIDDLE AND LOWER MISSISSIPPI VALLEY. ANTICIPATED STRONG SOUTHWESTERLY WINDS
AND LOW RELATIVE HUMIDITIES WILL LEAD TO CRITICAL WILDFIRE CONDITIONS ACROSS
PARTS OF THE SOUTHWEST AND SOUTHERN PLAINS MAY 12-MAY 13. LONG TERM DROUGHT
PERSISTS IN PARTS OF THE PLAINS, WESTERN US, WITH SOME RELIEF POSSIBLE IN THE
SOUTHEAST.
FOR WEDNESDAY MAY 14 - SUNDAY MAY
18: MODELS DEPICT A DEEP UPPER LEVEL TROUGH DEVELOPING OVER THE EASTERN
HALF OF THE CONUS OVER THE EARLIER PART OF THIS PERIOD, ALTHOUGH THERE ARE
SIGNIFICANT TIMING AND INTENSITY DIFFERENCES. THIS SURFACE LOW PRESSURE SYSTEM
COULD BRING RAIN TO THE EASTERN HALF OF THE CONUS AS IT MOVES THROUGH THE
EASTERN CONUS. IN GENERAL, MODELS INDICATE AN AMPLIFIED PATTERN OF A TROUGH
OVER THE EASTERN TWO THIRDS OF THE CONUS AND A RIDGE OVER THE WESTERN THIRD OF
THE CONUS AND BELOW NORMAL HEIGHTS OVER ALASKA. BELOW NORMAL TEMPERATURES ARE
FORECAST FOR THE EASTERN TWO THIRDS OF THE CONUS AND SOUTHERN COAST OF ALASKA,
WHILE ABOVE NORMAL TEMPERATURES ARE EXPECTED OVER THE WESTERN THIRD OF THE
CONUS AND NORTHERN ALASKA. THE WESTERN THIRD OF THE CONUS AND SOUTHERN ALASKA
IS ANTICIPATED TO HAVE WETTER THAN NORMAL CONIDTIONS AND DRIER THAN NORMAL
CONDITIONS ARE FORECAST FOR NORTHERN ALASKA AND THE WESTERN TWO THIRDS OF THE
CONUS.
FOR
MONDAY MAY 19 - THURSDAY MAY 22: THE 6Z GFS INDICATES A CONTINUED UPPER
LEVEL PATTERN OF TROUGHING ACROSS THE EASTERN TWO THIRDS OF THE CONUS AND
RIDGING ACROSS THE WESTERN THIRD OF THE CONUS. DUE TO THE INHERENT UNCERTAINTY
FOR THIS PERIOD, NO HAZARDS CAN BE MADE AT THIS TIME.
FORECASTER: MELISSA OU
$$