Hazardous Weather Outlook
SYNOPSIS: TWO STORM SYSTEMS ARE FORECAST TO DEVELOP ACROSS THE SOUTHERN PLAINS AND TRACK NORTHEAST ACROSS THE GREAT LAKES INTO SOUTHEAST CANADA DURING THE FIRST PART OF THE ASSESSMENT PERIOD. A WARM, MOIST FLOW FROM THE GULF OF MEXICO IS EXPECTED PRIOR TO A COLD FRONT PASSAGE ALONG THE EASTERN SEABOARD MID NEXT WEEK. HIGH PRESSURE IS EXPECTED TO GENERALLY PREVAIL ACROSS MUCH OF THE WESTERN U.S. DURING THIS PERIOD OF TIME, ALTHOUGH A FEW WEAK LOW PRESSURE SYSTEMS ARE FORECAST TO IMPACT THE FAR PACIFIC NORTHWEST. IN ALASKA, A SERIES OF SURFACE LOW PRESSURE SYSTEMS ARE ANTICIPATED TO MOVE ACROSS THE BERING SEA AND NORTHERN GULF OF ALASKA, BRINGING WET WEATHER TO SOUTHERN COASTAL AREAS.
HAZARDS
HEAVY RAIN STRETCHING FROM THE LOWER MISSISSIPPI VALLEY TO THE SOUTHERN GREAT LAKES, APRIL 25-27.
SEVERE WEATHER FOR PARTS OF THE SOUTHERN GREAT PLAINS AND LOWER MISSISSIPPI VALLEY, APRIL 25-26.
MUCH ABOVE NORMAL TEMPERATURES FOR PARTS OF THE MID-ATLANTIC AND NORTHEAST, APRIL 25-26.
CRITICAL FIRE WEATHER CONDITIONS FOR PARTS OF THE SOUTHWEST, APRIL 25-26.
WIDESPREAD FLOODING ACROSS PORTIONS OF THE NORTHERN AND CENTRAL GREAT PLAINS, AND THE MISSISSIPPI AND OHIO RIVER VALLEYS.
PERIODS OF MUCH BELOW NORMAL TEMPERATURES FOR PORTIONS OF THE INTERIOR NORTHWEST, GREAT BASIN AND ROCKIES, APRIL 25-30.
SEVERE DROUGHT IS INDICATED OVER MUCH OF THE SOUTHWEST, SOUTHERN ROCKIES, CENTRAL AND SOUTHERN PLAINS, LOWER MISSISSIPPI VALLEY, AND PARTS OF FLORIDA, ALABAMA, AND GEORGIA. SOME RELIEF IS EXPECTED FOR PORTIONS OF THE LOWER MISSISSIPPI VALLEY.
DETAILED SUMMARY
FOR MONDAY APRIL 25 – WEDNESDAY APRIL 27: A SURFACE LOW PRESSURE CENTER IS ANTICIPATED TO FORM NEAR THE TEXAS PANHANDLE, THEN MOVE NORTH-NORTHEASTWARD TOWARDS THE UPPER GREAT LAKES, IN RESPONSE TO A DEEPENING TROUGH OVER THE WEST-CENTRAL STATES. AS THE STORM TRACKS TOWARD THE UPPER GREAT LAKES REGION, A STRONG FLOW OF WARM, MOIST AIR IS FORECAST TO AFFECT MUCH OF THE EAST-CENTRAL U.S.. A WIDE SWATH OF HEAVY RAIN (2 INCHES OR MORE) IS EXPECTED FROM THE AK-LA-TX REGION AND OZARKS NORTH-NORTHEASTWARD TO THE SOUTHERN GREAT LAKES. UP TO 4 INCHES OF RAIN IS FORECAST OVER PARTS OF ARKANSAS, MISSOURI AND ILLINOIS. CONDITIONS ARE FAVORABLE FOR SEVERE WEATHER FOR PORTIONS OF THE SOUTHEAST GREAT PLAINS AND LOWER MISSISSIPPI VALLEY MONDAY AND TUESDAY.
A SECOND SYSTEM IS FORECAST TO DEVELOP ALONG THE TRAILING PORTION OF THE EASTWARD MOVING COLD FRONT AND RESULT IN AN EXTENSION OF THE HEAVY RAINFALL HAZARD AREA TO INCLUDE PORTIONS OF THE EASTERN TENNESSEE AND OHIO RIVER VALLEYS MAINLY DURING APRIL 27.
WIDESPREAD FLOODING IS EXPECTED TO CONTINUE ALONG THE JAMES RIVER IN SOUTH DAKOTA AND THE RED RIVER OF THE NORTH. MANY RIVERS THROUGHOUT THE MIDWEST ARE NEAR HISTORICALLY HIGH LEVELS AND FLOODING IS OCCURRING EVEN A DISTANCE AWAY FROM RIVER VALLEYS. USGS STREAM FLOW GAUGES SHOW SIGNIFICANT FLOODING IS ALSO OCCURING IN CENTRAL AND SOUTHERN INDIANA, AND WESTERN KENTUCKY. THE CONFLUENCE AREA FOR MANY OF THE LARGER RIVERS EAST OF THE ROCKIES IS THE MISSISSIPPI RIVER, NEAR ST. LOUIS. THIS AREA IN PARTICULAR IS SUSCEPTIBLE TO EXTENSIVE FLOODING. THE ADDITIONAL HEAVY RAINFALL EXPECTED DURING THIS PERIOD OVER THE MIDDLE MISSISSIPPI AND OHIO VALLEYS IS EXPECTED TO PROLONG AND SUBSTANTIALLY EXPAND FLOODING CONCERNS FOR THESE REGIONS. PLEASE REFER TO THE LATEST FLOOD STATEMENTS FROM LOCAL NATIONAL WEATHER SERVICE OFFICES.
ONGOING DROUGHT AND WILDFIRES IN THE SOUTHWEST, SOUTHERN ROCKIES, AND SOUTHERN GREAT PLAINS ARE IN SHARP CONTRAST TO THE FLOODING OCCURRING IN THE MIDWEST. VERY DRY SOIL CONDITIONS, ABOVE-NORMAL TEMPERATURES, PERIODS OF HIGH WINDS, AND LOW HUMIDITY ARE PREDICTED TO SUPPORT ELEVATED CRITICAL WILDFIRE CONDITIONS THROUGH APRIL 26.
THE STRONG SOUTHERLY FLOW AHEAD OF THE LOW PRESSURE SYSTEMS MOVING ACROSS THE MIDWEST ARE EXPECTED TO RESULT IN AN AREA OF MUCH ABOVE-NOMRAL TEMPERATURES FOR PORTIONS OF THE MID-ATLANTIC AND NORTHEAST MONDAY AND TUESDAY. DEPARTURES FROM NORMAL ARE FORECAST TO RANGE FROM 12-20 DEGREES ABOVE AVERAGE IN SOME OF THESE AREAS.
ELSEWHERE, ACROSS THE INTERIOR NORTHWEST, CENTRAL BASIN, AND NORTHERN AND CENTRAL ROCKIES, PERIODS OF MUCH BELOW NORMAL TEMPERATURES ARE FORECAST, EXTENDING INTO APRIL 30. TEMPERATURE DEPARTURES OF 12 TO 16 DEGREES BELOW NORMAL ARE ANTICIPATED.
FOR THURSDAY APRIL 28 – MONDAY MAY 02: A COLD FRONT IS FORECAST TO CROSS THE EASTERN SEABOARD AT THE START OF THIS PERIOD AND IS EXPECTED TO PRODUCE AREAS OF SHOWERS AND THUNDERSTORMS FROM NEW ENGLAND TO THE CAROLINAS WITH LOCALLY HEAVY RAINFALL AND THE POTENTIAL FOR SEVERE WEATHER.
MUCH BELOW-NORMAL TEMPERATURES ARE FORECAST TO CONTINUE INTO THE BEGINNING OF THIS PERIOD ACROSS THE INTERIOR NORTHWEST PORTION OF THE CONUS. TEMPERATURE DEPARTURES OF 12 TO 16 DEGREES BELOW NORMAL ARE ANTICIPATED IN SOME AREAS.
IN GENERAL DURING THIS PERIOD, A MEAN TROUGH IS FORECAST TO BE CENTERED ACROSS THE CENTRAL U.S., WITH A RIDGE OVER THE WESTERN ATLANTIC, AND WEAK RIDGING OVER THE SOUTHWEST. THERE ARE ENHANCED ODDS OF ABOVE NORMAL TEMPERATURES IN THE EAST AND SOUTHWEST, AND BELOW NORMAL TEMPERATURES IN THE NORTH-CENTRAL CONUS. FOR PRECIPITATION, THERE ARE ENHANCED ODDS OF ABOVE MEDIAN RAINFALL FOR PARTS OF THE EAST AND NORTHWEST WITH ENHANCED ODDS OF BELOW MEDIAN RAINFALL IN THE SOUTHWEST.
FOR TUESDAY MAY 03 – FRIDAY MAY 06: NO HAZARDS ARE DEPICTED ON THE MAP WITH CONFIDENCE AT THIS TIME RANGE EXCEPT FOR THE ONGOING, SEVERE DROUGHT AREAS, AND FOR PROLONGED FLOODING FOR PORTIONS OF THE MIDWEST.
NWS CLIMATE PREDICTION CENTER CAMP SPRINGS MD
300 PM EDT APRIL 22 2011
HEAVY RAIN STRETCHING FROM THE LOWER MISSISSIPPI VALLEY TO THE SOUTHERN GREAT LAKES, APRIL 25-27.
SEVERE WEATHER FOR PARTS OF THE SOUTHERN GREAT PLAINS AND LOWER MISSISSIPPI VALLEY, APRIL 25-26.
MUCH ABOVE NORMAL TEMPERATURES FOR PARTS OF THE MID-ATLANTIC AND NORTHEAST, APRIL 25-26.
CRITICAL FIRE WEATHER CONDITIONS FOR PARTS OF THE SOUTHWEST, APRIL 25-26.
WIDESPREAD FLOODING ACROSS PORTIONS OF THE NORTHERN AND CENTRAL GREAT PLAINS, AND THE MISSISSIPPI AND OHIO RIVER VALLEYS.
PERIODS OF MUCH BELOW NORMAL TEMPERATURES FOR PORTIONS OF THE INTERIOR NORTHWEST, GREAT BASIN AND ROCKIES, APRIL 25-30.
SEVERE DROUGHT IS INDICATED OVER MUCH OF THE SOUTHWEST, SOUTHERN ROCKIES, CENTRAL AND SOUTHERN PLAINS, LOWER MISSISSIPPI VALLEY, AND PARTS OF FLORIDA, ALABAMA, AND GEORGIA. SOME RELIEF IS EXPECTED FOR PORTIONS OF THE LOWER MISSISSIPPI VALLEY.
DETAILED SUMMARY